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Autonomous driving technology is more and more important nowadays, it has been changing the living style of our society. As for autonomous driving planning and control, vehicle dynamics has strong nonlinearity and uncertainty, so vehicle dynamics and control is one of the most challenging parts. At present, many kinds of specific vehicle dynamics models have been proposed, this review attempts to give an overview of the state of the art of vehicle dynamics models for autonomous driving. Firstly, this review starts from the simple geometric model, vehicle kinematics model, dynamic bicycle model, double-track vehicle model and multi degree of freedom (DOF) dynamics model, and discusses the specific use of these classical models for autonomous driving state estimation, trajectory prediction, motion planning, motion control and so on.

In numerous industries such as aerospace and energy, components must perform under significant extreme environments. This imposes stringent requirements on the accuracy with which these components are manufactured and assembled. One such example is the positional tolerance of drilled holes for close clearance applications, as seen in the “EN3201:2008 Aerospace Series – Holes for metric fasteners” standard. In such applications, the drilled holes must be accurate to within ±0.1 mm. Traditionally, this required the use of Computerised Numerical Control (CNC) systems to achieve such tight tolerances. However, with the increasing popularity of robotic arms in machining applications, as well as their relatively lower cost compared to CNC systems, it becomes necessary to assess the ability of robotic arms to achieve such tolerances. This review paper discusses the sources of errors in robotic arm drilling and reviews the current techniques for improving its accuracy.

Ultrafine particles, in particular solid sub-100 nm particles pose high risks to human health due to their high lung deposition efficiency, translocation to all organs including the brain and their harmful chemical composition; due to dense traffic, the population in urban environments is exposed to high concentrations of those toxic air contaminants, despite these facts, they are still widely neglected. Therefore, the EU-Commission set up a program for clean and competitive solutions for different problem areas which are regarded to be hotspots of such particles. HORIZON AeroSolfd is an EU project, co-funded by Switzerland that will deliver affordable, adaptable, and sustainable retrofit solutions to reduce exhaust tailpipe emissions from petrol engines, brake emissions and pollution in semi-closed environments.

Research institutes and companies are currently working on 3D numerical icing tools for the prediction of ice shapes on an international level. Due to the highly complex flow situation, the prediction of ice shapes on three-dimensional surfaces represents a challenge. An essential component for the development and subsequent validation of 3D ice accretion codes are detailed experimental data from ice shapes accreted on relevant geometries, like wings of a passenger aircraft for example. As part of the Republic of Austria funded research project JOICE, a mockup of a wingtip, based on the National Aeronautics and Space Administration common research model CRM65 was designed and manufactured. For further detailed investigation of electro-thermal de-icing systems, various heaters and thermocouples were included.

This paper provides an overview of the state-of-art multiscale “Icing Simulation Framework” capability developed at Raytheon Technologies Research Center. Specifically, the application of this framework to simulate droplet runback and runback icing will be presented. In summary, this high-fidelity framework tracks the physical mechanisms associated with droplet dynamics, ice nucleation, growth and interaction with the environment (e.g. adhesion, crystal growth, evaporation, sublimation, etc.) across all relevant scales (including nucleation at <10-7m to ~10-6m of coating/environment interaction to 10-2m of the component) which allows a rigorous investigation of how different environmental (e.g. LWC, MVD, pressure, velocity and temperature) and substrate (e.g. coating molecular and macroscopic specifications) characteristics affect the icing behavior.

This work presents a comprehensive numerical model for ice accretion and Ice Protection System (IPS) simulation over a 2D component, such as an airfoil. The model is based on the Myers model for ice accretion and extended to include the possibility of a heated substratum. Six different icing conditions that can occur during in-flight ice accretion with an Electro-Thermal Ice Protection System (ETIPS) activated are identified. Each condition presents one or more layers with a different water phase. Depending on the heat fluxes, there could be only liquid water, ice, or a combination of both on the substratum. The possible layers are the ice layer on the substratum, the running liquid film over ice or substratum, and the static liquid film between ice and substratum caused by ice melting. The last layer, which is always present, is the substratum. The physical model that describes the evolution of these layers is based on the Stefan problem. For each layer, one heat equation is solved.

In the scope of development or certification processes for the flight under known icing conditions, aircraft have to be tested in icing wind tunnels under relevant conditions. The documentation of these tests has to be performed at a high level of detail. The generated data is used to prove the functionality of the systems, to develop new systems and for scientific purposes, for example the development or validation of numerical tools for ice accretion simulation. One way of documenting the resulting ice geometry is the application of an optical 3D scanning or reconstruction method. This work investigates and reviews optical methods for three-dimensional reconstructions of objects and the application of these methods in ice accretion documentation with respect to their potential of time resolved measurement. Laboratory tests are performed for time-of flight reconstruction of ice geometries and the application of optical photogrammetry with and without multi-light approach.

Cold soaked fuel frost (CSFF) is frost that forms on aircraft wing surfaces following a flight because of cold excess fuel remaining in integrated fuel tanks. Previous investigations by Zhang et al. (2021a) and Zhang et al. (2021b) have focused on experimental measurements and correlation development for frost observed using a small frost wind tunnel employing a thermo-electric cooler to impose a surface temperature for a range of environmental conditions. To model the CSFF approach in more detail, an experimental facility was developed and described by McClain et al. (2020) using a thermal model of an integrated wing fuel tank placed inside of a climatic chamber. In this paper, experimental measurements of CSFF are presented using two aluminum wing skins. One of the skins was created using an aluminum rib structure, and the other skin was created without the rib.

The purpose of this paper to is to review the methodology applied by Collins Aerospace to develop, test and qualify a more robust surface ply rubber compound that has demonstrable improvements in durability and performance at sub-freezing temperatures. Using in-service products as a reference, pneumatic deicers in use on regional turboprop applications were selected as a basis for operational characteristics and observed failure modes. Custom test campaigns were developed by Collins to comparatively evaluate key characteristics of the surface ply material including low temperature elasticity, erosion durability, and fluid susceptibility. Collins’ proprietary engineered rubber formulations were individually evaluated and built into fully functional test deicers for component level testing to DO-160G environmental exposure, comparative ice shed performance in Collins’ Icing Wind Tunnel and erosion in Collins’ Rain Erosion Silo.

The paper describes a tools’ suite able of analyzing numerically 3D ice-accretion problems of aeronautical interest. The methodology consists of linking different modules each of them performing a specific function inside the ice-simulation chain. It has been specifically designed from the beginning with multi-step capability in mind. Such a feature plays a key role when studying the dynamic evolution of the icing process. Indeed, the latter has the character of a multi-physic and time-dependent phenomenon which foresees a strong interaction of the air- and water fields with the wall thermodynamics. Our multi-layer approach assumes that the physical problem can be discretized by a series of pseudo-steady conditions. The simulation process starts with the automatic generation of a Cartesian three-dimensional mesh which represents the input for the immersed boundary (IB) RANS solver.

Community noise at vertiports is one of the most important questions related to upcoming urban air mobility (UAM) operations. While fixed-wing and/or fixed-rotor aircraft can mainly be treated by their changing operational parameters, such as rotor or propeller rpm, tilt-wing or tilt-engine configurations are more difficult to simulate because of their constantly changing noise emission and spatial radiation characteristics. The work presented in this paper is providing an overview of the noise situation at a virtual vertiport which is being approached and departed by a tilt-wing air-taxi in different ways. Several different departure procedures are simulated with the same generic air-taxi. For the noise emission semi-empiric methods were used. During the air-taxi’s descent and climb, different tilt configurations are included, mainly defined by the time dependent engine’s tilt-angle, but also related to different approach paths.

Vehicle Acoustic Prototyping in the mid to high frequency range is challenging with numerical models only. To overcome this challenge, over the past decade, experimental techniques were developed that allow the engineer to incorporate Test-Based models in their (numerical) simulation as well. Using Virtual Point Technology these Test-Based models serve well to describe, for example, the complex dynamics of the vehicle body Noise Transfer Functions. Here the high modal density and damping characteristics are simply measured on a mule or prototype vehicle and coupled to numerical models of the drivetrain using Dynamic Substructuring. As such accurate predictions and/or risk assessments can be made much earlier in the mid and high frequency range during the vehicle development stage. While test-based models serve well to describe the coupled vehicle dynamics, loads to compute actual vehicle responses are needed as well.

A state-of-the-art review of the technical meaning and application of the term ‘maneuver’, used by the U.S. Army and ground vehicle engineering communities, was performed with regard to various military activities, including modeling and simulation (M&S), to focus on the value and applicability of the term to military vehicle dynamics. As shown, U.S. military doctrine has built through history and experience a unique concept of maneuver-in-general and its application in U.S. Army unified land operations. Yet, the term ‘maneuver’ needs further technical categorization and characterization for the purpose of dynamics of military unmanned ground vehicles (UGVs) and vehicle design for maneuver. While the NHTSA and SAE standards and definitions provide solid foundations for M&S of cars and trucks to enhance the safety of those vehicles (manned and autonomous), occupants, and pedestrians on roads, the standards cannot address all needs of military vehicles in maneuver.

The development of Digital Twin (DT) has become popular. A dominant description of DT is that it is a software representation that mimics a physical object to portray its real-world performance and operating conditions of an asset. It uses near real-time data captured from the asset and enables proactive optimal operation decisions. There are many other definitions of DT, but not many explicit evaluations of DT performance found in literature. The authors have an interest to investigate and evaluate the quality and stability of appropriate DT techniques in real world aircraft Maintenance, Repair, and overhaul (MRO) activities. This paper reviews the origin of DT concept, the evolution and development of recent DT technologies. Examples of DTs in aircraft systems and transferable knowledge in related vehicle industries are collated. The paper contrasts the benefits and bottlenecks of the two categories of DT methods, Data-Driven (DDDT) and Model-Based (MBDT) models.

Currently, the Aviation industry uses traditional methods of communication, coordination, & human interaction to give disposition to resolve any kind of nonconformance occurrences which occur during manufacturing or operation of commercial or defense products. This involves increased in-person interaction and additional travel, especially to address the nonconformance issues arising at supplier plants or airports around the globe. During Covid and post-Covid environments, human interactions for the transfer of detailed information at different & distant manufacturing plant locations has been difficult, since support engineering teams (Example: Liaison, Product Review, Quality, Supplier Quality, and Manufacturing Engineering, and/or Service Engineering) have been working remotely.

Development of any safety critical software applications such as in the aerospace industry needs to comply to specific standards (DO-178) to meet airworthiness requirements. This standard is applicable to all airborne software. As such, the software development needs to perform certain verification activities to comply to the standard objectives. One of the verification activities is source code inspection or review to check that the implementation meets the specification captured in the form of requirements and other aspects such as coding style guidelines and documentation, such as, indentation used in code, sufficient comments or notes in the code files etc. Generally, this activity is carried out manually, supplemented by tools which are deployed to check errors and standards in the code by means of static analysis and practices such as test-driven development (TDD), wherein, the testing and analysis is done prior to the reviews.

This paper will briefly review the idea of a reactionless drive. It will then analytically derive a reactionless drive based on a specific application of the Abraham-Lorentz force. Simulated data on such a drive and its key characteristics will be discussed. A benchtop working model of the theoretical drive derived in this paper will be presented. Most schemes for a reactionless drive being proposed today rely on emissions of ions, particles, or light; however while these schemes work in theory, they produce minuscule amounts of thrust, even at perfect conditions. No reactionless drive has ever been demonstrated to work in practice at any scale. When such a drive is developed, space travel will open up tremendously due to the fact that spacecraft will not have to carry propellant fuel while cruising. Findings demonstrate how this reactionless drive is mathematically feasible.

The aircraft asset life cycle processes are rapidly being digitalized. Many novel technologies enabled processes of recording these electronic transactions are being emerged. One such technology for recording electronic transactions securely is Blockchain, defined as distributed ledger technologies which includes enterprise blockchain. Blockchain is not widely used in the aerospace industry due to lack of technical understanding and questions about its benefits. Assessment and establishment of business case for implementing blockchain based solution is needed. The aerospace industry is very conservative when it comes to technology adoption and hence it is difficult to change legacy processes. Additionally, the industry is very fragmented. The technology is advancing at a faster rate and applies across geographies under various regulatory oversight which makes blockchain based solution implementation challenging.

RTCA DO-254/ EUROCAE ED-80 “Design Assurance Guidance for Airborne Electronic Hardware” is a widely accepted industry standard to ensure safety in avionics hardware. FAA and EASA have recognized DO-254 as an acceptable means of compliance with the applicable airworthiness regulations for the electronic hardware. While microprocessor based complex hardware utilization in safety critical avionic hardware are increasing and DO-254 compliance is mandated by the certification authorities, development of DO-254 compliant or safety certifiable hardware is becoming more and more important and provides competitive advantage in the industry. The avionics manufacturers need to correlate their existing processes and procedures with DO-254 in order to satisfy DO-254 objectives in their own quality management system structure, which may be challenging and tricky.

One of the most important components in vehicle dynamics studies is the tire, due to the fact that it is the only component that keeps the vehicle in contact with the ground. In the study of vehicle dynamics, all force transmission between the vehicle and the ground occurs through the contact area of the tire with the road. The maintenance of this contact during the steering allows the driver to have control over the vehicle and this is one of the premises for vehicle safety. The tread grooves help ensure that the friction between the rubber and the soil aggregate is maintained in different lane conditions, be it dry, wet, clean or dirty. Its depth is easy to measure, being regulated in Brazil by CONTRAN in, at least, 1.6 mm. However, even at depths greater than the minimum required by law, vehicle safety can be compromised in wet conditions, as the ability to drain water is greatly compromised at high speeds.