Magnetic variable-damping vibration-reducing control method for washing machine

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Solution Overview

Problem

Existing vibration reduction control methods for washing machines fail to adjust damping forces accurately in real-time based on varying motor speeds and vibration amplitudes, leading to inconsistent damping performance across different washing stages.

Innovation Solution

A magnetic variable-damping vibration reduction control method that uses a sensor unit to detect real-time vibration amplitudes and motor speeds, adjusting the input current to the shock absorber dynamically to achieve the required damping force, by referencing pre-set correspondence relationships between damping force, speed difference, and current values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed current is introduced to the shock absorber for each gear time period, then the control system is simple, but the damping force cannot be adjusted accurately in real-time to match varying vibration requirements

Engineering Contradiction:
Improvecontrol system complexityVSAvoiddamping force accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by transitioning from fixed current settings to dynamic current adjustment based on real-time motor speed and vibration amplitude feedback. The control system continuously modifies the current introduced to the shock absorber according to varying operating conditions, enabling the damping force to adapt dynamically rather than remaining static throughout each gear period.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback mechanisms by introducing sensors that detect vibration amplitude and motor speed in real-time. This feedback information is fed back to the control system, which then adjusts the current to the shock absorber accordingly. The closed-loop feedback ensures that the damping force accurately matches the actual vibration requirements throughout the washing process.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If real-time detection and adjustment of current is implemented, then the damping force accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvedamping force accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies self-service by enabling the control system to automatically adjust current based on sensor feedback without requiring manual intervention. The system self-regulates the damping force by detecting vibration conditions and motor speed, then autonomously modifying the current to the shock absorber, reducing the need for external control while maintaining high accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements parameter changes by dynamically modifying the electrical parameter (current) introduced to the shock absorber based on detected vibration amplitude and motor speed. This parameter adjustment allows the damping force to be precisely controlled throughout varying operating conditions, achieving accurate vibration reduction without requiring complex mechanical modifications.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If preconceived damping force is used for each gear time period, then the control method is simple, but the damping force does not match the actual vibration requirements when motor speed varies

Engineering Contradiction:
Improvecontrol method simplicityVSAvoidvibration reduction effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by replacing static preconceived damping forces with dynamic damping forces that adapt to real-time motor speed and vibration conditions. The system continuously adjusts the damping force throughout each gear period rather than maintaining a fixed predetermined value, ensuring the damping remains effective as operating conditions change.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using sensors to detect actual vibration amplitude and motor speed, then feeding this information back to adjust the damping force accordingly. This feedback mechanism ensures that the damping force reliably matches actual vibration requirements, preventing the mismatch that occurs with preconceived fixed damping values.

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

This approach optimizes the damping force generated in real-time, minimizing resonance and vibration, and ensures the damping force approximates the required force to the greatest extent, effectively addressing the limitations of fixed current settings in prior art.

Implementation Method 1

The cushion chamber is filled with magnetic fluid, the piston is internally provided with an electromagnet and an orifice which allows the magnetic fluid to pass through, and the electromagnet is connected with a main controller via the wire in the piston rod. The main controller changes the fluidity of the magnetic fluid via controlling the size of the current and utilizing the intensity change of the magnetism of the electromagnet

Methodology Applied
Scientific EffectMagnetorheological effect: Magnetorheological Fluid

Data Source

PatentEP3323925B1Magnetic variable-damping vibration-reducing control method for washing machine
Publication Date: 2020.01.01 QINGDAO HAIER DRUM WASHING MACHINE CO LTD
  • EP3323925B1 patent drawingFigure 1
  • EP3323925B1 patent drawingFigure 2
  • EP3323925B1 patent drawingFigure 3

AI summary

The present disclosure provides a magnetic variable-damping vibration reduction control method of a washing machine. A variable-damping shock absorber (33) is arranged at the bottom of the outer barrel (22) of a washing machine, one end of the variable-damping shock absorber (33) is connected with the outer drum (22), while the other end is connected with a housing (44) of the washing machine, and during stages with different rotating speeds, different currents are input into the variable-damping shock absorber (33), and the variable-damping shock absorber (33) generates corresponding damping forces to reduce vibration, wherein in the vibration reduction process, the amplitude of vibration and the actual rotating speed of the motor are detected in real time, the difference between the actual rotating speed and the target rotating speed is calculated, and the size of the input current is adjusted in real time based on the amplitude of the vibration and the difference between the actual rotating speed and the target rotating speed.