基于DSP2812的光栅细分技术研究

发布时间：2018-01-17 19:11

本文关键词：基于DSP2812的光栅细分技术研究　出处：《西南交通大学》2012年硕士论文　论文类型：学位论文

【摘要】：光栅技术应用极为广泛,除应用于大型精密数控机床、测量仪器外,在中小型测量设备上也有诸多应用,近年来在便携式精密测量仪器领域也逐渐推广应用,如西南交通大学牵引动力实验室研发的五连杆轮轨测量仪中也用到光栅编码器来测量角度。光栅细分是实现精密测量的必由之路,为跟踪该技术的发展,提高轮轨测量仪精度,本文对光栅细分技术进行了如下研究：首先,对光栅测量原理进行分析,研究了经典细分法方法及新型细分方法的特点,根据现代数字信号处理器(DSP)的发展现状,结合设计中采用直线式粗光栅,选取了一种软硬件结合的幅值相位细分法,设计了系统总体方案,对细分系统的主要组成模块进行了选择及功能设计其次,设计了细分硬件电路：差分放大电路滤除光栅尺输出信号中的直流分量,然后一路通过过零比较电路将正弦波转换为方波,另一路在通过低通滤波电路滤除高频噪声后,两路分别通过不同参数的加法及比例运算电路对幅值进行调节,以满足各自后续电路对输入信号的要求；DSP2812芯片的正交编码模块用于方波信号的辨向和计数,其A/D转换模块检测光栅信号正弦电压波形,串口通信模块向外发送细分计数结果。再次,编写了DSP软件：对QEP、 A/D模块及串口的功能进行设置,设计了数字滤波程序对采样数进行滤波,零点补偿程序模块消除温漂,设计幅值相位细分表,编写查表程序,实现了非完整脉冲位移细分计数,设计串口发送程序,实现了细分结果的正确发送。最后分析了光栅细分系统的测量误差,介绍了系统调节、测试情况,结果表明,系统的分辨率由0.04mm提高到0.001mm。
[Abstract]:The application of grating technology is very extensive, in addition to application of large precision CNC machine tools, measuring instruments, there are many applications in small and medium sized measurement equipment, in recent years in the field of portable precision measuring instrument is gradually popularized, such as angle encoder is also used five link rail measuring instrument Southwest Jiao Tong University traction power laboratory developed to measure. Grating precision measurement is the only way which must be passed for the development of the technology, tracking, improve the measuring accuracy of the wheel rail, the paper researched the grating subdivision technology:
First of all, the principle of grating measurement is analyzed, the characteristic of the classical subdivision method and new segmentation method, based on the modern digital signal processor (DSP) development status, combined with linear type coarse grating design, the amplitude and phase subdivision of a combination of hardware and software, the design scheme of the system, mainly consisting of the module of subdivision systems were selected and functional design
Secondly, the subdivision of hardware circuit design: difference DC component amplification circuit to filter the output signal of the grating, and then all the way through the zero crossing comparison circuit will be converted into sine wave square wave, in another way by a low pass filter circuit to filter the high frequency noise, additive and proportion of arithmetic circuit two respectively through different parameters adjustment the amplitude, in order to meet the requirements of each subsequent circuit of the input signal; orthogonal encoding module DSP2812 chip for square wave signal to identify and count the A/D conversion module to detect the grating signal waveforms, the serial communication module sends out subdivision count results.
Again, the DSP software of QEP, A/D module and serial port function set, the design program of digital filtering to filter the sampling number, zero compensation program module to eliminate temperature drift, amplitude phase subdivision design table, write the lookup procedure, realize the non complete pulse displacement subdivision counting, design of serial procedures, the right to send achieve the segmentation results.
At last, the measurement error of the grating subdivision system is analyzed, the system adjustment and the test situation are introduced. The result shows that the resolution of the system is improved from 0.04mm to 0.001mm.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP368.1;TN253

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