Washing Machine Load Detection Using Inertial Rotation Re-Measurement
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Solution Overview
Problem
Existing washing machines inaccurately determine the load of washings, especially when pre-washed clothes with high water content are placed in the washing drum, leading to incorrect water usage and inefficient washing processes.
Innovation Solution
A washing machine with an impeller that undergoes inertial rotation detection, where the control part re-detects the inertial rotation number under specified conditions to accurately determine the load, considering the initial and re-detected inertial rotation numbers, and adjusts water supply accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the impeller rotates for load determination, then the load can be determined according to the number of pulses, but when a small amount of wet washings is disposed on the peripheral part of the impeller, the impeller becomes difficult to rotate due to increased friction, leading to inaccurate load determination
Solution Approach 1:
The system performs preliminary actions by rotating the impeller multiple times before final load determination. The first rotation allows wet washings to move from the peripheral part to the center, reducing friction for subsequent rotations and ensuring accurate load measurement.
Solution Approach 2:
The impeller is rotated periodically multiple times with specified intervals. Between rotations, the impeller coasts freely allowing washings to redistribute, which reduces friction buildup and enables more accurate periodic measurements of the load.
2Reliability
If the impeller rotates in the case that a small amount of wet washings is disposed on the peripheral part of the impeller, then friction increases making the impeller difficult to rotate, but if the washings are at the center, the impeller rotates easily
Solution Approach 1:
The system uses feedback by comparing the number of pulses from multiple impeller rotations with reference data. The control unit analyzes the change in rotation ease between periods to accurately determine load category, compensating for the effects of wet washings location.
3Productivity
If only one-time impeller rotation is performed for load determination, then the process is simple, but the load determination becomes inaccurate when washings are wet and located on the peripheral part
Solution Approach 1:
The system performs preliminary rotations to redistribute wet washings from the periphery to the center before the final measurement rotation. This preliminary action ensures that the final load determination is accurate while maintaining reasonable processing speed.
Solution Approach 2:
The load determination uses periodic impeller rotations with specific intervals. The system performs multiple rotations at predetermined timings, allowing sufficient time for washings to redistribute while completing the measurement process efficiently.
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 method ensures correct and automatic detection of the wash load regardless of the amount and water content, optimizing water usage and washing efficiency by re-evaluating inertial rotation changes during the washing process.
Implementation Method 1
an inertial rotation number detection part for detecting a number of turns of inertial rotation of the impeller after the driving part stop driving
Implementation Method 2
the impeller 5 suffers a small resistance (friction) from the washings A, and the impeller 5 is easy to rotate
Data Source
AI summary
A washing machine includes: a dewatering drum provided with an impeller in a free rotation manner; a driving part for rotating the impeller; an inertial rotation number detection part for detecting an inertial rotation number after the driving part stops driving; and a control part for controlling the driving part and the inertial rotation number detection part and detecting the amount of the washings in the dewatering drum as a load according to the inertial rotation number. In the case of determining that a detection result of the inertial rotation number detection part satisfies a specified condition, the control part enables the driving part to drive again; and the inertial rotation number detection part re-detects the inertial rotation number of the impeller, and detects the load according to the detection result and the previous detection result.