Intelligent Control Algorithm of PTZ System Driven by Two-DOF Ultrasonic Motor

It is difficult for the traditional pan-tilt-zoom (PTZ) system driven by electromagnetic motor to meet the growing demand for video surveillance system. The key challenge is high positioning accuracy, high dynamic performance and miniaturization of the PTZ system. Here a PTZ system driven by two degree-of-freedom obelisk-shaped ultrasonic motor with single stator is presented, and its intelligent control algorithm is studied. The structure and driving mechanism of the presented PTZ system are analyzed by both simulation and experiment. To solve the complex nonlinear factors, e.g. time-variation, dead zone, the fuzzy PID control algorithm and the variable gain cross-coupled control strategy are combined to improve the control performance. The results show that the proposed algorithm has faster response, higher precision than traditional control algorithm, and it also has a good robustness to prevent the effect of interference.