Research On Technologies Of3D Measurement Based On Dual Linear Structured Light

Based on its non-contact, high speed, high precision and much information, optical measuringtechnology is widely attracted the attention of many researchers. It is widely used in the modernindustrial production and detection fields. With the continuous industry automation level, therequirements of the optical measurement are getting higher. The speed, precision and conveniencebecome the evaluation criterion of the measuring system. Focuses on solving the disadvantage of thesingle structured light, a new method for geometric size measurement based on dual structured light isintroduced in this paper. The main contents and achievements are as follows:(1) According to the principle of the line structured light, a system based on dual linear structuredlight is proposed.(2) According to the model of the dual linear structured light, we put forward a method which cancalibrate two laser beam planes simultaneity. In this method we can distinguish two laser lines on thecalibration board and obtain the calibration points on every laser line. Use these points we cancalibrate two laser beam planes.(3) We improved the existing algorithm for extracting the center of laser beam。 Firstly, get thecenter in pixel, then, calculate the normal direction of the light with the method of the gray grads.Finally, detect the precise values on the normal direction by use of the weighted gray gravity method.This method realized the algorithm for extracting the center of laser beam in sub-pixel. Besides thatwe use the information of the image, distinguish the two laser lines in the image and usecorresponding laser plane equation for3D reconstruction.(4) Study the influence factors of measurement system error. According to the simulation to findthe optimal structure parameter and guide the construction of the system. Choose the optical filter toavoid the influence of the environment, improve the measurement accuracy.The measurement system based on dual structured light can detect the geometric size of steps andbeam. Experiments show that the measurement accuracy for steps can get0.03mmand themeasurement accuracy for beam can get0.05mm. Compared with system based on single laser line,the measurement system in this paper is of high accuracy and stability.