Extraction of Bridge Fundamental Frequencies Utilizing a Smartphone MEMS Accelerometer

Abstract

Smartphone MEMS (Micro Electrical Mechanical System) accelerometers have relatively low sensitivity and high output noise density. Therefore, it cannot be directly used to track feeble vibrations such as structural vibrations. This article proposes an effective increase in the sensitivity of the smartphone accelerometer utilizing the stochastic resonance (SR) phenomenon. SR is an approach where, counter-intuitively, feeble signals are amplified rather than overwhelmed by the addition of noise. This study introduces the 2D-frequency independent underdamped pinning stochastic resonance (2D-FI-UPSR) technique, which is a customized SR filter that enables identifying the frequencies of weak signals. To validate the feasibility of the proposed SR filter, an iPhone device is used to collect bridge acceleration data during normal traffic operation and the proposed 2D-FI-UPSR filter is used to process these data. The first four fundamental bridge frequencies are successfully identified from the iPhone data. In parallel to the iPhone, a highly sensitive wireless sensing network consists of 15 accelerometers (Silicon Designs accelerometers SDI-2012) is installed to validate the accuracy of the extracted frequencies. The measurement fidelity of the iPhone device is shown to be consistent with the wireless sensing network data with approximately 1% error in the first three bridge frequencies and 3% error in the fourth frequency.

The Way Forward for Indirect Structural Health Monitoring (iSHM) Using Connected and Automated Vehicles in Europe

“…An extended review of SHM applications based on smart sensing units can be found in [56], while [57] discusses the use of such technologies for vehicle-assisted SHM. It is recognized that certain smart technologies (e.g., smartphones and cameras) have been developed for different type of applications and therefore may face certain limitations compared to traditional sensing monitoring units for SHM (e.g., low sensitivity, high input noise in slow acquisition sampling rate from smartphone-embedded accelerometers [58], and low-resolution cameras). Nonetheless, the ever-increasing development of sensor technologies may prove a promising tool for future indirect infrastructural monitoring operations using CAVs.…”

Design and Validation of a Scalable, Reconfigurable and Low-Cost Structural Health Monitoring System

“…Recently, several studies have compared low-cost MEMS sensors with traditional piezo-electric accelerometers on SHM monitoring tests on real structures. These investigations have shown the technical advantages and limitations of this new digital technology [ 24 , 25 , 26 , 27 , 28 , 29 ]. The MEMS technology has grown quickly in the last few years, new accelerometers being developed with improved properties, accuracy and sensitivity, but keeping their small size, wide variety of available models, and very low cost.…”

“…The MEMS technology has grown quickly in the last few years, new accelerometers being developed with improved properties, accuracy and sensitivity, but keeping their small size, wide variety of available models, and very low cost. For that reasons, MEMS accelerometers are suitable for structural monitoring, and many researchers have used this technology to develop new SHM systems [ 23 , 24 , 25 , 30 , 31 , 32 , 33 ].…”

Arc Length method for extracting crack pattern characteristics

“…1 Investigation of the vibrational response is a typical method which is utilized for structural health monitoring (SHM) over the past decades. 2 Mainly, the extraction of modal parameters is the basis of the judgment relating to structural integrity and safety. [3][4][5] It should be mentioned that these types of SHM methods are less applicable for structures such as tunnels compared to bridges and buildings.…”

“…In this regard, frequent monitoring of the health of structures is inevitable 1 . Investigation of the vibrational response is a typical method which is utilized for structural health monitoring (SHM) over the past decades 2 . Mainly, the extraction of modal parameters is the basis of the judgment relating to structural integrity and safety 3–5 .…”