Pedestrian Vehicle Sound Generator Frequency Band Control
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Solution Overview
Problem
Environmentally-friendly vehicles, such as hybrid and electric vehicles, lack recognizable engine sounds, leading to safety concerns for pedestrians and drivers, as they do not generate engine noise, making it difficult to identify the vehicle's state or speed, and existing sound generation systems are inadequate in providing sufficient information and matching actual vehicle behavior.
Innovation Solution
An environmentally-friendly vehicle sound generator control apparatus that uses pitch and volume control points to create a recognizable sound source by shifting and adjusting frequencies and volumes based on driving speed, forming a linear interconnection between control points to simplify and prompt sound source control, allowing for improved pedestrian recognition and driver safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a conventional virtual engine sound generation apparatus is used, then a sound similar to engine sound is generated based on vehicle speed, but the driver and pedestrian cannot properly recognize the actual vehicle state and behavior
Solution Approach 1:
The patent segments the monolithic engine sound into multiple frequency bands (low, mid, high frequencies) and processes each band independently with dedicated control points. This allows specific vehicle states (acceleration, deceleration, gear changes) to be represented by modifying individual frequency components, thereby transmitting richer vehicle state information without requiring a completely complex new sound generation system.
Solution Approach 2:
The patent changes the parameters of the virtual engine sound by introducing pitch control points and volume control points for each frequency band. By dynamically adjusting pitch (frequency) and volume parameters based on actual vehicle operating conditions, the system conveys detailed vehicle state information such as acceleration rate, deceleration, and gear changes, transforming a simple speed-based sound into an information-rich auditory feedback system.
2Reliability
If the volume of virtual engine sound is merely increased or decreased according to vehicle speed, then pedestrian recognition is improved, but the driver and pedestrian feel uncomfortable due to mismatch with actual vehicle behavior
Solution Approach 1:
The patent introduces dynamic control mechanisms where pitch and volume of each frequency band are adjusted in real-time based on actual vehicle behavior parameters such as acceleration, deceleration, and gear changes. This dynamic adaptation ensures the virtual engine sound continuously matches the driver's operational inputs and the vehicle's actual state, eliminating the discomfort caused by static speed-based volume control while maintaining high pedestrian recognition accuracy.
Solution Approach 2:
The system incorporates feedback loops that monitor actual vehicle operating conditions (acceleration, deceleration, gear state) and use this information to continuously adjust the virtual engine sound characteristics. This feedback mechanism ensures the generated sound remains synchronized with real vehicle behavior, providing both accurate pedestrian warning and driver comfort through realistic auditory feedback.
3Loss of information
If pitch and volume control points are used for each frequency band, then recognizable sound output is improved, but the control system becomes more complex
Solution Approach 1:
The patent divides the sound control system into segmented frequency bands (low, mid, high), each with its own pitch and volume control points. This segmentation allows independent optimization of each frequency range based on vehicle state, transmitting comprehensive vehicle information through coordinated manipulation of multiple simple control elements rather than requiring a single complex control mechanism.
Solution Approach 2:
The control points introduced in the patent serve multiple functions simultaneously: they control pitch and volume for pedestrian recognition, represent vehicle operating states for driver information, and can be independently adjusted for different frequency bands. This multi-functionality reduces the need for separate control systems for different purposes, managing complexity through versatile control elements.
Data Source
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AI summary
An environmentally-friendly vehicle sound generator control apparatus. The apparatus includes a sound playback unit including a sound comparison unit for comparing a frequency band-specific reference sound level data with an extracted plurality of frequency band-specific sound data for each frequency band in response to a comparison control signal of a control unit, a sound control unit for controlling a pitch or a volume of a plurality of frequency band-specific sample sound source data to form a plurality of frequency band-specific sample control sound source data if the extracted plurality of frequency band-specific sound data is smaller than the frequency band-specific reference sound level data, and a sound mixing unit for mixing the plurality of frequency band-specific sample control sound source data and transferring the mixed plurality of frequency band-specific sample control sound source data to the sound output unit so that a pedestrian's vehicle recognition sound can be outputted.