System, device and methods for localization and orientation of a radio frequency antenna array

• US 10,288,728 B2
• Filed: 05/01/2016
• Issued: 05/14/2019
• Est. Priority Date: 04/29/2015
• Status: Active Grant

• Current Assignee: Vayyar Imaging Ltd.
• Original Assignee: Vayyar Imaging Ltd.
• Inventors: Lomnitz, Yuval, Hoffman, Damian, Shayovitz, Shachar
• Primary Examiner(s): Bythrow, Peter M
• Application Number:
  US15/569,836
• Publication Number:
  US 20180128915A1
• Time in Patent Office: 1,108 Days
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 13/9005 with optical processing of the SAR signals
• CPC Class Codes: G01S 13/9029 specially adapted for moving target detection within a single SAR image or within multiple SAR images taken at the same time
• CPC Class Codes: G01S 13/904 SAR modes
• CPC Class Codes: H01Q 3/34 by electrical means active lenses or reflecting arrays H01Q3/46

Abstract

The methods and device disclosed herein provide an array such as a Radio Frequency (FR) antenna array for measuring the array movement or displacement of the array relative to a reference location. In some cases the array may be attached to or in communication with the device. The array comprises at least two transducers (e.g. RF antennas), wherein at least one of the at least two transducers is configured to transmit a signal towards the object, and at least one transceiver attached to said at least two transducers, the at least one transceiver is configured to repetitively transmit at least one signal toward an object and receive a plurality of signals affected or reflected while the array is moved in proximity to the object/medium or scene; and at least one processor unit, configured to: process the affected signals to yield a plurality of signal measurements and compare said signal measurements obtained at different locations over time of said second object and calculate a movement of the object relative to a reference location.

Claims

1. A device for measuring a movement of the device relative to a reference location, the device comprising:

an array, the array comprises at least three transducers, wherein at least one of said at least three transducers is configured to transmit a signal towards an object, and at least one transceiver attached to said at least three transducers, the at least one transceiver is configured to repetitively transmit at least one signal toward the object and receive a plurality of signals affected by the object while the array is moved in proximity to the object;

a data acquisition unit configured to receive and store said plurality of affected signals; and

at least one processor unit, said at least one processor unit is configured to;

process said affected signals to yield a plurality of signal measurements, said plurality of signal measurements comprise a plurality of transfer functions of said array wherein each of said plurality of transfer functions comprise said object response between a couple of transducers of said at least three transducers as function of frequency or time and wherein the at least one processor unit is configured to estimate said device movement trajectory x(t) or x(t), y(t) relative to the first reference location of said device;

compare said signal measurements obtained at different locations over time of said device and calculate a movement of the device relative to a reference location, wherein said movement comprises displacement trajectory x(t) or x(t), y(t) of said device with respect to said object and wherein said comparing signal measurements further comprises comparing a first set of signal measurements of said plurality of signal measurements received by a first couple of transducers of said array to a second set of signal measurement of said plurality of signal measurements received by a second couple of transducers of said array and retrieve said device movement distance on said object in respect to the reference location;

find a plurality of displacements delta (Δ

=Δ

_x, Δ

_y) of said device such that there exist two ordered sets of transducers pairs in the array, a first set of transducers pairs (L) and a second set of transducers pairs (R), such that all transducers pairs in said first set of transducers pairs are shifted by one of said plurality of displacements delta (Δ

) compared to a respective transducers pairs in said second set of transducers pairs;

compare transfer functions taken at each location at said object to transfer functions taken at other locations using a comparison metric and producing one or more comparison matrices D_Δ

(T₁, T₂) wherein each snapshot of recorded signals is compared to each other snapshot;

calculate log-likelihood functions for each displacement over a plurality of combinations of T₁, T₂, Δ

wherein the log-likelihood is the distance x(T₁)−

x(T₂) between the measurements taken at T₁, T₂ times is Δ

+d is determined as function of D_Δ

(T₁, T₂); and

calculate a log-likelihood of each trajectory using a movement model.

2. The device of claim 1, comprising combining each of said displacement with side information from an accelerometer, said accelerometer is in communication with said array.

3. The device of claim 2, comprising calculating the displacement trajectory x(t), or x(t) and y(t) in two dimensions from the set of at least one matrix D_Δ

(T₁, T₂).

4. The device of claim 3, wherein estimating the movement trajectory of said device further comprises estimating a two dimensional location x(t),y(t) and array rotation θ

(t).

5. The device of claim 1, comprising:

providing an interpolator said interpolator is configured to estimate from a first plurality of recorded transfer functions a second plurality of transfer functions, that would be obtained had the displacement and rotation changed by Δ

X, Δ

Y, Δ

θ

.

6. The device of claim 1, comprising:

providing an estimator for shift between measurement, said estimator is configured to compare a first set of transfer functions of said transfer functions recorded at a current snapshot, to a second set of transfer functions of said transfer functions recorded at a previous snapshot, after interpolating by the change Δ

X, Δ

Y, Δ

θ

, and finding the displacement and rotation Δ

X, Δ

Y, Δ

θ

for which best fit of the first set of transfer functions and the second set of transfer functions is obtained; and

providing an integrator configured to integrate the changes Δ

X, Δ

Y, Δ

θ

from snapshot to snapshot to obtain a complete trajectory x(t), y(t) θ

(t).

7. The device of claim 1, wherein for each of said plurality of displacements delta (Δ

) a matrix D_Δ

(T₁, T₂) is provided, said matrix comprising for each pair of said snapshots (T1,T2) a comparison result;

D_Δ

(T₁, T₂)=μ

({S_ij(T₁),S<sub>i′

j′</sub>

(T₂)}<sub>(i,j)∈

L(Δ

),(i′

,j′

)∈

R(Δ

)</sub>),

where μ

is a metric.

8. The device of claim 7, wherein the metric μ

is;

9. The device of claim 8, wherein the said log-likelihood function for the displacement in step c is:

10. The device of claim 1, wherein said array is a radio frequency (RF) antenna array and said at least three transducers are RF antennas.

13. The device of claim 1, wherein the transducers are antennas.

11. A device for measuring a movement of the device relative to a reference location, the device comprising

an array, the array comprises at least three transducers, wherein at least one transducer of said at least three transducers is configured to transmit a signal towards an object, and at least one transceiver attached to said at least three transducers, the at least one transceiver is configured to repetitively transmit at least one signal toward the object and receive a plurality of signals affected by the object while the array is moved in proximity to the object;

a data acquisition unit configured to receive and store said plurality of affected signals; and

at least one processor unit, said at least one processor unit is configured to;

process said affected signals to yield a plurality of signal measurements, wherein said plurality of signal measurements comprise a plurality of transfer functions of said array;

compare said signal measurements obtained at different locations over time of said device and calculate a movement of the device relative to a reference location, wherein said movement comprises displacement trajectory x(t) or x(t), y(t) of said device with respect to said object and wherein said comparing signal measurements further comprises comparing a first set of signal measurements of said plurality of signal measurements received by a first couple of transducers of said array to a second set of signal measurement of said plurality of signal measurements received by a second couple of transducers of said array and retrieve said device movement distance on said object in respect to the reference location; and

provide an interpolator said interpolator is configured to estimate from a first plurality of recorded transfer functions a second plurality of transfer functions, that would be obtained had the displacement and rotation changed by Δ

X, Δ

Y, Δ

θ

.

14. The device of claim 11, wherein the transducers are antennas.

12. A device for measuring a movement of the device relative to a reference location, the device comprising:

an array, the array comprises at least three transducers, wherein at least one of said at least three transducers is configured to transmit a signal towards an object, and at least one transceiver attached to said at least three transducers, the at least one transceiver is configured to repetitively transmit at least one signal toward the object and receive a plurality of signals affected by the object while the array is moved in proximity to the object;

a data acquisition unit configured to receive and store said plurality of affected signals; and

at least one processor unit, said at least one processor unit is configured to;

process said affected signals to yield a plurality of signal measurements, wherein said plurality of signal measurements comprise a plurality of transfer functions of said array, and compare said signal measurements obtained at different locations over time of said device and calculate a movement of the device relative to a reference location, wherein said movement comprises displacement trajectory x(t) or x(r), (t) of said device with respect to said object and wherein said comparing signal measurements further comprises comparing a first set of signal measurements of said plurality of signal measurements received by a first couple of transducers of said array to a second set of signal measurement of said plurality of signal measurements received by a second couple of transducers of said array and retrieve said device movement distance on said object in respect to the reference location;

provide an estimator for shift between measurement, said estimator is configured to compare a first set of transfer functions of said transfer functions recorded at a current snapshot, to a second set of transfer functions of said transfer functions recorded at a previous snapshot, after interpolating by the change Δ

X, Δ

Y, Δ

θ

, and finding the displacement and rotation Δ

X, Δ

Y, Δ

θ

for which best fit of the first set of transfer functions and the second set of transfer functions is obtained ;

and

provide an integrator configured to integrate the changes Δ

X, Δ

Y, Δ

θ

from snapshot to snapshot to obtain a complete trajectory x(t),y(t) θ

(t).

15. The device of claim 12, wherein the transducers are antennas.