Research And Implementation Of Traffic Information Acquisition Radar

Accompany with the increasing number of private cars in China, urban traffic have become a serious traffic problem. Indeed, development of intelligent transport systems is an effective way to solve the urban traffic problem. Traffic radar as a major part of the Intelligent Transportation System has all-weather, all-time, high accuracy and other characteristics. Therefore, traffic radar has attracted more attention. But, at present, the domestic research is backward, one of factor is lacking of a kind of multifunctional radar that can be used for acquiring traffic information.The goal of this thesis is researching a radar system which is applicable to acquire vehicle information on highway. The radar can measure the velocities, distances, azimuth angles and other basic information in the radiation range. Subsequently, multi-target tracking and track management are executed by the upper computer based on the measured data which is uploadedThe main contents of this thesis are summarized as follows:(1) First of all, study the principle of LFMCW, FSK, MFSK and FSK-FMCW that be used to measure velocity and distance, in hence, analyze the ability of distinguish in multiple targets situation of each principle. Compared with advantages and disadvantages of each radar principle, the principle of FSK is selected to implement the system. With the method of radar angle measurement discussed, the maximum unambiguous angle and angle measurement accuracy of the dual antenna phase angle measurement are analyzed. In the end, The OS-CFAR algorithm for multi-targets detection is studied and simulated.(2) Confirm the system parameters and design the system hardware. According to the design of indicators of the system, parameters of the system are analyzed and determined. Besides, the RF front-end is selected based on the requirements of radar principles. In order to realize that four-channel signals of the RF front-end are acquired respectively at real-time, the DSP+FPGA structure is designed. The filter amplifier module, the core processor module, acquisition module and the system power supply module are completed using the module design.(3) Firstly, in order to achieve the function of system software,the program flow chart is designed. Then, the program that involved FPGA module of data acquisition and the DSP module of signal processing are accomplished. It included external equipment chips logic control and the realization of the digital signal processing algorithms. Finally, the ultimate goal is to achieve the function that target information can be detected and estimated in the hardware system.(4) To improve ability of the multi-target detection, research the distribution character of clutter and then design digital filter in order to reduce clutter. The error correction method of I/Q channel amplitude and phase is studied to suppresse image frequency interference. The algorithm of OS-CFAR detection is achieved by the list structure in order to improve the operating efficiency of the system.(5) The measuring test is implemented in the real highway's scene. The test result indicates the important information of each target's velocity and location is measured accurately by this pepper developed radar. Additionally, based on the real-time Time-Frequency analysis image, a new method to estimate the flowrator and distinguish the vehicle type is proposed.