Vehicle Window Positioning via Spring Stiffness Monitoring

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Solution Overview

Problem

Existing systems for determining the position of movable vehicle elements, such as windows or sunroofs, face challenges in maintaining accurate positioning due to wear, voltage fluctuations, and climatic influences, often resulting in noise and unnecessary wear from premature compression of elastic mounts.

Innovation Solution

A control device that continuously monitors and adjusts the spring stiffness during movement, determining the position point by exceeding a threshold value, allowing for reliable positioning independent of wear and climatic changes, and recalculates this position after a defined number of insertion processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the movable element moves into the elastic mount without braking, then the drive system is simpler, but clearly audible noises occur and wear increases

Engineering Contradiction:
Improvedrive system complexityVSAvoidnoise and wear
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The control device determines the position point before the movable element actually enters the elastic mount by monitoring spring stiffness changes. This preliminary determination allows the drive to be switched off in advance, preventing the element from moving into the mount with excessive speed and force, thereby avoiding noise and wear without requiring complex braking mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the spring stiffness of the elastic mount during movement and uses this feedback to determine when the position point is reached. This real-time feedback mechanism enables precise control of the stopping position, ensuring the movable element is stopped before excessive compression occurs, thus preventing noise and wear while maintaining simple drive system design.

Inventive Principle:
Principle #23Feedback

2Device complexity

If the position for stopping the movable element is determined from indirectly measured position, then the control system is simpler, but the desired stopping position often does not match due to wear, voltage fluctuations or climatic influences

Engineering Contradiction:
Improvecontrol system complexityVSAvoidstopping position accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system replaces indirect position measurement methods with direct physical property monitoring by measuring spring stiffness. This substitution provides a more accurate and reliable indication of the movable element's position, as spring stiffness directly reflects the compression state of the elastic mount, making the stopping position determination independent of wear, voltage fluctuations, and climatic influences.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If the drive is stopped when blockage is detected from current curve increase, then the drive system is simpler, but the movable element enters the elastic mount without braking causing noise

Engineering Contradiction:
Improvecontrol system complexityVSAvoidnoise during insertion
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The control device continuously monitors spring stiffness during movement and uses this feedback to determine the position point before the movable element enters the elastic mount. This allows the drive to be switched off proactively, preventing noise-causing impact, rather than waiting for blockage detection after the element has already entered the mount with excessive speed.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system determines the position point in advance by monitoring changes in spring stiffness before the movable element actually contacts the elastic mount with excessive force. This preliminary action enables the drive to be switched off before noise-generating impact occurs, rather than reacting to blockage after the damage is already done.

Inventive Principle:
Principle #10Preliminary action

4Device complexity

If a predetermined mathematical function is used to determine speed and power reduction, then the control system is simpler, but the position determination is less accurate due to wear and climatic influences

Engineering Contradiction:
Improvecontrol system complexityVSAvoidposition determination accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system replaces predetermined mathematical functions with direct monitoring of spring stiffness physical properties. This substitution provides real-time, accurate measurement of the elastic mount's state, making position determination independent of wear and climatic influences, as the actual physical condition of the mount is measured rather than calculated based on assumptions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Ensures accurate and noise-free operation by preventing the movable element from compressing the elastic mount excessively, adapting to wear and climatic changes, thereby reducing wear on the drive system and ensuring reliable sealing.

Implementation Method 1

the spring stiffness, in that a blocking of the drive is avoided by continuously determining and monitoring a spring stiffness during a movement of the movable element into the elastic receptacle

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2414610B1Method to determine a particular position of a moveable element
Publication Date: 2015.03.04 ROBERT BOSCH GMBH
  • EP2414610B1 patent drawingFigure 1
  • EP2414610B1 patent drawingFigure 2
  • EP2414610B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for determining a position point of a movable element, particularly a window (33) or a roof of a motor vehicle that can be advanced into at least one elastic receptacle (36) by means of a drive, comprising the steps of continually determining a spring stiffness in relation to the moving element (33) in the elastic receptacle (36) and determining a position point upon exceeding a specified spring stiffness threshold value.