Modeling and Motion Control of a Micro-positioning Scott-Russell Mechanism

• Main Authors: Yao-Ting Tzeng, 曾耀霆
• Other Authors: Rong-Fong Fung
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/19781005777216838478

碩士 === 國立高雄第一科技大學 === 機械與自動化工程所 === 94 === Abstract The micro-positioning Scott-Russell (SR) mechanism driven by a piezoelectric actuator (PA) is designed to magnify the displacement of the PA. Main feature of the SR mechanism is its straight-line output for a given input displacement. In this paper, we derive the dynamic equation of the SR mechanism by Hamilton’s principle, identify the system by using the dynamic signal analyzer HP35670A, and compare dynamic responses between the numerical simulations and experimental results. In system controller design, two kinds of controllers are designed to be the motion control for the SR mechanism. In designing the first controller, the Ziegler-Nichols (Z-N) method and the real-code genetic algorithm (RGA) are employed to design the gains of the Proportional-Integral-Derivative (PID) controller. Their dynamic responses of precision positioning are compared numerically and experimentally. From the experimental result, the regulation error is about ±0.008 μm and the tracking error is about ±0.07 μm. In designing the second controller, the model reference adaptive fuzzy iv control (MRAFC) method is developed for the SR mechanism, where the fuzzy logic method (FLM) is utilized to find the best gain of the adaptation law in order to reduce the time of trial and error. This control method can remedy the shortcoming of the traditional controller with fixed gains, and make the SR mechanism keep its original working performance when external disturbances exist in the control system. From the experimental result, the regulation error is about ±0.004 μm and the tracking error is about ±0.08 μm .