Decoupling Control Using Linear Extended State Observer for Pitch Control of a Satellite Launch Vehicle

A launch vehicle, also known as a powered space vehicle, is utilized to transport a spacecraft beyond Earth's atmosphere. Its mission is to reach either Earth's orbit or another destination in outer space. However, during the launch vehicle's operation, spurious dynamics can occur, which can negatively impact the performance of its control system. These dynamics are typically manifested in various ways, including kinematic coupling terms resulting from the interaction between different channels, coupling caused by aerodynamic forces between channels, and coupling through the control configuration. The uncertainty introduced by these dynamics can be effectively addressed by employing a linear extended state observer, which is designed to decouple the uncertainty. To validate its efficacy, a comparison is made with a robust sliding mode control, which handles uncertainty in its own way. The unaddressed coupling of these dynamics poses a significant threat to flight safety. Therefore, it is imperative to study and develop a decoupling control strategy using the suggested method of the linear extended state observer.