Robot Cleaner Link Assembly for Adaptive Obstacle Passage

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Solution Overview

Problem

Existing robot cleaners struggle to stably pass over obstacles of various shapes and may get caught, interrupting their travel.

Innovation Solution

A robot cleaner equipped with a link assembly and a driving member assembly, including a motor and a sensor, allows for varying the vertical level of main wheels and auxiliary wheels to adapt to different floor conditions, enabling stable passage over obstacles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a member that hits the floor face is included to pass over an obstacle, then the robot cleaner can pass over certain obstacles, but the passable obstacles are limited and the robot may fail to pass over other obstacles

Engineering Contradiction:
Improveability to pass over obstaclesVSAvoidstability of passing over obstacles
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The link assembly is designed to be rotatable relative to the main body, allowing it to dynamically adjust its position and orientation. The rotation angle can be varied to adapt to different obstacle heights and types, transforming a static hitting member into a dynamic one that can optimize its trajectory for each specific obstacle encountered.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The controller rotates the link assembly to a predetermined rotation angle before the robot cleaner encounters the obstacle. This preliminary adjustment ensures that the link assembly is positioned optimally to hit the floor face at the correct trajectory when the obstacle is detected, enabling reliable passage over various obstacle types.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the link assembly is disposed to allow the robot cleaner to escape from an obstacle, then the robot can pass over obstacles, but the link assembly may interfere with the movement of the main body when not in operation

Engineering Contradiction:
Improveability to escape from obstaclesVSAvoidsmooth movement on floor
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The link assembly is disposed within a recess defined in the bottom face of the main body when not in operation. This nesting arrangement allows the link assembly to be stored compactly without protruding downward, preventing interference with the robot cleaner's movement on the floor while still being accessible for rotation when obstacle passage is required.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If the second link is able to rotate in one direction but not the other, then different forms of operation are possible and the robot can escape from various obstacles, but the mechanism becomes more complex

Engineering Contradiction:
Improvedifferent forms of operationVSAvoidcomplexity of link assembly
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The second link is designed with asymmetric rotation capability, allowing rotation in one direction (e.g., clockwise) but preventing rotation in the opposite direction (e.g., counterclockwise). This asymmetric design enables different operational modes for different obstacle types while using a relatively simple mechanical constraint rather than a complex control system.

Inventive Principle:
Principle #4Asymmetry

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 robot cleaner can effectively navigate and clean while avoiding interruptions from obstacles of diverse shapes by adjusting its wheel engagement and vertical level.

Implementation Method 1

a motor for providing a rotational force and a link assembly rotated by the motor

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a spring applied for a suspension function of main wheels

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

a spring restoring force becomes significantly reduced by an extended stroke

Methodology Applied
Scientific EffectSpring restoring force: Spring

Implementation Method 4

a sufficient frictional force is not able to be provided to the main wheels

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4064949B1Robot cleaner
Publication Date: 2026.02.25 LG ELECTRONICS INC
  • EP4064949B1 patent drawingFigure 1
  • EP4064949B1 patent drawingFigure 2~4
  • EP4064949B1 patent drawingFigure 5

AI summary

Provided is a robot cleaner including a main body including a suction portion disposed therein, a main wheel for moving the main body, wherein a vertical level of the main wheel varies in a vertical direction with respect to the main body, an auxiliary wheel disposed at a front portion or a rear portion of the main body, wherein a vertical level of the auxiliary wheel is fixed with respect to the main body, and a driving member assembly disposed in the main body, wherein the driving member assembly varies a vertical level of the main body from a floor face while rotating in forward and rearward directions of the main body, wherein the driving member assembly has different hitting radii when rotating forward and rearward.