TBM Real-Time Guidance Using GPS Retransmission and Laser Mapping
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Solution Overview
Problem
Current tunnel boring machine (TBM) guidance systems face challenges in providing real-time parametric guidance and accurate as-built mapping of tunnel dimensions and centerline due to errors in laser-based navigation and time-consuming surveying methods, which can lead to misalignment and increased costs.
Innovation Solution
An integrated navigation system using GPS retransmission, fault-tolerant inertial navigation, and self-contained mapping with permanent monuments to provide real-time guidance and as-built mapping of tunnel dimensions and centerline, employing a locomotive to transmit data to the TBM and update its position and trajectory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional laser-based navigation and surveying techniques are used for TBM guidance, then the system structure is simple and easy to implement, but measurement precision deteriorates due to error accumulation from progressive monument chaining
Solution Approach 1:
The patent replaces the mechanical/optical laser-based measurement system with a GPS-based satellite navigation system. The TBM is equipped with a GPS receiver that directly receives satellite signals to determine its position, eliminating the need for progressive monument chaining and theodolite measurements. This substitution provides continuous real-time positioning with accumulated precision over long distances without the error propagation inherent in conventional mechanical surveying methods.
2Productivity
If conventional surveying methods are used to map tunnel dimensions, then the equipment required is simple, but productivity deteriorates due to time-consuming surveying operations that require cessation of TBM work
Solution Approach 1:
The patent implements continuous tunnel mapping by mounting a laser scanner on the TBM that operates continuously during tunneling operations. As the TBM advances through the tunnel, the laser scanner continuously scans and records the tunnel wall geometry, eliminating the need to stop work for separate surveying operations. This continuous data collection process maintains uninterrupted tunneling productivity while simultaneously building the as-built map.
Solution Approach 2:
The patent merges the tunneling function and the mapping function into a single integrated system. The TBM serves dual purposes: it excavates the tunnel while simultaneously collecting mapping data through the mounted laser scanner. This combination of functions eliminates the separate surveying step and allows both tunneling and mapping to occur concurrently, maximizing productivity.
3Reliability
If progressive monument chaining is used for TBM guidance, then the initial system setup is simple, but reliability deteriorates due to error accumulation as the tunnel extends
Solution Approach 1:
The patent replaces the mechanical monument chaining system with an electronic GPS-based positioning system. Instead of physically establishing a chain of monuments and measuring distances between them with theodolites, the system uses satellite signals to directly determine the TBM's position in a global coordinate system. This eliminates the cumulative error problem inherent in progressive monument chaining and provides reliable alignment accuracy over the entire tunnel length.
4Measurement precision
If conventional laser guidance systems are used, then the equipment is simple and inexpensive, but measurement precision deteriorates due to light refraction, angle of incidence, and reception errors
Solution Approach 1:
The patent replaces the optical laser guidance system with an electronic GPS satellite navigation system. Instead of using laser beams that are susceptible to refraction, angle of incidence, and reception errors, the system receives electromagnetic signals from satellites and processes them electronically to determine position. This substitution eliminates the optical measurement errors and provides more precise and reliable position identification throughout the tunnel.
Data Source
AI summary
A system and methods are disclosed for providing the location of a tunnel boring machine (TBM) by establishing of a plurality of known locations or “monuments”; from these monuments located at least on, over or within the TBM's start point, known in the art as a “pit”. The present invention provides among other things an integrated navigation system that provides real-time parametric guidance information to the TBM, relative to the tunnel origin, past course and current trajectory, while simultaneously employing a non-contact measuring system in concert with said origin and course information for the final provision of an as-built map of tunnel dimensions and centerline.