A homogeneous extended state estimator-based super-twisting sliding mode compensator for matched and unmatched uncertainties

Abstract

In this research work, an output tracking problem of a kind of nonlinear motion control systems influenced by exogenous uncertainties using second-order super-twisting sliding mode control is studied. It is shown that when second-order super-twisting sliding mode control is implemented with finite-time convergent homogeneous extended state observer, the second-order sliding mode is achieved on the selected sliding manifold with efficient disturbance attenuation from the output. The presented control structure is tested on the air-gap control of an electromagnetic levitation suspension system using MATLAB platform. The observations prove the efficacy of the proposed algorithm providing excellent robust control efficiency along with precise attenuation of various disturbances.

Enhanced command filtered control with extended state observer for dual‐motor servo mechanisms considering backlash and friction

“…Among these techniques, the extended state observer (ESO), which can estimate the lumped disturbance with little model information, has been successfully implemented in various fields. Since the convergence speed is a critical indicator for an observer, the ESOs have been modified based on homogeneity property [36], terminal sliding-mode technique [37], and super-twisting algorithm [38] to achieve finite-time convergence. However, these ESOs only utilize the fractional power and the convergence speed may become slow when the estimation errors are far from equilibrium points.…”

Continuous sliding mode control for uncertain linear time-invariant systems with matched and unmatched uncertainties using the Lyapunov-function integral sliding mode

“…Ur Rehman et al (2020) proposed an adaptive SMC method based on the super-twisting algorithm (STA) by transforming a plant with unmatched uncertainties into a plant with matched uncertainties. Some scholars adopted the feedforward observation technique to reject the unmatched disturbance, such as the finite-time disturbance observer (FTDO) to design combined sliding mode surfaces (Hakimi and Binazadeh, 2019;Li et al, 2015;Wang et al, 2017Wang et al, , 2018bYang et al, 2018), the disturbance or uncertainty estimator for the ISM controller (Bonifacio et al, 2020;Kurkcu et al, 2018;Singh and Janardhanan, 2019), and the extended state observer (ESO) (Goel et al, 2020;Safa and Abdolmalaki, 2019;Wang et al, 2018a). For example, Goel et al (2020) proposed an SMC compensator-based STA, which implemented a finite-time convergent second-order sliding mode with the unmatched uncertainty and disturbance attenuation.…”

“…Some scholars adopted the feedforward observation technique to reject the unmatched disturbance, such as the finite-time disturbance observer (FTDO) to design combined sliding mode surfaces (Hakimi and Binazadeh, 2019;Li et al, 2015;Wang et al, 2017Wang et al, , 2018bYang et al, 2018), the disturbance or uncertainty estimator for the ISM controller (Bonifacio et al, 2020;Kurkcu et al, 2018;Singh and Janardhanan, 2019), and the extended state observer (ESO) (Goel et al, 2020;Safa and Abdolmalaki, 2019;Wang et al, 2018a). For example, Goel et al (2020) proposed an SMC compensator-based STA, which implemented a finite-time convergent second-order sliding mode with the unmatched uncertainty and disturbance attenuation. Bonifacio et al (2020) designed a full-order observer that incorporates the concept of sliding mode observer, and makes the estimation error get the ultimate uniform bounded stability (UUBS).…”

Robust-Optimal Control of Electromagnetic Levitation System with Matched and Unmatched Uncertainties: Experimental Validation

“…The chattering effect is quite dominant in the sliding mode control techniques; hence, the chattering suppression techniques for the sliding mode controller for the electromagnetic levitation system are designed [21].A homogenous extended-state observer-based super-twisting sliding mode control with a finite time horizon is implemented for the magnetic levitation system. [22].Higher-order super-twisting sliding mode control is proposed for the Maglev system; the novel approach is implemented for the third-order Maglev system, which offers finite-time convergence and negligible chattering effect [23]. Sliidng mode control with optimal control approach is designed for EML system [24].…”