The Research Of Signal Processing Circuit In Vehicle Volume Detection Radar

With the development of economy, the sharp increase in traffic volume increased traffic congestion; the establishment of Intelligent Traffic System (ITS) has become an urgent need. The collection of traffic information, acting as an input to the ITS, takes on an very important task for providing the whole ITS with accurate information sources. This paper presents a series of study of software and hardware aspects to solve many key practical questions, in order to develop a high precision, good stability, and wholly day volume detector to meet the needs of intelligent traffic development. Our traffic flow detection radar system includes of the RF circuit, the IF circuit, the digital circuit and the computer operating interface, etc. This paper focuses on the IF circuit and digital circuit design, debugging and achievement.With the background of the microwave traffic detector, this paper first presents the ITS, and the application of microwave traffic detector in ITS, and the advantage and disadvantage of various the traffic information collection technologies. The background and the main topics of my research are presented.Considering the requirements of vehicle volume detection radar, this paper presents the principles and the framework of vehicle volume detection radar. Then, the digital circuit board design and implementation, the system software and drivers and IF design and implementation are described.As the core components of the system, digital circuit board is responsible for the entire software algorithms and communication functions.This paper first describes the overall structure of the digital circuit board and the core components of DSP TMS320VC5502. Then, this paper presents signal conditioning, ADC, triangular wave, external memory interface, real-time clock, communication interface, power and reset circuit and anti-jamming circuit etc. Validated by experiments, the function and stability of the digital circuit board meets the needs of practical applications.The digital circuit board provides a platform for the system, and the software realizes the function of the system. This paper first describes the the overall frame of the radar sotware. Then, the drivers of the signal acquisition, spectrum analysis, EMIF interface design are discussed in detail. The actual application has verified the relevant codes.The amplitude of IF signal from RF is very weak, and very obvious leaked triangular wave exists. So, the digital signal processing unit cannot manage that singal. The IF circuit board deals with the signal amplification and filtering functions.Finally, this paper presents the test data from field experiments and error analysis. Validated by experiments, the stability and the accuracy of the vehicle volume detection radar have meet to the practical application.