| Summary: | 碩士 === 國立臺北科技大學 === 自動化科技研究所 === 93 === The mechanical systems, such as machine tools, semiconductor manufacture equipment, mechanical manipulators and automatic inspection machines, must be supported by motion controllers, which ensure robust, high speed and high accuracy tracking performance. To control the system adequately, the system parameters must be known and the parameters of controller has to be adjusted accordingly.
This paper presented a digital servo driver that realizes an auto-tuning feedback and feedforward controller design using off-line and on-line parameters identification. Firstly, the inertia constant, damping constant and the disturbed load torque of the servo motor are estimated by off-line identification. In manufacture processing, the system parameters are varied according to different working conditions. Therefore, two algorithms of on-line parameters identification are proposed to identify the variant inertia constant, damping constant and the disturbed load torque. The controller proposed here uses an I-PD feedback controller, which has larger bandwidth than cascade control of velocity and position loop, and a direct velocity and acceleration feedforward (DVAFF) controller to improve the tracking performance. By using the estimated inertia constant and damping constant, the I-PD controller and DVAFF controller can adaptively tune itself to compensate the parameter variations.
The proposed auto-tuning digital servo controllers are evaluated and compared experimentally with a traditional controller on a microcomputer-controlled servo motor positioning system. The simulated and experimental results show these controllers robustly sustain the control performance and dramatically reduce the tracking error even if the plant parameters are varied.
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