MIL-1394B总线故障隔离方法研究和实现

Research and implementation of MIL-1394B bus fault isolation method

MIL-1394B总线在国内外航空电子系统中应用越来越广泛,而MIL-1394B总线采用菊花链的物理层,单个节点的复位故障会导致整个网络的复位扩散,使整个网络不能正常通信。针对MIL-1394B总线在综合化航空电子设备的应用中故障难以隔离,提出一种通过先验信息隔离故障的方法。首先分析复位故障的原理,从而结合MIL-1394B总线在航空电子系统中预先分配节点号的先验信息,获取、分析AS643总线的SELF-ID包建立链接的信用值机制,设计一种检测信用值的方法,并改造节点的硬件设计,使节点链接的信用值低于阈值后可关闭错误链接,从而实现MIL-1394B的网络故障检测和隔离。该设计方法和机制通过实物系统进行验证,可用于高度综合化的航空电子系统中。

MIL-1394B bus is widely used in avionics system at home and abroad,but it adopts physical connecting mode of chrysanthemum chain,whose reset fault of a single node will lead to the reset diffusion of the whole network and the communication abnormality of whole network. Since the fault of MIL - 1394B bus is difficult to isolate in integrated avionics device,a fault isolation method using prior information is proposed. The principle of reset fault is analyzed,and then the prior information of node number in avionics system is pre-assigned in combination with MIL-1394B bus to acquire and analyze SELF- ID packet of AS643 bus,and establish the mechanism of link credit value. A method of detecting credit value is designed,and the hardware design of node is reformed to close the error link while the credit value is lower than the threshold,which can realize the fault detection and isolation of MIL-1394B network. The designed method and mechanism were verified by a physical system,and can be used in highly-integrated avionics system.