Vehicle Sailing Mode Exit Clutch Control

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Solution Overview

Problem

Existing drive unit control systems experience noticeable delays and impacts on the driving experience when exiting sailing mode, particularly due to the decoupling and re-coupling of the clutch, leading to inefficient acceleration and a less-than-smooth transition from sailing mode to normal driving.

Innovation Solution

The method involves predicting the exit trigger for sailing mode and prepping the clutch unit for engagement, adapting the shaft speed, and engaging the clutch unit without slipping to minimize delays and ensure a seamless transition, by regulating the clutch unit's hydraulic pressure and torque management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the clutch unit is disengaged to enable sailing mode, then energy efficiency is improved, but acceleration response and driving experience deteriorate

Engineering Contradiction:

Improveenergy efficiencyVSAvoidacceleration response

Core Design Contradiction:

Use of energy by moving objectVSSpeed

Solution Approach 1:

The control unit initiates clutch preparation and shaft speed adaptation before the actual exit from sailing mode is triggered. By predicting the exit condition and starting preparatory actions in advance, the system reduces the delay between throttle actuation and effective acceleration, thus improving acceleration response while maintaining energy efficiency during sailing mode operation.

Inventive Principle:

Principle #10Preliminary action

2Power

If the clutch unit is engaged after sailing mode, then torque transmission is restored, but noticeable delay and impact on driving experience occurs

Engineering Contradiction:

Improvetorque transmissionVSAvoiddelay in acceleration

Core Design Contradiction:

PowerVSLoss of time

Solution Approach 1:

The system performs preliminary shaft speed adaptation and clutch preparation actions before the clutch engagement is actually required. The control unit adapts the shaft speed in advance and initiates clutch engagement procedures predictively, so that when the clutch needs to transmit torque, the preparation is already complete or nearly complete, thereby minimizing the noticeable delay and improving the driving experience.

Inventive Principle:

Principle #10Preliminary action

3Extent of automation

If automatic clutch engagement is implemented, then sailing mode exit is automated, but noticeable impacts on driving experience occur

Engineering Contradiction:

Improveautomatic clutch engagementVSAvoiddriving experience

Core Design Contradiction:

Extent of automationVSEase of operation

Solution Approach 1:

The control unit predicts when the driver will want to exit sailing mode based on throttle pedal position and other parameters, and initiates clutch preparation and shaft speed adaptation in advance. This predictive automation smooths the transition by preparing the system beforehand, making the automatic engagement less noticeable and more seamless compared to reactive automation that waits for explicit exit conditions.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If shaft speed adaptation is performed after exit trigger, then clutch engagement is enabled, but acceleration delay increases

Engineering Contradiction:

Improveclutch engagement capabilityVSAvoidacceleration delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The control unit initiates shaft speed adaptation before the exit from sailing mode is fully triggered, using predictive logic based on throttle pedal position and vehicle state. By starting the shaft speed adaptation process in advance while the clutch is still being prepared, the system ensures that speed matching is already underway or complete by the time clutch engagement is required, thereby reducing acceleration delay while maintaining reliable engagement.

Inventive Principle:

Principle #10Preliminary action

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 reduces the delay between throttle pedal actuation and vehicle acceleration, enhancing the driving experience by smoothing the transition out of sailing mode and reducing noticeable impacts on the driver.

Implementation Method 1

regulating the clutch unit's hydraulic pressure

Methodology Applied

Scientific EffectHydraulic pressure regulation: Hydraulic Press

Implementation Method 2

engaging the clutch unit without slipping

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9333972B2Method and system for exiting a sailing mode of a vehicle

Publication Date: 2016.05.10 BAYERISCHE MOTOREN WERKE AG

AI summary

A method (600) for exiting a sailing mode of a vehicle (100) is described. The vehicle (100) comprises a clutch unit (103) which is disengaged in order to decouple a driving shaft (102) of the vehicle (100) from a driven shaft (105) of the vehicle (100), when the vehicle (100) is operated in the sailing mode. The method (600) comprises predicting (601) that a trigger for an exit of the sailing mode will occur, and initiating (602) the preparation of the clutch unit (103) for engagement, subject to predicting that a trigger for the exit of the sailing mode will occur. Furthermore, the method (600) comprises detecting (603) a trigger for the exit of the sailing mode, and adapting (604) a shaft speed (230) of the driving shaft (102), subject to detecting a trigger for the exit of the sailing mode. In addition, the method (600) comprises engaging (605) the clutch unit (103), subject to preparing the clutch unit (103) for engagement and subject to adapting the shaft speed (130), in order to exit the sailing mode.