Research And Implementation Of Vehicle Detection System Based On Wireless Magneto-resistive Sensor

Vehicle detection systems provide the data used by Intelligent Transportation Systems(ITS).The disadvantages of conventional vehicle detectors have led to the search for a reliable and cost-effective alternative system.The flexibility,easy of installation,remote maintenance,low cost and high accuracy of wireless sensor will lead to their ubiquitous deployment and thereby provide the fine-grained vehicle detection required to implement effective traffic monitoring and control.The thesis studied the software,hardware and detection algorithms of vehicle detection which is based on wireless magneto resistive sensor technology then improve the traditional vehicle detector,two effective vehicle detection algorithm have been proposed and software has been developed for data analysis and result illustration. Specifically,this study includes following three aspects.First,from the hardware design aspect,the principle of magneto resistive sensor used in vehicle detection has been analyzed,the technology of wireless communication(Zigbee) has been used in detecting the development of each internal node communication,a feasible discussion about magneto resistive sensor been used in vehicle testing based on the former study then a scenario of hardware design has been proposed.The vehicle testing system which is based on wireless magneto resistive sensor consists of five modules:signal acquisition,microcontroller,the circuits of signal conditioning,Zigbee wireless transmission,and power system.This testing system could achieve the function of collecting the vehicle detection information,wireless transmission and processing. Second,in the layout of sensor network,the distribution of sensors in central arrangement is based on the actual sensor network distribution and analyze the data from the experiments.Through adjusting the circuit of vehicle testing,the sensitivity will be improved then the testing diameter will equal to the normal width,in that way, the accuracy will be developed..Third,from the point of view of system data processing and analyzing,system has done research in algorithm of vehicle detector data analysis.The thesis has proposed a testing algorithm based on iterative optimal wavelet threshold which is based on the idea of adaptive threshold used to focus on testing whether vehicles passing by.For speed detection,the traditional algorithm of speed detection has been improved,a new speed detection method which is based on clock synchronization has been proposed.In that way the error of speed detection will be minimized.Through the data processing system, whether vehicles through the certain region can be detected and make a speed testing furthermore determine the direction of vehicles.Finally,a vehicle detection software which is used to detect the traffic situation of multi-kind of vehicles(different speed,driving direction) in the actual road and based on the vehicle detector used the technology of magneto resistive sensor has been designed and realized,the effectiveness of the algorithm and the reliability of the hardware has been tested.Experimental result shows that,the vehicle detection system which is based on magneto resistive sensor could achieve high detection accuracy.