通过构造增广系统的降维状态观测器，设计了在线诊断故障的故障诊断器。利用故障诊断的结果，设计了故障的动态自修复控制律使系统在故障情况下能够正常运行。最后，通过一个仿真算例来验证本文所提出的方法的可行性和有效性。-A fault diagnose was designed which could on-line diagnose faults by constructing a reduced-order state observer of the augmented system. By using the results of fault diagnosis, two dynamic self-restore control laws were designed to make the system work normally with faults. Finally, a numerical example validates the feasibility and effectiveness of the proposed approaches.