A novel 3- axis attitude stabilization with redundant thruster for a cube-satellite supported by reaction wheels

In the present study, a new attitude stabilization concept has been investigated for a satellite considering failure in one or more reaction wheels. In this approach control torques could be generated using only one thruster mounted on a two axis gimbal mechanism. In the other word, in the absence of reaction wheel(s), control torques are generated by applying a thruster rotating mechanism which can be turned around two axes by thruster vector. If any failure happened in reaction wheels, gimbal angles mechanisms will be added to the system as input controlling. Controller algorithm based on dynamic and kinematic equations of the satellite’s motion, has been developed in the presence of disturbances. Three-axis stabilization of the attitude in a LEO orbit satellites under disturbances has been executed by applying three reaction wheel actuators to produce torque in each direction. Disturbance torques that are commonly applied to the satellites are gravity gradient, solar radiation pressure and aerodynamics. For training the intelligent neuro-fuzzy controller, PID controller is employed. Numerical simulations show that, the recommend controlled method have acceptable results (in the presence of disturbances) and adding of a thruster actuator to the system as a redundancy, could enhance the space missions reliability and if any fault happened in the operation of reaction wheels, thruster mechanisms come in to control system , accurately, and sustained satellite stability at desirability attitude.