RESOLVED-MODE TELEOPERATED CONTROL OF HEAVY-DUTY HYDRAULIC MACHINES

This paper addresses the control problem for a class of heavy-duty hyd raulic machines in order to achieve coordinate motion control of the i mplement. A model and sensor-based control algorithm is proposed which is applied in conjunction with closed-loop components. The algorithm is basically a feedforward load compensating scheme which uses the mea sured hydraulic line pressures along with the appropriate portion of t he hydraulic model to control the joint velocities. The effects of non linear dynamic coupling between the links, loading, coupled actuation and power limitations are compensated in this technique. The closed-lo op part consists of PD components. A knowledge of some hydraulic param eters is the only requirement of this control scheme. The proposed app roach has been examined through simulation and is supported by experim ental evidence. The experiments were performed on a Caterpillar 215B e xcavator, The control program is written in the C language, running on a computer system which is interfaced between the human operator and the machine.