EV Synthetic Sound Control for Motor Torque Feedback
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Solution Overview
Problem
Existing sound generation devices for electric vehicles do not effectively allow drivers to recognize changes in motor torque, specifically the powerfulness of acceleration, through sound feedback.
Innovation Solution
A sound generation device that uses a sound controller to produce a synthetic sound signal with increased low-frequency output compared to high-frequency output as motor torque increases, enhancing the low-tone range sound pressure level to provide clear feedback on acceleration power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a sound generation device outputs sound at a predetermined frequency corresponding to motor rotation speed, then the driver can recognize vehicle speed changes, but the driver cannot recognize motor torque changes or acceleration powerfulness
Solution Approach 1:
The patent applies local quality by differentiating the sound output characteristics for different frequency bands. Specifically, it increases the sound pressure level in the low frequency band (below 500 Hz) more than in the high frequency band when motor torque increases, creating a localized enhancement in the low-frequency range that helps drivers perceive acceleration power
Solution Approach 2:
The patent changes the parameters of the synthetic sound by adjusting the sound pressure level of different frequency bands based on motor torque values. When motor torque increases, the system increases the overall sound pressure level and specifically amplifies the low-frequency component, transforming the sound characteristics to convey torque information
2Loss of information
If the sound pressure level in low frequency band is increased to enhance acceleration perception, then the driver can recognize acceleration powerfulness, but the overall sound output balance is altered
Solution Approach 1:
The patent implements dynamics by making the sound output characteristics variable based on operating conditions. The sound pressure level for each frequency band is dynamically adjusted according to the motor torque value, allowing the low-frequency enhancement to occur only when torque changes occur, while maintaining normal balance during steady-state operation
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 drivers to easily recognize vehicle acceleration power and perform accurate accelerator operations by reinforcing the low-tone sound feedback, promoting safer and more precise driving.
Implementation Method 1
a sound controller which sets plural frequencies corresponding to a motor rotation speed of the electric-powered motor and generates a synthetic sound signal indicating a synthetic sound including sounds at the plural frequencies
Data Source
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AI summary
A sound generation device 1 for a vehicle, the sound generation device 1 being installed in a vehicle 2 which travels using an electric-powered motor 3 as a power source, includes a sound control apparatus 10 which sets plural frequencies f1 to f9 corresponding to a motor rotation speed R and generates a synthetic sound signal SS indicating a synthetic sound SC including sounds at the plural frequencies and a speaker 20 which outputs the synthetic sound SC based on the synthetic sound signal SS generated by the sound control apparatus 10, and the sound control apparatus 10 sets an increase amount of an output of a sound in a low frequency band large compared to an increase amount of an output of a sound in a high frequency band in a frequency range of the synthetic sound SC in accordance with an increase in a motor torque value T.