Abstract:
An agricultural power control system including a moving element, a power source, a signal generating element and a torque modifying device. The moving element is configured to engage a quantity of crop material in a cyclical manner. The power source conveys power to the moving element. The signal generating element is configured to provide a signal relating to an anticipated quantity of crop material prior to the moving element engaging the quantity of crop material. The torque modifying device is configured to cause the power source to alter an amount of torque delivered to the moving element dependent upon the signal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a tractor and baler system, and, more particularly, to an engine output modification system associated with a tractor/baler system. 
       DESCRIPTION OF THE RELATED ART 
       [0002]    A plunger type hay baler includes a frame that is hitched to a tractor and is configured to receive crop material, such as hay or straw, into a pressing channel in which the crop material is pressed and formed into a bale. The baler includes a loading mechanism in which the crop material is collected from the ground and is then routed into the pressing channel in a manner that is synchronous with a plunger that moves in the pressing channel. As the plunger moves in a reciprocating manner in the pressing channel, each new flake of crop material is moved into the channel and is compacted into the bale. After a sufficient amount of crop material has been compressed, a twine threading mechanism inserts a twine through a portion of the compressed material and the twine is then knotted to complete the binding of the bale. The bale proceeds through the pressing channel and is ejected from the baling machine. 
         [0003]    The power requirements to run the baler are cyclical in nature since the crop material is introduced prior to the movement of the plunger in each reciprocating cycle. As the plunger compresses the material, it causes a reduction in the power take-off speed due to the increased load. The increased load is reflected back to the tractor and the engine compensates for the increased load by increasing the power output. The problem with this increased power output is that it lags the power requirement thereby causing the engine to overreact and overshoot after each load of the cycle of the plunger has been completed. One method to reduce this problem has been to have rotating masses associated with the baler to thereby reduce the PTO speed reduction and the engine overshoot. However, this method along with others has been ineffective in addressing the timing of the power production with the need for the power during the cyclical operation of the baler. 
         [0004]    What is needed in the art is a system that can coordinate the engine power production with the anticipated torque requirements of the baler. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention relates to a tractor baler interface system. 
         [0006]    The invention in one form is directed to an agricultural power control system including a moving element, a power source, a signal generating element and a torque modifying device. The moving element is configured to engage a quantity of crop material in a cyclical manner. The power source conveys power to the moving element. The signal generating element is configured to provide a signal relating to an anticipated quantity of crop material prior to the moving element engaging the quantity of crop material. The torque modifying device is configured to cause the power source to alter an amount of torque delivered to the moving element dependent upon the signal. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a side view of a tractor/baler system utilizing an embodiment of a method of the present invention. 
           [0008]      FIG. 2  is a schematical side view illustrating the plunger of the baler of  FIG. 1 . 
           [0009]      FIG. 3  is a graphical illustration illustrating the problem that is overcome by the present invention. 
           [0010]      FIG. 4  is a schematical block diagram illustrating the agricultural power control system including the tractor and baler of  FIGS. 1 and 2 . 
           [0011]      FIG. 5  is a schematical representation of a method utilized in the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    Referring now to the drawings, and more particularly to  FIG. 1 , there is illustrated a power control system  10  including a tractor  12  and a baler  14 . Baler  14  is hitched to tractor  12  and a power take off (PTO) shaft  16  supplies power from tractor  12  to baler  14 . As tractor  12  pulls baler  14  and baler  14  encounters crop material, crop material is fed into the baler and the crop material is processed into bales. 
         [0013]    Now, additionally referring to  FIGS. 2 and 3 , there is illustrated a side view of baler  14  having a reciprocating plunger therein. As crop material is pulled into the plunging section of baler  14 , the PTO RPM begins to reduce as the load is encountered by the plunger as illustrated in  FIG. 3 . This reduction in the PTO RPM is detected by mechanisms contained in tractor  12  and the reduced RPM of the engine that is reflective of the reducing PTO RPM is compensated for by an increase in the fuel supply to the engine there by causing the overshoot, again illustrated in  FIG. 3 . Since the cyclical nature of the crop intake is such that the engine control system acts faster than the next cycle of crop material, the engine RPM then is reduced to the nominal level and then after a short period of time the next cycle of crop material enters the baler/plunger system thereby again causing repeated reduction in engine RPM. The present invention overcomes this difficulty by anticipating the load and compensating for the anticipated torque requirement rather than reacting to the reduction in the PTO RPM. 
         [0014]    Although the foregoing description illustrates power being supplied by the engine of tractor  12 , this is for the ease of illustration and discussion. It is also to be understood that an engine may be installed on baler  14 , which would supply power to the functions of baler  14 . The interaction between baler  14  and tractor  12 , as described herein, is also applicable to the interaction with an engine installed on baler  14 . 
         [0015]    Now, additionally referring to  FIG. 4 , power control system  10  is illustrated schematically as including tractor  12  and baler  14 . Tractor  12  includes a PTO  16  that is engaged or disengaged by clutch  18  transferring power from engine  20 . Engine  20  is under the control of an engine control unit (ECU)  22  that receives a signal from torque modifier device  24 . A controller  26  also receives information from torque modifier  24  as well as operator inputs and inputs from other sensors and has controllable outputs including one that interfaces with clutch  18 . Although engine control unit  22 , torque modifier  24  and controller  26  have been illustrated and discussed as being separate controls, it is also possible that a single controller would perform all of the functions discussed herein. It is also possible that other combinations of hardware and software may carry out the functions of the present invention. 
         [0016]    Engine  20  is a power source which provides power to the various functions of tractor  12  and includes a linkage to PTO  16  by way of clutch  18 . Clutch  18  is under the control of controller  26  and includes an engaged position as well as a disengaged position thereby engaging engine  20  to PTO  16  when it is desired to provide power to an implement attached to tractor  12 . 
         [0017]    Baler  14  includes a crop intake  28  that feeds crop material into a compacting channel in which plunger  30  moves in a cyclical reciprocating manner. Sensors  32  include a sensor to detect the quantity of crop material coming in through crop intake  28  that is being supplied to the pressing channel which plunger  30  will then compress. Further, sensors  32  may be in the form of an anticipatory algorithm that makes a prediction of the amount of crop material that plunger  30  may encounter. Sensors  32  may also detect movement of baler  14  thereby providing information, which may indicate that after a limited number of cycles no more crop material will be coming into crop intake  28  based upon the non-movement of baler  14 . Baler  14  is typically connected to tractor  12  by way of a connection to a drawbar on tractor  12 . Additionally, PTO shaft  34  is drivingly connected to mechanisms that provide power to plunger  30 . Further, sensors  32  provide a signal along a communication channel  36  to torque modifier  24 . Although illustrated as sensors  32 , this may additionally include processing capability that provides a calculated torque requirement that is then passed on to torque modifier  24 . This processed sensor information that comes from element  32  allows tractor  12  to adjust the fuel and/or air mixture going to engine  20  so that the torque that is going to be required by plunger  30  is supplied while it is needed rather than lagging the needed use for torque. 
         [0018]    Further, plunger  30  will encounter crop material that is in the compacting channel from a previous cycle even if little or no additional crop material is added. The present invention anticipates the load plunger  30  will encounter, whether the load is due to the added crop material or from the positioning of the crop material in the compacting channel. The variable nature of the anticipated load is what is sensed and the information is used to alter engine performance to thereby supply torque commensurate with the load that is to be encountered. 
         [0019]    Element  32  may gauge the amount of crop material that is entering from crop intake  28  into the path of plunger  30 . The quantity of material that is going to be engaged in a cyclical manner can vary from cycle to cycle so the anticipated amount or quantity of crop material and the torque necessary to compress it is computed by element  32 , the signal containing the information regarding needed torque passes by way of communication channel  36  to torque modifier  24 . Torque modifier  24  provides information to ECU  22  thereby causing engine  20  to increase in torque output by increasing the fuel and/or air supply for a commanded amount of time. The occurrence as well as the duration of the transitional torque computed by the system is based on input from sensors  32 . Sensors  32  may utilize a comparative routine in which the amount of crop material previously encountered by plunger  30  is compared to the current measured amount of crop material and the necessary torque requirement developed based upon previous observations. Additionally, the algorithm in sensors  32  may additionally have predetermined time durations of torque based upon observational input from the sensors associated therewith to provide the signal representative of the amount and duration of torque needed by baler  14 . 
         [0020]    When controller  26  detects input from an operator indicating that clutch  18  should be disengaged, then this information is additionally passed along to torque modifier  24  so that signals from sensors  32  will be ignored when clutch  18  is disengaged. The feedback from baler  14  should be disregarded since engine  20  is no longer going to provide power to baler  14  due to the disengagement of clutch  18 . 
         [0021]    Now, additionally referring to  FIG. 5  there is schematically shown a method  100  that further illustrates the method of the present invention. At step  102 , a load is anticipated such as a new flake of crop material being detected. Method  100  proceeds to step  104 . If no increased load is anticipated, such as no new crop material being detected by sensors  32 , then method  100  returns to the beginning of the method. At step  104 , inputs from sensors  32  are considered. The inputs that are considered may include the last cycle engine pulldown, exemplified by either a speed or fuel usage change, the last plunger force measurement, the plunger speed, the plunger position and of course the detected crop intake. Based on the inputs that are received, the engine adjustment is determined at step  106 . This adjustment includes the amount and duration of torque requirement needed to process the new flake detected at step  102 . The determination considers the previous cycle or cycles of plunger  30  as well as the current plunger speed and plunger position. Method  100  then proceeds to step  108  where the necessary adjustments to the fuel and/or air intake for engine  20  is modified for the anticipated duration of crop encountering the cycle of plunger  30 . Step  108  is timed to correspond with a determined plunger position that may be adjusted based upon the current plunger speed. For example, if the plunger speed is above the nominal amount then the increased torque requirement might be reduced to accommodate the inertia that is contained in the current plunger speed. 
         [0022]    The present invention helps to control the speed change of the engine as well as the jerk encountered by the baler. Initially in the crop baling cycle, there is a pulldown of the engine during the high impulse compression part of the plunger cycle and the overshoot of the engine responds to the plunger pulse after the event has been eventually completed. The present invention overcomes this disadvantage. One embodiment reduces the initial engine pulldown by using a short “micro-burst” engine speed increase to compensate for the anticipated load. To reduce the overshoot, ECU  22  can also “freeze” the engine control that includes engine speed and fuel rate and prevent the system from overreacting. An additional advantage of the present invention is that it allows the baler to communicate with the tractor thereby tailoring the engine response to the anticipated load of the implement, herein represented by baler  14 . This reduces the engine speed changes while baling, it reduces fuel usage and offers less operator fatigue since the system is not cycling the engine from an under speed to an over speed condition. 
         [0023]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.