Abstract:With the development of science and technology, there is an urgent need to develop micrometer positioning technology in the fields of the precision manufacturing. The traditional electromagnetic motors are difficult to meet this demand as they are characterized by high speed and low torque. Piezoelectric actuator uses piezoelectric ceramics as transducers, and utilizes the inverse piezoelectric effect of piezoelectric ceramics to convert the electrical energy to the mechanical energy, which can masterly utilize certain structural forms to transfer motions and motive forces. In addition, due to the compact structure of piezoelectric actuator, the rotor inertia is small, and fast in response to braking, the load can be directly driven, and has good controllability for positioning and speed, therefore, piezoelectric actuator is widely used in equipment drive and control with high performance for precision manufacturing. For the selected piezoelectric positioning stage system using friction drive, an approximate time-domain mathematical model was established according to its physical mechanism. The parameters were identified by the open-loop experiment with the least squares method. The model output of the pulse width signal and the triangular wave signal were consistent with that of the actual system. Then, according to the form of the model, inverse system compensation plus sliding mode variable structure control scheme was designed. The stability of the control algorithm and its control parameters were discussed. The PI control method and the control algorithm proposed were used to track the same signal. The results showed that the control precision of the control algorithm used was much better than that of the PI control method, the maximum tracking error by using the proposed control algorithm was 0.01095mm. So it had good practical value in the drive and control of precision instruments and equipment.