Research On Vehicle HD Panoramic Image System

In the past few years,with the rapid increase in the number of automobile brands,the automotive electronics industry has developed rapidly.People began to pay attention to some electronic configurations when selecting cars,such as: AVM(Around View Monitor),LDW(Lane Detecting Warning),FCW.(Forward Collision Warning)and PCW(Pedestrian Collision Warning),etc.,are some applications for machine vision and image processing.Therefore,the technology of machine vision and image processing has also risen along with the development of the automotive electronics industry.With these features,the car is much more convenient during the journey,especially when parking,you need to park the car in the specified parking space.Because the existing social resources can not fully meet people's needs,especially for novices who have little driving experience,how to park the car in the corresponding parking space has become a headache for many newcomers.In response to this problem,many domestic and foreign-owned vehicles are equipped with a safety assisted driving system before leaving the factory,which can help the driver to park the storage,and the fisheye camera is the key to this technology.Therefore,fisheye cameras and related embedded systems are widely used in safety assisted driving systems.Today,many mid-to high-end domestic cars on the market are equipped with 360 look-around(vehicle panoramic image system),referred to as AVM.The system mainly installs a fisheye camera around the car,then collects the video around the car,and finally splices it into a panoramic image and displays it so that the driver can observe the situation outside the car.This function can be used when the parking space is relatively narrow,which can greatly reduce the risk of accidents such as scratches and make it easier for the driver to park the vehicle in the reserved parking space.However,with the advancement of technology,the AVM system on the market has gradually improved,but it is still far from enough.Today's AVM system is built on four common standard fisheye cameras.The captured image is also of ordinary quality,and it is even difficult to identify the license plate of the vehicle in front.If there is a frictional collision with the preceding car,it is not possible to identify who is the main person through the video screen.Therefore,the AVM system is no longer only used for parking.With the development of society and the advancement of technology,people's demand and specifications for products continue to increase.If the standard definition image technology of the vehicle standard definition cannot keep up with the advancement of technology,it will gradually be banned.A new generation of car HD panoramic image system will be born,referred to as HAVM(HD Around View Monitor),which can be comprehensively improved in terms of technology and video quality and system functions,and may lead the automotive industry ADAS(Advanced Driver Assistance System)system.Towards a new era.This thesis is aimed at the design of vehicle HD panoramic image system.From the design and trial adjustment of hardware board circuit to the research of software algorithm,a high-definition fisheye camera with interface type LVDS(MAX96705)is adopted,and the high-speed serial matching with it is adopted.The deserializer(MAX9286)deserializes the image video data stream and then performs experimental calibration and field calibration of the camera.The internal and external parameters obtained by calibration are used to generate panoramic images for perfect splicing of high-definition panoramic images of the vehicle.This thesis applies a high-speed serial deserializer MAX9286 chip,which de-strings 4-channel high-speed serial signals into 4 sets of high-speed parallel MIPI signals,and then directly inputs them into the MIPI interface of the CPU to perform image processing in the GPU,including images.Distortion correction,corner detection,perspective transformation,image stitching,and image enhancement processing,and finally output panoramic images directly from the LVDS interface of the CPU.Compared with the traditional standard definition ring system,it does not require complicated decoding and encoding circuits,and it is not easy to be interfered with the CVBS output,which greatly reduces the design cost and is superior in definition.The main research contents of this thesis are as follows:(1)The autor studied the basic knowledge and related technologies necessary to realize the vehicle HD panoramic image system.First,analyze the implementation principles of the current common surround vision system,as well as the commonly used surround vision system solutions.Second,research and implementation of the technical methods related to the system,including: distortion correction,corner detection,perspective transformation,image mosaic,image enhancement processing.(2)The autor completed the overall design scheme and detailed design of the vehicle HD panoramic image system in order to realize the specific functions of each module.The autor then analyzed the design principles and design goals of the system,integrate all the functional modules of the system,and design the sub-modules in detail to realize the image acquisition,internal parameter calibration,perspective change,image mosaic and Features such as image enhancement.(3)The autor implemented testing of system function modules on the toy car and on the real car,the internal parameters and external parameters of the four-way high-definition fisheye camera fixed around the toy car are calibrated,and then try to splicing into a complete image on the toy car.After the splicing is completed,whether the spliced image is misaligned carry out testing.The main results of this thesis are:(1)The author completed the design of the system board schematic diagram and the follow-up of the board production,patching,etc.,and then through the hardware debugging of the board,so that the system board can run normally,and then optimized by DDR Stress Test.Let the board run at optimum speed.(2)The author realized image acquisition on the system board,and performed distortion correction,corner detection,perspective transformation,image mosaic,image enhancement,etc.on the image,and displays a high-definition panoramic image on the display screen.(3)The author performed splicing test on the toy car and on the real car,including the installation skill of the camera and the position placement rules of the checkerboard calibration,and finally the panoramic image function can be realized on both the toy car and the real car.