Retro-reflecting Element with Passage Surface for Orientation Measurement

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Solution Overview

Problem

Current geodetic surveying systems face limitations in orientation measurement accuracy due to increased complexity, limited measurement range, and susceptibility to environmental influences, particularly in determining the yaw angle, which affects the precision and robustness of position determination.

Innovation Solution

An optical detection unit with a retro-reflecting element and a sensor arrangement that incorporates a passage surface for transmitted measuring light, allowing incidence angle-dependent position determination and using a referencing assembly for deviation compensation, enabling reliable and robust orientation measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a retroreflector with a small passage opening is used for orientation measurement, then the device complexity is reduced, but the measurement precision deteriorates due to asymmetrical imaging and displacement of radiation

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses a code pattern (photomask) that creates a replicated image on the sensor. Instead of directly measuring the small transmitted light spot, the code pattern creates a larger, more easily detectable image that preserves orientation information. This copying approach maintains measurement precision while allowing for a simpler optical design with the small passage opening.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transitions from measuring position in one dimension (direct spot detection) to measuring orientation through a coded pattern distribution across multiple dimensions on the sensor. The code pattern elements are arranged in specific spatial configurations that encode orientation information, allowing precise measurement without requiring a large passage opening.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If additional components are provided on the measuring aid instrument for orientation determination, then the measurement range is improved, but the device complexity increases and spatial extent becomes larger

Engineering Contradiction:
Improvemeasurement rangeVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions into the retroreflector itself. The retroreflector simultaneously performs its primary function of reflecting measurement light back to the instrument while also containing the passage opening and code pattern for orientation measurement. This multi-functionality eliminates the need for separate orientation determination components, reducing device complexity while maintaining measurement capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the retroreflector and the orientation measurement elements (passage opening and code pattern) into a single integrated component. Instead of having separate components for distance measurement and orientation determination, both functions are merged into the retroreflector assembly, reducing the overall device complexity and spatial extent.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If a small passage opening is used in the retroreflector, then the device compactness is improved, but the robustness deteriorates due to sensitivity to environmental influences and measurement errors

Engineering Contradiction:
Improvedevice compactnessVSAvoidrobustness
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent uses the code pattern on the sensor to provide feedback information about the incidence angle of the measurement light. By analyzing the position and distribution of the code pattern image on the sensor, the system can detect and compensate for environmental influences and measurement errors, thereby improving robustness despite the small passage opening that contributes to compactness.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent pre-arranges the code pattern on the sensor and the corresponding photomask on the retroreflector before measurement. This preliminary configuration ensures that the orientation measurement capability is built into the basic structure, allowing the system to maintain robustness through the designed-in geometric relationships rather than requiring active compensation mechanisms that would increase complexity.

Inventive Principle:
Principle #10Preliminary action

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

The solution provides highly accurate and robust orientation measurements by correlating the incidence angle of measuring light with the position on the sensor, improving the determination of spatial orientations and compensating for deviations, thus enhancing the precision and reliability of geodetic surveying.

Implementation Method 1

a retro-reflecting element which provides a reflection surface configured for retro-reflecting a first part of measuring light as reflected measuring light

Methodology Applied
Scientific EffectRetro-reflection: Retroreflector

Implementation Method 2

a passage surface configured for transmitting a second part of the measuring light as transmitted measuring light

Methodology Applied
Scientific EffectLight transmission: Refraction

Implementation Method 3

a sensor arrangement with a sensor configured and arranged subsequently (downstream, behind) of the retro-reflecting element (in relation to a beam incidence direction) so that the transmitted measuring light which is passing through the passage surface is detectable by the sensor

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP4343280A1Monitoring arrangement for an optical system
Publication Date: 2024.03.27 HEXAGON INNOVATION HUB GMBH
  • EP4343280A1 patent drawingFigure 1~2
  • EP4343280A1 patent drawingFigure 3~4
  • EP4343280A1 patent drawingFigure 5~6a

AI summary

Optical detection unit (20) comprising a retro-reflecting element (30) which provides a reflection surface configured for retro-reflecting a first part of measuring light as reflected measuring light for providing determination of a position of the optical detection unit (20) and a passage surface (32) configured for transmitting a second part of the measuring light as transmitted measuring light, further comprising a sensor arrangement (40) with a sensor (41) configured and arranged behind of the retro-reflecting element (30) so that the transmitted measuring light is detectable by the sensor (41). The optical detection unit (20) comprises a referencing assembly (50) with at least one illumination unit (54,55,56) configured to emit reference illumination light. The at least one illumination unit (54,55,56) is arranged with fixed positional relationship to the retro-reflecting element (30) and/or the sensor arrangement (40) and the referencing assembly (50) is configured and arranged to direct the reference illumination light onto the sensor (41).