Pavement Assessment Using a Dynamic Pressure Sensor System

Abstract

Various sensor systems are wildly used in inspecting the nation’s civil infrastructure of roads and bridges. Unfortunately, infrastructure integrity cannot be conveniently evaluated in an economically or a time efficient way using these existing systems. This work presents a non-destructive and non-contact acoustic sensing approach for fast inspection of roads and bridge deck conditions with vehicles running at normal speed without stopping traffic. This approach, which uses an instantaneous / realtime dynamic tire pressure sensor (DTPS), possesses the capability to inspect pavement conditions from a moving vehicle. By measuring the dynamic pressure changes (the pressure variation rather than the static pressure) inside the tire, useful signals from tire/road interaction can be amplified and isolated from environmental noise. Comparisons between the DTPS, a ground-mounted accelerometer, and a directional microphone were made successfully. In addition, the DTPS can also measure the dynamic response of the tire-road interaction and reduce the cost of currently used road profile measuring systems which use vehicle body-mounted profilers and/or axle-mounted accelerometers. A prototype real-time DTPS with both wired and wireless communication systems has been developed together with a separately designed rotating energy harvester. Both have been demonstrated on a testing van at speeds from 5 to 80 mph. A data analysis algorithm has been developed and optimized to enhance the detection accuracy and to remove axle dynamic motions from the measured DTPS data and to find the transfer function between the dynamic tire pressure change and the road profile. Comparisons between the DTPS response and known Pavement Condition Index (PCI) values for different roads have been carried out. The road profile resolution is approximately 5 to 10 cm in width and sensitivity is 0.3 cm for the height road surface features at driving speeds of 5 to 80 mph.