Ultrasonic Sensor Functional State Determination via Phase-Frequency Correction
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Solution Overview
Problem
Ultrasonic sensors in vehicles face challenges in accurately determining their functional state due to internal or external changes, which can lead to measurement falsification or failure, especially from transient effects and aging-related changes in mechanical properties.
Innovation Solution
A method involving the application of an electrical test signal to the ultrasonic sensor, detection of the phase-frequency response, comparison of phase angles below and above the resonant frequency with expected angles, and correction of the phase-frequency response to determine the functional state, thereby compensating for transient effects and reliably assessing the sensor's condition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrical test signals are applied to determine the functional state of the ultrasonic sensor, then the measurement capability is improved, but transient effects cause measurement falsification and reduce reliability
Solution Approach 1:
The method applies preliminary corrections to the phase-frequency response by comparing measured phase angles with expected phase angles at specific frequencies before determining the functional state. This preliminary correction removes transient effects from the measurement, ensuring that the functional state determination is based on corrected, reliable data rather than raw measurements contaminated by transient effects.
Solution Approach 2:
The method uses expected phase angles as reference values to compare against measured phase angles. The difference between measured and expected values provides feedback that indicates the presence of transient effects, which are then corrected. This feedback mechanism enables continuous monitoring and correction of measurement errors caused by transient effects.
2Reliability
If the phase-frequency response is used to determine the functional state, then the reliability is improved, but transient effects still cause measurement falsification
Solution Approach 1:
The method converts the harmful effect of transient effects on phase angle measurements into a beneficial correction process. By deliberately measuring phase angles at specific frequencies where transient effects manifest, the method identifies and quantifies the transient distortion, then uses this information to correct the entire phase-frequency response, transforming the measurement error into a correction opportunity.
3Reliability
If correction of the phase-frequency response is applied to compensate for transient effects, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The method changes the parameter being measured from raw phase angles to corrected phase angles by applying a correction factor derived from comparing measured and expected phase angles at specific frequencies. This parameter transformation simplifies the overall process by converting a complex transient effect compensation problem into a straightforward correction factor application that can be implemented through standard signal processing techniques.
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 method allows for a more reliable determination of the ultrasonic sensor's functional state, effectively addressing issues like contamination, icing, or aging-related changes, by minimizing the impact of transient effects and providing accurate mechanical property assessments.
Implementation Method 1
a sound transducer element (in particular a piezoelectric element) for vibration excitation and vibration detection of the diaphragm
Implementation Method 2
Ultrasonic sensors that are based on the resonance principle have a characteristic profile of the phase angle between the test and response signal
Data Source
AI summary
Method for determining a function state (FZ) of an ultrasonic sensor (2) for a vehicle (1), having the steps of: a) applying (S1) an electrical test signal (P) to the ultrasonic sensor (2); b) detecting (S2) an electrical response signal (A) from the ultrasonic sensor (2); c) determining (S3) a phase-frequency response (PF) comprising the phase angle (a) of the detected response signal (A) for the applied test signal (P) on the basis of an excitation frequency (f) of the applied test signal (P); d) comparing (S4) at least a first phase angle (P1) below and a second phase angle (P2) above a resonant frequency (R) in the determined phase-frequency response (PF) with a respective expected phase angle (PE1, PE2); e) correcting (S5) the determined phase-frequency response (PF) on the basis of the comparison; and f) determining (S6) the function state (FZ) on the basis of the corrected phase-frequency response (PFK).