Robot cleaner and method for controlling the same

• US 10,238,258 B2
• Filed: 09/16/2015
• Issued: 03/26/2019
• Est. Priority Date: 10/24/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kwak, Donghoon
• Primary Examiner(s): Camby, Richard M
• Application Number:
  US15/521,036
• Publication Number:
  US 20170325647A1
• Time in Patent Office: 1,287 Days
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles
• CPC Class Codes: A47L 9/28 Installation of the electric equipment, e.g. adaptation or attachment to the suction cleaner; Controlling suction cleaners by electric means
• CPC Class Codes: A47L 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2852 Elements for displacement of the vacuum cleaner or the accessories therefor, e.g. wheels, casters or nozzles
• CPC Class Codes: A47L 9/2857 User input or output elements for control, e.g. buttons, switches or displays
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/0257 using a radar radar systems designed for anti-collision purposes between land vehicles or between land vehicle and fixed obstacles G01S13/931
• CPC Class Codes: G05D 1/0259 using magnetic or electromagnetic means
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

Disclosed is a robot cleaner including a main body forming an appearance, at least one driving wheel installed on a lower portion of the main body, a driving unit configured to drive the driving wheel according to an operation of a driving motor, a first obstacle sensor positioned on the lower portion of the main body and configured to sense an obstacle on the floor, and a control unit configured to, when the sensed obstacle on the floor has a preset pattern, limit driving of the at least one driving wheel such that the at least one driving wheel is not hindered by the preset pattern when the main body rotates on the preset pattern according to driving of the at least one driving wheel.

Claims

1. A robot cleaner comprising:

a main body forming an appearance;

a driving wheel installed on a lower portion of the main body;

a driving motor configured to drive the driving wheel;

a first obstacle sensor positioned on the lower portion of the main body and configured to sense an obstacle on a floor; and

a controller configured to, when a contour of the sensed obstacle on the floor has a prescribed pattern, modify driving of the driving wheel by the driving motor,

wherein the prescribed pattern includes at least one of a rising edge or a falling edge, and

wherein the prescribed pattern includes a recess form in which the rising edge and the falling edge have at least a prescribed depth, and a width between the rising edge and the falling edge is within a prescribed range, or the prescribed pattern includes a step form including one of the rising edge or the falling edge.

2. The robot cleaner of claim 1, further comprising:

a memory configured to store a floor map identifying distances between the lower portion and sections of the floor, each of the sections having a size corresponding to a size of a region of the lower portion wherein the first obstacle sensor is positioned,

wherein the controller generates the floor map based on readings by the first obstacle sensor, and stores the generated floor map in the memory.

3. The robot cleaner of claim 1, wherein the prescribed pattern includes a form in which a plurality of recesses are repeated within a prescribed distance, or a form in which a plurality of steps are repeated at a certain distance interval.

4. The robot cleaner of claim 1, further comprising:

a second obstacle sensor positioned on at least one of a side or a top of the main body to sense another obstacle in front of the main body.

5. The robot cleaner of claim 4, wherein when the robot cleaner is traveling in a first direction, is positioned on the obstacle on the floor, and either the obstacle in front of the main body is sensed by the second obstacle sensor or if a cliff in front of the main body is sensed by the first obstacle sensor, the controller modifies the driving of the driving wheel by the driving motor such that the robot cleaner stops travelling in the first direction and travels in a second direction opposite to the first direction.

6. The robot cleaner of claim 5, wherein, after the robot cleaner travels in the second direction and the driving wheel is positioned off the obstacle on the floor, the controller further modifies the driving of the driving wheel by the driving motor such that the driving wheel travels along an outer edge of the obstacle on the floor.

14. The robot cleaner of claim 1, wherein the first obstacle sensor includes at least one of an infrared sensor, an ultrasonic sensor, a radio frequency (RF) signal sensor, or a position sensitive detector (PSD) sensor.

15. The robot cleaner of claim 1, wherein the first obstacle sensor includes a first sensor positioned on a front region of the lower portion and a second sensor positioned on another region of the lower portion between the first sensor and the driving wheel.

16. The robot cleaner of claim 1, further comprising a camera sensor positioned on the lower portion of the main body, the camera sensor detecting a movement of the robot cleaner based on captured image data of the floor.

17. The robot cleaner of claim 4, wherein the second obstacle sensor includes at least one of an infrared sensor, an ultrasonic sensor, radio frequency (RF) signal sensor, or a geomagnetic sensor.

7. A method for controlling a robot cleaner, the method comprising:

sensing, by a sensor positioned on a lower portion of a main body of the robot cleaner, an obstacle on a floor;

determining whether a contour of the obstacle on the floor corresponds to a prescribed pattern; and

when the contour of the sensed obstacle on the floor corresponds to the prescribed pattern and a portion of the main body of the robot cleaner is positioned on the obstacle, modifying driving of a driving wheel included in the robot cleaner,

wherein the prescribed pattern includes a recess form in which a rising edge and a falling edge have at least a prescribed depth, and a width between the rising edge and the falling edge is within a prescribed range, or the prescribed pattern includes a step form including one of the rising edge or the falling edge.

8. The method of claim 7, further comprising:

generating a floor map identifying distances between sections of the floor and the lower portion of the main body;

detecting the obstacle on the floor based on the floor map.

9. The method of claim 8, wherein the sections of the floor within the floor map have a size corresponding to a size of a region of the lower portion of the robot cleaner where the sensor is positioned.

10. The method of claim 7, wherein the present pattern includes a form in which a plurality of recesses are repeated within a prescribed distance, or a form in which a plurality of steps are repeated at a certain distance interval.

11. The method of claim 7, further comprising:

sensing another obstacle or a cliff in front of the main body; and

when the other obstacle or the cliff is sensed, modifying the driving of the driving wheel to cause the driving wheel to move along an outer edge of the other obstacle or the cliff.

12. The method of claim 7, further comprising:

when the robot cleaner is traveling in a first direction and a portion of the main body is positioned over the obstacle on the floor, sensing another obstacle or a cliff in front of the main body; and

when the other obstacle or the cliff is sensed, modifying the driving of the driving wheel cause the robot cleaner to travel in a second direction opposite to the first direction.

13. The method of claim 12, further comprising:

modifying the driving of the driving wheel to cause the robot cleaner to travel along an outer edge of the obstacle on the floor, after the robot cleaner travels in the second direction and a portion of the main body moves off of obstacle on the floor.