Hybrid Vehicle Filter Regeneration Control by Battery Charge State

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Solution Overview

Problem

Existing hybrid vehicles risk overdischarging the power storage device when performing fuel cutting of the engine to regenerate the particulate matter filter, particularly in high-speed conditions, without considering the state of charge of the battery.

Innovation Solution

A hybrid vehicle control system that adjusts engine operation based on the state of charge of the power storage device, performing fuel cutting and motoring when the charge is sufficient, and self-sustained operation or rotation stop when charge is low, to prevent overdischarge, while ensuring filter regeneration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fuel cutting of the engine is performed to regenerate the filter in the accelerator-off state, then filter regeneration is achieved, but the state of charge of the battery is excessively decreased causing overdischarge

Engineering Contradiction:
Improvefilter regenerationVSAvoidstate of charge of battery
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The control device dynamically adjusts engine operation mode based on real-time battery state of charge levels. When SOC is high, fuel cutting is performed for filter regeneration; when SOC is low, the engine switches to self-sustained operation to maintain battery charge, preventing overdischarge while ensuring filter regeneration when conditions permit

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the engine based on battery state of charge. The control device monitors SOC and transitions the engine between different operating modes (fuel cutting vs. self-sustained operation) by adjusting fuel supply and air intake parameters, thereby balancing filter regeneration needs with battery health protection

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the allowable input power of the battery is set to a smaller value upon satisfaction of filter regeneration conditions, then fuel cutting of the engine is facilitated, but the battery may be overdischarged

Engineering Contradiction:
Improvefilter regeneration efficiencyVSAvoidbattery charge level
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control device implements a feedback mechanism that continuously monitors battery state of charge and adjusts engine operation accordingly. The system uses SOC feedback to determine whether to permit fuel cutting for filter regeneration or to maintain engine operation to charge the battery, creating a closed-loop control system that prevents overdischarge while enabling filter regeneration when appropriate

Inventive Principle:
Principle #23Feedback

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

The system effectively prevents overdischarge of the power storage device by optimizing engine operation based on battery charge levels, ensuring reliable filter regeneration and maintaining vehicle performance.

Implementation Method 1

a filter that is placed in an exhaust system and that is configured to remove particulate matter

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

regenerative driving of the second motor... converting energy that is generated, when the vehicle is decelerated into electric power energy by the generating operation of the traveling motor

Methodology Applied
Scientific EffectRegenerative braking: Electromagnetic Induction

Implementation Method 3

causes the air (oxygen) to be supplied to the filter and to burn the particulate matter accumulated on the filter and thereby achieves regeneration of the filter

Methodology Applied
Scientific EffectOxidation combustion: Oxidation

Data Source

PatentEP3659881B1Hybrid vehicle
Publication Date: 2025.10.08 TOYOTA JIDOSHA KK
  • EP3659881B1 patent drawingFigure 1
  • EP3659881B1 patent drawingFigure 2~3
  • EP3659881B1 patent drawingFigure 4

AI summary

There is provided a hybrid vehicle (20, 120) that suppresses overdischarge of a power storage device (50). In the case where a braking force is applied to drive wheels accompanied with regenerative driving of a second motor (MG2) in an accelerator-off state upon satisfaction of a filter regeneration condition, when a state of charge of a power storage device (50) is equal to or higher than a reference value, an engine (22) and a first motor (MG1) are controlled such as to perform fuel cutting of the engine and motoring of the engine by the first motor. When the state of charge of the power storage device is lower than the reference value, on the other hand, the engine is controlled such as to perform self-sustained operation or rotation stop of the engine.