Particulate Matter Sensor After-Run Water Removal

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Solution Overview

Problem

Particulate matter sensors in vehicle exhaust systems are susceptible to delamination cracking due to water buildup and freezing, leading to potential failure, as current methods do not effectively mitigate this issue.

Innovation Solution

A method involving determining moisture conditions in the particulate matter sensor, initiating a heating element operation during the engine's after-run mode to remove liquid water, and regulating operational power to prevent saturation, ensuring the sensor operates within safe temperature and voltage limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the particulate matter sensor operates in cold environments, then the sensor can detect PM levels during normal operation, but water buildup and freezing cause delamination cracking leading to sensor failure

Engineering Contradiction:

Improvesensor reliabilityVSAvoidwater buildup and freezing damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary heating of the PM sensor during the after-run mode (after engine shutdown) to remove water from the sensor before freezing can occur. This proactive approach prevents water accumulation and subsequent freezing damage, thereby maintaining sensor reliability in cold environments.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The heating element applies preliminary anti-action by heating the sensor to prevent water from freezing. By maintaining the sensor temperature above freezing point during the after-run mode, the system counteracts the harmful freezing effect before it can cause delamination cracking.

Inventive Principle:

Principle #9Preliminary anti-action

2Reliability

If a heating element is added to remove water from the sensor, then delamination cracking is prevented, but device complexity and energy consumption increase

Engineering Contradiction:

Improvesensor protection from delaminationVSAvoidheating element and control system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The PM sensor includes an integrated heating element that serves the dual purpose of normal sensor operation and water removal. The sensor essentially serves itself by using its own heating capability to prevent delamination, reducing the need for separate protective systems and minimizing additional complexity.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The heating element is designed to perform multiple functions: it maintains the sensor at operating temperature during normal PM detection and also removes water during the after-run mode. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If the heating element operates continuously to remove water, then the sensor remains dry and functional, but energy consumption increases significantly

Engineering Contradiction:

Improvesensor dryness and functionalityVSAvoidheating element energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The heating element operates periodically rather than continuously, specifically during the after-run mode when the engine has just shut down and water is most likely to condense. This timed, periodic operation removes water effectively while minimizing energy consumption compared to continuous heating.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system performs water removal as a preliminary action during the after-run mode before the vehicle is parked or before cold temperatures can cause freezing. By removing water at this specific time window, the system ensures sensor protection without requiring prolonged or continuous heating, thus reducing overall energy consumption.

Inventive Principle:

Principle #10Preliminary 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 effectively prevents delamination cracking by ensuring the particulate matter sensor remains dry, thereby extending its lifespan and maintaining accurate readings.

Implementation Method 1

operating the heating element for a predetermined period of time at a predetermined temperature to remove the liquid water from the PM sensor

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

initiating operation of a heating element of the PM sensor; and operating the heating element for a predetermined period of time at a predetermined temperature

Methodology Applied

Scientific EffectConduction (thermal): Conduction (thermal)

Data Source

PatentUS10914223B1Particulate matter sensor hardware protection in after-run

Publication Date: 2021.02.09 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method for mitigating against failure of a particulate matter sensor of an automobile vehicle includes: determining if a key-off event is present, identifying an engine is off in a vehicle after-run mode; defining when local environmental conditions are outside of mechanical limits of a particulate matter (PM) sensor; identifying input values to reverse the local environmental conditions of the PM sensor; and controlling operation of a heating element of the PM sensor to achieve the input values to reverse the local environmental conditions during the vehicle after-run mode.