Trajectory planning is a major challenge in robotics and autonomous vehicles, ensuring both efficient and safe navigation. The primary objective of this work is to generate an optimal trajectory connecting a starting point to a destination while meeting specific requirements, such as minimizing travel distance and adhering to the vehicle’s kinematic and dynamic constraints. The developed algorithms for trajectory design, defined as a sequence of arcs and straight segments, offer a significant advantage due to their low computational complexity, making them well-suited for real-time applications in autonomous navigation. The proposed trajectory model serves as a benchmark for comparing actual vehicle paths in trajectory control studies. Simulation results demonstrate the robustness of the proposed method across various scenarios.

Soundouss, Halima, Msaaf, Mohammed, Belmajdoub, Fouad

Multi-Objective Robust Optimization for a Parallel Link Steering System: A Six Sigma and Monte Carlo Approach

2025-01-5036

To be published on 06/03/2025

The steering system is one of the most important assemblies for the vehicle. It allows the vehicle to steer according to the driver’s intention. For an ideal steering system, the steering angle for the wheel on the left and right side should obey the Ackman equation. To achieve this goal, the optimization method is usually initiated to determine the coordinates of the hard points for the steering system. However, the location of hard points varies due to the manufacturing error of the components and wear caused by friction during their working life. To decrease the influence of geometry parameter error, and system mass, and improve the robust performance of the steering system, the optimization based on Six Sigma and Monte Carlo approach is used to optimize the steering system for an off-road vehicle. At last, the effect is proved by the comparison of other methods. The maximum error of the steering angle is decreased from 7.78° to 2.14°, while the mass of the steering system is

Peng, Dengzhi, Deng, Chao, Zhou, Bingbing, Zhang, Zhenhua

Thermal Swell, Growth, and Hot Compressibility of Brake Friction Materials and Noise Insulators

J160_202505 (Current)

05/27/2025

This document specifies a universal method of measuring the thickness change of friction materials to determine the effects of temperature. The test applies to both disc and drum-type linings commonly used in hydraulic and air brake systems for automotive or commercial vehicle applications. This document describes several methods for thermal swell and growth. Method A is where the friction material is in contact with a heated surface to simulate the heat input to the pad that occurs during actual usage. Method B uses an oven to heat the freestanding material and is an approximate procedure requiring less instrumentation. Method A is recommended for disc brake pad assemblies, noise insulators, or flat coupons, while Method B is recommended for curved drum brake linings. This document also describes how to test the warmed-up disc brake pads and noise insulators for hot compressibility using Method A.

Brake Linings Standards Committee

Development of an Intelligent Instrumented Tire for Real-Time Hydroplaning Risk Estimation

10-09-03-0027

05/21/2025

This study introduces an innovative intelligent tire system capable of estimating the risk of total hydroplaning based on water pressure measurements within the tread grooves. Dynamic hydroplaning represents an important safety concern influenced by water depth, tread design, and vehicle longitudinal speed. Existing intelligent tire systems primarily assess hydroplaning risk using the water wedge effect, which occurs predominantly in deep water conditions. However, in shallow water, which is far more prevalent in real-world scenarios, the water wedge effect is absent at higher longitudinal speeds, which could make existing systems unable to reliably assess the total hydroplaning risk. Groove flow represents a key factor in hydroplaning dynamics, and it is governed by two mechanisms: water interception rate and water wedge pressure. In both the shallow water and deep water cases, the groove water flow will increase as a result of increasing the longitudinal speed of the vehicle for a

Vilsan, Alexandru, Sandu, Corina, Anghelache, Gabriel, Warfford, Jeffrey

Letter from the Guest Editors

10-09-02-0009

05/19/2025

Letter from the Guest Editors

Wang, Zhenfeng, Zhang, Yunqing, Qi, Ronghuai, Lu, Yukun

Identification of Suspension Kingpin Alignment Parameters Based on Screw Axis Theorem and Differential Calculation Model

2025-01-5034

05/06/2025

This paper presents an analytical approach for identifying suspension kingpin alignment parameters based on screw axis theorem and differential calculation model. The suspension kingpin caster and inclination alignment parameters can produce additional tire force, which affects vehicle handling dynamics. In wheel steering process, the multi-link suspension control arms lead to movement of the imaginary kingpin, which can cause change in suspension kingpin alignment parameters. According to the structure mechanism of commercial vehicle multi-link independent suspension, the kinematics characteristics of imaginary kingpin were analyzed based on the screw axis theorem. The angular velocity and translation velocity vectors were calculated. In order to avoid the influence of bushing deformation, the unique differential identification model was established to evaluate the suspension kingpin alignment parameters, and the identification results were compared with the ADAMS/Car data. The

Ding, Jinquan, Hou, Junjian, Zhao, Dengfeng, Guo, Yaohua

The Accelerated Roughness Noise Optimization of One PHEV Vehicle

2025-01-0087

05/05/2025

To optimize the noise that heard like ‘kalakala’ produced by the plug hybrid electric vehicle when accelerating with a small accelerated pedal opening while in the charging state of series modal. The LMS test device was used to acquire the noise of the driver's outer ear. Through filtering and playback analysis, it was confirmed that the noise is mainly contains the frequency bands of 250-400Hz and450-700Hz. The frequency bands of the noise were used as carriers for Hilbert transform, and their envelopes were obtained for Fourier transform analysis. It was found that the modulation order of the noise is 0.5 times of the engine ignition order, and the modulation frequency is 20-30Hz, which let the customer hears like roughness. Regarding the spectral characteristics of this noise, firstly, at the excitation source, selected a reasonable moment of inertia and frequency of the Crank torsional damper, to decrease the torsional excitation of the engine. Secondly, investigated the structural

Shouhui, Huang, Zhongxun, Hu, Zhao, Yun, Shanyin, Ren, Ruifeng, Dong, Teng, Charlie, Changshui, Zhou, Xu, Ling

Analysis of Subharmonic Torsional Resonance in Powertrains with Two-Stage Spring Isolators

2025-01-0096

05/05/2025

A vehicle powertrain system with a two-stage spring isolator separating a combustion engine from a transmission can exhibit significant nonlinear dynamics if the input torques cause the spring to continuously alternate between its first-stage and second-stage stiffnesses. In particular, this nonlinearity can result in subharmonic resonance of the system’s natural frequencies at half the frequency of the engine’s primary excitation order. A 1D torsional vibration model was prepared using Siemens’s Simcenter Amesim software to study these nonlinear vibrations. First, a correlated vehicle-level model was developed to replicate a half-order torsional resonance that was measured in a test of a research vehicle. Then, simplified theoretical models were used to study and demonstrate the sensitivity of this kind of subharmonic resonant response to changes in mean input torque level, amplitude of input torque oscillation, first-stage capacity of the spring isolator, and other factors.

Villiger, Jacob

Effects on Motorcycle Response Data Using Wheel Force Transducers

2025-01-0094

05/05/2025

Wheel Force Transducers (WFT) are precise and accurate measurement devices that seamlessly integrate into any vehicle. They can be applied in numerous vehicle applications for both on-road and in laboratory settings. The instrumentation requires replacing an original equipment manufacturer (OEM) wheel with a custom WFT system which is specific to the wheel hub design. An ideal design will minimally impact a vehicle's dynamics, but the vehicle system is inherently modified from the mass of the measurement device. Research and technical documentation have been published which provide conclusions explaining reduction in the unsprung mass reduces dynamic wheel load. However, there doesn’t appear to be clear compensation techniques for how a modified unsprung mass can be related to the original system, thus allowing the WFT signals to be more accurate to the OEM wheel forces. An experimental study was performed on a prototype motorcycle to better understand these differences. An

Frisco, Jacob, Larsen, William, Rhudy, Scott, Oosting, Nicholas, Laurent, Matthew

Road Noise Analysis using Component TPA and FBS with Vehicle Component Modifications

2025-01-0055

05/05/2025

Road noise caused by road excitation is a critical factor for vehicle NVH (Noise, Vibration, and Harshness) performance. However, assessing the individual contribution of components, particularly bushings, to NVH performance is generally challenging, as automobiles are composed of numerous interconnected parts. This study describes the application of Component Transfer Path Analysis (CTPA) on a full vehicle to provide insights into improving NVH performance. With the aid of Virtual Point Transformation (VPT), blocked forces are determined at the wheel hubs; afterward, a TPA is carried out. As blocked forces at the wheel hub are independent of the vehicle dynamics, these forces can be used in simulations of modified vehicle components. These results allow for the estimation of vehicle road noise. To simulate changes in vehicle components, including wheel/tire and rubber bushings, Frequency-Based Substructuring (FBS) is used to modify the vehicle setup in a simulation model. In this

Kim, Jungu, Reichart, Ron, de Klerk, Dennis, Schütler, Willem, Malic, Mario, Kim, Hyeongjun, Kim, Uije

Application of Blocked Force Methodology to an Electrified Beam Axle from a Medium-Duty Truck in Vehicle and in a Dynamometer Test Cell

2025-01-0054

05/05/2025

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

Electric Bus NVH Challenges and Refinement Using Innovative Approach

2025-01-0080

05/05/2025

The trend towards electrification propulsion in the automotive industry is highly in demand due to zero-emission and becoming more significant across the world. Battery electric vehicles have lower overall noise as compared to conventional I.C Engine counterparts due to the absence of engine combustion and mechanical noise. However, other narrowband and tonal noises are becoming dominant and are strongly perceived inside the cabin. With the ongoing push towards electrification, there is likely to be increased focus on the noise impact of gearing required for the transmission of power from the electric motor to the road. Direct coupling of E-motors with Axle has resulted in severe tonal noises from the driveline due to instant e-motor torque ramp up from 0 rpm and reverse torque on driving axle during regenerative braking. The tonal noises from the rear axle during vehicle running become very critical for customer perception. For automotive NVH engineers, it has become a challenge to

Doshi, Sohin, Kalsule, Dhanaji, Sawangikar, Pradeep, Suresh, Vineeth, Sharma, Manish

The Applications of Acoustic Black Holes to Attenuation of Coach/Bus Frame Structure Vibrations

2025-01-0065

05/05/2025

Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB

Xu, Chuanyan, Wang, Jianjun, Xing, Qisen, Chen, Hengbin, Huang, Xianli

Leveraging Vision Language Models and Prompt Engineering for Bearing Defect Classification from Vibration Signals

2025-01-0127

05/05/2025

Bearings are fundamental components in automotive systems, ensuring smooth operation, efficiency, and longevity. They are widely used in various automotive systems such as wheel hubs, transmissions, engines, steering systems etc. Early detection of bearing defects during End-of-Line (EOL) testing and operational phases is crucial for preventive maintenance, thereby preventing system malfunctions. In the era of Industry 4.0, vibrational, accelerometer, and other IoT sensors are actively engaged in capturing performance data and identifying defects. These sensors generate vast amounts of data, enabling the development of advanced data-driven applications and leveraging deep learning models. While deep learning approaches have shown promising results in bearing fault diagnosis, they often require extensive data, complex model architectures, and specialized hardware. This study proposes a novel method leveraging the capabilities of Vision Language Models (VLMs) and Large Language Models

Chandrasekaran, Balaji, Cury, Rudoniel

Brake Noise CAE Enhancement with the Synergy between Design of Experiments and Machine Learning

2025-01-0124

05/05/2025

The digitalization of industrial systems has led to increased data availability. Machine learning (ML) methodologies are now commonly used for data analysis in industrial contexts. Not all contexts have abundant data; sometimes data collection can be scarce or expensive. Design of Experiments (DOE) is a technique that provides an informative dataset for ML analysis when data are limited. It involves systematically designing experiments to collect relevant data points with regression models. Disc brake noise is a challenging problem in vehicle noise, vibration, and harshness (NVH). Different noise events occur under various operating conditions and across frequencies (1-16 kHz). To enhance computer-aided engineering (CAE) techniques for brake noise, ML is used to generate additional data. Sequential experimentation in DOE aligns well with ML’s ability to continuously learn and improve as more data become available. DOE is applied in CAE to collect data for training ML models. ML helps

Song, Gavin, Sridhar, Gurupriya, Vlademar, Michael, Venugopal, Narayana

Simulation and Experimental: Enhanced Stability Control of Electric Vehicle Based on Phase Plane Boundary Analysis

10-09-02-0017

05/05/2025

To optimize vehicle chassis handling stability and ride safety, a layered joint control algorithm based on phase plane stability domain is proposed to promote chassis performance under complicated driving conditions. First, combining two degrees-of-freedom vehicle dynamics model considering tire nonlinearity with phase plane theory, a yaw rate and side slip angle phase plane stability domain boundary is drew in real time. Then based on the real-time stability domain and hierarchical control theory, an integrated control system with active front steering (AFS) and direct yaw moment control (DYC) is designed, and the stability of the controller is validated by Lyapunov theory. Finally, the lateral stability of the vehicle is validated by Simulink and CarSim simulations, real car data, and driving simulators under moose test and pylon course slalom test. The experimental results confirm that the algorithm can enhance the maneuverability and ride safety for intelligent vehicles.

Liao, Yinsheng, Zhang, Zhijie, Su, Ailin, Zhao, Binggen, Wang, Zhenfeng

Application of AI/ML in Hydrobush Tuning to Enhance Overall Value Proposition

2025-01-0132

05/05/2025

In the highly competitive automotive industry, optimizing vehicle components for superior performance and customer satisfaction is paramount. Hydrobushes play an integral role within vehicle suspension systems by absorbing vibrations and improving ride comfort. However, the traditional methods for tuning these components are time-consuming and heavily reliant on extensive empirical testing. This paper explores the advancing field of artificial intelligence (AI) and machine learning (ML) in the hydrobush tuning process, utilizing algorithms such as random forest, artificial neural networks, and logistic regression to efficiently analyze large datasets, uncover patterns, and predict optimal configurations. The study focuses on comparing these three AI/ML-based approaches to assess their effectiveness in improving the tuning process. A case study is presented, evaluating their performance and validating the most effective method through physical application, highlighting the potential

Hazra, Sandip, Khan, Arkadip Amitava

Investigation and Application of Tire Model to Optimize Road Noise

2025-01-0111

05/05/2025

Tires have a significant impact on vehicle road noise. The noise in 80~160Hz is easily felt when driving on rough roads and has a great relationship with the tire structural design. How to improve the problem through tire simulation has become an important issue. Therefore, this paper puts forward the concept of virtual tire tuning to optimize the noise. An appropriate tire model is crucial for road noise performance, and the CDtire (Comfort and Durability Tire) model was used in the article. After conducting experimental validation to get an accurate tire model, adjust the parameters and structure of the tire model to generate alternative model scenarios. The transfer function of the tire center was analyzed and set as the evaluation condition for tire NVH (Noise, vibration, and harshness) performance. This enabled a comparison among various model scenarios to identify the best-performing tire scenario in focused frequency whose transfer function needed to be lowest. Manufacture the

Zhang, Ben, Yu Sr, Jing, Chen, Qimiao, Liu, Xianchen, Gu, Perry

A Study on Luxury Captain Seat Vibration in MPV Vehicles with Semi-Active Suspension

2025-01-0107

05/05/2025

More and more captain-seat-like, luxury individual seats have been appeared inside MPV vehicles in order to meet various customer needs and improve market competitiveness. In the same time, customer complaints about seat vibration also increase significantly. Thus, luxury captain seat vibration is becoming MPV issues facing the vehicle development engineers. Typically, luxury captain seats are much heavier due to the added mechanisms to provide functions like massage or temperature controls, etc., and it is not feasible to structurally improve the seat modal frequencies to meet the need for NVH issue resolution. This paper presents a systematical study on the second-row luxury captain seat vibration issue between 10-25Hz with MPV vehicles. An axle contribution is analyzed with a 4-poster shaker test, and the test data show that the seat vibration is more sensitive to rear axle excitation than that of front axle, and to the out-of-phase excitation than the in-phase one. The similar

Zhou, Changshui, Yu Sr, Jing, Gu, Perry, Zhang, Fan, Bu, Kunquan, Liu, Xinhua

Model Based NVH Simulator for Virtual Development

2025-01-0059

05/05/2025

For mature virtual development, enlarging coverage of performances and driving conditions comparable with physical prototype is important. The subjective evaluation on various driving conditions to find abnormal or nonlinear phenomena as well as objective evaluation becomes indispensable even in virtual development stage. From the previous research, the road noise had been successfully predicted and replayed from the synthesis of system models. In this study, model based NVH simulator dedicated to virtual development have been implemented. At first, in addition to road noise, motor noise was predicted from experimental models such as blocked force and transfer function of motor, mount and body according to various vehicle conditions such as speed and torque. Next, to convert driver’s inputs such as acceleration and brake pedal, mode selection button and steering wheel to vehicle’s driving conditions, 1-D performance model was generated and calibrated. Finally, the audio and visual

Park, Sangyoung, Dirickx, Tom, Kang, Yeon June, Nam, Jeong Min, Gonçalves, Vinícius Valencia

Study of Sound and Cabin Touchpoint Contributions to Subjective Perception of Secondary Ride

2025-01-0060

05/05/2025

Subjective perception of vehicle secondary ride is dependent on simultaneous touchpoint vibrations and audible inputs to the occupants. Standards such as ISO 2361 provide guidelines for objective assessments of human body thresholds to vibration [1]. However, when a human experiences vibration inputs at multiple touchpoints, as well as aural inputs, it becomes complicated to judge each individual contribution to the overall subjective perception [2]. Additional factors, such as ambient conditions, ergonomics, age, gender etc. also play a role. Secondary ride, which is defined as energy in the 10-30 Hz frequency range, is one such event that affects the customers’ perception of ride comfort and quality. The goal of this work is to develop a sound and vibration simulator model and execute a secondary ride jury study of vehicle driving over cleats. The aim of the study is to rank the contributions of each touch point vibration input, as well as sound to the overall subjective perception

Jayakumar, Vignesh, Joodi, Benjamin, Geissler, Christian, Pilz, Fernando, Lynch, Luke, Conklin, Chris, Weilnau, Kelby, Hodgkins, Jeffrey

Simulation of In-Vehicle Tire Noise Performance from Single-Tire Test Stand

2025-01-0061

05/05/2025

A test and signal processing strategy was developed to allow a tire manufacturer to predict vehicle-level interior response based on component-level testing of a single tire. The approach leveraged time-domain Source-Path-Contribution (SPC) techniques to build an experimental model of an existing single tire tested on a dynamometer and substitute into a simulator vehicle to predict vehicle-level performance. The component-level single tire was characterized by its acoustic source strength and structural forces estimated by means of virtual point transformation and a matrix inversion approach. These source strengths and forces were then inserted into a simulator vehicle model to predict the acoustic signature, in time-domain, at the passenger’s ears. This approach was validated by comparing the vehicle-level prediction to vehicle-level measured response. The experimental model building procedure can then be adopted as a standard procedure to aid in vehicle development programs.

Nashio, Hiroshi, Kajiwara, Kohei, Rinaldi, Giovanni, Sakamoto, Yumiko

Cairene Car-Culture: How are Automobility and Social Behavior Linked to The Development of The Soundscape and Urban Fabric of Cairo

2025-01-0069

05/05/2025

Cairo’s soundscape has witnessed changes due to the ongoing urban structure developments that accommodate the number of vehicles passing through the city. The soundscape produced by this growing automobility is affected not only by vehicles but also by their owners' behavior. Cairenes use their cars as a communication tool and an extension of private space. By viewing the vehicle as a component of the soundscape as well as a space that filters it, this study examines the synergy between social behavior, automobility, urban structure, and their interdependent relationship on the soundscape of Cairo. The study responds to literature elaborating on acoustic ecology, car culture, urban structure, and social behavior. The methodology applied in this study follows practice-based phenomenological research while documenting and reflecting on car cultural practices in Cairo from an aural perspective. Grounded theory contextualizes the analysis of archived audio and video material, semi

Abd El Naby, Abla Mohamed

Experimental Characterization of a Steel Spring Mount Using Virtual Point Transformation

2025-01-0046

05/05/2025

The application of virtual point transformation for determining the transfer dynamic stiffness of a helical coil spring is demonstrated in this experimental study. Rigid fixtures are attached to both ends of the spring, and frequency response functions are measured using impact hammer excitations. These frequency response functions are transformed into virtual points, analogous to a node in finite element analysis, with six degrees of freedom. The six degrees of freedom transfer dynamic stiffness is then extracted using the inverse substructuring method, which eliminates the need to account for fixture dynamics. The results are validated by a direct measurement approach. Additionally, the study investigates the effect of liquid applied sprayed damping coatings on the spring's transfer dynamic stiffness, revealing that the coating significantly reduces vibration amplitudes at the surge frequencies. This suggest that the springs effective damping properties are enhanced.

Neihguk, David, Herrin, D. W., de Klerk, Dennis

Experimental Investigation on Genetic Algorithm Optimized Proportional Integral Derivative Based Active Suspension System

2025-01-0014

05/05/2025

In this work, Genetic Algorithm (GA) optimized Proportional Integral Derivative (PID) controller is employed in the active suspension. The PID gain values are optimally tuned based on the objective function by the Integral Time Absolute Error (ITAE) criteria of various suspension measures like vehicle body displacement, suspension and tire deflections. The proposed GAPID controller is experimentally validated through the 3-DOF quarter-car (QC) test rig model. The fabricated model with passive suspension system (PASS) and active suspension system (ACSS) with an electrical actuator is presented. The schematic representation of the fabricated test set-up with and without ACSS is also illustrated. Further, simulation and experimental response of the fabricated model with and without ACSS are compared. It is identified that the proposed GAPID controller attenuates the sprung mass acceleration by about 41.64 % and 29.13 % compared with PASS for the theoretical as well as experimental cases

A, Arivazhagan, Kandavel, Arunachalam

A Comprehensive Review of Vehicle and Road Condition Estimation Techniques

10-09-02-0014

04/30/2025

This article reviews the key physical parameters that need to be estimated and identified during vehicle operation, focusing on two key areas: vehicle state estimation and road condition identification. In the vehicle state estimation section, parameters such as longitudinal vehicle speed, sideslip angle, and roll angle are discussed, which are critical for accurately monitoring road conditions and implementing advanced vehicle control systems. On the other hand, the road condition identification section focuses on methods for estimating the tire–road friction coefficient (TRFC), road roughness, and road gradient. The article first reviews a variety of methods for estimating TRFC, ranging from direct sensor measurements to complex models based on vehicle dynamics. Regarding road roughness estimation, the article analyzes traditional methods and emerging data-driven approaches, focusing on their impact on vehicle performance and passenger comfort. In the section on road gradient

Chen, Zixuan, Duan, Yupeng, Wu, Jinglai, Zhang, Yunqing

On-the-Market Air Suspension Systems for Passenger Cars

10-09-02-0016

04/28/2025

This article conducts a thorough review of contemporary air suspension systems on the market for passenger cars. The evolution of suspension structures and control methodologies are briefly discussed. The layout of air suspension systems is introduced in detail, with each component receiving a comprehensive description and analysis. The open-loop and closed-loop arrangements are explained. Various types of air springs are discussed and compared. The sensory system, special working conditions, and failure analysis are also elaborated. In the case studies, some example models are listed to show a complete guide of how air suspension is implemented on passenger cars, which includes functionalities, air spring configurations, control methods, signal flow, service modes, and diagnostic messages. The major sources are OEMs’ official websites and previously released documents, such as user manuals and maintenance manuals, which are valid up to April 2023. Finally, the article concludes with a

Ma, Changye, Lu, Yukun, Zhen, Ran, Liu, Yegang, Pan, Bingwei, Khajepour, Amir

Development of an Imperceptible Brake Failure Control Technology and Real Vehicle Application

10-09-02-0015

04/26/2025

With the advancement of control technology in the automotive field, there is a possibility of cross-system redundant control between various actuators. As for the braking system, current brake-by-wire system often uses mechanical backup braking methods to give the vehicle a certain braking capacity after failure. However, in the mechanical backup braking mode, the brake master cylinder is connected to the supporting wheel cylinder, and the brake assist is lost, which leads to an increase in brake pressure and makes it difficult for the driver to step on the brake pedal. Meanwhile, due to the limitation of the brake master cylinder stroke, the maximum braking deceleration of the vehicle is only 3 m/s2 after the driver fully presses the brake pedal. The above two defects greatly affect the safety of the vehicle during backup braking. To solve the above problems, this article takes electric vehicles as the research object, designs a new type of hydraulic circuit for the braking system

Tian, Boshi, Li, Liang, Liao, Yinsheng, Lv, Haijun, Hu, Zhiming, Sun, Yue, Qu, Wenying

Traction Voltage Level in Two-Wheelers: Considerations on Safety and Performance

2024-32-0062

04/18/2025

Most electric 2-wheelers on the market today seek to replace combustion engine vehicles from 50cc to 150cc which equates to an electric motor power between 2 and 12 kW. The traction voltage level of these vehicles is mostly between 44V and 96V. However, the actual choice of voltage on a specific vehicle seems to be arbitrary and higher voltage does not necessarily correlate with higher motor power. This paper seeks to highlight considerations and tradeoffs which feed the choice of traction voltage levels. Important criteria are electrical safety standards and their impact on vehicle electrical architecture, the performance and availability of key electronics parts such as capacitors, MOSFETs, and gate drivers, while also highlighting functional safety aspects. This paper shows by a comprehensive analysis of the motor drive that for the vehicle class mentioned above the traction voltage level can be kept below 60V without any performance impact, while also ensuring electrical and

Schmitt, Stefan

Fatigue Analysis of Motorcycle Rear Swing Arm on Different Road Surfaces

2024-32-0046

04/18/2025

The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on

Chiou, Yi-Hau, Hwang, Hsiu-Ying, Huang, Liang-Yu

Necessity of Body Torsional Rigidity of Personal Mobility Vehicles (PMVs) with an Inward Tilting Mechanism

2024-32-0013

04/18/2025

In traditional four-wheeled automobiles, the imbalance between the roll moment, which is the product of the centrifugal force during a turn acting on the center of gravity and the height of the center of gravity, and roll stiffness, which is the product of the left-right difference in tire vertical load and the tread width and commonly used among automotive suspension engineers, of the front and rear sections necessitates body torsional rigidity. However, there is a lack of specific cases and guidelines for constructing the body structure of three-wheeled PMVs (Personal Mobility Vehicles) with a tilting mechanism from the perspective of vehicle dynamics characteristics. In this paper, the basic considerations related to the dynamics of such three-wheeled PMVs are investigated. We use the term “torsional rigidity” to refer to the stiffness as the torsional deformation of the body itself, and the term “roll stiffness” to refer to the moment that counteracts the roll moment during a turn

Haraguchi, Tetsunori, Kaneko, Tetsuya

Development of a Robust Framework for Fault Detection and Quantification in Automotive Drum Brakes Using Vibration Measurements and ANN

10-09-03-0024

04/15/2025

Passenger safety is of utmost importance in the automotive industry. Hence, the health of the components, especially the brake system, should be effectively monitored. On account of the significance of artificial intelligence in recent times, any brake fault resulting during operation can be accurately detected using a combination of advanced measurement techniques and machine learning algorithms. The current study focuses on developing and evaluating a robust framework to quantify and classify the faults of a general automotive drum brake. For this purpose, a new experiment for a drum brake, which can be operated under a controlled environment with known levels of faults, is developed. The experiment is instrumented to measure the fundamental dynamic signals (such as brake torque, the angular velocity of the brake drum, and brake shoe accelerations) during a braking event. The response signals from several experiments with various faults and operating conditions serve as the input

Yella, Akash, Bharinikala, Yuva Venkat Ajay, Sundar, Sriram

Automatic Emergency Braking (AEB) System Performance Testing

J3087_202504 (Current)

04/14/2025

This document describes an SAE Recommended Practice for Automatic Emergency Braking (AEB) system performance testing which: Establishes uniform vehicle level test procedures Identifies target equipment, test scenarios, and measurement methods Identifies and explains the performance data of interest Does not exclude any particular system or sensor technology Identifies the known limitations of the information contained within (assumptions and “gaps”) Is intended to be a guide toward standard practice and is subject to change on pace with the technology Focuses on “Vehicle Front to Rear, In Lane Scenarios” expanded to include additional offset impacts This document describes the equipment, facilities, methods, and procedures needed to evaluate the ability of Automatic Emergency Braking (AEB) systems to detect and respond to another vehicle, in its forward path, as it is approached from the rear. This document does not specify test conditions (e.g., speeds, decelerations, clearance gaps

Active Safety and Driver Support Systems Standards Committee

Automotive Air Brake Hose and Hose Assemblies

J1402_202504 (Current)

04/14/2025

This SAE Recommended Practice covers minimum requirements for air brake hose assemblies made from reinforced elastomeric hose and suitable fittings for use in automotive air brake systems, including flexible connections from frame to axle, tractor to trailer, trailer to trailer, and other unshielded air lines with air pressures up to 1 MPa, that are exposed to potential pull or impact. This hose is not to be used where temperatures, external or internal, fall outside the range of -40 to +100 °C. Provisions for extreme low temperature performance testing to -54 °C are included in the document.

Hydraulic Hose and Hose Fittings Committee

Drive Quality Evaluation for Chassis Dynamometer and On-Road Testing

J2951_202504 (Current)

04/14/2025

This SAE Recommended Practice establishes uniform procedures for evaluating conformity between the actual and target drive speeds for chassis dynamometer and on-road testing utilizing standard fuel economy/energy consumption and emissions drive schedules.

Light Duty Vehicle Performance and Economy Measure Committee

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