The Research Of Vision Sensor And Its Application In Geometrical Measurement

A key purpose of computer vision research is to give a computer with man's vision capability.Then the computer can feel the environment in its vision field and understand the content of the feeling so that it can take corresponding action. Vision sensor system is an integration of optics, mechanics and electronics mainly based on CCD image sensor.This system is relational with mechanics,optics,electronics,computer vision,digital image processing and software engineering . The vision sensor system is devised by use of the principle of stero vision combining with the characteristic of man's vision system. This system can measure a workpiece's dimension without contacting the workpiece. This technology has simple algorithm,fast speed and high precision.Firstly this paper introduces the basic principle of the vision sensor ,that is, the basic principle of stero vision. And it simply introduces several common vision sensor methods used to measure two-dimensional or three-dimensional size and some algorithms in common use in these methods.And then the paper gives the image processing methods used in the geometrical parameter measuring system.According to the process of the image processing,it introduces the following three methods in order: image pretreatment method which consists of the average value of neighbour area and lowpass; image segmentation method which involves threshold segmentation,edge detection,image thinning and edge connecting; the image matching method consiting of picking up feature point,matching and rebuilding.Following the paper presents the devise of the geometrical parameter measuring system.Firstly it discribes the model of the system.Secondly it gives the research of camera calibration method based on the given model.At last it gives the hardware construction and the software design of this system.The software design consists of the total design of the software and the class libraries of the image processing.In the end the paper puts up the experiment analysis about the geometrical parameter measuring system.Fistly it introduces the experimet of camera calibration and gives several calibration results basing on different world coordinate system.Then measuring some objects by use of the calibration results.The paper gives these measuring results and analysis.