磁场式时栅位移传感器的误差分离与抑制方法研究

发布时间：2018-01-24 00:52

本文关键词： 时栅传感器测量精度误差分离抑制方法　出处：《重庆理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：磁场式时栅位移传感器是基于“时空转换”思想而研究的一种位移传感器,以磁场为介质将空间位移量转换为时间量,从而实现对角位移或直线位移的测量。磁场式时栅位移传感器作为一种精密位移测量传感器,测量精度是评判该传感器工作性能的一项重要指标,如何提高测量精度一直是该类型传感器的研究重点。因此,本课题对磁场式时栅位移传感器中误差分离及各类误差抑制方法的研究切合其研究重点,将有助于推动该类时栅位移传感器的进一步发展。国内外对位移传感器的误差分析与抑制有一定研究基础,误差主要分机械、电气及安装三方面。机械误差源于机械加工及加工元件参数不合理,可分为齿形、齿距、对极数、定转子齿数等;电气误差源于信号处理电路,可分为激励信号处理误差、弱感应信号处理误差等;安装误差源于传感器机械结构的安装不理想,主要集中于传感单元的安装。误差抑制方法主要分硬件处理方法和软件处理方法。硬件处理方法通过改变传感器机械或电气的参数达到提高测量精度的目的,如光栅采用精密刻线,旋转变压器优化齿形、齿距、对极数、定转子齿数比例等;软件处理方法是通过软件方式实现减小测量误差的算法,从而提高测量精度,如谐波修正法及逐点查表修正法等。硬件处理方法主要是从传感源头上抑制了测量误差的产生,所以是提高磁场式时栅位移传感器测量精度优先考虑及采用的方法,但需要对测量误差的来源做出较为准确的判断;软件处理方法不仅误差抑制效果显著,而且具有操作简单、成本低等优势。由于二者各有利弊,因而应综合考虑并合理应用两种方法。磁场式时栅位移传感器的测量误差主要包含0、1、2、3次及高次谐波成分,作者认为这种规律性强且固定存在的误差,大部分是可归结到传感器系统中某环节的,所以本课题以此为切入点,结合研究现状,本课题取长补短,主要从以下四方面对时栅测量误差进行研究。(1)分离了激励信号源误差,激励信号源的幅值和相位误差直接影响感应信号相位变化的线性度。为此,基于FPGA设计了采用闭环控制的高精度激励信号源。实验表明激励信号源精度提高,减小了传感器的的测量误差。(2)从理论上分离齿不均性对测量带来的误差,建立数学模型,并研究了抑制其误差的方法。然后,通过对比采用了不同加工工艺的传感器的测量性能,验证了定转子齿的不均匀性对传感器测量精度的影响。(3)分离了方波形成模块误差,并应用了改进型弱信号处理方法。为解决绝对零点偏移问题所带来的测量误差,引入了差动比较技术,实验表明差动技术抑制了时栅测量中的随机误差;(4)针对实验结果与理论数据存在一定差异的问题,也即解决模块误差的同时又带来新的误差的问题,对时栅各模块误差系统地进行了分析,采用整体抑制手段,如弱信号处理方法研究、标定方法研究、补偿算法研究等。课题以变磁阻型磁场式时栅位移传感器为研究对象,对其他磁场式、电场式及光场式时栅也据有适用性。
[Abstract]:Field type time grating displacement sensor is based on the space-time conversion of ideas and research a displacement sensor with magnetic field as medium transformation space displacement is the amount of time, so as to realize the measurement of angular displacement or linear displacement. The magnetic field type time grating displacement sensor as a precision displacement measurement sensor, the measurement accuracy is one of the most important the performance evaluation of the sensor, how to improve the measurement accuracy of this type of sensor has been a focus of research. Therefore, the research of practical error of grating displacement sensor and separation of all kinds of error suppression method of magnetic field when the research focus, will help promote the further development of the time grating displacement sensor error at home and abroad. The displacement sensor analysis has certain research foundation and error suppression, mainly mechanical, electrical and mechanical installation. Three error sources in mechanical processing and Hydraulic component parameters are not reasonable, can be divided into the tooth shape, tooth pitch, the number of poles, stator and rotor teeth; electrical error due to the signal processing circuit, can be divided into processing error excitation signal, weak induction signal processing error; installation error due to the mechanical structure of the sensor installation is not ideal, mainly focus on the sensor unit installation. Error suppression method is divided into hardware processing method and software processing method. The hardware processing method to improve the precision of measurement by changing the parameters of mechanical or electrical sensor, such as grating precision reticle, rotary transformer optimized tooth, tooth pitch, the number of poles, stator and rotor tooth number ratio; software processing method is to achieve the measurement errors of the algorithm by software method, so as to improve the measurement accuracy, such as harmonic correction method and pointwise look-up table method. The hardware processing method is mainly from the sensing source suppression measurement error So, when the magnetic field is to improve the measurement accuracy of grating displacement sensor priority method and the sources of measurement error but need to make more accurate judgments; software processing method not only the error suppression effect, and has the advantages of simple operation, low cost advantages. Because the two have advantages and disadvantages, and therefore should be considered the reasonable application of the two methods. The measurement error of field type time grating displacement sensor consists mainly of 0,1,2,3 and harmonic components, the author thinks that the error of this strong regularity and fixed there, most can be attributed to the sensor is a link in the system, so this article as a starting point, combined with the research status of this topic, learn from each other, mainly from the following four aspects of time grating measurement error. (1) isolated signal source error, amplitude and phase error excitation signal source directly affects the induction signal No change of phase linearity. Therefore, FPGA is designed by using high precision excitation signal source based on closed loop control. The experimental results show that the improved precision of the excitation signal source, reduces the measurement error. (2) were not separated teeth on the measurement error brought from the theory, the mathematical model and study method to eliminate the error. Then, the measurement performance of the sensor using a different processing by comparison, verify the effect of non-uniformity of stator and rotor tooth on the measurement accuracy of the sensor. (3) isolated Fang Bo formation module error, and the application of improved weak signal processing method. The measurement error brought to solve absolute zero offset problem, introduces the differential comparison technology, experiments show that the differential technology inhibited the random errors in the measurement of the gate; (4) for there are some differences between the experimental results and the theoretical data, namely solving module The error also brings new error, the error of time grating module are systematically analyzed. The overall suppression means, such as weak signal processing methods, calibration method, compensation method and so on. Subject to a variable reluctance type magnetic field type time grating displacement sensor as the research object, the other type of magnetic field, electric field type and light field type time grating also has applicability.

【学位授予单位】：重庆理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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