Laundry Load Detection Using Motor Generator Mode Voltage Measurement
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Solution Overview
Problem
Existing methods for determining the laundry load in washing machines are either time-consuming, inaccurate, or require complex algorithms and specific fabric-type information, and they do not effectively handle general washing programs.
Innovation Solution
A method that uses an electric motor with a power inverter to operate in generator mode, measuring voltage and torque values during acceleration and deceleration ramps to calculate the laundry load based on maximum voltage and torque values, without additional electrical components, and determines the load index using mathematical functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If water absorption method is used to estimate laundry load, then the method is simple to implement, but the measurement precision is low and takes long time
Solution Approach 1:
The patent replaces the water absorption-based estimation method with an electrical measurement system. The motor's electrical parameters (current, voltage, power) are measured during generator mode operation to determine laundry load, substituting mechanical/water-based measurement with electrical measurement for improved precision and speed.
Solution Approach 2:
The patent introduces the motor's generator mode as an intermediary mechanism. The motor acts as a mediator that converts mechanical energy from the rotating drum into electrical energy, allowing indirect measurement of laundry load through electrical parameters during the deceleration phase.
2Device complexity
If water absorption method is used to estimate laundry load, then the method is simple to implement, but the processing time is long
Solution Approach 1:
The patent replaces the time-consuming water absorption method with instantaneous electrical measurements. Electrical parameters are measured during the motor's generator mode operation, providing rapid laundry load determination without waiting for water absorption processes.
Solution Approach 2:
The patent performs laundry load determination during the deceleration phase before the main washing cycle begins. By utilizing the motor's generator mode during this preliminary phase, the system obtains load information early without extending the overall washing time.
3Measurement precision
If fabric-type specific algorithms are used to improve estimation accuracy, then the measurement precision improves for specific fabrics, but the device complexity increases and adaptability decreases
Solution Approach 1:
The patent creates a universal measurement method that works across all fabric types without requiring fabric-specific algorithms. The electrical measurement approach during generator mode provides consistent accuracy regardless of fabric composition, making the system adaptable to all washing programs including general programs without fabric information.
4Measurement precision
If additional electrical components are added to improve measurement precision, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The patent makes the motor serve dual functions: propulsion during motor mode and measurement device during generator mode. The motor's own electrical parameters are utilized to determine laundry load, eliminating the need for separate measurement components and keeping the system simple while achieving high precision.
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 method allows for quick and precise determination of the laundry load, improving accuracy and reducing processing time, and can be applied to various types of washing machines without additional components.
Implementation Method 1
controlling said drum by the motor in order to cause the motor to operate in said generator mode; determining first values which are indicative of the voltages across said energy storage means when the motor operates in generator mode
Data Source
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AI summary
The present invention relates to a method for determining a laundry load of a laundry treating machine (1) comprising an outer casing (2), a washing group which is placed inside the outer casing (2) and comprises, in turn, a washing tub (3), a rotatable drum (6) housed in axially rotatable manner inside the washing tub (3) and structured for housing the laundry to be treated, the laundry treating machine (1) is further provided with an electric motor (16) for rotating the drum (6) and a motor controller (23) which is configured to control said motor (16) and comprises a power inverter device (26), and a capacitor circuit (24), which is electrically associated with the power inverter device (26) and is designed to be charged by a voltage generated by said motor (16) when the motor (16) operates in said generator mode; the method comprising the steps of: controlling the drum (6) by the motor (16) in order to cause the drum (6) to perform one or more acceleration and deceleration ramps R(i); determining first values (Vbkd(j)) which are indicative of the voltages across the capacitor circuit (24) during said one or more deceleration ramps R(i); determining a maximum voltage value (VCMM) based on the biggest value of the determined first values (Vbkd(j)); determining the amount of laundry load on the basis of the maximum voltage value (VCMM).