Take-off and landing control for a coaxial ducted fan unmanned helicopter

2017 ◽  
Vol 89 (6) ◽  
pp. 764-776 ◽  
Author(s):  
Zhi Chen ◽  
Daobo Wang ◽  
Ziyang Zhen ◽  
Biao Wang ◽  
Jian Fu
Keyword(s):  
Control System ◽  
Flight Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Engineering Practice ◽  
Unmanned Helicopter ◽  
Flight Control System ◽  
Content Type ◽  
Ducted Fan ◽  
Coupling Characteristics

Purpose This paper aims to present a control strategy that eliminates the longitudinal and lateral drifting movements of the coaxial ducted fan unmanned helicopter (UH) during autonomous take-off and landing and reduce the coupling characteristics between channels of the coaxial UH for its special model structure. Design/methodology/approach Unidirectional auxiliary surfaces (UAS) for terminal sliding mode controller (TSMC) are designed for the flight control system of the coaxial UH, and a hierarchical flight control strategy is proposed to improve the decoupling ability of the coaxial UH. Findings It is demonstrated that the proposed height control strategy can solve the longitudinal and lateral movements during autonomous take-off and landing phase. The proposed hierarchical controller can decouple vertical and heading coupling problem which exists in coaxial UH. Furthermore, the confronted UAS-TSMC method can guarantee finite-time convergence and meet the quick flight trim requirements during take-off and landing. Research limitations/implications The designed flight control strategy has not implemented in real flight test yet, as all the tests are conducted in the numerical simulation and simulation with a hardware-in-the-loop (HIL) platform. Social implications The designed flight control strategy can solve the common problem of coupling characteristics between channels for coaxial UH, and it has important theoretical basis and reference value for engineering application; the control strategy can meet the demands of engineering practice. Originality/value In consideration of the TSMC approach, which can increase the convergence speed of the system state effectively, and the high level of response speed requirements to UH flight trim, the UAS-TSMC method is first applied to the coaxial ducted fan UH flight control. The proposed control strategy is implemented on the UH flight control system, and the HIL simulation clearly demonstrates that a much better performance could be achieved.

Control System Design of a Hex-Rotor Aircraft Based on the Neural Network Sliding Mode Method

2014 ◽  
Vol 971-973 ◽  
pp. 418-421 ◽  
Author(s):  
Chang Jun Zhao ◽  
Yue Bai ◽  
Xun Gong ◽  
Dong Fu Xu ◽  
Zhi Jun Xu
Keyword(s):  
Neural Network ◽  
Control System ◽  
Flight Control ◽  
Sliding Mode ◽  
Flight Performance ◽  
The Novel ◽  
Flight Control System ◽  
The Neural Network ◽  
Mode Method ◽  
Coupling Characteristics

For the existing Multi-rotor aircrafts, the under-actuation and strong coupling characteristics have a remarkable influence on their flight performance. In order to overcome this effect, a novel Hex-Rotor aircraft is proposed in this paper. Based on the unique configuration of its six driving rotors, the Hex-Rotor aircraft has the ability to achieve the real independent control on the space 6-DOF channels. An autonomous flight control system with neural network sliding mode is designed. The simulation proved that the novel Hex-Rotor aircraft has desired maneuvering capability,and thehe control system is able to guarantee the aircrafts tracking flight of the aircraft.

Modelling and hovering control for a coaxial unmanned helicopter using sliding mode

2018 ◽  
Vol 90 (5) ◽  
pp. 815-827 ◽  
Author(s):  
Zhi Chen ◽  
Daobo Wang ◽  
Ziyang Zhen
Keyword(s):  
Flight Control ◽  
Controller Design ◽  
Sliding Mode ◽  
Unmanned Helicopter ◽  
Nonlinear Controller ◽  
Control Logic ◽  
Coupling Analysis ◽  
Content Type ◽  
Chattering Free ◽  
Coupling Characteristics

Purpose To facilitate the nonlinear controller design, dynamic model of a novel coaxial unmanned helicopter (UH) is established and its coupling analysis is presented. Design/methodology/approach The chattering-free sliding mode controller (SMC) with unidirectional auxiliary surfaces (UASs) is designed and implemented for the coaxial ducted fan UH. Findings The coupling analysis based on the established model show severe coupling between channels. For coaxial UH’s special model structure, UAS-SMC controller is proposed to reduce the coupling characteristics between channels of the UH by setting controllers’ output calculation sequence. Originality/value The flight control law and control logic are successfully tested in numerical simulation and hardware in the loop (HIL) simulation. The results show best hovering performances without chattering problem, even under the bounded internal dynamics and external disturbances.

Design of sliding mode flight control system for a flexible aircraft

2021 ◽  
pp. 095441002110455
Author(s):  
Majeed Mohamed ◽  
Madhavan Gopakumar
Keyword(s):  
Control System ◽  
Rigid Body ◽  
Flight Control ◽  
High Speed ◽  
Sliding Mode ◽  
Flight Mechanics ◽  
Frequency Separation ◽  
Flight Control System ◽  
Flexible Aircraft ◽  
Aircraft Dynamics

The evolution of large transport aircraft is characterized by longer fuselages and larger wingspans, while efforts to decrease the structural weight reduce the structural stiffness. Both effects lead to more flexible aircraft structures with significant aeroelastic coupling between flight mechanics and structural dynamics, especially at high speed, high altitude cruise. The lesser frequency separation between rigid body and flexible modes of flexible aircraft results in a stronger interaction between the flight control system and its structural modes, with higher flexibility effects on aircraft dynamics. Therefore, the design of a flight control law based on the assumption that the aircraft dynamics are rigid is no longer valid for the flexible aircraft. This paper focuses on the design of a flight control system for flexible aircraft described in terms of a rigid body mode and four flexible body modes and whose parameters are assumed to be varying. In this paper, a conditional integral based sliding mode control (SMC) is used for robust tracking control of the pitch angle of the flexible aircraft. The performance of the proposed nonlinear flight control system has been shown through the numerical simulations of the flexible aircraft. Good transient and steady-state performance of a control system are also ensured without suffering from the drawback of control chattering in SMC.

Flight Control System Design and Autonomous Flight Control of Small-Scale Unmanned Helicopter Based on Nanosensors

2021 ◽  
Vol 16 (4) ◽  
pp. 675-688
Author(s):  
Xinfan Yin ◽  
Xianmin Peng ◽  
Guichuan Zhang ◽  
Binghui Che ◽  
Chang Wang
Keyword(s):  
Control System ◽  
Flight Control ◽  
Control Algorithm ◽  
Installation Space ◽  
Small Scale ◽  
Unmanned Helicopter ◽  
Flight Control System ◽  
Autonomous Flight ◽  
Position Controller ◽  
Attitude Controller

Due to the limitation of the size and power, micro unmanned aerial vehicle (MUAV) usually has a small load capacity. Aiming at the problems of limited installation space and easy being interfered in flight attitude measurement of the small-scale unmanned helicopter (SUH), a low-cost and lightweight flight control system of the SUH based on ARM Cortex-M4 core microcontroller and Micro-Electro-Mechanical Systems (MEMS) sensors is developed in this paper. On this basis, in order to realize the autonomous flight control of SUH, firstly, the mathematical model of the SUH is given by using the Newton-Euler formulation. Secondly, a cascade flight controller consisting of the attitude controller and the position controller is developed based on linear active disturbance rejection control (LADRC) and proportional-integral-derivative (PID) control. Furthermore, simulations are conducted to validate the performance of the attitude controller and the position controller in MATLAB/SIMULINK simulation environment. Finally, based on the Align T-REX 470L SUH experimental platform, the hovering experiment and the route flight experiment are also carried out to validate the performance of the designed flight control system hardware and the proposed control algorithm. The results show that the flight control system designed in this paper has high reliability and strong anti-interference ability, and the control algorithm can effectively and reliably realize the attitude stabilization control and route control of the SUH, with high control accuracy and small error.

Multivariable adaptive distributed leader-follower flight control for multiple UAVs formation

2017 ◽  
Vol 121 (1241) ◽  
pp. 877-900 ◽  
Author(s):  
Y. Xu ◽  
Z. Zhen
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
Flight Control ◽  
Control Strategy ◽  
Formation Control ◽  
Parametric Uncertainty ◽  
Lyapunov Theory ◽  
Formation Flight ◽  
Flight Control System ◽  
Multiple Uavs

ABSTRACTThe Unmanned Aerial Vehicles (UAVs) become more and more popular due to various potential application fields. This paper studies the distributed leader-follower formation flight control problem of multiple UAVs with uncertain parameters for both the leader and followers. This problem has not been addressed in the literature. Most of the existing literature considers the leader-follower formation control strategy with parametric uncertainty for the followers. However, they do not take the leader parametric uncertainty into account. Meanwhile, the distributed control strategy depends on less information interactions and is more likely to avoid information conflict. The dynamic model of the UAVs is established based on the aerodynamic parameters. The establishment of the topology structure between a collection of UAVs is based on the algebraic graph theory. To handle the parametric uncertainty of the UAVs dynamics, a multivariable model reference adaptive control (MRAC) method is addressed to design the control law, which enables follower UAVs to track the leader UAV. The stability of the formation flight control system is proved by the Lyapunov theory. Simulation results show that the proposed distributed adaptive leader-following formation flight control system has stronger robustness and adaptivity than the fixed control system, as well as the existing adaptive control system.

Effects of the actively morphing root chord and taper on helicopter energy

2019 ◽  
Vol 92 (2) ◽  
pp. 264-270
Author(s):  
Firat Sal
Keyword(s):  
Control System ◽  
Energy Consumption ◽  
Flight Control ◽  
Design Methodology ◽  
Chord Length ◽  
Flight Control System ◽  
Content Type ◽  
Helicopter Blade ◽  
Blade Root ◽  
Practical Implications

Purpose The purpose of this paper presents the effects of actively morphing root chord and taper on the energy of the flight control system (i.e. FCS). Design/methodology/approach Via regarding previously mentioned purposes, sophisticated and realistic helicopter models are benefitted to examine the energy of the FCS. Findings Helicopters having actively morphing blade root chord length and blade taper consume less control energy than the ones having one of or any of passively morphing blade root chord length and blade taper. Practical implications Actively morphing blade root chord length and blade taper can be used for cheaper helicopter operations. Originality/value The main originality of this paper is applying active morphing strategy on helicopter blade root chord and blade taper. In this paper, it is also found that using active morphing strategy on helicopter blade root chord and blade taper reasons less energy consumption than using either passively morphing blade root chord length plus blade taper or not any. This causes also less fuel consumption and green environment.

Sensitivity of automatic control of emergency manoeuvre to parametric uncertainty of the airplane model

2019 ◽  
Vol 91 (3) ◽  
pp. 407-419
Author(s):  
Jerzy Graffstein ◽  
Piotr Maslowski
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Flight Control ◽  
Parametric Uncertainty ◽  
Second Phase ◽  
Flight Control System ◽  
Content Type ◽  
Control Quality ◽  
Wide Range ◽  
The Impact

Purpose The main purpose of this work was elaboration and verification of a method of assessing the sensitivity of automatic control laws to parametric uncertainty of an airplane’s mathematical model. The linear quadratic regulator (LQR) methodology was used as an example design procedure for the automatic control of an emergency manoeuvre. Such a manoeuvre is assumed to be pre-designed for the selected airplane. Design/methodology/approach The presented method of investigating the control systems’ sensitivity comprises two main phases. The first one consists in computation of the largest variations of gain factors, defined as differences between their nominal values (defined for the assumed model) and the values obtained for the assumed range of parametric uncertainty. The second phase focuses on investigating the impact of the variations of these factors on the behaviour of automatic control in the manoeuvre considered. Findings The results obtained allow for a robustness assessment of automatic control based on an LQR design. Similar procedures can be used to assess in automatic control arrived at through varying design methods (including methods other than LQR) used to control various manoeuvres in a wide range of flight conditions. Practical implications It is expected that the presented methodology will contribute to improvement of automatic flight control quality. Moreover, such methods should reduce the costs of the mathematical nonlinear model of an airplane through determining the necessary accuracy of the model identification process, needed for assuring the assumed control quality. Originality/value The presented method allows for the investigation of the impact of the parametric uncertainty of the airplane’s model on the variations of the gain-factors of an automatic flight control system. This also allows for the observation of the effects of such variations on the course of the selected manoeuvre or phase of flight. This might be a useful tool for the design of crucial elements of an automatic flight control system.

System identification and robust attitude control of an unmanned helicopter using novel low-cost flight control system

2019 ◽  
Vol 234 (5) ◽  
pp. 634-645
Author(s):  
Mohammad Hossein Khalesi ◽  
Hassan Salarieh ◽  
Mahmoud Saadat Foumani
Keyword(s):  
Control System ◽  
Robust Control ◽  
System Identification ◽  
Flight Control ◽  
Low Cost ◽  
Superior Performance ◽  
Raspberry Pi ◽  
Unmanned Helicopter ◽  
Flight Control System ◽  
Robust Control System

In recent years, unmanned aerial systems have attracted great attention due to the electronic systems technology advancements. Among these vehicles, unmanned helicopters are more important because of their special abilities and superior performance. The complex nonlinear dynamic system (caused by main rotor flapping dynamics coupled with the rigid body rotational motion) and considerable effects of ambient disturbance make their utilization hard in actual missions. Attitude dynamics have the main role in helicopter stabilization, so implementing proper control system for attitude is an important issue for unmanned helicopter hovering and trajectory tracking performance. Besides this, experimental utilization of low-cost flight control system for unmanned helicopters is still a challenging task. In this article, dynamic modeling, system identification, and robust control system implementation of roll and pitch dynamics of an unmanned helicopter is performed. A TRex-600E radio-controlled helicopter is equipped with a novel low-cost flight control system designed and constructed based on Raspberry Pi Linux-based microcomputer. Using Raspberry Pi makes this platform simpler to utilize and more time and cost-effective than similar platforms used before. The experiments are performed on a 5-degree-of-freedom testbed. The robust control system is designed based on [Formula: see text] method and is evaluated in real flight tests. The experiment results show that the proposed platform has the ability to successfully control the roll and pitch dynamics of the unmanned helicopter.

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