Vehicle Approach Alert Device Temperature Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vehicle approach alert devices for electric and hybrid vehicles face reduced warning efficiency due to temperature-induced changes in speaker impedance, leading to decreased sound pressure and compromised noise reduction.
Innovation Solution
A vehicle approach alert device that includes a microcomputer to generate and correct the voltage level of the approach alert sound signal based on the speaker's temperature, maintaining constant sound pressure levels despite temperature changes, using a signal generator, temperature sensor, and power amplifier to ensure consistent warning efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sound pressure of the speaker output is increased to improve warning efficiency, then the warning efficiency increases, but the noise becomes a problem
Solution Approach 1:
The patent applies parameter changes by adjusting the voltage level of the alert sound signal dynamically based on temperature conditions. The microcomputer corrects the voltage level parameter to compensate for temperature-induced impedance changes, maintaining consistent sound pressure across different temperatures without requiring excessive noise generation
2Object-generated harmful factors
If the sound pressure of the speaker output is decreased to reduce noise, then the noise is reduced, but the warning efficiency decreases
Solution Approach 1:
The system dynamically changes the voltage level parameter based on temperature measurements. When the speaker temperature increases causing impedance increase and sound pressure decrease, the microcomputer increases the voltage level to compensate, ensuring warning efficiency is maintained without requiring the sound pressure to be constantly high
3Reliability
If the voltage level of the alert sound signal is increased to compensate for high temperature, then the sound pressure is maintained, but the energy consumption increases
Solution Approach 1:
The system employs dynamic adjustment of the voltage level based on real-time temperature conditions rather than maintaining a constantly high voltage level. The microcomputer monitors speaker temperature and adjusts the voltage parameter dynamically, increasing energy input only when temperature-induced impedance changes require compensation
Solution Approach 2:
The patent implements feedback control by monitoring the speaker temperature and using this information to adjust the voltage level of the alert sound signal. The temperature sensor provides feedback to the microcomputer, which then corrects the voltage level to maintain consistent sound pressure output
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
The solution maintains consistent sound pressure levels across varying temperatures, enhancing warning efficiency while balancing noise reduction and warning effectiveness.
Implementation Method 1
an obtaining device that obtains a sound outputting body temperature as temperature of the sound outputting body
Implementation Method 2
a speaker that outputs a vehicle approach alert sound when a voltage is applied
Implementation Method 3
material of a voice coil in the speaker is copper. A temperature coefficient of a resistivity of copper is about 4000 ppm/° C. Thus, the impedance of the voice coil is changed about 60% within the temperature range of 150° C.
Data Source
AI summary
A vehicle approach alert device includes: a microcomputer having a memory that stores approach alert sound data, and a signal generator that generates an approach alert sound voltage waveform signal based on the approach alert sound data. The vehicle approach alert device alerts approach of a vehicle by outputting a vehicle approach alert sound from a sound outputting body according to the approach alert sound voltage waveform signal. The microcomputer further includes: an obtaining device that obtains a sound outputting body temperature; and a sound pressure correcting device that corrects a voltage level of the approach alert sound voltage waveform signal to be larger as the sound outputting body temperature increases.