Particulate Filter Regeneration Control Under Excessive Temperature Risk

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Solution Overview

Problem

Existing methods for regenerating exhaust particulate filters in internal combustion engines face issues such as excessive temperature rise and thermal damage due to rapid combustion of deposited particulates during fuel cut, especially when the deposition amount is high and the filter temperature is elevated, leading to reduced regeneration opportunities and NOx generation.

Innovation Solution

Implement a control method that prohibits fuel cut when the deposition amount and temperature meet a predetermined excessive temperature rise condition and allows temporary oxygen supply under specific release conditions, such as low filter temperature, limited frequency, and time elapsed since the last release, to prevent excessive temperature rise and ensure filter regeneration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fuel cut is prohibited when deposition amount and temperature are high, then excessive temperature rise is prevented, but regeneration opportunities are reduced

Engineering Contradiction:
Improveexhaust particulate filter temperatureVSAvoidregeneration frequency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The control method dynamically adjusts the fuel cut prohibition decision based on real-time monitoring of deposition amount and temperature. Instead of a static prohibition rule, the system evaluates whether to prohibit fuel cut at each decision point based on current filter state, allowing adaptive regeneration opportunities while preventing excessive temperature rise.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (fuel cut permission status) based on detected parameters (deposition amount, temperature). By monitoring these parameters and adjusting control decisions accordingly, the system optimizes the balance between temperature control and regeneration frequency.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If weak lean control is continued to enable regeneration, then particulate removal is improved, but NOx generation and treatment problems arise

Engineering Contradiction:
Improveregeneration efficiencyVSAvoidNOx generation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

Instead of continuous weak lean control, the system implements periodic regeneration opportunities through controlled fuel cut operations. By timing fuel cut events appropriately based on filter state, the system achieves periodic particulate removal without sustained lean operation, thereby reducing continuous NOx generation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system converts the potential harm of high temperature (which would occur with frequent fuel cut) into a beneficial opportunity for regeneration. By carefully selecting when to permit fuel cut based on temperature and deposition monitoring, the system uses the exothermic combustion of particulates to achieve regeneration while controlling peak temperatures.

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

3Productivity

If fuel cut is permitted during deceleration, then regeneration occurs, but excessive temperature rise and thermal damage may occur

Engineering Contradiction:
Improveregeneration occurrenceVSAvoidthermal damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The control method continuously monitors filter temperature and deposition amount, using this feedback to make informed decisions about fuel cut permission. This closed-loop control ensures that fuel cut is only permitted when conditions are safe, preventing thermal damage while enabling regeneration when appropriate.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system prepares for potential temperature excursions by monitoring filter state in advance and making preventive control decisions. By detecting high temperature or high deposition conditions before fuel cut occurs, the system prevents excessive temperature rise and thermal damage before they can occur.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 thermal damage to the filter while maintaining regeneration opportunities by allowing controlled oxygen supply, even during high-load operations, thus suppressing excessive temperature rise and ensuring efficient particulate removal.

Implementation Method 1

the combustion of the exhaust particulates occurs

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

an exhaust particulate filter for collecting exhaust particulates which is disposed in an exhaust passage

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3786435B1Internal combustion engine control method and control device
Publication Date: 2026.01.21 NISSAN MOTOR CO LTD
  • EP3786435B1 patent drawingFigure 1
  • EP3786435B1 patent drawingFigure 2
  • EP3786435B1 patent drawingFigure 3~4

AI summary

An internal combustion engine (1) is provided with an exhaust particulate filter (6) disposed in an exhaust passage (4). When the particulate deposition amount and the temperature of the exhaust particulate filter (6) meet a predetermined excessive temperature rise condition, fuel cut during deceleration is prohibited. When a predetermined release condition is satisfied during the prohibition of the fuel cut, the fuel cut is temporarily permitted to perform the regeneration of the exhaust particulate filter (6).