Aircraft Cabin Door Research Articles

Multi-Sensor Fusion and YOLOv5 Model for Automated Detection of Aircraft Cabin Door

Multi-Sensor Fusion and YOLOv5 Model for Automated Detection of Aircraft Cabin Door

A mechanical system reliability degradation analysis and remaining life estimation method——With the example of an aircraft hatch lock mechanism

The failure mechanism and degradation analysis of an aircraft cabin door lock mechanism are studied. A data-driven degradation analysis is conducted based on the characteristics of two types of degradation data for the lock mechanism. The degradation process of the fluctuating elevation is described by Wiener process, and the lifetime is described using the Inverse Gauss (IG) process. The correlation between the two degradation processes is studied, and the correlation analysis is carried out with four copula functions. Moreover, the optimal model is obtained for reliability analysis using three model selection methods and Bayesian inference based on the Markov chain Monte Carlo (MCMC) method for parameter estimation. Finally, a residual life prediction model is proposed, and the accuracy of the model is tested with the error. The results show that the RUL prediction accuracy can be accepted, which helps to improve the reliability and service life of a type of aircraft lock mechanism.

Knowledge creation and application of optimal tolerance distribution method for aircraft product assembly

PurposeThis paper aims to illustrate the tolerance optimization method based on the assembly accuracy constrain, precession constrain and the cost of production of the assembly product.Design/methodology/approachA tolerance optimization method is an excellent way to perform product assembly performance. The tolerance optimization method is adapted to the process analysis of the hatch and skin of an aircraft. In this paper, the tolerance optimization techniques are applied to the tolerance allocation for step difference analysis (example: step difference between aircraft cabin door and fuselage outer skin). First, a mathematical model is described to understand the relationship between manufacturing cost and tolerance cost. Second, the penalty function method is applied to form a new equation for tolerance optimization. Finally, MATLAB software is used to calculate 170 loops iteration to understand the efficiency of the new equation for tolerance optimization.FindingsThe tolerance optimization method is based on the assembly accuracy constrain, machinery constrain and the cost of production of the assembly product. The main finding of this paper is the lowest assembly and lowest production costs that met the product tolerance specification.Research limitations/implicationsThis paper illustrated an efficient method of tolerance allocation for products assembly. After 170 loops iterations, it founds that the results very close to the original required tolerance. But it can easily say that the different number of loops iterations may have a different result. But optimization result must be approximate to the original tolerance requirements.Practical implicationsIt is evident from Table 4 that the tolerance of the closed loop is 1.3999 after the tolerance distribution is completed, which is less than and very close to the original tolerance of 1.40; the machining precision constraint of the outer skin of the cabin door and the fuselage is satisfied, and the assembly precision constraint of the closed loop is satisfied.Originality/valueThe research may support further research studies to minimize cost tolerance allocation using tolerance cost optimization techniques, which must meet the given constrain accuracy for assembly products.

Thermal Condition and Air Quality Investigation in Commercial Airliner Cabins

Cabin air quality and thermal conditions have a direct impact on passenger and flight crew’s health and comfort. In this study, in-cabin thermal environment and particulate matter (PM) exposures were investigated in four China domestic flights. The mean and standard deviation of the in-cabin carbon dioxide (CO2) concentrations in two tested flights are 1440 ± 111 ppm. The measured maximum in-cabin carbon monoxide (CO) concentration is 1.2 ppm, which is under the US Occupational Safety and Health Administration (OSHA) permissible exposure limit of 10 ppm. The tested relative humidity ranges from 13.8% to 67.0% with an average of 31.7%. The cabin pressure change rates at the end of the climbing stages and the beginning of the descending stages are close to 10 hPa·min−1, which might induce the uncomfortable feeling of passengers and crew members. PM mass concentrations were measured on four flights. The results show that PM concentrations decreased after the aircraft cabin door closed and were affected by severe turbulences. The highest in-cabin PM concentrations were observed in the oldest aircraft with an age of 13.2 years, and the waiting phase in this aircraft generated the highest exposures.

Evaluation of Key Performance of Aircraft Fabric Rubber Seal During Flight

In this Paper, the mechanic properties and sealing performance of the aircraft fabric rubber seal during flight are studied. First, the mechanic parameters, geometric structure, loading method of different aircraft cabin door fabric rubber seals, and gas conditions are analyzed. Second, the modified gas leakage rate formula of fabric rubber seal within wide ranges of temperature and gas pressure is derived based on the previous gas leakage rate formula of fabric rubber seal and the gas leakage rate experimental results. Then, the gas leakage rate prediction method of multicontact sealing surfaces is established. Finally, the variation law of the aircraft gas leakage rate with the altitude are determined based on the configuration number of the aircraft fuselage doors and the finite element results of the aircraft door seals. The research results will provide reliable scientific guidance for the mechanical performance evaluation and sealing performance prediction of fabric rubber seals.

Modeling Affordance Using Formal Methods

Affordances, or the physical interactions that an environment allows for a particular agent, are critical to the design of human-interactive systems. Researchers are developing formal models of human-device interaction that can be used to verify procedures, displays, and controls; however, no formal approaches to guide design exist for affordances. This paper presents such an approach. To model affordance formally, we instantiate an extant formalism from ecological psychology. A human-environment system model represents physical entities in an environment, properties such as 3-D spatial relations among them, and motor capabilities of a human operator. An application is demonstrated in an aircraft cabin door case study, and verification results aid in identifying an undesirable situation involving door openability.

Numerical Modelling and Damage Assessment of Rotary Wing Aircraft Cabin Door Using Continuum Damage Mechanics Model

The prediction of ultimate strength remains the main challenge in the simulation of the mechanical response of composite structures. This paper examines continuum damage model to predict the strength and size effects for deformation and failure response of polymer composite laminates when subjected to complex state of stress. The paper also considers how the overall results of the exercise can be applied in design applications. The continuum damage model is described and the resulting prediction of size effects are compared against the standard benchmark solutions. The stress analysis for strength prediction of rotary wing aircraft cabin door is carried out. The goal of this study is to extend the proposed continuum damage model such that it can be accurately predict the failure around stress concentration regions. The finite element-based continuum damage mechanics model can be applied to the structures and components of arbitrary configurations where analytical solutions could not be developed.

Co-Simulation Study on Over-Running Load Balance in Cabin Door Hydromechanical Drive System

Co-simulation based on LMS Virtual.Lab Motion and Imagine.Lab AMESim was used on aircraft cabin door hydromechanical drive system design. By analysis of 1-D hydraulic model and 3-D mechanism model co-simulation, we draw the conclusion that over-running load accounts for hydraulic motor over speed. To improve hydraulic system, the one-way throttle valve was employed to balance the over-running load according to the co-simulation results. Subsequently, the co-simulation outcome showed the improved-designed hydraulic system controlled the over-running load more effectively. Therefore, a convenient, reliable and accurate method of hydraulic system based on over-running load balance was available.

Assembly Sequence Planning for Aircraft Component Based on Improved Clashes Matrix

The aircraft parts contain the information of a great number of curves and surfaces, which makes it a big challenge for the aircraft components’ Assembly Sequence Planning (ASP) processes. The traditional interference matrix has limitation of expressing the assembly direction and can easily lead to the failure of ASP optimization. Hence, an improved interference matrix is provided in this paper to deal with the aircraft ASP problem based on the Genetic Algorithms (GA). With the mainly consideration of assembly time according to the assembly sequence evaluation criteria, the objective function is established and evaluated. This paper presents an application of the method in the aircraft cabin door assembly process supported by an 863 program. Meanwhile, the verification of the approach is shown in the practical example on MATLAB platform.