Design Of Displacement Detection System Based On PSD

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.