Research On Optimization Of FlexRay Automobile Bus Scheduling Algorithm

People are increasingly demanding safety and reliability,intelligent comfort and economical environmental protection of automobiles,resulting in an increase in the number of electronic controllers in the car and a sharp increase in signals.Traditional automotive buses such as CAN and LIN can no longer meet the development needs of automotive communication networks.Therefore,the FlexRay vehicle bus standard with high reliability and high bandwidth is an important development direction in the field of automotive electronics.The proper scheduling of FlexRay static segments and dynamic segment messages is critical to improving the overall performance of FlexRay communication systems and is a very important research topic.Therefore,this paper studies these two points.By analyzing the research status at home and abroad,few scholars have used FlexRay static time slots as the optimization target to study the FlexRay static segment.Aiming at this problem,this paper takes the slot multiplexing mechanism provided by the FlexRay 3.0.1 version protocol as the core,and proposes a new method of Integer Linear Programming(ILP)optimized scheduling with the least use of static time slots.Based on the analysis of single transmitter and multi-transmitter,the corresponding ILP optimization mathematical model is established,and the timing constraint equation and upper and lower bound constraints related to FlexRay protocol are established,and the slot number and period number of the signal are allocated.Through MATLAB and LINGO experiments,and compared with the previous ILP algorithm,the experimental results show that the algorithm can reduce the use of static time slots.For the FlexRay dynamic segment,consider the overall performance of the message's overall worst response time and bus utilization.In this paper,the FlexRay dynamic segment correlation protocol is studied in depth,and a new heuristic DM optimal scheduling algorithm is proposed.Based on the mathematics of the worst response and bus utilization of FlexRay dynamic segment messages,the mathematical model of heuristic DM optimal scheduling is established.The overall efficiency is optimized for performance indicators,and the dynamic slot number of the message is allocated.The simulation results of MATLAB show that the proposed algorithm can improve the comprehensive performance of the worst response time and bus utilization of dynamic segment messages.