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Article
Publication date: 25 July 2019

Yifei Ren and Zhiqiang Lu

In response to the station design and flexible resources allocation of the aircraft moving assembly line, a new problem named flexible resource investment problem based on…

Abstract

Purpose

In response to the station design and flexible resources allocation of the aircraft moving assembly line, a new problem named flexible resource investment problem based on project splitting (FRIP_PS), which minimizes total cost of resources with a given deadline are proposed in this paper.

Design/methodology/approach

First, a corresponding mathematical model considering project splitting is constructed, which needs to be simultaneously determined together with job scheduling to acquire the optimized project scheduling scheme and resource configurations. Then, an integrated nested optimization algorithm including project splitting policy and job scheduling policy is designed in this paper. In the first stage of the algorithm, a heuristic algorithm designed to get the project splitting scheme and then in the second stage a genetic algorithm with local prospective scheduling strategy is adopted to solve the flexible resource investment problem.

Findings

The heuristic algorithm of project splitting gets better project splitting results through the job shift selection strategy and meanwhile guides the algorithm of the second stage. Furthermore, the genetic algorithm solves resources allocation and job schedule through evaluation rules which can effectively solve the delayed execution of jobs because of improper allocation of flexible resources.

Originality/value

This paper represents a new extension of the resource investment problem based on aircraft moving assembly line. An effective integrated nested optimization algorithm is proposed to specify station splitting scheme, job scheduling scheme and resources allocation in the assembly lines, which is significant for practical engineering applications.

Details

Assembly Automation, vol. 39 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 29 January 2021

Hongwei Zhu, Zhiqiang Lu, Chenyao Lu and Yifei Ren

To meet the requirement of establishing an effective schedule for the assembly process with overall detection and rework, this paper aims to address a new problem named…

Abstract

Purpose

To meet the requirement of establishing an effective schedule for the assembly process with overall detection and rework, this paper aims to address a new problem named resource-constrained multi-project scheduling problem based on detection and rework (RCMPSP-DR).

Design/methodology/approach

First, to satisfy both online and offline scheduling, a mixed integer programming model is established with a weighted bi-objective minimizing the expected makespan and the solution robustness. Second, an algorithm that combines a tabu search framework with a critical chain-based baseline generation scheme is designed. The tabu search framework focuses on searching for a reasonable resource flow representing the execution sequence of activities, while the critical chain-based baseline generation scheme establishes a buffered baseline schedule by estimating the tradeoff between two aspects of bi-objective.

Findings

The proposed algorithm can get solutions with gaps from −4.45% to 2.33% when compared with those obtained by the commercial MIP solver CPLEX. Moreover, the algorithm outperforms four other algorithms in terms of both objective performance and stability over instances with different weighting parameters, which reveals its effectiveness.

Originality/value

The represented RCMPSP-DR considering the overall detection and rework is an extension of the scheduling problem for large-scale equipment. An effective algorithm is proposed to establish the baseline schedule and determine the execution sequence of activities for the assembly process, which is significant for practical engineering applications.

Details

Assembly Automation, vol. 41 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 20 December 2019

Junxia Jiang, Shenglin Zhang and Yuxiao He

The flexible automatic transportation and manual assembly jobs for large aircraft components demand an automated guided vehicle (AGV) system with heavy-duty capacity and…

Abstract

Purpose

The flexible automatic transportation and manual assembly jobs for large aircraft components demand an automated guided vehicle (AGV) system with heavy-duty capacity and omnidirectional movability. This paper aims to propose a four driving-steering wheels-four supporting-steering wheels (4DSW-4SSW) layout plan to enhance the controllability and moving stability of AGV.

Design/methodology/approach

The anti-vibration structure of DS wheels and high-torque steering mechanism of SS wheels with tapered rolling bearings are rigorously designed to meet the functional requirements. Based on the specific wheel layout and vehicle dynamics, the rotational kinematic model as well as the straight and rotational dynamic models of AGV are established by the authors. To well verify the motion characteristics of wheels under heavy load in three motion states including straight motion, self-rotation and rotation around a certain point, the simulations in ADAMS and factory experiments have all been conducted.

Findings

Simulation results indicate that normal and friction forces of DS wheels and SS wheels are very stable except for some small oscillations, which are caused by non-center load distribution on AGV. Experimental results on driving speed of AGV have directly demonstrated that its positioning accuracy is enough for use in real aircraft assembly lines.

Practical implications

The designed AGV system has been applied to the final assembly line of a certain aircraft in Aviation Industry Corporation of China, Ltd, whose assembly efficiency and flexibility have been significantly improved.

Originality/value

A new layout plan of wheels for an omnidirectional heavy-duty AGV is proposed, which enhances the operating and moving capacity of AGV. A function of human-machine collaboration is also offered by the AGV for transporting large workpieces intelligently and economically in aerospace and other heavy industries.

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Article
Publication date: 12 April 2011

Cheng Zou and Jihong Liu

Drilling is an important operation in aircraft wing assembly. In order to enhance this operation, automated machines are used. The purpose of this paper is to propose an…

Abstract

Purpose

Drilling is an important operation in aircraft wing assembly. In order to enhance this operation, automated machines are used. The purpose of this paper is to propose an off‐line programming system to generate NC code effectively and accurately for a five‐axis NC drilling machine applied in aircraft wing flexible assembly.

Design/methodology/approach

The NC program is divided into three hierarchical parts to correspond, respectively, to the whole wing, single rib and single hole. The programming procedure for such three‐layer wing structures is detailed, which includes product model modification, NC program generation and post‐processing.

Findings

By demonstration, the implemented system is proved to increase the efficiency and correctness of NC programming, and the generated program performed well on a flexible wing drilling system.

Research limitations/implications

The system can only program for automated drilling machine at present, however with further development both automated drilling and riveting machine in aircraft wing assembly can be programmed by this system. Another development might make this system universal for different machineries and other aircraft components.

Originality/value

The paper indicates a new way to program for rapid wing flexible drilling, and the generated NC program is more adaptable and easier to update for various aircraft wing structures.

Details

Assembly Automation, vol. 31 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 1 September 1975

Airscrew Howden Ltd

The Westland Lynx helicopter is a particularly fine example of the use of advanced fan technology in modern aircraft applications. The firm of Airscrew Howden have come a…

Abstract

The Westland Lynx helicopter is a particularly fine example of the use of advanced fan technology in modern aircraft applications. The firm of Airscrew Howden have come a long way from their original manufacture of the wooden ‘prop’ but they still continue to play a very essential part in all types of aircraft flying today; this takes the form of sophisticated fan designs to cover a wide variety of special air‐movement requirements that can arise in this sector.

Details

Aircraft Engineering and Aerospace Technology, vol. 47 no. 9
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 September 1970

Accles & Pollock Ltd. of Oldbury, Worcestershire, a TI Steel Tube Division company, will be exhibiting a comprehensive range of precision steel tube and tubular products…

Abstract

Accles & Pollock Ltd. of Oldbury, Worcestershire, a TI Steel Tube Division company, will be exhibiting a comprehensive range of precision steel tube and tubular products, including plain, annularly convoluted and thin wall tube, at Farnborough.

Details

Aircraft Engineering and Aerospace Technology, vol. 42 no. 9
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 7 September 2015

Qing Wang, Yadong Dou, Jiangxiong Li and Yinglin Ke

The purpose of this paper is to design a reasonable joining path and achieve assembly automation for multiple arc-shaped panels. A fuselage panel is primarily composed of…

Abstract

Purpose

The purpose of this paper is to design a reasonable joining path and achieve assembly automation for multiple arc-shaped panels. A fuselage panel is primarily composed of skins, stringers, frames and clips. Both inserted and nested structures are adopted in the panels to improve the strength and hermeticity of the fuselage. Due to the complex structures and relationships, it is a challenge to coordinate the arc-shaped panels in the assembly process.

Design/methodology/approach

A motion sequence model which achieves arc approximation based on the relative motion of multiple panels is established. The initial position of the panels is obtained by decomposing the computer-aided design model of the panels. Two translation rules, i.e. progressively decreasing translation and limited deformation translation, are applied to determine the moving path of the panels. If a panel is not at its path node, a search algorithm is used to find the nearest path node. Finally, the key algorithms are implemented in an integration system to promote joining automation of multiple panels.

Findings

The zigzag path is effective for the joining of multiple panels with complex mating relationships. The automation of the join–separate–rejoin operations is time-saving and safety-assuring. The proposed method is demonstrated in practical engineering and a good efficiency is obtained.

Practical implications

This method has been used in a middle fuselage assembly project. The practical results show that the zigzag path is convenient to be stored and reused, and the synchronous movements of multiple curved panels are precisely realized. Additionally, the posture accuracy of panels is significantly improved, and the operating time is reduced considerably.

Originality/value

This paper gives a solution including path planning and process integration to solve the joining problem of multiple panels. The research will promote the automation of fuselage assembly.

Details

Assembly Automation, vol. 35 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 1 October 1964

TO say that the Twenty‐fourth S.B.A.C. Show was an unqualified success is perhaps to gild the lily. True there were disappointments— the delay which kept the TSR‐2 on the…

Abstract

TO say that the Twenty‐fourth S.B.A.C. Show was an unqualified success is perhaps to gild the lily. True there were disappointments— the delay which kept the TSR‐2 on the ground until well after the Show being one—but on the whole the British industry was well pleased with Farnborough week and if future sales could be related to the number of visitors then the order books would be full for many years to come. The total attendance at the Show was well over 400,000—this figure including just under 300,000 members of the public who paid to enter on the last three days of the Show. Those who argued in favour of allowing a two‐year interval between the 1962 Show and this one seem to be fully vindicated, for these attendance figures are an all‐time record. This augurs well for the future for it would appear that potential customers from overseas are still anxious to attend the Farnborough Show, while the public attendance figures indicate that Britain is still air‐minded to a very healthy degree. It is difficult to pick out any one feature or even one aircraft as being really outstanding at Farnborough, but certainly the range of rear‐engined civil jets (HS. 125, BAC One‐Eleven, Trident and VCIQ) served as a re‐minder that British aeronautical engineering prowess is without parallel, while the number of rotorcraft to be seen in the flying display empha‐sized the growing importance of the helicopter in both civil and military operations. As far as the value of Farnborough is concerned, it is certainly a most useful shop window for British aerospace products, and if few new orders are actually received at Farnborough, a very large number are announced— as our ’Orders and Contracts' column on page 332 bears witness. It is not possible to cover every exhibit displayed at the Farnborough Show but the following report describes a wide cross‐section beginning with the exhibits of the major airframe and engine companies.

Details

Aircraft Engineering and Aerospace Technology, vol. 36 no. 10
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 November 1964

This aircraft, or more exactly this integrated weapons system, is undoubtedly of major importance to both the British aircraft industry and the Royal Air Force. It is…

Abstract

This aircraft, or more exactly this integrated weapons system, is undoubtedly of major importance to both the British aircraft industry and the Royal Air Force. It is beyond question the most exacting project which the British industry has undertaken and as such has demanded adoption of the latest techniques, materials, equipment and management procedures as well as pursuit of research and development programmes on an unprecedented scale. In terms of air power, this system represents a substantial advance on any comparable aircraft or system currently in service and will give the Royal Air Force a strike and reconnaissance capability at high and low level which is possibly unmatched by any other air force in the world. The design philosophy of the TSR‐2 as it applies to an aircraft designed primarily for the high‐speed, low‐level strike/reconnaissance role was described in detail in the December 1963 issue of Aircraft Engineering (Ref. 1) but since that initial appraisal of the TSR‐2 was written some eleven months ago, there has been a gradual release of further information concerning the aircraft, its systems, power plant and equipment. It is the purpose of this article to bring the story up to date in that particular context, although it should be emphasized that the TSR‐2 is still subject to the strictest security embargo and it will be many years before a detailed study of the complete weapons system can be published. It is not intended to cover the same ground as the earlier article (Ref. 1) attempted but, before proceeding to detailed consideration of the systems, a brief overall description of the aircraft is given for the sake of completeness.

Details

Aircraft Engineering and Aerospace Technology, vol. 36 no. 11
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 September 1942

F. Postlethwaite

AS little information has been published, the subject of bombsights is shrouded in mystery, and hence from time to time it is natural that the daily press should make…

Abstract

AS little information has been published, the subject of bombsights is shrouded in mystery, and hence from time to time it is natural that the daily press should make amazing disclosures concerning the alleged performances of new types of bombsights; including an American one capable of dropping bombs into a barrel from the sub‐stratosphere. Such statements can be viewed in their proper perspective if the functions of a bombsight are understood. The state of the enemy ground defences dictate the requirements of a bombsight, since if no opposition is met it is possible to drop delayed action bombs from a low altitude without using a bombsight. As ground defence improves, it is necessary to bomb from a greater height, and so the need for a bombsight increases. It is also necessary to bomb from a great height if armour‐piercing bombs are used, so that they can attain their terminal velocity. Unfortunately, or fortunately, depending on one's position at bomb release, accurate bomb aiming is a complicated matter, and errors increase with height. Thus, as high altitude bombing becomes necessary, so the bombsight becomes more complicated, and as ground defences become more accurate the operational difficulties of the aircraft increase and make still further demands on the bombsight. Thus, as the war proceeds a steady evolution can be observed in the types of bombsight used, as will be seen from those described in this article. Anti‐aircraft gunsights have progressed from simple open ones to those incorporated in the predictor system, and in a like manner bombsights have made similar progress. As each sight has had a bearing on the design of the other, it is interesting to compare the requirements and operation of a bombsight with those required for an anti‐aircraft gunsight.

Details

Aircraft Engineering and Aerospace Technology, vol. 14 no. 9
Type: Research Article
ISSN: 0002-2667

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