Your Destination for Mobility Engineering Resources

Ensuring safe operation and reliable control of mobility systems remains a significant challenge, particularly for nonlinear and high-dimensional applications subject to external disturbances with hard constraints and limited computational resources in real-time implementations. A reference governor (RG) can enforce constraints using an add-on scheme that preserves the pre-stabilizing controller while balancing the need to satisfy other requirements, including reference tracking and disturbance rejection. Thus, in this paper, we exploit RG-based strategies focusing on nonlinear mobility systems. While the method is generalizable to other applications, such as waypoint following for autonomous driving, the flight dynamics of a quadrotor system with twelve states are used as an example. We implement a disturbance rejection RG to satisfy safety constraints and track set points. To handle nonlinearity, we propose an optimal strategy to quantify the maximum deviation between the nonlinear
Dong, YilongLi, Huayi
This paper reports on the Catesby Aero Research Facility (CARF), which began commercial operation in 2019, and summarizes facility characteristics and associated measurement technologies, with an emphasis on vehicle-mounted component-force measurement devices. CARF is a proving ground converted from a former railway tunnel approximately 2.74 km in length and surfaced with high-quality tarmac. The road-surface quality was specified to be comparable to that of SUBARU's proving ground and was achieved using established construction methods. The course is approximately straight with a small longitudinal grade. Key course specifications include an approximately 40 m2 blockage area, a 6 m road width (maximum 8.4 m), flatness σ < 0.5 mm, and a gradient of 0.57%. Relative to outdoor coast-down testing, the tunnel length enables continuous measurement to very low speeds, thereby improving repeatability. A six-component force sensor integrated into the hub unit enables on-road measurement of
Shimoyama, Hiroshi
A machine learning (ML)-based meta-analysis was conducted to evaluate rear seat occupant safety performance in the Insurance Institute for Highway Safety (IIHS) Moderate Overlap Frontal (MOF) 2.0 crash test. ML models were trained on historical IIHS crash test data to predict rear passenger injury metrics using vehicle architecture, restraint system characteristics, crash pulse parameters, and vehicle kinematics as input features. The models demonstrated high predictive accuracy and were subsequently used in a Sobol sensitivity analysis to identify critical design parameters influencing injury outcomes. The analysis revealed that rear passenger injury metrics were most sensitive to restraint system parameters. Specifically, crash pulse magnitude was the dominant factor for head injury metrics, pretensioner activation time for neck tension force, and lap belt force for the Neck Injury Criterion (Nij). For chest-related metrics—sternum deflection, dynamic belt position, and maximum belt
Lalwala, MiteshKim, WonheeFurton, LisaSong, Jay
With rapid growth of Electric Vehicles (EVs) in the market, challenges such as driving range, charging infrastructure, and reducing charging time needs to be addressed. Unlike traditional Internal combustion vehicles, EVs have limited heating sources and primarily uses electricity from the running battery, which reduces driving range. Additionally, during winter operation, it is necessary to prevent window fogging to ensure better visibility, which requires introducing cold outside air into the cabin. This significantly increases the energy consumption for heating and the driving range can be reduced to half of the normal range. This study introduces the Ceramic Humidity Regulator (CHR), a compact and energy-efficient device developed to address driving range improvement. The CHR uses a desiccant system to dehumidify the cabin, which can prevent window fogging without introducing cold outside air, thereby reducing heating energy consumption. CHR is based on desiccant dehumidification
Sakai, NaokiTakahiko, NakataniShinoda, NarimasaIhara, YukioWakida, NorihiroKato, KyoheiAnoop, Reghunathan-Nair
Expeditionary environments (such as remote exploration missions, forward military operations, and disaster response zones) demand adaptive manufacturing solutions to support vehicle sustainment in the absence of traditional supply chains. This work introduces a conceptual mathematical framework for modeling the constraints and tradeoffs inherent to expeditionary manufacturing, with a focus on vehicle repair and spare parts fabrication using low-energy and simple automated systems including desktop-scale 3D printers and CNC machines. The model integrates key variables such as energy availability, material transport cost, fabrication time, and environmental limitations to support rapid decision-making on part manufacturability and in-field feasibility. A case study involving the on-demand production of some common wear and failure parts on a vehicle, including suspension components and the water pump, is used to demonstrate how this framework can guide the selection of suitable
Mollan, CalahanPandey, VijitashwaPatterson, Albert E.
Recent studies have demonstrated that the current Internal Combustion Engine (ICE) can be adapted to operate with hydrogen for the decarbonisation of transport and gensets. This is mostly done by conversion of conventional 4-stroke compression ignition diesel engines or spark ignition gas engines for heavy-duty vehicles or 4-stroke spark ignition gasoline engines for light-duty applications. This study aims to assess the adoption of pure hydrogen direct injection technology on a novel two-stroke opposed-piston engine designed by Carnot Engine Ltd. The engine provides a flexible platform that can operate in both compression ignition and spark ignition modes, allowing it to adopt multiple fuels. For the first time, a single cylinder prototype version of this new engine was operated and tested with hydrogen at Brunel University of London. During the engine experiment, a spark ignition timing sweep was carried out at low and mid-loads up to 10 bar IMEP to identify the Minimum ignition
Mohamed, MohamedRoeinfard, NimaWang, XinyanZhao, HuaWatts-Farmer, ArchieRahman, NadiurLempp, Francis
Accurate prediction of equilibrium combustion products and thermodynamic properties is essential for optimizing engine performance, enhancing combustion efficiency, and reducing emissions in diesel-powered systems. Traditional methods for combustion modeling often involve solving complex chemical equilibrium equations or thermodynamic relations, which could be computationally expensive and time-consuming. In this study, we present a data-driven approach using a deep neural network (DNN) model to predict the equilibrium combustion products and key thermodynamic characteristics of diesel under varying thermodynamic conditions. The proposed DNN model is trained on a comprehensive dataset generated from equilibrium calculations. The inputs include pressure, temperature, and equivalence ratio, covering a relatively wide range to encompass diesel equilibrium combustion under various conditions. Outputs are equilibrium combustion products and thermodynamic properties, including enthalpy
Ji, HuangchangWang, KaiGuo, ZhefengHan, YangLee, Timothy
As hydrogen internal combustion engines (H2-ICE) gain traction, optimizing exhaust aftertreatment technologies for nitrogen oxide (NOx) control has become increasingly critical. While selective catalytic reduction (SCR) systems remain the primary approach for NOx mitigation, oxidation catalysts are also being explored to facilitate hydrogen oxidation and improve overall exhaust treatment efficiency. This work presents a multifunctional catalyst (MFC) concept that combines supported Pd and Cu-zeolite to enable simultaneous NOx reduction and hydrogen oxidation within a single catalytic unit. Preliminary results show that hydrogen oxidation on supported Pd occurs above 300 °C, while Cu-zeolite achieves nearly complete NOx conversion. Experiments on individual components indicate that supported Pd initiates ammonia oxidation only after hydrogen is depleted. In the presence of hydrogen, ammonia conversion remains below 20%, indicating that hydrogen availability suppresses ammonia oxidation
Danghyan, VardanBecker, Jan MartinHünnekes, EdgarPatchett, Joseph
Ammonia is regarded as a potential alternative fuel, and its spray characteristics are crucial for efficient combustion in engines. For large-bore engines suitable for heavy-duty vehicles or ships, the adoption of large-diameter nozzles is expected to ensure an appropriate fuel flow rate while improving fuel-air mixing efficiency, thereby enhancing in-cylinder combustion performance. This paper conducted an experimental study on the characteristics of liquid ammonia sprays under wide thermodynamic conditions, a wide range of injection pressures, and a wide range of nozzle diameters. The study found that at room temperature, as the ambient pressure increases from 0.1 MPa to 4 MPa, the development of spray penetration slows down. However, at 0.05 MPa, the radial expansion of the near-field spray is greater, and the penetration is slightly behind that at 0.1 MPa. The liquid penetration increases with the increase in ambient temperature. This was because the increase in temperature reduced
Liu, YiZhong, JieHu, YuchenZhu, WuzheYunliang, QiQingchu, ChenWang, Zhi
Computed tomography (CT) is a valuable diagnostic technique for visualizing spray plume direction and assessing mixture quality within combustion chambers under engine-relevant conditions. High-speed extinction imaging followed by tomographic reconstruction enables temporally and spatially resolved measurements of liquid volume fraction and plume evolution in multi-plume sprays. Traditionally, tomographic reconstruction requires capturing multiple angular views by rotating the injector and averaging over numerous injections to ensure statistical convergence. This process is time-intensive, particularly due to the large volume of data acquisition and the corresponding delays in data saving, particularly when acquiring many injections per view angle. In this study, we investigate the minimum number of injections required to achieve sufficient CT image quality, thereby significantly reducing experimental time. Two injectors are evaluated: a symmetric 8-hole Spray M injector from the
Yi, JunghwaWan, KevinPickett, Lyle
The concept of the vehicle has changed as a result of many innovations over the last decade in the fields of connected, autonomous/automated, shared, and electric (CASE) technologies. At the same time, labor shortages in Japan are becoming more serious due to a decline in the working population. To help resolve these issues, a remote-controlled autonomous vehicle driving system called Telemotion has been developed that automates the movement of vehicles in production plants. This system is an autonomous driving and transportation system in which the recognition, judgment, and operation functions of driving are handled by a control system outside the vehicle that communicates wirelessly with the vehicle. This system utilizes artificial intelligence (AI) and other advanced technologies to realize safe unmanned autonomous driving, and is already in operation in production plants. Currently, efforts are under way to build a digital twin environment and conduct AI learning using computer
Hatano, YasuyoshiIwazaki, NoritsuguNagafuchi, YuheiIwahori, KentoTanaka, AtsushiUezu, SatoruKanou, TakeshiInoue, GoOkamoto, YukiOka, YuheiKakuma, DaisukeChiba, HiroyaEgashira, KazukiIshikuro, MegumiSawano, Takuro
Climate change concerns demand a drastic reduction in CO2 emissions, tending to what is called carbon neutrality. Even if political guidelines promote electrification, considering the transportation sector, not all applications have the same requirements and boundary conditions, and hence, their optimal solution is not necessarily the same. In this context, in parallel with pure electric powertrains, the internal combustion engine (ICE) still has a relevant role to play, mainly in hybrid powertrains, working together with an electrical motor. In this hybridization context, the spark-ignition (SI) engine uses to be the most adopted solution because of its lower cost and complexity. Consequently, it can be concluded that the SI engine will still play a significant role in the near future. However, when ICEs are considered, the search for carbon neutrality requires the use of fuels other than fossil fuels. At this point, many alternatives arise, from biofuels to synthetic e-fuels, or even
Robayo-Rueda, DanielLopez, J. JavierMartin, JaimeNovella, Ricardo
Parasitic inductance and capacitance of the battery pack can affect the performance of the electric powertrains. Characterizing these parasitic phenomena in an automotive battery pack is therefore crucial to ensuring performance and reliability. In this work, geometric models of a production automotive battery pack are developed to simulate the parasitic inductance of the busbar system, the parasitic inductance of individual modules, and other critical components. For these simulations, several assumptions and simplifications are introduced to reduce model complexity, while preserving the main electromagnetic behavior of the system. The impact of the different components on the battery pack impedance is investigated to evaluate parasitic capacitances, thereby simulating the worst-case scenario. Laboratory procedures are developed to accurately measure parasitic impedance, providing a reliable comparison between experimental data and analytical models and supporting the overall validity
Misley, MarcoD'Arpino, MatildeZhu, DiZhang, Liwen
The objective of this paper is to understand the effort required to integrate the hardware and software of in-vehicle cybersecurity systems. The in-vehicle cybersecurity method discussed is the SAE J1939-91C, which involves Network formation, Rekeying, and secure Message Exchange between Electronic Control Units (ECUs). The SAE J1939-91C network security protocol operates over a CAN-FD network to perform necessary cryptographic operations and key generation. To evaluate the method, test vectors were created to validate SAE J1939-91C key generations and cryptographic operations on the simulated ECU in-vehicle network system hardware (such as the Beacon or Pi devices). We introduce a lightweight, transport-agnostic benchmark comprising deterministic AES-CMAC test vectors and a simple verification utility, requiring no specialized hardware or build system. This minimal artifact set enables reproducible and machine-parsable validation of SAE J1939-91C security across diverse lab
Zachos, MarkMedam, Krishna Teja
The timing of video recordings, along with the spatial positioning of objects, is a fundamental parameter for calculating the speed time history. If the task involves determining the average speed of an object moving at approximately constant speed, it may be acceptable to average the speed over several to a dozen frames, using the fps (frames per second) parameter as the basic time unit.. However, if the objective is to compute speed from individual frames, the reliability of the timing becomes crucial. Without access to DVR hardware documentation, proprietary algorithms, or software – and considering the frequent hardware modifications and software updates - the most effective way to solve the problem is through a reverse-engineering approach. This study discusses several aspects of timing analysis, including: (1) making a test recording of a calibrated LED lightboard; (2) analyzing the relationship between the lightboard time and the presentation time stamp (pts) extracted from the
Wach, Wojciech
Lithium plating is a critical barrier to fast charging in electric and hybrid-electric vehicles, occurring at high state of charge (SOC) or low temperatures when Li+ deposits as metallic lithium on the anode surface instead of intercalating into graphite. At low temperatures, plated lithium may form dendrites that pierce the separator and trigger thermal runaway, while at high SOC, irreversible plating accelerates capacity fade by depleting cyclable lithium. Despite extensive study, lithium plating remains difficult to incorporate into battery management systems (BMS) due to computational complexity and the challenge of real-time detection, leading to reliance on conservative lookup maps. This work presents a lightweight empirical model for predicting plating-free charging limits in lithium nickel manganese cobalt (NMC) cells. A high-fidelity pseudo-2D electrochemical model was exercised across a wide range of charge rates and temperatures to capture the coupled effects of SOC
Sundar, AnirudhGhate, AtharvaZhu, QilunPrucka, RobertBarron, MorganFigueroa-Santos, Miriam
Methanol is one of the most readily produced e-fuels and remains in liquid form at ambient conditions, making storage and transportation relatively simple. In the marine sector, methanol has already been actively adopted as a pathway toward carbon neutrality. For automotive sectors, methanol offers significant potential for carbon emission reduction owing to its higher octane number and lower carbon content compared with gasoline. However, its high latent heat of vaporization and low vapor pressure suppress evaporation at low ambient temperatures, leading to increased emissions during cold-start operation. To address this issue, previous studies have explored heating the injector tip or fuel rail to enhance evaporation and atomization. The present study focuses on visualizing and quantifying the improvement in methanol evaporation characteristics under cold-start conditions by applying controlled heating to the injector tip. Experiments were conducted in a constant-volume chamber where
Lee, SeungwonKim, HyunsooBae, SuminHwang, JoonsikBae, Choongsik
There is an increasing adoption of Direct-Injection Spark-Ignition (DISI) engines in the market, which per 2024 US Environmental Protection Agency (EPA) Automotive Trends Report represents 73% of new vehicles sold in the US. And while it is well accepted that DISI offers advantages over Port Fuel Injection (PFI) technology in meeting stringent CO2 emissions and fuel economy requirements set by the EPA, DISI engines are also associated with increased formation of injector deposits. These deposits may foul injectors and accumulate on the injector tip causing distorted spray patterns and diffusive combustion. Ultimately, this leads to engine performance deterioration and increased harmful emissions. To control deposit formation, detergent-type chemistries are added to the fuel in small amounts. Deposit Control Additives (DCAs) function by preventing the formation of deleterious injector deposits as well as removing existing ones. This study used standardized protocols describing the
Soriano, NestorWilliams, RodCracknell, RogerLang, WendyChahal, Jasprit
Our laboratory has proposed the focusing compression principle which employs pulsed super-multi jets of gas colliding around the chamber center. This principle aims to achieve high thermal efficiency by reducing both exhaust and cooling losses. Exhaust loss is minimized due to relatively-silent high compression. Cooling loss is reduced due to thermal insulation caused by fuel-air mixture being confined to the chamber center and the compressible flow effect. In previous studies, we conducted fundamental gasoline combustion experiments on a proof-of-concept opposed-piston engine which incorporated this principle. This engine featured eight intake nozzles in an octagonal configuration and utilized non-sinusoidal and strongly asymmetric piston movements. The results indicated the possibility of high thermal efficiency based on less knocking under high compression, and the potential for stable combustion under lean-burn conditions. As a next step towards practical application with
Nishizawa, TomohikoNaitoh, KenBaba, ShotaroUkegawa, HirakuYamada, SotaOzono, YukaAbiko, MireiSuzuki, YosukeHara, NamitoIto, YoshikuniMatsubara, KosakuUenoyama, Kazuyuki
The world of Formula One (F1) is changing with impending 2026 F1 regulations imposing even stricter limits on engine component usage while increasing races. The valvetrain system, specifically the intake valves, is a critical determinant in controlling gas exchange within the cylinders, directly impacting air-fuel charge and power output. The aim of this investigation is to study the mechanisms of intake valve and valve seat wear which will influence engine performance due to leakage path development. The wear mechanism of the intake valves considers wear from impact from valve seat interaction, sliding and foreign particle abrasion for quantifying valve seat recession. An FIA 2026-2030 regulations compliant valve train model was developed in GT-Suite to help estimate valve seat wear. The validated model could predict valve recession for a given engine operating speed trace from racetrack data. This report presents a systematic methodology for developing valve seat wear quantification
Soh, Sean KendrickSamuel, Stephen
The increasing concentration of atmospheric pollutants in urban environments necessitates innovative solutions to mitigate their impact on public health and the environment. This work presents the AirCARE project, which investigates the integration of a catalytic converter and a particulate filter with a vehicle's radiator to create an active air purification system. The primary objective is to evaluate the feasibility and performance implications of this integrated system on the vehicle's thermal management. A comprehensive methodology combining computational modeling and experimental testing was employed. A 1D longitudinal vehicle model was developed to simulate the powertrain's heat generation and the cooling system's performance under various representative driving conditions. This model allows for a parametric study of the radiator, assessing the impact of the additional components on its heat exchange efficiency. Concurrently, experimental tests were conducted on a radiator to
de Carvalho Pinheiro, HenriqueSartoretti, Enrico
Tensile and cyclic behavior of high pressure die cast AE44 magnesium alloy have been studied at room temperature and elevated temperatures up to 350°C. Anelastic behavior has been found in both tensile and cyclic loading at the temperature below 200°C. With increasing temperature, the anelasticity disappears, and tensile and cyclic behaviors become like other engineering materials, such as steels and aluminum alloys, i.e. the total strain contains only elastic strain and plastic strain. A method to determine the yield strength at 0.2% plastic strain (σ0.2) is proposed. By using the proposed method, the yield strength σ0.2 is found to be higher than that determined using the traditional method, which is more suitable to the materials that do not exhibit anelasticity. It is believed that the anelasticity is closely related to twinning in Mg alloy, which disappears at elevated temperatures.
Liu, YiYang, WenyingCoryell, Jason
Despite advances in crash avoidance, occupant restraint systems remain crucial in protecting the motoring public. Following decades of improvement in occupant protection, including several supplemental restraint systems for front seat occupants, the safety of rear seat occupants has recently undergone scrutiny. Studies evaluating rear seat occupant injury risk via field crash data have reported reduced relative safety in rear seating positions and alluded to advanced rear seat restraints, such as pretensioners and load limiters, as potential solutions. While the pursuit of novel technologies has historically improved occupant outcomes, evaluation of new systems in both controlled laboratory environments and field crashes is necessary to understand potential consequences of widespread introduction. This study analyzed the prevalence of advanced seat belts (load limiters and pretensioners) in the rear seating positions in the U.S. fleet. Additionally, occupant injury risk was compared
Rapp van Roden, Elizabeth AnnMiller, BrucePearson, JosephWilliamson, JamesBrown, Thomas
This study experimentally investigates the combined effects of exhaust gas recirculation (EGR) and injection timing on the combustion and emission characteristics of a hydrogen direct injection engine. A single-cylinder 395 cc research engine was used, with injection timing varied from 60° to 180° BTDC and EGR rates from 0% to 30%. In-cylinder pressure, apparent heat release rate (AHRR), NOx, and unburned hydrogen concentrations were measured to analyze the influence of mixture formation and dilution on engine performance. Under non-EGR conditions, retarding the injection timing promoted mixture stratification, resulting in faster flame propagation and shorter combustion duration. However, localized high-temperature regions increased NOx formation, while incomplete combustion in lean or rich zones elevated unburned hydrogen emissions. When EGR was introduced, both ignition delay and combustion duration increased due to reduced oxygen concentration and thermal dilution. Nevertheless
Yang, HeetaeKi, YoungminKim, Jungho JustinKim, Jinsu