Robust Finite-Time Control of a Multirotor System via an Improved
Optimized Homogeneous Twisting Control: Design and Validation
Aimen Abdelhak Messaoui
1
, Omar Mechali
1
, Ali Zakaria Messaoui
2
and Iheb Eddinde Smaali
1
1
Ecole Supérieure Ali Chabati, Réghaia, Algeria
2
Laboratoire de Commande des Systèmes Complexes et Simulateurs, Ecole Militaire Polytechnique,
Bordj El-Bahri, Algeria
Keywords: The Attitude Tracking Control, Finite-Time Stability, Homogeneous Sliding Mode Control,
Pixhawk Autopilot, Quadrotor Aircraft.
Abstract: This paper presents theoretical and practical aspects of finite-time tracking control of a multirotor attitude
system. The vehicle is subjected to matched lumped disturbances. Inspired by the homogeneity theory, an
Improved Optimized Homogeneous Twisting Control (IOHTC) is proposed to deal with the fast dynamics’
response of the attitude states. Within the designed control scheme, the chattering issue of discontinuous
Sliding Mode Control (SMC) techniques can be mitigated due to the continuous control signal that is
generated by a non-switching function in the form of |𝑥|
sign(𝑥),𝑥 ∈ 𝑅,𝛼 ∈ 𝑅+. Besides, finite-time
convergence of the system’s states can be ensured to achieve accurate control. It is worth mentioning that
the disturbance rejection does not require the design of an observer since the control law integrates a
compensation term. Stability analysis of the closed-loop system is rigorously investigated by using a
homogeneous Lyapunov function. From the practical aspect, the control algorithm is embedded onboard the
quadrotor’s autopilot through a model-based design approach. A comparative study is made involving the
proposed IOHTC strategy and three other controllers. The obtained results show that the suggested controller
yields performance improvement regarding accuracy and robustness. Meanwhile, the chattering effect of
conventional SMC is remarkably alleviated.
1 INTRODUCTION
The quadrotor is among the most often used
multirotor aircraft because of its particular flight
mode, variety of sizes, and exceptional hovering
capabilities. Unfortunately, it is also considered a
well-known underactuated mechanical system.
However, since its invention in 1907, quadcopters
have found use in a wide range of application fields
(O. Mechali J. I., 2021) (O. Mechali J. I., 2021).
However, despite its alluring qualities, this kind of
system faces real challenges, especially in terms of
control. Accurate and robust aircraft attitude control
is necessary for autonomous quadrotor flying. Since
a quadrotor is a nonlinear system with highly coupled
dynamics, it is susceptible to internal modeling errors,
parametric uncertainty, and external disturbances.
Consequently, developing the system attitude
controller becomes challenging. In order to perform
the objectives of the flying mission, this aircraft’s
autonomous flight requires a sophisticated control
scheme. Additionally, the controller design appears
based on robustness, high control accuracy, and quick
convergence.
SMC, among other robust control approaches, is
an active topic in the unmanned aerial vehicle
community nowadays for controlling quadrotor
aircraft (S. Benmansour, 2023) (S. G. Khan, 2019).
The simplicity of design and the fast response are
among the benefits of such methods. In addition, it
accurately compensates for matched disturbances.
Several recent research works have focused on
synthesizing and implementing robust SMC-based
control laws for disturbance handling in the quadrotor
system. For example, through an integral SMC-based
approach, the study described in (S. Ullah, 2020)
seeks to enhance the stability of an underactuated
quadcopter. A robust backstepping-SMC control law
is suggested in a further inspired study (Almakhles,
2020) to deal with the quadrotor model with
disturbances. However, because a linear switching
manifold has been employed, it is guaranteed that the