Practical torque tracking control of electro-hydraulic load simulator using singular perturbation theory

Chenghu Jing; Hongguang Xu; Jihai Jiang

doi:10.1016/j.isatra.2020.02.035

Practical torque tracking control of electro-hydraulic load simulator using singular perturbation theory

ISA Trans. 2020 Jul:102:304-313. doi: 10.1016/j.isatra.2020.02.035. Epub 2020 Mar 3.

Authors

Chenghu Jing¹, Hongguang Xu², Jihai Jiang¹

Affiliations

¹ School of Mechanical and Electrical Engineering, Harbin Institute of Technology, Harbin 150001, China.
² School of Mechanical and Electrical Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address: hgxu@hit.edu.cn.

PMID: 32151393
DOI: 10.1016/j.isatra.2020.02.035

Abstract

Nonlinear and high-order characteristics could directly hinder the application of many advanced control algorithms for electro-hydraulic system which is a coupling system with double-dynamics of mechanical and hydraulic components. In this paper, a practical torque tracking control using singular perturbation theory is proposed for electro-hydraulic load simulator. The system model is transformed into a singularly perturbed form including a slow mechanical system and a fast hydraulic system. To achieve high accuracy and strong robustness, an active disturbance rejection control based on desired model compensation is developed for the slow mechanical system. It is proved that the mechanical system with developed slow controller is exponentially stable. A proportional control law is employed for the fast hydraulic system. This hydraulic system with developed fast controller is demonstrated to be exponentially stable. Stability of the whole closed-loop system is theoretically analyzed using the extended Tikhonov's theorem. Experimental results validate the presented control scheme.

Keywords: Disturbance rejection control; Electro-hydraulic servo system; Extended Tikhonov’s theorem; Flatness; Load simulator; Singular perturbation.