Simulation and testing of a hydraulic winch

The paper presents the lumped parameter model of a hydraulic winch developed in the Simcenter Amesim environment. It includes a detailed model of a load sensing direction control valve and of an overcentre valve for controlling an orbit motor with holding brake. The model of the winch, validated on a test rig in terms of pressure drop across the motor, has been used for analyzing different control strategies for obtaining the same velocity profile of the shaft and the total hydraulic energy supplied by the load sensing pump has been evaluated. As a first step, the independent metering architecture has been implemented. An additional simplification of the system was the removal of the local pressure compensator and the control of the speed in a closed loop using as feedback signal the output of an integrated tachometer. As a last step, the overcentre valve has been removed and the overrunning load has been imposed by a meter-out control of the flow rate.