Measuring relative-story displacement and local inclination angle using multiple position-sensitive detectors

• Published in: Sensors (Basel, Switzerland) Vol. 10; no. 11; pp. 9687 - 9697
• Main Authors: Matsuya, Iwao, Katamura, Ryuta, Sato, Maya, Iba, Miroku, Kondo, Hideaki, Kanekawa, Kiyoshi, Takahashi, Motoichi, Hatada, Tomohiko, Nitta, Yoshihiro, Tanii, Takashi, Shoji, Shuichi, Nishitani, Akira, Ohdomari, Iwao
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.11.2010; Molecular Diversity Preservation International (MDPI)
• Subjects: Digital cameras; Earthquakes; Electronic mail systems; Equipment Design; Light emitting diodes; local inclination angle; Micro-Electrical-Mechanical Systems - instrumentation; position-sensitive detector; PSD; relative-story displacement; Sensors; structural health monitoring; Vibration; Japan; PSD; position-sensitive detector; structural health monitoring; relative-story displacement; local inclination angle
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s101109687

We propose a novel sensor system for monitoring the structural health of a building. The system optically measures the relative-story displacement during earthquakes for detecting any deformations of building elements. The sensor unit is composed of three position sensitive detectors (PSDs) and lenses capable of measuring the relative-story displacement precisely, even if the PSD unit was inclined in response to the seismic vibration. For verification, laboratory tests were carried out using an Xθ-stage and a shaking table. The static experiment verified that the sensor could measure the local inclination angle as well as the lateral displacement. The dynamic experiment revealed that the accuracy of the sensor was 150 μm in the relative-displacement measurement and 100 μrad in the inclination angle measurement. These results indicate that the proposed sensor system has sufficient accuracy for the measurement of relative-story displacement in response to the seismic vibration.