Time-Offset Laser Scanning for Moving Object Identification

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Solution Overview

Problem

Existing methods for identifying moving objects in a scanned environment require scanning the environment twice, sacrificing scan time to retrieve additional information about moving objects, which is inefficient.

Innovation Solution

A scanning device with a stator and rotor configuration that allows for time-offset scanning intervals and angular positioning of measurement points, enabling efficient identification of moving objects by analyzing distance measurement data for mismatches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the environment is scanned twice to identify moving objects, then moving object identification accuracy is improved, but measurement time increases

Engineering Contradiction:
Improvemoving object identification accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements periodic scanning with offset time intervals, where the scanner performs multiple scan cycles with progressively shifted timing. Each scan captures data at different time offsets, and by comparing these periodic measurements, moving objects are identified through temporal changes in measurement point positions while stationary points remain consistent across scans.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent performs preliminary scanning to establish a reference point cloud of the environment before identifying moving objects. This preliminary scan creates a baseline against which subsequent scans are compared, allowing the system to pre-establish the expected positions of stationary objects and efficiently detect deviations caused by moving objects in later scans.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If the environment is scanned twice to identify moving objects, then moving object identification capability is improved, but productivity decreases

Engineering Contradiction:
Improvemoving object information retrievalVSAvoidscanning efficiency
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The patent maintains continuous scanning operation without stopping or resetting between scans. The scanner continuously emits measurement beams and collects data across multiple overlapping scan cycles, ensuring that the scanning process never idle. This continuous operation allows efficient processing of time-offset data to identify moving objects while maintaining high productivity through uninterrupted data collection.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If measurement points are densely distributed to improve spatial resolution, then point cloud quality is improved, but measurement time increases

Engineering Contradiction:
Improvespatial resolutionVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent merges data from multiple scan cycles with offset time intervals to achieve dense measurement point distribution. Instead of capturing all dense points in a single time-consuming scan, the system combines measurements from several overlapping scans taken at different times, effectively merging the data sets to create a high-resolution point cloud that would be too time-consuming to acquire in a single pass.

Inventive Principle:
Principle #5Merging (Combining)

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 device enhances spatial resolution of the generated 3D point cloud by doubling the resolution or reducing measurement time by half while effectively identifying moving objects.

Implementation Method 1

a measuring radiation source, a receiving radiation detecting unit, an evaluation unit... the evaluation unit records distance measurement data and related angle determination data based on detected receiving radiation

Methodology Applied
Scientific EffectTime of Flight: Time of Flight

Data Source

PatentEP4001839B1Scanning device for scanning an environment and enabling an identification of scanned moving objects
Publication Date: 2025.09.24 LEICA GEOSYSTEMS AG
  • EP4001839B1 patent drawingFigure 1
  • EP4001839B1 patent drawingFigure 2
  • EP4001839B1 patent drawingFigure 3

AI summary

The present invention relates to a scanning device being configured to enable efficient identification of scanned measurement points being associated with moving objects in an otherwise static environment. The scanning device is built as total station or laser scanner being typically used for scanning an environment and enabling, based on the scanning, the generation of a three dimensional (3D) point cloud representing the scanned environment.