Iterative Sound Source Localization Using TDOA and VDAA

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Solution Overview

Problem

Current sound source localization techniques are cumbersome and expensive due to the complexity of computing source location from time and volume differences measured by multiple microphones, especially in augmented reality environments.

Innovation Solution

A smart sound source locator system that uses an iterative approach with time-difference-of-arrival (TDOA) and volume-difference-at-arrival (VDAA) calculations, selectively choosing microphone combinations to improve localization accuracy while minimizing computational costs and noise errors, by employing distributed microphones and augmented reality functional nodes connected to cloud services.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional non-iterative localization formulas are used, then computation is simpler, but localization accuracy deteriorates in complex environments

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidlocalization accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies iterative refinement to dynamically improve localization accuracy. The system starts with an initial estimate from simple formulas and repeatedly refines it by incorporating additional measurements and correcting errors, transforming a static calculation into a dynamic optimization process that converges to higher precision results.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The iterative localization process uses feedback from residual errors to continuously improve accuracy. Each iteration calculates the difference between predicted and actual sensor measurements, then uses this feedback to adjust the estimated source location, progressively reducing errors and improving precision.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If more microphones are used, then localization accuracy is improved, but hardware cost and device complexity increase

Engineering Contradiction:
Improvelocalization accuracyVSAvoidmicrophone array complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses partial action by selecting and using only the necessary subset of microphones for each localization task. Rather than requiring all microphones to be active simultaneously, the system can achieve accurate localization with a minimal subset, reducing hardware requirements while maintaining precision.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The microphone array is segmented into multiple subsets that can be independently processed. The system divides the full set of microphones into different groups or pairs, allowing localization to be performed using only relevant segments for each specific source location, thereby reducing overall system complexity.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If iterative techniques are used, then localization accuracy is improved, but computational cost increases

Engineering Contradiction:
Improvelocalization accuracyVSAvoidcomputational energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary actions by pre-calculating geometric relationships, sensor positions, and optimization parameters before actual localization occurs. This preprocessing reduces the computational burden during real-time operation, allowing iterative refinement to proceed more efficiently with lower energy consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes parameters by adapting the iteration process based on signal quality, source distance, and environmental conditions. When conditions permit, fewer iterations are performed; when precision is critical or conditions are challenging, additional iterations are executed, optimizing energy usage based on actual needs rather than always maximizing computation.

Inventive Principle:
Principle #35Parameter changes

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

This approach enhances sound source localization accuracy while reducing computational expenses and noise errors, allowing for precise source identification in complex environments with improved efficiency and accuracy.

Implementation Method 1

Measurable differences in the arrival times of source signals among the sensors are used to infer the location of the source. In a constant velocity medium, the time differences of arrival (TDOA) are proportional to differences in source-sensor range (RD).

Methodology Applied
Scientific EffectTime difference of arrival (TDOA): Time of Flight

Implementation Method 2

A smart sound source locator determines the location from which a sound originates according to attributes of the signal representing the sound or corresponding to the sound being generated at a plurality of distributed microphones.

Methodology Applied
Scientific EffectVolume difference at arrival (VDAA): Sound

Data Source

PatentUS12047756B1Analyzing audio signals for device selection
Publication Date: 2024.07.23 AMAZON TECH INC
  • US12047756B1 patent drawing
  • US12047756B1 patent drawing
  • US12047756B1 patent drawing

AI summary

A system efficiently selects at least one device from multiple devices based on received audio signals. In some instances, the system receives audio signals from devices that each comprise at least one microphone. A respective audio signal of the audio signals includes a representation of a sound originating from a location. The system then determines a device to be used to respond to the sound. In some instances, the system analyzes times in which the received audio signals that represent the sound are generated and/or volumes of the sound as represented by the received audio signals. The system can then select the device based on the analysis.