Method of tracking an object

Patent metadata

Field	Value
Publication number	US-2019107615-A1
Application number	US-201715726082-A
Country	US
Kind code	A1
Filing date	Oct 5, 2017
Priority date	Oct 5, 2017
Publication date	Apr 11, 2019
Grant date	—

Abstract

A method of tracking an object includes establishing a track from a plurality of sequential Doppler radar frames f−1, f−2, f−3, etc. A location of a representative centroid of a cluster of data points is identified in a Doppler radar frame f. A radial velocity between a location of the track in the Doppler radar frame f−1 and the location of the representative centroid of the cluster in the Doppler radar frame f is calculated. An error between a Doppler velocity of the track in the Doppler radar frame f−1 and the calculated radial velocity is calculated. When the calculated error is less than a minimum error threshold, the representative centroid of the cluster in the Doppler radar frame f is associated with the track.

First claim

What is claimed is:

1 . A method of tracking an object, the method comprising:
establishing a track, with a computing unit, from a plurality of sequential Doppler radar frames f−1, f−2, f−3, etc.; identifying a location of a representative centroid of a cluster of data points in a Doppler radar frame f, with the computing unit; calculating a radial velocity, with the computing unit, between a location of the track in the Doppler radar frame f−1 and the location of the representative centroid of the cluster in the Doppler radar frame f; calculating an error, with the computing unit, between a Doppler velocity of the track in the Doppler radar frame f−1 and the calculated radial velocity; comparing the calculated error to a minimum error threshold, with the computing unit, to determine if the calculated error is equal to or greater than the minimum error threshold, or if the calculated error is less than the minimum error threshold; and associating the representative centroid of the cluster in the Doppler radar frame f with the track, with the computing unit, when the calculated error is less than the minimum error threshold.

2 . The method set forth in claim 1 , wherein identifying the location of the representative centroid of the cluster includes identifying Cartesian coordinates and a Doppler velocity for the representative centroid.

3 . The method set forth in claim 1 , wherein establishing the track from the plurality of sequential Doppler radar frames f−1, f−2, f−3, etc., includes identifying a location of the track in each of the respective Doppler radar frames f−1, f−2, f−3, etc., wherein the location of the track in each respective Doppler radar frame includes Cartesian coordinates and a Doppler velocity.

4 . The method set forth in claim 1 , wherein calculating the radial velocity includes calculating an X-axis velocity, a Y-axis velocity, and a Z-axis velocity.

5 . The method set forth in claim 4 , wherein:
the X-axis velocity is calculated from the equation:

x
.

=

(

x
c

-

x
t

)

Δ



T

;

the Y-axis velocity is calculated from the equation:

y
.

=

(

y
c

-

y
t

)

Δ



T

;

the Z-axis velocity is calculated from the equation:

z
.

=

(

z
c

-

z
t

)

Δ



T

;

wherein {dot over (x)} is the X-axis velocity, x c is the X-axis coordinate of the representative centroid in the Doppler radar frame f, x t is the X-axis coordinate of the track in the Doppler radar frame f−1, {dot over (y)} is the Y-axis velocity, y c is the Y-axis coordinate of the representative centroid in the Doppler radar frame f, y t is the Y-axis coordinate of the track in the Doppler radar frame f−1, ż is the Z-axis velocity, z c is the Z-axis coordinate of the representative centroid in the Doppler radar frame f, and z t is the Z-axis coordinate of the track in the Doppler radar frame f−1.

6 . The method set forth in claim 4 , wherein calculating the radial velocity includes calculating the radial velocity from the equation:

v
^

=

x
t



x
.

+

y
t



y
.

+

z
t



z
.

x
t
2

+

y
t
2

+

z
t
2

wherein {circumflex over (v)} is the radial velocity, {dot over (x)} is the X-axis velocity, {dot over (y)} is the Y-axis velocity, ż is the Z-axis velocity, x c is the X-axis coordinate of the representative centroid in the Doppler radar frame f, y c is the Y-axis coordinate of the representative centroid in the Doppler radar frame f, z c is the Z-axis coordinate of the representative centroid in the Doppler radar frame f, x t is the X-axis coordinate of the track in the Doppler radar frame f−1, y t is the Y-axis coordinate of the track in the Doppler radar frame f−1, and z t is the Z-axis coordinate of the track in the Doppler radar frame f−1.

7 . The method set forth in claim 1 , wherein calculating the error includes calculating the error from the equation:
ε tc =∥d t −{circumflex over (v)} ∥

wherein ε tc

Assignees

• Gm Global Tech Operations Llc

Inventors

• Eljarat Ishai
• Barkan Gonen
• Bilik Igal

Classifications

• G01S2007/4095

  Physics · mapped topic

• G01S13/505

  using Doppler effect for determining closest range to a target or corresponding time, e.g. miss-distance indicator · CPC title

• G01S13/581

  using transmission of interrupted pulse modulated waves and based upon the Doppler effect resulting from movement of targets · CPC title

• G01S13/60 Primary

  wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track (G01S13/64 takes precedence) · CPC title

• G01S13/58 Primary

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