Dual-Wedge Scan Pattern Control for Elliptical Mobile Scanning

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Solution Overview

Problem

Existing scanning instruments lack flexibility in adapting scan patterns for different survey tasks, such as urban and agricultural areas, due to limitations in beam deflection and pulse rate, leading to inefficient utilization of survey instruments.

Innovation Solution

A mobile scanning instrument with a beam deflection element comprising two rotatable wedges, configured to generate both circular and elliptical scan patterns by adjusting the rotation rates and directions of the wedges, allowing adaptable scan patterns for various survey tasks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single scan pattern is used in the scanning instrument, then the device complexity is reduced, but the adaptability to different survey tasks deteriorates

Engineering Contradiction:
Improvescan pattern adaptabilityVSAvoidbeam deflection mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic scan patterns by making the beam deflection mechanism adjustable between different operational modes. The second wedge can be rotated to different angular positions to dynamically change the scan pattern from circular to elliptical, allowing the system to adapt to different survey requirements without changing the physical structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The scanning instrument achieves multi-functionality by incorporating a universal beam deflection mechanism that can generate multiple scan patterns (circular and elliptical) using the same hardware components. The control unit enables the system to universally handle different survey tasks by selecting appropriate scan patterns based on the application requirements.

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

2Productivity

If the pulse rate is increased to improve survey efficiency, then the productivity increases, but the detection and assignment accuracy deteriorates due to MPiA ambiguity

Engineering Contradiction:
Improvesurvey efficiencyVSAvoiddistance measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent employs periodic modulation of the laser pulse emission synchronized with the beam deflection cycle. By using periodic action with specific duty cycles and timing, the system can operate at high pulse rates while maintaining measurement accuracy through the structured periodic pattern that helps distinguish between multiple pulses in flight.

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If a circular scan pattern is used for urban areas, then the measurement precision for vertical walls is improved, but the productivity decreases due to limited field of view

Engineering Contradiction:
Improvevertical wall detection accuracyVSAvoidsurvey coverage rate
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent introduces asymmetry by implementing elliptical scan patterns that can be oriented at different angles relative to the flight direction. This asymmetric scanning approach allows the beam to cover larger areas more efficiently while still maintaining the ability to detect vertical structures, breaking the symmetry limitation of traditional circular patterns.

Inventive Principle:
Principle #4Asymmetry

4Productivity

If the field of view is increased for landscape survey, then the productivity increases, but the measurement precision for specific features deteriorates

Engineering Contradiction:
Improvesurvey coverage rateVSAvoidfeature detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by allowing different regions of the scan pattern to have different characteristics. The elliptical pattern can be oriented to concentrate scanning lines in specific directions or areas of interest, providing higher measurement precision for important features while maintaining broad overall coverage through the extended field of view.

Inventive Principle:
Principle #3Local quality

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 flexible scan pattern adjustment, optimizing survey efficiency by providing stable angles of view and point density for both urban and agricultural areas, enhancing the usage rate of survey instruments.

Implementation Method 1

The first wedge is mounted rotatable about the central axis and has optical characteristics for deflecting the scanning beam with a first deflection angle. The second wedge is mounted rotatable about the central axis and has optical characteristics for deflecting the scanning beam with a second deflection angle

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4575563A1Elliptical pattern generation for scanning instruments
Publication Date: 2025.06.25 HEXAGON INNOVATION HUB GMBH
  • EP4575563A1 patent drawingFigure 1a~1b
  • EP4575563A1 patent drawingFigure 2a~3
  • EP4575563A1 patent drawingFigure 4

AI summary

The invention relates to a mobile scanning instrument mounted on a carrier vehicle, and configured to acquire point cloud data representing a target area. The mobile scan instrument comprise a beam deflection element having a first and a second wedge mounted rotatable about the central axis. The wedges deflect the scanning beam with a first and a second deflection angle. The two defection angles are different. The scanning instrument configured to provide a first scan pattern having a circular shape by rotating the wedges in the same direction and a second scan pattern having an elliptical shape by rotating the wedges in the opposite direction.