On the modeling and composite control of flexible parallel mechanism

摘要

One of the key problems in high speed motion control of a flexible parallel mechanism (PM) is to damp out the mechanical vibration arising from high inertial force acting on the linkages and other components. In this paper, the dynamic equations of a 2 degree-of-freedom (DOF) planar PM with flexible links are established by taking the singular perturbation approach (SPA). Thus the model of the mechanism can be separated into slow time-scale and fast time-scale subsystems. Based on the feedback linearization theory and input shaping technique, the large range rigid motion controller and the flexible link vibration controller can be designed separately. A composite control with the two separate controllers can then be applied in the PM to achieve the desired fast and accurate positioning.