Visual Aid Piezoelectric-Actuated Stage of H∞/QFT Combined Design

• Main Authors: Sheng-Hong You, 尤勝弘
• Other Authors: Meng-Shiun Tsai
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/32416941704663137694

碩士 === 國立中正大學 === 機械工程所 === 97 === A three-axis nano-positioning device is designed in the lab which consists of an X-Y table and a rotational stage on the top of the X-Y table. Each stage is actuated by a piezoactuator and the motion is sensed by laser displacement sensors and CCD camera. The dynamic models are developed using the Lagrange approach and analyzed through simulation. Due to install and fabrication errors, the dynamics of the X-Y table are coupled and thus a MIMO controller is developed to eliminate the coupling effects. The design process of the robust controller consists of two stages. First, the robust H∞ controller with the given specification is developed with different payloads. The H∞ controller is then reshaped by using the quantitative feedback theory (QFT). It is found that the noise effects and control efforts can be reduced significantly after applying the loop shaping of the QFT. The coupling of the X and Y axes is also eliminated. The simulation and experimental results show that the rise time of the design stage is about 0.1 sec for a 20 um input. The positioning accuracy it can achieve is within 0.1um.