Dishwasher Load Detection Using Pump and Heat Increase Data

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Solution Overview

Problem

Conventional dishwashers lack an efficient method to accurately detect the quantity of dishes in the washing container, leading to inefficient water usage and energy consumption, as users must manually select programs like economy mode or single-basket wash, which can result in excessive water heating due to inaccurate loading assessments.

Innovation Solution

A method that combines motor operation data from a circulating pump and heat increase measurements during pre-washing and heating phases to determine the quantity of dishes, using sensors to compare actual values with stored target values and adapt washing programs accordingly, linking these data sets to compensate for voltage fluctuations and ensure accurate water requirement adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If manual pre-selection of economy programme or single-basket wash is used, then water consumption is reduced, but the quantity of liquid used is greater than required due to inability to accurately detect dish quantity

Engineering Contradiction:
Improvewater consumptionVSAvoiddish quantity detection accuracy
Core Design Contradiction:
Loss of substanceVSMeasurement precision

Solution Approach 1:

The system uses feedback from motor operation data and heat increase measurements to continuously monitor and determine the actual quantity of dishes in the washing container. This feedback loop enables the control unit to adapt the washing programme and water quantity to the actual dish load, resolving the contradiction between reducing water consumption and accurately detecting dish quantity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The dishwasher automatically detects the dish quantity using sensors and measurement data from its own operation (motor data, temperature changes) without requiring user input. The system serves itself by determining the optimal washing programme and water quantity based on its own measurements, eliminating the need for manual programme selection and improving both water efficiency and detection accuracy.

Inventive Principle:
Principle #25Self-service

2Use of energy by stationary object

If manual programme selection is used, then device complexity is reduced, but energy consumption increases due to heating excessive water

Engineering Contradiction:
Improveenergy consumptionVSAvoiddetection system complexity
Core Design Contradiction:
Use of energy by stationary objectVSDevice complexity

Solution Approach 1:

The control unit receives feedback from temperature sensors and motor operation data to determine the actual dish quantity. This feedback enables the system to heat only the necessary amount of water required for the detected dish load, significantly reducing energy consumption while using existing sensors and processing capabilities.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes operational parameters (water quantity, heating temperature, programme selection) based on detected dish quantity. By dynamically adjusting these parameters according to the actual load, the system minimizes energy consumption for heating water while using the existing sensor and control infrastructure.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If coarse crockery states detection is used, then device complexity is reduced, but measurement precision of dish quantity is insufficient

Engineering Contradiction:
Improvedish quantity detection precisionVSAvoiddetection method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system merges multiple measurement approaches (motor operation data analysis, heat increase measurement, temperature sensor data) to determine dish quantity. By combining these different measurement methods, the system achieves high measurement precision without requiring a single complex detection device, as each method complements the others.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Existing components (motor, temperature sensors, heating element) are used for multiple functions: the motor drives the pump and its operation data indicates dish quantity, the temperature sensors monitor both washing temperature and heat increase for detection, and the heating element serves both washing and measurement purposes. This multi-functionality improves measurement precision without adding dedicated detection devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 method allows for precise adaptation of washing programs to the number of dishes, reducing water consumption by automatically optimizing water usage based on detected quantities, thereby minimizing energy expenditure.

Implementation Method 1

a circulating pump (20) is provided in the dishwasher

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

a continuous-flow heater (30) which is intended for heating the rinsing solution

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

the temperature required for heating the rinsing solution. This value, known as the heat increase, measures the change in temperature of the flowing water using a temperature sensor

Methodology Applied
Scientific EffectTemperature sensing:

Data Source

PatentUS8293022B2Method for detecting the quantity of dishes in the washing container of a dishwasher and dishwasher for carrying out said method
Publication Date: 2012.10.23 BSH HAUSGERATE GMBH

AI summary

A dishwasher and a method for detecting the quantity of dishes in the washing container of the dishwasher are provided. The method includes detecting data relating to the motor operation of a circulating pump and detecting data relating to the heat increase in the dishwasher during a pre-washing phase and a heating phase and comparing the detected data with stored target values. A quantity value for the quantity of dishes in the washing container is set based upon a comparison of the detected data with stored target values. The method also includes adapting the washing program according to the set dishes quantity value.