Washer Additive Dispensing Calibration Using Pressure Sensing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing dispensing systems for washing machines face challenges in accurately metering fluid additives due to variations in water pressure and the differences in density and viscosity of fluid additives, leading to inconsistent dosages and potential damage to the appliance.

Innovation Solution

A method and system that utilize a pressure sensor to measure and calibrate the dispensing of fluid additives by determining the time interval required to deliver a specific quantity, accounting for changes in water pressure and fluid properties, by measuring the pressure increase during a test interval and using this data to adjust the operation of the pumping device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an aspirator is used to dispense fluid additives, then the cost of the appliance is reduced, but the dosing accuracy deteriorates due to water pressure variations

Engineering Contradiction:

Improveappliance costVSAvoiddosing accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The system performs a preliminary test dispensing operation before the actual dosing to measure the real water pressure and flow characteristics. This preliminary action allows the control system to calculate and store calibration factors that will be used during actual dosing operations, ensuring accuracy without requiring expensive precision components.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses a pressure sensor to provide feedback about actual water pressure conditions during dispensing operations. This feedback enables the control system to dynamically adjust dosing parameters and compensate for pressure variations, maintaining dosing accuracy despite using a low-cost aspirator mechanism.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If a peristaltic pump is used to meter fluid additives, then the dosing accuracy is improved, but the appliance cost increases significantly

Engineering Contradiction:

Improvedosing accuracyVSAvoidappliance cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

Instead of using an expensive peristaltic pump, the system creates a functional copy of its dosing behavior through calibration. The control system learns the relationship between pump runtime and actual fluid dispensed through test operations, then uses this learned model to achieve accurate dosing with a simpler, cheaper pump mechanism.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The system replaces the mechanical precision of a peristaltic pump with a control-based approach. Instead of relying on mechanical components to ensure accurate dosing, the system uses electronic control with pressure sensing and calculated runtime adjustments to achieve the same dosing accuracy at lower cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If different fluid additives with varying densities and viscosities are used, then the versatility of the appliance is improved, but the dosing consistency deteriorates

Engineering Contradiction:

Improvefluid additive compatibilityVSAvoiddosing consistency

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system compensates for variations in fluid properties by dynamically adjusting dosing parameters based on measured pressure data. The calibration process accounts for density and viscosity differences by measuring actual dispensing characteristics for each fluid type and adjusting pump runtime and pressure thresholds accordingly, maintaining consistent dosing across different additives.

Inventive Principle:

Principle #35Parameter changes

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 ensures accurate and consistent delivery of fluid additives, improving the efficacy of the washing process while preventing excess detergent buildup and potential damage to the washing machine.

Implementation Method 1

measuring the amount of pressure increase ΔPINT above Ps in the fluid additive after the deactivating

Methodology Applied

Scientific EffectPressure measurement:

Data Source

PatentUS9027381B2Appliance bulk dispenser calibration using a pressure sensor

Publication Date: 2015.05.12 HAIER US APPLIANCE SOLUTIONS INC

AI summary

A system for calibrating a fluid additive dispensing system of an appliance such as e.g., a washing machine is provided. For example, the system can calibrate for significant differences in the pressure of the water supply provided to the appliance during operation. Calibrations can also be implemented for significant differences in viscosity and/or density of the fluid additives.