AU730557B2 - Spray line controller - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT (Original) APPLICATION NO:

LODGED:

.0 0 0 0000 000* 0 0 00 0 0:..0 00990 COMPLETE SPECIFICATION LODGED:

ACCEPTED:

PUBLISHED:

RELATED ART: NAME OF APPLICANT: ACTUAL INVENTOR(S): ADDRESS FOR SERVICE: INVENTION TITLE: GAVIN JOHN DAVIS

APPLICANT

LORD COMPANY, Patent Trade Mark Attorneys, of 4 Douro Place, West Perth, Western Australia, 6005, AUSTRALIA.

"SPRAY SYSTEM AND CONTROLLER" DETAILS OF ASSOCIATED PROVISIONAL APPLICATION NO'S: PO2013 filed on August 30, 1996.

The following Statement is a full description of this invention including the best method of performing it known to me/us:

TITLE

"Spray System and Controller" DESCRIPTION OF THE INVENTION The present invention relates to a spray system and controller therefor.

FIELD OF THE INVENTION Farmers regularly need to spray their crops with agricultural chemicals. One method of spraying crops is to drive along rows of crops with a spray boom extending substantially perpendicular to the path of travel. The spray boom has a plurality of hydraulic nozzles which spray the crops with chemicals. The spray boom normally consists of one or more sections of spray nozzles. The spray nozzles are of a size S: which allows a certain amount of chemical to be sprayed at a particular rate. It is desirable to have the crops sprayed with a predetermined amount of chemical per square metre. The speed at which the boom travels is related to the amount of chemical sprayed per square metre.

Current control systems are able to measure the speed of a vehicle towing the boom Sand regulate the flow rate of the chemical to be sprayed to account for variations in 0oo0• speed of the vehicle, while maintaining the amount of chemical sprayed per square metre at a relatively constant value.

The current method has problems. If the hydraulic nozzle size is required to be changed then each nozzle must be manually removed from the boom and the new sized nozzles inserted in place of the previous sized nozzles. Further, with current control systems, the speed of the vehicle is limited by the size of the sprays and the maximum capacity of the pump pumping the chemicals. This results in the maximum speed of the vehicle typically being 200% of a minimum effective speed.

It is also desirable to have a lower sized nozzle in order to keep the droplet size of the chemical within a certain range, this further reduces the maximum speed the vehicle can travel at.

SUMMARY OF THE PRESENT INVENTION In accordance with a first aspect of the present invention there is provided a spray system comprising a plurality of spray lines arranged to be mounted to a vehicle, each spray line being arranged to spray a common area of ground; at least one control valve provided on each of the spray lines to control the flow of a fluid to the spray line; Sga pressure measuring means arranged to measure the pressure of the fluid supplied to go i S• the spray lines the pressure being relative to the speed of travel of the vehicle; and a control means arranged such that when a pressure corresponding to one or more first pressure threshold values is sensed by the pressure measuring means, the control means opens the or each control valve on a respective spray line and when a pressure corresponding to one or more second pressure threshold values is sensed by the pressure measuring means, the control means closes the or each control valve on a respective spray line.

In accordance with a second aspect of the present invention there is provided a spray controller for controlling a plurality of spray lines mounted on a vehicle arranged to spray a common area of ground comprising: a pressure measuring means arranged to measure the pressure of the fluid supplied to the spray lines the pressure of fluid supplied being relative to the speed of travel of the vehicle; and and a control means arranged such that when a pressure corresponding to one or more first pressure threshold values is sensed by the pressure measuring means, the control means opens one or more control valves on a respective spray line and when a pressure corresponding to one or more second pressure threshold values is sensed by the pressure measuring means, the control means closes the or each control valve on a respective spray line.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a top view of a spray system in accordance with the present invention; Figure 2 is a schematic representation of the spray system of Figure 1; Figure 3 is a circuit diagram of a controller in accordance with the present invention; Figure 4 is a logic diagram of a controller in accordance with the present invention; and Figure 5 is a schematic representation of a method of controlling spray lines in accordance with the present invention; BRIEF DESCRIPTION OF THE INVENTION Referring to Figure 1, there is shown a spray system 10 which includes a tank 16 for holding a chemical to be sprayed, a boom 18, a primary spray line 20 and a secondary spray line 28. Also shown is a vehicle 12 towing a trailer 14. The spray lines 20 and 28 are mounted on the boom 18. The boom 18 and the tank 16 are mounted on the trailer 14.

The primary spray line 20 includes a plurality of spray sections 22, 24 and 26. The :secondary spray line 28 includes a plurality of spray sections 30, 32 and 34. Each spray Ssection 22, 24 and 26 of the primary spray line 20 is paired with an aligned spray section 30, 32 or 34 of the secondary spray line 28 to form a plurality of spray rows 21, 23 and 0 *0 Referring to Figure 2, there is shown the spray system 10. Shown are the tank 16, a o pump 40, a flow regulator 44, a flow meter 48, a spray line controller 15, the primary *0 :spray line 20 and the secondary spray line 28. The pump 40 is connected to the tank by a pipe 42. The flow regulator 44 is connected to the pump 40 by another pipe 56. The flow regulator 44 has a return pipe 46 connected back to the tank 16. The flow regulator 44 has an exit pipe 58 which connects it with the flow meter 48. The flow meter 48 is connected to a pressure measuring means 64 of the controller 15 by another pipe 60. The flow regulator 44 is controlled by a known control means (not shown). The pressure measuring means 64 is connected by a further pipe 62 to a plurality of primary spray a.

section valves 50, 52 and 54. The spray section valves 50, 52 and 54 are connected to the corresponding spray sections 22, 24 and 26 of the primary spray line 20. The further pipe 62 is also connected to a plurality of spray section valves 70, 72 and 74 which are connected to corresponding spray sections 30, 32 and 34 of the secondary spray line 28.

The controller 15 includes the pressure measuring means 64 and a control means 66 which: causes one or more spray section valves 50, 52, 54, 70, 72, and 74 to be opened when the pressure in the pipe 60 of the chemical being pumped to the plurality of spray lines 20 and 28 is above a high pressure threshold point; and (ii) causes one or more spray section valves 50, 52, 54 70, 72, and 74 to close when the pressure in the pipe 60 is below a low pressure threshold point.

Referring to Figure 3, there is shown a first embodiment of the spray control means 66.

The control means 66 includes a switch 302 for selecting spray line priority and a selector 303 for selecting single spray line only spraying, all spray lines spraying, or automatic 15 control of spraying. The switch 302 may have a default arrangement such that the primary spray line 20 has first priority. The selector 303 may have a default arrangement such that automatic control is the default selection.

The control means 66 further includes one or more inputs 308, 310 and 312 to enable a respective spray row 21, 23 or 25. The default arrangement further inputs 308, 310 and 312 such that all the spray rows 21, 23 and 25 are enabled. The control means 66 still further includes the pressure measuring means 64, one or more conductors 68 to the primary line spray section valves 50, 52 and 54 and the secondary line spray section valves 70, 72 and 74.

(I 6 The selector 303 may be a three position switch which either activates a switch 304 and deactivates a switch 306 for single spray line only spraying, activates the switch 306 and deactivates the switch 304 for all spray line spraying, or deactivates both switches 304 and 306 for automatic control. Both switches 304 and 306 will not be activated at the same time.

The pressure measuring means 64 includes a normally open low pressure switch 314 and a normally open high pressure switch 316. The low pressure switch 314 closes when pressure in the pipe 60 exceeds the low pressure threshold point, for example, 150 kilopascals, and opens when the pressure in the pipe 60 is below the low pressure 10 threshold point. The high pressure switch 316 closes when the pressure in the pipe **exceeds the high pressure threshold point, for example, 450 kilopascals, and opens when the pressure in the pipe 60 is below the high pressure threshold point. The switches 314 and 316 are connected to the pipe 60 and the further pipe 62 in order to measure the pressure therein.

If the switches 304 or 306 are not activated by the selector 303 then the spray lines will be controlled automatically.

The low pressure switch 314 and the high pressure switch 316 are arranged to be connected to a normally open relay switch 330, such that when the selector 303 is set to automatic control and the pressure in the pipe 60 is below the low pressure threshold point, and thus the low pressure switch 314 and the high pressure switch 316 are open, the relay switch 330 is open. When the pressure in the pipe 60 is above the low pressure threshold point, but below the high pressure threshold point, and thus the low pressure switch 314 is closed and the high pressure switch 316 is open, the relay switch 330 retains its previous state. When the pressure in the pipe 60 is above the high threshold 7 point, and thus both the low pressure switch 314 and the high pressure switch 316 are closed, the relay switch 330 is closed.

The line priority switch 302 is connected to a double pole double throw relay switch 336.

When the switch 302 is activated, this causes the relay switch 336 to change the activation priority of the spray lines 20 or 28. When the switch 302 is not activated, the priority is such that the primary spray line 20 activates first and the secondary spray line 28 activates second. When the switch 302 is activated the secondary spray line 28 is activated first and the primary spray line 20 is activated second.

During automatic control, the relay switch 334 is closed, therefore when the relay switch 330 is closed this results in a circuit being completed which causes the second priority S spray line to be activated.

The inputs 308, 310 and 312 are provided to conduct electrical current from a respective :'**switch (not shown) to enable each corresponding row 21, 23 or 25 to be activated.

Further rows may also be enabled.

15 A spray row 21, 23 or 25 may be disabled if the input 308, 310 and 312 corresponding to that row is not energised. The input 308, 310 or 312 activates a corresponding normally open relay switch 338, 340, 342, 344, 346 or 348 depending on the priority in which the spray line will be activated. The relay switches 338, 340, 342, 344, 346 and 348 each have a corresponding diode 350, 352, 354, 356, 358 and 360 as protection against any inductive reverse voltage spikes caused by a coil of each of the relay switches 338, 340, 342, 344, 346 and 348.

A diode 371 provides protection against any inductive reverse voltage caused by a coil of the relay switch 330.

(I

8 The selector 303 provides a manual override to the automatic control by activating either the switch 304 or the switch 306. The single spray line only switch 304 is connected to a normally closed relay switch 334, wherein if the switch 304 is closed this causes the ielay switch 334 to be opened. If the relay switch 334 is open then the circuitry of the control means 66 will be arranged such that only a single spray line will be activated.

The all spray lines switch 306 is connected to a normally open relay switch 332, wherein if the switch 306 is closed it causes the relay switch 332 switch to be closed. If the relay switch 332 is closed then the circuitry of the control means 66 will be arranged to energise all spray lines will be activated.

10 A diode 373 provides protection against any inductive reverse voltage caused by a coil of the relay switches 336, 334 and 332.

Referring to Figure 4, there is shown an alternative embodiment of the spray control means 66. The second embodiment of the control means 66 includes a switch 402 for selecting spray line priority and a selector 403 for selecting one of single spray line only spraying, all spray lines spraying, or spraying by automatic control. The default arrangements for the switch 402 and the selector 403 are the same as the default arrangements of the switch 302 and the selector 303 of the first embodiment of the control means 66.

The second embodiment of the control means 66 further includes one or more switches 408, 410 and 412 for enabling each respective spray row 21, 23 or 25. The default arrangement for the switches 408, 410 and 412 is such that all spray rows 21, 23 and are enabled. The second embodiment yet further includes the pressure measuring means 64, and conductors 68 to the primary line section valves 50, 52, and 54 and the secondary line section valves 70, 72, and 74.

The selector 403 may be a three position switch which either activates a switch 404 and deactivates a switch 406 for single spray line only spraying, activates the switch 406 and deactivates the switch 404 for all spray line spraying or deactivates both switchei 404 and 406 for automatic control. Both switches 403 and 404 will not be activated at the same time.

The pressure measuring means 64 includes a normally open low pressure switch 414 and a normally open high pressure switch 416. The low pressure switch 414 closes when the pressure in the pipe 60 exceeds the low pressure activation point, and opens when the pressure in the pipe 60 is below the low pressure threshold point. The high pressure 10 switch 416 closes when the pressure in the pipe 60 exceeds the high pressure threshold .ooo point, and opens when the pressure is below the high pressure activation point. The switches 414 and 416 are connected to the pipe 60 and a further pipe 62 in order to measure the pressure therein.

If the switches 404 and 406 are not activated by the selector 403 the spray lines will be I5 controlled automatically.

The low pressure switch 414 and high pressure switch 416 are arranged to be connected to a logical circuit 430, such that when the selector 403 is set to automatic control and the pressure in the pipe 60 is below the low pressure threshold point, the circuit 430 provides a logical off to the AND gate 432. When the pressure in the pipe 60 is above the low pressure threshold point, but below the high pressure threshold point, the circuit 430 retains its previous state. When the pressure is above the high pressure threshold point the circuit 430 provides a logical on to the AND gate 432.

If both inputs to the AND gate 432 are logically on the AND gate 432 produces a logical on output. If either of the inputs of the OR gate 434 are on then the OR gate 434 produces a logical on to a conductor 436. When the conductor 436 receives a logical on, both spray lines 20 and 28 will be activated.

The selector 403 provides a manual override to the automatic control by activating 6ither the switch 404 or the switch 406.

The single spray line only switch 404 is connected via an inverter to a logical AND gate 432, wherein when the switch 404 is closed, this causes the AND gate 432 to be logically off. The all spray line switch 406 is connected to a logical OR gate 434, wherein if the switch 406 is closed, it causes the OR gate 434 to be logically on.

If the AND gate 432 is logically off then the conductor 436 will not be energised and thus 10 only a single spray line will be activated. If the OR gate 434 is logically on then the .oo.

*0•conductor 436 will be energised and thus both spray lines will be activated.

The switches 408, 410, and 412 when activated provide an electrical current which enables corresponding sections of the primary spray line 20 and the secondary spray line 28 of the respective rows 21, 23 and 25 to be activated.

15 For each spray row 21, 23, and 25 there is a corresponding logical circuit 441 which controls the activation of the respective spray section valves 50 and 70, 52 and 72 or 54 and 74. The logical circuit 441 includes an invertor 429, a logical OR gate 438, another :•00 logical OR gate 440, a logical AND gate 442 and another logical AND gate 444. The invertor 429, the OR gates 438 and 440 and the AND gates 442 and 444 are arranged such that for each section activated by closing the respective section switch 408, 410 or 412, when the spray line priority switch 402 is not activated, the AND gate 442 provides a current to the conductor 68 to switch on the respective valve 50, 52 or 54, thus switching on the primary spray line first. When the conductor 436 is supplied with a logical on this causes the OR gate 440 to provide a logical on to the AND gate 444, 11 which supplies a current by another conductor 68 to the respective valve 70, 72 or 74, thus switching on the secondary spray line so that both of the primary and secondary spray lines are operated together.

If the spray line priority switch 402 is activated, the AND gate 444 provides a current to the conductor 68 to switch on the respective valve 70, 72 or 74, thus switching on the secondary spray line first. When the conductor 436 is supplied with a logical on this causes the OR gate 438 to provide a logical on to the AND gate 442 which supplies a current by the other conductor 68 to the respective valve 50, 52 or 54, thus switching on the primary spray line so that both of the primary and secondary spray lines are operated together.

.The method of use and operation of the present invention will now be described with reference to the accompanying drawings.

The spraying system 10 is towed along such that the spray lines 20 and 28 pass over crops to be sprayed. In use the pump 40 pumps the chemical to be sprayed from the tank 15 16 in through the pipe 42 and out through the other pipe 56. The chemical passes S- through the flow regulator 44. The flow regulator 44 directs a certain amount of the chemical through the returning pipe 46 back to the tank 16. The remainder of the chemical passes through the exit pipe 58 to the flow meter 48. Flow meter 48 measures the flow and by the known control means the flow is controlled. The chemical from the flow meter passes through the pipe 60 to the pressure measuring means 64. The chemical then flows through the pipe 62 to the spray section valves 50, 52, 54, 70, 72 and 74, which when open allow the chemical to flow to the corresponding spray sections 22, 24, 26, 30, 32 and 34 of the respective spray lines 20 and 28. The chemical is then sprayed onto the crops.

Control of the spray line section valves 50, 52, 54, 70, 72 and 74 are conducted by the spray line controller 15. Each spray row 21, 23 and 25 is activated by the switch corresponding to the inputs 308 and 310 or the switches 408, 410 and 412. The spray line priority is selected by the spray line priority switch 302 or 402. The spray line 20 or 28 selected to be activated first will have the spray sections 22, 24, 26, 30, 32 or 34 corresponding to that spray line 20 or 28 with first priority and the spray line sections 22, 24, 26, 30, 32 or 34 corresponding to the spray line 20 or 28 with second priority will be used second.

The spray line controller 15 operates as shown in Figure The selector 303 or 403 is used to select 102 single line spraying only 104, spraying from all lines 108 or automatic control of the spray lines 112. If spraying from one line only I. o• 104 is selected then only one spray line is enabled 106. If spraying from all lines 108 is selected then all spray lines are enabled 110.

If the speed of the vehicle 12 increases, the flow rate of the chemical through the pipe 15 will be increased by the known control means. This will cause the pressure in the pipe to increase. If the speed of the vehicle 12 decreases, the flow rate will be decreased by the known control means. This will cause the pressure in the pipe 60 to decrease.

If automatic control of the spray lines 112 is selected, then it is determined 114 whether the high pressure switch 316 or 416 is on. If the high pressure sensor is on 116 then both spray lines are enabled 118. If the high pressure switch 316 or 416 is not on, is determined 120 whether the low pressure switch 314 or 414 is on. If the low pressure switch 314 or 414 is on 122 then the previous state is maintained. That is, if the previous state was both lines being activated 118 then both lines continue to be activated. If the previous statewas only one line is activated 126 then the state remains as only one line 13 activated 126. If the low pressure switch 314 or 414 is not activated only one line is activated 124 and the second line is not enabled 126.

Switching on the second priority spray line will cause a drop of the pressure in the'pipe Also, when the second priority spray line is switched off a pressure increase will result. Therefore the difference between the high pressure threshold point and the low pressure threshold point should be large enough to prevent the system from becoming unstable and resulting in an oscillation between switching on and off the second priority spray line.

For each enabled spray row 21, 23 or 25 and each spray line 20 or 28 activated, the appropriate section valves 50, 52, 54, 70, 72 and 74 are opened. Each valve 50, 52, 54, 70, 72 or 74 opened and allows the chemical to be pumped in to the respective spray .i section 22, 24, 26, 30, 32 or 34 and then on to the crops.

Control by this method is independent of the speed of the vehicle 12 and typically allows a maximum speed of 400% of the minimum effective speed. In addition, if only one spray line is required of a certain nozzle size, that line can be manually selected without the need to change all the nozzles in the spray line.

It is to be considered within the scope of the present invention if more than two pressure threshold points are used and/or more than two spray lines are used.

It is also considered to be with in the scope of the present invention if a different number of spray rows are used.

Modifications and variations as would be apparent to the stated addressee are deemed to be within the scope of the present invention.

Claims (9)

1. A spray system comprising: a plurality of spray lines arranged to be mounted to a vehicle, each spray line being arranged to spray a common area of ground; at least one control valve provided on each of the spray lines to control the flow of a fluid to the spray line; a pressure measuring means arranged to measure the pressure of the fluid supplied to the spray lines, the pressure being relative to the speed of travel of the vehicle; and a control means arranged such that when a pressure corresponding to one or more first :0 pressure threshold values is sensed by the pressure measuring means, the control 00. means opens the or each control valve on a respective spray line and when a pressure :•.000 corresponding to one or more second pressure threshold values is sensed by the *pressure measuring means, the control means closes the or each control valve on a 9 o00 respective spray line. .0 o:

2. A spray system in accordance with claim 1, wherein the first pressure o threshold value corresponding to a particular spray line is higher than the second 0**o o pressure threshold value corresponding to that spray line and the control means is arranged such that if the pressure of the fluid is between the first pressure threshold value and the second pressure threshold value then the control valves retain their previous state, such that oscillation will not occur between opening and closing the or each control valve on the spray line.

3. A spray system in accordance with claim 1 or 2, wherein each spray line comprises a plurality of spray sections, each spray section being provided with a respective control valve.

4. A spray system in accordance claim 3, wherein a row of spray sections generally parallel to the direction of travel of the vehicle may be disabled from spraying.

A spray system in accordance with any one of the preceding claims, wherein a manual override is provided for spraying from a single spray line only or for spraying from all spray lines.

6. A spray controller for controlling a plurality of spray lines mounted on a vehicle arranged to spray a common area of ground comprising: a pressure measuring means arranged to measure the pressure of the fluid supplied to *°o the spray lines the pressure of fluid supplied being relative to the speed of travel of the vehicle; and and a control means arranged such that when a pressure corresponding to one or more first pressure threshold values is sensed by the pressure measuring means, the control means opens one or more control valves on a respective spray line and when a o*oo pressure corresponding to one or more second pressure threshold values is sensed by the pressure measuring means, the control means closes the or each control valve on a respective spray line. •1

7. A spray controller in accordance with claim 6, wherein the first pressure threshold value corresponding to a particular spray line is higher than the second pressure threshold value corresponding to that spray line and the control means is arranged such that if the pressure of the fluid is between the first pressure threshold value and the second pressure threshold value then the control valves retain their previous state, such that oscillation will not occur between opening and closing the or each control valve on the spray line. OFF:

8. A spray controller in accordance with claim 6 or 7, wherein each spray line comprises a plurality of spray sections, each spray section having a respective control valve and the spray controller allows for rows of spray sections to be disabled from spraying.

9. A spray controller in accordance with any one of claims 6 to 8, wherein a manual override is provided for spraying from a single spray line only or for spraying from all spray lines. A spray system substantially as hereinbefore described with reference to the attached drawings. o' 11. A spray controller substantially as hereinbefore described with reference to the go attached drawings. DATED THISil9h DAY OF DECEMBER 2000 I GAVIN JOHN DAVIS By his Patent Attorneys LORD COMPANY PERTH, WESTERN AUSTRALIA o *o