Abstract: In this paper, we consider the coordinated attitude control problem without velocity measurements. Based on the recently introduced unit quaternion output feedback for the attitude tracking of a rigid body, we present a class of decentralized coordinated control laws to solve the alignment problem for a group of spacecraft within a formation without velocity measurements. The approach...

Nonlinear pulse width modulation (PWM) controlled system is considered to achieve control performance of thrustercontrolled spacecraft. The actual PWM controlled motions occur, very closely, around the average model trajectory. Furthermore nonlinear PWM controller design can be directly applied to thruster controlled spacecraft to determine thruster on-time. Sliding mode control for attitude tr...

A novel approach is proposed for the attitude stabilization and reorientation of an axi-symmetric spacecraft subject to two gas jet actuators. The approach is based on a new formulation of the attitude kinematics. Abstract| In this paper we consider the problem of attitude stabilization of an axi-symmetric spacecraft using two pairs of gas jet actuators. These actuators provide control torques ...

This paper is to investigate the coordinated attitude control problem for flexible spacecraft formations. Considering the attitude maneuver control problem of a formation composed of flexible spacecraft, two classes of decentralized attitude coordination control laws using behavior-based control approach are proposed. The first class of controllers can steer the attitude states of the flexible ...

This paper presents a study of star tracker attitude estimation algorithms and implementation on an indoor ground-based Three Axis Spacecraft Simulator (TASS). Angle, Planar Triangle, and Spherical Triangle algorithms are studied for star pattern recognition. Least squares, QUEST and TRIAD algorithms are studied for attitude determination. A star field image is suspended above TASS. The indoor ...

Neural networks offer a unique approach to controlling a dynamically changing system. By updating synaptic weights of an interconnected, algebraic framework, desired system objectives can be reached despite an unknown operating environment. This research implements a neural network for controlling the attitude of a satellite with unknown system disturbances. The training and updating of the con...

This paper presents a nonlinear H∞ state feedback attitude control design method for spacecraft large angle maneuvers, which is subject to moment-of-inertia (MOI) uncertainty. Moreover, the operation of attitude maneuver is affected by external disturbances. The attitude control design thus employs a nonlinear H∞ method to achieve stability and robustness so that both MOI uncertainty and extern...

We consider the problem of attitude and angular velocity stabilization of a rigid spacecraft subject to a single actuator failure. Only two pairs of gas jet actuators are available to perform the control objectives. Various controllers have been proposed for this problem in the case that the spacecraft is axisymmetric about one of its axis. In this paper the spacecraft under consideration is a ...

We apply retrospective cost adaptive control (RCAC) to spacecraft attitude control with magnetic actuators. We compare two approaches to address the rank deficiency and time-varying nature of the input matrix. The first approach utilizes an average of the magnetic field based on a-priori knowledge, whereas the second approach uses three multi-input, single-output controllers. RCAC uses no infor...