简要回顾了容错技术的发展过程并分析了不同故障模型下系统的容错方式。对于瞬时故障、间歇性故障的容错可采用软件冗余方法,在实时嵌入式系统中采用软件容错时必须考虑任务的可调度性;而永久性故障则采用硬件冗余方法来解决。在此基础上,描述了一种实时双机嵌入式容错系统的模型,研究了构建容错系统需要解决的双机同步、故障检测及仲裁切换等关键问题和相应的解决方法。 Briefly reviewed the development of fault-tolerant technology and analyzed the fault-tolerant way of the system under different fault models. For transient faults, fault tolerance of intermittent faults can adopt the method of software redundancy. When using software fault tolerance in real-time embedded systems, the task schedulability must be considered; and permanent faults are solved by hardware redundancy. On this basis, a model of real-time two-machine embedded fault-tolerant system is described. The key problems and corresponding solutions to the fault-tolerant system, such as dual-machine synchronization, fault detection and arbitration handover, are studied.