Dynamic feedforward control of the 2-DOFs parallel manipulator of a hybrid machine tool

Dynamic feedforward control is a very good choice for heavy duty machine tools. In order to study the dynamic control of a 2-DOFs planar parallel manipulator, which is used in a heavy duty hybrid machine, dynamic feedforward control is introduced in this paper. Based on the kinematic analysis, the dynamic equation of the 2-DOFs parallel manipulator is derived using the Virtual Work Principle method. Furthermore, a dynamic feedforward control system is established. The dynamic control system consists of two parts, i.e. the kinematic control subsystem and the dynamic feedforward control subsystem. The latter one is designed to eliminate the influence of the parallel manipulator´s dynamic characteristics and the dynamic disturbances from milling process. Firstly, the dynamic control subsystem of single link for eliminating dynamic disturbance is introduced, and the simulation of the control subsystem is also given. Secondly, the dynamic control subsystem for eliminating the influence of the dynamic characteristics is analyzed. Then a whole dynamic control system is introduced at last. From the numerical simulation, it is proved that the dynamic feedforward control system proposed in this paper can eliminate the influence of dynamic disturbances and dynamic characteristics well.