Stabilization of a p-u Sensor Mounted on a Vehicle for Measuring the Acoustic Impedance of Road Surfaces

Abstract

The knowledge of the acoustic impedance of a material allows for the calculation of its acoustic absorption. Impedance can also be linked to structural and physical proprieties of materials. However, while the impedance of pavement samples in laboratory conditions can usually be measured with high accuracy using devices such as the impedance tube, complete in-situ evaluation results are less accurate than the laboratory results and is so time consuming that a full scale implementation of in-situ evaluations is practically impossible. Such a system could provide information on the homogeneity and the correct laying of an installation, which is proven to be directly linked to its acoustic emission properties. The present work studies the development of a measurement instrument which can be fastened through holding elements to a moving laboratory (i.e., a vehicle). This device overcomes the issues that afflict traditional in-situ measurements, such as the impossibility to perform a continuous spatial characterization of a given pavement in order to yield a direct evaluation of the surface’s quality. The instrumentation has been uncoupled from the vehicle’s frame with a system including a Proportional Integral Derivative (PID) controller, studied to maintain the system at a fixed distance from the ground and to reduce damping. The stabilization of this device and the measurement system itself are evaluated and compared to the traditional one.

A study on the assessment of traffic noise induced annoyance and awareness levels about the potential health effects among residents living around a noise-sensitive area

“…RTN (road traffic noise) in the most impacting noise source of the modern lifestyle (Ruiz-Padillo et al 2016 ). Although the parameters influencing the emission of noise usually considered include vehicle engines and flow composition, studies have also established “acoustic impedance of road surfaces” (Bianco et al 2020 ; Praticò et al 2021 ), “type of vehicle tyres” (Licitra et al 2017 ), “pavement ageing” (Teti et al 2020 ), and “pavement texture and material” (Praticò and Anfosso-Lédée 2012 ; Praticò 2014 ; Del Pizzo et al 2020 ; de León et al 2020 ) as other important parameters that should be considered.…”

An Overview of Acoustic Impedance Measurement Techniques and Future Prospects

“…As described in Section 4, the p-u probes also find their applications in free field impedance measurements. Bianco et al [95] and Praticò et al [96] show the specific applications of p-u probes in free field environment. Few other direct velocity sensors specific to free field techniques are discussed here.…”

Smart Wireless Acoustic Sensor Network Design for Noise Monitoring in Smart Cities

“…In terms of instrumentation, a contribution by Bianco et al [ 4 ] studied the development of a measurement instrument that can be fastened by means of holding elements to a moving laboratory, a vehicle, for example. This device overcomes the fact that the measurements are usually on-site, and allows one to perform a continuous spatial characterization of a given pavement in order to yield a direct evaluation of the surface’s equality.…”