Laundry Drum Load Detection Using Motor Current and Voltage
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Solution Overview
Problem
Existing laundry treatment appliances require additional sensors and have high effort for recording and evaluating operating parameters, making them costly and complex for load detection and control.
Innovation Solution
A control and measuring device that detects electric current and induced voltage through the electric motor to determine drum loading and air output, eliminating the need for additional sensors and enabling precise load classification and optimization of drying processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors (speed sensor, temperature sensors) are used for load detection and control, then measurement precision and control accuracy are improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The electric motor serves itself by providing both the drive function and the measurement function. The motor's own electrical parameters (current, voltage, power) are used to detect load conditions, eliminating the need for separate sensors. The control device evaluates these self-provided electrical signals to determine drum loading and air output.
Solution Approach 2:
The electric motor is given multiple functions: it acts as both the drive motor and the measurement device. The same motor that drives the drum also provides electrical signals that contain load information, allowing one component to fulfill multiple roles and reducing overall system complexity.
2Reliability
If additional sensors and measurement devices are installed for monitoring operating parameters, then reliability of load detection is improved, but ease of repair and maintenance deteriorate due to more components
Solution Approach 1:
The motor provides its own measurement signals without requiring external sensors that need maintenance. By using the motor's inherent electrical parameters for load detection, the system eliminates components that would require servicing, thereby improving ease of repair while maintaining reliable load monitoring.
3Device complexity
If electrical parameters (current, voltage, power) of the electric motor are used to determine drum loading and air output, then device complexity is reduced by eliminating sensors, but measurement precision must be maintained through accurate electrical parameter evaluation
Solution Approach 1:
The control device continuously monitors the electrical parameters of the motor and uses this feedback information to determine load conditions. By evaluating the relationship between electrical input and motor output, the system accurately infers drum loading and air output without mechanical sensors, maintaining precision through electrical measurement and calculation.
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 reduces maintenance needs, improves reliability, and allows for accurate determination of remaining drying time and load state, optimizing appliance performance and user utilization.
Implementation Method 1
the control and measuring device detects an electric current through the electric motor as an electrical parameter of the electric motor
Implementation Method 2
the control and measuring device detects an induced electrical voltage of the electric motor as an electrical parameter of the electric motor
Data Source
Figure 1
Figure 2
AI summary
A laundry treatment appliance 1 for drying and/or washing laundry has a rotatably mounted drum 2 , an electric motor 4 which is used to drive the drum 2 , and a control and measuring device 6 for the electric motor 4 . The control and measuring device 6 detects a voltage U induced by the electric motor 4 and an electric current I through the electric motor 4. The control and measuring device 6 also determines a load B and B as a function of these electrical parameters U, I of the electric motor 4 /or an air capacity L and/or a remaining drying time Δt of drum 2.