Ultrasonic Phased Array Filtering for Resonance-Free Obstacle Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional phased array sensors using resonant ultrasonic transducers face issues with damped resonant vibrations causing waveform distortion and amplifier saturation, leading to reduced distance resolution and difficulty in amplifying received signals effectively.
Innovation Solution
A phased array sensor utilizing a non-resonant ultrasonic transducer array with transmission-side and reception-side filters configured to remove resonant frequency components while allowing driving frequency components to pass, using band-pass, low-pass, or band-reject filters to prevent interference from damped vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If resonant ultrasonic transducers are used to transmit ultrasonic waves with large amplitude, then transmission efficiency is improved, but damped resonant vibrations cause waveform distortion and amplifier saturation during reception
Solution Approach 1:
The patent extracts and removes the harmful resonant frequency components from the received signal using a band-pass filter that allows only the driving frequency to pass through. This separates the useful signal from the harmful damped vibrations, resolving the contradiction between maintaining high transmission power and preserving signal integrity during reception.
Solution Approach 2:
The patent introduces a band-pass filter as an intermediary device between the ultrasonic transducer and the signal processing circuit. This filter mediates by blocking the harmful resonant frequency components while transmitting the useful driving frequency signal, thereby preventing amplifier saturation and waveform distortion.
2Measurement precision
If high amplification gain is applied to received voltage signals, then signal detection sensitivity is improved, but operational saturation of the amplifier occurs due to damped vibration
Solution Approach 1:
The patent extracts the harmful resonant frequency components from the received signal before amplification using a band-pass filter. By removing these components that cause amplifier saturation, the system can apply high amplification gain to enhance detection sensitivity without risking operational saturation or waveform distortion.
Solution Approach 2:
The patent performs preliminary filtering of the received signal to remove resonant frequency components before the amplification stage. This preliminary action prevents the damped vibrations from causing amplifier saturation, thereby enabling high gain amplification while maintaining signal waveform accuracy.
3Loss of information
If resonant frequency components are present in received signals, then transducer vibration information is preserved, but distance resolution decreases due to prolonged damped vibration
Solution Approach 1:
The patent selectively extracts and removes only the harmful resonant frequency components from the received signal using a band-pass filter tuned to the driving frequency. This removal of resonant components shortens the damped vibration duration and improves distance resolution, while the filter preserves the essential vibration information at the driving frequency needed for detection.
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 enables effective transmission and reception of ultrasonic waves while minimizing the adverse effects of damped resonant vibrations, maintaining signal integrity and improving distance resolution in obstacle detection.
Implementation Method 1
a plurality of non-resonant aerial ultrasonic transducers (110) arranged at a predetermined interval
Implementation Method 2
transmission-side and reception-side filters configured to remove resonant frequency components while allowing driving frequency components to pass
Implementation Method 3
the array radiates ultrasonic waves at an azimuth angle corresponding to the phase difference
Implementation Method 4
the array receives ultrasonic waves (received ultrasonic waves) that are reflected back from an obstacle, and generates a voltage signal (received voltage signal) based on the received ultrasonic waves
Data Source
AI summary
An ultrasonic phased array sensor of this invention includes non-resonant ultrasonic transducers, a transmission signal generation device generating rectangular burst wave driving voltage signal whose driving frequency is lower than the resonant frequency of the transducer, transmission-side channels transmitting driving voltage signals from the transmission signal generation device to transducers, a reception signal processing device, reception-side channels transmitting reception voltage signals that transducers generated to reception signal processing device, changeover switches switching connection of the transducers to the transmission-side channels and the reception-side channels, a detection device detecting a position of an obstacle, and transmission-side and reception-side filters inserted in the transmission-side and reception-side channels, respectively, the filters removing at least the resonant frequency components of the transducers while allowing the driving frequency components to pass.