Combined measurement system for double shield tunnel boring machine guidance based on optical and visual methods

Area of Science:

• Geotechnical Engineering
• Robotics and Automation
• Optical Measurement Systems

Background:

• Accurate positioning of the cutting shield is critical for the stability and efficiency of double shield tunnel boring machines (TBMs) during excavation.
• Existing methods may lack the precision or robustness required for real-time TBM guidance.
• The complex underground environment presents challenges for conventional measurement techniques.

Purpose of the Study:

• To develop and validate a combined measurement system for real-time detection of the cutting shield's position on a double shield TBM.
• To enhance the accuracy and reliability of TBM guidance systems through integrated sensing technologies.
• To provide a practical solution for monitoring TBM excavation parameters.

Main Methods:

• Development of a combined measurement system integrating optical feature points, a monocular vision sensor, a laser target sensor, and a total station.
• Implementation of coordinate transformations for determining the cutting shield's position within the total station reference frame.
• Presentation of a monocular vision-based position measurement method and calibration techniques for inter-component relationships.

Main Results:

• Experimental validation on a simulated double shield TBM platform.
• Achieved a mean deviation of 6.8 mm in position detection.
• Demonstrated that the system's accuracy satisfies the guidance requirements for double shield TBMs.

Conclusions:

• The developed combined measurement system offers a viable solution for precise cutting shield positioning in double shield TBM operations.
• The system's accuracy and reliability are confirmed through experimental verification.
• This technology has the potential to improve the safety and efficiency of tunnel boring operations.