Research And Design Of Vehicle Blind Spot Monitoring System Based On Microwave Radar

With the development of the automobile industry,the number of automobiles has been increasing,and automobile collision accidents have frequently occurred.Part of this is due to the presence of blind spots in the left and right rearview mirrors of the car.Therefore,the development of a blind real-time monitoring system can effectively prevent accidents caused by visual field blind spots.Microwave radar has the advantages of long detection range,high detection accuracy,can work around the clock,and is less affected by the environment.It has been widely used in automotive blind spot monitoring systems.This paper proposes a design scheme of a blind spot monitoring system based on microwave radar.The basic principle of microwave radar measurement,system hardware design,radar IF signal processing algorithm and system software design are discussed in detail.In the hardware design,the SMR-334 microwave radar,STM32F405RGT6 microcontroller and other components are selected to design the overall circuit of the microwave radar slave.STM32F103C8T6 microcontroller and other components are selected to design the overall circuit of the master controller and the circuit The parameters and functions of each component are discussed in detail.In the radar IF signal processing algorithm,due to the fact that the radar IF signal is mixed with Gaussian noise,high-frequency interference signals,etc.,it will affect the system’s false alarm rate.This article has studied and adopted a FIR filter algorithm with linear phase characteristics for radar IF.The signal is filtered,effectively improving the signal-to-noise ratio of the system.In this paper,microwave radar uses multi-frequency shift keying modulation method.It needs to extract the frequency spectrum and phase spectrum of the signal to measure the target.At present,the FFT algorithm is often used to extract the signal.Because this algorithm has spectral leakage problem,it will also affect the false alarm rate of the system.This paper introduces an improved all-phase FFT algorithm to improve the spectrum leakage problem and effectively improve the accuracy of phase measurement.In addition,the FFT algorithm has a fence effect when extracting frequency spectrum,which reduces the accuracy of the target measurement.To solve this problem,the linear frequency modulation Z transform algorithm is used in this paper to improve the frequency resolution of the frequency band between adjacent spectral lines of the peak spectrum.Increased frequency measurement accuracy.Using MATLAB to simulate the above algorithm,the simulation results verify the effectiveness of the algorithm.In the software design,this paper gives the flow chart of the main controller and the microwave radar slave,and finally uses the MDK integrated software development.The environment completes the software design and debugging of this article.At the end of the paper,the test experiments were carried out on the system microwave radar radar CAN communication function,vehicle speed acquisition function and system warning function.The actual test results show that the system designed in this paper can monitor real-time targets within ten meters of the left and right adjacent lanes of the vehicle.When a target is continuously approaching the vehicle,it can provide early warning information to the driver.