Browse Topic: Drivetrains

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The Influence of Time-Varying Meshing Stiffness on the Vibration Characteristics of Gears in Electric Drive Axle Reducers2026-99-02057/31/2026
The dynamic characteristics of the electric drive axle of the new energy commercial vehicle is an important performance to evaluate its quality, and the dynamic performance of the two-stage helical gear transmission system in the electric drive axle reducer directly reflects the dynamic performance of the electric drive axle. This study focuses on the secondary gear transmission system of the electric drive axle reducer of the new energy commercial vehicle, and mainly studies the influence of the tooth surface contact stiffness with the change of meshing on the vibration performance of the transmission system. Through establishing the coupled nonlinear dynamic model of torque-begear shaft of high-speed helical gear, the dynamic equations of the system under the influence of time-variable contact mesh stiffness are derived. Taking gear error excitation and support stiffness into consideration, a 3D model software is used to build the simulation virtual model of bevel gear of electric drive axle reducer, and the dynamic simulation analysis of its transmission system is carried out. By setting different tooth contact stiffness coefficients, the variation rules of translational vibration acceleration, angular acceleration and spectrum response of transmission gears are studied systematically. Simulation results indicate that selecting the contact stiffness coefficient within 80% to 90% of the average mesh stiffness value leads to improved meshing performance in the gear transmission system of an electric drive axle reducer. This configuration results in reduced vibration amplitude, narrower sidebands, and decreased dynamic transmission error, thereby effectively enhancing the NVH performance of the transmission system. The findings also provide an important reference for optimizing the meshing behavior of electric drive axle reducers.
Pan, Yunping, Song, Junchen, Du, Shuai, Wu, Changquan, Liao, Lieping
On Disturbance-Aware Minimum-Time Trajectory Planning: Evidence from Tests on a Dynamic Driving Simulator10-10-03-00267/13/2026
This work aims to investigate how disturbance-aware, robustness-embedding reference trajectories translate into actual driving performance when executed by professional drivers in a dynamic driving simulator. The study compares three planned reference trajectories against a free-driving baseline (NO-REF) to assess the trade-offs between lap time (LT) performance and steering effort: NOM, the nominal time-optimal trajectory; TLC, a track-limit-robust, time-optimal trajectory obtained by tightening margins to the track edges; and FLC, a friction-limit-robust, time-optimal trajectory obtained by tightening against axle/tire saturation. All reference trajectories share the same minimum LT objective with a small steering-smoothness regularizer, and are evaluated with two professional drivers driving a high-performance car on a virtual track. The reference trajectories stem from a disturbance-aware minimum-LT framework recently proposed by some of the authors, where worst-case disturbance growth is propagated over a finite horizon and used to tighten tire-friction and track-limit constraints, preserving performance while delivering probabilistic safety margins. LT and steering energy (SE) are evaluated as indicators of driving performance and steering effort, respectively, while RMS values of lateral deviation, speed error, and drift angle are used to characterize driving style. The results reveal a Pareto-like trade-off between LT and SE: NOM achieves the shortest LT, but with the highest SE, TLC minimizes SE at the expense of longer LT, while FLC lies near the efficient frontier, markedly reducing SE relative to NOM with only a minor LT increase. Removing reference trajectories (NO-REF) leads to both higher SE and longer LT, confirming that trajectory guidance improves pace and control efficiency. Overall, the findings highlight reference-based and disturbance-aware planning, particularly the FLC variant, as effective tools for training and for achieving fast yet stable trajectories.
Masoni, Matteo, Palermo, Vincenzo, Gabiccini, Marco, Gulisano, Martino, Previati, Giorgio, Gobbi, Massimiliano, Comolli, Francesco, Mastinu, Gianpiero, Guiggiani, Massimo
Development of a Load Responsive Mechanical Shifting Mechanism and its Benefits for Battery Electric Vehicles2026-37-00266/9/2026
Many high-end electric vehicles use an automatic two-speed transmission. The ability of the drivetrain to switch between two gear ratios improves vehicle performance and increases driving range. The aim of the presented research work is to transfer these advantages to small and lightweight battery-electric vehicles, which face significant cost and weight constraints and therefore cannot rely on highly sophisticated electric motors. Direct-drive systems are widely used in this vehicle class due to their simplicity and high baseline efficiency. However, they offer limited flexibility in adapting the operating point of the electric motor under varying load conditions. A two-speed transmission can overcome this limitation by enabling load point shifting, allowing the motor to operate closer to its optimal efficiency region during both urban and extra-urban driving. This results in improved energy consumption without adding substantial system complexity. Currently, only actuated transmissions are offered on the market, with automation adding a high degree of complexity and representing a major cost driver. Therefore, the focus during the concept development phase was on designing a fully mechanical, self-shifting system to meet the cost pressures of the targeted vehicle classes. Hence, the team at ITnA developed and patented a solution that enables automatic gear changes solely based on output torque, which reflects the motor load and the current driving situation. In the present work, both the operating principle of the technology and the advantages regarding the performance and efficiency of electric vehicles are described. Owing to its simple architecture and the absence of electronics, the transmission is inherently robust and durable, making it a significant contribution to the development of sustainable and affordable e-mobility for the mass market.
Napetschnig, Christof, Tromayer, Juergen, Stückler, David
Hitting the road IN THE ALL-NEW VNR26TOFHP06_016/1/2026
Volvo Trucks' revised VNR brings updated safety tech, improved fuel economy and driver comfort features to the regional haul segment. Volvo Trucks has continued its rollout of new models for every sector of the commercial truck market. The redesigned VNR is the latest model to see the spotlight. The new VNR naturally carries all of Volvo's latest safety tech, but also prioritizes maneuverability, fuel efficiency and configurability for a wide variety of fleet uses. “The VNR is an incredibly versatile truck,” said Maddie Sullivan, product marketing manager. “There are so many different configurations to meet our customer's needs. We offer four different cab sizes, three different axle configurations and two different chassis configurations.”
Wolfe, Matt
Sealing integrity in a FORMULA 1 LIMITED-SLIP DIFFERENTIAL26AUTP06_026/1/2026
High-temperature hydraulic control in a Formula 1 drivetrain requires dimensional stability, controlled sealing force, and resistance to wear under sustained pressure cycling. Inside the limited-slip differential, the sealing architecture plays a defined mechanical role in maintaining consistent torque management under race conditions. In Formula 1, drivetrain reliability and performance are closely linked. The limited-slip differential (LSD) governs torque distribution between the rear wheels, allowing controlled transfer of power to the wheel with greater available grip. By limiting speed difference across the rear axle, the differential contributes directly to traction and cornering behavior, particularly where grip levels vary across the vehicle. At the center of this assembly is a hydraulic actuator that clamps a friction clutch inside the differential. The actuator modulates clutch engagement to redirect torque as grip levels change through corner entry, mid-corner load transfer, and acceleration on exit. Its performance depends on precise hydraulic control, which in turn depends on sealing integrity. Within this system, seal integrity is paramount, as significant leakage could cause a catastrophic loss of system function and force the team to retire the car.
Clarke, Andrew
Research on Carbon Emission Calculation Algorithm for Trucks on Expressways in Xinjiang2026-99-17185/22/2026
In the field of measuring carbon emissions from road traffic, the carbon emission factor method has remarkable advantages in terms of standardization, operational simplicity, and adaptability. Backed by the IPCC international standard framework, this method offers convenient access to a dynamic factor database and incorporates an adaptive adjustment mechanism for real-world scenarios, such as technological advancements and regional disparities. Against this backdrop, this study employs the carbon emission factor method to establish refined measurement models based on load capacity and fuel consumption, respectively. These models are then applied to quantify carbon emissions from trucks on specific sections of the G30 highway in Xinjiang. The load-based model calculates emissions by integrating truck axle weight and driving distance, while the fuel-based model analyzes fuel consumption data in conjunction with driving mileage. A comparison of the two models in terms of measurement differences is also carried out in the research. Furthermore, it provides a granular breakdown of energy consumption data for fully loaded trucks exceeding 31 tons, as specified by national standards. This introduces a novel approach to precise carbon emission measurement in heavy-duty transportation in northwestern China. It also provides a method for establishing an emission mitigation policy that is region-specific on a scientific basis.
Li, Maowen, Han, Dongchen, Gao, Yansen, Bai, Haotian, Dai, Xiaomin
Thermal Management of Electric Microtruck Motors2026-01-50264/9/2026
This study investigates the gradeability performance of an L7e-class electric micro truck from both vehicle dynamics and thermal perspectives. A 1D simulation model (Amesim) was developed and validated with multiple test results. Using inputs such as motor characteristics, drivetrain configuration, and vehicle mass, the model analyzed vehicle performance on a 20% gradient, calculating the required torque, achievable motor speed, and corresponding vehicle speed. Furthermore, gradeability limits were evaluated, and the effects of gear ratio and airflow rate around the air-cooled motor on both gradeability and thermal behavior were examined. The findings provide practical insights for improving the powertrain and cooling system design of lightweight electric vehicles. The results showed that selecting an appropriate gear ratio can enable the motor to operate more efficiently under demanding driving conditions. A 20% increase in the gear ratio was found to delay motor heating by up to 10%. However, its effect was observed to be negative under driving conditions such as WLTP, which require variable RPM demand.
Turan, Azim, Kantaroğlu, Hasan Hüseyin, Akbaba, Mahir, Kasım, Recep Faruk, Yarar, Göktuğ
Methodology for Generating Off-Road Tracks for Powertrain Simulation of Off-Road Passenger Vehicles2026-01-02754/7/2026
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 over-dimensioning and high powertrain costs. The torque requirements must be defined in the very early stages of development, when real-world measurements are not available. As a result, these definitions must be based on simulation. This paper presents a simulation approach to address this engineering challenge. A key aspect is the modeling of the representative off-road track as input for the simulation. A method of track generation was developed by using real vehicle measurement data from off-road tracks, combined with GPS and road information. The virtual track modelling process was designed to match the overall torque behavior observed in both simulation and measurement to confirm a validated and trustful simulation approach. The validation of the approach will be shown.
Martin, Michael, Winkelheide, Jonas, Hartmann, Lukas, Sturm, Axel, Henze, Roman
Backlash Evasion Strategy for Enhancing Vehicle Cornering Performance2026-01-06404/7/2026
This study presents a torque distribution control strategy for EVs with e4WD powertrain to overcome the trade-off between ensuring vehicle acceleration and deceleration responsiveness and mitigating backlash shock in the driving system. The deterioration of the drivability which occurs from the intrinsic hardware characteristics of the drivetrain is prevented by designing a response-priority drive mode in which neither front or rear motor torque is allowed to change its sign. Instead, in such drive mode, the front motor torque is only allowed to perform regenerative braking while the rear motor torque is only allowed to produce positive acceleration torque. In order to avoid sacrificing the maximum acceleration by applying such strategy, the mode transition function is implemented as well. In addition, in order to prevent backlash impact due to drivetrain compliance, variable offset torque based on drivetrain compliance model is evaluated in real time and applied to each motor command generation strategy. The enhancement of vehicle drivetrain responsiveness directly leads to improved track driving performance, particularly for the neutral-balance phase during harsh cornering. The effectiveness of the suggested driveline torque distribution method is verified using an actual vehicle driven on the race track, and the vehicle responsiveness followed by track driving performance indices are numerically assessed for comparison.
Oh, JIWON, Lee, Ho Wook
Impact of Instantaneous Center of Rotation Variability on Path Planning and Performance of Park Assist Systems2026-01-00534/7/2026
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. Neglecting these variations can introduce trajectory inaccuracies, reducing the precision and reliability of automated parking systems. Although prior studies have explored estimation methods for the instantaneous center of rotation (ICR), limited research has examined how variations in the ICR influence overall parking performance. This paper addresses this gap by investigating the impact of ICR variation on path generation and motion control accuracy in parking assist systems. A simulation-based study using an SUV-class vehicle model is conducted to evaluate system behavior across diverse parking scenarios. The results demonstrate how ICR assumptions affect path precision and overall parking accuracy, providing insights to enhance path planning and control algorithms for real-world applications.
Awathe, Arpit, Patanwala, Abizer, Jain, Arihant, Varunjikar, Tejas
Experimental Validation of a Multi-Row Tapered Roller Bearing Analytical Model for Relating Preload to Frequency Response Characteristics2026-01-00084/7/2026
Roller bearings are used in many rotating power transmission systems in the automotive industry. During the assembly process of the power transmission system, some types of roller bearings (e.g., tapered roller bearings) require a compressive preload force. Those bearings' rolling resistance and lifespan strongly depend on the preload set during the installation process. Therefore, accurate setting of the preload can improve bearing efficiency, increase bearing lifespan and reduce maintenance costs over the life of the vehicle. A new method for bearing preload measurement has shown potential for both high accuracy and fast cycle time using the frequency response characteristics of the power transmission system. An open problem is experimental validation of the multi-row tapered roller bearing analytical model. After validation, the analytical model can be used to predict the assembled system damped natural frequency for a desired bearing preload. This work presents the experimental validation of the analytical model including the experimental test stand, test method, test results and comparison to analytical model. The developed test stand represents an automotive pinion shaft/gear as might be found in a rear axle and can be mounted either vertically or horizontally to simulate assembly and operational positions of the axle and to consider the effects of gravity. To measure bearing preload, the test stand is instrumented with a load cell, and each shaft has strain gages installed. Multiple accelerators are used to measure the system frequency response to an impulse provided by a modal hammer. For this work, three different bearing pairs in back-to-back configuration are tested at seven different preload values. The analytical model is evaluated using the same bearing designs and the preloads measured from the test stand. Results from the analytical model are compared to experimental results to validate the analytical model.
Gruzwalski, David, Mynderse, James
Sideslip Angle Estimation for Mining Trucks Based on Real-Time Cornering Stiffness Identification2026-01-06184/7/2026
High-precision estimation of key vehicle–road state parameters is crucial for ensuring the accurate and safe control of mining trucks (MT), as well as for reliable trajectory tracking. Among these parameters, the vehicle sideslip angle is particularly critical for assessing and predicting lateral stability. However, its direct measurement is challenging, and its estimation typically depends on an accurate characterization of tire cornering stiffness. For MT, large variations in loading conditions (from empty to fully loaded) pose significant challenges to sideslip angle estimation due to the resulting nonlinearity and variability of tire cornering stiffness. To address this issue, a novel joint estimation framework integrating the Moving Horizon Estimation (MHE) and Square-Root Cubature Kalman Filter (SCKF) is proposed to simultaneously achieve high-precision estimation of both tire cornering stiffness for each tire and vehicle sideslip angle. In this framework, the cornering stiffness of the front, middle, and rear axles is identified and updated in real time using MHE through a forgetting-factor least squares method based on yaw rate and lateral acceleration data within a fixed-length time window. The updated stiffness is then incorporated into the SCKF for accurate estimation of the sideslip angle. This sequential process effectively establishes a coupling between the estimation of the two parameters, forming an integrated joint estimation mechanism. The proposed framework is validated on the TruckSim–Simulink co-simulation platform, and the results confirm its superior accuracy and robustness, demonstrating its potential to improve the safety and control performance of MT.
Xia, Xue, Shen, Peihong, Jiao, Leqi, Li, Tao, Chen, Huiyong, Zhao, Kun, Jiao, Leqi, Zhao, Zhiguo
Dog Clutch Actuator Control to Mitigate NVH2026-01-00034/7/2026
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 it 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 and system refinement in electrified vehicle platforms.
Xu, Chengyi, Madireddy, Krishna Chaitanya, Verhun, Brandon
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 conventional binning methods, which can misrepresent load severity, our damage-matching approach maintained accurate replication of gear contact, gear bending, and bearing damage characteristics. This methodology enables early-stage durability validation of eAxle designs without dependence on physical testing or historical data. Our findings suggest a correlation between condensed and original damage profiles for transmission components, indicating that this virtual approach may be useful. The framework offers a potential method for virtual RLDA work that could help with design verification and optimisation for electric drivetrains.
Ligade, Pratik, Khan, Nuruzzama Mehadi, Koona, Rammohan Rao
Efficiency Improvement of an Electric Vehicle e-Transaxle through Gear, Bearing, and Lubricant Optimization Strategies2026-26-00531/16/2026
Improving transaxle efficiency is vital for enhancing the overall performance and energy economy of electric vehicles. This study presents a systematic approach to minimizing power losses in a single-speed, two-stage reduction e-transaxle (standalone) by implementing a series of component-level design optimizations. The investigation begins with the replacement of conventional transmission oil with a next-generation low-viscosity transmission fluid. By adopting a lower-viscosity lubricant, the internal fluid resistance is reduced, leading to lower churning losses and improved efficiency across a wide range of operating conditions. Following this, attention is directed toward refining the gear macro-geometry to create a gear set with reduced power losses. This involves adjustments to parameters such as module, helix angle, pressure angle, and tooth count, along with the introduction of a positive profile shift. These modifications improve the contact pattern, lower sliding friction, and achieve a more uniform distribution of forces along the gear flanks. As a result, load-related gear losses are significantly diminished. In the final stage of optimization, high-performance, low-friction bearing designs are incorporated to further reduce mechanical drag and enhance overall drivetrain efficiency. For bearing loss optimization strategies, energy-efficient ball bearing designs is examined and engineered to lower internal friction and increase operational lifespan. Energy Efficient bearing prove significant improvement in efficiency and further reducing mechanical losses within the drivetrain. Taken together, the findings highlight that careful selection of lubricants, refinement of gear geometry, and adoption of advanced bearing solutions can deliver notable gains in transaxle efficiency. These outcomes reinforce the potential of such targeted interventions as practical means for boosting drivetrain performance in electric vehicle applications.
Agrawal, Devesh, Bhardwaj, Abhishek, Bhandari, Kiran Kamlakar
Propeller Shaft Yoke Phase and Inclination Angle Optimization in Passenger Vehicles through Analytical Method2026-26-03481/16/2026
The customer perception of ride comfort with vehicle performance is the most important aspect in a vehicle design. The ride comfort and vehicle performance are influenced by driveline components i.e. propeller shaft phase angle, inclination angle and critical frequency of the driveline system. The optimization of the driveline system is essential to ensure the efficient and smooth power transfer. Propeller shaft is one of the critical components in the driveline to influence the vehicle performance. Propeller shaft characteristics influenced by several factors like vehicle max torque, propeller shaft joint type, materials properties, UJ phase and inclination angle and shaft unbalance value. The optimization of the above parameter within the tolerance limit enables to meet the required performance standard. Various methodologies are available to optimize these parameters to enhance the vehicle performance and comfort leads to customer satisfactions. This study focuses on the analytical optimization of the propeller shaft’s universal joint (UJ) phase and inclination angle and validated at vehicle level. An analytical model was employed to evaluate the velocity fluctuations across the full rotation of the propeller shaft by considering the different UJ phase angles (0° − 360°) and inclination angles (1° − 5°). It was observed from the study that optimization of these parameter improves the vibration performance and decreases the velocity fluctuations. The results shows that the well optimized propeller shaft will enhance smoothness in the driveline systems, reduction in NVH levels, vehicle performance and ride comfort. This study suggests the importance of the precise geometry alignment in driveline design and provide the further refinement methodology.
Kumar, Sarvesh, Sanjay, L, S, Manickaraja, Kanagaraj, Pothiraj
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 quenching pressure, played a major role in improving hardness distribution and the quality of the microstructure. Finishing steps after lapping, like vibro-deburring and manganese phosphating, were also introduced to achieve surface finishes that were very close to ground gears. With these combined measures, noticeable improvements were seen, MTE was reduced, the contact pattern shifted from being center-biased to diagonal-biased, drivetrain losses came down, NVH performance improved, and durability increased. Overall, the study highlights the steps taken to tackle scoring and noise issues in hypoid gears, with the aim of making them more reliable and efficient in operation.
Praveen, Abhinav, Deshpande, Praveen, Jain, Saurabh Kumar, Parmar, Mayur, Karle, Nilesh, Kanagaraj, Pothiraj, Pagar, Pawan
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 limitations, an alternative method is introduced in this study, incorporating additional & generated parameters and employing a multiple linear regression model based on machine learning techniques. This paper outlines the detailed steps of the machine learning process, including feature engineering methods such as feature extraction, transformation, selection, and reduction. It also explores model fine-tuning strategies guided by performance metrics. The proposed methodology significantly improves the accuracy of road class predictions while reducing the time, effort, and challenges associated with instrumentation, data acquisition, and post-processing activities.
P, Praveen Kumar, P, Dayalan, Sriramulu, Yoganandam
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
Clutch Thermal Adequacy Assessment in Repeat Restart Launch Conditions on Gradient2026-26-04341/16/2026
The clutch is a mechanical device that connects and disconnects engine power to the drivetrain through the clutch disc and cover assemblies. The disc, with friction material linings is mounted on the transmission shaft, transmits power when clamped between the flywheel and cover assembly. During operation, wear occurs due to speed differences and slippage between the engine and transmission. Clutch performance is evaluated under repeat restart conditions on steep gradients to assess thermal durability and reliability in commercial vehicles. The repeat restart test on a 12% gradient replicates truck launches under full load, where excessive slippage generates heat that may lead to friction material wear or failure if critical temperature limits are exceeded. To address the high cost and time of physical testing, a 1D thermal simulation was developed using GT Suite. The model replicates 90 repeat vehicle launches on a 12% gradient in first gear, integrating driver inputs and drive cycles to predict clutch housing air temperatures. The simulation shows a 95% correlation with test data, validating its accuracy and reliability. This virtual approach enables early-stage design validation and optimization of parameters influencing heat generation and thermal degradation, minimizing dependence on physical trials and reducing development time. Applied to heavy commercial vehicles, this methodology supports design of experiments for drivetrain parameter analysis, guiding optimal configurations that minimize thermal stress. The adoption of GT Suite as a digital validation tool improves product development efficiency, lowers warranty costs, and enhances product quality. It provides a strategic advantage in competitive markets through faster, data-driven decision-making and enables more reliable and robust clutch design in early development stages.
Munisamy, Sathishkumar, Chollangi, Damodar, Mane, Sudhir
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 development, such as tire size, tire vertical stiffness, front axle weight, and suspension geometry variations. This approach aims to reduce development time while enhancing accuracy. The predicted results have been found to closely align with physical measurements. The findings indicate that the proposed methodology significantly improves the precision of steering rack load predictions, thereby facilitating the design of more resilient and efficient steering systems.
Shirke, Umesh, Dabholkar, Aniruddh, Bardia, Vivek, Srivastava, Harshit, Prasad, Tej Pratap
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. Both parameters are critical for accurately predicting the load carrying capacity of sheet metal axle parts. A multi-step forming simulation is carried out on a rear-axle sheet metal link, which involves simulating all the stages of the forming process to accurately predict the plastic strains and thickness changes. The forming simulations are performed using the anisotropic material model Banabic-Barlat-Comsa (BBC) to capture the anisotropy effects. This model uses several coefficients to precisely characterize the yield surfaces, considering both uniaxial and biaxial yield stresses, as well as anisotropy coefficients. The output of the forming simulation, Equivalent Plastic Strain (EPS) and thickness data, are then mapped on to the FEA model as initial conditions for static strength calculation.
R B, Govind, Selvaraj, Nirmal Velgin
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. It also assesses how fluid fill levels in the gear housing affect lubrication effectiveness and influence energy losses. It further defines the relationship of oil volume with power losses, signifying its importance in improving gear performance. This developed simulation model will thus give a holistic understanding of fluid dynamics relating to energy dissipation within gear systems by analyzing how these variables interact with each other and kinematic viscosity. This level of detail gives a deeper insight into the mechanisms in operation, thereby fostering better methods in optimising churning losses. The results of this study demonstrate crucial practical implications for optimizing lubrication methods, enhancing gear housing designs, and selecting the most effective fluids for gear systems. This research strengthens current knowledge in the automotive engineering sector and drives the advancement of more efficient and eco-friendly drivetrain systems. Tackling real problems in engineering, this study bridges the divide between theoretical models and applications by equipping engineers with more advanced tools to enhance overall system performance and efficiency.
Khan, Aliya Javid, Praveen, Abhinav, Kanagaraj, Pothiraj, Jain, Saurabh Kumar, AP, Baaheedharan
Design & Optimization of CV Shaft System to Address Powertrain Induced NVH Issues2026-26-03361/16/2026
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 CV Shaft stiffness and tuning mass dampers. In this paper we focus on parametric changes on drive shaft torsional stiffness and tuned mass damper to address Engine roughness and driveline induced noise. Test measurement is done to measure baseline CV Shaft bending frequency without dampers. AMESIM 1D simulation model is developed to reproduce Bending frequency and mode shapes. Optimization for the convergence on stiffness and damper frequency is done. With the new stiffness shaft and tuned damper vehicle has improved on the noise pattern, magnitude of oscillations and shift in natural frequency.
M A, Abdul Azarrudin, Jayachandran, Suresh kumar, Kumar, Shivani, Bhardwaj, Kinshuk, M, Devamanalan, Kanagaraj, Pothiraj, Ahire, Manoj
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 different rear differential module (RDM) configurations. Excitation scenarios including propshaft imbalance, engine block vibration, torsional vibration, and axle whine are analyzed as distinct load cases. The study also emphasizes how propshaft mode segmentation affects force transmission to vehicle body under the driveline excitations. The findings contribute to a deeper understanding of driveline NVH behavior and offer practical guidance for achieving improved driveline NVH performance.
Joshi, Atul Kamalakarrao, Subramanian, MANOJ
Optimization of Propeller Shaft Design to Eliminate Launch Undulation (Lateral Shake) and Vibration Level2026-26-03341/16/2026
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 eccentric movement was linked to the improper propeller shaft split ratio and shorter fitting length. A detailed design study combined with vehicle-level experiments (Design of Experiments, DOE) confirmed that these factors significantly contribute to the positional shift of the second UJ connection and its resulting eccentric behavior. This study provides a comprehensive approach to addressing the issue, focusing on reducing vibrations transmitted to the floor and seats and give NVH refinement through the propeller design optimization. By doing so, it ensures improved vehicle performance without compromising other critical parameters.
Sanjay, L, S, Manickaraja, Kumar, Sarvesh, Kanagaraj, Pothiraj, Senthil Raja, T, B, Prem Prabhakar, M, Kiran
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
Revolutionary EV Motors Innovation in E-Mobility in Depth Analysis of Emerging Technologies, Comparative Insights & Their Ground Breaking Impact on Electric Vehicle Performance2026-26-00731/16/2026
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 metric with manufacturability and system integration insights this study not only ranks innovations readiness but also providing a strategic roadmap for accelerating the development and deployment of next-generation EV motor. The outcome serving as a high value guide for OEMs, supplier & R&D leader seeking to prioritize the investment, streamline development & lead the transition to ultra-efficient, intelligent electric mobility platform.
Jain, Gaurav, Premlal, P, Pathak, Rahul, Gore, Pandurang
Comparative Study of EV Transmission Performance Used in Various Vehicle Segments2026-26-05841/16/2026
The transition to electric mobility has accelerated the evolution of drivetrain technologies, particularly in the design and performance of electric vehicle (EV) transmissions. Unlike traditional internal combustion engine (ICE) vehicles, EVs utilize simpler yet diverse transmission systems cater to specific performance, efficiency, and application requirements. The growing adoption of electric vehicles across diverse transportation sectors has intensified the need for optimized electric transmission systems as per vehicle requirements. This research presents a comparative study of electric transmission performance across various vehicle segments, including Passenger Cars, Small commercial Vehicle, Commercial three-wheelers and All-terrain vehicles. The study evaluates different transmission configurations namely single-speed and multi-speed, based on key performance metrics such as Drag loss and Efficiency. Through a combination of literature review, and performance benchmarking, the analysis highlights how different segments prioritize specific transmission characteristics. The efficiency & drag losses were measured in the powertrain testbed where the test units were placed between two Transient Dynamometers at Output and one lower inertia prime mover at Input. The main aim of the test was to validate overall efficiency as a function of input speed and torque The study concludes that no single transmission architecture universally outperforms others across all segments; instead, optimal performance is highly dependent on use-case scenarios and design goals. These insights aim to support EV manufacturers and powertrain engineers in selecting or developing transmission systems that align with specific performance, cost, and efficiency targets. The paper also identifies areas for future research, including control strategy optimization and the impact of emerging materials and manufacturing technologies on transmission performance.
Jain, Sankalp, P, Ekhesh
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 the effectiveness of simulation-based validation in enhancing BEV power rating predictions, reducing physical testing dependencies, and accelerating vehicle development cycles while ensuring regulatory compliance.
Mahajan, Prasad, Kesarkar, Sidhesh, Ali, Shoaib
Multispeed EV Transmission – Gear Shift Simulation and Validation2026-26-01571/16/2026
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. The model consists complete vehicle from prime mover, gear box to wheels. Non-synchromesh gearboxes lack synchronizers, which are essential for matching the speeds of the input and output shafts during a gear change, the model is capable of 3D visualization of gear synchro ring and shifter sleeve teeth during gear shift event, which is vital to observe any gear crashing phenomenon during gear shift event and will compute parameters such as forces acting on synchro pack, synchronization time and jerk on vehicle during engagement. Additionally, this paper gives details of bench test setup for gearshift quality tuning and system level validation with vehicle controller. Simulation results show good correlation with bench level data and serve as vital feedback for initial gearshift quality assessment. Multiple iterations can be carried out on simulation model by changing design parameters of synchro pack and speed difference between input and output shafts to observe the effect on gear shift quality and validated on final prototypes.
Kansagara, Smit, Thambala, Prashanth, Sutar, Suresh, Todtermuschke, Karsten, Patel, Hiral
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-geometry parameters that minimize transmission error and reduces noise from an e-axle. In this paper, transmission error (TE) is calculated for four different load cases based on motor’s torque-characteristic curve. Then, equivalent radiated power (ERP) is calculated at these load cases to determine major source of excitation and then acoustic analysis is done without micro-geometry optimization (MGO) to record the sound pressure level. After this, gears micro geometries are optimized and same process is repeated to measure the optimized sound pressure level. It is seen that after micro-geometry optimization, sound pressure level corresponding to first harmonic of 1st gear pair decreased by approximately 30%, 20%, 23% and 21% for load cases 1, 2, 3 and 4 respectively and the sound pressure level for same loads corresponding to first harmonic of second gear pair has decreased approximately by 58%, 36%, 23% and 20% respectively. It is also observed that sound pressure level of electric motor remains unaffected by gear micro-geometry optimization. Thus the research shows that noise and vibrations can be reduced by optimizing the micro-geometry parameters using computational tools and by optimizing the noise levels at the initial design stages we can avoid design changes and project delays at the later stages of project.
Ankit, Priyadarshi, Kulkarni, Krishna, Momin, Vaseem
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 collect real data from the vehicle. Following the parameter estimation, a comparison between the numerical simulation and the actual dynamic behavior of the vehicle is proposed. Based on these tests, the system is analyzed under several proposed configurations.
de Oliveira, André Noronha, Bueno Caldeira, Aldélio, da Costa Neto, Ricardo Teixeira
Feasibility Analysis of a Hybrid CVT-Manual Transmission: A Comparative Performance Study2025-36-019712/18/2025
Transmission systems play a crucial role in vehicle performance, efficiency, and adaptability. Conventional transmissions, such as Continuously Variable Transmissions (CVTs) and Manual Transmissions (MTs), each offer distinct advantages—CVTs provide smooth gear transitions and optimized fuel efficiency, whereas MTs deliver superior driver control, mechanical simplicity, durability, and high torque efficiency. This study explores the feasibility of integrating a dual-mode CVT-MT transmission into passenger vehicles to enhance driving dynamics and fuel efficiency. The proposed system uses the first gear to improve initial acceleration, a critical factor in urban driving, stop-and-go traffic, and high-load scenarios where CVTs struggle with torque delivery. After launch, the drivetrain transitions into CVT mode, leveraging its continuously adjustable gear ratios for efficiency and smooth power delivery. A simulation model based on MATLAB / Simulink will analyze the performance of the hybrid system against a conventional CVT, evaluating power efficiency, fuel consumption, mechanical reliability and driving experience. To ensure accuracy, data validation will compare simulation results with real vehicle data, refining parameters and improving analysis fidelity. By addressing the limitations of traditional transmissions, this research evaluates whether a CVT-MT hybrid can enhance acceleration, fuel economy, and the longevity of the drivetrain. If effective, this concept could influence future transmission designs, balancing performance and efficiency for everyday driving.
Baldi, Eduardo, Lopes, Matheus Carlos Sinobio Elias D, Rodrigues, Gustavo Simão
Simplifying ELECTRIC DRIVELINES25TOFHP12_0212/1/2025
FEV has a solution to downsize and reduce the complexity of off-highway machines via its electrified planetary gearset architecture. IVT Expo 2025 in Chicago featured a summit where industry professionals presented and discussed the nuts and bolts of the technology that powers the off-highway vehicle industry. Electrification continues to be a centerpiece of these discussions, but OEMs and suppliers are beginning to supply answers to many of the questions that this challenge presents. During the expo, several presentations covered the integration of electric powertrains at the component and architecture level. One presented by Thomas Wellman, chief engineer, drivetrain systems, FEV North America, detailed an EPGS (electrified planetary gear-set) off-highway drivetrain architecture that is modular and scalable for a variety of powertrain configurations.
Wolfe, Matt
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 with prototype. The experimented method of digitally simulating line articulation significantly reduced the design iterations. And as a case study, the findings are discussed in detail.
Duraiswamy, Rupesh, Sankaran, Bhargav, Raj, Santhosh
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 performance of this approach across varying road gradients, vehicle speeds, and terrain characteristics. The paper further outlines the development of an automated control system for real-time angle adjustment and its integration into the vehicle’s existing electrical architecture.
Vijeth, Abhishek, Bhosle, Devidas Ashok, Cherian, Roshni, Dash, Prasanjita
Design and Development of a Novel Automatic Powershift Transmission for Battery-Electric Vehicles2025-32-009611/3/2025
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 optimizing power delivery under varying load conditions. A well-designed two-speed gearbox can overcome this limitation by improving energy efficiency without adding excessive weight or complexity. However, to be a competitive solution, the transmission must achieve high efficiency and reliability while remaining lightweight and affordable. To address these challenges, a novel Auto-Powershift Transmission system has been developed and patented. This innovative system features an automatic gear-shifting mechanism that operates without any external actuators, making it inherently simple, robust, and cost-effective. By autonomously adapting to the operating conditions of the electric motor, Auto-Powershift enhances overall drivetrain efficiency, contributing to extended range and improved vehicle performance. The present work details the working principles of this technology, its design advantages, and its impact on electric vehicle efficiency. With its lightweight structure and mechanical simplicity, Auto-Powershift represents a significant step toward making propulsion systems for small and lightweight battery-electric vehicles (BEVs) more practical and efficient.
Tromayer, Juergen, Stückler, David, Kirchberger, Roland
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 were satisfied within the tightly coordinated program schedule. The key technical requirement for the first prototype engine build was to validate its structural integrity in a hydraulic rig test wherein the loading blocks were representative of severe duty end user application including abusive load case scenarios. The rig test was completed successfully, and the prototype engine underwent comprehensive post-test examination for mechanical fatigue. Magnetic particle inspection confirmed no cracks in any of the structural engine components. Additional data acquisition during the test comprised of strain measurements at key locations. The correlation between test and FEA stresses was assessed for the cylinder block and oil pan under the given load cases. While most of the strain gauge locations demonstrate close agreement within 30% w.r.t FEA results, few thermocouples exhibit certain variations over 50%. Overall, the results indicate a reasonable correlation between test and FEA, with most locations showing that the FEA results are on the conservative side. The observed differences mainly arise from modelling assumptions, and experimental uncertainties. This comparative verification provides high confidence in the FEA model and the engine’s durability.
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 successfully met the climbing ability and acceleration criteria but fell slightly short of the top speed goal. These results were confirmed by the vehicle’s performance at the 2024 Baja SAE Competition.
Spilde, Riley, Liu, Yucheng
Measurement and Characterization of Electronically Controlled Driveline Clutch SystemsJ3011_202510 (Current)10/3/2025
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
BMW brings EV motor production to Steyr in Austria25AUTP10_0810/1/2025
In August, the BMW Group's Plant Steyr in Austria started producing the electric motors for its Neue Klasse EVs. The sixth-generation BMW eDrive is the first all-electric drivetrain that will be built at Steyr, and Steyr is BMW's first production site for the Gen6 electric motor. In preparation, BMW announced in 2022 that, by 2030, the automaker would invest over a billion euros in the Steyr location to expand development and production expertise for electric motors. “Three years ago, we announced that we would build this electric motor in Steyr. Today, we are proud to deliver it,” said Klaus von Moltke, SVP of engine production for BMW AG and plant director at Steyr, said in a statement. “What we are launching here today is more than just a production ramp-up. It is a firm commitment to Europe, to technology and to the future.”
Blanco, Sebastian
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 end, potentially leading to misalignment or increased friction between moving parts. Hence, it is very important to check the temperatures at various operating conditions and ensure to limit it within acceptance level to detect problems early on and prior to the Customer Vehicle operation. This paper emphasizes on the comparative test results of the Wheel ends’ temperature between Conventional and Unitized Bearings and its physical measurements carried out in a same Vehicle. Conventional bearings, which typically consist of separate Inner and Outer bearing assemblies, might exhibit higher operating temperatures compared to Unitized bearings owing to additional friction points and potential for misalignment. Unitized bearings, which integrate multiple components into a single assembly, tend to operate at lower temperatures compared to conventional bearings due to reduced friction and improved alignment. The Vehicle level temperature measurements at various worst-case conditions carried out and proved that the measured values are in correlation with estimated results. Maintaining appropriate temperatures in the Front Axle wheel ends is crucial for ensuring optimal performance of the Vehicle’s Braking system and drivetrain.
Pandiyan, Mahendran, Jayaraman, Karthik, R, Sabari, B, Ellavarasan, Bhanja, Subrat Kumar
Methodology for Replicating and Quantifying Clicking-Noise Phenomenon in Gen 3 Wheel Hub Bearings and CVJ Using NVH Analysis and Data Processing2025-01-03689/15/2025
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 demonstrate significant noise reduction improvements, highlighting the advantages of surface modifications in enhancing contact surface characteristics. This paper provides insights into testing and analysis processes, offering a robust framework for future studies aimed at mitigating NVH issues in automotive applications. The findings underscore the potential of innovative surface treatments in improving the acoustic performance of wheel hub bearing systems, contributing to the development of quieter and more reliable EVs.
Nardicchia, Riccardo, Mauro, Ivan
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 dynamic model. The required lateral force for steering is then allocated to healthy actuators to achieve fault-tolerant control. To verify the algorithm’s effectiveness, validation combines hardware and real-vehicle testing, conducting high-speed obstacle-avoidance tests under three fault conditions: front axle lock, rear axle lock, and both axles locked. Results show that under all three conditions, the proposed algorithm keeps lateral trajectory tracking errors within 0.35 m, ensuring vehicle safety even with steering system faults.
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
Articulating Joints and Driveshafts - Nomenclature - Terminology - ApplicationJ901_202507 (Current)7/22/2025
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
A New Electrified Planetary Gear Set - The Cost- and Fuel-Efficient Alternative to Continuously Variable Transmissions2025-01-03097/2/2025
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 complexity, as well as enhancing performance and fuel efficiency. The system design followed a structured approach, beginning with a morphological analysis and multi-criteria evaluation to refine potential drivetrain concepts. The final concept is characterized by its exceptionally compact design, which is achieved despite the use of commercial-off-the-shelf components. The functionality of the concept was validated through a prototype transmission that is tested in a series of driving scenarios, both on the road and on a chassis dynamometer. The results demonstrated a 17 % reduction of fuel consumption relative to the original vehicle that was equipped with a CVT, despite the absence of access to the engine control unit. These findings highlight the great potential of the ePGS system as a cost-effective, fuel efficient alternative for conventional CVT powered vehicles.
Jakoby, Moritz, Engels, Michael, Fahrbach, Timm, Andert, Jakob
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