A novel extended state observer.

Area of Science:

• Control Engineering
• Nonlinear Systems

Background:

• High-precision motion control systems often face challenges from lumped uncertainties and external disturbances.
• Existing disturbance observer designs may neglect critical dynamic terms, limiting performance.

Purpose of the Study:

• To introduce a novel extended state observer (ESO) for high-precision motion control.
• To address limitations of traditional observers by incorporating nonlinear and switching error feedback terms.

Main Methods:

• A new ESO design is proposed, feeding back output estimation error through nonlinear and switching terms.
• The design transforms disturbance observer design into a state observer problem, accounting for the uncertainty's derivative.
• The switching term is specifically utilized to mitigate external disturbance effects.

Main Results:

• The proposed ESO effectively estimates and compensates for lumped uncertainties and external disturbances.
• Numerical simulations demonstrated the observer's capability in handling complex dynamics.
• Experimental validation on a speed turntable confirmed the observer's high-precision motion control performance.

Conclusions:

• The novel extended state observer offers a robust solution for high-precision motion control.
• The observer's design effectively counteracts external disturbances, improving system accuracy.
• Both simulation and experimental results validate the proposed observer's superior performance.