Drum Washing Machine Natural Frequency Detection for Vibration Control
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Solution Overview
Problem
Existing washing machines face challenges in detecting natural vibration frequencies and dynamic properties, leading to increased vibrations and noise due to eccentric laundry distribution and mass deviation loads, which existing solutions do not adequately address.
Innovation Solution
An active system that measures force transfer to the base, allowing simultaneous detection of eccentric and dynamic loads, and adjusts the washing cycle based on identified dynamic properties to avoid resonance and reduce vibrations, including calibration for optimal placement and base quality assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mass eccentricity detection is used to reduce vibrations, then vibration control is improved, but the solution is insufficient because it does not detect mass deviation load
Solution Approach 1:
The sensor system is designed to perform multiple functions: detecting both mass eccentricity and mass deviation load simultaneously. The force transfer measurement mechanism serves dual purposes by providing data for both types of load detection, making the system more comprehensive without adding separate detection systems.
Solution Approach 2:
The force transfer to the base acts as an intermediary measurement that indirectly provides information about both mass eccentricity and mass deviation load. By measuring the force transfer through the base, the system can infer both types of loads without requiring direct sensors inside the drum, thus overcoming the limitation of previous single-function detection systems.
2Reliability
If active vibration control is implemented without knowledge of dynamic properties, then vibration reduction is achieved, but the control is not optimized because natural frequency and resonance are unknown
Solution Approach 1:
The system performs a calibration measurement during installation to identify the natural frequency and resonance characteristics of the washing machine-base system before normal operation begins. This preliminary action stores the dynamic properties for later use, enabling optimized vibration control throughout the appliance's operation without requiring continuous complex measurements.
Solution Approach 2:
The system uses the identified natural frequency and resonance data as feedback to continuously optimize vibration control strategies. By comparing operational conditions against the stored dynamic properties, the control system can adjust parameters to avoid resonance conditions and minimize vibrations, transforming static calibration data into dynamic control decisions.
3Reliability
If rotational frequency is controlled to avoid resonance, then vibration is reduced, but the washing cycle requires adjustment based on identified dynamic properties
Solution Approach 1:
The washing cycle is made dynamically adjustable based on the identified natural frequency and resonance characteristics. The control system automatically modifies rotational frequency profiles and washing parameters in real-time according to the stored dynamic properties, transforming a static washing cycle into an adaptive process that optimizes performance while avoiding resonance conditions.
4Measurement precision
If force transfer measurement is implemented, then simultaneous detection of eccentric and dynamic load is achieved, but the system complexity increases
Solution Approach 1:
The force transfer measurement system is designed to extract multiple types of load information (mass eccentricity, mass deviation load, dynamic properties) from a single measurement mechanism. This multi-functional approach allows comprehensive load detection without proportionally increasing system complexity, as one sensor system serves multiple detection purposes.
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 solution effectively reduces vibrations and noise by actively controlling the washing cycle, providing users with insights into placement quality and ensuring a quieter operation by identifying and adjusting for dynamic loads and base stability.
Implementation Method 1
at least one sensor (1) for indirectly measuring the force from a washing machine (2) to a base is placed in the immediate vicinity of at least one of support legs (3) of the washing machine (2), wherein the deformations of a body (4) of the washing machine (2) are directly related to the magnitude of the transmitted force
Implementation Method 2
Significant increase in the vibration amplitudes occurs in the resonance operating range of the washing machine, i.e. in the case of an interaction between the rotational frequency of the washing machine drum and the natural frequency of the washing machine
Implementation Method 3
mainly due to the eccentricity of the centre of gravity of the laundry rotating together with the drum, relatively large centrifugal forces occur that exert dynamic forces on the tub in which the drum is placed
Implementation Method 4
the washing machine body via connecting elements such as springs and damping elements
Data Source
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AI summary
The proposed invention relates to a method for detecting the natural vibration frequencies in the body (4) of a laundry washing machine while it is in operation with regard to the quality of its placement and the base on which it is placed. The method comprises an active system for detecting the transfer of force to the base, which enables the simultaneous detection of the eccentric and dynamic load in the drum and the identification of the dynamic properties of the washing machine. By controlling the rotational frequency of the washing machine drum, it is possible to actively adjust the washing cycle according to the loads in the drum and the dynamic properties of the washing machine. According to the proposed invention, at least one calibration is anticipated at the user's place of installation of the washing machine, which is used to identify the dynamic properties of the entire washing machine-base system.