Research On Image-based Long Guideway Distance Detection Technology

Non-contact distance detection technology is widely used in many fields of modem society and plays a very important role,such as measurement of moving objects,measurement in some harsh environments,the precision measurement of industrial parts,and so on.So it is very important to study and practice it.After studying the analyzing of the existing non-contact distance measurement methods,this paper presents a new method of distance measurement based on image processing to measure the specific position and moving distance of the target on the rail,and design the distance detection system.Firstly,this paper analyzes the demand of distance measurement system,and selects the appropriate hardware equipment according to the analysis.Then,Introduces and analyzes some image processing methods that used in the software part of the detecting system,such as image smoothing,edge detection,circle detection,morphological processing,character recognition,etc.And then using Matlab to simulate and compare several algorithms used in image smoothing and edge detection.In combination with the image collected in the practical application of the system to select some algorithms which are suitable for the application environment of the system of this paper,such as median filter,random Hough transform,template matching and so on.After using CCD camera,image acquisition card,PC machines and other devices to build distance detection system and using Visual C++ to write the program of image processing,detection distance and the results showed on the PC interface,we test the system by the experiment,and analyse the data and the error of the experiment.In the experiment,the distance detection system has been accurately detected the circle center and its displacement change,and accurately identified the number that in the circle,and then output the accurate measurement results.The system can meet the real-time requirement of online measurement.The experimental results show that the proposed method is correct and feasible,and the measurement accuracy can reach millimeter level.