Ultrasonic Transducer State Detection Using Frequency-Swept Probe Waves

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Solution Overview

Problem

Ultrasonic sensors mounted to vehicle bumpers face performance deterioration due to snow or mud adhering to microphones, which affects the detection performance of parking assistance systems, and existing methods for determining microphone state are inadequate due to interference from measurement circuit effects.

Innovation Solution

An object detection device that includes a transceiver, drive signal generation unit, transmitter and receiver circuits, and state determination unit, which uses frequency-modulated probe waves to measure voltage signals and determine the state of the transducer based on amplitude changes, allowing for accurate detection of abnormalities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If reverberation frequency measurement is used to determine transducer state, then abnormality detection is enabled, but measurement circuit effects are mixed in and prevent accurate microphone state determination

Engineering Contradiction:

Improvemicrophone state determination accuracyVSAvoidmeasurement accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent extracts only the voltage signal component from the transceiver during probe wave transmission, separating it from the reverberation frequency measurement that includes measurement circuit effects. By measuring the voltage signal generated in the transceiver during transmission and comparing it to a reference value, the system determines microphone state without contamination from receiver circuit effects.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses the voltage signal as an intermediary measurement parameter. Instead of directly measuring reverberation frequency which mixes circuit effects, the system measures the voltage signal generated during transmission as an intermediate step that directly reflects microphone state without including receiver circuit interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If snow or mud adheres to microphone surfaces, then detection performance deteriorates, but no effective self-diagnosis method exists

Engineering Contradiction:

Improvedetection performanceVSAvoidsnow or mud adhesion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs self-diagnosis by automatically measuring the voltage signal generated in the transceiver during probe wave transmission and comparing it to a reference value. This self-service mechanism enables the ultrasonic sensor to autonomously detect microphone state changes due to snow or mud adhesion without external intervention, maintaining reliable operation in adverse environmental conditions.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If frequency-modulated probe waves are used, then voltage signal measurement becomes possible, but circuit effects may still interfere

Engineering Contradiction:

Improvevoltage signal measurementVSAvoidstate determination accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent performs preliminary measurement of the voltage signal generated during probe wave transmission before final state determination. By measuring the voltage signal during the transmission phase and comparing it to a reference value stored in memory, the system preliminarily assesses microphone state, enabling accurate determination while preventing circuit effects from interfering with the final diagnosis.

Inventive Principle:

Principle #10Preliminary action

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 device effectively determines the state of the transducer by reducing interference from transmitter and receiver circuit effects, enabling precise detection of abnormalities and maintaining sensor performance despite environmental changes.

Implementation Method 1

Ultrasonic sensors mounted to vehicle bumpers, etc. use microphones as ultrasonic transceivers

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the voltage signal generated in the transceiver during probe wave transmission changes due to adhesion of snow or the like

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS12504525B2Object detection device

Publication Date: 2025.12.23 DENSO CORP

AI summary

An object detection device includes a transceiver configured to transmit/receive an ultrasonic wave; a drive signal generation unit configured to generate a drive signal for driving the transceiver; a transmitter circuit configured to cause the transceiver to transmit a probe wave, which is an ultrasonic wave, by driving the transceiver based on the drive signal; and a receiver circuit configured to generate a reception signal corresponding to a reception result of the ultrasonic wave of the transceiver, wherein the drive signal generation unit is configured to generate the drive signal so that frequency of the probe wave changes over time. The device further includes: a voltage measurement unit configured to measure a voltage signal generated in the transceiver while the transceiver transmits the probe wave with frequency changing over time; and a state determination unit configured to make a state determination regarding the transceiver based on the voltage signal.