Surveying Instrument Height Measurement Using Averaged Laser Region

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Solution Overview

Problem

Manual measurement of instrument height using a measuring tape is cumbersome and inaccurate, and existing laser methods are prone to errors due to irregularities and tilt, especially when using a laser distance-measuring device.

Innovation Solution

A surveying instrument equipped with a defocusing lens to expand the distance-measuring light beam, allowing multiple measurements within a predetermined region, combined with a tilt sensor for correction, and using visible laser light for centering, calculates an average distance to improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual measurement with a measuring tape is used, then the measurement process is simple, but the measurement accuracy is low and the work is troublesome

Engineering Contradiction:
Improveinstrument height measurement accuracyVSAvoidmeasurement operation complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces manual mechanical measurement with a laser-based optical measurement system. The laser distance-measuring device emits light to the measurement point and calculates distance based on light travel time, eliminating the need for manual tape measurement and significantly improving both accuracy and ease of operation.

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

Solution Approach 2:

The surveying instrument automatically performs the measurement process without requiring manual intervention for each measurement point. The system automatically targets multiple points within the irradiated region and computes the average distance, making the measurement process self-executing and reducing operational complexity.

Inventive Principle:
Principle #25Self-service

2Productivity

If laser distance-measuring device is used to measure instrument height, then the measurement speed is improved, but measurement accuracy deteriorates due to irregularities and tilts at distance-measuring points

Engineering Contradiction:
Improvemeasurement speedVSAvoidinstrument height measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent divides the measurement process into multiple segments by targeting multiple discrete points within the irradiated region. Instead of measuring a single point, the system measures multiple points (e.g., first distance-measuring point, second distance-measuring point) and calculates the average distance, thereby reducing the impact of irregularities and tilts at any single point.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the measurement parameter from a single-point measurement to a multi-point average measurement. By measuring distances to multiple points within the irradiated region and computing the average, the system transforms the measurement approach to compensate for local irregularities and tilts, thereby improving overall measurement accuracy while maintaining high measurement speed.

Inventive Principle:
Principle #35Parameter changes

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 and efficient measurement of instrument height by averaging multiple distance measurements, correcting for tilt and irregularities, and simplifying centering operations.

Implementation Method 1

a defocusing lens disposed in a light path of the distance-measuring light and configured to diffuse incident light, the distance-measuring light that has passed through the defocusing lens is emitted toward a position below the vertical axis

Methodology Applied
Scientific EffectLight diffusion: Scattering

Implementation Method 2

a light receiving unit configured to receive the distance-measuring light that has been emitted from the light transmitting unit and returned by being reflected by the distance-measuring object

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

an arithmetic unit configured to calculate a distance to the distance-measuring object by analyzing light being the distance-measuring light returned by being reflected by the distance-measuring object

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP4257923B1Surveying instrument
Publication Date: 2026.04.29 TOPCON CORPORATION
  • EP4257923B1 patent drawingFigure 1
  • EP4257923B1 patent drawingFigure 2
  • EP4257923B1 patent drawingFigure 3

AI summary

Provided is a surveying instrument capable of easily measuring an instrument height with precision. In a surveying instrument including an instrument height measuring unit configured to make a distance measurement by emitting distance-measuring light to a distance-measuring object below a vertical axis of a surveying instrument main body, and an arithmetic unit configured to calculate a distance to the distance-measuring object by analyzing light being the distance-measuring light that has returned by being reflected by the distance-measuring object, and calculate an instrument height, the instrument height measuring unit is configured to make a distance measurement by irradiating the distance-measuring light toward a predetermined region of the distance-measuring object centered on a point below the vertical axis of the surveying instrument main body, and the arithmetic unit is configured to calculate the instrument height by operating an average value of distance-measurement values in the region. By calculating an average value of results of distance measurements of a predetermined region, the measurement accuracy can be improved.