【作者】 牟丽娜；

【导师】 陈鸿；

【作者基本信息】 中北大学 ， 测试计量技术及仪器， 2007， 硕士

【摘要】 本文介绍了基于PSD的位移检测系统的研究和设计过程,重点介绍了二维PSD输出的非线性及BP神经网络的非线性校正方法。该系统是以重力直坝为背景而设计的一套自动检测大坝位移的装置。大坝由许多坝段构成,每个坝段作为一个测量节点,装有一套位移检测系统。基于PSD的位移检测系统主要是用来检测重力直坝的水平方向及铅直方向的位移情况,它主要由主机和各节点单机构成。该测量系统采用基于RS485总线的分布式主从结构,主机可以同时对各节点单机进行控制,并接收各节点单机传送回来的数据。由于二维PSD的输出具有严重的非线性失真,因此,本文详细介绍了BP神经网络的非线性校正方法,给出了PSD输出校正前、校正后的数据,提高了系统的测量精度。本文首先介绍了该课题的来源和背景以及设计该系统的目的和意义,并在此基础上提出了该系统要实现的功能,接下来的章节阐述了根据系统功能所设计的单节点检测系统的原理及硬件实现过程,介绍了PSD非线性的校正方法及系统软件设计,并给出了影响本系统测量精度的其他因素及消除这些因素影响的方法,最后说明经过软/硬件联调之后,系统满足其设计要求。本系统在保证测量精度及系统使用寿命的前提下,采用二维PSD作为敏感器件、激光器作光源的位移检测系统,提高测量系统的自动化程度,而且系统结构简单,使整个系统的可靠性和实用性也得到了很大的提高。更多还原

【Abstract】 The process of design and research on the displacement detection system based on PSD is introduced in this paper, especially the nonlinear of the planar PSD output and the non-linearity correcting method of the BP neural network. The displacement detection system in this paper is used to detect the displacement of the gravity bam.The dam is built up by several parts, each part can be a detect point, and a suit of the displacement detection system is installed. The displacement detection system based on PSD is used to detect the displacement of the gravity dam on horizontal orientation and perpendicular orientation. This displacement detection system is made up by host computer and some computers on each detect point. The network of system is based on RS485 protocol and sub-controllers are connected to the host. The host computer can control the computer on each detect point at the same time, and also can receive data from the computer on each detect point at the same time. Because of the nonlinear distortion of the planar PSD output, it’s introduced the non-linearity correcting method of the BP neural network detailed in this paper, and showed the data before and after the PSD correcting. From the figures it’s testified that BP neural network can improves the detect precision of the system very well.Firstly it’s introduced the origin and background of the project and the design purpose and significance; based on this it’s brought forward the function of the system, in the following chapters expatiated on the principle of the single point detection based on the system function and the realization of the hardware. Then it’s introduced the software of nonlinear correcting and the design of the system, and set out the influencing factors of detect precision of the system as well as the method to eliminate these factors. In the end it’s proved by the experiments that the designed system meets with the requirements of produce. The system on condition that guarantees the detect precision and the life of the system, introduces the planar PSD as the sensing element and the laser as the displacement detection system of the lamp-house, improved the autoimmunization degree of the detection system, further more the structure of the system is very simple, so that improved the reliability and practicability of the system.更多还原