Method and apparatus for controlling an implement of a work machine

A method for controllably moving a work implement of an earth moving machine in response to the position of an operator controlled joystick, the work implement including a boom and a bucket being attached thereto, the work implement including a plurality of work functions that includes a lifting and lowering function where the boom is actuated by a hydraulic lift cylinder and dumping and racking function where the bucket is pivoted by a hydraulic tilt cylinder, comprising the steps of:

• sensing the position of the joystick and responsively generating an operator command signal;
• sensing the elevational position of the boom and the pivotal position of the bucket, and responsively producing respective implement position signals;
• storing a look-up table for each work function, the look-up tables including a plurality of values corresponding to a plurality of work implement positions;
• receiving the implement position and operator command signals, determining the instant position of the work implement and the corresponding work function, modifying the operator command signal based on the instant work function, and producing an electrical valve signal in response to the modified operator command signal;
• and
• receiving the electrical valve signal, and controllably providing hydraulic fluid flow to the respective hydraulic cylinders in response to a magnitude of the electrical valve signal.

An apparatus for controllably moving a work implement of an earth moving machine, the work implement including a boom and a bucket being attached thereto, the work implement including a plurality of work functions that includes a lifting and lowering function where the boom is actuated by a hydraulic lift cylinder and dumping and racking function where the bucket is pivoted by a hydraulic tilt cylinder, comprising:

• an operator controlled joystick;
• joystick position sensing means for sensing the position of the joystick and responsively generating an operator command signal;
• implement position sensing means for sensing the elevational position of the boom and the pivotal position of the bucket, and responsively producing respective implement position signals;
• memory means for storing a look-up table for each work function, the look-up tables including a plurality of values corresponding to a plurality of work implement positions;
• controlling means for receiving the implement position and operator command signals, determining the instant position of the work implement and the corresponding work function, selecting a value from the respective look-up table in response to the respective work implement position, multiplying the value by the magnitude of the operator command signal, and responsively producing the electrical valve signal having a magnitude equal to the product;
• and
• valve means for receiving the electrical valve signal, and controllably providing hydraulic fluid flow to the respective hydraulic cylinders in response to a magnitude of the electrical valve signal.

A method for controllably moving a work implement of an earth moving machine in response to the position of an operator controlled joystick, the work implement including a boom and a bucket being attached thereto, the work implement including a plurality of work functions that includes a lifting and lowering function where the boom is actuated by a hydraulic lift cylinder and dumping and racking function where the bucket is pivoted by a hydraulic tilt cylinder, comprising the steps of:

• sensing the position of the joystick and responsively generating an operator command signal;
• sensing the elevational position of the boom and the pivotal position of the bucket, and responsively producing respective implement position signals;
• storing a look-up table for each work function, the look-up tables including a plurality of values corresponding to a plurality of work implement positions;
• receiving the implement position and operator command signals, determining the instant position of the work implement and the corresponding work function, selecting a value from the respective look-up table in response to the respective work implement position, multiplying the value by the magnitude of the operator command, and responsively producing the electrical valve signal having a magnitude equal to the product;
• and
• receiving the electrical valve signal, and controllably providing hydraulic fluid flow to the respective hydraulic cylinders in response to a magnitude of the electrical valve signal.