Ultrasonic Sensor Testing for Aging-Related Transducer Drift
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Solution Overview
Problem
Ultrasonic sensors in vehicles face measurement distortions and failures due to aging-related changes in electroacoustic transducer arrangements, leading to unreliable plausibility checks and potential discarding of usable data.
Innovation Solution
An ultrasonic sensor system that measures electrical parameters at multiple points by varying both frequency and amplitude of an electrical test signal, creating a multidimensional characteristic map to accurately assess the transducer's state, allowing for improved characterization and control of the sensor's condition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple ultrasonic sensors are installed with plausibility checks, then measurement reliability is improved, but false discarding of usable measurement results increases
Solution Approach 1:
The patent applies parameter changes by monitoring multiple electrical parameters (impedance, resonance frequency, amplitude) of the ultrasonic transducer and using these changes to dynamically adjust plausibility check thresholds. This allows the system to adapt to aging-related parameter drift and avoid false discarding of valid measurements while maintaining reliability.
Solution Approach 2:
The patent implements feedback by continuously monitoring the electrical characteristics of the transducer and using this information to adjust the plausibility check criteria. The system learns from the sensor's operational history and modifies its validation thresholds accordingly, preventing false rejection of usable data while maintaining accurate detection of actual faults.
2Reliability
If impedance characteristic is measured with constant small amplitude, then transducer condition can be monitored, but non-linear amplitude dependencies are not captured
Solution Approach 1:
The patent applies dynamics by varying the amplitude of the test signal across multiple measurement points rather than using a constant amplitude. This allows the system to capture the non-linear amplitude-dependent behavior of the transducer, providing a more complete and accurate characterization of its electrical characteristics across different operating conditions.
Solution Approach 2:
The patent extends the measurement from a single-point impedance check to a multi-dimensional characterization by measuring at multiple amplitude levels and frequencies. This creates a comprehensive map of the transducer's electrical behavior, capturing non-linearities that would be missed with constant amplitude testing alone.
3Device complexity
If simple plausibility check is used, then device complexity is reduced, but measurement precision deteriorates due to aging effects
Solution Approach 1:
The patent applies universality by using the electrical characteristic monitoring to serve multiple purposes: detecting transducer aging, adjusting plausibility check thresholds, and maintaining measurement accuracy. This multi-functional approach prevents measurement precision deterioration without requiring separate complex systems for each function.
Solution Approach 2:
The patent uses parameter changes by dynamically adjusting plausibility check thresholds based on monitored electrical characteristics. As the transducer ages and its electrical parameters drift, the system automatically adapts the validation criteria to maintain measurement precision while avoiding false rejections.
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
Enhances the reliability and accuracy of distance measurements by accounting for non-linear amplitude dependencies, extending the sensor's service life and maintaining consistent measurement quality over time.
Implementation Method 1
An ultrasonic sensor with an electroacoustic transducer arrangement for generating and detecting ultrasonic waves
Implementation Method 2
An ultrasonic wave is emitted, and an echo signal returning from the vehicle's surroundings is detected. The distance to the object is determined based on the signal's travel time.
Implementation Method 3
an echo signal returning from the vehicle's surroundings is detected
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
Proposed is an ultrasonic sensor system (1) for a motor vehicle (11), comprising an ultrasonic sensor (2) and a test control device (10). The ultrasonic sensor (2) comprises an electroacoustic converter arrangement (7) for generating and detecting ultrasonic waves and an electric test device (8), which is designed to output an electric test signal to the electroacoustic converter arrangement (7) and to detect an electric response signal of the electroacoustic converter arrangement (7) to the electric test signal. The test control device (10) is designed to detect a characteristic variable of the electric response signal at a plurality of measurement points (14, 15) by means of the electric test device (8) by varying a frequency and an amplitude of the electric test signal.