Laser Triangulation Displacement Measuring System With Compensation Of Dual Symmetrical Optical Path

Non-contact measurement technology of laser triangulation displacement has been widely used in industrial automation production.In order to compensate the error caused by non-uniform surface,the laser triangulation displacement measuring method with compensation of dual symmetrical optical path is proposed,which can effectively improve the system's anti-interference ability and measurement accuracy.Finally,the experimental prototype is developed and expected effect is achieved.In the±3 mm range,the system has sampling frequency of 88 KHz,linearity of±0.13%F.S.,and repeatability of 1?m.Main work of the thesis includes following aspects:1.The research status and working principle of laser triangulation method is analyzed.And grayscale centroid method is used to determine the center of the spot,which has high accuracy and low computational complexity,and is easy to be realized by hardware language programming.2.The mechanical structure and optical components of laser triangulation displacement measuring system with compensation of dual symmetrical optical path are designed.Imaging lens use double telecentric lens,Which is not sensitive to the small change of the image distance and object distance.In other words,the magnification of the spot image won't change when the measured object changes position.3.The laser diode driving control circuit based on ARM is designed,and the adaptive control of laser power is realized by PID control.The high-speed data acquisition circuit based on FPGA is designed to realize the acquisition and processing of the brightness and position information of the spot image on the image sensor.And MATLAB is used to realize the communication and data analysis and processing of measuring equipment.4.The system's measurement parameters are determined by calibration experiments.