Control System for Mining Machine

Abstract

A mining machine such as a mining shovel includes a digging assembly having an upward extending boom and a dipper arm generally horizontally supported by the boom. The dipper assembly includes a dipper disposed at one end of a dipper arm that can slide in translation with respect to the boom to crowd toward or retract from a vertical bank at the mining site. To translate the dipper assembly, the mining machine includes a crowd system having a crowd motor and a crowd actuator. An electronic controller receives the crowd motor torque, a crowd speed of the dipper assembly, and an inertia parameter associated with the dipper assembly. The electronic controller can determine an approximate location of the dipper with respect to the bank and, in a further aspect, can execute an anti-swing function if the dipper is in the bank.

We claim: 
     
         1 . A mining machine comprising:
 an undercarriage;   an upper structure rotatably supported to swing with respect to the undercarriage;   a digging assembly disposed on the upper structure, the digging assembly including:
 a boom connected to the upper structure at a lower end and extending upwardly to an upper end; 
 a dipper assembly including a dipper arm and a dipper disposed at a first end of the dipper arm, the dipper assembly slidably supported by the boom; 
 a crowd system for slidably moving the dipper assembly with respect to the boom in a crowd direction and in a retract direction, the crowd system including:
 a crowd motor disposed in the upper structure, 
 a crowd actuator operatively associated with the crowd motor and arranged to slide the dipper arm with respect to the boom; and 
 
   an electronic controller operatively associated with the crowd system and in electronic communication with the crowd motor, the electronic controller configured to receive a crowd speed and a crowd motor torque and to calculate a calculated crowd force and to determine an approximate location of the dipper based on the calculated crowd force.   
     
     
         2 . The mining machine of  claim 1 , wherein the electronic controller receives an inertia parameter associated with the dipper assembly and calculates the calculated crowd force based in part on the inertia parameter. 
     
     
         3 . The mining machine of  claim 2 , wherein the electronic controller converts the crowd speed to a crowd acceleration. 
     
     
         4 . The mining machine of  claim 3 , wherein the electronic controller calculates an inertial crowd force based on the inertia parameter and the crowd acceleration. 
     
     
         5 . The mining machine of  claim 4 , wherein the electronic controller calculates the calculated crowd force by subtracting the inertial crowd force from the crowd motor torque. 
     
     
         6 . The mining machine of  claim 1 , wherein the electronic controller receives a crowd force threshold and compares the crowd force threshold with the calculated crowd force to determine the approximate location of the dipper. 
     
     
         7 . The mining machine of  claim 1 , wherein the electronic controller is further configured with an anti-swing function to restrict a swing speed of the upper structure. 
     
     
         8 . The mining machine of  claim 7 , wherein the approximate location of the dipper maybe either one of an in-bank condition or an out-of-bank condition. 
     
     
         9 . The mining machine of  claim 8 , wherein the anti-swing function restricts the swing speed during the in-bank condition only. 
     
     
         10 . The mining machine of  claim 9 , wherein the electronic controller compares the calculated crowd force to a crowd force threshold to determine if the in-bank condition exists. 
     
     
         11 . The mining machine of  claim 1 , wherein the crowd actuator includes one or more crowd ropes attached to the dipper arm and disposed about a crowd drum disposed in the upper structure. 
     
     
         12 . The mining machine of  claim 11 , wherein the one or more crowd ropes include a first crowd rope attached proximate a first end of the dipper arm and a second crowd rope attached proximate a second end of the dipper arm. 
     
     
         13 . The mining machine of  claim 1 , wherein the crowd actuator is a hydraulic cylinder. 
     
     
         14 . A method of operating a mining machine comprising:
 sliding a dipper assembly in translation with respect to a boom arranged in an upward orientation on the mining machine by operation of a crowd motor;   receiving a crowd motor torque and a crowd speed;   receiving an inertia parameter associated with the dipper assembly;   calculating a calculated crowd force based in part on the crowd motor torque, the crowd speed, and the inertia parameter; and   determining an approximate location of a dipper disposed on the dipper assembly based on the calculated crowd force.   
     
     
         15 . The method of  claim 14 , further comprising converting the crowd speed to a crowd acceleration. 
     
     
         16 . The method of  claim 15 , wherein the step of calculating the calculated crowd force include determining an inertial crowd force from the crowd acceleration and the inertia parameter, and subtracting the inertia force from the crowd motor torque. 
     
     
         17 . The method of  claim 14 , wherein the approximate location of the dipper includes at least one of an in-bank condition and an out-of-bank condition. 
     
     
         18 . The method of  claim 17 , further comprising limiting a swing ability of an upper structure with respect to an undercarriage during the in-bank condition. 
     
     
         19 . An electronic controller for a mining machine having a dipper assembly slidably supported on a boom extending upwardly with respect to the mining machine, the electronic controller comprising:
 a crowd force function configured to determine a calculated crowd force based in part on a crowd motor torque generated by a crowd motor arranged to slide the dipper assembly with respect to the boom, a crowd speed of the dipper assembly sliding with respect to the boom, and an inertia parameter associated with the dipper assembly;   the crowd force function further configured to determine an approximate location of a dipper disposed on the dipper assembly based on the calculated crowd force, the approximate location including at least one of an in-bank condition and an out-of-bank condition; and   an anti-swing function configured to limit rotation of an upper structure with respect to an undercarriage about a vertical axis of the mining machine during the in-bank condition.   
     
     
         20 . The electronic controller of  claim 19 , wherein the crowd force function is further configured to convert the crowd speed to a crowd acceleration.