Diesel Particulate Filter Regeneration via Transmission Shift Timing

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Solution Overview

Problem

Existing methods for regenerating diesel particle filters in vehicles with automatic transmissions often lead to unexpected shifting, causing driver discomfort and safety concerns, and require specific operating conditions, limiting regeneration to favorable situations, which results in oversized filter designs and inefficient operation.

Innovation Solution

A method that delays transmission shifting interventions for particle filter regeneration until a change in driving performance requirement, such as accelerator pedal action or cruise control changes, and uses gear shifts to increase engine speed and exhaust gas temperature, while ensuring torque consistency and only initiating regeneration during favorable driving conditions or after a specified period.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If transmission shifting is performed immediately to initiate particle filter regeneration, then regeneration can start promptly, but driver comfort and safety are compromised due to unexpected shifting

Engineering Contradiction:

Improveregeneration initiation speedVSAvoiddriver comfort

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The system determines in advance whether particle filter regeneration is needed and prepares for it, but delays the actual transmission shifting until a suitable opportunity arises (driver-initiated acceleration or deceleration), thus preparing beforehand without executing immediately to avoid disturbing the driver

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The transmission shifting strategy becomes dynamic by adapting to driver behavior - shifting is postponed until the driver naturally changes acceleration demand, making the system flexible rather than rigid in its regeneration timing

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If transmission shifting is delayed until driver-initiated acceleration, then driver comfort is maintained, but regeneration may be postponed indefinitely under unfavorable conditions

Engineering Contradiction:

Improvedriver comfortVSAvoidregeneration execution reliability

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The system continuously monitors driving conditions and driver inputs periodically, waiting for the next appropriate opportunity (acceleration or deceleration event) to execute the delayed shifting, rather than giving up or forcing immediate action

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system uses feedback from driver acceleration demand and vehicle operating conditions to determine the optimal moment to execute the delayed shifting, creating a closed-loop control that adapts to real-time conditions

Inventive Principle:

Principle #23Feedback

3Reliability

If particle filter regeneration is limited to favorable operating conditions only, then regeneration can be performed effectively, but the filter storage capacity must be designed disproportionately large

Engineering Contradiction:

Improveregeneration effectivenessVSAvoidfilter storage capacity

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The system performs preliminary assessment of regeneration needs and driver behavior patterns to proactively create regeneration opportunities, rather than passively waiting for favorable conditions, thus reducing the burden on filter storage capacity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the timing parameter of regeneration execution by delaying it until driver-initiated acceleration occurs, rather than executing immediately or not at all, thus adapting regeneration to natural driving variations

Inventive Principle:

Principle #35Parameter changes

4Temperature

If transmission shifting is performed to increase engine speed for regeneration, then exhaust gas temperature increases enabling soot burn-off, but unexpected shifting causes driver distraction and safety concerns

Engineering Contradiction:

Improveexhaust gas temperatureVSAvoiddriver distraction

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The system converts what would normally be a disruptive event (unexpected transmission shifting) into a beneficial one by synchronizing it with driver-initiated acceleration, where the driver already expects and welcomes the shifting for performance reasons

Inventive Principle:

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

Solution Approach 2:

The transmission control becomes dynamic by adapting shifting decisions to real-time driver intent and vehicle operating conditions, rather than following a fixed regeneration schedule that ignores driver context

Inventive Principle:

Principle #15Dynamics

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 minimizes driver distraction, ensures safe and comfortable driving, allows regeneration across a wider range of operating conditions, and reduces the need for oversized filter designs by synchronizing regeneration with normal driving actions, thus improving operational efficiency and safety.

Implementation Method 1

the change in the switching state of the automatic transmission is delayed until there is a change in a driving performance requirement, which is triggered by a corresponding actuation of the accelerator pedal by the driver

Methodology Applied

Scientific EffectDriver behavior synchronization:

Implementation Method 2

by post-injection of combustion fuel into the exhaust duct upstream of the particle filter

Methodology Applied

Scientific EffectExothermic combustion: Combustion

Implementation Method 3

the exhaust gas temperatures causing the soot to burn off

Methodology Applied

Scientific EffectThermal heating: Heating

Implementation Method 4

The diesel particle filters absorb the particles contained in the exhaust gas, which are primarily soot

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP1785605B1Method for the regeneration of a diesel particulate filter and corresponding transmission control

Publication Date: 2008.09.17 VOLKSWAGEN AG

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AI summary

The invention relates to a method for regenerating a particulate filter (16) arranged in the exhaust system (14) of an internal combustion engine (10), in particular a diesel engine, wherein a switching state of an automatic transmission (26) is changed to influence the exhaust gas temperature of the internal combustion engine (10) so that a minimum engine speed is maintained or exceeded during regeneration. It is provided that if a desired engine speed is not present at the time a regeneration requirement is detected and/or the regeneration of the particulate filter (16) is completed, the change in the switching state of the automatic transmission (26) is delayed until a change in driving performance demand occurs, which is generated either by a corresponding accelerator pedal operation by the driver or by a change in the target power of a cruise control system.The procedure increases driving safety because the shift intervention for regeneration support is "hidden" behind an action by the driver, thus preventing the driver from being irritated by an unexpected shifting process.