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Ma et al. Complex Eng Syst 2023;3:10 Complex Engineering
DOI: 10.20517/ces.2023.14 Systems

Research Article Open Access

Fixed-time integral sliding mode tracking control of a
wheeled mobile robot

Ling Ma, Chenghu Wang, Cheng Ge, Hui Liu, Bo Li

Institute of Logistics Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.

Correspondence to: Associate Prof. Bo Li, Institute of Logistics Science and Engineering, Shanghai Maritime University, Shanghai
201306, China. E-mail: libo@shmtu.edu.cn

How to cite this article: Ma L, Wang C, Ge C, Liu H, Li B. Fixed-time integral sliding mode tracking control of a wheeled mobile
robot. Complex Eng Syst 2023;3:10. http://dx.doi.org/10.20517/ces.2023.14

Received: 1 May 2023 First Decision: 29 May 2023 Revised: 13 Jun 2023 Accepted: 20 Jun 2023 Published: 29 Jun 2023
Academic Editor: Mouquan Shen Copy Editor: Yanbing Bai Production Editor: Yanbing Bai

Abstract
This paper presents a fixed-time integral sliding mode control scheme for a nonholonomic wheeled mobile robot
(WMR). To achieve the trajectory tracking mission, the dynamic model of a WMR is first transformed into a second-
order attitude subsystem and a third-order position subsystem. Two novel continuous fixed-time disturbance ob-
servers are proposed to estimate the external disturbances of the two subsystems, respectively. Then, trajectory
tracking controllers are designed for two subsystems by utilizing the reconstructed information obtained from the dis-
turbance observers. Additionally, an auxiliary variable that incorporates the Gaussian error function is introduced to
address the chattering problem of the control system. Finally, the proposed control scheme is validated by a wheeled
mobile robotic experimental platform.

Keywords: Wheeled mobile robot, trajectorytracking, disturbance observer, fixed-time stability, integral sliding mode
control

1. INTRODUCTION
During the past decades, the wheeled mobile robot (WMR) has attracted extensive attention as it is widely
used in various fields. The research on the WMR mainly includes robot positioning, motion planning, and
motion control, among which the motion control is a fundamental problem. There are three main parts of
[1]
the motion control, including point stabilization, path planning, and trajectory tracking . The trajectory

© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0
International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, shar-
ing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you
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