Attitude Stabilization Of Rigid Spacecraft Research Articles

Angular Velocity-Free Control for Rigid Spacecraft Attitude Stabilization under Input Constraint

AbstractA novel attitude stabilization control scheme is presented for rigid spacecraft. As a stepping stone, a first-order passivity filter is proposed to generate a velocity-related signal from attitude measurements. Then, a velocity-free attitude stabilization controller is synthesized by using a hyperbolic tangent function. It is shown that the controller render the equilibrium points in the closed-loop system globally asymptotically stable. Moreover, the proposed control scheme is independent on the unknown spacecraft inertia and can explicitly account for input constraint with angular velocity measurements eliminated. Numerical simulation results are presented to verify the effectiveness of the control law derived in this paper in comparison with the conventional velocity-free attitude control approaches.

Robust and Optimal Attitude Control Law Design for Spacecraft with Inertia Uncertainties

This paper considers the robust and optimal three-axis attitude stabilization of rigid spacecraft with inertia uncertainties. The attitude motion of rigid spacecraft described in terms of either the Cayley-Rodrigues parameters or the Modified Rodrigues parameters is considered. A class of robust nonlinear control laws with relaxed feedback gain structures is proposed for attitude stabilization of rigid spacecraft with inertia uncertainties. Global asymptotic stability of the proposed control laws is shown by using the LaSalle Invariance Principle. The optimality properties of the proposed control laws are also investigated by using the Hamilton-Jacobi theory. A numerical example is given to illustrate the theoretical results presented in this paper.

On the attitude stabilization of rigid spacecraft

In this paper, we settle in the negative a longstanding problem concerning the existence of a smooth (static or dynamic) state variable feedback law locally asymptotically stabilizing a rigid spacecraft with two controls about a desired reference attitude. Modelling a spacecraft actuated by three thruster jets, one of which has failed, this well studied system is known to be locally reachable and locally asymptotically null controllable. We obtain our result as a corollary of a surprising result which asserts, for a class of nonlinear systems containing several examples of interest, that such a system is locally asymptotically stabilizable precisely when it can be linearized via state feedback transformations. We give a further result on the instability (in the sense of Lyapunov) of rigid spacecraft for certain feedback laws, but we are able to construct a feedback law locally asymptotically driving the closed-loop trajectories to a motion about the third principal axis. This law is derived using general principles comprising a nonlinear enhancement of root-locus design principles.