Design And Experimental Research Of Magnetic Induction Vehicle Detection System

With the increase of the number of vehicles,traffic problems such as road congestion and collision also increase.Therefore,intelligent transportation system has gradually become an important system to solve traffic problems.The system involves several subsystems,which are composed of large and complex parts.Geomagnetic vehicle detection technology is one of the front-end detection methods of the system,and is the main basic core part.In this paper,based on the geomagnetic vehicle detection technology,a geomagnetic vehicle detection system based on PNI magnetic sensor is designed,and in view of the interference characteristics of vehicles to the earth magnetic field,a finite state machine detection algorithm based on adaptive multi-threshold is proposed,as well as the calculation method of vehicle flow,vehicle speed and vehicle length based on this algorithm.Based on the research on geomagnetic vehicle detection technology,this paper mainly includes:Firstly,the detection principle and model of geomagnetic vehicles are analyzed,and the magnetic field interference signals of vehicles and the signals obtained by the detection system are analyzed to determine the components of the detection signals and the different processing methods of each component.Secondly,the overall scheme of detection equipment is analyzed and designed,and the detection equipment with low power consumption,small size and simple hardware composition is prepared,and the software program is written.Then combined with the actual data and model simulation,a finite state machine detection algorithm based on adaptive multi-threshold is designed and proposed,and the vehicle flow and speed detection algorithm based on this algorithm and the vehicle length detection algorithm based on waveform characteristic values are proposed.Finally,the test experiment of vehicle flow,vehicle speed and vehicle length was completed,and the experimental results were sorted out.The error sources of the test results and the methods to reduce the error were analyzed.The results show that the geomagnetic vehicle detection system proposed in this paper maintains a high detection accuracy,and the calculation of the algorithm is small and simple.To some extent,it can facilitate the related departments to manage the road traffic,which has important significance and broad application prospect.