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Journal Article

Worsening Perception: Real-Time Degradation of Autonomous Vehicle Perception Performance for Simulation of Adverse Weather Conditions

2022-01-06
Abstract Autonomous vehicles (AVs) rely heavily upon their perception subsystems to “see” the environment in which they operate. Unfortunately, the effect of variable weather conditions presents a significant challenge to object detection algorithms, and thus, it is imperative to test the vehicle extensively in all conditions which it may experience. However, the development of robust AV subsystems requires repeatable, controlled testing—while real weather is unpredictable and cannot be scheduled. Real-world testing in adverse conditions is an expensive and time-consuming task, often requiring access to specialist facilities. Simulation is commonly relied upon as a substitute, with increasingly visually realistic representations of the real world being developed.
Journal Article

Wireless Security in Vehicular Ad Hoc Networks: A Survey

2022-08-17
Abstract Vehicular communications face unique security issues in wireless communications. While new vehicles are equipped with a large set of communication technologies, product life cycles are long and software updates are not widespread. The result is a host of outdated and unpatched technologies being used on the street. This has especially severe security impacts because autonomous vehicles are pushing into the market, which will rely, at least partly, on the integrity of the provided information. We provide an overview of the currently deployed communication systems and their security weaknesses and features to collect and compare widely used security mechanisms. In this survey, we focus on technologies that work in an ad hoc manner. This includes Long-Term Evolution mode 4 (LTE-PC5), Wireless Access in Vehicular Environments (WAVE), Intelligent Transportation Systems at 5 Gigahertz (ITS-G5), and Bluetooth.
Journal Article

Using a Dual-Layer Specification to Offer Selective Interoperability for Uptane

2020-08-24
Abstract This work introduces the concept of a dual-layer specification structure for standards that separate interoperability functions, such as backward compatibility, localization, and deployment, from those essential to reliability, security, and functionality. The latter group of features, which constitute the actual standard, make up the baseline layer for instructions, while all the elements required for interoperability are specified in a second layer, known as a Protocols, Operations, Usage, and Formats (POUF) document. We applied this technique in the development of a standard for Uptane [1], a security framework for over-the-air (OTA) software updates used in many automobiles. This standard is a good candidate for a dual-layer specification because it requires communication between entities, but does not require a specific format for this communication.
Journal Article

Thermomechanical Fracture Failure Analysis of a Heavy-Duty Diesel Engine Cylinder Liner through Performance Analysis and Finite Element Modeling

2020-10-02
Abstract Diesel engines include systems for cooling, lubrication, and fuel injection and contain a variety of components. A malfunction in any of the engine systems or the presence of any faulty element influences engine performance and deteriorates its components. This research is concerned with the untimely appearance of vital cracks in the liners of a turbocharged heavy-duty Diesel engine. To find the root causes for premature failure, rigorous examinations through visual observations, material characterization, and metallographic investigations are performed. These include Scanning Electron Microscope (SEM) and Energy-Dispersive Spectroscopy (EDS), fracture mechanics analysis, and performance examination, which are also followed by Finite Element Moldings. To find the proper remedy to resolve the problem, drawing a precise and reliable picture of the engine’s operating conditions is required.
Journal Article

The Placement of Digitized Objects in a Point Cloud as a Photogrammetric Technique

2018-08-08
Abstract The frequency of video-capturing collision events from surveillance systems are increasing in reconstruction analyses. The video that has been provided to the investigator may not always include a clear perspective of the relevant area of interest. For example, surveillance video of an incident may have captured a pre- or post-incident perspective that, while failing to capture the precise moment when the pedestrian was struck by a vehicle, still contains valuable information that can be used to assist in reconstructing the incident. When surveillance video is received, a quick and efficient technique to place the subject object or objects into a three-dimensional environment with a known rate of error would add value to the investigation.
Journal Article

The Effect of Current Mode on the Crack and Failure in the Resistance Spot Welding of the Advanced High-Strength DP590 Steel

2020-09-09
Abstract The causes of failure due to cracking in the resistance spot welding of the advanced high-strength steels dual-phase 590 (DP590) were investigated using scanning electron microscopy (SEM), optical microscopy, and the tensile-shear test. The results showed that by increasing the current amount, the formation of the melting zone occurred in the heat-affected zone, leading to the cracking in this area, reducing the tensile strength and decreasing the mechanical properties; the initiation and growth of cracking and failure in this region also happened. In the heat-affected zone, by increasing the current amount with the softening phenomenon, the recrystallized coarse grains also occurred, eventually resulting in the loss of mechanical properties. The results of the tensile-shear test also indicated that by increasing the current up to 12 kA, the strength was raised, but the ductility was reduced.
Journal Article

The Autonomous Racing Software Stack of the KIT19d

2022-01-06
Abstract Formula Student Driverless (FSD) challenges engineering students to develop autonomous single-seater race cars in a quest to bring about more graduates who are well prepared to solve the real-world problems associated with autonomous driving. In this article, we present the software stack of KA-RaceIng’s entry to the 2019 competitions. We cover the essential modules of the system, including perception, localization, mapping, motion planning, and control. Furthermore, development methods are outlined, and an overview of the system architecture is given. We conclude by presenting selected runtime measurements, data logs, and competition results to provide an insight into the performance of the final prototype.
Journal Article

The Application of Flame Image Velocimetry to After-injection Effects on Flow Fields in a Small-Bore Diesel Engine

2021-09-14
Abstract This study implements Flame Image Velocimetry (FIV), a diagnostic technique based on post-processing of high-speed soot luminosity images, to show the in-flame flow field development impacted by after-injection in a single-cylinder, small-bore optical diesel engine. Two after-injection cases with different dwell times between the main injection and after-injection, namely, close-coupled and long-dwell, as well as a main-injection-only case are compared regarding flow fields, flow vector magnitude, and turbulence intensity distribution. For each case, high-speed soot luminosity movies from 100 individual combustion cycles are recorded at a high frame rate of 45 kHz for FIV processing. The Reynolds decomposition using a spatial filtering method is applied to the obtained flow vectors so that bulk flow structures and turbulence intensity distributions can be discussed.
Journal Article

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2022-09-07
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2023-12-18
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2024-02-12
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Journal Article

System for Strain-Distribution Visualization and Deformation Measurement of Tread Block under Fast-Rotating Tires

2021-11-29
Abstract Although tread block deformation analysis is important, the deformation measurement is difficult because fast-rotating tires maintain a continuous contact with the road surface. Furthermore, capturing small displacements near the edge of tread blocks using a high-speed camera is difficult because of the particularly limited resolution. Additionally, the tread blocks being significantly deformed at the edge and susceptible to wear powder, the state change of the feature points, is highly probable. To overcome these problems, a system that obtains high-resolution images and measures the deformation of a fast-rotating body (tire) is proposed herein. The developed system captures the deformation behavior through intermittent imaging. To further measure the strain distribution, fine tracking markers are drawn on the tread block using a laser processing machine. The displacement of the marker is calculated using the particle mask correlation method.
Journal Article

Studies of a Split Injection Strategy in a Gasoline Engine via High-Speed Particle Image Velocimetry

2021-07-06
Abstract An ongoing challenge with Gasoline engines is achieving rapid activation of the three-way catalyst during cold starts in order to minimize pollutant emissions. Retarded combustion is an effective way in achieving rapid light-up of the three-way catalyst and can be facilitated by stratified charge using late fuel injection. This, however, provides insufficient time for fuel entrainment with air, resulting in locally fuel-rich diffusion combustion. Employing a split injection strategy can help tackle these issues. The effects of a split injection strategy, using a high-pressure Solenoid injector, on the in-cylinder charge formation are investigated in the current study. The studies are performed inside an optical Gasoline engine using high-speed particle image velocimetry (PIV) in the central tumble and Omega tumble planes, by means of a high-speed laser and camera operating at a repetition rate of 10 kHz.
Journal Article

Structural Morphology, Elemental Composition, Mechanical and Tribological Properties of the Effect of Carbon Nanotubes and Silicon Nanoparticles on AA 2024 Hybrid Metal Matrix Composites

2022-01-13
Abstract This research involves the study of the different properties of aluminum alloy (AA) 2024 in the presence of carbon nanotubes (CNTs) and Silicon (Si) nanoparticles. Structural morphology, elemental composition, mechanical properties (density, tensile strength, elongation, and hardness), and tribological properties (wear rate and coefficient of friction) of AA 2024 in the presence of CNTs, Si, and its combinations at various proportions were evaluated using a Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Analyzer (EDX), Universal Testing Machine (UTM), Model HMV-2T Vickers hardness test machine, and pin-on-disk friction-and-wear test rig. The Hybrid Metal Matrix Composite (HMMC) material is prepared by a two-stage stir casting method. It was found that the density of the AA 2024 + 4%CNT + 2%Si is 2.22 g/cm3, ultimate tensile strength is 308 N/mm2, elongation is 15.5%, and Vickers hardness is 187.5 Vickers Hardness Number (VHN).
Journal Article

Stereo Vision-Based Road Debris Detection System for Advanced Driver Assistance Systems

2021-10-12
Abstract Reliable detection of obstacles around an autonomous vehicle is essential to avoid potential collision and ensure safe driving. However, a vast majority of existing systems are mainly focused on detecting large obstacles such as vehicles, pedestrians, and so on. Detection of small obstacles such as road debris, which pose a serious potential threat are often overlooked. In this article, a novel stereo vision-based road debris detection algorithm is proposed that detects debris on the road surfaces and estimates their height accurately. Moreover, a collision warning system that could warn the driver of an imminent crash by using 3D information of detected debris has been studied.
Journal Article

Spray Behaviors and Gasoline Direct Injection Engine Performance Using Ultrahigh Injection Pressures up to 1500 Bar

2021-07-28
Abstract High fuel injection pressure systems for Gasoline Direct Injection (GDI) engines have become widely used in passenger car engines to reduce emissions of particulates and pollutant gases. Current commercial systems operate at pressures of up to 450 bar, but several studies have examined the use of injection pressures above 600 bar, and some have even used pressures around 1500 bar. These works revealed that high injection pressures have numerous benefits including reduced particulate emissions, but there is still a need for more data on the possible benefits of injection pressures above 1000 bar. This article presents spray and engine data from a comprehensive study using several measurement techniques in a spray chamber and optical and metal engines. Shadowgraph imaging and Phase Doppler Interferometry (PDI) were used in a constant volume chamber to interpret spray behavior. Particle Image Velocimetry (PIV) was used to capture near-nozzle air entrainment.
Journal Article

Software-Based Approach for Sharing Real-Time Peripherals in a Virtualized Automotive Microcontroller Platform

2021-05-11
Abstract In the automotive domain, the evolution of electrical and electronic (E/E) architecture trend is toward consolidating multiple heterogeneous applications executing on individual devices onto a centralized powerful computing platform. Many forums debate the nature of this centralized computing platform. At least for another decade, automotive powertrain functions will continue their development on a multicore controller platform (MCU) instead of many core processors. Data security and the need to meet Automotive Safety Integrity Level D (ASIL-D)-compliant powertrain functions are some of the reasons for this preference. For the centralized computing platform, virtualizing the underlying MCU will facilitate the simultaneous execution of heterogeneous powertrain applications with guaranteed spatial and temporal isolation. A common problem in virtualizing the MCU is the sharing of peripherals, which are comparatively scarce.
Journal Article

Sliced Secure Boot: An Accelerated Secure Boot Concept Compatible with Automotive Safety Controllers

2023-06-08
Abstract The secure boot has successfully protected systems from executing untrusted software (SW), but low-power controllers lack sufficient time to check every memory cell while satisfying real-time functional safety requirements. Automotive controllers need to maintain security through multiple cycles of remote, unsupervised operation and safely reach a secure state when an anomaly is detected. To accelerate the boot time, we propose Sliced Secure Boot: build fingerprints by slicing orthogonally through memory blocks, protect each cell with a reusable fingerprint using a reproducible pattern with sufficient entropy, and randomly check one fingerprint pattern during boot. We do not claim that sampling offers equivalent protection to exhaustive checks but demonstrate that careful sampling can provide a sufficient level of detection while maintaining compatibility with both startup time and functional safety requirements.
Journal Article

Simulation Study on Influence of Environmental Temperature on Current-Carrying Capacity of Automotive Electrical Connector

2021-11-12
Abstract The purpose of this article is to reduce the adverse effects of temperature rise on the electrical connector, reduce the failure risk of electrical connector due to the mismatch of current-carrying capacity selection, and improve the service life of the electrical connector. This article takes a certain type of vehicle electric connector as the research object. An accurate contact pair model of the electrical connector is established by SOLIDWORKS software. The force and thermoelectric coupling simulation analysis of the 3D solid model with reasonable load and boundary conditions was carried out by ABAQUS software. The results show that the insertion force and positive force of the electrical connector terminal are in line with the values specified in the standard.
Journal Article

Securing the On-Board Diagnostics Port (OBD-II) in Vehicles

2020-08-18
Abstract Modern vehicles integrate Internet of Things (IoT) components to bring value-added services to both drivers and passengers. These components communicate with the external world through different types of interfaces including the on-board diagnostics (OBD-II) port, a mandatory interface in all vehicles in the United States and Europe. While this transformation has driven significant advancements in efficiency and safety, it has also opened a door to a wide variety of cyberattacks, as the architectures of vehicles were never designed with external connectivity in mind, and accordingly, security has never been pivotal in the design. As standardized, the OBD-II port allows not only direct access to the internal network of the vehicle but also installing software on the Electronic Control Units (ECUs).
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