Vehicle Clutch Torque Learning via Periodic Micro-Slip Control
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Solution Overview
Problem
Conventional micro-slip control methods for vehicle clutches in automated manual transmissions lead to continuous clutch wear and decreased fuel efficiency due to frequent slip and the need for continuous engine RPM control above 30 RPM, making it difficult to estimate transmission torque and maintain clutch durability and fuel efficiency.
Innovation Solution
A method and apparatus that control the frequency of clutch torque learning by determining vehicle movement, maintaining a micro-slip state for clutch torque learning, calculating learning reliability based on engine and clutch torque differences, and converting the clutch to a lock-up state when reliability exceeds an upper limit, while reverting to micro-slip state when reliability falls below a lower limit, thereby reducing slip frequency and maintaining clutch durability and fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If micro-slip control is continuously performed for clutch torque learning, then learning performance is improved, but clutch durability deteriorates due to continuous slip
Solution Approach 1:
The patent implements periodic micro-slip control at specific intervals (every 60 seconds or 300 seconds) rather than continuous control, allowing the clutch to learn torque characteristics periodically while remaining in lock-up state for the majority of time, thus balancing learning performance with durability
2Measurement precision
If micro-slip control is continuously performed for clutch torque learning, then learning performance is improved, but fuel efficiency decreases due to continuous engine RPM control above 30 RPM
Solution Approach 1:
The patent performs clutch torque learning periodically at predetermined intervals (60 or 300 seconds) rather than continuously, allowing the engine to operate at optimal RPM for fuel efficiency during normal operation while still acquiring necessary torque characteristics periodically
3Reliability
If the clutch is converted to lock-up state to improve fuel efficiency and durability, then slip frequency is reduced, but clutch torque learning cannot be performed
Solution Approach 1:
The patent performs clutch torque learning in advance at predetermined intervals before normal lock-up operation, ensuring torque characteristics are updated periodically while maintaining lock-up state for the majority of operation time to ensure durability and fuel efficiency
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces clutch slip frequency, enhancing durability and fuel efficiency, and improves transmission performance by optimizing clutch torque learning based on reliability calculations and state transitions.
Implementation Method 1
a frictional force generated by friction surfaces of the clutch
Data Source
AI summary
A method and an apparatus for controlling a clutch of a vehicle include determining whether a vehicle is moving under a condition in which a gearshift is coupled to the clutch. A clutch torque is learned in which the clutch is maintained in a micro-slip state by decreasing a target clutch torque for a corresponding gear level when it is determined that the vehicle is moving under the condition in which the gearshift is coupled to the clutch. Learning reliability is calculated by reflecting a difference between an engine torque and clutch torque. The clutch is maintained in the micro-slip state for the clutch torque learning or converting the clutch into a lock-up state, depending on a learning reliability level.