Hybrid Vehicle Engine Speed Control During Warm-Up

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hybrid vehicle control methods operate the engine at inefficient operating points during warming up, leading to deteriorated fuel consumption performance.

Innovation Solution

The engine is controlled to operate at higher rotation speeds on an optimal fuel consumption line, even during warming up, utilizing variable valve devices and exhaust gas recirculation to improve fuel efficiency, and switching between operating states based on the operation of fuel consumption devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the engine operates at inefficient operating points during warming up to promote engine warming, then the engine warming up is promoted, but fuel consumption performance deteriorates

Engineering Contradiction:
Improveengine temperatureVSAvoidfuel consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the engine rotation speed adaptable and changeable based on operating conditions. The ECU dynamically adjusts the engine rotation speed according to whether fuel consumption devices are operating, switching between higher rotation speeds (when devices are inactive) and lower rotation speeds (when devices are active), thereby optimizing the balance between warming up efficiency and fuel consumption performance

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the engine rotation speed parameter based on the operational state of fuel consumption devices. When these devices are not operating, the engine rotation speed is increased to maintain warmth without excessive fuel consumption. This dynamic parameter adjustment resolves the contradiction between maintaining temperature and minimizing fuel usage

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the engine operates at higher rotation speeds to maintain fuel consumption performance, then fuel consumption improves, but heat loss increases reducing warming up efficiency

Engineering Contradiction:
Improvefuel consumptionVSAvoidheat loss
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent employs feedback control where the ECU continuously monitors the operational state of fuel consumption devices and adjusts engine rotation speed accordingly. When fuel consumption devices are active, the system feedbacks a lower rotation speed setting; when they are inactive, it feedbacks a higher rotation speed setting. This closed-loop feedback mechanism optimizes the balance between fuel consumption and heat loss

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts engine rotation speed based on real-time operating conditions rather than maintaining a fixed speed. This dynamic adaptation allows the engine to operate at higher speeds only when necessary (when fuel consumption devices are inactive), thereby minimizing overall heat loss while maintaining fuel consumption performance

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4163171B1Hybrid vehicle control method and hybrid vehicle control device
Publication Date: 2025.10.15 NISSAN MOTOR CO LTD
  • EP4163171B1 patent drawingFigure 1
  • EP4163171B1 patent drawingFigure 2
  • EP4163171B1 patent drawingFigure 3

AI summary

A hybrid vehicle control method for a hybrid vehicle, the hybrid vehicle comprising: a drive motor; a battery supplying electric power to the drive motor; and an engine for power generation configured to supply electric power to the battery and the drive motor, and the control method comprising: operating the engine at a higher engine rotation speed in an operating state in which a fuel consumption device that contributes to improved fuel consumption performance does not operate than in an operating state in which the fuel consumption device operates.