WO2021114650A1

WO2021114650A1 - Tailskin clearance measurement system based on high-resolution camera image collection and processing

Info

Publication number: WO2021114650A1
Application number: PCT/CN2020/100744
Authority: WO
Inventors: 江玉生; 郑春燕; 杨志勇; 侯公羽; 江涛
Original assignee: 南京城市地下空间工程研究院有限公司
Priority date: 2019-12-14
Filing date: 2020-07-08
Publication date: 2021-06-17
Also published as: CN110954003A

Abstract

A tailskin clearance measurement system based on high-resolution camera image collection and processing. The tailskin clearance measurement system comprises a high-resolution camera, a data processing module, and a display module. The high-resolution camera is used for collecting an image of a tailskin clearance, the collected image is transmitted to the data processing module, an image recognition program is configured in the data processing module and recognizes a gap width in the collected image, and the obtained recognition result and the corresponding image are transmitted to the display module for being displayed. According to the system, a non-contact measurement mode is used, and by means of an application of the visual technology, human eye judgment is replaced with machine recognition; an imaging element converts a photographed target into an image signal and transmits the image signal to an image processing system, the tailskin clearance is accurately measured, operation is easy and convenient, and precision is high.

Description

Shield tail gap measurement system based on high resolution camera image acquisition and processing

Technical field

The invention belongs to the technical field of subway tunnel construction application, and is specifically a shield tail gap measurement system based on high-resolution camera image acquisition and processing.

Background technique

Shield tail clearance refers to the gap between the inner diameter of the shield tail steel ring and the outer diameter of the assembled pipe segments. Due to the difference in the stroke of the shield pushing jack, the posture correction, the difference in soil strength, etc., the shield tail clearance will be different in the up, down, left, and right directions. If the difference is too large, it will not only accelerate the abrasion of the shield tail sealing brush, but also "stuck" the tube pieces in the shield shell, which will cause the tube pieces to break, and even water inrush accidents may occur in severe cases.

The shield tail gap is generally 5cm~10cm. If the gap is too small, there will be the risk of the tube pieces rubbing against the inner wall of the shield shell, which will cause the tube pieces to be misaligned, damaged, and cracked. Therefore, every time a ring of segment is assembled, the shield tail gap must be normal and reasonable. At present, the shield tail clearance relies on manual measurement, which is not only inefficient, but also impossible to grasp in real time. Different measurement personnel often measure different positions. In addition to personal reading habits, it is difficult to ensure accuracy, and it is often difficult to reach large-size shield workers. The upper segment is more difficult to measure.

VMT’s SLUM system is widely used in Herrenknecht shields. 5 laser measuring sensors are installed on the assembling machine. As the assembling machine moves forward, the shield tail gap is measured. Due to the limitation of the working method, it cannot be installed in the equipment disc type. On the shield of the assembling machine.

The shield tail gap measurement system of Ishikawa Island Company is installed near the bottom of the jack. It relies on the air valve combined inclination sensor to work and can be controlled by the touch screen on the operation panel or the portable operation box. The measuring device is large in size and very inconvenient to install and use, so it is not suitable for subway shields.

Mitsubishi's shield tail gap measurement system has basically the same structure, installation location and working method as the above-mentioned Ishikawajima system. Mainly used in Mitsubishi subway shields, the protection is poor. Due to the harsh construction environment, the equipment often fails after being contaminated with mud or water.

In the shield tunneling system of Shanghai Lixin Surveying Company, a cross-section scanner is installed on the beam below the shield assembly machine. The scanner scans the tangential direction of the inner side of the tube by emitting a certain wavelength of radio waves, and fits the center of the tube through a program. Calculate the shield tail clearance through the coordinates of the center of the shield shell and the center of the tube at the same mileage. The radio wave signal is greatly affected by external interference and will be affected by the smoothness of the tube surface.

Summary of the invention

The technical problem to be solved by the present invention is that the measuring device for the shield tail gap of the shield machine in the prior art is large in size, difficult to install, easy to malfunction, and affects the measurement effect.

The technical solution of the present invention is: a shield tail gap measurement system based on image acquisition and processing of a high-resolution camera, including a high-resolution camera, a laser ranging module, a data processing module and a display module, the high-resolution camera is used to collect the shield tail gap The laser ranging module is used to measure the distance between the high-resolution camera and the shield gap. The collected image is transmitted to the data processing module. The data processing module is equipped with an image recognition program to identify the gap width in the collected image. The obtained recognition result and the corresponding image are transmitted to the display module for display.

Further, the high-resolution camera and laser ranging module are arranged in multiple groups on the shield machine along the circumferential direction of the shield tail, and the high-resolution camera aggregates and transmits the data to the shield machine PLC through the hub, and then the shield machine PLC Transfer to the data processing module.

As a preferred mode, the display module realizes the following contents by configuring a computer program:

1) Display historical records, and display the last recognition result, that is, the measurement result of the shield tail gap;

2) Read the collected recognition results and corresponding images according to the preset time interval, check the image resolution, and determine whether the image is clear according to the image resolution. If the gap of the image is judged to be clear, the measurement result will be displayed directly; if the gap imaging is not clear , It is displayed as a picture and a ruler, and a ruler is added to the image for direct reading by humans.

Further, a schematic diagram of the cross section of the shield tail is also displayed, and the position of the high-resolution camera is marked on the circumference of the shield tail in the schematic diagram.

The system of the present invention adopts a non-contact measurement method. Through the use of vision technology, machine recognition is used instead of human eye judgment. The imaging element converts the captured target into an image signal and transmits it to the image processing system to accurately measure the shield tail. Clearance, easy operation and high precision.

Description of the drawings

Figure 1 is a schematic diagram of the device layout of the shield tail gap measurement system of the present invention.

Fig. 2 is a schematic flow chart of configuring a computer program in the display module of the present invention.

Fig. 3 is a schematic diagram of a ruler marked on an image collected by the present invention.

Detailed ways

Shield tail clearance refers to the gap between the inner diameter of the shield tail steel ring and the outer diameter of the assembled tube segments. It is an important parameter describing the concentricity of the tube segments and the shield tail (shell). The shield tail gap should be maintained at a reasonable level during normal construction. Within the scope, excessive differences will lead to a series of follow-up problems. Reasonable management of shield tail clearance is an important part of shield construction organization. Reasons for excessive shield tail clearance differences: excessive thrust difference, poor propulsion jack stroke, posture correction , Soil strength difference, segment floating, etc.

If the gap between the shield tails is too large, it will cause the shield tail seals to wear faster, the tube fragments will break, and even water inrush accidents will occur; it will also cause the tube fragments to "stuck" in the shield shell, and the shield will appear in the shape of the shield. Many serious follow-up issues such as tunnel quality.

The shield tail clearance is an important parameter to control the normal tunneling of the shield, and it is the main basis for the segment assembly shape; in reality, the shield tail clearance measurement is often carried out manually after the tunneling is completed, which is not only inefficient, but also impossible to master. A real-time data; different measurement personnel often measure different positions, combined with personal reading habits, it is difficult to ensure accuracy, for large-size shield workers often difficult to reach the upper segment, so the measurement is more difficult, the present invention The main purpose is to realize the informatization of shield tail gap monitoring and management.

The invention provides a shield tail gap measurement system based on image acquisition and processing of a high-resolution camera. The high-resolution camera refers to a high-resolution camera, and refers to a camera with a resolution of more than 10 million. The system of the present invention includes a high-resolution camera, a laser ranging module, a data processing module, and a display module. The high-resolution camera is used to collect images of the shield tail gap, and the laser ranging module is used to measure the gap between the high-resolution camera and the shield. The collected images are transmitted to the data processing module. The data processing module is equipped with an image recognition program to recognize the gap width in the collected images, and the recognition results and corresponding images are transmitted to the display module for display.

The shield tail gap measurement system of the present invention is divided into two parts: field equipment and display module: (1) The shield tail gap collector is a high-resolution camera controlled under the ARM platform to collect gap images, calculate the gap width, and identify the calculation result Together with the gap image is transmitted to the terminal server through the network transmission line, the operator can also make corrections at any time. The measurement results can be seamlessly connected to the monitoring platform. The layout of the equipment is shown in Figure 1. (2) In the display module part, the latest measurement results are displayed on the interface by querying historical records, and the collected data is read according to the preset time interval. If the judgment gap is clear, the data can be directly displayed and converted into The standard up, down, left, and right positions are easy to understand; if the gap imaging is not clear and the knot does not meet the requirements, the system will directly display it as a picture and a ruler, which can be read manually. Its workflow is shown in Figure 2.

In the present invention, the installation position of the high-resolution camera must be free from construction interference and accurately align with the shield tail gap. For example, it is installed at the bottom of the lower left propulsion cylinder of the shield machine to capture images of the gap in real time; the high-resolution camera and laser ranging The modules work together to complete the image recognition gap work. The image acquisition is completed by the camera, and the distance measurement is completed by the laser distance measurement module. Combining the image and the distance, the gap width value in the image is obtained through image processing technology.

Figure 3 shows the actual gap image at a certain location. The scale in the figure is the corresponding corrected measurement scale obtained after the image coordinate system is converted according to the distance measurement value of the laser ranging module, which is equivalent to adding 1 to the image. :1. The ruler used for actual measurement is equivalent to the real ruler used for manual measurement. The data processing module automatically recognizes the outer contour boundary in the image to calculate the size of the gap. At the same time, the ruler in the image is used for manual visual recognition and reading Gap width.

Claims

The shield tail gap measurement system based on high resolution camera image acquisition and processing is characterized by including a high resolution camera, a laser ranging module, a data processing module and a display module. The high resolution camera is used to collect images of the shield tail gap. The distance measuring module is used to measure the distance between the high-resolution camera and the shield gap, and the collected images are transmitted to the data processing module. The data processing module is equipped with an image recognition program to identify the width of the gap in the collected image, and the obtained recognition results and The corresponding image is transmitted to the display module for display.
The shield tail gap measurement system based on high resolution camera image acquisition and processing according to claim 1, characterized in that the high resolution camera and the laser ranging module are arranged in multiple groups on the shield machine along the circumferential direction of the shield tail. The resolution camera transfers the data to the shield machine PLC through the hub, and then the shield machine PLC transmits to the data processing module.
The shield tail gap measurement system based on high-resolution camera image acquisition and processing according to claim 1, wherein the display module is configured with a computer program to achieve the following contents:

1) Display historical records, and display the last recognition result, that is, the measurement result of the shield tail gap;

2) Read the collected recognition results and corresponding images according to the preset time interval, check the image resolution, and determine whether the image is clear according to the image resolution. If the gap of the image is judged to be clear, the measurement result will be displayed directly; if the gap imaging is not clear , It is displayed as a picture and a ruler, and a ruler is added to the image for direct reading by humans.
The shield tail gap measurement system based on high resolution camera image acquisition and processing according to claim 3, characterized in that a schematic diagram of the cross section of the shield tail is displayed, and the position of the high resolution camera is marked on the circumference of the shield tail in the schematic diagram.