Motor Vehicle Parking Brake Control Segmentation

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Solution Overview

Problem

Existing parking lock systems in motor vehicles lack robust safety and functionality, particularly failing to prevent engagement of the parking lock when the transmission control unit fails, which can lead to unintended vehicle movement.

Innovation Solution

A device and method where a selector lever control unit communicates with a holding device to maintain the parking lock in a disengaged state, even if the transmission control unit fails, by actuating the actuator device through the transmission control unit, allowing the driver to manually control the parking lock engagement, and utilizing an electrically actuable hydraulic valve and electromagnetic locking mechanism for reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the transmission control unit is used to actuate both the actuator device and holding device, then the control structure is simplified, but the safety and reliability deteriorate because the parking lock cannot be prevented from engaging if the transmission control unit fails

Engineering Contradiction:
Improvecontrol structureVSAvoidsafety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The control function is segmented into two independent control units: the transmission control unit for actuating the actuator device, and the selector lever control unit for actuating the holding device. This segmentation ensures that a failure in one control unit does not compromise the entire parking lock system, as the other control unit can still function independently to maintain safety.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the transmission control unit continuously monitors and controls the parking lock, then the functionality is improved, but the energy consumption increases

Engineering Contradiction:
ImprovefunctionalityVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The transmission control unit is switched off or switched off depending on the shift position detected by the selector lever control unit. Instead of continuous operation, the control unit operates periodically or only when needed (e.g., when the vehicle is in motion or in specific gear positions), thereby reducing energy consumption while maintaining necessary functionality.

Inventive Principle:
Principle #19Periodic action

3Reliability

If the holding device is always active to prevent parking lock engagement, then the safety is improved, but the energy consumption increases

Engineering Contradiction:
ImprovesafetyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The holding device is actuated by the selector lever control unit based on detected shift positions rather than remaining continuously active. The holding device is engaged only when needed (e.g., when the vehicle is stationary or in park position) and disengaged when the vehicle is in motion or in driving positions, thereby maintaining safety while minimizing energy consumption.

Inventive Principle:
Principle #19Periodic 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

Enhances safety and functionality by ensuring the parking lock can be manually controlled even during transmission control unit failures, reducing energy consumption, and providing redundant energy supply to critical control units, thus preventing unintended vehicle movement.

Implementation Method 1

a holding device for holding the parking lock in the disengaged state... a holding magnet for holding the parking lock in the disengaged state

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

an electrically actuable hydraulic valve and electromagnetic locking mechanism for reliable operation

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP2705282B1Device for operating a parking brake of a motor vehicle and corresponding method
Publication Date: 2015.11.04 AUDI AG
  • EP2705282B1 patent drawingFigure 1
  • EP2705282B1 patent drawingFigure 2

AI summary

The invention relates to a device (1) for operating a parking brake (2) of a motor vehicle, said parking brake (2) comprising an actuatable actuator element (3) for disengaging the parking brake (2) counter to a restoring pressure, and an actuatable holding device (4) for holding the parking brake (2) when the latter is disengaged. The device (1) comprises a selector control device (23) and a transmission control device (22) communicating therewith, the selector control device (23) actuating the holding device (4) and the transmission control device (22) actuating the actuator element (3). The invention further relates to a method for operating a parking brake of a motor vehicle.