Effect of Road Roughness on the Vehicle Ride Comfort and Rolling Resistance

2006 ◽  
Author(s):  
A. M. A. Soliman
Keyword(s):  
Ride Comfort ◽  
Rolling Resistance ◽  
Road Roughness

The Time Domain Simulation of Non-Stationary Road Roughness

2013 ◽  
Vol 423-426 ◽  
pp. 1238-1242
Author(s):  
Hao Wang ◽  
Xiao Mei Shi
Keyword(s):  
Power Spectrum ◽  
Time Domain ◽  
Ride Comfort ◽  
Time History ◽  
Random Excitation ◽  
Power Spectrum Density ◽  
The Road ◽  
Road Roughness ◽  
Spectrum Density ◽  
History Of

The input of road roughness, which affects the ride comfort and the handling stability of vehicle, is the main excitation for the running vehicle. The time history of the road roughness was researched with the random phases, based on the stationary power spectrum density of the road roughness determined by the standards. Through the inverse Fourier transform, the random phases can be used to get the road roughness in time domain, together with the amplitude. Then, the time domain simulation of the non-stationary random excitation when the vehicle ran at the changing speed, would also be studied based on the random phases. It is proved that the random road excitation for the vehicle with the changing speed is stationary modulated evolution random excitation, and its power spectrum density is the stationary modulated evolutionary power spectrum density. And the numerical results for the time history of the non-stationary random inputs were also provided. The time history of the non-stationary random road can be used to evaluate the ride comfort of the vehicle which is running at the changing speed.

Simulation of Ride Comfort of Tracked Vehicle Based on Road Random Excitation

2012 ◽  
Vol 479-481 ◽  
pp. 93-97 ◽  
Author(s):  
Pi Jing Liu ◽  
Liang Hou ◽  
Wen Guang Lin ◽  
Xiu Yi Yu ◽  
Wei Huang
Keyword(s):  
White Noise ◽  
Theoretical Foundation ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Random Excitation ◽  
Tracked Vehicle ◽  
Road Roughness ◽  
Simulation Based ◽  
Set Up ◽  
Vertical Jumps

By simplifying the triangular tracked engineer vehicle into dynamic model of half-tracked vehicle with five freedom degrees which includes four vertical jumps and one rotation, a corresponding dynamic differential equation is set up to each degree of freedom. A method of road roughness simulation, based on the time series of White Noise, is also represented and then verified. The simulation analysis of the tracked vehicle ride comfort is built on MATLAB/SIMULINK, based on the incentive signal of an imitated road. The simulation results show that the method that White Noise generated road roughness is applicable and prove efficient in the ride comfort research of the triangular tracked engineer vehicle. Thus a theoretical foundation is established for the optimization for ride comfort of the triangular tracked engineer vehicle.

Structural-Acoustic Analysis of Automobile Passenger Compartment

2012 ◽  
Vol 236-237 ◽  
pp. 175-179 ◽  
Author(s):  
Shu Wen Zhou ◽  
Si Qi Zhang
Keyword(s):  
Frequency Response ◽  
Acoustic Analysis ◽  
Ride Comfort ◽  
Vehicle Body ◽  
Response Analysis ◽  
Passenger Compartment ◽  
Vector Method ◽  
Acoustic Cavity ◽  
Road Roughness ◽  
Acoustic Contribution

Besides the performances of handling, stability, ride comfort, power and fuel economy, the sound pressure levels in the automobile passenger compartments heavily influence the customer’s purchasing decision. The interior acoustics of automobile passenger compartment was analyzed in this paper. The frequency response analysis was performed on the vehicle body due to road roughness. The frequency response of vehicle body’s output spectrum, nodes’ velocity is used as the boundary condition of the acoustic cavity. With boundary element method and acoustic transfer vector method, the panel acoustic contribution was analyzed. By modifying the stiffness, damping or mass of the corresponding panel, the acoustic pressure levels at the driver’s and passenger’s ear were decreased.

scholarly journals ROAD PAVEMENT LONGITUDINAL EVENNESS QUANTIFICATION AS STATIONARY STOCHASTIC PROCESS

Transport ◽  
2019 ◽  
Vol 34 (3) ◽  
pp. 193-203 ◽  
Author(s):  
Bohuš Leitner ◽  
Martin Decký ◽  
Matúš Kováč
Keyword(s):  
Ride Comfort ◽  
Reference Model ◽  
Rolling Resistance ◽  
Geodetic Survey ◽  
Work Place ◽  
Quarter Car Model ◽  
Car Model ◽  
Road Pavement ◽  
Research Activities ◽  
Quarter Car

One of the requirements concerning pavement quality is the evenness of its surface. Pavement unevenness has a random character and has an adverse influence to rolling resistance, tyre–pavement coherence, safety and the driving comfort. Knowledge of “longitudinal unevenness” has been long recognized as an important criteria of road performance, not only for safety by causing vehicle vibrations and affecting ride comfort but also as a major factor in pavement deterioration and working conditions of vehicles. The paper presents two original devices for the measurement of pavement longitudinal unevenness designed as a reaction to results and experiences gathered from a few years’ research activities, measurements and evaluations of road pavement evenness carried out in the authors' work place (University of Žilina – UNIZA). The first equipment has been designed as a single-wheel trailing vehicle and has been constructed on the Double-mass Measuring Set (DMS) principle and it is referred to as UNIZA single-wheel vehicle JP VSDS. The main reason for designing the device were authors’ findings that the reference quarter car model (used for calculation of International Roughness Index – IRI) can provide evaluation, which can be in contradiction with ride safety. This fact is determined by overvaluation of the short wavelengths and undervaluation the longer wavelengths by reference model. The second one is a profiler with very high resolution of surface scanning using mathematical models for unevenness evaluation. The device is referred to as Dynamic Road Scanner (DRS). The reason for designing of this equipment was in the first place insufficient repeatability of transversal unevenness measurements of device used by Slovak Road Administration, but for the purpose of correctness and measurements accuracy verifying were also results of longitudinal unevenness measurements compared. The paper presents results of evaluation by international established dynamic quantifiers of longitudinal unevenness based on measurements performed by these devices on three selected road sections in Slovakia. In the next part of the paper are compared IRI values obtained by mathematical calculations using reference quarter car model “driving” on road section profile measured by geodetic survey with IRI values obtained by conversion of the unevenness degree C (measured by UNIZA single-wheel vehicle JP VSDS) and IRI values measured by profilometer DRS.

scholarly journals Optimization and testing of suspension system of electric mini off-road vehicles

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041988187
Author(s):  
Bin Yu ◽  
Zhice Wang ◽  
Dayou Zhu ◽  
Guoye Wang ◽  
Dongxin Xu ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Ride Comfort ◽  
Response Characteristic ◽  
Power Spectrum Density ◽  
Damping Coefficient ◽  
Road Vehicles ◽  
Road Vehicle ◽  
Road Roughness ◽  
Vibration Model ◽  
Spectrum Density

Mini vehicles with a small wheelbase are extremely sensitive to road roughness. The aim of this study is to explore the influence of road information on ride comfort and enhance the ride comfort of mini vehicles. According to the 5-degree-of-freedom vibration model of an electric mini off-road vehicle, the partial differential matrix equation of system motion is established using the Lagrange method, and the frequency response characteristic of the system is analyzed. The input matrix of pavement unevenness is obtained by considering the mutual power spectrum density between front and rear wheels. Road surface roughness information is obtained using an instrument for measuring road roughness. A comprehensive objective function and a constraint condition are established for comfort and safety. Based on the parameters obtained through the optimum design of a 1/4 vehicle model, the optimized stiffness and damping coefficient of suspension are obtained using a MATLAB optimization program. The law of the vibration performance of off-road vehicles with respect to suspension stiffness and the damping coefficient is obtained through the analysis of optimized results. A driving simulation and a test are conducted on the electric mini off-road vehicle. The results show that the use of the measured pavement data as simulation input is closer to the actual situation and provides higher accuracy compared to the simulated pavement model. According to the optimization and test results, the parameters optimized by a 1/2 vehicle (5 degrees of freedom) vibration model are better than those optimized by the 1/4 vehicle vibration model. The optimization results confirm reduction in acceleration, acceleration power spectrum density, and the root mean square of the weighted acceleration of the seat. This shows that the electric mini off-road vehicle provides better ride comfortability after optimization.

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.

Multi-Objective Optimization of Vehicle Air Suspension Based on Simulink-Mfile Mixed Programming

2014 ◽  
Vol 509 ◽  
pp. 63-69 ◽  
Author(s):  
Jin Hui Li ◽  
Jie He ◽  
Xu Hong Li
Keyword(s):  
Ride Comfort ◽  
Optimization Method ◽  
Vehicle Suspension ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
The Road ◽  
Suspension Parameters ◽  
Air Suspension ◽  
Mixed Programming ◽  
Road Roughness

In order to reduce the road damage of heavy trucks, comprehensively considering ride comfort and road friendliness, the multi-objective optimization method of vehicle suspension parameters with non-linear air spring was presented based on Simulink-Mfile mixed programming. The simulation model including vehicle dynamics module, road roughness module, ride comfort and road friendliness evaluation index modules was constructed in Simulink platform, and the multi-objective optimization model was developed in Mfile program which took the linear weighted sum of ride comfort and road friendliness indexes as the objective. Then the suspension parameters were optimized with genetic algorithm (GA). The results showed that, compared with before optimization, the vehicle ride comfort and road friendliness could be synthetically improved. And with the Simulink-Mfile mixed programming method, the optimization of nonlinear vehicle suspension could be successfully solved in time domain, which could provide a new idea for vehicle suspension design.

Belt Construction Optimization for Tire Weight Reduction Using the Finite Element Method

1993 ◽  
Vol 21 (2) ◽  
pp. 120-134 ◽  
Author(s):  
M. Weiss ◽  
S. Tsujimoto ◽  
H. Yoshinaga
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Weight Reduction ◽  
High Speed ◽  
High Performance ◽  
Ride Comfort ◽  
Rolling Resistance ◽  
The Finite Element Method ◽  
Belt Width ◽  
Element Method

Abstract The influence of five belt constructions on high speed endurance, ride comfort, and rolling resistance was investigated for a high performance 225/50R16 92V radial passenger car tire, using the finite element method. The belt constructions were combinations of belt edge shapes (cut, folded) and reinforcement materials (steel, aramid). The goal was to find optimized belt constructions for tire weight reduction, considering important tire properties like high speed endurance, ride comfort, and rolling resistance. A full aramid belt construction with a folded belt around a cut belt was chosen for design parameter variation calculations to reduce rolling resistance. This leads to a tire with smaller belt width, increased folding width, additional center cap ply, and reduced non-skid base and depth. The effect of inflation pressure and speed on rolling resistance was evaluated for this construction.

scholarly journals Random vibration of vehicle with hysteretic nonlinear suspension under road roughness excitation

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401775122 ◽  
Author(s):  
CR Hua ◽  
Y Zhao ◽  
ZW Lu ◽  
H Ouyang
Keyword(s):  
Random Vibration ◽  
Ride Comfort ◽  
Iteration Scheme ◽  
Analysis Method ◽  
Dynamic Features ◽  
Centre Of Gravity ◽  
Working Space ◽  
Power Spectral ◽  
Road Roughness ◽  
Effective Analysis

The analysis of random vibration of a vehicle with hysteretic nonlinear suspension under road roughness excitation is a fundamental part of evaluation of a vehicle’s dynamic features and design of its active suspension system. The effective analysis method of random vibration of a vehicle with hysteretic suspension springs is presented based on the pseudoexcitation method and the equivalent linearisation technique. A stable and efficient iteration scheme is constructed to obtain the equivalent linearised system of the original nonlinear vehicle system. The power spectral density of the vehicle responses (vertical body acceleration, suspension working space and dynamic tyre load) at different speeds and with different nonlinear levels of hysteretic suspension springs are analysed, respectively, by the proposed method. It is concluded that hysteretic nonlinear suspensions influence the vehicle dynamic characteristic significantly; the frequency-weighted root mean square values at the front and rear suspensions and the vehicle’s centre of gravity are reduced greatly with increasing the nonlinear levels of hysteretic suspension springs, resulting in better ride comfort of the vehicle.

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