Hybrid Vehicle Control Apparatus for Engine Start Optimization

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Solution Overview

Problem

Conventional hybrid vehicle systems face challenges in quickly and reliably starting the internal combustion engine during regenerative braking, leading to potential delays and discomfort due to inadequate deceleration control and unnecessary engine speed increases.

Innovation Solution

A hybrid vehicle control apparatus that strategically replaces regenerative braking torque with engagement torque or friction braking torque based on the probability of starting the internal combustion engine, using a dual clutch transmission or automated manual transmission to manage the connection state between the rotating electrical machine and the transmission mechanism, ensuring timely and certain engine start-ups without unnecessary engine speed increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If regenerative braking torque is replaced by friction braking torque during downshift, then deceleration stability is improved, but engine start response is delayed

Engineering Contradiction:
Improvedeceleration stabilityVSAvoidengine start response time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent dynamically switches between friction braking torque and clutch engagement torque based on real-time driving conditions and engine start probability. The control system adjusts the replacement strategy from static to dynamic, selecting friction braking for stability-critical scenarios and clutch engagement for quick engine start scenarios, thereby resolving the contradiction between deceleration stability and engine start response time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameter from fixed friction braking replacement to variable torque replacement that considers engine start probability. By introducing the parameter of engine start probability into the control logic, the system can adaptively adjust the braking torque replacement strategy, switching between friction braking and clutch engagement based on predicted engine start needs, thus balancing deceleration stability with engine start responsiveness.

Inventive Principle:
Principle #35Parameter changes

2Speed

If clutch engagement torque is used to replace regenerative braking torque, then engine start response is improved, but unnecessary engine speed increases occur

Engineering Contradiction:
Improveengine start response speedVSAvoidunnecessary engine speed increases
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent implements a feedback mechanism that continuously monitors driving conditions, deceleration requirements, and engine state to determine the probability of engine start. This feedback loop allows the control system to intelligently select between friction braking and clutch engagement, using clutch engagement only when engine start is likely needed, thereby avoiding unnecessary engine speed increases while maintaining quick engine start capability when required.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary assessment of engine start probability before selecting the braking torque replacement strategy. By evaluating driving conditions and predicting the likelihood of engine start in advance, the system prepares the appropriate braking mode (friction or clutch engagement) proactively, ensuring quick engine start when needed while preventing premature clutch engagement that would cause unnecessary engine speed increases.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If friction brake is used to maintain deceleration, then drivability is improved, but engine cannot be started quickly when needed

Engineering Contradiction:
ImprovedrivabilityVSAvoidengine start time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent dynamically adjusts the braking torque replacement strategy based on real-time assessment of drivability requirements and engine start probability. Rather than statically using friction braking for all downshift scenarios, the system adaptively switches between friction braking and clutch engagement modes, maintaining smooth deceleration when engine start is unlikely while enabling quick engine start when probability is high, thus resolving the contradiction between drivability and engine start speed.

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

The solution enables quick and certain engine start-ups while maintaining drivability by optimizing braking torque selection based on engine start probability, reducing deceleration variations and avoiding unnecessary engine speed increases.

Implementation Method 1

a clutch capable of cutting off an engine output shaft of the internal combustion engine and the input shaft... a first replacement controlling device which replaces regenerative braking torque of the rotating electrical machine by engagement torque of the clutch

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a brake apparatus capable of applying friction braking torque to the wheels... a second replacement controlling device which replaces the regenerative braking torque by the friction braking torque

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2765044B1Hybrid vehicle control apparatus
Publication Date: 2019.11.27 TOYOTA JIDOSHA KK
  • EP2765044B1 patent drawingFigure 1
  • EP2765044B1 patent drawingFigure 2
  • EP2765044B1 patent drawingFigure 3

AI summary

A hybrid vehicle control apparatus (100) is provided with: a first replacement controlling device which replaces regenerative braking torque of the rotating electrical machine by engagement torque of the clutch if probability of starting an internal combustion engine is high on demand of changing a connection state between a rotating electrical machine and a transmission mechanism in regenerative braking by the regenerative braking torque of the rotating electrical machine; and a second replacement controlling device which replaces the regenerative braking torque by friction braking torque if the start probability is low on the change demand.