Electrohydraulic control system for automatic control of earth mover shovel

摘要

The system controls the shovel (16) of an earth moving machine, which is operated controllably by a hydraulic lifting cylinder (14) and a tilting cylinder (15). The control system includes pressure sensing facilities, for producing pressure signals in response to the hydraulic pressures, which are each associated with the lifting and tilting cylinders. Position sensing facilities are provided for producing position signals, which represent the respective extensions of the lifting and tilting cylinders. Command signal production facilities receive the position and the pressure signals, and from these compute the responding correlative force vector angle, which represents the combined forces, which react at a reference point on the shovel. Cylinder speed command signals are produced as a result, which correspond to the difference between the force vector angle and the desired angle.