Dynamic Near-Optimal Control Allocation for Spacecraft Attitude Control Using a Hybrid Configuration of Actuators

• Published in: IEEE transactions on aerospace and electronic systems Vol. 56; no. 2; pp. 1430 - 1443
• Main Authors: Hu, Qinglei, Tan, Xiao
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-04-2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuation; Actuators; Aerodynamics; Attitude control; Avoidance; Computer simulation; Computing costs; Configurations; Control momentum gyros; Controllers; Dependent variables; Dynamic control; dynamic control allocation (CA); hybrid configuration of actuators; Lagrange multiplier; Maneuvers; Mathematical analysis; Optimal control; Optimization; Reaction wheels; Resource management; Singularities; Space vehicles; Spacecraft; Spacecraft attitude control; Torque; Wheels
• ISSN: 0018-9251; 1557-9603
• DOI: 10.1109/TAES.2019.2934697

This paper proposes a novel dynamic near-optimal control allocation scheme with combination of a saturated baseline controller for spacecraft attitude control using single-gimbal control moment gyros (CMGs) and reaction wheels. First, a saturated controller is proposed to stabilize the nominal system in the presence of actuation mismatch. Aided by a state-dependent variable, a dynamic control allocator is then proposed that allows for smooth switching between two actuation sets. Unlike the previous static constraint optimization formulations, the control allocation augments its performance function with penalty terms in order to enforce individual input constraints and configuration singularity avoidance. Moreover, this dynamic control allocation is implemented with an online update law, which has a modest computational complexity compared to its numerical optimization counterpart. The closed-loop boundedness is guaranteed by a constructive Lyapunov-design method. Simulation results demonstrate that during the attitude maneuvers, the input saturation constraint and the active avoidance of CMG singularities are enforced with a relatively small computational cost.