Adaptive NOx Trap Purge Control via Variable Reference Mapping

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Solution Overview

Problem

Existing nitrogen oxide (NOx) trap purge control methods fail to optimize the compromise between fuel consumption and pollutant emissions, as they are calibrated for worst-case driving conditions, leading to unnecessary fuel consumption in more favorable conditions.

Innovation Solution

A method that adjusts the purge control of the nitrogen oxide trap based on variable reference values dependent on temperature and hourly volumetric speed, using a map to determine optimal purge thresholds, and includes a bypass device and reformer to optimize NOx trap efficiency, allowing for adaptive control of the purge process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the NOx trap is purged frequently to ensure compliance with regulatory constraints in all driving conditions, then pollutant emissions are controlled, but fuel consumption increases unnecessarily

Engineering Contradiction:

Improvepollutant emissionsVSAvoidfuel consumption

Core Design Contradiction:

Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the purge control adaptive rather than static. The reference value for triggering purges is dynamically adjusted based on actual driving conditions (temperature, hourly volumetric speed) compared to worst-case calibration conditions. This allows the system to optimize fuel consumption by reducing unnecessary purges when conditions are favorable, while maintaining emission compliance when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of purge triggering threshold from a fixed worst-case value to a variable reference value that depends on actual driving conditions. By comparing actual temperature and speed parameters with calibrated worst-case parameters, the system adjusts the reference value to avoid unnecessary purges, thereby reducing fuel consumption while maintaining emission control.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the purge control is calibrated for worst-case driving conditions to ensure compliance, then regulatory constraints are met, but the system lacks adaptability to varying driving conditions

Engineering Contradiction:

Improveregulatory complianceVSAvoidadaptability to driving conditions

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the control parameter from a fixed worst-case threshold to a variable reference value that adapts to actual driving conditions. The reference value is calculated based on the ratio of actual temperature and hourly volumetric speed to calibrated temperature and speed, allowing the system to maintain reliability across varying conditions while improving adaptability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by continuously monitoring actual driving conditions (temperature and hourly volumetric speed) and comparing them with calibrated worst-case conditions. This feedback loop allows the system to adjust the purge control reference value in real-time, ensuring regulatory compliance while adapting to varying driving conditions.

Inventive Principle:

Principle #23Feedback

3Device complexity

If a fixed threshold is used for NOx trap purging, then the control system is simple, but it leads to unnecessary purging in favorable driving conditions

Engineering Contradiction:

Improvecontrol system complexityVSAvoidunnecessary fuel consumption

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent changes the purge threshold parameter from a fixed value to a variable reference value that depends on driving conditions. While this increases control complexity slightly, it eliminates unnecessary purges in favorable conditions, thereby reducing fuel consumption and energy loss.

Inventive Principle:

Principle #35Parameter changes

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 reduces unnecessary purging, improving fuel efficiency and adaptability to varying regulatory standards without structural modifications, ensuring the NOx trap is only purged when maximum adsorption capacity is reached.

Implementation Method 1

Then it is adsorbed on metal oxide sites (MO), according to the mechanism illustrated by the Figure 1A

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

The reformate is a mixture rich in hydrogen H2 and carbon monoxide CO produced by a reformer from a mixture of air and fuel

Methodology Applied

Scientific EffectPartial oxidation: Oxidation

Implementation Method 3

the sites formed by these metals make it possible to promote the various reactions which are the basis of the operation of the trap

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentEP2177729B1Method to control the purging of a Nitric oxygen trap

Publication Date: 2017.03.01 RENAULT SA

AI summary

The method involves comparing a part of nitrogen oxide content to a reference value, and controlling purging of nitrogen oxide trap according to a comparison result. A constant target value of purging efficiency of nitrogen oxide trap to be attained is stored in a memory. An assembly of temperature and regular speed values is stored. A cartography representing an assembly of reference values is established for the stored target value according to the stored assembly of temperature and regular speed values. An independent claim is also included for a computer program comprising instructions to execute steps of a nitrogen oxide trap purging controlling method.