Search results

1 – 10 of 593
To view the access options for this content please click here
Article
Publication date: 3 August 2020

Oznur Usanmaz, Murat Karaderili, Ozlem Sahin and Tamer Savaş

Unmanned aerial vehicles (UAVs) are more affected by adverse wind conditions in especially landing. Therefore, they need to change the runway in use. In case of this…

Abstract

Purpose

Unmanned aerial vehicles (UAVs) are more affected by adverse wind conditions in especially landing. Therefore, they need to change the runway in use. In case of this change, to eliminate the uncertain maneuvers, there is a need for a special prescribed track. The purpose of this study is the construction of a prescribed track at a single runway to provide a facility to change the runway in use.

Design/methodology/approach

Two forms of prescribed tracks, as standard and alternate, were constructed for UAVs by taking into consideration the key parameters to design flight procedures. Both tracks were assessed in a real-time simulation method. Moreover, unmanned vehicle simulation was used for a validation process.

Findings

According to the real-time simulation results, 8.14 NM and 6.64 NM of flight distance and 5.43 min and 4.43 min of flight time for the standard and alternate prescribed tracks were found, respectively. The obtained results were in favor of the alternate prescribed track. Furthermore, the prescribed track was assessed and validated in both air traffic control and UAV simulations. The feedback of pilots and controllers was very positive for a prescribed track, as it provided them with foresight and time to take care in any situations.

Practical implications

The prescribed track in this paper may be applied by airspace designers and UAV users to perform safe and efficient landing in adverse wind conditions.

Originality/value

In this study, a prescribed track was constructed for UAVs. Quantitative results were achieved using a real-time simulation method in terms of flight distance and flight time. Additionally, validation of the prescribed track was achieved by unmanned air vehicle simulation.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 10
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 6 January 2021

Navya Thirumaleshwar Hegde, V. I. George, C. Gurudas Nayak and Aldrin Claytus Vaz

This paper aims to provide a mathematical modeling and design of H-infinity controller for an autonomous vertical take-off and landing (VTOL) Quad Tiltrotor hybrid unmanned

Abstract

Purpose

This paper aims to provide a mathematical modeling and design of H-infinity controller for an autonomous vertical take-off and landing (VTOL) Quad Tiltrotor hybrid unmanned aerial vehicles (UAVs). The variation in the aerodynamics and model dynamics of these aerial vehicles due to its tilting rotors are the key issues and challenges, which attracts the attention of many researchers. They carry parametric uncertainties (such as non-linear friction force, backlash, etc.), which drives the designed controller based on the nominal model to instability or performance degradation. The controller needs to take these factors into consideration and still give good stability and performance. Hence, a robust H-infinity controller is proposed that can handle these uncertainties.

Design/methodology/approach

A unique VTOL Quad Tiltrotor hybrid UAV, which operates in three flight modes, is mathematically modeled using Newton–Euler equations of motion. The contribution of the model is its ability to combine high-speed level flight, VTOL and transition between these two phases. The transition involves the tilting of the proprotors from 90° to 0° and vice-versa in 15° intervals. A robust H-infinity control strategy is proposed, evaluated and analyzed through simulation to control the flight dynamics for different modes of operation.

Findings

The main contribution of this research is the mathematical modeling of three flight modes (vertical takeoff–forward, transition–cruise-back, transition-vertical landing) of operation by controlling the revolutions per minute and tilt angles, which are independent of each other. An autonomous flight control system using a robust H-infinity controller to stabilize the mode of transition is designed for the Quad Tiltrotor UAV in the presence of uncertainties, noise and disturbances using MATLAB/SIMULINK. This paper focused on improving the disturbance rejection properties of the proposed UAV by designing a robust H-infinity controller for position and orientation trajectory regulation in the presence of uncertainty. The simulation results show that the Tiltrotor achieves transition successfully with disturbances, noise and uncertainties being present.

Originality/value

A novel VTOL Quad Tiltrotor UAV mathematical model is developed with a special tilting rotor mechanism, which combines both aircraft and helicopter flight modes with the transition taking place in between phases using robust H-infinity controller for attitude, altitude and trajectory regulation in the presence of uncertainty.

Details

International Journal of Intelligent Unmanned Systems, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2049-6427

Keywords

To view the access options for this content please click here
Article
Publication date: 13 May 2019

Anna Maria Mazur and Roman Domanski

The presented research is carried out in reaction to the soaring costs of fuel and tight control over environmental issues such as carbon dioxide emissions and noise. The…

Abstract

Purpose

The presented research is carried out in reaction to the soaring costs of fuel and tight control over environmental issues such as carbon dioxide emissions and noise. The purpose of this paper is to study the feasibility of applying the environmental-friendly energy source in an unmanned aerial vehicles (UAVs) propulsion system.

Design/methodology/approach

Currently, the majority of UAVs are still powered by conventional combustion engines. An electric propulsion system is most commonly found in civilian micro and mini UAVs. The UAV classification is reviewed in this study. This paper focuses mainly on application of electric propulsion systems in UAVs. Investigated hybrid energy systems consist of fuel cells, Li-ion batteries, super-capacitors and photovoltaic (PV) modules. Current applications of fuel cell systems in UAVs are also presented.

Findings

The conducted research shows that hybridization allows for better energy management and operation of every energy source onboard the UAV within its limits. The hybrid energy system design should be created to maximize system efficiency without compromising the performance of the aircraft.

Practical implications

The presented study highlights the reduction of the energy consumption, necessary to perform the mission and maximizing of the endurance with simultaneous decrease in emissions and noise level.

Originality/value

The conducted research studies the feasibility of implementing the environmental-friendly hybrid electric propulsion systems in UAVs that offers high efficiency, reliability, controllability, lack of thermal and noise signature, thus, providing quiet and clean drive with low vibration levels. This paper highlights the main challenges and current research on fuel cell in aviation and draws attention to fuel cell – electric system modeling, hybridization and energy management.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 3 October 2016

Turgul Oktay, Mehmet Konar, Murat Onay, Murat Aydin and Mohamed Abdallah Mohamed

The purpose of this paper is to increase flight performance of small unmanned aerial vehicle (UAV) using simultaneous UAV and autopilot system design.

Abstract

Purpose

The purpose of this paper is to increase flight performance of small unmanned aerial vehicle (UAV) using simultaneous UAV and autopilot system design.

Design/methodology/approach

A small UAV is manufactured in Erciyes University, College of Aviation, Model Aircraft Laboratory. Its wing and tail is able to move forward and backward in the nose-to-tail direction in prescribed interval. Autopilot parameters and assembly position of wing and tail to fuselage are simultaneously designed to maximize flight performance using a stochastic optimization method. Results are obtained are used for simulations.

Findings

Using simultaneous UAV and autopilot system design idea, flight performance is maximized.

Research limitations/implications

Permission of Directorate General of Civil Aviation in Turkey is required for testing UAVs in long range.

Practical implications

Simultaneous design idea is very beneficial for improving UAV flight performance.

Originality/value

Creating a novel method to improve flight performance of UAV and developing an algorithm performing simultaneous design idea.

Details

Aircraft Engineering and Aerospace Technology, vol. 88 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 28 February 2019

Tao Han, Bo Xiao, Xi-Sheng Zhan, Jie Wu and Hongling Gao

The purpose of this paper is to investigate time-optimal control problems for multiple unmanned aerial vehicle (UAV) systems to achieve predefined flying shape.

Abstract

Purpose

The purpose of this paper is to investigate time-optimal control problems for multiple unmanned aerial vehicle (UAV) systems to achieve predefined flying shape.

Design/methodology/approach

Two time-optimal protocols are proposed for the situations with or without human control input, respectively. Then, Pontryagin’s minimum principle approach is applied to deal with the time-optimal control problems for UAV systems, where the cost function, the initial and terminal conditions are given in advance. Moreover, necessary conditions are derived to ensure that the given performance index is optimal.

Findings

The effectiveness of the obtained time-optimal control protocols is verified by two contrastive numerical simulation examples. Consequently, the proposed protocols can successfully achieve the prescribed flying shape.

Originality/value

This paper proposes a solution to solve the time-optimal control problems for multiple UAV systems to achieve predefined flying shape.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 12 no. 1
Type: Research Article
ISSN: 1756-378X

Keywords

To view the access options for this content please click here
Article
Publication date: 18 April 2016

Deepak B B V L and Pritpal Singh

In the previous decade, unmanned aerial vehicles (UAVs) have turned into a subject of enthusiasm for some exploration associations. UAVs are discovering applications in…

Abstract

Purpose

In the previous decade, unmanned aerial vehicles (UAVs) have turned into a subject of enthusiasm for some exploration associations. UAVs are discovering applications in different regions going from military applications to activity reconnaissance. The purpose of this paper is to overview a particular sort of UAV called quadrotor or quadcopter.

Design/methodology/approach

This paper includes the dynamic models of a quadrotor and the distinctive model-reliant and model-autonomous control systems and their correlation.

Findings

In the present time, focus has moved to outlining autonomous quadrotors. Ultimately, the paper examines the potential applications of quadrotors and their part in multi-operators frameworks.

Originality/value

This investigation deals with the review on various quadrotors, their applications and motion control strategies.

Details

International Journal of Intelligent Unmanned Systems, vol. 4 no. 2
Type: Research Article
ISSN: 2049-6427

Keywords

To view the access options for this content please click here
Article
Publication date: 15 April 2019

Prasad G., Abishek P. and Karthick R.

The purpose of this paper is to discuss the special applications of unmanned aerial vehicles (UAVs) for the transport of medical goods.

Abstract

Purpose

The purpose of this paper is to discuss the special applications of unmanned aerial vehicles (UAVs) for the transport of medical goods.

Design/methodology/approach

Experimental work has been carried out to predict the performance characteristics of UAVs.

Findings

The results have been obtained to predict the range and endurance of UAVs, which can be optimized based on the payload and source of power.

Originality/value

Real-time applications. As the medical products are necessary in the real time life saving events.

Details

International Journal of Intelligent Unmanned Systems, vol. 7 no. 2
Type: Research Article
ISSN: 2049-6427

Keywords

To view the access options for this content please click here
Article
Publication date: 14 June 2013

Christian Ivancsits and Min‐Fan Ricky Lee

This paper aims to address three major issues in the development of a vision‐based navigation system for small unmanned aerial vehicles (UAVs) which can be characterized…

Abstract

Purpose

This paper aims to address three major issues in the development of a vision‐based navigation system for small unmanned aerial vehicles (UAVs) which can be characterized as follows: technical constraints, robust image feature matching and an efficient and precise method for visual navigation.

Design/methodology/approach

The authors present and evaluate methods for their solution such as wireless networked control, highly distinctive feature descriptors (HDF) and a visual odometry system.

Findings

Proposed feature descriptors achieve significant improvements in computation time by detaching the explicit scale invariance of the widely used scale invariant feature transform. The feasibility of wireless networked real‐time control for vision‐based navigation is evaluated in terms of latency and data throughput. The visual odometry system uses a single camera to reconstruct the camera path and the structure of the environment, and achieved and error of 1.65 percent w.r.t total path length on a circular trajectory of 9.43 m.

Originality/value

The originality/value lies in the contribution of the presented work to the solution of visual odometry for small unmanned aerial vehicles.

To view the access options for this content please click here
Book part
Publication date: 2 May 2006

Olena Connor, Harry Pedersen, Nancy J. Cooke and Heather Pringle

The great success of unmanned aerial vehicles (UAVs) in performing near-real time tactical, reconnaissance, intelligence, surveillance and other various missions has…

Abstract

The great success of unmanned aerial vehicles (UAVs) in performing near-real time tactical, reconnaissance, intelligence, surveillance and other various missions has attracted broad attention from military and civilian communities. A critical contribution to the increase and extension of UAV applications, resides in the separation of pilot and vehicle allowing the operator to avoid dangerous and harmful situations. However, this apparent benefit has the potential to lead to problems when the role of humans in remotely operating “unmannedvehicles is not considered. Although, UAVs do not carry humans onboard, they do require human control and maintenance. To control UAVs, skilled and coordinated work of operators on the ground is required.

Details

Human Factors of Remotely Operated Vehicles
Type: Book
ISBN: 978-0-76231-247-4

To view the access options for this content please click here
Article
Publication date: 1 July 2019

Kashish Gupta, Bara Jamal Emran and Homayoun Najjaran

The purpose of this paper is to facilitate autonomous landing of a multi-rotor unmanned aerial vehicle (UAV) on a moving/tilting platform using a robust vision-based approach.

Abstract

Purpose

The purpose of this paper is to facilitate autonomous landing of a multi-rotor unmanned aerial vehicle (UAV) on a moving/tilting platform using a robust vision-based approach.

Design/methodology/approach

Autonomous landing of a multi-rotor UAV on a moving or tilting platform of unknown orientation in a GPS-denied and vision-compromised environment presents a challenge to common autopilot systems. The paper proposes a robust visual data processing system based on targets’ Oriented FAST and Rotated BRIEF features to estimate the UAV’s three-dimensional pose in real time.

Findings

The system is able to visually locate and identify the unique landing platform based on a cooperative marker with an error rate of 1° or less for all roll, pitch and yaw angles.

Practical implications

The proposed vision-based system aims at on-board use and increased reliability without a significant change to the computational load of the UAV.

Originality/value

The simplicity of the training procedure gives the process the flexibility needed to use a marker of any unknown/irregular shape or dimension. The process can be easily tweaked to respond to different cooperative markers. The on-board computationally inexpensive process can be added to off-the-shelf autopilots.

Details

International Journal of Intelligent Unmanned Systems, vol. 7 no. 3
Type: Research Article
ISSN: 2049-6427

Keywords

1 – 10 of 593