Plurality of autonomous mobile robots and controlling method for the same

1. A plurality of autonomous mobile robots, comprising:

a first mobile robot having an antenna configured to transmit and receive a signal; and

a second mobile robot having a first antenna and a second antenna disposed on a front area of a main body thereof, the first antenna and the second antenna being configured to transmit and receive signals to and from the antenna of the first mobile robot, and

wherein the second mobile robot comprises a control unit configured to determine a relative position of the first mobile robot using the signal received by the first antenna and the second antenna,

wherein the control unit of the second mobile robot is configured to:

determine a first distance between the antenna of the first mobile robot and the first antenna, based on the signal transmitted and received through the antenna of the first mobile robot and the first antenna of the second mobile robot,

determine a second distance between the antenna of the first mobile robot and the second antenna, based on the signal transmitted and received through the antenna of the first mobile robot and the second antenna of the second mobile robot, and

determine two intersections between a first circle and a second circle,

wherein a radius of the first circle corresponds to the first distance, and a center of the first circle corresponds to the first antenna, and

wherein a radius of the second circle corresponds to the second distance, and a center of the second circle corresponds to the second antenna.

2. The robots of claim 1 , wherein the first antenna and the second antenna are disposed to be symmetric to each other in right and left directions with respect to the front area of the main body.

3. The robots of claim 1 , wherein the first antenna and the second antenna are configured to receive signals transmitted in directions except for a direction traveling from the front area of the main body through the main body.

4. The robots of claim 1 , wherein an intensity of the signal received in the first antenna or the second antenna is reduced when the signal is received through the main body.

5. The robots of claim 1 , wherein an intensity of the signal received in the first antenna and the second antenna without passing through the main body after being output from the antenna of the first mobile robot is stronger than an intensity of the signal received in the first antenna and the second antenna through the main body after being output from the antenna of the first mobile robot.

6. The robots of claim 1 , wherein the control unit of the second mobile robot is configured to:

output a first signal to the first mobile robot through at least one of the first antenna or the second antenna;

receive a second signal output from the antenna of the first mobile robot in each of the first antenna and the second antenna, and

determine a first distance between the antenna of the first mobile robot and the first antenna and a second distance between the antenna of the first mobile robot and the second antenna when the second signal is received in each of the first antenna and the second antenna.

7. The robots of claim 1 , wherein the control unit of the second mobile robot is configured to determine the relative position of the first mobile robot based on an intensity of the signal received through the first antenna and the second antenna.

8. The robots of claim 7 , wherein the control unit of the second mobile robot is configured to:

determine two intersections between a first circle and a second circle,

wherein a radius of the first circle corresponds to a first distance between the antenna of the first mobile robot and the first antenna, and a center of the first circle corresponds to the first antenna, and

wherein a radius of the second circle corresponds to a second distance between the antenna of the first mobile robot and the second antenna, and a center of the second circle corresponds to the second antenna, and

determine an intersection located at a front of the second mobile robot of the two intersections as the relative position of the first mobile robot when the intensity of the signal received through the first antenna and the second antenna is equal to or greater than a reference value.

9. The robots of claim 8 , wherein the control unit of the second mobile robot is configured to determine an intersection located at a rear of the second mobile robot of the two intersections as the relative position of the first mobile robot when the intensity of the signal received through the first antenna and the second antenna is smaller than the reference value.

10. The robots of claim 1 , wherein the control unit of the second mobile robot is configured to determine a position of the antenna of the first mobile robot as the relative position of the first mobile robot.

11. The robots of claim 1 , wherein the first mobile robot comprises an Ultra-Wideband (UWB) tag to transmit and receive a UWB signal, and

wherein the antenna of the first mobile robot is electrically connected to the UWB tag.

12. The robots of claim 1 , wherein the second mobile robot comprises an Ultra-Wideband (UWB) anchor to transmit and receive a UWB signal, and

wherein the first antenna and the second antenna of the second mobile robot are electrically connected to the UWB anchor.

13. The robots of claim 1 , wherein the control unit of the second mobile robot is configured to determine an arrangement state of the first mobile robot and the second mobile robot based on an intensity of the signal received through the first antenna and the second antenna.

14. The robots of claim 1 , wherein the control unit of the second mobile robot is configured to determine a direction in which the first mobile robot is located with respect to a front of the second mobile robot, based on a phase difference of the signal received through the first antenna and the second antenna.

15. The robots of claim 1 , wherein the second mobile robot comprises:

a first Ultra-Wideband (UWB) anchor connected to the first antenna; and

a second UWB anchor connected to the second antenna,

wherein the control unit of the second mobile robot is configured to determine a direction in which the first mobile robot is located with respect to a front of the second mobile robot, based on a phase difference between a signal received by the first UWB anchor through the first antenna and a signal received by the second UWB anchor through the second antenna.

16. The robots of claim 15 , wherein the control unit of the second mobile robot is configured to:

calculate a distance to the first mobile robot, based on signals transmitted and received through at least one of the antenna of the first mobile robot, the first antenna of the second mobile robot, or the second antenna of the second mobile robot, and

determine the relative position of the first mobile robot based on the calculated distance and the direction.

17. A method for controlling a mobile robot, the method comprising:

determining, by a control unit of a mobile robot, a first distance between an antenna of the first mobile robot and a first antenna of the second mobile robot and a second distance between the antenna of the first mobile robot and a second antenna of the second mobile robot, respectively, when a signal is received through the first antenna and the second antenna of the second mobile robot;

determining, by the control unit, two intersections between a first circle and a second circle, the first circle having the first distance as a radius and the second circle having the second distance as a radius; and

determining, by the control unit, one of the two intersections as a relative position of the first mobile robot based on an intensity of the signal received in the first antenna and the second antenna.