Clutch Controller Torque Feedback for Straddle-Type Vehicle

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Solution Overview

Problem

Conventional clutch control methods in semi-automatic transmissions for vehicles fail to maintain optimal torque transmission, leading to impaired riding comfort due to abrupt changes in rotational speed differences between drive-side and driven-side members, resulting in shocks and excessive deceleration.

Innovation Solution

A clutch controller that estimates and regulates the target torque transmission by calculating the torque to be transmitted after complete engagement of the drive-side and driven-side members, using a combination of actual and estimated torque values to control the clutch actuator, ensuring a smooth and consistent torque delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the clutch controller controls the engagement state based on the difference in rotational speed between the drive-side member and the driven-side member, then the engagement process can be managed, but torque transmission becomes unstable and riding comfort deteriorates due to abrupt torque changes and shocks

Engineering Contradiction:
Improveclutch engagement controlVSAvoidtorque transmission stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the control parameter from rotational speed difference to torque difference (between actual transmission torque and target transmission torque). The clutch actuator is controlled based on the difference between actual transmission torque Tac and target transmission torque Ttg, which directly addresses torque transmission stability rather than relying on rotational speed differential control that causes abrupt torque changes and shocks during engagement.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the half-clutch state is maintained until the difference in rotational speed is almost zero, then torque transmission stability improves, but the engagement time becomes excessively long causing excessive vehicle deceleration

Engineering Contradiction:
Improvetorque transmission stabilityVSAvoidclutch engagement time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements feedback control by continuously monitoring the difference between actual transmission torque Tac and target transmission torque Ttg during clutch engagement. The clutch actuator control section adjusts the actuator output based on this torque difference feedback, enabling the system to achieve stable torque transmission without maintaining the half-clutch state for excessively long periods. This feedback mechanism allows the engagement process to be completed in appropriate time while ensuring torque stability.

Inventive Principle:
Principle #23Feedback

3Loss of time

If the clutch engagement is completed quickly by reducing rotational speed difference, then engagement time is reduced, but torque transmission becomes unstable causing shocks and impaired riding comfort

Engineering Contradiction:
Improveclutch engagement timeVSAvoidshocks and riding comfort
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The patent calculates the target transmission torque Ttg in advance based on the operating state of the straddle-type vehicle (engine torque, gear ratio, final drive ratio, centrifugal clutch torque). This preliminary determination of the target torque value allows the control system to guide the engagement process toward a predetermined stable state, enabling quick engagement completion without causing shocks or impairing riding comfort by preventing abrupt torque changes throughout the engagement process.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1975443B1Clutch having a clutch controller, method of controlling clutch, and straddle-type vehicle
Publication Date: 2018.12.05 YAMAHA MOTOR CO LTD
  • EP1975443B1 patent drawingFigure 1
  • EP1975443B1 patent drawingFigure 2
  • EP1975443B1 patent drawingFigure 3

AI summary

The present invention relates to a clutch having a clutch controller for controlling an engagement state of the clutch by actuating a clutch actuator, comprising: a target torque obtaining means for obtaining torque that is supposed to be transmitted from a drive-side member of the clutch to a downstream mechanism in a torque transmission path as target transmission torque, the downstream mechanism including a driven-side member of the clutch; and a control means for actuating the clutch actuator based on the target transmission torque, wherein the target torque obtaining means is configured to estimate torque to be transmitted from the drive-side member to the downstream mechanism in the torque transmission path after the drive-side member and the driven-side member are completely engaged, and is configured to obtain the estimated torque as the target transmission torque.