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 ...

A control system is proposed for a low Earth orbit gravity gradient stabilised microsatellite using Z wheel. The microsatellite is 3-axis stabilized using a yaw reaction wheel, with dual redundant 3-axis magnetorquers. Two vector magnetometers and four dual sun sensors are carried in order to determine the full attitude. The attitude was estimated using an Euler angles (small libration version)...

This paper proposes a low cost and small size attitude and heading reference system based on MEMS inertial sensors. A dual-axis rotation structure with a proper rotary scheme according to the design principles is applied in the system to compensate for the attitude and heading drift caused by the large gyroscope biases. An optimization algorithm is applied to compensate for the installation ang...

A robust control allocation scheme is developed for rigid spacecraft attitude stabilization in the presence of actuator partial loss fault, actuator failure, and actuator misalignment. First, a neural network fault detection scheme is proposed, Second, an adaptive attitude tracking strategy is employed which can realize fault tolerance control under the actuator partial loss and actuator failur...

High-accuracy pointing capabilities are desired for many three-axis stabilized small satellites. Momentum-based attitude control system actuators, initially developed for larger satellites. are being utilized by small satellites to meetthesc pointing requirements. This paper provides an overview of momentum devices available for small satellite applications and three-axis attitude control syste...

Magnetic torquing is attractive for generation of control torques on small satellites. The concept is that interaction between the Earth's magnetic eld and a magnetic eld generated by a set of coils in the satellite is used for actuation. This principle is inherently nonlinear, and diicult to use because control torques can only be generated perpendicular to the geomagnetic eld vector. So far, ...

Magnetic torquing is attractive as a control principle on small satellites. The actuation principle is to use the interaction between the earth's magnetic eld and magnetic eld generated by a coil set in the satellite. This control principle is inherently nonlinear, and diicult to use because control torques can only be generated perpendicular to the geomagnetic eld vector. This has been a serio...

Conventional magnetic attitude control methodologies require several orbital periods to accomplish the required attitude maneuvers due to the existence of an uncontrollable axis, namely the local Earth’s magnetic field vector. Since in some attitude maneuver missions the elapsed time is of critical importance, those time-consuming controllers are not satisfactory and we need a much faster contr...

The research presented in this report focuses on the spacecraft simulators, Whorl-I and Whorl-II, in the Space Systems Simulation Laboratory (SSSL) at Virginia Tech. The goal of this research is to develop a program to visualize the attitude of the simulators in real-time through Analytical Graphics Inc.’s Systems Tool Kit (STK). Spacecraft missions are high-risk and highexpense; therefore, ext...

in this paper, the design and implementation of adaptive speed controller for a sensorless synchronous reluctance motor (synrm) drive system is proposed. a combination of well-known adaptive input-output feedback linearization (aiofl) and adaptive backstepping (abs) techniques are used for speed tracking control of synrm. the aiofl controller is capable of estimating motor two-axis inductances ...