Washer Water Fill Control Using Pressure Sensing and Motor Pulses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laundry washing machines often inaccurately dispense water based on user-selected load sizes, leading to inefficiencies in water and energy usage, as the actual load size may differ from the selected setting, resulting in insufficient or excessive water for optimal washing.
Innovation Solution
A method involving motor pulses to spin the wash basket and take pressure readings to determine the sufficient amount of free water in the tub, with iterative cycles of water dispensing and reading, incorporating pause intervals to account for drips and air bubbles, and using flow rate measurements to calculate the optimal fill time based on load size and type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If water is added based on user-selected load size, then the wash tub reaches a predetermined water level, but the actual load size may not match the selection leading to water waste or insufficient water
Solution Approach 1:
The patent replaces the conventional mechanical pressure sensor system with an optical measurement system using a laser transmitter, receiver, and photodetector array to measure load size. This optical system provides more precise measurement of the load characteristics, enabling accurate determination of the required water amount without the limitations of mechanical pressure readings.
Solution Approach 2:
The patent implements a feedback control system where the optical measurement of load size is continuously monitored and used to adjust the water fill amount. The microprocessor compares the measured load characteristics with the required water amount and adjusts the water inlet valve accordingly, ensuring the wash tub receives the precise amount of water needed for the actual load size rather than relying on predetermined settings.
2Adaptability or versatility
If a predetermined water level is used for all load sizes, then the filling process is simple, but it cannot accommodate varying actual load sizes optimally
Solution Approach 1:
The patent replaces complex mechanical level sensors and multiple pressure switches with a simplified optical measurement system. The laser-based optical array directly measures load characteristics and translates them into water fill requirements, reducing mechanical complexity while enhancing adaptability to different load sizes through software-based control algorithms.
Solution Approach 2:
The patent changes the measurement parameter from mechanical pressure to optical properties (light reflection, transmission, or absorption) of the load. This parameter change enables the system to adapt to different load sizes by measuring optical characteristics that vary with load mass and distribution, providing versatile fill control without requiring multiple mechanical sensors for different water levels.
3Measurement precision
If optical measurement is used to determine load size, then water amount can be precisely controlled, but the system complexity increases
Solution Approach 1:
The patent replaces complex mechanical measurement systems with a compact optical measurement module that integrates the laser transmitter, receiver, and photodetector array into a single unit. This integration reduces the overall system complexity while maintaining high measurement precision for water amount control.
Solution Approach 2:
The patent uses optical copying principles where the laser creates a light pattern that reflects off or passes through the load, and the photodetector array captures this optical information. This optical copying method provides precise measurement of load characteristics without requiring direct physical contact or complex mechanical interaction with the laundry load.
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 accurately regulates the water level in the wash tub, ensuring sufficient water for washing while minimizing waste, by continuously adjusting the water fill process based on real-time measurements and load characteristics.
Implementation Method 1
a pressure sensor is used to measure liquid pressure at different water levels
Implementation Method 2
A motor pulse may be used to momentarily spin a wash basket inside of a wash tub partially filled with wash liquid
Data Source
AI summary
A washer fill system and method supply a suitable minimum amount of water necessary to wash a particular load of laundry based on readings taken from a pressure sensor that measures liquid pressure in the wash tub. Pressure sensor readings are taken intermittently during the fill process to determine when a sufficient amount of free water for washing the load of clothes has accumulated in the tub. This includes pressure readings taken while pulsing the washer motor to spin the wash basket. Other pressure readings may be taken during a pause in filling to measure the water run-off from the wetted clothes above the free water line, and the release of air bubbles from a load portion below the water line. Determining the sufficiency of the amount of wash liquid in the wash tub involves implementation of an algorithm with coefficients determined through regression analyzes, and may include other factors.