Motion control of the 2-DOF parallel manipulator of a hybrid machine tool

This paper focuses on the motion control of the two-degree-of-freedom (2-DOF) planar parallel manipulator of a hybrid machine tool. On the basis of the performance analysis of the kinematic control system, a parameter-tuning method is proposed for regulating the control parameters. To improve the response performance, the proportional-derivative control and a low-pass filter are introduced to the position-loop controller. The simulation shows that the response speed is increased and that the tracking error is reduced. Furthermore, the effect of load torque on the contour error is investigated, and the dynamic feedforward control is used to control the parallel manipulator. On the basis of the principle of dual-channel compensation, the feedforward compensator is designed. The simulations, that the moving platform moves along a linear trajectory and circular trajectory, show that the dynamic feedforward control can reduce the effect of load torque on contour error.