Title: Trajectory tracking for mobile manipulator based on nonlinear active disturbance rejection control

Authors: Mhmed Algrnaodi; Maarouf Saad; Mohamad Saad; Raouf Fareh; Abdelkarim Brahmi

Addresses: Department of Electrical Engineering, École de technologie supérieure, Université du Québec, Montreal, QC H3C 1K3, Canada ' Department of Electrical Engineering, École de technologie supérieure, Université du Québec, Montreal, QC H3C 1K3, Canada ' School of Engineering, Université du Québec en Abitibi-Téiscamingue (UQAT), Rouyn-Noranda, QC, J9X 5E4, Canada ' Department of Electrical Engineering, University of Sharjah, Sharjah, UAE ' Department of Electrical Engineering, École de technologie supérieure, Université du Québec, Montreal, QC, H3C 1K3, Canada

Abstract: This paper designs a nonlinear active disturbance rejection control (ADRC) to solve the trajectory tracking problem of a mobile manipulator (MM) in the presence of parameters' uncertainties, and nonlinear dynamics coupling effects of the MM system. The control scheme consists of a nonlinear extended state observer (NESO) and a nonlinear proportional derivative (PD) controller. Based on the Lagrange formulation, a dynamical model of the MM is formulated, where external disturbances and modelling uncertainties are assumed to be part of the 'total disturbance' which is estimated with an observer and rejected online in the control law. Since the proposed controller cannot be performed unless the full transformed state vector of the system model is available, an NESO is designed to estimate the transformed state vector as well as the uncertainties. The nonlinear PD controller utilises the state estimated by the NESO, and the effect of uncertainties is cancelled online by the control input. Experimental results of the MM proposed tracking controller show its validity and efficiency.

Keywords: active disturbance rejection control; mobile manipulator; modelling uncertainty; external disturbances; NESO; nonlinear extended state observer.

DOI: 10.1504/IJMIC.2021.120208

International Journal of Modelling, Identification and Control, 2021 Vol.37 No.2, pp.95 - 105

Received: 15 Sep 2020
Accepted: 22 Dec 2020
Published online: 11 Jan 2022 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article