Fuzzy Approximation-Based Finite-Time Control for a Robot With Actuator Saturation Under Time-Varying Constraints of...

Area of Science:

• Robotics
• Control Systems Engineering
• Nonlinear Control Theory

Background:

• Robotic systems often face challenges with actuator saturation and dynamic workspace constraints.
• Ensuring stability and performance under these conditions is crucial for practical applications.
• Existing methods may struggle with asymmetric saturation or introduce discontinuities.

Purpose of the Study:

• To develop a finite-time control strategy for n-link robots.
• To address actuator saturation and time-varying workspace constraints.
• To ensure the stability and performance of the robotic system within defined limits.

Main Methods:

• Design of Barrier Lyapunov functions (BLFs) to enforce workspace constraints.
• Transformation of asymmetric actuator saturation into a symmetric form using a hyperbolic tangent function.
• Integration of fuzzy-logic systems (FLSs) with the backstepping technique for control policy design.
• Application of Lyapunov stability theory to prove system stability.

Main Results:

• A novel finite-time control method for n-link robots with actuator saturation.
• Effective handling of asymmetric saturation nonlinearity without discontinuities.
• Demonstration of semiglobal finite-time stability (SGFS) for all error signals.
• Experimental validation confirming the method's effectiveness.

Conclusions:

• The proposed finite-time control method ensures robotic systems remain within time-varying workspace constraints.
• The approach effectively manages actuator saturation, enhancing system robustness.
• The method provides a stable and reliable control solution for complex robotic tasks.