Browse Topic: Axles

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Power loss evaluation in 4WD axle and correlation with Testing results2026-26-0107To be published on 01/16/2026
In the tractor, the efficiency depends on the transmission system, of all the losses major contribution is given by the transmission elements. To improve the efficiency, it became crucial to monitor the areas of power losses. Power loss in transmission refers the reduction in amount of power which being generated from the engine source to the final drive elements. There are various parameters and factors influence this condition, analyzing those conditions helps in identifying & improving the higher contributing components for driveline power loss. This study presents a comparative analysis of theoretical and experimental data regarding power loss in the gear train of a 70HP 4WD front axle. The investigation incorporates theoretical power loss calculations for individual components, including the bevel gear, bearings, thrust washer and seal arrangements. To evaluate and validate the power losses in the 4WD axle, a Gear Train Endurance test was conducted in a controlled laboratory
Jayapal, Jayaraj, Mahapatra, Soumya Ranjan, Sethi, Suvendu Kumar, JOSHI, SHRIKANT, BANGE, PRASHANT
Correlation of Power Rating for Battery Electric Vehicles Simulation vs. Test Validation in Accordance with regulatory compliance2026-26-0575To be published on 01/16/2026
Accurate power and energy assessment in Battery Electric Vehicles (BEVs) requires high-fidelity simulation models that reflect real-world performance. This study presents a power rating correlation of the Stellantis Dodge model in compliance with the GTR 21 standard, validating the simulation’s accuracy against physical test data. Simulations conducted using STLAsim, Stellantis’ proprietary tool, estimate EDM power at the inverter input and axle output under standardized conditions. The operating parameters were shared with the testing team to ensure consistency; however, the initial test results deviated by approximately 18 kW from the simulation target. To address this delta, EDM speed and vehicle speed were optimized, achieving a close alignment with the simulation and meeting the GTR 21 power rating criteria. The results demonstrate a strong correlation between the simulation and test data, confirming the model’s accuracy and reliability. This study underscores the effectiveness of
Mahajan, Prasad, ali, Shoaib
Novel Approach for Predicting Steering Rack Load Using Multibody Simulation2026-26-0378To be published on 01/16/2026
In the initial stages of a vehicle development program, the sizing of various components is a critical deliverable. The steering system, in particular, requires a precise estimation of the rack load for the appropriate sizing of the rack and assist units. Accurately predicting the load on the system during the early stages of development is challenging, especially in the absence of benchmark or legacy data. Commonly used processes for estimating parking steering effort often employ simplistic approaches that may fail to account for parameters such as tire size, vertical stiffness, and steering geometry, leading to reduced accuracy. This paper introduces an advanced methodology for predicting steering rack loads, which incorporates considerations such as contact patch size and pressure variation, as well as the tire jacking effect. The methodology involves mathematical modeling of the contact patch using mesh-grids, utilizing common inputs available in the early stages of vehicle
Shirke, Umesh, Dabholkar, Aniruddh, bardia, Vivek, Srivastava, Harshit, PRASAD, TEJ PRATAP
Simulation Driven Virtual Road Load and Accelerated Duty Cycle Generation for 3-Speed eAxle Systems2026-26-0401To be published on 01/16/2026
The transition from Internal Combustion Engine (ICE) vehicles to Battery Electric Vehicles (BEVs) introduces significant challenges in drivetrain development, particularly when historical road load data (RLDA) is unavailable. This research proposes a methodology for virtually generating and processing RLDA to evaluate the durability of a novel 3-speed electric axle (eAxle) system before physical prototype construction. By employing AVL Route Studio, we simulated diverse global driving conditions across urban, highway, and mixed terrains to generate high-frequency torque and speed data. Since the resulting millions of data points are impractical for direct fatigue assessment, we utilised Romax software to condense the virtual RLDA into an accelerated duty cycle while maintaining the original fatigue damage characteristics. Unlike traditional binning techniques that often mischaracterise load severity, our damage-matching approach ensures the condensed cycle accurately replicates gear
LIGADE, PRATIK, KHAN, Dr. NURUZZAMA MEHADI, Koona, Rammohan Rao
Machine Learning Approach to ISO Road Class Prediction Using Multiple Linear Regression2026-26-0667To be published on 01/16/2026
The inertial profiler methodology is traditionally employed in RLDA (Road Load Data Acquisition) to measure road profiles and classify test routes into ISO road classes. However, this approach demands significant time and effort during instrumentation. Also, during data acquisition, laser height sensor data is affected especially during adverse conditions such as rainy seasons or on surfaces with improper reflectivity. Additionally, substantial resources are required for data processing to convert raw measurements into road classifications. To address these challenges, an initial attempt was made to establish a relationship between axle acceleration responses and road profiles, enabling axle acceleration measurements during RLDA to predict ISO road classes. However, this approach relied on a simple linear model that considered only axle acceleration responses, rendering the predictions susceptible to inaccuracies due to varying parameters such as vehicle speed. To overcome these
P, Praveen Kumar, P, Dayalan, Sriramulu, Yoganandam
EVALUATION OF DRIVELINE NVH PERFORMANCE USING LINEAR DYNAMIC FINITE ELEMENT SIMULATION2026-26-0322To be published on 01/16/2026
Automotive driveline design plays an important role in the NVH characteristics of the overall vehicle. Driveline systems are an integral part of delivering torque from the engine/transmission to the tires which propel the vehicle and drivelines often experience a wide frequency of excitation which poses unique NVH challenges. With the increasing trend in the automotive industry to introduce turbocharged engines with fewer cylinders while delivering the same torque / power, the driveline systems are excited with increased lower frequency torsional vibration in addition to other vibrations transmitted from powertrain and road. In this paper, we address the key design consideration for developing an optimal driveline system with consideration to NVH while keeping durability and other functional requirements in perspective. We consider the example of a front wheel drive-based vehicle architecture with independent suspension. The effect of fundamental prop shaft frequency to determine
JOSHI, ATUL KAMALAKARRAO, Subramanian, MANOJ
Modelling and Analysis of Hypoid Gear Churning Loss in Rear Drive Axle: The Role of Oil Viscosity and Empirical Parameters2026-26-0508To be published on 01/16/2026
This definitive study investigates the variation of churning losses occurring with hypoid ring and pinion gear sets and puts primary importance to factors that determine energy dissipation in these mechanisms. A detailed investigation shows that viscosity is critical, particularly due to large temperature-dependent variations. Besides this, the study focuses on particular attention to experimental parameters derived from measured data to model churning losses. Churning Loss itself originates in the interaction between the rotation of the gears and the lubricating oil - a source of significant inefficiency within the overall drivetrain. A robust, comprehensive model has been formulated to take this into account. It does not only account for variable oil viscosity with temperature but integrates key empirical parameters that reflect observed behaviours in gear systems. The study adopts a multidimensional approach by considering the influence of various other factors. It investigates how
Khan, Aliya Javid, Praveen, Abhinav, Kanagaraj, Pothiraj, Jain, Saurabh Kumar, AP, Baaheedharan
Digital Simulation of Rear Axle Brake Lines Articulation for Commercial Vehicles2025-28-025711/06/2025
This paper focuses on defining the optimal length of rear axle brake lines (flexible polyamide tubes) for commercial vehicles by simulating the lines digitally by considering tube behavior and various axle articulation conditions. Currently, the length of rear axle brake lines are predominantly defined with the help of a physical mockup by articulating axle conditions in a vehicle. This approach requires actual components such as frame, axle, suspension, etc., which consumes considerable time and cost. Through technological advancements, prototyping can be reduced and convergence on digital to build can be achieved through digital simulation. This paper explores tube properties, axle configurations and definitions, and various methods of digitally simulating line articulation. Boundary conditions, space reservations and design criteria for pneumatic routing are defined for the type of line designed. Digital simulation of rear axle brake lines articulation was performed and compared
Duraiswamy, Rupesh, Sankaran, Bhargav, Raj, Santhosh
Enhancing Tipper Stability during Descent with Dynamic Angle Adjustment2025-28-027611/06/2025
Tippers transporting loose bulk cargo during prolonged descents are subject to two critical operational challenges: cargo displacement and rear axle lifting. Uncontrolled cargo movement, often involving loose aggregates or soil, arises due to gravitational forces and insufficient restraint systems. This phenomenon can lead to cabin damage, loss of control, and hazardous discharge of materials onto roadways. Simultaneously, load imbalances during descent can cause rear axle lift, increasing stress on the front steering axle, resulting in tire slippage and compromised maneuverability. This study proposes a dynamic control strategy that adjusts the tipper lift angle in real time to align with the descent angle of the road. By synchronizing the trailer bed angle with the slope of the terrain, the system minimizes cargo instability, maintains rear axle contact, and enhances braking performance, including engine and exhaust braking systems. Computational modelling is employed to assess the
Vijeth, Abhishek, Bhosle, Devidas Ashok, Cherian, Roshni, Dash, Prasanjita
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 Trucks2025-01-036409/15/2025
The Front Axle wheel end assembly is a critical component of Vehicle functionality, comprising a wheel hub positioned to rotate smoothly on an Axle spindle. This rotational movement is enabled by bearings positioned between the hub and the spindle, allowing for frictionless rotation. The Front Axle wheel ends’ temperature typically depends on several factors such as type of Vehicle, Load & driving conditions and health of the components involved. In general, the wheel ends can become warm during normal operation owing to friction generated by the rotation of the wheels and the interaction of various mechanical components such as Bearings and Brakes. However, if the temperature of the wheel ends becomes excessively hot, it could indicate potential issues such as Overheating brakes, Wheel bearing problems, improperly inflated tyres, and faulty components. As temperature rise, materials tend to expand. This expansion can affect the dimensions of critical components in the Front Axle wheel
Pandiyan, Mahendran, Jayaraman, Karthik, R, Sabari, B, Ellavarasan, Bhanja, Subrat Kumar
Design of a Fault-Tolerant Control Algorithm for Four-Wheel Steering Vehicle Steering Locking Based on Dynamic Model Reconstruction10-09-04-003608/21/2025
The motion control system, as the core executive component of the automatic hierarchical framework, directly determines whether autonomous vehicles can reliably and stably follow planned trajectories, making it crucial for driving safety. This article focuses on steering lock faults and proposes a cross-system fault-tolerant control (C-FTC) algorithm based on dynamic model reconstruction. The algorithm uses a classic hierarchical collaborative architecture: the upper-level controller employs an MPC algorithm to solve lateral velocity and yaw rate reference values in real-time, while the lower-level controller, designed based on the reconstructed dynamic model, uses an MPC algorithm to adaptively adjust actuator control quantities. In cases where four-wheel steering vehicles lose steering ability due to locked steering axles, the locked axle’s steering angle is treated as a state variable, and healthy actuator outputs are used as control variables to dynamically reconstruct the vehicle
Hu, Hongyu, Tang, Minghong, Chen, Guoying, Gao, Zhenhai, Wang, Xinyu, Gao, Fei
Validation of a Suspension Lifter Bracket through a Test Bench2025-36-030608/01/2025
In the Brazilian market, the 6x2 configuration for commercial vehicles is widely used. These vehicles feature a driven rear axle and a non-driven axle. For the non-driven axle, it is common to use a lifter system that allows the axle to be lifted when the vehicle is running empty. This system provides benefits such as reduced fuel consumption, lower tire wear, and reduced toll costs when charges are based on the number of axles in contact with the ground. Given these advantages, the system has a high demand, making it mandatory to perform a durability test prior to its market implementation. This paper will present the validation methodology for the lifter system bracket. To achieve this, the following stages will be discussed: CAE, instrumentation, data acquisition, test bench concept, test execution and results.
Leme, Cristiano, da Costa Rodrigues, Gilson, Figueiredo, Guilherme Galvão, de Souza Maria, Heitor Cunha, Pires, Luciano Rogério
Schaeffler optimizes rolling bearings for hydraulic and axle drives25TOFHP08_0608/01/2025
Rolling bearings with optimized friction and performance characteristics can have a significant influence on reducing the power loss, design envelope and weight of hydraulic motors and pumps, gearboxes and axles in construction machinery. If correctly designed, rolling bearings can make a significant contribution to reducing carbon dioxide emissions. Most construction machinery is still operated conventionally, using diesel engines and hydraulic components. In the widely used adjustable axial piston pumps and motors, the input and output shaft are usually supported by two tapered roller bearings that are adjusted against each other. When designing the bearing support, it is advisable to reduce the preload to precisely the required minimum allowed by the load spectrum. The lower bearing preload leads to permanently lower axial forces between the tapered roller end face and inner ring rib and, therefore, to a corresponding reduction in frictional torque.
Scharting, Stefan
Wear Protection for Electrified Transmissions Using e-Fluids without Active Sulfur04-18-03-001505/08/2025
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 Cell2025-01-005405/05/2025
The recent addition of fully electric powertrains to propulsion system options has increased the relevance of sound and vibration from electric motors and gearboxes. Electrified beam axles require different metrics from conventional beam axles for noise and vibration because they have multiple sources of vibration energy, including an electric motor and a reduction gearbox. Improved metrics are also driven by the stiff suspension connections and lack of significant isolation compared to electric drive units. Blocked force is a good candidate because it can completely characterize the vibration energy transmitted into a receiver and is especially useful because it is theoretically independent of the vehicle-side structure. While the blocked force methodology is not new, its application to beam axles is relatively unexplored in the literature. This paper demonstrates a case study of blocked force measurement of an electrified beam axle with a leaf spring suspension. The axle was tested
Shaw, Matthew D, Grimmer, Michael J
Hybrid 3D Sound Intensity Measurements and Simulations Applied to a Truck Rear Axle2025-01-010505/05/2025
This study presents a novel methodology for optimizing the acoustic performance of rotating machinery by combining scattered 3D sound intensity data with numerical simulations. The method is demonstrated on the rear axle of a truck. Using Scan&Paint 3D, sound intensity data is rapidly acquired over a large spatial area with the assistance of a 3D sound intensity probe and infrared stereo camera. The experimental data is then integrated into far-field radiation simulations, enabling detailed analysis of the acoustic behavior and accurate predictions of far-field sound radiation. This hybrid approach offers a significant advantage for assessing complex acoustic sources, allowing for quick and reliable evaluation of noise mitigation solutions.
Fernandez Comesana, Daniel, Vael, Georges, Robin, Xavier, Orselli, Joseph, Schmal, Jared
Fast Noise Prediction of an Electric Powertrain Integrated in Various Vehicles2025-01-007605/05/2025
As the automotive industry moves toward electrification, new challenges emerge in keeping pleasant acoustics inside vehicles and their surroundings. This paper proposes a method for anticipating the main sound sources at driver’s ear for custom driving scenarios. Different categories of Road and Wind noise were created from a dataset of multiple vehicles. Using innovative sound synthesis techniques, it enables Valeo to make early predictions of the emergence of an electric axle powertrain (ePWT) once it is combined with this masking noise. Realistic signals could be generated and compared with actual acoustic measurements to validate the method.
Redon, Milan, Dendievel, Clement, Pluton, Matthias
Compatibility between Stability and Curving Ability of Railway Vehicles Using Conventional and Unconventional Bogie Frame Models02-18-03-001404/09/2025
This article analyses the fundamental curving mechanics in the context of conditions of perfect steering off-flanging and on-flanging. Then conventional, radial, and asymmetric suspension bogie frame models are presented, and expressions of overall bending stiffness kb and overall shear stiffness ks of each model are derived to formulate the uniform equations of motion on a tangent and circular track. A 4 degree of freedom steady-state curving model is formulated, and performance indices such as stability, curving, and several parameters including angle of attack, tread wear index, and off-flanging performance are investigated for different bogie frame configurations. The compatibility between stability and curving is analyzed concerning those configurations and compared. The critical parameters influencing hunting stability and curving ability are evaluated, and a trade-off between them is analyzed. For the verification, the damped natural frequencies and mean square acceleration
Sharma, Rakesh Chandmal, Sharma, Sunil Kumar, Palli, Srihari, Rallabandi, Sivasankara Raju, Sharma, Neeraj
Fixture Stiffness Impact on Spindle Coupled Multi-Axial Input Durability Test for Front or Rear Axle with Non-isolated Subframes2025-01-825604/01/2025
The half vehicle spindle-coupled multi-axial input durability test has been broadly used in the laboratory to evaluate the fatigue performance of the vehicle chassis systems by automotive suppliers and OEMs. In the lab, the front or rear axle assembly is usually held by fixtures at the interfaces where it originally connects to the vehicle body. The fixture stiffness is vital for the laboratory test to best replicate the durability test in the field at a full vehicle level especially when the subframe of the front or rear axle is hard mounted to the vehicle body. In this work, a multi-flexible body dynamics (MFBD) model in Adams/Car was utilized to simulate a full vehicle field test over various road events (rough road, braking, steering). The wheel center loads were then used as inputs for the spindle coupled simulations of the front axle with a non-isolated subframe. Three types of fixtures including trimmed vehicle body, a rigid fixture with softer connections and a rigid fixture
Gao, Jianghua, Smith, Derek, Zhang, Xin, Yu, Xiao
Systematic Design Considerations of Motor Selections for EV Powertrain Abstract2025-01-850804/01/2025
As one of the most important design choices in the powertrain design cycle, motor selection is conventionally performed according to given automotive requirements. Motor-related powertrain design parameters like gear ratio, power output ratio between different axles, are excluded from the motor design process. In this paper, three comparative studies are performed to investigate the impact of these motor-related powertrain design parameters on the motor performance and the weight/cost/efficiency of the entire EV powertrain. In the first study, three PM motor designs—characterized by high, medium, and low rated speeds—will be assessed for a two-axle EV using various gear ratio configurations. The same motor design will be used for both axles. In the second study, five motor designs with varying power and ratings (PM, non-PM) but identical rated speeds will be evaluated for a two-axle EV, permitting different power ratings for the front and rear axles. The design trade-offs between motor
Movahed, Ehsan, Godbehere, Jonathan, Jia, Yijiang
Concept of an Electromechanical Brake-By-Wire System for Battery-Electric Vehicles2025-01-880404/01/2025
Brake-by-wire systems have received more and more attention in the recent years, but a close look on the available systems shows, that they have not reached full by-wire level yet. Most systems are still using hydraulic connections between main cylinder and the brake calipers on at least one axle to ensure functional safety. Mostly, this is the front axle, since the front brakes have to convert more kinetic energy during braking manoeuvers. Electromechanical actuators are currently used for rear brakes in hybrid brake-by-wire applications solely, since a loss of the front brake calipers can lead to severe conditions and control loss of the vehicle during braking. Further, the higher mass of battery electric vehicles (BEVs) leads to much higher braking forces on both axles and to increased sizes of the electromechanical calipers. This article presents a concept for a brake-by-wire system for battery electric vehicles, which features electromechanical brake actuators on all corners and a
Heydrich, Marius, Lenz, Matthias, Ivanov, Valentin, Stoev, Julian, Lecoutere, Johan
Real-time Terrain Analysis for Off-road Autonomous Vehicles2025-01-834304/01/2025
One challenge for autonomous vehicle (AV) control is the variation in road roughness which can lead to deviations from the intended course or loss of road contact while steering. The aim of this work is to develop a real-time road roughness estimation system using a Bayesian-based calibration routine that takes in axle accelerations from the vehicle and predicts the current road roughness of the terrain. The Bayesian-based calibration method has the advantage of providing posterior distributions and thus giving a quantifiable estimate of the confidence in the prediction that can be used to adjust the control algorithm based on desired risk posture. Within the calibration routine, a Gaussian process model is first used as a surrogate for a simulated half-vehicle model which takes vehicle velocity and road surface roughness (GD) to output the axle acceleration. Then the calibration step takes in the observed axle acceleration and vehicle velocity and calibrates the Gaussian process model
Lewis, Edwina, Parameshwaran, Aditya, Redmond, Laura, Wang, Yue
A Torque Distribution Strategy for the Six-Wheeled Lunar Rover2025-01-830804/01/2025
As a crucial tool for lunar exploration, lunar rovers are highly susceptible to instability due to the rugged lunar terrain, making control of driving stability essential during operation. This study focuses on a six-wheel lunar rover and develops a torque distribution strategy to improve the handling stability of the lunar rover. Based on a layered control structure, firstly, the approach establishes a two-degree-of-freedom single-track model with front and rear axle steering at the state reference layer to compute the desired yaw rate and mass center sideslip angle. Secondly, in the desired torque decision layer, a sliding mode control-based strategy is used to calculate the desired total driving torque. Thirdly, in the torque distribution layer, the optimal control distribution is adopted to carry out two initial distributions and redistribution of the drive torque planned by the upper layer, to improve the yaw stability of the six-wheeled lunar rover. Finally, a multi-body dynamics
Liu, Pengcheng, Zhang, Kaidi, Shi, Junwei, Yang, Wenmiao, Zhang, Yunqing, Wu, Jinglai
Comprehensive Gear Shift Schedule of Heavy-Duty Commercial Electric Trucks Based on Dual Axle Driving2025-01-851004/01/2025
A heavy-duty commercial electric truck is equipped with dual axles, with the middle axle driven by an electric motor and a three-speed transmission and the rear axle driven by an electric motor and a two-speed transmission. To consider the dynamic and economy performance of the whole vehicle, as well as the gear distribution characteristics in the vehicle operation, a comprehensive shifting schedule based on the cross-particle swarm algorithm is proposed. By establishing the longitudinal dynamics model of the truck, the optimal power shift schedule and the optimal economics shift schedule of each of the two transmissions are studied. Under the standard test conditions, an optimal gear control strategy based on the dynamic programming algorithm considering the shift interval is proposed, and the shift schedule for the standard conditions is derived through the hierarchical clustering method. Furthermore, with 0-100 km/h acceleration capability and specific energy consumption as the
Guo, Jun, Zhang, Yunqing, Wu, Jinglai
Bicycle Pitch-over Reconstruction Analysis2025-01-868404/01/2025
During a pitch-over event, the forward momentum of the combined bicycle and rider is suddenly arrested causing the rider and bicycle to rotate about the front wheel and also possibly propelling the rider forward. This paper examines the pitch-over of a bicycle and rider using two methods different from previous approaches. One method uses Newton’s 2nd Law directly and the other method uses the principle of impulse and momentum, the integrated form of Newton’s 2nd Law. The two methods provide useful equations, contributing to current literature on the topic of reconstructing and analyzing bicycle pitch-over incidents. The analysis is supplemented with Madymo simulations to evaluate the kinematics and kinetics of the bicycle and rider interacting with front wheel obstructions of different heights. The effect of variables such as rider weight, rider coupling to the bicycle, bicycle speed, and obstruction height on resulting kinematics were evaluated. The analysis shows that a larger
Brach, R. Matthew, Kelley, Mireille, Van Poppel, Jon
A Steering Control Method Applicable to an Eight-Wheeled Planetary Laboratory2025-01-830504/01/2025
In future planetary exploration missions, the Eight-Wheeled Planetary Laboratory (EWPL) will have sufficient capacity for tasks but will experience significant lateral slips during high-speed turns due to its large inertia. Modern technology allows for independent steering of all eight wheels, but controlling each wheel's steering angle is key to improving stability during turns. This paper introduces a novel rear-axle steering feed-forward controller to reduce sideslip. First, a mathematical model for the vehicle's steering is established, including kinematic equations based on Ackermann steering. Feed-forward zero side-slip control is applied to the third and fourth axles to counteract the side-slip angle of the center of mass. A multi-body dynamics model of the EWPL is then built in Chrono to evaluate the turning radius and optimize steering angle ratios for the rear axles. Finally, a steady-state cornering simulation on loose terrain compares the performance of the proposed
Liu, Jun, Zhang, Kaidi, Shi, Junwei, Yang, Wenmiao, Zhang, Yunqing, Wu, Jinglai
Evaluation Method for the Impacts of Truck Platoons Lateral Control on Pavement Performance2025-01-715202/21/2025
The introduction of autonomous truck platoons is expected to result in drastic changes in operational characteristics of freight shipments, which may in turn have significant impacts on efficiency, energy consumption, and infrastructure durability. Since the lateral positions of autonomous trucks traveling consecutively within a lane are fixed and similar (channelized traffic), such platooning operations are likely to accelerate damage accumulation within pavement structures. To further advance the application of truck platooning technology in various pavement environments, this study develops a flexible evaluation method to evaluate the impact of lateral arrangement within autonomous truck platoons on asphalt pavement performance. This method simplifies the impact of intermittent axle load applications along the driving direction within a platoon, supporting platoon controllers in directly evaluating pavement damage for different platoon configurations. Specifically, a truck platoon
Wenlu, Yu, Ye, Qin, Chen, Daoxie, Min, Yitong, Chen, Leilei
Definition and Measurement of Torque Biasing DifferentialsJ2817_202502 (Current)02/08/2025
This SAE Recommended Practice covers passive torque biasing axle and center differentials used in passenger car and light truck applications. Differentials are of the bevel gear, helical gear, and planetary types, although other configurations are possible.
Drivetrain Standards Committee
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 Targets2024-28-026912/05/2024
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_1212/01/2024
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 Drivelines02-18-01-000111/08/2024
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 Prototype2024-01-431911/05/2024
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_1210/01/2024
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_0408/01/2024
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)07/26/2024
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 Validation05-17-03-002006/19/2024
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 System2024-01-295006/12/2024
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
Integrated Chassis Control for Energy-Efficient Operation of a 2WD Battery-Electric Vehicle with In-Wheel Propulsion2024-01-255004/09/2024
Battery-electric vehicles (BEVs) require new chassis components, which are realized as mechatronic systems mainly and support more and more by-wire functionality. Besides better controllability, it eases the implementation of integrated control strategies to combine different domains of vehicle dynamics. Especially powertrain layouts based on electric in-wheel machines (IWMs) require such an integrated approach to unfold their full potential. The present study describes an integrated, longitudinal vehicle dynamics control strategy for a battery electric sport utility vehicle (SUV) with an electric rear axle based on in-wheel propulsion. Especially the influence of electronic brake force distribution (EBD) and torque blending control on the overall performance are discussed and demonstrated through experiments and driving cycles on public road and benchmarked to results of previous studies derived from [1]. It is shown that the approach improves energy efficiency and energy recovery
Heydrich, Marius, Mitsching, Thomas, Gramstat, Sebastian, Lenz, Matthias, Ivanov, Valentin
A methodology for modeling the thermal behavior of an electric axle in real driving cycles2024-01-258804/09/2024
The thermal behavior of the electric axle is an essential indicator which requires certain attention during the development process. Due to the complexity of heat generation mechanism and heat transfer boundary conditions, it is difficult to accurately predict the axle’s temperature, especially in real driving conditions. In this paper, a comprehensive 1D model is developed to simulate its heat transfer process effectively and accurately. The heat transfer model is developed based on the thermal network method, and the electric axle is divided into thermal mass according to its heat transfer characteristics. The heat generation model, which accounts for meshing loss, bearing loss, churning loss, and windage loss, exchanges heat flux and oil temperature information with the heat transfer model to take into account the effect of lubricating oil temperature on power loss. Meanwhile, 3D simulation is established for the lubricating oil flow inside the axle and the air flow around it, from
Hu, Xiaoyu, Shao, Hengheng, Hou, Yuanjing, Sun, Wanyu, Liu, Hongwei, Zhang, Lin
Analysis of Low-Frequency Brake Noise for Drum Brakes on Semi-Trailers2024-01-289504/09/2024
A road test on semi-trailers is carried out, and accelerations of some characteristic points on the braking system,axles,and truck body is measured,also brake pressure and noise around the support frame is acquired.The measured data was analyzed to determine the causes of the brake noise, and the mechanism of the noise of the drum brake of semi-trailers during low-speed braking was investigated. The following conclusions are obtained: (1) Brake noise of the drum brake of the semi-trailer at low-frequency is generated from vibrations of the brake shoes, axle, and body, and the vibration frequency is close to 2nd natural frequency of the axle. (2) Brake noise is generated from stick-slip motion between the brake shoes and the brake drum, where the relative motion between the brake drum and the brake shoes is changed alternately with sliding and sticking, resulting in sudden changes in acceleration and shock vibration. A multi-body dynamic model of the semi-trailer is established for
Tang, Hao, Shangguan, Wen-Bin, Kang, Yingzi, Zheng, Jing-Yuan, Lan, Wen-Biao
Fuzzy Control of Regenerative Braking on Pure Electric Garbage Truck Based on Particle Swarm Optimization2024-01-214504/09/2024
To improve the braking energy recovery rate of pure electric garbage removal vehicles and ensure the braking effect of garbage removal vehicles, a strategy using particle swarm algorithm to optimize the regenerative braking fuzzy control of garbage removal vehicles is proposed. A multi-section front and rear wheel braking force distribution curve is designed considering the braking effect and braking energy recovery. A hierarchical regenerative braking fuzzy control strategy is established based on the braking force and braking intensity required by the vehicle. The first layer is based on the braking force required by the vehicle, based on the front and rear axle braking force distribution plan, and uses fuzzy controllers. Achieve one-time distribution of the front axle braking force; the second layer, according to the magnitude of the braking intensity, divides the braking conditions into light braking, moderate braking and emergency braking, and realizes braking under the three
Zhang, Yu
On the Investigation of Car Steady-State Cornering Equilibria and Drifting2024-01-276404/09/2024
This paper proposes a thorough investigation of steady-state cornering equilibria for cars. Besides equilibria corresponding to normal driving behaviour - herein denoted as stable-normal turn, drifting is attracting increasing attention. When discussing drifting, it is typically assumed that yaw rate and steering angle have opposite signs, i.e. the driver is countersteering, and the rear axle is saturated. Interestingly, another unstable equilibrium is possible, herein referred to as unstable-normal turn. In this work, an attempt to give a comprehensive definition of drift is made. An inverse model is proposed to compute the driver inputs needed to perform a steady-state turn for a given radius and sideslip angle. The mathematical meaning of all equilibria is explored by linearizing the system and analyzing eigenvalues and eigenvectors of the resulting state matrices.
Righetti, Giovanni, Binetti, Elisabetta, Pinto de Castro, Ricardo, Lot, Roberto, Massaro, Matteo, Lenzo, Basilio
A Review of Production Multi-Motor Electric Vehicles and Energy Management and Model Predictive Control Techniques2024-01-277904/09/2024
This paper presents the characteristics of more than 260 trim levels for over 50 production electric vehicle (EV) models on the market since 2014. Data analysis shows a clear trend of all-wheel-drive (AWD) powertrains being increasingly offered on the market from original equipment manufacturers (OEMs). The latest data from the U.S. Environmental Protection Agency (EPA) shows that AWD EVs have seen a nearly 4 times increase in production from 21 models in 2020 to 79 models in 2023. Meanwhile single axle front-wheel-drive (FWD) and rear-wheel-drive (RWD) drivetrains have seen small to moderate increases over the same period, going from 9 to 11 models and from 5 to 12 models, respectively. Further looking into AWD architectures demonstrates dual electric machine (EM) powertrains using different EM types on each axle remain a small portion of the dual-motor AWD category. However, these architectures have been shown to have energy savings of 1 % to 5 % over that of identical dual-motor
Allca-Pekarovic, Alexander, Kollmeyer, Phillip, Middleton, Mairi, Emadi, Ali
Improve the Durability and Maintenance Feasibility of the Universal Joint Based on the Original Half-Shaft Foundation2024-01-244104/09/2024
Based on the particularity of the racing field of the Baja SAE China, the Baja Racing Team of our university has adopted rzeppa universal joint for vehicle design and field competition in the semi-axle parts of the race car in previous years. In view of the complex conditions of the Baja Competition, such as gravity test, climb test, handling test, endurance test, etc., it is necessary to optimize and develop a more convenient maintenance model. Installation and use of better performance, more suitable for off-road conditions of the shaft. In this paper, based on the development dynamics of automobile axles and the transverse comparison of various axles, a kind of telescopic cross-shaft universal joint axles is designed by using CATIA software to model and simulate kinematics and dynamics by using ANSYS software. At the same time, the stress and strain of the model are continuously optimized according to the change of axle wheel Angle and the torque matching of Baja Racing. The object
Zhang, Hengyu, He, Li, Xiao, Miaoqi
Method for Root Bending Fatigue Life Prediction in Differential Gears and Validation with Hardware Tests2024-01-224904/09/2024
An advanced multi-layer material model has been developed to simulate the complex behavior in case-carburized gears where hardness dependent strength and elastic-plastic behavior is characterized. Also, an advanced fatigue model has been calibrated to material fatigue tests over a wide range of conditions and implemented in FEMFAT software for root bending fatigue life prediction in differential gears. An FEA model of a differential is setup to simulate the rolling contact and transient stresses occurring within the differential gears. Gear root bending fatigue life is predicted using the calculated stresses and the FEMFAT fatigue model. A specialized rig test is set up and used to measure the fatigue life of the differential over a range of load conditions. Root bending fatigue life predictions are shown to correlate very well with the measured fatigue life in the rig test. Also fatigue life predictions are shown to correlate well with validation tests carried out on a full-scale axle
DeJack, Michael A., Tichy, Richard
Wheel & Axle Disconnect Controls on Hybrid Electric Powertrains2024-01-277604/09/2024
With the proliferation of electric vehicles in the market, it has become important for Automotive OEMs (Original Equipment Manufacturers) to focus on delivering a higher driving range while also maximizing performance. One approach OEMs are actively considering in meeting this goal is to include a secondary drive axle disconnect into the powertrain which has the potential to improve the overall driving range by about 6-8.3% [4]. This paper outlines the need for a novel controls architecture to make the Powertrain controls software modular and to reduce the development time needed to provide robust powertrain control software. To do this, the electrified powertrain torque controls at STELLANTIS NV takes a decentralized controls architecture approach, by separating the axle disconnect controls subsystem (ADCS) from the primary path of torque controls. The ADCS takes in information such as the desired axle state and controls the axle disconnect actuators to achieve that state. It then
Madireddy, Krishna Chaitanya, Verhun, Brandon, Xu, Chengyi, Sha, Hangxing, Tuller, Zachary, Patel, Nadirsh
Measurement and Modeling for Creep Groan of a Drum Brake in Trucks2024-01-235104/09/2024
An experiment is carried out to measure creep groan of a drum brake located in a trailer axle of a truck. The noise nearby the drum brake and accelerations on brake shoes, axle and trailer frame are collected to analyze the occurring conditions and characteristics of the creep groan. A multi-body dynamics model with 1/4 trailer chassis structures is established for analyzing brake component vibrations that generates the creep groan. In the model, the contact force between brake cam and brake shoes, the contact friction characteristics between brake linings and inner circular surface of brake drum, and the properties of chassis structure are included. Dynamic responses of brake shoes, axle and trailer frame during the braking process are estimated using the established model and the responses are compared with the measured results, which validate the model. Three conclusions of measurement and calculation are obtained. (1) The creep groan is usually generated when braking speed is lower
Zheng, Jing-Yuan, Shangguan, Wen-Bin, Tang, Hao, Lan, Wen-biao
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