Research On Next Generation In-vehicle Network Scheduling Algorithm

With the development of automotive technology and the popularization in people’s life,we have higher requirements for the fault tolerance and bandwidth of in-vehicle network,so the existing in-vehicle network such as CAN gradually cannot meet the requirements of great number of communication data.In this situation,the new generation in-vehicle network flexray emergened,with higher transmission rate,better real-time and higher reliability,In addition,it has already applied in some safety critical apps of some premium cars.In this paper,firstly we introduce the backgrounds,domestic and international research status and development trend of in-vehicle flexray network.Secondly analysising the communication protocol and mechanism of flexray network,at the same time it also introduce the key technology in communication such as media access control,clock synchronization,etc.Then it focus on the scheduling problem in the static segment of in-vehicle flexray network,after studying the possibility of scheduling and optimization,comparing the packing problem,genetic algorithm and linear integer programming methods,then the optimization problem of the message scheduling in static segment of flexray network is transformed into a two-dimensional packing problem;the objective is to find the minimum numbers of the used slots during the communication cycle in the static segment.So during coping the packing problem,the objective is to find the minimum height of the messages while these messages can not overlap;However,at this moment,the packing problem cannot completely deal with the priority relationship between the message during the scheduling,we introduce the constrains about the box width of packing problem,message conflict and priority.In the end,this paper tries to find the optimal solution of the mathematic model by using integer linear programming,In addition,it proves the feasibility of optimization algorithm in TC,EPS and ACC apps.