Abstract
In this dissertation, the design of a driving system and a nonlinear robust controller for a novel thin-disc type edge-driving ultrasonic motor for precisely positioning was developed. Using piezoelectric buzzer as the ultrasonic actuating component (stator), the novel design of thin-disc piezoceramic-driving ultrasonic actuator was performed. Under three constraints put on the specific geometry positions on the metal sheet, the varying behaviors of flexural waves were formed from different directions to construct the driving zone to rotate the rotor. The simple structure of the actuator, with low cost, had demonstrated that the mechanical design of the actuator and the rotor could be separated, depending on what we needed in applications. At first, the driving circuit with advance feature, composed of a DC-DC buck converter and a single-phase half-bridge series-resonance inverter, was implemented in this paper. Next, the related important dynamic characteristics, such as preload, velocity, hysteresis, and dead-zone, were analyzed. Through system identification technique to obtain the approximate mathematical model of the ultrasonic motor, the various designs of sliding-mode position controllers were proposed for the performance evaluation. Thus the novel ultrasonic actuating motor had been proven in the excellent positioning capability with robust rejection to noise disturbances by the means of effective simulations and experiments via position tracking commands of sinusoidal and periodic step functions.