Sensor Saturation Fault Detection via Signal Comparison

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Solution Overview

Problem

Existing sensor systems, particularly magnetic field sensors, face challenges in accurately diagnosing faults under critical conditions, leading to potential false positives and incorrect environmental attribute measurements due to material defects and environmental changes.

Innovation Solution

A diagnostic method and device that utilize signal comparator threshold values, positive and negative signal amplifier saturation thresholds, and a control circuit to compare current and previous amplified input signals, generating a diagnostic signal if certain conditions are met, allowing for continuous fault detection without interrupting the application function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sensor systems continuously monitor signals to detect faults, then measurement reliability is improved, but false positives occur due to amplifier saturation under critical conditions

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidfault detection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by establishing expected output states based on previous comparisons before making fault determination. The system pre-calculates what the output state should be based on historical data, then compares actual measurements against these pre-established expectations. This allows the system to distinguish between normal saturation behavior and actual faults, reducing false positives while maintaining continuous monitoring capability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using previous output states and comparison results to inform current fault detection decisions. The system feeds back historical measurement data and expected state information into the current evaluation process, creating a closed-loop diagnostic system that adapts to normal operating variations and reduces false alarms while maintaining high reliability.

Inventive Principle:
Principle #23Feedback

2Ease of manufacture

If diagnostic methods use fixed threshold values, then implementation is simplified, but false positives occur under varying environmental conditions

Engineering Contradiction:
Improvediagnostic implementation simplicityVSAvoidfault detection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies dynamics by transitioning from fixed threshold values to dynamic, adaptive thresholds based on previous comparisons and expected output states. The system continuously updates its reference values based on historical data, allowing the diagnostic thresholds to adapt to environmental variations such as temperature and humidity changes. This dynamic approach maintains implementation simplicity while significantly improving detection reliability under varying conditions.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If amplifier gain is increased to improve signal detection, then measurement sensitivity is improved, but amplifier saturation occurs more frequently under critical conditions

Engineering Contradiction:
Improvesignal detection sensitivityVSAvoidamplifier saturation
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of amplifier saturation into a beneficial diagnostic feature. Instead of treating saturation as purely harmful, the system uses saturation events as additional information sources for fault detection. By monitoring whether saturation occurs in unexpected conditions or patterns, the system transforms saturation from a measurement-limiting factor into a useful diagnostic indicator that helps distinguish normal operation from actual faults.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Enables accurate detection of faults and defects in sensor systems, improving measurement reliability and reducing false positives by continuously monitoring signal amplifier saturation, thereby ensuring accurate environmental attribute measurements.

Implementation Method 1

Magnetic sensors can incorporate Hall-effect sensors that generate an output voltage proportional to an applied magnetic field

Methodology Applied
Scientific EffectHall-effect: Hall Effect

Implementation Method 2

magneto-resistive materials whose electrical resistance changes in response to an external magnetic field

Methodology Applied
Scientific EffectMagneto-resistive effect: Magnetoresistance

Data Source

PatentEP3581952B1Sensor saturation fault detection
Publication Date: 2024.03.13 MELEXIS BULGARIA LTD
  • EP3581952B1 patent drawingFigure 1~3
  • EP3581952B1 patent drawingFigure 4~5
  • EP3581952B1 patent drawingFigure 6

AI summary

The present invention relates to a diagnostic method, comprising : i) providing at least a signal comparator threshold value (T), a positive signal amplifier saturation threshold value (P), a negative signal amplifier saturation threshold value (N) less than said positive signal amplifier saturation threshold value (P), ii) providing a current value of a first amplified input signal (A1) at a first time and a current value of a second amplified input signal (A2) obtained at a second time later than the first time, iii) comparing the current value of the first amplified input signal (A1) and the current value of the second amplified input signal (A2) to the signal comparator threshold value (T) and providing a new output state based on the comparison, iv) providing a current output state from a previous comparison, and determining an expected new output state based on the current output state, v) if the current output state is equal to a first value and the new output state is different from the expected new output state, checking whether the current value of the second amplified input signal (A2) exceeds the positive signal amplifier saturation threshold value (P) and/or whether the current value of the first amplified input signal (A1) is below the negative signal amplifier saturation threshold value (N), and if so, providing a diagnostic signal that indicates a fault, or: if the current output state is equal to a second value and the new output state is different from the expected new output state, checking whether the current value of the first amplified input signal (A1) exceeds the positive signal amplifier saturation threshold value (P) and/or whether the current value of the second amplified input signal (A2) is below the negative signal amplifier saturation threshold value (N), and if so, providing a diagnostic signal that indicates a fault.