Dishwasher Pump Current Sensing for Overfill and Wash Zone Detection

Solution Overview

Problem

Existing dishwasher technologies require bulky and expensive sensors to detect operational states such as extra wash zone activation and overfill situations, which is inefficient and costly.

Innovation Solution

A method and device that operate the dishwasher circulation pump motor at varying rotational speeds to measure and analyze the motor's operating current, allowing for the detection of operational states without the need for additional sensors, by differentiating between nominal and non-nominal operational states based on changes in motor current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional sensors are used to detect operational states, then detection capability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvedetection capabilityVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The circulation pump motor is made to serve multiple functions: it not only circulates water during washing cycles but also acts as a sensor for detecting operational states such as extra wash zone activation and overfill situations. By operating the motor at different rotational speeds and analyzing the resulting current consumption patterns, the system can detect various operational states without requiring separate detection devices.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The circulation pump motor detects operational states by analyzing its own operating current characteristics. The system operates the motor at different rotational speeds and monitors the current consumption to determine whether the dishwasher is in a nominal or non-nominal operational state, enabling self-detection without external sensors.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If additional sensors are used to detect operational states, then detection capability is improved, but cost increases

Engineering Contradiction:

Improvedetection capabilityVSAvoidcost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The circulation pump motor is made to serve multiple functions: it not only circulates water during washing cycles but also acts as a sensor for detecting operational states such as extra wash zone activation and overfill situations. By operating the motor at different rotational speeds and analyzing the resulting current consumption patterns, the system can detect various operational states without requiring separate detection devices.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The circulation pump motor detects operational states by analyzing its own operating current characteristics. The system operates the motor at different rotational speeds and monitors the current consumption to determine whether the dishwasher is in a nominal or non-nominal operational state, enabling self-detection without external sensors.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If the circulation pump motor is operated at varying rotational speeds for detection, then detection sensitivity is improved, but energy consumption increases

Engineering Contradiction:

Improvedetection sensitivityVSAvoidenergy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The circulation pump motor is operated at different rotational speeds in a periodic manner to enable detection of operational states. The system alternates between nominal and non-nominal rotational speeds, measuring current consumption at each speed level, and uses these periodic measurements to determine the operational state without continuous high-speed operation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The circulation pump motor operates dynamically at different rotational speeds depending on the detection phase. During normal washing cycles, the motor operates at nominal speed. During detection phases, the motor temporarily operates at non-nominal speeds to enable state detection, with the control system managing the transitions between different operational modes.

Inventive Principle:

Principle #15Dynamics

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

Enables the detection of extra wash zone activation and overfill situations with increased sensitivity and accuracy, reducing the need for expensive sensors and allowing for automatic adjustments to prevent flooding and ensure proper washing cycles.

Implementation Method 1

operate a motor driving a dishwasher circulation pump at at least one rotational speed differing from a nominal rotational speed and measure operating current of the motor

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS10244919B2Detecting operational state of a dishwasher

Publication Date: 2019.04.02 ELECTROLUX HOME PROD CORP NV

AI summary

The present invention relates to a method of and a device (40) for, detecting an operational state of a dishwasher (10), in particular activation of extra wash zones and overfill situations. The device (40) is arranged to operate a motor (22) driving a dishwasher circulation pump (21) at at least one rotational speed differing from a nominal rotational speed and measure operating current of the motor (22) driving the dishwasher circulation pump (21). Further, the device is arranged to determine whether the dishwasher (10) operates in an operational state differing from a nominal operational state based on the measured circulation pump motor operating current.