Sensing and control of liquid application using an agricultural machine

An agricultural machine applies liquid material to a field. Valve control signals control valves to apply the liquid material. Row pressure on the agricultural machine is sensed to identify when the valve is opened to apply the liquid material. The valve control signals are generated, based on the row pressure, to control the valves to apply the liquid material at a desired location in the field, relative to plant locations in the field.

FIELD OF THE DESCRIPTION

The present description relates to agricultural machines. More specifically, the present description relates to controlling liquid application using an agricultural machine.

BACKGROUND

There is a wide variety of different types of agricultural machines. Some agricultural machines are used to apply a liquid substance to a field. These agricultural machines can include, for instance, planters that have row units, sprayers, tillage equipment with sidedress bars, air seeders, etc.

A row unit is often mounted on a planter with a plurality of other row units. The planter is often towed by a tractor over soil where seed is planted in the soil, using the row units. The row units on the planter follow the ground profile by using a combination of a downforce assembly that imparts a downforce on the row unit to push disc openers into the ground and gauge wheels to set depth of penetration of the disc openers.

Row units can also be used to apply liquid material to the field over which they are traveling. In some scenarios, each row unit has a pulse-controlled valve (such as a valve controlled using a pulse width modulated signal) that is coupled between a pump (that pumps liquid from a source of liquid material), and an application assembly. As the valve is pulsed, the valve is moved between an open position and a closed position so liquid passes through the valve, from the source to the application assembly, and is applied to the field. Other row units may have valves that need not be pulse controlled.

An agricultural sprayer often includes a tank or reservoir that holds a substance to be sprayed on an agricultural field. The sprayer includes a boom that is fitted with one or more nozzles that are used to spray the substance on the field. A pump pumps the substance from the reservoir, along the boom, to the nozzles. As the sprayer travels through the field, the boom is disposed in a deployed position and the substance is pumped from the tank or reservoir, through the nozzles, so that it is sprayed or applied to the field over which the sprayer is traveling. As with row units, the nozzles can have corresponding valves that are controlled by a pulsed control signal (such as a pulse width modulated signal). As the control signal pulses, the valve is moved between an opened position and a closed position. When in the open position, liquid passes through the valve, so that it can be applied to the field. Other sprayers may have valves that are not operated by a pulse control signal.

These are just two examples of agricultural machines that can be used to apply a liquid material to a field. Others can be used as well.

SUMMARY

An agricultural machine applies liquid material to a field. Valve control signals control valves to apply the liquid material. Row pressure on the agricultural machine is sensed to identify when the valve is opened to apply the liquid material. The valve control signals are generated, based on the row pressure, to control the valves to apply the liquid material.

DETAILED DESCRIPTION

The present description proceeds with respect to two different examples of agricultural machines that apply a liquid substance to a field. The first is a planter and the second is a sprayer. These are examples only, and it will be appreciated that the present discussion could just as easily apply to other agricultural machines.

FIG.1is a top view of one example of an agricultural planting machine100. Machine100is a row crop planting machine that illustratively includes a toolbar102that is part of a frame104.FIG.1also shows that a plurality of planting row units106are mounted to the toolbar102. Machine100can be towed behind another machine, such as a tractor.FIG.1shows that liquid material can be stored in a tank107and pumped to valves109through a supply line111. In one example, a valve control system113controls valves109. In one example, system113controls valves109using a pulse width modulated control signal, although they can be controlled with a non-pulsed control signal as well. When they are pulsed, the flow rate through valve109is based on the duty cycle of the control signal (which controls the amount of time the valves are open and closed). The valves109are connected to an application assembly that applies liquid to the field.

FIG.1also shows that in one example, planter100includes a flow meter131that senses flow of fluid from tank107through the supply line111. Where planter100has a liquid return line that returns liquid to tank107from supply line111, then it can also have a return flow meter135that senses the flow of liquid returned to tank107. The difference between the flow sensed by flow meter131(exiting tank107into supply line111) and the flow sensed by meter135(returning to tank107from supply line111) is indicative of the flow of liquid applied through nozzles109.

Planter100also illustratively includes a pressure sensor133that senses pressure in supply line111. It can have multiple pressure sensors mounted to sense pressure at different locations along supply line111as well. Flow meter131illustratively generates a boom flow signal indicative of the fluid flow (such as mass flow rate) through supply line111and provides that signal to valve control system113. Flow meter135generates a return flow signal and provides that signal to valve control system113as well. Pressure sensor133illustratively generates a supply line pressure signal indicative of the pressure in supply line111, and provides that signal to valve control system113. Where there are multiple pressure sensors along supply line111, they each generate a different supply line pressure signal and supply it to system113. As is discussed in greater detail below, those signals can be used to identify an operational characteristic of the valves109and/or corresponding application assemblies (such as whether they are clogged or partially clogged, the flow rate through them during operation, the duration of the pulses, flow volume, etc.). They can also be used in controlling certain portions of planter110.

FIG.2is a side view showing one example of a row unit106, with valve109and system113shown as well, in more detail. Row unit106illustratively includes a chemical tank110and a seed storage tank112. It also illustratively includes a disc opener114, a set of gauge wheels116, and a set of closing wheels118. Seeds from tank112are fed by gravity into a seed meter124. The seed meter controls the rate at which seeds are dropped into a seed tube120or other seed delivery system, such as a brush belt, from seed storage tank112. The seeds can be sensed by a seed sensor122, which generates a seed signal123indicative of a speed passing through seed tube120. Signal123can be provided to pulsing valve control system113.

In the example shown inFIG.2, liquid material is pumped through supply line111to an inlet end of valve109. Valve109is controlled by control system113to open and close to allow the liquid to pass from the inlet end of valve109to an outlet end. System113can use a pulse width modulated signal to control the flow rate through valve109, but this is just one example and other control signals can be used to control valves109.

As liquid passes through valve109, it travels through an application assembly115from a proximal end (which is attached to an outlet end of valve109) to a distal tip (or application tip)117, where the liquid is discharged into a trench, or proximate a trench, opened by disc opener142(as is described in more detail below).

Before describing the operation of row unit106and valve control system113in more detail, a brief overview of some parts of row unit106and their operation, will first be discussed. First, it will be noted that there are different types of seed meters, and the one that is shown is shown for the sake of example only. For instance, in one example, each row unit106need not have its own seed meter. Instead, metering or other singulation or seed dividing techniques can be performed at a central location, for groups of row units106. The metering systems can include rotatable discs, rotatable concave or bowl-shaped devices, among others. The seed delivery system can be a gravity drop system (such as that shown inFIG.2) in which seeds are dropped through the seed tube120and fall (via gravitational force) through the seed tube into the seed trench. Other types of seed delivery systems are assistive systems, in that they do not simply rely on gravity to move the seed from the metering system into the ground. Instead, such systems actively capture the seeds from the seed meter and physically move the seeds from the meter to a lower opening, where they exit into the ground or trench.

A downforce actuator126is mounted on a coupling assembly128that couples row unit106to toolbar102. Actuator126can be a hydraulic actuator, a pneumatic actuator, a spring-based mechanical actuator or a wide variety of other actuators. In the example shown inFIG.2, a rod130is coupled to a parallel linkage132and is used to exert an additional downforce (in the direction indicated by arrow134) on row unit106. The total downforce (which includes the force indicated by arrow134exerted by actuator126, plus the force due to gravity acting on row unit106, and indicated by arrow136) is offset by upwardly directed forces acting on closing wheels118(from ground138and indicated by arrow140) and double disc opener114(again from ground138and indicated by arrow142). The remaining force (the sum of the force vectors indicated by arrows134and136, minus the force indicated by arrows140and142) and the force on any other ground engaging component on the row unit (not shown), is the differential force indicated by arrow146. The differential force may also be referred to herein as the downforce margin. The force indicated by arrow146acts on the gauge wheels116. This load can be sensed by a gauge wheel load sensor which may be located anywhere on row unit106where it can sense that load. It can also be placed where it may not sense the load directly, but a characteristic indicative of that load. Both sensing the load directly or indirectly are contemplated herein and will be referred to as sensing a force characteristic indicative of that load (or force). For example, it can be disposed near a set of gauge wheel control arms (or gauge wheel arm)148that movably mount gauge wheels116to shank152and control an offset between gauge wheels116and the discs in double disc opener114, to control planting depth. Arms (or gauge wheel arms)148illustratively abut against a mechanical stop (or arm contact member-or wedge)150. The position of mechanical stop150relative to shank152can be set by a planting depth actuator assembly154. Control arms148illustratively pivot around pivot point156so that, as planting depth actuator assembly154actuates to change the position of mechanical stop150, the relative position of gauge wheels116, relative to the double disc opener114, changes, to change the depth at which seeds are planted. This is described in greater detail below.

In operation, row unit106travels generally in the direction indicated by arrow160. The double disc opener114opens a furrow in the soil138, and the depth of the furrow162is set by planting depth actuator assembly154, which, itself, controls the offset between the lowest parts of gauge wheels116and disc opener114. As discussed above, seeds are metered or singulated by a metering system (e.g., seed meter124) and positioned in a furrow by the seed delivery system. Where the seed delivery system is a gravity drop system, the seeds are dropped through seed tube120, into the furrow162and closing wheels118close the soil. Where the seed delivery system is an assistive system, the seed is positioned in, or captured by, the assistive system and moved to a location proximate the furrow162where it is deposited or placed in the furrow162. System113controls valve109to apply a liquid through application assembly114to the field over which row unit106is traveling. The liquid can be applied in, or proximate, furrow162.

There may be seed sensors in both the seed metering system and the seed delivery system. In another example, there may be a seed sensor only in the seed metering system, or only in the delivery system, or elsewhere. In the example illustrated inFIG.2, only seed sensor122is shown, and it is shown mounted to seed tube120so that it detects seeds passing through seed tube120. A seed sensor on the seed metering system may sense the presence or absence of seeds in the seed metering system. The seed sensors are illustratively coupled to their corresponding systems (the seed metering system and/or seed delivery system) to sense an operating characteristic of the corresponding system. The sensors sense the presence or absence of a seed, or sense a characteristic indicative of a seed spacing interval within the system on which it is deployed.

The seed sensors can include a transmitter component and receiver component. The transmitter component emits electromagnetic radiation, or light, into the seed metering system or seed delivery system through a transparent or translucent side wall of the system. The receiver component then detects the reflected radiation and generates a signal indicative of the presence or absence of a seed adjacent to the sensor (e.g., sensor122) based on the reflected radiation. Of course, this is just one example of a seed sensor, and others may be used as well. The seed sensor signal123, generated by the seed sensor, is provided back to valve control system113, where it can be conditioned (such as amplified, filtered, linearized, normalized, etc.).

FIG.2also shows that, in one example, a pressure sensor127is disposed to sense pressure in valve109. The pressure sensor in valve109can be a differential pressure which measures the pressure drop across valve109, or it can be a pressure sensor that senses the pressure on the outlet end of valve109, but upstream of the distal tip117of application assembly115. That can be compared to the supply line pressure sensed by pressure sensor133(or where there are multiple supply line pressure sensors the signal from the closest such sensor) to obtain the pressure drop across the valve109. Pressure sensor127illustratively generates a pressure sensor signal indicative of the sensed pressure, and provides that pressure sensor signal to valve control system113.

FIG.3is a partial pictorial, partial block diagram showing one example of a self propelled agricultural spraying machine (or sprayer)180. Sprayer180illustratively includes an engine in engine compartment182, an operator in operators compartment184, a tank186, that stores liquid material to be sprayed, and an articulated boom188. Boom188includes arms190and192which can articulate or pivot about points194and196from a travel/storage position to a deployed position illustrated inFIG.3. Agricultural sprayer180is illustratively supported for movement by a set of traction elements, such as wheels198. The traction elements can also be tracks, or other traction elements as well.

When a spraying operation is to take place, boom arms190and192articulate outward to the position shown inFIG.3. Boom188carries nozzles200that spray material that is pumped from tank106through boom188by pumping system202, onto the field over which sprayer180is traveling. As with row unit106shown inFIG.2, the flow of liquid material through each of the nozzles200is controlled by a corresponding valve204. In the example illustrated inFIG.3, each nozzle200has a corresponding valve204. However, it will be noted that a single valve204may control the passage of material through multiple different nozzles. These and other architectures and arrangements are contemplated herein. The valves are controlled by valve control system113.

FIG.3also shows that sprayer180illustratively includes a boom flow meter206and a boom pressure sensor208. Flow meter206illustratively senses a value indicative of the flow of liquid material from tank186through boom188. In one example, the value is indicative of the mass flow rate of the liquid material through boom188.FIG.3also shows that pressure sensor208illustratively senses the pressure within boom188. Sprayer180can have a return line that returns liquid from boom188to tank186. In that case, flow meter207senses the return flow so the flow of liquid applied through the nozzles204is the difference in flow measured or sensed by meters206and207. Further, there can be additional boom pressure sensors along boom188. For instance, there may be a pressure drop across boom188so that multiple pressure sensors along boom188capture this pressure drop. These and other arrangements are contemplated herein.

It will be noted that the various pressure sensors described herein can be arranged in a number of different ways. For instance, they can be arranged so that they are referenced to atmospheric pressure, or they can be arranged as sets of pressure sensors or a differential pressure sensor, so they can be used to obtain a differential pressure indicative of the pressure drop across the valves or across other portions of the agricultural machine that is delivering the liquid material to the field.

FIG.4is a partial block diagram, partial schematic diagram showing one example of a portion of sprayer180, illustrated inFIG.3. Some of the items illustrated inFIG.4are similar to those shown inFIG.3, and they are similarly numbered.

FIG.4shows that a row pressure sensor210is disposed relative to each valve204or nozzle200(or to an outlet hose where one is used) on boom188. Row pressure sensors210are configured so that they provide a signal indicative of the pressure drop across the valve200or the nozzle204, or the valve/nozzle combination200/204or so that such a value can be derived. By way of example, it may be that row pressure sensor210senses the pressure at the outlet end of valve204and the inlet end of nozzle200. This pressure can be compared to the boom pressure sensed by boom pressure sensor208(or, where multiple boom pressure sensors are provided along boom188, the boom pressure sensor located closely proximate the row pressure sensor210under analysis) in order to obtain a pressure drop across valve204. Sensor210can also be referenced to atmospheric pressure in order to obtain a pressure drop across nozzle200. Thus, by sampling the row pressure sensor signal during pulsed operation of valve204, the value of the row pressure can be used to determine whether valve204is operating, whether nozzle200is clogged or partially clogged, the duration of the pulses in the pulsed operation of valve204, the amount of liquid material that flows through valve204and nozzle200during each pulse, among other things. These are all described in greater detail below. In one example, the valves are controlled so that the liquid material flows through nozzles200and is sprayed (as indicated by arrows212) onto the field214over which the sprayer is traveling.

It will be noted that valve control system113illustratively generates control signals to control valves204. The control signals are illustratively pulsed control signals (such as pulse width modulated signals) where the amount of time that the valves200are open and closed is determined by the duty cycle of the pulse width modulated signal). This is just one example and control system113need not control valves204with a pulsed control signal. It will also be appreciated that valve control system113can be similar to, or different from, valve control system113described above with respect toFIGS.1and2. For the purposes of the present description, it will be assumed that they are similar, so that only valve control system113, described with respect toFIGS.1and2above, will be described in more detail.

FIG.5is a block diagram showing one example of valve control system113in more detail. In the example shown inFIG.5, valve control system113illustratively controls the valves using a pulsed control signal, so that some items dealing with the pulsed operation are described. However, where the control signal is not a pulsed control signal, those items need not be used.

Valve control system113illustratively includes one or more processors300, pressure sampling logic302, orifice identifier logic304, row pressure identifying logic306, row flow rate identifier logic308, error/time delay correction logic310, valve control signal generator312, pulsed duration logic314, pulse frequency logic316, control signal generator logic318, valve blockage detector320, data store321, flow volume detector322, seed/chemical correlation logic324, and it can include other items326. Seed/chemical correlation logic324can include seed location/pattern identifier325, pulse frequency controller327, pulse duration controller329and it can include other items331. It will also be noted that, in one example, valve control system113can include a communication system328and user interface logic330. In another example, communication system328and user interface logic330are items in the operator compartment184of sprayer180, or in the operator compartment of a towing vehicle (such as a tractor) that is towing planter100. In any case, valve control system113may be able to interact with a user interface332that can include user input mechanisms334, output mechanism336, and it can include other items338.

FIG.5also shows that, in one example, valve control system113can receive the row pressure sensor signals340generated by the row pressure sensors210or127. It can receive boom/supply line pressure signal(s)342that is generated by boom pressure sensor208or supply line pressure sensor133and, where multiple boom or supply line pressure sensors are used, it can receive signals342from each of them. It can receive boom/supply line flow signal(s)343generated by flow sensors (or flow meters)131,206and, where a return line is used, it can receive the flow signals from meters135and207as well. It is also shown receiving seed signal123.

Before describing the valve control system113, and its operation, in more detail, a number of items in control system113, and their operation will first be described.

Pressure sampling logic302illustratively samples the pressure signals generated by row pressure sensors210and boom pressure sensor(s)208. In one example, it samples the pressure at a frequency that is higher than the frequency of the pulse width modulated signal that is used to control valves200. Thus, the pressure drop across the valves can be sampled at the same frequency as well. In one example, the sampling frequency is high enough so that the duty cycle of the pulse width modulated signal that is applied to each valve (or characteristic of the actual pulse of liquid through the valve—such as pulse duration, pulse frequency, etc.) can be identified within a threshold amount of time. For example, it may be that the pressures (or the signals) are sampled at a rate which is multiple times that of the duty cycle of the pulse width modulated signal. In one example, the sampling rate is sufficient so that a pressure signal can be sampled twice during the active portion of the pulse width modulated signal. In another example, the sampling frequency is sufficient so that the pressure signal can be sampled 4 times, 8 times, or more, during the active portion of the duty cycle of the pulse width modulated signal. With a sufficient sampling rate, the duration of the pulse of liquid material through the corresponding valve can be identified with a relatively high degree of accuracy, as can the beginning and the end of the pulse of liquid. The higher the sampling frequency, the higher the accuracy with which the characteristics of the pulse can be identified, and thus, the higher the accuracy with which the beginning and end of the pulse, the pulse frequency and pulse duration can be identified.

Row pressure identifying logic306illustratively receives the row pressure signals340and generates a row pressure signal or value indicative of the row pressure measured by the corresponding row pressure sensor. This can be the pressure within the body of the valve204, or it can be pressure at the outlet end of the valve (or further down stream toward the outlet end of the application assembly), so that the pressure drop across the valve can be identified. By way of example, if the valve is opened and the pressure at the outlet end of the valve measures at approximately atmospheric pressure (or at the same level of the other valves or at another expected level), then this will mean that the nozzle which is being fed by the valve is unclogged, and is allowing the liquid material to pass through it and be dispersed on the field. Thus, the pressure drop across the valve will be indicative of the value of the boom pressure indicated by the boom pressure sensor signal(s)342less the pressure sensed by the row pressure sensor being processed. However, if the valve is open, but the row pressure sensor signal indicates that the measured row pressure is higher than the expected pressure, this may mean that the corresponding nozzle is clogged, or partially clogged. Thus, it will be appreciated that row pressure identifying logic306can identify the actual pressure measured by the row pressure sensor being processed, or it can identify the pressure drop across the valve corresponding to the row pressure sensor signal, or both. These and other architectures are contemplated herein.

Flow rate identifier logic308illustratively receives the boom/supply line flow signal340, indicative of the flow rate of liquid material through the boom or supply line, that is generated by flow meter206or flow meter131. Where no return line is used, then these flow signals represent the total flow of liquid applied to the field. Where a return line is used, then the return flow signal is also received from meter135or207so the applied flow can be determined based on the difference between the flows measured by the meters. Row flow rate identifier logic308divides the mass flow rate applied by the number of active valves or nozzles, to identify an average flow rate through each nozzle. Orifice identifier logic304can then identify the average orifice size for each nozzle based upon the pressure drop across the corresponding valve, and based upon the average flow rate through the valve. This can be done using the following equation:
FV=ValveCv*√{square root over (PB−PR)}  Eq. 1

where FVis the flow rate through a valve;

Valve Cvis a flow coefficient that represents the average orifice size of the valves;

PBis the boom (or supply line) pressure indicated by one of boom/supply line pressure signal(s)342; and

PRis the row pressure identified by row pressure signal340.

Error/time delay correction logic310illustratively compares the pulse width modulated control signal that is controlling the valves to the row pressure signal to identify a time delay between when the control signal controls the valve to open or close and when the row pressure signal indicates that the valve actually opened or closed.

There may be a time delay for a variety of different reasons. For instance, it may take more or less time to open or close the valve based on general valve characteristics (such as spring strength), the current driver which drives the valve solenoid, the system pressure, the liquid characteristics, etc. These parameters can vary, and this can affect application accuracy, application rate, etc. Logic310can identify these delays in near real time, during operation. It generates error or delay signals indicative of the errors or delays and provides them to seed/chemical correlation logic324. As is described in more detail below, seed location/pattern identifier325can identify seed location or a pattern indicative of that location. Pulse frequency controller327and pulse duration controller329can use that information, along with the time delays, and can determine when the valves should be actuated, and for how long, to dispense the liquid material where desired. Based on the signals from seed/chemical correlation logic324, pulsed valve control signal generator312controls the valves to dispense the liquid material at the seed/plant location (e.g., for fertilizer), between seed/plant locations (e.g., for herbicide), or elsewhere.

Before describing that correlation is more detail, it should be noted that error/delay correction logic310also illustratively compares the flow rate through a particular valve (based upon the pressure drop across that valve and the calculated orifice size) and compares it against a target flow rate (which may be identified based on the boom or supply line flow rate, or the applied flow rate, divided by the number of nozzles on the system), the system average flow rate, or it may compare the flow rate across a given nozzle to the flow rate across other nozzles on the sprayer or planter. Based upon the comparison, error correction logic310may identify errors introduced because of specific gravity considerations. It can then generate corrections for specific gravity of the liquid, when the specific gravity of the liquid is obtained by error correction logic310. In one example, an operator can use user input mechanism334to enter the specific gravity of the liquid. In another example, the identity of the liquid can be obtained and the specific gravity of that liquid can be obtained from a remote system, from local memory (e.g., from data store321), etc.

Pulse duration logic314illustratively identifies the beginning of the pulse of liquid, the end of the pulse of liquid and the duration of the pulse of liquid through the valve corresponding to each row, based upon the sampled row pressure signals. This was described above. Pulse frequency logic316illustratively identifies the frequency of the pulse of liquid through the valve, as also discussed above.

Valve blockage detector320illustratively identifies valve blockages based upon the various sensor signals. For instance, as discussed above, if the pressure drop across a particular valve is relatively small, even when the valve is open, then this may indicate that that a nozzle is blocked, or partially blocked. The pressure drop across a valve may be compared to an expected pressure drop, to determine whether the nozzle is blocked, partially blocked, or whether the valve is broken, among other things. In another example, instead of comparing to an expected value, the pressure drop across the valve can be compared against that of other valves. This overcomes effects related to things like varying viscosity because, at any given time, the valves are all likely to be subject to similar conditions (which would affect things like viscosity).

Flow volume detector322illustratively detects the volume of flow across a particular valve for each activation of the valve. For instance, if the duration of the active portion of the pulse width modulated signal is identified by pulse duration logic314, and the flow rate through the corresponding valve and nozzle combination is identified by row flow rate identifier logic308, then the volume of liquid material dispensed for each valve actuation can be identified by flow volume detector322.

In addition, logic308can identify the flow rate for all rows. They can be aggregated over some time period and compared to the applied flow rate over that time period. Any difference can be used to adapt the flow rate calculation and therefore the pulse length commands as well. This can be used to deal with viscosity and other similar unknowns.

Seed/chemical correlation logic324illustratively receives seed signal123and the pulse start, pulse end, and pulse duration and pulse frequency from logic314and316, respectively, and generates a signal indicative of whether the liquid is to be dispensed at the seed/plant locations or between those locations or elsewhere, and also indicative of when the valve should be actuated, and for how long, to dispense the liquid at those locations. It can, for instance, correlated the dispersal of chemical through a particular nozzle, with the delivery of a seed through a corresponding row unit. By way of example, if the row unit illustratedFIG.2drops a seed, and the chemical being delivered by the application assembly is a fertilizer chemical, then seed/chemical correlation logic324correlates the timing between depositing a seed in the furrow, and the application of chemical through the pulse width modulated operation of valve109. In this way, chemical can be applied in on a per-seed basis which enhances the efficient application of chemical, where needed. Further, if the sprayer inFIGS.3and4is to spray a herbicide between the plant locations, then logic324correlates timing between actuating the valves and the plant locations. The operation of seed/chemical correlation logic324is described in greater detail below with respect toFIG.7.

Control signal generator logic318can illustratively generate other control signals, based upon the various sensor signals and values generated. The control signals can be used to control any of a wide variety of different types of controllable subsystems, such as the speed of a sprayer or towing vehicle, the seed delivery system or seed metering system, operator interface logic330, or a wide variety of other controllable subsystems. Also, valve control signal generator312can control the actuation of valves109,200.

FIGS.6A and6B(herein after referred to asFIG.6) show a flow diagram illustrating one example of the operation of valve control system113in generating control signals based upon the various sensor inputs. It is first assumed that a spraying system (or chemical application system) with a valve control system113is operating. This is indicated by block350in the flow diagram ofFIG.6. In one example, the system is deployed on a sprayer180. In another example, it is deployed on a planter row unit106. Further, it is assumed that the valve control signal generator312is generating pulsed signals to control the various valves through which the liquid is being applied or sprayed. However, the valves may be controlled in other ways, where the control signals are not pulsed, in which case some of the description below regarding pulsed valve control signals does not apply. The spraying system can be operational in other ways as well, and this is indicated by352.

Boom/supply line pressure identifier logic305then detects the boom pressure from boom/supply line pressure signal(s)342. The boom pressure is indicated by PB. Detecting the boom pressure PB is indicated by block354in the flow diagram ofFIG.6. In one example, it is sensed with the boom pressure sensor208or supply line pressure sensor131, which generates the sensor signal342. It can also be sensed by different boom pressure sensors located at different locations across boom188or supply line111. This is indicated by block356. The boom pressure sensor can be generated by aggregating sensor values sensed by different sensors. For instance, one or more of the row pressure sensor signals can be aggregated to obtain the boom pressure value. This is indicated by block358in the flow diagram ofFIG.6. The boom pressure can be sensed and identified in other ways as well. This is indicated by block360.

Boom/supply line flow rate identifier logic307then detects the application flow rate (e.g., the flow of liquid from tank186or107into either boom188or supply line111, respectively. This is indicated by block362in the flow diagram ofFIG.6. This can be sensed using the central flow meter206or supply line flow meter131. This is indicated by block364. In an example in which a return line is used, the flow through the return line can also be measured and subtracted from the flow into boom188or supply line111. This is indicated by block365. It can be sensed in other ways as well, such as aggregating the flow rate through the various valves or nozzles that the liquid material is passing through. This is indicated by block366.

Orifice identifier logic304then identifies a number of active valves or nozzles in the system. This is indicated by block368. In one example, this can be input by the operator using operator input mechanisms334. Determining the number of active valves or nozzles based on an operator or user input is indicated by block370in the flow diagram ofFIG.6. It can be done by detecting the number of active valves or nozzles automatically. For instance, when the valves are turned on, the value of the row pressure sensed by row pressure sensors210can be identified to determine whether fluid is passing through a valve and/or nozzle. In this way, the number of active valves or nozzles can be identified automatically. Identifying the number of active valves automatically is indicated by block372. The number of active valves can be identified in other ways as well. This is indicated by block374.

Orifice identifier logic304then generates a system orifice size indicator (Cv) for the spraying system. The system orifice size indicator Cvwill illustratively be an aggregate of all the orifices of the active nozzles. Generating the system orifice size indicator Cvis indicated by block376in the flow diagram ofFIG.6.

In one example, the system orifice indicator is based on the boom pressure PB and the application flow rate. The boom pressure PB is illustratively indicated by the sensor signal from boom pressure sensor208. The application flow rate is illustratively indicated by the signal from flow meter206(and where a return line is used, based on the flow rate indicated by meter207as well). Generating Cvbased on the boom pressure and application flow rate is indicated by block378in the flow diagram ofFIG.6. The same can be generated for planter100based on the supply line pressure from sensor132and flow valve from flow meter131(and possibly flow meter135). It can be generated in other ways as well. This is indicated by block380.

Orifice identifier logic304then identifies a valve orifice size indicator (Valve Cv) which is indicative of the orifice size of the valves (or the valve/nozzle combination) on the sprayer boom. Generating the valve orifice size indicator Cvis indicated by block382in the flow diagram ofFIG.6. In one example, Valve Cvis based upon the system Cvand the number of active valves. For instance, the system Cvcan be divided by the number of active valves to obtain a size for each valve orifice. This is indicated by block384. The Valve Cvcan be identified in other ways as well. This is indicated by block386.

The row pressure identifying logic306detects a row pressure (PR) for each row. This is indicated by block388. In one example, the row pressure is sampled based upon a sampling frequency indicated by pressure sampling logic302. The row pressure can be sampled at a frequency that is greater than the frequency of the pulsed valve control signal (e.g., the pulse width modulated valve control signal). This is indicated by block390. The row pressures can be sampled by sampling the row pressure signals340from each of the row pressure sensors210,127. This is indicated by block392. The row pressure, for each row, can be detected in other ways as well. This is indicated by block394.

Row flow rate identifier logic308then identifies a valve flow rate (FV) for each row. The value FVwill identify the mass flow rate of an amount of liquid material passing through the valve when the valve is actuated by the pulse width modulated control signal. Identifying FVfor each row is indicated by block396.

In one example, FVcan be identified based on PB, PRand valve Cv. For instance, the valve flow rate can be identified using equation 1 above. This is indicated by block396. The valve flow rate can of course be identified in other ways as well, such as by placing individual flow meters on the valves, or in other ways. This is indicated by block400.

Pulse duration logic314then identifies the beginning of each pulse, the end of each pulse, and the pulse duration (or the time that the valve is open). This is indicated by block402. In one example, the row pressure is monitored so that when the row pressure changes (indicating that the valve is open) this is monitored to identify when the pressure indicates that the valve is opened (the beginning of each pulse). The row pressure is also monitored to identify when the pressure indicates when the valve is closed (the end of the pulse). The amount of time between when the valve opens and when it closes will identify the duration of the pulsed flow of liquid material through the valve for that pulse. Thus, in one example, the row pressure is sampled at a high enough frequency that the beginning and end of the pulse and the pulse duration can be identified with a desired accuracy. The higher the sample frequency, the more accurately these pulse characteristics can be identified. Identifying the pulse beginning and end and the pulse duration based on a detected variation of PRis indicated by block404. The pulsed duration can be identified in other ways as well, and this is indicated by block406.

Pulse frequency logic316then identifies the pulse frequency. In one example, the pulse frequency is determined based upon the amount of time between transitions in the pulse width modulated signal from an inactive state to an active state. The frequency with which the pulse width modulated signal makes this transition is illustratively a measure of the pulse frequency, itself. Identifying the pulse frequency is indicated by block408.

As with the pulse duration, in one example, the pulse frequency can be identified by detecting variations in the row pressure PR indicating the valve opening and valve closing transitions. This is indicated by block410. The pulse frequency can be identified in other ways as well, and this is indicated by block412.

Valve blockage detector320then detects whether a given valve is blocked. This is indicated by414. For instance, detector320can monitor the row pressure signals340for each of the rows and identify whether the row pressure is changing with the pulse width modulated control signal (or with ah non-pulsed control signal). By way of example, if the row pressure remains the same, regardless of whether the corresponding valve is open or closed, this may indicate that the valve or nozzle is blocked or broken. Similarly, the amplitude of the pressure change can be monitored as well. If the pressure change is only slight, depending on whether the valve is open or closed, this may indicate that the nozzle is partially blocked. Detecting a valve or nozzle blockage based upon the row pressure PRis indicated by block416.

The valve or nozzle blockage can also be detected based upon the valve flow rate FV. If the flow rate through the valve is zero or less than expected, even when the valve is open this may indicate that the valve or nozzle is fully blocked or partially blocked. Detecting whether the valve or nozzle is blocked based on FVis indicated by block418.

Detecting whether the valve or nozzle is blocked or partially blocked can be done in other ways as well. This is indicated by block420.

Flow volume detector322then detects the volume of liquid flow in the system. This is indicated by block422. The flow volume can be detected at a number of different levels. For instance, the volume of liquid flow at each row (through each valve or valve/nozzle combination) can be identified. By way of example, it can be identified based upon the flow rate through each valve/nozzle combination, and the duty cycle of the control signal (or the amount of time that the valve is actually open). Identifying the flow volume on a per row basis is indicated by block424.

In some cases, it may be that a single valve services multiple nozzles. In that case, the flow volume can be identified on a per-valve basis. This is indicated by block426. The flow volume through a valve or valve/nozzle combination can be identified over a given period of time (such as the volume of flow per minute), etc. This is indicated by block428. In another example, the flow volume can be identified for each valve actuation (e.g., the amount of liquid passing through the valve for each valve actuation can be identified). This is indicated by block430. The flow volume can be detected in other ways as well. This is indicated by block432.

Based upon all of the values that are detected and/or generated, control signal generator logic318and valve control signal generator312then illustratively generate control signals to control the system. This is indicated by block434.

Logic312can generate a wide variety of different types of control signals. For instance, it can use seed/chemical correlation logic324to perform valve control based upon seed or plant location, so that liquid material is sprayed at the location of each seed or plant, between them, or relative to them in other ways, etc. This is indicated by block436. It can perform valve control to apply a desired quantity when spot spraying. Since the flow volume is known on a per system and per nozzle basis, then the valves can be controlled by valve control signal generator312to apply a desired volume at a desired location (such as when spot spraying for weeds or otherwise). The control can be performed based on the time delay detected by logic310or in other ways as well. Performing valve control to apply a desired quantity when spot spraying in indicated by block438.

Control signal generator logic312can control the machine based upon blockage detection. For instance, when a blockage of a particular nozzle or valve is detected, then the control signal for that valve can be disabled until the blockage is remedied. At the same time, control signal generator logic318can control user interface logic330to raise an alert for the operator. Similarly, logic312can control the frequency of the pulse width modulated control signal in an attempt to clear the blockage. Control signals can be generated to control the machine based on blockage detection in other ways as well. This is indicated by block440.

Control signal generator logic318can also generate a control signal and provide it to valve control signal generator312so that the pulse width modulated signals are generated to control the pulse frequency or duration. By way of example, assume that a sprayer is treating a certain type of plant or weed, and the application of additional liquid volume may be desired at a particular point in the field. The pulse frequency or pulse duration of the pulse width modulated signal can be varied to adjust the volume of liquid material applied. This is indicated by block442.

In another example, the system may be meant to apply liquid to a specific spot (e.g., close to the plant). The length of the spot to which liquid is applied will be dependent on valve actuations and driving speed. At relatively higher speed, the spot may be so long that the amount of liquid is not sufficiently concentrated. Thus, logic318can generate a pump control signal to control the pump that pumps the liquid material to increase pressure at higher speeds and decrease pressure at lower speeds. Controlling the pump to adjust pressure based on travel speed is indicated by block441. In another example, logic318generates speed control signals to control machine speed to attain the desired concentration. These can also be done while controlling the valves as well.

Control signal generator logic318can also generate a control signal to control user interface logic330in various ways. This is indicated by block444. By way of example, when a blockage is detected, a user interface output mechanism336can be controlled to surface this information for the operator. Mechanism336may be a visual, audible or haptic output device that is controlled to alert the operator to a blockage, or a set of blockages. The user interface logic can be controlled in other way as well.

It will be appreciated that a wide variety of other control signals can be generated. The control signals can be used to control subsystems of a planter100, of a towing vehicle, of a self propelled sprayer180, or a wide variety of other items. This is indicated by block446.

FIG.7is a flow diagram illustrating one example of the operation of seed/chemical correlation logic324in correlating the application of a liquid chemical with seed or plant location. Seed/chemical correlation logic324first detects the seed/location indicating the location of a seed/plant. The seed/plant location can be detected in a variety of different ways. For instance, the number of seed signals123can be detected for a threshold time period of time by seed location/pattern identifier325. Identifier325can then detect a pattern indicative of seed location. For example, it may identify that, based on the seed signal123, and the speed or location of the planter sensed by a speed sensor or location sensor (such as a GPS receiver), a seed is being dropped every 6 inches, beginning at a location identified by the seed signal123. Once the pattern is identified, controllers327and329can control valves109,204to apply the liquid as desired, relative to the seeds or plants. They can control the pulse of liquid (its beginning and ending, its frequency and duration) so it applies the liquid at the seed/plant locations, between those locations, elsewhere, etc.

In another example, identifier325identifies the seed/plant location based on the current seed signal123. For instance, it can identify seed location by detecting seed presence at the seed sensor and determining how long it will take for the seed to reach the ground. Based on that time, logic327and329can control the timing, pulse frequency and/or duration, respectively to apply the liquid material as desired relative to the seed.

Detecting the seed/plant location is indicated by block450. Detecting the location by identifying a pattern is indicated by block451. Detecting the seed/plant location from a seed sensor signal123is indicated by block452. The seed location can be identified in other ways as well. For instance, if a seed location map was generated when seeds were planted, that map may be stored (e.g., remotely or in data store321) and may identify the geographical coordinates of the seed/plant locations. Thus, when a sprayer is traveling over that portion of a field later, it can obtain the seed location map and identify seed location based upon that map. When it travels over the field, it can selectively apply the liquid material based on the seed locations. Detecting seed location based upon a seed location map is indicated by block454.

The seed location can be detected in other ways as well. This is indicated by block456.

Seed/chemical correlation logic324then provides an output to valve control signal generator312to generate a correlated, valve control signal, that is correlated to apply the liquid material based upon the seed/plant location. This is indicated by block458. In doing so, time delay correlation logic310identifies a time delay between when a valve is commanded to open or close and when it actually opens or closes based on liquid pulse beginning and ending (as detected by pulse duration logic314) which is, itself, based on the variation in the sensed row pressures. This is indicated by block455and it can be done for each valve that is being controlled. In addition, the time for the liquid to reach the field after passing through the nozzle can be sensed or estimated as well. Based on these delays, various parameters of the liquid pulse can be controlled to correlate the liquid delivery with the plant location to apply the liquid at a desired location relative to the plant location. The pulse frequency can be controlled by pulse frequency controller327, as indicated by block457. The pulse duration can be controlled by pulse duration controller329, as indicated by block459. In one example, the control signal provided to pulsed valve control signal generator312controls generator312to generate the pulse width modulated signal in order to synchronize the application of the liquid substance to the seed/plant location. This is indicated by block460. In another example, the control signals are also generated, and timed, to apply a desired amount of the liquid material per seed. This is indicated by block462. By way of example, once the flow rate through each nozzle or valve is known, timing and the duration of the pulse width modulated signal can be varied to apply a desired amount of material relative to a known seed/plant location. For instance, a small amount of material may be applied on either side of the seed while a relatively large amount of the material is applied at the same location of the seed. This is just one example. Also, the pulse width modulated signal can be generated to apply the liquid between (or to the side of or otherwise offset from) the seed/plant locations. This is indicated by block461. Similarly, the machine speed and/or pump pressure (e.g., pump displacement, etc.) can also be controlled to apply a desired amount at a desired spot. This is indicated by block463. Generating a correlated pulsed valve control signal, that is correlated to seed location, can be performed in other ways as well. This is indicated by block464.

FIG.8is a block diagram of an architecture in which machines are disposed in a remote server (or cloud computing) architecture500. Cloud computing provides computation, software, data access, and storage services that do not require end-user knowledge of the physical location or configuration of the system that delivers the services. In various examples, cloud computing delivers the services over a wide area network, such as the internet, using appropriate protocols. For instance, cloud computing providers deliver applications over a wide area network and they can be accessed through a web browser or any other computing component. Software or components of architecture500as well as the corresponding data, can be stored on servers at a remote location. The computing resources in a cloud computing environment can be consolidated at a remote data center location or they can be dispersed. Cloud computing infrastructures can deliver services through shared data centers, even though they appear as a single point of access for the user. Thus, the components and functions described herein can be provided from a service provider at a remote location using a cloud computing architecture. Alternatively, they can be provided from a conventional server, or they can be installed on client devices directly, or in other ways.

In the example shown inFIG.8, some items are similar to those shown in previous Figures and they are similarly numbered.FIG.8specifically shows that the machines100,180can communicate (by using communication system428in pulsing valve control system113) with one or remote systems504located in cloud502(which can be public, private, or a combination where portions are public while others are private).

FIG.8also depicts another example of a cloud architecture.FIG.8shows that it is also contemplated that some components430of pulsing valve control system113can be disposed in cloud502while others are not. By way of example, data store321can be disposed outside of cloud502, and accessed through cloud502. In one example, data store321can include historical data470, one or more seed maps472, liquid characteristics474(such as viscosity or specific gravity characteristics, etc.), desired application data476(such as desired amounts, where to apply relative to plant location, etc.), and it can include other data478. Regardless of where they are located, they can be accessed directly by machines100,180, through a network (either a wide area network or a local area network), they can be hosted at a remote site by a service, or they can be provided as a service through a cloud or accessed by a connection service that resides in the cloud. All of these architectures are contemplated herein.

When used in a LAN networking environment, the computer810is connected to the LAN871through a network interface or adapter870. When used in a WAN networking environment, the computer810typically includes a modem872or other means for establishing communications over the WAN873, such as the Internet. The modem872, which may be internal or external, may be connected to the system bus821via the user input interface860, or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer810, or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation,FIG.9illustrates remote application programs885as residing on remote computer880. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. It should also be noted that the different embodiments described herein can be combined in different ways. That is, parts of one or more embodiments can be combined with parts of one or more other embodiments. All of this is contemplated herein.

Example 1 is an agricultural machine, comprising:

a liquid reservoir that stores liquid to be applied to a field over which the agricultural machine is traveling;

a supply line that defines a supply conduit;

a plurality of valves disposed along the supply line, each valve having an inlet end and an outlet end and being controlled to move between an open position and a closed position by a pulsed control signal;

a pump system that pumps the liquid from the liquid reservoir along the supply line to the inlet ends of the valves;

a plurality of nozzles, at least one nozzle corresponding to each valve so that when the corresponding valve is open, the liquid flows through the valve to the corresponding nozzle;

a plurality of row pressure sensors each sensing pressure at the outlet end of one of the plurality of valves and generating a corresponding row pressure signal indicative of the sensed pressure;

pulse characteristic sensing logic that receives the row pressure signal from each row pressure sensor and identifies a pulse characteristic indicative of a liquid pulse provided by the corresponding valve in the open position and generates a valve pulse characteristic signal indicative of the pulse characteristic; and

a pulsed valve control signal generator that generates the pulsed control signal based on the valve pulse characteristic signal.

Example 2 is the agricultural machine of any or all previous examples and further comprising:

time delay logic configured to receive the pulsed control signal and the valve pulse characteristic signal and identify an open time delay between the pulsed control signal generating a valve open signal controlling the valve to open and the valve pulse characteristic signal indicating that the valve is in the open position.

Example 3 is the agricultural machine of any or all previous examples wherein the time delay logic is configured to receive the pulsed control signal and the valve pulse characteristic signal and identify a close time delay between the pulsed control signal generating a valve close signal controlling the valve to close and the valve pulse characteristic signal indicating that the valve is in the closed position.

Example 4 is the agricultural machine of any or all previous examples and further comprising:

seed/chemical correlation logic configured to identify plant location in the field and control timing of the pulsed control signal based on the identified plant location.

Example 5 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic comprises:

a valve control signal generator configured to generate a pulse control signal to control a timing characteristic of the pulsed control signal based on the plant locations in the field over which the agricultural machine is traveling, the open time delay and the close time delay.

Example 6 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic comprises:

a pulse frequency controller configured to generate a pulse frequency control signal to control a frequency of the pulsed control signal based on the plant locations in the field over which the agricultural machine is traveling, the open time delay and the close time delay.

Example 7 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic comprises:

a pulse duration controller configured to generate a pulse duration control signal to control a pulse duration of the pulsed control signal based on the plant locations in the field over which the agricultural machine is traveling, the open time delay and the close time delay.

Example 8 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic is configured to correlate the pulsed control signal with the plant locations to apply the liquid material between the plant locations.

Example 9 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic is configured to synchronize the pulsed control signal with the plant locations to apply the liquid material at the plant locations.

Example 10 is the agricultural machine of any or all previous examples and further comprising:

valve row flowrate identifier logic configured to identify a valve row flowrate for each valve based on a valve orifice size and the row pressure signal from the corresponding row pressure sensor.

Example 11 is the agricultural machine any or all previous examples wherein the seed/chemical correlation logic is configured to synchronize the pulsed control signal with the plant locations to apply a desired amount of the liquid material based on the valve flow rate.

Example 12 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic is configured to generate a pump control signal to control liquid pressure based on a travel speed of the agricultural machine to apply a desired amount of the liquid material.

Example 13 is the agricultural machine of any or all previous examples and further comprising:

a supply line pressure sensor configured to identify pressure in the supply conduit and generate a supply line pressure signal indicative of the sensed pressure in the supply conduit; and

row pressure identifying logic configured to identify a pressure drop across a given valve based on the row pressure signal and the supply line pressure signal.

Example 14 is the agricultural machine of any or all previous examples wherein the supply line pressure sensor comprises:

a plurality of supply line pressure sensors, the row pressure identifying logic identifying the pressure drop across the given valve based on the row pressure sensor signal and a supply line pressure signal generated from a closest one of the supply line pressure sensors to the row pressure sensor.

Example 15 is the agricultural machine of any or all previous examples and further comprising:

a valve blockage detector configured to identify a valve blockage condition for the given valve based on the pressure drop across the given valve.

Example 16 is the agricultural machine of any or all previous examples and further comprising:

a seed sensor configured to sense seed presence during a planting operation and generate a seed signal indicative of the sensed seed presence.

Example 17 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic comprises:

a seed location identifier configured to identify the plant location in the field based on the seed signal.

Example 18 is the agricultural machine of any or all previous examples wherein the seed/chemical correlation logic comprises:

a seed pattern identifier configured to identify a seeding pattern indicative of the plant location based on the seed signal.

Example 19 is an agricultural machine, comprising:

a liquid reservoir that stores liquid to be applied to a field over which the agricultural machine is traveling;

a supply line that defines a supply conduit;

a plurality of valves disposed along the supply line, each valve having an inlet end and an outlet end and being controlled to move between an open position and a closed position by a pulsed control signal;

a pump system that pumps the liquid from the liquid reservoir along the supply line to the inlet ends of the valves;

a plurality of nozzles, at least one nozzle corresponding to each valve so that when the corresponding valve is open, the liquid flows through the valve to the corresponding nozzle;

a plurality of row pressure sensors each sensing pressure at the outlet end of one of the plurality of valves and generating a corresponding row pressure signal indicative of the sensed pressure;

seed/chemical correlation logic configured to identify plant locations in the field and correlate the pulsed control signal with the plant locations to apply a desired amount of the liquid material based on the row pressure signals and the plant locations.

Example 20 is a method of controlling an agricultural machine, comprising:pumping liquid from a liquid reservoir along a supply line, that forms a supply conduit, to inlet ends of a plurality of valves disposed along the supply line;controlling the plurality of valves to move between an open position, in which the valves provide the liquid to a corresponding nozzle, and a closed position using a pulsed control signal, to apply the liquid to a field over which the agricultural machine is traveling;sensing pressure at the outlet end of each of the plurality of valves;generating a corresponding row pressure signal indicative of the sensed pressure;identifying a pulse characteristic indicative of a characteristic of a liquid pulse generated by the corresponding valve being in the open position, based on the row pressure signal;generating a valve pulse characteristic signal indicative of the pulse characteristic; andgenerating the pulsed control signal based on the valve pulse characteristic signal.