The Application Study Of Weigh-in-Motion System On Expressway

As an effective management tool for vehicle overloading problem,VehicleWeigh-in-Motion(WIM) systems were rapidly developed followingtransportation investigation,controlling serious vehicle overload and weighingcharge.It plays a important role of protecting freeway to use normally.For the highway weigh-in-motion systems,the weighing accuracy and thespeed of vehicle moving were the most important standard specification.Itindicated the technical level of WIM systems. On the basic of reserching thefacors affecting the measure definition,this paper selects the suitable sensor,alsoit designs the data acquisition and transmission system and weighing algorithm.This paper carries out experimental verification,and achieves more satisfactoryresults.The following is the main idea of the paper:Firstly,this paper analyzes the vehicles’ dynamics and kinds of factor whichwill decrease the precisim when weighing the running vehicles on the basis ofrefer to a large number of domestic and foreign literature.Secondly,after analyzing the factors affecting the measure definition and considering the sysytem structure,this paper selects piezoelectric quartz sensoras a weighing unit.Then the scheme of the sensor array is present.Also RS-232interface is selected to carry out the data transimission.All of these improve theweighing accuracy and system efficiency.Finally,based on signal characteristic of piezoelectric quartz sensors, thewavelet theory was applied to filter the noise. Then the phenomenon of “missaxle signal” is corrected by an integrality analyse used signal correlation. Finally,the BP neural network model is established and used to get the static vehicleweight, utilized the sensor output value of sensor and speed of vehicles.Experiment results indicate that the algorithm has a high accuracy andreliability.