RHC-based attitude control of spacecraft under geometric constraints

Purpose - The purpose of this paper is to propose an attitude control algorithm for spacecraft with geometric constraints. Design/methodology/approach - The geometric constraint is reformulated as a quadratic form when quaternion is used as attitude parameter, then the constraint is proved to be nonconvex and is further transformed to a convex one. By designing a new constraint formulation to satisfy the real constraint in the predictive horizon, the attitude control problem is reshaped to a convex planning problem which is based on receding horizon control. Findings - The proposed algorithm is more effective in handling geometric constraints than previous research which used single step planning control. Practical implications - With novel improvements to current methods for steering spacecraft from one attitude to another with geometric constraints, great attitude maneuver path can be achieved to protect instruments and meanwhile satisfy mission requirements. Originality/value - The attitude control algorithm in this paper is designed especially for the satisfaction of geometric constraints in the process of attitude maneuver of spacecraft. By the application of this algorithm, the security of certain optical instruments, which is critical in an autonomous system, can be further assured.