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Increased production rates and cost reduction are affecting manufacturing in all mobility industry sectors. One enabling methodology that could achieve these goals in the burgeoning “Industry 4.0” environment is the optimized deterministic assembly (DA) approach. It always forms the same final structure and has a strong link to design-for-assembly and design-for-automation. The entire supply chain is considered, with drastic savings at the final assembly line level through recurring costs and lead-time reduction. Unsettled Technology Areas in Deterministic Assembly Approaches for Industry 4.0 examines the evolution of previous assembly principles that lead up to and enable the DA approach, related simulation methodologies, and undefined and unsolved links between these domains. Click here to access the full SAE EDGETM Research Report portfolio.

Glaciated icing conditions potentially leading to in-service event are often encountered in the vicinity of deep convective clouds. Nowcasting of these conditions with space-borne observations would be of a great help for improving flight safety and air-traffic management but still remains challenging. In the framework of the HAIC (High Altitude Ice Crystals) project, methods to detect and track regions of high ice water content from space-based geostationary and low orbit mission are investigated. A first HAIC/HIWC field campaign has been carried out in Australia in January-March 2014 to sample meteorological conditions potentially leading to glaciated icing conditions. During the campaign, several nowcasting tools were successfully operated such as the Rapid Development Thunderstorm (RDT) product that detects the convective areas from infrared geostationary imagery.

This study presents the results of the ICE GENESIS 2021 Swiss Jura Flight Campaign in a way that is readily usable for ice accretion modelling and aims at improving the description of snow particles for model inputs. 2D images from two OAP probes, namely 2D-S and PIP, have been used to extract 3D shape parameters in the oblate spheroid assumption, as there are the diameter of the sphere of equivalent volume as ellipsoid, sphericity, orthogonal sphericity, and an estimation of bulk density of individual ice crystals through a mass-geometry parametrization. Innovative shape recognition algorithm, based on Convolutional Neural Network, has been used to identify ice crystal shapes based on these images and produce shape-specific mass particle size distributions to describe cloud ice content quantitatively in details. 3D shape descriptors and bulk density have been extracted for all the data collected in cloud environments described in the regulation as icing conditions.

Measurements in snow conditions performed in the past were rarely initiated and best suited for pure and extremely detailed quantification of microphysical properties of a series of microphysical parameters, needed for accretion modelling. Within the European ICE GENESIS project, a considerable effort of natural snow measurements has been made during winter 2020/21. Instrumental means, both in-situ and remote sensing were deployed on the ATR-42 aircraft, as well as on the ground (ground station at ‘Les Eplatures’ airport in the Swiss Jura Mountains with ATR-42 overflights). Snow clouds and precipitation in the atmospheric column were sampled with the aircraft, whereas ground based and airborne radar systems allowed extending the observations of snow properties beyond the flight level chosen for the in situ measurements.

Industrial requirements imply optimizing the development cycle, reducing manufacturing costs and reaching marketable product maturity as fast as possible. The design stage often involves multiple sites and various partners. In this context, the use of computer simulation becomes absolutely necessary to meet industrial needs. Nevertheless, this activity can be effective only if it is integrated correctly in the industrial organization. In the aeronautical and space systems industry, mechanical specifications often require the use of composites reinforced by continuous carbon fibers. The goal of this article is to describe how, on a time frame of nearly twenty years, a series of scientific and technical tasks were carried out in partnership in order to develop, validate and implement Resin Transfer Molding (RTM) flow simulation and cure analysis for high performance composites. The research stage started at the university in 1991.

ASRP (Assembly Simulation of Riveting Process) software is a special tool for assembly process modelling for large scale airframe parts. On the base of variation simulation, ASRP provides a convenient way to analyze, verify and optimize the arrangement of temporary fasteners. During the assembly of airframe certain criteria on residual gap between parts must be fulfilled. The numerical approach implemented in ASRP allows to evaluate the quality of contact on every stage of assembly process and solve verification and optimization problems for temporary fastener patterns. The paper is devoted to description of several specialized approaches that combine statistical analysis of measured data and numerical simulation using high-performance computing for optimization of fastener patterns, calculation of forces in fasteners needed to close initial gaps, and identification of hazardous areas in junction regions via ASRP software.

The work describes a concept application that aids a safety engineer to create a layup of equipment models by using an image scan of a schematic and a library of predefined standard component and their symbols. The approach uses image recognition techniques to identify the symbols within the scanned image of the schematic from a given library of symbols. Two recognition approaches are studied, one uses General Hough Transform; the other is based on pixel-level feature computation combining both structure and statistical features. The application allows the user to accept or edit the results of the recognition step and allows the user to define new components during the layup step. The tool then generates an output file that is compatible with a formal safety modeling tool. The identified symbols are associated to behavioral nodes from a model based safety tool.

Within this paper, the AIRBUS approach on the development of rivetless nutplates as an alternative to riveted anchor nuts is described. Within the frame of a wider analysis, it was identified that currently used riveted anchor nut elements does have disadvantages with negative impact on an optimized cost-efficient and lead-time driven design and manufacturing environment. Rivetless nutplate systems provide some features that are potentially capable to mitigate some of the identified disadvantages of riveted elements. The paper covers the key requirements and objectives that were put in place in order to identify the most beneficial solution(s). It furthermore contains detailed information on the rivetless nutplate systems selected by AIRBUS and the justification for the selection that was made.

The Environmental Control System is a relevant element of any conventional or More Electric Aircraft (MEA). It is either the key consumer of pneumatic power or draws a substantial load from the electric power system. The objective of this paper is to present a tool for the design of Environmental Control Systems and to apply it to an unconventional system. The approach is based on a recently proposed methodology, which is improved with respect to flexibility and ease-of-use. Furthermore, modeling and simulation of vapor compression cycles is discussed, which are candidate technological solutions for More Electric Aircraft concepts. A steady-state moving boundary method is presented to model heat exchangers for such applications. Finally, the resulting design environment is applied to optimization of an unconventional ECS architecture and exemplary results are presented.

The paper presents the numerical approach to simulation and optimization of A350 S19 splice assembly process. The main goal is to reduce the number of installed temporary fasteners while preventing the gap between parts from opening during drilling stage. The numerical approach includes computation of residual gaps between parts, optimization of fastener pattern and validation of obtained solution on input data generated on the base of available measurements. The problem is solved with ASRP (Assembly Simulation of Riveting Process) software. The described methodology is applied to the optimization of the robotized assembly process for A350 S19 section.

The main study illustrated in this paper deals with the computation of commands which allow an aircraft to recover a nominal energy trajectory from a low/high energy state during the approach phase. The commands taken into account in this paper are the slat/flap aerodynamic control surfaces which allow the aircraft to maintain the best lift performance for low velocities during the approach phase. In this study, it is supposed that the aircraft maintains a known vertical trajectory, simplified by a constant ground slope, while no engines and airbrakes are used. A non-linear optimization approach is studied in this paper and two methods are tested: a) Hermite-Simpson, trapezoidal collocation methods, b) Sequential numerical integration method. These different methods are tested and simulation results are given for comparison, with different initial velocities permitting to change the initial energy state.

The introduction of Fly-By-Wire (FBW) and the increasing level of automation contribute to improve the safety of civil aircraft significantly. These technological steps permit the development of advanced capabilities for detecting, protecting and optimizing A/C guidance and control. Accordingly, this higher complexity requires extending the availability of aircraft states, some flight parameters becoming key parameters to ensure a good behaviour of the flight control systems. Consequently, the monitoring and consolidation of these signals appear as major issues to achieve the expected autonomy. Two different alternatives occur to get this result. The usual solution consists in introducing many functionally redundant elements (sensors) to enlarge the way the key parameters are measured. This solution corresponds to the classical hardware redundancy, but penalizes the overall system performance in terms of weight, power consumption, space requirements, and extra maintenance needs.

Model Based Safety techniques have been developed for a number of years, though the models have not been customised to help address the safety considerations/ actions at each refinement level. The work performed in the MISSA Project looked at defining the content of “safety models” for each of the refinement levels. A modelling approach has been defined that provides support for the initial functional hazard analysis, then for the systems architectural definition level and finally for the systems implementation level. The Aircraft functional model is used to apportion qualitative and quantitative requirements, the systems architectural level is used to perform a preliminary systems safety analysis to demonstrate that a system architecture can satisfy qualitative and quantitative requirements.

The RTCA SC-230 committee began working on minimum operational performance standards (MOPS) for ice crystal detection using weather radar in 2018. The resulting MOPS document will be released in 2023. This paper presents the rationale, summarizes key requirements, and discusses means of validation for an ice crystal detection function incorporated in an airborne weather radar system.

The PLANET System was used for real-time satellite data transmission during the HAIC-HIWC Darwin field campaign (January to March 2014). The basic system was initially providing aircraft tracking, chat, weather text messages (METAR, TAF, etc.), and aeronautical information (NOTAMs) in a standalone application. In the framework of the HAIC project, many improvements were made in order to fulfill requirements of the onboard and ground science teams for the field campaign. The aim of this paper is to present the main improvements of the system that were implemented for the Darwin field campaign. New features of the system are related to the hardware component, the communication protocol, weather and tracking display, geomarkers on the map, and image processing and compression before onboard transfer.

This paper describes the Airbus plans to use ADS-B in the future concept of operations in both the European SESAR and the US NEXTGEN concepts of operations. It details the different steps that are currently considered by Airbus roadmap to deploy ADS-B services and functions. In particular, the following points are described: Use of ADS-B OUT in Non Radar Airspace Use of ADS-B IN and the associated Airbus functions to offer a better Air Traffic Situation Awareness (ATSAW) package: the various applications for airborne, in trail climb/descent procedures or enhanced visual acquisition are particularly detailed. Use of ADS-B for the future Spacing function as currently considered in the initial ASAS implementation for SESAR: the three “Remain Behind”, “Merge at Waypoint then Remain behind” and the “Heading then merge behind” applications are explained.

This paper presents the development of a high density packaging technology for wide band gap power devices, such as silicon carbide (SiC). These devices are interesting candidates for the next aircraft power electronic converters. Effectively they achieve high switching frequencies thanks to the low losses level. High switching frequencies lead to reduce the passive components size and to an overall weight reduction of power converters. Moreover, SiC devices may enable operation at junction temperatures around 250°C. The cooling requirement is much less stringent than for usual Si devices. This might considerably simplify the cooling system, and reduce the overall weight. To achieve the integration requirements for SiC devices, classical wire bonding interconnection is replaced by a stacked packaging using bump interconnection technologies, called sandwich. These technologies offer two thermal paths to drain heat out and present more power integration possibilities.

Increasing technical dependencies between the engineering disciplines driving the overall design of an aircraft and improving optimization techniques that make use of these interactions blur the lines between distinct disciplines and create demand for a harmonized flight physics model. In this paper we present considerations on a general framework that allows the representation of the equations and data from various domains in an object-oriented and scalable structure. Emphasis is put on the loads aspect with the distinct fields of gust loads, maneuver loads and ground loads analysis, which are essential for structural design. A fully generic, grid based data structure is presented, which is suitable for models of different granularity and applicability. All data is represented in this general form independent of its origin and may be transformed in between the different representations using splines. Coordinate transformations are handled automatically.

The paper is devoted to the simulation of A320 wing assembly on the base of numerical experiments carried out with the help of ASRP software. The main goal is to find fasteners’ configuration with minimal number of fastening elements that provides closing of admissible initial gaps. However, for considered junction type initial gap field is not known a priori though it should be provided as input data for computations. In order to resolve this problem the methodology of random initial gap generation based on available results of gap measurements is developed along with algorithms for optimization of fasteners' configuration on generated initial gaps. Presented paper illustrates how this methodology allows optimizing assembly process for A320 wing.

Traditionally, software in avionics has been totally separated from open-world software, in order to avoid any interaction that could corrupt critical on-board systems. However, new aircraft generations need more interaction with off-board systems to offer extended services, which makes these information flows potentially dangerous. In a previous work, we have proposed the use of virtualization to ensure dependability of critical applications despite bidirectional communication between critical on-board systems and untrusted off-board systems. We have developed a test bed to assess the performance impact induced by the use of virtualization. In this work, various configurations have been experimented that range from a basic machine without an OS up to the complete architecture featuring a hypervisor and an OS running in a virtual machine. Several tests (computation, memory, network) are carried out, and timing measures are collected on different hypervisors.