Ranging and angle of arrival antenna system for a mobile robot

• US 10,459,063 B2
• Filed: 02/16/2017
• Issued: 10/29/2019
• Est. Priority Date: 02/16/2016
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Sponsoring Entity: iRobot Corporation
• Inventors: Dube, Heath, Doughty, Brian, Shamlian, Steven, Lenser, Scott, Steltz, Erik
• Primary Examiner(s): Nguyen, Khai M
• APPLICATION: US 20170234961A1
• Time in patent office: 985 Days
• CPC Class Codes: G01S 1/68 Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information
• CPC Class Codes: G01S 3/023 Monitoring or calibrating
• CPC Class Codes: G01S 3/48 the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical, radial radar indicators providing co-ordinated display of direction and distance G01S7/10
• CPC Class Codes: H01Q 1/084 Pivotable antennas
• CPC Class Codes: H01Q 3/08 for varying two co-ordinates of the orientation
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A mobile robot includes a chassis, a shell moveably mounted on the chassis, and a cutting assembly mounted to the chassis. The mobile robot also includes a communication system that includes an antenna module disposed on a rear portion of the mobile robot. The antenna module includes a base assembly, and an antenna assembly mounted to the base assembly by a spring. The antenna assembly includes a ranging antenna, and at least three angle antennas arranged axisymmetrically about the ranging antenna, such that the ranging antenna and the three angle antennas define a tetrahedral geometry for determining an angle of arrival for one or more incident signals.

Claims

1. A mobile robot comprising:

a chassis;

a shell moveably mounted on the chassis;

a cutting assembly mounted to the chassis; and

a communication system comprising;

an antenna module disposed on a rear portion of the mobile robot, the antenna module comprising;

a base assembly; and

an antenna assembly mounted to the base assembly by a spring, the antenna assembly comprising;

a ranging antenna; and

at least three angle antennas arranged axisymmetrically about the ranging antenna, such that the ranging antenna and the at least three angle antennas define a tetrahedral geometry for determining an angle of arrival for one or more incident signals.

2. The mobile robot of claim 1, wherein each pair of the at least three angle antennas is separated by less than one half wavelength of the one or more incident signals.

3. The mobile robot of claim 1, wherein the ranging antenna and each of the at least three angle antennas is separated by less than one half wavelength of the one or more incident signals.

4. The mobile robot of claim 1, wherein a top of the antenna assembly is positioned at a height of at least 400 mm.

5. The mobile robot of claim 1, wherein the spring is preloaded.

6. The mobile robot of claim 1, wherein the one or more incident signals have a frequency between 5925 MHz and 7250 MHz.

7. The mobile robot of claim 1, wherein the angle of arrival is calibrated using parameters determined from the ranging antenna and the at least three angle antennas.

8. A system comprising:

a network of devices; and

a mobile robot, comprising;

a chassis;

a shell moveably mounted on the chassis;

a cutting assembly mounted to the chassis; and

a communication system comprising;

an antenna module disposed on a rear portion of the mobile robot, the antenna module comprising;

a base assembly; and

an antenna assembly mounted to the base assembly by a spring, the antenna assembly comprising;

 

a ranging antenna; and

 

at least three angle antennas arranged axisymmetrically about the ranging antenna, such that the ranging antenna and the at least three angle antennas define a tetrahedral geometry for determining an angle of arrival for one or more incident signals.

9. The system of claim 8, wherein the network of devices comprises at least one of a beacon, a set of beacons, a server, and a user device.

10. The system of claim 8, wherein the one or more incident signals have a frequency between 5925 MHz and 7250 MHz.

11. The system of claim 8, wherein each pair of two of the at least three angle antennas is separated by less than one half wavelength of the one or more incident signals.

12. The system of claim 8, wherein the ranging antenna and each of the at least three angle antennas is separated by less than one half wavelength of the one or more incident signals.

13. The system of claim 8, wherein a top of the antenna assembly is positioned at a height of at least 400 mm.

14. The system of claim 8, wherein the spring is preloaded.

15. The system of claim 8, wherein the angle of arrival is calibrated using parameters determined from the ranging antenna and the at least three angle antennas.

16. The system of claim 8, wherein a separation distance between each pair of the at least three angle antennas is between 0.5 and 1.5 centimeters.

17. The system of claim 8, wherein the at least three angle antennas form a base of the tetrahedral geometry.

18. The system of claim 8, wherein the ranging antenna is configured to measure a distance between the mobile robot and a device of the network of devices.

19. The system of claim 8, wherein the antenna assembly comprises a housing containing the ranging antenna and the at least three angle antennas, and the spring is disposed below the housing of the antenna assembly.

20. The system of claim 8, wherein the antenna assembly comprises a light indicator to provide an alert to a user.