Drum washing machine, and control method and apparatus for same

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Solution Overview

Problem

Conventional drum washing machine control methods face issues of collision with the drum during weighing and failure of dehydration for single items due to inherent defects in load imbalance detection and protection thresholds.

Innovation Solution

The control method for a drum washing machine sets the velocity fluctuation threshold for weighing protection based on the current load by using the corresponding relationship between loads and average starting powers, avoiding collisions and dehydration failures by dynamically adjusting the threshold according to the load range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed velocity fluctuation threshold (e.g., 170rpm) is used for weighing protection, then dehydration function is maintained for light loads, but drum collision occurs during weighing for heavy loads

Engineering Contradiction:
Improveweighing protectionVSAvoiddrum collision
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by transitioning from a fixed velocity fluctuation threshold to a dynamic threshold that adapts based on load conditions. The control device determines the current load weight and selects different velocity fluctuation thresholds accordingly: a first threshold for loads within a weight range, and a second threshold for loads exceeding that range. This dynamic adjustment prevents drum collision during weighing for heavy loads while maintaining dehydration function for light loads.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of velocity fluctuation threshold based on load weight. By establishing a correspondence between load weight and velocity fluctuation threshold, the system selects appropriate threshold values dynamically. This parameter change resolves the contradiction by ensuring the threshold is appropriate for the actual load condition, preventing both drum collision and dehydration failure.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the velocity fluctuation threshold is set to prevent drum collision, then safety is improved, but dehydration fails for single items due to overly conservative threshold

Engineering Contradiction:
Improvedrum collision preventionVSAvoiddehydration function
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the velocity fluctuation threshold parameter based on load weight conditions. For loads within a certain weight range, a first (higher) threshold is used that allows dehydration to proceed. For loads exceeding this range, a second (lower) threshold is used that prioritizes preventing drum collision. This parameter adaptation resolves the contradiction by matching the threshold to the actual risk level.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by implementing different velocity fluctuation thresholds for different load weight ranges. Instead of a uniform threshold, the system applies localized threshold values appropriate to specific load conditions. This allows the system to be permissive when safe (light loads) and conservative when necessary (heavy loads), resolving the contradiction between dehydration function and collision prevention.

Inventive Principle:
Principle #3Local quality

3Reliability

If a pre-weighing process with low accuracy requirement is performed, then weighing safety is ensured, but measurement precision is reduced

Engineering Contradiction:
Improveweighing safetyVSAvoidload weight measurement
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing a pre-weighing process before the formal weighing operation. This preliminary measurement, though with lower accuracy requirements, provides initial load weight information that enables the system to select an appropriate velocity fluctuation threshold in advance. This ensures safety during the subsequent weighing process without requiring the pre-weighing to be highly precise.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3330423B1Drum washing machine, and control method and apparatus for same
Publication Date: 2021.09.08 GUANGDONG WELLING ELECTRIC MACHINE MFG
  • EP3330423B1 patent drawingFigure 1~2
  • EP3330423B1 patent drawingFigure 3~4

AI summary

A drum washing machine, and a control method and a control apparatus for same are provided. The control method for the drum washing machine comprises the following steps: step S101, acquiring an average starting power of a drum in a starting process of the drum; step S102, acquiring a load range to which a current load of the drum belongs according to the average starting power; and step S103, setting a weighing protection velocity fluctuation threshold according to the load range to which the current load of the drum belongs. A value of a current load is obtained by using a correspondence between load with different weights and average starting powers, and a weighing protection velocity fluctuation threshold is set according to the value of the current load so as to avoid the phenomena of collision with the drum and non-dehydration in a case of only one piece of clothing. The method completes computation in a starting stage, and can be implemented by only few modifications on the basis of the conventional solution without the need to add extra control logic, thereby being convenient and practical, and lowering the upgrade cost of a whole product.