An active-disturbance-rejection controller for speed control of variable-displacement motor at the constant pressure network

The speed control of the variable-displacement hydraulic motor (VDHM) at a constant pressure network is very difficult through traditional PID (Proportion Integration Differentiation) algorithm, because of the influences from the time-varying property of the parameters, the nonlinearity and torque coupling. In this paper, a mathematical model of the VDHM system is depicted and an active disturbance rejection control (ADRC) of the VDHM speed is proposed. Compared with the traditional PID control algorithm, the proposed algorithm has many advantages, such as faster response and higher precision, robustness to the influence of the uncertainty and load disturbance of the model, and improved control performance, etc.. The simulating results have verified these advantages.