Vehicle Sound Generation Device for EV State Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles with electric motors lack a clear auditory cue for the driver to recognize changes in motor operation, as the operating noise is typically softer and less distinct than engine noise, making it difficult for the driver to perceive the vehicle's state and operation.
Innovation Solution
A vehicle sound generation device that uses a sound control circuit to produce a synthetic sound signal with a reference sound pressure component increasing with motor revolutions and variable sound pressure components that fluctuate within specific amplitudes and periods, enhancing the driver's perception of the vehicle's state through a more nuanced auditory feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple frequency-based sound generation method is used in electric vehicles, then the device complexity is reduced, but the driver's ability to recognize vehicle state changes deteriorates
Solution Approach 1:
The patent applies dynamics by making the sound pressure level variable rather than fixed. The sound pressure dynamically changes based on motor revolution changes, with different rates of change applied at different revolution ranges. This dynamic adjustment enhances the driver's ability to perceive vehicle state changes without requiring a completely complex system architecture.
Solution Approach 2:
The patent changes the parameter of sound pressure level in relation to motor revolutions. Specifically, it adjusts the rate of change of sound pressure with respect to motor revolutions differently across various revolution ranges. This parameter modification allows the system to provide better state recognition while maintaining relatively simple device complexity.
2Loss of information
If the sound pressure increases monotonically with motor revolutions, then the driver can perceive speed changes, but the sensitivity to detect specific state changes deteriorates
Solution Approach 1:
The patent applies periodic action by introducing fluctuations in the sound pressure pattern. Rather than a smooth monotonic increase, the sound pressure varies with periodic characteristics that enhance the driver's ability to detect specific state changes. This periodic variation in sound pressure provides more discernible cues for state detection while maintaining overall progression with motor revolutions.
3Ease of operation
If the rate of frequency change is uniform across all motor revolution ranges, then the system is simple to control, but the driver's perception of low speed changes deteriorates
Solution Approach 1:
The patent applies local quality by implementing different rates of sound pressure change for different motor revolution ranges. Specifically, the rate of change is set to be higher in lower revolution ranges and lower in higher revolution ranges. This localized differentiation enhances driver perception of speed changes in the critical low-speed range while maintaining overall system operability.
Data Source
AI summary
A vehicle sound generation device includes a sound control circuit that sets one or more frequencies according to a number of revolutions of the rotary power source, and generates a synthetic sound signal representing a synthetic sound including one or more element sounds having the one or more frequencies. The sound control circuit sets the synthetic sound so that a sound pressure of the synthetic sound includes a reference sound pressure component and a variable sound pressure component. A magnitude of the reference sound pressure component increases as the number of revolutions of the rotary power source increases, and a magnitude of the variable sound pressure component varies within a predetermined amplitude with a period of a predetermined increase amount of the number of revolutions as the number of revolutions of the rotary power source increases.