Full-State-Constrained Adaptive Control for a Class of UAVs Suffering from Coupled Uncertainties Using the HOBLF

Xiaofei Chang,Wenxing Fu,Kexuan Wang,Kang Chen,Jose Vicente Salcedo

doi:10.1155/2021/9963426

Xiaofei Chang, Wenxing Fu + Show 3 more

Open Access

https://doi.org/10.1155/2021/9963426

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Abstract

Nowadays, the practical tasks of UAVs are becoming more and more complicated and diversified. In the practical flight process, the large-scale changes of the flight environment, the modeling errors, and the external disturbances may induce the instability of the UAV flight system. Meanwhile, the constraints of the UAV attitudes also have to be guaranteed during the flight process. However, most existing control methods still have limitations in handling the constraints and the multisource disturbances simultaneously. To address this problem, in this paper, we focus on the actual output tracking control for the UAV systems with full-state constraints and multisource disturbances. Firstly, a high-order tan-type barrier Lyapunov function (HOBLF) has been constructed for the UAV to maintain the full-state constraints. Secondly, by combining the adaptive backstepping technique and the fuzzy logic systems, the modeling errors and the unknown nonlinearities of the UAV attitude control system can be handled. Moreover, by properly constructing several adaptive laws, the time-varying disturbances existing in the UAV attitude control system can be suppressed. Finally, the full-state-constrained antidisturbance controller is formed, ensuring that the tracking error approaches arbitrarily to small neighborhood and does not violate the given constraints. The simulation results illustrate the feasibility and the advantages of the proposed method.

Highlights

Unmanned aerial vehicles (UAVs) have attracted research interest on account of their simple structures, low price, high mobility, and high flexibility
The nonlinear characteristics and strong coupling of UAVs increase the difficulty of UAV control [3]. e aerodynamic parameter perturbations, modeling errors, and external interference caused by changes in flight conditions may cause instability of the flight system or even failure [4]
Chen et al [19] used a disturbance observer-based control (DOBC) scheme with transient performance design for UAVs to tackle the mismatched disturbance problem. Another effective way to account for the unknown dynamics in the UAV is employing active disturbance rejection control (ADRC) [20]

Summary

Introduction

Unmanned aerial vehicles (UAVs) have attracted research interest on account of their simple structures, low price, high mobility, and high flexibility. In [45], a higher-order barrier Lyapunov function (HOBLF) has been firstly proposed while achieving constraint satisfaction without solving the displayed solution of the system, especially for the higherorder uncertain nonlinear system. As far as the authors know, there is no relevant literature that has studied the state constraints of UAVs. In spite of the process, the HOBLF-based full-stateconstrained antidisturbance control has never been investigated for the UAVs. According to Sun et al [45], using the HOBLF can achieve practical output tracking control for a category of high-order uncertain nonlinear systems with full-state constraints. (i) is paper introduces a high-order tan-type BLF and applies it to the UAV system, whose three attitude angles have state constraints.

Problem Formulation and Related Knowledge

Main Results

Design the adaptive law as

Simulation Experiment

Conclusion