Patent Publication Number: US-2021172444-A1

Title: System For Distributing Particulate Material From An Agricultural Machine

Description:
FIELD OF THE INVENTION 
     The present invention pertains to agricultural equipment and, more specifically, to a system for distributing or spreading particulate material from an agricultural machine by determining a product application rate for distributing the particulate material and a ground speed of the agricultural machine, and by determining a fan speed for achieving the product application rate at the ground speed. 
     BACKGROUND OF THE INVENTION 
     Agricultural product delivery systems are known to utilize various mechanisms, including mechanical and pneumatic systems to move granular or particulate material or product, such as fertilizer, seed, insecticide or herbicide, from a product supply chamber, through a series of elongated tubes that extend from a product supply chamber to a product applicator, and placing the product on, or in a growing medium, such as soil. Such agricultural product delivery systems are commonly employed in planters, air drills, fertilizer and pesticide applicators and a variety of other agricultural implements. 
     In such agricultural product delivery systems, engine speed and ground speed are typically proportional to one another, and in hydrostatic drive product application systems, the fan speed for metering material onto an agricultural field is typically proportional to the engine speed. However, at certain times, such as during deceleration upon approaching turns, proportionality between engine speed and ground speed can be lost with engine speed dropping much more rapidly than ground speed. This loss in engine speed can cause a loss in fan speed necessary for metering material at the correct rate for the given ground speed. As a result, metered material can appear to “pulse” onto the ground with uneven spreading. A need therefore exists to provide a system for distributing particulate material from an agricultural machine which eliminates one or more of the foregoing disadvantages. 
     SUMMARY OF TEIE INVENTION 
     The present invention provides a control system configured to reference a data structure, such as a look up table, to variably control fan speed based on ground speed of an agricultural machine, independent of engine speed of the machine, to achieve a given application rate for a field. In one aspect, the control system can control a Pulse Width Modulation (PWM) solenoid to a pump causing a transfer of a given amount of fluid to achieve a correct fan speed according to the data structure. As a result, fan speeds can be prescribed for any application rate, such as a light application rate of 100 pounds per acre, with slowing the fan down, or a heavy application rate of 1000 pounds per acre, with speeding the fan up, all as a function of ground speed, while decoupled from engine speed. This can allow conserving horsepower by keeping the fan speed to only levels which are necessary for the application rate. 
     In one aspect, a control system can reference a look up table for precisely controlling fan speed in a hydraulic system based on ground speed to ensure a given application rate is continuously satisfied. For example, the machine may be running in the field at 18 mph (miles per hour) with an engine speed of 2100 RPM (revolutions per minute) and a corresponding fan speed of 6000 RPM (pump being 75% stroked) delivering a desired 600 pounds per acre. When decelerating to 14 mph, such as when approaching an 8 mph turn, the engine speed might drop to 1300 RPM, which might ordinarily result in the fan speed dropping to about 3714 RPM (pump being 75% stroked). However, this fan speed may be too low for the application rate (lower than 600 pounds per acre) at the 14 mph ground speed. Instead of allowing such a drop in fan speed, according to the invention, the control system can reference the look up table, such as at the 600 pounds per acre application rate and the 14 mph speed, and using a hydrostatic drive system, precisely control the fan speed to an improved 4667 RPM to continue to meet the given application rate (600 pounds per acre) for the ground speed (by changing the pump to be 100% stroked). In one aspect, the system can allow electronic control of a swash plate of a hydrostatic pump which can be changeable on demand. Different stroke/set-points can be used for different machine speeds according to the look up table. 
     In one aspect, the invention can provide variable fan speed control. One or more hydraulic configurations can be used to produce such variable fan speed control, including: a variable displacement pump in a hydrostatic (closed-loop) system with one or more variable or fixed-displacement motors; a variable displacement pump in an open-loop system with one or more variable or fixed-displacement motors; a fixed displacement pump with one or more variable-displacement motors; and a fixed displacement pump with a fixed-displacement motor and a hydraulic valve configured to control the flow rate of oil sent to the motor. 
     Specifically then, one aspect of the present invention can provide a system for distributing or spreading particulate material from an agricultural machine, the system including: a fan configured to provide an airflow in a supply line for distributing particulate material; a hydraulic system configured to drive the fan at multiple fan speeds; and a control system configured to control the hydraulic system, the control system executing a program stored in a non-transient medium operable to; determine a given product application rate for distributing the particulate material; determine a given ground speed of the agricultural machine; determine a fan speed for achieving the given product application rate at the given ground speed; and control the hydraulic system to drive the fan at the fan speed. 
     Another aspect of the present invention can provide a method for distributing or spreading particulate material from an agricultural machine, the method including: configuring a fan to provide an airflow in a supply line for distributing particulate material; configuring a hydraulic system to drive the fan at multiple fan speeds; determining a given product application rate for distributing the particulate material; determining a given ground speed of the agricultural machine; determining a fan speed for achieving the given product application rate at the given ground speed; and controlling the hydraulic system to drive the fan at the fan speed. 
     Other aspects, objects, features, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustration, there are shown in the drawings certain embodiments of the present invention. It should be understood, however, that the invention is not limited to the precise arrangements, dimensions, and instruments shown. Like numerals indicate like elements throughout the drawings. In the drawings: 
         FIG. 1  illustrates an isometric view of an exemplary embodiment of an agricultural application implement, in the form of a dry granular applicator, comprising a system for distributing particulate material in accordance with an aspect of the present invention; 
         FIG. 2  illustrates a side elevation view of the applicator of  FIG. 1 ; 
         FIG. 3  illustrates a schematic view of a system for distributing particulate material in accordance with an aspect of the present invention; and 
         FIG. 4  illustrates a data structure in the form of a graph for determining fan speed in accordance with an aspect of the present invention. 
     
    
    
     While the invention is described herein in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIGS. 1 and 2 , there is shown an agricultural application implement  10 , which could be a dry pneumatic granular applicator, which can include a system for unloading particulate material in accordance with an aspect of the present invention. As is known in the art, implement  10  generally includes a large wheeled transport unit  12  such as truck or tractor, and laterally extending particle delivery booms  14  and  16 , which may be pivoted to a stowed position close to the implement for storage or transport. Each boom  14 ,  16  extends laterally from the implement  10  in opposite directions. Each boom  14 ,  16  includes a plurality of boom sections  17 , such as left outer and left inner boom sections  17   a,    17   b  of boom  14 , and right inner and right outer boom sections  17   c,    17   d  of boom  16 . Each boom section  17  is defined by a large diameter supply line  102  for supplying the boom section with airflow from one or more fans  110  and entrained granular or particulate material, such as seed, fertilizer, herbicide, insecticide and the like. Each boom section  17  includes a plurality of boom tubes or conduits terminating at particle delivering units, which for the implement  10  are spreading outlets or nozzles. In the exemplary embodiment shown, left outer boom section  17   a  of boom  14  includes five nozzles  18 ,  19 ,  20 ,  22  and  24 ; left inner boom section  17   b  of boom  14  includes five nozzles  26 ,  28 ,  29 ,  30  and  32 ; right inner boom section  17   c  of boom  16  includes five nozzles  34 ,  35 ,  36 ,  38  and  40 ; and right outer boom section  17   d  of boom  16  includes five nozzles  42 ,  44 ,  45 ,  46  and  48 . Additionally, at the back of implement  10  there is a centrally mounted rear boom section  17   e  also defined by a large diameter supply line  102  for supplying the boom section with granular material. At the rear boom section  17   e  are five rear nozzles  50 ,  52 ,  54 ,  56  and  58  to provide full and complete coverage across the width of implement  10 , including the area between the inboard-most nozzles  32  and  34  of booms  14 ,  16 . The rear boom section  17   e  allows spread of the particulate material/product over/onto the ground over which the implement  10  passes for complete coverage. Although five boom sections  17 , with five nozzles per boom section, is shown by way of example, in other aspects greater or fewer boom sections  17 , and/or greater or fewer nozzles per boom section  17 , can be provided within the scope of the invention. 
     The transport unit  12  can be self-propelled by an engine in an engine compartment  59  and can include an operator cab  60  having a Human Machine Interface (HMI) available to the user. The transport unit  12  can comprise a frame  90  supported by wheels  92 . In the exemplary embodiment shown, an uncovered tank  62 , open to the environment and ambient atmospheric conditions, includes compartments  66  and  70  for carrying particulate material to be distributed by a metering array  80  for ultimate disbursement by nozzles  18 - 58 . Further smaller compartments  64  and  68  are provided to supply micro-nutrients or other materials to the metering array  80 . The supply of particulate in compartments  64 ,  66 ,  68 ,  70  can be replenished periodically from a supply vehicle (not shown). The tank  62  could have, for example, a capacity of about 350 cubic feet and/or 11 tons. 
     With additional reference to  FIG. 3 , a schematic view of a system  120  for distributing particulate material, which system can be implemented on the implement  10 , is provided in accordance with an aspect of the present invention. The system  120  can include a hydraulic system  122  configured to drive the one or more fans  110  at multiple fan speeds. The system  120  can receive mechanical power from an engine  124  in the engine compartment  59 , such as by way of rotation of a crankshaft  126  connected to the hydraulic system  122 , to derive hydraulic power for driving the one or more fans  110 . In one aspect, the hydraulic system  122  can comprises a hydrostatic drive arrangement including a variable axial piston pump  128 , or variable displacement pump, configured to drive a hydraulic motor  130 , which in turn drives the one or more fans  110 , and a hydraulic tank  132  in a fan control circuit. 
     A control system  134  can be configured to precisely control the hydraulic system  122  and the hydraulic power delivered therefrom. In one aspect, the control system  134  can execute a program  136  stored in a non-transient medium  138  operable to: determine a given product application rate for distributing particulate material, via the metering array  80 , the supply lines  102  and the sections  17 ; determine a given ground speed of the implement  10 ; determine a fan speed for achieving the given product application rate at the given ground speed; and control the hydraulic system  122  to drive the one or more fans  110  at the determined fan speed. The control system  134  can determine the given product application rate for distributing particulate material from a current location on prescription map. The location could be detected, for example, by a location sensor  140 , such as Global Positioning System (GPS), and compared to prescription map  142  stored in the non-transient medium  138 . The control system  134  can also determine the given product application rate for distributing particulate material from input from an HMI  144  available to the user in the operator cab  60 . The control system  134  can determine the given ground speed of the implement  10 , or current speed, from a vehicle speed sensor  146 . The control system  134  can then execute to determine a fan speed for the one or more fans  110  for achieving the given product application rate at the given ground speed. The control system  134  can then control the hydraulic system  122  to drive the one or more fans  110  at the determined fan speed, such as by controlling a Pulse Width Modulation (PWM) signal  150  provided to a solenoid  152  to selectively adjust the angle of swashplate contained in the variable axial piston pump  128 . Moreover, the control system  134  can execute a closed loop control system by sensing feedback from the hydraulic motor  130  corresponding to actual fan speed via RPM sensor  154 , calculating an error between the actual fan speed and the determined fan speed operating as a setpoint, and driving the pump  128  to more quickly and efficiently achieve the determined fan speed. 
     Accordingly, despite the engine  124  being configured to drive the hydraulic system  122  at multiple engine speeds, the hydraulic system  122  is operable to drive the one or more fans  110  at multiple fan speeds independently from the engine  124 . Nevertheless, the control system  134  could communicate with the engine  124 , such as via a Controller Area Network (CAN) bus  156  and CAN controller  158  of the engine, to detect such engine speeds. 
     In one aspect, the control system  134  can determine the fan speed for achieving the given product application rate at the given ground speed by calculating and/or referencing a data structure  160 , such as a look up table, stored in a non-transient medium  138 . The data structure  160  can correlate multiple fan speeds, for the one or more fans  110 , to multiple ground speeds, for the implement  10 , at given product application rates. For example, with additional reference to  FIG. 4 , the control system  134  can reference a first data structure  160   a  corresponding to a product application rate, such as a spread or distribution of 600 pounds per acre from a compartment of tank  62 , desired according to a current location on the prescription map  142  and/or an input from the HMI  144 . The control system  134  can then detect the ground speed of the implement  10 , such as 18 mph, from the vehicle speed sensor  146 . The control system.  1 . 34  can then control the hydraulic system  122  to drive the one or more fans  110  at a corresponding fan speed for the ground speed, such as 6000 RPM for 18 mph, via the PWM signal  150  adjusting tilt of the swashplate. The fan speeds of the data structure  160  can be correlated to ground speeds of the implement  10  according to a predetermined configuration of the implement  10 , including a length and/or a diameter of supply lines  102 , arrangement of sections  17  and/or nozzles  18 - 58 , and the like. 
     If the desired application rate changes, such as due to a change in location and/or input to the HMI  144 , control system  134  can reference a second data structure and/or calculation appropriate for the revised application rate. If the desired application rate stays the same, but the speed of the implement  10  changes to a new ground speed, such as decelerating to 14 mph when approaching an 8 mph turn, the control system  134  can control the hydraulic system  122  to drive the one or more fans  110  at a new fan speed corresponding to the new ground speed, such as 4667 RPM, via the PWM signal  150  further adjusting tilt of the swashplate. As a result, fan speeds can be prescribed for any application rate, all as a function of ground speed, while decoupled from engine speed. This can allow conserving horsepower by keeping the fan speed to only levels which are necessary for the application rate. 
     Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the above invention is not limited thereto. It will be manifest that various additions, modifications and rearrangements of the features of the present invention may be made without deviating from the spirit and the scope of the underlying inventive concept.