Traffic Detection Radar System Design And Implementation

With the rapid development of the national economy in the society today, urban population becomes larger and larger, transportation becames more and more popular, which leads to the severer problem of urban traffic safety and congestion. Therefore, the establishment of intelligent transport systems is greatly imperative. As an important source of traffic information in intelligent transportation systems, the microwave traffic detection radar can provide data support and assistant reference for urban transport management and road construction planning. By researching and designing the traffic detection radar system, we successfully develop the high-performance traffic detection radar, so as to meet the demand of actual road test.First of all, this dissertation describes the working theory of detection radar based on linear frequency modulation continuous wave system. After that, the key parameters are determined through the system demand analysis, and the composition design of the microwave traffic detection radar is completed according to working principle of radar. Besides, the general scheme of hardware and software of the system is designed.What’s more, the signal model of the traffic detection radar is established in this dissertation, and the transmitting signal, echo signal, IF signal, clutter and noise of the traffic detection radar are researched and analysed according to actual road situation. In order to be analysed quantitatively and provide signal data, signal simulation of eight lanes’IF signal under every condition is completed. At last, the analog IF signal is successfully generated with IF signal analog generator based on directly digital drequency synthesis technology (DDS), which is used in system’s joint test and simulation experiment.In order for the intermediate frequency signal to be digitally processed at the back-end, a IF signal processing board is designed and fabricated, which is made up of the power filtering module, the triangular wave generation module, the DC uplifting and amplitude limiting module, and the amplification filtering module, which is the most important of all. In this dissertation, the design of the new-style IF amplification circuit based on positive slope gain amplification effectively improves the target detection range, which increases the radar’s detection range from original4lanes to8lanes.The digital signal processing circuit is the hardware foundation to realize detecting algorithm, data storage and communication with host computer. TMS320F2812is used to be the core of digital signal processing hardware platform, the design of peripheral circuits, such as power management module and reset circuit, extensional SRAM and FLASH, and serial communication interface is described as well.The software design of the digital signal processing board is the key to accurately detect the road traffic information in real time, and mainly includes writing bottom driver codes and designing top layer algorithm. Through the design of the AD sampling module, FFT algorithm module, vehicle flow detection algorithm module and host computer communication module, vehicle flow detection and host computer communication function is successfully realized.At the last of this dissertation, the performance of this microwave traffic detection radar is tested on actual roads. The experimental results show that the detection radar can detect vehicle targets of4lanes stably and accurately. Besides, the joint test of simulation system successfully realizes correct count of8lanes, data storage and host computer communication.