Indoor Navigation Using Multi-Beam Laser Projector

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Solution Overview

Problem

Conventional indoor navigation techniques face challenges such as occlusion, sensitivity issues, and accuracy degradation due to incremental positioning errors, particularly in environments where surface texture is not available or when computational requirements are high, making them impractical for real-time applications in scenarios like building construction and aircraft assembly.

Innovation Solution

An indoor navigation system utilizing a multi-beam laser projector that emits beams in various directions, allowing cameras to estimate the position and orientation of the projector and attached objects in three dimensions, minimizing occlusion and sensitivity concerns through redundancy and direct referencing to building coordinates, with modest computational requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If vision-based navigation systems are used to interpret video scenes, then navigation capability is provided, but computational requirements become too great to run in real time

Engineering Contradiction:
Improvenavigation capabilityVSAvoidcomputational capacity
Core Design Contradiction:
Ease of operationVSPower

Solution Approach 1:

The patent replaces complex vision-based computational systems with a simpler laser-based ranging system. Instead of using cameras to capture and interpret video scenes (which requires high computational power), the system uses laser beams to directly measure distances to landmarks, dramatically reducing computational requirements while maintaining navigation capability

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

Solution Approach 2:

The system creates simplified optical copies of the environment by projecting laser beams to create measurable light spots on landmarks. Rather than capturing full video scenes and processing them computationally, the laser system creates direct optical measurements that can be processed with minimal computation

Inventive Principle:
Principle #26Copying

2Ease of operation

If incremental positioning methods are used for indoor navigation, then positioning capability is provided, but errors accumulate which degrade positioning accuracy

Engineering Contradiction:
Improvepositioning capabilityVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system performs preliminary calibration by establishing known landmark positions and laser beam geometries before navigation begins. This pre-established reference framework allows the system to calculate absolute positions directly rather than incrementally, preventing error accumulation while maintaining positioning capability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses multiple laser beams and multiple landmarks to create redundant measurements that provide feedback on positioning accuracy. By cross-validating position calculations from multiple independent measurement paths, the system can detect and correct errors before they accumulate

Inventive Principle:
Principle #23Feedback

3Device complexity

If object-tracking cameras are located close to one another, then device complexity is reduced, but sensitivity decreases due to small angle measurements

Engineering Contradiction:
Improvecamera configurationVSAvoidsensitivity
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transitions from two-dimensional camera image analysis to three-dimensional laser ranging measurements. By using laser time-of-flight or phase-shift measurements, the system achieves accurate distance measurements without relying on small angle differences between closely-spaced cameras, thereby maintaining sensitivity while keeping device complexity low

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

4Loss of information

If surface texture is used for vision-based navigation, then navigation information is extracted, but the system becomes dependent on texture availability which is not always present

Engineering Contradiction:
Improvenavigation informationVSAvoidenvironmental adaptability
Core Design Contradiction:
Loss of informationVSAdaptability or versatility

Solution Approach 1:

The system replaces vision-based texture analysis with laser-based geometric measurement. Instead of relying on surface texture patterns that may not be available, the laser system directly measures distances to geometric features, making the navigation system adaptable to environments with any surface texture or no texture at all

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

The system provides accurate and robust tracking of location and orientation in indoor spaces with reduced computational and power demands, avoiding issues like occlusion and sensitivity, and maintaining accuracy over time by using multiple beams spread over a large solid angle.

Implementation Method 1

a multi-beam laser projector that emits beams in various directions

Methodology Applied
Scientific EffectLaser: Laser

Data Source

PatentEP2976599B1Indoor navigation system and method
Publication Date: 2019.07.03 TRIMBLE INC
  • EP2976599B1 patent drawingFigure 1
  • EP2976599B1 patent drawingFigure 2
  • EP2976599B1 patent drawingFigure 3

AI summary

Disclosed is a method for indoor navigation. Two or more cameras capture images of a first set of spots made by one or more laser beams, and images of a second set of spots made by one or more laser beams. The laser beams making the set of spots are emitted by a laser projector in a set of four or more different directions during a time interval on surfaces of an indoor space. Three-dimensional locations of spots are estimated from images captured by at least two cameras during the first and second time intervals. A position of the laser projector in the indoor space during the first and second time intervals is estimated by space resection given the first and second sets of four or more different directions and the three-dimensional locations of the spots.