Research Of Displacement Error Detecting Device

The laser displacement detection device can accurately detect the displacement of the building and the deflection of the bridge.But the laser is influenced by the surrounding environment,which leads to the change of the transmission path.The displacement detection process will produce error.In this paper,the displacement error detection device is used to detect the displacement error caused by environmental factors.It can improve the accuracy of laser displacement detection technology.This displacement error detecting device,using optical imaging system imaging the displacement on the position sensitive detector and obtaining the displacement error caused by environmental factors through the information processing system.The research contents and results of this paper mainly include:1)Research and design of displacement imaging system.The principle of displacement error caused by environmental factors is analyzed.Discussing and selecting the appropriate laser source.The influence of beam expanding lens system and distance on size of laser spot is calculated and analyzed.The influence of focal length of imaging lens on the imaging position and precision of PSD is studied.It is found that the distance between the beam expanding lens has a great influence on the spot size.The proportional relationship between the focal length of the imaging lens and the displacement of the image on the PSD.2)Research and design of signal processing,acquisition and display system.Studying and designing PSD signal processing circuit.Simulation of the circuit is carried out.And produced a kind of circuit board.Real circuit board can achieve the signal amplification,conversion and addition and subtraction.Studying and selecting the suitable A/D converter and MCU.Making a physical circuit and connecting PC programming.Conducting signal acquisition and control.Realizing displacement data processing and display in the upper computer interface.Through research and analysis,determining the appropriate laser and focal length of the beam expander system.Selecting a focal length of the imaging lens size is 300 mm.Through the analysis of the actual test and record data of the PSD signal processing circuit.The reliability of the hardware circuit of PSD signal processing circuit is verified.Finally,establishing the model of the whole displacement error detection device and conducting it in the laboratory environment.The practical feasibility of the displacement error detecting device is verified.