Structural Displacement, Velocity and Acceleration Measurement System based on Accelerometer and GPS-RTK for Large-scale Civil Structures

Abstract

The latest displacement and velocity sensors such as LDV and LiDAR have limited application in large-scale civil structures, because it is difficult to find an appropriate sensor installation position on which the sensors can aim at the measurement point. Instead, GPS-RTK is widely applied to large civil engineering structures, but GPS-RTK has low sampling rate, accuracy and precision, and is frequently affected by environmental conditions such as bad weather and surrounded obstacles. In the study, a new structural response measurement system has been developed for the online measurement of displacement, velocity and acceleration of large-scale civil structures. The proposed system estimates the structural responses with high sampling rate, accuracy and precision by fusing measurements obtained from GPS-RTK and accelerometer based on two-stage Kalman filter. The proposed system has the following advantages over GPS-RTK sensors: (1) 6 DOF displacement, velocity and acceleration can be measured simultaneously with a single sensor system, (2) The accuracy (around 2 mm) and sampling rate (up to 100 Hz) of the proposed system are better than those of GPS-RTK, and (3) The performance of the system is less affected by environmental conditions. To verify the performance of the proposed system, a field experiments at Yeongjong grand bridge was performed.