Department of Instrument Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Sensors (Basel). 2012;12(8):9987-10000. doi: 10.3390/s120809987. Epub 2012 Jul 25.
A novel three-point method using a grating eddy current absolute position sensor (GECS) for bridge deflection estimation is proposed in this paper. Real spatial positions of the measuring points along the span axis are directly used as relative reference points of each other rather than using any other auxiliary static reference points for measuring devices in a conventional method. Every three adjacent measuring points are defined as a measuring unit and a straight connecting bar with a GECS fixed on the center section of it links the two endpoints. In each measuring unit, the displacement of the mid-measuring point relative to the connecting bar measured by the GECS is defined as the relative deflection. Absolute deflections of each measuring point can be calculated from the relative deflections of all the measuring units directly without any correcting approaches. Principles of the three-point method and displacement measurement of the GECS are introduced in detail. Both static and dynamic experiments have been carried out on a simple beam bridge model, which demonstrate that the three-point deflection estimation method using the GECS is effective and offers a reliable way for bridge deflection estimation, especially for long-term monitoring.
本文提出了一种利用光栅式电涡流绝对位置传感器（GECS）进行桥梁挠度估计的新的三点法。与传统方法中使用任何其他辅助静态参考点来测量设备不同，该方法直接使用沿跨度轴的测量点的真实空间位置作为彼此的相对参考点。每三个相邻的测量点定义为一个测量单元，一个带有 GECS 的直连接杆固定在其中心部分，连接两个端点。在每个测量单元中，通过 GECS 测量的中测量点相对于连接杆的位移被定义为相对挠度。无需任何修正方法，就可以直接从所有测量单元的相对挠度计算出每个测量点的绝对挠度。本文详细介绍了三点法的原理和 GECS 的位移测量。已经在一个简单的梁桥模型上进行了静态和动态实验，实验结果表明，使用 GECS 的三点挠度估计方法是有效的，为桥梁挠度估计提供了一种可靠的方法，特别是对于长期监测。
