Abstract: Aimed at a parallel manipulator with three translational degrees of freedom, a method on parameter identification and automatic tuning of the electromechanical coupling servo system is presented. In parameter identification process, the triangle shape input with variable frequency is adopted to overcome the disadvantages of pseudo-random number sequence, I.e. making the change of vibration amplitude of the motor dramatically, easy to impact motor and result in its velocity loop open and so on. Moreover, the rotary inertia can also be identified by the additive mass, and by the simulation and experiments in which a step input is adopted, this identified model is proved general and validated. Based on the above, the overshoot and rise time are acted as optimum goals, and the range of PID controller parameters of the servo system is given. At last, a series of the experiments are done to prove its correctness.

Key words: Parameter automatic tuning, Main module Parameter identification, Parallel manipulator