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Article
Publication date: 14 December 2017

Bo Xin, Yuan Li, Jian-feng Yu and Jie Zhang

The purpose of this paper is to investigate the nonlinear dynamics of the aircraft assembly lines. An approach for modeling and analyzing the production rate of an aircraft

Abstract

Purpose

The purpose of this paper is to investigate the nonlinear dynamics of the aircraft assembly lines. An approach for modeling and analyzing the production rate of an aircraft assembly line is introduced using the chaos theory.

Design/methodology/approach

First, two key system variables including reliability and learning ability are considered to control the dynamics model. The discrete-time dynamics equation of the production rate is established as a function of the reliability and the learning rate. Then an improved Gauss-learning curve is proposed and applied to aircraft assembling condition. Finally, the bifurcation diagrams and the maximal Lyapunov exponents are used and applied to the experimental study to analyze the dynamic behavior under different combinations of parameters.

Findings

On the basis of the experimental study, it is shown that chaotic behavior really exists in the aircraft assembly lines. The reliability and the Gauss-learning curve can nonlinearly affect the production rate.

Originality/value

This paper applied nonlinear dynamics and chaotic theory to the production analyses of the aircraft assembly lines for the first time. The proposed model has been successfully applied to a practical case, and the result justifies its advantage as well as feasibility to both theory and engineering application.

Details

Assembly Automation, vol. 38 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 8 June 2021

Xiao Chang, Xiaoliang Jia, Kuo Liu and Hao Hu

The purpose of this paper is to provide a knowledge-enabled digital twin for smart design (KDT-SD) of aircraft assembly line (AAL) to enhance the AAL efficiency…

Abstract

Purpose

The purpose of this paper is to provide a knowledge-enabled digital twin for smart design (KDT-SD) of aircraft assembly line (AAL) to enhance the AAL efficiency, performance and visibility. Modern AALs usually need to have capabilities such as digital-physical interaction and self-evaluation that brings significant challenges to traditional design method for AAL. The digital twin (DT) combining with reusable knowledge, as the key technologies in this framework, is introduced to promote the design process by configuring, understanding and evaluating design scheme.

Design/methodology/approach

The proposed KDT-SD framework is designed with the introduction of DT and knowledge. First, dynamic design knowledge library (DDK-Lib) is established which could support the various activities of DT in the entire design process. Then, the knowledge-driven digital AAL modeling method is proposed. At last, knowledge-based smart evaluation is used to understand and identify the design flaws, which could further improvement of the design scheme.

Findings

By means of the KDT-SD framework proposed, it is possible to apply DT to reduce the complexity and discover design flaws in AAL design. Moreover, the knowledge equips DT with the capacities of rapid modeling and smart evaluation that improve design efficiency and quality.

Originality/value

The proposed KDT-SD framework can provide efficient design of AAL and evaluate the design performance in advance so that the feasibility of design scheme can be improved as much as possible.

Details

Assembly Automation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 7 September 2015

Bo Xin, Yuan Li, Jianfeng Yu and Jie Zhang

The purpose of this paper is to investigate the multi-skilled workers assignment problem in complex assembly systems such as aircraft assembly lines. An adaptive binary…

Abstract

Purpose

The purpose of this paper is to investigate the multi-skilled workers assignment problem in complex assembly systems such as aircraft assembly lines. An adaptive binary particle swarm optimization (A-BPSO) algorithm is proposed, which is used to balance the workload of both assembly stations and processes and to minimize the human cost.

Design/methodology/approach

Firstly, a cycle time model considering the cooperation of multi-skilled workers is constructed. This model provides a quantitative description of the relationship between the cycle time and multi-skilled workers by means of revising the standard learning curve with the “Partition-And-Accumulate” method. Then, to improve the accuracy and stability of the current heuristic algorithms, an A-BPSO algorithm that suits for the discrete optimization problems is proposed to assign multi-skilled workers to assembly stations and processes based on modified sigmoid limiting function.

Findings

The proposed method has been successfully applied to a practical case, and the result justifies its advantage as well as adaptability to both theory and engineering application.

Originality/value

A novel cycle time model considering cooperation of multi-skilled workers is constructed so that the calculation results of cycle time are more accurate and closer to reality. An A-BPSO algorithm is proposed to improve the stability and convergence in dealing with the problems with higher dimensional search space. This research can be used by the project managers and dispatchers on assembly field.

Details

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

Keywords

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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: 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: 15 June 2015

Qing Wang, Peng Huang, Jiangxiong Li and Yinglin Ke

The purpose of this paper is to propose an innovative method to extend the operating range of the laser tracking system and improve the accuracy and automation of…

Abstract

Purpose

The purpose of this paper is to propose an innovative method to extend the operating range of the laser tracking system and improve the accuracy and automation of boresighting by designing a measurement instrument. Boresighting is a process that aligns the direction of special equipment with the aircraft reference axis. Sometimes the accurate measurement and adjustment of the equipment and the aircraft are hard to achieve.

Design/methodology/approach

The aircraft is moved by an automatic adjustment system which consists of three numerical control positioners. For obtaining the position of the bore axis, an instrument with two measurement points is designed. Based on the multivariate normal distribution hypothesis, an uncertainty evaluation method for the aiming points is introduced. The accuracy of the measurement point is described by an uncertainty ellipsoid. A compensation and calibration method is proposed to decrease the effect of manufacturing error and deflection error by the finite element analysis.

Findings

The experimental results of the boresighting measurement prove that the proposed method is effective and reliable in digital assembly. The measurement accuracy of the angle between the bore axis and the reference axis is about ±0.004°. In addition, the measurement result is mainly influenced by the position error of the instrument.

Originality/value

The results of this study will provide a new way to obtain and control the installation deviation of part in aircraft digital assembly and will help to improve the precision and efficiency. This measurement method can be applied to obtain the axis of a deep blind hole.

Details

Sensor Review, vol. 35 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 27 June 2019

Guijiang Duan, Zhibang Shen and Rui Liu

This paper aims to promote the integration of the relative position accuracy (RPA) measurement and evaluation in digital assembly process by adopting the model-based…

Abstract

Purpose

This paper aims to promote the integration of the relative position accuracy (RPA) measurement and evaluation in digital assembly process by adopting the model-based method. An integrated framework for RPA measurement is proposed based on a model-based definition (MBD) data set. The study also aims to promote the efficiency of inspection planning of RPA measurement by improving the reusability and configurability of the inspection planning.

Design/methodology/approach

The works have been carried out on three layers. In the data layer, an extended MBD data set is constructed to describe the objects and data for defining RPA measurement items; In definition layer, a model based and hierarchical structure for RPA item definition is constructed to support quick definition for RPA measurement items. In function layer, a toolset consisting three modules is constructed in a sequence from measurement planning to RPA value solving to visualized displaying again. Based on this framework, a prototype system is developed.

Findings

The paper provides an identified practice of model-based inspection. It suggests that MBD is valuable in promoting both the integration and efficiency of digital inspection.

Research limitations/implications

The templates and constructed geometry objects given in this paper are still limited in a scenario of aircraft assembly. The integrity and universality of them still need follow-up works.

Practical implications

The paper includes implications for the model based digital inspection, the digital assembly and the extended application of MBD.

Originality/value

This paper expands the application of MBD in inspection and fulfils the need to promote the integration and efficiency of digital inspection in large-scale component assembly.

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Article
Publication date: 6 February 2017

Junxia Jiang, Chen Bian and Yinglin Ke

The purpose of this paper is to design a new method to realize automatic assembly of aircraft components with large shafts such as canard and vertical tail. The assembly

Abstract

Purpose

The purpose of this paper is to design a new method to realize automatic assembly of aircraft components with large shafts such as canard and vertical tail. The assembly structure of component with large shaft and fuselage is a mating assembly structure, and it is a challenge to satisfy the precision and assembly requirement.

Design/methodology/approach

According to the assembly structure features and process requirements of an aircraft component with large shaft, the operating principle of precise assembly system for shaft-hole mating is analyzed in this paper. The model of compliant assembly for shaft-hole mating is constructed, and force condition analysis of the compliant assembly is performed. An automatic precise shaft-hole assembly method for aircraft assembly using 5 degrees of freedom spatial mechanism, compliance technology and servo feeding system is put forward based on the analysis. A 5 degrees of freedom passive compliant experimental equipment has been developed.

Findings

Application test results of the 5 degrees of freedom passive compliant experimental equipment show that the simulated canard can be mated automatically and accurately through this method with high efficiency and high quality as long as the tip of shaft enters into the range of hole’s chamfer.

Practical implications

This method has been used in an aircraft assembly project. The practical results show that the aircraft components with large shafts can be mated automatically and accurately through this method with high efficiency and high quality.

Originality/value

This paper presents a new method and designs a new assembly system to realize the assembly of the aircraft components with large shafts. The research will promote the automation of fuselage assembly.

Details

Assembly Automation, vol. 37 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 1 February 1987

Richard W. Moxon

This paper reviews the growth of the Brazilian aircraft industry, and evaluates the strategic choices and government policies that have influenced its development…

Abstract

This paper reviews the growth of the Brazilian aircraft industry, and evaluates the strategic choices and government policies that have influenced its development. Brazil's goals of military independence, technological development and improvement of its balance of payments have influenced the development path chosen and the requirements for success. Brazil's attempts to overcome the barriers to achieving technological competence, cost competitiveness, market acceptance and financial sustainability are described. It is argued that the government has played a crucial role in providing financial resources and a protected domestic market, but that it has allowed the key enterprise, Embraer, to maintain an emphasis on commercial viability and international competitiveness. Embraer's emphasis on product niches where it has potential competitive advantages has been a key to its success. It is argued that a clear competitive strategy, based on a thorough analysis to the key success factors in the industry, is a vital link between government goals and support and international competitive success.

Details

International Marketing Review, vol. 4 no. 2
Type: Research Article
ISSN: 0265-1335

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Article
Publication date: 3 August 2015

Qing Wang, Peng Huang, Jiangxiong Li and Yinglin Ke

The purpose of this paper is to increase the measurement accuracy of assembly deviations of an inertial navigation system, a new evaluation and optimal method of assembly

Abstract

Purpose

The purpose of this paper is to increase the measurement accuracy of assembly deviations of an inertial navigation system, a new evaluation and optimal method of assembly metrology system is proposed, which takes into account the uncertainty from laser tracker hardware and coordinate system transformation, and is based on the Monte Carlo method.

Design/methodology/approach

The uncertainty model of the laser tracker is established and its parameters are obtained from the known repeated test data by kriging interpolation and the least squares method. The errors of coordinate transformation are reduced by using a weighted point matching method, and the uncertainty of the transformation parameters is obtained based on the generalized inverse theory. The weighting coefficients of each reference point are optimized by the particle swarm optimization method according to the assembly requirements.

Findings

The experiment results show that measurement error and predicted results match well, and the assembly deviation uncertainty of large component is reduced by about 10 per cent compared with the singular value decomposition method.

Originality/value

This paper proposes a method to evaluate and eliminate the influence of random errors of the laser tracker during evaluation process of coordinate translation parameters and assembly deviations. The proposed method would be useful to improve the assembly measurement accuracy through less measurement times.

Details

Assembly Automation, vol. 35 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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