Robust fixed-time formation control for quadrotor unmanned aerial vehicles with directed topology

2021 ◽  
pp. 014233122110325
Author(s):  
Shikai Shao ◽  
Yuanjie Zhao ◽  
Xiaojing Wu
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Finite Time ◽  
Formation Control ◽  
Controller Design ◽  
Initial Conditions ◽  
Fixed Time ◽  
Settling Time ◽  
Lyapunov Theory ◽  
Directed Topology ◽  
Aerial Vehicles

Formation control is one of the key technologies for multiple unmanned aerial vehicles (UAVs). Compared with asymptotic or finite-time controllers, fixed-time controller can provide a guaranteed settling time, which does not depend on initial conditions and is an appealing property for controller design. Thus, robust fixed-time formation controller design for quadrotor UAVs under external disturbance and directed topology is investigated in this paper. A multi-variable super-twisting like integral sliding mode surface and a disturbance observer are respectively designed for position and attitude loops to guarantee robustness. Bi-limit homogeneity is utilized to design the whole closed-loop fixed-time controllers. By skillfully using bi-limit homogeneity technique and Lyapunov theory, the comprehensive stability of position and attitude loops is addressed. Finally, the multiple UAVs are utilized to track a pre-planned trajectory in 3D space and simulation results illustrate that the settling time can be reduced about 40% compared with finite-time controllers.

Finite/fixed-time consensus of nonlinear multi-agent systems against actuator faults and disturbances

2020 ◽  
Vol 42 (16) ◽  
pp. 3254-3266
Author(s):  
Yanhui Yin ◽  
Fuyong Wang ◽  
Zhongxin Liu ◽  
Zengqiang Chen
Keyword(s):  
Finite Time ◽  
Initial Conditions ◽  
Fixed Time ◽  
Settling Time ◽  
Design Parameters ◽  
Actuator Faults ◽  
Multi Agent Systems ◽  
Multiple Faults ◽  
Agent Systems ◽  
Multi Agent

This paper is concerned with the consensus tracking problem in nonlinear multi-agent systems against external disturbances and multiple actuator faults. The nonlinear dynamics are unknown and the leader’s input is unavailable to any follower. By using finite-time Lyapunov stability theory, a distributed discontinuous protocol is developed. On this basis, a fixed-time control protocol is further designed to obtain a settling time regardless of initial conditions. In addition, the practical finite-time consensus and practical fixed-time consensus are investigated by the adaptive technique, under which the bounds of the faults can be estimated online adaptively. The innovation of this work lies in the fact that the finite/fixed-time consensus problem is solved when multiple faults and mismatched nonlinearity are simultaneously considered. The relationship between the settling time and design parameters is well established. Finally, some numerical simulations are given to verify the effectiveness of the theoretical results.

Model decomposition-based optimal formation control for multiple unmanned aerial vehicles

2021 ◽  
pp. 014233122110430
Author(s):  
Khan Muhammad Shehzad ◽  
Hao Su ◽  
Gong-You Tang ◽  
Bao-Lin Zhang
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Formation Control ◽  
Controller Design ◽  
Feedforward Control ◽  
Position Information ◽  
Model Decomposition ◽  
Aerial Vehicles ◽  
Control Framework ◽  
Multiple Unmanned Aerial Vehicles ◽  
The Stability

This paper deals with the optimal formation control problem based on model decomposition for multiple unmanned aerial vehicles (UAVs). The main contribution of this paper is to integrate the formation control and the trajectory tracking into one unified feedforward control and feedback control framework in an optimal mode. We first establish the dynamic model of the leader-follower UAV formation system, and the communication network topology which only depends on the position information given by the leader. Second, to reduce the complexity of the model, each follower is decomposed into three isolated subsystems. Third, a step-by-step formation controller design scheme decomposed into feedforward control and optimal control of formation control is proposed. Finally, the proposed scheme has been extensively simulated and the results demonstrate the stability and the optimality.

scholarly journals Nonlinear Adaptive Line-of-Sight Path Following Control of Unmanned Aerial Vehicles considering Sideslip Amendment and System Constraints

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Zhengyang Cui ◽  
Yong Wang
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Finite Time ◽  
Control Strategies ◽  
Path Following ◽  
Fixed Time ◽  
Control Laws ◽  
Aerial Vehicles ◽  
Path Following Control ◽  
Heading Control ◽  
Cross Track

With growing worldwide interests in commercial, scientific, and military issues, there has been a corresponding rapid growth in demand for the development of unmanned aerial vehicles (UAVs) with more reliable and safer motion control abilities. This paper presents a new nonlinear path following scheme integrated with a heading control law for achieving accurate and reliable path following performance. Both backstepping and finite-time techniques are employed for developing the path following and heading control strategies capable of minimizing cross-track errors in finite-time with elegant transient performance, while the barrier Lyapunov function scheme is adopted to limit turning rates of the UAV for preventing it from capsizing which may be induced by overquick steering actions. A fixed-time nonlinear estimator, based on UAV kinematics, is designed for estimating the uncertainties with sideslip angles caused by external disturbances and inertial motions. To avoid the complicated calculation of derivatives of virtual control terms in backstepping, command filters and auxiliary systems are likewise introduced in the design of control laws. Extensive numerical simulation studies on a nonlinear UAV model are conducted to demonstrate the effectiveness of the proposed methodologies.

Bird Flocking Inspired Formation Control for Unmanned Aerial Vehicles Using Stereo Camera

2019 ◽  
Vol 13 (3) ◽  
pp. 3580-3589 ◽  
Author(s):  
Jonathan Lwowski ◽  
Abhijit Majumdar ◽  
Patrick Benavidez ◽  
John J. Prevost ◽  
Mo Jamshidi
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Formation Control ◽  
Stereo Camera ◽  
Aerial Vehicles

Design and flight-stability analysis of a closed fixed-wing unmanned aerial vehicle formation controller

2018 ◽  
Vol 233 (8) ◽  
pp. 1045-1054 ◽  
Author(s):  
Jialong Zhang ◽  
Bing Xiao ◽  
Maolong Lv ◽  
Qiang Zhang
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Collision Avoidance ◽  
High Speed ◽  
Physical Simulation ◽  
Controller Design ◽  
Formation Flight ◽  
External Factors ◽  
Flight Stability ◽  
Aerial Vehicles ◽  
Closed Formation

This article addresses a flight-stability problem for the multiple unmanned aerial vehicles cooperative formation flight in the process of the closed and high-speed flight. The main objective is to design a cooperative formation controller with known external factors, and this controller can keep the consensus of attitude and position and reduce the communication delay between any two unmanned aerial vehicles and increase unmanned aerial vehicles formation cruise time under the known external factors. Known external factors are taken into consideration, and longitude maneuvers using nonlinear thrust vectors were employed with unsteady aerodynamic models, according to the attitude and position of unmanned aerial vehicles, which were employed as corresponding input signals for studying the dynamic characteristics of unmanned aerial vehicles formation flight. In addition, the relative distance between any two unmanned aerial vehicles was not allowed to exceed their safe distance so that the controller could perform collision avoidance. An analysis of formation flight distance error shows that it converged to a fixed value that well ensured unmanned aerial vehicles formation flight stability. The experimental results show that the controller can improve the speed of a closed formation effectively and maintain the stability of formation flight, which provides a method for closed formation flight controller design and collision avoidance for any two unmanned aerial vehicles. Meanwhile, the effectiveness of proposed controller is fully proved by semi-physical simulation platform.

Lyapunov vector-based formation tracking control for unmanned aerial vehicles with obstacle/collision avoidance

2019 ◽  
Vol 42 (5) ◽  
pp. 942-950
Author(s):  
Kai Chang ◽  
Dailiang Ma ◽  
Xingbin Han ◽  
Ning Liu ◽  
Pengpeng Zhao
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Potential Field ◽  
Formation Control ◽  
Control Method ◽  
Spherical Surface ◽  
Moving Target ◽  
Local Optima ◽  
Formation Tracking ◽  
Aerial Vehicles ◽  
Repulsive Forces

This paper presents a formation control method to solve the moving target tracking problem for a swarm of unmanned aerial vehicles (UAVs). The formation is achieved by the artificial potential field with both attractive and repulsive forces, and each UAV in the swarm will be driven into a leader-centered spherical surface. The leader is controlled by the attractive force by the moving target, while the Lyapunov vectors drive the leader UAV to a fly-around circle of the target. Furthermore, the rotational vector-based potential field is applied to achieve the obstacle avoidance of UAVs with smooth trajectories and avoid the local optima problem. The efficiency of the developed control scheme is verified by numerical simulations in four scenarios.

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