Research on Pressure Control of an Electro-Hydraulic Servo System Based on Sliding-Mode Variable-Structure Direct Torque Control

Taking a direct-drive volume control (DDVC) electro-hydraulic servo system as the research object and aiming at problems of motor torque fluctuation, high-precision pressure control, dynamic response system, based on traditional direct (DTC), method sliding-mode variable structure is proposed to pressure. The loop part inner has rapid speed, resulting in higher accuracy. A nonlinear mathematical model was established for DDVC system. switch meter hysteresis controller DTC replaced with space vector pulse-width modulation technology. Then, PID module technology high-order variable-structure control. Through coupling relationship between electric machine constant-displacement pump, can be controlled high precision using Finally, MATLAB/Simulink simulation platform model, theoretical approach verified basis simulations experiments, performance regard hydraulic observed. experimental results show that designed able effectively reduce fluctuation improve characteristics superior methods speed regulation, it accuracy better response.