Fuzzy control of direct-driven hydraulic drive without conventional oil tank

The direct-driven hydraulic drive (DDH) combines the advantages of compact high power of the hydraulic system and flexible control of the electric motor. This paper concentrates on modelling of the direct-driven hydraulic setup and investigating control challenges. In the DDH setup, the speed and position control of a double-acting cylinder is implemented directly with a Synchronous Torque Motor drive in a close-loop system without conventional valve-control. In addition to this, hydraulic accumulator is employed as a replacement of the conventional oil tank. To achieve excellent control capabilities, a fuzzy controller is designed to control the rotation speed of the motor drive. The system is investigated by means of simulations. As a result, designed controller benefits the hydraulic system.