Multi-Axis Motion Sensor Mounting for Washing Drum Imbalance Detection

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Solution Overview

Problem

Existing laundry treatment devices face challenges in effectively monitoring the movement and balance of laundry drums, particularly at high speeds, which can lead to operational failures and require additional sensors or modifications to the drum or tub.

Innovation Solution

A motion monitoring arrangement with at least two multi-axis motion sensors, a mounting element for rigid installation on the drum or tub, and an operating device for evaluating signals, which communicates with the machine control to adapt evaluations based on mounting position data, allowing for real-time monitoring without modifying other device components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional motion sensors are mounted on the laundry drum or tub without fixed positioning, then the monitoring system can be implemented, but the measurement precision and reliability of drum movement detection deteriorates due to sensor position changes during operation

Engineering Contradiction:
Improvemonitoring reliabilityVSAvoidmovement detection precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-defining and storing the correct mounting positions of motion sensors in the machine control before operation begins. The system includes position information in advance, allowing the operating device to select and apply the appropriate evaluation method based on the pre-stored position data, ensuring both reliability and precision from the start of operation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If additional elements or structures are added to the laundry drum or tub for optical or magnetic detection, then unbalance detection capability is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveunbalance detection capabilityVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the detection function from complex mechanical or optical structures and implements it using simple motion sensors that detect acceleration and orientation. By taking out the essential detection requirement and fulfilling it with minimal components mounted on existing drum or tub structures, the system achieves reliable unbalance detection without adding complex elements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex mechanical detection systems (optical sensors, magnetic sensors, additional drum structures) with electronic motion sensors that measure acceleration and orientation. This substitution using electronic sensing and signal processing achieves the same detection capability with simpler, more compact, and more reliable components.

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

3Adaptability or versatility

If the machine control and motor electronics are modified to evaluate measurement signals directly, then integration is improved, but the ease of manufacture and implementation becomes more difficult

Engineering Contradiction:
Improvesystem integrationVSAvoidmanufacturing simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent segments the monitoring system into independent functional modules: motion sensors for data collection, an operating device for signal evaluation and unbalance detection, and machine control for coordination. This segmentation allows each module to be developed, tested, and manufactured independently, then integrated through standardized interfaces, improving both adaptability and ease of manufacture.

Inventive Principle:
Principle #1Segmentation

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 solution enables reliable, real-time monitoring of laundry drum movement and balance detection, preventing operational issues without the need for additional structures or complex modifications, resulting in simpler and more cost-effective laundry treatment devices.

Implementation Method 1

at least two motion sensors, each of which is designed for multi-axis motion detection

Methodology Applied
Scientific EffectAcceleration sensing: Accelerometer

Implementation Method 2

The motion sensors with multi-axis motion detection are preferably 3D sensors or at least 2D sensors

Methodology Applied
Scientific EffectGyroscope effect: Gyroscope

Data Source

PatentEP4067551B1Motion monitoring device for monitoring the movement of a drum of a washing machine
Publication Date: 2023.09.13 DIEHL AKO STIFTUNG & CO KG
  • EP4067551B1 patent drawingFigure 1
  • EP4067551B1 patent drawingFigure 2A~2B
  • EP4067551B1 patent drawingFigure 3A~3B

AI summary

A laundry treatment device (10) with a tub (14) suspended in the machine housing (10) so as to be oscillating (15, 16), a washing drum (18) rotatably mounted in the tub (12) about a rotary axis (19), and a machine control (22) for controlling the operation of the laundry treatment device (10) can be equipped with a motion monitoring arrangement (28) for monitoring a movement of the washing drum (18), which includes at least two multi-axis motion sensors (284, 285), at least one mounting element (281;281n) for rigidly mounting components of the motion monitoring arrangement (28) on the washing drum (18) or the tub (14) with fixed positions of the at least two motion sensors (284, 285) even during operation of the laundry treatment device (10), an operating device (282) for controlling the at least two motion sensors and evaluating the measurement signals of the at least two motion sensors and a communication element (287) for sending the evaluation results of the operating device to a control unit (21, 22) of the laundry treatment device.;