Reflecting Prism Positioning from Slanted Laser Scans

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Solution Overview

Problem

Existing surveying techniques using light-reflecting targets are inefficient and prone to errors due to assumptions about vertical laser scanning, which can lead to incorrect coordinate measurements when actual scanning is performed in a slightly slanted horizontal plane.

Innovation Solution

A surveying apparatus that uses laser light to measure a light-reflecting target set up on a surface, calculates a plane based on multiple points surrounding the target, and determines the target's position by intersecting this plane with a straight line, accounting for horizontal and vertical coordinates to accurately determine the target's position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If laser scanning is performed along a vertical plane containing the reflective prism, then the position of the reflective prism can be determined, but the actual laser scanning is performed in a slightly slanted horizontal plane which causes errors in obtaining coordinates

Engineering Contradiction:
Improvecoordinate measurement accuracyVSAvoidlaser scanning operation simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs laser scanning in the actual slanted horizontal plane and uses the returned point cloud data to calculate the true vertical position through mathematical computation. The determination unit feedbacks the actual scanning plane orientation and the surface calculator computes the vertical projection, correcting the coordinate error without requiring manual intervention to adjust scanning orientation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention changes the parameter of scanning plane orientation from the ideal vertical plane to the actual slanted horizontal plane, and then compensates for this parameter change through computational geometry. By accepting the actual scanning orientation and mathematically transforming the results, the system achieves both operational simplicity and measurement accuracy.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the position of the reflective prism is determined by laser scanning, then surveying can be performed, but precise initial setup and handling of the target is required which increases workload

Engineering Contradiction:
Improvesurveying operation efficiencyVSAvoidsetup and handling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system performs self-alignment by automatically determining the scanning plane orientation and calculating the vertical projection point from the point cloud data. The determination unit and surface calculator work together to self-correct positioning errors, eliminating the need for manual setup adjustments and reducing operational complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces manual mechanical setup and alignment operations with automated computational geometry. Instead of requiring physical adjustment of the reflective prism or scanning apparatus to achieve perfect vertical alignment, the system uses mathematical calculations on the point cloud data to compensate for misalignment, substituting mechanical precision requirements with computational solutions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This method enables efficient and accurate surveying operations by eliminating the need for precise initial setup and correcting for target tilt, reducing errors and workload associated with handling light-reflecting targets.

Implementation Method 1

a surveying apparatus measures the position of the reflecting prism by using laser light

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

receives reflection light from the object with a light-receiving unit

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4155665B1Surveying apparatus, surveying method, and surveying program
Publication Date: 2025.10.22 TOPCON CORPORATION
  • EP4155665B1 patent drawingFigure 1
  • EP4155665B1 patent drawingFigure 2A~2B
  • EP4155665B1 patent drawingFigure 3

AI summary

A technique for enabling efficient surveying operation that uses a light-reflecting target is provided. A surveying apparatus is configured to survey a reflecting prism and includes a controller, a surface calculator, and a position calculator. The controller performs positioning on three or more points on the set-up surface on which the reflecting prism is set up, by using laser light. The surface calculator calculates a plane of the set-up surface based on the positioning data of the three or more points in a case in which the position of the reflecting prism is surrounded by the three or more points in terms of a horizontal plane. The position calculator calculates a point of intersection of the plane and a straight line from the position of the reflecting prism to the plane, as a position on the set-up surface, at which the reflecting prism is set up.