Robot Cleaner Mop Cloth Attachment Detection Using Existing Sensors

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Solution Overview

Problem

Current robot cleaners with rotary mops face issues due to improper attachment of the mop cloth, leading to uneven cleaning, potential damage, and incomplete cleaning tasks, as the rotation and direction control are affected by the mop cloth's alignment and presence of foreign matter, which existing sensors fail to accurately detect without additional hardware.

Innovation Solution

A control method for robot cleaners that utilizes existing sensors like image, cliff, and gyro sensors to detect the correct attachment of the mop cloth and foreign matter, alerting the user and preventing cleaning operations when issues are detected, without requiring additional sensors, ensuring accurate cleaning patterns and preventing floor damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional sensors are added to detect mop cloth attachment, then detection accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by enabling existing sensors (image sensor, cliff sensor, gyro sensor, motor sensor) to serve dual purposes: their primary functions plus mop cloth attachment detection. The image sensor detects both obstacles and mop cloth presence, the cliff sensor detects both drops and mop cloth attachment state, the gyro sensor detects both robot orientation and attachment errors, and the motor sensor monitors both drive status and attachment anomalies.

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

2Device complexity

If existing sensors are used for mop cloth detection, then device complexity is reduced, but measurement precision may be insufficient

Engineering Contradiction:
Improvedevice complexityVSAvoiddetection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the detection task into multiple independent sensor channels, each analyzing specific aspects of mop cloth attachment. The image sensor segment detects visual presence and position, the cliff sensor segment detects attachment through gap measurement, the gyro sensor segment detects rotational anomalies, and the motor sensor segment detects current variations. This segmentation allows each sensor to contribute its strength while collectively achieving high detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback by continuously monitoring sensor data during operation and using this information to determine attachment state. The system collects real-time data from all sensors, processes this feedback information through the controller, and adjusts operation accordingly (stopping cleaning when attachment is incorrect). This closed-loop feedback ensures accurate detection using existing sensor capabilities.

Inventive Principle:
Principle #23Feedback

3Productivity

If the mop cloth is improperly attached, then cleaning efficiency decreases, but no detection mechanism is triggered

Engineering Contradiction:
Improvecleaning efficiencyVSAvoidcleaning reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by performing mop cloth attachment detection before initiating cleaning operations. The controller checks sensor data to confirm proper attachment status, and only permits cleaning to proceed when attachment is verified as correct. This preliminary verification prevents inefficient or damaging cleaning operations from occurring in the first place.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies preliminary anti-action by preventing cleaning operations when improper attachment is detected. The system proactively identifies attachment errors and blocks the cleaning process before it can cause damage or waste resources, thereby protecting both the cleaning task effectiveness and the equipment itself.

Inventive Principle:
Principle #9Preliminary anti-action

4Speed

If the spin mop rotates with misaligned mop cloth, then the robot can move, but cleaning quality deteriorates and direction control becomes inaccurate

Engineering Contradiction:
Improvemovement speedVSAvoidcleaning precision
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The patent uses feedback from the gyro sensor to detect rotational anomalies caused by misaligned mop cloth attachment. When the gyro sensor detects abnormal rotation patterns during spin mop operation, the controller interprets this as improper attachment and stops the cleaning operation, preventing poor cleaning quality and inaccurate direction control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces mechanical alignment verification mechanisms with sensor-based detection. Instead of relying on mechanical guides or physical alignment features, the system uses the image sensor, cliff sensor, gyro sensor, and motor sensor to detect attachment state and infer alignment accuracy, enabling precise control without complex mechanical structures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution enables reliable and meticulous cleaning by ensuring proper mop cloth attachment and detecting foreign matter, thereby maintaining cleaning efficiency and preventing damage to the cleaner and floor, all while avoiding the need for additional sensor hardware.

Implementation Method 1

an image sensor disposed in a surplus space between two rotating plates

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

two cliff sensors disposed in the surplus space between the rotating plate and a boundary surface below the main body

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Implementation Method 3

gyro sensor that detects a change in an orientation of the main body

Methodology Applied
Scientific EffectGyroscopic effect: Gyroscope

Implementation Method 4

a motor sensor that reads an output current value of the drive motor

Methodology Applied
Scientific EffectElectrical current measurement: Ohm's Law

Data Source

PatentEP4023133B1Artificial intelligence robot cleaner, and robot system comprising same
Publication Date: 2024.11.20 LG ELECTRONICS INC
  • EP4023133B1 patent drawingFigure 1
  • EP4023133B1 patent drawingFigure 2
  • EP4023133B1 patent drawingFigure 3

AI summary

Disclosed is a robot system including: a robot cleaner configured to perform wet cleaning in a cleaning zone; a server configured to communicate with the robot cleaner and perform control of the robot cleaner; and a user terminal configured to be in association with the robot cleaner, and control the robot cleaner as an application for the control of the robot cleaner is activated, wherein the robot cleaner includes: a main body configured to form an outer shape; a pair of rotary mop modules configured to be rotatably installed in the main body, move the main body while rotating, and have a mop cloth attached to a rotating plate of a lower portion; a drive motor configured to rotate the pair of rotary mop modules; a mop detecting unit configured to detect an error state of the mop cloth attached to the rotating plate and output a detection signal; and a controller configured to determine the error state of the mop cloth according to the detection signal from the mop detecting unit, and control driving of the rotary mop module.