Determining an imbalance of a component rotating about an axis of rotation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining unbalance in a swinging suspended object with a rotating component, such as a laundry treatment machine drum, are inefficient and do not accurately predict future imbalances, leading to suboptimal dehumidification and potential noise or vibration issues.
Innovation Solution
A method using sensors to record operating data, including vibrations, current, and speed, and a correlation unit trained with data to predict unbalances, allowing for precise imbalance detection and prediction with minimal effort and sensor usage, utilizing machine learning techniques like regression and neural networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional vibration measurement methods are used to determine imbalance, then measurement can be performed, but measurement precision and prediction accuracy are insufficient
Solution Approach 1:
The system performs preliminary measurement of imbalance at lower rotational speeds before the actual high-speed spinning process. The control device calculates the imbalance state in advance using vibration signals and current data collected during acceleration, allowing prediction of the imbalance that will occur at target spinning speeds without having to measure directly at those speeds.
Solution Approach 2:
The control device continuously receives vibration signals from vibration sensors and current data from current sensors during the acceleration phase, processes this feedback information to calculate imbalance, and uses this information to predict future imbalance states. This feedback loop enables accurate prediction without requiring complex sensor arrays at high speeds.
2Object-affected harmful factors
If drum speed is reduced to combat imbalance, then vibration and noise are reduced, but dehumidification effectiveness deteriorates
Solution Approach 1:
The system predicts the imbalance state that will occur at target spinning speeds by measuring imbalance at lower speeds during acceleration. This preliminary prediction allows the control device to determine whether the drum should accelerate to the target speed or remain at lower speed, enabling optimal speed selection before the spinning phase begins.
Solution Approach 2:
The control device changes the operational parameter (drum speed) based on the predicted imbalance state. If predicted imbalance is below a threshold, the drum accelerates to high speed for effective dehumidification. If predicted imbalance exceeds the threshold, the drum remains at lower speed to minimize vibration and noise, thus optimizing the trade-off between productivity and harmful factors.
3Reliability
If multiple sensors and complex processing are used to accurately predict future imbalances, then prediction accuracy improves, but device complexity and material expenditure increase
Solution Approach 1:
The vibration sensors and current sensors already present in the washing machine for other control functions are utilized for imbalance measurement. The control device performs multiple functions: it uses these sensors for both motor control and imbalance prediction, eliminating the need for additional dedicated sensors and reducing overall device complexity while maintaining prediction accuracy.
Solution Approach 2:
The control device uses its existing processing capabilities to analyze vibration signals and current data for imbalance prediction, rather than requiring separate dedicated processing systems. The system serves itself by utilizing its own existing sensors and computational resources to achieve accurate prediction without adding external complexity.
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
Enables accurate and efficient detection and prediction of unbalances, reducing unnecessary speed adjustments and minimizing material and processing effort, thereby improving dehumidification and reducing noise and vibration issues.
Implementation Method 1
the operating data are fed to a correlation unit associated with the control unit, in which learned correlations between unbalances and operating data are stored based on training data
Implementation Method 2
This dampens vibrations in the tub during spinning, with the damper legs converting the vibration energy into heat
Implementation Method 3
During this spin cycle, the laundry items are centrifuged at a sufficiently high speed to remove a large portion of the wash solution, rinse solution, or water they have absorbed
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method and a device 1 for carrying out the method for determining an imbalance on an object 3 suspended by means of a oscillating movement and having a rotating component 4, wherein the rotating component 4 is driven to rotate at a certain speed by means of an electric motor 14 by supplying a certain current to the electric motor 14, wherein sensors 15, 16, 26 continuously record operating data of the rotating component 4 and supply it to a control unit 20 connected to the sensors 15, 16, 26 for controlling the rotating component 4 according to the operating data, and wherein the control unit 20 determines the imbalance from the operating data.In this method, the sensors 15, 16, and 26 comprise a vibration sensor 26 associated with the object 3 for measuring vibrations of the object 3 in several mutually orthogonal dimensions, a current sensor 15 for measuring the current flowing through the motor 14, and a speed sensor 16 for measuring the speed of the motor 14. Furthermore, the operating data are fed to a correlation unit 21 belonging to the control unit 20. This correlation unit stores learned correlations between imbalances and operating data based on training data measured as operating data for the object 3 at a given imbalance. The imbalance is then determined from the operating data by the correlation unit 21. This method is particularly useful for controlling a spin-drying process in a laundry treatment machine 1.