高精度编码器数字化接口的研究与实现

发布时间：2018-11-11 17:03

【摘要】：正余弦编码器是一种测量角位移和角速度的精密传感器。随着数控系统以及现代工业控制系统对分辨率和精度的要求越来越高,仅依靠原始分辨率或四倍频计数已无法满足工控系统实时反馈精度需求,需要更高分辨率和精度的编码器位置转速等反馈信号。提高编码器分辨率的方法有硬件和软件两种方法,由于硬件方法对工艺设计等要求非常高,课题采用了软件方法对编码器信号进行电子学细分,以提升编码器信号的分辨率和精度。为了提高编码器位置信息的分辨率和精度,以获取更精确的电机位置、速度等信息,文中主要设计了基于改进坐标旋转数字计算(CORDIC)算法的编码器信号处理系统。首先通过信号调理电路对编码器信号进行差分放大和整形滤波等处理,然后四倍频计数得到粗码信息,接着采用基于改进CORDIC算法的电子学细分方法获得精插补信息,最后将粗码和精码信息整合,得到高分辨率和高精度的电机角位置信息。在测速方面,使用了变M测速方法和全微分测速方法。在通信方面,接口模块和上位机通过CANopen协议进行数据通信。课题采用了16位AD转换器,2048线正余弦编码器,编码器角度值达到了27位高分辨率。对编码器接口模块进行了测试,结果表明采用四倍频测量位置值精度在100角秒左右,而采用电子学细分方法获得的位置值精度在60角秒左右,全微分测速法测量的相对误差比变M测速法要小,精度较高,满足设计要求。
[Abstract]:The sinusoidal encoder is a precise sensor for measuring angular displacement and angular velocity. With the increasing demand for resolution and precision in numerical control system and modern industrial control system, it can not meet the demand of real-time feedback precision of industrial control system by relying only on original resolution or quaternion counting. Require higher resolution and accuracy of encoder position, rotational speed and other feedback signals. There are two methods to improve the resolution of encoder: hardware and software. Due to the very high requirement of hardware method to process design, the software method is used to subdivide the encoder signal electronically. To improve the resolution and accuracy of encoder signals. In order to improve the resolution and accuracy of position information of encoder and obtain more accurate information of motor position and speed, a signal processing system of encoder based on improved coordinate rotation digital calculation (CORDIC) algorithm is designed in this paper. First, the encoder signal is processed by signal conditioning circuit, such as differential amplification and shaping filtering, then the coarse code information is obtained by quaternion counting, and then the refined interpolation information is obtained by using the electronic subdivision method based on the improved CORDIC algorithm. Finally, the coarse code and the precision information are integrated to obtain high resolution and high precision position information of motor angle. In terms of velocimetry, the variable M method and the full differential method are used. In the aspect of communication, the interface module and upper computer communicate through CANopen protocol. A 16-bit AD converter and a 2048-line sinusoidal encoder are used. The angle of the encoder reaches 27 bits high resolution. The interface module of encoder is tested. The results show that the precision of position value measured by four times frequency is about 100 angle seconds, and the position value precision obtained by electronic subdivision method is about 60 angle seconds. The relative error of total differential velocimetry is smaller than that of variable M velocimetry, and the accuracy is higher.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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