Mixed Control Moment Gyro and Momentum Wheel Attitude Control Strategies C. Eugene Skelton II Attitude control laws that use control moment gyros (CMGs) and momentum wheels are derived with nonlinear techniques. The control laws command the CMGs to provide rapid angular acceleration and the momentum wheels to reject tracking and initial condition errors. Numerical simulations of derived control...

Scientific misconduct appears to be on the rise. However, an accused researcher may later be exonerated. The present research examines to what extent participants adhere to their attitude toward a researcher who allegedly committed academic misconduct after learning that the researcher is innocent. In two studies, participants in an exoneration and an uncorrected accusation condition learned th...

Predictive control technique is applied to the three-axis attitude control of spacecraft. The principal idea of predictive control is to construct a priori reference trajectory and build control command so that the actual system follows the reference trajectory. In the case of this study, the controlled variables are the quaternion attitude parameters and angular rates of spacecraft body axes. ...

Small satellites tend to be power-limited, so that actuators used to control the orbit and attitude must compete with each other as well as with other subsystems for limited electrical power. The Virginia Tech nanosatellite project, HokieSat, must use its limited power resources to operate pulsed-plasma thrusters for orbit control and magnetic torque coils for attitude control, while also provi...

The Distributed Spacecraft Attitude Control System Simulator (DSACSS) testbed at Virginia Polytechnic Institute and State University facilitates investigation of various control strategies for single and multiple spacecraft. DSACSS is comprised of two independent hardware-in-the-loop simulators and one software spacecraft simulator. The two hardware-in-theloop spacecraft simulators have similar...

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 ...

Torque-saturated control laws for spacecraft attitude control are considered. These control laws require no knowledge of the mass distribution of the spacecraft and thus are inertia-free. We examine two specific problems. In the first problem, the spacecraft has an arbitrary initial attitude and angular velocity, and the objective is to bring the spacecraft to rest with a specified attitude. In...