Adaptive spacecraft attitude tracking control with actuator uncertainties

Abstract

An adaptive control algorithm for the spacecraft attitude tracking problem when the spin axis directions and/or the gains of the flywheel actuators are uncertain is developed. A smooth projection algorithm is applied to keep the parameter estimates inside a singularityfree region and avoid parameter bursting. Numerical examples show that the controller successfully deals with unknown misalignments of the axis directions as well as the unknown gains of the flywheel actuators.

Adaptive Control of Uncertain Hamiltonian Multi-Input Multi-Output Systems: With Application to Spacecraft Control

“…Using standard arguments in [1], [11] which use Barbalat's lemma, one can easily show thatV → 0 and thus s → 0 as t → ∞. This also implies the tracking errorq → 0 as well.…”

“…[10], [15] for more details and applications of VSCMGs.) [11], [13], they can be simplified as follows:…”

“…Chang [7] has provided an adaptive, robust tracking control algorithm for nonlinear MIMO systems which is based on the "smooth projection algorithm," which has also been used in [8] and [9] for adaptive control of SISO systems. More recently, one of the authors [10], [11] has also provided an adaptive control scheme based on the smooth projection algorithm which is applied to spacecraft attitude tracking with uncertain misalignments/inertia of the actuator flywheels. However, these previous results [7], [10], [11] are based on purely mathematical approaches and do not exploit the useful physical properties of the Hamiltonian systems.…”

“…More recently, one of the authors [10], [11] has also provided an adaptive control scheme based on the smooth projection algorithm which is applied to spacecraft attitude tracking with uncertain misalignments/inertia of the actuator flywheels. However, these previous results [7], [10], [11] are based on purely mathematical approaches and do not exploit the useful physical properties of the Hamiltonian systems. More significantly, they considered MIMO systems represented by the differential equations without any terms in front of the highest derivative of the state variable vector, like the state-space form.…”

Unified Model Reference Adaptive Attitude Control of a Satellite in Presence of Uncertain Parameters: Design and Implementation

“…This problem has been solved by applying adaptive controllers. In adaptive control, the use of projection function is one of the common methods that estimation parameters are guaranteed to be bounded in the presence of uncertainty [4]. In [5], an adaptive controller has been designed for a rigid spacecraft in the presence of external disturbances and moment of inertia matrix uncertainties; in this method, a sliding mode controller has been designed without considering any constraints and then its performance will be improved by applying an adaptive control algorithm.…”