Adaptive super-twisting observer for fault reconstruction in electro-hydraulic systems. (May 2018)

• Record Type: Journal Article
• Authors: Bahrami, Mohamad; Naraghi, Mahyar; Zareinejad, Mohammad
• Is Part Of: ISA transactions. Volume 76(2018)
• Page Start: 235
• Page End: 245
• Publication Date: 2018-05
• Subjects: Super-twisting observer -- Gain adaptation -- Chattering effect -- Fault reconstruction -- Electro-hydraulic servo systems; Engineering instruments -- Periodicals; Engineering instruments; Periodicals; Electronic journals; 629.805
• DOI: 10.1016/j.isatra.2018.03.014
• Languages: English
• ISSNs: 0019-0578

Abstract

Abstract: An adaptive-gain super-twisting sliding mode observer is proposed for fault reconstruction in electro-hydraulic servo systems (EHSS) receiving bounded perturbations with unknown bounds. The objective is to address challenging problems in classic sliding mode observers: chattering effect, conservatism of observer gains, strong condition on the distribution of faults and uncertainties. In this paper, the proposed super-twisting sliding mode observer relaxes the condition on the distribution of uncertainties and faults, and the gain adaptation law leads to eliminate observer gain overestimation and attenuate chattering effects. After using the equivalent output-error-injection feature of sliding mode techniques, a fault reconstruction strategy is proposed. The experimental results are presented, confirming the effectiveness of the proposed adaptive super-twisting observer for precise fault reconstruction in electro-hydraulic servo systems. Highlights: An adaptive-gain super-twisting sliding mode observer is proposed for fault reconstruction. The Problems of chattering effect and conservatism of observer gains are addressed. The condition on the distribution of system faults and uncertainties is relaxed. A Lyapunov-based finite-time stability is presented and the boundedness of adaptive gains is proven.