Automatic Swing and Radius Control System and Method for a Machine Implement

Abstract

Systems and methods are provided for automatically controlling operation of an implement provided on a machine. A swing angle of an arm on which the implement is provided may be controlled by determining actual and desired swing angles, generating a swing angle error, and automatically operating actuators on the machine to align the implement along the desired swing angle. An effective radius of the implement assembly may similarly be controlled by determining actual and desired effective radii, generating a radius error, and automatically operating actuators on the machine to move the implement to the desired effective radius.

What is claimed is: 
     
         1 . A method of automatically controlling a swing angle of an arm on a machine so that an implement coupled to the arm is positioned along a desired swing angle that intersects a target point, the machine including a swing actuator configured to rotate the arm about a swing rotational axis, the method comprising:
 determining a first actual position associated with a first reference point on the machine;   determining a second actual position associated with a second reference point on the machine;   determining a target position associated with the target point;   determining an actual swing angle based on the first and second actual positions;   determining the desired swing angle based on the first actual position and the target position;   determining a swing angle error based on a difference between the actual swing angle and the desired swing angle; and   automatically operating the swing actuator to reduce the swing angle error.   
     
     
         2 . The method of  claim 1 , in which the first reference point comprises a first GPS sensor and the second reference point comprises a second GPS sensor, and in which the first actual position, second actual position, and target position are determined using a GPS system. 
     
     
         3 . The method of  claim 2 , in which
 the arm is coupled to a operator station;   the first GPS sensor is coupled to the operator station and is positioned along a longitudinal operator station axis proximate to a rear wall of the operator station; and   the second GPS sensor is coupled to the implement.   
     
     
         4 . The method of  claim 3 , in which the swing actuator is operably coupled to the operator station and the swing rotational axis is coaxial with a vertical operator station axis. 
     
     
         5 . The method of  claim 1 , in which the swing actuator is automatically operated until the swing angle error is substantially zero. 
     
     
         6 . A system for automatically controlling a swing angle of an arm provided on a machine so that an implement coupled to the arm is positioned along a desired swing angle that intersects a target point, the system comprising:
 an operator station supported for rotation about a vertical operator station axis and coupled to the arm;   a swing actuator operably coupled to the operator station and configured to rotate the operator station and arm relative to a swing axis substantially coincident with the vertical operator station axis;   a first reference point associated with the operator station;   a second reference point associated with the implement;   a controller operably coupled to the swing actuator and configured to:
 determine a first actual position associated with the first reference point on the machine; 
 determine a second actual position associated with the second reference point on the machine; 
 determine a target position associated with the target point; 
 determine an actual swing angle based on the first and second actual positions; 
 determine the desired swing angle based on the first actual position and the target position; 
 determine a swing angle error based on a difference between the actual swing angle and the desired swing angle; and 
 automatically operate the swing actuator to reduce the swing angle error. 
   
     
     
         7 . The system of  claim 1 , in which:
 the first reference point comprises a first GPS sensor communicatively coupled to the controller;   the second reference point comprises a second GPS sensor communicatively coupled to the controller; and   the controller communicates with a GPS system to determine the first actual position, second actual position, and target position.   
     
     
         8 . The system of  claim 7 , in which
 the first GPS sensor is coupled to the operator station and is positioned along an operator station axis proximate to a rear wall of the operator station; and   the second GPS sensor is coupled to the implement.   
     
     
         9 . The system of  claim 6 , in which the controller is configured to automatically operate the swing actuator until the swing angle error is substantially zero. 
     
     
         10 . A method of automatically controlling an effective radius of an arm linkage provided on a machine so that an implement coupled to the arm linkage is aligned with a target point, the machine including at least one arm linkage actuator configured to rotate about an arm linkage axis to adjust the effective radius of the arm linkage, the method comprising:
 determining a first actual position associated with a first reference point on the machine;   determining a second actual position associated with a second reference point on the machine;   determining a target position associated with the target point;   determining an actual effective radius based on a distance between the first actual position and the second actual position;   determining a desired effective radius based on a distance between the first actual position and the target position;   determining an effective radius error based on a difference between the actual effective radius and the desired effective radius; and   automatically operating the at least one arm linkage actuator to reduce the effective radius error.   
     
     
         11 . The method of  claim 10 , in which the first reference point comprises a first GPS sensor and the second reference point comprises a second GPS sensor, and in which the first actual position, second actual position, and target position are determined using a GPS system. 
     
     
         12 . The method of  claim 11 , in which:
 the arm is coupled to a operator station;   the first GPS sensor is coupled to the operator station and is positioned along a longitudinal operator station axis proximate to a rear wall of the operator station; and   the second GPS sensor is coupled to the implement.   
     
     
         13 . The method of  claim 12 , in which:
 the arm linkage includes a boom pivotably coupled to the operator station and supported for rotation about a boom axis, and a stick pivotably coupled to the boom and supported for rotation about a stick axis;   the machine includes a boom actuator operably coupled to the boom and a stick actuator operably coupled to the stick;   the arm linkage axis comprises at least one of the boom axis and the stick axis; and   the arm linkage actuator comprises at least one of the boom actuator and the stick actuator.   
     
     
         14 . The method of  claim 13 , further comprising:
 determining an initial elevation of the implement above a work surface prior to automatically operating the at least one arm linkage actuator; and   maintaining the implement at the initial elevation as the at least one arm linkage actuator is automatically operated.   
     
     
         15 . The method of  claim 10 , in which the at least one arm linkage actuator is automatically operated until the effective radius error is substantially zero. 
     
     
         16 . A system for automatically controlling an effective radius of an arm linkage provided on a machine so that an implement coupled to the arm linkage is aligned with a target point, the system comprising:
 an operator station supported for rotation about a vertical operator station axis and coupled to the arm linkage;   an arm linkage actuator operably coupled to the arm linkage and configured to rotate about an arm linkage axis to adjust the effective radius of the arm linkage;   a first reference point associated with the operator station;   a second reference point associated with the implement;   a controller operably coupled to the arm linkage actuator and configured to:
 determine a first actual position associated with the first reference point; 
 determine a second actual position associated with the second reference point; 
 determine a target position associated with the target point; 
 determine an actual effective radius based on a distance between the first actual position and the second actual position; 
 determine a desired effective radius based on a distance between the first actual position and the target position; 
 determine an effective radius error based on a difference between the actual effective radius and the desired effective radius; and 
 automatically operate the arm linkage actuator to reduce the effective radius error. 
   
     
     
         17 . The system of  claim 16 , in which:
 the first reference point comprises a first GPS sensor communicatively coupled to the controller;   the second reference point comprises a second GPS sensor communicatively coupled to the controller; and   the controller communicates with a GPS system to determine the first actual position, second actual position, and target position.   
     
     
         18 . The system of  claim 17 , in which
 the first GPS sensor is coupled to the operator station and is positioned along an operator station axis proximate to a rear wall of the operator station; and   the second GPS sensor is coupled to the implement.   
     
     
         19 . The system of  claim 18 , in which:
 the arm linkage includes a boom pivotably coupled to the operator station and supported for rotation about a boom axis, and a stick pivotably coupled to the boom and supported for rotation about a stick axis;   a boom actuator is operably coupled to the boom;   a stick actuator is operably coupled to the stick;   the arm linkage axis comprises at least one of the boom axis and the stick axis; and   the arm linkage actuator comprises at least one of the boom actuator and the stick actuator.   
     
     
         20 . The system of  claim 13 , in which the controller is further configured to:
 determine an initial elevation of the implement above a work surface prior to automatically operating the at least one arm linkage actuator; and   maintain the implement at the initial elevation as the at least one arm linkage actuator is automatically operated.   
     
     
         21 . The system of  claim 16 , in which the controller is configured to automatically operate the arm linkage actuator until the effective radius error is substantially zero.