Note: Descriptions are shown in the official language in which they were submitted.
CA 02450822 2003-12-23
AG CC1LT~ L ~'1~GLrCT ~PPLf~~1'fg~'.~ TI2~C:I~~NG f-~N~ C~NTI~~L
~I~,I~D ~F 'f~I~: ~NVLNTg~l~
This invention is related to precision farming in vvllich agricultural
implements
j apply products to a field in a location specific manner.
~r~CKGIW11N~ ~h''f~IE ~N'VENTI~N
The benefits of site specific product application c;ontrol are well known in
the
industry. Some product application variables that rnay be controlled according
to location
within a field may include product type and product rate. The product rate may
be rotated to an
amount in weight per unit area, or to a spacing between units such as
individual seeds. The
produci type and rate prescribed for an area may be dependent on factors such
as soft type,
historic yield data, and historic or expected precipitation. It has been found
that application of
agricultural products in such a prescribed manner can inczease yields and/or
reduce farming
l5 input costs to improve overall profits. Implements that use this type of
technology include
seeding, planting, fertilizing, and spraying equipment. On other equipment,
such as harvest
equipment, there may be data collection systems to coltect data to be used
with a prescription
farming system. The prescription farming system generally includes same device
for tracking
location within a field, such as BPS, and a mechanism to control the product
rate, type, or other
parameters to be controlled according to a prescription which is commonly
recorded on a
prescription map corresponding to the area of the field.
An implement configured for proscription farming typically has a control
system
in which the prescription map is stored, or capable of reading prescription
map data stored on a
device such as a disk or PCcard. The map can be displayed for the operator to
view in the
operator's cab. commonly color coding may be used on the map to illustrate
differences in
product rate or type corresponding to different areas of the field.
Critical farming operations such as seeding or planting must typically be
performed within a short window of time in order for the crop to mature within
the growing
season and for best yield amount and quality. Since speed and efi;ic.iency are
important in
3fl farming operations, there may be more than one implement operating in a
field at one time. A
problem arises when each such implement is using ir~dep~ndent precision
farming systems,
CA 02450822 2003-12-23
whereby each implement system operates without the knowledge of the other
implement's
operation. Two or more of the implements may apply product to the same
location, or the
implements may altogether miss a location resulting in zero product being
applied to that
lo;,atj on, each of which could adversely affect yield.
~'6JI~tNI~' OF 'I"I~E IhTV~;l~1'r'I01~1
The limitations and disadvantages of the prior art are overcome by a control
system for controlling the dispensing of agricultural crop products to a f
eld.
Tt is an object of the present invention to provide a control system for the
application of agricultural products, which aids in preventing the missed
application of products
or the duplicate application of products to locations within a field.
Tn accordance with an aspect of the present invention, there is provided
an agricultural implement system for performing an application of the
agricultural
product to the ground. The system includes: a~a agricultural implement having
a
plurality of product dispensing units for dispensing the agricultural product;
a
positioning system for tracking a location corresponding to the application of
the
agricultural product; a control system for controlling a rate of flow of the
agricultural
product from at least a portion of the product dispensing units; each of the
dispensing
units has a control valve operable to control the rate of flow of the
agricultural product
through the corresponding product dispensing unit in a variable manner in
response to
data received by the control system relating to a prior application of the
agricultural
product. The data identifies an application of the agricultural product made
in a
previous path of the agricultural irnplefnent so that the control system
reduces the rate
of flow of the agricultural product from at least one of the product
dispensing units to
prevent overlap in the application of the agricultural product.
Tn accordance with an aspect of the: present invention, there is provided a
method of performing an application of agricultural product to the ground
through a
plurality of product dispensing units of an agricultural implement. The method
ineiudes the steps of: tracking a location corresponding to the application of
the
agricultural praduct; controlling a rate of flow of the agric.~xltural product
from at least a
portion of the product dispensing units, each of the dispensing units having a
control
valve; the controlling step including the step of operating the control valve
to control
the rate of flo~h~ of the agricultural product through the corresponding
product
2
CA 02450822 2003-12-23
dispensing unit in a variable manner in response to data relating to a prior
application
of the agricultural product, the data identifying an application of the
agricultural
product made in a previous. path of the agricultural implement; reducing the
rat;c~ of flow
of the agricultural product from at least one of the produc;r dispensing units
to prevent
overlap in the application of the agricultural product.
It is a feature of this invention that the operator of a crop product
applicator
implement can be guided to appropriate locations for the dispensing of crop
products, depending
on information about whether there were prioapplicatior~.s of a crop product
at those locations.
I S It is another object of this invention to provide a control system for
controlling or
guiding the application of one or more agricultural producas by a product
applicator implement
dependent on information about one or more products that Rave previously been
applied.
It is an advantage of this invention that the agricultural products being
applied to
the field may be the same as or may be different than those being presently
applied by other
2~ implements at a rate that is dependent on the information about the
previously applied products.
It is another feature of this invention that the product application
information may
include for each previously applied product, one or more of: location
previously applied, rate
previously applied, type previously applied, date .previous:ly applied, or
other such information a.s
may be =awful in determining optimum rates for application of a product
presently being applied.
25 It is still another object of this invention to provide a control system
for
controlling or guiding the application or agricultural products by a product
applicator implement
which aids in preventing the missed application of produc:~a or the duplicate
application of
products to locations within a field.
It is another advantage of this :invention that the product application
information
3D can be related to the locations where product 'was previously applied by
this or another
implement.
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CA 02450822 2003-12-23
It is yet another object of this invention to provide a control system to
coordinate
the operation of two or more crop product applicators operating within a field
to prevent the
missed application of products or the duplicate application of products to
locations within a field.
It is still another feature of this invention that the prior application of
products can
be displayed for viewing by the operator so that the operator can make
decisions and provide
appropriate control actions for the present application of° a prodrict
within a field.
It is yet another object of this invention to provide a control system that
can
automatically calculate and provide control signals to the control system on a
product applicator
implement for controlling the dispensing of a product within a field.
It is still another advantage of this invention that ~ display monitor may
also be
provided with such a system for the operator to observe and moriaor the
operation of the control
system, and to provide the operator information for the guidance of the
implement to appropriate
locations within the field where product application is required.
It is yEt another feature of this invention that the control system can
control a
1 ~ plurality of dispense controls independently to apply products at a first
dispensing rate from a
first dispensing unit or group of units, and at a second dispensing rate from
a second dispensing
unit or group of units.
It is a further advantage of this invention that the independent eontrol of a
plurality of dispense controls can prevent duplicate application of product to
locations where the
implement may be overlapping locations where product has previously not been
applied and has
been applied.
It is a further object of this invention to provide a central control system
for
communicating with one or more control systems o:~ product ap~~licator
implements operating
within a field so that the operation of each of the implements within the
filed is coordinated to
prevent the missed application of products or the duplicate application of
products to locations
within a field.
It is a further feature of this invention that each product applicator control
system
may be independently calculating product dispensing rates for its location
based on information
being communicated with the central control system, or the central control
system may be
calculating and providing dispensing rate information to each product
applicator control system.
CA 02450822 2003-12-23
It is yet a further object of this invention to provide a control system for
each of
two or more applicator implements operating within a field, which includes a
communication
transceiver for communicating information by which they are coordinated so
that the two or
more implements may communicate such information with each other or with a
central control
system as described above.
These and other objects, features and advantages can be accomplished by
providing a control system for an agricultural implement, such as an
agricultural sprayer, used to
dispense a product to the ground wherein the dispensing units for the product
are provided with
control valves that can reduce the floe rate of product through selected
dispensing units to zero.
I Q By controlling the rate of flow through the dispensing units, overlap of
the application of the
product to the ground can be substantially eliminated. In alternative
embodiments of the
invention, the control mechanism can receive data from a remote source, such
as a central
controller or another implement operating in the field, to define There the
product needs to be
applied to the ground. The application of the product can also be controlled
through or in
I S conjunction with a prescription map. Preferably, each dispensing unit is
provided with a control
valve operably associated with the control system so that each dispensing unit
can be
independently controlled to provide a variable flow rate of the product to the
ground.
BRIEF DESCRIF'TI~N ~F DRAWINGS
2~ Fig. I is a schematic diagram illustrating a product application system
with
controls and an interfacing control system incorporating the principles of the
instant invention;
Figs. 2a-c are diagrammatic illustrations of exemplary paths that can be taken
by a
product application system in a field in which the product application system
overlaps areas
where product has been applied on a preceding path;
25 Fig. 3 is a logic flow diagram for a control algorithm by which a precision
farming control system of the present invention may operate;
Fig. 4 is a top plan view of an agricultural sprayer incorporating the
principles of
the present invention;
Fig. 5 is an enlarged partial elevational view of a spray boom of the sprayer
30 shown in Fig. 4 to depict the booms:
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CA 02450822 2003-12-23
Fig. 6 is a schematic diagram of a control system depicting an embodiment of
components that may be typically used for operating the precision farming
control system of the
present invention;
Fig. 7 is a schematic diagram of an alternative control system depicting
another
embodirrrent of components that ma:y be typically used for operating the
precision farming
control system of the present invention; and
Fig. 8 is a schematic diagram of another alternative embodiment of a control
system that may be typically used for operating the precision fanning control
system of the
present invention.
DETAILED DESCIaI~'~ I(~N l7F TfIE P FE I~ Ell~~~I3IIi~EI~"f S
Referring first to figs. I, 4 and 5, an agricultural product applicator
implement,
depicted in the form of an agricultural sprayer, incorporating the ,principles
of the instant
invention can'oest be seen. Any left and right references are date;mined by
standing behind the
implement and facing forwardly toward the direction of travel. In the product
application system
shown in Fig. 1 the product to be applied to the field is dispensed from the
sprayer heads 10
connected to a product distribution lines 13. A product flow control 11 is
provided for each
dispense unit 10 to control the product flow from the distribution line 13 to
each dispense unit
10. Each product flow control 11 is controlled by a solenoid control 12.
The implement preferably includes 2 product distribution lines 13, each with
sprayer heads 10, flow controls 11, and solenoid controls 12. The
over°all product flow to the
distribution lines is controlled by a flow control valve 14 in each
distribution Iine 1~, and each
ftow control valve 14 is controlled by a solenoid control 1 ~. Control valves
14- provide the ability
to shut off operation of a corresponding distribution 'oranch. Rates applied
from individual
sprayer heads 10 may also be controlled by corresponding control valves 11.
This may simply
be on/off control, or can be varia'ole control in a manner known in the art,
such as by Cycling
control valves 11 open and closed in pulses and controlling rates by varying
the pulse width
and/or frequency. The frequency control may be limited by the response limit
of the valve.
Frequency and pulse width may also be controlled to maintain a particular
spray droplet size or
spray pattern, while controlling rates, as is well acnown in the art.
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CA 02450822 2003-12-23
The product distribution lines I 3 are connected to a main distribution line I
~i
associated with a line pressure gage 30 and a line pressure sensor 3 I . Also
in this main
distribution line I 6 located upstream of the connection to the distribution
lines I3 is a line flow
sensor 32 . The main product distribution line I6 is connected to a 3-way flow
control valve I7
controlled by a servo-actuator I 8. Product flow is generated by a pump 20 and
is carried in the
output line I9 into the 3-way control valve I7. A b;ypass line 22 carries
excess flow as
controlled by the 3-way control valve I7 back to the product supply tank 23.
The pump 20
draws product from the product supply tank 20 through the pump inputs line 21
for delivery
through the output line 19.
I0 In the particular embodiment shown in Fig. I the 3-way control valve 17
controls
the product total dispense rate for product distributed to the sprayer heads
I0. The flow rate is
measured by the flow sensor 32. The distribution line pressure i~ also
detected by pressure
sensor 3I. Having both these bits of information allows the control system I00
to detect and
warn of potential errors in operation. Each sprayer head I 0 dispenses product
at a dispense rate
I S proportional to the distribution line pressure. if the measured total flow
is not equal to the total
flow expected, then it is likely that one or more sprayer heads are Torn,
damaged, o_r plugged.
The total flow rate however can be controlled by the; 3-way control valve I8
with flow rate
feedback from the sensor 32 so that even though nozzles may be worn, the
product application
rate is properly controlled. The system can continue to operated until a
sudden change in
20 pressure or flow indicates a problem or until the measure and expected flow
rates are beyond a
threshold of discrepancy.
A product application system as described above can be configured on an
implement 40 such as that shown in Fig. 4. This implement includes left and
right application
booms 41 and 42 respectively. Each application boom may be ~conf~gLired with
at least one
25 product distribution line I3 with product sprayer heads I O evenly spaced
along the Length of the
boom 41, 42 so that in the field position shown in Fig. 4, they are spacEd
transverse to the
direction of travel to apply product in a wide path. ~'ach boom o~~this
particular implement 40
includes a structural main boom 43 on which is mounted a applicator boom 44.
The distribution
line 13 forms the actual applicator boom sa~pported pivotally on the main boom
43 by several
30 arms 45. Alternatively, a dry boom may be used for structure izi place of
the distribution line 13
as the applicator boom 44, with the distribution line being supported along
the applicator boom
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CA 02450822 2003-12-23
44. The elevation of the product sprayer heads 10 relative to the field
surface or crop top may
be adjusted by pivotally adjusting the applicator boom 44.
Fig. 1 also illustrates other control components used in operating the
precision
farming control system of the present invention. Various remote controls 33-37
are used to
communicate with the sensors and controllers to control product application
according to the
invention. Each remote control 33T37 is connected to a control
c;orrtmvnication bus 38, which
allows various control components to communicate with each other. A first
remote control 33
gets signals from sensors 31 and 32 and controls servos 1~ and l~. The first
remote control 33
sends signals to and gets signals from other components connected to the bus
38. These signals
are sent and received with an identifier, which specifically indicates which
remote they are sent
from or are intended for. The message carried by the signal includes
information about which
sensor the signal is from or to which control the signal is for, and values
certain parameters.
The remotes 33- .37 are shown wgth cOnneCtlonS to sensors or controls in a
combination up to six
in total, but this total may more commcnly be up to twenty four connections,
depending on the
electrical current required by each connection. A second remote 34 is
connected to six dispense
unit solenoid controls 12 and provides these controls with signals
communicated from the bus
and communicates status of these control 12 to the bus. Similarly other
remotes 35, 36, and 37,
control and communicate the status of solenoid controls 12.
Fig. 6 illustrates a pre ferred embodiment of some: control components ire a
control
system 100 according to the invention. A console ~ 1 is a component by which
an operator can
input and receive data about the operation of the control system. It is
connected in
communication with the bus 38. A task controller 5~ and differential corrected
global
positioning system (DGPS) 53, are also connected to the control systerrf bus
38. Alternate
positioning systems may be used to perform the invention, howe;~%er Dh(JS is
currently the
industry preferred positioning system. control calculations may be performed
by one or more
of the components in the central system. In the preferred embodiments shown,
the task
controller 52 performs rats calculations and generates values for the control
signals.
The preferred embodiment includes in the control system 100 the capability for
prescription rate control. The desired application rate of each product to be
applied can be
produced using a GIS application software that produces a digital map of each
product's desired
application rats. IJocation specific field characteristics and prio~~°
yield data is typically used in
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CA 02450822 2003-12-23
producing this map. These digital maps are communicated to the task controller
52 on the
seeding or spraying implement by means of a prescription PCcard 54. ether
means of
configuring the control system witlR prescription rate data are possible.
Production and use of
product application prescription maps is well known in the art.
For prescription rate control, the task controller 52 compares the present
position
of the implement 40, which is provided by the DCrPS receiver 53, to the same
position in the
prescription map. The task contrall.er 52 gets the application rate for each
product to be applied
to that location from the prescription map and then calculates a dispense rate
value to apply to
the total flow rate control valve 17, or for more precise control, to each
solenoid control 12,
IO based on the speed at which the implement 40 is moving, and the area
covered by each dispense
unit I O that are controlled by that solenoid control I2, if more than oils
are controlled by a single
valve. The task controller 52 then communicates the desired dispense rate to
the apI'ropriate
flow control via the communicatiorF bus 3~ and the implement's remote controls
33-37. The
dispense rates are controlled depending on the application rate far the
particular location as well
1 S as the speed at which the implement is moving to achieve the appropriate
application rate.
The control system I00 may also include provision to compensate .for physical
offsets and delays inherent in the product application system. The al's
antenna may be located
near the front of the implement 40, or on a pulling vehicle such as a tractor
(not shown used for
pulling the implement 40. The sprayer heads I O are typically arranged along
and/or about a Line
20 on the implement 40 that is transverse to the direction of travel and that
is to the rear of the CaPS
antenna relative to the direction of movement of the implement in operation.
Thus as the
implement is moving across the field there is a delay from the moment the PI'S
antenna reaches
a location to the moment the transverse line of sprayer heads 10 reaches that
location, depending
on the speed at which the implemer;,t 40 is moving. <hnother possible delay to
changing the
25 dispense rates would relate to the difference in time for the prod.f~act
entering the distribution lines
until the product reaches the sprayer heads I0. A liquid sprayer for example
may be of the type
that injects product into a water carrier at a location in the distribution
lines, such as near where
the flow sensor 3215 Shown ~n Fig. 1. Thus, the product will not: reach the
dispense paints until a
certain time expires during which the product concentration or product type
previously in the
30 distribution lines has been dispensed.
CA 02450822 2003-12-23
For agricultural sprayers, the time for spray to trammel 'from the sprayer
head 10 to
the target, e.g. the plant or the ground, is also a significant delay. The
target may be at the
ground surface or generally within the elevation of a crop canopy, and the
sprayer heads 10 may
be set about 18 inches above that. sprayer heads arc therefore controlled in
advance of the target
to compensate for the distance it travels along with the applicator implement
before it reaches the
target elevation. The compensation period depends on the speed at which the
agricultural
sprayer is moving and the distance above the target at which sprayer heads 10
are set.
Rates at which the product is dispensed may be controlled by a prescription
rate
control system, or may be set by the operator and adjusted during operation,
or may be left fixed
during operation. ~Jhatever the case, the dispense rates may be farther
controlled by a system
that calculates dispense rates as described above in accordance with the
implement speed and set
application rates so that the proper application rate is achieved if the
implement speed varies as is
well known in the art. For control of the dispense rates and for tile delay
compensation control
described above, the implement controls also preferably include ~ speed sensor
39. Preferably,
the sensor 39 is configured to sense true ground speed so that implement or
pulling vehicle wheel
slippage does not introduce error as can occur with known systems that sense
wheel rotation.
Preferably the ground speed sensor 39 is a radar type sensor and the first
remote 33
communicates signals from this sensor 39 to the bus 38.
As the implement traverses the field, the task controller makes a record of
where
product has been applied. This record may also be in map format like that of
the prescribed
application rate data, and be stored on an as applied PCcard 55. ~i'he
invention described below
in more detail includes use of the data of prior proda;ict application to
reduce or eliminate
duplicate application.
Fig. 3 illustrates the preferred embodiment of a control algorithm for
controlling
the operation of a control system according to the invention. ~'~t an
initializing step d0, the
operator sets various operating parameters for the operation of the control
system which may
include the following: implement width; implement position relative to DGP~
antenna; delivery
delay period; and default rates.
The task controller 52 or other component in the control system will have
previously been initialized or become initialized at startup with information
about the number of
and the location of each of the sprayer heads 10 and to which control valves
11 and solenoids l2
CA 02450822 2003-12-23
they correspond to. It calculates the width of the area that each disperse
unit 10 will cover in
operation from the implement width and number of sprayer heads found or
entered by the
operator.
As the implement 40 traverses the field, the task controller 52, at step 6I,
establishes the location of the GPS antenna from the signal provided by the
L~C~PS system.At the
next step 62 of the operation, the control system I00 determines if the
dispense rates of the
system are to be controlled by a prescription application system tend the
dispense rate or rates are
determined accordingly. Prescription application control, however, is also not
essential to the
operation of the invention but is preferred.
Step 63 effects coordination with other similar implements that may be working
in the same field, as will be noted in greater detail below. A.t ste;p 64,
tf~e control system
determines from the as applied data (PGcard ~5) if product had been previously
applied to the
locations for which dispense rates are currently being calculated.
The dispense rates can be set to a reduced rate or to zero at step 65 for
those
I S sprayer heads I O that are so controlled. Far the type of control as
illustrated in Fig. 1, the
dispense unit control valves I 1 are positioned close to the sprayer heads I O
so that for controlling
the prevention of duplicate application of product, there need not be any
compensation for
product distribution delay, but perhaps preferably compensation would be
provided for positional
differences between the GPS antenna and the location of the sprayer heads
relative to the
antenna. This product eontrol system is also applicable for planters and
airseeders. '.For other
systems such as airseeders and other granular applicator implements that may
have longer
distribution lines between dispense roanit control valves 12 and sf>rayer
heads I0, the dispense
rates can be predicted and set in advance to compensate for delays as noted
above so the product
will be dispensed from the sprayer heads 10 at rates which are appropriate for
locations the
sprayer heads 10 are at. Several sprayer heads 10 may be controlled from a
single dispense unit
cantrol valve 12 or other metering or control mechaa.~ism.
At step 66, the actual application rate from the sprayer heads 1 fl, or for
less
precisely controlled systems, from the total flow sensor 32, or other
detection mechanism, can be
determined and stored as "as applied data" corresponding to the location the
sprayer heads are
currently dispensing from, or altcrnateiy but less preferably, are expected to
be dispensing from.
This "as applied data" may be stored in any conventvonal manner and preferably
on the as
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CA 02450822 2003-12-23
applied PCcard 55. This data may also have other useful applications for which
the PCcard 55
conveniently stores the data.
Fig. 2 illustrates an area of a field in which the control system according to
the
invention may operate. The width of the path over which the product applicator
implement 40
passes is shown as lines that are parallel to path vectors 70 to 7 3. The
implement ~raay take path
vector 70 around a marsh area in the field. The next path 7I taken can be a
straight path as
shown, As the implement 40 overlaps an area where product was previously
applied, the product
dispense points, e.g. sprayer heads 10, located at the; overlapping areas can
be set to a reduced or
zero rate. The actual application ~°ill occur in discrete or
incremental steps according to the
width of area that each dispense unit 10 is configured to cover, as opposed to
the smooth path
used for illustration. Fig. 5 illustrates more realistically the reduction in
duplicate application in
increments as dispense points that cover at least part of an area not
previously applied to (not
shown as hatched) are left on at the set rate. Another path vector 72 may be
the last full
application path for the field area, after which a path 73 may be take to
cover the remaining area
and not duplicate product application to the hatched area represf;nting the
previously applied
area. Likewise, all areas that are less than the full application width of the
implement may be
treated using a control system according to the present invention to reduce or
eliminate duplicate
application.
If multiple implements are simultaneously working ire a field, it is desirable
that
each will be able to avoid duplicate application, even to areas where the
other implement has
applied product. One preferred manner in which this may be done is by having
each implement
40 provided with a communicator, such as a radio trransceiver 5fi, with which
the implements
operating at the same time may get "as applied data" from each other.
In step 63, in the control algorithm depicted in Fig. 3 includes getting "as
applied
data°' from other implements performing the same type of operation in
the same field at the same
time. If operation of one implement is interrupted, the "as applied data" may
be stored on the as
applied PCcard 55 for use later or for use by other implements.
Fig. 7 shows an alternative embodiment in which more than one implement 40
may be performing like operations at the same time. In Fig. 7, the control
system 100 for an
implement is illustrated wherein the task controller :52 is associated ',vith
a central controller
system 57 at a remote location. Such a central task controller system may
include the ability to
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CA 02450822 2003-12-23
communicate other messages to the implement 40 for display to the implement
operator, and be
updated in real 'time. The central task controller 57 would compare the
implement's location
with the same location in the centrally stored digital map of application
rates and transmit the
desired application rate back to the implement 40 for that location. ~'he
central controller has the
current location stored and compares the current location with each location
message provided
by the BPS receiver. The central controller 57 would transmit this
differential position data
provided by the central BPS receiver and any required rate changes. The
implement 40 would
provide this received differential correction data to :its' GPS receiver and
the receiver would
correct its' location message provide to the implement, The implement's remote
controller
would also transmits its' real time as applied data back to the central
controller for recording in
the fields as applied database. This information would be used to determine if
another
implement has traversed a previously applied location. If so the central task
controller would
communicate to the second implement not to apply any product. ~ther implement
data, such as
implement speed, engine rpm, actuator drive signala, temperature and others,
could also be
communicated back to the central task controller for recording in a database.
After the completion of the application of products to the field by the
implements,
the central task controller 57 can determine if any part of the field has not
traversed from the
communicated as applied data. If this occurs, the central task controller can
communicate to the
operator to proceed to the specific field location to apply the missing
products. When the
implement traverses the missed location, the required application rate data is
communicated to
the implement remote controller. !-~s an enhancement of the operator interface
console 51, the
map of the field can be communicated to each implement indicating which parts
of the field has
be traversed. This would provide information to the°, operators of the
parts of the ffeld that have
not been traversed.
Another alternative embodiment of the control system 100 is shown in 1~ ig. 8
in
which multiple implements 40 are in communicatio:a with a central control
system 57 via each of
their radio transceivers 56. The central control system may inc:Ltude a task
controller ~2 by
which each of the multiple implements are controlled, or each implement may be
equipped with
its own task controller and be able to get updated "as applied data" for the
product as applied by
the multiple implements in real time, along with other messages.
_12_
CA 02450822 2003-12-23
The invention may not include delay compensation control, or variable rate
control in which case it may not include a ground speed sensor, such that the
application control
will be enhanced by the invention but less precise than with the preferred
embodiments. The
dispense rates may be set according to user controlled rates and she
im.plement will need to be
operated at a proper speed of movement to achieved the desired application
rate. Sprayer heads
will be controlled on, off, or at an alternate rate, according to she
invention.
All the sprayer heads 10 may be conurolled by the precision control system, or
alternatively only a certain number of sprayer heads inward from the ends of
each left and right
outer ends of the product application booms 41 and ~2, which may be sufficient
for controlling
10 prevention of duplicate application.
Alternately in other embodiments such as for airseeder implements, product may
be controlled to groups of product dispense points v~ith control provided to
vary the rate or allow
on/off control of the group of product dispense points. An airseeder, for
example, may have
sprayer heads connected by branch lines to a common product distribution line.
The airseeder
may control metering to one or more of these common product distribution
lines.
V~Ihile the embodiments illustrated and described above are presently
preferred,
one skilled in the art will understand that these embodiments are; offered by
way of example
only, arid that the invention disclosed herein ~~.ay be modified for use on
other implements, such
that the invention is not intended to be limited to any particular embodiment,
but is intended to
extend to modifications that fall within the scope of the claims.
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