基于光栅信号的直线电机加速度估计方法  

Linear motor acceleration estimation method based on grating signals

作　　者：李志军[1,2] 刘成颖[1,2] 孟凡伟[1,2] 周凯[1,2] 张智[1,2] 

机构地区：[1]清华大学机械工程系,北京100084 [2]精密超精密制造装备及控制北京市重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2015年第11期1258-1263,共6页Journal of Tsinghua University(Science and Technology)

基　　金：中物院超精密加工技术重点实验室开放资金自主项目(KF13010);国家科技重大专项(2009ZX04010-022)

摘　　要：直线电机进给系统中,外界干扰如推力、负载力和参数波动等严重影响了直线电机进给系统的性能。加速度控制是一种抑制外界干扰力作用的有效手段,其中获得相位滞后小的加速度信号是加速度控制中的关键内容。光栅尺是直线电机进给系统中最常用的位置传感器,研究基于光栅尺离散脉冲位置的加速度估计方法具有广泛意义。提出了一种基于约束最小二乘曲线拟合的加速度估计方法,该方法首先对直线电机初级的历史位置进行最小二乘曲线拟合,同时要求拟合曲线通过最新位置,然后根据拟合的二次曲线求得加速度。将该方法与基于最小二乘曲线拟合法进行对比,理论分析和仿真实验均表明:该方法在估计快速变化的加速度信号时,具有更小的相位滞后。在估计加速度时,该方法相当于一个有限冲激响应(FIR)滤波器,易于在实时控制系统中实现。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 he 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. Theo retical 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.

关 键 词：直线电机 加速度控制 加速度估计 约束最小二乘法 

分 类 号：TG156[金属学及工艺—热处理]