In this paper we propose a whole family of quadratic-like strong Lyapunov functions for the Super Twisting algorithm. They show that all trajectories converge in finite time to the origin, and a formula to estimate the convergence time for the considered family of Lyapunov functions is proposed. A methodology to select the Lyapunov function, providing for better estimation of the convergence time, is presented. The obtained results are illustrated through simulation.

No abstract

This paper presents a novel scheme for the speed/position control of permanent-magnet (PM) DC motor drives. A cascade control scheme, based on multiple instances of a second-order sliding-mode control (2-SMC) algorithm, is suggested, which provides accurate tracking performance under large uncertainty about the motor and load parameters. The proposed scheme has been implemented and tested experimentally on a commercial PM DC motor drive. The experimental results confirm the precise and robust performance, and the ease of tuning and implementation, featured by the proposed scheme

This paper presents a novel scheme for the speed/\ud position control of permanent-magnet (PM) dc motor drives. A\ud cascade-control scheme, based on multiple instances of a secondorder\ud sliding-mode-control (2-SMC) algorithm, is suggested,\ud which provides accurate tracking performance under large uncertainty\ud about the motor and load parameters. The overall control\ud scheme is composed of three main blocks: 1) a 2-SMC-based\ud velocity observer which uses only position measurements;\ud 2) a 2-SMC-based velocity control loop that provides a reference\ud command current; and 3) a 2-SMC-based current control loop\ud generating the reference voltage. The proposed scheme has been\ud implemented and tested experimentally on a commercial PM dc\ud motor drive. The experimental results confirm the precise and\ud robust performance and the ease of tuning and implementation,\ud featured by the proposed scheme

Abstract-A robust control solution is proposed to solve the air supply control problem in autonomous polymer electrolyte membrane fuel cells (PEMFC) based systems. Different second order sliding mode (SOSM) controllers are designed using a model of a laboratory test fuel cell generation system. Very good simulation results are obtained using such algorithms, showing the suitability of the SOSM approach to PEMFC stack breathing control. Subsequently, for experimental validation, a controller based on one of the previously assessed SOSM algorithms, namely a Super Twisting, is successfully implemented in the laboratory test bench. Highly satisfactory results are obtained, regarding dynamic behaviour, regulation error and robustness to uncertainties and external disturbances.