Laundry Drum Hall Sensor Control for Moisture-Based Drying
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Solution Overview
Problem
Existing washer-dryer systems lack an efficient and cost-effective method for controlling the drying process based on moisture levels, relying on expensive sensors or complex moisture measurement techniques.
Innovation Solution
A method utilizing a load sensor to detect weight and determine moisture levels by measuring spin speed during the wash cycle, calculating residual moisture, and adjusting the drying time based on these parameters, without the need for additional moisture sensors, using a 3D magnetic field sensor unit to monitor and control the drying process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If expensive moisture sensors or complex moisture measurement techniques are used, then measurement precision of moisture level is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces an intermediary substance (magnetic particles) that mediates between the laundry moisture content and the measurement system. The magnetic particles are absorbed by the laundry and their quantity correlates with moisture content, allowing indirect measurement through magnetic field detection rather than direct moisture sensing, thus avoiding complex moisture sensors
Solution Approach 2:
The patent replaces complex moisture measurement systems with a magnetic field-based detection system. Instead of using expensive moisture sensors that directly measure water content, the system uses magnetic field sensors to detect the quantity of magnetic particles, which serves as a proxy for moisture level, thereby substituting a complex measurement system with a simpler magnetic detection system
2Reliability
If drying time is extended to ensure thorough drying, then drying completeness is improved, but energy consumption and time efficiency worsen
Solution Approach 1:
The patent implements a feedback control system where the magnetic field sensor continuously monitors the quantity of magnetic particles in the laundry during the drying process. This real-time information feeds back to the control unit, which adjusts the drying cycle termination point based on actual moisture levels rather than fixed time schedules, ensuring thorough drying while minimizing energy consumption by stopping exactly when drying is complete
Solution Approach 2:
The patent changes the control parameter from fixed time-based drying cycles to dynamic moisture-level-based control. By monitoring magnetic particle quantity as a proxy for moisture content and adjusting the drying process accordingly, the system optimizes the balance between drying completeness and energy efficiency, terminating the process precisely when the desired dryness is achieved
3Device complexity
If load sensor is used to determine moisture level, then device complexity is reduced, but measurement precision of moisture level deteriorates
Solution Approach 1:
The patent introduces magnetic particles as an intermediary that creates a measurable relationship between laundry mass and moisture content. The magnetic particles are uniformly distributed and absorbed by the laundry, creating a consistent magnetic signature that correlates with moisture levels. This intermediary enables a simple load sensor to achieve precise moisture measurement by detecting the magnetic field strength, which varies with both mass and moisture content
Solution Approach 2:
The patent transforms the measurement approach by changing from direct moisture sensing to indirect magnetic field sensing. By incorporating magnetic particles into the laundry, the system converts moisture content information into magnetic field strength variations that can be detected by simple load sensors or magnetic field sensors, thereby maintaining measurement precision while reducing device 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
This approach allows for accurate and cost-effective moisture-dependent control of the drying process, optimizing drying time and energy usage while eliminating the need for expensive moisture sensors, enhancing the precision of residual moisture content management.
Implementation Method 1
detecting a load weight by means of the load sensor
Implementation Method 2
The direction and field strength of the magnetic field caused by the permanent magnet are measured with the 3D Hall sensor
Implementation Method 3
The 3D sensor, which works as a load sensor in this way, is attached to the rear wall of the oscillating system in the upper area and is designed as a 3D Hall sensor
Data Source
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Figure 3
AI summary
The dryer (W) has a control unit (C) for controlling a drying process based on sensor data of a magnetic field sensor unit and a three dimensional hall sensor (31), which is arranged at the dryer in a fixed manner. The magnetic field sensor unit is arranged at a shaft stub at a rear wall of a laundry drum (2) of the dryer. A permanent magnet is arranged at the laundry drum. The magnetic field sensor unit is arranged to sense deflection of a drum shaft (23). A drum housing (1), in which the laundry drum is rotatably supported for receiving clothes (3). An independent claim is also included for a method for controlling a drying process.