Automatic Clutch Control for Vehicle Rocking

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Solution Overview

Problem

Vehicles with automatically controlled clutches face difficulties in rocking procedures to free themselves from stuck conditions due to the engine's moment of inertia braking the vehicle's backward roll, reducing the effectiveness of the rocking function.

Innovation Solution

A method where the clutch opens immediately when the driver reduces the demand for driving force, disconnecting the engine from the power train, allowing maximum benefit from the backward roll and enabling the driver to rock the vehicle using the accelerator pedal, similar to the clutch pedal in manually controlled gearboxes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clutch remains closed during rocking procedure, then the engine provides continuous driving force, but the engine's moment of inertia brakes the vehicle's backward roll, reducing the effectiveness of the rocking function

Engineering Contradiction:
Improveeffectiveness of rocking functionVSAvoidengine's moment of inertia braking effect
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The control system opens the clutch in advance during the rocking procedure when the driver reduces driving force demand, before the backward roll occurs. This preliminary action removes the engine's moment of inertia before it can interfere with the rocking motion, allowing the vehicle to rock effectively without the braking effect.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The clutch control system dynamically adjusts its state based on driving conditions. During rocking procedure, when the driver reduces driving force demand, the clutch automatically opens to allow free rocking motion. When normal driving resumes, the clutch closes again to transmit driving force. This dynamic adaptation resolves the contradiction between providing continuous driving force and allowing effective rocking motion.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the clutch opens immediately when driving force demand is reduced, then the engine's moment of inertia no longer brakes the backward roll, but the vehicle loses continuous driving force transmission

Engineering Contradiction:
Improvebackward roll effectivenessVSAvoidcontinuous driving force transmission
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The clutch operates periodically, opening during rocking procedure when driving force demand is reduced and closing when normal driving resumes. This periodic action allows the system to alternate between two states: one optimized for rocking effectiveness (clutch open) and one optimized for continuous driving force transmission (clutch closed), resolving the contradiction between these two opposing requirements.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The control system automatically detects when the driver reduces driving force demand and autonomously opens the clutch without requiring manual intervention. Similarly, when normal driving conditions resume, the system automatically closes the clutch. This self-service capability allows the system to manage the contradiction between rocking effectiveness and continuous driving force transmission without burdening the driver.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If a fully automatically controlled clutch is used, then the driver has simplified controls with only accelerator and brake pedals, but the driver cannot directly control clutch opening during rocking procedure

Engineering Contradiction:
Improvecontrol simplicityVSAvoiddriver control over clutch during rocking
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The control system continuously monitors the driver's driving force demand through the accelerator pedal position and other sensors. When the system detects that the driver has reduced driving force demand (indicating the start of a rocking procedure), it automatically opens the clutch. This feedback mechanism allows the fully automatic clutch to adapt to the driver's implicit intentions, providing both control simplicity and adaptability during rocking procedures.

Inventive Principle:
Principle #23Feedback

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

Enables effective rocking of vehicles with automatically controlled clutches by minimizing the engine's moment of inertia impact on the power train, allowing the vehicle to derive maximum benefit from backward rolls and facilitating self-release from stuck conditions.

Implementation Method 1

the engine's moment of inertia, until the clutch opens, will brake the vehicle's backward roll

Methodology Applied
Scientific EffectMoment of Inertia: Moment of Inertia

Data Source

PatentEP2478246B1Method and system for control of a clutch
Publication Date: 2019.08.14 SCANIA CV AB
  • EP2478246B1 patent drawingFigure 1
  • EP2478246B1 patent drawingFigure 2
  • EP2478246B1 patent drawingFigure 3

AI summary

The present invention relates to a method for control of an automatically controlled clutch when setting a vehicle (100) in motion on a running surface, which vehicle (100) comprises a combustion engine for generating driving force intended for transmission to at least one powered wheel, and a throttle control for demanding driving force from said engine, the magnitude of the driving force demanded from the engine being controlled by a driver of the vehicle by means of said throttle control. The method comprises the step, when a first criterion for a representation of the grip of said powered wheels on said running surface is fulfilled, of - opening said automatically controlled clutch if the driver uses said throttle control to reduce the demand for driving force from said engine.