Browse Topic: Axles

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Methodology for generating off-road tracks for powertrain simulation of off-road passenger vehicles2026-01-0275To be published on 04/07/2026
For off-road driving, particularly on steep grades and over barriers, the engine torque is a key design criterion of off-road vehicles. In conventional powertrains with combustion engines, mechanical all-wheel-drive systems combined with differential locks are used to distribute the torque demand between the front and the rear axle based on wheel-specific traction. With the growing market share of electric powertrains, off-road applications are becoming increasingly relevant for electric passenger cars. In comparison to conventional powertrains, electric all-wheel-drive configurations do not have a mechanical torque transfer between the two axles. If one axle experiences low traction, the second axle can rely on its own torque capability only. Transfer of unused torque of the slipping axle to the other one is not possible. The challenge, therefore, is to specify the right torque requirements for each axle for off-road driving while avoiding an over-dimensioning and high powertrain
Martin, Michael, Winkelheide, Jonas, Hartmann, Lukas, Sturm, Axel, Henze, Roman
Analysis of the Impact on Ride Comfort from Splitting the Unsprung Mass in Vehicle Modeling2026-01-0212To be published on 04/07/2026
The study was conducted to investigate the differences in ride comfort analysis between treating the unsprung mass as a whole and modeling it separately. A classical two-degree-of-freedom single-wheel vehicle vibration model and a three-degree-of-freedom single-wheel vehicle vibration model with split unsprung mass were established, with their state-space descriptions determined. The fundamental vibration response quantities of both models were identified, and time-domain simulations under random road excitation were performed using Matlab/Simulink. The results indicate that the two modeling approaches exhibit minimal differences in ride comfort analysis for the sprung mass, but there are certain differences for the unsprung mass. Additionally, for the three-degree-of-freedom single-wheel vehicle vibration model with split unsprung mass, the axle-to-wheel mass ratio was introduced to analyze the changes in the fundamental vibration response quantities when the unsprung mass increases
Jie, Li, Wei, Deng
Impact of Instantaneous Center of Rotation Variability on Path Planning and Performance of Park Assist Systems2026-01-0053To be published on 04/07/2026
Parking assist systems are among the most widely adopted driver-assistance features in modern vehicles. A key component of these systems is the path planning module, which ensures accurate vehicle alignment within a parking slot while satisfying various constraints such as maintaining slot centering, avoiding collisions in confined spaces, minimizing maneuver count, and achieving the shortest feasible path. Multiple path generation techniques—such as geometric, polynomial-based, and search-based methods—have been developed to enable safe and efficient parking maneuvers. However, most of these approaches rely on the simplifying assumption that the vehicle’s instantaneous center of rotation (ICR) is fixed, typically located on the non-steering axle. In practice, the ICR is not constant and can vary significantly across vehicles due to several physical and kinematic factors, including steering geometry, tire slip characteristics, suspension configuration, and weight distribution
Awathe, Arpit, Patanwala, Abizer, Jain, Arihant, Varunjikar, Tejas
Dog Clutch actuator Control to mitigate NVH2026-01-0003To be published on 04/07/2026
Dog clutches have long been employed in the automotive industry across various applications, including transmission systems, transfer cases, axle disconnects, and hybrid driveline architectures. Their ability to provide direct mechanical engagement makes them ideal for torque transmission with minimal energy loss. However, the transition between engaged and disengaged states can introduce noise, vibration, and harshness (NVH), which may be perceptible to vehicle occupants and affect overall driving comfort. A typical dog clutch relies on interlocking teeth for torque transfer, and its actuation can result in NVH due to factors such as friction between mating surfaces, backlash between engagement components, teeth-on-teeth contact during synchronization, and impact forces during clutch engagement. This paper presents Stellantis’s approach to controlling the actuator system to mitigate NVH effects during clutch engagement and disengagement, focusing on strategies that enhance drivability
Xu, Chengyi, Sagi, Rama Rohit Varma, Madireddy, Krishna Chaitanya, Verhun, Brandon
Novel Approach for Predicting Steering Rack Load Using Multi-Body Simulation2026-26-03781/16/2026
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 assists 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
Hypoid Gear Performance Redefined: Addressing Scoring & Whine Noise Concerns2026-26-00781/16/2026
Rear drive vehicles transfer power to the rear wheels through the Gear Carrier Assembly, which is fit at the central section of the Rear Axle. The Gear Carrier Assembly includes hypoid ring and pinion gears, set at the heart of the system. However, one of the common issues with hypoid gears is gear scoring and whine noise, both of which can seriously affect durability and reduce the overall performance of a vehicle. In this study, the focus is on design changes as well as process improvements to address these problems and at the same time improve gear reliability. On the design side, changes such as refining the macro geometry, upgrading materials, and modifying the heat treatment cycle were carried out. These helped in improving properties like contact stress resistance, bending and impact strength, and also reduced motion transmission error (MTE). From the process point of view, careful control over carburizing, hardening, and quenching temperatures, along with adjustments in
Praveen, Abhinav, Deshpande, Praveen, Jain, Saurabh Kumar, Parmar, Mayur, Karle, Nilesh, Kanagaraj, Pothiraj, Pagar, Pawan
Modelling and Analysis of Hypoid Gear Churning Loss in Rear Drive Axle: The Role of Oil Viscosity and Empirical Parameters2026-26-05081/16/2026
This definitive study investigates the variation of churning losses occurring with hypoid ring and pinion gear sets and factors that determine energy dissipation in these mechanisms. An in-depth investigation confirms that viscosity is critical, particularly because of its significant temperature-dependent variations. Furthermore, the study rigorously analyzes the data's experimental parameters to examine churning losses. These losses result from the interaction between the rotating gears and the lubricating oil, contributing to notable inefficiencies in the overall drivetrain. A robust and highly effective model has been developed to address this issue comprehensively. It accounts for variable oil viscosity with temperature and integrates key empirical parameters that reflect observed behaviours in gear systems. The study employs a multidimensional approach to examine how oil density impacts hydrodynamic resistance, which is key to understanding lubricant flow under varying conditions
Khan, Aliya Javid, Praveen, Abhinav, Kanagaraj, Pothiraj, Jain, Saurabh Kumar, AP, Baaheedharan
Correlation of Power Rating for Battery Electric Vehicles: Simulation vs. Test Validation in Accordance with Regulatory Compliance2026-26-05751/16/2026
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 BEV model in compliance with the GTR 21[1] standard, validating the simulation’s accuracy against physical test data. Simulations were conducted using Matlab and Simulink based Simulation tool to estimate Electric Drive Module (EDM) power at the motor output and gearbox input under standardized conditions. The operating parameters were shared with the testing team to ensure consistency; however, the initial test results deviated by approximately 4% to 5% 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 power rating targets. The results demonstrate a strong correlation between the simulation and test data, confirming the model’s accuracy and reliability. This study underscores
Mahajan, Prasad, Kesarkar, Sidhesh, Ali, Shoaib
Experimental Evaluation of Metro Rail Bogie Frame through Bench Testing2026-26-05611/16/2026
Bogie frame is a main skeleton and structural member in railway system which is carrying all the loads such as Suspensions, Axles, wheels, car body, Motor, Gear box etc. The frame is subjected an exceptional and service stresses in Vertical, Longitudinal, Lateral and twist directions throughout the service life which should be withstand for a life span of 30 years without failure. The purpose of this project is to determine the Structural integrity of the Metro rail bogie frame in consideration with EN13749 standard. This paper is the outcome of bench testing of metro rail bogie frame with the application of multiaxial loading in static and dynamic campaign through which stress data is collected with strain gauge sensors and correlated with the FEA results at initial design phase. This helps to verify and evaluate the design and validate the quality of metro rail frame as per the requirement specified in EN13749:2021 European standard in early design stages.
Tormal, Uday Bapurao, Sinnarkar, Nitin, Shinde, Vikram
Analysis and Optimization of Noise and Vibrational Performance of an Electric Axle2026-26-03401/16/2026
As the electric mobility landscape evolves, there is a growing emphasis on addressing the Noise, Vibration, and Harshness (NVH) challenges associated with electric drivetrains. The absence of an IC engine in EVs shifts the focus to other noise contributors such as gear meshing, electric machine operation, and structural vibrations. Despite the known influence of micro-geometry on gear dynamics, current optimization practices often rely on empirical adjustments or standard guidelines without fully utilizing advanced computational methods to predict and optimize NVH performance. There exists a pressing need for a systematic approach to analyze and optimize gear micro-geometry to reduce noise and vibration in high-speed e-axle applications. This research aims to bridge that gap by investigating the relationship between micro-geometry optimization and NVH characteristics of an e-axle. Through detailed modelling and optimization techniques, this research aims to identify optimal gear micro
Ankit, Priyadarshi, Kulkarni, Krishna, Momin, Vaseem
Incorporation of Strain Hardening and Sheet Thinning Effects during Forming Process for an Accurate Prediction of Buckling Loads on Sheet Metal Axle Parts2026-26-03911/16/2026
In the automotive industry, during the early phase of development, numerical prediction of strength and durability of chassis parts become crucial as these predictions help in design optimization, selecting the appropriate material and identifying potential issues before physical prototypes are built. One of the crucial simulation requirements is the prediction of accurate load carrying capacity or bucking load of axle links. When it comes to the sheet metal axle links there is a deviation in the hardware test and CAE results for load carrying capacity due to the non-integration of forming effects in the numerical simulation, resulting in overdesign of parts, increased costs and development time. This study aims to address these challenges by integrating forming effects experienced by the part during forming process into static strength simulations. These effects include plastic straining, which contributes to material strain hardening and local thickness changes that lead to thinning
R B, Govind, Selvaraj, Nirmal Velgin
Power Loss Evaluation in 4WD Axle & Correlation with Testing Results2026-26-01071/16/2026
In tractors, efficiency is predominantly influenced by the transmission system, with transmission elements being the major contributors to power losses. Enhancing efficiency necessitates monitoring these power loss areas. Transmission power loss refers to the reduction in power from the engine to the final drive elements. Various parameters and factors affect these losses, and analyzing these conditions helps identify and improve the components that contribute most to driveline efficiency. This study correlates analytically calculated power loss with losses measured during testing under different load conditions. Additionally, critical parameters contributing to power loss in gears, bearings & in seals have been identified, and theoretical relationships have been established.
Jayapal, Jayaraj, Mahapatra, Soumya Ranjan, Sethi, Suvendu Kumar, Joshi, Shrikant, Bange, Prashant
Evaluation of Driveline NVH Performance Using Linear Dynamic Finite Element Simulation2026-26-03221/16/2026
Automotive driveline design plays an important role in defining a vehicle’s Noise, Vibration and Harshness (NVH) characteristics. Driveline system, responsible for torque transfer from the engine/transmission to the wheels, is exposed to a wide spectrum of vibrational excitations. The industry’s shift toward turbocharged engines with fewer cylinders while maintaining the equivalent torque and power has led to increased low-frequency torsional vibrations. This paper presents some key design considerations to drive the NVH design of a driveline system using linear dynamic FE simulations. Using an E-W All-Wheel Drive driveline architecture with independent suspension as a case study, the influence of various subsystem modes on driveline NVH performance is examined. The paper further explores the strategies for vibration isolation, motion control, and mode management to identify the optimal bushing rates and its location. Furthermore, it examines the ideal bushing specifications for
Joshi, Atul Kamalakarrao, Subramanian, MANOJ
Machine Learning Approach to ISO Road Class Prediction Using Multiple Linear Regression2026-26-06671/16/2026
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
Simulation Driven Virtual Road Load and Accelerated Duty Cycle Generation for 3-Speed eAxle Systems2026-26-04011/16/2026
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 (RLD) is unavailable This study presents a methodology for virtually generating and processing road load data (RLD) to assess the durability of a new 3-speed electric axle (eAxle) design before building a physical prototype. Using AVL Route Studio, we simulated a range of driving conditions including urban, highway, and mixed-terrain routes, covering diverse global scenarios. These simulations produced high-frequency torque and speed data representative of real-world operation. Given that the raw dataset contained millions of points, direct use for fatigue assessment was impractical. To address this, the data was imported into Romax, where it was condensed into an accelerated duty cycle while preserving the cumulative fatigue damage patterns from the original dataset. Unlike
Ligade, Pratik, Khan, Nuruzzama Mehadi, Koona, Rammohan Rao
Parameter Estimation and Analysis of the Vertical Dynamics of an 8WD Military Vehicle2025-36-002812/18/2025
Vehicle dynamics encompasses a vehicle’s motion along three principal axes: longitudinal, lateral, and vertical. The vertical component is particularly susceptible to vibrational forces that can impair passenger comfort and overall performance, and the suspension system filters these vibrations. Engineers and designers conduct various studies to enhance quality and develop innovative designs in this context. However, when it comes to military vehicles, this system is often treated as classified. Consequently, the proposed work aims to determine the parameters of this system for a wheeled military vehicle with four axles. To achieve this, a mathematical model is proposed utilizing the concepts of power flow and kinematic transformers through a modular system, intended to serve as the foundation for solving an inverse problem to identify these parameters. This approach employs two stochastic methods, particle swarm optimization (PSO) and differential evolution (DE), and field tests to
de Oliveira, André Noronha, Bueno Caldeira, Aldélio, da Costa Neto, Ricardo Teixeira
Enhancing Tipper Stability during Descent with Dynamic Angle Adjustment2025-28-027611/6/2025
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 Vehicles2025-28-025711/6/2025
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
Finite Element Analysis and Test Validation of New Cummins Agricultural Structural Engine2025-28-037610/30/2025
Cummins Inc. is an American multinational corporation that designs, manufactures, and distributes engines, filtration, and power generation products. This paper presents an overview of the design, analysis and testing carried out by Cummins to demonstrate the capability of a new structural engine for an agricultural tractor application. In general applications, the powertrain assembly is mounted onto a vehicle chassis via vibration isolators. Due to tight packaging constraints in agricultural tractors, leaving no room for the chassis rails. The engine in conjunction with the transmission and a front axle carrier becomes an integral member of the vehicle chassis. This leads to the engine being directly subjected to the wide range of agricultural tractor application specific loads. Multiple analysis lead design (ALD) iterations were carried out using cutting edge CAE software such as Ansys, Dassault Systems fe-safe, and PTC Creo to ensure all elements of the complex acceptance criteria
Pathak, Arun Jyoti
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
Analysis of Front Axle Wheel End Temperature Measurements in Heavy-Duty Trucks2025-01-03649/15/2025
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 Reconstruction10-09-04-00368/21/2025
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 Bench2025-36-03068/1/2025
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_068/1/2025
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
Wear Protection for Electrified Transmissions Using e-Fluids without Active Sulfur04-18-03-00155/8/2025
In electrified drivetrains, lubricants are commonly in contact with the motor and other electrical components as well as the gears and bearings. Copper, present in these electrical components, is susceptible to corrosion by fluids containing active sulfur, which can lead to catastrophic failure of the unit. Lubricating fluids for electric vehicles (referred to as e-fluids) must not cause corrosion and must maintain high performance while having suitable electrical conductivity, material compatibility, and heat transfer properties. We describe a new formulation without active sulfur that has recently entered the market, which can protect against copper corrosion. We show that this e-fluid can provide suitable wear protection under field trial conditions, and that the e-fluid provides improved wear protection in bearing (FE-8) tests compared to a traditional extreme pressure axle fluid (API GL-4). Surface analysis (X-ray photoelectron spectroscopy) measurements of the component surfaces
Hopper, Elizabeth R., Williams, Megan S., Gahagan, Michael
Application of Blocked Force Methodology to an Electrified Beam Axle from a Medium-Duty Truck in Vehicle and in a Dynamometer Test Cell2025-01-00545/5/2025
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
Hybrid 3D Sound Intensity Measurements and Simulations Applied to a Truck Rear Axle2025-01-01055/5/2025
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
Fast Noise Prediction of an Electric Powertrain Integrated in Various Vehicles2025-01-00765/5/2025
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 Models02-18-03-00144/9/2025
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
Fixture Stiffness Impact on Spindle Coupled Multi-Axial Input Durability Test for Front or Rear Axle with Non-isolated Subframes2025-01-82564/1/2025
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
Systematic Design Considerations of Motor Selections for EV Powertrain Abstract2025-01-85084/1/2025
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
Concept of an Electromechanical Brake-By-Wire System for Battery-Electric Vehicles2025-01-88044/1/2025
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
Real-time Terrain Analysis for Off-road Autonomous Vehicles2025-01-83434/1/2025
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 Rover2025-01-83084/1/2025
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 Driving2025-01-85104/1/2025
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 Analysis2025-01-86844/1/2025
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
A Steering Control Method Applicable to an Eight-Wheeled Planetary Laboratory2025-01-83054/1/2025
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 Performance2025-01-71522/21/2025
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)2/8/2025
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
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.
Rear Twist Beam Optimization by Cross Beam and Bush Orientation Technique to Meet Performance Targets2024-28-026912/5/2024
Born Electric SUVs generally feature a high centre of gravity (CG) with greater rear axle weight. They use sophisticated multi-link suspension, which offers large scope for ride comfort and handling optimisation. The development costs and time associated with the process will position the vehicle in a premium segment. Usually, the twist beam (RTB) is used in lower rear axle weight category vehicles due to its simple design and cost effectiveness. This study showcases exploration for implementation of RTB on higher weight category vehicles, which usually uses multi-link suspension. The limitation of the twist beam is to exhibit lateral force compliance oversteer during cornering, due to large moment arm from wheel centre to twist beam bush. Lack of lateral stiffness when compared to multi-link suspension causes delayed rear axle yaw response. It also has reduced scope in ride-handling optimization due to its simple structure and kinematics. So, in order to maximize the performance
Prabhakara Rao, Vageesh, Rasal, Shraddhesh, Asthana, Shivam, M, Sudhan, Vellandi, Vikraman
Honda pioneering new manufacturing tech for Zero electrified platform24AUTP12_1212/1/2024
Honda has long been at the cutting edge of mobility and tech, with everything from the Asimo robot of 20 years ago to plans for reusable rockets to launch lightweight satellites into orbit. During a Tech Day event in early October in Tochigi, Japan, the Japanese automaker announced further details of its upcoming Honda 0 architecture (Honda calls it “Honda Zero” but writes it with the number), its first in-house electric platform designed from the ground up. Honda also discussed some of the advanced manufacturing techniques it's pioneering to reach its core design and technology tenants.
Bassett, Abigail
Development and Experimental Validation of a Physics-Based Identification and Mitigation Strategy for Torsional Vibratory Behavior in Medium-Duty Commercial Vehicle Drivelines02-18-01-000111/8/2024
Torsional vibration generated during operation of commercial vehicles can negatively affect the life of driveline components, including the transmission, driveshafts, and rear axle. Undesirable vibrations typically stem from off-specification parts, or excitation at one or more system resonant frequencies. The solution for the former involves getting the system components within specification. As for the latter, the solution involves avoiding excitation at resonance, or modifying the parameters to move the system’s resonant frequencies outside the range of operation through component changes that modify one, or more, component inertia, stiffness, or damping characteristics. One goal of the effort described in this article is to propose, and experimentally demonstrate, a physics-based gear-shifting algorithm that prevents excitation of the system’s resonant frequency if it lies in the vehicle’s range of operation. To guide that effort, analysis was conducted with a numerical simulation
Dhamankar, Shveta, Ali, Junaid, Parshall, Evan, Shaver, Gregory, Evans, John, Bajaj, Anil K.
Energy Efficiency Evaluation of a Hybrid Electric Tractor-Semi-Trailer Prototype2024-01-431911/5/2024
The objective of the project was to evaluate the energy efficiency of a hybrid electric tractor-semi-trailer combination prototype. The prototype was developed for log hauling application by integrating an existing tractor with an electric semi-trailer to improve fuel consumption and reduce greenhouse gas emissions. One of the conventional axles of the quad axle semi-trailer was replaced with a drive axle powered by an electric motor. Tests were conducted on a 105 km test route with a maximum difference in elevation of 355 m, including a hilly section with a length of 89 km. The results indicated fuel savings ranging from 10.5% to 14% per test run, with an average fuel savings of 12% when the electric drive axle was engaged. The hybrid electric tractor semi-trailer consumed 17.5% less fuel up-hill and 9.4% less down-hill. Throughout each test run, the battery’s state of charge fluctuated, averaging between 88% at the start and 52% at the end. Prior to each run, the batteries were
Surcel, Marius-Dorin, Mercier, Steve, Bonsi, Adime Kofi
Q&A24AUTP10_1210/1/2024
During a recent Bosch tech showcase, we spoke with Joe Dear, engineering manager for electric propulsion systems at Linamar. The Guelph, Ontario-based parts manufacturer is no stranger to building unsung components for the auto industry, including gears, camshafts, connecting rods, and cylinder heads. The Linamar team was demonstrating a modified Ram 2500, a collaboration between Bosch and Linamar, that was outfitted with a prototype electric powertrain and new e-axles: a rigid axle on the rear (with a Bosch motor and inverter) and a steering axle up front.
Blanco, Sebastian
GEARING UP A NEW ELECTRIFIED TRUCK24TOFHP08_048/1/2024
Eaton and BAE Systems have collaborated to create an electric powertrain featuring BAE electronics and an Eaton four-speed transmission. One of the advantages that OEMs have long touted for battery-electric vehicles (BEVs) has been the elimination of components like the transmission. The instant torque that an electric motor can supply often mitigates the need for any sort of torque multiplication beyond what the chosen axle ratio can provide. However, what the industry has found is that this concept has its limitations in certain use cases. When asked to haul heavy loads over sustained grades or at freeway speeds, a direct drive BEV powertrain rapidly begins losing efficiency and range. Of course, batteries and motors can be scaled up to handle heavier loads, but these methods add both cost and weight to vehicles for which these numbers are already major concerns.
Wolfe, Matt
Wheel End Assembly and Axle Spindle Interface Dimensions - Truck and BusJ2475_202407 (Current)7/26/2024
This recommended practice contains dimensions and tolerances for spindles in the interface area. Interfacing components include axle spindle, bearing cones, bearing spacer, and seal. This recommended practice is intended for axles commonly used on Class 7 and 8 commercial vehicles. Included are SAE axle configurations FF, FL, I80, L, N, P, R, U, and W.
Truck and Bus Wheel Committee
Axle Flange Sources of Driveline Imbalance: Calculation Methods from Runout and Location Error, with Validation05-17-03-00206/19/2024
The axle, or differential, flange is understood to be a large source of vehicle driveline imbalance, or unbalance, through defining the center of rotation of a driveshaft. The tolerances and methods of manufacturing and assembly are therefore very important. The aim of the current investigation, is to understand and quantify the imbalance contributions from flange radial and axial runout, along with location error between the driveshaft and axle flange. An overview of the measured radial and axial runouts from a population of 100 axle assemblies is presented, including correlation of the imbalance amplitude distributions to some standard probability density functions. It was found from the investigation, that it is important to understand the nature of any source of runout, relative to any subassembly/component-level balancing, in modeling the transfer function from runout to imbalance loading. Methods for calculating the imbalance of an assembled driveline are presented, which include
Leslie, Andrew C., Liew, Andrew, Baddeley, Viv, Dent, Solomon, Meehan, Paul A.
A Hybrid Method for Characterization and Improvement of NVH Performance of Axle System2024-01-29506/12/2024
The axle system is a major contributor for road induced vehicle interior noise. However, it is challenging to characterize the NVH performance of the axle system because it is coupled with both the tire/wheel and the body structure. In this article, we introduce a global approach to control the NVH performance of the axle system. The force transmissibility based on the blocked force concept was defined as the indicator of NVH performance of the axle system. A hybrid method combining test and simulation was developed to assess the intrinsic NVH performance of the axle system. The force transmissibility of the axle system is the blocked force generated by the axle system at the body mounting points with a unit of input force on the wheel. It can be simulated easily by FEM with rigid boundary conditions. However, measuring the blocked forces of the axle system is much more complex because it requires very stiff boundary conditions, which are difficult to realize on a realistic test rig
Wang, Shanjin, Gagiu, Constantin
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