Rotation Mop Water Control Using Slip Rate Feedback

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Solution Overview

Problem

Existing robot cleaners with rotation mops face challenges in adjusting the water supply rate, leading to improper cleaning and potential safety hazards due to excess or insufficient water, which affects their movement and efficiency.

Innovation Solution

A robot cleaner system that includes a main body, a water tank, a rotation mop, a drive motor, a motion sensor, and a controller that calculates the slip rate based on actual and ideal speeds to adjust the water supply, using a floor sensor for additional adjustments, and stores data to determine optimal water content rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the water supplied to the rotation mop is increased to improve cleaning effectiveness, then the cleaning performance is improved, but the rotation mop deposits excess water on the floor creating safety hazards and preventing proper cleaning

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidexcess water deposition
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The controller receives feedback from the motion sensor about the robot cleaner's actual movement speed and compares it with the ideal speed to calculate slip rate. Based on this feedback, the controller dynamically adjusts the water supply amount to the rotation mop, reducing water supply when slip rate indicates excessive moisture and increasing it when cleaning effectiveness is insufficient, thereby resolving the contradiction between cleaning performance and safety

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the water supply parameter dynamically based on the calculated slip rate. By continuously monitoring movement parameters and adjusting water supply accordingly, the system optimizes the balance between having enough water for effective cleaning and avoiding excess water that causes safety hazards

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the water supplied to the rotation mop is decreased to prevent excess water deposition, then safety is improved, but the rotation mop contacts the floor with a relatively dry cloth such that the floor is not properly cleaned

Engineering Contradiction:
ImprovesafetyVSAvoidcleaning effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The motion sensor provides continuous feedback on the robot cleaner's movement, allowing the controller to calculate slip rate and adjust water supply in real-time. This feedback mechanism ensures that water supply is increased when movement indicates insufficient moisture and decreased when slip indicates excess water, maintaining safety while ensuring proper cleaning

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The water supply system transitions from a static fixed supply rate to a dynamic adjustable supply rate that changes based on actual movement conditions. The controller dynamically modifies water supply parameters according to calculated slip rate, enabling the system to adapt to varying cleaning conditions and maintain optimal balance between safety and cleaning effectiveness

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the water supply to the rotation mop is not adjusted according to movement conditions, then the system structure is simple, but the robot cleaner cannot move correctly and efficiently

Engineering Contradiction:
Improvesystem structureVSAvoidmovement efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The motion sensor and controller create a feedback loop that monitors movement and adjusts water supply accordingly. This feedback mechanism enables the system to maintain correct and efficient movement by automatically compensating for water-related friction changes, proving that the added complexity of feedback control is justified by the significant improvement in movement efficiency

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 system ensures the robot cleaner maintains optimal water levels for effective cleaning and efficient movement by dynamically adjusting water supply based on slip rates and floor conditions, preventing safety hazards and improving cleaning performance.

Implementation Method 1

a motion sensor which measures a reference motion of the main body while the rotation mop rotates

Methodology Applied
Scientific EffectMotion detection: Accelerometer

Implementation Method 2

a rotation mop which contacts a floor and moves the main body while rotating

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3440980B1Robot cleaner and controlling method thereof
Publication Date: 2021.10.27 LG ELECTRONICS INC
  • EP3440980B1 patent drawingFigure 1~2
  • EP3440980B1 patent drawingFigure 3~4
  • EP3440980B1 patent drawingFigure 5~6a

AI summary

The present application relates to a robot cleaner. The robot cleaner of the present application includes: a main body which forms an external shape; a water tank which stores water; a rotation mop which is in contact with a floor while rotating and moves the main body; a drive motor which rotates the rotation mop; a motion detection unit which measures a reference motion of the main body when the rotation mop rotates; and a controller which measures a slip rate based on an actual speed of the main body measured by the motion detection unit in the reference motion and an ideal speed of the main body estimated according to driving of the drive motor, and controls an amount of water supplied to the rotation mop.