Abstract: A depth fault-tolerant control strategy is proposedto make sure an autonomous underwater vehicle (AUV) can finish the expected tasks successfully when its one or more motion executers are in fault. The control strategy is based on reconstructable fault-tolerant control theory, and the active disturbance rejection control (ADRC) is used to achieve the design and implementation of controllers. The strategy includes two control methods, in which one is used when the motion executers work in normal and the other is used when one or more motion executers are in fault. These two methods can change from one to another according to the fault diagnosis of the executers. In simulation experiment, the control strategy is tested in different environmental disturbances and compared with the strategy with PID. The results show that the depth fault-tolerant control strategy based on reconstructable fault-tolerant control theory and ADRC is not only effective but also has stronger disturbance resistance.

Key words: control science and technology, autonomous underwater vehicle, fault-tolerant control, reconstructable fault-tolerant control, active disturbance rejection control method, depth control