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Battery Management System: Surface Vehicle Battery Diagnostic Technical Information ReportJ3356_202609 (Current)9/28/2026
The purpose of this document is to expressly describe the required diagnostics (DIAG) related to the on-road traction battery management systems (BMS). This document will attempt to clearly educate and explain four key areas of BMS DIAG: (1) fault identification, (2) fault classification, (3) system reaction, and (4) diagnostic data and reporting.
Battery Management Systems Committee
Battery Management System: Surface Vehicle Battery SOC Technical Information ReportJ3356/1_202609 (Current)9/28/2026
The purpose of this document is to expressly describe the method of calculating state of charge (SOC) related to the on-road traction battery management systems (BMS). This document will attempt to clearly educate and explain four key areas of BMS SOC: (1) basic SOC definition, (2) SOC calculation methods, (3) influence items for SOC, and (4) SOC warnings.
Battery Management Systems Committee
Battery Management System: Surface Vehicle Battery SOH Technical Information ReportJ3356/2_202609 (Current)9/28/2026
The purpose of this document is to expressly describe the method of calculating state of health (SOH) related to the on-road traction battery management systems (BMS). This document will attempt to clearly educate and explain four key areas of BMS SOH: (1) basic SOH definition, (2) SOH calculation methods, (3) influence items for SOH, and (4) SOH reporting.
Battery Management Systems Committee
Cable Assemblies and Attachable Plugs, External Electrical Power, Aircraft, General Specification ForAS7974B (Current)9/25/2026
This specification contains requirements for, and applies to, commercial and military aircraft external/ground electrical power cable assemblies, using either overmolded or attachable plug connectors used to connect external/ground electrical power to aircraft and to attachable plugs used as replacements for plugs damaged in service.
AE-8A Elec Wiring and Fiber Optic Interconnect Sys Install
Time-Dependent Power Flow Modeling for Non-Passive Loads in Battery Electric Propulsion Architectures2026-01-75639/22/2026
Traditional Linear Circuit Analysis (LCA) relies on steady-state voltage assumptions that are fundamentally incompatible with battery-exclusive propulsion architecture. Whilst LCA remains valid for hybrid systems, where an auxiliary source actively regulates the State-of-Charge (SOC), it fails when analyzing non-passive, constant-power loads. In pure electric architecture, the time-dependent decay of the discharge voltage forces a continuous, non-linear increase in current to satisfy mechanical power demands. A time-dependent power flow methodology is introduced to resolve this theoretical divergence. Using the conservation of energy operating explicitly within the power domain, the time-dependent coupling of current and voltage can be modeled. This approach supersedes steady-state approximations for higher fidelity predictions for component efficiency, system heat generation, and battery capacity requirements for pure electric propulsion systems. Citation: N. Ingarra, K. J. Kobus, J. G. Kobus “TIME-DEPENDENT POWER FLOW MODELING FOR NONPASSIVE LOADS IN BATTERY ELECTRIC PROPULSION ARCHITECTURES” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 11-13, 2026.
Ingarra, Nicholas A., Kobus, Krzysztof (Chris) J., Kobus, Jadon G.
Integrating MBSE with High-Fidelity Crash Simulation2026-01-75429/22/2026
Modern electrified ground vehicles introduce complex, multi-domain safety requirements, such as post-crash thermal runaway prevention, that expose the traceability limitations of Document-Based Systems Engineering (DBSE). This paper proposes a four-layer, bidirectional digital thread architecture that integrates Model-Based Systems Engineering (MBSE) with high-fidelity, non-linear Computer-Aided Engineering (CAE) crash simulations. Leveraging SysML, System-Theoretic Process Analysis (STPA), and Python-based orchestration middleware, the framework automates the translation of descriptive safety requirements into explicit finite element boundary conditions. The architecture programmatically extracts key performance indicators from massive binary solver outputs and injects them back into the SysML environment for automated compliance verification. Demonstrated through a simplified electric vehicle side-pole impact case study utilizing LS-DYNA and a 1D thermal model, the framework successfully eliminates manual data handoffs, accelerates multidisciplinary design optimization, and ensures robust, risk-driven requirement traceability across the engineering lifecycle.
Rye, Patrick J.
Optimizing Data Delivery for Ground Vehicle Teams2026-01-75399/22/2026
The radio-based wide area network (WAN) that forms the command-and-control backbone for deployments of multiple ground vehicles is a classic DIL (disconnected, intermittent, limited) communications infrastructure for bandwidth-intensive services like video streams, situational awareness feeds, and command-and-control messages. This paper describes an inter-vehicle network architecture that leverages the radio-aware routing features of an existing vehicle Ethernet switch/router to provide mission-optimized, fault-tolerant data delivery while minimizing both network overhead and vehicle SWaP requirements.
Al-Gharaibeh, Jafar, Bonney, Jordan
Deriving Instantaneous Electro-Thermal Parameters and Heat Generation from Constant-Current Discharge Data2026-01-75629/22/2026
Early-stage Battery Thermal Management System (BTMS) design can be constrained by limited manufacturer data, resulting in the use of steady-state thermal assumptions. An analytical methodology is introduced to extract the real-time cell resistance, instantaneous efficiency, and transient heat generation directly from standard constant-current discharge curves, and Open Circuit Voltage (OCV) profiles. By evaluating the time-dependent voltage differential against current, equivalent cell resistance and transient heat generation are computed without explicit ohmic measurement or calorimetric testing. This enables direct, real-time coupling of electrical and thermal models. Application to an NMC chemistry cell demonstrates concentration losses dominate below a 20% State-of-Charge (SOC), increasing transient heat generation, and decreasing instantaneous efficiency. Extracting the time-dependent electro-thermal parameters provides the required quantitative inputs for benchmarking cells & accurately sizing BTMS cooling capacities. Citation: N. A. Ingarra, K. J. Kobus, J. G. Kobus, “Deriving Instantaneous Electro-Thermal Parameters and Heat Generation from Constant-Current Discharge Data,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 11-13, 2026.
Ingarra, Nicholas A., Kobus, Krzysztof (Chris) J., Kobus, Jadon G.
Connecting Standard LI-ION Batteries in Series to form a High Voltage Array2026-01-75669/22/2026
The principles of high voltage (HV) battery array design, which is based on existing, off-the-shelf Li-Ion batteries (e.g., certified Lithium 6T Batteries), is presented. The battery array includes, besides the series connected battery modules, an HV switch controlled by a controller unit and additional safety components. The paper first reviews all the safety hazards associated with Li-Ion batteries and HV systems which generate design requirements and constraints. Then the basic design together with the principal components are described. Citation: O. Kost, “Connecting Standard Li-Ion Batteries in Series to Form a High Voltage Array,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 11-13, 2026.
Kost, O.
Experimental Comparison Between Real and Simulated Battery Pack Efficiency in Light Quadricycles Using a Custom Inertia Dynamometer2026-24-00089/21/2026
This study compares the energy efficiency of a real battery pack and a simulated battery pack using a hardware-in-the-loop battery emulator, through experimental testing on a dedicated inertia dynamometer for light quadricycles. The investigated LiFePo4 battery pack has a nominal voltage of 48 V and a nominal capacity of 100 Ah. Initial characterization identified a reduced State of Health based on capacity (SOHC), with a measured usable capacity of 48 Ah (from the nominal 100 Ah) and a corresponding reduction in charge acceptance capability. The emulator was configured to replicate the degraded battery characteristics, including the open-circuit voltage (OCV)-SOC relationship, internal resistance, and current limitations, enabling a direct comparison between simulated and experimental dynamic behavior. The experimental setup was designed to overcome the limitations of conventional chassis dynamometers for low-mass, independent four-wheel-drive quadricycles operating without mechanical friction braking systems. Multiple driving cycles were reproduced using a PLC-based closed-loop control system, with data acquisition performed via CAN communication. The comparative analysis highlights significant differences during regenerative braking events. While the emulator accurately reproduces baseline electrical behavior under mild operating conditions, the aged battery exhibits strong limitations during both high-power acceleration and severe deceleration phases. In particular, increased internal resistance and transient electrochemical polarization lead to premature saturation of charge acceptance, resulting in rejection of high-frequency current transients. Consequently, the experimentally observed energy recovery is significantly lower than the theoretical values predicted by the emulator. In addition, due to the absence of mechanical braking, the reduced regenerative capability directly leads to speed tracking deviations, as the required braking torque cannot be fully achieved. These results identify battery degradation as a key physical constraint affecting both energy efficiency and dynamic braking performance, highlighting the importance of improved electro-thermal and aging-aware model calibration for realistic system-level simulations.
Sementa, Paolo, Vaglieco, Bianca Maria, Altieri, Nunzio
EKF-Based Machine Learning Approach for Battery SOH Prediction in Commercial Vehicles Fleet2026-24-00029/21/2026
Estimating battery state of health (SOH) from field data is essential to ensure successful operation and increase the uptime of battery electric vehicles (BEVs). Most studies in the literature propose methods relying on datasets acquired under controlled laboratory conditions. However, SOH estimation becomes significantly more challenging when dealing with real-world data due to the increased variability and complexity of operating conditions. In this work, CAN telematics data, sampled at 1 Hz, were collected over approximately 20 months of operation from 10 electric commercial vehicles. During this period, a maximum battery degradation of 4% is observed within the fleet. Firstly, a model-based framework was introduced, in which a second-order battery equivalent circuit model (ECM) was coupled with an extended Kalman filter (EKF) to estimate the battery SOH. Results confirmed that the EKF is able to accurately capture the battery's physical behavior and degradation trend, yielding a maximum root mean square error (RMSE) of 1.23% when compared with the SOH signal provided by the onboard BMS. However, a Kalman filter requires accurate model parameter identification and high-frequency measurement data, leading to increased computational costs. To bridge these gaps, this paper utilizes the SOH estimates obtained from the EKF to train and validate a feedforward neural network (FNN) model, specifically designed to operate on aggregated metrics. The FNN model can provide accurate SOH estimates, with a RMSE as low as 0.26% during the testing phase. The approach proposed in this work combines the interpretability of model-based methods with the scalability and reduced data dimensionality of machine learning (ML) ones, making it more suitable for monitoring battery SOH in large fleets of BEVs.
D'Agostino, Valerio, Pulvirenti, Luca, Shanker, Anirudh, Cardone, Massimo, Rizzoni, Giorgio, Vitale, Francesco
Multi-Level CFD and System Simulation Approach for Optimization of Cooling Circuits in High Power Density Powertrains2026-24-00099/21/2026
This paper presents a CFD-based optimization workflow for the simulation and development of automotive cooling circuits, integrating three-dimensional steady-state analyses with one-dimensional transient modeling. The objective of the activity is to establish a robust methodology that links detailed component-level thermal characterization to system-level dynamic simulations, enabling the assessment of cooling performance under both driving and charging operating conditions. The thermal behavior of the cooling circuit components was first investigated using three-dimensional steady-state simulations performed with Ansys Fluent. For each relevant operating point, the fluid flow and heat transfer were resolved in full 3D, and temperatures were monitored at multiple locations within the components and along the circuit. The steady-state analyses provided spatially resolved temperature fields and heat transfer characteristics for a range of boundary conditions representative of real operating scenarios. From these results, temperature and performance maps were generated, describing the relationship between operating conditions, heat loads, and thermal responses of the components. These maps were then used for the calibration of one-dimensional models implemented in GT-Suite. The calibrated 1D models reproduce the thermal behavior observed in the 3D CFD simulations while allowing efficient simulation of the entire cooling system under transient conditions. This multi-level approach enables the combination of detailed local physics from CFD with the computational efficiency required for system-level dynamic analyses. Transient simulations were carried out in GT-Suite to evaluate the thermal response of the cooling circuit during both driving and charging phases. The driving phase accounts for variable thermal loads and flow conditions associated with vehicle operation, while the charging phase represents operating conditions specific to battery recharging scenarios. The calibrated 1D models were used to simulate the evolution of temperatures throughout the system over time, considering the interactions between components and the overall thermal inertia of the circuit. The results show that the designed cooling system is capable of maintaining component temperatures within the targeted limits across the analyzed operating conditions. The thermal containment is achieved for all components included in the cooling circuit under both dynamic driving and charging scenarios. The electric motor is oil-cooled and therefore is not part of the water-based cooling circuit addressed in this study. The proposed CFD-to-1D workflow provides a consistent and transferable methodology for the thermal development of cooling systems of high power density electrified powertrains. The novel contribution lies in (i) the application of the multi-level framework to a heavy-duty platform with SiC-based power modules and dedicated on-board charger developed within the Horizon Europe POWERDRIVE project, (ii) a DOE-based map generation strategy that preserves the conjugate heat transfer interactions between actively cooled components (power modules, OBC) and passively cooled neighbors (busbar, capacitors) within the reduced-order representation, and (iii) the integration of the reduced-order maps within a single transient system-level model covering both vehicle-at-rest charging and dynamic driving operating modes. This activity is carried out within the framework of the Horizon Europe project POWERDRIVE.
Chiappini, Daniele, Tribioli, Laura, Rodionov, Artem
Fuel Cell Electric Vehicle-to-Home Strategy for Residential Power Supply Continuity and Load Management2026-24-00269/21/2026
Power supply continuity for household appliances during high-demand peaks or periods of low solar generation remains a critical challenge for modern residential energy systems. Hydrogen-powered Fuel Cell Electric Vehicles (FCEVs) offer a compelling solution by extending their role from sustainable mobility to versatile mobile energy storage units. This study investigates the Vehicle-to-Home (V2H) operation of a high-performance fuel cell vehicle designed to provide backup power and peak-shaving capabilities in a domestic environment during high-demand or grid overload conditions. To evaluate this integration, a comprehensive MATLAB/Simulink simulation model was developed for a residential microgrid. The system comprises a photovoltaic array, a parallel battery energy storage system, and a Fuel Cell Electric Vehicle modeled according to the technical specifications of the Toyota Mirai, equipped with a high-efficiency 128 kW fuel cell stack (330 cells) and a dedicated 5.6 kg hydrogen storage system. The domestic electrical installation is designed for a maximum power absorption of 6 kW, operating at a standard voltage of 230 V and a frequency of 50Hz. The simulation incorporates a realistic residential load profile representative of a typical working day, characterized by distinct morning and evening consumption peaks that challenge service stability under overload conditions. The implemented control algorithm optimizes energy resource allocation by prioritizing the stationary residential battery for standard peak shaving operations. The Fuel Cell Electric Vehicle is dispatched as a secondary high-capacity power source during critical overload phases, such as the simultaneous activation of multiple high-power appliances, or when low solar irradiance prevents the photovoltaic system from adequately recharging the battery storage system. Simulation results demonstrate that the Toyota Mirai-based FCEV effectively ensures service continuity, mitigating domestic overloads and compensating for the inherent capacity limitations of stationary storage. The findings show that the fuel cell system can fully sustain the 6 kW demand during prolonged deficit periods. In conclusion, the study confirms that integrating hydrogen-based mobility into the domestic energy mix significantly enhances the resilience and operational flexibility of renewable-powered residential applications, transforming the vehicle into a strategic asset for household energy security.
Federici, Leonardo, Pistritto, Antonino, Cozzolino, Raffaello
Comparative Analysis of BEV Performance from Simulated Environment and Physical Hardware Platform2026-24-00059/21/2026
The proliferation of simulation environments has accelerated technological progress across various scientific domains by offering a cost-effective and time-efficient framework for data acquisition and analysis. In the automotive sector, high-fidelity modelling of vehicle components and driving scenarios bypasses the logistical constraints associated with hardware procurement and the intensive requirements of large-scale testing infrastructures. However, pre-calibrated or native software models often imply simplified hypotheses, missing relevant aspects of the entire powertrain-to-wheel energy chain. This study presents a comparative analysis of battery performance within a battery electric vehicle (BEV) by synchronizing virtual simulations with experimental hardware at the test bench. The methodology involves the concurrent modelling of the driving environment, the vehicle chassis, and the propulsion system, followed by the execution of identical driving cycles on a physical platform. The experimental setup comprises a fully instrumented BEV featuring an integrated electric motor and battery pack, specifically configured for high-precision signal acquisition. The virtual section starts with the development of a digital twin within a commercial simulation suite, parameterized according to the vehicle specific dynamic and energy requirements. This is followed by the integration of the electric propulsion system and a battery pack model based on the equivalent circuit model method. To ensure high fidelity, the battery model is experimentally calibrated via multi-step pulse discharge tests performed on the physical hardware. Subsequently, various driving scenarios from the simulated environment are translated into speed-time profiles and are replicated on the real vehicle using a PID-controlled actuator on the accelerator pedal. The battery pack that serves the vehicle is monitored during the cycle to collect information on the electrical performance. Finally, a comparison between the simulated and real battery behaviour is performed. This dual approach used in the present work, which compares the simulation accuracy against real-world performance, provides critical insights into the inherent advantages and technical boundaries of digital modelling in electromobility applications.
Sequino, Luigi, Sementa, Paolo, Altieri, Nunzio, Vaglieco, Bianca Maria, Sorrentino, Chiara
Computational Electro-Thermal and Degradation Modeling Framework for Lithium-Ion Batteries in Electric Vehicles2026-24-00119/21/2026
This paper presents an integrated computational framework that couples electro-thermal and degradation dynamics for lithium-ion batteries used in electric vehicles (EVs). The model is implemented using Python. At the cell level, the model describes charge and discharge behavior, state of charge (SOC), terminal voltage, internal resistance losses, and heat generation. An energy balance equation is used to estimate temperature variation during operation. Temperature-dependent resistance and capacity are included to represent nonlinear battery behavior under different load conditions. At the system level, feedback relationships between SOC, temperature, state of health (SOH), and degradation rate are modeled using system dynamics. Battery aging is represented through mathematical functions that relate capacity loss to temperature and usage cycles. This allows simulation of long-term performance under different driving scenarios. The model enables parametric and sensitivity analyses to evaluate the effects of discharge rate, ambient temperature, and degradation parameters. Results show the strong interaction between thermal behavior and battery aging. Model validation against experimental data is not performed in this study and remains an important direction for future research. The current work focuses on the derivation and parametric analysis of the modelling framework. The proposed framework provides a clear, low-cost, and scalable computational approach for EV battery analysis, design studies, and engineering education.
Gutierrez, Marcos, Taco, Diana
Life Cycle Assessment of Greenhouse Gas Emissions from a Plug-in Hybrid Electric Vehicle with Different Powertrain Configurations in Europe2026-24-00199/21/2026
Plug in hybrid electric vehicles play an important role in transportation decarbonization. Compared with battery electric vehicles, plug in hybrid electric vehicles generally have a lower production carbon footprint due to their smaller batteries, which require far less raw material. Despite their smaller capacity, these batteries are typically sufficient to cover most daily travel distances in pure electric mode. The hybrid powertrain can be configured in multiple ways depending on the number and position of electric machines within the driveline. These configuration differences significantly influence both the total carbon footprint and the use phase greenhouse gas emissions. In this study, we evaluate the life cycle greenhouse gas emissions of a plug-in hybrid electric vehicle with various powertrain configurations in the European context. All configurations share the same premium mid-size sport utility vehicle glider. Battery capacity ranges from 20 kWh to 45 kWh, enabling an electric range of over 200 km under the Worldwide Harmonized Light Vehicles Test Cycle. The number of electric machines varies from one, as in the P2 configuration, to three, as in the P1+P3+P4 configuration. Use phase emissions for each configuration were estimated in accordance with the latest European Union emission legislation. The P2 powertrain exhibited the lowest weighted fuel and electricity consumption, whereas the P1+P3+P4 layout demonstrated the highest overall electric and fuel consumption. A sensitivity analysis of use phase emissions was performed, followed by projections for scenarios with increased renewable energy shares in both electricity generation and liquid fuel production. Finally, an extreme scenario assuming 100 % renewable electricity and fuel was analyzed.
Nguyen, Duc-Khanh, Andersson, Simon, Kristoffersson, Annika
Simulation-Based Development and Evaluation of Heat-Quantity-Based Thermal Operating Strategies for Automotive Applications2026-24-00129/21/2026
Thermal management of hybrid electric vehicle (HEV) powertrains requires the simultaneous conditioning of multiple components operating at fundamentally different temperature levels. For thermal management systems, which directly couple the thermal circuits of the internal combustion engine (ICE), electric motor and inverter (EMINV), and traction battery (BAT) for example via controllable three-way valves and a ring-circuit, the decision of when and which components to couple has a direct impact on overall powertrain efficiency. Existing thermal operating strategies rely on empirically defined temperature thresholds and fixed component priority rankings, without quantifying the actual efficiency benefit associated with each coupling decision. This paper presents the development and simulation-based evaluation of a heat-quantity-based thermal operating strategy for a prototype HEV at TU Darmstadt. The strategy introduces three new computational modules — a Q-Indicator quantifying the thermal surplus or deficit of each component, an η-Indicator evaluating real-time component efficiencies as a function of temperature and operating point, and a Δη module computing the combined efficiency gain of each potential coupling pair prior to actuation. Coupling is executed only when the combined efficiency delta is positive, replacing empirical prioritization with a quantitative, efficiency-driven decision mechanism. The strategy is evaluated against an uncoupled baseline (REF-0) and a temperature-threshold-based predecessor strategy (REF-1) across a representative commuter cycle at ambient temperatures of −10 °C, 0 °C, and +30 °C using a co-simulation environment comprising a 1D ring-circuit fluid model in AVL Cruise M and a backward-facing 0D drivetrain model in MATLAB/Simulink. The results demonstrate measurable improvements in battery preconditioning and system efficiency at cold and moderate ambient temperatures. The heat-quantity-based strategy achieves comparable or superior thermal outcomes to the threshold-based approach while activating ring-circuit coupling more selectively. At warm ambient conditions, the strategy correctly withholds intervention based on a negative efficiency delta evaluation, confirming robust scenario-adaptive behavior. The findings highlight the potential of efficiency-driven coupling logic as a generalized and physically grounded basis for thermal operating strategy development in electrified powertrains.
Stenger, Erik, Fiore, Luis, Weimer, Niko, Beidl, Christian
Cost and Emission Aware Strategic Optimization: A Fleet-Level Tool to Support Scenario-Oriented Design2026-24-00349/21/2026
The transition toward low-emission transport systems requires not only technologically optimized Battery Electric Vehicles (BEVs) but also integrated methodologies capable of supporting industrial stakeholders throughout the deployment phase. In particular, for logistics operators, fleet sizing and charging infrastructure planning are tightly coupled with vehicle configuration and mission scheduling. Therefore, decision-support tools are required to minimize total operational costs and environmental impact while ensuring service continuity. Building upon a previously developed two-level BEV design framework, this work introduces a higher-level optimization tool aimed at extending powertrain design outcomes toward fleet-level decision-making, providing an integrated methodology capable of determining not only the optimal vehicle configuration but also the optimal number of vehicles and charging stations required to satisfy operational scheduling constraints. The proposed tool performs fleet charging management optimization under customizable objective functions. Two BEV configurations, equipped respectively with 7 and 10 battery packs, are selected as candidate solutions from the upstream two-level design framework. Starting from these configurations, the tool simultaneously optimizes fleet size, charging infrastructure dimensioning, and charging scheduling strategy. In the first case study, the objective is the minimization of fleet operational costs, primarily associated with charging energy, while introducing a tunable penalty factor on mission time-shifting for schedule flexibility. In the second case study, a CO2-based term is incorporated into the objective function through an equivalent emission cost. By varying its weighting factor, the analysis quantifies how environmental prioritization influences the optimal fleet and infrastructure configuration. Across all the examined scenarios, the optimal fleet size consistently converges to 3 vehicles with a single 50 kW DC charging station. The key difference between cost-driven and environmentally-oriented optimization lies in the battery configuration: in the cost-driven scenario, the 10-packs configuration achieves the lowest Total Cost of Ownership (1134 EUR/week), as its larger energy buffer reduces weekly grid energy demand and thus charging costs. Conversely, under CO₂-prioritized optimization, the optimal configuration shifts to the 7-packs, yielding a lower TCO of 1008 EUR/week and a 15% reduction in CO₂ emissions (127 vs 149 kgCO2/week). The proposed fleet-level optimization framework represents a scalable extension of the vehicle design methodology, enabling logistics companies to support electrification strategies through data-driven, application-specific, and sustainability-oriented decision-making.
Bartolucci, Lorenzo, Cennamo, Edoardo, Cordiner, Stefano, Donnini, Marco, Grattarola, Federico, Lombardi, Simone, Mulone, Vincenzo, Tribioli, Laura
Business Approach to Cope with Automotive Market Uncertainty2026-24-00249/21/2026
The global automotive industry is facing an unprecedented convergence of uncertainties driven by geopolitical tensions, evolving trade policies, emissions related regulations, and increasingly volatile consumer demand. Shifting emissions legislation, including the EU’s tightened CO2 targets and long-term plans to phase out internal combustion engines, is imposing strategic and financial pressures on automakers and suppliers as they navigate divergent regional regulatory trajectories. Demand side volatility further complicates the landscape. Consumer preferences are fluctuating due to economic pressures, infrastructure constraints, and uneven EV adoption patterns. While some markets show stagnation in battery electric vehicle uptake, hybrids are rising as consumers seek cost efficient alternatives amid uncertain energy and regulatory environments. Within this unstable context, the transition toward Software Defined Vehicles (SDVs) is emerging as a critical strategic response. SDVs, characterized by centralized computing, updatable software architectures, and over the air feature deployment, offer automakers greater adaptability in addressing regulatory shifts and market dynamics. By decoupling hardware from software cycles, SDVs enable faster innovation, reduced development risk, and new digital revenue models, while virtualization and AI driven analytics enhance development efficiency and lifecycle value.
Cavanna, Filippo, Potenza, Luca
CONTACTS, ELECTRICAL CONNECTOR, SOCKET, CRIMP REMOVABLE (FOR MIL-DTL-24308 CONNECTORS)AS39029/63F (Current)9/20/2026
AE-8C1 Connectors Committee
CRIMPING TOOL AND ACCESSORIES, REMOTE CRIMP HEAD, HYDRAULIC, WIRE SIZE 8 TO 0000 FOR INSULATED AND UN-INSULATED CRIMP BARRELSAS5259/1C (Current)9/20/2026
AE-8C2 Terminating Devices and Tooling Committee
A Study on TSC (Technical Safety Concept) Design and Verification in EMB (Brake by Wire) Systems2026-01-08019/14/2026
The Electro-Mechanical Brake (EMB) system is a dry-type Brake-by-Wire technology that eliminates hydraulic components and directly controls friction braking using electrical actuators at each wheel. The EMB architecture consists of a Main Center Control Unit, a redundant Backup Center Control Unit, and four Wheel Control Units communicating via CAN FD. Due to its direct involvement in vehicle braking, compliance with ISO 26262 functional safety requirements is critical. As system complexity increases, potential risks such as hardware failures and communication faults must be systematically addressed. The proposed TSC was developed according to ISO 26262, covering the concept phase (Part 3), system-level development (Part 4), and software implementation (Part 6). Safety goals and Functional Safety Requirements derived from HARA are used to guide system architecture design and TSC development. Key design principles include modularity, redundancy, fault detection, and fail-safe operation. Verification is conducted at both system and vehicle levels using ECU-in-the-Loop Simulation (EILS), Hardware-in-the-Loop Simulation (HILS), and real-vehicle tests. Fault scenarios, including Main Center Control Unit failures and CAN communication losses, are injected using a custom LabVIEW-based fault injection tool. The study evaluates Fault Tolerant Time Interval (FTTI) settings, error handling mechanisms, and control handover strategies under fault conditions. The results show that redundancy and localized communication enable stable operation and smooth control transfer within the FTTI window without noticeable impact on braking performance or driver awareness. This study demonstrates the robustness of the proposed EMB architecture. Future work will focus on prognostics and maintenance strategies to support safe deployment in autonomous and electric vehicles. [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Kim, Dokun
Ultrasonic Frequency-Domain Reverse-Time Migration Imaging Incorporating Element Directivity Correction2026-99-14199/11/2026
The finite width of ultrasonic array elements results in a non-uniform angular radiation pattern of elastic waves in solids, deviating from the ideal point-source assumption commonly adopted in reverse-time migration (RTM). This angular radiation non-uniformity produces a crack tip-dominated imaging amplitude with weak crack flank representation, manifesting as a pronounced depth-dependent amplitude imbalance along vertically oriented defects. As a result, cracks may be misinterpreted as point reflectors, which compromises the reliability of characterization in ultrasonic nondestructive testing (NDT). This study proposes an ultrasonic frequency-domain reverse-time migration (FDRTM) imaging method incorporating element directivity correction. A longitudinal-wave directivity model in solids is formulated in the frequency domain and normalized at each frequency to ensure consistent scaling during multi-frequency stacking. During backward wavefield reconstruction using full matrix capture (FMC) data, the angular-dependent energy distribution associated with the receiving direction is explicitly corrected, rebalancing the angular energy distribution in the reconstructed wavefield. Defect imaging is then performed using a frequency-domain cross-correlation imaging condition, followed by stacking over frequency and normalization. Validation experiments were conducted on an artificially manufactured vertical crack in a 7075 aluminum alloy specimen. The results indicate that, relative to conventional RTM, the proposed method reduces crack tip dominance and enhances the relative visibility and continuity of crack flanks. Compared with conventional RTM, the peak imaging amplitude increases by 22.44%, and the amplitude at a depth of 6.8 mm is enhanced by 24.39%. In addition, the proposed method outperforms the total focusing method (TFM) in crack profile continuity and the relative visibility of crack flanks. The results confirm that incorporating element directivity correction into frequency-domain RTM mitigates depth-dependent amplitude imbalance and restores crack flank visibility, thereby improving the reliability of crack defect characterization in ultrasonic NDT.
Chen, Si, Zhang, Yifeng, Ma, Tengfei, Xu, Zheng, Jiang, Jiansheng, Gao, Jiaqi
Affine Formation Control of Multi-Agent Systems with Switching Topologies2026-99-11289/11/2026
Tackling the heavy computation of affine formation control under switching topologies—rooted in frequent stress matrix recalculation—this paper presents a distributed control framework fusing consistency estimation with dynamic error constraints for efficient coordination. In a leader-follower architecture, affine transformation parameters are estimated by followers using local information—global stress matrix solutions are thus avoided. A time-varying constraint function and Lyapunov stability analysis are devised to ensure tracking errors converge to specified accuracy within a predetermined time. Both theoretical analysis and simulation results show that this method greatly simplifies computation. It also supports flexible formation transformations such as translation and scaling, making it a stable and reliable solution for dynamic scenes.
Liu, Guicai, Li, Jianzhen, Zhou, Junyi, Tang, Jiye
Linkages and Propagation Mechanisms of Risk Sources during Electric Vehicles Transportation2026-99-15289/11/2026
This study addresses safety issues in three representative logistics scenarios for electric vehicles (EVs) as cargo-car carriers, roll-on/roll-off (Ro-Ro) vessels, and containers. To address the heterogeneity across these modes, we develop an integrated “process–spatiotemporal load–risk factor” framework that embeds operational steps and confinement conditions into the indicator system, overcoming the limitations of single-scenario or single-factor studies in explaining chain-type propagation. Building on process mapping and spatiotemporal load characteristics, we develop a risk indicator system spanning “person-equipment-transported object-operation & environment-system management.” Expert judgments are then analyzed using an integrated DEMATEL-ISM approach to quantify inter-factor linkages and transmission pathways. The results indicate that regulatory oversight and carrier-side emergency equipment constitute the deep root causes of thermal runaway. The most hazardous transmission route is “regulatory oversight, procedural compliance and skill-experience match”, while “battery type, road/sea conditions and hoisting impacts” forms the shortest path. These findings reveal weaknesses in management and equipment that are amplified by operational execution and limited personnel capability, ultimately precipitating severe transportation incidents.
Yuan, Libo, Jiang, Huifu, Qin, Xiao
Design and Analysis on a Traction-type Power-assisted Follow-up Vehicle for Emergency Rescue2026-99-15479/11/2026
To address problems in China’s emergency rescue scenarios—such as limited functionality, insufficient mobility, poor adaptability to complex terrain, the labor-intensive nature of manual carrying, and the lack of flexibility of fully automatic carts—a traction-type emergency rescue power-assisted follow-up vehicle was designed and developed. With the core design goals of “lightweight, high mobility, and human-machine collaboration”, this power-assisted follow-up vehicle has multiple advantages. At the structural level, it supports rapid folding and unfolding, enabling convenient operation and adaptation to transportation needs in various emergency rescue scenarios. In terms of material selection, it balances strength and lightweight properties, and its key components possess anti-cutting and flame-retardant capabilities, allowing adaptation to the harsh environment of emergency rescue. The power system adopts modular replaceable batteries and is equipped with a high-performance control unit, motor, and shock-absorbing suspension design. This enables normal operation in a variety of complex terrains. The control system is centered on human-machine collaboration. It features simple operation and automatic adjustment of operating status, effectively reducing the operational burden and physical exertion of rescuers. Meanwhile, it supports the master-slave expansion function, allowing flexible switching from a two-wheel structure to a four-wheel structure to meet diverse rescue needs such as material transportation and casualty transfer. This power-assisted follow-up vehicle can effectively solve the material transportation problem in the “last few kilometers” of emergency rescue.
Xu, Jiang, Hou, Yumeng, Yang, Han
Fault Detection and Isolation Method for BDS/GPS Hybrid Constellation Oriented to Airworthiness Retrofit2026-99-14159/11/2026
This work deals with the topic of integrating a multi-GNSS solution within existing avionics, specifically concentrating on airworthiness approval issues, thereby addressing risks associated with susceptibility in standalone GPS solutions. An older aircraft, still relying on existing GPS solutions, remains susceptible to jamming, spoofing, or single-point failures, which, in turn, pose risks associated with integrity requirements necessary for ADS-B or TAWS operation. An approach for a fault detection and isolation (FDI) scheme applicable to a BDS/GPS hybrid satellite system configuration suitable for airworthiness projects would thus be relevant. A transparent proxy architecture is proposed, which consists of a form-fit GPS/BDS dual-mode antenna replacement and an RF power splitter. This design makes it possible to provide BeiDou Navigation Satellite System (BDS) signals with neither changes in the interfaces nor structural changes being required to existing flight management systems. It includes a signal processing module that combines adaptive quality weighting on carrier-to-noise ratios, satellite elevation angles, and code-minus-carrier differences, as well as a carrier phase smoothing process via the Hatch filter. A multiple-channel approach in a parallel position system is designed, with different channels for GPS-only, BDS-only, as well as hybrid solutions, with weighted least squares estimation incorporating the Huber robust reweighting rule, along with Receiver Autonomous Integrity Monitoring (RAIM) with fault detection and exemption in every channel. A cross-constellation integrity monitoring algorithm is presented for the purpose of identifying constellation-level spoofing attacks that evade conventional single-system RAIM integrity. Simulation results, carried out for four different interference levels, show that the hybrid channel provides a 34% improvement in horizontal positioning accuracy compared with the GPS-only mode of operation. The cross-check method is able to effectively detect GPS spoofing attacks with position divergence exceeding 50m within a detection time of 25 seconds, along with a navigation availability of 99.9% under nominal operating conditions.
Ou, Chongjie, Zhang, Kezhi, Zhu, Haijie
Scheduling Table Architecture of Remote Data Conversion Unit2026-99-14129/11/2026
This paper addresses the determinacy issue of multi-task execution in the Remote Data Conversion Unit of an integrated modular avionics (IMA) system in a non - operating system environment. A three - level hierarchical static scheduling table architecture for the Remote Data Conversion Unit is proposed. In this architecture, the maximum execution cycle of functional parameters is used as the device scheduling table cycle, the minimum execution cycle is used as the scheduling block cycle, and the worst - case execution time is used as the functional execution time. Through hierarchical design, the orderly connection of functions, scheduling blocks, and devices is achieved. A periodic interrupt mechanism is adopted between scheduling blocks to ensure time alignment at the scheduling block cycle level. Inside the scheduling block, a polling mechanism is used to perform static sorting according to the worst - case execution time of functions, and a wait function is introduced to achieve time alignment and fault isolation. For fault - tolerant faults, a delayed response strategy is adopted to avoid violating atomicity. For non - fault - tolerant faults, rapid detection and restart processing are achieved relying on periodic interrupts. A Simulink model is used to conduct a comparative simulation of the Remote Data Conversion Unit using a competition mechanism and the scheduling table mechanism. The results show that under normal and fault conditions, this architecture significantly reduces data transmission jitter, improves system determinacy and fault - tolerance ability, meets the requirements of the DO - 297 standard for functional independence and safety, and provides an effective solution for improving the determinacy of the civil aviation Remote Data Conversion Unit.
Hao, Yongqi, Wu, Meng, Miao, Zhiqi, Xu, Guanglei
Analysis of Latency-Influencing Factors in Vehicle-Road-Cloud Integrated Systems Based on Fault Tree Analysis and Analytic Hierarchy Process2026-99-15439/11/2026
Vehicle–road–cloud integrated systems have great potential in terms of improving traffic efficiency and achieving intelligent automatic driving through the integration of on–board terminals, roadside facilities, and cloud computing. However, their operational capabilities are heavily reliant on ultra-low-latency collaborative communication. This paper constructs a latency fault tree model to comprehensively analyze multi-source triggering paths of computation delay and reveals the formation mechanism of the delay path from “germination–induction–evolution”. On this basis, the Analytic Hierarchy Process is used to construct a three-level evaluation framework, and the influencing factors are quantitatively evaluated using NS-3 simulation data of the 004-V2X Communication Performance Testing Dataset. The result shows that the weight value of the network communication layer is the largest, 0.498, which shows that the bottleneck of performance in network communication is the wireless link quality. The cloud processing layer is second 0.327, which is dominated by the computational complexity and resource allocation policy. The impact of the onboard terminal layer is the smallest, 0.175. The FTA–AHP framework supported by empirical data can find the key factors affecting delay, which can help engineering optimization. It is noted that the AHP consistency check (CR) just checks the inner transitivity of expert judgment (i.e., the matrix consistency), while it cannot assure the objectivity and the bias elimination. We reduce the subjectivity by combining multiple experts, anchoring judgment with the simulation data, and performing a sensitivity check on the perturbation of the weights.
Xu, Yunchuan, Wang, Xiaomeng, Wang, Yan
CRIMPING TOOL AND ACCESSORIES, HAND OPERATED, DIE TYPE, WIRE SIZES 8 TO 0000 UN-INSULATED AND INSULATED CRIMP BARRELSAS5259/3C (Current)9/9/2026
AE-8C2 Terminating Devices and Tooling Committee
Recommended Practice of a Common Set of Tests for Sodium-Ion Battery Cells for the Propulsion of Battery Electric Road VehiclesJ3335_202609 (Current)9/9/2026
This document provides a recommended test guideline for secondary sodium-ion cells used for propulsion of electric vehicles including battery electric vehicles (BEV), hybrid electric vehicles (HEV), and other similar propulsion applications (e.g., forklift trucks). The objective of this document is to define common test procedures covering electrical performance, mechanical safety performance, thermal safety performance, and electrical safety performance. The results of these procedures can be used for comparative purposes. Requirements for pass/fail criteria are not defined in this document but are to be defined by the users of the document.
Battery Standards Testing Committee
Dynamic Characteristics Analysis of Needle Roller Bearings in Planetary Gear Trains with Consideration of Inner Bore Spalling Defects of Planet Gears2026-99-12799/4/2026
Driven by the growing demand for higher efficiency and load-bearing capacity in fields such as new energy vehicles and heavy-duty engineering machinery, planetary gear sets are increasingly operating at elevated rotational speeds, coupled with a corresponding expansion of their revolution radii. This dual trend directly induces a substantial surge in centrifugal acceleration acting on the internal needle roller bearings. Under the cyclic stress inherent to transmission operations, such enhanced acceleration not only accelerates the initiation of spalling faults on the inner bores of planet gears but also exacerbates the propagation and deterioration of these faults throughout the service life. To elucidate the influence mechanism of inner bore spalling on the dynamic response of planetary gear bearings, this study develops a specialized dynamic model. This model explicitly incorporates the compound kinematic effects of simultaneous rotation and revolution, thereby ensuring a high-fidelity reconstruction of actual operating scenarios. The research systematically investigates how different spalling types and dimensional parameters affect the system’s dynamic behavior. Numerical results demonstrate a positive correlation between the severity of the spalling defect and the dynamic response intensity. Specifically, the expansion of defect dimensions under harsh operating regimes markedly exacerbates both the contact impulses at the needle-roller interface and the overall vibration acceleration amplitudes. Notably, the amplitude increment of the needle rollers is far more pronounced than that of other components. These findings enrich the theoretical understanding of fault-induced dynamic responses in planetary gear systems and provide a solid theoretical and model-based foundation for optimizing the fault diagnosis, condition monitoring, and maintenance strategies of the associated needle roller bearings.
Zou, Desheng, Lai, Junbin, Guo, Wei, Dong, Peng, Xu, Xiangyang, Sun, Qiang
Numerical Investigation of Spiral Tubes and Turbulators for Enhanced Metal Hydride Reactors2026-99-12589/4/2026
Solid-state hydrogen storage is severely limited by poor thermal performance of storage reactors, which leads to non-uniform temperature fields and slow reaction kinetics. A numerical model for metal hydride hydrogen storage technology was implemented by means of COMSOL Multiphysics 6.3, based on hydrogen sorption behavior for LaNi5-based material. After experimental validation, a spiral-wound tube with embedded turbulators was introduced into the reactor. The influence of turbulator cross-sectional ratio and shape on hydrogen-absorption performance was then investigated. When the turbu-lator occupied 1/40 of the cross-section, the temperature distribution became more uniform and the reaction rate increased markedly; the time to achieve 80% conversion was reduced by approximately 9.29%. The study demonstrates that tailoring the turbulator geometry (circular vs. square) and exploiting its synergy with the spiral tube accelerates reaction kinetics and balances the temperature field. Under 0.8 MPa and 313 K, a hydrogen uptake of 1.4 wt% was achieved. The simple structure can be mass-produced by CNC (Computer Numerical Control) tube-bending, making it attractive as a portable hydrogen source for mobile devices such as unmanned aerial vehicles.
Lin, Jiangnan, Jin, Tingxiang
A Simultaneous Impulse and Oscillatory Component Decomposition Method for Fault Diagnosis of Rolling Bearings2026-99-12049/4/2026
Due to the interference of oscillatory components and noise, the periodic impulses associated with localized bearing faults become difficult to extract, leading to unreliable diagnostic performance. To solve this problem, the study proposes a simultaneous impulse and oscillatory component decomposition method (SIOCD). The method designs and solves a novel optimization model to decompose oscillatory components and fault impulse components from noisy vibration signals. To achieve component separation in the optimization model, distinct penalty functions are introduced for oscillatory and impulse components. For oscillatory components, a regularization term is applied to achieve their extraction by minimizing the component bandwidth in the frequency domain. For impulse components, a penalty function is designed to achieve their decomposition by enhancing both sparsity within groups (SWG) and sparsity across groups (SAG) in the time domain. Then, an iterative solver is derived using an alternating minimization framework and the majorization-minimization (MM) algorithm. Finally, the proposed method’s effectiveness is demonstrated through comprehensive simulation and experimental analyses, and the results demonstrate that it achieves superior performance over existing approaches in fault feature extraction and enhancement.
Sun, Haoran, Zhang, Jinduo, Han, Tianyu, Shi, Xi
Degradation-Based Reliability and RUL Prediction for Railway Wire Harness Connectors Under Multi-Temperature Conditions: An Adaptive Wiener-DGM Hybrid Model2026-99-12719/4/2026
Railway wire harness connectors are critical elements in modern rail transport systems, ensuring reliable signal transmission, power distribution, and communications across the subsystems that govern traction, braking, and passenger information. The progressive deterioration of these connectors under harsh operating conditions, particularly temperature variations encountered during continuous railway operations, poses significant challenges to system reliability and operational safety. This paper presents a hybrid framework integrating an adaptive Wiener process with a deep generative model (DGM) for reliability assessment and remaining useful life (RUL) prediction of railway wire harness connectors under multi-temperature conditions. The proposed methodology combines Arrhenius-based temperature acceleration with a Wiener degradation model that characterizes temperature-dependent degradation kinetics. Specifically, a variational autoencoder (VAE) is employed as the deep generative network to learn the complex nonlinear degradation patterns that conventional parametric models may fail to capture. Furthermore, a particle filter algorithm is incorporated to enable real-time Bayesian parameter updating and state estimation, thereby allowing the model to be refined in an adaptive manner as new monitoring data become available. The effectiveness of the proposed method is validated through accelerated degradation tests on electrical connectors at four temperature levels (25°C, 55°C, 85°C, and 105°C), demonstrating that the RMSE is reduced by 23.5%, 18.2%, and 32.1% compared with the standard Wiener process, LSTM-based approach, and Gaussian process regression, respectively. The analytically derived reliability function and RUL distribution provide comprehensive uncertainty quantification to support maintenance decision-making in railway systems.
Wu, Jiajun, Chen, Yongping
INSTALLING AND REMOVAL TOOLS, CONNECTOR, ELECTRICAL CONTACT, TYPE III, CLASS 1, COMPOSITION BAS81969/16B (Current)9/4/2026
AE-8C2 Terminating Devices and Tooling Committee
Connectors, Electrical, Circular, Miniature, Composite, High Density, Quick Coupling, Environment Resistant, Removable Crimp Contacts Associated Hardware, General Specification forAS29600D (Current)9/4/2026
This SAE Aerospace Standard (AS) covers miniature, composite, high density, threaded coupling, self-locking, circular, environment-resistant, electrical connectors utilizing removable crimp contacts, and associated hardware, which are capable of continuous operation within a temperature range of -65 to +175 °C (-85 to 347 °F). These connectors are supplied under an AS9100 reliability assurance program. See 6.1 for intended use and applications.
AE-8C1 Connectors Committee
COVER ASSEMBLY, ELECTRICAL, FOR MS27212 TERMINAL BOARD ASSEMBLYAS18029F (Current)8/31/2026
AE-8C2 Terminating Devices and Tooling Committee
INSTALLING AND REMOVAL TOOLS, CONNECTOR ELECTRICAL CONTACT, TYPE I, CLASS 1, COMPOSITION CAS81969/17B (Current)8/31/2026
AE-8C2 Terminating Devices and Tooling Committee
INSTALLING AND REMOVAL TOOLS, CONNECTOR, ELECTRICAL CONTACT, TYPE III, CLASS 2, COMPOSITION AAS81969/12B (Current)8/31/2026
AE-8C2 Terminating Devices and Tooling Committee
Improvement of Cyclic Stability of P2-Na 0.67 Co 0.67 Mn 0.33 O 2 Cathode Material by Al 2 O 3 Coating2026-99-04228/28/2026
P2-type layered oxides are good cathode materials in high-performance sodium-ion batteries since they have desirable two-dimensional ion migration pathways. However, their instability at interfaces and their attenuation as cycles persist also remain a significant challenge. To increase their electrochemical stability, surface coating is also a good plan, but the balance between the coating and ionic conductivity is one of the key challenges. This study constructed an immensely thin layer of alumina (Al2O3) coating, and the influence of the amount of the coating (0.3-1.2 wt percent) on the working of the material was methodically examined. Electrochemical analysis showed that the lowest levels of Al2O3 (0.3 wt) provide the greatest improvement in performance. The optimized sample showed a retention capacity of 96.35 after 100 cycles of operation at 1C, significantly higher compared with samples that had increased coating contents. An analysis of cyclic voltammetry and impedance spectroscopy was subsequently done to corroborate the presence of a 0.3 wt% coating, which infected the electrode-electrolyte interface by inhibiting side reactions but minimally obstructing sodium-ion transport and thus promoting reaction reversibility and improved interfacial kinetics. These results highlight the importance of a less-is-more rule when it comes to surface coating and provide a novel understanding of how long-life sodium-ion battery cathodes can be designed by carefully engineered interfaces.
Hu, Chao, Peng, Rui, Zhou, Yu, Zhou, Dengmei, Tian, Liangliang
Design, Simulation, and Experimental Evaluation of an R290-Based Dual Secondary Loop Thermal Management System for Electric Vehicles14-15-03-00188/28/2026
The transition toward low global warming potential (GWP) refrigerants, driven by increasingly stringent environmental regulations and carbon reduction targets, has imposed new requirements on thermal management systems (TMSs) for electric vehicles (EVs). These systems must ensure efficient operation across a wide range of ambient conditions while maintaining high energy efficiency and environmental compatibility. Among potential alternatives, R290 (propane) has emerged as a promising natural refrigerant due to its favorable thermophysical properties and low environmental impact. In this study, an R290-based dual secondary loop TMS is proposed and evaluated for wide-temperature-range EV applications. A one-dimensional system model was developed using Dymola and validated through experimental testing on a dedicated performance test bench. TMS performance was investigated under multiple steady-state operating conditions, including high-load cooling, battery fast charging, and low-temperature heating, and benchmarked against a conventional R1234yf-based direct TMS. The results demonstrate that the R290-based dual secondary loop system achieves improved performance compared to a conventional R1234yf direct system, with a coefficient of performance (COP) increase of 4.29% under high-load cooling conditions at 43°C and up to 27.27% under high-load heating conditions at −10°C. Furthermore, under extreme low-temperature conditions (−18°C), the system delivers a heating capacity of 7 kW with a COP of 1.8, demonstrating strong low-temperature adaptability without the need for auxiliary heating. The results confirm that the proposed R290-based dual secondary loop system provides significant advantages in energy efficiency and wide-temperature adaptability, offering a promising solution for next-generation EVTMSs.
Zhang, Yunpeng, Mohammed, Mustafa Mudassir, Gu, Yiliang, Zhou, Guoliang
Study of Port Fuel Injection Engine Cold Start Unburned Hydrocarbons Reduction Using Computational Fluid Dynamics with a Reduced Iso-Octane Mechanism Considering Various Isomers and Thermal Decompositions03-19-04-00218/27/2026
A modeling study was performed to find solutions to reduce the unburned hydrocarbons during cold start of a PFI (port fuel injection) SI (spark ignition) engine. Through modeling, the root cause for the high unburned hydrocarbons of the baseline engine during cold start was found. The slow combustion, which is due to the high amount of exhaust gas flowing back into the intake port and then becoming trapped inside the cylinder, is the root cause. A new valve lift, which can reduce the internal residual by 26%, was designed. Along with a fuel amount decrease of 35%, the UHC (unburned hydrocarbons) before the three-way catalyst can be reduced by 40%. The exhaust temperature using the new valve lift design increases by 400°C, which improves the performance of the three-way catalyst for further reducing UHC. In addition to the adoption of the new valve lift, an active SAI (secondary air injection) strategy was also investigated. Modeling results show that SAI can promote secondary combustion in the exhaust pipes to increase exhaust temperature and thus is beneficial for further oxidizing unburned hydrocarbons. The amount of active SAI mass flow rate should be controlled to less than 25% of the intake air flow rate to avoid the cooling effect dominating over the oxidation process. The duration of SAI should be from EVO (exhaust valve opening) to IVO (intake valve opening). For combustion modeling, a newly reduced iso-octane chemical kinetic mechanism was developed using carbon flux analysis to extract major reaction pathways for a wide range of practical engine temperature conditions. In the new reduced mechanism, a skeletal sub-mechanism for species starting from iso-octane to C4 is coupled with a recently updated H2/O2/CO/C1–C4 detailed sub-mechanism. Including a reduced NOx (oxides of nitrogen) sub-mechanism, the final mechanism has 681 species and 3332 reactions. Before the new reduced iso-octane mechanism was used, it had been validated with available experimental data of ignition delay times, laminar flame speeds, and important species profiles in the literature. Both the investigation of PFI engine unburned hydrocarbons reduction under cold start operating conditions and the development of a reduced chemical mechanism are the objectives of this work.
Guo, Dongshao, Zhang, Licheng, Yang, Shiyou, Bourg, Cyrus, Sun, Yong, Abidin, Zainal, Lin, Shujun
Development of Remote Cab Controller for Construction Machinery14-15-03-00178/27/2026
This article focuses on the research and development of a remote cab controller for pure electric loaders, aiming to address the threats posed by traditional loaders operating in harsh and hazardous environments to drivers’ health and safety. First, the functional requirements of the controller were analyzed, based on which the hardware design with a multicore microprocessor as the core was completed, featuring functions such as signal acquisition, controller area network (CAN) communication, and H-bridge driving. On this basis, a control algorithm framework for remote driving was developed, including modules for signal input, analysis and processing, and signal output. Detailed control strategies were formulated for key components: For the pedal sensor, algorithms for opening degree calculation, automatic zero-position calibration, and dual-signal redundant fault diagnosis were proposed; for the steering module, precise angle calculation and force feedback feel simulation were achieved; and for the electric control handle, a hysteresis control algorithm was developed to suppress shocks caused by overly fast operations. In addition, a hierarchical fault diagnosis mechanism was established to ensure system safety. To verify the controller performance, a complete remote driving system was built. Field test results show that the system exhibits good signal following and control responsiveness in terms of traveling and working functions. Efficiency tests indicate that the remote driving efficiency can reach 80% of that of in-person operation under short-term test conditions, demonstrating the technical feasibility and control effectiveness of the developed controller. While the prototype exhibits promising performance for pilot deployment, long-term reliability metrics such as mean time between failures (MTBF) remain to be validated through extended field operation.
Lu, Yueqi, Ji, Shaobo, Yu, Qiuye, Li, Meng, Xu, Haozhi, An, Meng
Test Guidelines for Assessment of Electrical Insulation Material Aging in a High Voltage SystemARP7375 (Current)8/24/2026
To provide test guidelines, recommendations, and referenced standards for insulation materials in a high energy system especially at high voltages (AC, DC, and PWM) and at operational altitudes, for the purpose of defining/measuring the effects of insulation aging. This document is a part of a family of documents related to the impact of ageing on insulating materials devoted to aviation applications. Aging mechanisms, and the markers to monitor them, have been defined in AIR7374. For sake of brevity, the main conclusions are used here. ARP7375 focuses on the ways to measure these markers on representative samples (either coupons or electrical insulation systems) for aerospace applications.
AE-11 Aging Models for Electrical Insulation in Hi-Enrgy Sys
CRIMPING TOOL AND ACCESSORIES, 18 VDC BATTERY ELECTRIC, PORTABLE HYDRAULIC, WIRE SIZE 8 TO 00 UN-INSULATED, AND SIZE 8 THRU 2 INSULATED CRIMP BARRELSAS5259/8A (Current)8/24/2026
AE-8C2 Terminating Devices and Tooling Committee
WIRE, ELECTRICAL, FLUOROPOLYMER-INSULATED CROSSLINKED MODIFIED ETFE, LOW FLUORIDE, NORMAL WEIGHT, 80 MICROINCH SILVER-COATED COPPER 200 °C, 600 VOLT, ROHSAS22759/50C (Current)8/18/2026
AE-8D Wire and Cable Committee
WIRE, ELECTRICAL, FLUOROPOLYMER-INSULATED, CROSSLINKED MODIFIED ETFE, LOW FLUORIDE, LIGHTWEIGHT, 80 MICROINCH SILVER-COATED HIGH-STRENGTH COPPER ALLOY, 200 °C, 600 VOLT, ROHSAS22759/47C (Current)8/18/2026
AE-8D Wire and Cable Committee
Unshielded High Voltage Primary CableJ1654_202608 (Current)8/18/2026
This SAE Standard covers unshielded cable, 22 gauge and larger, intended for use at a nominal system voltage up to 600 V or 1000 V (ACrms or DC). It is intended for use in surface vehicle electrical systems.
Cable Standards Committee
WIRE, ELECTRICAL, FLUOROPOLYMER-INSULATED, CROSSLINKED MODIFIED ETFE, LOW FLUORIDE, NORMAL WEIGHT, 80 MICROINCH SILVER-COATED HIGH-STRENGTH COPPER ALLOY, 200 °C, 600 VOLT, ROHSAS22759/49C (Current)8/17/2026
AE-8D Wire and Cable Committee
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