Tunnel Boring Machine Leveling Instrument Beam Splitter Guidance
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Solution Overview
Problem
Existing systems for guiding tunnel boring machines require structural modifications and high-power lasers, leading to increased costs and precision issues due to vibrations, while existing solutions either require additional lasers or suffer from imprecision in determining the center of the prism and measuring angles.
Innovation Solution
A guidance device using a beam splitter member to split the incident laser beam into two divergent beams, allowing a single low-power laser to simultaneously determine the position and angles of the tunnel boring machine, with the beam splitter member being large enough to be continuously struck during the center search phase, ensuring continuous angle measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a remote laser is installed on the total station to measure pitch and yaw angles, then measurement capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces a beam splitter as an intermediary optical element that divides the single laser beam into multiple paths, allowing one laser to simultaneously illuminate multiple prisms and sensors. This mediator enables the total station to measure position and orientation angles without adding multiple separate lasers or complex structural modifications.
Solution Approach 2:
The patent makes a single laser serve multiple functions by using the beam splitter to direct the beam to different targets (prism for position, angular sensor for orientation). This multi-functional approach eliminates the need for separate lasers for different measurement purposes, reducing device complexity while maintaining comprehensive measurement capability.
2Measurement precision
If a high-power laser is used to cross the translucent prism plane and reach the angular sensor, then measurement capability is improved, but cost and safety risks increase
Solution Approach 1:
The patent segments the optical path using a beam splitter, creating separate measurement paths for position detection (via prism) and orientation detection (via angular sensor). This segmentation allows a low-power laser to illuminate multiple targets simultaneously without requiring high power to penetrate translucent materials, reducing cost and safety risks.
3Adaptability or versatility
If multiple prisms are used with a single laser, then measurement capability is improved, but measurement accuracy decreases due to vibrations and time lag
Solution Approach 1:
The beam splitter acts as a mediator that simultaneously directs the laser beam to multiple targets (prism and angular sensor) without sequential timing delays. This eliminates the time-lag problem associated with sequentially targeting multiple prisms, maintaining measurement accuracy even during vibrations by capturing all data points at the same moment.
4Adaptability or versatility
If a small orifice is pierced in the prism center to allow beam passage to the angular sensor, then single laser measurement is enabled, but diffraction phenomena reduce measurement accuracy
Solution Approach 1:
The patent extracts the angular sensor from behind the prism by using the beam splitter to create a separate optical path. Instead of forcing the beam through a small orifice in the prism, the beam splitter diverts part of the beam to the angular sensor, eliminating the need for a small orifice and avoiding diffraction-related accuracy losses.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise determination of the tunnel boring machine's position and orientation in real-time without structural modifications to the total station, using a low-power laser and maintaining precision during vibrations, thus simplifying implementation and reducing costs.
Implementation Method 1
a beam splitter arranged so as to separate an incident beam into a first beam directed towards the prism (11) and a second beam directed towards the angular sensor (12)
Implementation Method 2
a prism (11) arranged to reflect an incident beam so that the reflected beam is parallel to the incident beam
Data Source
Figure 1
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AI summary
The present invention relates to a leveling instrument (10) for guiding a tunnel-boring machine (1), including a reflective prism (11), having a known shape, and an angular sensor (12), said guide being characterized in that it includes an optical beam separating member (14) arranged so as to separate an incident beam into a first beam (L1) directed toward the prism (11), and a second beam (L2) directed toward the angular sensor (12), and so as to send back the beam (R1) that is reflected by the prism (11) parallel to the incident beam.