Autonomous cleaning robot provided with a wet cleaning device

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Solution Overview

Problem

Autonomous cleaning robots face issues with wheel slippage due to uneven friction forces from mops, leading to navigation problems and reduced cleaning performance, and existing solutions either require complex and costly control units or compromise cleaning quality.

Innovation Solution

Repositioning the mop supports behind the drive wheels' axes of rotation to increase friction and support force, allowing transverse movement to prevent wheel slippage and improve cleaning efficiency, while maintaining a compact and economical design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the mop supports are arranged at the front and rear of the drive wheels, then the structure is simple, but the support force exerted by the mops on the floor is low

Engineering Contradiction:
Improvestructural simplicityVSAvoidmop support force
Core Design Contradiction:
Ease of manufactureVSForce

Solution Approach 1:

The mop supports are repositioned from a longitudinal arrangement (front and rear of drive wheels) to a transverse arrangement (behind the drive wheels along the width). This dimensional repositioning allows the mops to be directly supported by the main body weight without being intermediated by the drive wheels, thereby increasing the support force while maintaining structural simplicity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the mop supports move parallel to the main direction of travel, then the cleaning coverage is maximized, but the drive wheels slip on the surface

Engineering Contradiction:
Improvecleaning coverageVSAvoidwheel traction
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The mop supports are positioned behind the drive wheels in the transverse direction, creating a force distribution that prevents the drive wheels from slipping before the cleaning operation begins. The rear positioning of the mop supports ensures that the friction forces generated during cleaning do not cause the drive wheels to lose traction, thereby maintaining reliable wheel-ground contact while achieving effective cleaning coverage.

Inventive Principle:
Principle #9Preliminary anti-action

3Measurement precision

If complex control units are added to compensate for wheel slippage, then navigation accuracy improves, but manufacturing costs increase significantly

Engineering Contradiction:
Improvenavigation accuracyVSAvoidcontrol unit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of using complex control units to compensate for the harmful effect of wheel slippage, the invention converts the potential harm into a benefit by strategically positioning the mop supports behind the drive wheels. This positioning ensures that the friction forces from the mops actually stabilize the drive wheels rather than causing slippage, thereby maintaining navigation accuracy without requiring additional complex control systems.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Enhances cleaning quality by increasing mop support force, preventing wheel slippage, and optimizing surface coverage, thus improving the overall performance and efficiency of the autonomous cleaning robot.

Implementation Method 1

a suction unit which is housed at least partly in the main body and which is configured to generate an air flow through the suction opening

Methodology Applied
Scientific EffectAir flow generation:

Implementation Method 2

the fact that the mop holders move parallel to the main direction of travel of the wet cleaning robot significantly increases the risk of the drive wheels slipping on the surface to be cleaned when the mops do not exert the same frictional forces on the floor to be cleaned

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4115785B1Autonomous cleaning robot provided with a wet cleaning device
Publication Date: 2024.04.17 SEB SA
  • EP4115785B1 patent drawingFigure 1~2
  • EP4115785B1 patent drawingFigure 3~4
  • EP4115785B1 patent drawingFigure 5~7

AI summary

The autonomous cleaning robot (2) comprises a main body (3) having a lower face (4) and a suction opening (5) opening into the lower face (4); a wet cleaning device (14) comprising two mop holders (15), each mounted to move in translation relative to the main body (3) along a direction of translation (T), and two mops mounted respectively on the two mop holders (15); and two drive wheels (7) configured to roll on the surface to be cleaned and mounted to rotate on the main body (3) around two substantially parallel axes of rotation. The two mop holders (15) are located behind the axes of rotation of the drive wheels (7), and the direction of translation (T) extends substantially parallel to the axes of rotation of the two drive wheels (7).