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.

Analysis of the energy harvesting potential–based suspension for truck semi-trailer

2018 ◽  
Vol 233 (11) ◽  
pp. 2955-2969 ◽  
Author(s):  
Mohamed AA Abdelkareem ◽  
Mina MS Kaldas ◽  
Mohamed Kamal Ahmed Ali ◽  
Lin Xu
Keyword(s):  
Ride Comfort ◽  
Simulation Analysis ◽  
Conflict Analysis ◽  
Driving Safety ◽  
Dissipated Energy ◽  
Ride Quality ◽  
Surface Model ◽  
Long Distance ◽  
Class C ◽  
The Right

As the articulated trucks are mainly used for long distance transportations, the design of the suspension system became a major concern and a research hotspot not only for ride comfort and driving safety but also for energy consumption. Therefore, the objective of this study is to conduct a comprehensive parametrical–based conflict analysis between the ride comfort and road holding together with the potential power of the shock absorbers. The simulation analysis is performed using a 23 degree-of-freedom full truck semi-trailer mathematical model with random road surface model. The bounce and combined excitation modes for the truck model are applied to present the pro and contra of the simplified and realistic analysis. The bounce mode is applied for a road Class C and truck driving speed of 20 m/s, while the combined mode is performed with the same truck-speed but considering a Class C road for the left track and Class D road for the right track considering the time delay between the truck axles. The truck dynamics including the mean potential power, average dynamic tire load and bounce, and pitch and roll accelerations is comprehensively combined in the conflict analysis–based suspension and driving parameters. The obtained simulation results showed that the articulated truck suspension should be designed considering a realistic excitation condition. In contrast to the bounce mode, under the combined road input, the tractor ride quality and road handling performances are improved when a heavily damped suspension is considered. Furthermore, the otherwise dissipated energy through the damping events can reach an overall value between 2 and 4 kW.

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.

Optimum design for passive suspension system of a vehicle to prevent rollover and improve ride comfort under random road excitations

2016 ◽  
Vol 230 (4) ◽  
pp. 426-441 ◽  
Author(s):  
Abolfazl Seifi ◽  
Reza Hassannejad ◽  
Mohammad A Hamed
Keyword(s):  
Frequency Domain ◽  
Ride Comfort ◽  
Suspension System ◽  
Vertical Acceleration ◽  
Optimized Design ◽  
Power Spectral ◽  
Road Roughness ◽  
Vehicle Suspension System ◽  
Iso 2631

The main functions of suspension system are to provide ride comfort for the passengers and vehicle handling (road holding). But, in many studies, full attention to the ride comfort leads to the determination of incorrect suspension system parameters as well as other problems such as rollover and reducing road-holding ability in the vehicle. The aim of this study is to present a method for the optimized design of the vehicle suspension system in order to improve the ride comfort, road holding, workspace and preventing rollover, considering a full vehicle model with 11-DOF. The most important feature of this study is that the prevention of rollover factor and all of suspension functions are considered simultaneously. In this research, in order to assess the ride comfort, the vertical acceleration values of seats that are caused by random road roughness are calculated by power spectral density of road in frequency domain. In the context of prevention of rollover, Fishhook manoeuvre is performed using a mathematical model for the roll motion, and then the dynamic behaviour of the variables is considered in rollover threshold. Then, the optimization problem is solved to minimize the vertical acceleration values and vehicle roll angle by considering the physical limitation and safety of the model. The results of the optimization show that the vertical acceleration, in frequency domain at the desired boundary values (as defined in ISO 2631), decreases and rollover resistance of the vehicle increases.

Ride Quality of High-Speed Trains Traveling Over the Corrugated Rails

2006 ◽  
Author(s):  
H. Farahpour ◽  
D. Younesian ◽  
E. Esmailzadeh
Keyword(s):  
High Speed ◽  
Ride Comfort ◽  
The Body ◽  
Ride Quality ◽  
Comfort Index ◽  
Suspension Systems ◽  
Power Spectral ◽  
High Speed Trains ◽  
Train Speed ◽  
Secondary Suspension

Ride comfort of high-speed trains is studied using Sperling's comfort index. Dynamic model is developed in the frequency domain and the power spectral density (PSD) of the body acceleration is obtained for four classes of tracks. The obtained acceleration PSD is then filtered using Sperling's filter. The effects of the rail roughness and train speed on the comfort indicators are investigated. A parametric study is also carried out to evaluate the effects of the primary and secondary suspension systems on the comfort indicators.

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.

Development of a Rigid Ring Quarter-Vehicle Model With an Advanced Road Profile Algorithm for Durability and Ride Comfort Predictions

2008 ◽  
Author(s):  
James Allen ◽  
Moustafa El-Gindy ◽  
Kevin Koudela
Keyword(s):  
Ride Comfort ◽  
Integration Time ◽  
Vertical Acceleration ◽  
Vehicle Model ◽  
Time Step ◽  
Element Analysis ◽  
Rigid Ring ◽  
Fully Integrated ◽  
Road Profile ◽  
Vertical Contact

In this paper a new five-degree-of-freedom in-plane Rigid Ring Quarter-Vehicle Model (RRQVM) with a Force Dependent Effective Road Profile (FDERP) is derived and programmed in MATLAB/Simulink©. This novel fully integrated model uses the tire-road vertical contact force to update the effective road height and slope at each integration time step. The model is capable of simulating the response of a free rolling tire over arbitrarily uneven road surfaces to study vehicle ride comfort and durability with efficient, accurate results. The RRQVM is validated with tire spindle vertical acceleration data from virtual Finite Element Analysis (FEA) Quarter-Vehicle Model (QVM) tests. A baseline in-plane RRQVM with a Force Independent Effective Road Profile (FIERP) is also developed for comparison with the FDERP RRQVM. Results show that the FDERP RRQVM predicts the vertical tire spindle acceleration more accurately than the FIERP RRQVM when compared to the FEA RRQVM results, especially at speeds above 11 km/hr. Therefore, the advanced FDERP model provides the RRQVM with a more accurate effective road profile than a conventional FIERP model.

scholarly journals Classification Scheme for Random Longitudinal Road Unevenness Considering Road Waviness and Vehicle Response

2009 ◽  
Vol 16 (3) ◽  
pp. 273-289 ◽  
Author(s):  
Oldřich Kropáč ◽  
Peter Múčka
Keyword(s):  
Correction Factor ◽  
Ride Comfort ◽  
Vibration Response ◽  
Suitable Alternative ◽  
The Road ◽  
Novel Approach ◽  
Power Spectral ◽  
Road Profile ◽  
Basic Parameters ◽  
Single Number

A novel approach to the road unevenness classification based on the power spectral density with consideration of vehicle vibration response and broad interval of road waviness (road elevation PSD slope) is presented. This approach enables transformation of two basic parameters of road profile elevation PSD (unevenness index,C, and waviness,w) into a single-number indicatorCwwhen using a correction factorKwaccounting forw. For the road classification proposal two planar vehicle models (passenger car and truck), ten responses (reflecting ride comfort, dynamic load of road and cargo, ride safety) and three different vehicle velocities have been considered. The minimum of ten estimated vibration response ranges sum for a broad waviness interval typical for real road sections (w= 1.5 to 3.5) has been used for the correction factor estimation. The introduced unevenness indicator,Cw, reflects the vehicle vibration response and seems to be a suitable alternative to the other currently used single-number indicators or as an extension of the road classification according to the ISO 8608: 1995, which is based on constant waviness value,w= 2.

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.

scholarly journals Effects of Vehicular Speed on the Assessment of Pavement Road Roughness

2019 ◽  
Vol 9 (9) ◽  
pp. 1783 ◽  
Author(s):  
Giuseppe Loprencipe ◽  
Pablo Zoccali ◽  
Giuseppe Cantisani
Keyword(s):  
Surface Characteristics ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
The Road ◽  
Road Pavement ◽  
Road Profile ◽  
Vehicular Speed ◽  
On The Road ◽  
Single Number ◽  
Iso 2631

Good ride quality is a fundamental requirement for all road networks in modern countries. For this purpose, it is essential to monitor and evaluate the effect of irregularities on road pavement surfaces. In the last few decades, many roughness indices have been proposed, with the aim to represent shortly the pavement surface characteristics and the relative performances, using a single number and a correspondent scale of values. In this work, a comparison between three different evaluation methods (International Roughness Index, ISO 8608 road profile classification and frequency-weighted vertical acceleration awz according to ISO 2631) was carried out, applying these methods to some real road profiles. The similarities and differences between the obtained results are described, evaluating the effect of the road characteristic speed on the roughness thresholds. In fact, the specific aim of the analyses is to underline the need to use different thresholds depending on the speed at which the vehicular traffic can travel on the road sections. In this way, it will be possible to identify appropriate thresholds for the various types of roads, having for each of them a specific range of design or operating speed.

Comprehensive Analysis for Influence of Controllable Damper Time Delay on Semi-Active Suspension Control Strategies

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Yechen Qin ◽  
Feng Zhao ◽  
Zhenfeng Wang ◽  
Liang Gu ◽  
Mingming Dong
Keyword(s):  
Time Delay ◽  
Dynamic Characteristics ◽  
Ride Comfort ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Active Suspension ◽  
Test System ◽  
Suspension Control ◽  
Simulation Results

This paper presents a comprehensive comparison and analysis for the effect of time delay on the five most representative semi-active suspension control strategies, and refers to four unsolved problems related to semi-active suspension performance and delay mechanism that existed. Dynamic characteristics of a commercially available continuous damping control (CDC) damper were first studied, and a material test system (MTS) load frame was used to depict the velocity-force map for a CDC damper. Both inverse and boundary models were developed to determine dynamic characteristics of the damper. In addition, in order for an improper damper delay of the form t+τ to be corrected, a delay mechanism of controllable damper was discussed in detail. Numerical simulation for five control strategies, i.e., modified skyhook control SC, hybrid control (HC), COC, model reference sliding mode control (MRSMC), and integrated error neuro control (IENC), with three different time delays: 5 ms, 10 ms, and 15 ms was performed. Simulation results displayed that by changing control weights/variables, performance of all five control strategies varied from being ride comfort oriented to being road handling oriented. Furthermore, increase in delay time resulted in deterioration of both ride comfort and road handling. Specifically, ride comfort was affected more than road handling. The answers to all four questions were finally provided according to simulation results.

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