Real-time dynamic displacement monitoring with double integration of acceleration based on recursive least squares method

Abstract

Due to the difficulty of establishing fixed reference points, it is difficult to monitor displacement of a civil engineering structure in the field for long term. Although to integrate acceleration signals numerically is a common and low-cost displacement measurement method, the schemes proposed in the field of seismology are not suitable for long-term structural monitoring environment because of batch calculations of existing algorithms. In this paper, combining a baseline correction technique based on recursive least squares, a recursive high-pass filter and a recursive integrator, through multi-round baseline correction, filtering and integration, the authors develop an online and real-time acceleration integral scheme. This scheme is then applied to a numerical simulation case and a shaking table test, where the accuracy and reliability are proved. Finally, the applicability of the scheme in real monitoring environment is confirmed through utilizing it to monitor displacement of a real bridge.