Abstract:The characteristics and Bode diagrams analysis indicated that there was a highly complementarity between the PID control and the piezoelectric ceramic (PZT) micro actuators in the positioning control process of DC motor. Taking advantage of this complementarity, we can build up the composite positioning control (CPC) system. The CPC system has been modeled and simulated by using the Matlab software. The dynamic response curve showed that, while loaded by step and continuous reference displacement signals, the system would automatically switch between the PID control and the PZT control, complete dynamic tracking to target objects, according to the magnitude of the reference signal and the requirement of the positioning accuracy. This behavior brings it a more prompt and precise result in positioning process than any of the single positioning controllers.