BEV Sound Control for Relative Speed Perception of Nearby Vehicles

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Solution Overview

Problem

Drivers of battery electric vehicles (BEVs) face difficulty in determining the relative speed of other vehicles due to reduced audible cues, which diminishes their speed perception, especially when encountering vehicles with high silence performance like BEVs or fuel cell electric vehicles (FCEVs).

Innovation Solution

A sound control system for BEVs that uses sensors to detect surrounding vehicles, generates artificial sounds simulating engine or wind noises, and adjusts sound characteristics based on relative speed and distance to enhance speed perception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the silence performance of the battery electric vehicle is enhanced, then the noise level of the vehicle is reduced, but the driver's ability to hear sounds from other vehicles is reduced

Engineering Contradiction:
Improvenoise levelVSAvoidaudible cues from other vehicles
Core Design Contradiction:
Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The patent introduces an intermediary system (sound generation device and processing circuit) that mediates between the silent operating conditions and the driver's need for auditory information. The system generates artificial sounds that represent the acoustic environment, allowing the driver to perceive relative speeds of other vehicles without compromising the vehicle's silence performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a copy of the acoustic information that would normally be heard from other vehicles. Instead of relying on actual sounds from the environment, the system generates synthetic sound signals that replicate the essential information about other vehicles' speeds and positions, allowing the driver to maintain situational awareness in a silent cabin.

Inventive Principle:
Principle #26Copying

2Object-affected harmful factors

If the silence performance of the battery electric vehicle is enhanced, then the noise level of the vehicle is reduced, but the driver's speed perception is reduced

Engineering Contradiction:
Improvenoise levelVSAvoidspeed perception
Core Design Contradiction:
Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The system acts as an intermediary that translates visual information about other vehicles' motion into auditory cues. The processing circuit analyzes image data showing the movement of other vehicles and generates corresponding sound signals that convey speed information, allowing the driver to perceive relative speeds without relying on natural acoustic cues that would increase cabin noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a copy of speed perception information by converting visual observations of other vehicles' motion into artificial sound signals. The system replicates the information that would normally be obtained through hearing engine sounds or wind noise, but does so through a controlled synthetic process that doesn't require the vehicle to make noise.

Inventive Principle:
Principle #26Copying

3Loss of information

If artificial sounds are generated to represent other vehicles, then the driver's speed perception is improved, but the device complexity increases

Engineering Contradiction:
Improvespeed perceptionVSAvoidsound control system
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent implements a multi-functional system where the same processing circuit and sound generation device perform multiple tasks: detecting other vehicles, analyzing their motion, generating appropriate sound signals, and outputting them through speakers. This universal approach consolidates what could be separate complex subsystems into an integrated solution that improves speed perception while managing overall device complexity.

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

Data Source

PatentEP4675611A1Sound control system and battery electric vehicle
Publication Date: 2026.01.07 TOYOTA JIDOSHA KK
  • EP4675611A1 patent drawingFigure 1
  • EP4675611A1 patent drawingFigure 2
  • EP4675611A1 patent drawingFigure 3A~3B

AI summary

A sound control system (1) that is applied to a battery electric vehicle (10) includes: a speaker (70) that is equipped in the battery electric vehicle (10); a sensor (11) that is configured to detect information about a peripheral environment of the battery electric vehicle (10); and a processing circuit (110). The processing circuit (110) is configured to recognize a target vehicle based on the information detected by the sensor (11), the target vehicle being at least one of other vehicles that travel in the periphery of the battery electric vehicle (10), is configured to generate an artificial sound related to the target vehicle, is configured to output the artificial sound from the speaker (70), and is configured to change the characteristic of the artificial sound depending on the relative speed of the target vehicle with respect to the battery electric vehicle (10).