【作者】 权清科；

【导师】 谭久彬；

【作者基本信息】 哈尔滨工业大学 ， 仪器科学与技术， 2008， 硕士

【摘要】 电容式位移传感器由于具有结构简单、分辨率高、动态特性好、能实现非接触式测量等特点,在精密加工、高精度定位、超精密测量等领域得到广泛的应用。电容位移传感器的输出信号较小,而且输入输出特性存在一定的非线性,如何实现电容信号的提取以及对其输入输出特性进行有效的非线性处理就成了影响电容传感器性能的关键。本文基于调频式电容位移传感器输出信号的特点,对调频信号频率测量技术以及非线性校正技术进行深入了的研究,具体研究工作如下:首先,在对频率测量的方法进行归纳、总结的基础上,设计了以现场可编程门阵列(FPGA)为核心的频率测量模块,对多周期同步测频进行了方法改进,实现FPGA内部多周期同步测频逻辑代码的编写;其次,对基于神经网络的非线性校正以及曲线拟合技术进行了研究,设计了基于傅立叶级数神经网络的非线性校正算法并进行仿真,实现了算法向DSP芯片中程序的移植。再次,研制了基于TMS320VC5402芯片的电容位移传感器非线性校正和信号处理模块,进行了DSP外围的FLASH存储器扩展、串口通信、液晶显示等模块的软硬件设计。最后,对频率测量以及非线性校正模块进行了性能测试、实验和研究,为电容位移传感器性能的改进提供了理论和数据的参考。更多还原

【Abstract】 With the advantages of simple structure, high accuracy, fast response and no contact measurement, capacitance sensor has been widely used in the domains of precision machining, ultra-precision orientation, ultra-precision measurement and so on. However, due to the small output signal of the capacitance sensor and the non-linearity of the Input-Output curve, how to gain the capacitive signal and how to carry out effective non-linearity correction, has become the key which influences the performance of the capacitance sensor.Based on the processing of output data from the frequency modulation type capacitance sensor, this paper gives the in-depth study on the technology of measuring frequency and the technology of non-linearity correction. The main research is given as follows:Firstly, in this paper the method of measuring frequency is concluded and summarized. The circuit of measuring frequency based on FPGA is designed. The method on the synchronous multi-cycle frequency measurement is improved, and the VHDL program of the multi-cycle frequency measurement is given;Secondly, the application of Artificial Neural Networks (ANN) technology on non-linearity correction and curve fitting is studied. The emulator of non-linearity correction, which is based on Fourier Progression Artificial Neural Networks (FANN), is realized, at the same time the naturalization of the non-linearity correction program to Digital Signal Processor (DSP) is achieved;Third, the hardware circuit based on TMS320VC5402 of non-linearity correction and data processing is designed, including FLASH memory, serial data transfer and LCD display module;Finally, the experiment is carried out to testing the performance of the frequency measurement module and the non-linearity correction module. The result of the experiment affords the principle and reference to improve the capability of the capacitance sensor system.更多还原