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Article
Publication date: 8 October 2018

Luitpold Babel

The purpose of this paper is to present a new approach for finding a minimum-length trajectory for an autonomous unmanned air vehicle or a long-range missile from a release point…

Abstract

Purpose

The purpose of this paper is to present a new approach for finding a minimum-length trajectory for an autonomous unmanned air vehicle or a long-range missile from a release point with specified release conditions to a destination with specified approach conditions. The trajectory has to avoid obstacles and no-fly zones and must take into account the kinematic constraints of the air vehicle.

Design/methodology/approach

A discrete routing model is proposed that represents the airspace by a sophisticated network. The problem is then solved by applying standard shortest-path algorithms.

Findings

In contrast to the most widely used grids, the generated networks allow arbitrary flight directions and turn angles, as well as maneuvers of different strengths, thus fully exploiting the flight capabilities of the aircraft. Moreover, the networks are resolution-independent and provide high flexibility by the option to adapt density.

Practical implications

As an application, a concept for in-flight replanning of flight paths to changing destinations is proposed. All computationally intensive tasks are performed in a pre-flight planning prior to the launch of the mission. The in-flight planning is based entirely on precalculated data, which are stored in the onboard computer of the air vehicle. In particular, no path finding algorithms with high or unpredictable running time and uncertain outcome have to be applied during flight.

Originality/value

The paper presents a new network-based algorithm for flight path optimization that overcomes weaknesses of grid-based approaches and allows high-quality solutions. The method can be applied for quick in-flight replanning of flight paths.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 3 May 2016

Andrzej Robert Majka

The purpose of the paper is to determine the optimal conditions of the take-off and the optimal trajectory of the initial climb minimizing the fuel consumption of the aircraft…

Abstract

Purpose

The purpose of the paper is to determine the optimal conditions of the take-off and the optimal trajectory of the initial climb minimizing the fuel consumption of the aircraft aided in the ground phase of the take-off by the system using the MAGLEV technology.

Design/methodology/approach

The study concerned determining the optimal trajectory of the initial phase of the transport aircraft climb aided in the phase of acceleration by the system using the magnetic levitation phenomenon. The simplified algorithm of the Ritz–Galerkin method was used in this work which uses an approximate solution to boundary value problems for determining the optimal flight trajectory. It uses the method of approximation of the flight path by the third-degree polynomial. The method allows determining the optimal trajectory of the flight satisfying the initial/final conditions and control functions and path constrains for an aircraft. General stating of the task supposes determining the optimal trajectory of movement of a flying vehicle described by the system of ordinary differential equations. The resulting sparse non-linear programming problem has been solved using own elaborated software. The typical profiles computation has been performed with a tool combining three degree of freedom flight dynamics differential equations with procedure-oriented flight control.

Findings

Different conditions of the take-off of the aircraft aided by the ground system using the MAGLEV technology give possibilities to shape the trajectory of the initial stage of the aircraft climb after the lift-off to decrease the negative influence on the environment. Optimization of the departure trajectory minimizing fuel consumption or noise emissions can become the basis for working out new procedures for a new kind of take-off modified in relation to the optimal solution which will increase the safety of this segment of the flight.

Research limitations/implications

The analysis was carried out only for the departure trajectory to minimize fuel consumption, without investigation of possibilities of noise reduction. The trajectory guaranteeing minimization of the fuel consumption would also give a solution characterized by minimal emission of substances harmful for the environment.

Practical implications

Application of the innovatory solution of aided take-off is connected with modification of the climbing procedures after the take-off to minimize the negative effect of the aircraft on the surrounded environment. The results can become the basis for working out new procedures which will minimize negative influence to the natural environment in the vicinity of the airports of air transport and increase safety of the take-off and landing operations.

Originality/value

Innovative method of the take-off implies new shape of the trajectory. The study presents the results of the climb trajectory optimization of the aircraft supported at the ground stage by the technology using magnetic levitation phenomenon.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 88 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 21 March 2011

Mohammad Rahim and Seyed Móhammad‐Bagher Malaek

The purpose of this paper is to present a novel approach in terrain following (TF) flight using fuzzy logic. The fuzzy controller as presented in this work decides where and how…

Abstract

Purpose

The purpose of this paper is to present a novel approach in terrain following (TF) flight using fuzzy logic. The fuzzy controller as presented in this work decides where and how the aircraft needs to change its altitude. The fast decision‐making nature of this method promises real‐time applications even for tough terrains in terms of shape and peculiarities. The method could always assist to design trajectories in an off‐line manner.

Design/methodology/approach

To achieve the aforementioned goal, the method effectively incorporates the dynamics of the aircraft. Basically, the mathematical method employs special relationships among existing slope of the terrain and its derivative together with aircraft flying speed and height above the ground to construct suitable fuzzy rules. The fuzzification method is based on Sugeno and three rule‐sets are used for fuzzy structure. These rules are implemented using Fuzzy Logic Toolbox in MATLAB.

Findings

Different case studies conducted for flights in XZ‐plane show the effectiveness of the method as compared to other existing methods available to the authors. The results illustrate a good tracking based on the fuzzy approach while using both 18 and 27 rules with respect to the optimal approach. Furthermore, it is shown that decreasing number of rules from 27 to 18 rules causes only minor changes in the solution.

Practical implications

The current work offers a new approach in low‐level flights where maintaining a suitable height above the ground is essential. This is especially important for civil aircraft approaching an airport with low or non‐visibility and during aborted landing manoeuvres. The domain of the current work is however confined to only planning of TF manoeuvres. Nevertheless, the work could be expanded into TF/terrain avoidance and three‐dimensional manoeuvres which are not in the scope of the current work.

Originality/value

The current work addresses the problems associated with low‐level flight; such as TF using artificial intelligence and fuzzy logic. The provided intelligence helps the aircraft conduct TF manoeuvres by understanding the general patterns of the existing terrain. The method is fast enough to be applied for real‐time applications.

Details

Aircraft Engineering and Aerospace Technology, vol. 83 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 8 May 2018

Marc Immer and Philipp Georg Juretzko

The preliminary aircraft design process comprises multiple disciplines. During performance analysis, parameters of the design mission have to be optimized. Mission performance…

Abstract

Purpose

The preliminary aircraft design process comprises multiple disciplines. During performance analysis, parameters of the design mission have to be optimized. Mission performance optimization is often challenging, especially for complex mission profiles (e.g. for unmanned aerial vehicles [UAVs]) or hybrid-electric propulsion. Therefore, the purpose of this study is to find a methodology that supports aircraft performance analysis and that is applicable to complex profiles and to novel designs.

Design/methodology/approach

As its core element, the developed method uses a computationally efficient C++ software “Aircraft Performance Program” (APP), which performs a segment-based mission computation. APP performs a time integration of the equations of motion of a point mass in the vertical plane. APP is called via a command line interface from a flexible scripting language (Python). On top of APP’s internal radius of action optimization, state-of-the-art optimization packages (SciPy) are used.

Findings

The application of the method to a conventional climb schedule shows that the definition of the top of climb has a significant influence on the resulting optimum. Application of the method to a complex UAV mission optimization, which included maximizing the radius of action, was successful. Low computation time enables to perform large parametric studies. This greatly improves the interpretation of the results.

Research limitations/implications

The scope of the paper is limited to the methodology that allows for advanced performance analysis at the conceptual and preliminary design stages with an emphasis on novel propulsion concepts. The methodology is developed using existing, validated methods, and therefore, this paper does not contain comprehensive validation. Other disciplines, such as cost analysis, life-cycle assessment or market analysis, are not considered.

Practical implications

With the proposed method, it is possible to obtain not only the desired optimum mission performance but also off-design performance of the investigated design. A thorough analysis of the mission performance provides insight into the design’s capabilities and shortcomings, ultimately aiding in obtaining a more efficient design.

Originality/value

Recent developments in the area of hybrid or hybrid-electric propulsion systems have shown the need for performance computation tools aiding the related design process. The presented method is especially valuable when novel design concepts with complex mission profiles are investigated.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 4
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 3 January 2017

Alessandro Ceruti and Pier Marzocca

This paper aims to describe a methodology to optimize the trajectory of unconventional airship performing a high-altitude docking manoeuvre.

Abstract

Purpose

This paper aims to describe a methodology to optimize the trajectory of unconventional airship performing a high-altitude docking manoeuvre.

Design/methodology/approach

The trajectories are based upon Bezier curves whose control points positions are optimized through particle swarm optimization algorithm. A minimum energy strategy is implemented by considering the airship physical properties. The paper describes the mathematical model of the airships, the trajectories modelling through Bezier’s curves and the optimization framework. A series of test cases has been developed to evaluate the proposed methodology.

Findings

Results obtained show that the implemented procedure is able to optimize the airship trajectories and to support their in-flight docking; a strong influence of the wind speed and course on the trajectories planning is highlighted.

Research limitations/implications

The wind speed considered in these simulations depends only on altitude, and gusts effect has been neglected.

Practical implications

The proposed model can support the study of unconventional airship trajectories and can be useful to evaluate best in-air docking strategies.

Originality/value

The paper addresses the problem of trajectory optimization for a class of new air vehicles with an heuristic approach.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 3 July 2017

Philipp Heinemann, Michael Schmidt, Felix Will, Sascha Kaiser, Christoph Jeßberger and Mirko Hornung

The paper aims to assess the potential of aircraft operation from city centres to achieve shortened travel times and the involved aircraft design process.

Abstract

Purpose

The paper aims to assess the potential of aircraft operation from city centres to achieve shortened travel times and the involved aircraft design process.

Design/methodology/approach

The paper describes the methodical approach and iterative procedure of the design process. An assessment of potential technologies is conducted to provide the required enhancements to fulfil the constraints following an inner-city operation. Operational procedures were analysed to reduce the noise propagation through flight path optimization. Furthermore, a ground-based assisted take-off system was conceived to lower required take-off field length and to prevent engine sizing just for the take-off case. Cabin design optimization for a fast turnaround has been conducted to ensure a wide utilization spectrum. The results prove the feasibility of an aircraft developed for inner city operation.

Findings

A detailed concept for a 60-passenger single aisle aircraft is proposed for an Entry-Into-Service year 2040 with a design range of 1,500 nautical miles for a load factor of 90 per cent. Although the design for Short Take-off and Landing and low noise operation had to be traded partly with cruise efficiency, a noteworthy reduction in fuel burn per passenger and nautical mile could be achieved against current aircraft.

Practical implications

The findings will contribute to the evaluation of the feasibility and impact of the Flightpath 2050 goal of a 4-h door-to-door by providing a feasible but ambitious example. Furthermore, it highlights possible bottlenecks and problems faced when realizing this goal.

Originality/value

The paper draws its value from the consideration of the overall sizing effects at aircraft level and from a holistic view on an inner-city airport/aircraft concept design for a 4-h door-to-door goal.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 4
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 9 July 2019

Eduardo Sepulveda Palacios and Howard Smith

The purpose of this paper is to characterise the effects of mission and performance parameters on the design space of low observable subsonic unmanned combat aerial vehicles…

Abstract

Purpose

The purpose of this paper is to characterise the effects of mission and performance parameters on the design space of low observable subsonic unmanned combat aerial vehicles (UCAVs) operating in typical Hi-Lo-Hi ground strike missions.

Design/methodology/approach

Conceptual design methodologies appropriate to low observable, tailless UCAVs have been integrated into a multidisciplinary aircraft design environment, GENUS, developed at Cranfield University’s aircraft design group. A basic Hi-Lo-Hi mission is designed and a baseline configuration is established through the GENUS framework. Subsequently, an evolutionary optimiser and a robust gradient-based optimiser are used to obtain convergent design solutions for various leading edge sweep angles, mission ranges, cruise Mach numbers and other operational constraints.

Findings

The results indicate that performance constraints, specifically in the form of specific excess power (SEP), have a large influence on the overall sizing of subsonic tailless UCAVs. This requirement drives the engine sizing, which represents a considerable proportion of the empty and gross mass of the vehicle. Cruise Mach number studies show that no significant advantages exist for operating at low speeds while maintaining performance requirements consistent with combat missions. There is a drastic increase in the vehicle’s mass and thrust requirements for flight speeds above Mach 0.8, with low sweep configurations showing a more pronounced effect. Increases in the range are not overly dependent on the leading edge sweep angle. Top-level radar cross section (RCS) results also favour configurations with higher leading edge sweep angles, especially from the nose-on aspect. Finally, research and development costs are shown to be directly linked to engine size.

Originality/value

This research shows the use of an integrated aircraft design environment that incorporates aerodynamics, performance, packaging and low observability aspects into the optimisation loop. Through this methodology, this study supports the efforts towards characterising and establishing alternate visions of the future of aerial warfare through the use of low cost, survivable unmanned platforms in network-centric cooperative tasks.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 10
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 15 February 2013

Shih‐Wei Yang, Chern‐Sheng Lin, Shir‐Kuan Lin, Shu‐Hsien Fu and Mau‐Shiun Yeh

The purpose of this paper is to propose an automatic optical inspection system for measuring the surface profile of a microlens array.

Abstract

Purpose

The purpose of this paper is to propose an automatic optical inspection system for measuring the surface profile of a microlens array.

Design/methodology/approach

The system set‐up was constructed according to the principle of the Fizeau interferometer. After capturing the ring interference fringe images of the microlens with a camera, the diameter, profile information and optical properties were analyzed through a microlens surface profile algorithm using innovative image pre‐processing with a precision of less than 0.09 micron.

Findings

By integrating with the genetic algorithm, the XY‐Table shortest moving path of the system is calculated to achieve the purpose of high‐speed inspection and automatic microlens array surface profile measurement.

Originality/value

The measurement results of this system were also compared with other systems, including the atomic force microscope and stylus profiler, to verify the measurement precision and accuracy of this system.

Article
Publication date: 28 March 2008

Xiao‐Bing Hu, Ezequiel Di Paolo and Shu‐Fan Wu

The purpose of this paper is to present a comprehensive self‐adaptive genetic algorithm (GA) based on fuzzy mechanism, aiming to improve both the optimizing capability and the…

Abstract

Purpose

The purpose of this paper is to present a comprehensive self‐adaptive genetic algorithm (GA) based on fuzzy mechanism, aiming to improve both the optimizing capability and the convergence speed.

Design/methodology/approach

Many key factors that affect the performance of GAs are identified and analyzed, and their influences on the optimizing capability and the convergence speed are further elaborated, which prove to be very difficult to be described with explicit mathematical formulas. Therefore, a set of fuzzy rules are used to model these complicated relationships, in order to effectively guide the online self‐adaptive adjustments, such as changing the crossover and mutation probabilities, and thus to improve the optimizing capability and convergence speed.

Findings

Simulation results illustrates that, compared with a normal GA and another self‐adaptive GA based on explicit mathematical modeling of the key factors, the new GA is more advanced in terms of the optimizing capability and the convergence speed.

Originality/value

This paper develops a fuzzy‐rule‐based approach to describe the relationships between multiple GA parameters and online states, and the approach is useful in the design of a comprehensive self‐adaptive GA.

Details

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

Keywords

Article
Publication date: 4 December 2017

Wu Deng, Meng Sun, Huimin Zhao, Bo Li and Chunxiao Wang

This study aims to propose a new airport gate assignment method to effectively improve the comprehensive operation capacity and efficiency of hub airport. Gate assignment is one…

Abstract

Purpose

This study aims to propose a new airport gate assignment method to effectively improve the comprehensive operation capacity and efficiency of hub airport. Gate assignment is one of the most important tasks for airport ground operations, which assigns appropriate airport gates with high efficiency reasonable arrangement.

Design/methodology/approach

In this paper, on the basis of analyzing the characteristics of airport gates and flights, an efficient multi-objective optimization model of airport gate assignment based on the objectives of the most balanced idle time, the shortest walking distances of passengers and the least number of flights at apron is constructed. Then an improved ant colony optimization (ICQACO) algorithm based on the ant colony collaborative strategy and pheromone update strategy is designed to solve the constructed model to fast realize the gate assignment and obtain a rational and effective gate assignment result for all flights in the different period.

Findings

In the designed ICQACO algorithm, the ant colony collaborative strategy is used to avoid the rapid convergence to the local optimal solution, and the pheromone update strategy is used to quickly increase the pheromone amount, eliminate the interference of the poor path and greatly accelerate the convergence speed.

Practical implications

The actual flight data from Guangzhou Baiyun airport of China is selected to verify the feasibility and effectiveness of the constructed multi-objective optimization model and the designed ICQACO algorithm. The experimental results show that the designed ICQACO algorithm can increase the pheromone amount, accelerate the convergence speed and avoid to fall into the local optimal solution. The constructed multi-objective optimization model can effectively improve the comprehensive operation capacity and efficiency. This study is a very meaningful work for airport gate assignment.

Originality/value

An efficient multi-objective optimization model for hub airport gate assignment problem is proposed in this paper. An improved ant colony optimization algorithm based on ant colony collaborative strategy and the pheromone update strategy is deeply studied to speed up the convergence and avoid to fall into the local optimal solution.

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