Adaptive Model-Free Sliding Mode Control with Forgetting Factor for Stratospheric Airship

This work proposes a model-free adaptive sliding mode control strategy incorporating an adaptive forgetting factor for attitude stabilization of stratospheric airships subject to model uncertainties. First, to mitigate overshoot, oscillation, and slow convergence issues associated with the compact-form dynamic linearization based MFAC (CFDL-MFAC) technique for attitude regulation, an adaptive forgetting factor is in-troduced into the CFDL-MFAC architecture, constituting the CFDL-MFAC with variable forgetting factor method. Second, sliding mode control is synergistically integrated to ensure con-vergence properties of the overall scheme, with stability analysis provided to prove convergence. Finally, numerical simulations are conducted to validate the efficacy of the proposed adaptive model-free sliding mode control approach.