Design And Implementation Of Vehicle Audio And Video System Software Based On Car Life Protocol

CarLife is Baidu's network of solutions,and it's also the first domestic crossplatform car networking solution.In the car machine terminal,whether it is Linux,QNX,Android,CarLife can be well adapted.In the mobile device side,CarLife can also support Android and IOS dual operating system,and covered a wide proportion.At present,the domestic research on the vehicle information system has not formed a unified standard,car manufacturers develop according to their own needs.Based on the analysis of the shortcomings and shortcomings of traditional vehicle information,this thesis studies and implements a new vehicle information system based on Baidu CarLife protocol.The hardware platform designed for this system is based on ARM's Cortex-A9 as the main control unit,for coordinating the system's external circuit and supporting CarLife protocol standards.In order to meet the requirements of low delay and high performance,the Linux operating system is chosen as the software platform,and the design and development of the connection engine and audio and video engine are the significant tasks to complete.The main contents of this paper are as follows:(1)In order to make up for the existing vehicle information system on the market which can not cross the platform,this thesis decide to determine the use of CarLife protocol for car-side development.By analyzing the system requirements and functional requirements,this thesis presents the overall architecture of the system,including the design of the hardware platform and the CarLife software design scheme.The design and implementation of the connection engine and audio and video engine are the difficulties in this thesis.(2)In order to solve the existing car information system does not support Android and IOS dual platform,this thesis designed and implemented a new solution: for the Android system,this thesis based on the AOA protocol design and implementation of a solution for Android audio accessories;for the IOS system,this thesis based on the EAP protocol design and implementation of the iPhone and the car between the dualscreen interaction,compared to CarPlay,the program only needs MFI certification,but also supports IPV4 / IPV6 communication.(3)For the traditional car Bluetooth tedious manual matching connection,this thesis achieve the Bluetooth automatic matching function in the car side,automatic matching connection,without the need for traditional manual search connection.(4)Multi-module audio playback task needs to be handled in the audio module,including navigation TTS modules,multimedia modules and other audio modules.The data channel audio data needs to be dealt with to achieve audio focus management strategy,and navigation voice broadcast and local audio conflict processing to achieve front and back play is a significant task to complete.In CarLife,the system test environment is set up;the basic functions,performance(stability,compatibility,CPU usage,memory usage,video delay,connection delay,etc.)are tested in detail in this paper.The test result shows that,CarLife designed in this thesis can achieve the desired requirements,achieve the basic functions of vehicle information systems,and make performance reliable and stable.