This article studies the appointed-time attitude tracking control of spacecraft on special orthogonal group, with forbidden zone, parameter uncertainties, and external disturbances. A novel projection function is proposed, such that normalized boresight vector sensitive instrument mapped to a reduced dimensional in Euclidean space. If uniformly bounded, constraint zone will be satisfied at all ...

This paper considers the problem of attitude synchronization control of a group of flexible spacecraft under an undirected communication graph and in the absence of measurements of both modal variables and spacecraft angular velocities. To solve this problem, a nonlinear observer is introduced to estimate the unmeasurable modal variables and spacecraft angular velocities. Then, the backstepping...