Browse Topic: Vehicle ride

Items (624)
Air springs are increasingly replacing traditional shock absorbers in vehicle suspension systems due to their superior mechanical properties, including adjustable stiffness, nonlinear characteristics, and excellent damping performance. To further explore the potential of air suspension in improving ride comfort, this paper focuses on air suspension. We first conducted mechanical characteristic experiments on air springs to obtain their stiffness and damping characteristics under different inflation pressures and excitation frequencies. These tests provide essential mechanical parameters for subsequent modeling and simulation. Based on the experimental data, a simplified 1/4 air suspension simulation model is constructed, taking into account the nonlinear stiffness and damping properties of the air springs. To simulate real-world driving conditions, a random road surface model is introduced as the excitation input. Simulation analysis is conducted to compare the air suspension system with the traditional passive suspension system. The results indicate that, compared to the passive suspension system, the air suspension system integrated with Model Predictive Control(MPC) significantly reduces key performance indicators, including suspension deflection, wheel dynamic load, and sprung mass vertical acceleration. This indicates that the suspension with model predictive control can effectively suppress vehicle vibrations, thereby enhancing ride comfort and driving stability. The results of this study provide an important basis for the optimal design of air suspension systems and have practical application value for improving the suspension performance of the vehicle.
Yin, Zhi
In response to the problem of manual transmission rattle noise in the acceleration process of a truck, the mechanism of the problem is analysed, and the scheme is developed and verified from two aspects: reducing the torsional vibration of the system and reducing the response of the transmission gear. The results show that, on the one hand, reducing the clutch stiffness and optimizing the torsional vibration of the system can reduce the rattle noise of the transmission; On the other hand, it can also reduce the rattle noise of transmission gears by improving the engagement precision of transmission gears and reducing the gear clearance. Considering the improvement effect, cost, and influence on other performance of the two schemes, the appropriate engineering scheme is selected to effectively solve the problem and improve the riding comfort of the product.
Yang, ZhijieXu, Binghua
With the country’s economy and people’s consumption capacity increasing, railroad transportation tasks have become more and more frequent, and it is growing the demand for the transportation of high-value goods, fresh produce, etc. Compared with traditional Freight vehicles, express freight vehicles have great advantages in terms of carrying capacity, mobility, and transportation cost, but when it run at a speed of 160 km/h, it often occurs that failure of axle-box rubber springs, primary vertical dampers, secondary lateral dampers, anti-yaw dampers, and air springs. How to ensure the safety and stability of the train under suspension system failure conditions is a problem that needs to be solved during the design process. In this paper, through multi-body system dynamics software, a nonlinear dynamics model of lateral and vertical coupling of the vehicle system is established to analyze the influence of suspension system failure on the stability of 160 km/h express freight vehicles. The analysis results show lowering the operating speeds can meet the Ride Quality of the Vehicles in special conditions.
Gao, ZhixiongMa, KaiXiao, YanmeiChen, WeidongWei, XiaoSha, ChengyuBian, Huihui
In recent years, the automotive industry has faced increasing pressure to accelerate development cycles and reduce costs. Simultaneously, ride comfort standards have risen due to the ongoing integration of autonomous driving functionalities. Consequently, it has become essential to ensure that ride comfort attains a high degree of maturity at the very early stages of the automotive development process. This necessitates the establishment of objective criteria that enable the reliable estimation of subjective ride comfort, utilizing simulation-based assessment methods. This study introduces a methodological framework designed to systematically translate the manufacturer specific subjective perception and assessment of ride comfort into objective descriptions using a dynamic driving simulator. The framework is conceived as a generic approach, enabling the comprehensive application to a wide spectrum of subjective ride comfort phenomena, while being specifically optimized for the challenges of the automotive industry. Employing this framework facilitates the derivation of highly detailed, objective descriptions of subjective ride comfort evaluations, which promotes the achievement of advanced ride comfort maturity for new vehicles in early development phases and supports the overall enhancement of ride comfort. The exemplary application of the framework to a transient, one-dimensional ride comfort phenomenon demonstrates its capability to derive robust objective models from subjective evaluations conducted with professional test drivers in a dynamic driving simulator environment.
Stroesser, SimonZwosta, TobiasAngrick, ChristianNeubeck, JensWagner, Andreas
Semi-active suspension systems enhance ride comfort and handling performance by adaptively modulating damping characteristics. However, conventional model-based controllers often fail to maintain optimal performance under uncertain and time-varying vehicle conditions. This article proposes Bayesian Optimization–Tuned Proximal Policy Optimization with Non-Parametric Rewards (BO-NRPPO), a novel reinforcement learning (RL) framework that integrates Bayesian Optimization (BO) with Proximal Policy Optimization (PPO) and a non-parametric reward function (NRF). The proposed approach enables adaptive self-tuning, data-driven reward shaping, and uncertainty-aware policy learning. Moreover, a Trapezoidal Simple Moving Average (TSMA)–based reward normalization scheme is introduced to accelerate convergence and stabilize training. Simulation results across diverse driving scenarios demonstrate that BO-NRPPO outperforms the passive suspension, the classical Linear Quadratic Regulator (LQR), and PPO with parametric rewards. Specifically, compared to the passive suspension and the LQR baseline, BO-NRPPO achieves up to 6.63% and 5.14% improvements in handling stability, respectively. Concurrently, it delivers maximum enhancements of 46.96% and 42.55% in ride comfort over these two baselines. For real-world vehicle applications, this adaptive self-tuning capability significantly reduces the time-consuming manual calibration efforts typically required in chassis development. Furthermore, Hardware-in-the-loop (HiL) validation confirms its real-time applicability and robustness under uncertain driving conditions, highlighting its immense potential as a scalable intelligent suspension control solution.
Chen, GuoyingWang, XinyuWang, JiaqiZhan, XinwangBi, ChenxiaoCong, ShiqiHua, MinSun, TianjunGao, Zhenhai
Kenworth's new C580 vocational truck made its debut at CONEXPO 2026. The C580 is the replacement for the long-serving C500 and aims to build on that truck's legacy thanks to new tech, more muscle and improved interior amenities. According to Kenworth, the C580 rides on the C500 platform, but has been endowed with Kenworth's latest cab, which brings modern comfort and technology features. Truck & Off-Highway Engineering was in attendance for Kenworth's introductory press conference for the C580 in Las Vegas.
Wolfe, Matt
The suspension system with variable damping and variable stiffness actuators can realize four-quadrant mechanical output, effectively combining the energy efficiency of the semi-active suspension with the performance levels approaching those of active suspensions. However, the practical effectiveness of this system depends heavily on the ability of the control strategy to adapt to different driving conditions. In order to meet this challenge, this research has developed a multi-mode suspension collaborative control strategy to optimize energy efficiency and ride comfort in various operating scenarios. Based on the four-quadrant characteristics of the actuator, a suspension mode switching framework has been established, and the suspension work is divided into passive, semi-active, pseudo-active and active modes. In order to determine the appropriate switching boundary, first calculate the root mean square (RMS) value of the sprung mass acceleration and suspension dynamic deflection under passive conditions. With the existing human comfort sensitivity as a reference, the switching threshold of sprung mass acceleration is 0.527 m/s2, and the switching threshold of suspension dynamic deflection is 8.31×10−3m, and the corresponding conversion rules are formulated. Then, the LQR controller optimized by the genetic algorithm is used to allocate the control force adaptively according to the suspension mode to realize cooperative multi-mode operation. The simulation results on B-D composite road surfaces show that compared with traditional passive suspension, this method can reduce the sprung mass acceleration, suspension dynamic deflection and tire dynamic load by 10.59%, 16.65% and 32.9% respectively. These results confirm that the collaborative control strategy significantly improves the ride comfort, vehicle adaptability and overall performance in complex road conditions.
Li, ZhiyingLi, JeiZhu, AndingBai, XianxuLi, WeihanLi, Rui
To address the challenge of balancing voltage support and current limitation in grid-forming converters (GFCs)—a challenge induced by the uncontrollability of active power during transient faults in microgrids and weak grids—a low voltage ride through (LVRT) strategy utilizing adaptive virtual impedance with a variable resistance-to-inductance ratio is proposed. This strategy is designed to maximize the satisfaction of reactive power support and current limiting characteristics. By adaptively generating virtual impedance based on changing line parameters, the method enables adaptation to large disturbance conditions involving variations in line impedance and Short Circuit Ratio (SCR). First, a transient model of the virtual impedance for GFCs is established to clarify the transient instability mechanism. During the transient period, the power loop is controlled to prevent power angle divergence. Second, the influence mechanism of virtual impedance on reactive current and output current during transients is analyzed. By integrating inrush current limitation and LVRT requirements, an adaptive virtual impedance control strategy is formulated to achieve collaborative optimization of transient LVRT and current limiting. Finally, the effectiveness of the proposed control strategy is verified through MATLAB/Simulink simulation experiments.
Pang, BoYang, XiangzhenLiu, Fang
As an emerging innovative mode of public transportation, electric modular buses (EMBs) offer a novel solution to the problems of existing public transportation systems, due to the coupling-decoupling processes. In this paper, we study the energy consumption characteristics of EMBs by joining vehicle-to-vehicle (V2V) charging and reduction in aerodynamic drag due to coupling. For the pursuit of energy economy, ride comfort, and operational efficiency, we constructed an optimization scheme based on the simulated annealing (SA) algorithm to facilitate the coupling-decoupling process. The simulation results show that EMBs can meet 82.5 % of service requests compared with 61.8 % for the benchmark group, and V2V presents a significant contribution to energy efficiency, especially at low battery state of charge (SOC). Additionally, sensitivity analysis is conducted to study the impact of initial SOC, operation interval, and route type. The results provide insights for optimizing EMBs’ operations and emphasize the potential role of EMBs in supporting low-carbon and sustainable urban mobility systems.
Liao, PengGuo, JiaheNing, DonghongLi, SijiaWang, Tao
For Urban Air Mobility taxis, passengers will experience different levels of heave motion during flight. Researchers at NASA Armstrong Flight Research Center conducted two studies in which passengers were exposed to varying levels of heave motion in the Armstrong Virtual Reality Passenger Ride Quality Laboratory. In the first study, twenty-three volunteers from the Armstrong workforce evaluated the motions on a five-point rating scale and a binary comfort scale; in the second study, fifty volunteers evaluated a flight experience with varying levels of stimuli using a five-point comfort scale and a five-point passenger acceptance scale. This paper combines the results of these two studies to observe the relationship between heave motion and passenger rider quality and acceptance. Both passenger comfort and acceptance were found to decrease with increasing heave acceleration The statistically significant relationship between the magnitude of heave acceleration and passenger comfort for individual studies and combined results are discussed.
Ramia, SaravanakumaarTzarnotzky, UriHendrickson, CoryRoss, JeremyGuy, ColetteHanson, Curtis
Automated Vehicles (AV) pose new challenges in road safety, multimodal interaction, and urban planning, requiring a holistic approach that prioritizes sustainability and protects all road users. The KASSA.AST project addresses this by deploying and evaluating an automated shuttle in southern Austria on three routes. The study area is a Park & Ride zone near a train station, enabling seamless transfers and higher transit use. To assess the safety impacts of the automated shuttle, four Mobility Observation Boxes (MOBs) were deployed. These AI-based systems detect and classify road users, track their trajectories and geospatial coordinates, and identify safety-critical events via Surrogate Safety Measures (SSMs). Over 10 days, a trajectory dataset captured interactions among vehicles and the shuttle. The resulting real-world dataset is a core contribution. This dataset underpins microscopic behavior modeling. Trajectory pairs yield car-following and interaction metrics (relative distance, relative speed, acceleration) to calibrate custom models for realistic mixed traffic. Simulations generate a structured interaction database with time spans, trajectories, conflict points, and SSMs (such as Time-to Collision—TTC, Post-Encroachment Time—PET, and Deceleration-rate-to-avoid-crash—DRAC). These outputs support detailed analysis of shuttle interactions, including near misses. To reveal patterns, clustering identified three interpretable safety-relevant regimes: (i) a low-demand background regime (n = 96) with low speeds and near-zero deceleration demand, (ii) a fast-and-tight regime (n = 33) with reduced TTC, elevated critical-event speeds, and high DRAC/Modified (M)DRAC demand, and (iii) an AV-regulated regime (n = 10) dominated by the shuttle as adversary, showing short TTC but stable moderate speeds (~4 m/s) and conservative headway policies. Ensemble-tree supervised learning reproduced these regimes with high accuracy and revealed that critical-event speeds and counterpart headway are the strongest discriminators, while AV role metadata contributes marginally. This integrated approach—linking field data, behavior modeling, simulation, and machine learning—provides a robust framework for assessing AV safety in urban contexts.
Losada Arias, ÁngelRosenkranz, PaulHula, AndreasAleksa, MichaelSaleh, PeterErdelean, Isabela
This research provides a unique contribution to the field of in-wheel motor drive (IWMD) electric vehicles (EVs) by addressing the challenges associated with the use of permanent magnet synchronous motors (PMSMs) for traction. These motors, integrated into the unsprung masses, increase the wheels’ rotational inertia, reducing ride smoothness on uneven roads. To mitigate this issue, we present an optimal Kalman filter for a magnetorheological (MR) control suspension system that correlates road inputs between the front and rear wheels. This filter significantly improves the estimation accuracy of state variables by incorporating the motor’s vertical motion, along with potential enhancements from wheelbase preview. To determine the most suitable coil spring types for use with MR dampers, we used the WDW-600 computer-controlled electronic universal testing machine to evaluate three coil spring types: constant-pitch (model A), variable-pitch (model B), and conical (model C). To assess the impact of controlled vibration on dynamic performance, we compared the dynamic characteristics of IWMD EVs equipped with passive, uncorrelated, and correlated suspension systems, all of which have controlled inverters integrated into their design. The results indicate that motor vertical acceleration and dynamic tire load are the primary factors influencing the dynamic behavior of EVs. Additionally, the vehicle’s vibration performance metrics are negatively impacted by the in-wheel motor driving system in both passive and uncorrelated suspension systems. However, the MR-controlled suspension system with a conical spring significantly enhances ride comfort and dynamic stability by addressing complex stiffness and evaluating the effects of different coil spring types on the structural response of EVs. This analysis is based on a correlated-suspension-system scenario.
Gad, Ahmed ShehataJabeen, Syeda DarakhshanEl-Zomor, Haytham M.Tolba, MohamedElamy, Mamdouh I.
In order to improve the comfort performance in commercial vehicles, this study proposes a hierarchical control strategy that integrates the evaluation and migration of control algorithms. First, a quarter-vehicle model with four-degree-of-freedom (4-DOF) is constructed, incorporating the dynamics of the wheel, frame, driver’s cab, and seat. The key modal characteristics of the model are then verified through amplitude–frequency analysis, confirming their consistency with the typical vibration patterns observed in actual commercial vehicles, which provides the foundation for subsequent control strategy evaluation and migration. Then, based on a standard two-degree-of-freedom (2-DOF) suspension model, a weighted comprehensive evaluation function is developed to account for comfort, structural safety, handling stability, and both time- and frequency-domain performance indicators. Using this evaluation function, various control algorithms—including Skyhook control (SH), acceleration-based damping control (ADD), and proportional–integral–derivative control (PID)—are systematically assessed. The control algorithm is migrated to the 4-DOF model to carry out the hierarchical collaborative control. The results show that this method can effectively inhibit vibration transmission to enhance ride comfort and improve structural safety at the same time, while maintaining an acceptable level of handling performance. The transferability and applicability of the hierarchical control method are validated for the considered vertical dynamics scenarios. This article provides a new theoretical method and technical pathway for the comfort-oriented performance optimization of commercial vehicles.
Pan, TingPang, JianzhongWu, JinglaiZhang, JiuxiangKang, GongZhang, Yunqing
To effectively improve the performance of chassis control of distributed drive intelligent electric vehicles (EVs) under difference road conditions, especially in combing road information and chassis control for improving road handling and ride comfort, is a challenging task for the distributed drive intelligent EVs. Simultaneously, inaccurate chassis control and uncertainty with system input, are always existing, e.g., varying road input or control parameters. Due to the higher fatality rate caused by variable factors, how to precisely chose and enforce the reasonable chassis control strategy of distributed drive intelligent EVs become a hot topic in both academia and industry. To issue the above mentioned, an adaptive torque vector hierarchical controller based on road level and adhesion is proposed, which optimizes the comprehensive. First, combined with the characteristic of the unbalance dynamic force caused by the air gap between the stator and the rotor of the in-wheel motor, a nonlinear vehicle model based on motor unbalanced electromagnetic force is developed. Then, using the deep neural network, an algorithm for road level and adhesion recognition based on system response data is designed. Meanwhile, an adaptive torque vector controller based on road information is designed to improve the driving safety and handling stability of chassis. Finally, the proposed algorithm is validated on the full-car test rig platform, results show that the proposed algorithm can improve chassis performance under double lane-change test. The research achievements develop a reasonable algorithm to apply to the improving road handling and ride comfort performance for distributed drive intelligent EVs.
Wang, ZhenfengZhao, GaomingZhang, ZhijieZhou, ZitaoHuang, TaishuoMa, Changye
Resilient mounts are critical in controlling vibration transfer from sources such as engines, motors, and suspension to the vehicle structure. Conventional optimization methods rely on finite element analysis (FEA), which, while accurate, is computationally intensive and limits iterative NVH development. This paper introduces a Frequency Response Function Substructuring (FBS)-based approach that decomposes the system into substructures characterized by FRFs, significantly reducing computational cost without compromising accuracy. Key contributions include: (1) recovering subsystem FRFs from coupled system data in-situ for mount optimization, (2) extending FBS to handle enforced motion, and (3) proposing an alternative strategy for cases with unknown or unmeasurable loads. The methodology is demonstrated on a mid-size pickup truck model to optimize seat track response under a Four post shake load by refining body mounts. These advances broaden the applicability of FBS for efficient NVH optimization in complex systems.
Haider, SyedAbbas, AhmadJahangir, YawarMaddali, Ramakanth
Software-defined vehicles offer customers a greater degree of customization of vehicle controls and driving experience. One such feature is user-adjustable tuning of vehicle ride and handling, where customers can vary ride height, damper stiffness, front-rear torque balance, and other aspects of vehicle dynamics. While promising a great customer experience, such a feature can expose the vehicle to a wider range of structural loads than those in the nominal design condition, particularly when such tuning is extended to cover spirited “sport” mode driving, off-road driving, etc. In this paper we present a novel methodology combining Road Load Data Acquisition (RLDA) data and real-world telemetry data to estimate the impact of user-adjustable vehicle-dynamics tuning on structural durability. In doing so, the method combines the physics of damage accumulation (from RLDA data) with user behavior (from telemetry data) to present an accurate assessment of the impact on durability, moving beyond traditional durability methods that do not model a range of real-world usage behavior. The study has been conducted using one instrumented vehicle (RLDA) and de-identified telemetry data from over 20,000 Rivian customer vehicles. The study analyzes the impact of variations in ride height, damper stiffness of active dampers, and roll stiffness of the suspension on vehicle structural durability. By combining usage frequency of the different settings with the damage accrued in these settings, the methodology estimates the high-cycle fatigue pseudo-damage variation for a wide range of customers and compares real world damage risk with the damage accounted for in the baseline durability testing. Through the analysis, we recommend a way to optimize the Accelerated Duty Cycle (ADC) for Over the Road (OTR) testing to minimize real-world risk, while keeping the duty cycle simple and practical for testing, i.e., test for an optimized combination of a few dominant settings and not a wide range of settings. The approach also suggests a path to a real-time fleet monitoring system to identify high-durability-risk customers and develop mitigation strategies.
Demiri, AlbionRamakrishnan, SankaranWhite, DylanKhapane, PrashantBorton, Zackery
Active suspension systems play a crucial role in improving vehicle ride comfort and handling stability. However, most existing studies focus on the low-frequency range below 20 Hz, leaving the suppression of high-frequency vibrations within 50–500 Hz largely unexplored, even though these vibrations strongly affect in-cabin noise and ride quality. To address this gap, this study introduces a quarter-car suspension model incorporating both bushing dynamics and a rigid-ring tire within a reinforcement learning (RL) framework. A major challenge for RL-based suspension control is its degradation in high-frequency performance. To overcome this issue, we design an innovative training framework that integrates multiple synergistic strategies. First, frequency-domain rewards are incorporated as auxiliary signals to explicitly guide policy optimization in the high-frequency band. Second, long short-term memory (LSTM) networks are embedded in both the Actor and Critic to capture the sequential dependencies of time-domain suspension signals, thereby enhancing temporal feature extraction. Finally, model predictive control (MPC) expert knowledge is injected through reward shaping, which accelerates convergence and stabilizes the learned policy. This combination allows the proposed controller to effectively exploit both data-driven learning and model-based insights for full-band suspension optimization. Simulation results show that the method achieves a 29.67% reduction in body acceleration RMS in the 0–20 Hz range compared with a passive suspension, and further achieves a 62.65% reduction in the 50–500 Hz range relative to a baseline RL controller. By explicitly targeting vibration responses in the in-cabin acoustic control band (20–500 Hz), this study establishes a foundation for integrated suspension-acoustic optimization, offering new insights into ride comfort and NVH enhancement in intelligent vehicles.
zhu, ZhehuiZhang, LijunMeng, DejianHu, Xingyu
In recent years, premium vehicles have increasingly incorporated suspension systems capable of adjusting ride height. The primary function of these systems is to enable the vehicle to traverse uneven terrain by elevating the chassis, thereby preventing contact between the underbody and the road surface. Notably, air spring-based mechanisms enhance ride comfort by modulating the wheel rate. The system proposed in this study achieves ride height adjustment through vertical displacement of the spring’s lower seat. By constructing a detailed mechanical topology model using a dynamic simulation tool, this research aims to evaluate the feasibility of improving driving performance not only through height regulation but also by actively controlling the vehicle’s posture during motion.
Park, JaeyongSang Hoon, LeeJong Min, KimChoi, Jang Han
The performance of chassis suspension mechanisms critically affects vehicle handling, ride comfort, and safety. Implementing real-time health monitoring for chassis systems contributes to preventing severe consequences such as increased body roll or loss of handling stability caused by shock absorber softening or spring stiffness degradation under deteriorating operating conditions, while circumventing the substantial costs associated with professional facility-based chassis inspections. With the rapid development of sensing and data analytics technologies, data-driven approaches are increasingly used in health monitoring. This study aims to achieve online monitoring of chassis suspension performance degradation using a deep neural network (DNN). First, a half-car model incorporating both vertical and pitch motions was established to simulate bumpy road conditions, with the aim of constructing a dataset that includes key vehicle suspension parameters and vehicle states related to their degradation characteristics. Subsequently, a DNN model comprising three hidden layers is developed to assess suspension performance degradation. To optimize model performance, the effects of different numbers of neurons and hidden layers on model accuracy are explored. Experimental results show that the maximum absolute percentage errors of the DNN model in predicting suspension stiffness and damping coefficients are less than 0.13% and 0.17%, respectively, with average absolute percentage errors below 0.046% and 0.06%. The coefficients of determination (R2) exceed 0.999. The proposed method accurately predicts the trend of key suspension parameters, providing robust data support for health management and maintenance decision-making. This is expected to reduce safety risks and maintenance costs while enhancing overall vehicle performance and reliability.
Liao, YinshengLei, YisongSu, AilinWang, ZhenfengShi, ShuaiZhang, LeiZhang, JunzhiMa, Changye
This paper presents an initial handling qualities analysis of an Electric Vertical Take-Off and Landing (eVTOL) hexacopter. The analysis uses the Distributed Electric Propulsion Simulation (DEPSim), developed by Penn State University (PSU) and the Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM), developed by Continuum Dynamics, Inc. (CDI). The study focuses on evaluating a generic AAM hexacopter performing Handling Qualities Task Elements (HQTE) as defined by the DOT / FAA. A trajectory controller was developed to enable simulation of prescribed flight paths, allowing automated simulation of four HQTEs: Heliport Approach, Hovering Turn and Hold, Pirouette, Lateral Reposition and Hold. Design modifications incorporating lateral mast tilt and Direct Side Force Control (DSFC) were implemented to enhance yaw control and ride qualities. Piloted simulations were conducted at the PSU rotorcraft flight simulation facility using DEPSim, employing an Attitude Command Attitude Hold (ACAH) architecture with mode switching to Translational Rate Command / Position Hold (TRC / PH) and TRC plus DSFC modes. Two of the four HQTEs were tested in piloted simulations. Though formal ratings were not collected at this time, pilot commands and performance indicated that TRC / PH and TRC plus DSFC modes enhance handling qualities over ACAH mode. The DSFC control law was found to have substantially reduced roll attitude, which could potentially enhance visual cueing, pilot comfort, and pilot-perceived handling qualities.
Lee, SoohyeonHorn, JosephQuackenbush, ToddKeller, Jeffrey
Nowadays, customers expect excellent cabin insulation and superior ride comfort in electric vehicles. OEMs focus on fine tuning the suspension system in electric vehicle to isolate the road induced shocks which finally offers superior ride quality. This paper focuses on enhancing the ride comfort by reducing the road excitation which originates mainly due to road inputs. Higher steering wheel vibration is perceived on the test vehicle on rough road surfaces. To determine the predominant force transfer path, Multi reference Transfer Path Analysis (MTPA) is performed on the front and rear suspension. Based on the finding from MTPA, various recommendations are explored and the effect of each modification is discussed. Apart from this, Operational Deflection Shape (ODS) analysis is used to determine the deflection shape on the entire steering system . Based on ODS findings, recommendations like dynamic stiffness improvements on the steering column and steering wheel are explored and the impact on the steering wheel vibration is discussed. With all the counter measures proposed, steering wheel vibration levels are reduced by ~ 7 dB . Component level modal targets are proposed to avoid the vibration concern due to road excitation.
S, Nataraja MoorthyRao, ManchiSelvam, EbinezerRaghavendran, Prasath
The customer perception of ride comfort with vehicle performance is the most important aspect in a vehicle design. The ride comfort and vehicle performance are influenced by driveline components i.e. propeller shaft phase angle, inclination angle and critical frequency of the driveline system. The optimization of the driveline system is essential to ensure the efficient and smooth power transfer. Propeller shaft is one of the critical components in the driveline to influence the vehicle performance. Propeller shaft characteristics influenced by several factors like vehicle max torque, propeller shaft joint type, materials properties, UJ phase and inclination angle and shaft unbalance value. The optimization of the above parameter within the tolerance limit enables to meet the required performance standard. Various methodologies are available to optimize these parameters to enhance the vehicle performance and comfort leads to customer satisfactions. This study focuses on the analytical optimization of the propeller shaft’s universal joint (UJ) phase and inclination angle and validated at vehicle level. An analytical model was employed to evaluate the velocity fluctuations across the full rotation of the propeller shaft by considering the different UJ phase angles (0° − 360°) and inclination angles (1° − 5°). It was observed from the study that optimization of these parameter improves the vibration performance and decreases the velocity fluctuations. The results shows that the well optimized propeller shaft will enhance smoothness in the driveline systems, reduction in NVH levels, vehicle performance and ride comfort. This study suggests the importance of the precise geometry alignment in driveline design and provide the further refinement methodology.
Kumar, SarveshSanjay, LS, ManickarajaKanagaraj, Pothiraj
In the evolving landscape of the automotive industry, enhancing passenger comfort and ride quality has become a key differentiator for manufacturers. While suspension systems have traditionally received significant attention, powertrain isolation through engine mounts plays an equally critical role in controlling noise, vibration, and harshness (NVH). Engine mounts are not only responsible for supporting the powertrain’s weight but also for mitigating the transmission of unbalanced engine forces to the vehicle body. Modern engine mount designs aim to eliminate any metal-to-metal contact between the powertrain and chassis, thereby achieving optimal vibration isolation. This study proposes a refined approach to completely decouple the powertrain from the vehicle structure, ensuring minimal vibration transfer and thereby extending the operational life and performance of the engine mount system.
Hazra, SandipNaik, Sarang PramodMore, Vishwas
The automotive market trend is shifting more and more to SUVs and crossovers. This, therefore, means increasing consumer demand for off-road abilities in passenger vehicles. While dedicated off-road platforms provide a path to performance robustness, getting the same level of functionality out of a passenger vehicle with minimal architectural changes proves to be a great feat for engineers. One highly critical performance determinant in the domain of off-road ability is wheel articulation, it requires independent movement capacity of the wheels to keep contact and stability over uneven terrain. Traditional articulations found in passenger car suspensions—created for comfort, packaging, and on-road dynamics—are limited by suspension geometry, damper alignment as well as compliance setup. Damper side loads- were not considered a significant factor in suspension systems that are operating within their original intended design envelope for on-road use. However, when the vehicle is taken off-road, extreme conditions lead to lateral forces during an unseated exaggerated wheel travel, these can result in seal degradation as well as rod bending increasing friction (stiction) leading ultimately to damper failure. Seal durability and general component integrity are not the only issues increased side loading will decrease articulation reduce traction and degrade ride quality during severe terrain inputs. Articulation- is essentially a measure of flexibility in the suspension which directly controls off-road performance characteristics. With limited articulation there is wheel lift traction loss and increased chassis contact. A major limitation to achieving full articulation is damper side load-the perpendicular force to the damper shaft created from angular misalignment in suspension travel. This also increases the compressive stress on the damper rod. Therefore, an optimization of the rod diameter, length, and material is required. The Ramp Travel Index (RTI) is a means of expressing articulation by using the measure of ramp height that can be attained by a vehicle climbing with one wheel while maintaining contact with others. A high RTI indicates good off-road capability. There exists an interrelationship between suspension geometry, damper side load characteristics, and axle alignment in determining off-road performance; this paper proposes an optimization guideline to overall improve wheel articulation specifically for passenger vehicles through these parameters: wheel travel, suspension hard points, and damper mounting orientations.
Siddiqui, ArshadIqbal, ShoaibDwivedi, Sushil
In automotive suspension systems, components like bump stoppers and jounce bumpers play critical roles in controlling suspension travel and enhancing ride comfort. Material selection for these components is driven by functional demands and performance criteria. Traditionally, Natural rubber (NR) has traditionally been favored for bump stopper applications due to its excellent vibration absorption, tear resistance, cost-effectiveness, and biodegradability. However, in more demanding environments, it has been largely replaced by microcellular polyurethane (PU) elastomers, which offer superior durability, environmental resistance, and enhanced noise, vibration, and harshness (NVH) performance. This study revisits NR with the goal of re-establishing its viability by enhancing its performance to match or surpass that of PU. Through compound optimization and advanced material processing techniques, significant improvements have been achieved in NR’s mechanical strength, compression set resistance, and environmental durability. Also a convolute bump stopper design was explored to enhance energy absorption and packaging efficiency. Compared to traditional solid profiles, the convoluted geometry provided progressive stiffness characteristics, improved deformation control, and optimized ride comfort under dynamic loading conditions. Traditional NR design and formulation were compared against PU and next-generation NR in terms of Aging Durability Factor, stiffness, fatigue durability, vehicle-level buzz, squeak, and rattle (BSR), as well as ride and handling performance. A comparative assessment of carbon emissions between PU and NR was also conducted to evaluate environmental impact. The result is a next-generation NR formulation that delivers performance comparable to PU while retaining the ecological and economic advantages of natural rubber. This research demonstrates a sustainable pathway toward high-performance elastomeric materials, bridging the gap between conventional and advanced solutions in modern engineering applications.
Murugesan, AnnarajanHingalaje, AbhijeetPerumal, MathavanPawar, Rohit
This study presents an integrated vehicle dynamics framework combining a 12-degree-of-freedom full vehicle model with advanced control strategies to enhance both ride comfort and handling stability. Unlike simplified models, it incorporates linear and nonlinear tire characteristics to simulate real-world dynamic behavior with higher accuracy. An active roll control system using rear suspension actuators is developed to mitigate excessive body roll and yaw instability during cornering and maneuvers. A co-simulation environment is established by coupling MATLAB/Simulink-based control algorithms with high-fidelity multibody dynamics modeled in ADAMS Car, enabling precise, real-time interaction between control logic and vehicle response. The model is calibrated and validated against data from an instrumented test vehicle, ensuring practical relevance. Simulation results show significant reductions in roll angle, yaw rate deviation, and lateral acceleration, highlighting the effectiveness of the proposed approach. Overall, the framework offers a scalable and robust foundation for developing adaptive stability control systems in modern four-wheeled vehicles
Duraikannu, DineshDumpala, Gangi Reddi
Diesel powertrains are inherently characterized by high vibration levels and low-frequency excitations, which are extremely demanding for passenger comfort and vehicle refinement. Conventional passive engine mounts often fall short in mitigating such vibrations effectively across a wide range of operating conditions. Passive mounts are inadequate for effectively isolating vibrations in powerful, lightweight vehicles or those without a balancer shaft 3-cylinder engine ordiesel engines. Consequently, this has prompted the consideration of active engine mounts as an alternative solution for solving NVH (Noise, Vibration, Harshness)-related issues. This paper explores the application of adaptive control algorithms in active engine mount systems for diesel powertrains in passenger vehicles. Through the integration of real-time feedback loops with smart control strategies the system adaptively controls mount stiffness and damping to minimize engine-induced vibrations. The study presents simulation and experimental results showing enhanced vibration isolation, better ride quality, and lower transmitted forces to the vehicle chassis. In addition, the adaptive control ensures high robustness under varying driving conditions, such as load variations and engine transients. This trend opens up the future for next-generation diesel vehicle NVH solutions with a comfort-performance-fuel efficiency balance.
Hazra, SandipKhan, Arkadip Amitavamore, Vishwas
Bogie suspension systems are becoming increasingly popular in tipper vehicles to enhance their performance and durability, especially in demanding environments like construction and mining areas [1]. Bolsters contribute significantly to the overall performance and durability of the bogie suspension systems of tipper vehicles by evenly distributing the loads across the whole suspension system. They act as shock absorbers and negate the impact caused by the rough terrains and heavy loads, thereby reducing stress on individual components and maintaining the structural integrity of the vehicle. Bolsters also help in improving the ride comfort and to maintain the position of the suspension system [2]. This study focuses on the comprehensive testing and evaluation of bolsters to understand their modes and displacement data derived from field data. The primary objective is to analyse the performance and behaviour of bolsters under various operational conditions. Critical manners of deformation and displacement patterns were identified by methodically examining the collected data from the field. The purpose of these acumens is to inform and guide the consequent design modifications, to which they will be of utmost importance. The result of these evolutions in the design of bolsters will eventually lead to more effectual and durable bolsters which in turn will improve their trustworthiness and efficiency in real-world applications. Due to a number of aspects measuring bolster displacement and modes data in the field is a challenging task. Because the bolster may move unpredictably in jagged and rough terrain, it is more difficult to measure displacement and modes precisely. Precise data collection depends on the sensor’s placement. It can be difficult to identify the best places for sensors in the field that prevent interference and produce accurate data. It is crucial to make sure that every measurement tool is accurately attuned both before and during data collection activity. Sensor drift due to field conditions may demand frequent recalibration due to the complex and multidirectional movement of bolsters in tipper vehicles. It takes sophisticated algorithms and analytical methods to accurately capture these movements and realize their modes. Due to its placement within the vehicle’s suspension system, the is challenging to reach for measurement. This may curb the kinds of sensors and techniques that are available for use. In general, an assortment of environmental, technical and practical obstacles must be overcome in order to measure bolster displacement and modes data in the field. Careful planning, sturdy tools and pioneering analytical techniques are needed to handle these complications and guarantee accurate and reliable data collection.
V Dhage, YogeshKolage, Vikas
The automotive industry constantly strives to enhance vehicle safety, comfort, and customer satisfaction. One of the critical aspects influencing these factors is the mitigation of Buzz, Squeak, and Rattle (BSR) issues, which can significantly impact perceived vehicle quality and user experience. This paper focuses on the BSR challenges specifically encountered in bench seat latch & striker mechanisms. Vibrations and movement, especially during vehicle operation, exacerbate Buzz, Squeak & Rattle (BSR) problems, leading to acoustic disturbances that detract from the overall ride quality. Latch and striker in seat system is prone to squeaks and rattles (S&R) due to improper fitment, environmental conditions, or mechanical stress. These issues not only compromise the auditory experience but may also raise concerns about component durability and functionality. This paper outlines the root causes of BSR phenomena in these components, emphasizing the role of design optimization, material selection, and assembly precision in addressing these challenges. By addressing these concerns, automotive manufacturers can ensure a higher standard of quality, reinforcing customer trust and satisfaction in their products.
Deole, Sameer ShrikantRahman, ShafeeqMohammed, RiyazuddinShah, Prashant
Engine mount brackets are a primary structural components of passenger vehicles that supports the powertrain to the chassis via engine mounts. These brackets are important to control vibrations and the transmission of noise into the cabin as well as vehicle stability. Since they support the engine mounts, these brackets play a role in determining ride comfort and load distribution on the mounts and the engine. While traditionally made from steel, cast iron and aluminum, we are trying to redesign engine mount brackets with recyclable engineering plastics to fit current demands of light-weighting, cost efficiency, and sustainability. The present work is concerned with the design of a plastic engine mount bracket, which aims to hit specified natural frequency targets in order to avoid resonance and fulfill strict NVH (Noise, Vibration, and Harshness) requirements. Because of the superior mechanical strength, thermal stability, and vibration-dampening properties, PPS, glass-fiber reinforced polyamide (PA66-GF50), PEEK (polyether ether ketone), and other high-performance reinforced plastics like polyphenylene sulfide were taken into consideration. These materials can be used in structural automotive applications in place of metals. Through the Finite Element Analysis, modal analysis, CAE based durability simulations and vehicle-level testing the optimized bracket proven to meet structural and dynamic performance specifications. The findings confirm that, in the form of plastic bracket, recyclable designs can be technically feasible and sustainable alternatives to metal designs, which help reduce vehicle weight, increase fuel efficiency and vehicle manufacturability without sacrificing durability and safety.
Hazra, SandipGupta, DeepakKhan, ArkadipGite, Yogesh
The vertical dynamic stiffness and damping of a tyre are critical to ride comfort and overall dynamics, particularly for low-frequency excitations in urban and highway driving. As the tyres are the primary interface between the vehicle and the road, absorbing surface irregularities before the suspension engagement, precise tyre parametrization is essential for accurate ride models. This study investigates an experimental methodology characterizing the vertical dynamic behavior of pneumatic tyres using a Flat Trac test machine. Contrary to the conventional approaches that depend on intricate shaker rigs or frequency dependence function models, the proposed technique uses a realistic force displacement loop-based methodology which is appropriate for ride models. Dynamic stiffness is computed from slope of a linear regression fitted to force and displacements during vertical sinusoidal excitation. Damping is derived from hysteresis energy loss per cycle. The tests were conducted under various conditions by varying vertical loads, inflation pressures (IP), excitation frequencies, and deflection amplitudes (4–8 mm). The generated stiffness and damping curves from the test results can be directly applied in quarter-car models and could potentially be extended to the full-vehicle ride simulations for ride characteristics assessment studies. Research indicates that the dynamic stiffness of a non-rolling tyre is consistently higher than that of a rolling tyre. Under rolling conditions, dynamic stiffness increases with test speed due to excitation frequency effects. Additionally, vertical dynamic stiffness correlates positively with inflation pressure (IP); increasing it from 216 to 264 kPa yields a 12–14% rise in stiffness for both rolling and non-rolling condition. The proposed framework facilitates the integration of realistic tyre vertical dynamics into vehicle ride models while maintaining minimal complexity, thereby improving simulation fidelity and supporting better design and evaluation of ride quality in early stage of vehicle development.
Duryodhana, DasariSethumadhavan, ArjunTomer, AvinashGhosh, PrasenjitMukhopadhyay, Rabindra
With increased deterioration of road conditions worldwide, automotive OEMs face significant challenges in ensuring the durability of structural components. The tyre being the primary point of contact with the road is expected to endure harshest of impacts while maintaining the other performance functions such as Ride & Handling, Rolling resistance, Braking. Thus, it is considered as the most challenging component in terms of design optimization for durability. The current development method relies on physical testing of initial samples, followed by iterative construction changes to meet durability requirements, often giving trade-off in Ride & Handling performance. To overcome these challenges, a frugal simulation-based methodology has been developed for predicting tyre curb impact durability before vehicle-level testing so that corrective action can be taken during the design stage.
Sundaramoorthy, RagasruobanLenka, Visweswara
Tire noise reduction is important for improving ride comfort, especially in electric vehicle due to lack of engine noise and majority of the noise generated in-cabin is from tire-road interaction. Therefore, the tire tread pattern contribution is one of the important criteria for NVH performance apart from other structurally generated noise and vibration. In this work a GUI-based pitch sequence optimization tool is developed to support tire design engineers in generating acoustically optimized tread sequences. The tool operates in two modes: without constraints, where the pitch sequence is optimized freely to reduce tonal noise levels; and with constraints, where specific design rules are applied to preserve pattern consistency and manufacturability. The key point to be considered in this pitch sequence is that it should be reducing the tonal sound and equally spread i.e., the same pitch cannot be concentrated on one side which may lead to non-uniformity. So, the restriction is that the highest and lowest pitch types cannot occur adjacent to one another. This design rule helps in reducing undesirable pattern non-uniformity and improves both acoustic and structural performance. This tool helps in faster design iteration and integration with downstream development processes. This tool is also validated in current OE projects showing promising improvements in tire noise behavior while maintaining realistic design feasibility.
Sampathraghavan, LakshmiRamarathnam, Krishna KumarMantripragada PhD, Krishna TejaRamachandran, Neeraj
Determination of part tolerances for reduced variation in suspension level performance by using Multi-objective Robust Design Optimization (MORDO) The car industry is very competitive, and companies need to satisfy their customers to keep or grow their market share. It’s important for car makers to build affordable cars that provide a good driving experience, comfort for passengers, and safety for everyone. Suspension systems are very important for how a vehicle rides, handles, and stays stable, and they directly affect how driving feels. If parts are not positioned correctly, it can really impact how well a vehicle works. As a result, suggested limits for where suspension parts are placed are given to prevent issues with Kinematics and Compliance (K&C) properties. So, designing parts with the right tolerances is very important in making vehicles. It helps lower production costs and keeps the vehicle's performance consistent. This paper shows a step-by-step method to find the strongest solution that meets all the requirements for suspension performance. Multi-objective Robust Design Optimization (MORDO) and Reverse Multi-objective Robust Design Optimization (R-MORDO) have been used to find strong solutions while keeping K&C parameters intact. K&C analysis is done with ADAMS/CAR software, and Multi-Objective Robust Design optimization is done using Mode Frontier.
Pathak, JugalGanesh, Lingadalu
Vehicle dynamics is a vital area of automotive engineering that focuses on analyzing how a vehicle responds to driver inputs and external factors like road conditions and environmental influences. Achieving optimal performance, safety, and ride comfort requires a detailed understanding of longitudinal, lateral, and vertical dynamic behavior. The objective of this paper is to develop and validate the model of a concept Race car and evaluate its vehicle dynamics behavior using IPG CarMaker, a high-fidelity virtual testing environment widely used in industry. The model incorporates a range of vehicle parameters, including suspension parameters like spring and damper characteristics, mass distribution, tire properties and powertrain parameters. The performance evaluation is done as per standard guidelines, including Constant Radius turn test, Sine Steer test and other standard tests like Acceleration, Braking along with Ride and Comfort classification. The key parameters that are calculated and validated are vehicle accelerations in the principal axes, stopping distance, yaw velocity and yaw velocity gain, vehicle roll characteristics, steering parameters, ride and driver comfort metrics. Validation of simulation outputs is achieved through comparison with empirical data obtained from literature and mathematical calculations based on vehicle dynamics principles. The test results show a close correlation between mathematical and simulated values, therefore accurately predicting vehicle behavior.
Agrewale, Mohammad Rafiq B.Vaish, Ujjwal
Aluminum alloy wheels have become the preferred choice over steel wheels due to their lightweight nature, enhanced aesthetics, and contribution to improved fuel efficiency. Traditionally, these wheels are manufactured using methods such as Gravity Die Casting (GDC) [1] or Low Pressure Die Casting (LPDC) [2]. As vehicle dynamics engineers continue to increase tire sizes to optimize handling performance, the corresponding increase in wheel rim size and weight poses a challenge for maintaining low unsprung mass, which is critical for ride quality. To address this, weight reduction has become a priority. Flow forming [3,4], an advanced wheel rim production technique, which offers a solution for reducing rim weight. This process employs high-pressure rollers to shape a metal disc into a wheel, specifically deforming the rim section while leaving the spoke and hub regions unaffected. By decreasing rim thickness, flow forming not only enhances strength and durability but also reduces overall wheel weight. This study investigates and compares the mechanical properties of conventional GDC and LPDC cast alloy wheels with flow-formed counterparts, focusing on the rim region. Results reveal that the flow-forming process facilitates a 30% thickness reduction in the rim section. Furthermore, it leads to a slight increase in yield and tensile strength while significantly improving elongation in parallel to the flow-forming direction. The study also examines microstructural changes, including the deformation behavior of silicon dendrites [5].
Singh, Ram KrishnanMedaboyina, HarshaVardhanG K, BalajiGopalan, VijaysankarSundaram, RaghupathiPaua, Ketan
Engineers have developed a next-generation wearable system that enables people to control machines using everyday gestures — even while running, riding in a car, or floating on turbulent ocean waves.
This paper presents StaRide, a novel coordinated control framework for wheel-legged vehicles that simultaneously addresses handling stability and ride comfort challenges. The proposed approach integrates three key components: (1) a nonlinear model predictive control (NMPC) scheme enhanced with roll-steering dynamics for trajectory optimization, (2) an linear quadratic regulator (LQR)-based active suspension system utilizing leg mechanisms as virtual dampers, and (3) an adaptive impedance controller with behavior-dependent stiffness adjustment. The framework demonstrates significant improvements over conventional methods through extensive experimental validation, achieving 42% higher stable steering speeds (4.8 m/s vs 3.38 m/s), 46% pitch angle reduction on obstacles, and 39% lower vibration RMS on rough terrain. Real-time performance is maintained with 100Hz NMPC and 500Hz LQR execution rates. Results show particular effectiveness in preventing rollover during aggressive maneuvers while ensuring comfort during normal operation, establishing a new paradigm for wheel-legged vehicle control that successfully bridges the stability-comfort trade-off. The system's generalizability suggests potential applications in other hybrid locomotion platforms.
Xu, MingfanXu, ChuyanYang, ZiyiYuan, HaoyangZhu, ZheweiQin, Yechen
Distributed-drive electric vehicles (DDEVs) significantly enhance off-road maneuverability but suffer from compromised high-speed stability and robustness. This research introduces a front-centralized and rear-distributed (FCRD) architecture that synergistically leverages the advantages of each configuration. The electric-drive-wheel (EDW) on the rear suspension can provide three working modes: (a) Drive-connected mode, (b) Drive-disconnected mode, (c) Brake mode. It is the key actuator for vehicle mode-switching, which supports the vehicle with three driving modes: (a) DDEV, (b) front-wheel drive (FWD), (c) all-wheel drive (AWD). A hierarchical control architecture employs the upper-layer controller with Back Propagation Neural Network (BPNN) for mode identification and decision-making. The lower-layer controller enables the intelligent torque distribution and collaborative control of the motors. The control strategy is pre-trained in the VCU (vehicle control unit) with off-line data annotations to achieve the maximal instantaneous system efficiency. At the same time, a cost function is designed to suppress unreasonable frequent mode switching that may deteriorate handling characteristics and ride comfort. The off-line data training results indicate that the overall accuracy of mode identification reaches 91.7%, of which the DDEV mode accuracy 98% and AWD mode accuracy 85%. Finally, the test vehicle with the calibrated EDW prototype is fully constructed and drives in Shanghai suburbs for a road test with parameters recorded throughout the whole cycle. The test vehicle has a balanced performance in power output, driving efficiency, and control robustness. The high-way cruising conditions activate the efficiency-oriented AWD mode of 82% overall propulsion system efficiency, which overcomes the problem of high-speed attenuation in electric vehicles and effectively improves the range at premise of safety and stability.
Ding, XiaoyuChen, XinboWang, WeiZhang, JiantaoKong, Aijing
The suspension system, as a critical component of vehicle chassis, connects body frame and wheels, therefore affecting the ride comfort and handing stability of vehicles. To prevent high-frequency oscillations from large control increments of traditional algorithms, an ideal reference model is introduced to ensure a more smooth and efficient suspension responses that align with actual physical characteristics. The ideal skyhook, ideal groundhook, and ideal skyhook-groundhook models are evaluated with respect to their frequency response. As a result, the optimal configuration-ideal skyhook-groundhook model, exhibits the best overall performance and is incorporated with wheelbase preview mechanism as reference model (WP-SHGH). Further, a wheelbase-preview controller based on MPC framework (WPMPC-SHGH) is developed to regulate the responses of semi-active suspension. The Adams/Car-Simulink co-simulation platform is built for validation and comparison on the impact and ISO-B random roads. Compared to the passive suspension and the similar controller without reference model, the proposed WPMPC-SHGH significantly reduces vertical acceleration and pitch acceleration of vehicle body, which thereby enhances vehicle ride comfort. In addition, while maintaining suspension performances, the WPMPC-SHGH anticipates less control forces and leads to a reduction in energy consumption of semi-active suspension.
Yang, LiWang, QingyunTan, KanlunChen, HaoZhang, Zhifei
Vehicle electrification has introduced new powertrain possibilities, such as the use of four independent in-wheel motors, enabling the development of control strategies that enhance vehicle safety and drivability. The development of a model capable of simulating vehicle behavior is fundamental for control system design. A high-fidelity model takes into account several parameters, such as vehicle ride height, track width, wheelbase, and others, making it possible to evaluate the vehicle’s behavior and allowing for prior validation of the design, thus contributing to improved vehicle safety and performance. In this context, this study presents a lateral dynamic model of a Formula 4WD vehicle with in-wheel motors, enabling the simulation and analysis of the vehicle’s behavior in cornering maneuvers. To achieve this, the complete lateral model is developed using MATLAB Simulink as the platform, incorporating the semi-empirical Hans Pacejka tire model, calculating yaw moment, and analyzing forces to accurately describe the vehicle’s dynamics.
Dias, Gabriel Henrique RodriguesAraujo, Lucas MontenegroVitalli, RogérioGuerreiro, Joel FilipeSantos Neto, Pedro José dosDaniel, Gregory BregionEckert, Jony Javorski
This paper explores riding characteristics of Shared Two-Wheeled Vehicles (STWV, including Shared Bicycles (SB) and Shared Electric Bicycles (SEB)) by using order data of nine cities. We first compute the mean values of three key elements of riding characteristics and make a comparison between different cities. It shows that STWV primarily serve short trips. Then, we use Python to fit the distribution of STWV riding distance and the distribution of SEB riding speed. We find that (1) Exponential distribution fits SB riding distance and Rayleigh distribution fits SEB riding distance. The regularity of the distribution for SB is more universal than that of SEB. (2) Modified standard logistic distribution in this paper fits SEB riding speed. The findings above indicate that SEB is not governed by the rules that govern human dynamics, thus expanding the scope of two-wheeled transportation service and introducing greater uncertainty.
Liu, LuWei, LiyingLuo, Sida
In the future battlefield, logistics UAVs will play an increasingly important role. The development of logistics UAVs abroad is rapid. Sort out the current development status of logistics UAVs in countries such as the United States, Russia, Israel, and Ukraine, including mission tasks, functional characteristics, and main performance indicators. In addition, the future technological trends of logistics UAVs are studied and predicted. Firstly, diversification of functions, which logistics UAVs will achieve diversified functions in the future, such as material transportation, aerial refueling, unmanned mother aircraft, and transfer of wounded personnel; Secondly, intelligent commendation and control, which logistics UAVs pursue the optimal efficiency in the four steps of ordering, dispatching, delivering, and evaluating in the “food delivery” mode; Finally, resource collaboration. In the collaborative logistics mode of “free riding”, logistics UAVs over a wide area are interconnected, achieving the free flow of our resources on the battlefield.
Zhai, JundaLiu, DaweiBai, QiangqiangHua, JinxingWang, XiaoyueYang, JianZou, XiaoyingGao, Yuxuan
This study investigates the critical factors influencing the performance of hydro-pneumatic suspension systems (HPSS) in mining explosion-proof engineering vehicles operating in complex underground coal mine environments. To address challenges such as poor ride comfort and insufficient load-bearing capacity under harsh mining conditions, a two-stage pressure HPSS was analyzed through integrated numerical modeling and field validation. A mathematical model was established based on the structural principles of the suspension system, focusing on key parameters including cylinder bore (195–255 mm), piston area (170–210 mm), damping orifice diameter (7–8 mm), check valve flow area, and accumulator configurations (low-pressure: 1.2 MPa, high-pressure: 6 MPa). Experimental trials were conducted in active coal mines, simulating typical mining scenarios such as uneven road surfaces (120 mm obstacles), heavy-load gangue transportation, and confined-space operations in thin coal seams (<1.5 m). This study conducted experimental validation of a hydro-pneumatic suspension system (HPSS) for mining explosion-proof engineering vehicles under multi-condition operational scenarios in active coal mines. Field tests were performed to simulate typical mining environments, including uneven road surfaces (120 mm obstacles), variable-speed driving (constant speed, acceleration, deceleration), and inclined terrains (uphill, downhill, and near-horizontal road surfaces). Comprehensive performance evaluations focused on dynamic stroke stability, vibration attenuation, and safety metrics were carried out by replicating real-world mining conditions. Results demonstrated that optimizing the cylinder bore diameter and adjusting the piston area significantly enhanced dynamic stroke stability, ensuring consistent load-bearing capacity across diverse mining terrains. Furthermore, tuning the damping orifice diameter effectively improved anti-rollover capability while maintaining ride comfort, achieving a balanced trade-off between vibration suppression and operational safety. Parameter adjustments to the HPSS, validated through rigorous field trials, proved critical for enhancing driving stability and safety in complex underground mining environments. These findings provide actionable insights for designing robust suspension systems tailored to the extreme demands of mineral extraction operations.
Song, YanLiang, Yufang
The stabilizer link, also commonly referred to as the sway bar link or anti-roll bar link, plays a crucial role in the suspension system. It connects the sway bar to suspension components such as the knuckle, control arm, or strut. The primary function of the stabilizer link is to reduce body roll during cornering or when driving over uneven terrain. It helps stabilize the wheels during extreme articulation events and ensures smoother operation in terms of ride comfort and handling. Additionally, it is designed to assist in distributing forces across the suspension system, particularly in off-road or rugged terrain applications. This case study presents the failure of a stabilizer link assembly during extreme articulation events. The front stabilizer link failed during vehicle-level durability and functional testing across multiple terrains. Based on the root cause analysis, design strategies were developed to prevent such failures and to ensure reliable operation during demanding off-road and extreme articulation conditions. These strategies aim to develop a robust stabilizer link assembly that maintains the kinematic performance of passenger vehicles during extreme articulation events.
S, Praveen KumarChilakala, RaghavendraSenthil Raja, TJadhav, PrashantKundan, LalJ, AkhilPawar, Sandip
In motorcycle racing and other competitions, there is a technique to intentionally slide the rear wheel to make turns more quickly. While this technique is effective for high-speed riding, it is difficult to execute and carries risks such as falling. Therefore, an anti-sideslip control system that suppresses unintended or excessive sideslip is needed to ensure safe, natural, and smooth turning. In anti-sideslip control, the slip angle is usually used as a control parameter. However, for motorcycles, it is necessary to know the absolute direction of the vehicle's movement. To determine this, GPS or optical sensors are required, but using such sensors for driving is costly and may not provide accurate measurements due to contamination or other environmental factors, making it impractical. Therefore, an anti-sideslip control system was developed by calculating another parameter that indicates the characteristics of the slip angle, without measuring the slip angle itself, thus eliminating the need for impractical sensors. To detect sideslip, lean angles calculated using two different methods are used. The first lean angle calculates the true value even when side slip occurs, while the second lean angle shows a higher value than the true value when side slip occurs. The difference between these is defined as the slide amount, which can be detected as a parameter representing side slip. When a sideslip is detected, the drive force reduction control suppresses the sideslip to bring the slide amount closer to the target slide amount. To suppress sideslip, drive force reduction through ignition retardation is used. As an experiment, the slide amount obtained by the current method was compared with the values from a GPS device capable of calculating the slip angle. It was confirmed that the differential value of the slip angle obtained from the GPS and the slide amount had a very similar waveform. Furthermore, a test was conducted to verify whether the anti-sideslip control effectively suppressed sideslip during actual driving, and it was confirmed that applying this control allowed for more stable cornering. The effectiveness and validity of the anti-sideslip control were confirmed through the above experiment.
Nakano, KyosukeKawai, KazunoriTakeuchi, Michinori
Single motorcycle accidents are common in Nagano Prefecture where is mountainous areas in Japan. In a previous study, analysis of traffic accident statistics data suggested that the fatality and serious injury rates for uphill right curves and downhill left curves are high, however the true causes of these accidents remain unclear. In this study, a motorcycle simulator was used to evaluate the driving characteristics due to these road alignments. Evaluation courses based on combinations of uphill/downhill slopes and left/right curves were created, and experiments were conducted. The subjects of the study were expert riders and novice riders. The results showed that right curves are even more difficult to see near the entrance of the curve when accompanied by an uphill slope, making it easier to delay recognition and judgment of the curve. Expert riders recognized curves faster than novice riders. Additionally, expert riders take a large lean of the vehicle body, actively attempted to ride on the inside corner, while that of novice riders was less. On the other hand, for downhill left curves, there was a tendency for delayed judgment of sharp curves, and riders were more likely to increase their speed. Also, the expert riders recognized curve curvature earlier and had a greater lean angle of the vehicle body than the novice riders, but there was no significant difference. From these results, the road alignment combination of uphill/downhill slopes and left/right curve has a significant impact on the risk of motorcycle accidents.
Kuniyuki, HiroshiKatayama, YutaKitagawa, TaiseiNumao, Yusuke
In response to the growing demand for environmental performance, the mobility industry is actively developing electrification, and in particular, the use of Battery Electric Vehicles (BEV) in commuting motorcycles is advancing. However, in the case of vehicles for leisure, which require high riding performance, there are problems such as cruising range and charging time, and there are currently few mass-produced models. Therefore, we proposed a Hybrid Electric Vehicle (HEV) type Motorcycle (MC) to achieve both environmental performance and high riding performance by means other than BEV. The proposed vehicle is equipped with a strong type hybrid system in which an engine and a drive motor are connected in parallel via a hydraulic electronically controlled clutch. It is possible to drive only by motor (EV driving) or by hybrid driving powered by both the engine and the motor (HEV driving). In order to improve environmental performance, it is necessary to develop a function for switching between EV and HEV driving and an automatic transmission function. In motorcycles, which are lighter than passenger cars, it has been an important issue to achieve the required functions without causing discomfort to the rider. In order to solve this problem, we worked on torque distribution control between the engine and motor according to the rider operation and the remaining battery capacity and developed coordinated control of the electronically controlled hydraulic clutch and electronically controlled transmission unit. We achieved low fuel consumption comparable to that of the 250cc class while maintaining the riding feeling. This paper describes the configuration of the strong hybrid system to achieve both environmental performance and high riding performance, and then discusses the electronic control technology, the technical issues, and the solutions.
Obayashi, KosukeTerai, ShoheiJino, KenichiKawai, Daisuke
To say 2025 has been a bumpy ride for North American electric vehicle OEMs would be an understatement not heard since Jack Swigert informed Houston that Apollo 13 was experiencing a problem. However, despite a tariff tug of war, EPA upheaval and continually changing tax incentives, OEMs are pushing ahead with plans to electrify the commercial truck segment. In late August, ZM Trucks celebrated the grand opening of its U.S. headquarters and assembly facility in Fontana, California. Truck & Off-Highway Engineering was in attendance for the opening ceremony, which included the U.S. debut of the ZM8 Class 4/5 truck.
Wolfe, Matt
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