Detecting presence, size, and direction of motion of an object using radio-frequency techniques

Patent metadata

Field	Value
Publication number	US-2016377703-A1
Application number	US-201514746902-A
Country	US
Kind code	A1
Filing date	Jun 23, 2015
Priority date	Jun 23, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

Various embodiments transmit a radio-frequency (“RF”) beam using two or more RF antennas of a mobile device, e.g. a mobile phone. The RF signals that make up the RF beam are selected to create an emission pattern associated with object detection. Some of the RF antennas can be multi-purpose, where in addition to transmitting the RF beam, the antennas are used for RF communications. Upon receiving a reflected radiation pattern of the RF beam from an object, the reflected radiation pattern is analyzed to identify characteristics of the object. Depending upon what characteristics have been identified, one or more actions can be automatically performed.

First claim

We claim:

1 . An object-detection method comprising:
transmitting, using a mobile device, a radio-frequency (“RF”) beam using at least two antennas of the mobile device, at least one of the antennas being re-purposed from a primary purpose to a secondary purpose associated with object detection; receiving, using the mobile device, a reflected radiation signal from an object, the reflected radiation signal based, at least in part, on the RF beam; processing, using the mobile device, the reflected radiation signal effective to determine a characteristic of the object; and automatically executing, using the mobile device, an action based on the determined characteristic.

2 . The object-detection method of claim 1 wherein transmitting the RF beam further comprises generating the RF beam with an emission pattern that is based, at least in part, on an object to be detected.

3 . The object-detection method of claim 2 wherein the emission pattern comprises at least two interference lines.

4 . The object-detection method of claim 1 wherein the characteristic comprises a velocity associated with the object.

5 . The object-detection method of claim 1 wherein the action comprises an action associated with a power-saving mode.

6 . The object-detection method of claim 1 wherein the at least one antenna being re-purposed for the RF beam comprises an antenna associated with wireless local area network communications.

7 . The object-detection method of claim 1 wherein receiving the reflected radiation signal further comprises receiving the reflected radiation signal using an antenna temporarily re-purposed from a primary function to receive the reflected radiation signal.

8 . A mobile device comprising:
at least two radio-frequency (“RF”) antennas; a processor; and a computer-readable memory storage device comprising processor-executable instructions which, responsive to execution by the processor, implement, at least in part:
a beam-former module configured to enable the mobile device to:
determine an emission pattern for an RF beam based, at least in part, on an object that is to be detected;
re-purpose an antenna of the at least two RF antennas to transmit the RF beam; and
re-purpose an antenna of the at least two RF antennas to receive a radiation pattern reflected off the object; and

a signal-analysis module configured to enable the mobile device to:
analyze the received radiation pattern effective to determine a characteristic associated with the object; and
determine when to automatically execute an action based, at least in part, on the determined characteristic associated with the object.

9 . The mobile device of claim 8 wherein the characteristic associated with the object comprises a proximity of the object to the mobile device.

10 . The mobile device of claim 8 wherein the beam-former module is further configured to enable the mobile device to:
transmit the RF beam via at least two RF antennas in bursts.

11 . The mobile device of claim 10 wherein the beam-former module is further configured to enable the mobile device to:
rotate transmission of the RF beam through at least two RF antennas.

12 . The mobile device of claim 8 further configured to automatically transition into a power-saving mode when it is determined that the object has left a region of transmission associated with the mobile device.

13 . The mobile device of claim 8 wherein the at least two antennas are selected from a group of antennas comprising:
a main transmit antenna purposed for cellular communications,
a main receive antenna purposed for cellular communications,
a wireless local area network (“Wi-Fi”) antenna purposed for Wi-Fi communications,
a Bluetooth antenna purposed for Bluetooth communications, and
a diversity antenna purposed for multi-path improvement.

14 . The mobile device of claim 8 wherein the emission pattern comprises an isotropic shape.

15 . An object-detection method comprising:
determining, using a mobile device, a first emission pattern for a first radio-frequency (“RF”) beam, the emission pattern based, at least in part, on an object to be detected via the first RF beam; transmitting, using the mobile device, the first RF beam using at least two RF antennas of the mobile device; receiving, using the mobile device, a reflected radiation signal from the object, the reflected radiation signal based, at least in part, on the first RF beam; and processing, using the mobile device, the reflected radiation signal effective to determine a characteristic associated with the object.

16 . The object-detection method of claim 15 wherein determining the first emission pattern further comprises:
determining a respective frequency for each respective RF signal of the first RF beam based, at least in part, on resultant constructive and destructive interference in the first emission pattern.

17 . The object-detection method of claim 15 wherein determining the first emission pattern further comprises:
determining a respective frequency for each respective RF signal of the first RF beam based, at least in part, on a resultant Doppler Effect in the first emission pattern.

18 . The object-detection method of claim 15 further comprising:
responsive to processing the reflected radiation signal, determining, using the mobile device, a second emission pattern for a second RF beam, the second emission pattern configured to obtain more resolution with respect to the object than the first RF beam; and
transmitting, using the mobile device, the second RF beam using at least two RF antennas of the mobile device.

19 . The object-detection method of claim 15 wherein the at least two RF antennas are re-purposed from primary functions to transmit the first RF beam.

20 . The object-detection method of claim 15 wherein the object comprises a person.

Assignees

• Motorola Mobility Llc

Inventors

• Pais Martin R
• Aguilar Suzette Marie

Classifications

• G01S13/58

  Velocity or trajectory determination systems; Sense-of-movement determination systems · CPC title

• G01S7/411 Primary

  Identification of targets based on measurements of radar reflectivity (G01S7/415 takes precedence) · CPC title

• G01S13/04

  Systems determining presence of a target (based on relative movement of target G01S13/56) · CPC title