Observer-based Fault Diagnosis Incorporating Online Control Allocation for Spacecraft Attitude Stabilization under Actuator Failures

QL Hu, B Li (Harbin Institute of Technology, China) & MI Friswell (Swansea University)

The Journal of the Astronautical Sciences, Vol. 60, No. 2, June 2013, pp. 211-236


This paper proposes a novel observer-based fault diagnosis method, incorporating an online control allocation scheme, for an orbiting spacecraft in the presence of actuator failures/faults, unexpected disturbances and input saturation. The proposed scheme solves a difficult problem in spacecraft fault tolerant control design by compensating for the loss in effectiveness and time-varying faults using redundant actuators, so that the overall system is stable, despite external disturbances and input saturation. This is accomplished by developing an observer-based fault diagnosis mechanism to reconstruct or estimate the actuator faults/failures. An online control allocation scheme is then used to redistribute the control signals to the healthy actuators in the case of faults/failures, without reconfiguring the controller, so that the control signal distribution is based on the reconstructed actuator effectiveness level. Simulation results using a rigid spacecraft model show good performance in the presence of faults, including total actuator failure scenarios, external disturbances and actuator input saturation, which validates the effectiveness and feasibility of the proposed scheme.

Paper Availability

This material has been published in the The Journal of the Astronautical Sciences, Vol. 60, No. 2, June 2013, pp. 211-236. Unfortunately the copyright agreement with Springer does not allow for the PDF file of the paper to be available on this website. However the paper is available from Springer - see the link below.

Link to paper using doi: 10.1007/s40295-014-0021-1

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