Dishwasher Sensor-Based Machine Care Scheduling to Reduce Energy Waste

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Solution Overview

Problem

Dishwashers often start machine care programs based on a predetermined number of cycles rather than the actual degree of soiling, leading to inefficient energy and detergent use, premature aging, or impaired cleaning performance.

Innovation Solution

A system with a control device, sensor unit, and memory unit that detects and analyzes the time curve of sensor signals from the washing liquor, allowing for targeted execution of cleaning programs based on temporal functional values, such as turbidity, conductivity, and temperature, to optimize the operation of the dishwasher.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If machine care programs are started after a predetermined number of washing cycles, then the dishwasher operates automatically without user intervention, but energy and detergent are consumed unnecessarily when the dishwasher is not actually soiled

Engineering Contradiction:

Improveautomatic execution of machine care programVSAvoidenergy consumption during unnecessary cleaning cycles

Core Design Contradiction:

Extent of automationVSLoss of energy

Solution Approach 1:

The system continuously monitors sensor signals (turbidity, conductivity, temperature) from the washing liquor and uses this feedback to determine when machine care programs are actually needed. The control device compares detected sensor signal characteristics against stored reference values to assess the actual degree of soiling, triggering cleaning programs only when necessary rather than on a fixed schedule.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The dishwasher monitors its own operational state through integrated sensors and automatically determines when maintenance is needed based on actual usage conditions. The system serves itself by detecting its own soiling level and initiating appropriate cleaning programs without external intervention or predetermined scheduling.

Inventive Principle:

Principle #25Self-service

2Device complexity

If machine care programs are started after a predetermined number of washing cycles, then the system follows a simple control logic, but the cleaning performance deteriorates when the program is delayed too long

Engineering Contradiction:

Improvecontrol logic for scheduling cleaning programsVSAvoidcleaning performance of the dishwasher

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The control device continuously receives feedback from sensor units monitoring washing liquor properties and compares current sensor signal characteristics with stored reference values. This enables real-time assessment of soiling degree, allowing the system to trigger machine care programs at the optimal moment rather than relying on fixed cycle counters, thus maintaining cleaning performance while using manageable control complexity.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary monitoring and assessment of soiling conditions through continuous sensor detection before triggering machine care programs. By detecting trends in sensor signals over multiple washing cycles and assessing the actual degree of soiling in advance, the system prepares to initiate cleaning programs at the optimal time, preventing performance deterioration.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If machine care programs are executed frequently to maintain cleaning performance, then the dishwasher remains clean, but components age prematurely due to excessive cleaning cycles

Engineering Contradiction:

Improvecleaning performance of the dishwasherVSAvoidservice life of dishwasher components

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system uses sensor feedback to detect the actual degree of soiling and triggers machine care programs only when soiling thresholds are exceeded. This prevents unnecessary frequent cleaning cycles, reducing wear on components while maintaining cleaning performance by executing programs only when actually needed based on real-time monitoring of washing liquor properties.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The dishwasher autonomously monitors its own condition and initiates maintenance only when genuinely required, avoiding premature or excessive cleaning cycles that would accelerate component aging. The system serves itself by intelligently determining the optimal balance between maintaining cleanliness and preserving component life.

Inventive Principle:

Principle #25Self-service

4Device complexity

If individual sensor values are used to control the dishwasher, then the control system remains simple, but long-term trends in soiling cannot be identified

Engineering Contradiction:

Improvesensor evaluation systemVSAvoidtemporal development of soiling degree

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The system transitions from evaluating single static sensor values to analyzing temporal development of sensor signals across multiple washing cycles. By storing and comparing sensor signal characteristics over time and detecting trends in the temporal dimension, the system identifies long-term soiling patterns while maintaining manageable control complexity through systematic evaluation methods.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The control device continuously monitors sensor signals and compares current readings with historical data from previous washing cycles. This feedback mechanism enables detection of trends in sensor signal development over time, allowing the system to identify long-term soiling patterns and predict when machine care programs will be needed, preserving temporal information without excessive complexity.

Inventive Principle:

Principle #23Feedback

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 that cleaning programs are executed when necessary, reducing energy consumption, maintaining performance, and prolonging component life by considering the development of sensor signals over time.

Implementation Method 1

a turbidity sensor for detecting a turbidity of the washing liquor

Methodology Applied

Scientific EffectTurbidity detection:

Implementation Method 2

a conductivity sensor for detecting a conductivity of the washing liquor

Methodology Applied

Scientific EffectConductivity detection:

Implementation Method 3

a temperature sensor for detecting a temperature of the washing liquor

Methodology Applied

Scientific EffectTemperature detection:

Implementation Method 4

The ascertaining unit is designed to integrate the time curve of the at least one sensor signal to determine an integral value

Methodology Applied

Scientific EffectIntegration of time curve:

Implementation Method 5

a separate washing cycle is carried out at a higher temperature after a predetermined number of washing cycles

Methodology Applied

Scientific EffectThermal heating: Heating

Data Source

PatentUS12251071B2System with a dishwasher, method, and computer program product

Publication Date: 2025.03.18 BSH HAUSGERATE GMBH

AI summary

A system includes a dishwasher including a washing chamber, a sensor unit designed to detect a time curve of at least one sensor signal of a washing liquor and to output the detected time curve of the at least one sensor signal, a memory unit designed to store the time curve of the at least one sensor signal, an ascertaining unit designed to ascertain a temporal functional value based on the time curve of the at least one sensor signal, and a control device designed to carry out a washing program for washing washware in the washing chamber of the dishwasher and to carry out a specified action as a function of the temporal functional value.