Time-varying sliding-coefficient-based decoupled terminal sliding-mode control for a class of fourth-order systems

Area of Science:

• Control Systems Engineering
• Nonlinear Dynamics
• Robotics

Background:

• Fourth-order systems present significant control challenges due to their complexity.
• Existing decoupled control methods often lack optimal dynamic response and error minimization.

Purpose of the Study:

• To develop a time-varying sliding-coefficient-based decoupled terminal sliding mode control strategy.
• To enhance the dynamic response and reduce integral absolute error (IAE) and integral time absolute error (ITAE) for fourth-order systems.

Main Methods:

• Decoupling a fourth-order system into two second-order subsystems.
• Designing sliding surfaces using time-varying coefficients.
• Embedding control targets between subsystems.
• Applying terminal sliding mode control for finite-time convergence.

Main Results:

• The proposed strategy achieved faster dynamic response compared to existing methods.
• Demonstrated significant reduction in Integral Absolute Error (IAE) and Integral Time Absolute Error (ITAE).
• Successful finite-time convergence of subsystems to equilibrium points.

Conclusions:

• The time-varying sliding-coefficient-based decoupled terminal sliding mode control offers superior performance for fourth-order systems.
• The method shows practical applicability, as validated by inverted pendulum system simulations.
• This approach provides a robust and efficient solution for complex control problems.