Browse Topic: Roll

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Necessity of Body Torsional Rigidity of Personal Mobility Vehicles (PMVs) with an Inward Tilting Mechanism2024-32-001304/18/2025
In traditional four-wheeled automobiles, the imbalance between the roll moment, which is the product of the centrifugal force during a turn acting on the center of gravity and the height of the center of gravity, and roll stiffness, which is the product of the left-right difference in tire vertical load and the tread width and commonly used among automotive suspension engineers, of the front and rear sections necessitates body torsional rigidity. However, there is a lack of specific cases and guidelines for constructing the body structure of three-wheeled PMVs (Personal Mobility Vehicles) with a tilting mechanism from the perspective of vehicle dynamics characteristics. In this paper, the basic considerations related to the dynamics of such three-wheeled PMVs are investigated. We use the term “torsional rigidity” to refer to the stiffness as the torsional deformation of the body itself, and the term “roll stiffness” to refer to the moment that counteracts the roll moment during a turn
Haraguchi, Tetsunori, Kaneko, Tetsuya
Impact of Toe and Thrust Angle Misalignment on Roll Behaviour of a Heavy Commercial Road Vehicle2024-26-005601/16/2024
Heavy Commercial Road Vehicles (HCRVs) may be more susceptible to rollover incidents due to their higher centre of gravity position than passenger vehicles, and rollover is one of the significant causes of HCRV accidents. Therefore, variation in vehicle roll behaviour becomes crucial to the safety of an HCRV. Toe misalignment is a commonly observed phenomenon in HCRVs, and studying its impact on roll behaviour is important. In this work, the impact of the symmetric toe and thrust misalignment on the roll behaviour of an HCRV is analysed using IPG TruckMaker®, a vehicle dynamics simulation software. A ramp steer manoeuvre was used for the simulations, and the toe misalignment on a wheel was chosen from the range [−0.21°, 0.21°]. Variation in roll behaviour was quantified using the steering wheel angle at which one-wheel lift-off (OWL) occurred (SWA_L). Additionally, an analytical model was formulated to predict OWL and the model predictions were compared with the results from IPG
Chandran, Amarchand, Grandhe, Roshan, Mukhopadhyay, Arko, Sharma, Mitanshu, Shankar Ram, C S
Nonlinear Observer for Estimating Gravity Vector and Flight Path Angles of a High-Performance Aircraft01-17-01-000708/14/2023
This paper proposes a nonlinear observer for the estimation of gravity vector and angles with respect to velocity vector (flight path angle, bank angle) of a high-performance aircraft. The technique is computationally simpler than the extended Kalman filter (EKF) and hence is suitable for onboard implementations when the digital flight control computer (DFCC) has computational burdens. Flight test data of a highly maneuvering flight such as wind-up turns and full rolls have been used to validate the technique.
Chandrasekaran, Kamali, Jain, Shikha
Performance Enhancement of Semi-active Continuous Skyhook Control Using Chaotic Map Particle Swarm Optimization-Based Stability Augmentation System15-16-01-000209/16/2022
Abstract Enhancing the performance of a ride-oriented algorithm to provide ride comfort and vehicle stability throughout different terrains is a challenging task. This article aims to improve the performance of the state-of-the-art continuous skyhook algorithm in coupled motion modes with an optimally tuned stability augmentation system (SAS). The tuning process is carried out using a chaotic map-initialized particle swarm optimization (C-PSO) approach with ride comfort and roll stability as a performance index. A large van model built-in CarSim is co-simulated with a C-PSO algorithm and control system designed in MATLAB. To realize the feasibility and effectiveness of the proposed system, a software-in-loop test is conducted on five complex ride terrains with different dominant vehicle body motion modes. The test results are compared against the passive system, four corner continuous skyhook control, and four corner type-1 fuzzy control. The test results confirm the effectiveness of
Rajasekharan Unnithan, Anand Raj, Subramaniam, Senthilkumar
Performance Enhancement of Semi-active Continuous Skyhook Control Using Chaotic Map Particle Swarm Optimization-Based Stability Augmentation System15-16-01-0002-TEST-REC09/16/2022
Abstract Enhancing the performance of a ride-oriented algorithm to provide ride comfort and vehicle stability throughout different terrains is a challenging task. This article aims to improve the performance of the state-of-the-art continuous skyhook algorithm in coupled motion modes with an optimally tuned stability augmentation system (SAS). The tuning process is carried out using a chaotic map-initialized particle swarm optimization (C-PSO) approach with ride comfort and roll stability as a performance index. A large van model built-in CarSim is co-simulated with a C-PSO algorithm and control system designed in MATLAB. To realize the feasibility and effectiveness of the proposed system, a software-in-loop test is conducted on five complex ride terrains with different dominant vehicle body motion modes. The test results are compared against the passive system, four corner continuous skyhook control, and four corner type-1 fuzzy control. The test results confirm the effectiveness of
Rajasekharan Unnithan, Anand Raj, Subramaniam, Senthilkumar
Parameters Optimization of a Double Gyroscope Concept for a Two-Wheel Vehicle15-15-02-000904/20/2022
Abstract The concept of making a two-wheeled self-stabilizing vehicle can be a possibility soon. These vehicles use control moment gyroscopes (CMGs) to provide enough torque for the vehicle to prevent it from rolling and falling to the ground. CMGs can be used with different numbers and configurations. In this article, the aim is to offer a design procedure for a double gyroscope system, which can be used for any two-wheel vehicle to be self-stabilized. The procedure is based on using optimization algorithms in reaching the optimum double gyroscope configuration for a certain two-wheel vehicle to reach a zero-degree roll angle in the least time possible, which is the novel part of the procedure. A design procedure for a double gyroscope with the yaw axis as a spinning axis for a two-wheel vehicle is offered. This procedure has been tested for both a small two-wheel robot and a two-wheel enclosed vehicle. The research method started with a presentation of motion equations, followed by a
Aboelsaoud, Mostafa, Taha, Ahmed Abdelsalam, Mabrouk, Mohamed Yasser, Aboelazm, Mohamed, Elgamal, Hassan
Parameters Optimization of a Double Gyroscope Concept for a Two-Wheel Vehicle15-15-02-0009-TEST-REC04/20/2022
Abstract The concept of making a two-wheeled self-stabilizing vehicle can be a possibility soon. These vehicles use control moment gyroscopes (CMGs) to provide enough torque for the vehicle to prevent it from rolling and falling to the ground. CMGs can be used with different numbers and configurations. In this article, the aim is to offer a design procedure for a double gyroscope system, which can be used for any two-wheel vehicle to be self-stabilized. The procedure is based on using optimization algorithms in reaching the optimum double gyroscope configuration for a certain two-wheel vehicle to reach a zero-degree roll angle in the least time possible, which is the novel part of the procedure. A design procedure for a double gyroscope with the yaw axis as a spinning axis for a two-wheel vehicle is offered. This procedure has been tested for both a small two-wheel robot and a two-wheel enclosed vehicle. The research method started with a presentation of motion equations, followed by a
Aboelsaoud, Mostafa, Taha, Ahmed Abdelsalam, Mabrouk, Mohamed Yasser, Aboelazm, Mohamed, Elgamal, Hassan
Three-axle Bus Handling Dynamics Evaluation Index2022-01-034103/29/2022
This paper evaluates the handling characteristics of three-axle bus by using the unique comprehensive vehicle handling evaluation index. With the theory of total variance, the generalized side-slip angle unified transfer function is introduced to derivate the evaluation indexes of reaction time, transition time, damping ratio and total variance considering the suspension roll steer and camber thrust. The three-axle bus suspension roll steer and camber thrust produces extra lateral force. The three-axle vehicle response degree following the step steer input is analyzed with the effect of suspension roll on three-axle bus by using the total variance approach. The vehicle designers could use this approach to get optimization design parameters of bus suspension. The unique total variance evaluation index considering the suspension roll steer is useful and could serve as an important tool for evaluating the effect of suspension roll on three-axle bus handling dynamics.
Ding, Jinquan
In-Depth Considerations for Electric Vehicle Braking Systems Operation with Steep Elevation Changes and Trailering2021-01-126310/11/2021
As the automotive industry prepares to roll out an unprecedented range of fully electric propulsion vehicle models over the next few years - it really brings to a head for folks responsible for brakes what used to be the subject of hypothetical musings and are now pivotal questions for system design. How do we really go about designing brakes for electric vehicles, in particular, for the well-known limit condition of descending a steep grade? What is really an “optimal’ design for brakes considering the imperatives for the entire vehicle? What are the real “limit conditions” for usage that drive the fundamental design? Are there really electric charging stations planned for or even already existing in high elevations that can affect regenerative brake capacity on the way down? What should be communicated to drivers (if anything) about driving habits for electric vehicles in routes with significant elevation change? The present work attempts to consolidate past published information and
Antanaitis, David
Novel Methodology to Compute Halfshaft Joint Forces and Virtually Simulate Powertrain Wiggle2021-01-066504/06/2021
Vibrations affect vehicle occupants and should be prevented early in design process. Powertrain (PT) wiggle is one of the well-known issues. It is the 3rd order lateral vibration, forced by half shaft inner LH/RH plunging tripod joints [1,2]. Lateral PT resonance (7-15Hz) occurs at certain vehicle speed during acceleration and may excite lateral, pitch and roll PT modes. Typically, PT wiggle occurs in speed range of 5-25kph. Vibration is noticeable on driver and passenger seats mostly in lateral direction. The inner half shaft joints are the major source of vibration. Unfortunately, existing MBD tools like Adams [3] are missing detailed tripod joint representation because of complex mechanical interactions inside the joint. At least three sliding contacts between tripod rollers and joint housing, lubricant inside the can and combination of rotation and plunging make the modeling too complicated. This paper is dedicated to provide a novel methodology in tripod joint modeling which
Opeiko, Alexandre, Paul, Abhishek, Vipradas, Aditya
Active roll stabilization introduced for Audi's large crossovers20AUTP10_0810/01/2020
Audi is fitting its largest crossover models with a new, active anti-roll system that the company said enhances cornering capability and reduces body roll without sacrificing ride comfort. Unlike other active anti-roll systems, Audi's electromechanical roll stabilization (eAWS) doesn't rely on hydraulics and is claimed to be “virtually maintenance-free.” Large crossovers and SUVs can be challenging to engineer with assertive vehicle dynamics because their weight and higher center of gravity typically mitigate against sporty cornering unless the suspension is uncomfortably stiff. But the powered anti-roll bars at each axle in the eAWS system permit a comparatively soft tune for the base suspension, firming cornering dynamics only when required.
Visnic, Bill
Hybrid Fuzzy-PID Control Development for a Truck Air Suspension System02-13-01-000405/11/2020
A hybrid fuzzy and proportional-integral-derivative (PID) controller is proposed for roll angle handling of a three-axle truck with an active air suspension system. The conventional truck suspension system has four air springs for the rear wheels and two leaf springs for the front wheels, which cannot properly control the pitch angle, and here in this study is upgraded into front air springs. Therefore in the full air suspension system, the pitch angle is controlled by the active suspension system. Roll reduction of a heavy vehicle can improve the ride comfort and rollover tendency of the truck, simultaneously. The relation of air spring pressures and vehicle dynamics is developed in a simple and accurate model. Using this comprehensive model, it is possible to control the variables of vehicle dynamics such as roll, pitch, and height of the truck. The truck air suspension system is examined in step steering, fishhook, and asymmetric rough road (types E and G power spectral density [PSD
Nazemian, Hossein, Masih-Tehrani, Masoud
3D Imaging the Biolocomotion of Fruit FliesTBMG-3687905/01/2020
The last thing you probably do when a fly buzzes toward you is marvel at its graceful wing and body kinematics. But that’s exactly what researchers at Cornell University’s Itai Cohen Group do on a daily basis.
SUV Kinematics during a Steer-Induced Rollover Resolved Using Consumer-Grade Video, Laser Scans and Match-Moving Techniques2020-01-064204/14/2020
Rollover crashes are complex events that generate motions in all six degrees of freedom (6DOF). Directly quantifying the angular rotations from video can be difficult and vehicle orientation as a function of time is often not reported for staged rollover crashes. Our goal was to evaluate the ability of using a match-moving technique and consumer-grade video cameras to quantify the roll, pitch and yaw angles and angular velocities of a rollover crash. We staged a steer-induced rollover of an SUV at 106 km/h. The vehicle was fitted with tri-axial accelerometers and angular rate sensors, and five consumer-grade video cameras (2 on tripods, 2 on drones, 1 handheld, ~30 fps) captured the event. Roll, pitch and yaw angles were determined from the video using specialized software. We then compared the vehicle orientation angles from the video data to the integrated angular rate data measured by onboard sensors, and also compared the angular rates from the differentiated video data to the
Young, Cole R., King, David J., Siegmund, Gunter P.
Micro-Mobility Vehicle Dynamics and Rider Kinematics during Electric Scooter Riding2020-01-093504/14/2020
Micro-mobility is a fast-growing trend in the transportation industry with stand-up electric scooters (e-scooters) becoming increasingly popular in the United States. To date, there are over 350 ride-share e-scooter programs in the United States. As this popularity increases, so does the need to understand the performance capabilities of these vehicles and the associated operator kinematics. Scooter tip-over stability is characterized by the scooter geometry and controls and is maintained through operator inputs such as body position, interaction with the handlebars, and foot placement. In this study, testing was conducted using operators of varying sizes to document the capabilities and limitations of these e-scooters being introduced into the traffic ecosystem. A test course was designed to simulate an urban environment including sidewalk and on-road sections requiring common maneuvers (e.g., turning, stopping points, etc.) for repeatable, controlled data collection. A commercially
Garman, Christina MR, Como, Steven G., Campbell, Ian C., Wishart, Jeffrey, O'Brien, Kevin, McLean, Scott
Alleviating the Magnetic Effects on Magnetometers Using Vehicle Kinematics for Yaw Estimation for Autonomous Ground Vehicles2020-01-102504/14/2020
Autonomous vehicle operation is dependent upon accurate position estimation and thus a major concern of implementing the autonomous navigation is obtaining robust and accurate data from sensors. This is especially true, in case of Inertial Measurement Unit (IMU) sensor data. The IMU consists of a 3-axis gyro, 3-axis accelerometer, and 3-axis magnetometer. The IMU provides vehicle orientation in 3D space in terms of yaw, roll and pitch. Out of which, yaw is a major parameter to control the ground vehicle’s lateral position during navigation. The accelerometer is responsible for attitude (roll-pitch) estimates and magnetometer is responsible for yaw estimates. However, the magnetometer is prone to environmental magnetic disturbances which induce errors in the measurement. The present work focuses on alleviating magnetic disturbances for ground vehicles by fusing the vehicle kinematics information with IMU senor in an Extended Kalman filter (EKF) with the vehicle orientation represented
Dudekula, Ahammad Basha, Naber, Jeffrey D.
The Effect of Obesity on Rollover Ejection and Injury Risks2020-01-121904/14/2020
Obesity rates are increasing among the general population. This study investigates the effect of obesity on ejection and injury risk in rollover crashes through analysis of field accident data contained in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database. The study involved front outboard occupants of age 15+ years in 1994+ model year vehicle rollover crashes. Occupants were sorted into two BMI groups, normal (18.5 kg/m2 ≤ BMI < 25.0 kg/m2) and obese (BMI ≥30 kg/m2). Complete and partial ejection risks were first assessed by seating location relative to roll direction and belt use. The risk of serious-to-fatal injuries (MAIS 3+F) in non-ejected occupants were then evaluated. The overall risk for complete ejection was 2.10% ± 0.43% when near-sided and 2.65% ± 0.63% when far-sided, with a similar risk for both the normal and obese BMI groups. Complete ejection was highest for unbelted occupants, irrespective of BMI, and uncommon for belted occupants
Parenteau, Chantal, Smedley, Janine, Carhart, Michael, Dibb, Alan
Investigation of the Effect of Tire Deformation on Open-Wheel Aerodynamics2020-01-054604/14/2020
This paper introduces a finite element (FE) approach to determine tire deformation and its effect on open-wheeled racecar aerodynamics. In recent literature the tire deformation was measured optically using cameras during wind tunnel testing. Combined loads like accelerat-ing at corner exit are difficult to reproduce in wind tunnels and would require several camer-as to measure the tire deformation. In contrast, an FE approach is capable of determining the tire deformation in combined load states accurately and additionally provides the possibility to vary further parameters, for example, the coefficient of friction. The FE tire model was validated using stiffness measurements, contact patch measurements and steady-state cornering measurements on a flat belt tire test rig. The deformed shape of the FE model was used in a computational fluid dynamics (CFD) simulation. A sensitivity study was created to determine the effect of the tire deformation on aerodynamics for un-loaded, purely
Eder, Philipp, Gerstorfer, Thomas, Lex, Cornelia, Amhofer, Thomas
Motorcycle Out-Of-Plane Dynamics Estimation:2019-32-057801/24/2020
This paper presents a study on the state estimation of out-of-plane dynamics of motorcycles based on the Sharp 71 model. The Sharp 71 model is a linear time-variant system that describes the out-of-plane dynamics of a motorcycle. Comparisons with multi-body simulations and measurement data show that this relatively simple model is capable of principally representing the lateral dynamics of the motorcycle. Two relevant variables of out-of-plane dynamics are the roll angle and the tire lateral forces. The structure of the Sharp 71 model offers the possibility of estimating these two variables model-based with the aid of corresponding measured output variables. The input variable is the steering torque, which obviously cannot be measured with reasonable effort. Therefore, an unknown-input observer is used to estimate the states. This state estimator allows a systematic consideration of the unknown input variable. The unknown-input observer is designed for different sets of outputs and the
Winkler, Alexander, Haas, Sandra, Grabmair, Gernot
Countering the Destabilizing Effects of Shifted Loads through Pneumatic Suspension Design10-04-01-000111/08/2019
This article proposes a novel approach to reduce the destabilizing impacts of the shifted loads of heavy trucks (due to improper loading or liquid slosh) by pneumatic suspension design. In this regard, the pneumatically balanced suspension with dual leveling valves is introduced, and its potential for the improvement of the body imbalance due to the shifted load is determined. The analysis is based on a multi-domain model that couples the suspension fluid dynamics, shifted-load impacts, and tractor-semitrailer dynamics. Truck dynamics is simulated using TruckSim, which is integrated with the pneumatic suspension model developed in AMESim. This yields a reasonable prediction of the effect of the suspension airflow dynamics on vehicle dynamics. Moreover, the ability of the pneumatic suspension to counteract the effects of two general shifted loads - static (rigid cargo) and dynamic (liquid) - is studied. The simulation results indicate that the dual-leveling-valve suspension results in a
Chen, Yang, Ahmadian, Mehdi
New-generation Nissan Versa breaks for higher ground19AUTP10_1410/01/2019
Subcompact cars hardly are spotlight-grabbers at the moment, but Nissan's nonetheless delivered up an all-new 2020 Versa that notches higher fuel economy, quicker acceleration, tighter S-curve poise and a quieter cabin compared to the outgoing Versa. “Nissan's third-generation Versa is well-balanced in terms of performance, handling, and ride comfort,” Jose Romo, the car's marketability engineer, told Automotive Engineering during a recent media ride-and-drive program in Nashville, Tenn.
Buchholz, Kami
A Dictionary of Terms for the Dynamics and Handling of Single Track Vehicles (Motorcycles, Scooters, Mopeds, and Bicycles)J1451_201909 (Current)09/24/2019
Terminology within this document is limited to the dynamics and handling characteristics of single track, two-wheeled vehicles.
Motorcycle Technical Steering Committee
New Method for Decoupling the Powertrain Roll Mode to Improve Idle Vibration2019-01-158806/05/2019
Modern engines have high torque outputs and have low RPM due to increased demand for fuel efficiency. Vibrations caused by such engines have to be mitigated. Decoupling the roll mode from the remaining five rigid body modes results in a response which is predominantly about the torque roll axis (TRA) and helps reduce vibrations. Therefore, placing the mounts on the TRA early in the design phase is crucial. Best NVH performance can be obtained by optimizing the powertrain mount parameters viz; Position, Orientation and Stiffness. Many times, packaging restricts the mounts to be placed about the TRA resulting in degradation in NVH performance. Assuming that the line through the engine mount (Body side) centers is the desired TRA, we propose a novel method of shifting the TRA by adding mass modifying the powertrain inertia such that the new TRA is parallel to and on top to the desired TRA. This in turn will decouple the roll mode and reduce vibrations. This problem is formulated as an
Haider, Syed F., Abbas, Ahmad, Sturla, Francisco
Development of an Accelerated Test for Tire Flat-Spotting2019-01-150906/05/2019
Tire flat-spotting occurs when tires remain in a loaded condition without rolling for an extended period of time, and can be temporary or permanent depending on the length of storage, vehicle loading and environmental factors. Tire non-uniformity caused from flat-spots often induce shake and shimmy vibration in vehicles due to increased tire-wheel force variation input into the chassis. This results in increased warranty costs for OEMs and tire suppliers and customer dis-satisfaction in third-party quality surveys such as J. D. Power IQS. Flat-spotting is of particular concern for slow-moving vehicle inventory parked for long periods at plants and/or dealership lots. OEMs often stipulate or recommend inventory storage practices for dealers that require physical movement of vehicles at some set duration to reduce the risk of tires developing permanent flat-spots. OEMs also provide component level flat-spotting requirements to tire manufacturers during sourcing and specification timing
Kavarana, Farokh, Fritz, Scott
Driveline NVH Integration of An NA Truck Program2019-01-155906/05/2019
In the current automotive industry, it is common that the driveline subsystem and components are normally from different automotive suppliers for OEMs. In order to ensure proper system integration and successful development of driveline system NVH performances, collaboration efforts between OEMs and suppliers are very demanding and important. In this paper, a process is presented to achieve successfulness in developing and optimizing vehicle integration through effective teamwork between a driveline supplier and a major OEM. The development process includes multiple critical steps. They include target development and roll down, targets being specific and measurable, comprehension of interactions of driveline and vehicle dynamics, accurate definition of sensitivity, proper deployment of modal mapping strategy, which requires open data sharing; and system dynamics and optimization. More specially, the supplier can work with OEM to seek the most cost-effective solutions, through tuning
Peng, Ying, Shi, Zhenghong, Folts, Christopher, Kopp, Gregory, Sun, Zhaohui, Sandstrom, Alexander
Analysis of Rear Seat Sled Tests with the 5th Female Hybrid III: Incorrect Conclusions in Bidez et al. SAE 2005-01-17082019-01-061804/02/2019
Objective: Sled test video and data were independently analyzed to assess the validity of statements and conclusions reported in Bidez et al. SAE paper 2005-01-1708 [7]. Method: An independent review and analysis of the test data and video was conducted for 9 sled tests at 35 km/h (21.5 mph). The 5th female Hybrid III was lap-shoulder belted in the 2nd or 3rd row seat of a SUV buck. For one series, the angle was varied from 0, 15, 30, 45 and 60 deg PDOF. The second series involved shoulder belt pretensioning and other belt modifications. Results: Bidez et al. [7] claimed “The lap belts moved up and over the pelvis of the small female dummy for all impact angles tested.” We found that there was no submarining in any of the tests with the production lap-shoulder belts. Bidez et al. [7] claimed “H3-5F dummies began to roll out of their shoulder belt at… 30 degrees. Complete loss of torso support was seen at 45 degrees without significant kinetic energy dissipation.” We found that the
Viano, David, Parenteau, Chantal
Differential Speed Steering Control for Four-Wheel Distributed Electric Vehicle2019-01-123504/02/2019
In order to perform differential control instead of the mechanical differential and improve the steering performance of distributed electric vehicles, a two-level differential speed steering control strategy is proposed. Firstly, an upper-layer controller to track the yaw rate is designed based on PID feedback and 3-D lookup table model, which could shorten the response time and reduce the impact of model parameters mismatch. Then, in order to improve the robustness to external disturbances and parameter uncertainties, a lower-layer controller to track the wheel speed is proposed based on integral sliding mode control. Moreover, three simulations are conducted to validate the proposed strategy. The first simulation results indicate that the driving torques of the inner and outer wheels are distributed properly to avoid wheel slip. In the second simulation, when the conventional steering system fails, the proposed control strategy could avoid vehicle losing steering function. The last
Liu, Zhiting, Pei, Xiaofei, Chen, Zhenfu, Yang, Bo, Guo, Xuexun
Bolts, Screws, and Studs, Screw Thread RequirementsAS3062D (Current)02/13/2019
E-25 General Standards for Aerospace and Propulsion Systems
Safety and Comfort for All: An affordable Hill-Hold and Automated Parking Brake System2019-26-000501/09/2019
With an ever-increasing number of vehicles on Indian roads, the safety and ease of driving has become a very important criterion for the customers. In passenger and commercial vehicles, while launching a vehicle on gradient or stop and go traffic in hilly region, the vehicle tends to roll back/forward in the opposite direction of the intended movement. This undesirable movement is also a safety issue, as this may cause collision with the vehicle on the rear or in front. It requires a skilled driver to coordinate between the clutch pedal, brake (also handbrake in some situations) and accelerator pedal to prevent the vehicle from rolling back while handling such situations. It also leads to clutch disc wear and heating as the driver may tend to slip the clutch to prevent the vehicle from rolling back. Hill hold is a driver assist feature which prevents the vehicle roll back/roll forward during launch operation on uphill/downhill conditions. Hill-hold is offered as an add-on feature on
Iyer, Ramkumar, Awade, Yogesh, Doshi, Pritesh, Dabhade, Abhishek, Jadhav, Vinod
Study on Weave Behavior Simulation of Motorcycles Considering Vibration Characteristics of Whole Body of Rider2018-32-005210/30/2018
In motorcycles, the mass difference between a vehicle and a rider is small and motions of a rider impose a great influence on the vehicle behaviors as a consequence. Therefore, dynamic properties of motorcycles should be evaluated not merely dealing with a vehicle but considering with a man-machine system. In the studies of a simulation for vehicle dynamics, various types of rider models have been proposed and it has already been reported that rider motions have a significant influence on the dynamic properties. However, the mechanism of the interaction between a rider and a vehicle has not been clarified yet. In our study, we focused on weave motion and constructed a full vehicle simulation model that can reflect the influences of the movements of the rider’s upper body and lower body. To construct the rider model, we first measured the vibrational characteristics of a human body using a vibration test bench. Based on the measured data, 26 degrees of freedom was determined as the
Uchiyama, Hajime, Tanaka, Kenichi, Nakagawa, Yoshihiro, Kinbara, Eiji, Kageyama, Ichiro
Assessing Tire Performance from Vehicle Dynamic Transfer Functions2018-32-004810/30/2018
The aim of this study is to develop techniques which can be used to assess tire performance for a motorcycle in a race track and correlate them with subjective perceptions of race riders. This approach focusses on using vehicle level performance parameters and transfer functions to assess tire performance. A subjective assessment study is performed to understand rider’s perception. Tire behavior is then studied by assessing the dynamic performance of the motorcycle in a race track. Analysis techniques are then developed to interpret the data measured and understand tire performance. Based on these techniques, vehicle dynamic parameters and transfer functions that can be used to asses tire performance are developed. Correlations between objective findings and subjective perceptions are then identified. These studies show that the choice of a tire in a race track is not only decided by tire grip but also by factors like steering effort, roll rates and feedbacks perceived by the rider
Mohan, Barath, Velagapudi, Sai Praveen, Raju, KVM
Theoretical and Fundamental Consideration to Accord between Self-Steer Speed and Rolling in Maneuverability of Motorcycles2018-32-004910/30/2018
This paper considers the phenomenon that the self-steer speed when riders bank a motorcycle. This paper points out that this phenomenon originates from capsize mode. Further, it is specified that the first order differential equation representing capsize mode is included in the equation of motion of the steering system. Furthermore, it is specified that this differential equation is the first order differential equation for the roll angle. Therefore, as the roll angle increases, the roll angle further increases and the steering angle also changes, which is the mechanism of capsize mode. Finally, as a result of parameter studies, it is stated that the design parameters that most affect capsize mode were front and rear camber stiffness.
Sakai, Hideki
Bolts, Screws and Studs, Screw Thread RequirementsAS3062C (Historical)08/23/2018
E-25 General Standards for Aerospace and Propulsion Systems
Comparison of Active Front Wheel Steering and Differential Braking for Yaw/Roll Stability Enhancement of a Coach2018-01-082004/03/2018
Both active front wheel steering (AFS) and differential braking control (DBC) can improve the vehicle handling and stability. In this article, an AFS strategy and a DBC strategy are proposed and compared. The strategies are as follows: A yaw instability judging module and a rollover instability judging module are put forward to determine whether the coach is in a linear state and whether the additional torque/angle module should be actuated. The additional torque module based on linear quadratic regulator (LQR) and the additional steering wheel angle module based on adaptive proportion integral differential (PID) fuzzy controller are designed to make the actual yaw rate and sideslip angle track the reference yaw rate and sideslip angle. Under some typical driving conditions such as sinusoidal, J-turning, crosswind, and straight-line brake maneuver on the μ-split road, simulation tests are carried out for the coach with no control, DBC strategy, and AFS control, respectively. The
Zheng, Hongyu, yangyang, miao, Wang, Linlin, Zhang, Jiaxu
Ride Comfort Enhancement Using Active Stabilizer2018-01-056304/03/2018
Ongoing research on active stabilizers involves not only control of the roll angle of the vehicle based on steering input but also improving ride comfort by reducing roll vibration caused by the antiphase road surface input. In that context, roll skyhook control, which applies skyhook theory to provide feedback on the vehicle roll and drive the actuators, has already been presented. Although vibration in all frequency bands can be reduced if there is no control delay, time lags or phase delays in control elements such as the communication, computation, low-pass filter, or actuators can amplify vibration. Consequently, a sufficient effect of controlling cannot be obtained. This paper will address wheelbase filtering, which produces a frequency that minimizes roll oscillation, and is used to suppress the influence of the undesirable vibration. Control signal filters considering roll-lateral coupled motions were designed, and an experiment with an actual vehicle was conducted to confirm
Fujii, Daigo, Yabumoto, Hirokazu, Koumura, Shingo
Study of Riding Assist Control Enabling Self-standing in Stationary State2018-01-057604/03/2018
In motorcycles traveling at medium to high speed, roll stability is usually maintained by restoration forces generated by a self-steering effect. However, when the vehicle is stationary or traveling in low speed, sufficient restoring force does not occur because some of the forces, such as centrifugal force, become small. In our study, we aimed at prototyping a motorcycle having roll stability when the vehicle is stationary or at low speed with a steering control for self-standing assist, while maintaining stability properties in medium to high speed. A model was built to represent dynamics of roll motion, which is composed of a fixed point mass located above the vehicle’s center of gravity and another movable point mass below that gravity center. According to the model, when steered, the roll moment direction generated by the shift of the movable point mass becomes the same as the direction generated by the ground contact point shift of the front tire. Thus, the total roll moment is
Araki, Makoto, Akimoto, Kazushi, Takenaka, Toru
Fuzzy Observer for Nonlinear Vehicle System Roll Behavior with Coupled Lateral and Vertical Dynamics2018-01-055904/03/2018
The study of vehicle state estimation performance especially on the aspect of observer-based control for improving vehicle ride comfort and road handling is a challenging task for vehicle industry. Since vehicle roll behavior with various road excitations act an important part of driving safety, how to accurately obtain vehicle state under various driving scenes are of great concern. However, previous researches seldom consider coupling relation between vehicle vertical and lateral response with steering input under various road excitation. To address this issue, comprehension analyses on vehicle roll state estimation with coupled input are present in this paper. A full-car nonlinear Takagi-Sugeno (T-S) fuzzy model is first created to describe vehicle lateral and vertical coupling dynamics. Then, a T-S model-based fuzzy observer design approach is used to estimate the vehicle state considering nonlinear coupling dynamics of tire lateral force and semi-active suspension actuator force
Wang, Zhenfeng, Dong, Mingming, Qin, Yechen, Wang, Zhenyu, Xu, Tao, Shi, Xiaoyan, Gu, Liang
An Analytical Review and Extension of Two Decades of Research Related to PC-Crash Simulation Software2018-01-052304/03/2018
PC-Crash is a vehicular accident simulation software that is widely used by the accident reconstruction community. The goal of this article is to review the prior literature that has addressed the capabilities of PC-Crash and its accuracy and reliability for various applications (planar collisions, rollovers, and human motion). In addition, this article aims to add additional analysis of the capabilities of PC-Crash for simulating planar collisions and rollovers. Simulation analysis of five planar collisions originally reported and analyzed by Bailey [2000] are reexamined. For all five of these collisions, simulations were obtained with the actual impact speeds that exhibited excellent visual agreement with the physical evidence. These simulations demonstrate that, for each case, the PC-Crash software had the ability to generate a simulation that matched the actual impact speeds and the known physical evidence. Simulation of a full-scale rollover test reported by Asay [2010] is also
Rose, Nathan A., Carter, Neal
Multi-Objective Optimization to Improve SUV Ride Performances Using MSC.ADAMS and Mode Frontier2018-01-057504/03/2018
Ride is an important attribute which must be accounted in the passenger segment vehicles. Excessive H point acceleration, Steering wheel acceleration, Pitch acceleration can reduce the comfort of the driver and the passengers during high frequency and low frequency rough road events. Excessive Understeer gradient, roll gradient, roll acceleration and Sprung mass lift could affect the Vehicle driver interaction during Steady state cornering, Braking and Step steer events. The concept architecture of the vehicle plays an important role in how comfort the vehicle will be. This paper discusses how to improve SUV ride performances by keeping handling performance attributes same or better than base vehicle. Multi Objective Optimization was carried out by keeping spring, bushing and damper characteristic as the design variables to avoid new system or component development time and cost. The first step in this process is DOE (Design of Experiments method) which allows to select critical or
Lenka, Visweswara Rao, Anthonysamy, Baskar, Londhe, Abhijit, Hatekar, Harshad
The Tire Characteristic Effect on Motorcycle Maneuverability Using a Riding Simulator2017-32-001811/05/2017
The stability factor is widely used for four-wheel vehicles as an index representing the turning performance of a vehicle. Stability factor for two-wheel vehicles has been proposed as an indicator of cornering performance from the same way of thinking. In line traceability evaluation as a sensory evaluation item of motorcycles, the expressions of understeer and oversteer are sometimes used, but the relation with stability factor for two-wheel vehicles has not been investigated. In this paper, a test in which the slip angle characteristics of the front and rear tires were varied using a riding simulator was conducted, and the correlation between the stability factor and the rider evaluation was investigated to derive an index showing the line traceability.
Miki, Masayuki, Kimura, Tetsuya
Investigation and Model-Based Compensation of the Pitch Dynamic Impact on Longitudinal Acceleration Measurement on Motorcycles2017-32-005311/05/2017
In this study we focus on systematic disturbances caused by the motorcycle pitch dynamic when measuring longitudinal acceleration on motorcycles using low-cost acceleration sensors. Major systematic influences in the sensor measurement like gravitational acceleration, suspension dynamics and the road slope are addressed. During acceleration phases the motorcycle pitch angle changes according to the suspension setting. As a result the longitudinal sensing axis of the accelerometer includes parts of the gravitational acceleration and lags parts of the longitudinal acceleration. Gravitational acceleration has also significant influence on inclined roads. To obtain correct values of the effective longitudinal acceleration, the disturbances in the measured signal are analyzed and in further consequence compensated. For this purpose a linearized in-plane-dynamics model of the motorcycle is derived from a comprehensive multibody simulation. The mathematical description of the motorcycle
Winkler, Alexander, Grabmair, Gernot
A Prediction Method of Fatigue Strength for Crankshaft Fillet Rolling Process2017-01-240610/08/2017
This work addresses the problem of fatigue strength prediction of crankshaft fillet rolling processes to improve its accuracy. It is empirical to usually consider the effect of fillet rolling process on crankshaft fatigue performance. The fatigue performance of rolling process is mainly determined by induced compressive residual stresses, increased hardness and reduced roughness. Because the first two factors are difficult to measure the arc surface of fillet rolled cranks, it is difficult to predict the enhanced rate of crankshaft rolled performance to baseline unrolled’s. In this work a prediction method of fatigue strength for ductile cast iron crankshafts rolling process is presented. This method indirectly predicts the effect of the increased hardness on fatigue performance by the resonant bending fatigue test and modelling of crankshaft fillet rolling dynamic for the induced compressive residual stress. The finite element (FE) model for the resonant bending fatigue test rig is
Yang, Wu, Yin, Xiuting, Zhan, Zhang Song, Shen, Huixian, Qing, Huibin, Zeng, Qingqiang, Kang, Liyun
Super-Hydrophobic Coatings as a Part of the Aircraft Ice Protection System2017-01-213909/19/2017
This paper reviews the current knowledge on super-hydrophobic coatings (SHC). Using an ideal super-hydrophobic surface patterned with identical cylindrical flathead posts forming a square network with constant periodicity, models are proposed to explain SHC, wear and ice adherence on SHC. The models demonstrate that SHC based on Cassie-Baxter state improve the bead mobility compared to SHC based on Wenzel state and more suitable for aircraft application. Their erosion resistance can be improved by increasing the post height and the hydrophobic material thickness. Their ice adhesion reduction factor (IARF) is better but SHC based on Cassie-Baxter state have a limitation to reduce ice adherence dependence on the surface pattern and IARF of the hydrophobic material. The bead mobility is calculated from advancing and receding water contact angles (WCA). The airflow test is recommended to measure the advancing and receding WCA because the test is more representative of phenomena observed
Fortin, Guy
Fatigue Performance Improvements of Wheel Bearing Rolling Elements2017-01-252409/17/2017
Wheel bearings are safety-critical automotive components. For this application, the steel rolling elements are subjected to fatigue failure and therefore play a key role in overall bearing fatigue life performance. This performance is influenced by metallurgical, mechanical, and physical properties obtained by precise manufacturing process parameters. These properties are continuously analyzed and are evolving at all bearing manufacturing companies. Last year, the Precision Bearing Components (PBC) Group of NN Inc., a global supplier of steel rolling elements for wheel bearings, developed a non-conventional heat treatment process for 100Cr6 (SAE 52100) rolling element steel for improved fatigue performance. The results of wheel bearing rolling contact fatigue (RCF) tests showed the importance of rolling element dimensional stability. As retained austenite transformed to the martensite phase, rolling element volume increase occurred, leading to fatigue failure. The fatigue life of
Rizzo, Sebastiano, Pagliassotto, Stefano
The Analysis of the Stiffness-Damping Parameters of a H-Bahn Vehicle2017-01-189006/05/2017
H-Bahn ("hanging railway") refers to the suspended, unmanned urban railway transportation system. Through the reasonable platform layout, H-Bahn can be easily integrated into the existing urban transit system. With the development of urban roads, the associated rail facilities can be conveniently disassembled, moved and expanded. The track beam, circuits, communication equipment, and sound insulation screen are all installed in a box-type track beam so that the system can achieve a high level of integration and intelligence. The carriage of the modern H-banh vehicle is connected with the bogies by two hanging devices. The vehicle is always running in the box-type track beam; therefore there are less possibilities of derailment. Consequently, the key work focuses on the running stability evaluation and curve negotiation performance analysis. In order to study the factors affecting running stability, the different stiffness and damping parameters in the primary and secondary suspension
Zhang, Xingyu, Yang, Bo, Zhang, Manchuang, Hu, Sanbao
Vibration Analysis of Rotating Tires Focused on Effect of Rotation Using a Three - Dimensional Flexible Ring Model2017-01-190306/05/2017
The tire is one of the most important parts, which influence the noise, vibration, and harshness of the passenger cars. It is well known that effect of rotation influences tire vibration characteristics, and earlier studies presented formulas of tire vibration behavior. However, there are no studies of tire vibration including lateral vibration on effect of rotation. In this paper, we present new formulas of tire vibration on effect of rotation using a three-dimensional flexible ring model. The model consists of the cylindrical ring represents the tread and the springs represent the sidewall stiffness. The equation of motion of lateral, longitudinal, and radial vibration on the tread are derived based on the assumption of inextensional deformation. Many of the associated numerical parameters are identified from experimental tests. Unlike most studies of flexible ring models, which have mainly discussed radial and circumferential vibration, this study presents eigen functions concerning
Matsubara, Masami, Tsujiuchi, Nobutaka, Ise, Tomohiko, Kawamura, Shozo
Torsional Vibration Analysis of Six Speed MT Transmission and Driveline from Road to Lab2017-01-184506/05/2017
When a manual transmission (MT) powertrain is subjected to high speeds and high torques, the vehicle driveshaft, and other components experience an increase in stored potential energy. When the engine and driveshaft are decoupled during an up or down shift, the potential energy is released causing clunk during the shift event. The customer desires a smooth shift thus reduction of clunk will improve experience and satisfaction. In this study, a six-speed MT, rear-wheel-drive (RWD) passenger vehicle was used to experimentally capture acoustic and vibration data during the clunk event. To replicate the in-situ results, additional data was collected and analyzed for powertrain component roll and pitch. A lumped parameter model of key powertrain components was created to replicate the clunk event and correlate with test data. The lumped parameter model was used to modify clutch tip-out parameters, which resulted in reduced prop shaft oscillations. By reducing the prop shaft oscillations the
Furlich, Jon, Blough, Jason, Robinette, Darrell
Design of an Integrated Yaw-Roll Moment and Active Front Steering Controller using Fuzzy Logic Control2017-01-156903/28/2017
This paper presents an advanced control system, which integrates three fuzzy logic controllers namely; Direct Yaw-moment Control (DYC), Active Roll-moment Control (ARC) and Active Front Steering (AFS) to enhance vehicle cornering and overturning stability. Based on a well-developed and validated fourteen degree of freedom (DOF) full vehicle model with non-linear tire characteristics, a reference 3-DOF yaw-roll plane vehicle model is introduced to control yaw rate, sideslip angle, and roll angle of the vehicle body. The control actions of both direct yaw and active roll moments are performed by generating differential braking moments across the front wheels, while the control action of the active steering is performed by modifying the steering wheel angle. Different standard cornering tests are conducted in MATLAB / Simulink environment such as J-turn, fishhook and lane change maneuvers. The simulation results show a substantial improvement in vehicle stability by employing the proposed
Elhefnawy, Amro, sharaf, Alhossein, Ragheb, Hossam, Hegazy, Shawky
Optimization of Contact Profiles using Super-Ellipse2017-01-134903/28/2017
In many rolling or sliding contact mechanisms, like roller bearings, journal bearings, gearings or any contact between two semi-infinite bodies, concentrated stress occurs at the edges of the contact. This stress, due to what is called edge effect, is known to be very fatigue damaging. To avoid this concentrated stress in common roller bearings, the rolling surface of the roller and/or of the track is crowned. The crowning shapes usually include a straight line and one or several circular arcs. Even if such crowning profiles are efficient in avoiding edge effects, they are far from being optimized in terms of contact pressure distribution. In recent years, crowning shapes based on a logarithmic function developed by Lundberg have been improved and optimized for the purpose of industrialization. However, the resulting profiles are fairly complex and have only been developed for roller bearings and not for other types of rolling or sliding contacts. This paper presents a new profile type
Duchemin, Matthieu, Tugui, Cezar, Collee, Vincent
Experimental and Simulation Studies on Instability of a Two Wheeler Vehicle2017-01-156303/28/2017
Two and three wheeler vehicles are largely used in many developing and under developing countries because of their lower cost, better fuel economy and easy handling. Although, the construction of them is simpler than the four wheeler vehicle, they pose some problems related to instability. Wobbling is the main cause of instabilities in two wheeler and three wheeler vehicles. In this study, a mathematical model was proposed and developed to determine wobble instability of a two wheeler. Nonlinear equations were formulated by using kinematics and the D’Alembert’s principle with the help of multi body formalism. The non-linear equations found in the study were linearized with respect to rectilinear and upright motion, considering no rolling. It led to formation of matrix. The real part of the Eigen value of the matrix was found to be negative, implication of whose was an asymptotic stable motion. It was observed that, the above real part of Eigen value was a function of different
Behera, Abhijeet, Sivalingam, Murugan
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