Note: Descriptions are shown in the official language in which they were submitted.
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PASSIVE SENSORS FOR AUTOMATIC FAUCETS
AND BATHROOM FLUSHERS
The present invention is directed to novel optical sensors. The
present invention is, more specifically, directed to novel optical sensors for
controlling operation of automatic faucets and bathroom flushers, and in
particular, to novel flow control sensors for providing control signals to
electronics used in such faucets and flushers.
BACKGROUND OF THE INVENTION
Automatic faucets and bathroom flushers have been used for many
years. An automatic faucet typically includes an optical or other sensor that
detects the presence of an object, and an automatic valve that turns water on
and off, based on a signal from the sensor. An automatic faucet may include
a mixing valve connected to a source of hot and cold water for providing a
proper mixing ratio of the delivered hot and cold water after water actuation.
The use of automatic faucets conserves water and promotes hand washing,
and thus good hygiene. Similarly, automatic bathroom flushers include a
sensor and a flush valve connected to a source of water for flushing a toilet
or urinal after actuation._ The use of automatic bathroom flushers generally
improves cleanliness in public facilities.
In an automatic faucet, an optical or other sensor provides a control
signal and a controller that, upon detection of an object located within a
target region, provides a signal to open water flow. In an automatic bathroom
flusher, an optical or other sensor provides a control signal to a controller
after a user leaves the target region. Such systems work best if the object
sensor is reasonably discriminating. An automatic faucet should respond to
a user's hands, for instance, it should not respond to the sink at which the
faucet is mounted, or to a paper towel thrown in the sink. Among the ways of
making the system discriminate between the two it has been known to limit
the target region in such a manner as to exclude the sink's location.
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However, a coat or another object can still provide a false trigger to the
faucet. Similarly, this could happen to automatic flushers due to a movement
of bathroom doors, or something similar.
An optical sensor includes a light source (usually an infra-red emitter)
and a light detector sensitive to the IR wavelength of the light source. For
faucets, the emitter and the detector (i.e., a receiver) can be mounted on the
faucet spout near its outlet, or near the base of the spout. For flushers, the
emitter and the detector may be mounted on the flusher body or on a
bathroom wall. Alternatively, only optical lenses (instead of the emitter and
the receiver) can be mounted on these elements. The lenses are coupled to
one or several optical fibers for delivering light from the light source and
to
the light detector. The optical fiber delivers light to and from the emitter
and
the receiver mounted below the faucet.
In the optical sensor, the emitter power and/or the receiver sensitivity
is limited to restrict the sensor's range to eliminate reflections from the
sink,
or from the bathroom walls or other installed objects. Specifically, the
emitting beam should project on a valid target, normally clothing, or skin of
human hands, and then a reflected beam is detected by the receiver. This
kind of sensor relies on the reflectivity of a target's surface, and its
emitting/receiving capabilities. Frequently, problems arise due to highly
reflective doors and walls, mirrors, highly reflective sinks, the shape of
different sinks, water in the sink, the colors and rough/shiny surfaces of
fabrics, and moving users who are walking by but not using the facility.
Mirrors, doors, walls, and sinks are not valid targets, although they may
reflect more energy back to the receiver than rough surfaces at the right
angle incidence. The reflection of valid targets such as various fabrics
varies
with their colors and the surface finish. Some kinds of fabrics absorb and
scatter too much energy of the incident beam, so that less of a reflection is
sent back to the receiver.
A large number of optical or other sensors are powered by a battery.
Depending on the design, the emitter (or the receiver) may consume a large
amount of power and thus deplete the battery over time (or require large
batteries). The cost of battery replacement involves not only the cost of
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batteries, but more importantly the labor cost, which may be relatively high
for skilled personnel.
There is still a need for an optical sensor for use with automatic
faucets or automatic bathroom flushers that can operate for a long period of
time without replacing the standard batteries. There is still a need for
reliable
sensors for use with automatic faucets or automatic bathroom flushers.
SUMMARY OF THE INVENTION
The present invention is directed to novel optical sensors and novel
methods for sensing optical radiation. The novel optical sensors and the
novel optical sensing methods are used, for example, for controlling the
operation of automatic faucets and flushers. The novel sensors and flow
controllers (including control electronics and valves) require only small
amounts of electrical power for sensing users of bathroom facilities, and thus
enable battery operation for many years. A passive optical sensor includes a
light detector sensitive to ambient (room) light for controlling the operation
of
automatic faucets or automatic bathroom flushers.
According to one aspect, an optical sensor for controlling a valve of an
electronic faucet or bathroom flusher includes an optical element located at
an optical input port and arranged to partially define a detection field. The
optical sensor also includes a light detector and a control circuit. The light
detector is optically coupled to the optical element and the input port,
wherein
the light detector is constructed to detect ambient light. The control circuit
is
constructed for controlling opening and closing of a flow valve. The control
circuit is also constructed to receive signal from the light detector
corresponding to the detected light.
The control circuit is constructed to sample periodically the detector.
The control circuit is constructed to sample periodically the detector based
on
the amount of previously detected light. The control circuit is constructed to
determine the opening and closing of the flow valve based on a background
level of the ambient light and a present level of the ambient light. The
control
circuit is constructed to open and close the flow valve based on first
detecting
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arrival of a user and then detecting departure of the user. Alternatively, the
control circuit is constructed to open and close the flow valve based on
detecting presence of a user.
The optical element includes an optical fiber, a lens, a pinhole, a slit or
an optical filter. The optical input port is located inside an aerator of a
faucet
or next to an aerator of the faucet.
According to another aspect, an optical sensor for an electronic faucet
includes an optical input port, an optical detector, and a control circuit.
The
optical input port is arranged to receive light. The optical detector is
optically
coupled to the input port and constructed to detect the received light. The
control circuit controls opening and closing of a faucet valve, or a bathroom
flusher valve
Preferred embodiments of this aspect includes one or more of the
following features: The control circuit is constructed to sample periodically
the detector based on the amount of light detected. The control circuit is
constructed to adjust a sample period based on the detected amount of light
after determining whether a facility is in use. The detector is optically
coupled to the input port using an optical fiber. The input port may be
located in an aerator of the electronic faucet. The system includes batteries
for powering the electronic faucet.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic view of an automatic faucet system including a
control circuit, a valve and a passive optical sensor for controlling water
flow.
Fig. 1A is a cross-sectional view of a spout and a sink of the automatic
faucet system of Fig. 1 using a fiberoptic coupling to the passive optical
sensor.
Fig. 1B is a cross-sectional view of a spout and a sink of the automatic
faucet system of Fig. 1 using an electric coupling to the passive optical
sensor.
Fig. 1C is a cross-sectional view of an aerator used in the automatic
faucet system of Fig. 1.
Fig. 1D is a cross-sectional view of another embodiment of the aerator
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used in the automatic faucet system of Fig. 1.
Fig. lE is a perspective view of another embodiment of the aerator
used in the automatic faucet system of Fig. 1.
Fig. 1F is a cross-sectional view of the aerator shown in Fig. 1D.
5 Figs. 2 and 2A show schematically other embodiments of automatic
faucet systems, including another embodiment of a valve and a passive
optical sensor for controlling water flow.
Figs. 3, 3A, 3B, 3C and 3D show schematically a faucet and a sink
relative to different optical detection patterns used by passive optical
sensors
employed in the automatic faucet systems of Figs. 1, 1B, 2, and 2A.
Fig. 4 shows schematically a side view of a toilet including an
automatic flusher.
Fig. 4A shows schematically a side view of a urinal including an
automatic flusher.
Figs. 5, 5A, 5B, 5C, 5D, 5E, 5F and 5G show schematically side and
top views of different optical detection patterns used by passive optical
sensors employed in the automatic toilet flusher of Fig. 4.
Figs. 5H, 51, 5J, 5K and 5L show schematically side and top views of
different optical detection patterns used by passive optical sensors employed
in the automatic urinal flusher of Fig. 4A.
Figs. 6, 6A, 6B, 6C, 6D and 6E show schematically optical elements
used to form the different optical detection patterns shown in Figs. 3 through
3D and in Figs. 5 through 5L.
Fig. 7 is a cross-sectional view of an embodiment of an automatic
flusher used for flushing toilets or urinals.
Fig. 8 is a perspective exploded view of a valve device used in the
automatic faucet system of Figs. 1, 1A or 1B.
Fig. 8A is an enlarged cross-sectional view of the valve device shown
in Fig. 8.
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. 4, including a
leak detector for detecting water leaks in an automatic faucet system.
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Fig. 9 is an enlarged cross-sectional view of a moving piston-like
member used in the valve device shown in Fig. 7 or 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. 10 is block diagram of a control system for controlling a valve
operating the automatic faucet systems of Figs. 1 through 2A, or bathroom
flushers of Figs 4 and 4A.
Fig. 10A is block diagram of another control system for controlling a
valve operating the automatic faucet systems of Figs. 1 through 2A, or
bathroom flushers of Figs 4 and 4A.
Fig. 10B is a schematic diagram of a detection circuit used in passive
optical sensor used in the automatic faucet system or the automatic flusher
system.
Fig. 11 is a block diagram that illustrates various factors that affect
operation and calibration of the passive optical system.
Figs. 12, 12A, 12B, 12C, 12D, 12E, 12F, 12G, 12H and 121 show a
flow diagram of an algorithm for processing optical data detected by the
passive sensor operating the automatic flusher system.
Figs. 13, 13A and 13B show a flow diagram of an algorithm for
processing optical data detected by the passive sensor operating the
automatic faucet system.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
Fig. 1 shows an automatic faucet system 10 controlled by a sensor
providing signals to a control circuit constructed and arranged to control
operation of an automatic valve. The automatic valve, in turn, controls the
flow of hot and cold water before or after mixing.
Automatic faucet system 10 includes a faucet body 12 and an aerator
30, including a sensor port 34. Automatic faucet system 10 also includes a
faucet base 14 and screws 16A and 16B for attaching the faucet to a deck
18. A cold water pipe 20A and a hot water pipe 20B are connected to a
mixing valve 22 providing a mixing ratio of hot and cold water (which ratio
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can be changed depending on the desired water temperature). Water
conduit 24 connects mixing valve 22 to a solenoid valve 38. A flow control
valve 38 controls water flow between water conduit 24 and a water conduit
25. Water conduit 25 connects valve 38 to a water conduit 26 partially
located inside faucet body 12, as shown. Water conduit 26 delivers water to
aerator 30. Automatic faucet system 10 also includes a control module 50
for controlling a faucet sensor and solenoid valve 38, powered by batteries
located in battery compartment 39.
Referring to Figs. 1 and 1A, in a first preferred embodiment, automatic
faucet system 10 includes an optical sensor located in control module 50 and
optically coupled by a fiberoptic cable 52 to sensor port 34 located in
aerator
30. Sensor port 34 receives the distal end of fiberoptic cable 52, which may
be coupled to an optical lens located at sensor port 34. The optical lens is
arranged to have a selected field of view, which is preferably somewhat
coaxial within the water stream discharged from aerator 30, when the faucet
is turned on.
Alternatively, the distal end of fiberoptic cable 52 is polished and
oriented to emit or to receive light directly (i.e., without the optical
lens).
Again, the distal end of fiberoptic cable 52 is arranged to have the field of
view (for example, field of view A, Fig.1A) directed toward sink 11, somewhat
coaxial within the water stream discharged from aerator 30. Alternatively,
sensor port 34 includes other optical elements, such as an array of pinholes
or an array of slits having a selected size, geometry and orientation. The
size, geometry and orientation of the array of pinholes or the array of slits
is
designed to provide a selected detection pattern (shown in Figs. 3 ¨ 3D, for a
faucet and Figs. 5 ¨ 5L, for a flusher).
Referring still to Figs. 1 and 1A, a fiberoptic cable 52 is preferably
located inside water conduit 26 in contact with water. Alternatively,
fiberoptic
cable 52 could be located outside of the water conduit 26, but inside of
faucet
body 12. Figs. 1C, 1D, and lE show alternative ways to provide sensor port
34 inside aerator 30 and alternative ways to arrange an optical fiber 52
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coupled to an optical lens 54. In other embodiments, optical lens 54 is
replaced by an array of pinholes or an array of slits.
Fig. 1B illustrates a second preferred embodiment of the automatic
faucet system. Automatic faucet system 10A includes faucet body 12 and an
aerator 30 including an optical sensor 37 coupled to a sensor port 35.
Optical sensor 37 is electrically connected by a wire 53 to an electronic
control module 50 located inside the body of the faucet. In another
embodiment, electronic control module 50 located outside of the faucet body
next to control valve 38 (Fig. 1)
In another embodiment, sensor port 35 receives an optical lens,
located in from of optical sensor 37, for defining the detection pattern (or
optical field of view). Preferably, the optical lens provides a field of view
somewhat coaxial within the water stream discharged from aerator 30, when
the faucet is turned on. In yet other embodiments, sensor port 35 includes
other optical elements, such as an array of pinholes or an array of slits
having a selected size, geometry and orientation. The size, geometry and
orientation of the array of pinholes, or the array of slits are designed to
provide a selected detection pattern (shown in Figs. 3 ¨ 3D, for a faucet and
Figs. 5 ¨ 5L, for a flusher).
The optical sensor is a passive optical sensor that includes a visible or
infrared light detector optically coupled to sensor port 34 or sensor port 35.
There is no light source (i.e., no light emitter) associated with the optical
sensor. The visible or near infrared (NIR) light detector detects light
arriving
at sensor port 34 or sensor port 35 and provides the corresponding electrical
signal to a controller located in control unit 50 or control unit 55. The
light
detector (i.e., light receiver) may be a photodiode, or a photoresistor (or
some other optical intensity element having an electrical output, whereby the
sensory element will have the desired optical sensitivity). The optical sensor
using a photo diode also includes an amplification circuitry. Preferably, the
light detector detects light in the range from about 400-500 nanometers up to
about 950-1000 nanometers. The light detector is primarily sensitive to
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ambient light and not very sensitive to body heat (e.g., infrared or far
infrared
light).
Figs. 2 and 2A illustrate alternative embodiments of the automatic
faucet system. Referring to Fig. 2, automatic faucet system 10B includes a
faucet receiving water from a dual-flow faucet valve 60 and providing water
from aerator 31. Automatic faucet 12 includes a mixing valve 58 controlled
by a handle 59, which may be also coupled to a manual override for valve
60. Dual-flow valve 60 is connected to cold water pipe 20A and hot water
pipe 20B, and controls water flow to the respective cold water pipe 21A and
hot water pipe 21B.
Dual flow valve 60 is constructed and arranged to simultaneously
control water flow in both pipes 21A and 21B upon actuation by a single
actuator 201 (See Fig. 8A). Specifically, valve 60 includes two flow valves
arranged for controlling flow of hot and cold water in the respective water
lines. The solenoid actuator 201 (Fig. 8A) is coupled to a pilot mechanism
for controlling two flow valves. The two flow valves are preferably diaphragm
operated valves (but may also be piston valves, or large flow-rate "fram"
valves described in connection with Figs. 9 and 9A). Dual flow valve 60
includes a pressure release mechanism constructed to change pressure in a
diaphragm chamber of each diaphragm operated valve and thereby open or
close each diaphragm valve for controlling water flow. Dual flow valve 60 is
described in detail in PCT Application PCT/US01/43277, filed on November
20, 2001.
Referring still to Fig. 2, coupled to faucet body 12 there is a sensor
port 35 for accommodating a distal end of an optical fiber (e.g., fiberoptic
cable 52), or for accommodating a light detector. The fiberoptic cable
delivers light from sensor port 35 to a light detector. In one preferred
embodiment, faucet body 12 includes a control module with the light detector
and a controller described in connection with Figs. 10 and 10A. The
controller provides control signals to solenoid actuator 201 via electrical
cable 56. Sensor port 35 has a detection field of view (shown in Figs. 3A and
3B) located outside of the water stream emitted from aerator 31.
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Referring to Fig. 2A, automatic faucet system 10C includes faucet
body 12 also receiving water from dual-flow faucet valve 60 and providing
water from aerator 31. Automatic faucet 10C also includes mixing valve 58
controlled by handle 59. Dual-flow valve 60 is connected to cold water pipe
5 20A and hot water pipe 20B, and controls water flow to the respective
cold
water pipe 21A and hot water pipe 21B.
A sensor port 33 is coupled to faucet body 12 and is designed to have
a field of view shown in Figs. 3C and 3D. Sensor port 33 accommodates the
distal end of an optical fiber 56A. The proximal end of optical fiber 56A
10 provides light to an optical sensor located in a control module 55A
coupled to
dual flow valve 60. Control module 55A also includes the control electronics
and batteries. The optical sensor detects the presence of an object (e.g.,
hands), or detects a change in the presence of the object (i.e., movement) in
the sink area. Control electronics control the operation of and the readout
from the light detector. The control electronics also include a power driver
that controls the operation of the solenoid associated with valve 60. Based
on the signal from the light detector, the control electronics direct the
power
driver to open or close solenoid valve 60 (i.e., to start or stop the water
flow).
The design and operation of actuator 201 (Fig. 8A) is described in detail in
PCT Applications PCT/US02/38757; PCT/US02/38758; and
PCT/US02/41576.
Fig. 1C shows a vertical cross-section of an aerator 30A located at
the discharge end of the spout of faucet 12. Aerator 30A includes a barrel 62
attachable to faucet body 12 using threads 63. Barrel 62 supports a ring 64
which in turn supports wire mesh screens 65. Barrel 62 also supports an
annular member 70, a jet-forming member 72, and an upper washer 74. Jet
forming member 72 includes several elongated slots 76 for providing water
passages. Jet forming member 72 and screens 65 include a passage 36 for
optical fiber 52. Water flows through aerator 30A from top to bottom. In
aerator 30A, a water stream flows from water conduit 26 (Fig. 1A) and is
broken up by the vertically elongated slots 76 of the water jet-forming
member 72. Then water flows through to wire mesh screens 65, which are
supported by ring 64. Ring 64 also enables air intake (suction) through gaps
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67 (which it forms between itself and the barrel 62) inside a chamber 66.
Just above wire mesh screens 65, in chamber 66, air mixes with water so
that a mixture of air and water passes through screens 65. The optical fiber
52 is located in the center of the above described elements inside a tubular
member 36, which holds lens 54.
Fig. 1D shows a second embodiment of an aerator with a centrally
located port for a passive sensor. In this embodiment, the aerator 30B
includes at least two lenticularly arranged wire mesh members 86A and 86B,
providing a central opening for a passage 88. Aerator 30B also includes an
insert member 90 including several holes 92 and a central hole 88 for
accommodating tubular member 52. Aerator 30B is attached to faucet 12
using threads 83. Water flows from water conduit 26 to an upper chamber
91 and then through holes 92. Air enters chamber 93 via holes 84. The
mixture of water and air then flows through two screens 86A and 86B
assembled in a lenticular arrangement. Housing 82 has a surrounding
support part oriented inwards, which supports the two screens 86A and 86B.
Optical fiber 52 extends inside water pipe 26 (Fig. 1A) through aerator 30B
from the top and through the wire mesh screens 86A and 86B. As the
individual water jets formed by holes 92 enter lower chamber 93, air is drawn
via openings 84 into chamber 93. Inside chamber 93, water mixes with air
and the mixture is forced through screens 86A and 86B.
Figs. lE and 1F show alternative ways to provide the optical field
aligned with the water stream (i.e., alternative embodiment of an aerator and
a sensor port located therein). Fig. lE is a perspective view of an aerator
30C and Fig. 1F is a cross-sectional view of aerator 30C used in the
automatic faucet system of Fig. 1. Aerator 30C is coupled to faucet body 12
and the water conduit 26 using using threads 83. Optical fiber 52 is located
outside the water conduit and introduced via an adapter 97. Alternatively,
adapter 97 can include the light detector coupled to a control module using
an electrical cable instead of fiberoptic cable 52. (For simplicity, the wire
mesh members and the air openings are not shown in Figs. lE and 1F).
Fig. 3 shows schematically a cross-sectional view of a first preferred
detection pattern (A) for the passive optical sensor installed in automatic
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faucet 12. The detection pattern A is associated with sensor port 34 and is
shaped by a lens, or an element selected from the optical elements shown in
Figs. 6¨ 6E. The detection pattern A is selected to receive reflected ambient
light primarily from sink 11. The pattern's width is controlled, but the range
is
much less controlled (i.e., Fig. 3 shows pattern A only schematically because
detection range is not really limited).
A user standing in front of a faucet will affect the amount of ambient
(room) light arriving at the sink and thus will affect the amount of light
arriving
at the optical detector. On the other hand, a person just moving in the room
will not affect significantly the amount of detected light. A user having his
hands under the faucet will alter the amount of ambient (room) light being
detected by the optical detector even more. Thus, the passive optical sensor
can detect the user's hands and provide the corresponding control signal.
Here, the detected light doesn't depend significantly on the reflectivity of
the
target surface (unlike for optical sensors that use both a light emitter and a
receiver). After hand washing, the user removing his hands from under the
faucet will again alter the amount of ambient light detected by the optical
detector. Then, the passive optical sensor provides the corresponding
control signal to the controller (explained in connection with Figs. 10, 10A
and 10B).
Figs. 3A and 3B show schematically a second preferred detection
pattern (B) for the passive optical sensor installed in automatic faucet 10B.
The detection pattern B is associated with sensor port 35, and again may be
shaped by a lens, or an optical element shown in Figs. 6 ¨ 6E. A user having
his hands under faucet 10B alters the amount of ambient (room) light
detected by the optical detector. As mentioned above, the detected light
doesn't depend significantly on the reflectivity of the user's hands (unlike
for
optical sensors that use both a light emitter and a receiver). Thus, the
passive optical sensor detects the user's hands and provides the
corresponding control signal to the controller. Figs. 13, 13A, and 13B
illustrate detection algorithms used for the detection patterns A and B.
Figs. 3C and 3D show schematically another detection pattern (C) for
the passive optical sensor installed in automatic faucet 10C. The detection
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pattern C is associated with sensor port 33, and is shaped a selected optical
element. The selected optical element achieves a desired width and
orientation of the detection pattern, while the range is more difficult to
control.
In this embodiment, a user standing in front of faucet 10C will alter the
amount of detected ambient light somewhat more than a user passing by. In
this embodiment, light reflections from sink 11 influence the detected light
only minimally.
Fig. 4 shows schematically a side view of a toilet including an
automatic flusher 100, and Fig. 4A shows schematically a side view of a
urinal including an automatic flusher 100A. Flusher 100 receives pressurized
water from a supply line 112 and employs a passive optical sensor to
respond to actions of a target within a target region 103. After a user leaves
the target region, a controller directs opening of a flush valve 102 that
permits water flow from supply line 112 to a flush conduit 113 and to a toilet
bowl 116.
Fig. 4A illustrates bathroom flusher 100A used for automatically
flushing a urinal 120. Flusher 100A receives pressurized water from supply
line 112. Flush valve 102 is controlled by a passive optical sensor that
responds to actions of a target within a target region 103. After a user
leaves
the target region, a controller directs opening of a flush valve 102 that
permits water flow from supply line 112 to a flush conduit 113.
Bathroom flushers 100 and 100A may have a modular design,
wherein their cover can be partially opened to replace the batteries or the
electronic module. Bathroom flushers with such a modular design are
described in U.S. Patent Application 60/448,995, filed on February 20, 20037
and published under US patent publication numbers 2004/0164261 Al and
2004/0227117 Al.
Figs. 5 and 5A show schematically side and top views of an optical
detection pattern used by the passive optical sensor installed in the
automatic toilet flusher of Fig. 4. This detection pattern is associated with
sensor port 108 and is shaped by a lens, or an element selected from the
optical elements shown in Figs. 6 ¨ 6E. The pattern is angled below
horizontal (H) and directed symmetrically with respect to toilet 116. The
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range is somewhat limited not to be influenced by a wall (W); this can be also
done by limiting the detection sensitivity.
Figs. 5B and 5C show schematically side and top views of a second
optical detection pattern used by the passive optical sensor installed in the
automatic toilet flusher of Fig. 4. This detection pattern is shaped by a
lens,
or another optical element. The pattern is angled both below horizontal (H)
and above horizontal (H). Furthermore, the pattern is directed
asymmetrically with respect to toilet 116, as shown in Fig. 5C.
Figs. 5D and 5E show schematically side and top views of a third
optical detection pattern used by the passive optical sensor installed in the
automatic toilet flusher of Fig. 4. This detection pattern is again shaped by
a
lens, or another optical element. The pattern is angled above horizontal (H).
Furthermore, the pattern is directed asymmetrically with respect to toilet
116,
as shown in Fig. 5E.
Figs. 5F and 5G show schematically side and top views of a fourth
optical detection pattern used by the passive optical sensor installed in the
automatic toilet flusher of Fig. 4. This detection pattern is angled below
horizontal (H) and is directed asymmetrically across toilet 116, as shown in
Fig. 5G. This detection pattern is particularly useful for "toilet side
flushers,"
described in US Publication No. 2003-0019022, or US Publication No. 2003-
0066125.
Figs. 5H and 51, show schematically side and top views of an optical
detection pattern used by the passive optical sensor installed in the
automatic urinal flusher of Fig. 4A. This detection pattern is shaped by a
lens,
or another optical element. The pattern is angled both below horizontal (H)
and above horizontal (H) to target ambient light changes caused by a person
standing in front of urinal 120. This pattern is directed asymmetrically with
respect to urinal 120 (as shown in Fig. 51), for example, to eliminate or at
least reduce light changes caused by a person standing at a neighboring
urinal.
Figs. 5J, 5K and 5L, show schematically side and top views of another
optical detection pattern used by the passive optical sensor installed in the
automatic urinal flusher of Fig. 4A. This detection pattern is shaped by a
lens,
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or another optical element, as mentioned above. The pattern is angled
below horizontal (H) to eliminate the influence of light caused by a ceiling
lamp. This pattern may be directed asymmetrically to the left or to the right
with respect to urinal 120 (as shown in Figs. 5K or 5L). These detection
5 patterns are particularly useful for "urinal side flushers," described in
US
Publication No. 2003-0019022, or US Publication No. 2003-0066125.
In general, the field of view of a passive optical sensor can be formed
using optical elements such as beam forming tubes, lenses, light pipes,
reflectors, arrays of pinholes and arrays of slots having selected geometries.
10 These optical elements can provide a down-looking field of view that
eliminates the invalid targets such as mirrors, doors, and walls. Various
ratios of the vertical field of view to horizontal field of view provide
different
options for target detection. For example, the horizontal field of view may be
1.2 wider than the vertical field of view or vise versa. A properly selected
15 field of view can eliminate unwanted signal from an adjacent faucet or
urinal.
The detection algorithm includes a calibration routine that accounts for a
selected field of view including the field's size and orientation.
Figs. 6 through 6E illustrate different optical elements for producing
desired detection patterns of the passive sensor. Figs. 6 and 6B illustrate
different arrays of pinholes. The thickness of the plate, the size and the
orientation of the pinholes (shown in cross-section in Figs. 6A and 6C) define
the properties of the field of view. Figs. 6D and 6E illustrate an array of
slits
for producing a detection pattern shown in Figs. 5B and 5H. This plate may
also include a shutter for covering the top or the bottom detection field.
Fig. 7 illustrates in detail an automatic flush valve suitable for use with
automatic bathroom flusher 100 or automatic bathroom flusher 100A. Other
flush valves are described in the above-references PCT applications. Yet
other suitable flush valves are described in US Patents 6,382,586 and
5,244,179. In each case, the flush valve is controlled by a passive optical
sensor described herein.
Referring to Fig. 7, automatic flush valve 140 is a high performance,
electronically controlled or manually controlled tankless flush valve.
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=
16
Automatic flush valve 140 uses a passive optical sensor 130 (shown in Fig.
7). Passive optical sensor 130 includes a lens 134 for defining the detection
field and providing ambient light to a light receiver 132. Plastic enclosure
135 includes an optical window 136, which may also include optical elements
described in connection with Figs. 6 ¨ 6E. The controller is located on a
circuit board 138. Plastic enclosure 135 also houses the batteries for
powering the entire flushing system.
Referring still to Fig. 7, flush valve 140, includes an input union 112,
preferably made of a suitable plastic resin. Union 112 is attached via threads
to an input fitting that interacts with the building water supply system.
Furthermore, union 112 is designed to rotate on its own axis when no water
is present so as to facilitate alignment with the inlet supply line. Union 112
is
attached to an inlet pipe 142 by a fastener 144 and a radial seal 146, which
enables union 12 to move in or out along inlet pipe 142. This movement
aligns the inlet to the supply line. However, with fastener 144 secured, there
is a water pressure applied by the junction of union 112 to inlet 142. This
forms a unit that is rigid sealed through seal 146. The water supply travels
through union 112 to inlet 142 and thru the inlet valve assembly 150 an inlet
screen filter 152, which resides in a passage formed by member 178 and is
in communication with a main valve seat 156. The operation of the entire
main valve can be better understood by also referring to Figs. 9, and 9A.
As also described in connection with Figs. 8, 9, and 9A, electro-
magnetic actuator 201 controls operation of the main valve, which is a "fram
piston valve" 270. In the opened state, water flows thru a passage 152 and
thru passages 158 into passages 159A and 159B, into main outlet 114. In
the closed state, the fram element 278 (Figs. 9 and 9A) seals the valve main
seat 156 thereby closing flow through passage 158. Automatic flusher 140
includes an adjustable input valve 150 controlled by rotation of a valve
element 174 threaded together with valve elements 162 and 164. Valve
elements 162 and 164 are sealed from body 170 via one or several o-rings
163. Furthermore, valve elements 162 and 164 are held down by threaded
element 160, when element 174 is threaded all the way. This force is
CA 02507504 2012-06-19
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transferred to element 154 and 178. The resulting force presses down
element 180
When valve element 160 is unthreaded all the way, valve assembly
150 and 151 moves up due to the force of spring 184 located on guide
element 186 in this adjustable input valve. The spring force combined with
inlet fluid pressure from pipe 142 forces element 151 against the valve seat
in contact with 0-ring 182 resulting in a sealing action of the 0-ring 182. 0-
Ring 182 (or another sealing element) blocks the flow of water to inner
passage of 152, which in turn enables servicing of all internal valve element
including elements behind shut-off valve 150 without the need to shut off the
water supply at the inlet 112. This is a major advantage of this embodiment.
According to another function of adjustable valve 140, the threaded
retainer is fastened part way resulting in valve body elements 162 and 162 to
push down the valve seat only partially. There is a partial opening that
provides a flow restriction reducing the flow of input water thru valve 150.
This novel function is designed to meet application specific requirements. In
order to provide for the installer the flow restriction, the inner surface of
the
valve body includes application specific marks such as 1.6 W.0 1.0 GPF
urinals etc. for calibrating the input water flow.
Automatic flush valve 140 is equipped with the above-described
sensor-based electronic system located in housing 135. Alternatively, the
sensor-based electronic flush system may be replaced by an all mechanical
activation button or lever. Alternatively, the flush valve may be controlled
by
a hydraulically timed mechanical actuator that acts upon a hydraulic delay
arrangement, as described in PCT Application PCT/US01/43273. The
hydraulic system can be adjusted to a delay period corresponding to the
needed flush volume for a given fixture such a 1.6 GPF W.0 etc. The
hydraulic delay mechanism can open the outlet orifice of the pilot section
instead of electro-magnetic actuator 201 for duration equal to the installer
preset value.
Referring again to Fig. 7, depending on the passive optical sensor
signal, the microcontroller executes a control algorithm and provides ON and
OFF signals to valve actuator 201, which, in turn, opens or closes water
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delivery. The microcontroller can also execute a half flush or delayed flush
depending on the mode of use (e.g., a toilet, a urinal, a frequently used
urinal
as in a ball park). The microcontroller can also execute a timed flush (one
flush per day or per week in facilities such as ski resorts in summer) to
prevent drying of the water trap.
Figs. 8, 8A and 8B illustrate an automatic valve 38 constructed and
arranged for controlling water flow in automatic faucet 10. Specifically,
automatic valve 38 receives water at a valve input port 202 and provides
water from a valve output port 204, in the open state. Automatic valve 38
includes a body 206 made of a durable plastic or metal. Preferably, valve
body 206 is made of a plastic material but includes a metallic input coupler
210 and a metallic output coupler 230. Input and output couplers 210 and
230 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 water lines
24 and 25, respectively. Valve body 206 includes a valve input port 240, and
a valve output port 244, and a cavity 207 for receiving the individual valve
elements shown in Fig. 8.
Metallic input coupler 210 is rotatably attached to input port 240 using
a metal C-clamp 212 that slides into a slit 214 inside input coupler 210 and
also a slit 242 inside the body of input port 240 (Fig. 8). Metallic output
coupler 230 is rotatably attached to output port 244 using a metal C-clamp
232 that slides into a slit 234 inside output coupler 230 and also a slit 246
inside the body of output port 244. When servicing the faucet 12, this
rotatable arrangement prevents tightening the water line connection to any of
the two valve couplers unless attaching the wrench to the designated
surfaces of couplers 210 and 230. (That is, a service person cannot tighten
the water input and output lines by gripping on valve body 206.) This
protects the relatively softer plastic body 206 of automatic valve 38.
However, body 206 can be made of a metal in which case the above-
described rotatable coupling is not needed. A sealing 0-ring 216 seals input
coupler 210 to input port 240, and a sealing 0-ring 238 seals output coupler
230 to output port 244.
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Referring to Figs. 8, 8A, and 8B, metallic input coupler 210 includes
an inlet flow adjuster 220 cooperatively arranged with a flow control
mechanism 310 (Fig. 8). Inlet flow adjuster 220 includes an adjuster piston
222, a closing spring 224 arranged around an adjuster pin 226 and pressing
against a pin retainer 218. Input flow adjuster 220 also includes an adjuster
rod 228 coupled to and displacing adjuster piston 222. Flow control
mechanism 310 includes a spin cap 312 coupled by screw 314 to an
adjustment cap 316 in communication with a flow control cam 320. Flow
control cam 320 slides linearly inside body 206 upon turning adjustment cap
316. Flow control cam 320 includes inlet flow openings 321, a locking
mechanism 323 and a chamfered surface 324. Chamfered surface 324 is
cooperatively arranged with a distal end 229 of adjuster rod 228. The linear
movement of flow control cam 320, within valve body 206, displaces
chamfered surface 324 and thus displaces adjuster rod 228. Adjuster piston
222 also includes an inner surface 223 cooperatively arranged with an inlet
seat 211 of input coupler 210. The linear movement of adjuster rod 228
displaces adjuster piston 222 between a closed position and an open
position. In the closed position, sealing surface 223 seals inner seat 211 by
the force of closing spring 224. In the opened position, adjuster rod 228
displaces adjuster pin 222 against closing spring 224 thereby providing a
selectively sized opening between inlet seat 211 and sealing surface 223.
Thus, by turning adjustment cap 316, adjuster rod 228 opens and closes inlet
adjuster 220. Inlet adjuster 220 controls or closes completely the water flow
from water line 24. The above-described manual adjustment can be
replaced by an automatic motorized adjustment mechanism controlled by a
microcontroller.
Referring still to Figs. 8, 8A and 8B, automatic valve 38 also includes
a removable inlet filter 330 removably located over an inlet filter holder
332,
which is part of the lower valve housing. Inlet filter holder 332 also
includes
an 0-ring and a set of outlet holes 267 shown in Fig. 8. The "fram piston"
270 is shown in detail in Figs. 9 and 9A. Referring again to Fig. 8A, water
flows from input port 202 of input coupler 210 through inlet flow adjuster 220
and then through inlet flow openings 321, and through inlet filter 330 inside
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inlet filter holder 332. Water then arrives at an input chamber 268 inside a
cylindrical input element 276 providing pressure against a pliable member
278 (Fig. 9).
Automatic valve 38 also includes a service loop 340 (or a service rod)
5 designed to pull the entire valve assembly, including attached actuator
200,
out of body 206, after removing of plug 316. The removal of the entire valve
assembly also removes the attached actuator 200 (or actuator 201) and the
piloting button described in PCT Application PCT/US02/38757 and in PCT
Application PCT/US02/38757. To enable easy installation and servicing,
10 there are rotational electrical contacts located on a PCB at the distal
end of
actuator 200. Specifically, actuator 200 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
15 and the actuator may be connected to movable contact pins. Such distal,
actuator contact assembly achieves easy rotational contacts by just sliding
actuator 200 located inside valve body 206.
Fig. 8C illustrates automatic valve 38 including a leak detector for
indicating a water leak or water flow across valve device 38. The leak
20 detector includes an electronic measurement circuit 350 and at least two
electrodes 348 and 349 coupled respectively to input coupler 210 and output
coupler 230. (The leak detector may also include four electrodes for a four-
point resistivity measurement). Valve body 206 is made of plastic or another
non-conductive material. In the closed state, when there is no water flow
between input coupler 210 and output coupler 230, electronic circuit 350
measures a very high resistance value between the two electrodes. In the
open state, the resistance value between input coupler 210 and output
coupler 230 drops dramatically because the flowing water provides a
conductive path.
There are various embodiments of electronics 350, which can provide
a DC measurement, an AC measurement including eliminating noise using a
lock-in amplifier (as known in the art). Alternatively, electronics 350 may
include a bridge or another measurement circuit for a precise measurement
CA 02507504 2012-06-19
21
of the resistivity. Electronic circuit 350 provides the resistivity value to a
microcontroller and thus indicates when valve 38 is in the open state.
Furthermore, the leak detector indicates when there is an undesired water
leak between input coupler 210 and output coupler 230. The entire valve 38
is located in an isolating enclosure to prevent any undesired ground paths
that would affect the conductivity measurement. Furthermore, the leak
detector can indicate some other valve failures when water leaks into the
enclosure from valve 38. Thus, the leak detector can sense undesired water
leaks that would be otherwise difficult to observe. The leak detector is
constructed to detect the open state of the automatic faucet system to
confirm proper operation of actuator 200.
Automatic valve 38 may include a standard diaphragm valve, a
standard piston valve, or a novel "fram piston" valve 270 explained in detail
in
connection with Figs. 9 and 9A. Referring to Fig. 9, valve 270 includes a
distal body 276, which includes an annular lip seal 275 arranged, together
with pliable member 278, to provide a seal between input port chamber 268
and output port chamber 269. The distal body 276 also includes one or
several flow channels 267 (also shown in Fig. 8) providing communication (in
the open state) between input chamber 268 and output chamber 269.
Pliable member 278 also includes sealing members 279A and 279B
arranged to provide a sliding seal, with respect to valve body 272, between
pilot chamber 292 and output chamber 271. There are various possible
embodiments of seals 279A and 279B (Fig. 9). This seal may be a one-
sided seal or a two-sided seal as 279A and 279B shown in Fig. 9.
Furthermore, there are various additional embodiments of the sliding seal
including 0-rings, etc.
The present invention envisions valve device 270 having various
sizes. For example, the "full" size embodiment has the pin diameter A =
0.070", the spring diameter B = 0.310", the pliable member diameter C =
0.730", the overall fram and seal's diameter D = 0.412", the pin length E =
0.450", the body height F = 0.2701", the pilot chamber height G = 0.220", the
fram member size H = 0.160", and the fram excursion I = 0.100". The overall
height of the valve is about 1.35" and diameter is about 1.174".
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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 = 0.34", 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" and the diameter is about 0.455". 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 270 receives fluid at
input port 268, which exerts pressure onto diaphragm-like member 278
providing a seal together with a lip member 275 in a closed state. Groove
passage 288 inside pin 286 provides pressure communication with pilot
chamber 292, which is in communication with actuator cavity 300 via
communication passages 294A and 294B. An actuator (described in PCT
Application PCT/US02/38757) provides a seal at surface 298 thereby sealing
passages 294A and 294B and thus pilot chamber 300. When the plunger of
actuator 200 moves away from surface 298, fluid flows via passages 294A
and 294B to control passage 296 and to output port 269. This causes
pressure reduction in pilot chamber 292. Therefore, diaphragm-like member
278 and piston-like member 288 move linearly within cavity 292, thereby
providing a relatively large fluid opening at lip seal 275. A large volume of
fluid can flow from input port 268 to output port 269.
When the plunger of actuator 200 seals control passages 294A and
294B, pressure builds up in pilot chamber 292 due to the fluid flow from input
port 268 through "bleed" groove 288 inside guide pin 286. The increased
pressure in pilot chamber 292 together with the force of spring 290 displace
linearly, in a sliding motion over guide pin 286, from member 270 toward
sealing lip 275. When there is sufficient pressure in pilot chamber 292,
diaphragm-like pliable member 278 seals input port chamber 268 at lip seal
275. The soft member 278 includes an inner opening that is designed with
guiding pin 286 to clean groove 288 during the sliding motion. That is,
groove 288 of guiding pin 286 is periodically cleaned.
The embodiment of Fig. 9 shows the valve having a central input
chamber 268 (and guide pin 286) symmetrically arranged with respect to
vent passages 294A and 294B (and the location of the plunger of actuator
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200). However, the valve device may have input chamber 268 (and guide
pin 286) non-symmetrically arranged with respect to passages 294A, 294B
and output vent passage 296. That is, in such a design, this valve has input
chamber 268 and guide pin 286 non-symmetrically arranged with respect to
the location of the plunger of actuator 200. The symmetrical and non-
symmetrical embodiments are equivalent.
Automatic valve 38 has numerous advantages related to its long term
operation and easy serviceability. Automatic valve 38 includes inlet adjusted
220, which enable servicing of the valve without shutting of the water supply
at another location. The construction of valve 38 including the inner
dimensions of cavity 207 and actuator 200 enable easy replacement of the
internal parts. A service person can remove screw 314 and spin cap 312,
and then remove adjustment cap 316 to open valve 38. Valve 38 includes
service loop 340 (or a service rod) designed to pull the entire valve
assembly, including attached actuator 200, out of body 206. The service
person can then replace any defective part, including actuator 200, or the
entire assembly and insert the repaired assembly back inside valve body
206. Due to the valve design, such repair would take only few minutes and
there is no need to disconnect valve 38 from the water line or close the water
supply. Advantageously, the "fram piston" design 270 provides a large
stroke and thus a large water flow rate relative to its size.
Another embodiment of the "fram piston" valve device is described in
PCT applications PCT/US02/34757, filed December 4, 2002, and
PCT/US03/20117, filed June 24, 2003. Again, the entire operation of this
valve device is controlled by a single solenoid actuator that may be a
latching
solenoid actuator or an isolated actuator described in PCT application
PCT/US01/51054, filed on October 25, 2001.
Fig. 10 schematically illustrates control electronics 400, powered by a
battery 420. Control electronics 400 includes battery regulation unit 422, no
or low battery detection unit 425, passive sensor and signal processing unit
402, and the microcontroller 405. Battery regulation unit 422 provides power
for the whole controller system. It provides 6.0 V power through 6.0V power
1 to "no battery" Detector; it provides 6.0 V power to low battery detector;
it
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also provides 6.0 V to power driver 408. It provides a regulated 3.0 V power
to microcontroller 405.
"No battery" detector generates pulses to microcontroller 405 in form
of "Not Battery" signals to notify microcontroller 405. Low Battery detector
is
coupled to the battery/ power regulation through the 6.0V power. When
power drops below 4.2V, the detector generates a pulse to the
microcontroller (i.e., low battery signal). When the "low battery" signal is
received, microcontroller will flash indicator 430 (e.g., an LED) with a
frequency of 1Hz, or may provide a sound alarm. After flushing 2000 times
under low battery conditions, microcontroller will stop flushing, but still
flash
the LED.
As described in connection with Fig. 10B, passive sensor and signal
processing module 402 converts the resistance of a photoresistor to a pulse,
which is sent to microcontroller through the charge pulse signal. The pulse
width changes represent the resistance changes, which in turn correspond to
the illumination changes. The control circuit also includes a clock/reset unit
that provides clock pulse generation, and it resets pulse generation. It
generates a reset pulse with 4Hz frequency, which according to the clock
pulse, is the same frequency. The reset signal is sent to microcontroller 405
through "reset" signal to reset the microcontroller or wake up the
microcontroller from sleep mode.
A manual button switch may be formed by a reed switch, and a
magnet. When the button is pushed down by a user, the circuitry sends out
a signal to the clock/reset unit through manual signal IRQ, then forces the
clock/ reset unit to generate a reset signal. At the same time, the level of
the
manual signal level is changed to acknowledge to microcontroller 405 that it
is a valid manual flush signal.
Referring still to Fig. 10, control electronics 400 receives signals from
optical sensor unit 402 and controls an actuator 412, a controller or
microcontroller 405, an input element (e.g., the optical sensor), a solenoid
driver 408 (power driver) receiving power from a battery 420 regulated by a
voltage regulator 422. Microcontroller 405 is designed for efficient power
operation. To save power, microcontroller 405 is initially in a low frequency
CA 02507504 2012-06-19
sleep mode and periodically addresses the optical sensor to see if it was
triggered. After triggering, the microcontroller provides a control signal to
a
power consumption controller 418, which is a switch that powers up voltage
regulator 422 (or a voltage boost 422), optical sensor unit 402, and a signal
5 conditioner 416. (To simplify the block diagram, connections from power
consumption controller 418 to optical sensor unit 402 and to signal
conditioner 416 are not shown.)
Microcontroller 405 can receives an input signal from an external input
element (e.g., a push button) that is designed for manual actuation or control
10 input for actuator 410. Specifically, microcontroller 405 provides
control
signals 406A and 406B to power driver 408, which drives the solenoid of
actuator 410. Power driver 408 receives DC power from battery and voltage
regulator 422 regulates the battery power to provide a substantially constant
voltage to power driver 408. An actuator sensor 412 registers or monitors
15 the armature position of actuator 410 and provides a control signal 415
to
signal conditioner 416. A low battery detection unit 425 detects battery
power and can provide an interrupt signal to microcontroller 405.
Actuator sensor 412 provides data to microcontroller 405 (via signal
conditioner 416) about the motion or position of the actuator's armature and
20 this data is used for controlling power driver 408. The actuator sensor
412
may be an electromagnetic sensor (e.g., a pick up coil) a capacitive sensor, a
Hall effect sensor, an optical sensor, a pressure transducer, or any other
type
of a sensor.
Preferably, microcontroller 405 is an 8-bit CMOS microcontroller
25 TMP86P807M made by Toshiba. The microcontroller has a program
memory of an 8 Kbytes and a data memory of 256 bytes. Programming is
done using a Toshiba adapter socket with a general-purpose PROM
programmer. The microcontroller operates at 3 frequencies (fc = 16MHz, fc=
8MHz and fs = 332.768kHz), wherein the first two clock frequencies are used
in a normal mode and the third frequency is used in a low power mode (i.e., a
sleep mode). Microcontroller 405 operates in the sleep mode between
various actuations. To save battery power, microcontroller 405 periodically
samples optical sensor 402 for an input signal, and then triggers power
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consumption controller 418. Power consumption controller 418 powers up
signal conditioner 416 and other elements. Otherwise, optical sensor 402,
voltage regulator 422 (or voltage boost 422) and a signal conditioner 416 are
not powered to save battery power. During operation, microcontroller 405
also provides indication data to an indicator 430. Control electronics 400
may receive a signal from the passive optical sensor or the active optical
sensor described above. The passive optical sensor includes only a light
detector providing a detection signal to microcontroller 405.
Low battery detection unit 425 may be the low battery detector
model no. TC54VN4202EMB, available from Microchip Technology. Voltage
regulator 422 may be the voltage regulator part no. TC55RP3502EMB, also
available from Microchip Technology (http://www.microchip.com).
Microcontroller 405 may alternatively be a microcontroller part no. MCU
COP8SAB728M9, available from National Semiconductor.
Fig. 10A schematically illustrates another embodiment of control
electronics 400. Control electronics 400 receives signals from optical sensor
unit 402 and controls actuator 412. As described above, the control
electronics also includes microcontroller 405, solenoid driver 408 (i.e.,
power
driver), voltage regulator 422, and a battery 420. Solenoid actuator 411
includes two coil sensors 411A and 411B. Coil sensors 411A and 411B
provide a signal to the respective preamplifiers 416A and 416B and low pass
filters 417A and 417B. A differentiator 419 provides the differential signal
to
microcontroller 405 in a feedback loop arrangement.
To open a fluid passage, microcontroller 405 sends OPEN signal
406B to power driver 408, which provides a drive current to the drive coil of
actuator 410 in the direction that will retract the armature. At the same
time,
coils 411A and 411B provide induced signal to the conditioning feedback
loop, which includes the preamplifier and the low-pass filter. If the output
of a
differentiator 419 indicates less than a selected threshold calibrated for the
retracted armature (i.e., the armature didn't reach a selected position),
microcontroller 405 maintains OPEN signal 406B asserted. If no movement
of the solenoid armature is detected, microcontroller 405 can apply a
different (higher) level of OPEN signal 406B to increase the drive current (up
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to several time the normal drive current) provided by power driver 408. This
way, the system can move the armature, which is stuck due to mineral
deposits or other problems.
Microcontroller 405 can detect the armature displacement (or even
monitor armature movement) using induced signals in coils 411A and 411B
provided to the conditioning feedback loop. As the output from differentiator
419 changes in response to the armature displacement, microcontroller 405
can apply a different (lower) level of OPEN signal 406B, or can turn off
OPEN signal 406B, which in turn directs power driver 408 to apply a different
level of drive current. The result usually is that the drive current has been
reduced, or the duration of the drive current has been much shorter than the
time required to open the fluid passage under worst-case conditions (that has
to be used without using an armature sensor). Therefore, the control system
saves considerable energy and thus extends the life of battery 420.
Advantageously, the arrangement of coil sensors 411A and 411B can
detect latching and unlatching movement of the actuator armature with great
precision. (However, a single coil sensor, or multiple coil sensors, or
capacitive sensors may also be used to detect movement of the armature.)
Microcontroller 405 can direct a selected profile of the drive current applied
by power driver 408. Various profiles may be stored in, microcontroller 405
and may be actuated based on the fluid type, the fluid pressure (water
pressure), the fluid temperature (water temperature), the time actuator 410
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. Based on the water pressure and the known sizes
of the orifices, the automatic flush valve can deliver a known amount of flush
water.
Fig. 10B provides a schematic diagram of a detection circuit used for
the passive optical sensor 50. The passive optical sensor does not include a
light source (no light emission occurs) and only includes a light detector
that
detects arriving light. As compared to the active optical sensor, the passive
sensor enables reduced power consumption since all power consumption
related to the IR emitter is eliminated. The light detector may be a
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photodiode, a photo-resistor or some other optical element providing
electrical output depending on the intensity or the wavelength of the received
light. The light receiver is selected to be active in the range or 350 to
1,500
nanometers and preferably 400 to 1,000 nanometers, and even more
preferably, 500 to 950 nanometers. Thus, the light detector is not sensitive
to body heat emitted by the user of faucet 10, 10A, 10B or 10C, or body heat
emitted by the user located in front of flushers 100 or 100A.
Fig. 10B shows a schematic diagram of the detection circuit used by
the passive sensor, which enables a significant reduction in energy
consumption. The detection circuit includes a detection element D (e.g., a
photodiode or a photo-resistor), two comparators (U1A, and U1B) connected
to provide a read-out from the detection element upon receipt of a high pulse.
Preferably, the detection element is a photo-resistor. The voltage Vcc is +5
V (or + 3V) received from the power source. Resistors R2 and R3 are voltage
dividers between Vcc and the ground. Diode D1 is connected between the
pulse input and output line to enable the readout of the capacitance at
capacitor C1 charged during the light detection.
Preferably, the photo-resistor is designed to receive light of intensity in
the range of 1 lux to 1000 lux, by appropriate design of optical lens 54 or
the
optical elements shown in Figs 6 through 6E. For example, optical lens 54
may include a photochomatic material or a variable size aperture. In general,
the photo-resistor can receive light of intensity in the range of 0.1 lux to
500
lux for suitable detection. The resistance of the photodiode is very large for
low light intensity, and decreases (usually exponentially) with the increasing
intensity.
Referring still to Fig. 10B, upon receiving a "high" pulse at the input
connection, comparator UlA receives the "high" pulse and provides the "high"
pulse to node A. At this point, the corresponding capacitor charge is read out
through comparator Uigto the output 7. The output pulse is a square wave
having a duration that depends on the photocurrent (that charged capacitor
C1 during the light detection time period. Thus, microcontroller 34 receives a
signal that depends on the detected light.
CA 02507504 2012-06-19
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In the absence of the high signal, comparator UlA provides no signal to
node A, and therefore capacitor C1 is being charged by the photocurrent
excited at the photo resistor D between Vcc and the ground. The charging
and reading out (discharging) process is being repeated in a controlled
manner by providing a high pulse at the control input. The output receives a
high output, i.e., the square wave having duration proportional to the
photocurrent excited at the photo resistor. The detection signal is in a
detection algorithm executed by microcontroller 405.
By virtue of the elimination of the need to employ an energy
consuming IR light source used in the active optical sensor, the system can
be configured so as to achieve a longer battery life (usually many years or
operation without changing the batteries). Furthermore, the passive sensor
enables a more accurate means of determining presence of a user, the user
motion, and the direction of user's motion.
The preferred embodiment as it relates to which type of optical
sensing element is to be used is dependent upon the following factors: The
response time of a photo-resistor is on the order or 20-50 milliseconds,
whereby a photo-diode is on the order of several microseconds, therefore the
use of a photo-resistor will require a significantly longer time form which
impacts overall energy use.
Furthermore, the passive optical sensor can be used to determine
light or dark in a facility and in turn alter the sensing frequency (as
implemented in the faucet detection algorithm). That is, in a dark facility
the
sensing rate is reduced under the presumption that in such a modality the
faucet or flusher will not be used. The reduction of sensing frequency further
reduces the overall energy consumption, and thus this extends the battery
life.
Fig. 11 illustrates various factors that affect operation and calibration
of the passive optical system. The sensor environment is important since the
detection depends on the ambient light conditions. If there the ambient light
in the facility changes from normal to bright, the detection algorithm has to
recalculate the background and the detection scale. The detection process
differs when the lighting conditions vary (585), as shown in the provided
CA 02507504 2012-06-19
algorithms. There are some fixed conditions (588) for each facility such as
the walls, toilet locations, and their surfaces. The provided algorithms
periodically calibrate the detected signal to account for these conditions.
The above-mentioned factors are incorporated in the following algorithm.
5 Referring to Figs. 12 ¨ 121, the microcontroller is programmed to
execute a flushing algorithm 600 for flushing toilet 116 or urinal 120 at
different light levels. Algorithm 600 detects different users in front of the
flusher as they are approaching the unit, as they are using the toilet or
urinal,
and as they are moving away from the unit. Based on these activities,
10 algorithm 600 uses different states. There are time periods between each
state in order to automatically flush the toilet at appropriately spaced
intervals. Algorithm 600 also controls flushes at particular periods to make
sure that the toilet has not been used without detection. The passive optical
detector for algorithm 600 is preferably a photoresistor coupled to a readout
15 circuit shown in Fig. 10B.
Algorithm 200 has three light modes: a Bright Mode (Mode 1), a Dark
Mode (Mode 3), and a Normal Mode (Mode 2). The Bright Mode (Mode 1) is
set as the microcontroller mode when resistance is less than 2k0 (Pb),
corresponding to large amounts of light detected (Fig. 12). The Dark Mode
20 (Mode 3) is set when the resistance is greater than 2M0 (Pd),
corresponding
to very little light detected (Fig. 12). The Normal Mode (Mode 2) is defined
for a resistance is between 2k0 and 2M0, corresponding to ambient,
customary amounts of light are present. The resistance values are
measured in terms of a pulse width (corresponding to the resistance of the
25 photoresistor in Fig. 10B). The above resistance threshold values differ
for
different photoresistors and are here for illustration only.
The microcontroller is constantly cycling through algorithm 600, where
it will wake up (for example) every 1 second, determine which mode it was
last in (due to the amount of light it detected in the prior cycle). From the
30 current mode, the microcontroller will evaluate what mode it should go
to
based on the current pulse width (p) measurement, which corresponds to the
resistance value of the photoresistor.
CA 02507504 2012-06-19
31
The microcontroller goes through 6 states in Mode 2. The following
are the states required to initiate the flush: An Idle status in which no
background changes in light occur, and in which the microcontroller
calibrates the ambient light; a TargetIn status, in which a target begins to
come into the field of the sensor; an ln8Seconds status, during which the
target comes in towards the sensor, and the pulse width measured is stable
for 8 seconds (if the target leaves after 8 seconds, there is no flush); an
After8Seconds status, in which the target has come into the sensor's field,
and the pulse width is stable for more than 8 seconds, meaning the target
has remained in front of the sensor for that time (if the target leaves after
8
seconds (and after which, if the target leaves, there is a cautionary flush);
a
TargetOut status, in which the target is going away, out of the field of the
sensor; an In2Seconds status, in which the background is stable after the
target leaves. After this last status, the microcontroller flushes, and goes
back to the Idle status.
When the target moves closer to the sensor, the target can block the
light, particularly when wearing dark, light-absorbent clothes. Thus, the
sensor will detect less light during the TargetIn status, so that resistance
will
go up (causing what will later be termed a TargetInUp status), while the
microcontroller will detect more light during the TargetOut status, so that
resistance will go down (later termed a TargetOutUp status). However, if the
target wears light, reflective clothes, the microcontroller will detect more
light
as the target gets closer to it, in the TargetIn status (causing what will
later
be described as a TargetInDown status), and less during the TargetOut
status (later termed a TargetOutDown status). Two seconds after the target
leaves the toilet, the microcontroller will cause the toilet to flush, and the
microcontroller will return to the Idle status.
To test whether there is a target present, the microcontroller checks
the Stability of the pulse width, or how variable the p values have been in a
specific period, and whether the pulse width is more variable than a constant,
selected background level, or a provided threshold value of the pulse width
variance (Unstable). The system uses two other constant, pre-selected
values in algorithm 600, when checking the Stability of the p values to set
the
CA 02507504 2012-06-19
32
states in Mode 2. One of these two pre-selected values is Stable1, which is
a constant threshold value of the pulse width variance. A value below means
that there is no activity in front of unit, due to the p values not changing
in
that period being measured. The second pre-selected value used to
determine Stability of the p values is Stable2, another constant threshold
value of the pulse width variance. In this case a value below means that a
user has been motionless in front of the microcontroller in the period being
measured.
The microcontroller also calculates a Target value, or average pulse
width in the After8Sec status, and then checks whether the Target value is
above (in the case of TargetInUp) or below (in the case of TargetInDown) a
particular level above the background light intensity: BACKGROUND x
(1+PERCENTAGEIN) for TargetInUp, and BACKGROUND x (1-
PERCENTAGEIN) for TargetInDown. To check for TargetOutUp and
TargetOutDown, the microcontroller uses a second set of values:
BACKGROUND x (1+PERCENTAGEOUT) and BACKGROUND x (1-
PERCENTAGEOUT).
Referring to Fig. 12, every 1 second (601), the microcontroller will
wake up and measure the pulse width, p (602). The microcontroller will then
determine which mode it was previously in: If it was previously in Mode 1
(604), it will enter Mode 1 (614) now. It will similarly enter Mode 2 (616) if
it
had been in Mode 2 in the previous cycle (606), or Mode 3 (618) if it had
been in Mode 3 in the previous cycle (608). The microcontroller will enter
Mode 2 as default mode (610), if it cannot determine which mode it entered
in the previous cycle. Once the Mode subroutine is finished, the
microcontroller will go into sleep mode (612) until the next cycle 600 starts
with step 601.
Referring to Fig. 12A (MODE 1-bright mode), if the microcontroller
was previously in Mode 1 based on the p value being less than or equal to
2k0, and the value of p now remains as greater than or equal to 2k0 (620)
for a time period measured by timer 1 as greater than 8 seconds, but less
than 60 seconds (628), the microcontroller will cause a flush (640), all Mode
1 timers (timers 1 and 2) will be reset (630), and the microcontroller will go
to
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33
sleep (612) until the next cycle 600 starts at step 601. However, if p changes
while timer 1 counts for more than 8 seconds, or less than 60 (628), there
will
be no flush (640). Simply, all Mode 1 timers will be reset (630), the
microcontroller will go to sleep (612), and Mode 1 will continue to be set as
the microcontroller mode until the next cycle 600 starts.
If the microcontroller was previously in Mode 1, but the value of p is
now greater than 2k0 but less than 2M0 (622), for greater than 60 seconds
(634) based on the timer 1 count (632), all Mode 1 timers will be reset (644),
the microcontroller will set Mode 2 (646) as the system mode, so that the
microcontroller will start in Mode 2 in the next cycle 600, and the
microcontroller will go to sleep (612). However, if p changes while timer 1
counts for 60 seconds (134 to 148), Mode 1 will remain the microcontroller
mode and the microcontroller will go to sleep (612) until the next cycle 600
starts.
If the microcontroller was previously in Mode 1, and p is now greater
than or equal to 2M0 (624) while timer 2 counts (636) for greater than 8
seconds (638), all Mode 1 timers will be reset (650), the microcontroller will
set Mode 3 (652) as the new system mode, and the microcontroller will go to
sleep (612) until the next cycle 600 starts. However, if p changes while timer
2 counts for 8 seconds, the microcontroller will go to sleep (steps 638 to
612), and Mode 1 will continue to be set as the microcontroller mode until the
start of the next cycle 600.
Referring to Fig. 12B (MODE 3 ¨ dark mode), if the microcontroller
was previously in Mode 3 based on the value of p having been greater than
or equal to 2M0, but the value of p is now less than or equal to 2kf2 (810)
for
a period measured by timer 3 (812) as greater than 8 seconds (814), the
microcontroller will reset timers 3 and 4, or all Mode 3 timers (816), the
microcontroller will set Mode 1 as the state (818) until the start of the next
cycle 600, and the microcontroller will go to sleep (612). However, if the
value of p changes while timer 3 counts for 8 seconds, the microcontroller
will go from step 814 to 612, so that the microcontroller will go to sleep,
and
Mode 3 will continue to be set as the microcontroller mode until the next
cycle 600 starts.
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34
If the microcontroller was previously in Mode 3 based on the value of
p having been greater than or equal to 2MQ, and the value of p is still
greater
than or equal to 2M0 (820), the microcontroller will reset timers 3 and 4
(822), the microcontroller will go to sleep (612), and Mode 3 will continue to
be set as the microcontroller mode until the start of the next cycle 600.
If the microcontroller was previously in Mode 3, but p is now between
2k0 and 2M0 (824), for a period measured by timer 4 (826) as longer than 2
seconds (828), timers 3 and 4 will be reset (830), Mode 2 will be set as the
mode (832) until the next cycle 600 starts, and the microcontroller will go to
sleep (612). However, if p changes while timer 4 counts for longer than 2
seconds, Mode 3 will remain the microcontroller mode, and the
microcontroller will go from step 828 to step 612, going to sleep until the
next
cycle 600 starts. If an abnormal value of p occurs, the microcontroller will
go
to sleep (612) until a new cycle starts.
Referring to Fig. 12C (MODE 2¨ normal mode), if the microcontroller
mode was previously set as Mode 2, and now p is less than or equal to 2k0
(656), for a period measured by timer 5 (662) as more than 8 seconds (664),
all Mode 2 timers will be reset (674), Mode 1 (Bright Mode) will be set as the
microcontroller mode (676), and the microcontroller will go to sleep (612).
However, if p changes while timer 5 counts for longer than 8 seconds, the
microcontroller will go to sleep (steps 664 to 612), and Mode 2 will remain
the microcontroller mode until the next cycle 600 starts.
However, if now p is greater than or equal to 2M0 (658) for a period
measured by timer 6 (668) as longer than 8 seconds (670), the toilet is not in
Idle status (i.e., there are background changes, 680), and p remains greater
than or equal to 2M0 while timer 6 counts for over 5 minutes (688), the
system will flush (690). After flushing, timers 5 and 6 will be reset (692),
Mode 3 will be set as the microcontroller mode (694), and the microcontroller
will go to sleep (612). Otherwise, if p changes while timer 6 counts for
longer
than 5 minutes, the system will go from step 688 to 612, and go to sleep.
If the microcontroller mode was previously set as Mode 2, now p is
greater than or equal to 2M0 (658) for a period measured by timer 6 (668) as
more than 8 seconds (670), but the toilet is in Idle status (680), timers 5
and
CA 02507504 2012-06-19
6 will be reset (682), Mode 3 will be set as microcontroller mode (684), and
the microcontroller will go to sleep at step 612.
If p is greater or equal to 2M0, but changes while timer 6 counts (668)
to greater than 8 seconds (670), the microcontroller will go to sleep (612),
5 and Mode 2 will remain as the microcontroller mode. If p is within a
different
value, the microcontroller will go to step 660 (shown in Fig. 12D).
Referring to Fig. 12D, alternatively, if the microcontroller mode was
previously set as Mode 2, and p is greater than 2k0 and less than 2M0
(661), timers 5 and 6 will be reset (666), pulse width Stability will be
checked
10 by assessing the variance of the last four pulse width values (667), and
the
Target value is found by determining the pulse width average value (step
669).
At this point, when the status of the microcontroller is found to be Idle
(672), the microcontroller goes on to step 675. In step 675, if the Stability
is
15 found to be greater than the constant Unstable value, meaning that there
is a
user present in front of the unit, and the Target value is larger than the
Background x (1+Percentageln) value, meaning that the light detected by the
microcontroller has decreased, this leads to step 679 and a TargetInUp
status (i.e., since a user came in, towards the unit, resistance increased
20 because light was blocked or absorbed), and the microcontroller will go
to
sleep (612), with Mode 2 TargetInUp as the microcontroller mode and status.
When the conditions set in step 675 are not true, the microcontroller
will check if those in 677 are. In step 677, if the Stability is found to be
greater than the constant Unstable value, due to a user in front of the unit,
25 but the Target value is less than the Background x (1-PercentageIn)
value,
due to the light detected increasing, this leads to a "TargetInDown" status in
step 681, (i.e., since a user came in, resistance decreased because light off
of his clothes is reflected), and the microcontroller will go to sleep (612),
with
Mode 2 TargetInDown as the microcontroller mode and status. However, if
30 the microcontroller status is not Idle (672), the microcontroller will
go to step
673 (shown in Fig. 12E).
Referring to Fig. 12E, if the system starts in the TargetInUp status
(683), at step 689 the system will check whether the Stability value is less
CA 02507504 2012-06-19
36
than the constant Stable2, and whether the Target value is greater than
Background x (1+Percentageln) (689). If both of these conditions are
simultaneously met, which would mean that a user is motionless in front of
the unit, blocking light, the microcontroller will now advance to In8SecUp
status (697), and go to sleep (612). If the two conditions in step 689 are not
met, the system will check whether Stability is less than Stable1 and Target
is less than Backgroundx(1+Percentageln) at the same time (691), meaning
that there is no user in front of the unit, and there is a large amount of
light
being detected by the unit. If this is the case, the system status will now be
set as Mode 2 Idle (699), and the microcontroller will go to sleep (612). If
neither of the sets of conditions in steps 689 and 691 is met, the system will
go to sleep (612).
If the TargetInDown status (686) had been set in the previous cycle,
the system will check whether Stability is less than Stable2 and Target is
less
than Background x (1-PercentageIn) at the same time in step 693. If this is
so, which would mean that there is a user motionless in front of the unit,
with
more light being detected, the microcontroller will advance status to
In8SecDown (701), and will then go to sleep (612).
If the two requirements in step 693 are not met, the microcontroller will
check if Stability is less than Stable1 while at the same time Target is
greater
than Background x (1-PercentageIn) in step 698. If both are true, the status
will be set as Mode 2 Idle (703), due to these conditions signaling that there
is no activity in front of the unit, and that there is a large amount of light
being
detected by the unit, and it will go to sleep (612). If Stability and Target
do
not meet either set of requirements from steps 693 or 698, the
microcontroller will go to sleep (612), and Mode 2 will continue to be the
microcontroller status. If status is not Idle, TargetInUp or TargetInDown, the
microcontroller will continue as in step 695 (shown in Fig. 12F)
Referring to Fig. 12F, if In8SecUp had been set as the status (700), it
will check whether Stability is less than Stable2, and at the same time Target
is greater than Background x (1+Percentageln) in step 702. If these
conditions are met, meaning that there is a motionless user before the unit,
and that there is still less light being detected, the timer for the InaSec
status
CA 02507504 2012-06-19
37
will start counting (708). If the two conditions continue to be the same while
the timer counts for longer than 8 seconds, timer 7 is reset (712), the
microcontroller advances to After8SecUp status (714), and finally goes to
sleep (612). If the two conditions change while the timer counts to above 8
seconds (710), the microcontroller will go to sleep (612). If in step 702 the
requirements are not met by the values of Stability and Target, the In8Sec
timer is reset (704), in step 706 the microcontroller status is set as
TargetInUp, and the microcontroller will proceed to step 673 (Fig. 12E).
Referring to Fig. 12E, if the microcontroller status was set as
In8SecDown (716), the microcontroller checks whether Stability is less than
Stable2, and at the same time Target is less than Background x (1-
PercentageIn) in step 718, to check whether the user is motionless before
the unit, and whether it continues to detect a large amount of light. If the
two
values meet the simultaneous requirement, the In8Sec status timer will start
counting (724). If it counts for longer than 8 seconds while the two
conditions
are met (726), timer 7 will be reset (728), the status will be advanced to
After8SecDown (730), and the microcontroller will go to sleep (612).
If the timer does not count for longer than 8 seconds while Stability
and Target remain at those ranges, the microcontroller will not advance the
status, and will go to sleep (612). If the requirements of step 718 are not
met
by the Stability and Target values, the In8SecTimer will be reset (720), and
the microcontroller status will be set to TargetInDown (722), where the
microcontroller will continue to step 673 (Fig.12E). If the Mode 2 state is
none of those covered in Figs. 12C-F, the system continues through step 732
(shown in Fig. 12G)
Referring to Fig. 12G, in step 734, if the system was in the
After8SecUp status (734), it will check whether Stability is less than
Stable1,
that is, whether there is no activity before the unit. If so, timer 7 will
start
counting (742), and if Stability remains less than Stable1 until timer 7
counts
for longer than 15 minutes (744), the microcontroller will flush (746), the
Idle
status will be set (748), and the microcontroller will go to sleep (612). If
Stability does not remain less than the Stable1 value until timer 7 counts for
CA 02507504 2012-06-19
38
longer than 15 minutes, the microcontroller will go to sleep (612) until the
next cycle.
If Stability was not less than Stable1, the microcontroller checks
whether it is greater than Unstable, and whether Target is greater than
Background x (1+PercentageOut) (738). If both simultaneously meet these
criteria, meaning that there is a user moving in front of the unit, but there
is
more light being detected because they are moving away, the microcontroller
advances to Mode 2 TargetOutUp as the microcontroller status (740), and
the microcontroller goes to sleep (612). If Stability and Target do not meet
the two criteria in step 738, the microcontroller goes to sleep (612).
If the microcontroller was in After8SecDown (750), it will check
whether the Stability is less than Stable1 at step 752. If so, timer 7 will
begin
to count (754), and if it counts for greater than 15 minutes (756), the
microcontroller will flush (758), Idle status will be set (760), and the
microcontroller will go to sleep (612). If Stability does not remain less than
Stablel until timer 7 counts to greater than 15 minutes, the microcontroller
will go to sleep (612) until the next cycle.
If the Stability is not found to be less than Stable1 at step 752, the
microcontroller will check whether Stability is greater than Unstable, while
at
the same time Target is less than Background x (1-PercentageOut) at step
762. If so, this means that there is a user in front of the unit, and that it
detects less light because they are moving away, so that it will advance the
status to TargetOutDown at step 764, and will go to sleep (612). Otherwise,
if both conditions in step 762 are not met, the microcontroller will go to
sleep
(612). If the Mode 2 state is none of those covered in Figs. 12C-G, system
continues through step 770 (shown in Fig. 12H).
Referring to Fig. 12H, if TargetOutUp had been set as the status
(772), the microcontroller will check whether Stability is less than Stable1
while Target is less than Background x (1+PercentageOut), in step 774. If
so, it will set the status as In2Sec (776), and the microcontroller will go to
sleep (612). However, if Stability and Target do not simultaneously meet the
criteria in step 774, the microcontroller will check if Stability is greater
than
Unstable and at the same time Target is greater than Background x
CA 02507504 2012-06-19
39
(1+PercentageOut) in step 778. If so, it will set the status as After8SecUp
(780), and it will go to 732 where it will continue (See Fig.12). If Stability
and
Target do not meet the criteria of either step 774 or 778, the microcontroller
will go to sleep (612).
If the microcontroller is in TargetOutDown status (782), it will check
whether Stability is less than Stable1, and Target greater than Background x
(1-PercentageOut) simultaneously (783). If so, it would mean that there is no
activity in front of the unit, and that there is less light reaching the unit,
so that
it will advance status to In2Sec (784), and go to sleep (612). However, if
Stability and Target do not meet both criteria of step 783, the
microcontroller
will check whether Stability is greater than Unstable, and Target is less than
Background x (1-PercentageOut) simultaneously in step 785. If so, the
microcontroller will set status as After8SecDown (788), and go to step 732
where it will continue (See Fig. 12G). If Stability and Target meet neither
set
of criteria from steps 783 or 785, the microcontroller will go to sleep (612).
Referring to Fig. 121, if the microcontroller set In2Sec status in the
previous cycle (791), it will check whether Stability is less than Stable1
(792),
which is the critical condition: since the user has left, there are no
fluctuations in the light detected via resistance. It will also check whether
the Target value is either greater than Background x (1-PercentageIn), or
less than Background x (1+Percentageln), in step 792. If this is the case,
there is no activity in front of the unit, and the light detected is neither
of the
two levels required to signify a user blocking or reflecting light, which
would
indicate that there is no user in front of the unit. The system would then
start
the In2Sec status timer in step 794, and if it counts for longer than 2
seconds
(796) with these conditions still at hand, the microcontroller will flush
(798),
all Mode 2 timers will be reset in step 799, the status will be set back to
Idle
in step 800, and the microcontroller will go to sleep (612). If the Stability
and
Target values change while the In2Sec timer counts to greater than 2
seconds (796), the microcontroller will go to sleep (612) until the start of
the
next 600 cycle.
If Stability and Target values do not meet the two criteria set in step
792, the In2Sec timer is reset (802), the status is changed back to either
CA 02507504 2012-06-19
TargetOutUp or TargetOutDown in step 804, and the microcontroller goes to
step 770 (Fig.12H). If the microcontroller is not in In2Sec status either, the
microcontroller will go to sleep (612), and start algorithm 600 again.
5 Figs 13, 13A, and 13B illustrate a control algorithm for faucets 10, 10A
and 108. Algorithm 900 includes two modes. Mode 1 is used when the
passive sensor is located outside the water stream (faucet 10B), and Mode 2
is used when the passive sensor's field of view is inside the water stream
(faucets 10 and 10A). In Mode 1 (algorithm 920) the sensor located outside
10 the water stream detects the blocking of the light by a nearby user's
hands,
and checks for how long the low light remains steady, interpreting it as the
user at the sink, but also excluding a darkening of the room the unit is
placed
in as a similar signal. This sensor then will directly turn off the water once
the user has left the faucet, or once it no longer detects unstable, low
levels
15 of light.
In Mode 2 (algorithm 1000), the photoresistor inside the water stream
also uses the above variables, but takes an additional factor into
consideration: running water can also reflect light, so that the sensor may
not be able to completely verify the user having left the faucet. In this
case,
20 the algorithm also uses a timer to turn the water off, while then
actively
checking whether the user is still there. Modes 1 or 2 may be selectable, for
example, by a dipswitch.
Referring to Fig. 13, algorithm 900 commences after the power goes
on (901), and the unit initializes the module in step 902. The microcontroller
25 then checks the battery status (904), resets all timers and counters
(906),
and closes the valve (shown in Figs. 1, 2, 4 and 4A) in step 908. All
electronics are calibrated (910), and the microcontroller establishes a
background light threshold level, (BLTH), in step 912. The microcontroller
will then determine which mode to use in step 914: In Mode 1, the
30 microcontroller executes algorithm 920 (to step 922, Fig. 13A) and in
Mode
2, the microcontroller executes algorithm 1000 (to step 1002, Fig.13B).
Referring to Fig. 13A, if the microcontroller uses Mode 1, the passive
sensor scans for a target every1/8 of a second (924). The scan and sleep
CA 02507504 2012-06-19
,
41
time may be different for different light sensors (photodiode, photoresistor,
etc. and their read out circuits). For example, the scan frequency can be
every 1/4 second or every% second. Also, just as in the algorithm shown in
Fig. 12, the microcontroller will go through the algorithm and then go to
sleep
in between the executed cycles. After scanning, the microcontroller
measures the sensor level (SL), or value corresponding to the resistance of
the photoresistor, at step 925. It will then compare the sensor level to the
background light threshold level (BLTH): if the SL is greater than or equal to
25% of the BLTH (926), the microcontroller will further determine whether it
is
greater than or equal to 85% of the BLTH (927). These comparisons
determine the level of ambient light: if the SL is higher than or equal to 85%
of the BLTH calculated in step 912, it would mean that it is now suddenly
very dark in the room (947), so that the microcontroller will go into Idle
Mode,
and scan every 5 seconds (948) until it detects the SL being less than 80% of
the BLTH, meaning there is now more ambient light (949). Once this is
detected, the microcontroller will establish a new BLTH for the room (950),
and cycle back to step 924, at which it will continue to scan for a target
every
1/8 of a second with the new BLTH.
If SL is smaller than 25% of the previously established BLTH, this
would mean that the light in the room has suddenly dramatically increased
(direct sunlight, for example). The scan counter starts counting to see if
this
change is stable (928) as the microcontroller cycles through steps 924, 925,
926, 928 and 929,until it reaches five cycles (929). Once it does reach the
five cycles under the same conditions, it will establish a new BLTH in step
930 for the now brightly lit room, and begin a cycle anew at step 922 using
this new BLTH.
If, however, the SL is between 25% greater than or equal to, but no
greater than 85% of the BLTH (at steps 926 and 927), light is not at an
extreme range, but regular ambient light, and the microcontroller will set the
scan counter to zero at step 932, measure SL once more to check for a user
(934), and assess whether the SL is between greater than 20% BLTH or less
than 25% BLTH (20%BLTH<SL<25%BLTH) at step 936. If not, this would
mean that there is a user in front of the unit sensor, as the light is lower
than
CA 02507504 2012-06-19
42
regular ambient light, causing the microcontroller to move on to step 944,
where it will turn the water on for the user. Once the water is on, the
microcontroller will set the scan counter to zero (946), scan for the target
every 1h of a second (948), and continue to check for a high SL, that is, for
low light, in step 950 by checking whether the SL is less than 20% of the
BLTH. When SL decreases to less than 20% of BLTH (950), meaning that
the light detected increased, the microcontroller will move on to step 952,
turning on a scan counter. The scan counter will cause the microcontroller to
continue scanning every 1/8 of a second and checking that SL is still less
than
20% of BLTH until over 5 cycles through 948, 950, 952 and 954 have passed
(954), which would mean that there now has been an increase in light which
has lasted for more than 5 of these cycles, and that the user is no longer
present. At this point the microcontroller will turn the water off (956). Once
the water is turned off, the whole cycle is repeated from the beginning.
Referring to Fig. 13B (algorithm 1000 for faucet 10), the
microcontroller scans for a target every 1/8 of a second (1004), although,
again, the time it takes between any of the scans could be changed to
another period, for example, every 1/4 of a second. Once more, the
microcontroller will go through the algorithm and then go to sleep in between
cycles just as in the algorithm shown in Fig. 12. After scanning, the
microcontroller will measure the sensor level (1006), and compare the SL
against the BLTH. Once again, if the SL is greater than or equal to 25% of
the BLTH, the microcontroller will check whether it is greater than or equal
to
85% of the BLTH. If it is, it will take it to mean that the room must have
been
suddenly darkened (1040). The microcontroller will then go into Idle Mode at
step 1042, and scan every 5 seconds until it detects the SL being less than
80% of the BLTH, meaning it now detects more light (1044). Once it does,
the microcontroller will establish a new BLTH for the newly lit room (1046),
and it will cycle back to step 1004, starting the cycle anew with the new
BLTH for the room.
If the SL is between greater than or equal to 25% or less than 85% of
the BLTH, the microcontroller will continue through step 1015, and setting the
scan counter to zero. It will measure the SL at step 1016, and assess if it is
CA 02507504 2013-08-23
43
greater than 20% BLTH, but smaller than 25% BLTH (20% BLTH<SL<25%
BLTH), at step 1017. If it is not, meaning there is something blocking light
to
the sensor, the microcontroller will turn water on (1024); this also turns on
a
Water Off timer, or WOFF (1026). Then, the microcontroller will continue to
scan for a target every 1/8 of a second (1028). The new SL is checked
against the BLTH, and if the value of SL is not between less than 25% BLTH,
but greater than 20% BLTH (20% BLTH<SL<25%BLTH), the microcontroller
will loop back to step 1028 and continue to scan for the target while the
water
runs. If the SL is within this range (1030), the WOFF timer now starts to
count (1032), looping back to the cycle at step 1028. The timer's function is
simply to allow some time to pass between when the user is no longer
detected and when the water is turned off, since, for example, the user could
be moving the hands, or getting soap, and not be in the field of the sensor
for
some time. The time given (2 seconds) could be set differently depending
upon the use of the unit. Once 2 seconds have gone by, the microcontroller
will turn the water off at step 1036, and it will cycle back to 1002, where it
will
repeat the entire cycle.
However, if at step 1017 SL is greater than 20% BLTH, but smaller
than 25% BLTH (20% BLTH<SL<25% BLTH), the scan counter will begin to
count the number of times the microcontroller cycles through steps 1016,
1017, 1018 and 1020, until more than five cycles are reached. Then, it will
go to step 1022, where a new BLTH will be established for the light in the
room, and the microcontroller will cycle back to step 1002, where a new cycle
through algorithm 1000 will occur, using the new BLTH value.
Having described various embodiments and implementations of the
present invention, it should be apparent to those skilled in the relevant art
that the foregoing is illustrative only and not limiting, having been
presented
by way of example only. There are other embodiments or elements suitable
for the above-described embodiments, described in the above-listed
publications. The functions of any one element may be carried out in various
ways
CA 02507504 2012-06-19
44
in alternative embodiments. Also, the functions of several elements may, in
alternative embodiments, be carried out by fewer, or a single, element.
