Note: Descriptions are shown in the official language in which they were submitted.
CA 02530941 2012-07-31
COMMUNICATION SYSTEM FOR MULTIZONE IRRIGATION
BACKGROUND OF THE INVENTION
This application also claims priority from PCT Application
PCT/US03/020117 filed on June 24, 2003 and also claims priority from PCT
Applications PCT/US02/38757 and PCT/US02/38758 both filed on December 4,
2003.
The present invention relates to communications systems and methods for
automated irrigation systems, which provide central and local control of
delivered
amounts of water.
There are various sprinkler devices for watering gardens, yards, or for
agricultural uses. These devices may have a controller installed at a source
of
pressurized water and a remotely located sprinkler. The sprinklers include a
rotatable water guide with a water nozzle. When water is ejected from the
nozzle, it flows initially through the water guide piece that rotates over a
full circle
or over a semicircular pattern. The spraying speed is frequently determined by
the water flow speed. That is, the water speed governs the rotation of the
water
guide piece and thus the irrigation pattern.
Many irrigation controllers are time based. The water delivery is activated
over a selected period of time regardless of the temperature, air humidity,
soil
moisture or other vegetation growth factors. Furthermore, the water delivery
may
vary with the water source pressure and other factors.
Therefore, there is still a need for reliable water delivery systems and
control methods capable of delivering selected or known amounts of water.
There is still also a need for automated water delivery systems and methods
that
enable a local loop feedback control and/or can detect local malfunctions.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 2 -
SUMMARY OF THE INVENTION
The present invention relates to communication systems and methods for
automated irrigation systems installed in-ground or above-ground. The
automated irrigation systems control and meter the amounts of water delivered
from one or several irrigation zones.
One type of the communication system is used for selectively controlling
multiple zones and delivering a selectable water amount (or irrigating
different
amounts of water from the individual zones) according to the local irrigation
needs. A multizone irrigation system includes a central control unit having a
central controller interfaced with a central valve and a central communication
unit. The central valve regulates water flow for irrigation from a water
source.
The central communication unit is constructed to transmit or receive
communication signals providing irrigation information. Each zone includes a
sprinkler control unit including a sprinkler connected to a water pipe for
irrigation
of a land area. The sprinkler control unit includes a local controller
interfaced
with a local valve for controlling water flow to the sprinkler. The sprinkler
control
unit also includes a local communication unit constructed to receive
communication signals from the central communication unit and provide received
irrigation information to the local controller. In a bi-directional system,
one or
several local communication units are constructed to transmit communication
signals to the central communication unit which provide received information
to
the central controller. The central controller thus can store specific
irrigation
cycles including the water amounts delivered by each sprinkler or each zone.
The local controller controls operation of the local valve based on the
irrigation
information received from the central controller and information provided by
:the
individual local sensors.
According to one embodiment, a communication system used in an
irrigation system includes a central controller interfaced with a central
valve and a
central communication unit, and a number of sprinkler units each unit
including a
local controller interfaced with a local valve for controlling water flow to a
sprinkler, and a local communication unit. The central valve regulates water
flow
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 3 -
for irrigation from a water source. The central communication unit is
constructed
to transmit communication signals providing irrigation information. The
sprinkler units are constructed to irrigate a land area. The local
communication
unit is constructed to receive communication signals from the central
communication unit and provide received irrigation information to the local
controller. The local controller is constructed to control operation of the
local
valve based on the irrigation information.
The central communication unit is constructed to receive the
communication signals, and the local communication unit is constructed to
transmit communication signals.
The central communication unit and the local communication unit are
coupled to water conduits connected to the water source and are constructed to
generate pressure waves transmitted through water in the conduits. The central
communication unit and the local communication unit include a pressure sensor
arranged to detect the pressure waves.
The central communication unit and the local communication unit are
coupled to water conduits connected to the water source and are constructed to
generate pressure pulses or ultrasound waves transmitted through water in the
conduits.
Furthermore, the automated systems and methods enable water-delivery
based on a local loop feedback control and/or control of a delivered amount of
water at different water pressures. These systems can be used for watering
lawns, gardens, yards, golf courses, or for agricultural uses.
According to yet another embodiment, a remotely located irrigation system
includes a controller connected to receive data from a sensor, and a valve
device
including an actuator. The system has a water input port constructed to be
coupled to a water conduit receiving water from a remotely located water
source.
The controller is located near the water input port and provides control
signals to
the actuator. The actuator initiates the on and off states of the valve device
CA 02530941 2012-07-31
- 4 -
located near, and connected to, the water input port for providing water to a
water delivery device such as a sprinkler or a drip irrigation device.
According to yet another aspect, an irrigation system includes a water
input port constructed receiving water from a remotely located water source,
and
a controller located near the water input port and connected to at least one
sensor. The system also includes a valve device including an actuator located
near and connected to the water input port, wherein the valve device is
constructed to receive control signals from the controller for providing water
to a
sprinkler.
Preferred embodiments may include one or more of the following features:
The controller may be battery operated. The actuator is a latching actuator
(as
described in U.S. Patent 6,293,516), a non-latching actuator (as described in
U.S. Patent 6,305,662), or an isolated operator (as described in PCT
Application
PCT/US01/51098).
The sensor may be a precipitation sensor, humidity sensor, a soil moisture
sensor, or a temperature sensor.
The remotely located irrigation system may include an indicator
associated with the controller. The remotely located irrigation system may
include a wireless communication unit connected to the controller for
receiving
data or sending data. The remotely located irrigation system may include
manual data input associated with the controller.
The controller may be constructed to provide control signals to at least two
actuators, each associated with one valve device and located near and
connected to the water input port, wherein the valve device is constructed to
receive control signals from the controller for providing water to a water
delivery
unit.
The controller may be constructed as a time based controller, or as a non-
time based controller.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 5 -
The irrigation system may be constructed to be removably located at a
selected location. The irrigation system may be constructed to be mounted on a
mobile irrigation platform. The mobile irrigation platform may be self-
propelled.
BRIEF DESCRIPTION OF THE DRAWINGS
Figs. 1 and 1A are perspective views of a stationary water delivery unit.
Fig. 1B is a detailed perspective view of the water delivery unit of Fig. 1
also showing various controls located therein.
Fig. 1C is a perspective view of a mobile platform for the water delivery
unit of Fig. 1.
Fig. 2 is a block diagram of a sensor and control system for a single zone
of the water delivery unit of Fig. I.
Figs. 3 and 3A show schematically two embodiments of a control system
for the water delivery unit of Fig. 1.
Fig. 4 shows schematically a precipitation sensor that can be used in the
water delivery unit of Fig. 1.
Figs. 5 and 5A show schematically two embodiments of a soil humidity
sensor that can be used in the water delivery unit of Fig. 1.
Fig. 6 shows schematically a multizone, in ground irrigation system
including a multiplicity of local valves and sprinkler units.
Fig. 6A shows schematically a multizone in ground irrigation system
including a pressure communication system.
Fig. 6B shows schematically a single water delivery unit and an
associated valve assembly for the multizone water delivery unit of Fig. 6 or
6A.
Fig. 7 is a block diagram of a sensor and control system for a multi-zone
water delivery unit.
Fig. 8 is a perspective exploded view of a valve device used in the water
delivery unit of Fig. I.
Fig. 8A is an enlarged cross-sectional view of the valve device shown in
Fig. 8.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 6 -
Fig. 8B is an enlarged cross-sectional view of the valve device shown in
Fig. 8A, but partially disassembled for servicing.
Fig. 8C is a perspective view of the valve device of Fig. 1 including a leak
detector.
Fig. 9 is an enlarged cross-sectional view of a moving piston-like member
used in the valve device shown in Figs 8, 8A, and 8B.
Fig. 9A is a detailed perspective view of the moving piston-like member
shown in Fig. 9
Fig. 9B is an enlarged cross-sectional view of another embodiment of the
moving piston-like member that can be used in the valve shown in Figs 8, 8A,
and 8B.
Fig. 10 is a cross-sectional view of a first embodiment of an
electromechanical actuator used in the valve shown in Figs. 8, 8A and 8B.
Fig. 10A is a perspective exploded view of the electromechanical actuator
shown in Fig. 10
Fig. 10B is a cross-sectional view of a second embodiment of an
electromechanical actuator used in the valve shown in Figs. 8, 8A and 8B.
Fig. 10C is a cross-sectional view of a third embodiment of an
electromechanical actuator for controlling the valve shown in Figs. 8, 8A and
8B.
Fig. 10D is a cross-sectional view of another embodiment of a membrane
used in the actuator shown in Figs. 10, 10A, 10B and 10C.
Fig. 10E is a cross-sectional view of another embodiment of the
membrane and a piloting button used in the actuator shown in Figs. 10, 10B and
10C.
Fig. 11 is a block diagram of a control subsystem for controlling operation
of the electromechanical actuator shown in Figs. 10, 10B or 10C.
Fig. 11A is a block diagram of another embodiment of a control subsystem
for controlling operation of the electromechanical actuator shown in Figs. 10,
10B
or 10C.
Fig. 11B is a block diagram of data flow to a microcontroller used in the
control subsystem of Figs. 11 or 11A.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 7 -
Figs. 12 and 12A show the relationship of current and time for the valve
actuator shown in Fig. 10, 10B or 10C connected to a water line at 0 psi and
120
psi in a reverse flow pressure arrangement, respectively.
Fig. 12B shows the dependence of the latch time on water pressure (in a
reverse flow pressure arrangement) for various actuators.
Figs. 13 and 13A illustrate a pressure-based communication algorithm for
the communication system shown in Fig. 6A.
Figs. 14A and 14B depict Table 1 and Table 2, respectively, which
illustrate communication time schedule and code for the communication system
shown in Fig. 6A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The described irrigation systems use different types of communication
systems for irrigation providing controlled amounts of water or providing
metered
amounts of water delivered from one or several irrigation zones. The
irrigation
systems are either above-ground or in-ground and use different control
systems,
valves and sensors, as described below.
A single zone irrigation system 10 or 40 includes a remotely located
controller connected to receive data from at least one local sensor, and
includes
a valve device actuated by an actuator. The irrigation system has a water
input
port constructed to be coupled to a water conduit receiving water from a
remotely
located water source. The controller is located near the water input port and
provides control signals to the actuator. The actuator initiates the on and
off
states of the valve device for providing water to a sprinkler or a drip
irrigation
device.
A multizone irrigation system 230A includes a central control unit having a
central controller interfaced with a central communication unit. There may be
a
central valve that regulates water flow for irrigation from a water source.
The
central communication unit is constructed to transmit or receive communication
signals providing irrigation information, as shown in Tables 1 and 2. Each
zone
includes an irrigation control unit (e.g., a sprinkler control unit)
constructed to
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 8 -
control irrigation from a sprinkler, a drip irrigation device, or similar. The
sprinkler
control unit includes a local controller interfaced with a local valve for
controlling
water flow to the sprinkler. The sprinkler control unit also includes a local
communication unit constructed to receive communication signals from the
central communication unit and provide received irrigation information to the
local
controller.
In a bi-directional communication system, one or several local
communication units (associated with irrigation control units) are constructed
to
transmit communication signals to the central communication unit, which
provides the received information to the central controller. The central
controller
thus can store specific irrigation cycles including the water amount delivered
by
each sprinkler or each zone. The local controller controls operation of the
local
valve based on the irrigation information received from the central controller
and
information provided by the individual local sensors.
Figs. 1, 1A, and 1B show a stationary above-ground water delivery unit
10, which includes several sensors and a controller for automated delivery of
selected amounts of water depending on the environmental conditions. The
water delivery (irrigation) unit 10 includes water input port 22, a sprinkler
24, and
an environmentally sealed body 26 supported on a stake 28. The water delivery
unit 10 is located remotely from a water source (or a faucet) and is connected
to
a water hose (or a water pipe) at port 22. The module's body 26 includes a
user
interface control unit 30 sealably enclosed by door 29 to be protected from
moisture and other elements. The module's body includes one or several ports
for various sensors, for example, sensors 64 through 72 described in
connection
with Figs. 2 through 5A. For example, module body 26 includes a port 34 with a
transparent cover for a light sensor 70 (shown in diagrammatically Figs. 2 and
7)
and a port 36 providing thermally conductive coupling for a temperature sensor
72 (also shown diagrammatically in Figs. 2 and 7).
Sprinkler 24 is controlled by a control system and an actuator, all
described below in connection with Figs. 10 through 11B. The control system
controls the spray pattern of the sprinkler. The sprinkler may be located at a
CA 02530941 2012-07-31
- 9 -
selected height and angle to achieve a desired coverage area, depending on the
water pressure and the flow orifices. User interface and controls 30 include
various input display and indicator elements described in connection with the
embodiment of Figs. 3 and 3A. Sprinkler 24 may have various embodiments
described in U.S. Patents 4,580,724; 5,031,835; 5,031,833; 5,238,188;
5,695,122; or 6,164,562.
Water delivery unit 10 is an automated system controlled by a
microprocessor that executes various modes of operation. Preferably, the
entire
water delivery unit 10 is battery operated. Water delivery unit 10 can provide
a
pre-programmed water delivery without measuring the "local conditions" or by
measuring the "local conditions" using one or several sensors. The sensor date
may be used to override a pre-selected algorithm (such as skip one watering
course after detecting rain). Alternatively, water delivery unit 10 can
provide
water delivery based on a local loop feedback control by measuring local
conditions such as precipitation, humidity, soil moisture, temperature and/or
light
and using the measured data to deliver a selected amount of water at varying
water pressures.
Water delivery unit 10 includes a water pressure sensor (e.g., a sensor
system described in connection with Figs. 11 through 12B), which determines
the
local water pressure. The local controller includes a memory with stored
properties of sprinkler 24 (or another water delivery device such as a drip
irrigation system). Based on the orifice size of sprinkler 24 and the control
valve,
a controller calculates the water delivery time for delivering a desired
amount of
water over the irrigated area. (This approach differs significantly from the
timed
water delivery of many prior art systems, where the delivered amount of water
varies due to varying water pressure. This approach also differs from many
prior
art systems, where the water pressure or orifice sizes are not known.)
The present systems and methods are also highly suitable for watering
large areas such as parks, golf courses, or agricultural fields using water
delivery
unit 10, where the "local" conditions vary due to an uneven terrain (e.g.,
small
hills with dry soil or valleys where water has accumulated), and due to
different
CA 02530941 2012-07-31
- 10 -
soil, or different vegetation. The present systems and methods are also highly
suitable for fields or orchards where different agricultural products are
grown. In
each case, the local controller receives data from at least one sensor and
calculates the desired water amount using stored algorithms. Based on the
local
water pressure, water delivery unit 10 delivers the calculated water amount
over
the irrigated area. The design of water delivery unit 10 is also highly
suitable for
using "gray water" pumped or delivered from canals or water reservoirs. The
present design of valves and actuators (described in connection with Figs. 8
through 10E) doesn't get easily plugged by sand or small particles.
Fig. 10 illustrates a mobile irrigation platform 40, which operates similarly
to water delivery unit 10. Mobile irrigation platform 40 includes a frame 42,
one
or several sprinklers 44 and 46, and a body 48. Sprinklers 44 or 46 may have
various embodiments described in U.S. Patents 4, 580,724; 5,031,835;
5,031,833; 5,238,188; 5,695,122; or 6,164,562.
Mobile irrigation platform 40 also includes two rear wheels 50 and 52, both
of which are independently propelled by water pressure from a water supply
(not
shown in Fig. 10), and a front wheel 54. The movement of each rear wheel 50
and 52 is actuated by a solenoid valve (or another electromagnetic actuator)
located at the input of each wheel so as to control its propulsion. Rear
wheels 50
and 52 also include the respective brakes 56 and 58 actuated by water
pressure.
This arrangement provides the stopping and starting of irrigation platform 40
and
enables its left-right rotation by means of shutting off the water supply to
any one
of wheels 50 or 52, or brakes 56 or 58. The corresponding actuators are
controlled by a microcontroller located inside body 48. Body 48 also includes
a
local navigation device for directing or monitoring the platform's motion.
To achieve a straight-line motion with both valves to both wheels 50 and
52 open, irrigation platform 40 uses a proportional flow valve arrangement
that
provides a desired rate of the water supply to the propelled wheels. The
proportional flow valve arrangement is placed at a location having equal
distance
to each wheel so as to insure equal rate of the wheel rotation. Furthermore,
CA 02530941 2012-07-31
- 11 -
each wheel 50 or 52 is mounted onto frame 42 using a spring-loaded
independent suspension arrangement (not shown in Fig. 10). The spring-loaded
independent suspension arrangement provides conformance to ground at
different heights that may be different for each wheel at times.
Front wheel 54 is spinning free (i.e., is not self-propelling as wheels 50
and 52), but is equipped with two rotation encoders. The first rotation
encoder
determines the forward or reverse motion. The second rotation encoder is
located inside an enclosure 55. The second rotation encoder determines the
wheel's clockwise or counterclockwise rotation with respect to frame 42. That
is,
the second encoder measures the left or right side turns by monitoring the
rotational axis of a fork 53, which secures wheel 54 to frame 42. Detailed
description of the rotation encoders is provided in U.S. Provisional
Application
60/337,112, filed on December 4, 2001, entitled "Cart Management System,"
published as US 2003/0102969, on June 5, 2003.
Sprinklers 44 and 46 have their spray nozzles directed at a selected angle
(for example, downward with a slight outward angle so as to obtain a spray
coverage to the left, right, front and rear of the frame's outline). Each
sprinkler
44 or 46 is controlled by the control system and the actuator described below.
The control system controls the spray pattern and the water amount. The
sprinklers may be located at a selected height or may even be telescopically
elevated at actuation to provide a longer trajectory and to enable watering of
areas that the platform cannot access. Each sprinkler 44 and 46 may include a
solenoid controlled, proportional flow valve that enables turning on/off of
each
individual sprinkler (or sprayer) and enables control of the spray distance
and
trajectory.
Mobile irrigation platform 40 includes a water inlet port (not shown)
connectable to a garden hose. The water inlet port enables 3600 rotation with
respect to the water supply hose with further means of insuring that the
platform
will not override the hose by virtue of a rotating right angle rigid arm,
which will
extend and retain the hose beyond the platform traversing path.
CA 02530941 2012-07-31
- 12 -
Fig. 2 shows schematically the control system for a single zone irrigation
platform 10. Control system includes a controller 62 for controlling operation
of
a valve actuator 80 constructed and arranged to control water delivery to at
least
one sprinkler (or another type of an irrigation device). Different types of
valves,
sensors, actuators and controllers are described below, all of which are
preferably battery operated. Controller 62 may be connected to one, two or
more sensors. For example, controller 62 is connected to a precipitation
sensor
64, a humidity sensor 66, a soil moisture sensor 68, a light sensor 70 and a
temperature sensor 72. Controller 62 may also be connected to a leak sensor 78
for detecting and indicating a water leak present in the water delivery unit,
e.g., at
a remote location, or in the ground.
Control system 60 may be connected to other external controllers,
sensors, or a central operation unit using standard wires. Alternatively,
control
system 60 may communicate with other external units using a device described
in U.S. Patent Application 09/596,251, filed on June 16, 2000, and PCT
Application PCT/US01/40913, entitled "Method and Apparatus for Combined
Conduit/ Electrical Conductor Junction Installation".
Alternatively, control system 60 uses a wireless communication unit 76 for
sending data to or receiving data from a central communication unit, for
downloading software or input data into the memory of controller 62, or for
receiving remote sensor data. Controller 62 may also include one or several
displays and a manual data input 74. Depending on a control algorithm and the
data received from one or several sensors 64 through 72, controller 62
provides
ON and OFF signals to valve actuator 80, which opens or closes water delivery.
Preferably, valve actuator 80 actuates a valve device 250 described in
connection with Figs. 8 through 8B. Alternatively, valve actuator 80 may
control
various other types of valves, such as a diaphragm valve, a piston valve, ball
valve, or any other valve known in the field.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 13 -
Referring to Figs. 3 and 3A, stationary water delivery unit 10 or mobile
water delivery unit 40 include user interface controls 30A. User interface
controls
30 (or 30A) include several switches, selectors and indicators including a
rain
sensor indicator 102, a photo sensor indicator 104, a temperature sensor
indicator 106, and a humidity sensor indicator 108 (whereas the module's body
includes the corresponding rain sensor, the photo sensor, the temperature
sensor, and the humidity sensor). User interface controls 30 (or 30A) also
include a soil selector 110, a vegetation-type selector 112, and a daytime
(AM,
PM) selector 116, all of which may also include associated indicators. User
interface controls 30 or 30A also include a watering location indicator 120
and a
rain delay indicator 122, which is constructed and arranged to indicate no
watering due to precipitation as detected by rain sensor 64.
The entire control and indicator system is packaged in a robust, outdoor
sealed container capable of withstanding humid and hot or cold environment and
also capable of withstanding mechanical shocks due to rough handling. For
example, the photo-sensor is located behind a clear window, and the
temperature sensor is located inside a temperature conductive conduit
protecting
the temperature sensor and providing good thermal coupling. Rain sensor 64
includes opening 32 covered by a removable screen and wire mesh, as
described below in connection with Fig. 4. Watering time selector 116 includes
two switches constructed and arranged to select daylight or night watering
time
and their frequency. For example, a user can select two nighttime waterings,
the
first one several hours after sunset and the second one half hour before
sunrise.
Each switch includes a built in visible indicator constructed and arranged to
indicate the selected watering schedule.
Still referring to Figs. 3 and 3A, soil selector 110 includes, for example,
three switches constructed and arranged for a user to select the type of soil
to be
irrigated. Based on the type of soil, the microcontroller automatically
adjusts the
watering schedule and volume optimal for the selected type of soil and
vegetation based on the vegetation type selected by selector 112. Both soil
selector 110 and vegetation-type selector 112 may include a visible indicator
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 14 -
such as a light emitting diode (LED). User interface controls 30 or 30A also
include a power switch 101 and may include an RF communication module
(module 76 shown in Figs. 2 or 7) constructed and arranged to receive
commands related to various watering cycles.
The rain sensor detects the amount of natural precipitation and provides
the corresponding signal to the microcontroller. The microcontroller may delay
a
watering cycle based on the amount of precipitation. The late watering cycle
is
displayed to a user by rain delay indicator 122. Rain delay indicator 122
includes
a single color visible LED, or another indicating element. A user can manually
select the vegetation type using vegetation type selector 112. The selected
type
of vegetation is then indicated by one of four single color visible LEDs.
(Alternatively, a single multi-color or two dual color light indicators may be
used.)
For example, in the embodiment where controls 30 are constructed and
arranged as a hose-end controller (as shown in Figs. 1, 1A and 1B), a user
will
physically move the hose-end controller, including the hose connected to a
water
source, to another location. Watering location indicator 120 indicates the
location
so that this location and prior locations will be communicated to another user
(or
the same user without needing to remember the locations). The selected
locations may be changed, for example, once a day so that a parcel of land is
watered once every three or four days depending on a selected algorithm.
Fig. 3A schematically illustrates another embodiment of the remote
location control unit, that is, remote location control unit's user interface
30A.
User interface controls 30A include rain sensor 102, photo sensor 104,
temperature sensor 106, humidity sensor 108, watering location indicator 120,
soil selector 110, and vegetation type selector 112. User interface 30A's
remote
location controls also include a clock 126, with an associated clock-adjust
knob,
and an associated AM - PM selector 116. The selected time may be stored in
the memory of controller 62.
Fig. 4 shows schematically a rain sensor (or precipitation sensor) 64. The
rain sensor includes an input port 32 (seen on bodies 26 and 48), a funnel-
shaped member 132, and a detector 140. The input port 32 includes a coarse
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 15 -
convex inlet screen and a fine concave inlet screen 131 for eliminating solid
contaminants and transmitting only water. Funnel-shaped member 132 includes
a funnel inlet 134 and a funnel drain port 136 having a size that ensures that
accumulated water will exit in forms of droplets. Detector 140 includes piezo-
electric sensor 144 and electric-electric element 146. Piezo-electric disk 144
is
positioned at an optimal location using positioning elements 142. Piezo-
electric
sensor 140 includes a sealed junction with electrical conduits exiting from
the
main body via one or several conduits. The droplet sensor 140 detects the size
and frequency of the individual droplets exiting funnel drain port 136. The
size
and frequency of the droplets depends on the amount of water accumulated
inside funnel-shaped member 132.
Fig. 5 shows schematically a ground moisture sensor or a soil moisture
sensor 150. Soil moisture sensor 150 (i.e., soil moisture sensor 68) includes
a
rigid containment chamber 152 with a semi-permeable membrane 154 and two
ports 156 and 158. Refill port 158 is used to deliver liquid inside rigid
containment member 152, and pressure measurement port 156 is used to
measure pressure above liquid level in cavity 159 inside rigid containment
chamber 152. Soil moisture sensor is inserted into soil 149 so that semi-
permeable membrane 154 is completely inserted inside the soil. Membrane 154
allows migration of water molecules from containment chamber 152 to the soil,
wherein the migration rate depends on the hygroscopic force (F) between the
soil
and the liquid inside containment chamber 152. The hygroscopic force, of
course, depends on the moisture content inside soil 149. Due to the water
migration, there is reduced pressure in region 156, which is detected by a
pressure sensor located inside body 26 (and indicated by user interface
controls
30). The ground moisture sensor of Fig. 5 is relatively independent of the
type of
the soil because the hygroscopic force is predominantly related to the
moisture
content of the soil and the type of the soil plays a very small part in the
algorithm.
Therefore, the ground moisture sensor does not need to be calibrated each time
when inserted inside soil 149.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 16 -
Fig. 5A shows schematically another embodiment of the ground moisture
sensor 150A (i.e., soil moisture sensor 68). Soil moisture sensor 150A
includes
a rigid containment chamber 152, a semi-permeable membrane 154 and a liquid
fill port 158. Inside rigid containment chamber 152 there is a float 164
including
two magnets 166 and 168 (generally, one or several magnets may be used).
Float 164 is cooperatively arranged with a reed sensor 162 located on the
external surface of, or associated with, rigid containment chamber 152.
The ground moisture sensor is filled with liquid through liquid refill port
158. Float 164 is located near or at the liquid surface, depending on its
construction. Due to the hygroscopic force (F) directed from inside of rigid
containment chamber 152 toward soil 149, water migrates from inside of
chamber 154. As the liquid seeps out through semi-permeable membrane 154,
water level drops, which changes the location (the relative height) of float
164.
Reed sensor 162 detects location of magnets 166 or 168 and provides a signal
to
the microcontroller regarding the water level inside rigid containment chamber
152. Based on this electrical signal the ground moisture content is determined
using a calibration curve. Thus the microcontroller receives information about
the ground moisture from the ground moisture sensor 150 or 150A. There may
be several ground moisture sensors located around the water territory and
these
may be hardwired to the microcontroller or may provide information using RF or
other wireless coupling.
Another embodiment of soil moisture sensor 64 includes two electrodes
located on a stake and insertable in the ground. The two electrodes are
separated by a predetermined distance. The resistance or ion migration between
the two electrodes varies depending on the ground moisture. The electrodes
may be made of metals providing a different potential and thus causing
migration
of ions there between. A measurement circuit connected to the two electrodes
measures the corresponding potential. Alternatively, the two electrodes may be
made of an identical, non-corrosive metal (e.g., stainless steel 300 series)
connected to an electrical circuit. The electrical circuit provides a two-
point or a
four-point measurement of electrical conductivity between the electrodes,
which
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 17 -
conductivity corresponds to the soil moisture. The measured conductivity data
is
provided to a microcontroller 62, which then determines the moisture content
of
the soil and determines the irrigation cycle according to a selected
algorithm.
Alternatively, at least one of the electrodes may include conductive and
isolating
regions located at different depths in the ground. Based on the conductivity
value measured at different levels, the moisture sensor measures the moisture
profile at different depths in the ground. Again, microcontroller 62 uses the
depth
moisture profile for calculating an appropriate irrigation cycle.
Alternatively, the ground moisture sensor may be a capacitive sensor
having a porous dielectric. The dielectric material is in contact with the
ground
and water migrates between the capacitive plates by the capillary effect from
the
ground. Depending on the ground moisture, the dielectric constant of the
capacitor varies. Thus, the capacitance value corresponds to measured
moisture content of the ground.
According to another embodiment, the ground moisture sensor (i.e., the
soil moisture sensor) includes a gypsum board coated with a water pearmeable
film and two electrodes located inside the gypsum board and separated by a
predetermined distance. The moisture sensor measures the resistance between
the two electrodes, which corresponds to the ground moisture migrating into
the
gypsum material.
Fig. 6 shows schematically a multizone in-ground water delivery unit 230.
Water delivery unit 230 includes a control module with control system 60A and
a
plurality of water pipes 232 and 234 for delivering water to a number of
valves
250 and a number of in-ground sprinklers, as shown in Fig. 6B. Control system
60A is shown in detail in Fig. 7.
Referring to Fig. 6B, a sprinkler system 236 includes a sealed enclosure
238 for housing a valve 250 and optionally local control system 60 (or local
control system 235). Coupled to enclosure 238 is a housing 240 and a
protective
cover 241, all of which are located in ground 149. Housing 240 includes a pop-
up element 242 having a water delivery port (or a sprinkler) located generally
at a
CA 02530941 2012-07-31
- 18 -
distal end 244. Pop-up element 242 also includes a vertical antenna 246
coupled
to wireless communication unit 76 (Fig. 2) for wireless communication.
According to another embodiment, the pop up vertical antenna is constructed
independently from the sprinkler and includes a metal element raised and
lowered by water pressure delivered from valve 250, or a spring-loaded metal
elements raised by water pressure and retracted by a spring.
The present design may be used with various embodiments of in ground
pop-up (riser) sprinklers described in US Patents 4,781,327; 4,913,351;
5,611,488; 6,050,502; 5,711,486; and US Patent Publications 2001/0032890;
2002/0092924; 2002/0153432.
Each valve 250 and the associated sprinkler 236 may include one control
system 60 (which in this embodiment is a local control system) located inside
enclosure 238 and communicating with a central control or interface system via
antenna 246. Local control system 60 (shown in Fig. 2) may also be connected
to leak detector 78 for detecting water leaks at valve 250. Wireless
communication unit 76 may include a transmitter and a receiver, or just a
receiver. At a preselected time, pop-up element 242 rises above ground 149 (by
water pressure delivered from valve 250) and antenna 246 is used to establish
wireless communication. Advantageously, most of the time, antenna 246 is
retracted below ground thus eliminating any obstructions to people or
machinery.
In general, a multizone irrigation system (e.g., irrigation system 230A
shown in Fig. 6A) includes a communication system for selectively controlling
different zones and delivering a selectable water amount (or delivering
different
amounts of water according to the local irrigation needs). The multizone
irrigation system includes a central control unit 300. Each zone includes a
sprinkler control unit connected to a sprinkler. Sprinkler control unit
includes a
local communication unit constructed to receive communication signals from the
central communication unit and provide received irrigation information to the
local
controller. In a bi-directional system, one or several local communication
units
are constructed to transmit communication signals to the central communication
unit, which provides received information to the central controller. The
central
CA 02530941 2012-07-31
- 19 -
controller thus can store specific irrigation cycles including the water
amount
delivered by each sprinkler or each zone. The local controller controls
operation
of the local valve based on the irrigation information received from the
central
controller and information provided by the individual local sensors.
According to another embodiment, the communication system is a
wireless communication system, wherein the central communication unit includes
an RE transmitter and the local communication units include an RF receiver.
Alternatively, both the central communication unit and the local communication
units each include an RE transceiver. The wireless communication system uses
the rising antenna described above.
According to another embodiment, the communication system is a hard-
wired communication system, wherein the communication wire is located along
the water pipes. This embodiment is described U.S. Patent Application
09/596,251, now US Patent 6,748,968, and PCT Application PCT/US01/40913,
entitled "Method and Apparatus for Combined Conduit/ Electrical Conductor
Junction Installation".
According to yet another embodiment, the communication system uses
water medium in the irrigation pipes for transmitting communication messages.
The messages between the central communication unit and the local
communication units are transmitted using pressure waves. The communication
system utilizes ultrasound waves generated by a piezoelectric elements
commonly used in ultrasound systems. The central communication unit and
each local communication unit include ultrasound transducers (or transducer
arrays) for emitting and detecting ultrasound waves. The ultrasound transducer
design, spacing and location are arranged to optimal transmission in water
pipes
depending on the pipe layout.
According to yet another embodiment, the communication system utilizes
an acoustic/vibratory driver (electro magnetic or magnostrictive) at the
central
control unit. The acoustic/vibratory driver is coupled to the waterline and
each
local control system includes an acoustic/vibratory receiver. The
acoustic/vibratory driver generates waves in the water column within the
irrigation
CA 02530941 2012-07-31
- 20 -
pipes and/or the piping walls. The waves carry coded information transmitted
from the central controller to the local controller. For bi-directional
communication, each local control system includes a driver next to the zone
valve.
According to yet another embodiment, the communication system utilizes
oscillating pressure waves propagating in the water conduits, which waves vary
in rate, pulse width, and possibly in pulse magnitude. The pressure
oscillations
are attained by an oscillating pump, a two-way solenoid or another means
residing at central controller unit 300. The pressure waves are detected by
pressure sensors 239 (or pressure switches) associated with the sprinkler
control
units.
According to yet another embodiment, the communication system utilizes
pressure waves generated by opening and closing a valve and propagating in the
water conduits. This communication system is described in detail in connection
with Figs. 6A, 13A, 13B, 14A and 14B.
Fig. 6A illustrates an in-ground irrigation system 230A including a uni-
directional or bi-directional communication system utilizing pressure pulses.
Irrigation system 230A includes a central control unit 300 and sprinkler
control
units 2311, 2312, ... 236N. Central control unit 300 includes a central
control
system 60, a central valve 302 (e.g., a solenoid valve, a rotary valve or
another
motorized valve) and a central pressure transducer (sensor) 304 for measuring
water pressure in the main input water line 301. One embodiment of the central
control system 60 is described in connection with Fig. 2 and includes a
central
controller (processor) 62. Sprinkler control unit 2311 includes a local
control
system 2351, a sprinkler 2361, a local irrigation valve 2501 (e.g., a solenoid
valve,
a rotary valve or another motorized valve), and a local pressure transducer
(sensor) 2391. All elements are powered by a battery. Similarly, sprinkler
control
unit 2312 includes a local control system 2352, a sprinkler 2362, a local
irrigation
valve 2502, and a local pressure transducer (sensor) 2392. Again, all these
elements may be powered by a battery.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 21 -
All N sprinkler control units 231N include similar element elements though
variation in the units is possible depending on the irrigation needs. The
sprinkler
control units have a modular design enabling field modification of the unit.
That
is, a technician installing or servicing the units can add or remove various
sensors. For example, some local control systems 235 may include no soil or no
humidity sensors, or other may include no sensors at all, but all include a
central
controller (i.e., a processor, memory and communication interface). According
to
one preferred embodiment, each sprinkler control unit 231 includes a self-
contained power supply unit for recharging the batteries. The power supply
unit
includes a solar element utilizing the photovoltaic effect to provide power to
the
batteries. Alternatively, the power supply unit includes a miniature water
turbine
utilizing the water flow energy for generating and providing electrical power
to the
batteries.
Central control system 60 communicates with the sprinkler units 2311-
231N, utilizing changes in the water pressure as the signaling means. Central
valve 302 is constructed to allow water to exit water pipe 232 via a port 301
and
thus lower water pressure in pipes 234. Sprinkler units 231 include local
controllers 235 that control valves 250 for sprinkling or for sending pressure
signals by opening and closing and thus lowering and restoring water pressure
in
pipes 234. Pressure sensors 239 detect the changes in water pressure that
constitute the communication signals and provide the corresponding electrical
signal to local control systems 235.
Generally, each pressure sensor (transducer) 239 is made from high-
strength, watertight, non-corrosive material such as stainless steel. The
input
pressure range is, for example, between 0 - 414 kPa (or 0 - 60 psi). The
electrical output signal, between 4-20 mA, is then sent to the controller,
which
interprets the signal and uses it to determine the next action in the
irrigation
system, including determining amount of watering, and sending back signals by
changing the water pressure. The pressure gauge should have good
repeatability, and be able to reproduce an identical signal each time the same
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-22 -
pressure is applied to it under the same conditions. It should also have a
short
response time, or length of time required for an output signal to be produced
when the pressure is sensed.
The programmable controller of each sprinkler unit 231 has interfaces for
receiving signals from pressure sensor 239, and for opening and closing
sprinkler
valves 250 for pressure signaling (i.e., data communication) and sprinkling.
Each
local controller can be programmed to both receive input from the pressure
gauge (corresponding to communication signals from central control unit 300)
and to send signals to central control unit 300, at particular time slots. The
schedule for signals receiving and transmitting of communication at particular
times is selected and designated for each sprinkler unit 231 to avoid
crosstalk or
communication errors.
The communication system uses a stipulated code of pressure changes,
sending and decoding messages conveyed by each coded signal. Central
control system 60 transmits messages to the sprinkler units utilizing pressure
changes to convey amounts of irrigation based on the variables measured by the
central system's sensors and / or preset values entered by a user using the
system's controls. For example, central control system provides a set length
of
watering time one morning as based on rain the night before, and given the
vegetation the sprinklers were set to water, etc. Each sprinkler unit also
detects
variables such as the wetness of the soil at the sprinkler's location. Based
on
these measurements, each sprinkler varies the amount of watering further
refining the sensitivity of the system. If one sprinkler unit senses a higher
amount of soil moisture than the general system, it could water 20% more than
the instruction from the control system. If a sprinkler measures precipitation
due
to someone having watered the specific location with a hose, without having
watered the entire property irrigated by the in ground watering system, the
sprinkler unit's controller can also then reduce the amount it waters by a
specific
percentage. The magnitude of these changes is preset for each measurement
involved.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-23 -
Referring still to Fig. 6A, the communication signals are based on drops in
water pressure. The water pressure drops are initiated by controller 235n
opening
valve 250n and letting water out of the water pipe. The water pressure goes up
to its original value once the valve is closed again allowing pressure to rise
to the
average water pipe pressure once more. The rise in water pressure up to the
main water pipe pressure occurs relatively quickly once the valve is closed
again.
These drops in pressure and rises to average pressure are used as code
elements (i.e., each "low pressure" and "standard pressure," or L and S shown
in
Table 1 and 2), where a certain combination of rises and drops is detected by
the
pressure detectors, and is interpreted for irrigation purposes. The
combination
"LSLS," is executed by controller 235 opening the valve, closing it, opening
it
once more, and closing it again, each time for one second or another time
interval sufficient for pressure recovery and detection.
Referring to Tables 1 and 2, each communication starts with a header
("LSLS"), so that any random change in water pressure is not read as a message
by the pressure sensor. Each message transmission also ends with a footer, so
that the system could ascertain end of transmission. In this example, a 5 sec.
lowering of pressure (i.e., "LLLLL"), where the valve is open, allowing for
water to
exit the system, functions as a footer. (However, the unit interval may be
shorter
than 1 sec. And depends on the pressure recovery from "low" pressure to
"standard" pressure.) Pressure detector 239n detects changes in the water
pressure and controller 235n "translates" the messages, and determines what
messages to transmit. Controller 235n directs opening and closing of valve
250,
therefore lowering or raising the water pressure and sending the communication
signal. The communication message may include the following header, first
coded term, spacer, second coded term, and footer (i.e., end of transmission
string): LSLS/LSL/SSSSS/LSSL/LLLLL.
The code for each part of the message is selected depending on the
amount of information being communicated, and how it is being communicated.
For example, if only one type of information is being transmitted, the code
can be
simpler, and the spacer may not be necessary. If more information is being
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 24 -
communicated, the code can be more complex, having more changes in
pressure for each term. The same terms can also have more than one meaning
depending on their location in the entire message. The controller and control
unit
can be made to distinguish each meaning as dependent upon the location of the
term within the message.
Each sprinkler unit 231 may transmit a signal back to central control unit
300 at a predetermined time to prevent cross-talk, as shown in Tables 1 and 2.
Local control system 2351 can transmit a signal including the header, the code
for the amount the watering varied from the amount required by control system
60 ("0-20% less"), the spacer between the two signals, and the code giving the
reason for the length of the watering period ("humidity level"). Then control
system 60 transmits a message of its own to the sprinkler at the predetermined
time. The reply message may include the header, and the code meaning
"message received." Controller 2351 receives the signal via readings from
pressure detector 239n, and does not attempt to send the signal once more.
This pattern continues for each sprinkler unit. In the example shown,
other sprinklers in the system have watered different amounts, and for
different
reasons. For example, sprinkler 2363 has watered 40-60% less than required
due to the type light levels measured in its area. Sprinkler 2364 has not
varied
the amount of watering required by control unit 60 because of precipitation
levels
at its location. In this last case, the control system did not receive the
message,
so that sprinkler 2364's controller 2354 have to resend its message to the
control
system. It do so right away, within the two minutes allotted to the control
unit to
communicate with sprinkler 2364 to communicate, to make sure the message
was received before the next sprinkler unit sent its message, and so that the
control unit not confuse two sprinkler units' messages. This system has been
used as an example only, and is by no means exclusive of embodiments, which
can include new codes, meanings, times for communication, or message
structures.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 25 -
Figs. 13A and 13B illustrate a communication algorithm for controlling
irrigation system 230A (shown in Fig. 6A). Referring to Fig. 13A, initially
each
local control system performs a calibration of the standard pressure in water
pipe
232 (step 902). During the calibration, each pressure sensor 239n measures
water pressure before any valve is opened, and provides the pressure to the
associated local controller 235n. If no valves are open in the system, all the
pressure readings (Soo.. .Son) in the system are substantially the same. If
any
measured pressure value for is lower than a pre-selected minimum at step 904,
the system has a water leak, or a similar problem. Pmin is a specified
percentage
(40 or 50% or another value specific to the irrigation system) of a normal
pressure in the irrigation system in kPa or psi. Upon detecting a low water
pressure, central control system 60 records an error message (step 940) and
stops the irrigation process (step 942). Minor leaks at some points in the
system
do not stop the watering process, but are registered; error signals are
transmitted
to central control system 60. Each sprinkler control unit 231 detecting a
lower
than normal pressure can separately shut down and not partake in the
irrigation
process. As explained below, if a sprinkler unit does not signal back to
central
control system 60, system 60 stores that information and indicates that the
error
exists, to point it out and have it serviced.
The value of having the standard pressure (So) calculated every time the
system commences communication is twofold: any variances in water pressure
are offset, and leaks can be detected. Once standard pressure is calculated,
central control system 60 communicates to local control systems 235n the
amount of watering necessary for each sprinkler in the system (step 906),
based
on central control system 60's sensors and controls.
At the allocated time, central control system 60 sends pressure-based
messages to each local control 235n regarding the amount of watering necessary
for the territory being irrigated (step 906). Once the message is received,
the
sprinkler unit confirms the receipt of the message in the time allotted for
central
control system-sprinkler unit communication (step 907).
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-26 -
Central control system 60 causes the sprinkler units to adjust their
irrigation amounts by its messages according to the desires of the user, and
the
central control system's sensors (step 910). Each local control system 235,
executes irrigation based on two types of input: (A) the irrigation data
received
from central control system 60, and (B) readings from their local sensors 64,
66,
68, 70, and 72. Specifically, the input from local sensors 64, 66, 68, 70, and
72
is used to adjust the irrigation data received from central control system 60
at
step 906.
As described in Fig. 14A, based on a soil humidity reading from soil
sensor 68, local control system 2353 from sprinkler unit 3 reduces the
watering by
20% less than the value transmitted from central control system 60. This is
done, for example, for sprinkler systems located in a local valley that
received
more surface water. Alternatively, the irrigation amount is increased based on
a
soil humidity reading from soil sensor 68 by a local control system located on
a
hill where the soil has water loss.
If central control system 60 does not receive the sprinkler unit confirmation
(step 908), and the control system 60 has not sent the message twice (step
944),
it resends the message to the sprinkler unit in question (step 906). If
central
control system 60 transmits the irrigation message twice without return
confirmation (step 944), it enters an error message for that sprinkler unit
(step
948). If a message has not been sent to all sprinkler units, central control
system
60 (step 912) initiates transmission of the irrigation message to the next
sprinkler
at the pre-selected time slot (step 908).
Table 1 (Fig. 14A) describes in further detail central control system 60
(CU) irrigation messages to the sprinkler units (SUs), following the flow
diagram
in Fig. 13A. The top half of the table describes the messages from central
control system 60 to the sprinkler units (steps 902-906). The bottom half of
the
table describes the sprinkler units' confirmation messages to the central
control
system (steps 907, 948, 944).
The time allocation for communicating with the local control systems is
pre-selected depending on the number of sprinkler units and complexity of the
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 27 -
irrigation instructions. For example, central control system 60 transmits the
irrigation instructions to local control system 235i ten minute after 6AM for
a pre-
selected period of ten minutes. This is a reserved time slot for local control
system 2351, which system "wakes up" and "listens" for irrigation
instructions,
while the other local control systems 2352 through 235n are inactive. Time
slots of
other lengths can be selected.
As an example, if the preset timing for the start of the communication
algorithm is 2:00AM, pressure will be calibrated at 2:00-2:01AM. Central
control
unit 60 has a time allotted for communication with each sprinkler unit: in
this
case, the central control system 60 has allotted 7 minutes for transmitting
the
irrigation message to sprinkler unit 1, and is ready at 2:10AM to send the
message. Similarly, sprinkler unit l's controller "listens" for the message at
2:10AM. Central control unit 60's irrigation message to sprinkler unit 1
consists
of a header ("LSLS"), instructions for the irrigation time ("LLS"), and a
footer
("LULL"), indicating the end of the message. The meaning of the message is to
water for one hour. Each message to the sprinkler units follows a similar
format.
Sprinkler unit 1 transmits its confirmation message at 2:18, sprinkler unit 2
at 2:28, etc. Similarly, the central control unit is ready to receive these
messages
at these same times. The message follows the same format as above: a header
("LSLL"), a message received/not received signal ("LSLL" or "LLS"), and a
footer
("LLLLL").
Referring again to Fig. 13A, central control system 60 checks if it received
at least one confirmation (step 913). If not, it enters an error message (step
915)
and stops the irrigation process. This confirms once more that the sprinkler
units
are sending the messages, and that the central control unit is properly
detecting
them.
Referring now to Fig. 13B, once irrigation (step 914) occurs, each sprinkler
sends central control system 60 a message regarding how much it watered, and
why. The standard pressure is remeasu red (S10-S1n) for the central control
unit
and all sprinkler units. Again, if this measurement is not less than the set
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-28 -
minimum (step 918), an error message is set (step 934) and the system stops
(step 936).
If the pressure is set for signaling, the sprinkler units send central control
system 60 the confirmation messages (step 920). The central control system
sends back a confirmation to the sprinkler units at step 921. If the sprinkler
units
do not receive confirmation (step 922), and the sprinkler units have not sent
the
message twice already (step 928), the message is resent (step 920). However,
if
the message had already been sent (step 930), the central control unit sets an
error message for future servicing (step 930).
These steps are further described in Fig. 14B, in which sprinkler unit 1 is
about to transmit its irrigation report to the central control system. The top
half of
table 2 in Fig. 14B corresponds to the messages from the sprinkler units'
messages to the central control system (steps 920, 928). The bottom half of
the
table describes the central control system's confirmation message to the
sprinkler units (steps 921, 922). Transmittal for sprinkler unit us set for
6:10-
6:18AM, so that central control system 60 is ready to receive at that time as
well.
The sprinkler units and the central control unit has transmit and receive
times set
up so that each is transmitting and receiving simultaneously, and can
associate
the messages with each other. Sprinkler unit 1 sends a message consisting of a
header ("LSLS"), the signal for the amount it watered ("LLS"), a spacer
("SSSSS"), a signal for the reason ("LSLL"), and a footer ("LLLLL"). In this
case
the message means that the sprinkler unit watered 0-20% less than was required
by the central control system due to local humidity levels. Sprinkler units 1-
4
sent different messages, in the same format, giving different reasons for the
way
they irrigated. (See Table 2, Fig. 14B)
Central control system 60 then confirms the messages by each sprinkler
unit. Again, there is a preset time that central control system 60 transmits,
and
that the sprinkler units receive: for sprinkler unit 1, that is 6:18-6:22AM.
For
sprinkler unit 2, 6:28-6:32AM, etc. The messages consist of a header, a
received
or not received message, and a footer (i.e., end of communication string).
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 29 -
At this point, if the central control system sent messages to all the
sprinkler units (step 924), it shuts the system down until the next scheduled
communication. The system will then turn on, recalibrate, and communicate in
the same manner as that described above.
The parameters described can be changed, and are not inclusive: the
time for communication, the number of times the message can be resent, the
number of components (both for the sprinkler units and the central control
system), and the nature of the messages, for example, can all be modified.
According to another embodiment, an ultrasonic communication system
provides communication between the central control unit and the sprinkler
units.
While water is an ideal medium for transmitting mechanical sound waves, the
irrigation pipes may "complicate" the propagation and detection of the signal.
The system is similar to the system shown in Fig. 6A, but pressure detectors
239
are replaced by piezoelectric transducers, and the control units include a
pulser
providing electrical signals to the transducer. As known in the art, the
transducers' piezoelectric elements convert the controllers' electrical
signals into
mechanical vibrations in the "transmit" mode. In the "receive" mode, the
piezoelectric elements convert mechanical vibrations into electrical signals
provided to the controllers.
In the ultrasonic communication system, the generated longitudinal sound
waves travel through the water in the water pipes. However, the communication
system is sensitive to changes in the generated waves. Therefore, the
ultrasonic
communication system is designed with smooth pipes generally free of
blemishes and discontinuities, which cause energy reflections. The reflection
sensitivity can, however, be used to provide orientation and distance which
can
be used to identify the transmitter. That is, once the control unit received a
signal, the nature of the signal could be used to ascertain which sprinkler
unit
had sent it. This is a desirable quality when setting up communication codes,
particularly in simpler irrigation systems. In the ultrasound communication
system, the central control system communicates with the local control system
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 30 -
using algorithms similar to flow diagram 900. However, since the ultrasound
system enables a higher data transmission rate, the communication code may be
much more elaborate that the code examples provided in Tables 1 and 2.
Depending on the size and materials of the irrigation system, the
scattering of the signals and their absorption could become a concern, and it
may
be necessary to have some of the sprinkler units relay signals so they can
more
easily and clearly reach more remote parts of the system. Controllers at
certain
points along the system is programmed to resend signals to the control unit
from
sprinkler units further away, and vice-versa. The necessity for this relay
could be
reduced not only by optimizing the shape and size of the system, but also by
generally using relay transmitters and strategic locations of ultrasonic
transducers or selection of suitable arrays.
The above described communications systems increase their reliability by
optionally using an error control algorithm. The system can use either a
forward
error correction strategy (FEC) or an automatic repeat request strategy (ARR).
The FEC algorithm, such as the Hamming code) provides for error correction
where a transmission error is detected. The ARQ algorithm initiates
automatically re-transmission if a communication error or corrupted data are
detected. The FEC protocol is generally not preferred for the irrigation
communication system of Fig. 6A, since re-transmission of the signal is
possible.
The FEC protocol requires much more redundant information transmission than
the ARQ protocol. The redundancy requires a larger data transfer due largely
to
the fact that the number of overhead bits needed to implement an error
detection
scheme is much less than the number of bits needed to correct the same error.
Fig. 7 illustrates diagrammatically a multi-zone irrigation control system
60A. Irrigation control system 60A includes controller 62 receiving data from
one
or several sensors 64 through 72, described above. Controller 62 provides
drive
ON or OFF signals to valve actuators 801, 802, 803. . . 80N. Valve actuators
801,
802, 803. . . 80N actuate individual valve devices that in turn provide water
to
separate sprinklers (or any other irrigation units). Again, controller 62 may
have
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 31 -
an associated wireless communication unit 76 for sending data to, or receiving
data from, a central communication unit, a remote sensor, or any other device.
Figs. 8, 8A and 8B illustrate an automatic valve device 250 constructed
and arranged for controlling water flow in water delivery unit 10, 40, or 236.
Specifically, automatic valve device 250 receives water at a valve input port
252
and provides water from a valve output port 254, in the open state. Automatic
valve device 250 includes a body 256 made of a durable plastic or metal.
Preferably, valve body 256 is made of a plastic material but includes a
metallic
input coupler 260 and a metallic output coupler 280. Input and output couplers
260 and 280 are made of metal (such as brass, copper or steel) so that they
can
provide gripping surfaces for a wrench used to connect them to a water line
inside water delivery unit 10 (or in ground unit 236). Valve body 256 includes
a
valve input port 290, and a valve output port 294.
Metallic input coupler 260 is rotatably attached to input port 290 using a C-
clamp 262 that slides into a slit 264 inside input coupler 260 and also a slit
292
inside the body of input port 290. Metallic output coupler 280 is rotatably
attached to output port 294 using a C-clamp 282 that slides into a slit 284
inside
output coupler 280 and also a slit 296 inside the body of output port 294.
When
servicing delivery unit 10 (or in ground unit 236), this rotatable arrangement
prevents tightening the water line connection to any of the two valve couplers
unless attaching the wrench to the surface of couplers 260 and 280. (That is,
a
service person cannot tighten the water input and output lines by gripping on
the
valve body 256.) This protects the relatively softer plastic body 256 of
automatic
valve device 250. However, body 256 can be made of a metal in which case the
above-described rotatable coupling is not needed. A sealing 0-ring 266 seals
input coupler 260 to input port 290, and a sealing 0-ring 288 seals output
coupler
280 to input port 294.
Referring to Figs. 8, 8A, and 8B, metallic input coupler 260 includes an
inflow adjuster 270 cooperatively arranged with a flow control mechanism 360.
Inflow adjuster 270 includes an adjuster piston 272, a closing spring 274
arranged around an adjuster pin 276 and pressing against a pin retainer 268.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-32 -
Inflow adjuster 270 also includes an adjuster rod 278 coupled to and
displacing
adjuster piston 272. Flow control mechanism 360 includes a spin cap 362
coupled by screw 364 to an adjustment cap 366 in communication with a flow
control cam 370. Flow control cam 370 slides linearly inside body 256 upon
turning adjustment cap 366. Flow control cam 370 includes inlet flow openings
371, a locking mechanism 373 and a chamfered surface 374. Chamfered
surface 374 is cooperatively arranged with a distal end 279 of adjuster rod
278.
The linear movement of flow control cam 370, within valve body 256, displaces
chamfered surface 374 and thus displaces adjuster rod 278. Adjuster piston 272
also includes an inner surface 273 cooperatively arranged with an inlet seat
261
of input coupler 260. The linear movement of adjuster rod 278 displaces
adjuster
piston 272 between a closed position and an open position. In the closed
position, sealing surface 273 seals inner seat 261 by the force of closing
spring
274. In the opened position, adjuster rod 278 displaces adjuster piston 272
against closing spring 274 thereby providing a selectively sized opening
between
inlet seat 261 and sealing surface 273. Thus, by turning adjustment cap 366,
adjuster rod 278 opens and closes inflow adjuster 270. Inflow adjuster 270
controls the water input flow to sprinkler 24. The above-described manual
adjustment can be replaced by an automatic motorized adjustment mechanism
controlled by microcontroller 62.
Referring still to Figs. 8, 8A and 8B, automatic valve device 250 also
includes a removable inlet filter 380 removably located over an inlet filter
holder
382, which is part of the lower valve housing. Inlet filter holder 382 also
includes
an 0-ring and a set of outlet holes 317 shown in Fig. 9. The "fram" piston 326
is
shown in detail in Fig. 9A. Water flows from input port 252 of input coupler
260
through inflow adjuster 270 and then through inlet flow openings 371, and
through inlet filter 380 inside inlet filter holder 382. Water then arrives at
an input
chamber 318 inside a cylindrical input element 324 (Fig. 9) providing pressure
against a pliable member 328.
Automatic valve device 250 also includes a service loop 390 (or a service
rod) designed to pull the entire valve assembly, including attached actuator
80,
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-33 -
out of body 256, after removing of plug 366. The removal of the entire valve
assembly also removes the attached actuator 80 and piloting button 705 (shown
in Fig. 10). To enable easy installation and servicing, there are rotational
electrical contacts located on a PCB at the distal end of actuator 80.
Specifically,
actuator 80 includes, on its distal end, two annular contact regions that
provide a
contact surface for the corresponding pins, all of which can be gold plated
for
achieving high quality contacts. Alternatively, a stationary PCB can include
the
two annular contact regions and the actuator may be connected to movable
contact pins. Such distal, actuator contact assembly achieves easy rotational
contacts by just sliding actuator 80 located inside valve body 502.
Fig. 8C illustrates automatic valve device 250 including leak detector 78
(Fig. 2) for indicating a water leak or water flow across valve device 250.
Leak
sensor 78 includes electronic measurement circuit 500 and at least two
electrodes 502 and 504 coupled respectively to input coupler 260 and output
coupler 280. (The leak sensor may also include four electrodes for a four-
point
resistivity measurement). Valve body 256 is made of plastic or another non-
conductive material. In the closed state, when there is no water flow between
input coupler 260 and output coupler 280, electronic circuit 500 measures a
very
high resistance value between the two electrodes. In the open state, the
resistance value between input coupler 260 and output coupler 280 drops
dramatically because the flowing water provides a conductive path.
There are various embodiments of electronics 500, which can provide a
DC measurement, an AC measurement including eliminating noise using a lock-
in amplifier (as known in the art). Alternatively, electronics 500 may include
a
bridge or another measurement circuit for a precise measurement of the
resistivity. Electronic circuit 500 provides the resistivity value to
microcontroller
62 and thus indicates when valve device 250 is in the open state. Furthermore,
leak sensor 78 indicates when there is an undesired water leak between input
coupler 260 and output coupler 280. The entire valve 250 is located in an
isolating enclosure (e.g., enclosure 26 in Fig. 1, or enclosure 238 in Fig.
6A) to
prevent any undesired ground paths that would affect the conductivity
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-34 -
measurement. Furthermore, leak sensor 78 can indicate some other valve
failures when water leaks into enclosure 26 or 238 from valve device 250.
Thus,
leak detector 78 can sense undesired water leaks that would be otherwise
difficult to observe. Leak detector 78 is constructed to detect the open state
of
the irrigation system to confirm proper operation at a remote location.
Automatic valve device 250 may include a standard diaphragm valve, a
standard piston valve, or a novel "fram" piston valve 320 explained in detail
in
connection with Figs. 9, 9A, and 9B. Referring to Fig. 9, valve 320 includes
distal
body 324, which includes an annular lip seal 325 arranged, together with
pliable
member 328 (Fig. 9A), to provide a seal between input port chamber 318 and
output chamber 319. Distal body 324 also includes one or several flow channels
317 (also shown in Fig. 8) providing communication (in the open state) between
input chamber 318 and output chamber 319. Pliable member 328 also includes
sealing members 329A and 329B arranged to provide a sliding seal, with respect
to valve body 322, between pilot chamber 342 and output chamber 319. There
are various possible embodiments of seals 329a and 329b (Fig. 9). This seal
may be a one-sided as seal or two-sided seal 329A and 329B shown in Fig. 9.
Furthermore, there are various additional embodiments of the sliding seal
including 0-rings, etc.
The present invention envisions valve device 326 having various sizes.
For example, the "full" size embodiment has the pin diameter A = 0.070", the
spring diameter B = 0.360", the pliable member diameter C = 0.730", the
overall
fram and seal's diameter D = 0.812", the pin length E = 0.450", the body
height F
= 0.380", the pilot chamber height G = 0.280", the fram member size H =
0.160",
and the fram excursion I = 0.100". The overall height of the valve is about
1.39"
and diameter is about 1.178".
The "half size" embodiment of the "fram piston" valve has the following
dimensions provided with the same reference letters. In the "half size" valve
A =
0.070", B = 0.30, C = 0.560", D = 0.650", E = 0.38", F = 0.310", G = 0.215", H
=
0.125", and I = 0.60". The overall length of the 1/2 embodiment is about
1.350"
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 35 -
and the diameter is about 0.855". Different embodiments of the "fram piston"
valve device may have various larger or smaller sizes.
Referring to Figs. 9 and 9A, the fram piston valve 320 receives fluid at
input port 318, which exerts pressure onto diaphragm-like member 328 providing
a seal together with a lip member 325 in a closed state. Groove passage 338
provides pressure communication with pilot chamber 342, which is
communicates with actuator cavity 350 via passages 344A and 344B. An
actuator (shown in Figs. 10, 10A or 10B) provides a seal at surface 348
thereby
sealing passages 344A and 344B and thus pilot chamber 342. When the plunger
of actuator 80 or 81 moves away from surface 348, fluid flows via passages
344A
and 344B to control passage 346 and to output chamber 319. This causes
pressure reduction in pilot chamber 342. Therefore, diaphragm-like member 328
and piston-like member 332 move linearly within cavity 342, thereby providing
a
relatively large fluid opening at lip seal 325. A large volume of fluid can
flow from
input port 318 to output chamber 319.
When the plunger of actuator 80 seals control passages 344A and 344B,
pressure builds up in pilot chamber 342 due to the fluid flow from input port
318
through "bleed" groove 338. The increased pressure in pilot chamber 342
together with the force of spring 340 displace linearly, in a sliding motion
over
guide pin 336, fram piston 326 toward sealing lip 325. When there is
sufficient
pressure in pilot chamber 342, diaphragm-like pliable member 328 seals input
port chamber 318 at lip seal 325. The soft member 328 includes an inner
opening that is designed with guiding pin 336 to clean groove 338 during the
sliding motion. That is, groove 338 of guiding pin 336 is periodically
cleaned.
Therefore, fram piston 326 is uniquely designed for controlling flow of
"unclean"
water ("gray water") for irrigation.
The embodiment of Fig. 9 shows the valve having a central input chamber
318 (and guide pin 336) symmetrically arranged with respect to vent passages
344A and 344B (and the location of the plunger of actuator 80). However, the
valve device may have input chamber 318 (and guide pin 336) non-symmetrically
arranged with respect to passages 344A, 344B and output vent passage 346.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 36 -
That is, in such a design, this valve has input chamber 318 and guide pin 336
non-symmetrically arranged with respect to the location of the plunger of
actuator
80. The symmetrical and non-symmetrical embodiments are equivalent.
Fig. 9B illustrates another embodiment of the "fram piston" valve device.
Valve device 400 includes a valve body providing a cavity for a valve assembly
414, an input port 419, and an output port 421. Valve assembly 414 includes a
proximal body 402, a distal body 404, and a fram member or assembly 426.
Fram member 426 includes a pliable member 428 and a support member 432.
Pliable member 428 may be a diaphragm-like member with sliding seal lips 429A
and B. Support member 432 may be plunger-like member or a piston like
member, but having different structural and functional properties than a
conventional plunger or piston. The valve body provides a guide surface 436
located on the inside wall that includes one or several grooves 438 and 438A.
These are novel grooves constructed to provide fluid passages from input
chamber located peripherally (unlike the central input chamber shown in Fig.
9).
Fram member 426 defines a pilot chamber 442 arranged in fluid
communication with actuator cavity 450 via control passages 444A and 444B.
Actuator cavity 450 is in fluid communication with output port 421 via a
control
passage 446. Groove 438 (or grooves 438 and 438A) provides a communication
passage between input port 419 and pilot chamber 442.
Distal body 404 includes an annular lip seal 425 co-operatively arranged with
pliable member 428 to provide a seal between input port 419 and output port
421. Distal body 404 also includes flow channel 417 providing communication
(in
the open state) between input port 419 and output port 421 for a large amount
of
fluid flow. Pliable member 428 also includes sliding seal lips 429A and 429B
(or
one sided sealing member depending on the pressure conditions) arranged to
provide a sliding seal with respect to valve body 422, between pilot chamber
442
and input port 419. (Of course, groove 438 enables a controlled flow of fluid
from
input port 419 to pilot chamber 442, as described above.) The entire operation
of
valve device 400 is controlled by a.single solenoid actuator, such as the
isolated
actuator, 81.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
-37 -
Figs. 10, 10A, 10B, and 10C illustrate several embodiments of the isolated
actuator. Isolated actuator 80 includes solenoid windings 728 wound about
solenoid bobbin 714 and magnet 723 located in a magnet recess 720. The
actuator also includes a resiliently deformable 0-ring 712 that forms a seal
between solenoid bobbin 714 and actuator base 716, and includes a resiliently
deformable 0-ring 730 that forms a seal between solenoid bobbin 714 and pole
piece 725. All of these components are held together by a solenoid housing 718
(i.e., can 718), which is crimped at actuator base 716 to hold magnet 723 and
pole piece 725 against bobbin 714 and thereby secure windings 728 and
actuator base 716 together.
Isolated actuator 81 also includes a resilient diaphragm membrane 764
that may have various embodiments shown and described in connection with
Figs. 10D and 10E. As shown in Fig. 10, resilient diaphragm membrane 764 is
mounted between actuator base 716 and piloting button 705 to enclose armature
fluid located in a fluid-tight armature chamber in communication with armature
port 752. Resilient diaphragm membrane 764 includes a distal end 766, 0-ring
like portion 767 and a flexible portion 768. Distal end 766 comes in contact
with
the sealing surface in the region 708. Resilient diaphragm membrane 764 is
exposed to the pressure of regulated fluid provided via conduit 706 in
piloting
button 705 and may therefore be subject to considerable external force.
Furthermore, resilient diaphragm membrane 764 is constructed to have a
relatively low permeability and high durability for thousands of openings and
closings over many years of operation.
Referring to still to FIG. 10, isolated actuator 80 is provided, for storage
and shipping purposes, with a cap 703 sealed with respect to the distal part
of
actuator base 716 and with respect to piloting button 705 using a resiliently
deformable 0-ring 732. Storage and shipping cap 703 includes usually water
that counter-balances fluid contained by resilient diaphragm membrane 764;
this
significantly limits or eliminates diffusion of fluid through resilient
diaphragm
membrane 764.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 38 -
Isolated actuator 81 may be constructed either as a latching actuator
(shown in FIG. 10) or a non-latching actuator. The latching embodiment
includes
magnet 723 (as shown) providing magnetic field having orientation and force
sufficient to overcome the force of coil spring 748 and thereby retain
armature
740 in the open state even after there is no drive current flowing in the
solenoid's
windings 728.
In the non-latching embodiment, there is no permanent magnet (i.e., no
magnet 723). Thus, to keep armature 740 in the open state, a drive current
must
continue to flow in windings 728 to provide the necessary magnetic field.
Armature 740 moves to the closed state under the force of spring 748 if there
is
no drive current. On the other hand, in the latching embodiment, a drive
current
is applied to windings 728 in opposite directions to move armature 740 between
the open and closed states, but no drive current is necessary to maintain
either
state.
Referring still to FIG. 10, actuator base 716 includes a wide base portion
substantially located inside can 718 and a narrowed base extension threaded on
its outer surface to receive cap 703. The inner surface of the base extension
threadedly engages complementary threads provided on the outer surface of
piloting button 705. Resilient diaphragm membrane 764 includes a thickened
peripheral rim 767 located between the base extension lower face and piloting
button 705. This creates a fluid-tight seal so that the membrane protects the
armature from exposure to external fluid flowing in the main valve.
For example, the armature liquid may be water mixed with a corrosion
inhibitor, e.g., a 20% mixture of polypropylene glycol and potassium
phosphate.
Alternatively, the armature fluid may include silicon-based fluid,
polypropylene
polyethylene glycol or another fluid having a large molecule. The armature
liquid
may in general be any substantially non-compressible liquid having low
viscosity
and preferably non-corrosive properties with respect to the armature.
Alternatively, the armature liquid may be Fomblin or other liquid having low
vapor
pressure (but preferably high molecular size to prevent diffusion).
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 39 -
If there is anticorrosive protection, the armature material can be a low-
carbon steel, iron or any soft magnetic material; corrosion resistance is not
as
important a factor as it would otherwise be. Other embodiments may employ
armature materials such as the 420 or 430 series stainless steels. It is only
necessary that the armature consist essentially of a ferromagnetic material,
i.e., a
material that the solenoid and magnet can attract. Even so, it may include
parts,
such as a flexible or other tip, that is not ferromagnetic.
Resilient diaphragm membrane 764 encloses armature fluid located in a
fluid-tight armature chamber in communication with armature port 752 or 790
formed by the armature body. Furthermore, resilient diaphragm membrane 764
is exposed to the pressure of regulated fluid in the main valve and may
therefore
be subject to considerable external force. However, armature 740 and spring
748 do not have to overcome this force, because the conduit's pressure is
transmitted through resilient diaphragm membrane 764 to the incompressible
armature fluid within the armature chamber. The force that results from the
pressure within the chamber therefore approximately balances the force that
the
conduit pressure exerts.
Referring still to Figs. 10, 10A, 10B and 10C, armature 740 is free to move
with respect to fluid pressures within the chamber between the retracted and
extended positions. Armature port 752 or 790 enables the force-balancing fluid
displaced from the armature chamber's lower well through the spring cavity 750
to the part of the armature chamber from which the armature's upper end (i.e.
distal end) has been withdrawn upon actuation. Although armature fluid can
also
flow around the armature's sides, arrangements in which rapid armature motion
is required should have a relatively low-flow-resistance path such as the one
that
port 752 or 790 helps form. Similar considerations favor use of an armature-
chamber liquid that has relatively low viscosity. Therefore, the isolated
operator
(i.e., actuator 81) requires only low amounts of electrical energy for
operation and
is thus uniquely suitable for battery operation.
In the latching embodiment shown in FIG. 10, armature 740 is held in the
retracted position by magnet 723 in the absence of a solenoid current. To
drive
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 40 -
the armature to the extended position therefore requires armature current of
such
a direction and magnitude that the resultant magnetic force counteracts that
of
the magnet by enough to allow the spring force to prevail. When it does so,
the
spring force moves armature 740 to its extended position, in which it causes
the
membrane's exterior surface to seal against the valve seat (e.g., the seat of
piloting button 705). In this position, the armature is spaced enough from the
magnet that the spring force can keep the armature extended without the
solenoid's help.
To return the armature to the illustrated, retracted position and thereby
permit fluid flow, current is driven through the solenoid in the direction
that
causes the resultant magnetic field to reinforce that of the magnet. As was
explained above, the force that magnet 723 exerts on the armature in the
retracted position is great enough to keep it there against the spring force.
However, in the non-latching embodiment that doesn't include magnet 723,
armature 740 remains in the retracted position only so long as the solenoid
conducts enough current for the resultant magnetic force to exceed the spring
force of spring 748.
Advantageously, resilient diaphragm membrane 764 protects armature
740 and creates a cavity that is filled with a sufficiently non-corrosive
liquid,
which in turn enables actuator designers to make more favorable choices
between materials with high corrosion resistance and high magnetic
permeability.
Furthermore, diaphragm membrane 764 provides a barrier to metal ions and
other debris that would tend to migrate into the cavity.
Resilient diaphragm membrane 764 includes a distal sealing surface 766,
which is related to the seat opening area, both of which can be increased or
decreased. The distal sealing surface 766 and the seat surface of piloting
button
705 can be optimized for a pressure range at which the valve actuator is
designed to operate. Reducing distal sealing surface 766 (and the
corresponding tip of armature 740) reduces the plunger area involved in
squeezing the membrane, and this in turn reduces the spring force required for
a
given upstream fluid-conduit pressure. On the other hand, making the plunger
tip
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 41 -
area too small tends to damage resilient diaphragm membrane 764 during valve
closing over time. Preferable range of tip-contact area to seat-opening area
is
between 1.4 and 12.3. The present actuator is suitable for a variety of
pressures
of the controlled fluid including pressures of about 150 psi. Without any
substantial modification, the valve actuator may be used in the range of about
30
psi to 80 psi, or even water pressures of about 125 psi.
Referring still to FIGs. 10, 10A, 10B and 10C, piloting button 705 has an
important novel function for achieving consistent long-term piloting of any
solenoid valve. Solenoid actuator 81 together with piloting button 705 are
installed together as one assembly into the electronic faucet; this minimizes
the
pilot-valve-stroke variability at the pilot seat in region 708 (FIGS. 10, 10B
and
10C) with respect to the closing surface (shown in detail in FIG. 10E), which
variability would otherwise affect the piloting operation. This installation
is faster
and simpler than prior art installations.
The assembly of operator 81 (or 81A, or 81B) and piloting button 705 is
usually put together in a factory and is permanently connected thereby holding
resilient diaphragm membrane 764 and the pressure loaded armature fluid (at
pressures comparable to the pressure of the controlled fluid). Piloting button
705 is coupled to the narrow end of actuator base 716 using complementary
threads or a sliding mechanism, both of which assure reproducible fixed
distance
between distal end 766 of diaphragm membrane 764 and the sealing surface of
piloting button 705. The coupling of operator 80 and piloting button 705 can
be
made permanent (or rigid) using glue, a set screw or pin. Alternatively, one
member may include an extending region that is used to crimp the two members
together after screwing or sliding on piloting button 705.
It is possible to install solenoid actuator 81 (or 81A or 81B) without
piloting
button 705, but this process is somewhat more cumbersome. Without piloting
button 705, the installation process requires first positioning the pilot-
valve body
with respect to the main valve and then securing the actuator assembly onto
the
main valve as to hold the pilot-valve body in place. If proper care is not
taken,
there is some variability in the position of the pilot body due to various
piece-part
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 42 -
tolerances and possible deformation. This variability creates variability in
the
pilot-valve member's stroke. In a low-power pilot valve, even relatively small
variations can affect timing or possibly sealing force adversely and even
prevent
the pilot valve from opening or closing at all. Thus, it is important to
reduce this
variability during installation, field maintenance, or replacement. On the
other
hand, when assembling solenoid actuator 81 (81A or 81B) with piloting button
705, this variability is eliminated or substantially reduced during the
manufacturing process, and thus there is no need to take particular care
during
field maintenance or replacement. In automatic valve 250, piloting button 705
is
co-operatively constructed and arranged with the design of cavity 350 and
sealing surface 348 to enable a novel way of assembling a pilot-valve-operated
valve 250.
Referring to FIGS. 10D and 10E, as described above, resilient diaphragm
membrane 764 includes an outer ring 767, flex region 768 and tip or distal
sealing region 766. The distal tip of the plunger is enclosed inside a pocket
flange behind the distal sealing region 766. Preferably, diaphragm membrane
764 is made of EPDM due to its low durometer and compression set by NSF part
61 and relatively low diffusion rates. The low diffusion rate is important to
prevent the encapsulated armature fluid from leaking out during transportation
or
installation process. Alternatively, resilient diaphragm membrane 764 can be
made out of a flouro-elastomer, e.g., VITON, or a soft, low compression
rubber,
such as CRI-LINE flouro-elastomer made by CRI-TECH SP-508.
Alternatively, diaphragm membrane 764 can be made out of a Teflon-type
elastomer, or just to include a Teflon coating. Alternatively, resilient
diaphragm
membrane 764 can be made out of NBR (natural rubber) having a hardness of
40-50 durometer as a means of reducing the influence of molding process
variation yielding flow marks that can form micro leaks of the contained fluid
into
the surrounding environment. Alternatively, resilient membrane 764 can include
a metallic coating that slows the diffusion through the diaphragm member when
the other is dry and exposed to air during storage or shipping of the
assembled
actuator.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 43 -
Preferably, resilient diaphragm membrane 764 has high elasticity and low
compression (which is relatively difficult to achieve). Diaphragm membrane 764
may have some parts made of a low durometer material (i.e., parts 767 and 768)
and other parts of high durometer material (front surface 766). The low
compression of resilient diaphragm membrane 764 is important to minimize
changes in the armature stroke over a long period of operation. Thus, contact
part 766 is made of high durometer material. The high elasticity is needed for
easy flexing of resilient diaphragm membrane 764 in regions 768. Furthermore,
resilient membrane part 768 is relatively thin so that the diaphragm can
deflect,
and the plunger can move with very little force. This is important for long-
term
battery operation.
Referring to FIG. 10E, another embodiment of resilient diaphragm
membrane 764 can be made to include a forward slug cavity 772 (in addition to
the rear plunger cavity shaped to accommodate the plunger tip). The forward
slug cavity 772 is filled with a plastic or metal slug 774. The forward
surface 770
including the surface of slug 774 is cooperatively arranged with the sealing
surface of piloting button 705. Specifically, the sealing surface of piloting
button
705 may include a pilot seat 709 made of a different material with properties
designed with respect to slug 774. For example, pilot seat 709 can be made of
a
high durometer material. Therefore, during the sealing action, resilient and
relatively hard slug 774 comes in contact with a relatively soft pilot seat
709.
This novel arrangement of resilient diaphragm membrane 764 and piloting button
705 provides for a long term, highly reproducible sealing action.
Resilient diaphragm membrane 764 can be made by a two stage molding
process whereby the outer portion is molded of a softer material and the inner
portion that is in contact with the pilot seat is molded of a harder elastomer
or
thermo-plastic material using an over molding process. The forward facing
insert
774 can be made of a hard injection molded plastic, such as acceptable co-
polymer or a formed metal disc of a non-corrosive non-magnetic material such
as
300 series stainless steel. In this arrangement, pilot seat 709 is further
modified
such that it contains geometry to retain pilot seat geometry made of a
relatively
CA 02530941 2012-07-31
- 44 -
high durometer elastomer such as EPDM 0 durometer. By employing this design
that transfers the sealing surface compliant member onto the valve seat of
piloting button 705 (rather than diaphragm member 764), several key benefits
are
derived. There are substantial improvements in the process related concerns of
maintaining proper pilot seat geometry having no flow marks (that is a common
phenomenon requiring careful process controls and continual quality control
vigilance). This design enables the use of an elastomeric member with a
hardness that is optimized for the application.
However, automatic valve device 250 may be used with other solenoid
valves such as the bistable solenoid model no. AXB724 available from Arichell
Technologies Inc., West Newton, MA. Alternatively, actuator 80 may include a
latching actuator (as described in U.S. Patent 6,293,516), a non-latching
actuator
(as described in U.S. Patent 6,305,662), or an isolated operator 81 as shown
in
Figs. 10 through 100 or described in PCT Application PCT/US01/51098, which is
incorporated by reference. In general, a number of solenoid valves may be used
such as described in U.S. Patent 4,225,111. An alternative bistable solenoid
is
described in U.S. Patent 5,883,557 or 5,599,003.
Fig. 11 schematically illustrates a fluid flow control subsystem for a
latching actuator 81. The flow control system includes again microcontroller
814,
sensor or power switch 818, and solenoid driver 820. As shown in Fig. 10,
latching actuator 81 includes at least one drive coil 728 wound on a bobbin
and
an armature that preferably is made of a permanent magnet. Microcontroller 814
provides control signals 815A and 815B to power driver 820, which drives
solenoid 728 for moving armature 740. Solenoid driver 820 receives DC power
from battery 824 and voltage regulator 826 regulates the battery power to
provide
a substantially constant voltage to current driver 820. Coil sensors 843A and
843B pick up induced voltage signal due to movement of armature 740 and
provide this signal to a conditioning feedback loop that includes
preamplifiers
845A, 845B and flow-pass filters 847A, 847B. That is, coil sensors 843A and
843B are used to monitor the armature position.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 45 -
Microcontroller 814 is again designed for efficient power operation.
Between actuations, microcontroller 814 goes automatically into a low
frequency
sleep mode and all other electronic elements (e.g., input element or sensor
818,
power driver 820, voltage regulator or voltage boost 826) are powered down.
Upon receiving an input signal from, for example, a motion sensor,
microcontroller 814 turns on a power consumption controller 819. Power
consumption controller 819 powers up signal conditioner that provides power to
microcontroller 814.
Also referring to Fig. 10, to close the fluid passage 708, microcontroller
814 provides a CLOSE control signal 815A to solenoid driver 820, which applies
a drive voltage to the coil terminals. Provided by microcontroller 814, the
CLOSE
control signal 815A initiates in solenoid driver 820 a drive voltage having a
polarity that the resultant magnetic flux opposes the magnetic field provided
by
permanent magnet 723. This breaks magnet 723's hold on armature 740 and
allows the return spring 748 to displace valve member 740 toward valve seat
708. In the closed position, spring 748 keeps resilient diaphragm membrane 764
pressed against the valve seat of piloting button 705. In the closed position,
there is an increased distance between the distal end of armature 740 and pole
piece 725. Therefore, magnet 723 provides a smaller magnetic force on the
armature 740 than the force provided by return spring 748.
To open the fluid passage, microcontroller 814 provides an OPEN control
signal 815B (i.e., latch signal) to solenoid driver 820. The OPEN control
signal
815B initiates in solenoid driver 820 a drive voltage having a polarity such
that
the resultant magnetic flux opposes the force provided by bias spring 748. The
resultant magnetic flux reinforces the flux provided by permanent magnet 723
and overcomes the force of spring 748. Permanent magnet 723 provides a force
that is great enough to hold armature 740 in the open position, against the
force
of return spring 748, without any required magnetic force generated by coil
728.
Referring to Fig. 11, microcontroller 814 discontinues current flow, by
proper control signal 815A or 815B applied to solenoid driver 820, after
armature
740 has reached the desired open or closed state. Pickup coils 843A and 843B
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 46 -
(or any sensor, in general) monitor the movement (or position) of armature 740
and determine whether armature 740 has reached its endpoint. Based on the
coil sensor data from pickup coils 843A and 843B (or the sensor),
microcontroller
814 stops applying the coil drive, increases the coil drive, or reduces the
coil
drive. .
To open the fluid passage, microcontroller 814 sends OPEN signal 815B
to power driver 820, which provides a drive current to coil 842 in the
direction that
will retract armature 740. At the same time, coils 843A and 843B provide
induced signals to the conditioning feedback loop, which includes a
preamplifier
and a low-pass filter. If the output of a differentiator 849 indicates less
than a
selected threshold calibrated for armature 740 reaching a selected position
(e.g.,
half distance between the extended and retracted positions, or fully retracted
position, or another position), microcontroller 814 maintains OPEN signal 815B
asserted. If no movement of armature 740 is detected, microcontroller 814 can
apply a different level of OPEN signal 815B to increase the drive current (up
to
several times the normal drive current) provided by power driver 820. This
way,
the system can move armature 740, which is stuck due to mineral deposits or
other problems.
Microcontroller 814 can detect armature displacement (or even monitor
armature movement) using induced signals in coils 843A and 843B provided to
the conditioning feedback loop. As the output from differentiator 849 changes
in
response to the displacement of armature 740, microcontroller 814 can apply a
different level of OPEN signal 815B, or can turn off OPEN signal 815B, which
in
turn directs power driver 820 to apply a different level of drive current. The
result
usually is that the drive current is reduced, or the duration of the drive
current is
much shorter than the time required to open the fluid passage under worst-case
conditions (that has to be used without an armature sensor). Therefore, the
system of Fig. 8 saves considerable energy and thus extends the life of
battery
824.
Advantageously, the arrangement of coil sensors 843A and 843B can
detect latching and unlatching movements of armature 740 with great precision.
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 47 -
(However, a single coil sensor, or multiple coil sensors, or capacitive
sensors
may also be used to detect movement of armature 740.) Microcontroller 814 can
direct a selected profile of the drive current applied by power driver 820.
Various
profiles may be stored in microcontroller 814 and may be actuated based on the
fluid type, fluid pressure, fluid temperature, the time actuator 840 has been
in
operation since installation or last maintenance, a battery level, input from
an
external sensor (e.g., a movement sensor or a presence sensor), or other
factors.
Optionally, microcontroller 814 may include a communication interface for
data transfer, for example, a serial port, a parallel port, a USB port, or a
wireless
communication interface (e.g., an RF interface). The communication interface
is
used for downloading data to microcontroller 814 (e.g., drive curve profiles,
calibration data) or for reprogramming microcontroller 814 to control a
different
type of actuation or calculation.
Referring to Fig. 10, electromagnetic actuator 81 is connected in a reverse
flow arrangement when the water input is provided via passage 706 of piloting
button 705. Alternatively, electromagnetic actuator 81 is connected in a
forward
flow arrangement when the water input is provided via passage 710 of piloting
button 705 and exits via passage 706. In the forward flow arrangement, the
plunger "faces directly" the pressure of the controlled fluid delivered by
passage
710. That is, the corresponding fluid force acts against spring 748. In both
forward and reverse flow arrangements, the latch or unlatch times depend on
the
fluid pressure, but the actual latch time dependence is different. In the
reverse
flow arrangement, the latch time (i.e., time it takes to retract plunger 740)
increases with the fluid pressure substantially linearly, as shown in Fig.
12B. On
the other hand, in the forward flow arrangement, the latch time decreases with
the fluid pressure. Based on this latch time dependence, microcontroller 814
can
calculate the actual water pressure and thus control the water amount
delivery.
Fig. 11A schematically illustrates a fluid flow control system for another
embodiment of the latching actuator. The flow control system includes again
microcontroller 814, power consumption controller 819, solenoid driver 820
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 48 -
receiving power from a battery 824 or voltage booster 826, and an indicator
828.
Microcontroller 814 operates in both sleep mode and operation mode, as
described above. Microcontroller 814 receives an input signal from an input
element 818 (or any sensor) and provides control signals 815A and 815B to
current driver 820, which drives the solenoid of a latching valve actuator 81.
Solenoid driver 820 receives DC power from battery 824 and voltage regulator
826 regulates the battery power. A power monitor 872 monitors power signal
delivered to the drive coil of actuator 81 and provides a power monitoring
signal
to microcontroller 814 in a feedback arrangement having operational amplifier
870. Microcontroller 814 and power consumption controller 819 are designed for
efficient power operation, as described above.
Also referring to Fig. 11A, to close the fluid passage, microcontroller 814
provides a CLOSE control signal 815A to solenoid driver 820, which applies a
drive voltage to the actuator terminals and thus drives current through coil
728.
Power monitor 872 may be a resistor connected for applied drive current to
flow
through (or a portion of the drive current). Power monitor 872 may
alternatively
be a coil or another element. The output from power monitor 872 is provided to
the differentiator of signal conditioner 870. The differentiator is used to
determine a latch point, as shown in Fig. 12A.
Similarly, as described in connection with Fig. 11, to open the fluid
passage, microcontroller 814 sends CLOSE signal 815A or OPEN signal 815B to
valve driver 820, which provides a drive current to coil 728 in the direction
that
will extend or retract armature 740 (and close or open passage 708). At the
same time, power monitor 872 provides a signal to opamp 870. Microcontroller
814 determines if armature 740 reached the desired state using the power
monitor signal. For example, if the output of opamp 870 initially indicates no
latch state for armature 740, microcontroller 814 maintains OPEN signal 8156,
or
applies a higher level of OPEN signal, as described above, to apply a higher
drive current. On the other hand, if armature 740 reached the desired state
(e.g.,
latch state shown in Fig. 12 as point 662, and shown in Fig. 12A as point
664),
microcontroller 814 applies a lower level of OPEN signal 8156, or turns off
OPEN
CA 02530941 2005-12-22
WO 2005/002321 PCT/US2004/020504
- 49 -
signal 815B. This usually reduces the duration of drive current or the level
of the
drive current as compared to the time or current level required to open the
fluid
passage under worst-case conditions. Therefore, the system of Fig. 12A saves
considerable energy and thus extends life of battery 824.
Fig. 12B shows the pressure dependence of the latch time in the reverse
flow arrangement. The measured dependence shows increasing latch time with
increasing pressure. Based on curve 666, the microcontroller can calculate the
input water pressure at membrane 764. Specifically, after the solenoid of the
actuator is activated, microcontroller 814 searches for the latching point 662
in
Fig. 12 or point 664 in Fig. 12A. When the timer reaches the latching point,
microcontroller 814 deactivates the solenoid. Based on the latch time,
microcontroller 814 calculates the corresponding water pressure, using stored
calibration data. Based on the water pressure and the size of the orifices,
the
controller directs the irrigation system to deliver a known amount of water
discharged by the sprinkler (or another water delivery unit).
While the invention has been described with reference to the above
embodiments, the present invention is by no means limited to the particular
constructions described and/or shown in the drawings. In any additional
equivalent embodiment, any one of the above-described elements may be
replaced by one or more equivalent elements, or similarly any two or more of
the
above-described elements may be replaced by one equivalent element.
The present invention also comprises any modifications or equivalents within
the
scope of the following claims. What is claimed is:
