Autonomous Mobile Device and Method for Navigating the Same to a Base Station

• US 20130124031A1
• Filed: 08/07/2012
• Published: 05/16/2013
• Est. Priority Date: 11/14/2011
• Status: Active Grant

• Current Assignee: ASUSTek Computer, Inc.
• Original Assignee: Agait Technology Corporation
• Inventors: CHEN, Tien-Chen, LEE, Kai-Sheng, CHEN, Peng-Sheng
• Granted Patent: US 8,660,736 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027

Abstract

A method of navigating an autonomous mobile device to a base station is provided. In the method, when a detector detects a navigating signal sent out by the base station, the mobile device rotates in a first direction until the detector fails to detect the navigating signal, and a first time point is set at this time. Then, the mobile device rotates in a second direction opposite to the first direction until the detector fails to detect the navigating signal, and a second time point is set at this time. Afterward, the mobile device rotates in the first direction by a time computed based on the first and second time points to make the detector face the base station, and then, moves toward a direction pointed by the detector.

Claims

1. A method for navigating an autonomous mobile device to a base station that sends out a main navigating signal, the autonomous mobile device including a movable case, a main detector disposed on the case, and a control unit for controlling movement of the case, said method comprising the following steps of:

a) when the main detector detects the main navigating signal, configuring the control unit to rotate the case in a first direction until the main detector fails to detect the main navigating signal, and configuring the control unit to set a first time point when the main detector fails to detect the main navigating signal;

b) configuring the control unit to rotate the case in a second direction opposite to the first direction until the main detector fails to detect the main navigating signal, and configuring the control unit to set a second time point when the main detector fails to detect the main navigating signal;

c) configuring the control unit to compute a calibration time according to the first and second time points;

d) configuring the control unit to rotate the case in the first direction by the calibration time so as to make the main detector substantially point toward the base station; and

e) configuring the control unit to move the case toward a direction pointed by the main detector.

2. The method as claimed in claim 1, further comprising, after step e), the steps of:

configuring the control unit to determine whether the main detector detects the main navigating signal;

when it is determined that the main detector does not detect the main navigating signal, configuring the control unit to rotate the case until the main detector detects the main navigating signal; and

configuring the control unit to repeat step a) to c).

3. The method as claimed in claim 1, the autonomous mobile device further including a pair of side detectors fixedly disposed on the case at opposite positions angularly spaced apart from the main detector, said method further comprising, before step a), the steps of:

configuring the control unit to determine whether at least one of the main detector and the side detectors detects the main navigating signal; and

configuring the control unit to rotate the case until the main detector detects the main navigating signal.

4. The method as claimed in claim 1, the autonomous mobile device further including a first side detector disposed on the case at a first position angularly spaced apart from the main detector, the base station including a main transmitter sending out the main navigating signal that covers a main area and a first auxiliary transmitter sending out a first auxiliary navigating signal that covers a first side area at one of opposite sides of the main area, the first side detector and the first auxiliary transmitter being disposed at a same one of opposite sides of an imaginary line through the main detector and the main transmitter when the main detector faces the main transmitter,

wherein said method further comprises, before step a), the steps of:

configuring the control unit to determine whether at least one of the main detector and the first side detector detects the first auxiliary navigating signal;

when it is determined that at least one of the main detector and the first side detector detects the first navigating signal, configuring the control unit to rotate the case until the first side detector detects the first auxiliary navigating signal;

configuring the control unit to move the case toward the direction pointed by the main detector until the first side detector detects the main navigating signal; and

configuring the control unit to rotate the case until the main detector detects the main navigating signal.

5. The method as claimed in claim 4, the autonomous mobile device further including a second side detector disposed on the case at a second position opposite to the first side detector with respect to the main detector and angularly spaced apart from the main detector, the base station further including a second auxiliary transmitter sending out a second auxiliary navigating signal that covers a second side area at the other one of the opposite sides of the main area, the second side detector and the second auxiliary transmitter being disposed at the other one of the opposite sides of the imaginary line when the main detector faces the main transmitter,

wherein said method further comprises, before step a), the steps of:

configuring the control unit to determine whether at least one of the main detector, the first side detector and the second side detector detects the second auxiliary navigating signal;

when it is determined that at least one of the main detector, the first side detector and the second side detector detects the second navigating signal, configuring the control unit to rotate the case until the second side detector detects the second auxiliary navigating signal;

configuring the control unit to move the case toward the direction pointed by the main detector until the second side detector detects the main navigating signal; and

configuring the control unit to rotate the case until the main detector detects the main navigating signal.

6. The method as claimed in claim 5, the main navigating signal, the first auxiliary navigating signal and the second auxiliary navigating signal being coded using mutually distinct encoding modulations,

wherein the control unit is configured to determine which one of the main navigating signal, the first auxiliary navigating signal and the second auxiliary navigating signal is detected according to the respective encoding modulations.

7. The method as claimed in claim 1, wherein, in step c), the control unit is configured to compute the calibration time as a half value of a time difference between the first and second time points.

8. An autonomous mobile device capable of docking on a base station that sends out a main navigating signal, said autonomous mobile device comprising:

a movable case;

a main detector disposed on said case; and

a control unit for controlling movement of said case, and operable to implement a method for navigating said autonomous mobile device to the base station, the method including the following steps of

i) when said main detector detects the main navigating signal, rotating said case in a first direction until said main detector fails to detect the main navigating signal, and setting a first time point when said main detector fails to detect the main navigating signal,

ii) rotating said case in a second direction opposite to the first direction until the main detector fails to detect the main navigating signal, and setting a second time point when said main detector fails to detect the main navigating signal,

iii) computing a calibration time according to the first and second time points,

iv) rotating said case in the first direction by the calibration time so as to make said main detector substantially point toward the base station, and

v) moving said case toward a direction pointed by said main detector.

9. The autonomous mobile device as claimed in claim 8, wherein said control unit is further operable, after step v), to:

determine whether said main detector detects the main navigating signal;

when it is determined that said main detector does not detect the main navigating signal, rotate said case until said main detector detects the main navigating signal; and

repeat step i) to v).

10. The autonomous mobile device as claimed in claim 8, further comprising a pair of side detectors fixedly disposed on said case at opposite positions angularly spaced apart from said main detector,

wherein said control unit is further operable, before step i), to:

determine whether at least one of said main detector and said side detectors detects the main navigating signal; and

rotate the case until the main detector detects the main navigating signal.

11. The autonomous mobile device as claimed in claim 8, the base station including a main transmitter sending out the main navigating signal that covers a main area, and a first auxiliary transmitter sending out a first auxiliary navigating signal that covers a first side area at one of opposite sides of the main area,

wherein said autonomous mobile device further comprises a first side detector disposed on said case at a first position angularly spaced apart from said main detector, said first side detector and the first auxiliary transmitter to be disposed at a same one of opposite sides of an imaginary line through said main detector and the main transmitter when said main detector faces the main transmitter,

wherein said control unit is further operable, before step i), to

determine whether at least one of said main detector and said first side detector detects the first auxiliary navigating signal,

when it is determined that at least one of said main detector and said first side detector detects the first navigating signal, rotate said case until said first side detector detects the first auxiliary navigating signal,

move said case toward the direction pointed by said main detector until said first side detector detects the main navigating signal, and

rotate said case until said main detector detects the main navigating signal.

12. The autonomous mobile device as claimed in claim 11, the base station further including a second auxiliary transmitter sending out a second auxiliary navigating signal that covers a second side area at the other one of the opposite sides of the main area,

wherein said autonomous mobile device further comprises a second side detector disposed on said case at a second position opposite to said first side detector with respect to said main detector and angularly spaced apart from said main detector, said second side detector and the second auxiliary transmitter to be disposed at the other one of the opposite sides of the imaginary line when said main detector faces the main transmitter,

wherein said control unit is further operable, before step i), to:

determine whether at least one of said main detector, said first side detector and said second side detector detects the second auxiliary navigating signal,

when it is determined that at least one of said main detector, said first side detector and said second side detector detects the second navigating signal, rotate said case until said second side detector detects the second auxiliary navigating signal,

move said case toward the direction pointed by said main detector until said second side detector detects the main navigating signal, and

rotate said case until said main detector detects the main navigating signal.

13. The autonomous mobile device as claimed in claim 12, the main navigating signal, the first auxiliary navigating signal and the second auxiliary navigating signal being coded using mutually distinct encoding modulations,

wherein said control unit is operable to determine which one of the main navigating signal, the first auxiliary navigating signal and the second auxiliary navigating signal is detected according to the respective encoding modulations.

14. The autonomous mobile device as claimed in claim 8, wherein said control unit is operable to compute the calibration time as a half value of a time difference between the first and second time points.

15. A system comprising:

a base station for sending out a main navigating signal; and

an autonomous mobile device capable of docking on said base station, and including

a movable case,

a main detector disposed on said case, and

a control unit for controlling movement of said case, and operable to implement a method for navigating said autonomous mobile device to said base station, the method including the following steps of

A) when said main detector detects the main navigating signal, rotating said case in a first direction until said main detector fails to detect the main navigating signal, and setting a first time point when said main detector fails to detect the main navigating signal,

B) rotating said case in a second direction opposite to the first direction until the main detector fails to detect the main navigating signal, and setting a second time point when said main detector fails to detect the main navigating signal,

C) computing a calibration time according to the first and second time points,

D) rotating said case in the first direction by the calibration time so as to make said main detector substantially point toward said base station, and

E) moving said case toward a direction pointed by said main detector.