Robot cleaner and control method thereof

Patent metadata

Field	Value
Publication number	US-9399284-B2
Application number	US-201414164595-A
Country	US
Kind code	B2
Filing date	Jan 27, 2014
Priority date	Jan 29, 2013
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

A robot cleaner includes a main body, a traveling unit installed in the main body, to move the main body, an ultrasonic sensor to emit an oscillation wave, to receive a reflection wave reflected from an object surface, and to output vibration generated by the oscillation wave and vibration generated by the reception of the reflection wave as an electrical signal, a waveform analyzer to calculate a generation time period of the electrical signal output from the ultrasonic sensor, and a controller to determine information about the object surface based on the calculated generation time period of the electrical signal, and to control movement of the traveling unit based on the information about the object surface.

First claim

What is claimed is:

1. A robot cleaner comprising:
a traveling unit to move the robot cleaner;
an ultrasonic sensor to emit an oscillation wave, to receive a reflection wave reflected from an object surface, and to output vibration generated by the oscillation wave and vibration generated by the reception of the reflection wave as an electrical signal; and
a controller to determine information about the object surface based on the electrical signal output from the ultrasonic sensor, and to control movement of the traveling unit based on the information about the object surface,
wherein the electrical signal is an electrical signal of a composite wave appearing when the oscillation wave overlaps the reflection wave, or an electrical signal of a composite wave appearing when an aftershock generated by inertia of the oscillation wave overlaps the reflection wave,
the controller calculates an average amplitude of the composite wave based on the electrical signal of the composite wave, and determines the information about the object surface based on the average amplitude of the composite wave, and
the controller calculates at least one of a tail length which is a signal having a value smaller than the average amplitude in the electrical signal and an average deviation of the composite wave, and determines the information about the object surface based on the at least one of the tail length and the average deviation.

2. The robot cleaner according to claim 1 , further comprising a waveform analyzer to calculate a waveform length of the composite wave based on the electrical signal of the composite wave,
wherein the controller compares the waveform length of the composite wave to a reference waveform length to determine the information about the object surface.

3. The robot cleaner according to claim 1 , further comprising an Analog-to-Digital (AD) converter converting the electrical signal of the composite wave into a digital signal,
wherein the controller calculates the average amplitude of the composite wave using the digital signal.

4. The robot cleaner according to claim 1 , wherein the controller controls a cleaning mode based on the information about the object surface.

5. The robot cleaner according to claim 1 , wherein the information about the object surface includes one or more of information about a material of the object, information about whether or not the object has been contaminated, and information about whether or not an empty space exists, and
wherein if it is determined that the material of the object is a soft material, that the object has been contaminated, or that an empty space exists, the controller controls avoidance traveling.

6. The robot cleaner according to claim 1 , wherein the ultrasonic sensor has a closed structure.

7. The robot cleaner according to claim 1 , further comprising a waveform analyzer to detect and analyze at least one wave among an oscillation wave, a reflection wave, and an echo wave from the electrical signal,
wherein the controller determines the information about the object surface based on information about the at least one wave among the oscillation wave, the reflection wave, and the echo wave.

8. The robot cleaner according to claim 7 , wherein the controller determines the information about the object surface based on an intensity of the reflection wave.

9. The robot cleaner according to claim 7 , wherein the controller determines the information about the object surface based on a number of echo waves.

10. The robot cleaner according to claim 7 , wherein the waveform analyzer detects a first attenuation rate between the reflection wave and the echo wave and a second attenuation rate between a plurality of echo waves, and
wherein the controller determines the information about the object surface based on at least one attenuation rate of the first attenuation rate and the second attenuation rate.

11. A robot cleaner comprising:
a traveling unit to move the robot cleaner;
an ultrasonic sensor to emit an oscillation wave, to receive a reflection wave reflected from an object surface, and to output vibration generated by the oscillation wave and vibration generated by the reception of the reflection wave as an electrical signal;
a controller to determine information about the object surface based on the electrical signal output from the ultrasonic sensor, and to control movement of the traveling unit based on the information about the object surface and information from another ultrasonic sensor,
wherein the electrical signal is an electrical signal of a composite wave appearing when the oscillation wave overlaps the reflection wave, or an electrical signal of a composite wave appearing when an aftershock generated by inertia of the oscillation wave overlaps the reflection wave,
the ultrasonic sensor and the other ultrasonic sensor are disposed at different distances from the object surface to respectively detect composite waves in which different kinds of interferences occur when another reflection wave is reflected from an object surface made of the same material as the object surface;
a waveform analyzer to calculate a first waveform length of a first electrical signal output from the ultrasonic sensor, and a second waveform length of a second electrical signal output from the other ultrasonic sensor, and to analyze a first kind of interference of the composite wave in the first electrical signal and a second kind of interference of the composite wave in the second electrical signal, and
the controller determines the information about the object surface based on the first waveform length and the second waveform length, and a material of the object surface based on the first kind of interference and the second kind of interference.

12. A robot cleaner comprising:
a traveling unit to move the robot cleaner;
an ultrasonic sensor to emit an oscillation wave, to receive a reflection wave reflected from an object surface, and to output vibration generated by the oscillation wave and vibration generated by the reception of the reflection wave as an electrical signal;
a controller to determine information about the object surface based on the electrical signal output from the ultrasonic sensor, and to control movement of the traveling unit based on the information about the object surface; and
a waveform analyzer to detect and analyze feature points from the electrical signal of the composite wave,
wherein the electrical signal is an electrical signal of a composite wave appearing when the oscillation wave overlaps the reflection wave, or an electrical signal of a composite wave appearing when an aftershock generated by inertia of the oscillation wave overlaps the reflection wave,
the controller determines the information about the object surface based on the result of the analysis of the feature points, and
the feature points correspond to a first time at which the composite wave starts to attenuate and a second time at which the attenuation of the composite wave terminates.

13. The robot cleaner according to claim 12 , wherein the waveform analyzer further detects a gradient at which the composite wave attenuates between the first time and the second time, and
wherein the controller determines the information about the object surface based on at least one of the first time, the second time, and the gradient.

14. The robot cleaner according to claim 12 , wherein the waveform analyzer further detects a maintenance time period from a time at which the reflection wave is received to the first time, and
wherein the controller determines the information about the object s

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kwon Joonhyung
• Kim Shin
• Chun Ji Won

Classifications

• G01N29/11

  by measuring attenuation of acoustic waves · CPC title

• G01N2291/2632

  flat · CPC title

• A47L2201/06

  Control of the cleaning action for autonomous devices; Automatic detection of the surface condition before, during or after cleaning · CPC title

• A47L9/2826 Primary

  the condition of the floor · CPC title

• A47L2201/04

  Automatic control of the travelling movement; Automatic obstacle detection · CPC title