Fuzzy control for linear plants with uncertain output backlashes

Area of Science:

• Control Systems Engineering
• Fuzzy Logic Control
• Nonlinear Systems

Background:

• Systems with uncertain output backlash present significant challenges in achieving precise tracking performance.
• Traditional control methods often require complex compensation mechanisms or backlash inverses, which can be difficult to implement or tune.

Purpose of the Study:

• To develop a fuzzy controller that implicitly compensates for uncertain output backlash without explicit inverse models.
• To ensure stable system operation without limit cycles despite the presence of backlash.
• To enhance controller robustness against variations in backlash and plant parameters.

Main Methods:

• Design of a fuzzy control mechanism to inherently address the delay effects of output backlash.
• Implicit compensation strategy integrated within the fuzzy logic framework.
• Extension of the approach for two-input two-output (TITO) linear plants with output backlash.

Main Results:

• The proposed fuzzy controller effectively compensates for uncertain output backlash, leading to good tracking performance.
• Demonstrated stability of the controlled system without limit cycles.
• The controller exhibits robustness to variations in backlash parameters and plant dynamics.
• Successful application to linear, nonlinear, and experimental amplifier-motor systems.

Conclusions:

• The developed fuzzy controller offers an effective and robust solution for systems with uncertain output backlash.
• The implicit compensation approach simplifies controller design and improves performance.
• The methodology is applicable to both single-input single-output (SISO) and TITO systems.