Motorcycle Torque Control for Backlash Shock During Acceleration

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Solution Overview

Problem

Straddled vehicles experience shocks due to backlash between power transmission members during acceleration or deceleration, which can vary depending on running conditions and are not effectively adjusted by existing technologies.

Innovation Solution

A straddled vehicle with a control device that acquires parameters related to vehicle behavior changes, such as turning state, pitch angle, and road friction, to adjust the torque output from the power source during torque changes, reducing the magnitude of shocks transmitted to the driven member based on these conditions.

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 disconnection, then switching smoothness is improved, but shock magnitude increases during acceleration or deceleration

Engineering Contradiction:
Improveswitching smoothnessVSAvoidshock magnitude
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The control device dynamically adjusts the torque output parameter from the power source based on vehicle running conditions (speed, acceleration, deceleration). By changing the torque parameter in real-time, the system reduces shock magnitude during acceleration/deceleration while maintaining adequate backlash for smooth switching operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The control device monitors vehicle running conditions and feedback this information to adjust torque output. This closed-loop control ensures that torque is reduced when backlash recovery is detected (during acceleration from deceleration state) and normal torque is restored when conditions stabilize, thereby managing shock while preserving switching functionality.

Inventive Principle:
Principle #23Feedback

2Speed

If torque output from the power source is increased to improve acceleration performance, then acceleration responsiveness is improved, but shock from backlash recovery increases

Engineering Contradiction:
Improveacceleration responsivenessVSAvoidshock from backlash recovery
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The control device modifies the torque output parameter based on detected running conditions. When acceleration from a deceleration state is detected (indicating backlash recovery), the torque parameter is reduced to minimize shock. When normal acceleration conditions exist, full torque is delivered to maintain responsiveness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The control device performs preliminary detection of running conditions (speed, acceleration state) before torque changes occur. By identifying when the vehicle transitions from deceleration to acceleration, the system proactively reduces torque output in advance of backlash recovery, preventing shock before it occurs.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If existing acceleration/deceleration control devices are used to reduce shock, then shock reduction is achieved, but they cannot effectively adjust shock magnitude based on varying running conditions

Engineering Contradiction:
Improveshock reductionVSAvoidadjustment to running conditions
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The control device adjusts the torque output parameter dynamically based on multiple running condition parameters (vehicle speed, acceleration state, deceleration state). This multi-parameter control enables effective shock reduction that adapts to varying running conditions, unlike fixed control strategies.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The control system transitions from static shock reduction to dynamic adaptation. By continuously monitoring running conditions and adjusting torque output in real-time, the system adapts shock reduction magnitude to match actual vehicle state, providing versatile performance across different operating scenarios.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3978742B1Straddled vehicle
Publication Date: 2024.05.01 YAMAHA MOTOR CO LTD
  • EP3978742B1 patent drawingFigure 1(A)~1(B-c)
  • EP3978742B1 patent drawingFigure 2
  • EP3978742B1 patent drawingFigure 3

AI summary

The present teaching provides a straddled vehicle capable of adjusting a shock on the straddled vehicle resulting from backlash between power transmission members thereof and accompanying an acceleration or a deceleration to a magnitude suitable for a running condition thereof. The straddled vehicle includes a power source, a driven member, a power transmission path, and a control device. The power transmission path includes a first power transmission member and a second power transmission member. The control device has an acquisition unit and a control unit. The acquisition unit acquires at least one parameter indicating a degree of a vehicle behavior change being feasible due to an increase or a decrease in torque from the power source, or a running condition of the straddled vehicle that is likely to generate an acceleration or a deceleration. The control unit performs, in a torque change period, a change process to change the torque being outputted from the power source, based on the at least one parameter. The torque change period includes at least a part of a non-transmission period from when the first and second power transmission members have been switched from a transmission state to a non-transmission state with an acceleration or a deceleration of the straddled vehicle until when the first and second power transmission members have been switched from the non-transmission state to the transmission state.