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

Abstract

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.

Numerical generation of road profile through spectral description for simulation of vehicle suspension

“…The method of SOH is also used to generate the road profile from split spectrum which is described by Eq. (6). In this case corresponding to road class A, the target variance are σ 2 z = 10.8 × 10 −6 m 2 , σ 2 z ′ = 2.12 × 10 −4 and target standard deviation are σ z = 3.3 × 10 −3 m, σ z ′ = 0.0145.…”

“…Dodds and Robson [3] suggested that the road profile can be assumed as homogeneous and isotropic twodimensional Gaussian random processes and proposed a spectral model of road profile and its classification method which is adopted by the ISO [4] for classification of road profiles. Successively the various spectral models of road profile have been proposed in the literature [5,6] but the ISO model is common in use because of its simplicity. Since the input and output spectral densities of a dynamical system are related through its transfer function, the direct spectral simulation using transfer function approach is possible without going through the time domain simulation of a vehicle model.…”

Current approaches to quantify the longitudinal road roughness

“…The new approach corrected a spectrum parameters C and w to one parameter -corrected unevenness index C w (Kropáč and Múčka 2009a). The direct approach to the correction for the effect of waviness consists in evaluation of the C w according to the relationship…”

Comparing of Data Collection for Network Level Pavement Management of Urban Roads and Highways

“…It is necessary for highway agencies to understand the source of errors for IRI and its in uence on performance evaluation. Some of the previous studies were conducted to investigate the source of uncertainty on IRI from the perspectives of collection and calculation methods [17][18][19][20][21]. And some of other studies even questioned the use of this index for road quality evaluation [22,23].…”