An Adaptive Control Scheme Based on Non-Interference Nonlinearity Approximation for a Class of Nonlinear Cascaded...

Area of Science:

• Control Engineering
• Nonlinear Systems Theory
• Adaptive Control

Background:

• Nonlinear cascaded systems present significant control design challenges due to complex dynamics and uncertainties.
• Existing control methods often struggle with inherent system nonlinearities.

Purpose of the Study:

• To propose a novel, simplified nonlinearity approximation scheme for model-free adaptive control.
• To enhance the stability and performance of controllers for nonlinear cascaded systems.

Main Methods:

• Approximating system nonlinearity using steady and alternating components based on local tracking errors.
• Independent estimation of nonlinearity for each subsystem.
• Employing a squared-error correction procedure to regulate weight coefficients for stability.

Main Results:

• The proposed model-free adaptive controller demonstrates effective control of nonlinear cascaded systems.
• Achieved superior control performance compared to radial basis function network control in simulations and experiments.
• Validated effectiveness on a flexible joint system.

Conclusions:

• The novel nonlinearity approximation scheme offers a simple and robust solution for adaptive control.
• The method is suitable for practical engineering applications requiring high performance and stability.
• Outperforms existing advanced control techniques like RBF network control.