Bridge cable group cable force synchronous monitoring system and method based on microwave full-field sensing

Abstract

The invention discloses a bridge cable group cable force synchronous monitoring system and method based on microwave full-field sensing. The bridge cable group cable force synchronous monitoring method comprises the steps of: enabling a front-end beam direction of a microwave radar to be aligned with a to-be-detected bridge cable, controlling a transmitting antenna to repeatedly transmit linear frequency modulation continuous wave microwave radar signals, enabling a plurality of receiving antennas to receive the reflection signals of a plurality of to-be-detected cables, and acquiring a multi-channel intermediate frequency baseband signal through frequency mixing; and then realizing multi-measuring-point positioning and vibration response synchronous measurement of a plurality of inhaul cables based on a distance-angle combined dimension according to the multi-channel intermediate-frequency baseband signal, and achieving online synchronous monitoring and early warning of an inhaul cable group. According to the bridge cable group cable force synchronous monitoring system and the method, a plurality of measuring points on the plurality of inhaul cables of the bridge are positioned and distinguished through distance-angle combined dimensions, vibration response information of the multiple measuring points of the inhaul cable group is synchronously extracted, and online synchronous, accurate and rapid measurement is carried out on the cable force of the inhaul cable group.

Description

technical field [0001] The invention relates to a technology in the field of civil engineering testing, in particular to a system and method for synchronously monitoring cable forces of bridge cable groups based on microwave full-field sensing. Background technique [0002] The existing robot-assisted bridge cable force detection technology is to detect the surface and interior of the cable during the climbing process of the cable, but this kind of industrial robot is relatively heavy, the degree of intelligence is not high, the equipment cost is high, and the measurement consumption is high. Time. In addition, based on the mathematical relationship between the cable force and the natural frequency of the cable, through the vibration frequency measurement method, the bridge cable force monitoring method represented by the acceleration sensor and the fiber optic sensor can realize online monitoring, but only a certain root can be monitored. Single-point test of a certain pos...

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Problems solved by technology

[0002] The existing robot-assisted bridge cable force detection technology is to detect the surface and interior of the cable during the climbing process of the cable, but this kind of industrial robot is relatively heavy, the degree of intelligence is not high, the equipment cost is high, and the measurement consumption is high. Time

In addition, based on the mathematical relationship between the cable force and the natural frequency of the cable, through the vibration frequency measurement method, the bridge cable force monitoring method represented by the acceleration sensor and the fiber optic sensor can realize online monitoring, but only a certain root can be monitored. Single-point test of a certain position of the cable, when performing multi-point test of multiple cables or a certain cable, it is necessary to arrange multiple acceleration sensors or fiber grating vibration sensor groups to realize the distributed measurement of the cable force. However, this contact The traditional vibration measurement method requires more complex sensor installation, complex network wiring, and time-consuming and laborious testing.

[0003] The cable vibration monitoring method based on video is mainly used in non-contact measurement, but this method is easily affected by environmental factors such as light, the measurement accuracy is low, and the frequency response bandwidth is limited; while the existing cable force monitoring based on microwave radar The method is limited by the transmission bandwidth, the distance resolution is low, and the problems of static clutter interference, adjacent multi-component coupling and aliasing interference of the same distance unit components are prominent, resulting in the inability to achieve high-precision deformation and vibration measurement

In particular, in the cable force test for actual engineering, due to the long cables, multiple cables are often in the same or adjacent distance units and it is difficult to distinguish, and it is easy to produce multiple cables adjacent to the distance unit within the radar beam radiation range. Vibration coupling and multiple cable vibration aliasing interference of the same distance unit lead to a significant decrease in the vibration measurement accuracy of the cable, or even failure

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