Parallel Multi-Extended State Observers based {ADRC} with Application to High-Speed Precision Motion Stage
Guojie Tang, Wenchao Xue, Hao Peng, Yanlong Zhao, Zhijun Yang
TL;DR
The paper tackles tracking under uncertain dynamics by proposing a parallel multi-ESOs based ADRC framework. It establishes a quantitative link between ESO estimation error $\tilde{e}$ and the output tracking error $\bar{e}$, then deploys parallel LESOs of different orders with a switching mechanism guided by a performance indicator, backed by stability analysis. The method is validated on a high-speed rigid-flexible coupling (RFC) motion stage, where parallel multi-ESOs ADRC achieves improved tracking and robustness compared with traditional single-ESO ADRC. The findings demonstrate practical impact for precision motion control in the presence of large nonlinearities and friction-related disturbances.
Abstract
In this paper, the parallel multi-extended state observers (ESOs) based active disturbance rejection control approach is proposed to achieve desired tracking performance by automatically selecting the estimation values leading to the least tracking error. First, the relationship between the estimation error of ESO and the tracking error of output is quantitatively studied for single ESO with general order. In particular, the algorithm for calculating the tracking error caused by single ESO's estimation error is constructed. Moreover, by timely evaluating the least tracking error caused by different ESOs, a novel switching ADRC approach with parallel multi-ESOs is proposed. In addition, the stability of the algorithm is rigorously proved. Furthermore, the proposed ADRC is applied to the high-speed precision motion stage which has large nonlinear uncertainties and elastic deformation disturbances near the dead zone of friction. The experimental results show that the parallel multi-ESOs based ADRC has higher tracking performance than the traditional single ESO based ADRC.