Washing Machine Eccentricity Detection Using Motor Electrical Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Washing machines face challenges in detecting and addressing diagonal eccentricity during the dehydration stroke, leading to increased operation time and energy consumption, as well as potential damage from vibration noise, without the need for additional hardware like vibration sensors.
Innovation Solution
A control method for washing machines that detects diagonal eccentricity by analyzing the average and ripple values of electrical signals, such as current or voltage, during specific speed ranges, allowing for adjustments in motor speed to prevent eccentricity and maintain efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the washing machine rotates at high speed during dehydration stroke, then dehydration efficiency is improved, but vibration and machine damage occur when laundry is unbalanced
Solution Approach 1:
The system performs preliminary eccentricity detection by analyzing motor electrical signals (current or voltage) at a predetermined speed before initiating high-speed dehydration rotation. This advance detection allows the control to prevent high-speed rotation when eccentricity is present, thereby avoiding vibration and machine damage while maintaining dehydration efficiency when conditions are favorable
2Measurement precision
If vibration sensors or additional hardware are added to detect eccentricity, then detection accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The washing machine utilizes its existing motor and electrical signal measurement capabilities to perform self-diagnosis for eccentricity detection. By analyzing the electrical signals (current or voltage) already being monitored for motor control, the system achieves accurate eccentricity detection without requiring external vibration sensors or additional measurement hardware, thereby maintaining simplicity while improving reliability
3Productivity
If the washing machine continues operation with detected eccentricity, then productivity is maintained, but harmful vibration and noise increase
Solution Approach 1:
The system implements a feedback control mechanism where electrical signals from the motor are continuously monitored during dehydration operation. When eccentricity is detected through analysis of these signals, the control automatically adjusts or stops the dehydration operation to prevent harmful vibration and noise, while allowing continuous operation when no eccentricity is present, thus maintaining productivity under favorable conditions
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 enables quick detection and response to diagonal eccentricity, reducing vibration noise, preventing machine damage, and maintaining energy efficiency without additional hardware, thereby enhancing the washing machine's quality and user satisfaction.
Implementation Method 1
The dehydration stroke is made by centrifugal force acting on the laundry inside the washing tank by the high speed rotation of the motor
Implementation Method 2
a detector detecting an electrical signal of a motor, and a controller controlling the operation of the washing machine based on an average value and a ripple value of the electrical signal
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A washing machine of the present disclosure includes a rotating tub configured to receive laundry, a motor configured to apply a driving force to the rotating tub, a detector configured to detect electrical signal of the motor; a controller configured to receive the electrical signal detected by the detector for a predetermined time when the speed of the motor during a dehydration stroke is a predetermined speed, obtain an average value of the electrical signal received during the predetermined time, check a ripple value in the received electrical signal, obtain an eccentric value corresponding to the obtained average value and the ripple value, and control an operation of the motor to stop or maintain the dehydration stroke based on the obtained eccentric value and a driver configured to drive the motor in respond to a control command of the controller.