Torque load control system and method

Abstract

A machine may include a torque producing system, and a torque consuming device including load controls operable to generate a request for torque. The machine may also include a control system coupled to the torque producing system and the load controls. The control system may be operable to receive the request for torque, determine a torque limit based on the requested torque, and communicate the torque limit to the load controls, the load controls being operable to adjust operation of the torque consuming device based on the torque limit.

1 - 46 . (canceled) 
     
     
         47 . A machine comprising:
 a torque producing system;   a torque consuming device including load controls operable to generate a request for torque; and   a control system coupled to the torque producing system and the load controls, operable to
 receive the request for torque, 
 determine a torque limit based on the requested torque and based on an amount of torque being produced by the torque producing system, and 
 communicate the torque limit to the load controls, the load controls being operable to adjust operation of the torque consuming device based on the torque limit to prevent a speed of the torque producing system from falling below a predetermined speed. 
   
     
     
         48 . The machine of  claim 47 , wherein the torque consuming device is operable to exert a torque load on the torque producing system. 
     
     
         49 . The machine of  claim 48 , wherein the torque limit sets a limit on the torque load that the torque consuming device exerts on the torque producing system. 
     
     
         50 . The machine of  claim 48 , wherein when the torque load is less than or equal to the torque limit, a speed of the torque producing system is greater than or equal to a target speed. 
     
     
         51 . The machine of  claim 50 , wherein the target speed is at or above an underspeed set point of the torque producing system. 
     
     
         52 . A machine comprising:
 a torque producing system;   one or more torque consuming devices capable of consuming torque in excess of a rated capacity of the torque producing system; and   a control system coupled to the torque producing system and the one or more torque consuming devices, the control system including a torque load control operable to limit operation of the one or more torque consuming devices based on an amount of torque being produced by the torque producing system to prevent exceeding of the rated capacity of the torque producing system and to prevent a speed of the torque producing system from falling below a predetermined speed.   
     
     
         53 . The machine of  claim 52 , wherein the torque producing system has an actual operating capacity, and the rated capacity is less than or equal to the actual operating capacity. 
     
     
         54 . The machine of  claim 52 , wherein the rated capacity is indicative of a torque producing capability of the torque producing system. 
     
     
         55 . The machine of  claim 52 , wherein the torque load control is configured to limit torque consumption to a torque limit. 
     
     
         56 . The machine of  claim 55 , wherein when torque consumption is less than or equal to the torque limit, a speed of the torque producing system is greater than or equal to a target speed. 
     
     
         57 . A machine comprising:
 a torque producing system operable within a range of operating speeds;   a torque consuming device operable to generate a signal requesting torque from the torque producing system; and   a control system coupled to the torque producing system and the torque consuming device, operable
 to maintain the torque producing system at a target operating speed as the torque requested varies by controlling torque consumed by the torque consuming device based on the torque requested, an amount of torque being produced by the torque producing system, and one or more additional machine operating parameters, and 
 to prevent a speed of the torque producing system from falling below a predetermined speed. 
   
     
     
         58 . The machine of  claim 57 , wherein the target operating speed is variable. 
     
     
         59 . The machine of  claim 57 , wherein the target operating speed is a steady state speed. 
     
     
         60 . The machine of  claim 57 , wherein the target operating speed is at or above an underspeed set point of the torque producing system, the torque producing system being susceptible to stalling when the torque producing system operates below the underspeed set point. 
     
     
         61 . The machine of  claim 57 , wherein the control system is operable to determine a torque limit, and limit the torque consumed to the torque limit. 
     
     
         62 . A method for machine modification, comprising:
 modifying a machine that includes a torque producing system to include
 a torque consuming device coupled to controls operable to provide a torque request signal based on operating parameters of the torque consuming device, and 
 a torque load control configured to
 determine a torque load limit for the torque producing system, based on an amount of torque being produced by the torque producing system, the machine being operable to control operation of the torque consuming device based on the torque load limit and the torque request signal, and 
 prevent a speed of the torque producing system from falling below a predetermined speed. 
 
   
     
     
         63 . The method of  claim 62 , wherein modifying the machine includes replacing a component of the machine with the torque consuming device. 
     
     
         64 . The method of  claim 62 , wherein modifying the machine includes adding the torque consuming device to the machine. 
     
     
         65 . The method of  claim 62 , wherein the torque consuming device is operable to exert a torque load on the torque producing system. 
     
     
         66 . The method of  claim 62 , wherein the controls are operable to provide a torque consumption signal indicative of the torque consumed by the torque consuming device. 
     
     
         67 . The method of  claim 66 , wherein the controls are operable to limit the torque consumed by the torque consuming device in response to the torque load limit. 
     
     
         68 . The method of  claim 62 , further including modifying the machine to include torque producing system controls operable to provide input signals used by torque load control to determine the torque load limit. 
     
     
         69 . A method for modifying a machine including a torque producing system, and a torque consuming device coupled to controls operable to provide a torque request signal, the method of machine modification comprising:
 modifying a control system of the machine to
 include a torque load control operable to determine a torque load limit for the torque producing system, which is based on an amount of torque being produced by the torque producing system, and 
 control an operation of the torque consuming device based on the torque load limit and the torque request signal to prevent a speed of the torque producing system from falling below a predetermined speed. 
   
     
     
         70 . The method of  claim 69 , wherein including the torque load control includes adding the torque load control to the control system. 
     
     
         71 . The method of  claim 69 , further including modifying the control system to include a torque error estimator operable to adjust the torque load limit to compensate for error. 
     
     
         72 . The method of  claim 69 , wherein controlling the operation includes maintaining a torque load exerted by the torque consuming device on the torque producing system at or below the torque load limit. 
     
     
         73 . The method of  claim 69 , wherein modifying the control system includes replacing a component of the control system with the torque load control.