RF in-wall image registration using position indicating markers

• US 10,209,357 B2
• Filed: 04/28/2016
• Issued: 02/19/2019
• Est. Priority Date: 04/28/2016
• Status: Active Grant

• Current Assignee: Fluke Corporation (Fortive Corp.)
• Original Assignee: Fluke Corporation (Fortive Corp.)
• Inventors: Rhead, Jamie, Heydron, Paul H., Corrigan, Christopher D., Knight, Brian
• Primary Examiner(s): Bythrow, Peter M
• Application Number:
  US15/140,941
• Publication Number:
  US 20170315228A1
• Time in Patent Office: 1,027 Days
• Field of Search: 342 22
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 13/888 through wall detection
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 2013/468 by Triangulation, i.e. two antennas or two sensors determine separately the bearing, direction or angle to a target, whereby with the knowledge of the baseline length, the position data of the target is determined
• CPC Class Codes: G01S 7/24 the display being orientated or displaced in accordance with movement of object carrying the transmitting and receiving apparatus, e.g. true-motion radar
• CPC Class Codes: G01S 7/4026 Antenna boresight

Abstract

A radio frequency (RF) imaging device comprises an RF sensor assembly, a position sensor, a processor, and a memory. The RF sensor assembly receives an RF signal for capturing an RF image of a portion of a space behind a surface. The position sensor receives a plurality of signals respectively emitted by a plurality of position markers at known positions relative to the surface. The processor determines a plurality of angles at which the plurality of signals respectively arrive at the position sensor and determines, based on the plurality of angles and the known positions of the plurality of position markers, a position of the RF imaging device relative to the surface. The memory stores the RF image in association with the determined position of the RF imaging device. A time-of-flight or triangulation of signal data may be used for position determination.

Claims

1. A radio frequency (RF) imaging device comprising:

an RF sensor assembly configured to receive an RF signal for capturing an RF image of a portion of a space behind a wall;

a position sensor configured to receive a plurality of signals respectively emitted by a plurality of position markers removably affixed at known positions in a plane defined by the wall, a position marker of the plurality of position markers being removably affixed by at least one of;

an adhesive, a thumbtack, or a magnet;

a processor configured to determine a plurality of angles at which the plurality of signals respectively arrive at the position sensor and determine, based on the plurality of angles and the known positions in the plane defined by the wall of the plurality of position markers, a position of the RF imaging device relative to the wall; and

a memory configured to store the RF image in association with the determined position of the RF imaging device.

2. The RF imaging device of claim 1, wherein the RF sensor assembly captures a plurality of RF images, each RF image being captured while the RF imaging device is positioned relative to the wall at a respective plurality of positions that are different from each other, wherein each RF image is an image of a portion of the space behind the wall at the respective position of the RF imaging device, and wherein the memory stores each RF image in association with the position of the RF imaging device at which the RF image was captured.

3. The RF imaging device of claim 2, wherein the processor is configured to assemble a panoramic RF image of the space behind the wall based on the plurality of RF images.

4. The RF imaging device of claim 3, wherein the processor is configured to assemble the panoramic RF image by collating the plurality of RF images captured at the respective plurality of positions.

5. The RF imaging device of claim 1, further comprising a tilt sensor configured to determine an orientation of the RF sensor assembly at a time when the RF image is captured.

6. The RF imaging device of claim 5, wherein the orientation of the RF sensor specifies a rotation of the RF image about an axis in relation to a plane defined by the wall.

7. The RF imaging device of claim 6, wherein the processor is configured to assemble a panoramic RF image of the space behind the wall by:

collating a plurality of RF images captured at a respective plurality of positions on the wall; and

rotating one or more RF images in the plurality of RF images such that the RF images have an orientation that matches the orientation of other RF images of the plurality of RF images.

8. The RF imaging device of claim 1, wherein the position marker of the plurality of position markers includes an RF transmitter that transmits a signal of the plurality of RF signals to the position sensor.

9. The RF imaging device of claim 1, wherein:

the position marker of the plurality of position markers includes a passive transmitter; and

the RF imaging device further comprises a position marker activating circuit configured to transmit an activating signal that activates the passive transmitter and induces the transmitter of the position marker to emit a respective signal of the plurality of signals.

10. The RF imaging device of claim 9, wherein the position marker of the plurality of position markers is a radio frequency identification (RFID) tag.

11. The RF imaging device of claim 1, wherein the position sensor includes a plurality of antennas arranged in an array and having an intra-array spacing between the antennas.

12. A radio frequency (RF) imaging device, comprising:

an RF sensor assembly configured to emit an RF wave in a direction relative to a wall, sense a reflection of the RF wave from one or more objects in a space behind the wall, and capture reflection data representing the sensed reflection of the RF wave;

a position sensor configured to receive a plurality of signals respectively emitted by a plurality of position markers removably affixed at known positions in a plane defined by the wall, and capture signal data representing the plurality of signals as received, a position marker of the plurality of position markers being removably affixed by at least one of;

an adhesive, a thumbtack, or a magnet; and

a processor operatively coupled to the RF sensor assembly and the position sensor and configured to;

receive the reflection data representing the sensed reflection of the RF wave;

determine image data representing an RF image of the space behind the wall based on the received reflection data;

receive the signal data representing the plurality of signals;

determine a position of the position sensor with respect to the plurality of position markers based on the known positions in the plane defined by the wall of the plurality of position markers and triangulation of the signal data; and

associate the determined position of the position sensor with the image data representing the RF image of the space behind the wall.

13. The RF imaging device of claim 12, further comprising a memory configured to store the determined position with the RF image, wherein the determined position indicates a position on the wall at which the reflection data for RF image was captured.

14. The RF imaging device of claim 12, further comprising a communication interface configured to transmit the RF image and the associated determined position to a receiving device.

15. The RF imaging device of claim 12, wherein the position marker of the plurality of position markers includes an active transmitter having a power source, wherein the transmitter is configured to transmit a signal of the plurality of signals to the position sensor.

16. The RF imaging device of claim 12, wherein the position marker of the plurality of position markers includes a passive transmitter that is induced to transmit a signal of the plurality of signals in response to receiving an activating signal.

17. The RF imaging device of claim 16, further comprising a transmitter configured to transmit the activating signal to the passive transmitter.

18. The RF imaging device of claim 12, wherein the image data representing an RF image of the space behind the wall represents a three-dimensional (3D) RF image.

19. A system comprising:

a plurality of position markers removably affixed at different known locations in a plane defined by a wall configured to transmit a respective plurality of signals, a position marker of the plurality of position markers being removably affixed by at least one of;

an adhesive, a thumbtack, or a magnet; and

a radio frequency (RF) imaging device comprising;

a position sensor configured to receive the plurality of signals and capture signal data representing the plurality of signals as received;

an RF sensor assembly configured to emit an RF wave in a direction relative to the wall, sense a reflection of the RF wave from one or more objects in a space behind the wall, and capture reflection data representing the sensed reflection of the RF wave;

a processor operatively coupled to the RF sensor assembly and the position sensor and configured to;

receive the signal data representing the plurality of signals;

determine a time-of-flight for each of the plurality of signals from the respective position marker that transmitted the respective signal;

determine a position of the RF imaging device based at least in part on the known locations in the plane defined by the wall of the plurality of position markers and the time-of-flight for each of the plurality of signals;

receive the reflection data representing the sensed reflection of the RF wave;

determine an RF image of the space behind the wall based on the reflection data representing the sensed reflection of the RF wave; and

associate the RF image with the determined position of the RF imaging device.

20. The system of claim 19, wherein the time-of-flight for a signal of the plurality of signals is a length of time elapsed from transmission of the signal of the plurality of signals by a respective position marker to reception of the signal by the position sensor and wherein the time-of-flight is indicative of a distance between the respective position marker and the position sensor.