ECU Remote Swipe For In-Vehicle CAN Networks Based On Optimized Differential Algorithm

Nowadays,the Internet is booming,and cars as people’s basic travel tools are also integrated into the Internet trend,gradually developing into smart cars.Car software is constantly pushing out new products,but the reality is that each new product can not be invested overnight,and needs to be constantly improved and adjusted according to user feedback.If the traditional solution is to recall the car in the factory or in the 4S store for a unified upgrade and repair,it will be a very heavy task,which will affect the user experience and satisfaction on the one hand,and on the other hand will cost a lot of manpower and material resources,so Over-the-Air(OTA),an over-the-air(OTA)download technology for remote upgrade software,has been introduced into the automotive industry.Automotive OTA technology is a technology that remotely manages data,firmware or application software on a vehicle terminal through a communication network.As a remote upgrade terminal,the communication between the ECU(Electronic Control Unit)carried on the vehicle mainly relies on the on-board CAN(Controller Area Network)network,which currently has the disadvantage of limited transmission bandwidth,making it difficult to transfer oversized files to achieve high-speed upgrades.Therefore,it is very important to study how to balance transmission speed and transmission quality in OTA upgrade to improve user’s upgrade experience.Firstly,this paper researches the OTA technology architecture,analyzes the OTA differential upgrade process,and proposes an optimized ECU remote refresh scheme based on the characteristics of the in-vehicle CAN network.The research first analyzes the current development status of OTA technology,points out the challenges and problems faced by OTA development,puts forward the demand for ECU remote swipe,and designs an improved OTA process and technical framework;then the core steps of OTA differential upgrade are studied,and the differential algorithm Bsdiff,which is applied to car upgrade,is analyzed to have great room for improvement.A combined optimization scheme is proposed around the two phases of the differential process,introducing the Div Suf Sort suffix array construction algorithm to optimize the string index generation phase,and using the Zstd lossless compression algorithm instead of the original algorithm of Bzip2 compression algorithm to complete the process of compressing and decompressing the differential packets.The experimental results show that the differential upgrade solution based on the combination of Div Suf Sort algorithm and Zstd algorithm can effectively reduce the total time required for the upgrade and achieve the purpose of improving the upgrade efficiency.Secondly,in order to ensure the robustness of the upgrade process,this paper designs an OTA fault tolerance mechanism and a burial point analysis mechanism.The fault tolerance mechanism mainly includes two aspects,on the one hand,it detects the remaining memory space of the vehicle before the upgrade to prevent the event that the upgrade cannot happen due to insufficient memory.On the other hand,after the upgrade,the old version of the vehicle upgrade software is retained in the service platform,so that the version can be restored in time when the new software upgrade fails or has compatibility problems.The buried monitoring mechanism generates buried logs by collecting key data during the upgrade process,and the service platform can further collect and analyze the data based on the buried logs.The experimental results show that the optimization of the core process of OTA upgrade and the design of fault tolerance mechanism effectively avoid the upgrade failure caused by insufficient network capacity in the process of ECU remote flushing under the on-board CAN network,and avoid the risk of upgrade failure due to insufficient memory.By adding the buried point analysis mechanism,the observability of the OTA upgrade process and the fast root cause location on the server side are realized,further enhancing the stability of the service.