Sensor Fault Detection via Discharge Time Constant Comparison

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Solution Overview

Problem

Existing methods for detecting faults in sensors, particularly piezoelectric sensors used in vehicles, are inadequate as they only record measurement errors indirectly, lacking precision and reliability in diagnosing sensor malfunctions.

Innovation Solution

A method that filters measurement signals using a time-dependent discharge function with logarithmization to determine parameter values, comparing first and second discharge time constants to accurately detect sensor faults, thereby enhancing diagnostic accuracy and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If indirect detection methods using calibration procedures and pseudosensor values are used, then sensor faults can be detected, but the detection precision and reliability are insufficient

Engineering Contradiction:
Improvesensor fault detection reliabilityVSAvoidfault detection precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces indirect mathematical transformation methods (calibration procedures and pseudosensor value calculations) with direct physical measurement of the sensor's discharge time constant. This substitution of measurement approach enables direct observation of the sensor's actual physical state rather than inferring faults through complex data transformations, thereby improving both detection precision and reliability simultaneously.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If sensor characteristics are directly measured using discharge time constant, then detection precision improves, but measurement and evaluation complexity increases

Engineering Contradiction:
Improvefault detection precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the discharge time constant as a separate, isolated characteristic parameter from the sensor's output signals. By focusing measurement efforts on this single extracted parameter rather than analyzing complex raw sensor data, the method achieves high detection precision while keeping the measurement and evaluation process relatively simple. The extraction of this specific physical characteristic simplifies the overall diagnostic approach.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If continuous monitoring of discharge time constant is performed, then sensor availability and safety improve, but energy consumption and processing load increase

Engineering Contradiction:
Improvesensor operation safetyVSAvoidenergy consumption for continuous monitoring
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic measurement of the discharge time constant at predetermined intervals rather than continuous monitoring. This periodic approach maintains sensor operation safety by detecting faults when they occur, while significantly reducing energy consumption and processing load compared to continuous monitoring. The system balances safety requirements with resource efficiency by measuring only when necessary.

Inventive Principle:
Principle #19Periodic 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

This approach ensures precise detection of sensor faults, reducing their influence on measurements and enabling timely maintenance by generating warning events, thus ensuring high reliability and availability of vehicle components.

Implementation Method 1

a sensor (1), in particular a piezoelectric sensor (1), for vehicles... wherein measurements (2) are carried out using the sensor (1)... wherein the sensor (1) monitors a vehicle component

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

filtered signals (9) are formed by filtering the measurement signals (3), wherein the parameter values of the time-dependent discharge function comprising a time matrix with a first time, a second time up to an N-time are determined by taking the logarithm of the filtered signals (9)

Methodology Applied
Scientific EffectSignal filtering and logarithmic transformation:

Implementation Method 3

discharge time data with a first discharge time constant (τ1) of the sensor are read from a data storage (TEDS) of the sensor... a second discharge time constant (τ2) is determined from the discharge function... by comparing the first discharge time constant (τ1) with the second discharge time constant (τ2)

Methodology Applied
Scientific EffectCapacitive discharge: Capacitance

Data Source

PatentEP3633390B1Method and device for detecting faults of a sensor
Publication Date: 2023.11.15 SIEMENS MOBILITY AUSTRIA GMBH
  • EP3633390B1 patent drawingFigure 1~2
  • EP3633390B1 patent drawingFigure 3~4
  • EP3633390B1 patent drawing

AI summary

A method for detecting disturbances in a sensor (1), wherein measurements (2) are performed, discharge time data with a first discharge time constant τ1 are read from a data memory of the sensor (1), and corresponding measurement signals (3) as well as the discharge time data are transmitted to a processing unit (4), wherein signal processing (5), signal evaluation (6), and data evaluation (7) are performed in the processing unit (4), and wherein filtered signals (9) are generated by filtering (8) the measurement signals (3). It is proposed that parameter values ​​of a discharge function b- are determined by taking the logarithm (10) of the filtered signals (9), that a second discharge time constant τ2 is determined from the discharge function b-, and that disturbances, errors, or damage to the sensor (1) are detected by comparing (11) the first discharge time constant τ1 with the second discharge time constant τ2. This allows the influence of sensor disturbances on the measurements (2) to be reduced.