基于动态估算的直流电机速度测量方法

摘要

针对常规直流电机测速方法中存在的精度低、低速测量滞后严重等问题,设计了一种高精度的速度动态估算方法.在M/T法的基础上,利用FPGA的高速、实时性特征,将光电编码器反馈信号进行滤波、倍频、鉴相,实现速度计算.针对控制信号的上升沿到第一个被测脉冲上升沿之间的不完整被测脉冲,利用小数估计不完整被测脉冲的思想,用前一个相邻完整脉冲来估算不完整被测脉冲值.仿真结果表明,该速度估算方法可以准确地测量直流电机的速度,测量结果输出滞后时间小于2 μs.%In order to solve the problems existing in the DC motor such as low accuracy,seriously measurementlag on the low speed,a new high precision velocity dynamic estimation is proposed.On the basis of M/T method,by using the high speed property and real-time property of FPGA,the feedback signals of photoelectric encoder are carried out for filtering,frequency multiplication,phase discrimination as well as speed calculation.On the basis of fractional estimation of the incomplete measured pulses that are the measurement pulses between the rising edge of the control signal and the first measured pulse rising edge,the previous adjacent complete pulse is used to estimate the incomplete measured pulse value.The simulation results show that the speed estimation method can accurately measure the speed of DC motor,the measurement output lag time is less than 2 μs.