Microphone Array Siren Detection for Occluded Emergency Vehicles

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Solution Overview

Problem

Autonomous vehicles struggle to detect and respond to emergency vehicles, especially when they are occluded or out of range of the perception system, as visual cues like flashing lights may not be discernible, and sirens can be difficult to identify accurately.

Innovation Solution

Equipping autonomous vehicles with microphone arrays to detect siren noise, using models to estimate bearing, range, and velocity of the emergency vehicle, and comparing this information with environmental data to determine an appropriate response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual perception systems are used to detect emergency vehicles, then detection accuracy can be improved when vehicles are visible, but detection fails when emergency vehicles are occluded or out of range

Engineering Contradiction:
Improvedetection accuracyVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent combines visual perception systems with acoustic detection systems (microphone arrays) to create a multi-modal detection system. The acoustic system detects sirens and estimates emergency vehicle characteristics, while the visual system provides complementary detection when vehicles are visible. This merging of different sensing modalities ensures reliable detection whether the vehicle is visible or occluded.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The acoustic detection system acts as an intermediary that provides detection capability when visual systems fail. The microphone array detects siren sounds and infers emergency vehicle presence, position, and motion characteristics, serving as a mediator that bridges the gap when direct visual observation is impossible.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If acoustic detection systems are added to detect sirens, then detection capability in occluded situations is improved, but system complexity increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The acoustic detection system serves multiple functions: detecting siren presence, estimating emergency vehicle bearing, determining range, and calculating velocity. This multi-functionality reduces the need for separate systems and justifies the added complexity by providing comprehensive detection and tracking capabilities from a single acoustic subsystem.

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

Solution Approach 2:

The microphone array system is self-contained, using multiple microphones to automatically perform beamforming, siren detection, and parameter estimation without requiring external assistance. The system processes acoustic signals internally to generate emergency vehicle characteristics, reducing the burden on other vehicle systems.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If multiple microphones are used to estimate bearing and velocity, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveparameter estimation accuracyVSAvoidmicrophone array complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The microphone array is segmented into multiple spatially distributed microphones, each capturing acoustic signals from different positions. This segmentation enables the system to perform spatial processing, beamforming, and time-difference-of-arrival calculations to accurately estimate bearing and velocity of emergency vehicles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from single-point acoustic detection to spatial acoustic field analysis by distributing microphones across multiple dimensions. This dimensional expansion enables the system to extract bearing and velocity information from the spatial and temporal characteristics of acoustic wavefronts.

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

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 the autonomous vehicle to detect and respond to emergency vehicles even when they are not visibly detected, providing critical information for safe maneuvering and reaction to the emergency situation.

Implementation Method 1

an audio recording of the environment can be captured by a microphone array of the perception system

Methodology Applied
Scientific EffectAcoustic detection: Sound

Data Source

PatentEP3616183B1Detecting and responding to sirens
Publication Date: 2025.11.12 WAYMO LLC
  • EP3616183B1 patent drawingFigure 1
  • EP3616183B1 patent drawingFigure 2
  • EP3616183B1 patent drawingFigure 3A

AI summary

The technology relates to detecting and responding to emergency vehicles. This may include using a plurality of microphones (152) to detect a siren noise corresponding to an emergency vehicle and to estimate a bearing of the emergency vehicle. This estimated bearing is compared to map information to identify a portion of roadway on which the emergency vehicle is traveling. In addition, information identifying a set of objects in the vehicle's environment as well as characteristics of those objects is received from a perception system is used to determine whether one of the set of objects corresponds to the emergency vehicle. How to respond to the emergency vehicle is determined based on the estimated bearing and identified road segments and the determination of whether one of the set of objects corresponds to the emergency vehicle. This determined response is then used to control the vehicle in an autonomous driving mode.