Counter-Rotating Cleaning Rollers for Wall and Corner Debris Pickup

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Solution Overview

Problem

Autonomous cleaning robots face challenges in effectively cleaning close to walls and corners due to limitations in their design, which prevents them from efficiently ingesting debris in these hard-to-reach areas.

Innovation Solution

The autonomous cleaning robot is equipped with a pair of counter-rotating cleaning rollers and a side brush that cooperates with the rollers to direct debris upward, along with sensors and a motorized drivetrain, allowing the robot to maneuver and ingest debris from corners and crevices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the robot uses conventional cleaning design with standard roller and brush configuration, then the device complexity is low, but the cleaning effectiveness close to walls and corners deteriorates

Engineering Contradiction:
Improvecleaning effectivenessVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cleaning system is divided into functionally independent modules: a side brush assembly with adjustable arm, a pair of counter-rotating cleaning rollers, and a debris ingestion system. This segmentation allows each component to be optimized for its specific function while working together to solve the corner cleaning problem.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The side brush arm is designed to be adjustable and movable, allowing it to dynamically adapt its position and angle to reach into corners and along walls. The counter-rotating rollers provide dynamic debris lifting action that adapts to different floor conditions and debris types.

Inventive Principle:
Principle #15Dynamics

2Area of stationary object

If the robot maneuvers close to walls and corners to clean these areas, then the cleaning coverage is improved, but the ability to ingest debris deteriorates due to limited space

Engineering Contradiction:
Improvecleaning coverageVSAvoiddebris ingestion efficiency
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The side brush is positioned and angled to sweep debris from the wall-corned area laterally toward the center of the robot, creating a three-dimensional debris collection path that encompasses both corner areas and the central ingestion zone. This dimensional approach allows debris from restricted corner spaces to be effectively funneled into the ingestion path.

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

Solution Approach 2:

The side brush acts as an intermediary mechanism that bridges the gap between debris located in hard-to-reach corner areas and the main debris ingestion system. It sweeps and directs debris from the peripheral corner zones into the central area where the counters rotating rollers and ingestion system can effectively collect and process it.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the robot uses a single brush or roller configuration, then the device complexity is low, but the ability to direct raised debris upward into the robot deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoiddebris direction and ingestion
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The counter-rotating rollers create a mechanical action that lifts and directs debris upward into the robot. The opposing rotation directions generate a scissoring effect that effectively picks up and propels debris from the floor surface into the ingestion path.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The rollers are designed with curved surfaces that effectively engage with and lift debris from the floor. The rotational motion and curved geometry work together to scoop up debris and direct it upward into the robot body.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

The solution enables the robot to effectively clean close to walls and in corners by ensuring debris is directed into the cleaning path, enhancing its ability to collect debris from difficult-to-reach areas and maintaining an effective cleaning path width.

Implementation Method 1

a side brush is further mounted to the chassis to rotate beneath the chassis adjacent a lateral side of the chassis

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The cleaning rollers are drivable to counter-rotate while the robot is propelled, thereby cooperating to direct raised debris upward into the robot between the rollers

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

first, second, and third sensors mounted to the chassis and responsive to radiation reflected upward from a floor surface beneath the sensors

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3646769B1Cleaning system for autonomous robot
Publication Date: 2023.07.12 IROBOT CORP
  • EP3646769B1 patent drawingFigure 1A
  • EP3646769B1 patent drawingFigure 1B
  • EP3646769B1 patent drawingFigure 1C

AI summary

An autonomous cleaning robot (100) comprises a chassis (110), at least one motorized drive wheel (120a, 120b) mounted to the chassis (110) and arranged to propel the robot (100) across a surface, and a pair of cleaning rollers (310a, 310b) mounted to the chassis (110) and having outer surfaces (350) exposed on an underside of the chassis (110) and to each other (310a, 310b). The cleaning rollers (310a, 310b) are drivable to counter- rotate while the robot (100) is propelled, thereby cooperating to direct raised debris upward into the robot (100) between the rollers (310a, 310b). A side brush (140) is further mounted to the chassis (110) to rotate beneath the chassis (110) adjacent a lateral side (104a) of the chassis (110) about an upwardly extending side brush axis (Zc), and the outer surface (311a) of a first of the cleaning rollers of the pair (310b) extends laterally beyond the outer surface (312a) of a second of the cleaning rollers of the pair (310a) and laterally beyond the side brush axis (Zc), such that the first cleaning roller (310b) defines a cleaning width (WR, WR1) spanning the side brush axis (Zc).