Ultrasonic Transducer Memory for Echo Detection

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Solution Overview

Problem

Ultrasonic sensors face challenges in distinguishing between echo responses and ringing times, which are influenced by factors like dirt, aging, and mechanical damage, leading to limited detection of sensor deterioration and potential failure.

Innovation Solution

Incorporating an integrated memory in ultrasonic transducers to store their unique ringing times, allowing for comparison with installed values to detect deviations and adjust the reception window, thereby enhancing the detection of sensor-related changes and environmental influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the ultrasonic transducer operates continuously to detect echoes, then the detection capability is improved, but the ringing time causes false echoes and reduces measurement accuracy

Engineering Contradiction:

Improveecho detection accuracyVSAvoidringing time interference

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent stores the post-oscillation time in memory before the ultrasonic transducer is installed in the vehicle. This preliminary measurement allows the system to know the baseline ringing characteristics of each transducer, enabling accurate distinction between ringing and actual echoes during operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses the stored post-oscillation time to dynamically adjust the reception window timing. By comparing the actual ringing duration with the stored baseline, the evaluation device can compensate for variations and accurately determine when echo detection should begin, preventing false readings.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the reception window is set to start after a fixed time to avoid ringing, then the interference from ringing is reduced, but the shortest detectable distance increases

Engineering Contradiction:

Improveecho distinction accuracyVSAvoidshortest detectable distance

Core Design Contradiction:

Measurement precisionVSLength of moving object

Solution Approach 1:

The patent changes the reception window start time parameter dynamically based on the stored post-oscillation time of each individual transducer. Instead of using a fixed conservative time delay, the system adjusts the reception window to start exactly when each transducer's ringing stops, optimizing the shortest detectable distance for each sensor.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If the post-oscillation time is measured after installation to account for environmental influences, then the accuracy under real conditions is improved, but the ability to detect sensor degradation is reduced

Engineering Contradiction:

Improvepost-oscillation measurement accuracyVSAvoidsensor degradation detection

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent performs the post-oscillation time measurement in advance, before the transducer is installed in the vehicle and exposed to environmental influences. This baseline measurement allows the system to detect future degradation by comparing current performance against the original factory conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of measuring post-oscillation time after installation and trying to distinguish degradation from environmental effects, the patent inverts the approach by measuring before installation. This allows the system to use the pre-installed baseline to detect when environmental factors or aging cause deviations from the original characteristics.

Inventive Principle:

Principle #13The other way round (Inversion)

4Measurement precision

If individual post-oscillation times are stored for each transducer, then the detection of sensor changes is improved, but the device complexity increases

Engineering Contradiction:

Improvesensor change detection accuracyVSAvoidmemory and readout requirements

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a universal memory structure and readout procedure that can handle any number of ultrasonic transducers. The same memory storage and comparison logic works for single or multiple sensors, reducing the complexity increase that would result from individualized processing for each transducer.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enables more precise detection of sensor degradation and potential failure, reducing the shortest detectable distance and ensuring accurate distance measurements by accounting for environmental and installation-related changes.

Implementation Method 1

Ultrasonic sensors use an ultrasonic transducer to convert an electrical excitation signal into an ultrasonic pulse

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The ultrasonic transducers are also used to receive echoes of the ultrasonic pulses

Methodology Applied

Scientific EffectPiezoelectric effect: Converse Piezoelectric Effect

Data Source

PatentEP2358545B1Ultrasonic transducer, ultrasonic sensor and method for operating an ultrasonic sensor

Publication Date: 2019.11.06 ROBERT BOSCH GMBH

Figure 1~2

AI summary

An ultrasonic transducer has an integrated memory (6) for storing a reverberation time of the ultrasonic transducer (1) in the uninstalled state.