Robust flight mode transition control for tail-sitter formation flying with communication delays

2021 ◽  
pp. 107754632110371
Author(s):  
Deyuan Liu ◽  
Hao Liu ◽  
Xin Li
Keyword(s):  
Flight Control ◽  
Formation Control ◽  
Formation Flying ◽  
Control Method ◽  
System Stability ◽  
Communication Delays ◽  
Transition Control ◽  
Continuous Formation ◽  
Flight Mode ◽  
Mode Transitions

In this article, the formation control problem is investigated for a team of unmanned tail-sitters subject to communication delays. A robust distributed and continuous formation control scheme is developed to achieve the desired aggressive time-varying formation flying in flight mode transitions between forward and vertical flights. The proposed control method consists of a translational controller and a rotational controller for each individual tail-sitter to govern the position and attitude motions, respectively. It is proven that the formation system stability can be guaranteed in the presence of communication delays and multiple uncertainties. Simulation results are presented for a team of tail-sitters to illustrate the advantages of the proposed formation flight control algorithm.

scholarly journals Emergency Flight Control Based on the Fan Wing

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Lin Meng ◽  
Shuo Wang ◽  
Ye Chen ◽  
Yang Gao
Keyword(s):  
Control System ◽  
Flight Control ◽  
Control Method ◽  
Cross Flow ◽  
Flight Control System ◽  
Longitudinal Control ◽  
Emergency Control ◽  
Flight Mode ◽  
Pitch Moment ◽  
Cross Flow Fan

FanWing has been taken to the visual field because of its performance combination of fixed-wing aircraft and helicopter. Its flight mode is currently limited mainly by a remote control, while the research of automated flight control is on the rise. The fan wing could offer lift, thrust, and the additional pitch moment for longitudinal control. At the same time, the roll moment and the yaw moment can be generated by the differential rotation of the cross-flow fan to realize the lateral control. It provides the possibility for its emergency flight control when the aerodynamic control becomes inefficient at a low speed. The difficulties in designing the emergency control system in both the longitudinal and lateral controls are analyzed. And it emphasizes the importance of selecting its center of gravity and the emergency control method of longitudinal control in engineering. The simulation results show that as an emergency flight control system, fan wing control is feasible. The study of the fan wing control will provide a reference solution for its further engineering applications.

scholarly journals Simulation-based Assessment of Quadrotor Linear Control Schemes

2019 ◽  
Vol 8 (3) ◽  
pp. 3654-3662
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
System Stability ◽  
Linear Control ◽  
Six Degrees Of Freedom ◽  
Blade Element Theory ◽  
Common Control ◽  
Flight Mode ◽  
Control Schemes ◽  
Lqr Controller

This work aims at finding the most suited control scheme for a typical quad-rotor. Selecting the appropriate controller is essential to achieve system stability. The most common control schemes are compared in terms of their performance in hovering mode. The quad-rotor propellers are modeled based on both momentum theory and blade element theory. The model describing the six-degrees of freedom system is used to develop a control strategy using different types of controllers such as PID, Fuzzy, Optimal, LQ), as well as LQR controller. The current work is confined to linear control schemes in hovering flight mode, where the comparison is based on achieving stable attitude in hovering. The simulation results show that the LQR controller is the most efficient control method to minimize the steady-state error

scholarly journals Formation Control of Unmanned Vessels with Saturation Constraint and Extended State Observation

2021 ◽  
Vol 9 (7) ◽  
pp. 772
Author(s):  
Huixuan Fu ◽  
Shichuan Wang ◽  
Yan Ji ◽  
Yuchao Wang
Keyword(s):  
Formation Control ◽  
Control Method ◽  
Tracking Error ◽  
External Environment ◽  
Control Force ◽  
Extended State ◽  
Parameter Perturbation ◽  
State Observation ◽  
Saturation Constraint ◽  
The Stability

This paper addressed the formation control problem of surface unmanned vessels with model uncertainty, parameter perturbation, and unknown environmental disturbances. A formation control method based on the control force saturation constraint and the extended state observer (ESO) was proposed. Compared with the control methods which only consider the disturbances from external environment, the method proposed in this paper took model uncertainties, parameter perturbation, and external environment disturbances as the compound disturbances, and the ESO was used to estimate and compensate for the disturbances, which improved the anti-disturbance performance of the controller. The formation controller was designed with the virtual leader strategy, and backstepping technique was designed with saturation constraint (SC) function to avoid the lack of force of the actuator. The stability of the closed-loop system was analyzed with the Lyapunov method, and it was proved that the whole system is uniformly and ultimately bounded. The tracking error can converge to arbitrarily small by choosing reasonable controller parameters. The comparison and analysis of simulation experiments showed that the controller designed in this paper had strong anti-disturbance and anti-saturation performance to the compound disturbances of vessels and can effectively complete the formation control.

String Instabilities in Formation Flight: Limitations Due to Integral Constraints

2004 ◽  
Vol 126 (4) ◽  
pp. 873-879 ◽  
Author(s):  
P. Seiler ◽  
A. Pant ◽  
J. K. Hedrick
Keyword(s):  
Flight Control ◽  
Formation Control ◽  
Energy Savings ◽  
Feedback Loops ◽  
Formation Flight ◽  
Control Laws ◽  
Aerodynamic Efficiency ◽  
Preceding Vehicle ◽  
Specific Control ◽  
Theoretical Results

Flying in formation improves aerodynamic efficiency and, consequently, leads to an energy savings. One strategy for formation control is to follow the preceding vehicle. Many researchers have shown through simulation results and analysis of specific control laws that this strategy leads to amplification of disturbances as they propagate through the formation. This effect is known as string instability. In this paper, we show that string instability is due to a fundamental constraint on coupled feedback loops. The tradeoffs imposed by this constraint imply that predecessor following is an inherently poor strategy for formation flight control. Finally, we present two examples that demonstrate the theoretical results.

Trajectory Control Method Of UAV In Autonomous Flight Mode Using Neural Network MELM Algorithm

2020 ◽  
Author(s):  
Oleksii Fesenko ◽  
Robert Bieliakov ◽  
Hrygorii Radzivilov ◽  
Volodymyr Hulii ◽  
Oleh Kovalchuk ◽  
...  
Keyword(s):  
Neural Network ◽  
Control Method ◽  
Trajectory Control ◽  
Autonomous Flight ◽  
Flight Mode

Control Strategy of Wind Photovoltaic and Energy Storage System Stability Running

2013 ◽  
Vol 336-338 ◽  
pp. 547-550
Author(s):  
Ji Hong Zhang ◽  
Zhen Kui Wu ◽  
Hua Li ◽  
Han Shan Li
Keyword(s):  
Energy Storage ◽  
Distributed Generation ◽  
Control Strategy ◽  
Control Method ◽  
Storage System ◽  
Energy Storage System ◽  
System Stability ◽  
Mathematics Model ◽  
Generation Efficiency ◽  
Micro Grid

Micro grid may exert adequately distributed generation efficiency, and that wind Photovoltaic and Energy Storage is a key equipment in the micro grid. Aiming at the distributed generation existing intermittence and randomicity characteristic, the paper discussed the micro grid P/Q control method under the connection grid state and the micro grid U/F control method under the disconnection grid state. It also studied the distributed generation parameters variational law under the micro grid different run mode, and built the correlative mathematics model and tested by simulation. The results show: the control strategy ensured the mice grid running stably, and achieved the system anticipative design request, and offered theory foundation for the distributed generation extend application.

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