Multi-angle measurement collection and analysis approach of bridge dynamic response using smartphones

Applications of computer vision are becoming prevalent in measuring bridge response. Response can be calculated when tracking structural features such as bolts or connections in video frames while the bridge is subjected to loadings. Usually static and dynamic responses are measured. During routine bridge inspections cameras could be used to monitor structural deformations, however, the challenge is to make sure that the camera is placed in the same location during the subsequent inspection to allow accurate comparison response. This study explores if videos capturing a bridge subjected to loading from multiple angles/locations can be analysed to derive accurate and comparable response. Smartphones placed at different positions to the bridge are used to capture its dynamic response. Structural feature are selected, and their location are calculated in video frames. Feature locations from both smartphones are transformed to a reference coordinate system (obtained from structural drawings). Results show that locations of features can be accurately transformed to the reference coordinate system. Obtained structural response can be compared and analysed.