Research And Design Of Weigh-in-motion With Axle Group Platforms Instrument Based On Expert System

Weigh-in-motion(WIM)technology has been developed for many years in our country,and has been widely used in the highway transportation system,such as the weight charge system and the overload detection system.At present,the dynamic weighing system is widely used for the Axle-load and the Full-vehicle.The former as early products,with short scale structure,the weighing accuracy is not high but the cost is low;the latter as a follow-up product,use long scale structure,improve the weighing accuracy but lower efficiency,improve the project cost.The axle group dynamic weighing advantages on the basis of the two,using a single scale can accommodate a triple axle group as the main platform,realizes the sampling time is relatively long,improve the sampling precision and the integrity of sampling,axle group is divided into a plurality of axles and avoid weighing error,enhanced the anti cheating ability;while achieving a relatively low construction cost,construction difficulty and short construction time,and good road environment adaptability,has become the first choice of dynamic weighing replacement.The weighing instrument as the system data acquisition and processing unit,axle type identification,axle group load and the total vehicle weight calculation function by its implementation,its performance determines the weighing accuracy of the whole system and recognition rate of the axle type.In this paper the corresponding axle group type weighing instrument design scheme is proposed,including software multi-threaded development,design and selection of modular hardware instrument,weighing data pre-processing and expertsystem design of four parts.The main contents of this paper are as follows:First,the historical background of the development of dynamic weighing technology is introduced,and the main problems faced at the present stage are discussed.In view of the existing problems of weighing products,the design scheme of axle group dynamic weighing system and instrument is put forward.Second,the main components of the axle group dynamic weighing system are introduced in detail,and the function and working principle of each structure are explained.According to the requirements of the design scheme of the axle group dynamic weighing system,the hardware circuit of the instrument is designed in a modular way.Third,the software design of the axle group dynamic weighing instrument based on the WinCE multi-thread modular programming technology based on the embedded operating system and the instrument screen program design based on the MCGS configuration software.Fourth,according to the characteristics of axle group identification signal,discusses the specific principle on axle identification,coupling identification function realization;analyzes the characteristics of axle type weighing signal,using the weighted recursive average filtering algorithm and smoothing algorithm for weighing signal filtering processing,expounds the selection method and calculation of axle group and according to the effective load weighing segment.Fifth,according to weighing axle groups dynamic data,the corresponding design expert system,the expert system of vehicle dynamic weighing data,realize the vehicle axle identification function,improve the total vehicle weight and axle load group weighing precision and improve the operation ability of fault tolerance.Through the test and according to the verification regulations,the weighing accuracy and the axle type recognition rate of the axle group dynamic weighing system are evaluated.The main innovations of this paper are as follows:The dynamic weighing data is analyzed by expert system,with significant differences between the characteristics of different types of axles as axle type criterion,based on the axle identification results performed corresponding rule analysis effective weighing section data,calculate the total vehicle weight and axle load.While ensuring stable and reliable operation of the system,the weighing accuracy and the axle type recognition rate are improved,and the fault-tolerant operation capability is improved.The instrument and supporting system design of this project has passed the type of evaluation,the total vehicle weight error is less than 0.5%,rigid biaxial reference vehicle axle load error is less than 0.5%,other reference vehicle single axle or axle group load error of less than 1%,to meet the "JJG 907-2006 Automatic Instruments for Weighing Road Vehicles in Motion" and "GBT21296-2007 Automatic Instruments for Weighing Road Vehicles in Motion" in the accuracy grade 1,single axle or axle group load accuracy grade B initial verification requirements.