Fractional-Order Control for Robust Position/Yaw Tracking of Quadrotors With Experiments

Abstract

Quadrotors are highly maneuverable light weight drones, which are prone to aerodynamic disturbances, vibrations and uncertainties. These factors stand for a problem that demands robust control laws. For position tracking, the control problem is exacerbated because the plant is underactuated in the coordinates of interest, requiring a high performance attitude tracking to resolve underactuation. In this paper, a novel fractional-order controller is proposed by considering a well-posed map that relates the position/yaw control to desired attitude references. The attitude control is continuous and enforces and sustains a sliding motion in finite-time for exponential convergence of the tracking errors to fulfill a "virtual" position controller. The resulting closed-loop system is robust against continuous disturbances that are not necessarily differentiable in the conventional sense. A numerical study based on simulations is presented to analyze the advantages of the fractional actions to design a physically realizable controller, and experiments are discussed to expose the reliability of the proposed fractional scheme implemented in an 'X' configuration quadrotor.

Global exponential stabilization of a quadrotor by hybrid control

“…The quadrotor is a typical kind of unmanned aerial vehicle (UAV) equipped with four rotors that are aligned with direction, sensors, power storage, and DC motor (Lazim et al, 2019; Wu et al, 2018). Nevertheless, the quadrotor control is not an easy task because of its nonlinear dynamics and aerodynamic disturbances (Izaguirre-Espinosa et al, 2018). Researchers have been devoted to addressing this problem for decades.…”

Recurrent Neural Network With Fractional Learning-Based Fixed-Time Formation Tracking Constrained Control for a Group of Quadrotors

“…It is also known that the tracking specifications for the (adaptive) fixed-time control include tolerable tracking error for a highly demanded trajectory in a given time range for the system with uncertainties. Some representative papers on trajectory tracking control of quadrotor or spacecraft using (adaptive) fixed-time control [22], [32]- [44] are discussed and summarized as follows: (i) the finite-time bounded error control [22], [33], [39], [41], [42], [44], (ii) the finite-time regulation control [34]- [35], [38], (iii) without considering the constrained input [34], [37]- [38], [40], (iv) the occurrence of chattering control [35], [36], (v) the requirement of an observer for state or disturbance estimation [22], [36], [39], [42], [44], and (vi) the complex adaptive scheme with more computation time [32]. Moreover, no paper discusses the formation control using adaptive fixed time control with the capability of obstacle avoidance and formation change [22], [32]- [44].…”

A Unified SO(3) Approach to the Attitude Control Design for Quadrotors

“…As such, the attitude control can be designed separately and independently. Even so, some existing works go one step further and deal with both translational and rotational motions at the same time, such as Zhao et al [4], Shi et al [7], and García et al [12], Nikhilraj et al [14], and Izaguirre-Espinosa et al [15]. This paper focuses its study on the second type of motion.…”

“…Parametric uncertainties may exist in practice, such as mass and/or moment of inertia of the quadrotor and oftentimes adaptive controllers are utilized to deal with them, see, for example, Lee [3], Zhao et al [4], Bhatia et al [11], García et al [12], and Chu et al [17]. Some authors also addressed the issue of external disturbances and/or uncertain system dynamics with robust control designs including Lee [3], Zhao et al [4], Lee [6], Tian et al [8], Jiang et al [9], Bhatia et al [11], García et al [12], Tian et al [13], Izaguirre-Espinosa et al [15], and Chu et al [17]. Among them, Tian et al [8], García et al [12], Tian et al [13], and Izaguirre-Espinosa et al [15] used sliding mode control.…”

“…Some authors also addressed the issue of external disturbances and/or uncertain system dynamics with robust control designs including Lee [3], Zhao et al [4], Lee [6], Tian et al [8], Jiang et al [9], Bhatia et al [11], García et al [12], Tian et al [13], Izaguirre-Espinosa et al [15], and Chu et al [17]. Among them, Tian et al [8], García et al [12], Tian et al [13], and Izaguirre-Espinosa et al [15] used sliding mode control.…”