Straddled Vehicle Driveline Control for Backlash Shock Reduction

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Solution Overview

Problem

Straddled vehicles experience shock due to backlash between power transmission members when transitioning from a decelerating to an accelerating state, which affects vehicle stability and responsiveness.

Innovation Solution

A straddled vehicle configuration that includes a power transmission path with first and second power transmission members having backlash, a braking device, and a control device that prevents the power transmission members from being in the deceleration position during the transition from deceleration to acceleration, by increasing torque and reducing braking force to maintain them in the acceleration position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If backlash between power transmission members is increased to allow smooth switching between power transmission and power disconnection, then ease of operation is improved, but shock during acceleration state changes increases

Engineering Contradiction:
Improvesmooth switching between power transmission and power disconnectionVSAvoidshock to the vehicle
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The control device performs preliminary action by controlling the power source to prevent the power transmission members from being in the deceleration position during a period before and after the switching time. This proactive control ensures that when the vehicle transitions from deceleration to acceleration, the power transmission members are already positioned to minimize backlash impact, thereby reducing shock while maintaining smooth switching capability

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If the control device prevents power transmission members from being in the deceleration position during transition period, then shock reduction is improved, but device complexity increases

Engineering Contradiction:
Improveshock to the vehicleVSAvoidcontrol system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The control device utilizes feedback by monitoring the switching time when the vehicle transitions from deceleration to acceleration state. Based on this feedback, the control device adjusts the power source output to maintain power transmission members in an optimal position during the transition period. This feedback mechanism enables effective shock reduction through a relatively simple control strategy that responds to actual vehicle state changes

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3967903B1Straddled vehicle
Publication Date: 2023.09.06 YAMAHA MOTOR CO LTD
  • EP3967903B1 patent drawingFigure 1~1(C)
  • EP3967903B1 patent drawingFigure 2
  • EP3967903B1 patent drawingFigure 3

AI summary

Provided is a straddled vehicle capable of reducing shock to the vehicle resulting from backlash between power transmission members thereof when the vehicle changes from a decelerating state to an accelerating state, with a change in state of a braking device. The straddled vehicle includes a vehicle wheel, a vehicle body, a power source, a power transmission path, and a braking device. The power transmission path includes a first power transmission member and a second power transmission member that transmit power when in engagement with each other. The control device controls at least the power source to prevent the first power transmission member and the second power transmission member from being in a deceleration position during a period from a point before a switching time until a point after the switching time. The switching time is a time when the straddled vehicle is switched from a state in which the straddled vehicle is decelerating because of operation of the braking device to a state in which the straddled vehicle is accelerating using a torque being outputted from the power source along with the operation of the braking device being discontinued.