Research On Target Detection And Location Method Of Vehicle-mounted MIMO Millimeter Wave Radar

With the increasing development of transportation in modern society,traffic accidents are occurring more and more frequently.Research on vehicle-mounted millimeter wave radar has become an important part of reducing road traffic accidents,which plays an important role in improving traffic safety and reducing pedestrian and car accidents.Vehicle-mounted millimeter-wave radar has become a key technology for safe driving of vehicles due to its unique advantages that it is not susceptible to haze,rain and snow.Various large research institutions and automobile manufacturers have been committed to complete the design of a cost-effective on-board millimeter-wave radar suitable for family cars in a limited space and at an appropriate cost.Because of the "multiple-transmit-multiple-receive" feature of MIMO radar,it has special advantages in target range,speed,and azimuth angle detection.Therefore,MIMO radar has become a popular direction in the field of radar research over the years.Under the condition that the number of received signal channels remains unchanged,MIMO radar generates a virtual array to expand the antenna aperture,thereby increasing the freedom of the system,making it a significant improvement in the accuracy of target angle estimation,and has the advantages of small size and low cost.This article first analyzes the current research status of vehicle-mounted millimeter-wave radar at home and abroad.Secondly,clarify the basic principle of linear frequency modulation continuous wave radar,and deduced the extraction process of detecting target information,including target distance,speed and angle.Then,on the basis of the original millimeter wave radar,MIMO technology is added,and the angle estimation of the target is studied by using the MIMO radar,and the Capon algorithm,MUSIC algorithm,ESPRIT algorithm and ROOT-MUSIC algorithm and other MIMO radar DOA angle estimation algorithms are studied.On this basis,the MUSIC algorithm and ROOT-MUSIC algorithm in the MIMO radar are further studied.Aiming at the problem of the MUSIC algorithm with a large amount of calculation and the need for spectral peak search,and the high computational complexity of the ROOT-MUSIC algorithm,a low-complexity algorithm is proposed.Degree beam space unitary transformation method to reduce computational complexity and computational complexity and improve the accuracy of target angle estimation.The effectiveness of the method is verified by MATLAB simulation experiment.Finally,aiming at the problem of small aperture of uniform linear array and insufficient angular resolution,a co-prime array model based on MIMO radar is proposed to improve the accuracy of angle estimation.Research the DOA estimation accuracy of MUSIC algorithm applied to three array models of traditional coprime array,uniform linear array,and MIMO coprime array.Simulation results show that MIMO coprime array is superior to uniform linear array and traditional coprime array.Angle estimation accuracy.In general,the research in this thesis aims at the target detection and positioning direction problem of vehicle-mounted MIMO millimeter wave radar,and solves the DOA angle estimation accuracy and calculation complexity from different angles.Each content complements each other and forms a relatively complete set of theoretical results.It provides technical support for the research of vehicle-mounted MIMO millimeter wave radar target detection and positioning methods.