DPF Regeneration Safety via Brake Torque and Gear Ratio Control

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Solution Overview

Problem

The regeneration of a particle filter in a stationary motor vehicle poses traffic safety risks due to torque transmission from the power train, which can cause the vehicle to move unexpectedly during the regeneration process.

Innovation Solution

Applying a safety brake action and selecting a higher gear step in the automatic gearbox to reduce torque transmission to the tractive wheels while maintaining the necessary exhaust gas temperature for regeneration, utilizing existing vehicle components and software to optimize brake and gear configurations based on surface conditions and vehicle weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the power train transmits torque to maintain exhaust gas temperature during particle filter regeneration, then the regeneration process can proceed, but the vehicle may move unexpectedly creating traffic safety risks

Engineering Contradiction:

Improveparticle filter regenerationVSAvoidtraffic safety risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control system applies preliminary braking action before the vehicle can move during regeneration. The brake system is activated in advance to counteract the torque from the power train, preventing the harmful effect of unexpected vehicle movement before it occurs.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The brake system acts as an intermediary between the power train and the vehicle motion. It mediates the torque transmission by applying counteracting force, allowing the power train to maintain exhaust temperature while preventing the vehicle from moving unexpectedly.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a higher gear step is selected to reduce torque transmission, then traffic safety is improved, but the exhaust gas temperature may drop below the necessary level for regeneration

Engineering Contradiction:

Improvetorque transmission to tractive wheelsVSAvoidexhaust gas temperature

Core Design Contradiction:

Object-affected harmful factorsVSTemperature

Solution Approach 1:

The control system changes the gear step parameter to a higher gear ratio, which reduces the torque transmission to the tractive wheels. This parameter change allows the vehicle to remain stationary with reduced torque while the brake system compensates to maintain the necessary exhaust gas temperature for regeneration.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If brake action is applied to keep the vehicle stationary, then traffic safety is maintained, but additional energy is consumed and brake wear increases

Engineering Contradiction:

Improvevehicle movement preventionVSAvoidbrake energy consumption

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The control system dynamically adjusts the brake application based on real-time conditions during regeneration. The brake torque is modulated to match the power train output, applying only the necessary force to prevent movement while minimizing energy consumption and brake wear throughout the regeneration process.

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 method ensures safe regeneration of the particle filter by keeping the vehicle stationary and reducing torque transmission, thereby enhancing traffic safety during the regeneration process without the need for additional components, and is cost-effective and easily implementable in existing vehicles.

Implementation Method 1

applying brake action to keep the vehicle stationary

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

choosing a gear step in said gearbox which is higher than an initial gear step of said gearbox in order to reduce the torque transmitted to the tractive wheels

Methodology Applied

Scientific EffectGear: Gear

Implementation Method 3

a power train with an engine, automatic gearbox and torque converter

Methodology Applied

Scientific EffectTorque converter:

Data Source

PatentEP2828494B1Device and method for improvement in safety of dpf regeneration

Publication Date: 2019.03.06 SCANIA CV AB

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Figure 3
Figure 4a~4b

AI summary

The invention relates to a method for safety improvement when a motor vehicle (100) comprising a power train with an engine (230), automatic gearbox (240) and torque converter (237) is stationary and particle filter (320) for the exhaust gases of the engine (230) is being regenerated, comprising the step of applying safety brake action to keep the vehicle (100) stationary despite torque transfer being maintained in said power train. The method comprises also the step of choosing in said gearbox (240) a gear step which is higher than an initial gear step of said gearbox (240) in order to reduce the torque transferred to the vehicle's tractive wheels (247a, 247b) when the vehicle is thus kept stationary. The invention relates also to a computer programme product comprising programme code (P) for a computer (200; 210) for implementing a method according to the invention. The invention relates also to a device for safety improvement when a motor vehicle (100) is stationary and a particle filter (320) for the exhaust gases of the engine (230) is being regenerated, and to a motor vehicle (100) equipped with the device.