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.
References
[1]
Hatada, T; Takahashi, M; Suzuki, Y; Matsuya, I; Kanekawa, K; Nitta, Y; Nishitani, A. Measurement of Relative Story Displacements by Noncontact-Type Sensors on Forced Vibration Test of an Actual Building. J. Struct. Constr. Eng. AIJ？2010, 75, 11257–11264.
[2]
Kanekawa, K; Matsuya, I; Sato, M; Tomishi, R; Takahashi, M; Miura, S; Suzuki, Y; Hatada, T; Katamura, R; Nitta, Y; Tanii, T; Shoji, S; Nishitani, A; Ohdomari, I. An Experimental Study on Relative Displacement Sensing Using Phototransistor Array for Building Structures. IEEJ Trans. Elec. Electron. Eng？2010, 5, 251–255, doi:10.1002/tee.20524.
[3]
Matsuya, I; Tomishi, R; Sato, M; Kanekawa, K; Nitta, Y; Takahashi, M; Miura, S; Suzuki, Y; Hatada, T; Katamura, R; Tanii, T; Shoji, S; Nishitani, A; Ohdomari, I. Development of Lateral-Displacement Sensor for Real-Time Detection of Structural Damage. IEEJ Trans Elec Electron Eng？2011, 6. in press.
[4]
Oshima, M; Hayashi, T; Fujioka, S; Inaji, T; Mitani, H; Kajino, J; Ikeda, K; Komada, K. VHS Camcorder with Electronic Image Stabilizer. IEEE Trans. Consum. Electron？1989, 35, 749–758, doi:10.1109/30.106892.
[5]
Park, JW; Lee, JJ; Jung, HJ; Myung, H. Vision-Based Displacement Measurement method for High-Rise Building Structures Using Partitioning Approach. NDT E. Int？2010, 43, 642–647, doi:10.1016/j.ndteint.2010.06.009.
[6]
Matsuya, I; Tomishi, R; Sato, M; Kanekawa, K; Takahashi, M; Miura, S; Suzuki, Y; Hatada, T; Oshio, M; Katamura, R; Nitta, Y; Tanii, T; Shoji, S; Nishitani, A; Ohdomari, I. Development of Noncontact-Type Relative Story displacement Monitoring System. Proceedings of the fifth International Workshop on Advanced Smart Materials and Smart Structures Technology (ANCRiSST), Boston, MA, USA, 29 July–1 August 2009; pp. 161–166.
[7]
Matsuya, I; Oshio, M; Tomishi, R; Sato, M; Kanekawa, K; Takahashi, M; Miura, S; Suzuki, Y; Hatada, T; Katamura, R; Nitta, Y; Tanii, T; Shoji, S; Nishitani, A; Ohdomari, I. Noncontact-Type Relative Displacement Monitoring System Using Position Sensitive Detector. AIJ J. Technol. Des？2010, 16, 469–472, doi:10.3130/aijt.16.469.
[8]
Kiyoshige, S. Review of the Vibration Reduction Technology in the Digital Single-Lens Reflex Camera System ( Digital Single-Lens Reflex Camera). J. Inst. Image Inf. TV Eng？2007, 61, 279–283.
[9]
Kim, JA; Bae, EW; Kim, SH; Kwak, YK. Application of Sensitivity Analysis for Design of Six-Degree-of-Freedom Measurement System. Opt. Eng？2001, 40, 2837–2844, doi:10.1117/1.1418714.
[10]
Kwon, K; Park, JJ; Cho, N. A Highly Sensitive Multi-Dimensional Motion Measurement System Using a Spherical Reflector. Meas. Sci. Technol？2006, 17, 2421–2429, doi:10.1088/0957-0233/17/9/008.
[11]
Data Sheet of Two-Dimensional PSD (S2044); Hamamatsu Photonics K.K.: Hamamatsu, Japan. Available online: http://jp.hamamatsu.com/resources/products/ssd/pdf/s1880_s2044_kpsd1015e06 (accessed on 13 August 2010).
