A Chattering Mitigating Sliding Mode Control for Rigid Spacecraft Attitude Control Maneuver

In this work, an effort is made to propose a chattering mitigating sliding mode controller for attitude maneuver control of a rigid modelled spacecraft. Unit quaternion is used here to represent the attitude kinematics. Firstly, a new sliding output function is defined that have relative degree two and then, control law is formulated in second order sliding mode using homogeneity controller. The proposed controller can ensure quick convergence to equilibrium and limit the chattering in control and states. Simulation is conducted for different initial settings of unit quaternion and angular velocity with external disturbances and inertia matrix uncertainty subjected. Results show the controller efficacy in maintaining both transient and steady state performance.