Non-contact visual monitoring system and method for a flexible protective structure against rockfall disaster

Patent metadata

Field	Value
Publication number	US-12347126-B2
Application number	US-202318261620-A
Country	US
Kind code	B2
Filing date	Jun 5, 2023
Priority date	Jun 7, 2022
Publication date	Jul 1, 2025
Grant date	Jul 1, 2025

Abstract

The invention relates to the technical field of intelligent construction and maintenance, and relates to a non-contact visual monitoring system and method for a flexible protective structure against rockfall disasters; it comprises a hardware system and a data analysis system, and the hardware system uses a multipoint distributed high-resolution high-speed camera to capture dynamic image sequences of a protective structure under the rockfall impact in a non-contact mode; the data analysis system comprises an impact deformation state full-field tracking module and a multipoint impact large deformation extraction module, and the impact deformation state full-field tracking module captures spatio-temporal changes of impact deformation of the protective system by adopting a full-field optical flow method, constructs a two-dimensional velocity amplitude distribution diagram and performs full-field spatio-temporal tracking of large deformation of the system.

First claim

What is claimed:

1. A non-contact visual monitoring system for a flexible protective structure against rockfall disasters, characterized in that the non-contact visual monitoring system comprising:
a hardware system and a data analysis system, the hardware system uses a multipoint distributed high-resolution high-speed camera to collect a dynamic image sequence of a flexible protective structure under a rockfall impact in a non-contact mode;
wherein the data analysis system comprises an impact deformation state full-field tracking module and a multipoint impact large deformation extraction module for the flexible protective structure,
wherein the impact deformation state full-field tracking module for the flexible protective structure captures a full-field deformation state of the flexible protective structure under the rockfall impact by adopting a full-field optical flow method,
wherein the impact deformation state full-field tracking module
processes the dynamic image sequence of the flexible protective structure under the rockfall impact captured by the multipoint distributed high-resolution high-speed camera to obtain spatio-temporal changes of impact deformation of the flexible protective structure,
uses the full-field optical flow method to obtain a full-field velocity vector distribution of the flexible protective structure, and
builds a two-dimensional velocity amplitude distribution diagram and tracks all frame images captured by the multipoint distributed high-resolution high-speed camera, to capture a full-field and whole-process tracking of the impact deformation state of the flexible protective structure;

wherein the multipoint impact large deformation extraction module uses an image feature point detection and matching algorithm to extract a multipoint dynamic impact large deformation of the flexible protective structure under the rockfall impact and a maximum elongation based on the multipoint dynamic impact large deformation and evaluating a performance status of the flexible protective structure based on the maximum elongation.

2. A non-contact visual monitoring method for a flexible protective structure against rockfall disasters, characterized in that the non-contact visual monitoring system comprises the following steps:
1) capturing dynamic image of flexible protective structures under rockfall impact disasters;
2) tracking full-field deformation state of the flexible protective structure;
In 2), a specific method for full-field deformation state tracking of the flexible protective structure is as follows:
A grayscale of an image captured by a high-speed camera at t and t+dt is equal, namely:

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Where, I(x+u(x,y),y+v(x,y),t+dt) is the image grayscale information of the pixel (x,y) at t+dt I(x,y,t) is the grayscale information of the pixel (x,y) at t u(x,y) and v(x,y) are the horizontal and vertical displacement field components of the pixel (x,y) respectively: dt is the time interval;
The grayscale information of the pixel (x,y) at t+dt is approximated by the first-order Taylor expansion formula into:

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Assignees

• Univ Southwest Jiaotong

Inventors

• Tian Yongding
• Tong Jiahui
• Lyu Yangfeng
• Yang Xiaoyu
• Chen Jiaxin
• Ma Lintao
• Xu Hu
• Yu Zhixiang

Classifications

• G06T2207/30184

  Infrastructure · CPC title

• G06T2207/20208

  High dynamic range [HDR] image processing · CPC title

• G01B11/16 Primary

  for measuring the deformation in a solid, e.g. optical strain gauge · CPC title

• G06T7/207

  for motion estimation over a hierarchy of resolutions (multi-resolution motion estimation or hierarchical motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/53) · CPC title

• G06T7/269

  using gradient-based methods · CPC title