Kinematic Steering Law for Conically Constrained Torque-Limited Spacecraft Attitude Control

A novel algorithm for attitude control of a spacecraft subjected to conically constrained inclusion and exclusion regions using a kinematic steering law and a rate-based attitude servo system is presented. The tracking errors are defined using switched modified Rodrigues parameters to yield, leveraging the nonuniqueness of the parametrization, a nonsingular description. Lyapunov theory and logarithmic barrier potential functions are used to derive a kinematic steering law suitable for both attitude regulation and tracking scenarios. Conditions for constraint enforcement under limited-control-torque capability are studied. Numerical examples of a regulation and a tracking problem are shown. A Monte Carlo simulation is performed to show constraint avoidance with a variety of worst-case initial conditions under bounded-torque control capabilities.