Study Of Volume Measurement System Based On Machine Vision

"Green channel" is a policy proposed by China in favor of farmers, but in policy implementation, there appears to be some fake"green channel"vehicles, evaded paying normal fees and disturbed the normal traffic order. Now commonly used detection method is manual inspection, which increased the human cost and affected the traffic efficiency. It requires technical means to accomplish the vehicles detection, improve the mechanical and electrical charging system, which long-term policy on the implementation of the green channel has an important practical significance.In view of the above requirements, this paper puts forward a proportion method testing system, which is according to the contrast between the truckload, cargo volume and the density of goods, by calculation and analysis to distinguish their consistency between the goods and declared goods. Complete proportion method detection system consists of weighing test system, optical volume measurement system and license plate recognition system. This paper will focus on the optical volume measurement system that is the core among the three parts.With the rapid development of the computer image processing and optical technology and related disciplines, machine vision measurement technology in industrial measurement has been widely used. It is a kind of using CCD camera as image sensor, combining with image processing technique to complete non-contact measurement. Optical volume measurement system is based on machine vision measurement technology which is using strcture light measurement method . its basic principle is through structured light projector to the surface of the object to project a structure light pattern, and then get a distorted inage caused by the object height is recorded from another angle, so as to realize the 3-d contour object measurement. This measurement system uese the CCD camera and laser installed above the driveway to shoot and measure the top of carriage, and uses the CCD camera, laser, and photoelectric sensor installed in the side of the driveway to measure carriage length. At last, it through HALCON software processing can get the effective loading volume of the vehicle.First this paper from the basic theory of the machine vision measurement system, to design the optical volume measurement system. Through analyzing and comparing the existing camera calibration methods, combining with the actual situation and the project requirement put forward the calibration method of the volume measurement system - camera calibration based on HALCON software. Image acquisition and preprocessing. Then make smoothly processing, binary processing, thinning on the laser stripes, and then after curve fitting method, to restore it to the actual three d measurement data. Volume calculation. On the basis of analyzing mathematical theory, propose two calculation methods of irregular cross-sectional area, combined with the system, make a detailed design analysis on measuring carriage length. Finally analyzes the realization of volume measurement system, including hardware installed and software workflow, while analysis its experimental test data and the error.The green channel vehicle detection is a complicated process, it needs many means to improve testing precision.Proportion method detection is a part of the green channel vehicle detection. Optical volume measurement method is an innovation in the area of vehicle detection. The current systems engineering degree is not high, therefore, it needs to accumulate a large number of experimental data to try to find more have detection judgment function statistical laws or relationship factors, and continuously modify the detection algorithm to improve the detection performance.