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This paper focuses on the attitude pointing control problem underpointing-forbidden constraints and performance constraints. The spacecraft isexpected to align its sensor's boresight to a desired direction, while theterminal control accuracy and the attitude adjustment rapidity should also beguaranteed simultaneously. To resolve this problem, a switching controllerstructure is proposed in this paper based on the reduced-attituderepresentation, fusing the artificial potential field (APF) methodology and thePrescribed Performance Control (PPC) scheme together. Firstly, a novelartificial potential field is presented, and a particular function is designedfor the mollification of the switching process, aiming at providing a smoothtransition for the system status. Subsequently, we propose a specialperformance function, which can freeze the PPC part when necessary. In thisway, the intrinsic contradictory between the fast attitude maneuver andforbidden direction avoidance is tackled  Further, an asynchronous switching strategy is designed, guarantees thesystem's stability. Based on these proposed issues, a switching backsteppingcontroller is developed, and a tracking differentiator(TD) is employed togenerate a smooth approximation of differential signals. Numerical simulationresults are illustrated to show the effectiveness of the proposed scheme.

Spacecraft Attitude Pointing Control under Pointing Forbidden Constraints with Guaranteed Accuracy