Research On The Theory And Realization Of Millimeter Wave Automotive Collision Avoidance Radar

With the development of the automobile industry,the number and performance of the vehicle are constantly improving,so the requirements for the safety of the car are also increasing.Millimeter wave automotive collision avoidance radar is an active anticollision safety system.It can independently analyze dangerous targets and give warning to drivers in advance.It is also an important part of the advanced driving assistance system(ADAS).In recent years,China has made remarkable achievements in the microwave integrated circuits of millimeter wave radar,breaking through the technical blockade abroad.Based on the above background,a millimeter wave auto collision radar system based on FPGA is researched and designed in this paper.Firstly,the basic principle of millimeter wave radar are researched,including the transmitting and receiving of the millimeter wave radar signal,Methods and characteristics of velocity measurement,distance measurement and multi-target recognition under different modulation modes.Based on the design requirements for multi-target recognition,this paper selects the frequency shift keying(FSK)system square wave modulation.Secondly,the overall structure and working process of millimeter wave automotive collision avoidance radar system are designed,and the signal processing algorithm of millimeter wave automotive collision avoidance radar system is mainly studied.The all phase FFT(APFFT)algorithm is used instead of the traditional FFT algorithm to reduce the leakage of spectrum and improve the accuracy of measurement results.The system is simulated by MATLAB software,and the simulation results under different conditions are analyzed.Some reasons for the error are found out,and the error compensation method is put forward.Then,the realization method of millimeter wave auto collision radar system based on FPGA is designed.Various module in the system process are built by QuartusII software.In the distance calculation module,the CORDIC algorithm is used instead of the traditional look-up table method.On the premise of the same calculation precision,the memory resources on the chip are saved.The function simulation of millimeter wave automotive collision avoidance radar system based on FPGA is carried out by Modelsim software,and the MATLAB simulation results of the same parameters are compared to verify the effectiveness of the design and implementation of the system.Finally,the CycloneIV chip of Alteral is used to load this system to carry out the test.The system is connected with the computer through the serial port,and the test process is controlled by MATLAB software,and the test results are analyzed and compared by MATLAB software.The test results show that the design realizes the millimeter wave auto collision radar system based on FPGA,which can recognize single target and multi target,measure distance and velocity.Under a variety of conditions,the relative error of the measurement results is less than 1%.The functions of target tracking and crisis warning are realized.