Resetting Disturbance Observers with application in Compensation of bounded nonlinearities like Hysteresis in Piezo-Actuators
For control engineers dealing with piezoelectric actuators, this work offers a new method to improve hysteresis compensation by addressing the contradictory requirements in linear DOB design.
This paper introduces a novel nonlinear resetting disturbance observer (RDOB) using a constant-gain lead-phase element to compensate for bounded nonlinearities like hysteresis in piezoelectric actuators, overcoming fundamental limitations of linear disturbance observers. Experimental results on a practical piezoelectric setup demonstrate performance improvement over linear DOB.
This paper presents a novel nonlinear (reset) disturbance observer for dynamic compensation of bounded nonlinearities like hysteresis in piezoelectric actuators. Proposed Resetting Disturbance Observer (RDOB) utilizes a novel Constant-gain Lead-phase (CgLp) element based on the concept of reset control. The fundamental limitations of linear DOB which results in contradictory requirements and in a dependent design between DOB and feedback controller are analysed. Two different configurations of RDOB which attempt to alleviate these problems from different perspectives are presented and an example plant is used to highlight the improvement. Stability criteria are presented for both configurations. Performance improvement seen with both RDOB configurations compared to linear DOB is also verified on a practical piezoelectric setup for hysteresis compensation and results analysed.