Work machine with power optimization

Abstract

A mobile work machine is provided with a prime mover supported by a chassis, a first hydraulic pump driven by the prime mover, a work attachment powered by the prime mover, and a traction system. The traction system can include a ground engagement assembly for propelling the chassis. The mobile work machine can include an electronic controller configured to execute a traction speed control algorithm in which the position of the power reduction device is operated by the electronic controller to reduce available fluid pressure to a traction control device without receiving an actual traction speed feedback signal at the electronic controller. Alternatively, or in addition, a commanded position of the power reduction control device can be calculated by the electronic controller as a function of a requested prime mover operating speed demand reduced by a calculated adjustment factor.

1 - 20 . (canceled) 
     
     
         21 . A mobile work machine comprising:
 a) a prime mover supported by a chassis;   b) a traction system including:
 i) a ground engagement assembly for propelling the chassis; 
 ii) a hydraulic pump driven by the prime mover; 
 iii) a hydraulic motor for driving the ground engagement assembly, the hydraulic motor being powered by the hydraulic pump; 
 iv) a user-operated traction control device for controlling a hydraulic fluid flow to a control input of the hydraulic pump; 
 v) a power reduction device for controlling a hydraulic fluid flow to the traction control device; and 
 vi) a user-selected traction speed control input; 
   c) a work attachment powered by the prime mover; and   d) an electronic controller for operating the prime mover and the power reduction device, the electronic controller being configured to:
 i) operate the prime mover at a requested operating speed based on a user-selected input; 
 ii) monitor an actual operating speed of the prime mover; and 
 iii) execute a traction speed control algorithm when the electronic controller has verified that the user-selected traction speed control input has been activated and when actual operating speed of the prime mover relative to the requested operating speed meets a threshold condition in which the position of the power reduction device is operated by the electronic controller to reduce available fluid pressure to the traction control device without receiving an actual traction speed feedback signal at the electronic controller. 
   
     
     
         22 . The mobile work machine of  claim 21 , wherein the user-selected traction speed control input is a button or switch. 
     
     
         23 . The mobile work machine of  claim 22 , wherein the button or switch is located on a control console located at the rear end of the work machine. 
     
     
         24 . The mobile work machine of  claim 21 , wherein the mobile work machine is a compact utility loader with operator controls and a standing platform located at a rear end of the work machine. 
     
     
         25 . The mobile work machine of  claim 21 , wherein the prime mover is one or both of an internal combustion engine and an electric motor. 
     
     
         26 . The mobile work machine of  claim 21 , wherein the threshold condition is a fixed value. 
     
     
         27 . A mobile work machine comprising:
 a) a prime mover supported by a chassis;   b) a traction system including:
 i) a ground engagement assembly for propelling the chassis; 
 ii) a hydraulic motor for driving the ground engagement assembly; 
 iii) a power reduction device for controlling hydraulic fluid flow to the traction control device; and 
 iv) a user-operated traction control device for controlling hydraulic fluid flow to the hydraulic motor, the traction control device including a first traction control device for controlling hydraulic fluid flow from a first hydraulic pump directly to a first hydraulic motor and including a second traction control device for controlling hydraulic fluid flow from a second hydraulic pump directly to a second hydraulic motor, and wherein the power reduction device controls fluid flow from the first and second hydraulic pumps to the first and second traction control devices; 
   c) a work attachment powered by the prime mover; and   d) an electronic controller for operating the prime mover and the power reduction device, the electronic controller being configured to:
 i) operate the prime mover at a requested operating speed based on a user-selected input; 
 ii) monitor an actual operating speed of the prime mover; 
 iii) execute a traction speed control algorithm when the actual operating speed of the prime mover relative to the requested operating speed meets a threshold condition in which the position of the power reduction device is operated by the electronic controller to reduce available fluid pressure to the traction control device. 
   
     
     
         28 . The mobile work machine of  claim 27 , wherein the position of the power reduction device is calculated without receiving an actual traction speed feedback signal at the electronic controller. 
     
     
         29 . The mobile work machine of  claim 27 , wherein the power reduction device is a control valve assembly and the prime mover is one or both of an internal combustion engine and an electric motor. 
     
     
         30 . The mobile work machine of  claim 29 , wherein the traction control device delivers hydraulic fluid used as pilot pressure to control the position of a swashplate of the first and second hydraulic pumps. 
     
     
         31 . The mobile work machine of  claim 29 , wherein the control valve assembly is a two position, three-port valve. 
     
     
         32 . A mobile work machine comprising:
 a) a prime mover supported by a chassis;   b) a traction system including:
 i) a ground engagement assembly for propelling the chassis; 
 ii) a hydraulic pump driven by the prime mover; 
 iii) a hydraulic motor for driving the ground engagement assembly, the hydraulic motor being powered by the hydraulic pump; 
 iv) a power reduction device for controlling a hydraulic fluid flow to a traction control device; and 
 v) a control console including:
 A) the user-operated traction control device for controlling a hydraulic fluid flow to a control input of the hydraulic pump; 
 B) a first user-operated input for setting one or both of a maximum allowable traction speed and a maximum prime mover torque via operation of the power reduction device; 
 
   c) a work attachment powered by the prime mover; and   d) an electronic controller for operating the prime mover and the power reduction device, the electronic controller being configured to:
 i) operate the prime mover at a requested operating speed based on a user-selected input; 
 ii) monitor an actual operating speed of the prime mover; and 
 iii) execute a traction speed control algorithm in which the position of the power reduction device is operated by the electronic controller to reduce available fluid pressure to the traction control device without receiving an actual traction speed feedback signal at the electronic controller, wherein the traction speed control algorithm is executed when either or both of the actual operating speed of the prime mover relative to the requested operating speed meets a threshold condition and when the maximum allowable traction speed or maximum prime mover torque set by the first user-operated input has been exceeded. 
   
     
     
         33 . The mobile work machine of  claim 32 , wherein the first user-operated input is a physical switch or is accessed via a touch screen. 
     
     
         34 . The mobile work machine of  claim 32 , further including a second user-operated input, wherein the execution of the traction speed control algorithm based on the threshold condition being met is prevented unless the second user-operated input has been positioned or selected to enable the traction speed control algorithm. 
     
     
         35 . The mobile work machine of  claim 32 , wherein the mobile work machine is a compact utility loader with the control console and a standing platform being located at a rear end of the work machine. 
     
     
         36 . The mobile work machine of  claim 32 , wherein the prime mover is one or both of an internal combustion engine and an electric motor. 
     
     
         37 . The mobile work machine of  claim 32 , wherein the threshold condition is a fixed value.