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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.

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.

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.

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.

Coordination feature (CF) is the information carrier in dimension and shape transfer process in aircraft manufacturing. The change of its geometric size, shape, position or other attributes would affect the consistency of accumulated errors between two or more assemblies. To identify these “key characteristics” that have a close relationship with the assembly precision, a comprehensive method was developed under digital manufacturing environment, which was based on importance calculation. The multi-hierarchy and multi-station assembly process of aircraft products were also taken into consideration.

First, the interaction and evaluation relationship between components at different manufacturing stages was decomposed with a hierarchical net. Second, to meet coordination accuracy requirements, with the integrated application of Taguchi quality loss function, accuracy principal and error correction coefficient H, the quality loss between target features and candidate features at adjacent assembly hierarchies were calculated, which was based on their precision variation. Third, the influence degree and affected degree of the features were calculated with DEMATEL (decision-making trial and evaluation laboratory) method, and the concepts of centrality degree index and cause degree index were proposed for calculating the complete importance degree to eventually identify the CFs.

Based on the proposed methodology, CFs, affecting the skin profile and the flush coordination accuracy, were successfully identified at different assembly hierarchies to a certain type of wing flap component.

Benefit results for the engineering application showed that the deviation of skin profile was more accurate than before, and the tolerance was also closer to the centerline of required assembly precision range. Moreover, the stability in the assembly process was increased by 26.9 per cent, which could bring a higher assembly quality and an enhancement on aircraft’s flight performance.

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.

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.

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.

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.

A large number of fastener holes have to be drilled with high quality in the circumferential splice region during the assembly of aircraft fuselage. The purpose of this paper is to design an automatic stepping mechanism for a circumferential splice drilling machine, to meet the requirements of large workspace and high accuracy in drilling at the same time.

A docking position detection method based on magnetic proximity sensors is proposed for the positioning of the arc-shaped rail with respect to the circumferential rails, which significantly improves the accuracy and reliability of automatic stepping. The slipping phenomenon of the end-effector is analyzed, and the optimized counter weights are used to eliminate the slipping and improve the working stability of the stepping mechanism.

An automatic stepping mechanism is developed for the circumferential splice drilling machine, which comprises the docking position detection method and the elimination/suppression method of the end-effector’s slipping.

The proposed automatic stepping mechanism has been integrated into the circumferential splice drilling machine for the fuselage assembly in an aircraft company in China.

An automatic stepping scheme for the circumferential splice drilling machine is proposed, which enhances the efficiency in circumferential splice drilling in aircraft fuselage assembly.

The Aviation Division of the Dunlop Co. Ltd. (Engineering Group) is to install Dynex power units, designed and built by Applied Power (U.K.) Ltd., in the latest design of hydraulic production test rigs at the Division's Coventry factory. The company is completely re‐equipping its production test facilities by providing every rig with the higher pressures and flows which future trends in fluid technology will demand, and to ensure that each testing station is capable of handling service fluids currently in use, including kerosene, DTD 585, Skydrol, Lockheed 22 and Oronite.

The purpose of this paper is to propose an on-line iterative compensation method combining with a feed-forward compensation method to enhance the assembly accuracy of a metrology-integrated robot system (MIRS).

By the integration of a six degrees of freedom (6DoF) measurement system (T-Mac), the robot’ movement can be tracked with real-time measurement. With the on-line measured data, the proposed iterative compensation for absolute positioning and the feed-forward compensation for relative linear motion are integrated into the assembly process to improve the assembly accuracy.

It is found that the MIRS exhibits good performance in both accuracy and efficiency with the application of the proposed compensation method. With the proposed assembly process, a component can be automatically aligned to the target in seconds, and the assembly error can be decreased to 0.021 mm for position and 0.008° for orientation on average.

This paper presents a 6DoF MIRS for high-precision assembly. Based on the system, a novel on-line compensation method is proposed to enhance the assembly accuracy. In this paper, the assembly accuracy and the corresponding distance parameter are given by a series of experiments as reference for assembly applications.

IN the two years since the last Farnborough Air Show was held by the Society of British Aerospace Companies the aircraft industry has achieved an almost complete metamorphosis from the body blows in the form of major programme cancellations that almost felled it in 1965 to the very healthy position that it holds today.

IT is indeed an honour to appear before you to address you on the subject “American Methods of Aircraft Production.” We in America have long held the Royal Aeronautical Society in high regard, amply justified by the excellence of its published papers and the example it has set in organisation and in the conducting of an aeronautical society. Indeed, a few years ago when several of us in America decided that we, too, should have an aeronautical society, we planned our own organisation very largely on yours. We are very much pleased that the relationship which has existed between your Society and the Institute of the Aeronautical Sciences in America throughout the brief career of the latter has been so close and friendly and I can assure you that we intend to do everything possible on our part to continue this highly desirable condition.

The future of the current family of wide‐bodied transports is examined in the environment of the changing world‐wide fuel supply situation. Synthetic hydrocarbon and cryogenic fuels are considered in the context of impact on airline fleets and their maintenance. The probability of the emergence of new technology aircraft, still utilising hydrocarbon fuel is considered in view of the possible shortening of their useful life by the introduction of cryogenic fuels. Possible effects on maintenance of the new technologies which would be included in such aircraft are discussed. Finally, the characteristics of the two most promising cryogenic fuels are compared and the effects of one of these fuels on fuel system design, maintenance, and service as well as facilities and equipment are reviewed.