Pressure Sensor Failure Discrimination via Voltage Segmentation

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Solution Overview

Problem

Existing pressure measurement systems fail to accurately distinguish between overpressure and sensor failure, leading to incorrect fault detection due to signal saturation.

Innovation Solution

A pressure measurement system with a deformable membrane, featuring a lower and upper stop to limit deformations, and a resistive bridge that distinguishes between overpressure, underpressure, and sensor failure through controlled output voltage saturation, using an electronic amplification circuit to differentiate between nominal operation, overpressure, and fault conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electronic circuit amplifies the electrical signal from the sensor with fixed voltage ranges for failure detection, then the circuit can detect sensor failures, but it cannot distinguish between overpressure and sensor failure when the output signal reaches the high voltage zone

Engineering Contradiction:
Improvefailure detection capabilityVSAvoidfault discrimination accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The voltage output range is segmented into distinct zones: nominal operation range (between threshold1 and threshold2), overpressure saturation zone (above threshold2), and failure detection zones (below threshold1 or above supply voltage). This segmentation allows the system to distinguish between different fault conditions by observing which zone the output voltage falls into, resolving the ambiguity between overpressure and sensor failure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the output voltage parameter behavior under different conditions: in nominal operation the voltage varies linearly with pressure, in overpressure the voltage saturates at a maximum value, and in failure the voltage reaches extreme values (0 or supply voltage). By monitoring these parameter changes and their saturation characteristics, the system can accurately discriminate between different fault types.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the output signal voltage increases according to pressure without limitation, then the signal accurately represents pressure magnitude, but the signal reaches the high voltage zone dedicated to failures in the event of overpressure causing incorrect fault detection

Engineering Contradiction:
Improvepressure signal accuracyVSAvoidfault detection accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system prepares distinct voltage threshold levels (threshold1, threshold2, and supply voltage) in advance to mark the boundaries between different operational states. These pre-defined thresholds enable the system to immediately and accurately identify whether an overpressure condition or a sensor failure has occurred, preventing incorrect fault detection before it happens.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If the electronic circuit uses fixed voltage thresholds for failure detection, then the detection logic is simple, but the system cannot differentiate between nominal operation limits and actual sensor failures

Engineering Contradiction:
Improvedetection logic simplicityVSAvoidfault detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The detection logic is segmented into multiple threshold comparisons: comparing output voltage against threshold1 to detect low-side failures, against threshold2 to detect overpressure saturation, and against supply voltage to detect high-side failures. This segmented approach maintains relative simplicity while significantly improving detection accuracy by creating clear decision boundaries between different fault types.

Inventive Principle:
Principle #1Segmentation

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 precise differentiation between overpressure, underpressure, and sensor failure by controlling output voltage within specific ranges, preventing false fault detection and ensuring accurate pressure measurement.

Implementation Method 1

a resistive bridge arranged on the deformable membrane, said resistive bridge being configured to deliver a bridge voltage representative of a deformation of the deformable membrane caused by a pressure applied to said deformable membrane

Methodology Applied
Scientific EffectPiezoresistive effect: Piezoresistive Effect

Implementation Method 2

an electronic amplification circuit connected to the resistive bridge capable of delivering an output voltage as a function of the bridge voltage

Methodology Applied
Scientific EffectElectrical amplification:

Data Source

PatentEP3011294B1System for measuring pressure able to discriminate a failure from an over-pressure or under-pressure
Publication Date: 2020.07.22 AUXITROL
  • EP3011294B1 patent drawingFigure 1~2
  • EP3011294B1 patent drawingFigure 3
  • EP3011294B1 patent drawingFigure 4

AI summary

The invention relates to a system for measuring pressure, including a pressure sensor comprising: a deformable membrane on which is placed a resistive bridge able to deliver a bridge voltage representative of a deformation of the deformable membrane caused by a pressure applied to said deformable membrane; a system for limiting the deformation of the deformable membrane, able to limit the bridge voltage in the case of an over-pressure or an under-pressure on the deformable membrane; and an amplifying electronic circuit connected to the resistive bridge, able to deliver an output voltage depending on the bridge voltage; the limiting system and the electronic circuit are conjointly configured so that the output voltage makes it possible to distinguish the case of failure of the pressure sensor and/or of the electronic circuit from the case of an over-pressure or under-pressure on the deformable membrane.