Motorcycle Engine Speed Control for Comfort and Fuel Efficiency

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Solution Overview

Problem

Conventional vehicle control devices struggle to set the engine rotation speed to achieve comfortable riding, as the target engine rotation speed is often affected by the required driving force and fuel efficiency optimization.

Innovation Solution

A vehicle control device that calculates a target engine rotation speed initially, followed by calculating a driving force target value and a target throttle opening degree, allowing for easier adjustment of the engine rotation speed to achieve comfortable riding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the target engine rotation speed is set based on fuel efficiency optimization and required driving force, then fuel efficiency is improved, but the engine rotation speed cannot be readily adjusted to achieve comfortable riding

Engineering Contradiction:
Improvefuel efficiencyVSAvoidease of setting engine rotation speed for comfortable riding
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The control device segments the control parameters into distinct components: target engine rotation speed, target transmission ratio, driving force target value, and target throttle opening degree. This segmentation allows independent calculation and adjustment of each parameter, enabling the engine rotation speed to be set for comfort while maintaining fuel efficiency through separate optimization of other parameters.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control device performs preliminary calculation of the target engine rotation speed based on comfort requirements before calculating the driving force target value and target throttle opening degree. This preliminary action establishes the engine rotation speed as an independent control variable, allowing comfortable riding to be achieved without compromising fuel efficiency.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by moving object

If the target engine rotation speed is set to optimize fuel efficiency, then energy consumption is reduced, but acceleration responsiveness deteriorates

Engineering Contradiction:
Improvefuel efficiencyVSAvoidacceleration responsiveness
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The control device dynamically adjusts the target engine rotation speed, target transmission ratio, and target throttle opening degree based on real-time driving conditions and accelerator operation amount. This dynamic control allows the system to optimize fuel efficiency during steady-state operation while rapidly responding to acceleration requests when the rider operates the accelerator.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control device changes multiple parameters simultaneously (engine rotation speed, transmission ratio, throttle opening degree) in response to driving conditions. By coordinating changes in these parameters, the system can maintain fuel efficiency while improving acceleration responsiveness when needed.

Inventive Principle:
Principle #35Parameter changes

3Power

If the driving force target value is calculated based on accelerator operation amount and target engine rotation speed, then acceleration performance is improved, but control complexity increases

Engineering Contradiction:
Improveacceleration performanceVSAvoidcontrol calculation complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The control device segments the control calculations into distinct functional units: target engine rotation speed calculation, target transmission ratio calculation, driving force target value calculation, and target throttle opening degree calculation. This segmentation simplifies the overall control logic by breaking down complex calculations into manageable, independent steps.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control device performs preliminary calculations of target engine rotation speed and target transmission ratio before calculating the driving force target value. This preliminary action reduces the complexity of the final driving force calculation by establishing known parameters in advance, making the overall control process more manageable.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2851253B1Vehicle control method, vehicle control device, and motorcycle provided therewith
Publication Date: 2025.04.30 YAMAHA MOTOR CO LTD
  • EP2851253B1 patent drawingFigure 1
  • EP2851253B1 patent drawingFigure 2
  • EP2851253B1 patent drawingFigure 3

AI summary

To provide a vehicle control device capable of relatively readily setting an engine rotation speed to a rotation speed that achieves a comfortable sense of riding. A target engine rotation speed calculation unit (11) calculates a target engine rotation speed. A target transmission ratio calculation unit (13) calculates a target transmission ratio, based on the target engine rotation speed. A driving force target calculation unit (15) calculates a driving force target value that is a target value as to a driving force of a vehicle, based on the target engine rotation speed. A target throttle opening degree calculation unit (18) calculates a target throttle opening degree, based on the driving force target value and the target engine rotation speed such that a driving force corresponding to the driving force target value is obtained.