Vacuum cleaner and control method thereof

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Solution Overview

Problem

Robot cleaners face challenges in accurately recognizing obstacles due to varying floor materials and environmental conditions, leading to potential collisions and increased cleaning time.

Innovation Solution

A self-driving cleaner equipped with a pattern irradiation unit, camera, and controller that adjusts reference brightness based on floor material and light pattern characteristics to optimize obstacle detection and avoidance, using a laser sensor to detect floor material information and adjust settings accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a light pattern is used for obstacle detection, then the robot cleaner can detect obstacles in general conditions, but it fails to recognize the light pattern when the floor absorbs light or direct sunlight is strong

Engineering Contradiction:
Improveobstacle recognition accuracyVSAvoiddetection reliability under varying light conditions
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the parameter of light wavelength by using infrared light instead of visible light for pattern projection. Infrared light is not affected by floor material light absorption characteristics and can penetrate through various floor surfaces consistently, resolving the issue of unreliable detection under different lighting conditions and floor materials

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary substance (infrared light) that mediates between the light source and the floor surface. This intermediary infrared radiation interacts differently with floor materials compared to visible light, providing consistent pattern recognition regardless of floor absorption characteristics or ambient sunlight conditions

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the robot cleaner uses a fixed reference brightness for obstacle detection, then the detection process is simple, but the accuracy decreases when floor material characteristics vary

Engineering Contradiction:
Improvedetection process simplicityVSAvoidobstacle detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent makes the reference brightness dynamic by continuously adjusting it based on the average brightness of the captured image. This dynamic adaptation allows the detection system to automatically compensate for variations in floor material reflectivity and ambient lighting conditions, maintaining high detection accuracy without requiring complex manual calibration

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements a feedback mechanism where the captured image brightness is analyzed and used to adjust the reference brightness for subsequent detection. This closed-loop feedback ensures that the detection threshold adapts to current lighting conditions and floor characteristics, maintaining accuracy while keeping the system relatively simple

Inventive Principle:
Principle #23Feedback

3Reliability

If the robot cleaner reduces moving speed when brightness is low, then collision prevention is improved, but cleaning productivity decreases

Engineering Contradiction:
Improvecollision preventionVSAvoidcleaning speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent dynamically adjusts the moving speed based on real-time obstacle detection results and light pattern brightness. When obstacles are detected or brightness is low, speed is reduced for safety; when the path is clear and lighting is good, speed increases to maintain productivity. This dynamic speed control optimizes both safety and efficiency

Inventive Principle:
Principle #15Dynamics

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 obstacle recognition accuracy, reduces erroneous detections, and prevents collisions, thereby shortening cleaning time and improving operational efficiency.

Implementation Method 1

an infrared emitter for emitting infrared rays in a predetermined pattern toward a lower front side

Methodology Applied
Scientific EffectInfrared light emission: Infrared Radiation

Implementation Method 2

a camera for capturing front light rays reflected from the light pattern

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a laser sensor configured to detect information related to a material of the floor

Methodology Applied
Scientific EffectLaser beam reflection: LIDAR

Data Source

PatentEP3795050B1Vacuum cleaner and control method thereof
Publication Date: 2024.01.10 LG ELECTRONICS INC
  • EP3795050B1 patent drawingFigure 1
  • EP3795050B1 patent drawingFigure 2~3
  • EP3795050B1 patent drawingFigure 4~5

AI summary

In order to achieve the objective of the present invention, a self-driving vacuum cleaner according to one embodiment of the present invention, comprises: a main body for traveling through a cleaning area and sucking foreign substances from the floor in the cleaning area; a drive unit for moving the main body in the cleaning area; a pattern irradiation unit, disposed on a front surface of the main body, for irradiating light in a predetermined pattern toward the lower front side of the main body; a camera, disposed on the front surface of the main body, for photographing the front of the main body; and a controller for detecting a light pattern formed by the pattern irradiation unit using an image photographed by the camera, determining whether an obstacle exists in front of the main body on the basis of the brightness of the detected light pattern, and controlling the drive unit to pass or avoid the obstacle on the basis of the determination result.