Ultrasonic Signal Processing Device for Vehicle Distance Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ultrasonic sensors in vehicles face challenges in accurately measuring distance using time-of-flight (TOF) due to interference from reverberations and varying threshold values, which affects their performance in alarm, auto-brake, and auto-parking functions.
Innovation Solution
The ultrasonic system employs a signal processing device with a digital-to-analog converter, low-noise amplifier, programmable gain amplifier, and a reflected wave detection unit that performs envelope detection and threshold comparisons to differentiate between reverberation periods and actual reflected waves, allowing for precise distance measurement by setting multiple threshold values and using differential and integral operations to determine the presence and distance of a target object.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional ultrasonic sensors use simple threshold-based reflected wave detection, then the device complexity is low, but the measurement precision deteriorates due to interference from reverberations
Solution Approach 1:
The patent segments the signal processing into distinct functional units: envelope detection unit, reverberation determination unit, and reflected wave detection unit. Each unit performs a specific function in the signal analysis process, allowing complex reverberation discrimination to be broken down into manageable processing stages that improve measurement precision while maintaining organized system structure
Solution Approach 2:
The patent employs dynamic threshold determination where the threshold value is not fixed but adapts based on the envelope detection signal characteristics and reverberation period identification. The system dynamically adjusts detection criteria based on real-time signal analysis, enabling accurate distinction between reverberations and actual reflected waves across varying acoustic environments
2Reliability
If the system uses multiple threshold values and envelope detection to distinguish reverberations from reflected waves, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The patent implements feedback mechanisms where the reverberation determination unit continuously monitors the envelope detection signal and provides feedback to the reflected wave detection unit. This feedback loop allows the system to learn from signal patterns and adjust detection decisions, improving reliability by cross-validating whether detected waves are true reflections or reverberations based on accumulated signal characteristics
Solution Approach 2:
The envelope detection unit serves as an intermediary between the raw received signal and the final reflected wave detection. It processes the signal into an envelope representation that highlights amplitude variations, making it easier to distinguish between reverberation patterns and actual target reflections. This intermediate processing layer simplifies the overall detection logic while improving reliability
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 approach enhances the accuracy and reliability of distance measurement by effectively distinguishing between reverberations and actual reflections, improving the performance of ultrasonic sensors in vehicle applications such as alarm, auto-brake, and auto-parking functions.
Implementation Method 1
an ultrasonic transmitting/receiving device 2 configured to be connected directly or indirectly to the signal processing device 1A; the ultrasonic transmitting/receiving device 2 includes a piezoelectric element
Implementation Method 2
an envelope detection unit 164, configured to output an envelope detection signal obtained by envelope detection of an absolute value of a received signal
Data Source
AI summary
The present disclosure provides a signal processing device. The signal processing device includes: a transmission signal generation unit, configured to generate a transmission signal for a transmitted wave of sound wave; a reception signal output unit, configured to output a received signal based on a received wave of sound wave; and a reflected wave detection unit. The reflected wave detection unit is configured to detect a first reflected wave of the transmitted wave that may be included in the received wave based on a first timing when an envelope detection signal, which is a signal obtained by envelope detection of an absolute value of the received signal during a reverberation period in which a reverberation of the transmitted wave remains, is lower than a first threshold value.