Pavement roughness evaluation method based on the theoretical relationship between acceleration measured by smartphone and IRI
Zhen Zhang, Hongliang Zhang, Song Xu, Wenjiang Lv
Abstract
Smartphones have integrated various sensors (e.g. GPS, acceleration sensor) and can be used to evaluate roads roughness. In this study the theoretical algorithm, in which the vehicle suspension parameters were included, would be established to calculate International Roughness Index (IRI) from acceleration using smartphones. Firstly, based on Android Studio 2.0, a client application installed on smartphones was developed. Next, the physical parameters of a quarter actual vehicle model (QAVM) were identified utilizing the front wheel drop test in accordance with complex modal theory. Then, the relationships among acceleration, IRI and the profile elevation were established through the derivation of theoretical formula. Finally, a validation analysis was implemented to evaluate the feasibility and reliability of this methodology. The validation experimental results on three asphalt pavement segments indicated that the collected acceleration data utilizing smartphone were basically consistent with that by accelerometers. Meanwhile, IRI calculated by the proposed theoretical methodology was close to that obtained by digital survey vehicle (DSV) and the maximum relative error between them was below 10%. Overall, due to the consideration of vehicle dynamic characteristics, the proposed method could improve the measurement accuracy and enable various vehicles to be used for road roughness evaluation.