Development Of Vehicle Detection System Based On Geomagnetism

The modernization of the city has greatly improved the living standards of the people,the rapid increase in the number of motor vehicles,the difficulty of parking and the crowded roads,which have seriously affected the quality of life of the Chinese economy and people.If we can quickly and accurately detect the parking lot,roadside parking,and road traffic conditions and so on,and make appropriate decisions,will fundamentally solve the problem of parking and road congestion.Therefore,it is necessary to design a high precision vehicle detection system to monitor the parking and road traffic conditions in real time.In this thesis,based on the comprehensive study of the geomagnetic detection algorithm and the wireless spread spectrum technology,a set of wireless communication system is designed,Study on several problems that seriously affect the geomagnetic vehicle detector,the main work of this thesis includes:(1)The system detects the three axis value of the magnetic field by the detector to judge the information of the vehicle flow,vehicle speed and parking position.The weighted function is used to modify the datum,the adaptive algorithm is used to update the datum and the state automatically.The actual test results show that the traffic flow rate can reach more than 98.8%,parking detection can reach more than 99.5%.(2)Combining the latest LORA spread spectrum communication technology with the geomagnetic vehicle detector,design a wireless network super long distance vehicle information detection system based on AMR sensor,the communication distance of the geomagnetic sensing system is increased.(3)This system is based on low power hardware design,and then through the design of software algorithm working on the function module of reasonable switching,low power consumption power supply system,laid the foundation for long time stable working system.The final realization of the system can work under the limit pressure for 5~8 years.The system consists of a wireless geomagnetic sensor,a repeater and a data receiving gateway.The detection of wireless geomagnetic vehicle detection node of the vehicle caused by changes in the intensity of the earth's magnetic field,the algorithm is processed by a dedicated route to the acquisition center through the traffic data management software analysis,It will play an important role in improving the traffic capacity of urban roads and alleviating the urban traffic congestion.