SAE Standards Research Articles

FMVSS 141 repeatability study

FMVSS 141 requires non-internal combustion engine (ICE) vehicles to emit audible exterior sound from 0 to 30 kph, with requirements for 1/3-octave band frequency level, overall level and level changes with speed change. This paper studies the results of a single vehicle measured at two different locations. SAE International has conducted a study of several vehicle measured at different locations in order to lead to improvements in relevant SAE standards. This paper investigates test results from a specific vehicle, not part of the SAE study, measured at two different locations in Japan and US, including one location (US) which has three separate certified travel lanes.

Comparison of Tire Rolling Resistance Measuring Methods for Different Surfaces

The rolling resistance of car tires is one of the most important parameters characterizing tires today. This resistance has a very significant contribution to the energy consumption of wheeled vehicles. The climate crisis has forced tire and car manufacturers to place great emphasis on the environmental impact of their products. Paradoxically, the development of electric vehicles has led to an even greater importance of rolling resistance, because in electric vehicles, a large part of the influence of grade resistance and inertial resistance has been eliminated due to re-generative braking, which resulted in rolling resistance and air resistance remain as the most important factors. What is more, electric and hybrid vehicles are usually heavier, so the rolling resistance is increased accordingly. To optimize tires for rolling resistance, representative test methods must exist. Unfortunately, the current standards for measuring rolling resistance assume that tests are carried out in conditions that are far from real road conditions. This article compares the results of rolling resistance tests conducted in road conditions with the results of laboratory tests conducted on roadwheel facilities. The overview of results shows that the results of tests conducted in accordance with ISO and SAE standards on steel drums are very poorly correlated with more objective results of road tests. Significant differences occur both in the Coefficients of Rolling Resistance (CRR) and in the tire ranking. Only covering the drums with replicas of road surfaces leads to a significant improvement in the results obtained. For investigations of rolling resistance in non-steady-state conditions, the flat track testing machine (TTF), equipped with asphalt cassettes, is shown to provide measurement data in agreement with the road test data.

Finite element analysis and optimization of a Formula SAE car chassis

In motorsport engineering, achieving the ideal balance between speed, agility, and safety is a monumental challenge. Formula SAE competitions, where collegiate racing teams design high-performance vehicles, emphasize the pivotal role of the chassis, the backbone of the racing machine. Ensuring chassis compliance with regulations and optimizing structural integrity and weight is a formidable task. This study addresses this multifaceted challenge by focusing on the development, simulation, and optimization of a Formula SAE car's chassis. Rigorous analysis of four chassis versions seeks to strike a balance between rigidity and weight, enhancing performance while adhering to rules. Longitudinal torsion, diamond torsion, lateral acceleration, and braking tests assess structural rigidity and stress distribution, ensuring predictability and preventing potential failures. The mesh uses one-dimensional elements (1 mm size) and material properties akin to SAE 1020 steel. The fourth iteration consistently demonstrated superior performance across all tests. Despite a slight weight increase, it exhibited a longitudinal torsional rigidity of 1985 Nm/deg, well-aligned with Formula SAE standards, and a formidable diamond torsional rigidity of 56,304 Nm/deg. Critical stress analysis during lateral acceleration and braking tests remained well within permissible limits, with a chassis weight of approximately 35 kg. In summary, this work meets stringent Formula SAE standards, offering a systematic methodology for chassis design and optimization. The fourth iteration excels in various critical tests and serves as a valuable contribution to motorsport engineering, providing a blueprint for enhanced competitiveness and performance in the 2023 Formula SAE Brazil competition.

Indoor Environmental Quality Assessment of Train Cabins and Passenger Waiting Areas: A Case Study of Nigeria

The adequacy of the indoor environmental quality (IEQ) in mass transit microenvironments is crucial to the well-being of exposed commuters. By 2050, many developing tropical countries will host even more megacities, which will feature an increase in people mobility and higher occupancy density. The paucity of IEQ studies, the technology gap, and inadequate policy measures to assure safer and sustainable mobility in many developing tropics have reinforced the current study objective. Also, the recent COVID-19 pandemic has highlighted the IEQ links and risks to health in transport, which, given the climate peculiarities, transport reforms, and huge commuter traffic in Nigeria, inform the study motivation. The indoor air quality (CO2, PM, VOCs, NO2), thermal, acoustic, and visual environments were objectively assessed in train passenger cabins and waiting areas, during 15 trips in the dry and rainy seasons in Nigeria. The results were analyzed by following the IEQ requirements defined in the ISO, CEN, ASHRAE, and SAE standards. The results indicate gaps in the IAQ (inadequate ventilation in 9 trains), defective thermal comfort (9 trains), exceedance in the PM limit (PM10: 47.9–115 μg/m3, PM2.5: 22.5–51.3 μg/m3), noise (Leq range: 64–85 dBA), and low illuminance levels (10 trains), hence the need for IEQ, interventions, stakeholder awareness, and broader IEQ studies on transport cabins in these regions.

Validation of scenario-based virtual safety testing using low-cost sensor-based instrumented vehicle

Autonomous vehicle (AV) requires millions of miles on road to test the reliability of safety systems. It is also difficult to test the AV for critical scenarios which are rare but will endanger road users. Therefore, virtual safety testing simulation platforms are introduced to test the safety systems of the autonomous vehicles in critical scenarios. However, developing the virtual safety testing simulation platform requires information about the environment and driving data from the real world. Besides, it is challenging to build a system to collect driving data which is normally cost intensive especially in developing countries. Paradoxically, these developing countries have poor traffic environment which can provide valuable scenarios for safety testing test cases. Therefore, in this paper, a scenario-based testing using virtual simulation platform is developed using data captured by a low-cost sensor-based instrumented vehicle. The instrumented vehicle is built by low-cost off-the-shelf components for the testing purpose. The instrumented vehicle is used for validation process in IPG CarMaker’s vehicle model using SAE standards. Then, the validated vehicle model is used as an autonomous vehicle in IPG CarMaker for the virtual scenario-based safety testing. The whole validation process from data collection to data logging is carried out using various economic sensors instead of a single industrial system. This approach greatly reduce the cost of the instrumented vehicle and the result of the scenario-based testing shows that the virtual scenarios developed in IPG CarMaker can be used for validation purpose with actual scenarios using low-cost sensor based instrumented vehicle as low as 4% root mean square percentage error.

High-Power Converters and Challenges in Electric Vehicle Wireless Charging – A Review

This article reviews various inductive and capacitive wireless charging systems to achieve high-power infrastructures. The characteristics of SAE, ICINRP, and IEEE safety standards for wireless charging technology were highlighted. The working of compensation circuits, resonant converters, and challenges in wireless power transfer (WPT) systems was discussed. The mechanism of different compensation circuits used in the WPT was discussed in detail. In addition, the design of the converter circuit topology of inductive and capacitive power transfer systems in electric vehicle (EV) batteries was highlighted. The foreign object detection (FOD) methods that prevent output power variations due to metal/living objects in the charging environment were explored. The foreign object detection (FOD) techniques in terms of impedance variations in the primary side of the charging circuit were explained. This review on EVs would help researchers and industrialists to identify and develop novel charging infrastructure with low cost and charging time.

Performance Enhancement of Degraded Engine Oil with Blends of Neem Oil and Avocado Oil for Lubrication

A blending of different non-edible vegetable oils (Neem and Avocado) with synthetic oil (SAE 20W50) that is commercially available has attracted several studies towards making it sustainable, biodegradable, and environmentally suitable for mineral oil for lubricant production. The physicochemical, thermo-oxidative stability and corrosion properties of Nigerian degraded engine oil (Society of Automotive Engineers SAE 20W50) were studied using mixing ratios of 40/60, 50/50, and 60/40 blends of neem/degrade engine oil and Avocado/degraded engine oil respectively. The study revealed specific gravity values of 0.893, 0.897, 0.901 for neem/degraded engine oil and 0.893, 0.897, 0.901 for avocado/degraded engine oil which fall within SAE standard of 0.901. pH values for neem/degraded engine oil were: 5.83, 5.85, 5.62 and 5.59, 5.49, and 5.71 for avocado/degraded engine oil indicating acidic compared to (SAE 20W50) of 7.12. The viscosity of neem/degraded engine oil and avocado/degraded engine oil was found to be lower compared to the SAE 20W50. The Neem and Avocado oil each has a promising effect on the physicochemical properties of the SAE 20W50 blend.

Forecasting technical performance and cost estimation of designed rim wheels based on variations of geometrical parameters

Abstract Rim wheel testing through the SAE standard is necessary for driving safety. This study focused on rim wheel tests carried out using the dynamic radial fatigue test method, which has been included in the SAE standard using Fusion360 for the design and ANSYS for the simulation. With different parameters for the rim wheel type, only some parameters of the tested rim wheels were able to pass the standardization by SAE; 16 rim wheels passed the test, while the other 11 rim wheels did not pass. Simulation results suggested that variations in the thickness, geometry, and material affected the displacement of the safety factor, which was inversely proportional. In addition, the variation in the rim wheel produced a change in the safety factor due to changes in its mass and cost, which were directly proportional. The results of this study will aid in rim wheel design, not only in terms of achieving the best performance but also with regard to cost efficiency.

Comparative study of Global, European and Italian Standards on Hydrogen Refueling Stations

The purpose of this paper is to give a strategic overview of the existing standards governing the construction and operation of hydrogen refueling stations. A succinct and comprehensive study of hydrogen refueling station standards globally, in Europe, and in Italy is conducted and discussed in light of the new European Hydrogen Strategy and Roadmap. Among the numerous topics examined, a particular emphasis is placed on the standards in force for on-site hydrogen production via water electrolysis, hydrogen storage, both liquid and gaseous, and refueling protocols for light-duty and heavy-duty vehicles, on an international level through the provision of ISO, IEC, and SAE standards; on a European level through the examination of the CEN/CENELEC database; and on an Italian national level through the analysis of the UNI database.

The evaluation of forces acting on excavator bucket and its capacity

Excavators are commonly used machines in mining, material transport operations, ground levelling, agriculture, forestry applications and construction. The design of an excavator hoe type bucket is a critical task in the context of the digging forces developed by the actuators during the digging operation (Material Removing). The bucket is a highly essential component of the backhoe loader since it carries the entire load of excavated material. The important criteria for the design to be safe is that, the digging forces of the actuators must be greater than the resistive force offered by the terrain to be excavated. Due to an excessive quantity of resistive loads, an adverse effect on the bucket parts occurs, and it may fail during excavation operations. The bucket is being held back by a variety of forces that are preventing it from moving into the soil such as gravitational force and remolding force. This method can be used to predict digging forces and to run an excavation task autonomously. Bucket capacity, bucket life, poor design of tool, results in weak excavation of the ground, high wear of the tool, wastage of the time and power thus reducing the productivity and efficiency of a product. Prediction of resistive forces is a difficult task so soil tool interaction model plays an essential role also soil parameters such as density, cohesiveness differs as per material type. As the resistive forces are applied, steps such as penetration, separation, and escape are considered. The resistive forces for the worst soil condition characteristics have been estimated here. The reformulated basic Fundamental Earth Moving Equation,considers the terrain slope and interaction of the bucket as it moves through the soil. It is modified to support inclined soil surfaces and transient tool motion states. This paper focuses on the method of evaluating bucket capacity and digging forces, as well as the resistive forces provided by stiff soil, in accordance with ISO and SAE standards.

SAE Light Vehicle Exterior Sound Level History

<div class="section abstract"><div class="htmlview paragraph">The Society of Automotive Engineers Light Vehicle Exterior Sound Committee recognizes the value of preserving historical knowledge regarding the standards developed and reviewed by the committee. To memorialize the knowledge gained and lessons learned over the years, the current committee reached out to the chair of the committee during its formative years, Mr. Richard Schumacher, to discuss the rationale and reasoning for many of the early decisions made regarding vehicle sound standards. This work preserves those discussions and relates the history of some of the most commonly used sound level standards.</div><div class="htmlview paragraph">In this paper and presentation, the formation of the committee is discussed, particularly in relation to EPA’s original concern with vehicle noise, as well as the alignment between SAE standards and ISO standards for vehicle noise measurements. The role of the committee is examined, and the review process for SAE vehicle sound standards is explained. A variety of lessons learned and specific instances of standard modification or revision based on the findings of committee members and users of the standards are highlighted. Best practices for implementing standards, including the use of technically skilled individuals to perform testing, are described.</div><div class="htmlview paragraph">As part of this work, the categories for standard review are explained, challenges that the committee has faced through the years are discussed, and the histories of specific standards are reviewed. Historical information about J57, J366, J986, J1030, J1169, J1470, J1492, and J2805 is included. It is the authors’ hope that collecting this information will preserve the information passed down through the committee and provide insight into the development of vehicle sound standards.</div></div>

On the Expansion of On-Board Diagnostics (OBD) to Electric Propulsion Systems in Battery Electric Vehicles

<div class="section abstract"><div class="htmlview paragraph">Currently the On-Board Diagnostics (OBD) requirements enforced by government agencies do not cover electric vehicles. Although the California Air Resources Board (CARB) mandates all light and medium duty vehicles and heavy duty engine dynamometer certified engines equipped with fossil fuel-powered engines, including all hybrid vehicles, must follow the OBD requirements in California Code of Regulation (CCR) 1968.2 and 1971.1, Battery Electric vehicles (BEVs), are exempted from OBD requirements. The legislators, such as CARB, have started to make proposals for on-board systems to monitor electric propulsion system health. In addition, there may be customer needs to obtain standard vehicle service information and the Original Equipment Manufacturers (OEMs) may also have the desire for common diagnostic strategies across different vehicle applications to lower the development costs. This paper, different from other published technical papers or proposals from OEMs or government agencies, analyzes the feasibility and compatibility of the existing OBD system design requirements, and aligns them with the need of industrial-common OBD system architecture and existing/upcoming SAE standards to propose the monitoring and reporting requirements on the identified primary propulsion system components/systems from technical point of view. This study makes some key technical proposals/solutions for the possible use of OBD-like monitoring and reporting requirements for Electric Propulsion Systems, including, what are the monitoring requirements, what is to be monitored, what are the malfunction indicator light (MIL) illumination requirements, and what are the generic scan tool (GST) interface requirements that are based on J1979-2 (i.e., Unified Diagnostic Services -UDS) to facilitate the repair service by technicians, including from independent service shops.</div></div>

Numerical study on strength optimization of Go-Kart roll-cage using different materials and pipe thickness

This paper aims to optimize the Go-Kart rollcage strength using different materials and pipe thickness. Chassis design is done based upon the SAE standards provided in the Go-Kart events. Ergonomics factor is also considered keeping in mind the driver’s safety and comfort. Chassis design has been done in CAD software SOLIDWORKS version 2018. Front, Rear and Side impact analysis is carried out for three different materials viz. (AISI 4130, 1018 and 1020) and pipe thickness (0.5, 1.0, 1.2, 1.4, 1.6, 2 mm) using Finite Element (FE) software ANSYS 16.0. Results are analysed in terms of Factor of Safety, Deformation and von-Mises Stress. Based upon the results acquired through FE analysis, cost and weight of the materials, it is concluded that AISI 1020 material with thicknesses of 1.4 mm are well suitable for fabricating Go-Kart roll cage. This investigation will provide fundamental strength optimisation strategy and act as a priori in designing the Go-Kart vehicle.

Empirical Models for the Realistic Generation of Cooperative Awareness Messages in Vehicular Networks

Most V2X (Vehicle-to-Everything) applications rely on broadcasting awareness messages known as CAM (Cooperative Awareness Messages) in ETSI or BSM (Basic Safety Message) in SAE standards. A large number of studies have been devoted to guarantee their reliable transmission. However, to date, the studies are generally based on simplified data traffic models that generate awareness messages at periodic intervals or with a constant message size. These models do not accurately represent the real generation of CAM messages that follow specific mobility-based rules. Using simplified and unrealistic traffic models can significantly impact the results and validity of the studies, and hence accurate models for the generation of awareness messages are necessary. This paper proposes the first set of models that can realistically generate CAM messages. The models have been created from real traces collected by two car manufacturers in urban, sub-urban and highway test drives. The models are based on mth order Markov sources, and model the size of CAMs and the time interval between CAMs. The models are openly provided to the community and can be easily integrated into any simulator.

Symposium: The Role of Human Factors Standards in Advancing Science and Practice: Some Examples from Automotive, Nuclear, Healthcare, and Petrochemical Industries

The Human Factors and Ergonomics Society (HFES) has created a Task Force to help implement Goal D of the HFES Strategic plan ( https://www.hfes.org/about-hfes/strategic-plan ), to “translate the science of HF/E into practice.” One way for that to occur is for HFES publications to cite standards. This symposium will raise awareness of this idea and provide additional supporting materials. The focus is on 4 example applications - automotive (in particular, SAE standards for motor vehicles), healthcare (with a focus on AAMI), nuclear (from both the IEEE and NRC perspectives), and oil and gas. Papers in this symposium will (1) describe organizations and the groups within them that develop human factors standards for each of the 4 applications, (2) describe how to find human factors standards relevant to these applications, (3) summarize some of those standards, and (4) identify where human factors input is needed to improve the standards of each organization.

A holistic methodology to correct heat transfer and bearing friction losses from hot turbocharger maps in order to obtain adiabatic efficiency of the turbomachinery

Turbocharger performance maps provided by manufacturers are usually far from the assumption of reproducing the isentropic performance. The reason being, those maps are usually measured using a hot gas stand. The definition of the effective turbocharger efficiency maps include the mechanical losses and heat transfer that has occurred during the gas stand test for the turbine maps and only the heat transfer for the compressor maps. Thus, a turbocharger engine model that uses these maps provides accurate results only when simulating turbocharger operative conditions similar to those at which the maps are recorded. However, for some critical situations such as Worldwide harmonized Light vehicles Test Cycles (WLTC) driving cycle or off-design conditions, it is difficult to ensure this assumption. In this article, an internal and external heat transfer model combined with mechanical losses model, both previously developed and calibrated, has been used as an original tool to ascertain a calculation procedure to obtain adiabatic maps from diabatic standard turbocharger maps. The turbocharger working operative conditions at the time of map measurements and geometrical information of the turbocharger are necessary to discount both effects precisely. However, the maps from turbocharger manufacturers do not include all required information. These create additional challenges to develop the procedure to obtain approximated adiabatic maps making some assumptions based on SAE standards for non-available data. A sensitivity study has been included in this article to check the validity of the hypothesis proposed by changing the values of parameters which are not included in the map data. The proposed procedure becomes a valuable tool either for Original Equipment Manufacturers (OEMs) to parameterize turbocharger performance accurately for benchmarking and turbocharged engine design or to turbocharger manufacturers to provide much-appreciated information of their performance maps.

Development of a shear force measurement dummy for seat comfort.

Seat comfort is one of the main factors that consumers consider when purchasing a car. In this study, we develop a dummy with a shear-force sensor to evaluate seat comfort. The sensor has dimensions of 25 mm × 25 mm × 26 mm and is made of S45C. Electroless nickel plating is employed to coat its surface in order to prevent corrosion and oxidation. The proposed sensor is validated using a qualified load cell and shows high accuracy and precision (measurement range: −30–30 N; sensitivity: 0.1 N; linear relationship: R = 0.999; transverse sensitivity: <1%). The dummy is manufactured in compliance with the SAE standards (SAE J826) and incorporates shear sensors into its design. We measure the shear force under four driving conditions and at five different speeds using a sedan; results showed that the shear force increases with speed under all driving conditions. In the case of acceleration and deceleration, shear force significantly changes in the lower body of the dummy. During right and left turns, it significantly changes in the upper body of the dummy.

System Considerations for the Application of Thermal Management Solutions to Electrified Vehicle Traction Batteries: Benchmarks and Technical Specification Development

With an increasing demand in traction battery performance for electrified vehicles, thermal management definition and temperature uniformity specifications are a moving target for supplier product development and OEM system integration. Alternative cell formats, integration schemes and cell-to-pack scaling are trending stop-gaps to this challenge. Highlights of select vehicle system benchmarks and the evolving demands for lithium-ion battery thermal management will be discussed with focus on scaled temperature gradients, heat transfer efficiency, as well as system volume, weight, and cost. Recent efforts by the United States Advanced Battery Consortium to define such targets and SAE standards defining battery thermal management systems will be also be explored.

Electric Vehicle Infrastructure Standardization

One of the most frequently asked questions that a third party safety organization is asked centers on “What standard applies to EV infrastructure products?” This paper will outline the various standardization activities for charging infrastructure for both conductive and wireless power transfer technologies. It will discuss the development status, expected publication schedules, and technology covered for various UL, SAE, and IEC standards centered on electric vehicle charging use. Further, the paper will discuss the certification aspects of these standards, such as where the standards are applicable and how certification is handled, within various global locations.

A Material Compatibility Study of Automotive Elastomers with high FFA based Biodiesel

Abstract Application of renewable fuels and changes in fuel composition often create many trouble in gaskets, seals, elastomers and O-rings in the engine fuel system. In a CI engine fuel system, fuel comes in touch with different elastomeric components. The compatibility of automotive fuel system components like seals, gaskets and hose materials using conventional fossil based diesel has long been recognized and documented but there is concern over the use of elastomeric materials with biodiesel. Based on these concerns, a study of compatibility of Natural rubber, Nylon and EPDM (Ethylene Propylene Diene Monomer) with biodiesel and diesel was carried out. High FFA oil, which is a byproduct of edible and non-edible oil refineries, is available at low price and in considerable quantities at vegetable oil refinery sites. In the current study, high FFA oil is synthesized into biodiesel by two step process i.e. esterification followed by transesterification. The methyl ester content of biodiesel is determined by GCMS. The fuel properties of the produced biodiesel were found to be comparable with that of biodiesel specifications. Static immersion test in biodiesel and diesel has been carried out as per SAE J1748 standards. This paper aims to characterize the compatibility of Natural rubber, Nylon and EPDM, commonly encountered in the automotive fuel system in diesel engines. Static immersion test in B100 and diesel fuel was carried out at 55±2 °C (SAE J1748 para 5.2) for 500 hours. Fuels were replaced weekly as suggested in SAE standard. Before the immersion test, mass measurements and visual inspection were recorded. Before and after immersion, comparative behavior was investigated by weight loss, volume change, hardness; tensile strength measurements. Changes in surface morphology were studied by Scanning Electron Microscopy. It was found that natural rubber showed less detrimental effects while significant detrimental effect on EPDM and Nylon was observed.