Compensating nonlinear temperature dependence of ultrasonic motor.

This article aims at realizing the linear parameter-varying (LPV) controller synthesis to compensate temperature dependence for the ultrasonic motor (USM). Initially, based on the improved optimal frequency tracking scheme, the compact LPV model is investigated to approximate the nonlinear temperature dependence. With the aid of the simulation tool, the accuracy of the proposed LPV model is proven. The LPV controller can be an appropriate choice to ensure the stability of passive nonlinear system. In view of the very strictly passivity (VSP) theorem, the VSP LPV controller is constructed as negative feedback. A set of well-designed experimental setup employed the Shinsei USR60 type USM is built afterwards, and the controller implemented by the host is applied to verify the control effect. Compared with the non-model-based controller, the USM with the proposed controller displays better performance, such as more stable output rotational speed. The feasible model in this paper is of great significance to USM. Particularly, the proposed modeling and control methodology are beneficial to the existing optimum frequency tracking technology for the USM.