Robot Cleaner Wall-Following Control Using Dual Sensor Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing robot cleaners face inefficiencies in cleaning the area between the wall and themselves due to limitations in sensor effectiveness and the need for backward driving when encountering obstacles, which results in incomplete cleaning and increased operation time.

Innovation Solution

A robot cleaner equipped with a first detector using distance sensors and a second detector featuring tactile or photo sensors, along with an auxiliary brush unit, allows for efficient wall following without backward driving by generating contact signals to control angular velocities and maintain contact with the wall, ensuring thorough cleaning of the area between the wall and the cleaner.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the robot cleaner uses a bumper sensor for wall following, then it can detect walls through collision, but it must drive backward and approach the wall again, resulting in inefficient cleaning operations

Engineering Contradiction:
Improvewall detection capabilityVSAvoidcleaning efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the mechanical bumper sensor system with an optical distance sensor system. The distance sensor uses optical beams to detect wall positions and measure distances without physical contact, eliminating the need for mechanical collision-based detection and subsequent backward driving operations.

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

Solution Approach 2:

The patent introduces an intermediary optical beam as a mediator between the robot and the wall. The optical distance sensor emits optical beams that reflect off the wall and return to the sensor, providing indirect measurement of wall position and distance without requiring physical contact or backward movement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the robot cleaner uses a distance sensor for wall following, then it can approach the wall without collision, but it cannot effectively clean certain areas between the wall and the robot due to sensor limitations and errors

Engineering Contradiction:
Improvecollision avoidanceVSAvoidcleaning coverage precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent segments the detection function into multiple distance sensors positioned at different locations on the robot. This segmentation allows the system to detect wall positions at multiple points simultaneously, improving the precision of wall following and ensuring complete cleaning coverage by compensating for individual sensor limitations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a feedback control system where the distance sensor continuously measures the distance to the wall, and the robot adjusts its position and orientation based on this feedback. The controller processes the sensor data and makes real-time adjustments to maintain optimal cleaning distance and coverage, eliminating the precision errors caused by sensor limitations.

Inventive Principle:
Principle #23Feedback

3Reliability

If the robot cleaner repeatedly drives backward and approaches the wall for wall following, then it can detect walls using the bumper sensor, but the cleaning operation time increases significantly

Engineering Contradiction:
Improvewall detection accuracyVSAvoidcleaning operation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by using the distance sensor to detect and measure wall positions before the robot makes contact or approaches too closely. This advance detection allows the robot to plan its movement path in advance, eliminating the need for repeated backward driving and forward approach cycles required by bumper sensor-based systems.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical collision-based bumper sensor system with an optical distance measurement system. This substitution allows the robot to detect walls and measure distances optically without mechanical contact, enabling continuous forward movement and eliminating time-consuming backward and forward cycling operations.

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

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

This solution enables the robot cleaner to efficiently clean the entire area between the wall and itself by rotating with controlled angular velocities based on contact signals, eliminating the need for backward driving and ensuring comprehensive coverage without collisions.

Implementation Method 1

a first detector configured to detect a wall to be followed by the robot cleaner

Methodology Applied
Scientific EffectDistance sensing: Time of Flight

Implementation Method 2

a second detector configured to generate a contact signal through contact with the wall

Methodology Applied
Scientific EffectTactile sensing: Pressure-sensitive Paint

Implementation Method 3

tactile or photo sensors

Methodology Applied
Scientific EffectPhoto sensing: Photoelectric Effect

Data Source

PatentEP3047773B1Robot cleaner and controlling method thereof
Publication Date: 2021.03.03 SAMSUNG ELECTRONICS CO LTD
  • EP3047773B1 patent drawingFigure 1
  • EP3047773B1 patent drawingFigure 2
  • EP3047773B1 patent drawingFigure 3

AI summary

A robot cleaner based on wall following and a controlling method thereof are provided. The robot cleaner includes a first detector configured to generate a wall detection signal by detecting a wall, a second detector configured to generate a first contact signal through contact with the wall, a cleaner main body in which the first and second detectors are disposed and which includes a driver configured to drive on a surface to be cleaned, and a controller which is mounted on the cleaner main body and to which the first and second detectors and the driver are electrically coupled. The controller controls the driver so that the robot cleaner moving to one direction moves along the wall by the wall detection signal, the robot cleaner rotates to a first direction to be in contact with the wall in response to the first contact signal not being generated within a preset time, and the robot cleaner rotates to a second direction opposite to the first direction to be spaced from the wall in response to the generated first contact signal.