Hybrid Vehicle Engine Start Thresholds for Autonomous Moving Control

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Solution Overview

Problem

Hybrid vehicles face inefficiencies in energy consumption due to frequent activation and deactivation of the internal combustion engine, particularly during automatic driving, where the engine is often deactivated at suboptimal points, leading to reduced energy efficiency.

Innovation Solution

A vehicle moving apparatus that autonomously controls the activation and deactivation of the internal combustion engine based on requested power, using both the engine and electric motor to maintain high energy efficiency by activating the engine at optimal points and limiting power output until exhaust gas recirculation begins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the engine start determination value is set to a great value to prevent frequent switching, then the switching frequency between activation and deactivation is reduced, but the energy efficiency decreases because the engine is not activated at optimal points

Engineering Contradiction:

Improveswitching frequency stabilityVSAvoidenergy efficiency

Core Design Contradiction:

Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the engine start determination value adjustable based on driving conditions. The control unit dynamically selects between a first start determination value (for manual driving) and a second start determination value (for automatic driving), allowing the system to adapt to different operational contexts and resolve the contradiction between stability and energy efficiency.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of the engine start determination value based on the driving mode. By setting different threshold values for manual versus automatic driving, the system optimizes the balance between preventing frequent switching and maintaining energy efficiency, as the requested power characteristics differ between driving modes.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the engine is kept deactivated to save energy during automatic driving, then energy consumption is reduced, but the power output capability is insufficient when rapid acceleration is needed

Engineering Contradiction:

Improveenergy consumptionVSAvoidpower output capability

Core Design Contradiction:

Use of energy by moving objectVSPower

Solution Approach 1:

The patent applies preliminary action by activating the engine in advance when the requested power reaches the second start determination value during automatic driving. This proactive approach ensures the engine is ready to provide power when needed, rather than waiting until power deficiency occurs, thus balancing energy savings with power availability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control unit continuously monitors the requested power during automatic driving and uses this feedback to determine when to activate the engine. When the requested power reaches the second start determination value, the system responds by activating the engine, creating a closed-loop control that balances energy consumption and power output capability.

Inventive Principle:

Principle #23Feedback

3Use of energy by moving object

If the engine activation threshold is lowered to improve energy efficiency, then the engine activates at optimal points, but the switching frequency increases during manual driving

Engineering Contradiction:

Improveenergy efficiencyVSAvoidswitching frequency stability

Core Design Contradiction:

Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The patent segments the driving conditions into manual driving and automatic driving, applying different engine start determination values to each segment. This segmentation allows the system to optimize for energy efficiency during automatic driving (where frequent switching is less problematic) while maintaining stability during manual driving (where a higher threshold prevents excessive switching).

Inventive Principle:

Principle #1Segmentation

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 enhances energy efficiency by optimizing engine usage and reducing frequent switching, ensuring high energy output even at low requested power levels, particularly during automatic driving.

Implementation Method 1

limiting power output until exhaust gas recirculation begins

Methodology Applied

Scientific EffectExhaust gas recirculation:

Data Source

PatentUS12472924B2Vehicle moving apparatus with engine start determination values and engine power limitation for moving control

Publication Date: 2025.11.18 TOYOTA JIDOSHA KK

AI summary

A vehicle moving apparatus executes a moving control to autonomously move a vehicle by controlling power output from an internal combustion engine and an electric motor. The moving control maintains an index value expressing a moving state within a predetermined range and decelerates the vehicle by causing the vehicle to coast. The apparatus uses a second start determination value that is smaller than a first start determination value when the moving control is executed, and limits power output from the internal combustion engine until exhaust gas recirculation control starts, which allows the power to move the vehicle to be output at high energy efficiency during autonomous moving control.