摘要

This paper studies the effect of structure parameters on the dynamic characteristics of a planar PRRRP parallel manipulator. The stiffness model is derived by considering the effect of joint. Based on the stiffness matrix, the vibration equation of this parallel manipulator is investigated to study the dynamic characteristics. The natural frequency is computed, and the effect of Y and Z coordinate on the natural frequency is discussed. Moreover, the sensitivity model of the dynamic characteristic to critical structure parameters is proposed. The thickness of column and leg, the radial stiffness of bearing, and the lumped mass on the end-effector are determined based on the natural frequency and sensitivity index. The results are useful to the structure design of parallel manipulators.