Browse Topic: Drivetrains

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Design & Optimization of CV shaft system to address powertrain induced NVH issues2026-26-0336To be published on 01/16/2026
The automotive industry is a crucial sector that plays a significant role globally. Government policies have a profound impact on this automotive industry in defining the regulatory standards and emission controls. Such regulations incentivized automakers to invest in research and development complying those standards towards reduction of vehicle emission which intern result in higher torsional vibrations and excitations amplitudes. To address the rising NVH related concerns in driveline system. Drive shafts (CV shafts) is an important component in power-train system in vehicle. Drive shaft’s main purpose to transfer torque from engines to wheels at multiple speeds with different articulation angles. The roughness generated by the engine follows a transfer path from engine to transaxle and transaxle to half shafts in monocoque vehicles which generates discomfort to the drivers whenever the vehicle is driven. The roughness can also be addressed by proper design of driveshaft stiffness
M A, Abdul Azarrudin, Jayachandran, Suresh kumar, KUMAR, Shivani, Bhardwaj, Kinshuk, M, Devamanalan, Kanagaraj, Pothiraj, ahire, Manoj
Optimization of Propeller shaft design to eliminate Launch Undulation (Lateral shake) and Vibration level2026-26-0334To be published on 01/16/2026
During vehicle launches in 1st gear, a lateral shake (undulation) and a pronounced metallic hitting noise were observed in the underbody. The noise was identified as the propeller shaft's second universal joint (UJ) yoke striking the fuel tank mounting bracket. Sensitivity to these issues varied with acceleration inputs: light pedal input during a normal 1st gear launch on a flat road resulted in minimal undulation, whereas wide open throttle (WOT) conditions in 1st gear produced significant lateral shake and intensified hitting noise. Further investigation revealed that the problem persists across all gears and occurs consistently during normal driving conditions, with continuous impact between the propeller shaft yoke and the fuel tank mounting bracket. Extensive experimental measurements at the vehicle level indicated that these issues were primarily caused by the center-mounted propeller shaft joint deviating from its central position and rotating eccentrically under torque. This
Sanjay, L, S, Manickaraja, Kumar, Sarvesh, Kanagaraj, Pothiraj, Senthil Raja, T, B, Prem Prabhakar, M, Kiran
Efficiency Enhancement of Electric Vehicle Drivetrains through Advanced Gearbox Strategies2026-26-0053To be published on 01/16/2026
In the pursuit of sustainable mobility solutions, optimizing drivetrain efficiency has emerged as a critical factor in enhancing the overall performance, reliability, and market acceptance of electric vehicles (EVs). This study specifically focuses on achieving efficiency improvements within the gearbox system of Electric Vehicles, a major contributor to mechanical losses in the drivetrain. Key technical strategies explored include the adoption of low-viscosity lubricants, utilization of low-friction bearings, incorporation of high-efficiency oil seals, and the application of low-loss gear designs. Collectively, these enhancements aim to reduce mechanical frictional losses, leading to tangible benefits such as increased vehicle driving range, reduced energy consumption, lower carbon emissions, and decreased long-term maintenance costs. In addition to component-level improvements, the study investigates the integration of a 2-speed gearbox within electric vehicles as a system-level
Agrawal, Devesh, Bhardwaj, Abhishek, Bhandari, Kiran Kamlakar
Power loss evaluation in 4WD axle and correlation with Testing results2026-26-0107To be published on 01/16/2026
In the tractor, the efficiency depends on the transmission system, of all the losses major contribution is given by the transmission elements. To improve the efficiency, it became crucial to monitor the areas of power losses. Power loss in transmission refers the reduction in amount of power which being generated from the engine source to the final drive elements. There are various parameters and factors influence this condition, analyzing those conditions helps in identifying & improving the higher contributing components for driveline power loss. This study presents a comparative analysis of theoretical and experimental data regarding power loss in the gear train of a 70HP 4WD front axle. The investigation incorporates theoretical power loss calculations for individual components, including the bevel gear, bearings, thrust washer and seal arrangements. To evaluate and validate the power losses in the 4WD axle, a Gear Train Endurance test was conducted in a controlled laboratory
Jayapal, Jayaraj, Mahapatra, Soumya Ranjan, Sethi, Suvendu Kumar, JOSHI, SHRIKANT, BANGE, PRASHANT
Modelling and Analysis of Hypoid Gear Churning Loss in Rear Drive Axle: The Role of Oil Viscosity and Empirical Parameters2026-26-0508To be published on 01/16/2026
This definitive study investigates the variation of churning losses occurring with hypoid ring and pinion gear sets and puts primary importance to factors that determine energy dissipation in these mechanisms. A detailed investigation shows that viscosity is critical, particularly due to large temperature-dependent variations. Besides this, the study focuses on particular attention to experimental parameters derived from measured data to model churning losses. Churning Loss itself originates in the interaction between the rotation of the gears and the lubricating oil - a source of significant inefficiency within the overall drivetrain. A robust, comprehensive model has been formulated to take this into account. It does not only account for variable oil viscosity with temperature but integrates key empirical parameters that reflect observed behaviours in gear systems. The study adopts a multidimensional approach by considering the influence of various other factors. It investigates how
Khan, Aliya Javid, Praveen, Abhinav, Kanagaraj, Pothiraj, Jain, Saurabh Kumar, AP, Baaheedharan
Revolutionary EV Motors Innovation in E-mobility in Depth Analysis of Emerging Technologies, Comparative Insights & Their Ground Breaking Impact on Electric Vehicle Performance2026-26-0073To be published on 01/16/2026
This paper delivers a forward-looking data-driven assessment of the transformative innovation in electric vehicle motor systems with targeting breakthroughs in the power density, energy efficiency, thermal robustness, manufacturability & better intelligent control. A rigorous Multi Criteria Decision Making (MCDM) framework is done to systematically evaluate and defining the rank of emerging motor technologies across eight weighted performance indicators. The findings reveal that which design strategies & material advancements offering the greatest potential for redefine propulsion performance that enabling lighter more compact & more efficient drivetrain capable of sustained high power operation. High ranking solution exhibit strong alignment with the industry's push toward scalable, low cost & rare earth-independent systems while other are identified as high risk/high reward pathway requiring targeted research to overcome critical problems. By integrating engineering performance
Jain, Gaurav, PREMLAL, P, Pathak, Rahul, Gore, Pandurang
Novel Approach for Predicting Steering Rack Load Using Multibody Simulation2026-26-0378To be published on 01/16/2026
In the initial stages of a vehicle development program, the sizing of various components is a critical deliverable. The steering system, in particular, requires a precise estimation of the rack load for the appropriate sizing of the rack and assist units. Accurately predicting the load on the system during the early stages of development is challenging, especially in the absence of benchmark or legacy data. Commonly used processes for estimating parking steering effort often employ simplistic approaches that may fail to account for parameters such as tire size, vertical stiffness, and steering geometry, leading to reduced accuracy. This paper introduces an advanced methodology for predicting steering rack loads, which incorporates considerations such as contact patch size and pressure variation, as well as the tire jacking effect. The methodology involves mathematical modeling of the contact patch using mesh-grids, utilizing common inputs available in the early stages of vehicle
Shirke, Umesh, Dabholkar, Aniruddh, bardia, Vivek, Srivastava, Harshit, PRASAD, TEJ PRATAP
Simulation Driven Virtual Road Load and Accelerated Duty Cycle Generation for 3-Speed eAxle Systems2026-26-0401To be published on 01/16/2026
The transition from Internal Combustion Engine (ICE) vehicles to Battery Electric Vehicles (BEVs) introduces significant challenges in drivetrain development, particularly when historical road load data (RLDA) is unavailable. This research proposes a methodology for virtually generating and processing RLDA to evaluate the durability of a novel 3-speed electric axle (eAxle) system before physical prototype construction. By employing AVL Route Studio, we simulated diverse global driving conditions across urban, highway, and mixed terrains to generate high-frequency torque and speed data. Since the resulting millions of data points are impractical for direct fatigue assessment, we utilised Romax software to condense the virtual RLDA into an accelerated duty cycle while maintaining the original fatigue damage characteristics. Unlike traditional binning techniques that often mischaracterise load severity, our damage-matching approach ensures the condensed cycle accurately replicates gear
LIGADE, PRATIK, KHAN, Dr. NURUZZAMA MEHADI, Koona, Rammohan Rao
Multispeed EV Transmission – Gear Shift Simulation and Validation2026-26-0157To be published on 01/16/2026
The advancement of electric vehicle (EV) transmission systems is currently a prominent trend aimed at decreasing carbon emissions and providing eco-friendly transportation alternatives. Most of the EV transmissions are single speed, but research conducted on multi speed EV transmissions show higher efficiency, good performance, high speed and torque demand when compared with single speed counterparts. Most of the multi speed EV transmissions that are developed are of non-synchromesh type, which have direct effect on NVH, driving dynamics and durability of drivetrain components. Due to aforementioned factors, gearshift analysis becomes critical for development. Simulation model is developed at early development phase for initial feedback. Using the feedback, drivetrain can be optimized furthermore and test on physical parts can be conducted for final verification. This paper provides a simulation based approach for modelling non-synchromesh two speed EV transmission using Simulation X
Patel, Hiral, Thambala, Prashanth, Sutar, Suresh, Todtermuschke, Karsten
EVALUATION OF DRIVELINE NVH PERFORMANCE USING LINEAR DYNAMIC FINITE ELEMENT SIMULATION2026-26-0322To be published on 01/16/2026
Automotive driveline design plays an important role in the NVH characteristics of the overall vehicle. Driveline systems are an integral part of delivering torque from the engine/transmission to the tires which propel the vehicle and drivelines often experience a wide frequency of excitation which poses unique NVH challenges. With the increasing trend in the automotive industry to introduce turbocharged engines with fewer cylinders while delivering the same torque / power, the driveline systems are excited with increased lower frequency torsional vibration in addition to other vibrations transmitted from powertrain and road. In this paper, we address the key design consideration for developing an optimal driveline system with consideration to NVH while keeping durability and other functional requirements in perspective. We consider the example of a front wheel drive-based vehicle architecture with independent suspension. The effect of fundamental prop shaft frequency to determine
JOSHI, ATUL KAMALAKARRAO, Subramanian, MANOJ
Machine Learning Approach to ISO Road Class Prediction Using Multiple Linear Regression2026-26-0667To be published on 01/16/2026
The inertial profiler methodology is traditionally employed in RLDA (Road Load Data Acquisition) to measure road profiles and classify test routes into ISO road classes. However, this approach demands significant time and effort during instrumentation. Also, during data acquisition, laser height sensor data is affected especially during adverse conditions such as rainy seasons or on surfaces with improper reflectivity. Additionally, substantial resources are required for data processing to convert raw measurements into road classifications. To address these challenges, an initial attempt was made to establish a relationship between axle acceleration responses and road profiles, enabling axle acceleration measurements during RLDA to predict ISO road classes. However, this approach relied on a simple linear model that considered only axle acceleration responses, rendering the predictions susceptible to inaccuracies due to varying parameters such as vehicle speed. To overcome these
P, Praveen Kumar, P, Dayalan, Sriramulu, Yoganandam
Propeller Shaft Yoke Phase and Inclination angle Optimization in Passenger Vehicles through Analytical Method2026-26-0348To be published on 01/16/2026
Customer satisfaction is the most important parameter to achieve the success in the highly competitive automobile industry. Comfortable ride and handling are one of the important aspects for customer viewpoint. Propeller shaft is the critical components in the vehicle to affect the smooth operation of the vehicle. Propeller shaft universal joint (UJ) phase and inclination angle significantly affect the vehicle performance during frequent braking and acceleration. So, for this conditions, comprehensive study of the propeller shaft should be performed for smooth operation. In this paper, Propeller shaft UJ phase and inclination angle optimization is studied through analytical method, which are very essential parameter for optimizing induced vibration performance and comfort. Propeller shaft characteristics influenced by several factors like vehicle torque, propeller shaft joint type, materials properties, UJ phase and inclination angle and shaft unbalance value. By optimizing the above
Kumar, Sarvesh, Sanjay, L, S, Manickaraja, Kanagaraj, Pothiraj
Correlation of Power Rating for Battery Electric Vehicles Simulation vs. Test Validation in Accordance with regulatory compliance2026-26-0575To be published on 01/16/2026
Accurate power and energy assessment in Battery Electric Vehicles (BEVs) requires high-fidelity simulation models that reflect real-world performance. This study presents a power rating correlation of the Stellantis Dodge model in compliance with the GTR 21 standard, validating the simulation’s accuracy against physical test data. Simulations conducted using STLAsim, Stellantis’ proprietary tool, estimate EDM power at the inverter input and axle output under standardized conditions. The operating parameters were shared with the testing team to ensure consistency; however, the initial test results deviated by approximately 18 kW from the simulation target. To address this delta, EDM speed and vehicle speed were optimized, achieving a close alignment with the simulation and meeting the GTR 21 power rating criteria. The results demonstrate a strong correlation between the simulation and test data, confirming the model’s accuracy and reliability. This study underscores the effectiveness of
Mahajan, Prasad, ali, Shoaib
Enhancing Tipper Stability during Descent with Dynamic Angle Adjustment2025-28-027611/06/2025
Tippers transporting loose bulk cargo during prolonged descents are subject to two critical operational challenges: cargo displacement and rear axle lifting. Uncontrolled cargo movement, often involving loose aggregates or soil, arises due to gravitational forces and insufficient restraint systems. This phenomenon can lead to cabin damage, loss of control, and hazardous discharge of materials onto roadways. Simultaneously, load imbalances during descent can cause rear axle lift, increasing stress on the front steering axle, resulting in tire slippage and compromised maneuverability. This study proposes a dynamic control strategy that adjusts the tipper lift angle in real time to align with the descent angle of the road. By synchronizing the trailer bed angle with the slope of the terrain, the system minimizes cargo instability, maintains rear axle contact, and enhances braking performance, including engine and exhaust braking systems. Computational modelling is employed to assess the
Vijeth, Abhishek, Bhosle, Devidas Ashok, Cherian, Roshni, Dash, Prasanjita
Digital Simulation of Rear Axle Brake Lines Articulation for Commercial Vehicles2025-28-025711/06/2025
This paper focuses on defining the optimal length of rear axle brake lines (flexible polyamide tubes) for commercial vehicles by simulating the lines digitally by considering tube behavior and various axle articulation conditions. Currently, the length of rear axle brake lines are predominantly defined with the help of a physical mockup by articulating axle conditions in a vehicle. This approach requires actual components such as frame, axle, suspension, etc., which consumes considerable time and cost. Through technological advancements, prototyping can be reduced and convergence on digital to build can be achieved through digital simulation. This paper explores tube properties, axle configurations and definitions, and various methods of digitally simulating line articulation. Boundary conditions, space reservations and design criteria for pneumatic routing are defined for the type of line designed. Digital simulation of rear axle brake lines articulation was performed and compared
Duraiswamy, Rupesh, Sankaran, Bhargav, Raj, Santhosh
Design and Development of a Novel Automatic Powershift Transmission for Battery-Electric Vehicles2025-32-009611/03/2025
The increasing adoption of battery-electric propulsion in two- and 3-wheelers, small cars, and four-wheeled delivery vehicles has created a growing demand for technological advancements to improve their autonomy. Due to cost and weight constraints, these vehicles cannot incorporate highly sophisticated electric motors, as seen in the premium car sector. Therefore, achieving the best possible efficiency in urban and extra-urban commuting requires innovative solutions. One promising approach is the integration of a two-speed transmission into the drivetrain, which allows for load point shifting within the electric motor’s operating map. This strategy significantly reduces energy consumption while maintaining optimal performance. The presented research focuses on the design and development of a simple, cost-efficient two-speed transmission that provides a viable alternative to direct drive systems. While direct drive configurations are highly efficient, they often lack flexibility in
Tromayer, Juergen, Stückler, David, Kirchberger, Roland
Strength Analysis of Non-Power Wheelsets of CRH5 EMU Based on ANSYS Workbench2025-99-007210/17/2025
In order to study the strength of the non-power wheelset of CRH5 EMU, a three-dimensional digital model was established, and the finite element analysis software ANSYS Workbench was used to establish the non-power wheelset finite element model of CRH5 EMU. For the axle and wheel of the train, based on the European EN13103 and International Union of Railways UIC510-5 standards respectively, Calculate the load value of the axle and wheel under each working condition and load it to the corresponding position, and then simulate and analyze the stress distribution and deformation results of the wheel and axle, and evaluate and analyze them.
Huang, Zhenqing
System Design of Drivetrain for a Baja SAE Four-Wheel Drive Vehicle2025-01-506910/16/2025
A solid, reduced-weight drivetrain system with improved maneuverability was developed and tested by the Desert Hare Off-road Team from South Dakota State University (SDSU) for the 2024 Baja SAE Competition. Based on an analysis of previous competition results, driver feedback, and competition requirements, the designed drivetrain system should enable the Baja vehicle to achieve a top speed of 40 mph (64.37 kph) on a 40° slope and cover 150 ft in 4.5 s from a standing start. Following the systems engineering design approach, the drivetrain system was decomposed into six components. While every team had to use the same engine provided by SAE, the transfer case was designed, and the remaining components—including the transmission, differentials, axles, half shafts, and tires—were selected from the available options. The designed drivetrain was then installed on the team’s 2024 Baja vehicle for testing and validation. Test results indicated that the vehicle with the new drivetrain system
Spilde, Riley, Liu, Yucheng
Measurement and Characterization of Electronically Controlled Driveline Clutch SystemsJ3011_202510 (Current)10/03/2025
This SAE Recommended Practice covers the most common applications of electronically controlled on-demand clutch systems used in passenger (car and light truck) vehicle applications. This practice is applicable for torque modulation devices used in transfer cases, electronic limited slip differential (eLSD) cross-axle devices, rear drive module (RDM) integrated torque transfer devices with or without disconnect capability, and other related torque transfer devices.
Drivetrain Standards Committee
Methodology for Replicating and Quantifying Clicking-Noise Phenomenon in Gen 3 Wheel Hub Bearings and CVJ Using NVH Analysis and Data Processing2025-01-036809/15/2025
This paper presents a comprehensive methodology for replicating and quantifying the clicking-noise phenomenon occurring between Generation 3-wheel hub bearings and Constant Velocity Joints (CVJ), particularly in electric vehicles (EVs) where quiet operation makes this noise more noticeable. The study focuses on characterizing the system through contact pressure and distribution measurements, alternating torque tests, and advanced NVH (Noise, Vibration, and Harshness) data processing. The methodology includes detailed descriptions of the physical phenomena, driving conditions generating the noise, and the specific test setup used to simulate real-world conditions. The NVH analysis make use of high-pass filtering techniques to isolate clicking-noise events from background noise, ensuring accurate identification and quantification. Candidate solutions are assessed based on their ability to mitigate clicking noise through the utilization of inherent system components. The results
Nardicchia, Riccardo, Mauro, Ivan
Analysis of Front Axle Wheel End Temperature Measurements in Heavy-Duty Trucks2025-01-036409/15/2025
The Front Axle wheel end assembly is a critical component of Vehicle functionality, comprising a wheel hub positioned to rotate smoothly on an Axle spindle. This rotational movement is enabled by bearings positioned between the hub and the spindle, allowing for frictionless rotation. The Front Axle wheel ends’ temperature typically depends on several factors such as type of Vehicle, Load & driving conditions and health of the components involved. In general, the wheel ends can become warm during normal operation owing to friction generated by the rotation of the wheels and the interaction of various mechanical components such as Bearings and Brakes. However, if the temperature of the wheel ends becomes excessively hot, it could indicate potential issues such as Overheating brakes, Wheel bearing problems, improperly inflated tyres, and faulty components. As temperature rise, materials tend to expand. This expansion can affect the dimensions of critical components in the Front Axle wheel
Pandiyan, Mahendran, Jayaraman, Karthik, R, Sabari, B, Ellavarasan, Bhanja, Subrat Kumar
Design of a Fault-Tolerant Control Algorithm for Four-Wheel Steering Vehicle Steering Locking Based on Dynamic Model Reconstruction10-09-04-003608/21/2025
The motion control system, as the core executive component of the automatic hierarchical framework, directly determines whether autonomous vehicles can reliably and stably follow planned trajectories, making it crucial for driving safety. This article focuses on steering lock faults and proposes a cross-system fault-tolerant control (C-FTC) algorithm based on dynamic model reconstruction. The algorithm uses a classic hierarchical collaborative architecture: the upper-level controller employs an MPC algorithm to solve lateral velocity and yaw rate reference values in real-time, while the lower-level controller, designed based on the reconstructed dynamic model, uses an MPC algorithm to adaptively adjust actuator control quantities. In cases where four-wheel steering vehicles lose steering ability due to locked steering axles, the locked axle’s steering angle is treated as a state variable, and healthy actuator outputs are used as control variables to dynamically reconstruct the vehicle
Hu, Hongyu, Tang, Minghong, Chen, Guoying, Gao, Zhenhai, Wang, Xinyu, Gao, Fei
Validation of a Suspension Lifter Bracket through a Test Bench2025-36-030608/01/2025
In the Brazilian market, the 6x2 configuration for commercial vehicles is widely used. These vehicles feature a driven rear axle and a non-driven axle. For the non-driven axle, it is common to use a lifter system that allows the axle to be lifted when the vehicle is running empty. This system provides benefits such as reduced fuel consumption, lower tire wear, and reduced toll costs when charges are based on the number of axles in contact with the ground. Given these advantages, the system has a high demand, making it mandatory to perform a durability test prior to its market implementation. This paper will present the validation methodology for the lifter system bracket. To achieve this, the following stages will be discussed: CAE, instrumentation, data acquisition, test bench concept, test execution and results.
Leme, Cristiano, da Costa Rodrigues, Gilson, Figueiredo, Guilherme Galvão, de Souza Maria, Heitor Cunha, Pires, Luciano Rogério
Schaeffler optimizes rolling bearings for hydraulic and axle drives25TOFHP08_0608/01/2025
Rolling bearings with optimized friction and performance characteristics can have a significant influence on reducing the power loss, design envelope and weight of hydraulic motors and pumps, gearboxes and axles in construction machinery. If correctly designed, rolling bearings can make a significant contribution to reducing carbon dioxide emissions. Most construction machinery is still operated conventionally, using diesel engines and hydraulic components. In the widely used adjustable axial piston pumps and motors, the input and output shaft are usually supported by two tapered roller bearings that are adjusted against each other. When designing the bearing support, it is advisable to reduce the preload to precisely the required minimum allowed by the load spectrum. The lower bearing preload leads to permanently lower axial forces between the tapered roller end face and inner ring rib and, therefore, to a corresponding reduction in frictional torque.
Scharting, Stefan
Articulating Joints and Driveshafts - Nomenclature - Terminology - ApplicationJ901_202507 (Current)07/22/2025
The following definitions and illustrations are intended to establish common nomenclature and terminology for driveshafts and their articulating joints used in various drivetrain applications. In addition, useful guidelines are included for the application of driveshafts and their joints. For more specific details, refer to AE-07.
Drivetrain Standards Committee
Optimisation of Rotor Skewing of a Yokeless and Segmented Armature Axial Flux Machine2025-01-031107/02/2025
This paper presents an optimisation approach for rotor skewing in a Yokeless and Segmented Armature (YASA) design Axial Flux Machine (AFM) for electric vehicle applications. Torque ripple amplitudes are a critical factor influencing the noise, vibration and harshness (NVH) behaviour of electric motors. The focus of this paper is to reduce the torque ripple amplitudes of the dominant harmonics over the entire torque-speed characteristic of the AFM. The principle of the proposed approach is a segmented permanent magnet configuration of the AFM, where individual magnet segments can be circumferentially shifted to achieve optimal skewing configurations. Initial optimisations are performed using 2D finite element (FE) simulations, modelled as linear motors with multiple slices and different numbers of magnet segmentation. However, the accuracy of the 2D FE results is limited due to the lack of interaction between the individual segments and the insufficient representation of three
Müller, Karsten, Maisch, Hannes, De Gersem, Herbert, Burkhardt, Yves
A New Electrified Planetary Gear Set - The Cost- and Fuel-Efficient Alternative to Continuously Variable Transmissions2025-01-030907/02/2025
In order to mitigate the effects of climate change, the global transport sector, one of the largest emitters of CO2, needs to drastically reduce its emissions. Although hybridization and electrification are becoming increasingly popular as a solution for a variety of applications, their use in two- and three-wheelers, as well as in recreational and powersports vehicles, remains limited due to their high costs and complexity compared to conventional drivetrains with continuously variable transmissions (CVTs). Despite their affordability and simplicity, CVTs suffer from low mechanical efficiency, with transmission losses ranging from 20–50 %, highlighting a significant opportunity for improvement. In response to these limitations, this study presents the development and experimental evaluation of an electrified planetary gear set (ePGS) in a lightweight off-road vehicle. It is designed to overcome the efficiency limitations of CVTs while maintaining high driving comfort and low system
Jakoby, Moritz, Engels, Michael, Fahrbach, Timm, Andert, Jakob
Heavy-Duty Vehicle Lubricating GreasesJ2695_202506 (Current)06/30/2025
This SAE Recommended Practice was developed by SAE and the section “Standard Classification and Specification for Service Greases” cooperatively with ASTM and NLGI. It is intended to assist those concerned with the design of heavy-duty vehicle components and with the selection and marketing of greases for the lubrication of certain components on heavy-duty vehicles like trucks and buses. The information contained herein will be helpful in understanding the terms related to properties, designations, and service applications of heavy-duty vehicle greases.
Fuels and Lubricants TC 3 Driveline and Chassis Lubrication
Definition and Measurement of Power Transfer Unit Speed-Dependent Parasitic LossJ3039_202505 (Current)05/23/2025
This SAE Recommended Practice covers power transfer units (PTUs) used in passenger car and sport utility vehicles to support all wheel drive (AWD) operation. PTUs are typically full-time use geared devices (see 3.1). Some PTUs have additional features such as part-time on-demand capability via electronically actuated disconnect features, and other configurations are possible.
Drivetrain Standards Committee
Directivity Driven Simulation Methodology for Efficient Acoustic Encapsulation2025-01-004805/05/2025
Noise reduction at the source level is key to achieve the overall vehicle level interior targets. This paper presents a novel approach that integrates directivity analysis with simulation techniques to optimize acoustic encapsulation design for automotive sound sources to achieve the targeted radiation levels. The foundation for this methodology is to measure the angular distribution of sound pressure levels around the noise source so called Directivity, at every frequency of interest and determine the most effective acoustic encapsulation to achieve the targeted sound radiation. Accurate measurement of directivity in physical testing with fine angular resolutions can be complex and expensive, this study utilizes numerical simulation techniques using FEA to mitigate the challenges in mid frequency range. The scope of the study is focused on mid frequency sound pressure levels between 500-2500 Hz, which are determined to be significant contributors to overall DU noise. The first step is
Kaluvakota, Srikanth, Ghaisas, Nikhil, Pilz, Fernando
Hybrid 3D Sound Intensity Measurements and Simulations Applied to a Truck Rear Axle2025-01-010505/05/2025
This study presents a novel methodology for optimizing the acoustic performance of rotating machinery by combining scattered 3D sound intensity data with numerical simulations. The method is demonstrated on the rear axle of a truck. Using Scan&Paint 3D, sound intensity data is rapidly acquired over a large spatial area with the assistance of a 3D sound intensity probe and infrared stereo camera. The experimental data is then integrated into far-field radiation simulations, enabling detailed analysis of the acoustic behavior and accurate predictions of far-field sound radiation. This hybrid approach offers a significant advantage for assessing complex acoustic sources, allowing for quick and reliable evaluation of noise mitigation solutions.
Fernandez Comesana, Daniel, Vael, Georges, Robin, Xavier, Orselli, Joseph, Schmal, Jared
Application of Blocked Force Methodology to an Electrified Beam Axle from a Medium-Duty Truck in Vehicle and in a Dynamometer Test Cell2025-01-005405/05/2025
The recent addition of fully electric powertrains to propulsion system options has increased the relevance of sound and vibration from electric motors and gearboxes. Electrified beam axles require different metrics from conventional beam axles for noise and vibration because they have multiple sources of vibration energy, including an electric motor and a reduction gearbox. Improved metrics are also driven by the stiff suspension connections and lack of significant isolation compared to electric drive units. Blocked force is a good candidate because it can completely characterize the vibration energy transmitted into a receiver and is especially useful because it is theoretically independent of the vehicle-side structure. While the blocked force methodology is not new, its application to beam axles is relatively unexplored in the literature. This paper demonstrates a case study of blocked force measurement of an electrified beam axle with a leaf spring suspension. The axle was tested
Shaw, Matthew D, Grimmer, Michael J
Fast Noise Prediction of an Electric Powertrain Integrated in Various Vehicles2025-01-007605/05/2025
As the automotive industry moves toward electrification, new challenges emerge in keeping pleasant acoustics inside vehicles and their surroundings. This paper proposes a method for anticipating the main sound sources at driver’s ear for custom driving scenarios. Different categories of Road and Wind noise were created from a dataset of multiple vehicles. Using innovative sound synthesis techniques, it enables Valeo to make early predictions of the emergence of an electric axle powertrain (ePWT) once it is combined with this masking noise. Realistic signals could be generated and compared with actual acoustic measurements to validate the method.
Redon, Milan, Dendievel, Clement, Pluton, Matthias
Compatibility between Stability and Curving Ability of Railway Vehicles Using Conventional and Unconventional Bogie Frame Models02-18-03-001404/09/2025
This article analyses the fundamental curving mechanics in the context of conditions of perfect steering off-flanging and on-flanging. Then conventional, radial, and asymmetric suspension bogie frame models are presented, and expressions of overall bending stiffness kb and overall shear stiffness ks of each model are derived to formulate the uniform equations of motion on a tangent and circular track. A 4 degree of freedom steady-state curving model is formulated, and performance indices such as stability, curving, and several parameters including angle of attack, tread wear index, and off-flanging performance are investigated for different bogie frame configurations. The compatibility between stability and curving is analyzed concerning those configurations and compared. The critical parameters influencing hunting stability and curving ability are evaluated, and a trade-off between them is analyzed. For the verification, the damped natural frequencies and mean square acceleration
Sharma, Rakesh Chandmal, Sharma, Sunil Kumar, Palli, Srihari, Rallabandi, Sivasankara Raju, Sharma, Neeraj
T.R.I.C.K. 2.0: Enhanced Vehicle Dynamics Analysis and Estimation Harnessing Advanced Vehicle Sensors10-09-03-002504/09/2025
Automotive signal processing is dealt with in several contributions that propose various techniques to make the most out of the available data, typically for enhancing safety, comfort, or performance. Specifically, the accurate estimation of tire–road interaction forces is of high interest in the automotive world. A few years ago the T.R.I.C.K. tool was developed, featuring a vehicle model processing experimental data, collected through various vehicle sensors, to compute several relevant virtual telemetry channels, including interaction forces and slip indices. Following years of further development in collaboration with motorsport companies, this article presents T.R.I.C.K. 2.0, a thoroughly renewed version of the tool. Besides a number of important improvements of the original tool, including, e.g., the effect of the limited slip differential, T.R.I.C.K. 2.0 features the ability to exploit advanced sensors typically used in motorsport, including laser sensors, potentiometers, and
Napolitano Dell’Annunziata, Guido, Farroni, Flavio, Timpone, Francesco, Lenzo, Basilio
Fixture Stiffness Impact on Spindle Coupled Multi-Axial Input Durability Test for Front or Rear Axle with Non-isolated Subframes2025-01-825604/01/2025
The half vehicle spindle-coupled multi-axial input durability test has been broadly used in the laboratory to evaluate the fatigue performance of the vehicle chassis systems by automotive suppliers and OEMs. In the lab, the front or rear axle assembly is usually held by fixtures at the interfaces where it originally connects to the vehicle body. The fixture stiffness is vital for the laboratory test to best replicate the durability test in the field at a full vehicle level especially when the subframe of the front or rear axle is hard mounted to the vehicle body. In this work, a multi-flexible body dynamics (MFBD) model in Adams/Car was utilized to simulate a full vehicle field test over various road events (rough road, braking, steering). The wheel center loads were then used as inputs for the spindle coupled simulations of the front axle with a non-isolated subframe. Three types of fixtures including trimmed vehicle body, a rigid fixture with softer connections and a rigid fixture
Gao, Jianghua, Smith, Derek, Zhang, Xin, Yu, Xiao
Concept of an Electromechanical Brake-By-Wire System for Battery-Electric Vehicles2025-01-880404/01/2025
Brake-by-wire systems have received more and more attention in the recent years, but a close look on the available systems shows, that they have not reached full by-wire level yet. Most systems are still using hydraulic connections between main cylinder and the brake calipers on at least one axle to ensure functional safety. Mostly, this is the front axle, since the front brakes have to convert more kinetic energy during braking manoeuvers. Electromechanical actuators are currently used for rear brakes in hybrid brake-by-wire applications solely, since a loss of the front brake calipers can lead to severe conditions and control loss of the vehicle during braking. Further, the higher mass of battery electric vehicles (BEVs) leads to much higher braking forces on both axles and to increased sizes of the electromechanical calipers. This article presents a concept for a brake-by-wire system for battery electric vehicles, which features electromechanical brake actuators on all corners and a
Heydrich, Marius, Lenz, Matthias, Ivanov, Valentin, Stoev, Julian, Lecoutere, Johan
Systematic Design Considerations of Motor Selections for EV Powertrain Abstract2025-01-850804/01/2025
As one of the most important design choices in the powertrain design cycle, motor selection is conventionally performed according to given automotive requirements. Motor-related powertrain design parameters like gear ratio, power output ratio between different axles, are excluded from the motor design process. In this paper, three comparative studies are performed to investigate the impact of these motor-related powertrain design parameters on the motor performance and the weight/cost/efficiency of the entire EV powertrain. In the first study, three PM motor designs—characterized by high, medium, and low rated speeds—will be assessed for a two-axle EV using various gear ratio configurations. The same motor design will be used for both axles. In the second study, five motor designs with varying power and ratings (PM, non-PM) but identical rated speeds will be evaluated for a two-axle EV, permitting different power ratings for the front and rear axles. The design trade-offs between motor
Movahed, Ehsan, Godbehere, Jonathan, Jia, Yijiang
Application of Model-Based Horizon Prediction to Enhance Control Algorithm Performance by Compensating for Time Delays in Automotive Drivelines2025-01-857404/01/2025
Accurate estimation of crucial quantities in automotive drivetrain systems is essential for optimizing performance, durability, and emissions. However, the presence of time delays, arising from tasks scheduling and communication latency between control units, can significantly hinder the effectiveness of advance control algorithms. Closed-loop performance is often limited by the equivalent time delay between the control action command, its effect on the system, and the measurement of the reaction. Frequently, commands and measurements originate from different sources, requiring precise coordination to accurately estimate the driveline response. This paper presents a novel model-based approach that integrates Kalman filtering with horizon prediction techniques to effectively address time-delay compensation. By leveraging the descriptive capabilities of physics-based models, the proposed method enables to overcome synchronization misalignment between commands, actuations and measurements
Rostiti, Cristian, Patel, Nadirsh, Catkin, Bilal
Real-time Terrain Analysis for Off-road Autonomous Vehicles2025-01-834304/01/2025
One challenge for autonomous vehicle (AV) control is the variation in road roughness which can lead to deviations from the intended course or loss of road contact while steering. The aim of this work is to develop a real-time road roughness estimation system using a Bayesian-based calibration routine that takes in axle accelerations from the vehicle and predicts the current road roughness of the terrain. The Bayesian-based calibration method has the advantage of providing posterior distributions and thus giving a quantifiable estimate of the confidence in the prediction that can be used to adjust the control algorithm based on desired risk posture. Within the calibration routine, a Gaussian process model is first used as a surrogate for a simulated half-vehicle model which takes vehicle velocity and road surface roughness (GD) to output the axle acceleration. Then the calibration step takes in the observed axle acceleration and vehicle velocity and calibrates the Gaussian process model
Lewis, Edwina, Parameshwaran, Aditya, Redmond, Laura, Wang, Yue
A Torque Distribution Strategy for the Six-Wheeled Lunar Rover2025-01-830804/01/2025
As a crucial tool for lunar exploration, lunar rovers are highly susceptible to instability due to the rugged lunar terrain, making control of driving stability essential during operation. This study focuses on a six-wheel lunar rover and develops a torque distribution strategy to improve the handling stability of the lunar rover. Based on a layered control structure, firstly, the approach establishes a two-degree-of-freedom single-track model with front and rear axle steering at the state reference layer to compute the desired yaw rate and mass center sideslip angle. Secondly, in the desired torque decision layer, a sliding mode control-based strategy is used to calculate the desired total driving torque. Thirdly, in the torque distribution layer, the optimal control distribution is adopted to carry out two initial distributions and redistribution of the drive torque planned by the upper layer, to improve the yaw stability of the six-wheeled lunar rover. Finally, a multi-body dynamics
Liu, Pengcheng, Zhang, Kaidi, Shi, Junwei, Yang, Wenmiao, Zhang, Yunqing, Wu, Jinglai
Comprehensive Gear Shift Schedule of Heavy-Duty Commercial Electric Trucks Based on Dual Axle Driving2025-01-851004/01/2025
A heavy-duty commercial electric truck is equipped with dual axles, with the middle axle driven by an electric motor and a three-speed transmission and the rear axle driven by an electric motor and a two-speed transmission. To consider the dynamic and economy performance of the whole vehicle, as well as the gear distribution characteristics in the vehicle operation, a comprehensive shifting schedule based on the cross-particle swarm algorithm is proposed. By establishing the longitudinal dynamics model of the truck, the optimal power shift schedule and the optimal economics shift schedule of each of the two transmissions are studied. Under the standard test conditions, an optimal gear control strategy based on the dynamic programming algorithm considering the shift interval is proposed, and the shift schedule for the standard conditions is derived through the hierarchical clustering method. Furthermore, with 0-100 km/h acceleration capability and specific energy consumption as the
Guo, Jun, Zhang, Yunqing, Wu, Jinglai
Bicycle Pitch-over Reconstruction Analysis2025-01-868404/01/2025
During a pitch-over event, the forward momentum of the combined bicycle and rider is suddenly arrested causing the rider and bicycle to rotate about the front wheel and also possibly propelling the rider forward. This paper examines the pitch-over of a bicycle and rider using two methods different from previous approaches. One method uses Newton’s 2nd Law directly and the other method uses the principle of impulse and momentum, the integrated form of Newton’s 2nd Law. The two methods provide useful equations, contributing to current literature on the topic of reconstructing and analyzing bicycle pitch-over incidents. The analysis is supplemented with Madymo simulations to evaluate the kinematics and kinetics of the bicycle and rider interacting with front wheel obstructions of different heights. The effect of variables such as rider weight, rider coupling to the bicycle, bicycle speed, and obstruction height on resulting kinematics were evaluated. The analysis shows that a larger
Brach, R. Matthew, Kelley, Mireille, Van Poppel, Jon
Coupled Lateral-Longitudinal Vehicle Dynamics Modeling to Predict the Loads Experienced by Side Gears in the Differentials2025-01-851904/01/2025
Lumped parameter vehicle dynamics models are generally used in early design and development of vehicles due to simplicity and computational efficiency. In the literature, these models are generally divided into longitudinal, lateral, and vertical dynamics. Most of these formulations are limited to bicycle models with the vehicle represented as a lumped mass but seldomly coupled lateral-longitudinal lumped parameter models are proposed. In this paper, a coupled lateral-longitudinal lumped parameter model is developed that can be used to investigate the loads (torque & speed) experienced by the side gears in the differential. Side gears are connected to the left and right wheels through half shafts (axle shafts) and are in-mesh with pinion gears as part of a differential assembly. The differential experiences torque loading during all driving conditions but the pinion gear starts to rotate (mesh with side gears) when there is speed difference left to right (turning, split-mu, gravel, off
Sondkar, Prashant, Karra, Anudeep, Sandhu, Jaspal, Fischer, Charles
A Steering Control Method Applicable to an Eight-Wheeled Planetary Laboratory2025-01-830504/01/2025
In future planetary exploration missions, the Eight-Wheeled Planetary Laboratory (EWPL) will have sufficient capacity for tasks but will experience significant lateral slips during high-speed turns due to its large inertia. Modern technology allows for independent steering of all eight wheels, but controlling each wheel's steering angle is key to improving stability during turns. This paper introduces a novel rear-axle steering feed-forward controller to reduce sideslip. First, a mathematical model for the vehicle's steering is established, including kinematic equations based on Ackermann steering. Feed-forward zero side-slip control is applied to the third and fourth axles to counteract the side-slip angle of the center of mass. A multi-body dynamics model of the EWPL is then built in Chrono to evaluate the turning radius and optimize steering angle ratios for the rear axles. Finally, a steady-state cornering simulation on loose terrain compares the performance of the proposed
Liu, Jun, Zhang, Kaidi, Shi, Junwei, Yang, Wenmiao, Zhang, Yunqing, Wu, Jinglai
Evaluation Method for the Impacts of Truck Platoons Lateral Control on Pavement Performance2025-01-715202/21/2025
The introduction of autonomous truck platoons is expected to result in drastic changes in operational characteristics of freight shipments, which may in turn have significant impacts on efficiency, energy consumption, and infrastructure durability. Since the lateral positions of autonomous trucks traveling consecutively within a lane are fixed and similar (channelized traffic), such platooning operations are likely to accelerate damage accumulation within pavement structures. To further advance the application of truck platooning technology in various pavement environments, this study develops a flexible evaluation method to evaluate the impact of lateral arrangement within autonomous truck platoons on asphalt pavement performance. This method simplifies the impact of intermittent axle load applications along the driving direction within a platoon, supporting platoon controllers in directly evaluating pavement damage for different platoon configurations. Specifically, a truck platoon
Wenlu, Yu, Ye, Qin, Chen, Daoxie, Min, Yitong, Chen, Leilei
Definition and Measurement of Torque Biasing DifferentialsJ2817_202502 (Current)02/08/2025
This SAE Recommended Practice covers passive torque biasing axle and center differentials used in passenger car and light truck applications. Differentials are of the bevel gear, helical gear, and planetary types, although other configurations are possible.
Drivetrain Standards Committee
Design and Development of Range Extended-Hybrid Power Train for Two-Wheeler2025-28-019402/07/2025
Environmental awareness is being fostered in every sector, with particular emphasis on the automotive industry. Conventional internal combustion engines are responsible for greenhouse gas emissions and health issues. Researchers are looking for alternative technologies to reduce carbon footprint and for a green environment. In this study, electric drivetrain is designed for 20% range extension and retrofitted in conventional two-wheeler. An effective control technique has been developed, thoroughly tested, and effectively implemented on the two-wheeler. The hybrid drivetrain architecture is assessed for complexities such as the required space for the battery and the location for fitting the electric motor. During low-speed conditions, the electric motor reduced the emissions and minimized fuel consumption. Consequently, the overall utilization of internal combustion engines at low-speed conditions has decreased, leading to a decrease in the vehicle's fuel consumption and exhaust gases.
Banad, Chandrashekhar B, Devunuri, Suresh, Nair, Jayashri Narayanan, Hadagali, Balappa, Prasad, Gvl
Machining Studies on AISI 4140 Steel as Automotive Axle and Drive Shafts in Automobile via Numerical Simulation2024-01-523212/10/2024
This study focuses on machining automobile parts such as drive shafts and axles made of low alloy steel AISI 4140. The influence of cutting inserts geometrical parameters, viz., relief angle (RIA), rake angle (RAA), and nose radius (NA) are studied by designing experiments using Taguchi’s methodology. Numerical simulation is conducted using DEFORM-2D; a suitable L9 orthogonal array (OA) is considered for this work for varying combinations of inputs, and the resultant cutting force, maximum principal stress, and tool life are determined. Adopting a signal-to-noise (S/N) ratio minimizes the outputs for better machining conditions and achieves high-quality components with precision, tolerance, and accuracy. The ideal conditions obtained from the S/N ratio are RAA of 6°, RIA of 3°, and NR of 0.6 mm. Analysis of variance presents that the NR influences the resultant cutting force, wear depth, and work piece damage 73.51%, RAA following by 23.99%, and RIA by 2.03% achieved with a R2 value of
Senthilkumar, N.
Definition and Measurement of Transfer Case Speed-Dependent Parasitic LossJ2985_202412 (Current)12/06/2024
This SAE Recommended Practice covers transfer cases used in passenger car and light truck applications. Transfer cases are of the chain, geared, manually and electronically shifted types although other configurations are possible. The operating points (speeds, temperatures, etc.) were chosen to mirror those of the United States Environmental Protection Agency Vehicle Chassis Dynamometer Driving Schedules (DDS).
Drivetrain Standards Committee
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