Ultrasonic Echo Identification Using Multi-Frequency Correlation
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Solution Overview
Problem
Conventional ultrasonic systems face challenges in accurately identifying reflected waves due to noise interference and Doppler effects, leading to difficulties in setting threshold values and increased circuit costs, especially when the distance to the obstacle increases or when relative speeds between the vehicle and the object are significant.
Innovation Solution
The ultrasonic system employs a sound wave processing device that uses a semiconductor chip with integrated components for correlation-convolution integral processing, including a driver unit, analog front end, digital processing unit, and multiple reference wave data frequencies, enabling parallel processing and relative evaluation of correlation-convolution integral values to identify the own wave, thereby reducing the need for dynamic threshold adjustments and circuit costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the number of samples is reduced, then circuit costs are reduced, but measurement precision deteriorates due to noise interference and frequency shifts
Solution Approach 1:
The patent changes the parameter of reference wave frequency by preparing multiple reference waves with different frequencies (first reference wave with frequency f1, second reference wave with frequency f2). This allows the system to identify the own wave through frequency comparison even with reduced sample numbers, resolving the contradiction between circuit cost reduction and measurement precision maintenance.
Solution Approach 2:
The patent implements a feedback mechanism where the determination unit compares correlation-convolution integral values from multiple reference waves with different frequencies. By evaluating which reference wave produces the maximum correlation value, the system provides feedback to accurately identify the own wave, maintaining measurement precision even when sample numbers are reduced.
2Length of stationary object
If the distance between the ultrasonic system and the object increases, then measurement range is extended, but reliability deteriorates due to noise interference and difficulty in setting threshold values
Solution Approach 1:
The patent uses multiple reference waves with different frequencies to compare correlation-convolution integral values. This parameter change approach allows reliable own wave identification even at extended distances where noise interference increases and traditional threshold setting becomes difficult, as the system relies on relative comparison rather than absolute threshold values.
3Measurement precision
If correlation-convolution integral processing is performed for multiple reference wave data, then own wave identification accuracy is improved, but device complexity increases
Solution Approach 1:
The patent segments the processing by dividing it into distinct functional units: a correlation-convolution integral processing unit that handles the mathematical operations, and a determination unit that performs the comparison and identification. This segmentation maintains high own wave identification accuracy while managing device complexity through functional separation.
Solution Approach 2:
The determination unit serves multiple functions: it receives correlation-convolution integral values from multiple reference waves, compares these values, identifies the own wave, and can also determine frequency shifts. This multi-functionality improves own wave identification accuracy without proportionally increasing device complexity.
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 allows for accurate identification of reflected waves even with reduced sample sizes and under noisy conditions, minimizing circuit costs and effectively handling Doppler effects, thus enhancing the reliability of distance measurements.
Implementation Method 1
an ultrasonic wave transmitting/receiving device (5) that transmits and receives a sound wave
Implementation Method 2
measuring time TOF (Time Of Flight) until returning of a reflected wave from the obstacle
Implementation Method 3
correlation-convolution integral processing based on the reference wave data and an actually received reception signal is performed, so as to emphasize the reflected wave
Implementation Method 4
measuring time TOF (Time Of Flight) until returning of a reflected wave from the obstacle
Data Source
AI summary
A sound wave processing device includes a transmission signal generation unit that generates a transmission signal for transmitting a sound wave, a received wave signal output unit that outputs a received wave signal based on receiving the sound wave, a correlation-convolution integral processing unit that performs correlation-convolution integral processing in parallel for each reference wave data, on the basis of the received wave signal and a plurality of reference wave data, and an own wave identification unit that determines whether or not the received sound wave is own wave, which is a reflected wave of the sound wave transmitted by the transmission signal generation unit, on the basis of a correlation-convolution integral value output from the correlation-convolution integral processing unit.