Radar-based target tracking using motion detection

Patent metadata

Field	Value
Publication number	US-11567185-B2
Application number	US-202016866854-A
Country	US
Kind code	B2
Filing date	May 5, 2020
Priority date	May 5, 2020
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

In an embodiment, a method includes: receiving reflected radar signals with a millimeter-wave radar; performing a range discrete Fourier Transform (DFT) based on the reflected radar signals to generate in-phase (I) and quadrature (Q) signals for each range bin of a plurality of range bins; for each range bin of the plurality of range bins, determining a respective strength value based on changes of respective I and Q signals over time; performing a peak search across the plurality of range bins based on the respective strength values of each of the plurality of range bins to identify a peak range bin; and associating a target to the identified peak range bin.

First claim

What is claimed is:

1. A method comprising:
receiving reflected radar signals with a millimeter-wave radar;
performing a range discrete Fourier Transform (DFT) based on the reflected radar signals to generate in-phase (I) and quadrature (Q) signals for each range bin of a plurality of range bins;

for each range bin of the plurality of range bins,
determining a respective short-term movement (STM) strength value based on changes of respective I and Q signals over a single frame, and
determining a respective long-term movement (LTM) strength value based on changes of respective I and Q signals over a plurality of frames;

performing a peak search across the plurality of range bins based on the respective STM strength values of each of the plurality of range bins to identify a peak STM range bin;
performing a peak search across the plurality of range bins based on the respective LTM strength values of each of the plurality of range bins to identify a peak LTM range bin;
associating a target to an identified peak range bin, wherein the identified peak range bin corresponds to the peak STM range bin or to the peak LTM range bin; and
assigning a state to the target from a set of states, wherein the set of states comprises a moving state indicative of movement of the target, a static state indicative of lack of movement of the target, and an unsure state indicative of a state different from the static state and the moving state, wherein, when the target is in the unsure state, the target transitions from the unsure state to the moving state when the identified peak range bin corresponds to the peak STM range bin, and the target transitions from the unsure state to the static state when the identified peak range bin corresponds to the peak LTM range bin and does not correspond to the peak STM range bin.

2. The method of claim 1 , wherein the target never transitions directly from the moving state to the static state.

3. The method of claim 1 , wherein determining the respective STM strength values for each range bin based on changes of the respective I and Q signals over the single frame comprises determining the respective STM strength values for each range bin based on

∑

c
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1

PN
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1

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R

r
,

c
+
1

-

R

r
,
c

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wherein PN represents a number of chirps per frame, R r,c+1 represents a value of range bin R r for chirp c+1, and R r,c represents a value of range bin R r for chirp c.

4. The method of claim 1 , wherein the target never transitions directly from the static state to the moving state.

5. The method of claim 1 , wherein determining the respective LTM strength values for each range bin based on changes of the respective I and Q signals over the plurality of frames comprises determining the respective LTM strength values for each range bin based on

∑

w
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1

W
-
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R

r
,
i
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r
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wherein W represents a number of frames, R r,i,w+1 represents a value of range bin R r for chirp i of frame w+1, and R r,i,w represents a value of range bin R r for chirp i of frame w.

6. The method of claim 1 , wherein determining the respective STM or LTM strength value for each range bin based on changes of the respective I and Q signals over the plurality of frames comprises determining the respective strength values for each range bin based on changes of the respective I and Q signals corresponding to a first chirp of each of the plurality of frames.

7. The method of claim 6 , wherein determining the respective STM or LTM strength values for each range bin based on changes of the respective I and Q signals corresponding to the first chirp of each of the plurality of frames comprises determining the respective STM or LTM strength values for each range bin based on

∑

ω
=
1

W
-
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R

r
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R

r
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ω

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wherein W represents a number of frames, R r,1,w+1 represents a value of range bin R r for chirp 1 of frame w+1, and R r,1,w represents a value of range bin R r for chirp 1 of frame w.

8. The method of claim 6 , wherein each of the plurality of frames comprises at most a single chirp, the method further comprising:
determining a velocity of the target; and
associating a peak to the target when the determined velocity is higher than a predetermined velocity threshold.

9. The method of claim 1 , further comprising:
tracking the target with a track;
settin

Assignees

• Infineon Technologies Ag

Inventors

• Will Christoph

Classifications

• G01S7/352

  Receivers · CPC title

• G01S13/584

  adapted for simultaneous range and velocity measurements · CPC title

• G01S7/358

  using I/Q processing · CPC title

• G01S13/726 Primary

  Multiple target tracking · CPC title

• G01S13/64

  Velocity measuring systems using range gates · CPC title