Coupled Vertical-Lateral Dynamics of a Pneumatic Tired Vehicle: Part II—Simulated Versus Experimental Data

1978 ◽  
Vol 100 (4) ◽  
pp. 319-325 ◽  
Author(s):  
N. S. Nathoo ◽  
A. J. Healey
Keyword(s):  
Damping Ratio ◽  
Sensitivity Study ◽  
Lateral Acceleration ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Trade Off ◽  
Lateral Dynamics ◽  
Power Spectral ◽  
Spectral Density Functions ◽  
Frequency Components

The vertical and lateral acceleration response of an automobile to roadway roughness inputs was simulated using a ten degree-of-freedom mathematical model. The simulated response compared favorably with that obtained experimentally in terms of their power spectral density functions and root mean squared values in the 0.1–10 Hz frequency range. Furthermore, within the context of ride quality, a sensitivity study was conducted to determine the effect of variations in the suspension damping ratio, anti-roll bar stiffness and lateral “pneumatic” stiffness on vehicle response variables. The indication is that a trade-off exists between the reduction in lateral and roll motions due to an increase in suspension damping and the resulting increase in the higher frequency components in the vertical acceleration. The model that has been developed is well suited for performing design trade-off analysis.

Ride Comfort of Five-Axle Tractor/Semi-Trailer

2000 ◽  
Author(s):  
Zhenyu Jiang ◽  
Moustafa El-Gindy ◽  
Donald Streit
Keyword(s):  
Ride Comfort ◽  
General Concept ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Gaussian Random Process ◽  
Long Distance ◽  
Power Spectral ◽  
Road Profile ◽  
Computer Based ◽  
Simulation Results

Abstract The issue of ride comfort for vehicle operations has recently generated considerable interest especially in heavy vehicle systems since long-distance drivers are more likely to experience high levels of vibration. This paper introduces the general concept of vibration-related health problems, discusses ride comfort assessment criteria and methods, and then focuses on the methodology of using computer simulation to analyze ride comfort. The computer-based ride comfort model can be divided into three sub-models: vehicle model, driver/seat model, and road profile input model. Several vehicle models and driver/seat models are reviewed and detailed modeling techniques are introduced. A five-axle tractor/semi-trailer/driver combination ride comfort simulation model is developed in this paper using the software DADS. Both four-spring tandem suspension and independent air spring suspension are studied. Road profiles are assumed as static zero mean Gaussian random process. Vertical acceleration at the interface between seat and driver body is obtained from simulation results. Power spectral density and root mean square (RMS) vertical acceleration are calculated based on simulation results. RMS acceleration at ISO classified good and average roads are compared with ISO 8-hour fatigue vibration limit. It is found that RMS acceleration of this particular vehicle simulated in this paper is below the ISO 8-hour fatigue limit for both good and average roads when traveling at the speed of fifty miles per hour. This implies a good ride comfort. Axle dynamic load coefficients (DLC) are calculated for four suspension configurations that are combinations of air springs and steel springs. Results show that large DLC doesn’t necessarily indicate bad ride quality.

scholarly journals Roughness-induced vehicle energy dissipation from crowdsourced smartphone measurements through random vibration theory

2020 ◽  
Vol 1 ◽  
Author(s):  
Meshkat Botshekan ◽  
Jacob Roxon ◽  
Athikom Wanichkul ◽  
Theemathas Chirananthavat ◽  
Joy Chamoun ◽  
...  
Keyword(s):  
Inverse Analysis ◽  
Random Vibration ◽  
Statistical Physics ◽  
Mechanistic Model ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Fluctuation Dissipation ◽  
Power Spectral ◽  
Road Roughness ◽  
L2 Norm

Abstract We propose, calibrate, and validate a crowdsourced approach for estimating power spectral density (PSD) of road roughness based on an inverse analysis of vertical acceleration measured by a smartphone mounted in an unknown position in a vehicle. Built upon random vibration analysis of a half-car mechanistic model of roughness-induced pavement–vehicle interaction, the inverse analysis employs an L2 norm regularization to estimate ride quality metrics, such as the widely used International Roughness Index, from the acceleration PSD. Evoking the fluctuation–dissipation theorem of statistical physics, the inverse framework estimates the half-car dynamic vehicle properties and related excess fuel consumption. The method is validated against (a) laser-measured road roughness data for both inner city and highway road conditions and (b) road roughness data for the state of California. We also show that the phone position in the vehicle only marginally affects road roughness predictions, an important condition for crowdsourced capabilities of the proposed approach.

A comprehensive tune of coupled roll and lateral dynamics and parameter sensitivity study for a vehicle fitted with hydraulically interconnected suspension system

2020 ◽  
Vol 235 (1) ◽  
pp. 143-161
Author(s):  
Hengmin Qi ◽  
Nong Zhang ◽  
Yuanchang Chen ◽  
Bohuan Tan
Keyword(s):  
Sensitivity Analysis ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Sensitivity Study ◽  
Parameter Sensitivity ◽  
Suspension System ◽  
Body Motion ◽  
Parameter Sensitivity Analysis ◽  
Sideslip Angle ◽  
Lateral Dynamics

Roll and lateral dynamics of a vehicle are heavily coupled together, the increase of roll stability does not necessarily result in the improvement of stability in the lateral plane, but the decrease in lateral stability possibly contributes to instability in the roll plane. To address this challenge, a comprehensive tune of coupled roll and lateral dynamics for a vehicle fitted with hydraulically interconnected suspension system is presented in this paper. A typical sport utility vehicle is selected and modeled with 10 degrees of freedom to conduct the dynamic simulation. Also, the fluid equations of the proposed hydraulically interconnected suspension system with nonlinear damper model are derived and incorporated into the vehicle model. Furthermore, the integrated model is validated by the field test. The simulation is also conducted to assess and compare the vehicle roll and lateral dynamic performances under fishhook maneuver. The results show that the well-tuned hydraulically interconnected suspension can suppress its body motion in roll plane, enhance the yaw rate tracking ability, minimize the sideslip angle at the center of gravity, and also decrease the slip angles for tires. Last, the parameter sensitivity analysis for a strongly nonlinear hydraulically interconnected suspension system illustrates how individual hydraulically interconnected suspension parameters (roll stiffness, roll stiffness nonlinearity, roll stiffness distribution ratio, and damping ratio) contribute to different dynamic aspects of a vehicle. The results indicate that, by controlling hydraulically interconnected suspension key parameters, the vehicle dynamic performance can be effectively controlled in both roll and lateral planes. The parameter sensitivity analysis findings have pointed out the direction for controller design and laid the foundation for active hydraulically interconnected suspension system development in the future.

scholarly journals The coupled effects of bending and torsional flexural modes of a high-speed train car body on its vertical ride quality

2019 ◽  
Vol 233 (4) ◽  
pp. 979-993 ◽  
Author(s):  
Vahid Bokaeian ◽  
Mohammad A Rezvani ◽  
Robert Arcos
Keyword(s):  
Analytical Model ◽  
Quality Index ◽  
High Speed ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Beam Model ◽  
High Speed Train ◽  
Flexural Mode ◽  
Car Body ◽  
Rail Irregularities

This study is focused on the effects of bending and torsional flexural modes of the car body on the ride quality index of a high-speed train vehicle. The Euler–Bernoulli beam model is used to extract an analytical model for a high-speed train vehicle car body in order to investigate its bending and torsional flexural vibrations. The rigid model includes a car body, two bogie frames, and four wheelsets such that, each mass has three degrees of freedom including vertical displacement, pitch motion, and roll motion. The results obtained with the proposed analytical model are compared with experimental measurements of the car body response of a Shinkansen high-speed train. Moreover, it is determined that the bending and torsional flexural modes have significant effects on the vertical acceleration of the car body, particularly in the 9–15 Hz frequency range. Furthermore, the ride quality index is calculated according to the EN 12299 standard and it is shown that the faster the train the more affected is the ride quality by the flexural modes. In addition, the effect of coherence between two rail irregularities (the right and the left rails) on the results of the simulation is investigated. The results conclude that if the irregularities are completely correlated the torsional flexural mode of the car body does not appear in the response. Also, the first bending flexural mode in such cases is more excited compared with the partially correlated or uncorrelated rail irregularities. Therefore, the ride quality index in completely correlated cases is higher than other cases.

The Effect of Elevated Guideway Construction Tolerances on Vehicle Ride Quality

1975 ◽  
Vol 97 (4) ◽  
pp. 408-416 ◽  
Author(s):  
J. K. Hedrick ◽  
R. J. Ravera ◽  
J. R. Anderes
Keyword(s):  
Cross Section ◽  
Quality Criteria ◽  
Design Parameters ◽  
Ride Quality ◽  
Live Load ◽  
General Technique ◽  
Trade Off ◽  
Frequency Decomposition ◽  
Space Boundary

In this paper the ride quality of a vehicle traversing an elevated guideway is related directly to guideway construction tolerances and design parameters. Moreover, the construction tolerances are modeled in terms familiar to a guideway contractor. The tolerances modeled for an elevated, two-span semicontinuous, concrete guideway are: surface finish, camber deviations, pier survey errors, and pier settlement. The major design parameters relating to live-load deflection, stiffness (material and cross-section), and pier spacing are included. A general technique is presented for relating these tolerances to vehicle ride quality by means of a digital computer simulation. Various ride quality criteria are considered, including rms acceleration, acceleration spectral density, acceleration frequency decomposition, and a deterministic state space boundary. Numerical results are presented for a particular vehicle-guideway configuration and as such are valid only for the system considered. It is shown that for this system, equivalent ride quality can be maintained while adjusting the various construction tolerances. This trade-off capability allows the contractor to choose the least costly combination of tolerance parameters.

System Identification and Lateral Dynamics of the Active Tilt-Controlled Electric Three Wheeler

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Jigneshsinh Sindha ◽  
Basab Chakraborty ◽  
Debashish Chakravarty
Keyword(s):  
Control System ◽  
System Identification ◽  
Load Transfer ◽  
Lateral Acceleration ◽  
Stable Operation ◽  
Technological Advancement ◽  
Track Width ◽  
Lateral Dynamics ◽  
Vehicle Trajectory ◽  
The Impact

Abstract Active tilt control system (ATC) is considered to be a prominent technological advancement in the three wheelers (3Ws), which improves the drive and comfort capabilities of 3W, leading to additional benefits of excellent maneuverability and small track width. An experimental prototype along with its simulation model is developed, to study the impact of the tilt actuation control system (TAS) and active steer (AS) system on the overall drive experience and stability improvement. A steering direct tilt control (SDTC) strategy is implemented on the vehicle, which allows stable operation of the system during the entire drive range. A transfer function (TF) of the TAS is estimated from the measurements on the prototype using the system identification tool. The derived TF is then utilized to investigate the response of the complete vehicle in terms of vehicle trajectory, perceived acceleration and load transfer across the rear wheels during the double lane change (DLC) and constant turn maneuvers. The results of the analysis indicate that the perceived acceleration felt by the driver is up to 45% less than the lateral acceleration along with up to 36% reduction in load transfer across the rear wheels.

Vibration Control of a Rigid and Flexible High-Speed Railway Vehicle

2020 ◽  
Author(s):  
Semiha Türkay ◽  
Aslı S. Leblebici
Keyword(s):  
High Speed ◽  
Low Frequency ◽  
Railway Vehicle ◽  
Allowable Limit ◽  
Low Frequencies ◽  
Railway Line ◽  
Power Spectral ◽  
Spectral Density Functions ◽  
The Right ◽  
Euler Bernoulli Beam

Abstract In this paper, the vertical carbody dynamics of the railway vehicle excited by random track inputs are investigated. The multi-objective ℋ∞ controllers for carbody weight of the actual, heavy and a mass confined in a polytopic range have been designed with the aim of reducing the wheel forces, heave, pitch and roll body accelerations of the vehicle. Later, the carbody mass is modelled as a free-free Euler Bernoulli beam and the low frequency flexural vibrations of the train body are examined. An omnibus ℋ∞ controller is synthesized to suppress both the rigid and low frequencies flexible modes of the railway vehicle. The performances of the ℋ∞ controllers are verified by using the passive and active suspension responses on the right and left rail track disturbances that are represented by the power spectral density functions authenticated for the stochastic real track data collected from the Qinhuangdao-Shenyang passenger railway line in China. Simulation results showed that all controllers exhibit a very good performance by effectively reducing the car-body accelerations in vicinity of the resonanat frequencies while keeping the wheel-rail forces in the allowable limit.

scholarly journals Effect of the Anti-Yaw Damper on Carbody Vertical Vibration and Ride Comfort of Railway Vehicle

2020 ◽  
Vol 10 (22) ◽  
pp. 8167
Author(s):  
Mădălina Dumitriu ◽  
Dragoș Ionuț Stănică
Keyword(s):  
Ride Comfort ◽  
Vertical Vibration ◽  
Theoretical Research ◽  
Railway Vehicle ◽  
Vertical Acceleration ◽  
Damping Force ◽  
Comfort Index ◽  
Lateral Vibrations ◽  
Power Spectral ◽  
Vertical Vibrations

The theoretical research on means to reduce the vertical vibrations and improve the ride comfort of the railway vehicle relies on a mechanical model obtained from the simplified representation of the vehicle, while considering the important factors and elements affecting the vibration behaviour of the carbody. One of these elements is the anti-yaw damper, mounted longitudinally, between the bogie and the vehicle carbody. The anti-yaw damper reduces the lateral vibrations and inhibits the yaw motion of the vehicle, a reason for which this element is not usually introduced in the vehicle model when studying the vertical vibrations. Nevertheless, due to the position of the clamping points of the anti-yaw damper onto the carbody and the bogie, the damping force is generated not only in the yawing direction but also in the vertical and longitudinal directions. These forces act upon the vehicle carbody, impacting its vertical vibration behaviour. The paper analyzes the effect of the anti-winding damper on the vertical vibrations of the railway vehicle carbody and the ride comfort, based on the results derived from the numerical simulations. They highlight the influence of the damping, stiffness and the damper mounting angle on the power spectral density of the carbody vertical acceleration and the ride comfort index.

scholarly journals A study on wavelet analysis of SSVEP Signals

2018 ◽  
Vol 7 (2.25) ◽  
pp. 10
Author(s):  
Bincy Babu ◽  
R Chandrasekaran ◽  
Josline Elsa Joseph ◽  
Thella Shalem Rahul ◽  
T R Thamizhvani ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Spectral Estimation ◽  
Power Spectral Analysis ◽  
Feature Analysis ◽  
Eeg Signals ◽  
Power Spectral ◽  
Frequency Components ◽  
Bci System

Almost every Brain Control Interfcae (BCI) system is framed based on Steady State Visual Evoked Potential (SSVEP) which is predicted through distinguishing overriding frequency components in Electroencephalography (EEG) signals. The proposed system aims in accurate feature extraction of SSVEP signals. Power spectral analysis and wavelet analysis are done for feature analysis. The feature set variation for male and female subjects are obtained. Compared power spectral estimation and wavelet analysis, merits and demerits of each approach can be identified from the outcomes. It offers a theoretical reference of practical choice for BCI application.  

scholarly journals Optimum Resolution Bandwidth for Spectral Analysis of Stationary Random Vibration Data

1993 ◽  
Vol 1 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Allan G. Piersol
Keyword(s):  
Spectral Analysis ◽  
Spectral Density ◽  
Power Spectral Density ◽  
Random Vibration ◽  
Damping Ratio ◽  
Frequency Resolution ◽  
Power Spectral ◽  
Averaging Time ◽  
Resolution Bandwidth

This article presents a methodology for selecting the frequency resolution bandwidth for the spectral analysis of stationary random vibration signals in an optimum manner. Specifically, the resolution bandwidth that will produce power spectral density estimates with a minimum mean square error is determined for any given measurement duration (averaging time), and methods of approximating the optimum bandwidth using practical spectral analysis procedures are detailed. The determination of the optimum resolution bandwidth requires an estimate for the damping ratio of the vibrating structure that produced the measured vibration signal and the analysis averaging time. It is shown that the optimum resolution bandwidth varies approximately with the 0.8 power of the damping ratio and the bandwidth center frequency, and the −0.2 power of the averaging time. Also, any resolution bandwidth within ±50% of the optimum bandwidth will produce power spectral density (PSD) estimates with an error that is no more than 25% above the minimum achievable error. If a damping ratio of about 5% for structural resonances is assumed, a constant percentage resolution bandwidth of 1/12 octave, but no less than 2.5 Hz, will provide a near optimum PSD analysis for an averaging time of 2 seconds over the frequency range from 20 to 2000 Hz. A simple scaling formula allows the determination of appropriate bandwidths for other damping ratios and averaging times.

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