Control method of laundry machine

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Solution Overview

Problem

Laundry machines experience excessive noise and vibration during high-speed spinning cycles due to unbalanced drum rotation, which existing control methods fail to adequately address.

Innovation Solution

A control method for a laundry machine that determines the irregular vibration region and implements balancing steps before, during, and after the drum passes through this region, using a balancer with specific speed settings to maintain dynamic balance and reduce vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the drum rotates at high speed during spinning cycle, then water removal efficiency is improved, but noise and vibration increase significantly

Engineering Contradiction:
Improvewater removal efficiencyVSAvoidnoise and vibration
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The control method performs preliminary actions by detecting drum displacement before the drum enters the irregular vibration region, calculating unbalance amount in advance, and preparing balancing operations at appropriate speeds before high-speed rotation begins, thereby preventing excessive vibration before it occurs

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the balancing speed and timing based on real-time detection of drum displacement and calculated unbalance amount. The balancing operation is performed at variable speeds (including lowering speed to 300-700 rpm during irregular vibration region passage) rather than fixed speed, allowing adaptive response to changing vibration conditions

Inventive Principle:
Principle #15Dynamics

2Object-generated harmful factors

If ball balancer is used for drum balancing, then vibration reduction is achieved, but balancing effectiveness is insufficient in irregular vibration region

Engineering Contradiction:
Improvevibration levelVSAvoidbalancing effectiveness
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The control method implements continuous feedback by detecting drum displacement throughout the spinning cycle, calculating unbalance amount based on detected displacement, and adjusting balancing operations accordingly. The system monitors whether the drum passes through irregular vibration region and modifies balancing speed and timing based on this feedback, ensuring effective vibration control

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes operational parameters by adjusting the balancing speed dynamically. When the drum passes through the irregular vibration region, the balancing speed is lowered to 300-700 rpm to improve balancing effectiveness in this problematic speed range, whereas normal balancing may occur at higher speeds. This parameter adjustment ensures reliable balancing across all operating conditions

Inventive Principle:
Principle #35Parameter changes

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

Effectively reduces drum vibration even in irregular vibration regions, particularly during high-speed rotation, by ensuring the balancer is positioned correctly to compensate for unbalance and stabilize the drum.

Implementation Method 1

a laundry machine comprising a balancer... a balancing step implemented at least one time before a rotation speed of a drum enters the irregular vibration region, while the rotation speed is passing the irregular vibration region and after the rotation speed passes the irregular vibration region

Methodology Applied
Scientific EffectDynamic balancing: Balance

Data Source

PatentEP2470701B1Control method of laundry machine
Publication Date: 2017.08.09 LG ELECTRONICS INC
  • EP2470701B1 patent drawingFigure 1
  • EP2470701B1 patent drawingFigure 2
  • EP2470701B1 patent drawingFigure 3

AI summary

A control method of a laundry machine is disclosed. The control method of a laundry machine comprising a balancer includes a step configured to determine an irregular vibration region of the laundry machine and a balancing step implemented at least one time before a rotation speed of a drum enters the irregular vibration region, while the rotation speed is passing the irregular vibration region and after the rotation speed passes the irregular vibration region.