Roof Window State Detection Using Multi-Axis Accelerometer

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Solution Overview

Problem

Existing solutions for determining the state of building roof windows are often costly, unreliable, mechanically complex, and require individual adaptation, lacking in cost-efficiency and ease of installation.

Innovation Solution

A window state detection system utilizing a multi-axis accelerometer integrated with the handle arrangement, which provides gravitational acceleration information to determine if the roof window is locked or open, and calculates the window opening value based on reference data adapted to the specific installation angle of the roof window, allowing for easy installation and retrofitting across different roof structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Hall sensor and magnet or opto-electric device are used to determine window state, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvewindow state detection accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical sensing systems (Hall sensors, magnets, opto-electric devices) with a simplified accelerometer-based system. The accelerometer detects gravitational acceleration changes to determine window state, eliminating the need for multiple mechanical components while maintaining detection accuracy.

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

Solution Approach 2:

The invention extracts only the essential function needed for window state detection from complex sensor systems. By using solely an accelerometer to detect gravitational changes, the system removes unnecessary components (magnets, Hall sensors, opto-electric devices) while preserving the core measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If inclinometer is arranged at sash frame to determine angular position, then measurement precision is improved, but device complexity and individual adaption requirements increase

Engineering Contradiction:
Improveangular position detection accuracyVSAvoidadaptability to different roof windows
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The accelerometer serves multiple functions: it detects both the angular position of the sash and the installation angle of the window. This multi-functionality eliminates the need for separate sensors for different measurement tasks, making the system universally applicable to various roof window configurations without requiring individual adaptation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system performs self-calibration by automatically determining the installation angle from accelerometer data. The microcontroller processes the gravitational acceleration measurements to calculate the installation angle, eliminating the need for manual calibration or individual adaptation during installation.

Inventive Principle:
Principle #25Self-service

3Reliability

If multiple sensors are used to reliably determine window states, then reliability is improved, but cost and device complexity increase

Engineering Contradiction:
Improvewindow state determination reliabilityVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces multiple mechanical sensors with a single accelerometer that provides sufficient reliability for window state determination. The accelerometer's ability to detect gravitational acceleration changes in different orientations allows reliable detection of open/closed states without requiring multiple sensor components.

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

Solution Approach 2:

The invention merges the functions of multiple sensors into a single accelerometer. By combining angle detection and state determination capabilities into one device, the system achieves reliable window state monitoring while reducing component count and overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Measurement precision

If complex mechanical systems are used for window state detection, then measurement precision is improved, but ease of manufacture and installation deteriorate

Engineering Contradiction:
Improvewindow state detection accuracyVSAvoidease of installation
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The invention extracts the essential detection function from complex mechanical systems, leaving only the necessary accelerometer component. This simplification makes the system easier to manufacture and install, as it requires fewer parts and less complex integration while maintaining detection accuracy through intelligent use of gravitational acceleration data.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The system offers a cost-effective, simple, and power-efficient method for reliably determining the state and opening value of roof windows, eliminating the need for complex mechanical integration and individual adaptation, while maintaining water tightness across varying roof pitches.

Implementation Method 1

The multi axis accelerometer arrangement is configured to provide gravitational acceleration information

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP4528053A1Detection of window state of a roof window based on gravitational acceleration information
Publication Date: 2025.03.26 VKR HOLDING AS
  • EP4528053A1 patent drawingFigure 1
  • EP4528053A1 patent drawingFigure 2
  • EP4528053A1 patent drawingFigure 2a~2b

AI summary

The disclosure relates to a building roof window comprising a window state detection system (2). The roof window comprises a movable frame (3) which is supported by a fixation frame (4) by means of a hinge arrangement (14) that allows the movable frame (3) to move relative to the fixation frame (4). The movable frame (3) comprises a handle arrangement (6) which is connected to at least one locking part (5a) of a locking system (5). The handle arrangement (6) is configured to be operated by human hand to be moved relative to the movable frame (3) and thereby displace the locking part (5a) between different states (S1-S3) comprising one or more locking states (S1, S2) and an unlocked state (S3). The locking system (5) in the one or more locking states (S1, S2) is configured to maintain the movable frame (3) in a predefined, locked position (CP, VP), wherein the locking system (5) in the unlocked state (S3) is configured to allow the movable frame to open towards a substantially fully open position. The window state detection system (2) comprises a data processing arrangement (11) and a multi axis accelerometer arrangement (10). The multi axis accelerometer arrangement (10) is arranged at the handle arrangement and comprises one or more multi axis accelerometers, wherein the multi axis accelerometer arrangement (10) is configured to provide gravitational acceleration information (SEO). The data processing arrangement is configured to provide data processing of the gravitational acceleration information (SEO) so as to determine if the roof window is in a predefined locked state (CS, VS) or in an open state (OS), and determine a window opening value representing an angular position of the movable frame (3) relative to the fixation frame (4). The determination of the window opening value is based on reference data comprising data which is based on an installation angle of the roof window.