This paper investigates alternate control techniques for the attitude control of a three axis stabilized flexible communications satellite consisting of a large reflector and a solar array. The control configurations consisted of three classes: Class 1 sensors and actuators co-located on the central body, Class 2 actuator on the central body and sensors distributed, and Class 3 -actuators and s...

We provide stabilizing and tracking feedback control laws for the kinematic system of an underactuated axisymmetric spacecraft subject to input constraints. As a special case we also provide a feedback control to track a specified direction in inertial space. All proposed control laws achieve asymptotic stability with exponential convergence. One of the novelties of the proposed control design ...

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 ...

Hardware and software architecture of a novel spacecraft Attitude Determination and Control System (ADCS) based on smartphones using Variable Speed Control Moment Gyroscope (VSCMG) as actuator is proposed here. A spacecraft ground simulator testbed for Hardware-in-the-loop (HIL) attitude estimation and control with VSCMG is also described. The sensor breakouts with independent micro-controller ...

Active magnetic control is studied as a means to improve the capabilities and perfonnance of gravity gradient stabilized spacecraft. Active magnetic control eliminates the need for a passive damper and can reduce significantly the costs and complexity of other functional parts of the spacecraft. The system under study includes three magnetic torquers, one three-axis magnetometer, and a control ...

In this paper, we consider the minimum-time reorientation problem of an axi-symmetric rigid spacecraft with two independent control torques mounted perpendicular to the spacecraft symmetry axis. The objective is to reorient the spacecraft from an initial attitude, with some angular velocity, to a nal attitude with a certain angular velocity in minimum time. All possible control structures, incl...