基于FPGA的电容式编码器数据采集系统设计与实现

Design and Implementation of Capacitive Encoder's DAQ Based on FPGA

摘要:

为了精确地获取电容式编码器输出信号中所携带的位置信息,文章设计了一套基于现场可编程门阵列(FPGA)的电容式编码器数据采集系统;文中介绍了带通滤波器、同步正交解调、低通滤波器和Cordic等系统模块,并详细分析了系统的稳定性和误差;实验结果表明,在转速度为800 rpm时,角度分辨率可达到0.192度,在一个周期内最大误差0.002 8度,平均误差0.000 8度,静止抖动0.007 26度,统能够实时的获取转子的位置信息,同时具有较好的精度和稳定性。

Abstract:

In order to accurately obtain the position information from the output signal, this paper proposed a capacitive encoder’s data acquisition system based on FPGA. Algorithm of band pass filter, synchronous quadrature demodulator, low pass filter, and Cordic have been adopted in the design. And we make a detail discussion about the system stability and error .The results show:as rotational speed is 800rpm,resolution is 0.192 degree and the mean error is 0.0008 degree. The system not only obtains the position information of rotor in a real time, but also has a good resolution and accuracy.