Abstract: An online reconfigurable control scheme is proposed for overactuated closedloop systems, including the controller, control allocation, and fault diagnosis. In the fault diagnosis, the signed directed graph(SDG) method is adopted to locate the possible faulty components as soon as possible. For the faults that cannot be isolated, an on-line fault isolation method is designed. After the faults are isolated, the control allocation is used to redistribute the control efforts. How to isolate faults on-line is explained based on a spacecraft model with overactuated reaction wheels, and simulations of online fault tolerance are carried out to testify our scheme.

Key words: reconfigurable control, fault isolation, closed-loop system, SDG