Robust Variable Structure Attitude Control with L2-gain Performance for Flexible Spacecraft Including Input Saturation

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

Journal of Systems and Control Engineering, Vol. 224, No. 2, 2010, pp. 153-167

Abstract

This paper presents the design of a robust controller, based on variable structure control, for the rotational maneuvering and vibration reduction of a flexible spacecraft with input saturation. The dynamic equations of motion are formulated as a finite dimensional mathematical model, but accounting for the infinite number of natural vibration modes of the flexible appendages. Based on this model, a variable structure controller is designed for rotational maneuvers and vibration suppression, and its exponential stability is demonstrated. The synthesis of the control system assumes that only the pitch angle and its derivative are accessible for feedback, and that the flexible modes are not measured. Saturation limits are introduced into the controller design to cope with the actuation limitations, and the stability of the modified control solution is verified. The prescribed robust performance is obtained by ensuring that the L2-gain synthesis, from a torque disturbance to the penalty output, is less than a specified level. Simulation results are presented for the attitude maneuvering and elastic mode stabilization of an orbiting flexible spacecraft, which demonstrate the excellent performance of the proposed controller and illustrate its robustness to external disturbances.

Paper Availability

This material has been published in the Journal of Systems and Control Engineering, Vol. 224, No. 2, 2010, pp. 153-167, the only definitive repository of the content that has been certified and accepted after peer review. Copyright and all rights therein are retained by the IMechE.


Link to paper using doi: 10.1243/09596518JSCE884

Journal of Systems and Control Engineering