Design of Non Linear Controller for a Satellite Attitude Control Simulator

The cost and error of theSatellite Attitude Control System design can be minimize by using ground test simulator. However, it construction difficulties are associated with creating zero gravity and no friction environments. Air bearing simulator provides the environment for investigation of satellite attitude dynamics and control problems. Large angle manoeuvre usually present highly non-linear plant and if the system parameters are not well determined the plant can also present some kind of uncertainty. As a result, controller designed by linear control technique can have its performance and robustness degraded. This paper presents the application of the State-Dependent Riccati Equation (SDRE) method to design and test an attitude control algorithm for 3-D satellite simulator. The simulator model is general since it is inertia moment dependent. The matlab/simulink simulator model is similar to 3-D INPE simulator which allows testing satellite hardware and software. The control strategy is based on gas jets and reaction wheel torques to perform three axes large angle manoeuvre. Simulation has investigated that SDRE controller performance and robustness for angular velocity reduction associated with stringent pointing requirement. This work served to validate the numerical simulator model and to verify the functionality of the control algorithm designed