A Hybrid of Force and Position Control with Energy Saving in the Electro-Hydraulic System

Abstract

Generally, the electro-hydraulic system (EHS) has force and position controls. The control of these parameters to the desired value multiple PID controllers are often used, which are sensitive to changes in system parameters. In addition, the existing EHS is often used as a single proportional direction control valve (PDCV) to control those parameters that cause loss and waste energy. Therefore, in this paper, a fuzzy controller is proposed to control force and position. Simultaneously, the EHS that is used for control will be added the inverter to adjust the speed of the electric motor (EM) to drive a fixed displacement gear pump, and a proportional pressure relief valve (PPRV), in order to save energy. A proposed fuzzy controller and the EHS are implemented to the hydraulic press. The experimental results showed that the hybrid of force and position control by using a fuzzy controller has a superior performance compared to the multiple PID controllers. Moreover, the proposed EHS is also more effective in saving power consumption than conventional EHS.