Research on torque control of servo hydraulic motor with position disturbance

The electro-hydraulic torque control system is extensively used in the industrial equipment. Especially in some cases, there will exist a position disturbance while the torque control command is implemented. Traditionally, in order to receive a better torque control effect, the form of valve-controlled hydraulic motor will be given priority in this type of torque control system, which tends to produce larger surplus torque. Therefore, in this paper, a structure based on servo hydraulic motor whose displacement is variable was proposed to accommodate the situation of position disturbance, which can replace the traditional valve-controlled hydraulic motor to carry out torque control assignment. Through establishing the mathematical model of the proposed structure, output torque open-loop transfer function and its simplified form were obtained. Besides, the influence factors in the proposed structure on the dynamic performance was analysed. Finally, the simulation was conducted, verifying the performance of the proposed structure.