基于虚拟传感器的拉索频率获取研究——以南京夹江大桥为例

Research on Cable Frequency Acquisition Based on the Virtual Sensor——Taking Nanjing Jiajiang Bridge as an Example

索结构在桥梁结构中运用十分广泛,作为斜拉桥和吊桥的主要受力及传力构件,其本身的自振特性能够直接反映桥梁结构的安全状况。然而,常规的测量技术大多需要在索上安装所需类型传感器,该操作十分烦琐与危险。因此,文章提出了一种更加经济、高效、安全的非接触式测量方法,将高速摄像机作为远程虚拟传感器结合编写的图像处理代码实现拉索动力响应参数的获取,并且将该方法应用于南京夹江桥拉索运动响应测试。结果显示摄影测量与传统测量方法的结果相近,误差仅为0.80%~1.42%,精度较高,能满足工程测量的需求。

The cable structure is widely used in bridge structure. As the main load-bearing and load-transmitting components of cable-stayed bridges and suspension bridges, its natural vibration characteristics can directly reflect the safety status of the bridge structure. However,most conventional measurement technologies require the installation of the required type of sensor on the cable,which is cumbersome and dangerous. Therefore, this paper proposes a more economical, efficient and safer noncontact measurement method. The high-speed camera is used as a remote virtual sensor to obtain the dynamic response parameters of the cable in combination with the written image processing code, and the method is applied to the cable motion response test of Nanjing Jiajiang Bridge.The results show that the results of photogrammetry and traditional measurement methods are similar with the error of only 0.80%-1.42%, and the accuracy is high, which can meet the needs of engineering measurement.