A disturbance observer-based control scheme is proposed in this paper to deal with the attitude stabilization problems of spacecraft subjected external disturbances, parameter uncertainties, and input nonlinearities. Particularly, approach addresses dead-zone issue, a non-smooth nonlinearity affiliated that significantly increases controller design difficulties. novel nonlinear observer (NDO) d...

An efficient and accurate computational approach is proposed for optimal attitude control of a rigid body. The problem is formulated directly as a discrete time optimization problem using a Lie group variational integrator. Discrete necessary conditions for optimality are derived, and an efficient computational approach is proposed to solve the resulting two point boundary value problem. The us...

In this paper, combined attitude control of an underactuated helicopter experimental system is considered. The controlled helicopter experimental system has two inputs and three outputs, namely, this system is underactuated. The combined attitude controller includes a nonlinear MIMO controller based on adaptive sliding mode control and non-adaptive nonlinear controllers. Control system stabilit...