Washing Machine Dual-Sensor Spin Control for Energy-Efficient Drying
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Solution Overview
Problem
Existing washing machines often waste energy by having fixed spin cycle durations and rotational speeds, which are not adjusted based on laundry load, leading to inadequate drying or excessive energy use.
Innovation Solution
A washing machine equipped with at least two water sensors, one at the bottom and another away from it, to measure water levels and water thrown out during rotation, with a controller adjusting the drum rotation based on the difference between sensor outputs to determine when the spin cycle can cease, ensuring accurate and efficient drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single water sensor is used to measure water level during spin cycle, then the device complexity is reduced, but the measurement precision is insufficient to accurately determine when spin cycle should terminate
Solution Approach 1:
The patent divides the water measurement function into two separate sensors: a first water sensor positioned to measure water level in the tub, and a second water sensor positioned to measure water level in the pump outlet pipe. This segmentation allows each sensor to measure different aspects of water removal, providing more comprehensive and accurate data for determining spin cycle termination than a single sensor could provide.
2Productivity
If fixed spin cycle duration is used, then the device complexity is reduced, but the productivity is reduced due to inadequate drying or excessive energy use
Solution Approach 1:
The patent implements a feedback control mechanism where the controller continuously monitors outputs from both water sensors during the spin cycle. Based on the measured water levels in the tub and pump outlet pipe, the controller dynamically adjusts the spin cycle duration and termination point. This feedback loop enables the system to adapt to different laundry loads and water removal rates, optimizing drying efficiency without requiring complex pre-programmed timing sequences.
3Loss of energy
If spin cycle terminates based on fixed time, then the ease of operation is improved, but the loss of energy occurs due to excessive spinning after adequate drying is achieved
Solution Approach 1:
The patent replaces traditional mechanical timing mechanisms with an electronic control system that uses sensor feedback to determine spin cycle termination. Instead of relying on fixed mechanical timers, the controller electronically monitors water level measurements from both sensors and automatically terminates the spin cycle when drying objectives are achieved. This substitution eliminates energy waste from excessive spinning while maintaining automatic operation through intelligent sensor-based 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 solution allows for more accurate and energy-efficient spin cycle termination, avoiding spikes in sensor readings and ensuring laundry is adequately dried without excessive energy use, regardless of load size.
Implementation Method 1
the first water sensor is a capacitive sensor
Implementation Method 2
the second water sensor is a capacitive sensor
Implementation Method 3
a motor for driving rotation of the drum in the tub
Implementation Method 4
the drum of the washing machine is rotated at a relatively high rate of rotation to cause excess water in the laundry to be spun out (through 'centrifugal' force)
Data Source
AI summary
A washing machine has a rotatable drum for receiving items to be washed and a tub in which the drum is mounted for rotation. A first water sensor is located at or towards the bottom of the tub and is arranged to measure the level of water collected at the bottom of the tub. A second water sensor is located at a part of the tub away from the first water sensor and measures the amount of water being thrown out of the drum as the drum rotates. The drum is rotated in accordance with a difference of the outputs of the sensors.