Design Of Vehicle Weigh-In-Motion System

In recent years, over-road freight vehicles in China is a common phenomenon. In the region seriously, almost all freight vehicles are varying degrees of overloading. Weigh in motion is an essential technology in expressway management, and it is emerging in China. By using the WIM(Weigh-In-Motion) system, the loss of road surface can effectively slow down. It can save the cost of road maintenance, and reduce traffic accidents caused by overloading. With the tax systems, it can also prevent the huge loss of the tax revenue.On the basis of refer to a large number of domestic and foreign literature, this article havd analysized the the various factors of dynamic vehicle weighing system that affect measurement accuracy. It obtained that the factors of dynamic vehicle weighing system not only contain the static weight, but also include the speed of vehicles, the vibration of vehicles, the ground is not smooth, and so on. Then the idea of improving the accuracy of WIM system was suggested from both hardware and software angles.Then, the hardware of the WIM system had been designed. This system used Straingauge Load Cell, and designed the signal amplifier cuicuit, AD converter circuit, signal acquisition circuit, MCU control circuit and communication circuits. The article also gives the signal flow chart.The data signal processing has a very big impact for accuracy of WIM system. Papers also researched several signal processing algorithms on the dynamic weighing: the maximum measurement, the average algorithm, the EMD algorithm, the neural network algorithm, and the parameter estimation algorithm, with an emphasis on the estimated parameters algorithm. Using matlab, the simulation showed the algorithm achieved good results.Finally, the paper detailed the WIM system software development methods and development process. The system uses SQL Server 2000 database as a development platform, and Visual Basic 6.0 as application development tools, and its user-friendly.