Vehicle deviation line automatic detection system, image processing technology

The automotive vehicle driving wandering the course of a relatively common failure. The failure will result in driving the process, the driver always need to apply a corrective force on the steering wheel, which will increase the difficulty of the operation of the driver, the driver likely to cause fatigue, heavy steering, speed up the parts and tire wear, resulting in system dynamic sliding phenomenon. Especially when the emergency brake on the highway, may also cause serious skid, which caused a major traffic accident, the harm is enormous. The national standard GB7258-2004 "Safety requirements for operation of motor vehicles" is a mandatory standard, the 4.13 states: linear motor drive, its front and rear drive shaft connection with the center line of track should be the same. Now, however, can not exist a set of scientific and accurate detection of the vehicle for the system deviation. Vehicles are usually carried out only at the factory wheel alignment test, people are also found in the actual use of the vehicle after the repair there is deviation problems. There is deviation in order to avoid the problem of automotive products into the market, all vehicles before leaving the factory testing is very necessary.This paper presents a wandering line of vehicles to achieve automatic detection system.The detection system connected with the production line, the vehicle test track trigger photoelectric switches, driver CCD (Charge Couple Device) cameras capture images of vehicles. Image processing module is the vehicle deviation line automatic inspection system, the core content of the main content of this thesis is that the system is based on LabVIEW to image processing and image capture technology. The first chapter of the machine vision, digital image processing concept, development status at home and abroad made a brief introduction. The second chapter analyzes the choice of image processing hardware. Including optical lens, CCD camera, photoelectric switches, light sources and lighting systems, etc., for the practical use of different applications. Through repeated testing, the accuracy of the system meets the requirements of factory production, efficient, adaptable, high degree of automation. The third chapter in theory, through comparative study, the final choice a reasonable recognition method of image processing: median filter, LOG sharpening operator (Laplacian of Gaussian). After image enhancement, image smoothing, edge sharpening, after making the collected images highlight the target area, the edge of clear and complete, by template matching and accurate positioning of the vehicle, the vehicle was finally calculated the deviation information. Chapter IV focuses on the on LabVIEW platform, modular thinking in the application of IMAQ function, to achieve the above functions, to achieve real-time detection. Extraction of the vehicle is different from the usual method of contour to locate the vehicle, the optical sign is proposed as an alternative test method aids, this method greatly reduces the complexity of procedures, convenient and intuitive, and high precision to meet the complex the test environment. Chapter V of the system accuracy do experiments. Finally, the results of this study design and inadequate to do a simple summary. 

Keywords: vehicle deviation test, LabVIEW, image processing, machine vision