Washing machine and method for controlling washing machine
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Solution Overview
Problem
Conventional washing machines lack effective overload sensing and vibration control during spin-drying, leading to increased failure rates due to reliance on separate MEMS sensors, which can malfunction, and excessive vibration or noise.
Innovation Solution
A washing machine with a processor that calculates the wet and dry clothes weights to determine overload and control the spin-dry tub's rotational speed, limiting it if overloaded, and uses torque and acceleration sensors to manage vibration, without relying on external MEMS sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the spin-dry tub is rotated at a preset maximum rotational speed for all loads, then the spin-drying efficiency is improved, but the washing machine experiences overload and excessive vibration when the laundry weight is heavy
Solution Approach 1:
The patent implements dynamic rotational speed adjustment based on detected laundry weight. The processor determines the actual weight of laundry and dynamically sets the maximum rotational speed of the spin-dry tub accordingly, rather than using a fixed preset speed. This allows the system to optimize spin-drying efficiency for each load while preventing overload and excessive vibration when laundry weight is high, thereby resolving the contradiction between productivity and reliability.
2Measurement precision
If a separate MEMS sensor is attached to sense vibration, then the vibration sensing capability is improved, but the system becomes more complex and the failure rate increases when the sensor is damaged or malfunctions
Solution Approach 1:
The patent makes the motor serve multiple functions: it not only drives the spin-dry tub but also acts as a vibration sensor by detecting torque variations during rotation. The processor monitors the torque required to rotate the motor at different speeds and uses these variations to detect excessive vibration. This eliminates the need for separate MEMS sensors, reducing system complexity and potential failure points while maintaining vibration sensing capability.
Solution Approach 2:
The motor performs self-diagnosis by monitoring its own torque characteristics during operation. The processor detects vibration by analyzing torque variations in the motor itself, allowing the system to sense its own operational state without external sensors. This self-service approach reduces dependency on separate sensing components.
3Reliability
If the maximum rotational speed is reduced when overloaded, then the overload protection is improved, but the spin-drying efficiency decreases
Solution Approach 1:
The system dynamically adjusts the maximum rotational speed based on the detected laundry weight. When the laundry weight is within the optimal range, the system operates at high rotational speed for efficient spin-drying. When the laundry weight exceeds the threshold indicating overload, the system automatically reduces the maximum rotational speed to prevent excessive vibration and overload damage. This dynamic adjustment resolves the contradiction by optimizing efficiency when safe and protecting reliability when necessary.
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 enables the washing machine to sense overload and vibration without external sensors, improving stability and reducing failure rates by dynamically adjusting the spin-drying speed and stopping the process when necessary.
Implementation Method 1
a motor for driving a spin-dry tub such that a maximum rotational speed of the spin-dry tub has a preset value during spin-drying
Implementation Method 2
The processor may calculate a rotational inertia value by rotating the spin-dry tub in a state where the laundry is put into the spin-dry tub, and may acquire the dry clothes weight and the wet clothes weight on the basis of the calculated rotational inertia value
Implementation Method 3
the washing water contained in the laundry is separated and removed from the laundry by a centrifugal force when the spin-dry tub is rotated at a high speed
Data Source
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AI summary
A washing machine is disclosed. The present washing machine comprises: a motor for driving a spin-dry tub such that a maximum rotational speed of the spin-dry tub has a preset value during spin-drying; and a processor for acquiring dry clothes weight and wet clothes weight of laundry put into the spin-dry tub, determining whether the washing machine is overloaded in the spin-drying on the basis of the acquired dry clothes weight and wet clothes weight, and controlling driving of the motor such that the maximum rotational speed of the motor is a value less than the preset value during the spin-drying, if the washing machine is determined to be overloaded.