Motorcycle Speed Control Torque Smoothing During Activation

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Solution Overview

Problem

Conventional motorcycle speed control systems cause abrupt changes in vehicle speed when starting or releasing speed control, leading to a deteriorated riding experience due to sudden deceleration or acceleration, especially during turns, as they do not effectively manage torque changes based on vehicle state.

Innovation Solution

A motorcycle system that includes a torque change reducer to limit the change in output torque when starting or releasing speed control, using a limit value setter and adjuster to set and adjust the limit torque based on vehicle state, such as deceleration rate and lean parameters, ensuring a smoother transition and improved riding feel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vehicle speed control is started during traveling with set vehicle speed lower than current vehicle speed, then vehicle speed is limited to prevent exceeding set speed, but engine torque is suddenly limited causing vehicle speed to sharply drop and deteriorating riding feeling

Engineering Contradiction:
Improvevehicle speed control effectivenessVSAvoidriding feeling
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the torque limitation gradual rather than abrupt. The controller limits engine torque progressively when vehicle speed control is activated, allowing the vehicle speed to decrease gradually rather than sharply. This dynamic approach maintains control effectiveness while improving riding comfort by reducing the suddenness of torque limitation.

Inventive Principle:
Principle #15Dynamics

2Productivity

If vehicle speed control is released during traveling, then engine torque limitation is removed, but engine torque is suddenly increased causing vehicle speed to abruptly rise and deteriorating riding feeling

Engineering Contradiction:
Improvevehicle speed control responsivenessVSAvoidriding feeling
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the torque release gradual rather than instantaneous. When vehicle speed control is released, the controller increases engine torque progressively, allowing vehicle speed to rise gradually rather than abruptly. This dynamic approach maintains control responsiveness while improving riding comfort by reducing the suddenness of torque increase.

Inventive Principle:
Principle #15Dynamics

3Reliability

If vehicle speed control is started or released during turning, then speed control function is activated, but vehicle body is leaned causing riding feeling to be deteriorated

Engineering Contradiction:
Improvevehicle speed control functionalityVSAvoidriding feeling during turning
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by detecting the leaning state of the vehicle body during turning and adjusting the torque limitation strategy accordingly. When turning is detected, the controller modifies how torque is limited or released, taking into account the specific condition of the leaned vehicle body. This localized adjustment maintains speed control functionality while improving riding feeling during turning maneuvers.

Inventive Principle:
Principle #3Local quality

4Reliability

If engine torque is suddenly limited at start of vehicle speed control in motorcycle, then vehicle speed is limited, but degree of deceleration felt by rider is higher than in automobile due to lighter vehicle weight

Engineering Contradiction:
Improvevehicle speed limitationVSAvoiddeceleration impact on rider
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by preparing for the impact of sudden torque limitation through gradual implementation. The controller limits engine torque progressively rather than suddenly, cushioning the deceleration impact on the rider. This approach maintains the effectiveness of vehicle speed limitation while reducing the harmful deceleration impact that is particularly noticeable in motorcycles due to their lighter weight.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3974273B1motorcycle
Publication Date: 2024.01.17 YAMAHA MOTOR CO LTD
  • EP3974273B1 patent drawingFigure 1
  • EP3974273B1 patent drawingFigure 2
  • EP3974273B1 patent drawingFigure 3

AI summary

A motorcycle includes a vehicle speed controller (32) configured to perform vehicle speed control that at least prevents vehicle speed (V) from exceeding set vehicle speed (Vs) and a torque change reducer (33) configured to reduce a change of the output torque of a driving source (5) when the vehicle speed control is turned on or off or the set vehicle speed (Vs) is changed during travelling. The torque change reducer (33) includes a limit value setter (331) configured to set a limit value (Ta) of a change amount of the limit torque (Tm) in accordance with a vehicle state and a limit torque adjuster (332) configured to receive the limit torque (Tm) from a limit torque calculator (322) of the vehicle speed controller (32) and adjust the limit torque (Tm) such that the change amount of the limit torque (Tm) does not exceed the limit value (Ta).