Research On Road Traffic Vehicle Detection Technology Based On Geomagnetic Sensor

With the rapid development of the city,the increasing demand of urban road traffic,traffic congestion,management difficulties,frequent accidents and other problems are increasingly prominent,seriously hampering the economic development of cities,in order to alleviate urban traffic congestion,improve urban traffic efficiency,intelligent transportation system has been proposed and rapid development.The vehicle detection system as the core content of the intelligent transportation system,plays a fundamental and key role in the ITS.Based on traditional vehicle detection technology,it has the disadvantages of high cost of installation and maintenance,weak anti-interference ability and high power consumption.This paper proposes a kind of vehicle geomagnetic detection system scheme of state machine-based adaptive detection algorithms,which is based on the characteristic of vehicle geomagnetic detection signal,based on AMR magnetoresistive sensor,and designs a low power consumption and Low-cost Road traffic vehicle detection system.At first,this paper introduces the research background and significance of the subject as well as the present research situation at home and abroad,meanwhile summarizes the research contents and main objectives of this subject.Secondly,the model of vehicle magnetic field and the model of magnetic anomaly are introduced,the principle of magnetoresistive sensor and the working principle and characteristics of AMR sensor are described in detail,and an adaptive state machine geomagnetic vehicle detection algorithm is introduced and the realization process of the algorithm is expounded.Then,the general design frame of the geomagnetic vehicle detection system is put forward,which consists of the geomagnetic collection unit,the data receiving unit and the Man-machine interaction unit,in which the geomagnetic collecting unit is responsible for the collection and processing of the geomagnetic vehicle information.The data receiving unit is responsible for the Zig Bee network establishment and the data wireless communication The Man-machine Interaction Unit is responsible for real-time display of geomagnetic data and data storage and query.The main contents of this paper include the hardware design and embedded software realization of the geomagnetic collection system and data receiving system,as well as the design and realization of the man-machine interaction system,in which the hardware design includes power management unit,Signal Processing Unit,AMR Sensor acquisition unit,data conversion and storage unit,Micro control Unit and Zig Bee communication unit;Embedded software includes system initialization,real-time clock unit,data acquisition and storage unit and Zig Bee communication unit software,man-machine interaction software includes data acquisition parameter configuration,geomagnetic data dynamic real-time display and data storage and query.After completing the whole system design and implementation,the system carries out hardware circuit and Zig Bee network communication test,as well as tests and verifies the system function in the laboratory environment and the actual road environment,at the same time carries on the data analysis and the verification to the geomagnetic vehicle detection algorithm,and verifies the reliability and the stability of the detection algorithm through many groups of tests.The test results show that the system has a good effect on the actual road vehicles,satisfying the expected design requirements,and has certain engineering application reference value.Finally,in the test process,the deficiencies and problems of the system,put forward the improvement and optimization advice,and prospected the next research direction.