Browse Topic: Needs assessment

Items (111)
Under China’s intelligent manufacturing strategy, manufacturing enterprises are expected to achieve digital and networked operations by 2025, with full digital transformation by 2030. Intelligent factories, the core of this transformation, rely on interconnected, integrated, and data-fused systems. This paper focuses on the micro-assembly intelligent workshop at the Nanjing Research Institute of Electronics Technology, which produces micro-circuit modules for large-scale complex electronic systems. The workshop combines discrete and process manufacturing modes, presenting unique challenges for digital management. A digital management platform based on a five-layer architecture (device, network, data, application, and decision layers) is proposed to address multi-dimensional business needs, including production scheduling, logistics, execution, and decision optimization. A hierarchical workflow structure of the workshop, consisting of a main workflow and several sub-processes, is in-depth studied and designed. The platform is constructed based on requirements analysis and workflow design of the workshop and integrates systems such as MES, APS, WMS, and SCADA, supported by AI-driven big data analytics. This study offers a practical framework for advancing digital transformation in the electronics industry.
Zhang, JianWang, JiafengGuo, Yongzhao
The increasing complexity of modern software-intensive systems, particularly in the automotive domain, demands new approaches to bridge the gap between high-level engineering specifications and executable, safety-compliant code. This need is amplified by the rapid transition toward software-defined vehicles, where highly dynamic, updateable software functions significantly enlarge the scope and frequency of engineering activities and require scalable, transparent, and adaptive development processes. While recent advances in Large Language Models have demonstrated strong capabilities in automating tasks such as requirements analysis, code generation, and documentation, their deployment in safety-critical engineering workflows remains challenging due to the need for transparency, traceability, and controlled decision-making. This paper presents a modular multi-agent Large Language Model (LLM) pipeline that automates key steps of the systems engineering lifecycle - from requirement structuring and compliance checking to code and test generation - using specialized LLM agents orchestrated within a unified architecture. A central contribution of this work is the integration of a Human-in-the-Loop subsystem, which introduces configurable review checkpoints at critical stages such as requirements analysis, compliance assessment, code generation, and test creation. The human-in-the-loop module enables engineers to approve, reject, or modify intermediate results, ensuring human oversight, enhancing trustworthiness, and enabling adherence to functional safety standards. The system supports heterogeneous input formats and provides end-to-end traceability through structured outputs and detailed monitoring of performance metrics including model usage, token consumption, and automation efficiency. Initial evaluations indicate that the combination of multi-agent specialization and human-in-the-loop-guided oversight can significantly reduce engineering effort while maintaining the transparency and reliability required for regulated domains. By embedding controllable human supervision into the LLM-driven pipeline, this work offers a practical and scalable architecture for integrating Artificial Intelligence (AI) automation into safety-critical systems engineering processes, with particular relevance to automotive software development.
Padubrin, MarcelKulzer, André CasalGuerocak, Erol
Civil vehicles, commonly seen as complex products, involve many high-tech aspects, several fields working together, many investments spent on projects, and challenging management. Through the entire life-cycle of aircraft development, the application of requirement-driven systems engineering methodologies helps to manage the aircraft development process while addressing the needs of the market and of stakeholders. The operational needs of an aircraft are design inputs for aircraft development, and the precision, authenticity, and comprehensiveness of these needs influence the efficiency of the development processes and the quality of the products. When the design and research-and-development activities are based on accurate and complete needs, the development interval for such projects can be shortened significantly, and the costs of R&D lowered. Especially because it is one of the fundamental phases of establishing whether aircraft meet the design requirements, design verification is becoming one of the most critical stages of civil aircraft development. Consequently, designing a more methodical and effective way of verifying designs becomes a central theme in current aviation technology development. There is a human-centered design verification approach that emphasizes requirement-oriented processes, using systematic requirement analysis and conceptual design procedures in order to maximize the congruency between design results and intended requirements. This study aims to perform a holistic analysis of the aircraft design validation process that is based on research, while offering some innovative techniques and strategies for civil aviation on effective validation practices.
Wang, YiHuang, JunkaiZhang, Xinyu
Operating tractors on inclined & uneven terrains for prolonged operations presents safety and ergonomic challenges. Applications such as shuttle operations, loader use, or long-duration implement usage prove to be highly critical based on field observations across Mahindra tractor platforms and it requires skill & experience for maneuvering at ease across usage. We identified the need to offload these repeatable tasks from the operator to improve control & offer comfort. This paper explains the role of Advanced drive assistance features developed for Mahindra tractors suited for all prime mover types – ICE, Alternate Fuels including electric. These features include Hill Hold, Electronic parking brake, Cruise control & Creep mode. Each feature is designed to offload frequent manual tasks from the operator and ensure smoother, safer operation. Hill hold and electronic parking brake work in tandem to offer unparalleled safety by eliminating the fear of tractor roll back in uneven terrain and surfaces both in launch and normal operational scenarios. Cruise and Creep control in a combination have been designed to reduce operator fatigue and increase productivity.
M, RojerSundaram, PavithraNatarajan, SaravananDevakumar, KiranMuniappan, Balakrishnan
As the core transportation tool of high-speed railroad, the design, and optimization of EMU is the current research hotspot. This paper aiming to improve design efficiency, optimize performance parameters. From the perspective of vehicle level, based on the requirements and operation scenarios of the whole vehicle, according to the RFLP method, combined with the SysML and M-design, we conduct the vehicle requirements analysis, functional decomposition, architecture analysis, whole vehicle index system establishment, and the auxiliary power supply(APU) system is calculated by the parameters, the battery design is optimized by PSO. The results show that integrated modeling makes the interface between systems clearer and improves the model reuse rate; the performance design and parameter optimization quantify the modeling indicators, the system energy consumption is lowered, and the closed-loop verification of requirements is realized, which is of some value to the refined design of other systems.
Guan, LinWang, BaominWang, QingyongZhou, LujieWan, Keyan
This study presents a comprehensive methodology for the design and optimization of hybrid electric powertrains across multiple vehicle segments and electrification levels. A full-factorial simulation framework was developed in MATLAB/Simulink, featuring a modular, physics-based vehicle model combined with a backward simulation approach and an ECMS (Equivalent Consumption Minimization Strategy) -based energy management algorithm. The objective is to evaluate three hybrid powertrain architectures, namely Series Hybrid (SH), Series-Parallel Hybrid with a single gear stage (SHP1), and Series-Parallel Hybrid with a double gear stage (SHP2), across three vehicle classes (Sedan, Mid-SUV, Large-SUV), four different internal combustion engines (ICEs), and three application types (HEV, PHEV, REEV). More than 10,000 unique configurations were simulated and filtered through a two-step performance requirements analysis. The first phase assessed individual vehicle-level performance targets, while the second phase applied combined constraints to identify only those configurations that simultaneously satisfied all criteria. Remaining candidates were then evaluated using a multi-criteria assessment framework, incorporating metrics such as component commonality, fuel and energy consumption, NVH (noise, vibration, and harshness), and cost proxies. From an architectural perspective, SH required the highest P3 e-machine sizing, while SHP2 allowed for the lowest sizing and most efficient overall system design. SHP1 provided a robust intermediate solution with simplified component scaling. Final component definitions for each architecture, vehicle type, and application provide a practical reference for future hybrid powertrain development. The proposed framework enables structured trade-off analysis and supports data-driven decisions for scalable and efficient hybrid electric vehicle platforms.
Amati, NicolaMarello, OmarMancarella, AlessandroCavallaro, DavideIanni, LucaCascone, ClaudioPaulides, Johannes JH
Electric Vertical Takeoff and Landing (eVTOL) vehicles undergoing advanced air mobility (AAM) operations feature increasingly autonomous systems (IAS) with non-traditional role allocations. Ensuring the safety of these operations and their novel human–machine teaming (HMT) paradigms requires an appropriate body of knowledge created through relevant, reproducible research. In this paper, we briefly examine the meaning of teaming; current regulation, standards, and guidance; and the knowledge required to build resilient HMTs before turning our attention to how this knowledge is being created by recent research and what conclusions or recommendations can be made. We identify the need for further research into the holistic performance of HMTs, the effect of novel allocations of roles between humans and machines, the ability of humans to provide resilience to unforeseen dangers when acting as a part of these teams; and the characteristics required for clear, timely, and accurate communication between the humans and machines. This work is done in the context of eVTOL aircraft with an indirect flight control system (IFCS) undergoing urban air mobility operations.
Neogi, NatashaGraydon, MalloryHolbrook, JonMaddalon, JeffreyMcCormick, Frank
Diverse solutions will likely be needed to decarbonize the commercial truck sector in the United States. Battery-powered vehicles play a predominant role but in some cases, fuel cell trucks are more advantageous for the consumer. This study examines several medium- and heavy-duty applications designed for different driving range requirements to identify the design space where battery and fuel cell trucks are attractive. Also considered are the impacts of purchase price, fuel cost, and vehicle usage. We examine the top 10 truck classes as well as bus applications based on vehicle population, fuel usage, and driving distances. We assume a 2030 scenario where both batteries and FC systems become less costly and more efficient, as targeted by the U.S. Department of Energy. Even for smaller-class vehicles, where battery electric vehicles are expected to be the most economical among clean vehicle solutions, the results are not straightforward. Based on vehicle design, usage, and external operating conditions, some scenarios exist in which fuel cell-based powertrains are necessary to meet consumer needs. In heavier vehicles with long-range operational requirements, fuel cell-powered trucks are already seen as the leading contender to diesel. This work also quantifies the impact of new powertrain weight on cargo carrying capacity, and the need for additional downtime for recharging or refueling. These estimates could potentially guide future technological development to ameliorate the detrimental impact of these factors by guiding future cost reduction targets for these technologies to ensure competitiveness.
Vijayagopal, RamBirky, Alicia
Advancements in sensor technologies have led to increased interest in detecting and diagnosing “driver states”—collections of internal driver factors generally associated with negative driving performance, such as alcohol intoxication, cognitive load, stress, and fatigue. This is accomplished using imperfect behavioral and physiological indicators that are associated with those states. An example is the use of elevated heart rate variability, detected by a steering wheel sensor, as an indicator of frustration. Advances in sensor technologies, coupled with improvements in machine learning, have led to an increase in this research. However, a limitation is that it often excludes naturalistic driving environments, which may have conditions that affect detection. For example, reductions in visual scanning are often associated with cognitive load [1]; however, these reductions can also be related to novice driver inexperience [2] and alcohol intoxication [3]. Through our analysis of the research, we discover that the tendency to explore these singular driver states with only a comparison to “normal” driving is common. Additionally, research on interventions for these driver states is relatively scarce (fewer than 10% of cognitive load-related papers we examined assessed or discussed intervention solutions) and narrowly tailored to specific states [e.g., 4, vis-à-vis cognitive load]. States that share common behavioral and physiological markers tend to be explored independently when a more universal and integrated approach may be warranted. In this paper, we identify the need for a driver state and intervention framework that addresses these limitations by exploring state indicators and their overlap, interventions for one or multiple states, and major research gaps. Our framework offers practical approaches for handling one or many driver states, including interventions that may be deployed at different timings during a trip.
Seaman, SeanZhong, PeihanAngell, LindaDomeyer, JoshuaLenneman, John
The growing number of automobiles on the road has raised awareness about environmental sustainability and transportation alternatives, sparking ideas about future transportation. Few short-term alternatives meet consumer needs and enable mass production. Because they do not accurately reflect real-world driving. Current models are unable to estimate vehicle emissions. However, the purpose of this research is to present an application of an adaptive neuro-fuzzy inference system for managing the various factors contributing to vehicle gasoline engine exhaust emissions. It examines how well the three known standardized driving cycles (DSCs). Accurately reflect real-world driving and evaluate the impact of real-world driving on vehicle emissions. Indirect emissions are inversely proportional to the vehicle’s fuel consumption. The methodology used is Eco-score methodology to calculate indirect emissions of light vehicles. Expected emission charge estimates for different using styles. Emission rates range substantially between battery classes. The vehicle’s gasoline efficiency is four times better than a similar automobile, but neither mass nor charge multiplied appreciably. The range of this car is not restrained by the battery length, which increases driver comfort, while automobile meets customer expectations in addition to environmental worries and advantages. Despite the fact that they continue to be affordable, they offer a possibility for mass manufacturing reducing overall environmental effects. In keeping with the consequences, the adaptive neuro-fuzzy inference system works nicely to simulate and regulate vehicle engine exhaust emissions. However, the final objective of a regulatory-oriented studies software that focuses on air pollution from mobile sources is to identify and quantify any outcomes that the emissions may have on human fitness. However, before we invest highbrow and economic sources, we need to first recognize the restrictions of modern information and methodologies that preclude accurate estimates of risk to human health. Destiny research packages should be justified by way of their promise to triumph over these boundaries. The goal of this extent, then, is to identify troubles and pick out a studies schedule with a purpose to be only in advancing our potential to quantify the fitness dangers related to air pollution.
Shiba, Mohamed S.Abouel-Seoud, Shawki A.Aboelsoud, W.Abdallah, Ahmed S.
The planning of mountain campus bus routes needs to take into account user demand, convenience, and other factors. This study adopts a comprehensive research method that combines quantitative and qualitative viewpoints. From the perspective of university students, this article studies the demand of campus public transportation and proposes the layout of campus bus routes in mountainous universities to meet the needs of users. The psychological needs questionnaire was used to investigate college students’ expectation of bus station service function. Taking three mountain universities as examples, the integration and selectivity of campus road networks are evaluated by using space syntax analysis, which provides valuable insights into the quality of bus stop areas. This article discusses the correlation between psychological needs assessment of college students and objective conditions of campus road network. The study concludes with the following findings: (1) The pedestrian environment quality at the university bus station in the mountain falls below the standard, highlighting a considerable disparity between the current conditions and the expectations of students and faculty. (2) Both the teaching and residential areas of the mountainous university exhibit a heightened reliance on public transportation and usage frequency. (3) Enhancements in public transport support infrastructure have the potential to significantly reduce transportation costs. (4) Considering the constraints imposed by unalterable elements of the existing pedestrian network, the positive impact of bus stop facilities and green landscapes can alleviate challenges associated with limited road network options, thus facilitating pedestrian mobility. This research lays the groundwork for further optimization of the campus layout in mountainous colleges and universities.
Duan, RanTang, RuiWang, ZhigangZhao, YixueWang, QidaYang, JiyiSu, Jiafu
Electric Vehicles (EVs) have rapidly grown as a means for clean mobility, as they zero down tail pipe emission of greenhouse gases. Additionally, greenhouse gases such as Hydro-Fluoro-Carbon (HFCs) based refrigerants used in Mobile Air-Conditioning (MAC) are under global scrutiny for their high Global Warming Potential (GWP). To prevent earth environment to pass the climate tipping point that will be irreversible within human capacity, actions such as rapid phase down of high GWP rated HFCs under Kigali Amendment to Montreal Protocol are enacted. India being amongst signatory nations is now working to fast track phase-down use of high GWP refrigerant and transit to low GWP refrigerant options. Nearly half of national HFCs use and emissions are for manufacture and service MAC. Vehicle OEMs supplying to markets in developing countries (e.g. European nation and non-Article 5 Parties) have already phased out HFC-134a (GWP=1400) through alternate refrigerant solutions. The work presented here discusses a novel methodology to use sustainable low GWP refrigerant-based MACs in EVs. The existing MAC system operates through dual DX (Direct expansion) system cooling loop, one for cabin cooling requirement and another to ensure optimum cell temperature of high voltage battery. The refrigerant HFC-134a is not sustainable. To meet global commitments, alternative low GWP options such as R152a (GWP=124) can be considered. The superior thermal properties and low direct cost of R152a, makes it a suitable alternative to HFC-134a. The work also discusses development of intelligently controlled Secondary Loop-Mobile Air Conditioning (SL-MAC) system to address operational constraint with mildly flammable nature of R152a. In the proposed architecture, R152a is use as primary medium to produce refrigeration effect to cool the coolant by deploying chiller unit. The cooled coolant is then circulated in secondary loop comprising of two parallel cooling loops, to extract heat from cabin and HV battery systems. Suitable decision matrices have been consider to design the SLMAC configuration and components involved with it. Cooling performance have been compared basis the transition from DX system with HFC-134a to SLMAC system with R152a refrigerant, together with gap analysis and proposed solutions for bridging performance gaps.
Maurya, AnuragVenu, SantoshKapoor, SangeetKhan, Farhan
Computer modelling, virtual prototyping and simulation is widely used in the automotive industry to optimize the development process. While the use of CAE is widespread, on its own it lacks the ability to provide observable acoustics or tactile vibrations for decision makers to assess, and hence optimize the customer experience. Subjective assessment using Driver-in-Loop simulators to experience data has been shown to improve the quality of vehicles and reduce development time and uncertainty. Efficient development processes require a seamless interface from detailed CAE simulation to subjective evaluations suitable for high level decision makers. In the context of perceived vehicle vibration, the need for a bridge between complex CAE data and realistic subjective evaluation of tactile response is most compelling. A suite of VI-grade noise and vibration simulators have been developed to meet this challenge. In the process of developing these solutions VI-grade has identified the need for a means of accurately interpreting and presenting CAE vibration predictions at hardpoints such as the seat-rail (which can be efficiently and accurately modelled) as equivalent vibration at the driver tactile interfaces. This need has resulted in the development of a seat transmissibility approach to transform the seat-rail vibration to an accurate reproduction of vibration at the seat to driver interface points. This paper will describe an efficient measurement based seat transmissibility approach, and identify additional benefits such as the ability to make virtual seat swaps or experience the vibration that would be perceived by people with different physical characteristics (body mass, height, etc.).
Franks, GrahamTcherniak, DmitriKennings, PaulAllman-Ward, MarkKuhmann, Marvin
This chapter delves into the field of multi-agent collaborative perception (MCP) for autonomous driving: an area that remains unresolved. Current single-agent perception systems suffer from limitations, such as occlusion and sparse sensor observation at a far distance. To address this, three unsettled topics have been identified that demand immediate attention. First, it is crucial to establish normative communication protocols to facilitate seamless information sharing among vehicles. Second, collaboration strategies need to be defined, including identifying the need for specific collaboration projects, determining the collaboration partners, defining the content of collaboration, and establishing the integration mechanism. Finally, collecting sufficient data for MCP model training is vital. This includes capturing diverse modal data and labeling various downstream tasks as accurately as possible.
Chen, GuangChalmers, SethZheng, Ling
Tradespace exploration (TSE) describes the activity occurring early in the design process through which stakeholders explore a broad solution space in search of more-optimal alternatives. In doing so, these stakeholders attempt to maximize the utility inherent in the chosen solution while understanding the tradeoffs and compromises that may be required to find an acceptable solution. In the field of vehicle design, tradespaces are often comprised of vast amounts of alternatives which increases the complexity of the decision-making process. Additionally, the number of stakeholders has grown, as decision-makers seek to include more variety in both perspectives and expertise. As such, decision-making stakeholders can often find themselves working at odds and attempting to maximize vastly different objectives in the process. One way to rectify these contrasting viewpoints can be to intentionally introduce a group framing prior to the start of decision making. In this experiment, teams of students were presented with a TSE problem represented by morphological matrices and utility functions and asked to find the most optimal vehicle configuration from the constituent alternatives. Students worked through three problems in three conditions, simulating a conventional team decision-making approach, an antagonistic approach, and a group-framed collaborative approach.
Sutton, MeredithTurner, CameronHartman, GregoryGorsich, DavidSkowronska, Annette
Radical greenhouse gases emissions reduction necessity is bringing deep evolution in mobility behaviors and is the core reason for a significant diversification of automotive powertrain technologies, making it more and more complex for customers to find the best suited technology. This paper proposes a customer-oriented approach that translates needs into technical requirements that can be used as choice guidelines. First, customers answer a small survey on their driving habits and the class of car they want. Real life driving cycles are then recorded, and Simulink simulations, based on lowest equivalent consumption calculations, allow to identify and size an ideal powertrain that can then become a benchmark for vehicle final selection. As a methodology development step, this paper focused on Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV) and Fuel Cell Electric Vehicle (FCEV), and on two case studies: a customer driving in urban areas with a small city car, and another one who needs the space of a SUV for frequent highway trips, the former advised to choose a BEV with a small battery, the latter a FCEV. Investigation of more complex case studies would then only require enriching the inputs of the method, adding other architectures and other key choice parameters, such as the availability and cost of energy (charging station at work, H2 fueling stations nearby), total cost of ownership, and the availability of alternative mobility solutions for punctual transportation needs, still relying on the basic principles illustrated in this paper.
Couillandeau, MatthieuEl Ganaoui-Mourlan, OuafaeMiliani, El HadjCarlos Da Silva, DanielOussedik, NassilaLombard, TristanMendes Alves, Breno
As model-based systems engineering is proliferating throughout the aerospace industry as a method to manage the development of complex cyber-physical systems, opportunities to leverage formal methods for verification and validation purposes are significant. As a system model described in SysML can contain the level of semantics required to define strict system requirements, it is possible to create a translation tool to generate SRL (SADL (Semantic Application Design Language) Requirements Language) to leverage ASSERT™ (Analysis of Semantic Specifications and Efficient generation of requirements-based Tests) for verification and validation of the system requirements. SADL [13] is a controlled English grammar that translates directly into OWL (Web Ontology Language) [14]. As part of the validation of the SRL requirements, ASSERT™ leverages a theorem prover to look for conflict and completeness errors. For verification, ASSERT™ uses a Satisfiability Modulo Theories (SMT) solver for the generation of test cases and procedures. This paper extends the Braking System Control Unit (BSCU) portion of the Wheel Braking System (WBS) example within Appendix E of ARP4754B [2] described in [1] to demonstrate an example of capturing system requirements in Cameo using SysML, creating test cases and procedures from ASSERT™ exporting from SysML and translating to SRL/SADL, and exporting the Cameo system model data along with the test cases, test procedures, and requirements analysis data from ASSERT™ into the Rapid Assurance Curation Kit (RACK). RACK is a data curation platform which facilitates reporting on Development Assurance and safety assessments guidelines like those used for aircraft certification.
McMillan, CraigLee, LawrenceRussell, DanielPrince, DanielHasanovic, NihadDurling, MichaelSiu, KitVaranasi, Sarat ChandraMeng, BaoluoKleven, Everett
Historically, patch antennas have been used for SmallSat communications. While new antenna technologies are in development, some are not optimized for size, mass, and performance — especially beyond low-Earth orbit (LEO). Engineers at NASA’s Marshall Space Flight Center identified the need for a small form factor antenna to provide high data rate communications for such missions.
A digital twin is a virtual model that accurately imitates a physical asset. This can be as complex as an entire vehicle, a subsystem, and down to a small functioning component. The digital twin has a level of fidelity that aligns to the goals of the project team. The usage of a digital twin inside a digital engineering (DE) ecosystem permits architecture and design decisions for optimized product behavior, performance, and interactions. This paper demonstrates a methodology to incorporate the digital twin concept from requirement analysis, low fidelity feature level simulation, rapid prototypes running inside a System Integration Lab, and high fidelity virtual prototypes executing in an entirely virtual environment.
Kanon, Robert J.Griffin, Kevin W.Fernando, RaveenShah, AmirKouba, RussFeury, Mark
Automotive system functionalities spread over a wide range of sub-domains ranging from non-driving related components to complex autonomous driving related components. The requirements to design and develop these components span across software, hardware, firmware, etc. elements. The successful development of these components to achieve the needs from the stockholders requires accurate understanding and traceability of the requirements of these component systems. The high-level customer requirements transformation into low level granularity requires an efficient requirement engineer. The manual understanding of the customer requirements from the requirement documents are influenced by the context and the knowledge gap of the requirement engineer in understanding and transforming the requirements. The manual way of understanding the requirements of the automotive systems always involve a certain amount of ambiguity, misunderstanding, bias etc. in analyzing the functionality of the requirements. The complex automotive system, which is solely developed based on human understanding always causes some violations in transforming the actual requirements from the stockholders in a product functionality. Hence, to mitigate this human influence on this aspect of requirement understanding, an intelligent system, which either to assists the manual requirement analysis or completely analyze the requirements alone is required. In this regard, an intelligent system is proposed here to analyze the automotive requirements efficiently by reducing human conflict, manual efforts, and to improve design and execution performance of an automotive component. The proposed system uses deep learning based Natural Language Processing (NLP) based algorithms to analyze and understand the requirement corpus from a set of platform requirements. The training of the deep learning CNN algorithms is performed on a huge set of pre-implemented platform requirements. The inference of the new customer requirements is done using the trained deep learning-based models to classify the requirements into one of the pre-defined platform requirement classes, thereby assisting the manual analysis using its intelligent component by also providing the traceability.
D H, SharathP.C., KarthikTG, SreekanthAnsari, Asadullah
ABSTRACT This GVSETS paper outlines the strategy for integrating Digital Engineering (DE) practices into the Detroit Arsenal (DTA) acquisition, engineering, and sustainment communities. A DTA DE Community of Practice (CoP) is being led by Program Executive Office (PEO) Ground Combat Systems (GCS), PEO Combat Support & Combat Service Support (CS&CSS), Combat Capabilities Development Command (DEVCOM) Ground Vehicles Systems Center (GVSC), and Tank-Automotive & Armaments Command (TACOM). In addition, Program Management Offices (PMOs) will document their DE implementation plans as part of all planning documents per Assistant Secretary of the Army for Acquisition, Logistics & Technology (ASA[ALT]) guidance [1]. In this paper, each of the DTA organizations will address the following: Ongoing DE Related Efforts; Upcoming / Planned Efforts / Opportunities; Lessons Learned; and Challenges / Issues / Help Needed. Additionally, each DTA organization explains its current and future states along with its corresponding gap analysis which contains its respective near-, intermediate- and long-term DE goals. Citation: E. Alexander, G. Reilly, A. Kwietniewski, B. Berklich, “Detroit Arsenal Digital Engineering Implementation & Way Forward”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 16-18, 2022.
Alexander, EricReilly, GlennKwietniewski, AndrewBerklich, Bill
SAE TOMORROW TODAY: Electric or Eclectic? Alternate Routes on the Road to Zero Emissions131852/21/2022
Electrify everything? Not so fast. Achieving sustainable mobility will require multiple solutions. There is no silver bullet. In this episode of SAE Tomorrow Today, we speak with the co-authors of Racing Toward Zero: The Untold Story of Driving Green, who advocate a multi-faceted approach to a green future. Kelly Senecal, co-founder of Convergent Science, and Felix Leach, Associate Professor of Engineering Science at the University of Oxford, argue that the government regulations and media hype pushing battery electric vehicles (BEVs) to the forefront are misguided. For the biggest, fastest impact on carbon emissions, Senecal and Leach believe in advancing a variety of propulsion systems - not go all in on single approach like electrification. Most vehicles on the planet use the internal combustion engine, so improving its technology and fuels can have a huge, immediate impact on reducing emissions globally. There are great electric vehicles available today, but they are a small part of the market and don't meet every consumer need. Hybrids, meanwhile, can be greener than electrics in regions reliant on coal and natural gas to produce electricity. Longer term, hydrogen and fuel cells may have a role to play. For a limited time, SAE is offering a 40% discount off the list price. Order Racing Toward Zero: The Untold Story of Driving Green now!
Hineman, Marcie
Brake pedal feel improvement, 1-D Calculation2021-36-04262/10/2022
Brake pedal feeling has recently become increasingly important since high volume markets, such as China and India, are becoming more demanding. Furthermore, costs are also a key point when designing and improving a vehicle and reducing them is a priority. In this paper, the improvement of a vehicle with brake pedal feeling complaints, using a robust procedure that uses 1D simulation tools with the aim of reducing the cost, is presented. The methodology is divided into three different phases. The first phase consists of a benchmarking activity of different competitor vehicles and the Vehicle under study, evaluating braking performance, braking regulation results, brake pedal feeling and component sizing. The second phase consists of identifying the differences and the gap analysis of the vehicle pedal feeling when compared with the competitor vehicles and finding out ways to improve it by using the 1D simulation tool, checking that the changes would meet the regulation requirements. The output from this phase is a selection of different braking components off the shelf, to keep costs low and get short lead times, which would improve brake pedal feeling. The third phase consists of testing the new components in order to check the pedal feel improvements and that the Vehicle under study still meets the regulation requirements. This paper presents some results, but not all, for confidentiality reasons from the subjective and objective evaluations of brake pedal feeling from each of the different phases as well as the brake regulation test results. IDIADA’s procedure for improving brake pedal feeling by using off the shelf components and reducing vehicle testing as much as possible. The only parts that can be changed to improve the brake pedal feeling are very limited and the Vehicle under study is very close to the boundary values of the brake regulation requirements, making this project difficult and very challenging. The procedure explained in this paper to improve the brake pedal feeling succeeds in reducing the test iterations and in using off-the-shelf components. This procedure includes very well correlated 1D simulation tools to reduce vehicle testing as much as possible. New procedure for improving the brake pedal feeling has been developed, reducing time and cost, and successfully improving the brake pedal feeling of the vehicle under test.
Musa, PauloLima, RicardoMolina, NarcisSquadrani, Fabio
Non-exhaust and exhaust particles from traffic were evaluated to account for nearly equal proportions in traffic-related emissions. Among non-exhaust emissions, tyre wear has been a crucial contributor to Particulate matter (PM), with its mass contribution as high as 30% to non-exhaust emissions from traffic. As exhaust emissions control regulation becomes stricter, which leads to a substantial reduction in exhaust emissions from road traffic, currently relative contributions of non-exhaust particles generated from tyre wear to PM is becoming more important. Accordingly, possible regulatory requirement and effectively control strategy of tyre wear particles needs to be developed. This review paper covers the physical properties, chemical composition, emission rates, and mathematic model development of tyre wear particles. Three main methods, including the road simulation in the laboratory, the source analysis, and the on-road direct measurement under real driving conditions, were used to analyse the tyre wear particles in the existing literature. The particle number concentration presented primarily a unimodal distribution, while there was no consensus regarding the peak position of the distribution. The most important chemical components of tyre wear were within coarse and fine particles.
Liu, YeChen, HaiboGao, JianbinDave, KaushaliChen, Junyan
Privately-owned vehicles were never so safe as they are today. Nor have they made so much sense. That thought hit me between the nostrils recently, as I sprayed a pungent disinfectant on the steering wheel of my family's B-segment runabout. Carefully wiping down the car's touch points with antibacterial cleaners has become a new pandemic ritual for us after returning home from food shopping and other essential missions. My little tribe generally keeps the interiors of our two vehicles tidy. Finding the occasional French fry buried in a seat track is, however, preferable to the dangerous microbes deposited every minute in the typical bus, train, or ride-share. The term “clean,” as understood by transit passengers, means a few spritzes by a custodial crew racing to meet uptime targets.
Brooke, Lindsay
Note: On April 17, 2020, the European Parliament adopted the Commission proposal to postpone the Medical Devices Regulation until May 26, 2021, due to COVID-19.
The U.S. Engineer Research and Development Center (ERDC) Military Engineering Program on Remote Assessment of Infrastructure for Ensured Maneuver (RAFTER) Boreal Aspects of Ensured Maneuver (BAEM) identifies the need for modeling over-snow vehicle performance, as many factors related to vehicle setup and land surface condition contribute to vehicle efficiency. Accurately estimating snow macromechanical characteristics—such as elastic modulus, stiffness, and strength—is critical for understanding how effectively a vehicle will travel over snow-covered terrain.
This SAE Recommended Practice applies to three-point hitch (Type A) backhoes as defined in SAE J326 when mounted on either an agricultural tractor as defined in ANSI/ASAE S390 or other off-road self-propelled work machine as defined in SAE J1116. This criterion is intended for the manufacturer of the backhoe, whether or not the backhoe is manufactured or marketed by the same company that manufactures or markets the propelling machine.
OPTC1, Personnel Protection (General)
No abstract. Part of Introduction: Helicopter rotor hubs are geometrically complex components that experience a wide rage of aerodynamic behaviors and flow physics. This includes strong unsteadiness, large amounts of separation, laminar-turbulent transition, and interactional aerodynamic behaviors (Ref. 1). At high forward flight speeds (high advance ratios), the parasitic drag of the hub accounts for O(30 percent) of the total power required to fly (Ref. 1). A common method for characterizing this contribution is the hub drag factor, Kf e, which correlates the flat-plate area of the hub with the helicopter gross weight and functions as a technology factor (Ref. 2). In a recent assessment of needs for future vertical lift systems, Ormiston suggested that the hub drag factor needs to be reduced from the current state of the art of Kf e = 0:5 down to a value 0.2 (Ref. 3).
Coder, James
On-Road and Chassis Dynamometer Evaluation of a Pre-Transmission Parallel PHEV2019-01-03654/2/2019
This paper details the vehicle testing activities performed during the Year 4 of the EcoCAR 3 competition by the Wayne State University team on a Pre-Transmission Parallel PHEV. The paper focuses on two main testing platforms: the chassis dynamometer and the closed-course track (on-road). The focus of the former is to evaluate the emissions and energy consumption associated with different driving scenarios, while the latter has been used to assess the vehicle performance and their impact on the consumer appeal. The paper presents the objectives of each test, the setup accomplished for the different vehicle testing platforms, the results obtained and the comparison with the values expected from simulations. In addition, the impact of the results on the refinement of the control strategies and on the validation of the simulation models are discussed. The EcoCAR 3 competition challenges sixteen North American universities to re-engineer a 2016 Chevrolet Camaro to reduce its environmental impact without compromising performance and consumer acceptability. Over the course of Year 4 the Control and Modeling and Simulation team used various simulation platforms to test the control algorithms designed for each operational mode of the vehicle. While Model-in-the-Loop (MIL) and Hardware-in-the-Loop (HIL) environments have been the main focus of Year 2 and Year 3, during this last competition year a considerable amount of time has been spent on chassis dynamometer and closed-course vehicle testing. The control strategies have been tested over a variety of drive cycles to identify the need for refinements and improve the robustness of the algorithms. In addition, the results obtained have been used to validate the components plant model and to support further development of the operational strategies within the non-vehicle platforms.
Di Russo, MiriamArora, VaibhavLyu, RonghuiKu, Jerry C.
During Operation Iraqi Freedom and Operation Enduring Freedom, improvised explosive devices were used strategically and with increasing frequency. To effectively design countermeasures for this environment, the Department of Defense identified the need for an under-body blast-specific Warrior Injury Assessment Manikin (WIAMan). To help with this design, information on Warfighter injuries in mounted under-body blast attacks was obtained from the Joint Trauma Analysis and Prevention of Injury in Combat program through their Request for Information interface. The events selected were evaluated by Department of the Army personnel to confirm they were representative of the loading environment expected for the WIAMan. A military case review was conducted for all AIS 2+ fractures with supporting radiology. In Warfighters whose injuries were reviewed, 79% had a foot, ankle or leg AIS 2+ fracture. Distal tibia, distal fibula, and calcaneus fractures were the most prevalent. The most common injury mechanisms were bending with probable vehicle contact (leg) and compression (foot). The most severe injuries sustained by Warfighters were to the pelvis, lumbar spine, and thoracic spine. These injuries were attributed to a compressive load from the seat pan that directly loaded the pelvis or created flexion in the lumbar spine. Rare types of injuries included severe abdominal organ injury, severe brain injury, and cervical spine injury. These typically occurred in conjunction with other fractures. Mitigating the frequently observed skeletal injuries using the WIAMan would have substantial long-term benefits for Warfighters.
Danelson, KerryWatkins, LauraHendricks, JonathanFrounfelker, PatriciaPizzolato-Heine, KarenValentine, RayLoftis, Kathryn
ABSTRACT While complex systems transform the landscape, the Systems Engineering discipline is also experiencing a transformation to a model-based discipline. In alignment with this, one of the International Council on Systems Engineering (INCOSE) strategic objectives is to accelerate this transformation. INCOSE is building a broad community that promotes and advances model based methods to manage the complexity of systems which seamlessly integrate computational algorithms and physical components across domains and traditional system boundaries. This paper covers contextual drivers for transformation as well as challenges, enablers, and INCOSE resources aligned with accelerating the transformation of Systems Engineering to a model-based discipline.
Peterson, Troy
Engine Stop/Start System (ESS) promises to reduce greenhouse emissions and improve fuel economy of vehicles. Previous work of the Authors was concentrated on bridging the gap of improvement in fuel economy promised by ESS under standard laboratory conditions and actual driving conditions. Findings from the practical studies lead to a conclusion that ESS is not so popular among the customers, due to the complexities of the system operation and poor integration of the system design with the driver behavior. In addition, due to various functional safety requirements, and traffic conditions, actual benefits of ESS are reduced. A modified control algorithm was proposed and proven for the local driving conditions in India. The ways in which a given driver behaves on the controls of the vehicles like Clutch and Brake Pedals, Gear Shift Lever were not uniform across the demography of study and varied significantly. In addition, Authors also discovered that some drivers also deployed the parking brake during an idle stop. Thus, a concept of autonomous learning algorithm was envisaged, which would learn the driver behavior on the controls which influence the functions of ESS and then adapt the same conditions to trigger the auto engine stop and restart. This was aimed at improving the user experience and yet ensure the benefits of the ESS. In this paper, the findings from previous works are analyzed to make grounds for the new submission and to identify the need for User Experience of ESS. The solution implemented to detect the driver behavior from the set of possible ways is discussed in detail and simulation case studies are discussed to ascertain the functions and benefits of the new algorithm.
Athani, GopalGavarraju, Srinivasa RajuJain, PunitAddala, ShashankP, Satishkumar
A group of rotorcraft original equipment manufacturers (OEMs) and military and commercial operators have come together to review the current state of mechanical diagnostics (MD) for on board rotorcraft Health and Usage Monitoring Systems (HUMS). HUMS has become an integral part of the modern rotorcraft both in commercial and military operations to enhance safety and enable Condition-Based Maintenance (CBM). Commercial oil and gas operators depend on the HUMS vibration monitoring and MD to comply with regulations and customer requirements for ensured safety of off-shore transportation. Under the auspices of the HUMS Technical Committee within the American Helicopter Society (AHS), the authors have assessed the performance of HUMS MD through both quantitative and qualitative means. First, results from the U.S. Army fleet, which comprises thousands of deployed HUMS on multiple aircraft models, were examined. Second, qualitative surveys of both commercial/military operators and rotorcraft/HUMS original equipment manufacturers (OEMs) were completed. Finally, a literature survey focused on HUMS research and development (R&D) and operational analysis was conducted. Based on this assessment, gaps in the performance of current HUMS MD, needs for future R&D, and challenges to closing those gaps are identified. Collaborative, pre-competitive efforts are also recommended to help close the gaps and generally raise the performance of HUMS MD to enable further enhancements to safety and to support expanded CBM initiatives.
Wade, DanielTucker, BrianDavis, MarkKnapp, DougHasbroucq, SophieSaporiti, MorenoGarrington, MalcomRudy, Alexander
The release of the ISO 26262 in November 2011 was a major milestone for the safeguarding of safety-related systems that include one or more electrical and / or electronic (E/E) systems and that are installed in series production passenger cars. Although no specific requirements exist for a model-based software development process, ISO 26262 compiles general requirements and recommendations that need to be applied to model-based development. The second edition of the ISO 26262 has been distributed for review with a final publication scheduled for 2018. This revised edition not only integrates the experiences of the last few years but also extends the overall scope of safety-related systems. In order to determine the necessary adaptions for already existing software development processes, a detailed analysis of this revision is necessary. In this work, we focus on an analysis and the impact on model-based software development of safety-related systems. First, it is important to point out the main questions that need to be considered for this kind of gap analysis. Based on this gap analysis the main differences on requirements and in particular, methods for model-based development will be elaborated.
Doerr, HeikoEnd, ThomasKaland, Lena
The popularity of new Human-Machine-Interfaces (HMIs) comes with growing concerns for driver distraction. In part, this concern stems from a rising challenge to design systems that can make functions accessible to drivers while maintaining drivers’ ability to cope with the complex driving task. Therefore, engineers need assessment methods which can evaluate how well a user interface achieves the dual-goal of making secondary tasks accessible, while allowing safe driving. Most prior methods have emphasized measuring off-road glances during HMI use. An alternative to this is to consider both on-road and off-road glances, as done in Kircher and Ahlstrom’s AttenD algorithm [1]. In this study, we compared two types of prevalent visual-manual user interfaces based on AttenD. The two HMIs of interest were a touchscreen-based interface (already in production) and a remote-rotary-controller-based interface (a high-fidelity prototype). Five in-vehicle tasks were evaluated, including a continuous-control task, a shortcut task, a menu-navigation task, a list-operation task and a function-switch task. Sixteen participants’ glance behavior was manually coded to apply AttenD. Results suggested that with a higher-positioned display and haptic feedback, the rotary-controller helped drivers maintain attention to the roadway better than the touchscreen-based interface for simple continuous control and shortcut tasks. For the more complex tasks, the results were mixed with interesting insights. Additionally, the AttenD also revealed significant individual differences in attention management strategy. In summary, AttenD-like algorithms not only can compare different HMIs, but also can reveal individual attention allocation strategies.
Zhang, YuAngell, LindaPala, SilviuHara, TetsuyaVang, Doua
The Deep Orange framework is an integral part of the graduate automotive engineering education at Clemson University International Center for Automotive Research (CU-ICAR). The initiative was developed to immerse students into the world of an OEM. For the 6th generation of Deep Orange, the goal was to develop an urban utility/activity vehicle for the year 2020. The objective of this paper is to describe the development of a multimaterial lightweight Body-in-White (BiW) structure to support an all-electric powertrain combined with an interior package that maximizes volume to enable a variety of interior configurations and activities for Generation Z users. AutoPacific data were first examined to define personas on the basis of their demographics and psychographics. The resulting market research, benchmarking, and brand essence studies were then converted to consumer needs and wants, to establish vehicle target and subsystem requirement, which formed the foundation of the Unique Selling Points (USPs) of the concept. The various sub-systems within the vehicle were then developed; a systems integration approach was used to balance design, engineering, and project (cost, weight, and timing) compromises. The paper discusses the BiW as an enabler of the vehicle USPs, including an very low, flat floor, a utility-oriented asymmetric door concept, and an integrated hatch and rear bumper which create a low lift-over height for loading and unloading. The development of the topology, geometry, and properties of the BiW structure in relation to the chassis, powertrain, and occupant packaging elements required balancing design space, functionality, cost, and weight. Novel manufacturing processes, materials, and joining techniques are described in addition to elaborations on the final realization of the BiW concept.
Flegel, ChristopherBhivate, ParthLi, LiangMathur, YashPhalgaonkar, SanketBenton, MarkMuralidharan, PrasanthBrooks, JohnellPilla, SrikanthVenhovens, PaulLewis, DavidDeBry, GarrettPayne, Craig
The Deep Orange framework is an integral part of the graduate automotive engineering education at Clemson University International Center for Automotive Research (CU-ICAR). The initiative was developed to immerse students into the world of an OEM. For the 6th generation of Deep Orange, the goal was to develop an urban utility/activity vehicle for the year 2020. The objective of this paper is to explain the interior concept that offers a flexible interior utility/activity space for Generation Z (Gen Z) users. AutoPacific data were first examined to define personas on the basis of their demographics and psychographics. The resulting market research, benchmarking, and brand essence studies were then converted to consumer needs and wants, to establish technical specifications, which formed the foundation of the Unique Selling Points (USPs) of the concept. Then the various sub-systems within the vehicle were developed; a systems integration approach was used to balance design, engineering and project (cost, weight and timing) compromises. The vehicle provides a flexible interior concept designed to support the active lifestyles of Gen Z that enables a broad range of use cases including stationary activities. The paper discusses the occupant packaging, seating, personalization and customization of the interior, power supply, infotainment, color selection, and interior lighting concepts which provide novel ways to support users in urban environments.
Kale, ManjilDiwan, RajatRenganathan Dinesh, FnuBenton, MarkMuralidharan, PrasanthVenhovens, PaulBrooks, JohnellLiu, ChunKaiJacobs, JuliePayne, Craig
The Deep Orange framework is an integral part of the graduate automotive engineering education at Clemson University International Center for Automotive Research (CU-ICAR). The initiative was developed to immerse students into the world of an OEM. For the sixth generation of Deep Orange, the goal was to develop an urban utility/activity vehicle for the year 2020. The objective of this paper is to describe the development and implementation of a dual-purpose powertrain system enabling vehicle propulsion as well as stationary activities of the Deep Orange 6 vehicle concept. AutoPacific data were first examined to define personas on the basis of their demographics and psychographics. The resulting market research, benchmarking, and brand essence studies were then converted to consumer needs and wants, to establish vehicle target and subsystem requirement, which formed the foundation of the Unique Selling Points (USPs) of the concept. The Deep Orange 6 vehicle contains a very low floor supporting the active lifestyles of the target consumers through re-configurability of the interior, which enables a broad range of use cases including invehicle stationary activities. This concept required the development of a shallow dual-purpose electrical energy storage and power conversion system for the purpose of propelling the vehicle as well as powering various 110 VAC in-vehicle stationary activities for an extended period of time, at low noise levels and with zero local emissions. The paper explains simulation based sub-system sizing and component selection to meet the overall vehicle performance and fuel economy targets. Furthermore, special attention will be paid to the development of a control logic keeping functional safety in mind especially related to the two modes of operation of the vehicle’s energy supply and power conversion system. The paper concludes with a description of the subsystem testing, including driveline and vehicle integration as part of the vehicle performance validation process.
Ivanco, AndrejMariappan Selvaraj, BalanMurali, KawshikNarayanan, ArjunSarkar, AvikSingh, AviralSoni, AkshayBenton, MarkMuralidharan, PrasanthBrooks, JohnellVenhovens, PaulPayne, Craig
ABSTRACT System complexity continues to grow, creating many new challenges for engineers and decision makers. To maximize value delivery, amidst this complexity, “both” Systems Engineering and Decision Analysis capabilities are essential. For well over a decade the systems engineering profession has had a significant focus on improving systems engineering processes. While process plays an important role, the focus on process was often at the expense of foundational engineering axioms and their contribution to system value. As a consequence, Systems Engineers were viewed as process shepherds which diluted their technical influence on programs. With the recent shift toward Model Based Systems Engineering (MBSE) the Systems Engineering discipline is “getting back to basics,” focusing on value delivery via foundational engineering axioms built upon first principles, using established laws of engineering and science. This paper will share how Pattern Based Systems Engineering (PBSE), as outlined within INCOSE’s Model Based Systems Engineering (MBSE) initiative, is a methodology which explicates system value through an understanding and explicit modeling of first principles, better re-uniting Systems Engineering and Decision Analysis capabilities.
Peterson, TroySchindel, Bill
ABSTRACT This presentation shows the process a team should use to initiate a design project based on the needs of the customer. The VRS project supports the future integration and development needs of four combat platforms (Abrams, AMPV, Bradley, and Stryker) and TARDEC’s PM CVP. For this presentation, and to simplify the explanation, the TRADOC developed capability for Silent Watch is used to demonstrate the processes of analyzing Capability Description Documents (CDD), creating and deriving good requirements, allocating them to specific functions and activities, describing those activities to the lowest level, designing, building, and eventually testing.
Ratajczak, Gregor A.MacFadyen, Keith
Car infotainment systems feature an increasing number of functions to keep pace with consumer needs. The GENIVI Alliance aims to facilitate this evolution of infotainment systems by developing a common baseline where services of different suppliers can easily be integrated on a single hardware platform. Since the huge number of services creates more dependencies and interactions, more effort is required to ensure the same level of quality. We present a novel approach and effective tooling to reduce the effort for the interface verification of in-vehicle software components. Our models create different views of the system. Consistency checks and automated transformations between the views reduce the modeling effort and ensure compatible interactions of distributed software components. Layered reference models separate the description of the structure and the behavior of the services' communication. This simplifies the behavior descriptions and facilitates the usage of different communication technologies, e.g., D-Bus or CAN. Since the reference models are executable specifications, they can be used to verify the communication of the modeled services. This can be tested live or from a trace. In case of required changes to an interface, regression testing can be performed automatically using only the model. We evaluate the benefits and implications of our approach and tool with a case study of an in-vehicle audio function.
Drabek, ChristianPaulic, AnnetteWeiss, Gereon
The automotive industry strives to develop high quality vehicles in a short period of time that satisfy the consumer needs and stand out in the competition. Full exploitation of simulation and Computer-Aided Engineering (CAE) tools can enable quick evaluation of different vehicle concepts and setups without the need of building physical prototypes. Addressing the aforementioned statements this paper presents a method for optimising the Electric Power-Assisted Steering (EPAS) ECU parameters employing solely CAE. The objective of the optimisation is to achieve a desired steering response. The developed process is tested on three specific steering metrics (friction feel, torque build-up and torque deadband) for two function parameters (basic steering torque and active return) of the EPAS. The optimisation method enabled all metrics to fall successfully within the target range.
Ljungberg, MarcusNybacka, MikaelGil Gómez, GasparKatzourakis, Diomidis
The U.S. National Research Council recently identified the need for a near-term space mission of Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS). The primary objective of the ASCENDS mission is to make CO2 column measurements across the troposphere during the day and night over all latitudes and all seasons, and in the presence of scattered clouds. These measurements would be used to significantly reduce the uncertainties in global estimates of CO2 sources and sinks, provide an increased understanding of the connection between climate and CO2 exchange, improve climate models, and close the carbon budget for improved forecasting and policy decisions.
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