Enhancement of Sliding Mode Control Performance for Perturbed and Unperturbed Nonlinear Systems: Theory and Experimentat
- PDF / 3,084,536 Bytes
- 18 Pages / 595.276 x 790.866 pts Page_size
- 102 Downloads / 220 Views
ORIGINAL ARTICLE
Enhancement of Sliding Mode Control Performance for Perturbed and Unperturbed Nonlinear Systems: Theory and Experimentation on Rehabilitation Robot Brahim Brahmi1 · Ibrahim El Bojairami2 · Maarouf Saad3 · Mark Driscoll2 · Samir Zemam3 · Mohamed Hamza Laraki3 Received: 19 February 2020 / Revised: 6 August 2020 / Accepted: 16 November 2020 © The Korean Institute of Electrical Engineers 2020
Abstract This paper presents the design and validation of a new adaptive variable gain reaching law, integrated with sliding mode control (SMC), to control perturbed and unperturbed nonlinear systems. The novelty behind this law stems from its capability to overcome the main limitations involved with SMC. In contrast to existing reaching laws, system’s performance can be substantially enhanced via this law, with significant reduction in the chattering phenomenon, along ensuring rapid convergence time of system’s trajectories towards equilibrium. The designed law not only integrates the features of both the exponential reaching law (ERL) and the power rate reaching law (PRL), but also overcomes their limitations. Simulation and comparison studies against ERL and PRL were carried out to validate the effectiveness and advantages of the proposed reaching law scheme (Proposed-RL). Furthermore, controlled experimental investigations were conducted using an exoskeleton robot (ETS-MARSE) to validate the scheme in real-time. Keywords Reaching law · Sliding mode control · Chattering · Perturbed and unperturbed system · Exoskeleton robot
1 Introduction
* Brahim Brahmi [email protected] Ibrahim El Bojairami [email protected] Maarouf Saad [email protected] Mark Driscoll [email protected] Samir Zemam [email protected] Mohamed Hamza Laraki [email protected] 1
Mechanical Engineering Department, New Mexico technology, Socorro, NM, USA
2
Mechanical Engineering Department, McGill University, Montreal, Canada
3
Electrical Engineering Department, École de Technologie supérieure, Montreal, Canada
Robust control usually addresses the complex system analysis and control design for imperfectly known process models. It refers to the control of unknown systems with unknown dynamics subject to unknown perturbations. Major objectives of robust control are to ensure the overall stability and satisfactory system’s performance in the presence of dynamic disturbances. However, a critical issue that usually emerges when adopting robust control schemes is the involved uncertainties, raising the question of how to overcome those. Sliding mode control (SMC) is one of the widely common employed robust strategies in robotics systems [11, 14, 17, 20] due to its prominent features. One significant, perhaps the leading, feature of SMC is its complete insensitiveness to parametric uncertainties and external disturbances during sliding mode. To achieve this, in SMC, a switching surface is chosen so that system’s trajectories can begin from anywhere but are constrained to reach a ne
Data Loading...
