Slew Rate and Control Constrained Spacecraft Attitude Maneuver with Reaction Wheel Failure

Abstract

Attitude maneuvers are required for reorienting the satellite for meeting various mission objectives. A higher satellite slew rate during maneuvers is a desirable characteristic for any mission design. At the same time, a higher slew rate demands a higher actuator torque capacity which is always constrained due to the physical limits of the actuator. This paper discusses the satellite attitude maneuver problem under slew rate and actuator capacity constraints. A quaternion feedback controller with quaternion and angular rate feedback is implemented to achieve a rest to rest reorientation maneuver. The control gains are computed based on the slew rate limits while the control commands incorporate the actuator limits. Three different configurations of four reaction wheels, (a) pyramid configuration, (b) skew configuration with three wheels along the body axes and the fourth wheel along body diagonal and (c) skew configuration with skew angle of 45°, are studied. The paper further discusses single reaction wheel failure conditions for all the three configurations and demonstrates satellite rest to rest maneuver within the slew rate and actuator limits.