Decoupling and Synchronization Control of Asymmetric Flexure-Linked Dual-Drive Gantry Stage

Abstract

A decoupling and synchronization control strategy based on a model-compensated extended state observer is proposed in control of a dual-drive gantry positioning stage with asymmetric flexure-linked structures. A gantry dynamic model considering the features of the flexure-linked structures and the impact of load acceleration is built using Lagrangian equations. Translational and rotational control loops are designed according to this model, while extended state observers with compensation of known coupling items in the model are deployed in each control loop to estimate and attenuate the total disturbances composed of unmodeled dynamics, unknown couplings, etc. The experimental results show that the proposed control strategy, which is simple to realize and requires few parameters to be measured, can effectively decouple the dynamics of dual axes and attenuates disturbances, greatly improving the dynamic response and synchronization accuracy of the gantry stage.

Keywords

• asymmetric flexure-linked structure
• dual-drive gantry positioning stage
• decoupling
• synchronization control
• extended state observer