Aerospace Manufacturing Research Articles

Pull control of material supply for low-volume assembly lines: a reorder point method for aerospace manufacturing

In many medium- and high-volume assembly environments, e.g., automobile manufacturing, pull control of material supply facilitates resilient and lean manufacturing processes through consumption-based replenishment in aggregated quantities of one or more complete material requirements of an assembly cycle. However, in material-intensive low-volume environments such as aerospace manufacturing, this aggregation at the assembly level would lead to excessive supply; thus, material must be replenished gradually over an assembly cycle. The relevant research is limited, and grouping-based principles proposed for such environments can lead to suboptimal task aggregation and undesirable preemption. This paper presents a reorder-point-based pull control method that enables highly precise replenishment. It was developed and evaluated through a simulation study of a wing assembly line for large passenger aircraft. The simulation results suggest that the proposed method is highly effective for the complex assembly environment investigated and can reduce work in process even further than existing methods.

A Review of Dynamic Vehicular Motion Simulators: Systems and Algorithms

Vehicular motion simulators have evolved to become an important contributor to major industries, including defense, aerospace, and vehicle manufacturing. During the past few decades, many efforts have been made towards developing robust, adaptive motion simulators with the highest level of fidelity and realism. Thus, it is important to recollect, in order to evaluate the current state of complex robotic systems, encouraging careful planning of further improvements in the future. This article focuses on the current motion simulators’ structural designs and working principles alongside the currently developed motion control algorithms to achieve the highest fidelity. Furthermore, within the era of industry 4.0 and the fast-paced merging of technologies into key industries, some suggestions are made for future works which it is believed are worth investigating to provide robustness and adaptivity to the control of simulation systems, improving their fidelity and realism alongside reducing motion sickness experienced by the simulator operator.

Development and application of magnesium alloy parts for automotive OEMs: A review

China is currently vigorously implementing the “energy conservation and emission reduction” and “dual carbon” strategies. As the most resource-advantaged light metal material in China, Magnesium (Mg) alloy is progressively expanding its application in automobile, rail transportation, aerospace, medical, and electronic products. Chongqing University, Shanghai Jiaotong University, and Australian National University have conducted extensive research on the preparation, properties, and processes of Mg alloys. In the past 20 years, the proportion of Mg alloy in the automotive industry has gradually expanded, whereas currently the design and development of Mg alloy parts for automobiles has rarely been reported. Thus, the application models and typical parts cases of Mg alloy are summarized mainly from the four systems of the whole vehicle (body system, chassis system, powertrain system, interior, and exterior system). Subsequently, two actual original equipment manufacturers (OEM) cases are used to introduce the development logic of reliable die-cast Mg alloy, including forward design, formability analysis, process design analysis, structural redesign, manufacturing, and testing, aiming to share the methods, processes, and focus of attention of automotive OEMs for developing Mg alloy parts to enhance the confidence and motivation of applying Mg alloy in automotive field. Eventually, the multiple challenges faced by Mg alloy materials are sorted out and how to face these challenges are discussed. National policies and regulations, environmental protection and energy saving, and consumer demand will continue to promote the application of Mg.

Make in India initiative: Boon to reduce lobbies with respectto defense and aerospace manufacturing technologies

Make in India initiative in defense and aerospace is one of the most ambitious projects in India and has had asignificant impact on the socioeconomic, political, and technological factors of the country. The public might haveheard several controversies and scams about defense deals, from horrific to inspiring stories in the defense andaerospace sectors. The beauty of this initiative is that every patriotic individual who wants his/her country to be self-reliant on technology has different views on this project. The current study tries to shed light on various problemsand lobbies in defense deals and also tries to understand breakthroughs in technology in defense products fromthe Indian private and public sectors, “Make in India” promotes employment opportunities and skill developmentin the defense and aerospace sectors. Through semantic foreign direct investment in defense technologies, wecan have good diplomatic and economic relations with other countries.

A review of arc stability analysis methods for aluminum alloy welding

Aluminum alloy has become an essential war material for aerospace manufacturing, transportation manufacturing, and other fields for its superior thermal conductivity, corrosion resistance, and other strengths. In the aluminum alloy welding process, the stability of the arc can indicate the quality of the weld formation. This paper mainly reviews the probability density method, the principle of the approximate entropy method, and the analysis of aluminum alloy welding arc stability in the application. Analyzing the stability of the welding arc can help promote the improvement of welded joint quality and welding fabrication.

КОНЦЕПТУАЛЬНАЯ МОДЕЛЬ ЦИФРОВОГО ЗАВОДА ПРОИЗВОДСТВЕННОГО ПРЕДПРИЯТИЙ АЭРОКОСМИЧЕСКОЙ ОТРАСЛИ

The article discusses the conceptual model of a digital factory of an aerospace manufacturing enterprise, describes the key elements and their relationship.

Evaluating the performance of an aerospace manufacturing company through a case study research

Evaluating the performance of an aerospace manufacturing company through a case study research

Study on the Mechanism and Countermeasures of Digital Transformation Affecting Enterprise Performance in Xi'an Aerospace Manufacturing Industry

Study on the Mechanism and Countermeasures of Digital Transformation Affecting Enterprise Performance in Xi'an Aerospace Manufacturing Industry

航天产品故障模式及影响分析改进研究

航天产品故障模式及影响分析改进研究

Dexterity distribution design for attitude adjustment of multi-joint robotics based on singularity-free workspace decomposition

This paper presents a dexterity distribution design method for attitude adjustment of multi-joint robotics based on singularity-free workspace decomposition (SWD). The requirement of attitude adjustment for platform is described by time-varying Euler angles, by which the structural prototyping of universal-prismatic-spherical + spherical (UPS + S) parallel robot body can be generated via mechanism concept design. According to Kutzbach-Grubler formula regarding degree of freedom (DOF), the forward kinematics model is built, meanwhile, the reachable posture workspace of the robot can be depicted in 3D space by exploiting tilt-and-torsion method. The Jacobian matrix is extracted to reckon dexterous performance of the mechanism, including condition number, minimum singular value, manipulability and comprehensive evaluation index. The singularity degree within the design domain, from singularity-free to fully singularity, is comparatively ranked in polar coordinates, which constitutes the essence of SWD, the performance spectrum corresponding to the structural parameters can hereby be acquired for larger workspace and smaller singularity. The impedance control errors with parameter perturbation further validate the consistency of the singularity-free attitude from the perspective of dynamics. The physical experiments are carried out to verify the outcomes by virtue of multi-axis pose sensor array. Hence the presented SWD method has important application prospects regarding DOF coupling, especially in medical rehabilitation, industrial robotics, aerospace manufacturing and so forth.

A Review of Research Progress on Machining Carbon Fiber-Reinforced Composites with Lasers.

Carbon fiber-reinforced composites are widely used in automobile, aerospace and military lightweight manufacturing due to their excellent mechanical properties such as light weight, excellent fracture resistance, corrosion resistance and wear resistance, etc. However, because of their high hardness, anisotropy and low interlayer strength characteristics, there are many problems with machine carbon fiber-reinforced composites with traditional methods. As a non-contact processing technology, laser machining technology has lots of advantages in carbon fiber-reinforced composites processing. However, there are also some defects produced in laser machining process such the heat affected zone, delamination and fiber extraction due to the great difference of physical properties between the carbon fibers and the resin matrix. To improve the quality of carbon fiber-reinforced composites laser machining, lots of works have been carried out. In this paper, the research progress of carbon fiber-reinforced composites laser machining parameters optimization and numerical simulation was summarized, the characteristics of laser cutting carbon fiber-reinforced composites and cutting quality influence factors were discussed, and the developing trend of the carbon fiber-reinforced composites laser cutting was prospected.

Indirect measurement of cutting forces during robotic milling using multiple sensors and a machine learning-based system identifier

Robotic machining has attracted great interest in the fields of aerospace and automotive manufacturing because of its advantages over conventional computer numerical controlled (CNC) machine tools; robotic machining is flexible and can fabricate components with complex (sculpted) geometries and of large dimensions. The principal challenge, however, is the poor structural rigidity of robots, leading to high-level vibration and chatter during machining. The cutting force must be monitored to detect and suppress chatter as well as optimize machining. A practical method is required to measure the cutting force during machining without impeding robot movement. This study presents an indirect method that accurately measures the milling force using an accelerometer located on the spindle and a flange-mounted capacitive force sensor. A Kalman filter was used to compensate for the dynamics between the robot tool center point (TCP) and the location of the accelerometer. In the context of pose-dependent modeling of the dynamics of the robot, a novel machine-learning (ML)-based identifier is presented that rapidly identifies the relevant dynamics (i.e., the modal parameters) without any initial human guesswork. Data from dynamic simulations and experiments were used to train and validate the ML-based identifier. The validation results showed that the identifier rapidly predicted the behaviour of physical systems with an average accuracy of 98.49 % compared to the modal analysis method. Next, the cutting forces were indirectly measured using the acceleration signals and a Kalman filter, developed based on the modal parameters. The forces measured by the proposed method were in good agreement with the reference forces, measured using a table dynamometer; the average peak-to-peak accuracy was 90.17 % for the AC component of the cutting force, and the average time-domain accuracy was 95.27 % when the DC component was also considered.

A comparative study on high pulse energy femtosecond laser drilling of high-aspect-ratio holes under different pressure conditions

Laser drilling of high-aspect-ratio holes is gradually on the agenda in the field of aerospace manufacturing. We present a comparative study of high pulse energy femtosecond laser micro-hole machining of thermal barrier coated superalloys under different pressure conditions. The ablation results showed that severe contaminative ablation patterns occurred near the geometric focus position, which is related to the remarkable refraction of the plasma near the geometric focus. Adopting negative defocus positions can restrain the plasma defocusing effect and eliminate these ablation defects. As compared to the case in the atmospheric pressure condition, the drilled holes had good retention in diameters, and the aperture size as small as 30 μm can be achieved in the low-pressure environment, which is attributed to a good suppression of the plasma defocusing effect. The drilled samples have convergent and divergent shapes struck within the hole in the low-pressure condition while the hole profiles show good collimation along the thickness direction in the atmospheric pressure environment. This can be attributed to the fact that the pulse energy can be well dispersed to the hole sidewall because of the plasma defocusing effect in the atmospheric pressure environment, and the sidewall materials can be effectively removed. The maximum aspect ratio of the hole can reach 15.7 based on the drilling results. The presented results provide some guidance for the machining of micro-holes with high aspect ratios on other occasions.

Mathematical model of laser tracker measur-ing system for multiple control of large constructions

Laser trackers are widely used to non-contact measure large-scale aerospace products. If it is impossible to inspect the entire product with a single laser tracker with a fixed position, multi-station inspection is used. This paper aims todescribes the multi-station control of large-sized products geometry with using a laser tracker as a measuring tool. A three-segment welded cylindrical shell with a diameter of 4100 mm, a height of 1560 mm and a thickness of 24 mm is considered as an object of control. The coordinates of laser tracker and enhanced referring system points are determined from the conditions of their full visibility and the minimum measurement error. A mathematical model of the measuring system for large shell multi-station control for determining the relationship between the coordinates of points measured from different stations of the laser tracker is constructed. The reference points coordinates and laser tracker station coordinates of the measuring system are established in order to minimize the number of mathematical model unknown variables. The calculation results of the of the selected measuring system maximum allowable error was carried out. The experimental studies were carried out to confirm the main mathematical model assumptions. 276 points on the outer surface of the large shell were measured with laser tracker. To determine the deviation of the surface from the theoretical contour, a digital model of the theoretical contour of the assembly was built in the Spatial Analyzer software. The measured control points were compared with the surface of the digital model. The results of the experimental studies confirmed the main mathematical model approaches and showed that the error of the measuring system corresponds to the required values.

SUSTAINING COMPETITIVE ADVANTAGE DURING COVID-19 PANDEMIC: A PRELIMINARY CASE STUDY OF AEROSPACE MANUFACTURING INDUSTRY IN MALAYSIA

The coronavirus (Covid-19) hits the world at a stage where companies plans are affected due to unplanned business disruptions and operations and the aerospace manufacturing industry is one of the industries that was hit severely. This paper is a preliminary attempt to investigate the impact of COVID-19 on the competitive advantage of one of the aerospace manufacturing companies as a case study. Through a comprehensive literature study and survey, this paper presents an interpretation of competitive advantage theory where the research framework presents the impact of internal and external influences on a company’s competitive advantage and whether strategic management mediates the impact. It illustrates the general concepts and development of hypotheses using the internal and external influences and strategic management. Quantitative analysis using survey will be used to collect and analysis of data from 30 leaders and executives that have been chosen for this study using PLS SEM. It is expected that this study will present a guide that illustrates how theories, general concepts and processes can be managed, allowing strategic management personnel to understand their market position and, from there, identify where the future direction.

Adaptive Lighting for Curved and Nonuniform Objects in Optomechanical Inspection Systems

Visual inspection is omnipresent and critical in precision manufacturing. However, complex geometries of parts hinder uniform illumination, and high reflectivity challenges accurate focusing for digital visual data collection. This research provides a novel adaptive illuminance distribution for consistent lighting to facilitate quality imaging over complex-shaped, highly reflective surfaces. The central approach entails using arrays of independently controlled light sources to reliably generate different lighting patterns, structures, and colors. Such results consider the geometry, the 3-D pose of parts in the environment, and the surface topography of the workpiece to be inspected, hence amplifying the capabilities of an image capturing system. In this article, we discuss the mathematical problem formulation, analytic solution, optimality of the proposed lighting, and experimental results in imaging curved parts common in aerospace manufacturing. The efficacy of the resulting defect identification is tested using a deep neural network.

Tensile Performances of Continuous Fiber Reinforced Thermoplastic Composites with holes processed by 3D Printing, Laser and Drilling

The continuous fiber-reinforced thermoplastic composites (called CFRTPCs) have been used in transportation, aerospace, sports and leisure products because of their great green recyclability and mechanical performances. This study evaluated the 3D printing process for the rapid manufacturing of CFRTPCs. The effect of laser and drilling processes, the size and shape of holes on mechanical performances of CFRTPCs were evaluated individually and mutually. The results proved that the small holes and low fiber content helped improve the strain at break while the big holes and the high fiber content helped improve the ultimate tensile strength and elastic modulus. The ultimate tensile strength and elastic modulus of specimens with square or big holes were higher than those of samples with circle or small holes. The ultimate tensile strength and elastic modulus of specimens with circle holes by laser were higher than those of samples with circle holes by drilling while the trend of strain at break was opposite. The micro morphology of the tensile breakage was observed and analysed to study the failure mechanism. This work makes an important contribution to the design of 3D printed CFRTPCs parts with holes.

Experimental study on laser peen forming of aluminium alloy 2024-T351 plate

Laser peen forming technology LPF is proposed on the basis of laser peen strengthening technology and mechanical peen forming technology. It is an advanced high-efficiency and long-life manufacturing technology for panels. This forming technology has a wide application prospect in the field of aerospace manufacturing. In the forming process, there are many factors affecting the forming process, such as laser pulse energy, shot peening times, shot peening path, material, structure and so on. At present, there are few studies on the influence of laser peen forming process parameters on the shape of parts, which can not meet the technical requirements of forming process. In this paper, based on the single curvature bending forming of al2024-T351 aluminum alloy, the elastic-plastic deformation of metal surface formed by laser shot peening is investigated. The spot morphology formed by laser shot peening is analyzed. The influence law of different forming process parameters on the forming shape of parts is established. The results show that the thickness is the main influencing factor for the curvature radius of the impact area. The radius of curvature increases with the increase of thickness, and decreases with the increase of pulse energy and coverage. Using the regression analysis method, the mathematical model of laser peen forming curvature radius is established. The predicted results are consistent with the experimental results, and the maximum relative deviation is 2.6%.

Investigation report of aero engine air die hole processing

At present, there are a variety of problems in the aerospace manufacturing industry, especially the machining of aero-engine air film holes. In this paper, by investigating the current research status of aero-engine gas film hole machining at home and abroad, the characteristics and difficulties of the current gas film hole machining are introduced, and the comparison between ordinary laser machining and femtosecond laser machining is made.

Safety considerations for autonomous, modular robotics in aerospace manufacturing.

Industrial robots are versatile machines that can be used to implement numerous tasks. They have been successful in applications where-after integration and commissioning-a more or less static and repetitive behaviour in conjunction with closed work cells is sufficient. In aerospace manufacturing, robots still struggle to compete against either specialized machines or manual labour. This can be attributed to complex or custom parts and/or small batch sizes. Here, applicability of robots can be improved by enabling collaborative use-cases. When fixed protective fences are not desired due to handling problems of the large parts involved, sensor-based approaches like speed and separation monitoring (SSM) are required. This contribution is about how to construct dynamic volumes of space around a robot as well as around a person in the way that their combination satisfies required separation distance between robot and person. The goal was to minimize said distance by calculating volumes both adaptively and as precisely as possible given the available information. We used a voxel-based method to compute the robot safety space that includes worst-case breaking behaviour. We focused on providing a worst-case representation considering all possible breaking variations. Our approach to generate the person safety space is based on an outlook for 2D camera, AI-based workspace surveillance.