Modeling and active vibration control of an intelligent flexible manipulator system

The dynamic model of an intelligent flexible manipulator system, which consists of a sevo-motor, a harmonic gear reducer, a flexible manipulator and a couple of PZT (piezoelectric) actuators, is derived using the assumed mode method and Hamilton's principle. In order to improve system precision and to suppress elastic vibration of the flexible manipulator rapidly, a composite strategy combing the PD (proportional derivative) controller applied to servo-motor and fuzzy controller applied to PZT actuators, is presented. After some numerical simulations, the experimental system of the intelligent flexible manipulator system is designed and set up. Both the simulation and comparative experimental results verify that the presented strategy is practicable. The PD control algorithm can improve position precision of the sevo-motor in system motion control, and the fuzzy control algorithm can reduce elastic vibration of the flexible manipulator through PZT actuators. The experimental results show that the vibration damping of the manipulator is reduced to 3.5 s from 6.5 s. So the proposed control strategy can improve position precision of the flexible manipulator's end-effector and enhance operating efficiency of the system.