Analysis, Design and Control of a Single-Degree of Freedom Piezoelectric Compliant Stage with Amplification Mechanisms

• Main Authors: Wei-ChihWang, 王維志
• Other Authors: Kuo-Shen Chen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/89082958686838461862

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 98 === Automatic Optical Inspection (AOI) plays an important role on modern semiconductor and optoelectronics industries. A typical AOI equipment consists of a camera mounted on a gantry for performing large-area inspection. Fast and accurate maneuver would influence the inspection efficiency. However, the motion induced vibration during fast transition could significantly increase the settling time and therefore deteriorate the inspection rate. In this thesis, a piezoelectric driven compliant stage was design as the carrier for camera. By integrating control scheme with the stage, it is possible to suppress the vibration and therefore improve the performance of AOI. In the first part of this thesis, a novel compliant stage was design and realized. By integrating mechanical amplifier with piezoelectric actuator and capacitance probe, this stage could achieve a natural frequency of 393Hz and stoke of 71μm. Essential structural dynamics tests, as well as finite element simulations were performed for characterizing the system dynamics for feedback control. In the second part of this thesis, the stage control was implemented by both PID and sliding mode control schemes. First, the equivalent system was constructed by MATLAB/Simulink, and discussing the step response effects of the parameter of PID and sliding mode controller. Because the disturbances of the environment, it may make the stage away from its steady position. For the purpose of robustness over possible dynamic parameter variation during service, this thesis also addressed the robustness of the controller. The control schemes were implemented and realized by FPGA module of LabVIEW and CompactRIO system. Experiment data showed that the results of system under a payload of 0.614kg(mass uncertainty 731%) and a 20.32μm step input. The overshoots of PID control and SMC, where reduced to 0.89% and 3% in comparison with the original 43.8% with no control. The settling time is also reduced to 35ms and 39.3ms from original 249.7ms. For the performances against disturbance with a disturbed force of 1.02N, it returns to steady position that takes about 29ms and 24ms. In comparison with commercial Physik Instrumente (PI) P-611 stage, the stage proposed by this work provides a better dynamic performance such as response time and robustness, which are essential for AOI and related applications. As a result, we believe that by further structural and control design optimization, this prototype would have great potential for AOI and other possible industrial applications.