VIBRATION SIGNAL FUNDAMENTAL FREQUENCY ESTIMATION OF BRIDGE STAYED CABLE BASED ON ERA ALGORITHM

For bridge stayed cable, the fundamental frequency of vibration signal is an important index. The health status of a bridge can be judged by the deviation degree of fundamental frequency of vibration signal between theory and practice. There are many algorithms to extract the fundamental frequency from vibration signal of stayed cable. But the errors are always very large relatively. In this paper, The ERA algorithm is modified and used to extract the fundamental frequency from vibration signal of stayed cable. The force of stayed cable can be calculated based on the fundamental frequency. So the health status of bridge stayed cable can be determined. Selection of the minimised realisation matrix carefully in ERA algorithm, the fundamental frequency extract by ERA algorithm has higher precision than traditional algorithms. Digital simulation and engineering testing results show that the method is effective and feasible.