Dual-Clutch Transmission Actuator Position Learning

Solution Overview

Problem

In dual-clutch gearboxes, the transmission of engine torque during vehicle deceleration can cause deformations leading to transverse displacement of primary shafts, which distorts actuator position control, resulting in noise, shocks, or blockages during gear changes.

Innovation Solution

A method and device that successively supply different torque values to a primary shaft, recording actuator positions at specific phases of synchronization and dog clutching to precisely determine the required positions of actuators during deceleration, allowing for precise control of actuator positions and reducing noise and shocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If torque is transmitted during vehicle deceleration, then engine torque is transmitted to the primary shaft, but this causes deformations leading to transverse displacement of primary shafts which distorts actuator position control

Engineering Contradiction:

Improveengine torque transmissionVSAvoidactuator position control precision

Core Design Contradiction:

PowerVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by performing a learning phase before normal operation. During this learning phase, the system pre-determines the positions that actuators must take during synchronization and dog clutch phases under deceleration conditions. These pre-determined positions are stored and then used during actual vehicle operation to compensate for the deformations caused by torque transmission, thereby maintaining precise actuator position control despite the harmful effects of casing deformations.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If actuator positions are controlled based on learned positions during deceleration, then gear changes can be executed, but noise, shocks, or blockages occur due to distorted position control

Engineering Contradiction:

Improvegear change executionVSAvoidnoise, shocks, and blockages

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs feedback by using position sensors to detect the actual positions of actuators during the learning phase. This detected position information is fed back to the control system, which then determines the correct actuator positions for synchronization and dog clutch phases. During normal operation, this feedback mechanism ensures that actuators are positioned accurately despite casing deformations, preventing noise, shocks, and blockages during gear changes.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies parameter changes by varying the torque applied to the primary shaft during the learning phase. By successively applying at least two torques with different discrete values, the system captures actuator positions under different loading conditions. This allows the control system to adapt to the non-linear behavior of the gearbox casings under deceleration, thereby eliminating noise and shocks during actual gear changes.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If traditional position control is used during deceleration, then actuator positions can be maintained, but transverse displacement of primary shafts causes distortion and potential blockage

Engineering Contradiction:

Improveactuator position maintenanceVSAvoidprimary shaft alignment stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by performing a learning phase before normal operation. During this learning phase, the system pre-determines the positions that actuators must take during synchronization and dog clutch phases under deceleration conditions. These pre-determined positions are stored and then used during actual vehicle operation to compensate for the deformations caused by torque transmission, thereby maintaining precise actuator position control despite the harmful effects of casing deformations.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3526494B1Method and device for learning synchronisation and engagement positions of actuators of a dual-clutch transmission (DCT) of a decelerating vehicle

Publication Date: 2020.11.04 PSA AUTOMOBILES SA

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AI summary

A device (DA) is charged with learning the positions of actuators (AC1 - AC2) in a dual-clutch transmission (BV) of a vehicle. The transmission (BV) has two parts (PB1 -PB2), each one comprising an actuator (AC1) that can act on an associated synchroniser (S1). Said device (DA) is arranged so as to trigger the successive supply of torques having different discrete values to a primary shaft (AP1) of one part (PB1) and to trigger, for each of said torques, a synchronisation phase involving an actuator (AC2) and a synchroniser (S2) of the other part (PB2), then to record first and second positions of the actuator (AC2) at the end of sub-phases for controlling position and force of the synchronisation phase, then to trigger a phase of engagement of said actuator (AC2) and synchroniser (S2), and then to record a third position of the actuator (AC2) at the end of said engagement phase.