Vacuum Cleaner Motor Load Detection for Automatic Surface Adaptation

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Solution Overview

Problem

Vacuum cleaners and robots require user input to set operating modes for the blower and brush, leading to potential non-optimal cleaning settings, especially on changing surfaces, and consume excessive energy.

Innovation Solution

A method to automatically adjust the electric drive's power based on load conditions without additional sensors, using a load indicator to determine the torque and current of the electric motor, allowing for optimal speed and power adaptation, and employing pulse width modulation to optimize energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If user input is required to set operating mode for blower and brush, then operating mode can be set, but cleaning performance becomes non-optimal on changing surfaces and user may forget to set mode

Engineering Contradiction:
Improvemanual mode settingVSAvoidcleaning performance
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The vacuum cleaner system automatically detects surface type through sensor inputs and autonomously adjusts operating parameters for blower and brush without requiring user intervention. The control unit processes sensor data and self-regulates motor speeds to optimize cleaning performance on different surfaces.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system continuously receives feedback from sensors detecting surface characteristics and dynamically adjusts operating modes based on real-time conditions. This closed-loop control ensures optimal cleaning performance adapts automatically as the vacuum transitions between different surface types.

Inventive Principle:
Principle #23Feedback

2Device complexity

If fixed operating mode is used for blower and brush, then device complexity is reduced, but cleaning performance is non-optimal on frequently changing surfaces

Engineering Contradiction:
Improveoperating mode controlVSAvoidsurface adaptation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system dynamically adjusts operating parameters based on real-time surface detection. Rather than fixed modes, the control unit continuously varies blower and brush speeds according to detected surface characteristics, enabling adaptive optimization without complex manual mode selection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (motor speeds, power levels) automatically based on sensor feedback about surface type. This allows the vacuum to adapt its cleaning characteristics dynamically without requiring multiple fixed operating modes or user intervention.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high power is used for blower and brush to ensure cleaning performance, then cleaning effectiveness is maintained, but energy consumption increases

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidmotor power consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The system optimizes power consumption by dynamically adjusting motor parameters based on actual cleaning needs and detected surface characteristics. The control unit modulates blower and brush speeds to provide only the necessary power for effective cleaning, avoiding unnecessary energy expenditure on already-clean or hard surfaces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Rather than continuously operating at full power, the system applies partial power only when and where needed based on sensor detection. This selective action maintains cleaning effectiveness while minimizing overall energy consumption by reducing motor power during periods or areas requiring less cleaning intensity.

Inventive Principle:
Principle #16Partial or excessive action

4Adaptability or versatility

If additional sensors are added to detect surface type and optimize operation, then adaptability to different surfaces is improved, but device complexity and cost increase

Engineering Contradiction:
Improvesurface detection capabilityVSAvoidsensor system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system uses existing sensors in the vacuum cleaner for multiple purposes, including surface type detection in addition to their primary functions. This multi-functional use of existing components enables surface adaptation without adding dedicated sensors, thereby avoiding increased device complexity and cost.

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 ensures optimal cleaning performance with minimal energy consumption, extends the battery life, and automatically adjusts to different surfaces, preventing motor overload and damage.

Implementation Method 1

Determining an induced voltage of the electric motor by means of the control unit

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The electric motor is operated by the control unit at a predetermined speed with the help of a pulse width modulated battery voltage with a predetermined duty cycle

Methodology Applied
Scientific EffectPulse width modulation: Phase Modulation

Data Source

PatentEP3479745B1Method for operating an electric drive, preferably a ventilator and/or of a brush of a vacuum cleaner or a vacuum cleaning robot
Publication Date: 2022.10.26 MIELE & CO KG
  • EP3479745B1 patent drawingFigure 1~2
  • EP3479745B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for operating an electric drive (A), preferably a blower and/or a brush of a vacuum cleaner or a robotic vacuum cleaner, wherein the electric drive (A) comprises a voltage source (Q), an electric motor (M), and a control unit (S). The method comprises at least the following steps: operating (100) the electric motor (M) by the control unit (S) at a predetermined speed using a pulse-width modulated voltage (Uq) from the voltage source (Q) with a predetermined duty cycle; detecting (200) the voltage (Uq) of the voltage source (Q); determining (300) the effective voltage (Ueff) applied to the electric motor (M) by multiplying the duty cycle by the voltage (Uq) of the voltage source (Q); and determining (400) the induced voltage (Ui) of the electric motor (M).and • Determining (500) a load indicator of the electric motor (M) by subtracting the induced voltage (Ui) of the electric motor (M) from the effective voltage (Ueff) applied to the electric motor (M).