Method of determining inertia in a laundry treating appliance
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Solution Overview
Problem
Existing laundry treating appliances face challenges in accurately determining the inertia of a laundry load during the spin extraction phase, particularly with wet loads, leading to inaccuracies and inefficiencies in liquid removal and cycle control.
Innovation Solution
A method involving an extraction stabilization phase followed by a sensing phase with deceleration and acceleration phases, where motor torque data and basket acceleration rate data are sensed to determine the inertia of the laundry load, using a V-profile approach that minimizes water extraction during sensing, improving accuracy and reducing cycle time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the basket rotates at high speed during spin extraction to remove liquid from the laundry load, then liquid removal efficiency is improved, but the accuracy of inertia determination deteriorates due to water extraction during sensing
Solution Approach 1:
The spin extraction cycle is divided into distinct phases: an extraction phase where the basket rotates at high speed to remove liquid, and a separate sensing phase where the basket rotates at reduced speed to accurately measure inertia. This segmentation allows each phase to optimize its specific function without interference from the other.
Solution Approach 2:
The extraction phase is performed before the sensing phase, removing the majority of liquid from the laundry load in advance. This preliminary action ensures that during the subsequent inertia measurement, minimal water extraction occurs, thereby maintaining measurement accuracy.
2Device complexity
If a traditional sensing method is used to determine inertia during spin extraction, then the measurement process is simple, but the operation cycle time increases due to extended sensing duration
Solution Approach 1:
The sensing phase uses periodic acceleration and deceleration of the basket at controlled rates to generate the necessary data for inertia calculation. This periodic action allows for rapid completion of measurements compared to traditional continuous sensing methods, reducing the overall time required.
Solution Approach 2:
The rotational speed parameters are dynamically adjusted during the sensing phase, with the basket accelerated and decelerated at specific rates to optimize the measurement process. By changing speed parameters strategically, the system achieves accurate inertia determination in a shorter time frame.
3Loss of time
If the basket is accelerated and decelerated rapidly during inertia sensing, then the measurement time is reduced, but the motor torque requirements increase
Solution Approach 1:
The system dynamically adjusts the acceleration and deceleration rates based on the detected load conditions. By optimizing these rates in real-time, the system achieves the shortest possible measurement time while keeping torque demands within acceptable limits for the motor.
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
The V-profile method provides more accurate and reliable inertia determination for wet laundry loads, reducing standard deviations and operation cycle time compared to prior methods, while maintaining consistency across varying load sizes and motor temperatures.
Implementation Method 1
rotating the basket at speeds high enough to impart a sufficient centrifugal force on the laundry load to remove the liquid
Implementation Method 2
motor torque data and basket acceleration rate data are sensed during the acceleration and deceleration phases
Data Source
AI summary
An embodiment of a method of determining inertia of a laundry load may comprise an extraction stabilization phase, where liquid is extracted from the laundry load by rotating the basket at first rotational speed, and a sensing phase. The sensing phase may include a deceleration phase, where the basket speed decreases to a second rotational speed, followed by an acceleration phase, where the basket speed increases back toward the first rotational speed. The inertia of the laundry load may be determined from data sensed during the deceleration and acceleration phases.