The Design Of 3D Structured-Light Sensor

In the 3-D profile measurement field, using the technology of line laser projection and machine vision processing has become a practical, stable and non-contact measuring method. Active laser light source line structured light sensor can be more effective to eliminate the impact of external stray light. Therefore, to produce excellent line structure light is one of the key techniques of the sensor measurement.Based on the principle of line structured light 3D measurement sensor,this paper mainly focuses on the optical path system,the optimization of structure parameters and calibration, follows:Firstly,several important methods for the evaluation of laser beam quality are introduced according to the mechanism of semiconductor laser light.The advantages and disadvantages of several laser collimation methods are compared.With the establishment of the aspheric equation of knowledge,this paper put forward a method by using two pieces of the aspheric column lens to collimate the original beam and carries out simulation on the optical design software ZEMAX,and finally achieves the satisfied effect.At last,it presents a method for shaping the point beam by usint the Powell prism and gives a relatively simple modeling approach.Secondly,through the analysis of the principle of laser triangulation method,it introduces two kinds of methods to establish the mathmatic model of sensors,gives the basis of the optimization of structural parameters by the mathematical formula and finds the optimal results using nonlinear programming method in the Matlab software.Finally,it introduces the conversion relation between the world coordinate, camera coordinate, image coordinate system and pixel coordinate system in the theory of calibration.The steps of Zhang’s calibration are explained in details and then the replication experiment is carried out to calibrate the camera’s internal and external parameters and the light plane equation coefficients.This paper has only been accomplished some basic work in the design of the line structured light 3D sensor but provides an important theorectial evidence for measurement using this sensor.