Real-time Information Mapping Technology Between Vehicle Terminal And Android Device

Android mobile devices have rich navigation,media resources and Internet access capabilities,so the integration of In-Vehicle Infotainment system(IVI)with Android mobile device is a hot issue of auto manufacturers.Vehicle terminals are a series of IVI terminal devices,through real-time information mapping with mobile devices,users could continue using mobile devices in the vehicle,where the smallness of mobile phone screen,the slowness and tediousness of IVI updating are solved.Further,the traditional tactile operation of the IVI is easy to cause distraction,so this paper presents the way of visual gesture operation.In this paper,the real-time mapping technology of the screen and operation information between vehicle terminal and Android device are studied,and verified on the i.MX 6 platform.First of all,this paper builds embedded Linux system and software development environment on the i.MX 6 IVI platform,and studys USB communication methods between the i.MX 6 platform and Android device.After making cross compiling of android debug bridge source code,the i.MX 6 platform can run adb and use the port forwarding technology,which forwards the port of i.MX 6 local TCP connection to the target port of Android device,then the USB network communication between the terminal devices on i.MX 6 and Android device is realized.Secondly,this paper designs the vehicle terminal-Android device interconnection system.The whole system is composed of link layer,transport layer,connection management layer and application layer.The application layer has the functions of screen mapping,audio transmission and user operation mapping.Through the screen sharing technology,android screen image acquisition and processing methods,as well as the active updating technology of LED vehicle display screen,this paper implements the screen mapping technology.In the case of running a variety of applications in the Android device,the technology presents a maximum delay of 85 ms.Aiming at the navigation scene,this paper proposes a real-time screen mapping method based on interframe difference transmission,which can improve the delay of vertical navigation mapping to 40 ms and improve the delay of horizontal screen to 60 ms.Finally,this paper studies the real-time mapping technology of user operation information,realizes the technology of indirect operation of android device through invehicle keys and touch screen terminal,and studies the recognition and mapping technology of visual gesture information collected by in-vehicle camera terminal.The camera is placed at the ceiling above the vehicle shift area to collect gestures,and the improved Gaussian foreground detection model in the YCbCr space is used to segment the foreground in real time.The areas with the error size are filtered by the double threshold method,and the filter and the morphological treatment is used to smooth the foreground,the center of the hand is located by the distance transformation and the minimum bounding box of the candidate area,and the arm portion is removed.Then the classifier,which is integrated the finger number detection,the Hu moment matching and the motion trajectory judgment,identifies the gesture.The technology accurately identifies and distinguishes the 8 pre-defined in-vehicle gesture semantics,maps them as the operations for Android devices.After GPU accelerating,the image processing at i.MX 6 platform speeds up to 15 fps.The results show that the technology proposed in this paper can effectively realize the real-time mapping of screen information and tactile operation information.For the mapping of visual gesture information,the technology can identify the pre-defined invehicle gesture semantics,howevet,the gesture need be placed with higher standard,and when the gesture moves slightly faster,it is difficult to identify the end of the movement trajectory,which will cause mapping failure easily,so there is still room for improvement.