弹上CAN总线网络设计仿真与实时性分析

CAN Bus Network Design and Real-time Analysis of Missile System

弹上CAN总线通信对实时性有较高要求。基于某型空地导弹控制系统,设计了弹上CAN总线网络。串行发送延时、硬件接口延时及媒体访问延时是网络延迟的主要原因。采用非抢占优先级的M/M/1排队论模型研究了该总线系统的介质访问延时,并在该弹上总线网络上进行了仿真验证。结果表明:800k和1000k波特率下该总线网络正常通信,最大延迟时间分别为508μs和292μs,远小于最低10ms的数据发送周期,满足实时性要求。

Missile boarded CAN bus has strict requirements for real-time characteristic. Based on an air-to-ground missile control system, CAN bus network was designed. Serial transmission delay, hardware interface delay and media access delay are main reasons of bus delay. Media access delay of the network was studied with non-preemptive priority queuing theory model. Actual CAN bus network simulation shows that this network work well under 800kbps and 1000kbps Baud rate, with maximum delay time 509μs and 292μs, respectively. The delay time is far less than the minimum lOres periodic,meeting the real-time requirements.