Research On Multi Degree-of-freedom Ultrasonic Motor And Its Application

Multi-degree-of-freedom Ultrasonic Motor(MDOF-USM) is a new special motor, whichwith the character of simple structure, high integration, small and lightweight, self-locking,power-off, immune to electromagnetic interference, Multidimensionalmotion output, etc.MDOF-USM converts energy by the use of inverse piezoelectric effect, theory of mechanicalvibration, friction coupling.This paper is to study on the subject of MDOF-USM withengineering applications, which achieving complex motion output, belong to electromechanicalintegration. To sum up, the main contents include the following aspects:A novel MDOF-USM of cone-shaped structure was designed. Single foot drive mode wasadopted. Piezoelectric stack with four quadrants was employed as the exciting element, which wasdriven by two sinusoidal signals with a phase difference of90degree. The elliptical motion of thedriving foot along the X-Z or Y-Z plane was able to make the slide move linearly. Parametric modelof the MDOF-USM was set up in ANSYS and then the finite element model was imported intoOptimus, which is a multi-disciplinary optimization software. Genetic algorithm was chosen to findthe globally optimal solution. The results of the optimization indicate that the performance of theMDOF-USM has been significantly improved. The validity of the model and the stability of thealgorithm were also verified.Basing on the performance ofstater structure of MDOF-USM and requirements of achievingtwo DOF motion output, this research makes two solutions for the fitting of the stator and theslide.One is the clamping and testing program with stator fixed, the other is the X-Y platform withthe stator sliding along two DOF rail and the slide fixed on the base.The X-Y platform of owndesign,has good novelty and originality with dexterously assembling the stator, makes beakthoughon the limit of spatial.According to the principle of a cone type Multi-DOF Ultrasonic Motor and its application onX-Y Platform, requirements of its driving circuit were submitted, which adopt two driving methods,analog circuit and digit circuit. Then makingaanalysis on signal output and logic control. The digitcircuit, which based on a single PSoC, has the advnatage of easy to logic control, fewer chips,embed communication even enable the motor achieving complex trajectory.