A Novel Electromagnetic Actuated and Damped 3-DOF Precision Positioning Stage with Flexure Suspension

• Main Authors: Chih-Hsien Lin, 林志憲
• Other Authors: 傅立成
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/54038890231774114820

碩士 === 國立臺灣大學 === 電機工程學研究所 === 96 === This thesis proposes a novel planar electromagnetic actuated and damped positioning stage for precision positioning applications. The moving stage is suspended by the monolithic parallel flexure mechanism, whose motion comes from the elastic deformation of the flexure. A linear electromagnetic actuator which consists of a near-uniform magnetic field and four coils is designed and implemented to provide the propelling force and torque for 3-DOF motions. In order to suppress the vibration of the flexure suspension mechanism, an eddy current damper is designed and integrated with the electromagnetic actuator. Since the electromagnetic damper experiences no contact, it is obviously more adequate than other kinds of contact damper to be incorporated into precision motion control. The three salient features of the novel system design in the research include: (1) to have large moving range (in mm level), (2) to achieve precision positioning, and (3) to design a compact mechanism. For the purpose of gaining system robustness and stability, a robust adaptive sliding-mode controller is proposed to enhance the system performance for both regulation and tracking tasks. The developed robust adaptive control architecture consists of two components: 1) sliding mode controller, and 2) robust adaptive law. With the designed controller, the stage can achieve high positioning resolution, where the tracking error in each axis is kept within 10μm. Experiment results show the vibration of the flexure mechanism can be suppressed by the eddy current damper successfully in a series of time-domain and frequency domain tests. Besides, the designed traveling range of the positioning stage is 3mm x 3mm in planar motion, and tracking and contouring performance are also examined to assure the appealing dynamic property of the stage.