Road Profile, Vehicle Dynamics, and Ride Quality Rating

In order to isolate the propagation of unwanted vibrations to passengers and improve vehicle maneuverability, it is common practice to predict road profile roughness in the scope of active suspension design. An algebraic estimator designed for the estimation of the road profile excitation has been investigated in this study based on vehicle dynamics responses. An approximation of road profile excitation by a piecewise constant function has been proposed using the operational calculus method and the differential algebraic theory. The proposed technique allows for the usage of cheap instrumentation with a small number of sensors and employs a straightforward calibration process. Accurate approximation of the road profile was obtained from the measurement of sprung mass and unsprung mass vertical displacements. The performance and robustness of the proposed algebraic predictor is compared with an augmented Kalman estimator. Numerical results are provided to analyze the effectiveness and the limitations of the proposed algorithm for road profile reconstruction. Furthermore, a comparison with real profile was studied.

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Estimation of Gravel Roads Ride Quality Through an Android-Based Smartphone

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118758693 ◽

2018 ◽

Vol 2672 (40) ◽

pp. 14-21 ◽

Cited By ~ 6

Author(s):

Waleed Aleadelat ◽

Cameron H. G. Wright ◽

Khaled Ksaibati

Keyword(s):

Low Cost ◽

Ride Quality ◽

Initial Validation ◽

Road Condition ◽

Gravel Roads ◽

Signal Demodulation ◽

Smartphone Sensors ◽

Quality Rating ◽

Local Agencies ◽

Gravel Road

This study demonstrated the ability of smartphone sensors in evaluating gravel roads conditions. Seventy gravel roads with various conditions, surface materials, and geometric features were included in this study. The analysis was based on signal demodulation and wavelet transformation to reduce the effect of many external factors (i.e., speed dependency, engine vibrations, and suspension system) that may affect the obtained measurements. It was found that the acquired signals from a smartphone accelerometer can reflect the actual conditions of a gravel road. In addition, the location and the severity of surface deteriorations such as potholes could be identified. A regression model ( R2 = 0.78) based on the acquired signals from smartphones was developed to predict the overall rating of the gravel road condition according to the Riding Quality Rating Guide (RQRG) system. An initial validation analysis, conducted on 35 new gravel roads, showed that this model was able to return reasonable ratings. Also, the statistical analysis showed that any difference between the predicted and the actual ratings of <1.3 was not significant. The proposed methodology can be considered as a baseline for building a low cost crowdsourcing platform that helps local agencies in managing their inventory of gravel roads.

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Low-speed vehicle dynamics and ride quality using controlled D.C. electromagnets

Automatica ◽

10.1016/0005-1098(77)90081-4 ◽

1977 ◽

Vol 13 (6) ◽

pp. 605-610 ◽

Cited By ~ 12

Author(s):

B.V. Jayawant ◽

P.K. Sinha

Keyword(s):

Vehicle Dynamics ◽

Ride Quality ◽

Low Speed

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Ride Comfort of Five-Axle Tractor/Semi-Trailer

10.1115/imece2000-1202 ◽

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.

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Design and Experimental Study of Progressive Spring for Formula Student Race Car

10.21203/rs.3.rs-856008/v1 ◽

2021 ◽

Author(s):

Anmol Shripad Patil ◽

Eshita Nandi ◽

Prasad Nanasaheb Punekar ◽

Suyash Wagh

Keyword(s):

Vehicle Dynamics ◽

Design Procedure ◽

Ride Quality ◽

Linear Rate ◽

Spring Rate ◽

Roll Control ◽

Race Car ◽

Linear Spring ◽

Design Calculations ◽

Major Factors

Abstract The purpose of carrying out the present work is to design, manufacture & test the progressive springs on an FS vehicle. This is one type of helical spring with a variable spring rate. The main purpose of designing progressive springs is to avail all the advantages of the variable spring rate over the linear spring rate and better ride quality along with roll control, compared to linear rate springs. We took several factors of vehicle dynamics under consideration before settling on progressive springs. Before starting with the design procedure, we had set objectives and followed the standard methodology of spring design to get the required output. Along with that, we took design philosophy under consideration. We reviewed all the parameters before finalizing the spring material as it is one of the major factors. We carried out all the necessary design calculations to complete the dimensions and stiffness of the spring. The conclusion helped us to achieve better ride quality and roll control accompanying the optimized spring design satisfying all the necessities such as load, stiffness, and deflection of progressive springs.

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Eigenvalue Analysis of Multibody Models of Railroad Vehicles Including Track Flexibility

Volume 4: 8th International Conference on Multibody Systems, Nonlinear Dynamics, and Control, Parts A and B ◽

10.1115/detc2011-48212 ◽

2011 ◽

Author(s):

Jose´ L. Escalona ◽

Rosario Chamorro ◽

Antonio M. Recuero

Keyword(s):

Vehicle Dynamics ◽

Equations Of Motion ◽

Steady Motion ◽

Differential Algebraic Equations ◽

Eigenvalue Analysis ◽

Ride Quality ◽

Algebraic Equations ◽

Essential Information ◽

Railroad Vehicles ◽

The Stability

The stability analysis of railroad vehicles using eigenvalue analysis can provide essential information about the stability of the motion, ride quality or passengers comfort. The system eigenvalues are not in general a vehicle property but a property of a vehicle travelling steadily on a periodic track. Therefore the eigenvalue analysis follows three steps: calculation of steady motion, linearization of the equations of motion and eigenvalue calculation. This paper deals with different numerical methods that can be used for the eigenvalue analysis of multibody models of railroad vehicles that can include deformable tracks. Depending on the degree of nonlinearity of the model, coordinate selection or the coordinate system used for the description of the motion, different methodologies are used in the eigenvalue analysis. A direct eigenvalue analysis is used to analyse the vehicle dynamics from the differential-algebraic equations of motion written in terms of a set of constrained coordinates. In this case not all the obtained eigenvalues are related to the dynamics of the system. As an alternative the equations of motion can be obtained in terms of independent coordinates taking the form of ordinary differential equations. This procedure requires more computations but the interpretation of the results is straightforward.

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Validation of a Real-Time Multibody Model for an X-by-Wire Vehicle Prototype Through Field Testing

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4028030 ◽

2015 ◽

Vol 10 (3) ◽

Cited By ~ 3

Author(s):

Roland Pastorino ◽

Emilio Sanjurjo ◽

Alberto Luaces ◽

Miguel A. Naya ◽

Wim Desmet ◽

...

Keyword(s):

Real Time ◽

Collision Detection ◽

Vehicle Dynamics ◽

Field Testing ◽

Simulation Environment ◽

Multibody Model ◽

Graphical Environment ◽

Road Profile ◽

Lateral Vehicle Dynamics ◽

Vehicle Motion

This research focuses on the experimental validation of a real-time vehicle multibody (MB) model whose bodies are considered rigid. For this purpose, a vehicle prototype has been built and automated in order to repeat reference maneuvers. Numerous sensors on the prototype gather the most relevant magnitudes of the vehicle motion. Two low speed maneuvers involving the longitudinal and lateral vehicle dynamics have been repeated multiple times in a test area. Then, a real-time MB model of the vehicle prototype has been self-developed as well as a simulation environment that includes a true graphical environment, a true road profile, and collision detection. Subsystems like brakes and tires have also been modeled. Both test maneuvers have been simulated with the MB model in the simulation environment using inputs measured experimentally. Selected simulation variables have been compared to their experimental counterparts provided with a confidence interval (IC) that characterizes the field testing (FT) process errors. The results of the comparisons show good correlation between simulation predictions and experimental data, thus allowing to extract useful guidelines to build accurate real-time vehicle MB models. In this way, the present work aims to contribute to the scarce literature on vehicle complete validation studies.

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