EV Tone Control via Motor Vibration Order Extraction
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Solution Overview
Problem
Electric vehicles (EVs) lack a natural sound during deceleration or regenerative braking, leading to discomfort for drivers and pedestrians, and existing tone control technologies fail to effectively mimic the sound of internal combustion engines, which are essential for enhancing driving pleasure and safety.
Innovation Solution
A method that uses a vibration sensor signal processing controller to extract order components from motor vibrations, convert them into frequencies, and apply level control to output a tone that matches the EV's power performance, including deceleration intentions, using a fade-out algorithm and weight values from CAN data to determine deceleration conditions and adjust sound levels for both indoor and outdoor speakers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If tone control stores and plays back virtual sounds for EVs, then the EV produces noise during operation, but the sound does not naturally reflect the motor vibration characteristics during deceleration or regenerative braking
Solution Approach 1:
The patent extracts actual motor vibration signals during deceleration and regenerative braking, then synthesizes and outputs these copied real-world vibrations through speakers. This creates authentic EV-specific sounds that accurately reflect the motor's actual behavior during different operating conditions, rather than using generic virtual engine sounds.
Solution Approach 2:
The patent replaces the traditional mechanical engine sound generation system with an electronic signal processing system. Instead of relying on mechanical combustion engine vibrations, the system uses sensors to detect motor vibrations, processes these signals electronically, and reproduces them through speakers, substituting mechanical sound generation with electronic synthesis.
2Loss of energy
If the EV operates quietly during deceleration, then energy efficiency is improved, but driver and pedestrian awareness of vehicle presence and deceleration intent is reduced
Solution Approach 1:
The patent introduces an intermediary sound generation system that mediates between the quiet EV operation and the need to communicate deceleration intent. The system processes motor vibration signals and outputs enhanced sounds through speakers, serving as an intermediary that conveys vehicle state information without requiring mechanical engine noise.
Solution Approach 2:
The patent generates periodic sound outputs during deceleration that correspond to the periodic nature of motor vibrations. By synchronizing sound output with the motor's rotational frequency and its harmonics, the system creates rhythmic, recognizable patterns that effectively communicate vehicle presence and deceleration intent to drivers and pedestrians.
3Measurement precision
If order components of motor vibration are extracted in real time, then accurate tone control is achieved, but computational complexity and processing requirements increase
Solution Approach 1:
The patent segments the complex motor vibration signal into discrete order components (fundamental frequency and harmonics). By breaking down the continuous vibration signal into specific frequency components that can be independently analyzed and processed, the system achieves precise tone control while managing computational complexity through structured signal decomposition.
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
This solution provides a natural and consistent sound during EV deceleration, masking unpleasant high-frequency noise and enhancing braking performance awareness, thereby improving driver and pedestrian safety and vehicle marketability.
Implementation Method 1
vibration signals of a rotating motor
Data Source
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AI summary
A method of controlling a tone of an electric vehicle (EV) includes calculating order components from vibration signals of a rotating motor of the EV, extracting an Nth order component having a determination coefficient R2 which represents linearity with respect to an output torque of the motor and is greater than or equal to a predetermined value, converting an RPM of the motor into a frequency and calculating an order frequency, arranging the order components by applying a vibration level of the Nth order component to a level of the order frequency to be output and setting an EV mode tone, and in a deceleration of the EV, determining a deceleration condition and applying the vibration level of the Nth order component to level control of the order frequency.