Browse Topic: Vehicle handling

Items (498)

On Disturbance-Aware Minimum-Time Trajectory Planning: Evidence from Tests on a Dynamic Driving Simulator

7/13/2026

This work aims to investigate how disturbance-aware, robustness-embedding reference trajectories translate into actual driving performance when executed by professional drivers in a dynamic driving simulator. The study compares three planned reference trajectories against a free-driving baseline (NO-REF) to assess the trade-offs between lap time (LT) performance and steering effort: NOM, the nominal time-optimal trajectory; TLC, a track-limit-robust, time-optimal trajectory obtained by tightening margins to the track edges; and FLC, a friction-limit-robust, time-optimal trajectory obtained by tightening against axle/tire saturation. All reference trajectories share the same minimum LT objective with a small steering-smoothness regularizer, and are evaluated with two professional drivers driving a high-performance car on a virtual track. The reference trajectories stem from a disturbance-aware minimum-LT framework recently proposed by some of the authors, where worst-case disturbance growth is propagated over a finite horizon and used to tighten tire-friction and track-limit constraints, preserving performance while delivering probabilistic safety margins. LT and steering energy (SE) are evaluated as indicators of driving performance and steering effort, respectively, while RMS values of lateral deviation, speed error, and drift angle are used to characterize driving style. The results reveal a Pareto-like trade-off between LT and SE: NOM achieves the shortest LT, but with the highest SE, TLC minimizes SE at the expense of longer LT, while FLC lies near the efficient frontier, markedly reducing SE relative to NOM with only a minor LT increase. Removing reference trajectories (NO-REF) leads to both higher SE and longer LT, confirming that trajectory guidance improves pace and control efficiency. Overall, the findings highlight reference-based and disturbance-aware planning, particularly the FLC variant, as effective tools for training and for achieving fast yet stable trajectories.

Masoni, Matteo, Palermo, Vincenzo, Gabiccini, Marco, Gulisano, Martino, Previati, Giorgio, Gobbi, Massimiliano, Comolli, Francesco, Mastinu, Gianpiero, Guiggiani, Massimo

BO-NRPPO: A Bayesian Optimization–Tuned Proximal Policy Optimization Framework for Semi-Active Suspension Control

10-10-03-0025

6/25/2026

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, Guoying, Wang, Xinyu, Wang, Jiaqi, Zhan, Xinwang, Bi, Chenxiao, Cong, Shiqi, Hua, Min, Sun, Tianjun, Gao, Zhenhai

Limit Stability Control for Corner Module Vehicles Based on Hierarchical Hybrid Game

10-10-04-0032

5/18/2026

Corner module vehicles (CMVs) achieve the decoupling of driving, braking, steering, and suspension, significantly enhancing vehicle handling potential, but under extreme operating conditions, the interactions between actuators severely constrain the improvement of vehicle handling performance. In order to mitigate conflicts between subsystems and enhance vehicle handling stability, a hierarchical hybrid game–based limit stability control method for CMVs is proposed in this article. Taking into account the handling potential of subsystems under limit conditions, a Stackelberg leader–follower game is designed by first designating Direct Yaw moment Control (DYC) as the leader and Active Rear Steering (ARS) as the follower. Subsequently, the DYC–ARS and Active Suspension System (ASS) were constructed into a non-cooperative game system, and the Nash equilibrium solution was solved through iteration. The lower-level controllers, respectively, established a tire force distribution model that minimizes the overall tire utilization rate and an active suspension force distribution model that does not affect the vehicle’s pitch, in order to enhance the safety margin of the vehicle under extreme conditions. Finally, the Hardware-in-the-Loop test results proved the effectiveness of the proposed controller.

Peng, Jinxin, Xiao, Feng, Ke, Yuan, Jin, Liqiang

Hierarchical Control Strategy Evaluation and Migration for a Four-Degree-of-Freedom Quarter Commercial Vehicle

02-19-03-0014

4/9/2026

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, Ting, Pang, Jianzhong, Wu, Jinglai, Zhang, Jiuxiang, Kang, Gong, Zhang, Yunqing

Integrated Effects of Suspension Geometry and Tire Pattern Design on Vehicle Pull Reduction under Acceleration in High-Performance and Electric Vehicles

2026-01-0593

4/7/2026

Vehicle pull under acceleration is a phenomenon commonly observed in high-performance vehicles and electric vehicles (EVs), primarily arising asymmetric driveshaft angles, drivetrain architecture, and suspension geometry. In addition to these mechanical factors, tire characteristics, particularly the tire lateral force generated at the contact patch, significantly influence this effect. The lateral force is intricately tied to the dynamics of the contact patch and the geometric design of the tire tread pattern. This study investigates the relationship between tread pattern geometry and vehicle pull under acceleration, emphasizing the role of tire lateral force variations. By employing finite element (FE) simulation, lateral force response variations (dfy/dfx) resulting from tread block deformation were analyzed. Based on these simulation, a robust analytical methodology for tread pattern evaluation and optimization was established. The developed tread pattern characteristic parameter was validated through a thorough comparison between physical testing and FE simulation results, demonstrating high consistency. Vehicle-level testing further confirmed that the application of the optimized tread pattern design significantly reduced vehicle pull under acceleration. Moreover, performance criteria for tire lateral force were defined based on the maximum torque and output requirements of high-performance and electric vehicles. The study concludes that implementing the developed tread pattern characteristic parameter enables the design of tires with enhanced resistance to vehicle pull under acceleration. Such advancements are poised to enhance steering stability, handling performance, and overall safety in vehicles with high torque outputs, especially EVs and high-performance models.

Yoon, Youngsam, Jang, Dongjin, Kim, Hyungjoo, Lee, Jaekil

Data-Driven Study on Chassis Suspension Performance Degradation

2026-01-0582

4/7/2026

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, Yinsheng, Lei, Yisong, Su, Ailin, Wang, Zhenfeng, Shi, Shuai, Zhang, Lei, Zhang, Junzhi, Ma, Changye

Oscillatory Behavior of Understeering Vehicles

2026-01-0623

4/7/2026

Oscillations in understeering vehicles are occasionally described in the literature, primarily in terms of the poles of the yaw rate response, but perhaps not completely appreciated in their complexity. This work shows that as speed of an understeering vehicle increases, the increasingly underdamped poles of the yaw rate transfer function combine with the effects of a low frequency zero and a reduced steady-state response to result in oscillations greater than would be expected from eigenvalues alone. A speed range for acceptable yaw rate response is suggested, and it is shown that a typical understeering passenger car operates within this range. As the understeering vehicle’s speed increases beyond this range, the high-speed limit of the oscillation frequency is found.

Williams, Daniel

System-Level Performance of Torque Vectoring Controllers for Electric Vehicles with In-Wheel Motors

10-10-04-0029

3/13/2026

Torque Vectoring (TV) is a critical control technology for enhancing the vehicle dynamics and stability of electric vehicles equipped with four-wheel-independent-drive (4WID) systems. A central challenge in TV design is managing the trade-off between maximizing handling performance and minimizing energy consumption, a crucial factor for EV range. While numerous advanced TV control strategies have been proposed, a comprehensive and comparative benchmark of foundational controllers evaluated on a platform that captures this trade-off is notably absent from the literature. Among the numerous TV control strategies proposed in literature, they are typically evaluated using simplified vehicle models that neglect the detailed dynamics and efficiency losses of the electric powertrain. This study addresses this gap by presenting a comprehensive comparison of six distinct TV control strategies—PID, LQR, two first-order Sliding Mode Controls (SMC), and two second-order SMCs. The controllers are evaluated on a high-fidelity, multi-domain simulation platform that integrates a detailed 14-DOF vehicle dynamics model with electro-thermal models of the motors and energy storage system. The findings reveal a clear, quantifiable trade-off between control precision and energy efficiency. The LQR and suboptimal SOSM controllers delivered superior yaw rate tracking and vehicle stability but incurred a measurable energy penalty. In contrast, the PID and continuous FOSM controllers provided a robust balance of performance and efficiency. More than an exercise on application of different control methods, this research highlights the necessity of using integrated simulation methodologies for the practical design and calibration of active chassis systems, ensuring that gains in dynamic performance do not come at an unacceptable cost to vehicle range and powertrain reliability.

de Carvalho Pinheiro, Henrique, Carello, Massimiliana

Yaw Coordinated Control Based on Fuzzy Control and Stability Region Theory

10-10-03-0018

2/23/2026

Electric vehicle chassis integration control aims to improve vehicle handling and comfort. Previous studies encountered significant practical limitations, such as computational overhead in real-time execution scenarios. Designing effective and efficient algorithms for actuator coordination remains challenging. This article presents a synergetic controller for chassis coordination, combining fuzzy logic and stability region theory. First, the controller targets are the yaw rate and side slip angle, which are obtained from a highly accurate multi-body dynamic model. In addition, based on the generated fuzzy rules, the system calculates the required additional yaw moments for each actuator and optimizes their output. Then, the designed controller can distribute control effort optimally in real-time between braking and rear-wheel steering based on the stability status of the vehicle. Furthermore, a stability factor approach is used to formulate a dynamic safety strategy executed by the chassis. It helps to create the safety boundary of the vehicle and avoid excessive force and angle of execution. Finally, real-vehicle tests are conducted, and the experimental results and real-vehicle tests demonstrate significant improvements: steering wheel angle reduction by 10%, enhanced yaw stability (9% higher safety threshold) for the slalom test, and better elk testing performance (>2%). The proposed method offers practical, real-world applicability and provides valuable insights and a reference for yaw control research in the automotive industry.

Liao, Yinsheng, Hu, Zhiming, Cheng, Yuanshu, Lin, Ruya, Sun, Yue, Gao, Sixiao, Zhang, Junzhi

Computational Study on Dynamic Handling Performance of a Retro Fitted Electric Two-Wheeler Using 125cc Powered ICE Reference

2026-28-0047

2/12/2026

With the development in motor technology and battery technologies, the scope for a low-cost EV has been increasing in India. There remains an after-mark potential for conversion of an ICE powered two-wheeler to an EV power train. Such a move reduces the carbon footprint from the vehicle drastically and is still being explored. This study investigates the effect of replacing the ICE with an electric motor in a 125cc motorcycle, with a particular focus on vehicle handling performance using Slalom test. The two wheelers were modelled using calculated mass properties and estimated / calculated moments of inertia using CAD for both ICE and electric powertrains. The electric propulsion system took into consideration the role of a battery pack in the mass and MI calculation. The framework with degrees of freedom is well established in BIKESIMTM simulation environment. A slalom test with automatic gear shift and throttle to maintain speed of the vehicle was set-up to estimate the handling performance. The speeds of the vehicle were computed for 60kmph condition. The output parameters of interest were the steering angle, steering torque, yaw rate, lateral acceleration and lean angle. Within the assumptions of this work, the results from the simulations indicated that handling performance of the retrofitted EV power train was comparable to that of an ICE vehicle and rider may not feel it to be drastically different.

Sankarasubramanian, Hariharan, M, Shaghasra, V, Ramprathap

Improving Semi-Truck Torque Overlay Steering Systems to Boost On-Center Performance: Hardware Design Investigation

02-19-02-0012

2/4/2026

In class 8 semi-trucks, the hydraulic steering gear and torque overlay system are critical components affecting the steering feel design and vehicle control. Transitioning from traditional hydraulic gears to hydraulic gears with torque overlay steering (TOS) systems for increased enhancement of driver comfort is beneficial but has also resulted in drawbacks for on-center steer feel, especially at high vehicle speeds (60+ km/h). This article evaluates the impact of three design mechanisms within hydraulic steering gears of a TOS system that have shown improvement in on-center performance for traditional hydraulic gears. The study compares a standard assembly of TOS, i.e., baseline, and a design-optimized ideal prototype, to evaluate the effectiveness of the three design mechanisms: valve curve performance, on-center friction, and torsion bar stiffness. The two samples underwent high-speed vehicle testing to gather driver feedback and assess potential enhancements to the on-center steering feel. The final design changes on the ideal prototype were based on the best valve curve and on-center friction, as limitations in the torsion bar modification process precluded its use in the vehicle. The vehicle qualification team found insufficient evidence linking these design features to improved overall steering performance. Further research will be conducted to analyze the impact of torsion bar change as well as software controller performance within the TOS as a follow-up study.

Bari, Praful Rajendra, Chaudhuri, Nilankan

Performance Evaluation and Optimization of Engine Brake System using Chassis Dynamometer

2026-26-0511

1/16/2026

Engine braking is a deceleration technique that leverages the internal friction and pumping losses within the engine. By closing the throttle and potentially selecting a lower gear, the engine creates a retarding force that slows the vehicle. This practice contributes to better fuel economy, decreased brake system load, and improved vehicle handling in specific driving scenarios, such as steep declines or slippery road surfaces. To alleviate stress on their primary braking systems and prevent overheating, heavy vehicles frequently incorporate engine-based braking. While older trucks relied on simple exhaust brakes with a butterfly valve to restrict exhaust flow, these had limited impact. Hence contemporary heavy vehicles almost exclusively use more advanced engine braking technologies. Traditionally, our heavy-duty vehicles use Exhaust brake system to elevate the braking performance on hilly terrains. Hence an improved sample of Engine brake was developed for enhanced braking performance. A study to map the performance of Engine braking at different field conditions was conducted at Chassis Dynamometer Lab on M&HCV Tipper Vehicle model. Conditions are: a) Different speeds/gears. b) Different gradients. Vehicle fitted with improved sample of Exhaust brake is tested on Chassis dyno for its performance. Braking power derived & plotted at various Engine speeds and compared with the performance results of existing Engine brake sample. Iterations carried out using various gears at different levels of gradient to simulate real world performance of Engine braking and tested the capabilities of the brake sample to the extreme levels of over speeding engine revolutions. The results obtained from this exercise fortified in evaluating and optimizing the improved sample of exhaust brake and it in turn aided in better performance of the vehicle on road.

M, Vipin Prakash, Rajappan, Dinesh Kumar, R, Suresh, N, Gopi Kannan

New Generation Natural Rubber-Based Bump Stopper with Improved NVH Characteristics

2026-26-0292

1/16/2026

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, Annarajan, Hingalaje, Abhijeet, Perumal, Mathavan, Pawar, Rohit

Influence of Bushing Stiffness Measurement Methodology on Axle Elasto-Kinematics

2026-26-0094

1/16/2026

The handling of a vehicle is crucial to the perception of its dynamic characteristics, such as comfort, stability, composure, sportiness, and precision. Kinematics and Elasto-kinematics, also known as Kinematics and Compliance (K&C), form the basis of an automobile's handling characteristics. Kinematics focuses on the movement of suspension components, including wheels, axles, and linkages, and how these movements relate to the vehicle's body motion. Compliance refers to the suspension's ability to deform under load, primarily due to the flexibility of springs, bushings, and other elastic components. Elastomer bushings, as flexible elements in the kinematic chain, significantly impact K&C and require a detailed study. Suspension bush stiffness is typically measured through static and dynamic tests, in various directions – radial, axial, torsional, etc. Tests involve applying a force or torque and measuring the resulting deflection and/or rotation. These measurements are used to determine the bush's stiffness characteristics, which are crucial for suspension design and analysis. The forces or torques the bushes are subjected to during these measurements are typically on the higher end of the spectrum of what the bush is expected to withstand during its operation. However, the normal forces which the bushing will encounter during city or highway driving are usually much lower than the ones it was measured for. Herein lies a problem. Elastomers, due to their inherent viscoelasticity, exhibit a behavior known as the Payne effect. This causes a decrease in the stiffness of the elastomer with an increase in the strain amplitude. In short, the stiffness of the bush during its normal driving conditions is, at times, considerably different than the stiffness used during the design and analysis of the suspension/axle. This paper studies the consequences of Payne effect in suspension bushings, on axle K&C and vehicle handling. To start with, a multi-body dynamics (MBD) axle model was used to determine the loads expected on the suspension bushes during normal operations. The stiffness of the bushes was then measured for these force amplitudes. The MBD model was updated with the new stiffness values, and K&C simulations were repeated. Comparing the new K&C results with previous ones (which had standard bushing stiffness) showed a significant improvement, providing an improved correlation with the K&C measurements from the test bench. For example, the correlation of Lateral Force Compliance Steer (LFCS), improved by 9%. Using these K&C results in the full vehicle models made the models more accurate when compared to real-world measurements on the proving grounds. The deviation in the correlation of the Understeer Gradient went down from 21% to 9%. The same for Yaw Gain went down from 6% to 1%. These appreciable improvements in correlation validated the approach discussed in the paper.

Avhad, Anish

Systematic Study to Understand and Resolve Brake Pull in Commercial Vehicles Using Simulation and Proving Ground Tests

2026-26-0083

1/16/2026

In traditional commercial vehicles with leaf spring suspension and Recirculating Ball Joint (RCBT) steering systems often experience undesirable pulling due to unsymmetrical steering mechanism during braking, especially when the suspension and steering hardpoints are not properly tuned. This work analyzes the mechanisms responsible for pulling tendencies, primarily addressing brake steer and bump steer, which occur due to misalignments in the suspension and steering geometries. Brake steer occurs when braking forces create an imbalance in torque, resulting in the vehicle deviating to one side. On the other hand, bump steer refers to the unwanted changes in the wheel alignment when the suspension undergoes travel, leading to instability or unintended steering input. These two phenomena, if not controlled, can result in undesirable vehicle handling, especially under heavy braking conditions. This work focuses on evaluating these mechanisms and suggests strategies for minimizing their impact through accurate suspension and steering hardpoint tuning. A dedicated methodology was formulated to optimize suspension and steering hardpoints, leveraging Adams Car MBD simulations for fast and accurate predictions of pull direction. Adjustments were made to the front leaf spring pivot and Pitman arm draglink pivot to address bump steer, and the knuckle-to-draglink joint was optimized to minimize brake steer. Simulation outcomes showed that the severe right pull initially observed was reduced to a mild left pull after these changes. Despite offering valuable tuning strategies and directional predictions, the study acknowledges that exact pull magnitude cannot be predicted with certainty due to complex vehicle dynamics. However, the study successfully establishes a method for predicting pull direction, which can serve as a strong foundation for further refining suspension and steering system designs in small commercial vehicles.

Pandhare, Vinay Ramakant, M, Anantha Padmnabhan, Nizampatnam, Balaramakrishna, Londhe, Abhijit, Doundkar, Vikas

Adoptive Safety Solutions in Road Simulators for Commercial Vehicle Structural Validation

2026-26-0533

1/16/2026

Road Simulators used to carry out accelerated structural durability validation of a vehicle. As a commercial vehicle manufacturer, for our commercial vehicles structural validation, we are using 8 poster road simulators. We use road load data, torture track data, synthetic profiles or road events as the input test data. From a mini 4 wheeler trucks to high capacity 8 wheeler truck, and any bus variant is being tested at road simulator. All the vehicle variants are tested with prescribed road and load conditions for the pre-determined life. Each wheel of the vehicle is positioned on the wheel pan of the hydraulic actuators so that each actuator excites the corresponding vibration data. The vehicle is being restrained as per the manufacturers recommendation. Manufacturer recommendations widely addresses the risks associated with the test rigs. In addition to that there are risks associated with the vehicle running, vehicle handling, vehicle positioning. For example, when durability test running when EB power goes off, the vehicle will move down rapidly affects test vehicle as well as test system, when any of the restraint fails, the vehicle wheel dislocates from its position and fall off from test rig can cause heavy damage. Very few OEM’s use heavy vehicle road simulators. Hence the safety related information is very limited. We have identified many areas of road simulator operation in which the safety of the human, test vehicle and test rig is concerned and we have implemented the tailor made solutions for the safer structural validation at road simulator. To name a few, modular vehicle platform for drive on vehicle, primary and secondary restraints, steering locks, hydraulic whip locking (HWL), wireless E stops, Auto power off test halt system (APOTS), auto pit entry locking systems, Break wire test halt system (BWTHS) Wireless wheel slip detection system (WDS).

Arumugam, Paramasivam, N, Gopi Kannan, N, Mahendra, Muthu kumar, Pandurangan, Singh, Laxman, Tiwari, Manish, V, Subash

Design of a McPherson Strut Based Split Link Front Suspension for a Higher Rear to Front Weight Ratio SUV with Least Turning Circle Diameter

2026-26-0092

1/16/2026

Generally, in an electric sports utility vehicle with rear mounted powertrain the mass distribution is greater in the rear compared to front. This higher rear to front weight distribution results in oversteer behavior during high-speed cornering deteriorating vehicle handling & risking passenger safety. To compensate this inherent oversteer nature of such vehicles & produce understeer behavior, the steering rack is placed frontwards of the front wheel center for toe-out behavior due to lateral compliance during cornering. This compensation measure results in lower Ackermann percentage resulting in higher turning circle diameter deteriorating vehicle maneuverability. This paper proposes a design to obtain ideal understeer gradient with minimal turning circle diameter through utilization of split link technology with a McPherson Strut based suspension framework & frontwards placed steering rack. This suspension is utilized in our Mahindra Inglo platform. This paper elaborates on how through split links, variable knuckle length arm can be achieved which helps in achieving greater outer to inner wheel steering turn angle rate effectively improving Ackermann percentage & minimizing turning circle diameter. Apart from that the design mentioned herein allows greater manipulation of longitudinal & lateral compliance due to partial decoupling of both by split links. This overall improves longitudinal compliance resulting in better plushness during bumps improving ride without compromising handling characteristics of the vehicle. The suspension design is also optimized for wheel travel of 185mm, higher than benchmarks to provide enough wheel traction as well as comfort on hilly terrains & city roads of India.

Nadkarni, Ameya Ravindra, Mhatre, Nitij, Patnala, Avinash, NAYAK, Bhargav

Torque Vectoring Control Techniques for Vehicle Parking

2026-26-0590

1/16/2026

Parking in confined spaces can be quite challenging. It is often a herculean task to align the vehicle in the parking slots where the driver has to make several attempts to park properly. One such ingenious technology that augments vehicle handling, directional controlling and overall driving agility is torque vectoring. It is becoming a pioneer in creating smarter, more responsive vehicles unlike traditional vehicles. With torque vectoring, EV’s can precisely control the torque delivered to each wheel with independent motors per wheel. In confined spaces as well by selectively distributing torque to individual wheels, it optimizes traction and vehicle control, making tasks like parking, sharp turns, and navigating narrow streets smoother and more efficiently. This paper confers about the use of torque vectoring techniques in electric vehicles for smoother and more proficient vehicles handling in tight spaces like parking, which significantly reduces driver efforts while maximizing the handling characteristics. With the aid of CarMaker and Simulink co-simulation environment, different test cases of parking are performed, and test data is analyzed to foreshow the advantage of torque vectoring in reducing vehicle turning radius and directional controlling while parking. In addition to this, the comparison for vehicle parking of both with and without torque vectoring vehicles is done to assert the key advantages.

Gangad, Vikas Shridhar, Gautam, Era, Chaudhari, Gitesh, Penta, Amar

Predictive Simulation Framework for Tyre Curb Impact Durability Assessment and Design Optimization

2026-26-0396

1/16/2026

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, Ragasruoban, Lenka, Visweswara

Experimental Evaluation of High Energy Impact Test of Wheel Rim

2026-26-0504

1/16/2026

High energy impact testing using free fall mass is a crucial method for evaluating the structural integrity, and safety performance of automotive components subjected to sudden impact forces. This study focuses on assessing critical parts such as wheel rims, suspension knuckles, commonly exposed to unintentional impacts during vehicle operation, maintenance, or collisions. The test involves dropping a standardized mass from predetermined heights onto the component to simulate real-world impact scenarios. Key performance indicators include deformation, crack propagation, fracture resistance, and energy absorption capacity. Wheel rims and knuckles are evaluated for their ability to maintain structural integrity under localized impact without compromising vehicle handling or safety. Seats and related interior structures are tested to ensure occupant protection during crash-like events. Other components, such as brackets, mounts, or housings, are included based on functional criticality and exposure risk. Results from the free fall impact tests inform design optimizations, material selection (e.g., aluminium alloys, composites, high-strength steels), and manufacturing processes to improve product reliability and compliance with automotive safety requirements. This approach supports the development of robust vehicle systems capable of withstanding harsh real-world conditions, ultimately enhancing vehicle safety, performance, and customer satisfaction.

Roham, Prasad, Bagade, Mohan, Sinnarkar, Nitin, Pawar, Prashant R, Shinde, Vikram

Modelling and Simulation of Key Vehicle Dynamics Parameters for a Conceptual Race Car

2026-26-0085

1/16/2026

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

Steering on-Center Feel and Yaw Response Enhancement through Optimization of System Level Characteristics

2026-26-0082

1/16/2026

To export India based SUVs to European markets, change in steering position is required to suit vehicle driving condition. Ideally, RHD and LHD variants of the same vehicle should have similar levels of ride and handling performance parameters. However, due to various packaging constraints and regulations, there is a possibility of minor change in Hard-points of steering or suspension system which may lead to different behavior in terms of body roll and steering response. While cornering or double lane change maneuvers, difference in steering phase angles or steering stiffness or suspension hardpoints results in different roll behavior as well as understeer characteristics of the vehicle. The present study shows key parameters and optimization methodology to maintain same level of ride and handling performance in both RHD and LHD variants. Objective measurements and physical kinematics and compliance tests were carried out with various configurations of RHD and LHD variants to understand the roll gradient, understeer characteristics as well as steering on-center response and deadbands. Multi Body Dynamics models were developed to investigate and carry out sensitivity analysis to understand the impacts of different suspension and steering systems to achieve the same level of performance in both the variants. The results showed that with minimal changes in hardpoints, tuning of suspension and steering components could lead to optimization of R&H metrics in RHD and LHD variants. As a result, methodology was developed for identification of variation in steering performance through subjective and objective correlation, based on which optimization of system level characteristic was carried out to enhance steering and handling performance.

Hussain, Inzamam Ul, Kamarthi, Ashwin, Rewale, Pratik, Nehal, S B, Rasal, Shraddhesh, Naidu, Kethireddi

Advance Techniques to Optimize Variable Gear Ratio Steering for High Centre of Gravity Vehicles

2026-26-0086

1/16/2026

Vehicles with a high center of gravity (CG) and moderate wheel track, like compact Sport Utility Vehicles (SUVs), have a relatively low Static Stability Factor (SSF) and thus are inherently less stable and more susceptible to rollover crashes. Moreover, to be more maneuverable in highly populated urban areas, a smaller Turning Circle Diameter (TCD) is necessary. Here, Variable Gear Ratio (VGR) steering systems have major benefits over traditional Constant Gear Ratio (CGR) systems in terms of enhancing both roll stability and agility. To adapt VGR steering systems to a particular vehicle dynamic, Full Vehicle (FV) and Driver-in-the-Loop (DIL) simulations are utilized. Using this method, exact calibration is possible according to realistic driving conditions so that the VGR steering C-factor curve is properly tuned for optimal handling in on-center, off-centre, and transitional areas of the Steering Wheel Angle (SWA). Primary performance measures—e.g., SWA gradients at different lateral accelerations and C-factor changes for different SWA ranges—are examined in the DIL environment to maintain a natural feel during steering. In addition, DIL simulation allows a check on cycloidal curve character, manufacturing asymmetry, and its effect on total drive performance.

Rewale, Pratik, Kopiec, Jakub, Kumar, Deva, Rasal, Shraddhesh, Hussain, Inzamam, Nehal, S B

Effect of Flow Forming Process on the Mechanical Properties and Microstructure of GDC & LPDC Cast Aluminium Alloy Wheels

2026-26-0298

1/16/2026

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 Krishnan, Medaboyina, HarshaVardhan, G K, Balaji, Gopalan, Vijaysankar, Sundaram, Raghupathi, Paua, Ketan

Minimizing Impacts of Road Adhesion Perturbations: Uncertainty Allocation for Control Synthesis of X-by-Wire Chassis

2025-01-7327

12/31/2025

Model-based optimal control has been widely adopted for vehicular stability enhancement. However, existing schemes still suffer from unmodelled external disturbances such as road adhesion variations, which leads to significant performance degradation. The recent progress in X-by-wire chassis brings promising solution to address this challenge. Utilizing independent steering along with distributed driving systems, this paper proposes a vehicular control programs that actively distribute tire forces in both longitudinal and lateral directions to minimize the impact of external parameter perturbations. Firstly, an adhesion disturbance modeling approach integrating composite slip and single-wheel reachability analysis is developed to accurately characterize the feasible region of tire forces under adhesion disturbances. Secondly, based on the disturbance propagation mechanism, the sensitivity differences of various tire force distribution strategies to key vehicle states are systematically analyzed, leading to the proposal of an active distribution criterion with minimal disturbance response sensitivity. Furthermore, a stochastic model predictive control (SMPC) framework integrating state covariance constraints and probabilistic constraints is designed, which improves control accuracy while significantly suppressing the propagation of state uncertainty. Simulation results demonstrate that the proposed method effectively reduces state fluctuation ranges under typical longitudinal and lateral conditions, thereby enhancing vehicle handling stability and robustness under adhesion uncertainty.

Lv, Haoran, Tang, Chen, Zhang, Pengjun, Xiong, Lu

On Optimal Tire Usage in the Path-Tracking Control of Four-Wheel Independent Steering Four-Wheel Independent Drive Electric Vehicles

12-09-02-0014

10/22/2025

Four-wheel independent steering four-wheel independent drive electric vehicles have an independent steering motor and an independent driving motor for each wheel, for a total of eight motors. About 28 works in this emerging field have shown path-tracking control algorithms for these vehicles, 18 of them explicitly or implicitly aspire for a condition known as optimal tire usage. This article first defines this optimality condition and explains its significance. Second, this article identifies three indicators of tire usage that aid in assessing the existing algorithms. Third, this article performs block diagram examination of four of the 18 works, revealing significant commonalities across the 28 works and identifying areas for improvement in three of the four algorithms. Lastly, this article suggests motor control systems to fill these gaps. Furthermore, it employs these motor control systems in one of the four algorithms, and illustrates path-tracking and achievement of the optimality condition in simulation. This shows that the motor control systems are sufficient (in simulation) to meet the optimality condition in one work. They are likely sufficient for all path-tracking algorithms employing appropriate control allocation to achieve the optimality condition.

Kumar, Dileep, Potluri, Ramprasad

Coordinated Strategy of Trajectory Tracking and Stability Control for Autonomous Vehicles with Switched Envelope and Composite Evaluation

10-10-01-0003

10/13/2025

Trajectory tracking and lateral stability under extreme conditions are critical yet conflicting control objectives due to nonlinear tire dynamics and road adhesion limitation, where accurate characterization of vehicle dynamics for each objective is essential to enable coordinated performance. This article proposes a coordinated control strategy based on switched envelope and composite evaluation to improve both tracking accuracy and stability. Unlike previous stability envelope methods that rely solely on the vehicle’s rear tire saturation boundary to prevent instability, the switched envelope approach incorporates both front and rear tire saturation boundaries to simultaneously mitigate steering loss and instability in trajectory tracking. A critical steering angle, derived from tire slip dynamics and phase plane stability analysis, is formulated as the switching criterion. Additionally, a composite stability evaluation is developed by combining a future disturbance resistance index with the current stability utilization metric, providing a comprehensive measure of vehicle control capability and preventing frequent oscillations among control objectives. Integrated with a switched envelope model predictive control framework, it enables adaptive adjustment of state constraints and control weights to dynamically balance trajectory tracking accuracy and stability. Finally, co-simulations using CarSim and MATLAB/Simulink, along with hardware-in-the-loop experiments, demonstrate the effectiveness of the proposed strategy in enhancing vehicle handling and stability under severe driving scenarios.

Shi, Wenbo, Wang, Junlong, Ding, Haitao, Xu, Nan

Hyundai Palisade: A luxury three-row SUV without the price tag you'd expect

25AUTP10_15

10/1/2025

Years ago, Hyundai hosted a Palisade drive program for journalists consisting mostly of driving on a gravel road for a few hours. It was weird, and many a journalist told them so. It may not be a direct reaction to that feedback, but on a recent drive program of the new 2026 Palisade, Hyundai made sure that we drove the well-equipped SUV on regular, albeit twisty roads in the Napa region of Northern California. The automaker also took us off-road again. This time, with boulders. Hyundai's Palisade has long found itself in the shadow of Kia's Telluride. Built on the same platform, design-wise, the Kia always tended to turn more heads. With the 2026 upgrade, the Palisade is coming into its own looks-wise, while being outfitted with upgrades that keep the SUV punching above its weight class.

Baldwin, Roberto

From Temperature to Wear: A Quantitative Analysis of Tire Influence on Vehicle Cornering Using Handling Key Performance Indicators

2025-01-5060

9/16/2025

Vehicle behavior is strongly influenced by tire performance, as tires serve as the primary interface between the vehicle and the road surface. Since identical vehicles equipped with different tire sets—or even the same tires operating under varying thermal and wear conditions—can exhibit significantly different handling characteristics, this study aims to quantify their impact on both steady-state and transient cornering responses through a dedicated evaluation methodology. To demonstrate the generalization of the proposed approach, three completely different validated vehicle digital twins—a passenger car, a sports car, and a formula car—are analyzed in a virtual environment, employing Vi-Car Real Time for vehicle and scenario representations, and RIDEsuite for tire modeling, considering thermal and wear effects. The simulations were designed using a structured design of experiments approach, resulting in 15 predefined combinations of tire temperature and wear states. Results show that operating outside the tire’s optimal thermal and wear conditions significantly affects vehicle handling balance, responsiveness, and driver perception of agility. These effects scale with tire performance level: while standard passenger car tires exhibit limited sensitivity, slick formula tires show substantial variations in grip and cornering stiffness, reaching deviations of approximately 10% and 35% from their nominal values, respectively. Vehicle steady-state analyses indicate that front axle wear increases understeer, while rear axle wear reduces overall stability—resulting, for example, in a 25% increase in peak sideslip angle in the sports car configuration. Transient analyses further confirm that temperature has a more pronounced effect than wear, particularly on yaw rate and lateral acceleration response times, with variations reaching up to ±10% relative to optimal thermal conditions. This work highlights the need to include tire condition effects in handling target definition and validation processes, recommending careful monitoring of tire states during standardized ISO maneuvers. Fixed metrics should be replaced by performance ranges that reflect actual tire operating states, whether for custom-developed or off-the-shelf tires.

Aratri, Roberto, Romagnuolo, Fabio, De Pinto, Stefano, Farroni, Flavio, De Bellis, Sergio, Bottiglione, Francesco, Mantriota, Giacomo, Sakhnevych, Aleksandr

Early Detection of the Loss of Control of Motorsport Vehicles

10-09-03-0029

6/30/2025

The article investigates how to detect as quickly as possible whether the driver will lose control of a vehicle, after a disturbance has occurred. Typical disturbances refer to wind gusts, obstacle avoidance, a sudden steer, traversing a pothole, a kick by another vehicle, and so on. The driver may be either human or non-human. Focus will be devoted to human drivers, but the extension to automated or autonomous cars is straightforward. Since the dynamic behavior of vehicle and driver is described by a saddle-type limit cycle, a proper theory is developed to use the limit cycle as a reference trajectory to forecast the loss of control. The Floquet theory has been used to compute a scalar index to forecast stable or unstable motion. The scalar index, named degree of stability (DoS), is computed very early, in the best case, in a few milliseconds after the disturbance has ended. Investigations have been performed at a dynamic driving simulator. A 14 DoF vehicle model, virtually driven by a real human driver, was employed. A number of evasive maneuvers have been examined, both for understeer and oversteer vehicles. The early detection of the loss of control is possible. The sensing of the loss of control could be enhanced with respect to a classical ESP, although a more in-depth investigation is needed. Some issues referring to the robustness of the computation of the DoS are still to be investigated. Nonetheless the DoS seems already applicable for motorsport vehicle and drivers.

Della Rossa, Fabio, Fontana, Matteo, Giacintucci, Samuele, Gobbi, Massimiliano, Mastinu, Giampiero, Previati, Giorgio

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

2025-01-5036

6/3/2025

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 reduced by 3.15%. Thus, the vehicle handling performance and fuel efficiency are improved.

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

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

2025-01-5034

5/6/2025

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 results show that the method can be used in the development of commercial vehicle suspension and active chassis control.

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

Road Surface Adaptive Stationary Steering Coordinated Control of Four-Wheel Hub Motor Vehicles

2025-01-5031

4/29/2025

The wheel hub motor–driven electric vehicle, characterized by its independently controllable wheels, exhibits high torque output at low speeds and superior dynamic response performance, enabling in-place steering capabilities. This study focuses on the control mechanism and dynamic model of the wheel hub motor vehicle’s in-place steering. By employing differential torque control, it generates the yaw moment needed to overcome steering resistance and produce yaw motion around the steering center. First, the dynamic model for in-place steering is established, exploring the various stages of tire motion and the steering process, including the start-up, elastic deformation, lateral slip, and steady-state yaw. In terms of control strategy, an adaptive in-place steering control method is designed, utilizing a BP neural network combined with a PID control algorithm to track the desired yaw rate. Additionally, a control strategy based on tire/road adhesion ellipse theory is developed to enhance vehicle handling stability under different road conditions. The simulation results indicate that the control strategy effectively optimizes the vehicle’s steering response, reducing the center of gravity displacement by approximately 50% and 75% along the y-axis and x-axis, respectively, under high-friction conditions, while maintaining the maximum tracking error for the desired yaw rate at around 0.5%. Under low-friction conditions, the center of gravity displacement along the y-axis decreases from a maximum of 0.32 m to 0.19 m, with the tracking error for the desired yaw rate stabilizing at approximately 0.6%. This ensures the vehicle’s stability and safety during extreme steering maneuvers. This research provides a theoretical foundation and practical reference for the design of control systems in future distributed drive electric vehicles.

Huang, Bin, Cui, Kangyu, Zhang, Zeyang, Ma, Minrui

Deceleration Testing on Various Driving Surfaces for Off-Road Vehicle Operation

2025-01-8704

4/1/2025

Recreational Off-Highway Vehicles (ROVs) also referred to as “side-by-side” vehicles are involved in accidents / crashes due to driver error. This can often be attributed to an operator’s inexperience and failure to differentiate vehicle handling characteristics from that of a traditional automobile. Decelerating testing of ROVs on various surfaces has not been published for these types of vehicles. This work presents test data for use in accident reconstruction and examines the dynamic performance of two exemplar ROVs on various driving surfaces including asphalt, packed dirt, loose gravel and loose, deep sand. Exemplar vehicles, specifically a 4-person “pure-sport” ROV and a single bench utility ROV, are used to gather practical deceleration performance data. Deceleration data comparing tests with fully-locked brakes to tests where the operator manually modulates the brakes to achieve maximum deceleration without brake lockup are also included. The data presented herein is particularly valuable for analysis of ROV skid marks.

Swensen, Grant, Warner, Wyatt, Warner, Mark

Trajectory Tracking Fault-Tolerant Control for Distributed Drive Electric Vehicles Considering Steering Actuator Faults

2025-01-8299

4/1/2025

Trajectory tracking control is a key component of vehicle autonomous driving technology. Compared with traditional vehicles, Distributed Driven Electric Vehicle (DDEV) is an ideal vehicle for trajectory tracking control because of its high space utilization, redundant control freedom and fast system response. However, the chassis execution system of DDEV has a relatively large number of sensors, which significantly increases its probability of failure. In this paper, we propose a trajectory tracking fault-tolerant control method for DDEV considering steering actuator faults. Firstly, we establish the dynamic model of the steering actuator and the trajectory tracking model of DDEV. The model is linearized and discretized by using Taylor series expansion and forward Euler method. Next, considering multi-objective constraints such as motion comfort, actuator saturation and road adhesion boundary, the trajectory tracking control strategy of DDEV is designed by using model predictive control theory and quadratic programming method. At the same time, we design the fitting formulas of tire longitudinal force, lateral force and aligning torque based on magic formula tire model. On this basis, a trajectory tracking fault-tolerant control strategy under steering actuator faults is designed using differential drive assisted steering principle and robust sliding mode control theory. Finally, we establish a joint simulation platform by MATLAB/Simulink and vehicle dynamics simulation software CarSim. The experimental results show that the designed trajectory tracking fault-tolerant control strategy could help DDEV to complete the trajectory tracking driving task well in the event of steering actuator failure.

Wang, Deping, Li, Lun, Teng, Yuhan, Zhu, Bing, Chen, Zhicheng

Coordinated Control Strategy for Longitudinal, Lateral, and Vertical Motions of Distributed Electric Vehicles Based on Model Predictive Control

2025-01-8300

4/1/2025

Distributed electric vehicles, equipped with independent motors at each wheel, offer significant advantages in flexibility, torque distribution, and precise dynamic control. These features contribute to notable improvements in vehicle maneuverability and stability. To further elevate the overall performance of vehicles, particularly in terms of handling, stability, and comfort, this paper introduces an coordinated control strategies for longitudinal, lateral, and vertical motion of distributed electric vehicles. Firstly, a full-vehicle dynamics model is developed, encompassing interactions between longitudinal, lateral, and vertical forces, providing a robust framework for analyzing and understanding the intricate dynamic behaviors of the vehicle under various operating conditions. Secondly, a vehicle motion controller based on Model Predictive Control is designed. This controller employs a sophisticated multi-objective optimization algorithm to manage and coordinate several critical subsystems, including Active Front-Wheel Steering, Direct Yaw Moment Control, Active Suspension System, and Anti-Slip control, significantly enhancing the vehicle's overall handling performance and coordination among implementation systems Finally, to prevent tire slippage and lock-up, an optimized torque distribution method based on slip ratio feedback is proposed. This method constraint torque distribution by calculating the maximum transmissible longitudinal force through the anti-slip control module, achieving integrated anti-slip and torque allocation. The proposed control strategy is validated through a comprehensive co-simulation platform integrating CarSim and Simulink. Simulation results demonstrate that the proposed scheme effectively improves vehicle ride comfort and enhances maneuverability and stability under various driving conditions. This research highlights the extensive application potential and practical engineering value of the proposed cooperative control strategy in advancing the performance of distributed electric vehicles.

Jia, Jinchao, Yue, Yang, Sun, Aobo, Liu, Xiao-ang

A Torque Distribution Strategy for the Six-Wheeled Lunar Rover

2025-01-8308

4/1/2025

As a crucial tool for lunar exploration, lunar rovers are highly susceptible to instability due to the rugged lunar terrain, making control of driving stability essential during operation. This study focuses on a six-wheel lunar rover and develops a torque distribution strategy to improve the handling stability of the lunar rover. Based on a layered control structure, firstly, the approach establishes a two-degree-of-freedom single-track model with front and rear axle steering at the state reference layer to compute the desired yaw rate and mass center sideslip angle. Secondly, in the desired torque decision layer, a sliding mode control-based strategy is used to calculate the desired total driving torque. Thirdly, in the torque distribution layer, the optimal control distribution is adopted to carry out two initial distributions and redistribution of the drive torque planned by the upper layer, to improve the yaw stability of the six-wheeled lunar rover. Finally, a multi-body dynamics simulation platform for the six-wheel lunar rover is built using the open-source multi-physics simulation engine Chrono, exploring its dynamic behavior in soft ground conditions. Various operating scenarios are tested to verify the effectiveness, reliability, and safety of the designed coordinated control strategy. This research provides a reference for the design and control strategies of lunar rovers in future lunar exploration missions and offers guidance for the design and motion control of extraterrestrial planetary surface exploration vehicles.

Liu, Pengcheng, Zhang, Kaidi, Shi, Junwei, Yang, Wenmiao, Zhang, Yunqing, Wu, Jinglai

Rough Road Vehicle Dynamics Analysis for Vehicle Vibration Assessment

2025-01-8306

4/1/2025

This study is to demonstrate a vehicle dynamics simulation process to assess vehicle vibration performance. A vehicle dynamics model including non-linear tuning elements and flexible vehicle body is simulated on ride roads. The goal of the simulation is acceleration responses at the passenger locations in frequency domain. Body interface loads are recovered from the vehicle dynamic simulations. Frequency response function (FRF) of the body structure is ready in a fashion that input forces are applied to all body interface locations to the suspension and powertrains. This will give acceleration response sensitivity of the body structure to each body interface. The sum of body interface loads multiplied by FRF at each interface produces acceleration responses in frequency domain. A mid-size sedan model was used to demonstrate the process. A full vehicle dynamics model using Ansys Motion was simulated on a virtual ride road at a constant speed. The body loads were recovered in time domain and Fast Fourier Transformed (FFT) to convert them in frequency domain. The Body-In-white model was run a harmonic analysis to get body FRF. Python code was used to automate data communication and acceleration response calculation. The vehicle acceleration performance at the passenger locations is plotted in frequency domain. This process successfully demonstrated vehicle vibration performance at driver positions in terms of suspension tuning. It can make several design recommendations not available in the 100% vehicle dynamics approach, where the accelerations from the passenger locations are obtained from the same vehicle dynamics simulation. Not mentioning acceleration performance in frequency domain, it can pinpoint contributions of each load path from body interface points to the passenger locations. The contribution from each load path enables engineers to explore the design compromises: the most cost effective or the most timing effective design changes or both.

Hong, Hyung-Joo, Maddula, Pavan Kumar, Jun, Hyochan

Research on Control Algorithm for Active Rear Wheel Steering System of Passenger Cars

2025-01-8755

4/1/2025

With the continuous development of automobile technology, vehicle handling performance and safety have become increasingly critical research areas. The active rear-wheel (ARW) steering system, a technology that significantly enhances vehicle dynamics and driving stability, has garnered widespread attention. By coordinating front-wheel steering with rear-wheel angle adjustments, ARW improves handling flexibility and stability, particularly during high-speed driving and under extreme conditions. Therefore, designing an efficient ARW control algorithm and optimizing its performance are vital to enhancing a vehicle's overall handling capability. This study delves into the control algorithm design and performance optimization of ARW. First, a comprehensive vehicle dynamics model is constructed to provide a solid theoretical basis for developing control algorithms. Next, optimal control theory is applied to regulate the rear-wheel steering angle, and an LQR control strategy with variable weight coefficients is proposed to address the linear and nonlinear characteristics of tire lateral slip. Finally, comparative simulation verification is conducted using CarSim software, referencing a conventional front wheel steering (2WS) vehicle, a proportional steering control strategy for front and rear wheels, and a proportional feedforward plus yaw rate feedback control strategy. The results demonstrate that under conditions such as angle step inputs, double-lane change maneuvers, and limit double-lane changes on low-friction roads, the vehicle equipped with the LQR control strategy with variable coefficients achieves excellent control performance. The algorithm enhances stability and active safety, meeting all control objectives with objective and quantitative evaluation criteria.

Zhang, Yi, Zheng, Hongyu, Kaku, Chuyo, Zong, Changfu, Zhang, Yuzhou

Aerodynamic Effect on Vehicle Handling

2025-01-8754

4/1/2025

Vehicle handling is significantly influenced by aerodynamic forces, which alter the normal load distribution across all four wheels, affecting vehicle stability. These forces, including lift, drag, and side forces, cause complex weight transfers and vary non-linearly with vehicle apparent velocity and orientation relative to wind direction. In this study, we simulate the vehicle traveling on a circular path with constant steering input, calculate the normal load on each tire using a weight transfer formula, calculate the effect of lift force on the vehicle on the front and rear, and calculate the vehicle dynamic relation at steady state because the frequency of change due to aerodynamic load is significantly less than that of the yaw rate response. The wind velocity vector is constant while the vehicle drives in a circle, so the apparent wind velocity relative to the car is cyclical. Our approach focuses on the interaction between two fundamental non-linearity’s: the nonlinear aerodynamic forces and the nonlinear relationship between tire lateral force, attack angles, and normal loads. Real-time calculation of the understeer coefficient is performed as the vehicle traverses the circular path. We then compared how yaw rate, tire slip angles, and understeer changed for different types of cars (neutral, understeer, and oversteer) at various car and wind speeds. The understeer car showed high variation as at certain speeds the vehicle switched from understeer to slight oversteer due to loss of traction at rear tires.

Patil, Harshvardhan, Williams, Daniel

A Study of Tire Handling and Ride Performance Map According to Tire Tread Wear State

2025-01-8760

4/1/2025

The electric vehicle market, vehicle ECU computing power, and connected electronic vehicle control systems continue to grow in the automotive industry. The results of these advanced and expanded vehicle technologies will provide customers with increased cost savings, safety, and ride quality benefits. One of these beneficial technologies is the tire wearing prediction. The improved prediction of tire wear will advise a customer the best time to change tires. It is expected that this prediction algorithms will be essential part for both the optimization of the chassis control systems and ADAS systems to respond to changed tire performance that varies with a tire’s wear condition. This trend is growing, with many automakers interested in developing advanced technologies to improve product quality and safety. This study is aimed at analyzing the handling and ride comfort characteristics of the tire according to the depth of tire pattern wear change. The handing and ride comfort characteristics were measured on several tire test rigs for analysis and the vehicle dynamics simulation was conducted to help understand how vehicle performance varies with tire wear conditions.

Kim, Changsu, Kwon, Seungmin, Sung, Dae-Un, Ryu, Yonghyun, Ko, Younghee

Modal Analysis Approach for Analysis and Design of Vehicle Transient Behavior

2025-01-8794

4/1/2025

In order to manage the serious global environmental problems, the automobile industry is rapidly shifting to electric vehicles (EVs) which have a heavier weight and a more rearward weight distribution. To secure the handling and stability of such vehicles, understanding of the fundamental principles of vehicle dynamics is inevitable for designing their performance. Although vehicle dynamics primarily concerns planar motion, the accompanying roll motion also influences this planar motion as well as the driver's subjective evaluation. This roll motion has long been discussed through various parameter studies, and so on. However, there is very few research that treats vehicle sprung mass behavior as “vibration modes”, and this perspective has long been an unexplored area of vehicle dynamics. In this report, we propose a method to analytically extract the vibration modes of the sprung mass by applying modal analysis techniques to the governing equations of vehicle handling and stability. Specifically, we solve the general eigenvalue problem of the system to obtain complex eigenvalues and complex eigenvectors, use these to decouple the original equations of motion, and reconstruct the original vehicle behavior by superimposing each analytically solved vibration mode. As a result, it was revealed that the sprung mass behavior of the vehicle consists of two fundamental modes: “Mode 1,2,” which are primarily roll motions excited by front lateral forces, and “Mode 3,4,” which are planar motions excited by rear lateral forces coupled with roll. Furthermore, an analysis of the causal relationship between design variables and vibration modes reveals that during the initial roll response at turn-in, Mode 1,2 promote roll, whereas Mode 3,4 suppress it, making the rise gradual, or that design modification that delays planar motion associated with Mode 3,4 results in a two-stage increase in roll response, elucidating mechanisms of phenomena that could previously be understood only through parameter studies.

Kusaka, Kaoru, Yuhara, Takahiro

Fuzzy Sliding Mode Control of Intelligent Electric Vehicles Based on Phase Plane Stability Domain Boundaries

2025-01-8802

4/1/2025

In order to effectively improve the chassis handling stability and driving safety of intelligent electric vehicles (IEVs), especially in combing nonlinear observer and chassis control for improving road handling. Simultaneously, uncertainty with system input, are always existing, e.g., variable control boundary, 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 prescribed performance control strategy of IEVs become a hot topic in both academia and industry. To issue the above mentioned, a fuzzy sliding mode control method based on phase plane stability domain is proposed to enhance the vehicle’s chassis performance during complex driving scenarios. Firstly, a two-degree-of-freedom vehicle dynamics model, accounting for tire non-linearity, was established. Secondly, combing with phase plane theory, the stability domain boundary of vehicle yaw rate and side-slip phase plane based on vehicle dynamic model was drew in real time. The boundary was validated with a high-fidelity CarSim® software. Thirdly, combining fuzzy logic and sliding mode control, a fuzzy sliding mode controller based on dynamically identified phase boundary was designed. The stability of the algorithm was validated using Lyapunov theory. Finally, using a cooperative platform of CarSim and Matlab/Simulink, the proposed approach was presented under sinusoidal and J-Turn conditions. Results confirm that the proposed fuzzy sliding mode control method based on phase plane stability domain significantly improves the vehicle’s chassis handling stability and driving safety under various conditions. The research achievements develop a reasonable algorithm to apply to the improving road handling and ride comfort performance for a IEVs.

Liao, Yinsheng, Wang, Zhenfeng, Guo, Fenghuan, Deng, Weili, Zhang, Zhijie, Zhao, Binggen, Zhao, Gaoming

Optimized Design and Analysis of a High-Performance, Track-Focused Quad Bike for the Indian Market

2025-28-0061

2/7/2025

This paper presents a complete approach to the optimized design and analysis of a trach-focused quad bike suitable for the Indian market. The process of design integrates several analytical factors, including driver ergonomics, aesthetics, and strategic component placement, to establish optimum vehicle dimensions. The primary objective is to address the unique demands of the Indian terrain and user preferences through ensure comfort, functionality, and visual appeal. The selection process for tires and suspension geometry is precisely conducted with the advanced OptimumKinematics software. This optimization provides greater performance and stability that the vehicle can accurately manage a variety of road conditions. The space frame chassis of a vehicle’s core structure features, engineered to minimalize tubing and facilitate ease of fabrication, contributing to both structural integrity and weight reduction. A robust 600cc four-cylinder engine is selected that emphasizing an optimal power-to-weight ratio, guarantees both swiftness and power. Superior stopping distance achieved by carefully design the braking system to enhance safety and control. This project’s engineering focuses to meet rigorous performance and durability standards by the detailed design and analysis of structural components using SolidWorks software. Meticulously designed the suspension dynamics to enhance the handling and ride comfort. The stability during high-speed manoeuvres accomplished with the diligence results in a vehicle with a low center of gravity. Extreme torsional and bending stiffness is provided to chassis while designing to ensure that the vehicle remains rigid under various stresses. Structurally strong components, agile handling, and robust performance in quad bike resulted so far characterised by its lightweight. The speed, safety, and durability are essentially balanced by the design and making it an ideal for track focused devotees in the Indian market.

Thanikonda, Praveen Kumar, Shaik, Amjad, Tappa, Raju, Ratlavath, Ramu, Navar, Adarsh, Challa, Ajith Kumar

Feedforward Control of Clamping Force in Electronic Mechanical Brake System Based on Inertia Identification and Load Torque Observation

2025-01-7051

1/31/2025

The braking system is an essential element for ensuring the safe operation of vehicles. This research investigates the influence of electronic mechanical brakes on the control performance of permanent magnet synchronous motors, with a particular focus on variations in the load torque and inertial load. This study addresses challenges such as delayed responses in the clamping force and diminished control accuracy. To mitigate these issues, a Luenberger load torque observer is utilized for the real-time identification of load torque. The identified load torque is subsequently converted into a compensation current, which is integrated into the current loop as a feed-forward compensation signal to enhance the control performance. Additionally, to reduce the impact of variations in inertial load on the overall control system, this study employs a model reference adaptive algorithm for the online identification of rotational inertia, with the identification results being fed back to the load torque observer. The efficacy of this approach was validated through the development of a corresponding simulation model. Simulation outcomes indicate that the proposed strategy for identifying rotational inertia and implementing load torque feed-forward compensation significantly enhances the accuracy of clamping force control and the system's resistance to interference in electromechanical brakes, thereby offering a novel technical pathway for achieving high-precision brake control.

Wan, Xiaobo, Shang, Ruipeng, Li, Yingchun

Design of Electric Power Steering Control for Compensating the Torque Steer Effect due to Torque Vectoring Control

10-09-02-0010

1/24/2025

The increased popularity of electric vehicles featuring distributed powertrains is enabling an easy and cost-effective implementation of torque vectoring. This is a renowned technique for controlling vehicle lateral dynamics having the objective of improving both vehicle handling and stability. Nevertheless, the application of torque vectoring at the front axle can increase the difficulty of usual driving tasks. This is because differential longitudinal forces at front tires generate a steering wheel torque, which can be badly perceived by the driver, up to the point of jeopardizing the benefits of having a torque vectoring control. The aim of this article is thus to study in detail the steering torque corruption caused by front axle torque vectoring for proposing some electric power steering control strategies compensating for this effect. Indeed, the electric power steering controllers developed in this study are designed based on the analytical derivation of the torque steer theory, which comprehensively highlights the contribution of each tire contact action to the steering torque. This innovative approach allows including the effect of front axle yaw moment in the generation of the steering feedback, which is currently neglected in the literature. Driver-in-the-loop simulations at a dynamic driving simulator are adopted for assessing the suitability of the proposed electric power steering control strategies in restoring proper steering feedback when the vehicle is featuring torque vectoring capabilities at the front axle. Moreover, different knowledge levels about the vehicle states are considered in the proposed electric power steering control strategies, proving that the compensation strategy can be effectively deployed even in production vehicles, which require the estimation of some key parameters for the torque steer theory, such as tire contact forces.

Asperti, Michele, Vignati, Michele, Sabbioni, Edoardo

Tire Change Influence on Handling Performance

2024-36-0004

12/20/2024

The tire is one of the components that is most influent on vehicle dynamics behavior and is a part that suffer wear and needs to be replaced. In this case what a doubt is always recurrent, keep the same tire or change the model or brand but keeping the sizes. Some vehicle owners want to change not only the worn-out tire but change its sizes for aesthetic proposals. There is a belief on the tire market if keeps the same outer diameter is acceptable. The proposal for this study is to compare the handling performance considering different sizes and models or brands of tires. For this study a vehicle modeled in multibody representing the vehicle mass inertias, suspension mechanisms kinematics and components dampers and stiffness will be the adopted tool. The constant radius and constant speed steady state maneuver defined by standard SAE J266 [1] was performed, on the virtual environment, changing the tire properties and comparing the key handling performance metrics as understeer gradient, roll gradient and steering sensitivity. With the interpretation of theses metrics is possible to understand if the tire change in terms of size or brand could influence on vehicle handling performance.

Terra, Rafael Tedim, Chaves, Marilia, Santos, Alex Cardoso

Real Time Vehicle State Estimation Using Error Map Function

2024-28-0266

12/5/2024

The estimation of vehicle handling and control parameters in dynamic conditions is challenging due to errors and delays in real-time data logging with low-resolution onboard sensors. These issues significantly impact the performance of vehicle stability and control algorithms, particularly in vehicles under testing. This study presents error mapping concept parallel to statistical error method for real-time vehicle state estimation that addresses the limitations of low-resolution sensors with errors and delays in measured signal. In this study, a real-time (RT) model is developed and trained with in-house electric SUV to estimate yaw velocity and slip angle. The model leverages other measured signals available from the vehicle’s onboard sensor setup. It integrates an error and delay function with error predictive model to estimate the targeted parameter signal response in real time. The RT model introduces an error function method that enhances prediction accuracy by combining the error map value with the error weight of the target signal. The error function for the target signal filters systematic and trend errors from vehicle measurement data, accounting for vehicle specifications and environmental conditions. The error model generalizes to predict target signal errors under various maneuvers. Model training and error mapping is iterative, have performed using on-track test logs from two data sources. In each iteration, the error map is refined by assigning error weights to parameters, making the model adaptive to evolve error characteristics in future training sessions. This process can enhance the model's accuracy and reliability across different driving conditions. The initial model validation has been performed with ISO ramp steer and ISO chirp tests, demonstrate the direction and scope for enhancing real-time vehicle state estimation using error map function at lower cost.

Kumar, Avinash, Asthana, Shivam, Rasal, Shraddhesh, M, Sudhan, Vellandi, Vikraman

Parametrized Twist Beam Suspension for Enhanced Ride and Handling: A Design Iteration Approach

2024-28-0181

12/5/2024

The parametrized twist beam suspension is a pivotal component in the automotive industry, profoundly influencing the ride comfort and handling characteristics of vehicles. This study presents a novel approach to optimizing twist beam suspension systems by leveraging parametric design principles. By introducing a parameter-driven framework, this research empowers engineers to systematically iterate and fine-tune twist beam designs, ultimately enhancing both ride quality and handling performance. The paper outlines the theoretical foundation of parametrized suspension design, emphasizing its significance in addressing the intricate balance between ride comfort and dynamic stability. Through a comprehensive examination of key suspension parameters, such as twist beam profile, material properties, and attachment points, the study demonstrates the versatility of the parametric approach in tailoring suspension characteristics to meet specific performance objectives. To validate the effectiveness of this method, the research presents a series of case studies in which parametric variations are applied to existing twist beam suspension designs. The results reveal substantial improvements in ride comfort and handling dynamics, highlighting the potential for this approach to revolutionize suspension system development. In conclusion, the parametrized twist beam suspension approach offers a promising avenue for automotive engineers to achieve optimal ride and handling characteristics through systematic design iteration. By providing a structured framework for parameter adjustments, this research contributes to the advancement of suspension technology, ultimately leading to safer, more comfortable, and better-performing vehicles.

Pakala, Pradeep Kumar, Ganesh, Lingadalu

Continuous Curvature Parking Path Planning for Unmanned Mining Trucks Using Transition Curves and Model Predictive Control

02-18-01-0003

11/15/2024

Geometric methods based on Reeds–Shepp (RS) curves offer a practical approach for the parking path planning of unmanned mining truck, but discontinuous curvature can cause tire wear and road damage. To address this issue in mine scenario, a continuous curvature parking path planning method based on transition curve and model predictive control (MPC) is proposed for mine scenarios. Initially, according to the shovel position information issued by the cloud dispatching platform, a reference line is planned using RS curves. In order to mitigate the wear and tear of the tires and the damage to unstructured roads due to the in situ steering caused by the sudden change of the curvature, a transition curve consisting of clothoid–arc–clothoid that satisfies the kinematics of continuous vehicle steering is designed on the basis of RS curves to achieve the continuity of road curvature, which will contribute to the economy of tire and handling performance. The calculation of Fresnel integral involved by clothoid is simplified by using Chebyshev polynomial fitting method. Moreover, MPC is employed to re-plan an obstacle-avoidance path based on the reference line by designing a rational cost function. Finally, a simulation test platform is built considering the typical parking scenarios for unmanned mining trucks. The simulation results verify the effectiveness of the planning algorithm proposed in this article, and it shows the potential to reduce maintenance costs and improve mining efficiency.

Zhang, Haosen, Chen, Qiushi, Wu, Guangqiang

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