Networked Loudspeaker Self-Calibration via Timestamp Analysis

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Solution Overview

Problem

Current methods for setting up networked loudspeakers for sophisticated three-dimensional audio effects in VR/AR systems require manual effort, specialized knowledge, and expensive equipment, leading to human error and accessibility issues for average consumers.

Innovation Solution

A method for self-organizing a networked loudspeaker platform using time-synchronized microphone arrays and additional sensors, which generates a stimulus signal and records precise timestamps to estimate the location and orientation of loudspeaker participants, establishing a global frame of reference without human intervention beyond a simple setup request.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual measurement and calibration methods are used for networked loudspeakers, then measurement precision can be achieved, but device complexity and ease of operation deteriorate due to requiring specialized knowledge and expensive equipment

Engineering Contradiction:
Improvelocation estimation accuracyVSAvoidsetup procedure accessibility
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs automatic self-calibration by having each loudspeaker participant generate stimulus signals and record timestamps autonomously. The coordinator loudspeaker collects this data and computes locations without human intervention, allowing average consumers to set up the system simply by requesting a setup procedure.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical measurement processes with an automated acoustic field-based system. Instead of physically measuring and plotting locations manually, the system uses stimulus signal propagation through the acoustic field and timestamp recording to automatically determine loudspeaker locations and orientations.

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

2Ease of operation

If automated calibration methods are implemented, then ease of operation improves, but measurement precision may deteriorate without specialized equipment and expertise

Engineering Contradiction:
Improvesetup automationVSAvoidlocation estimation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system uses recorded timestamp data from stimulus signals as feedback to compute and refine loudspeaker location estimates. The coordinator loudspeaker processes the collected timestamp data to determine precise locations and orientations, ensuring accurate measurements even without specialized external equipment.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Each loudspeaker participant serves multiple functions: it acts as both a stimulus signal generator and a measurement receiver with its microphone arrays. This multi-functionality eliminates the need for separate specialized measurement equipment while maintaining measurement precision through the inherent capabilities of the loudspeaker system itself.

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

3Measurement precision

If precise timestamp recording is used for location estimation, then measurement precision improves, but device complexity increases due to time-synchronization requirements

Engineering Contradiction:
Improvetimestamp accuracyVSAvoidtime-synchronization system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The coordinator loudspeaker acts as an intermediary that manages the time-synchronization process. It collects timestamp data from all participants and performs the location computations, simplifying the system architecture by centralizing the synchronization management function rather than requiring complex distributed synchronization across all loudspeakers.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If networked loudspeaker system self-organizes automatically, then ease of operation improves, but reliability may worsen without human intervention for error correction

Engineering Contradiction:
Improvehuman intervention requirementVSAvoidsetup procedure robustness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary calibration actions automatically during the setup procedure, computing loudspeaker locations and orientations before actual use. This preliminary self-organization ensures the system is properly configured and ready for operation without requiring human intervention for error correction during critical setup phases.

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

Enables accurate and automated setup of networked loudspeakers, allowing for precise reproduction of three-dimensional audio effects without manual effort, improving accessibility and reducing human error.

Implementation Method 1

Each loudspeaker participant generates a stimulus signal and records precise start and end timestamps of the stimulus signal

Methodology Applied
Scientific EffectSound wave propagation: Sound

Implementation Method 2

The data is compiled to estimate locations of loudspeaker participants within the time-synchronized network

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP3451707B1Measurement and calibration of a networked loudspeaker system
Publication Date: 2023.09.27 HARMAN INT IND INC
  • EP3451707B1 patent drawingFigure 1~3
  • EP3451707B1 patent drawingFigure 4
  • EP3451707B1 patent drawingFigure 5

AI summary

A system and method for measuring and calibrating a time-synchronized network of loudspeaker participants. Each loudspeaker participant has a plurality of microphone arrays. The system and method generates a stimulus signal at each network participant and records precise sensor data including start and end timestamps of the stimulus signal. The sensor data is compiled to estimate locations of loudspeaker participants within the time-synchronized network to establish a global frame of reference for all of the loudspeaker components in the network.