Ultrasonic Sensor Degradation Detection via Decay Frequency Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting sensor degradation in ultrasonic sensors used in driver assistance systems are unreliable, particularly in detecting total failures, which can lead to the system becoming partially or completely 'blind' due to environmental influences like snow or ice, and require additional complex and costly electronics for frequency-dependent measurements.
Innovation Solution
A method that involves emitting a transmission pulse and detecting echo signals in distance sensors, with the degree of degradation determined by analyzing the frequency response in decay intervals, using existing receiving units and simple hardware or software implementations, allowing for reliable monitoring of sensor functionality without affecting operational functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency-dependent measurement methods are used to detect sensor degradation, then measurement precision is improved, but device complexity and cost increase due to additional electronics
Solution Approach 1:
The ultrasonic sensor performs self-diagnosis by utilizing its own transmission and reception capabilities. The sensor transmits test pulses and evaluates the echo signals without requiring external testing equipment or additional electronics, thereby achieving accurate degradation detection while maintaining system simplicity
Solution Approach 2:
The sensor's receiving unit is used for dual purposes: both during normal distance measurement operations and during self-diagnosis mode. This eliminates the need for separate dedicated testing hardware, reducing device complexity while maintaining measurement precision through the same universal component
2Measurement precision
If frequency-dependent measurement methods are used to detect sensor degradation, then measurement precision is improved, but manufacturing cost increases due to additional electronics
Solution Approach 1:
The ultrasonic sensor performs self-diagnosis by utilizing its own transmission and reception capabilities. The sensor transmits test pulses and evaluates the echo signals without requiring external testing equipment or additional electronics, thereby achieving accurate degradation detection while maintaining system simplicity
Solution Approach 2:
The sensor's receiving unit is used for dual purposes: both during normal distance measurement operations and during self-diagnosis mode. This eliminates the need for separate dedicated testing hardware, reducing device complexity while maintaining measurement precision through the same universal component
3Productivity
If decay behavior evaluation is performed with each send-receive cycle, then productivity is improved, but reliability of functionality assessment deteriorates due to difficulty in making reliable statements about sensor functionality
Solution Approach 1:
Instead of evaluating the entire decay behavior waveform, the method focuses on specific local characteristics of the echo signal, particularly the presence or absence of distinct echo peaks and their amplitude thresholds. This localized evaluation approach maintains high productivity by processing only critical features while improving reliability through objective, quantifiable criteria
Solution Approach 2:
The method uses objective parameter thresholds (amplitude thresholds, time thresholds) to assess sensor functionality. By transforming the subjective evaluation of decay behavior into measurable parameters with defined criteria, the system achieves both rapid execution and reliable assessment of sensor health status
4Device complexity
If simple detection methods are used to monitor sensor functionality, then device complexity is reduced, but reliability of detecting total failures deteriorates
Solution Approach 1:
The ultrasonic sensor performs self-diagnosis by utilizing its own transmission and reception capabilities. The sensor transmits test pulses and evaluates the echo signals without requiring external testing equipment or additional electronics, thereby achieving accurate degradation detection while maintaining system simplicity
Solution Approach 2:
The method uses objective parameter thresholds (amplitude thresholds, time thresholds) to assess sensor functionality. By transforming the subjective evaluation of decay behavior into measurable parameters with defined criteria, the system achieves both rapid execution and reliable assessment of sensor health status
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 provides reliable information on the degree of sensor degradation, distinguishing between fully functional, partially blind, and completely blind sensors, avoiding erroneous assessments and reactions, and can be implemented cost-effectively without additional latency or complexity.
Implementation Method 1
distance sensors, in particular ultrasonic sensors, which measure the distance to objects in the environment of the vehicle based on a transmitted pulse-echo method
Implementation Method 2
The ultrasonic transducer is excited with two different frequencies
Implementation Method 3
the decay behavior of the ultrasonic sensor is evaluated after a transmission process
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to methods (100) for detecting sensor degradation in distance sensors (18, 19), having the following steps: a) emitting (102) at least one transmission pulse (32); b) detecting (104) a sensor signal (30) at least in a decay interval (ΔT2); and c) determining a degree of degradation on the basis of a frequency response (34) of the detected sensor signal (30). The invention also relates to a computer program product, a distance sensor unit and a driving assistance system for carrying out such methods.