Input shaping and variable structure control for simultaneous precision positioning and vibration reduction of flexible spacecraft with saturation compensation

• Published in: Journal of sound and vibration Vol. 318; no. 1; pp. 18 - 35
• Main Author: Hu, Qinglei
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 25-11-2008; Elsevier
• Subjects: Control systems; Exact sciences and technology; Flexible spacecraft; Fundamental areas of phenomenology (including applications); Input shaping; Physics; Rigid-body dynamics; Saturation; Shapers; Solid dynamics (ballistics, collision, multibody system, stabilization...); Solid mechanics; Structural and continuum mechanics; Variable structure control; Vibration; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Rigid bodies; Input shaping; Positioning; Attitude control; Vibration; Variable structure control; Stabilization; Variable structure system; Spacecraft; Pitch angle; Non linear control; Control synthesis; Modeling; Deformable body; Closed feedback; Robust control; Uncertain system; Two body system; Active system; Feedback; Vibration control
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2008.03.068

This paper treats the question of simultaneous robust attitude control and vibration suppression of orbiting spacecraft with flexible appendages. The spacecraft consists of a rigid body and two flexible appendages and the finite dimensional representation of the flexible spacecraft is assumed to be of arbitrary order. Robust nonlinear variable structure control (VSC) strategy integrated with input shaping technique is concerned for the pitch angle control and elastic vibration suppression under actuator saturation limit. More specially, the input shaper is implemented outside of the feedback loop, which is designed for the reference model and achieves the exact elimination of residual vibration; while for the feedback loop, the variable structure controller is designed to make the closed-loop system behave like the reference model with the input shaper in the presence of parametric uncertainty, external disturbances and actuator saturation. To prevent the presence of input saturation from destroying the system performance, a saturation compensator is designed as well for the variable structure attitude control system. For the synthesis of the attitude controller, only the pitch angel and its derivative are used. Simulation results are presented which show that in the closed loop, pitch angel control and elastic mode stabilization are accomplished in spite of uncertainty and external disturbance.