Autonomous mobile cleaner and control method thereof

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Solution Overview

Problem

Conventional autonomous mobile cleaners rely on ultrasonic waves for navigation, which can be blocked by obstacles or reflected by surrounding objects, leading to malfunctions and difficulties in moving the main body without user intervention, and may damage the air pipe due to excessive tension.

Innovation Solution

An autonomous mobile cleaner with a main body, suction unit, air pipe, driving wheels, wheel sensors, and a controller that controls the movement of the main body based on wheel rotation, avoiding obstacles without using ultrasonic waves, and maintaining a predetermined distance from the suction unit to minimize user force and tension on the air pipe.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If ultrasonic sensors are used for autonomous navigation, then the cleaner can move autonomously, but the ultrasonic signals may be blocked by obstacles or reflected by surrounding objects causing malfunctions

Engineering Contradiction:
Improveautonomous navigation capabilityVSAvoidnavigation reliability
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent replaces the ultrasonic sensing system with a mechanical sensing system. Specifically, it uses the rotation state of driving wheels detected by wheel sensors to infer movement information, substituting acoustic field detection with mechanical motion detection. This resolves the contradiction by eliminating ultrasonic signal blockage issues while maintaining autonomous navigation capability through mechanical feedback.

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

Solution Approach 2:

The patent introduces wheel rotation as an intermediary to infer navigation status. Instead of directly detecting environment obstacles with ultrasonic waves, the system uses wheel rotation sensors as intermediaries to indirectly determine movement state and position, avoiding direct interaction with problematic ultrasonic signal propagation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the main body is moved by user force without a power system, then the structure remains simple, but the user needs to apply significant force overcoming friction and may damage the air pipe

Engineering Contradiction:
Improvestructure simplicityVSAvoidease of movement
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent enables the main body to move itself by incorporating a driving unit with driving motor and driving wheels. The system autonomously generates the force needed for movement, eliminating the need for user physical effort. This resolves the contradiction by making the system self-sufficient for locomotion while maintaining relatively simple structure through direct drive architecture.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent segments the movement function into a dedicated driving unit separate from the main body structure. The driving unit with motor and wheels is distinct from the cleaning components, allowing independent optimization of movement capability without complicating the overall structure excessively.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If the main body follows the suction unit without distance control, then the system is simple to control, but the air pipe may experience excessive tension and damage

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidair pipe durability
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The patent implements feedback control by using wheel sensors to detect driving wheel rotation and providing this information to the controller. The controller uses this feedback to regulate the main body's movement, ensuring it follows the suction unit at an appropriate distance. This resolves the contradiction by adding minimal feedback mechanism that prevents air pipe overload while maintaining simple overall control architecture.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces dynamic distance control where the main body's position relative to the suction unit is actively adjusted based on wheel rotation feedback. Rather than fixed rigid connection, the system dynamically maintains optimal distance, preventing excessive air pipe tension while keeping control logic simple.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3236829B1Autonomous mobile cleaner and control method thereof
Publication Date: 2022.05.11 LG ELECTRONICS INC
  • EP3236829B1 patent drawingFigure 1~2
  • EP3236829B1 patent drawingFigure 3~4
  • EP3236829B1 patent drawingFigure 5a~5b

AI summary

Provided is an autonomous mobile cleaner including a main body, a suction unit having a handle and configured to suck up surrounding foreign material, an air pipe configured to connect the main body and the suction unit and guide the foreign material into the main body, at least one driving wheel installed below the main body, a driving unit configured to drive the driving wheel by operating a driving motor, a wheel sensor configured to sense rotation of the driving wheel, and a controller configured to control the movement of the main body through the driving unit on the basis of the rotation of the driving wheel sensed by the wheel sensor.