Control method of laundry machine

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Solution Overview

Problem

Laundry machines generate significant noise and vibration during the spinning cycle due to unbalanced loading and high-speed rotation, which existing technologies have not effectively addressed.

Innovation Solution

A control method that rotates the drum within a specific RPM band in a transient region at a predetermined acceleration inclination less than the minimum drum speed acceleration, reducing noise and vibration by implementing a flexible support structure and balancer system to manage unbalance and vibration effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the drum is rotated at high speed during the spinning cycle, then the extraction efficiency is improved, but noise and vibration are significantly increased

Engineering Contradiction:
Improveextraction efficiencyVSAvoidnoise and vibration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by adjusting the acceleration inclination of the drum speed in the transient region. Specifically, the acceleration inclination is set to be less than a preset minimum value during the transient region (low RPM band), and then increased to a normal value after exiting the transient region. This dynamic adjustment of acceleration parameters reduces noise and vibration during the critical transient phase while maintaining efficient extraction performance at higher speeds.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the drum acceleration is increased to reduce spinning cycle time, then productivity is improved, but noise and vibration are exacerbated

Engineering Contradiction:
Improvespinning cycle timeVSAvoidnoise and vibration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements periodic action by dividing the acceleration process into distinct phases: a first acceleration phase with reduced acceleration inclination while passing through the transient region, followed by a second acceleration phase with normal acceleration inclination after exiting the transient region. This staged acceleration approach reduces harmful noise and vibration during the transient phase while still achieving the target speed efficiently, thus balancing productivity improvement with noise reduction.

Inventive Principle:
Principle #19Periodic action

3Loss of time

If the drum passes through the transient region quickly, then the spinning cycle time is reduced, but noise and vibration increase due to unbalanced loading

Engineering Contradiction:
Improvespinning cycle timeVSAvoidnoise and vibration
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the acceleration inclination dynamic rather than constant. The control system dynamically adjusts the acceleration inclination based on the drum's current RPM, specifically reducing it when the drum is in the transient region and increasing it when the drum exits the transient region. This dynamic control allows the system to minimize noise and vibration during the problematic transient phase while maintaining overall spinning cycle efficiency.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2470711B1Control method of laundry machine
Publication Date: 2017.05.24 LG ELECTRONICS INC
  • EP2470711B1 patent drawingFigure 1
  • EP2470711B1 patent drawingFigure 2
  • EP2470711B1 patent drawingFigure 3~4

AI summary

The control method of a laundry machine is disclosed. The control method of a laundry machine includes a step configured to rotate a drum in an RPM band belonging to a transient region and higher at a predetermined acceleration inclination less than a preset minimum drum speed acceleration inclination of the spinning cycle for a predetermined time period.