Design And Implementation Of Vehicle Multimedia System Supporting Dynamic Update Of Application Programs

With the rapid development of the Internet,innovative technologies in software related fields have been widely used in the field of automotive electronics.At the same time,software defining Automotive has become the main idea of automotive function design.Vehicle multimedia system is the "core" of vehicle software and the communication center of various vehicle software.With the whole life cycle of the vehicle,ensuring the update timeliness of vehicle software is an effective means to maintain the stable operation of the vehicle.The traditional on-board software update method has some problems,such as difficult update,low efficiency and strong professional technology.At present,when using the latest OTA（over the air）technology to update the software,it is also faced with the need to close the software first and restart the software after the update is completed.On the one hand,the software service will not only be interrupted,On the other hand,the software update is not transparent to users,which undoubtedly increases the difficulty of operating the software for users.And the software update speed is too slow,which will greatly increase the safety risk of the car.Therefore,it is very important to provide a software dynamic update method to meet the uninterrupted of on-board software to be updated.At present,the existing software dynamic update method is mainly to update the software of the data server,but on the one hand,the software dynamic update method of updating the data server does not support the on-board embedded equipment.On the other hand,there is a problem that the software cannot be safely rolled back to the previous version when the update fails in the process of dynamic update,which needs to be solved urgently.On the basis of in-depth study of the existing software dynamic update methods,and improving the existing software dynamic update methods,this paper proposes a software dynamic update method based on auxiliary threads,and uses this method to design a vehicle multimedia system that supports application program dynamic update.The system is composed of automobile OTA and vehicle multimedia terminal,which realizes the iterative upgrading of application program in vehicle multimedia system in the whole life cycle of automobile.The main work of this paper is as follows:1.The existing mainstream software dynamic update methods and vehicle multimedia operating system are deeply studied,and the related technologies.Then it focuses on the shortcomings of the existing software dynamic update methods,and puts forward the software dynamic update method based on auxiliary thread,which is mainly composed of two parts: 1)auxiliary thread generation module: used to generate the function patch to be updated called by auxiliary thread.2)Software dynamic update control module: used to control the whole update process of the software to be updated.When the software crashes due to dynamic update,it can roll back to the previous version of the software by long jump.2.Using the dynamic update method based on auxiliary thread proposed in this paper,an on-board multimedia system supporting dynamic update of application program is designed.After that,the parking aid software supporting dynamic update and the audio and video playback software supporting dynamic update are written.3.The system is implemented on NXP ls1028 a platform based on Linux +QT.The software dynamic update experiment is carried out on the parking aid software and audio and video software.At the same time,the data is recorded by adding log in the program to obtain the test results.For the parking aid software and audio and video software,in each simulation test scenario,the on-board multimedia system supporting the dynamic update of application program proposed in this paper can stably,reliably and efficiently complete the dynamic update of software,which proves the feasibility,stability and easy operation of the on-board multimedia system supporting the dynamic update of application program.For the parking aid software and video software,in each simulation test scenario,the Vehicle multimedia system supporting the dynamic update of application programs proposed in this paper can stably,reliably and efficiently complete the dynamic update of software,which proves the feasibility,stability and easy operation of the Vehicle multimedia system supporting the dynamic update of application programs.