Vehicle Clutch Torque Learning for Stable Micro Slip Control

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Solution Overview

Problem

The stability of micro slip control in dry clutch systems is compromised due to changes in clutch characteristics during learning, leading to unstable micro slip states and potential gear shifting impacts, which affects the accuracy and marketability of vehicles with automatic manual transmissions or dual clutch transmissions.

Innovation Solution

A control method that determines the possibility of learning clutch characteristics by maintaining a slip amount within a reference range, calculates the change in clutch torque before and after learning, and adjusts the clutch torque by incorporating this change to stabilize micro slip control, thereby preventing instability and improving learning accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If clutch characteristics learning is performed frequently to improve control accuracy, then manufacturing precision is improved, but reliability deteriorates due to unstable micro slip control

Engineering Contradiction:
Improveclutch control precisionVSAvoidmicro slip control stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The system performs preliminary checks to determine whether learning conditions are satisfied before initiating clutch characteristics learning. This includes verifying that micro slip control is stable and that the operating state is appropriate for learning, thereby preventing unreliable learning operations from degrading control stability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors clutch characteristics and micro slip control stability, using this feedback to determine when learning should be performed and when it should be avoided. The learning process itself provides feedback to update the T-S curve, which then improves subsequent control accuracy

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If clutch characteristics learning is performed to improve control accuracy, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improveclutch control precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The clutch system performs self-learning of its own characteristics by automatically monitoring its operational state and updating its T-S curve based on observed behavior. This eliminates the need for external calibration equipment or complex manual adjustment mechanisms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes the representation parameters from raw sensor data to a simplified T-S curve model that captures essential clutch characteristics. This model can be stored and reused, reducing the complexity of real-time control calculations while maintaining high precision

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11339838B2Control method of clutch for vehicle
Publication Date: 2022.05.24 HYUNDAI MOTOR CO LTD
  • US11339838B2 patent drawing
  • US11339838B2 patent drawing
  • US11339838B2 patent drawing

AI summary

A control method of a clutch for a vehicle may include determining whether or not learning of clutch characteristics is possible; learning the clutch characteristics when the learning of the clutch characteristics is possible; determining a clutch torque for controlling the clutch in consideration of a change amount in the clutch torque before and after the learning and controlling the clutch by the determined clutch torque; and determining whether or not it is difficult to continue to learn the clutch characteristics.