Linear motor acceleration estimation method based on grating signals
LI Zhijun1,2, LIU Chengying1,2, MENG Fanwei1,2, ZHOU Kai1,2, ZHANG Zhi1,2
1. Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
2. Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control, Beijing 100084, China
Abstract：The performance of linear motor servo systems is greatly degraded by disturbances such as the cutting force, cogging force, and inertia variations. Acceleration control can effectively suppress disturbances, but such control requires accurate acceleration estimates with less phase lag. Optical encoders are widely used for position measurements in linear motor systems, so the acceleration can be easily estimated from the quantized positions. An acceleration estimation method is given here based on the constrained least squares polynomial fitting technique. The curve fitting is based on a least squares analysis of the historical position of the linear motor with the latest position of the linear motor on the resulting curve fit. Theoretical analyses and simulations both confirm that this method has less phase lag than the normal least squares polynomial fitting technique. This method works like a finite impulse response(FIR) filter for the acceleration estimate, which is convenient for real time control systems.
李志军, 刘成颖, 孟凡伟, 周凯, 张智. 基于光栅信号的直线电机加速度估计方法[J]. 清华大学学报（自然科学版）, 2015, 55(11): 1258-1263.
LI Zhijun, LIU Chengying, MENG Fanwei, ZHOU Kai, ZHANG Zhi. Linear motor acceleration estimation method based on grating signals. Journal of Tsinghua University(Science and Technology), 2015, 55(11): 1258-1263.
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2015, Vol. 55 
