Research On The Key Technology Of FMCW Vehicle-Mounted Millimeter Wave Forward Vision Imaging

As a walking tool for both long and short distances,convenient and comfortable transportation tool,cars have been greatly popularized in various parts of the world.However,the convenience of cars is accompanied by the frequent occurrence of traffic accidents,It also makes people's life safety and property face great threat.Therefore,compared with other in-vehicle equipment research,it is more urgent to research the vehicle-mounted auxiliary system to guarantee the driver's life safety.Most traffic accidents are caused by the driver's irregular driving behavior,which has prompted automobile manufacturers to rush into driverless cars.An important technology in this field is on-board forward-looking imaging,which helps the car obtain the road information ahead,and then the car control system makes corresponding instructions to the car,thereby regulating the driver's operating behavior and ensuring Driver's safety.This thesis is based on the key problems of FMCW millimeter wave vehicle radar forward vision imaging,Around how to further improve the azimuth resolution and the antenna array suitable for vehicle implementation.Finally,relying on the excellent working characteristics of the millimeter wave radar,the millimeter wave radar and the MIMO sparse array technology are combined to achieve high-resolution imaging of the front area of the vehicle in all weather and all day.This thesis focuses on how to further improve the azimuth resolution of the vehicle's high-looking azimuth,continuously optimize the form of the antenna array,and finally obtains a MIMO sparse array suitable for vehicle-looking high-resolution imaging.Through analysis,it is concluded that the azimuth resolution of SAR is greatly reduced compared to the frontal view under front view;for the array antenna,whether it is in the near field or the far field,its high-resolution imaging depends on the length of the antenna array,However,the limited size of the vehicle-mounted platform antenna limits the azimuth resolution of the vehicle's forward-looking array imaging;the use of MIMO arrays can greatly improve the resolution of the forward-looking imaging,and the size of the MIMO array that is required by the vehicle's resolution can be realized on the vehicle;Using standard BP algorithm and improved TCC-BP algorithm can achieve highresolution focused imaging of vehicle MIMO array,but when these two algorithms are implemented on the vehicle,the real-time imaging rate is not high,and the number of antennas can be reduced to reduce the amount of calculation;The sparse optimization method of grouping realizes sparse optimization of MIMO array.The design method is only applicable to the far field,and the design method is further improved.The sparse optimization design of MIMO suitable for near field is analyzed,or the sparse optimization of near field MIMO is designed by the element-by-element idea.Array to further reduce the complexity of the system.