Applying Robust Quasi-Sliding Mode Approach for Attitude Control of a Flexible Spacecraft

Maneuvering and controlling the attitude with the highest accuracy, speed and lowest power consumption has always been one of the challenges in the field of spacecraft control system design. The flexibility of satellites causes a change in the dynamics of the whole system. In this article, the Robust Quasi-Sliding Mode Control (RQSMC) method has been utilized to control the attitude of the flexible spacecraft in the presence of disturbances. Considering the non-linearity of the equations of the flexible spacecraft, the impossibility of modeling this system ideally and the inability of mathematical descriptions to fully explain the movement of this flight system, this article uses the RQSMC method as a suitable idea for the attitude control of the flexible spacecraft. For this purpose, the three-degree-of-freedom model of the flexible spacecraft including different disturbances in each direction under quaternion kinematics will be presented in the dynamic modeling section of this article, and then a RQSMC will be designed that also has the ability to control chattering.  The checking of functional parameters such as energy consumption index, agility index and body angular rates constraints showed that this controller has a desirable performance in accurate and fast spacecraft orientation.