Citizen Sensors for SHM: Use of Accelerometer Data from Smartphones

Abstract

Ubiquitous smartphones have created a significant opportunity to form a low-cost wireless Citizen Sensor network and produce big data for monitoring structural integrity and safety under operational and extreme loads. Such data are particularly useful for rapid assessment of structural damage in a large urban setting after a major event such as an earthquake. This study explores the utilization of smartphone accelerometers for measuring structural vibration, from which structural health and post-event damage can be diagnosed. Widely available smartphones are tested under sinusoidal wave excitations with frequencies in the range relevant to civil engineering structures. Large-scale seismic shaking table tests, observing input ground motion and response of a structural model, are carried out to evaluate the accuracy of smartphone accelerometers under operational, white-noise and earthquake excitations of different intensity. Finally, the smartphone accelerometers are tested on a dynamically loaded bridge. The extensive experiments show satisfactory agreements between the reference and smartphone sensor measurements in both time and frequency domains, demonstrating the capability of the smartphone sensors to measure structural responses ranging from low-amplitude ambient vibration to high-amplitude seismic response. Encouraged by the results of this study, the authors are developing a citizen-engaging and data-analytics crowdsourcing platform towards a smartphone-based Citizen Sensor network for structural health monitoring and post-event damage assessment applications.

Multi-factor authentication using accelerometers for the Internet-of-Things

“…Recent research [8][9][10][11] in the field of sensor based device identification has proven it is feasible to generate device identifiers using accelerometer sensor data. This work was improved upon in [5] and applied in a Healthcare setting.…”

Biomechanically influenced mobile and participatory pedestrian data for bridge monitoring

“…[23][24][25][26][27][28][29][30] Engaging citizens through ''Citizens for SHM'' (CS4SHM) for structural vibration response measurement, as proposed by the authors, opens a new avenue of sustainable sensor systems but faces significant technical challenges due to numerous uncertainties in the measurement process. 26,27 Uncertainties in the device orientation 31 as well as in the time and the space domains 32 can be eliminated by multisensory data as long as the sensor is in direct contact with the structure of interest. Yet, the usability of sensor data carried or worn by human is still of question.…”

Public-participant quick cable force investigation method using smartphone for bridges in disaster area

“…Smartphones have been applied on some fields besides communication, such as real-time occupancy information acquisition of buildings, 14 conducting questionnaire survey, 15 human health monitoring, 16 car crash detection, 17 structural vibration measurement, 18 structural displacement measurement, 19,20 and seismic sensing. 13,21 Most of the mobile applications can complete data storage and processing on the mobile devices themselves, and embed related softwares or sensors that can be used for SHM. Thus, in 2012, our team had initially proposed the idea for SHM using the smartphones technique in civil engineering 22 and validated the feasibility of this smartphone-based method by applying to cable force test in 2015.…”

“…These issues have also hindered the practical implementation of SHM methodologies on massive scales, such as the networks of highway bridges. 13 Modern smartphones as the highly integrated devices have computational power, information storage capacity, and communication networks. Moreover, smartphones are equipped with a variety of sensors, which make them to be the good choice for distributed monitoring.…”