Control device and method for a laundry care device
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Solution Overview
Problem
Existing control methods for BLDC motors in laundry care appliances consume excessive energy and are heavily loaded during startup due to the application of maximum torque, even when lower torque is required, leading to inefficient operation and reduced motor lifespan.
Innovation Solution
A control device that detects a convergence value of the torque-generating current during a control phase in a first reversing cycle and sets a reference value for the torque-generating current in a subsequent reversing cycle, allowing for efficient and precise control by continuously reducing the torque current until a specified angular error threshold is met, and optionally adding an offset value to ensure robust startup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If maximum torque is applied during control phase to ensure motor startup, then reliability of motor startup is improved, but energy consumption increases and motor is heavily loaded
Solution Approach 1:
The patent applies dynamics by continuously reducing the torque-generating current Iq during a convergence phase of the control phase, transitioning from a static maximum current approach to a dynamic adaptation process. The current is reduced until a specified angular error threshold is met, allowing the system to maintain startup reliability while minimizing energy consumption and motor loading.
Solution Approach 2:
The patent implements feedback by detecting the angular error between actual and desired rotor positions and using this information to adjust the torque-generating current. The convergence value of Iq is detected based on the angular error threshold, and this convergence value becomes the reference for subsequent reversing cycles, creating a closed-loop control system that optimizes startup performance.
2Reliability
If maximum torque is applied during control phase to ensure motor startup, then motor startup reliability is improved, but motor service life deteriorates due to heavy loading
Solution Approach 1:
The patent reduces motor loading by dynamically adjusting the torque-generating current during the convergence phase rather than applying maximum torque continuously. This dynamic approach ensures reliable startup while reducing mechanical stress and thermal loading on the motor, thereby extending motor service life.
Solution Approach 2:
The patent applies partial action by using only the necessary amount of torque required for startup. Instead of applying excessive maximum torque throughout the entire control phase, the system reduces the current to the convergence value once the angular error threshold is met, applying just enough torque to ensure reliable startup without overloading the motor.
3Use of energy by moving object
If convergence value detection and reference value setting are implemented in subsequent reversing cycles, then energy consumption is reduced, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by detecting the convergence value of the torque-generating current during the control phase of the first reversing cycle and storing it as a reference value. This reference value is then used in subsequent reversing cycles, eliminating the need to repeat the full convergence detection process and thereby reducing energy consumption while maintaining control accuracy.
Solution Approach 2:
The patent recovers useful information by detecting the convergence value during the first reversing cycle and reusing it as a reference value for subsequent cycles. Instead of discarding this information, the system stores and retrieves it, reducing computational overhead and energy consumption in later cycles while maintaining reliable motor control.
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 reduces energy consumption and motor loading, extending the lifespan of the drive motor while ensuring reliable startup by adjusting the torque current based on actual load conditions.
Implementation Method 1
DC motors in the form of brushless permanent magnet motors, which are also referred to as BLDC or PMSM motors, are often used to rotate a laundry drum
Implementation Method 2
a torque-generating current Iq in order to rotate a rotatably mounted laundry drum
Data Source
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AI summary
A control device (100) for operating a drive motor (120), in particular a BLDC drive motor, based on a torque-generating current Iq, to rotate a rotatably mounted washing drum of a laundry care appliance according to a laundry care program running during operation, wherein the laundry care program comprises at least a first reversing cycle and a second reversing cycle, each comprising a control phase and a regulation phase of the rotation of the washing drum. The control device (100) is configured to detect a convergence value of the torque-generating current Iq during the control phase of the first reversing cycle and to set a reference value for the torque-generating current Iq, which is based on the detected convergence value, during the control phase of the second reversing cycle.