Phase leading active disturbance rejection control for a nanopositioning stage

Area of Science:

• Control Engineering
• Nanotechnology
• Mechatronics

Background:

• Piezoelectric nanopositioning systems suffer from reduced accuracy due to hysteresis.
• Existing inverse hysteresis models struggle with uncertainties and disturbances.
• Linear active disturbance rejection control (LADRC) shows promise but is limited by phase lag in disturbance estimation.

Purpose of the Study:

• To develop an enhanced active disturbance rejection control strategy for piezoelectric nanopositioning.
• To improve the estimation and compensation of total disturbances in the presence of hysteresis.
• To achieve superior positioning accuracy and dynamic performance.

Main Methods:

• A phase-leading extended state observer (PLESO) was designed by integrating a phase-leading network into a linear extended state observer.
• The PLESO's advantages in estimating time-varying total disturbances were analyzed.
• Phase-leading active disturbance rejection control (PLADRC) was implemented using the PLESO.

Main Results:

• The PLESO demonstrated improved estimation of time-varying total disturbances.
• PLADRC compensated for total disturbances more effectively than LADRC.
• Experimental results confirmed PLADRC's superiority in dynamic responses and disturbance rejection.

Conclusions:

• The developed PLESO offers an effective, nonlinearity-free method to enhance active disturbance rejection control (ADRC).
• PLADRC significantly improves positioning accuracy in piezoelectric systems by mitigating hysteresis effects.
• The proposed approach provides a practical solution for precise nanopositioning applications.