Design and Development of Piezoelectric Shear-driving Multi-DOF Ball-type Actuator and Performance Analysis

• Main Authors: Chun-Nan Wu, 吳俊男
• Other Authors: 黃光裕
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/47806295706996055439

碩士 === 國立臺灣大學 === 機械工程學研究所 === 94 === The paper presents a novel design of a Multi-DOF ball-type Actuator (MDBA), which is developed for achieving multi-axial rotation and precision rotating angle control. Three piezoelectric actuating units are applied to drive frictionally a ferromagnetic steel ball, and each actuating unit is composed of a wear-resistant ceramic contact plate and two d15-type piezoelectric shear plates, whose polarized directions are perpendicular to each other. The three actuating units are installed on three corner surfaces of a steel base respectively. To produce sufficient contact force between the actuating unit and the ball, the permanent magnet is used to supply the magnetic preload on the ball. The piezoelectric shear plate is driven by the unsymmetrical saw-toothed signal to realize inertial actuation. The actuating process is monitored by detecting visually the position of a reflective mark attached on the actuated ball, and from the captured images the speed and the angular displacement of the ball can be derived. Diverse control combinations of the actuating units can be applied to vary the rotating direction of the ball. Furthermore, the number of driving pulses and the driving frequency are the main operational parameters for precise controlling the rotational angle and the speed.