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铁路桥梁动挠度测量一直是困扰工程界的难题。传统的相对式测量方法需要在测量现场找到静止不动的基准点，难以实现。用地震式传感器测量动挠度，传感器的有限低频效应导致输出信号的畸变。本文提出一种结合信号恢复处理，用地震式低频振动传感器测量桥梁动挠度的新方法。利用信号恢复技术，补偿因地震式低频振动传感器频率特性而畸变的输出信号。本文深入讨论系统存在零点时的恢复方法以及噪声下信号恢复处理的不适定性问题。利用桥梁动挠度的部分先验知识，外推信噪比差的部分低频谱线，反演原始信号。本文的研究为列车激励下桥梁空间振动形态的测量提供了便捷有效的手段。
Dynamic measurement of railway bridges deflection has always been a problem that plagues the engineering community. The traditional relative measurement method needs to find a stationary reference point at the measurement site, which is difficult to achieve. Using a seismic sensor to measure dynamic deflection, the sensor’s limited low-frequency effects cause the output signal to distort. In this paper, a new method of measuring the dynamic deflection of a bridge by using a seismic low-frequency vibration sensor combined with signal recovery processing is proposed. Use signal recovery technology to compensate for the distorted output signal due to the frequency characteristics of the seismic low-frequency vibration sensor. This paper discusses in depth the method of recovery when the system has zero and the ill-posed problem of signal recovery processing under noise. By using the partial prior knowledge of the dynamic deflection of the bridge, part of the low-frequency spectral lines with a poor signal-to-noise ratio are extrapolated and the original signal is inverted. The research in this paper provides a convenient and effective method for the measurement of vibration modes of bridges under train excitation.