Vehicle Automatic Transmission Clutch Torque Feedback Control
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Solution Overview
Problem
Existing vehicle automatic transmission systems experience vibrational rotation fluctuations due to elastic torsion elements, leading to increased load on transmission components and deteriorated gear shift feeling, especially in lightweight vehicles requiring high torque and operating on irregular terrain.
Innovation Solution
Implementing a torque feedback-control mechanism that brings the clutch into a sliding state and feedback-controls transmission torque to a target torque before disengagement, reducing vibrational fluctuations and load on transmission components during shift operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the clutch is gradually disengaged to prevent torsional torque from being instantly released, then clutch disengagement shock is eliminated, but shift time is extended
Solution Approach 1:
The clutch is brought into a half-engagement state before the shift operation to preliminarily reduce torsional torque. This preliminary action allows the torsion element to converge its fluctuation, so when the clutch is fully disengaged during shifting, no significant shock occurs and the shift can proceed quickly without extending shift time.
Solution Approach 2:
The clutch operation rate is dynamically adjusted based on the engagement state. During half-engagement, the clutch is operated at a lower rate to gently reduce torsional torque. When the half-engagement state is detected, the operation rate is increased to hasten disengagement, optimizing both shock reduction and shift time.
2Productivity
If the clutch is disengaged before torsional torque fluctuation is converged, then shift operation can proceed, but vibrational rotation fluctuation occurs and load on transmission components increases
Solution Approach 1:
The system performs preliminary torque reduction by bringing the clutch into half-engagement state before disengagement. This allows the torsion element to converge its fluctuation in advance, ensuring that when the shift operation proceeds with clutch disengagement, vibrational rotation fluctuation is minimized and load on transmission components is reduced.
Solution Approach 2:
The clutch control device monitors the sliding state of the clutch to detect the half-engagement state. This feedback mechanism allows the system to determine when torsional torque has been sufficiently reduced and when it is safe to proceed with clutch disengagement and shift operation, preventing excessive load on transmission components.
3Loss of time
If the clutch operation rate is increased after half-engagement state is detected, then clutch disengagement is hastened, but torsional torque may be instantly released
Solution Approach 1:
The clutch is brought into half-engagement state before increasing the operation rate. This preliminary action ensures that torsional torque has already been reduced and the torsion element has converged its fluctuation. Only after this convergence is achieved is the operation rate increased, preventing instant release of torsional torque while still hastening disengagement.
Solution Approach 2:
The control system uses feedback from clutch sliding state monitoring to detect half-engagement. This feedback triggers the increase in operation rate at the optimal moment, ensuring that torsional torque has been sufficiently reduced before rapid disengagement begins, thus avoiding harmful torque release while minimizing disengagement time.
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
This approach effectively reduces vibrational rotation fluctuations, prevents excessive load on transmission components, and improves gear shift feeling by stabilizing the torque transmission process.
Implementation Method 1
a clutch damper is often provided downstream of the clutch in order to reduce a shock occurring when the torque is transmitted
Implementation Method 2
a clutch damper is often provided downstream of the clutch in order to reduce a shock occurring when the torque is transmitted
Implementation Method 3
a torsion element in a torque transmission path downstream of the clutch is elastically restored from the torsion
Implementation Method 4
the torsion of the torsion element is vibrationally fluctuated
Data Source
AI summary
An automatic transmission device for a vehicle driven by transmitting a torque of an engine to driving wheels includes a clutch provided in a torque transmission system extending from the engine to the driving wheels, a transmission located between the clutch and the driving wheels in the torque transmission system, and a transmission controller. The transmission controller is configured or programmed to perform a torque feedback-control to bring the clutch into a sliding state in response to issue of a shift command and feedback-control a transmission torque to a target torque, disengage the clutch after the torque feedback-control, change a shift stage of the transmission according to the shift command after disengaging the clutch, and engage the clutch after changing the shift stage.