The Busload Prediction Model of CANFD Based on Mathematical Statistics

Abstract

A busload prediction models of four kind of frame formats has been established in the paper, the mathematical expectation of the busload for FBFF (FD Base Frame Format), CBFF (Classical Base Frame Format), FEFF(FD Extended Frame Format)and CEFF(Classical Extended Frame Format)is obtained based on the model in order to predict the busload of each message, it can be used for network design. The comparative analysis shows that when the message length is 8 bytes or less, the transmission efficiency of the CBFF is slightly higher than that of the FBFF, while when the message length is between 9 up to 64 bytes, the transmission efficiency of the FBFF is far higher than that of CBFF. The communication bandwidth is greatly increased with flexible data rate, and the longer the message is, the larger the bandwidth will be. The research results have been successfully applied to a variety of vehicle CANFD network design to predict the busload of each message, and application results show that the simulation accuracy is high and the efficiency of CANFD network design is improved effectively.