Information processing device, and information processing method
To obtain a speed expansion range. A speed detection apparatus includes: a transmission antenna array that transmits a plurality of chirp signals multiplexed between a plurality of transmission antennas arranged in a vertical direction; a reception antenna array that includes a plurality of reception antennas receiving the plurality of chirp signals that has been reflected; and a speed determination unit that calculates a plurality of speed candidates on the basis of the plurality of chirp signals received by the reception antenna array, determines whether or not a plurality of vertical arrival angle estimation values corresponding to the plurality of speed candidates falls within a vertical angle threshold range, and determines, as a true speed, one speed candidate from the plurality of speed candidates on the basis of a determination result.
1 . A speed detection apparatus, comprising:
a transmission antenna array that transmits a plurality of chirp signals multiplexed between a plurality of transmission antennas arranged in a vertical direction;
a reception antenna array that includes a plurality of reception antennas receiving the plurality of chirp signals that has been reflected; and
a speed determination unit that
calculates a plurality of speed candidates on a basis of the plurality of chirp signals received by the reception antenna array,
determines whether or not a plurality of vertical arrival angle estimation values corresponding to the plurality of speed candidates falls within a vertical angle threshold range, and
determines, as a true speed, one speed candidate from the plurality of speed candidates on a basis of a determination result.
2 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit determines, as the true speed, one speed candidate corresponding to one vertical arrival angle estimation value included in the vertical angle threshold range.
3 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit determines, as a true vertical arrival angle, one vertical arrival angle estimation value included in the vertical angle threshold range.
4 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit dynamically calculates the vertical angle threshold range on a basis of the number of and intervals between the plurality of transmission antennas that transmits the plurality of chirp signals.
5 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit dynamically calculates the vertical angle threshold range on a basis of a distance from the transmission antenna array.
6 . The speed detection apparatus according to claim 5 , wherein
the speed determination unit dynamically calculates the vertical angle threshold range on a basis of a table in which a plurality of vertical angle threshold ranges is registered corresponding to a plurality of distances from the transmission antenna array.
7 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit sets a vertical angle threshold range with a value within a range that satisfies the following formula
θ
FoVp
-
p
=
min
θ
ele
❘
"\[LeftBracketingBar]"
sin
-
1
(
-
1
N
ant
·
n
+
sin
θ
ele
)
-
θ
ele
❘
"\[RightBracketingBar]"
subject
to
[
Math
.
12
]
0
≤
θ
ele
≤
sin
-
1
(
1
N
ant
·
n
)
θ FoVp-p being a width of angle threshold values in the vertical direction,
θ ele being a vertical angle value,
N ant being the number of the plurality of transmission antennas that transmits the plurality of chirp signals to be used for vertical arrival angle estimation,
n being a ratio between an interval between the plurality of transmission antennas in the vertical direction and a wavelength in free space of the chirp signal transmitted by the transmission antenna array.
8 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit dynamically calculates the vertical angle threshold range on a basis of a mounting height of the speed detection apparatus in the vertical direction.
9 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit sets a vertical angle threshold range with a value within a range that satisfies the following formula
❘
"\[LeftBracketingBar]"
θ
FoV
+
❘
"\[RightBracketingBar]"
<
1
2
×
min
θ
ele
❘
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sin
-
1
(
-
1
N
ant
·
n
+
sin
θ
ele
)
-
θ
ele
❘
"\[RightBracketingBar]"
[
Math
.
13
]
❘
"\[LeftBracketingBar]"
θ
FoV
-
❘
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<
{
1
2
×
min
θ
ele
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sin
-
1
(
-
1
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ant
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n
+
sin
θ
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-
θ
ele
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"\[RightBracketingBar]"
,
if
1
2
×
min
θ
ele
❘
"\[LeftBracketingBar]"
sin
-
1
(
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ant
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n
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-
θ
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<
sin
-
1
(
t
r
)
+
θ
err
sin
-
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(
l
r
)
+
θ
err
,
if
1
2
×
min
θ
ele
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sin
-
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(
-
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ant
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-
θ
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≥
sin
-
1
(
t
r
)
+
θ
err
θ Fov+ being a vertical angle threshold value above a mounting center line of a speed detection apparatus in the vertical direction,
θ Fov− being a vertical angle threshold value below the mounting center line of the speed detection apparatus in the vertical direction,
θ ele being a vertical angle value,
N ant being the number of the plurality of transmission antennas that transmits the plurality of chirp signals to be used for vertical arrival angle estimation,
n being a ratio between an interval between the plurality of transmission antennas in the vertical direction and a wavelength in free space of the chirp signal transmitted by the transmission antenna array,
t being a mounting height of the speed detection apparatus in the vertical direction,
r being a detection distance of the speed detection apparatus,
θ err being a mounting angle error of the speed detection apparatus.
10 . The speed detection apparatus according to claim 1 , further comprising
a chirp control unit that controls the plurality of chirp signals transmitted from the plurality of transmission antennas such that when the plurality of chirp signals multiplexed between the plurality of transmission antennas is separated for each of the plurality of transmission antennas, intervals between the plurality of chirp signals from the same transmission antenna are equal and a plurality of intervals between the plurality of chirp signals from different transmission antennas are substantially equal.
11 . The speed detection apparatus according to claim 1 , wherein
the chirp control unit multiplexes the plurality of chirp signals between the plurality of transmission antennas in time division.
12 . The speed detection apparatus according to claim 1 , wherein
the chirp control unit multiplexes the plurality of chirp signals between the plurality of transmission antennas in phase division.
13 . The speed detection apparatus according to claim 1 , wherein
one speed is determined from the plurality of speed candidates, the number of the plurality of speed candidates being equal to or less than the number of the plurality of transmission antennas that transmits the plurality of chirp signals to be used for vertical arrival angle estimation.
14 . The speed detection apparatus according to claim 1 , wherein
the transmission antenna array and the reception antenna array constitute a vertical MIMO array with substantially equal intervals.
15 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit performs arrival angle estimation by fast Fourier transform (FFT) or discrete Fourier transform (DFT).
16 . The speed detection apparatus according to claim 1 , wherein
the speed determination unit performs arrival angle estimation by CAPON, MUSIC, ESPRIT, or compression sensing.
17 . An information processing device, comprising:
a speed determination unit that
calculates a plurality of speed candidates on a basis of a plurality of chirp signals received by a reception antenna array of a speed detection apparatus including a transmission antenna array and the reception antenna array, the transmission antenna array transmitting a plurality of chirp signals multiplexed between a plurality of transmission antennas arranged in a vertical direction, the reception antenna array including a plurality of reception antennas receiving the plurality of chirp signals that has been reflected, and
determines whether or not a plurality of vertical arrival angle estimation values corresponding to the plurality of speed candidates falls within a vertical angle threshold range, and determines, as a true speed, one speed candidate from the plurality of speed candidates on a basis of a determination result.
18 . An information processing method, comprising:
in a speed detection apparatus including
a transmission antenna array that transmits a plurality of chirp signals multiplexed between a plurality of transmission antennas arranged in a vertical direction, and
a reception antenna array that includes a plurality of reception antennas receiving the plurality of chirp signals that has been reflected,
calculating a plurality of speed candidates on a basis of the plurality of chirp signals received by the reception antenna array; and
determining whether or not a plurality of vertical arrival angle estimation values corresponding to the plurality of speed candidates falls within a vertical angle threshold range, and determining, as a true speed, one speed candidate from the plurality of speed candidates on a basis of a determination result.