Clutch Controller Torque and Speed Management

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Solution Overview

Problem

Conventional semi-automatic vehicles face issues with maintaining appropriate torque transmission through the clutch, leading to impaired riding comfort due to excessive torque increase or decrease, as existing technologies struggle to control the clutch engagement based on rotational speed differences between the drive-side and driven-side members.

Innovation Solution

A clutch controller system that includes an actuator, actual torque obtaining section, request torque obtaining section, and a control unit to perform first and second control operations. The control unit adjusts the clutch engagement based on the difference between actual and request torques, and engine speed to ensure appropriate torque transmission and prevent excessive engine speed changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the clutch engagement is controlled based on rotational speed difference between drive-side and driven-side members, then the clutch engagement timing can be determined, but appropriate torque cannot be constantly transmitted and riding comfort is impaired

Engineering Contradiction:
Improverotational speed differenceVSAvoidtorque transmission stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The control method transitions from using only rotational speed difference as the control parameter to using a composite parameter that includes both rotational speed difference and engine torque. This parameter change allows the system to account for both the mechanical state (speed difference) and the power source state (engine torque), thereby maintaining appropriate torque transmission while managing the engagement process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The control strategy dynamically adjusts the clutch engagement behavior based on real-time conditions. By continuously monitoring both rotational speed difference and engine torque, the system adapts the engagement rate and timing to maintain optimal torque transmission, preventing both excessive torque increases and prolonged low-torque states that would impair riding comfort.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the half-clutch state is maintained until rotational speed difference is almost zero, then torque transmission is improved, but engine speed becomes excessively unstable

Engineering Contradiction:
Improvetorque transmissionVSAvoidengine speed stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The control system implements feedback by continuously monitoring both rotational speed difference and engine torque, and adjusting the clutch engagement accordingly. This dual-parameter feedback mechanism allows the system to determine the optimal disengagement timing from half-clutch state, preventing excessive engine speed fluctuations while maintaining appropriate torque transmission. The system disengages the clutch before rotational speed difference reaches zero when engine torque indicates this is appropriate, thus stabilizing engine speed.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the clutch engagement is controlled to match request torque, then torque transmission accuracy is improved, but engine speed may excessively increase in certain operation ranges

Engineering Contradiction:
Improvetorque transmission accuracyVSAvoidengine speed stability
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The control system dynamically adapts its behavior based on engine operation range. In operation ranges where engine torque increases with engine speed, the system modifies the engagement control to prevent excessive engine speed increases, while in other ranges it maintains torque-matched engagement for accuracy. This dynamic adjustment resolves the contradiction between torque precision and engine speed stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the control parameters based on engine operation conditions. When operating in ranges prone to excessive speed increase, the system adjusts the engagement rate and disengagement timing parameters to prioritize engine speed stability, while in other ranges it prioritizes torque transmission accuracy. This parameter adaptation allows the system to handle different operational contexts appropriately.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP1975440B1Vehicle with clutch controller, and method of controlling clutch
Publication Date: 2019.06.12 YAMAHA MOTOR CO LTD
  • EP1975440B1 patent drawingFigure 1
  • EP1975440B1 patent drawingFigure 2
  • EP1975440B1 patent drawingFigure 3

AI summary

The present invention relates to a vehicle having an engine and a clutch provided in a torque transmission path, said clutch being controlled by a clutch controller comprising: an actuator for changing the degree of engagement between a drive-side member and a driven-side member of a clutch, the members being located downstream of an engine in a torque transmission path; an actual torque obtaining section for obtaining torque transmitted from the drive-side member to a downstream mechanism of the torque transmission path as actual transmission torque, the downstream mechanism including the driven-side member; a request torque obtaining section for obtaining torque determined based on an accelerator operation as request transmission torque; and a control unit, wherein the control unit is configured to perform a first control, under which the actuator is actuated based on a difference between the actual transmission torque and the request transmission torque, such that the actual transmission torque approximates the request transmission torque, and wherein, in an operation range in which engine torque outputted from the engine increases as the engine speed increases, the control unit is configured to perform a second control, in place of the first control, under which the actuator is actuated such that an engine speed increases or decreases to a predetermined engine speed.