Adaptive Vehicle Approach Sound Control Under SPL Limits

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Solution Overview

Problem

Silent electric and hybrid vehicles pose a challenge in notifying pedestrians of their approach due to their quiet operation, and existing notification systems can be improved to better comply with regulatory sound pressure level restrictions.

Innovation Solution

A vehicle approach notification system that includes a filter, a notification sound controller, and a setter, which uses vehicle information to select the appropriate notification sound source, filter properties, or control parameters to generate a notification sound that meets regulatory requirements, and outputs this sound through an exterior loudspeaker.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a notification sound is output to notify pedestrians of approaching vehicles, then pedestrian safety is improved, but the sound pressure level may exceed regulatory restrictions

Engineering Contradiction:

Improvepedestrian safetyVSAvoidsound pressure level

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The notification sound controller dynamically adjusts sound pressure levels and frequency characteristics based on vehicle speed, pedestrian distance, and environmental conditions to maintain effectiveness while complying with regulatory restrictions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system transitions from static notification sounds to dynamic, adaptive sound profiles that change in real-time based on operational parameters, allowing optimization of both safety and regulatory compliance

Inventive Principle:

Principle #15Dynamics

2Difficulty of detecting and measuring

If the notification sound is made louder to improve pedestrian awareness, then detection capability is improved, but energy consumption increases

Engineering Contradiction:

Improvedetection capabilityVSAvoidenergy consumption

Core Design Contradiction:

Difficulty of detecting and measuringVSUse of energy by moving object

Solution Approach 1:

The system applies notification sound at minimum necessary levels for effective detection, using higher levels only when required by environmental conditions or pedestrian vulnerability, thereby optimizing energy efficiency while maintaining detection capability

Inventive Principle:

Principle #16Partial or excessive action

3Device complexity

If a single notification sound profile is used for all vehicle conditions, then device complexity is reduced, but adaptability to different conditions deteriorates

Engineering Contradiction:

Improvesystem complexityVSAvoidadaptability to conditions

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The notification sound controller serves multiple functions by selecting from pre-defined sound profiles and dynamically adjusting parameters, enabling a single device to adapt to various vehicle speeds, environmental conditions, and pedestrian scenarios without requiring separate systems

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12269495B2Vehicle approach notification system and vehicle approach notification method

Publication Date: 2025.04.08 PANASONIC AUTOMOTIVE SYST CO LTD

AI summary

A vehicle approach notification system includes a filter; a notification sound controller which generates a signal corresponding to a notification sound for notifying of approaching of a vehicle, based on a sound signal obtained from a notification-sound sound source; and a setter which obtains vehicle information of the vehicle, and sets, according to the vehicle information, at least one of the notification-sound sound source to be used in generation of the notification sound, a filter property to be applied to the filter, or a control parameter to be applied to the notification sound controller in generation of the notification sound. The notification sound controller outputs the signal generated, through the filter to an exterior loudspeaker provided to the vehicle.