Method and apparatus for generating and tracing cleaning trajectory of home cleaning robot

• US 20040204804A1
• Filed: 04/08/2004
• Published: 10/14/2004
• Est. Priority Date: 04/08/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Kl-wan, Hong, Sun-gi, Lee, Hyoung-ki, Bang, Seok-won, Kim, Il-hwan
• Granted Patent: US 7,860,608 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: A47L 2201/02 Docking stations; Docking operations
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93

Abstract

A method and apparatus generating and tracing a cleaning trajectory of a home cleaning robot the method including: controlling the home cleaning robot to straightly travel as much as a set distance from the docking station and then rotationally travel, maintaining the set distance from the docking station, until the home cleaning robot reaches one of two walls; controlling the home cleaning robot to travel as much as the set distance along the wall if the home cleaning robot reaches the wall and resume rotational-traveling around the docking station, maintaining a distance between the docking station and the home cleaning robot increased by the set distance until it reaches one of the two walls; and repeatedly controlling the home cleaning robot to travel as much as the set distance along the wall if the home cleaning robot reaches the wall and resume rotational-traveling around the docking station, maintaining a distance between the docking station and the home cleaning robot increased by the set distance until it reaches one of the two walls until the home cleaning robot arrives at a point where it cannot travel in a direction in which a distance between the docking station and the home cleaning robot increases.

Claims

1. A method of generating a cleaning trajectory of a home cleaning robot that includes a sound wave receptor by using a docking station that includes a sound wave transmitter, the method comprising:

controlling the home cleaning robot to travel in a straight direction as much as a set distance from the docking station and then to rotationally travel, maintaining the set distance from the docking station, until the home cleaning robot reaches one of two walls;

controlling the home cleaning robot to travel as much as the set distance along the wall if the home cleaning robot reaches the wall and resume rotational-traveling around the docking station, maintaining a distance between the docking station and the home cleaning robot increased by the set distance until the home cleaning robot reaches the one of the two walls; and

repeatedly controlling the home cleaning robot to travel as much as the set distance along the one of the two walls if the home cleaning robot reaches the one of the two walls and resumes rotational-traveling around the docking station, maintaining a distance between the docking station and the home cleaning robot increased by the set distance until the home cleaning robot reaches the other one of the two walls, until the home cleaning robot arrives at a point where the home cleaning robot cannot travel in a direction in which a distance between the docking station and the home cleaning robot increases.

2. The method of claim 1, wherein the distance between the docking station and the home cleaning robot is calculated based on a difference between a time when the sound wave transmitter transmits a sound wave and a time when the sound receptor receives the sound wave transmitted from the sound wave transmitter.

3. The method of claim 1, wherein if an obstacle is sensed at a point while the home cleaning robot rotationally travels, the home cleaning robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is not less than the set distance, the home cleaning robot rotationally travels, maintaining a distance from the docking station equal to the set distance plus a distance between the docking station and the home cleaning robot at the predetermined point where the obstacle had been sensed.

4. The method of claim 1, wherein if an obstacle is sensed at a point while the home cleaning robot rotationally travels, the home cleaning robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is less than the set distance, the home cleaning robot is controlled to travel along the obstacle until the home cleaning robot arrives at a point where a distance between the docking station and the home cleaning robot is the same as a distance between the docking station and the home cleaning robot at the predetermined point where the obstacle has been sensed and then rotationally traveling maintaining a distance between the docking station and the home cleaning robot.

5. The method of claim 2, wherein the difference between the time when the sound wave transmitter transmits the sound wave and the time when the sound wave receptor receives the sound wave transmitted from the sound wave transmitter is measured based on a difference between the time when a predetermined time synchronization signal transmitted from the docking station is received by the home cleaning robot and the time when the sound wave is received by the sound wave receptor.

6. The method of claim 2, wherein the difference between the time when the sound wave transmitter transmits the sound wave and the time when the sound wave receptor receives the sound wave transmitted from the sound wave transmitter is measured based on a predetermined timing signal.

7. The method of claim 1, wherein a program enabling the method is recorded on a computer-readable recording medium.

8. The method of claim 3, wherein a program enabling the method is recorded on a computer-readable recording medium.

9. The method of claim 4, wherein a program enabling the method is recorded on a computer-readable recording medium.

10. A method of tracing a cleaning trajectory that is generated using the method of claim 1, the method of tracing comprising:

comparing the distance between the docking station and the home cleaning robot, which is measured by using the sound wave transmitted from the docking station to the home cleaning robot, with a predetermined distance that the home cleaning robot is supposed to maintain from the docking station when following the cleaning trajectory; and

generating an angular velocity command so that a direction that the home cleaning robot travels is shifted based on a result of the comparison carried out in the comparison of the distance between the docking station and the home cleaning robot.

11. The method of tracing of claim 10, wherein the distance between the docking station and the home cleaning robot is calculated based on a difference between the time when the sound wave transmitter transmits a sound wave to the sound wave receptor and the time when the sound receptor receives the sound wave transmitted from the sound wave transmitter.

12. The method of tracing of claim 10, wherein a program enabling the method is recorded on a computer-readable recording medium.

13. The method of claim 1, wherein the cleaning trajectory of the home cleaning robot is expressed by the following equation:

{dot over (x)}(t)=v(t)cos γ

(t) {dot over (y)}(t)=v(t)sin γ

(t) {dot over (γ

)}(t)=w(t),

wherein v(t) represents a linear velocity command, and w(t) represents an angular velocity command.

14. An apparatus that generates and traces a cleaning trajectory of a home cleaning robot, the apparatus comprising:

a sound wave transmitter which is included in a docking station;

a sound wave receptor which is included in a home cleaning robot;

a distance calculator, which calculates a distance between the docking station and the home cleaning robot by using a difference between the time when the sound wave transmitter transmits a sound wave and the time when the sound wave receptor receives the sound wave transmitted from the sound wave transmitter; and

a travel controller, which receives the distance between the docking station and the home cleaning robot from the distance calculator, controls the home cleaning robot so that the home cleaning robot straightly travels as much as a set distance from the docking station, rotationally travels maintaining the set distance with the docking station until reaching one of two walls, straightly travels as much as the set distance along the one of the two walls, and resumes rotational-traveling maintaining a distance between the docking station and the home cleaning robot increased by the set distance until reaching the other one of the two walls.

15. The apparatus of claim 14, wherein the travel controller outputs an angular velocity command by using a difference between the docking station and the home cleaning robot, received from the distance calculator, and a predetermined distance that the home cleaning robot is supposed to maintain from the docking station when following a predetermined cleaning trajectory, such that the home cleaning robot returns to the predetermined cleaning trajectory.

16. The apparatus of claim 14, wherein the travel controller receives a calculated distance R_m between the docking station and the home cleaning robot from the distance calculator, compares a calculated distance R with the distance R_m that the home cleaning robot is to maintain from the docking station at a predetermined location, and shifts an angular velocity w(t) of the home cleaning robot based on whether or not R_m is larger than R.

17. The apparatus of claim 14, wherein if the home cleaning robot senses an obstacle at a predetermined point during the home cleaning, the home cleaning robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is not less than the set distance, the home cleaning robot rotationally travels, maintaining a distance from the docking station equal to the set distance plus a distance between the docking station and the home cleaning robot at the predetermined point where the obstacle had been sensed.

18. The apparatus of claim 14, wherein if the home cleaning robot senses an obstacle at a predetermined point during the home cleaning, the home cleaning robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is less than the set distance, the home cleaning robot is controlled to travel along the obstacle until it arrives at a point where a distance between the docking station and the home cleaning robot is the same as a distance between the docking station and the home cleaning robot at the predetermined point where the obstacle has been sensed and then rotationally travels maintaining a distance between the docking station and the home cleaning robot.

19. The apparatus of claim 14, further comprising:

a time synchronization signal transmitter which is included in the docking station and generates and transmits a time synchronization signal; and

a time synchronization signal receptor which is included in the home cleaning robot and receives the time synchronization signal.

20. The apparatus of claim 14, further comprising:

a first timer which is included in the docking station and generates a timing signal with which the sound wave is transmitted to the home cleaning robot in synchronization; and

a second timer which is included in the home cleaning robot and generates the same timing signal as that provided from the first timer.

21. The apparatus of claim 19, wherein the sound wave is an ultrasonic wave.

22. The apparatus of claim 19, wherein the time synchronization signal is one of an infrared signal and a radio frequency signal.

23. The apparatus of claim 14, wherein the sound wave receptor which is included in the home cleaning robot is an all-directional sound wave sensor.

24. A computer readable medium encoded with processing instructions for performing a method of generating a cleaning trajectory of a home cleaning robot that includes a sound wave receptor by using a docking station that includes a sound wave transmitter, the method comprising:

controlling the home cleaning robot to travel in a straight direction as much as a set distance from the docking station and then to rotationally travel, maintaining the set distance from the docking station, until the home cleaning robot reaches one of two walls;

controlling the home cleaning robot to travel as much as the set distance along the one of the two walls if the home cleaning robot reaches the one of the two walls and resume rotational-traveling around the docking station, maintaining a distance between the docking station and the home cleaning robot increased by the set distance until the home cleaning robot reaches the other one of the two walls; and

repeatedly controlling the home cleaning robot to travel as much as the set distance along the one of the two walls if the home cleaning robot reaches the one of the two walls and resume rotational-traveling around the docking station, maintaining a distance between the docking station and the home cleaning robot increased by the set distance until the home cleaning robot reaches the other one of the two walls until the home cleaning robot arrives at a point where the home cleaning robot cannot travel in a direction in which a distance between the docking station and the home cleaning robot increases.

25. The computer readable medium according to claim 24, wherein the distance between the docking station and the home cleaning robot is calculated based on a difference between a time when the sound wave transmitter transmits a sound wave and a time when the sound receptor receives the sound wave transmitted from the sound wave transmitter.

26. The computer readable medium according to claim 24, wherein if an obstacle is sensed at a point while the home cleaning robot rotationally travels, the home cleaning robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is not less than the set distance, the home cleaning robot rotationally travels, maintaining a distance from the docking station equal to the set distance plus a distance between the docking station and the home cleaning robot at the predetermined point where the obstacle had been sensed.

27. The computer readable medium according to claim 24, wherein if an obstacle is sensed at a point while the home cleaning robot rotationally travels, the home cleaning robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is less than the set distance, the home cleaning robot is controlled to travel along the obstacle until the home cleaning robot arrives at a point where a distance between the docking station and the home cleaning robot is the same as a distance between the docking station and the home cleaning robot at the predetermined point where the obstacle has been sensed and then rotationally traveling maintaining a distance between the docking station and the home cleaning robot.

28. An apparatus generating and tracing a traveling trajectory of a robot, the apparatus comprising:

a sound wave transmitter located at a designated location;

a sound wave receptor located on the robot;

a distance calculator calculating a distance between the designated location and the robot by using a difference between the time when the sound wave transmitter transmits a sound wave and the time when the sound wave receptor receives the sound wave transmitted from the sound wave transmitter; and

a travel controller receiving the distance between the designated location and the robot from the distance calculator, controlling the robot so that the robot straightly travels as much as a set distance from the designated location, rotationally travels maintaining the set distance with the designated location until reaching one of two walls, straightly travels as much as the set distance along the one of the two walls, and resumes rotational-traveling maintaining a distance between the designated location and the robot increased by the set distance until reaching the other one of the two walls.

29. The apparatus of claim 28, wherein the travel controller outputs an angular velocity command by using a difference between the designated location and the robot, received from the distance calculator, and a predetermined distance that the robot is supposed to maintain from the designated location when following a predetermined trajectory, such that the robot returns to the predetermined trajectory.

30. The apparatus of claim 28, wherein the travel controller receives a calculated distance R_m between the designated location and the robot from the distance calculator, compares a calculated distance R with the distance R_m that the robot is to maintain from the designated location at a predetermined location, and shifts an angular velocity w(t) of the robot based on whether or not R_m is larger than R.

31. The apparatus of claim 29, wherein if the robot senses an obstacle at a predetermined point during the traveling trajectory, the robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is not less than the set distance, the robot rotationally travels, maintaining a distance from the designated location equal to the set distance plus a distance between the designated location and the robot at the predetermined point where the obstacle had been sensed.

32. The apparatus of claim 28, wherein if the robot senses an obstacle at a predetermined point during the traveling trajectory, the robot travels as much as a predetermined distance along the obstacle, and if the predetermined distance is less than the set distance, the robot is controlled to travel along the obstacle until it arrives at a point where a distance between the designated location and the robot is the same as a distance between the designated location and the robot at the predetermined point where the obstacle has been sensed and then rotationally travels maintaining a distance between the designated location and the robot.

33. The apparatus of claim 28, further comprising:

a time synchronization signal transmitter located at the designated location and generating and transmitting a time synchronization signal; and

a time synchronization signal receptor included in the robot and receiving the time synchronization signal.

34. The apparatus of claim 28, further comprising:

a first timer located at the designated location and generating a timing signal with which the sound wave is transmitted to the robot in synchronization; and

a second timer located in the robot and generating the same timing signal as that provided from the first timer.

35. The apparatus of claim 28, wherein the sound wave is an ultrasonic wave.

36. The apparatus of claim 33, wherein the time synchronization signal is one of an infrared signal and a radio frequency signal.

37. The apparatus of claim 28, wherein the sound wave receptor included in the robot is an all-directional sound wave sensor.