Barrier function-based adaptive nonsingular terminal sliding mode control technique for a class of disturbed...

Area of Science:

• Control Systems Engineering
• Non-linear Dynamics

Background:

• Non-linear dynamic systems are susceptible to external disturbances, impacting their stability and performance.
• Existing sliding mode controllers often require knowledge of disturbance bounds and can suffer from chattering or singularity issues.

Purpose of the Study:

• To design an adaptive non-singular terminal sliding mode controller (NTSMC) for robust stability of non-linear systems.
• To ensure finite-time convergence and singularity-free dynamics in the presence of external disturbances.
• To achieve tracking error convergence without overestimating controller gains or prior knowledge of disturbance bounds.

Main Methods:

• Design of an adaptive non-singular terminal sliding mode controller (NTSMC).
• Integration of Barrier Functions (BFs) as an adaptation mechanism for the NTSMC.
• Lyapunov-based stability analysis to guarantee asymptotic convergence of tracking errors.

Main Results:

• The proposed NTSMC achieves robust stability for non-linear dynamic systems under external disturbances.
• Finite-time convergence and singularity-free control are demonstrated.
• Tracking errors converge to a predefined neighborhood of the origin without requiring knowledge of disturbance upper bounds.

Conclusions:

• The adaptive NTSMC with barrier functions provides an effective solution for robust control of non-linear systems.
• The method offers improved performance by avoiding controller gain overestimation and disturbance bound dependency.
• Simulations and experimental results validate the proposed approach's effectiveness.