U.S. patent application number 13/783586 was filed with the patent office on 2016-03-03 for dynamic allocation of radar beams in automotive environments with phased array radar.
This patent application is currently assigned to Toyota Motor Engineering & Manufacturing North America, Inc.. The applicant listed for this patent is Toyota Motor Engineering & North America, Inc.. Invention is credited to Jae Seung Lee, Tsuyoshi Nomura, Paul Donald Schmalenberg.
Application Number | 20160061936 13/783586 |
Document ID | / |
Family ID | 55359917 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160061936 |
Kind Code |
A1 |
Schmalenberg; Paul Donald ;
et al. |
March 3, 2016 |
DYNAMIC ALLOCATION OF RADAR BEAMS IN AUTOMOTIVE ENVIRONMENTS WITH
PHASED ARRAY RADAR
Abstract
A radar apparatus that focuses a subset of transmit beams within
a field of view (FOV) is provided. The radar apparatus has a phased
array transmitter that is operable to generate a transmit beam
within the FOV, and a phased array receiver that is operable to
receive a receive beam reflected from within the FOV. The apparatus
also has a radar controller with an electronic circuit and
electronic memory, the electronic memory having a plurality of
pre-calculated beam density curves. The radar controller is
operable to execute each of the plurality of pre-calculated beam
density curves and steer at least one transmit beam generated from
a particular executed beam density curve towards a sub-area of the
FOV.
Inventors: |
Schmalenberg; Paul Donald;
(Ann Arbor, MI) ; Nomura; Tsuyoshi; (Ann Arbor,
MI) ; Lee; Jae Seung; (Ann Arbor, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
North America, Inc.; Toyota Motor Engineering & |
|
|
US |
|
|
Assignee: |
Toyota Motor Engineering &
Manufacturing North America, Inc.
Erlanger
KY
|
Family ID: |
55359917 |
Appl. No.: |
13/783586 |
Filed: |
March 4, 2013 |
Current U.S.
Class: |
342/81 |
Current CPC
Class: |
G01S 13/42 20130101;
G01S 7/282 20130101; G01S 2013/916 20130101; G01S 13/93 20130101;
G08G 1/167 20130101; G01S 13/931 20130101; G01S 2013/0254
20130101 |
International
Class: |
G01S 7/282 20060101
G01S007/282; G01S 13/93 20060101 G01S013/93 |
Claims
1. A radar apparatus comprising: a phased array transmitter
operable to generate a transmit beam within a field of view (FOV);
a phased array receiver operable to receive a receive beam
reflected from within said FOV; a radar controller having an
electronic circuit and an electronic memory, said electronic memory
having a plurality of pre-calculated beam density curves stored
thereon; said radar controller operable to execute each of said
plurality of pre-calculated beam density curves and steer at least
one transmit beam generated from an executed beam density curve
towards a sub-area of said FOV.
2. The radar apparatus of claim 1, wherein said phased array
transmitter transmits a plurality of transmit beams within said FOV
as a function of said executed beam density curve with said radar
controller steering a subset of said plurality of transmit beams
towards said sub-area within said FOV.
3. The radar apparatus of claim 2, wherein said subset of steered
transmit beams are generated from said executed beam density
curve.
4. The radar apparatus of claim 3, wherein said subset of steered
transmit beams provide an increased beam density at said sub-area
within said FOV.
5. The radar apparatus of claim 4, wherein said sub-area is
selected from the group consisting of an area of a curved road in
front of a motor vehicle traveling thereon, an entrance to an
enclosed area and an exit from an enclosed area.
6. The radar apparatus of claim 5, further comprising a beam
density optimizer algorithm stored in said electronic memory, said
beam density optimizer algorithm operable to calculate a beam
density distribution for said sub-area.
7. (canceled)
8. The radar apparatus of claim 6, wherein said FOV is divided into
a plurality of zones by said radar controller, said beam density
optimizer algorithm having a weighting function operable to weight
a first subset of said plurality of zones higher than a second
subset of said plurality of zones.
9. The radar apparatus of claim 8, wherein said executed beam
density curve is a function of said first subset of FOV zones.
10. The radar apparatus of claim 9, wherein said first subset of
FOV zones have a target identified therewithin.
11. The radar apparatus of claim 10, wherein said radar controller
executes a beam density curve and said phased array transmitter
transmits a first subset of transmit beams evenly across said FOV
and a second subset of transmit beams directed only to said first
subset of FOV zones.
12. The radar apparatus of claim 11, further comprising a motor
vehicle having said radar apparatus attached thereto.
13. The radar apparatus of claim 12, wherein said first subset of
FOV zones cover a curved portion of a road said motor vehicle is
traveling on, said curved portion located at an angle not equal to
zero from a longitudinal center line of said motor vehicle.
14. The radar apparatus of claim 13, wherein said radar controller
executes said beam density curve as a function of a yaw rate of
said motor vehicle.
15. The radar apparatus of claim 14, wherein said pre-calculated
beam density curves correspond to different radii curved roads said
motor vehicle can travel on.
16-19. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] The use of radar systems on motor vehicles, for example, for
collision avoidance and other applications, is known. Such radar
systems typically transmit radar beams directly in front of a
traveling motor vehicle and/or directly to the side of the vehicle
in order to provide information on blind spots. However, heretofore
radar systems do not accommodate when the motor vehicle is
traveling along a curved road. Therefore, a radar apparatus that
can focus a subset of radar beams within a field of view (FOV) and
at an angle from a projected longitudinal center line of the motor
vehicle would be desirable.
SUMMARY OF THE INVENTION
[0002] A radar apparatus that focuses a subset of transmit beams
within a field of view (FOV) is provided. The radar apparatus has a
phased array transmitter that is operable to generate a transmit
beam within the FOV, and a phased array receiver that is operable
to receive a receive beam reflected from within the FOV. The
apparatus also has a radar controller with an electronic circuit
and electronic memory, the electronic memory having a plurality of
pre-calculated beam density curves. The radar controller is
operable to execute each of the plurality of pre-calculated beam
density curves and steer at least one transmit beam generated from
a particular executed beam density curve towards a sub-area of the
FOV.
[0003] In some instances, the phased array transmitter transmits a
plurality of transmit beams within the FOV as a function of the
executed beam density curve, and the radar controller steers a
subset of the plurality of transmit beams towards the sub-area
within the FOV. The subset of steered transmit beams are generated
from the executed beam density curve and provide an increased beam
density at the sub-area. The sub-area within the FOV can be an area
of a curved road in front of a motor vehicle traveling on the road,
an entrance into an enclosed area, an exit from an enclosed area, a
particular area on an airport runway, and the like.
[0004] In some instances, the radar apparatus has a beam density
optimizer algorithm that is operable to calculate a beam density
distribution for the sub-area within the FOV. Although not
required, the beam density optimizer algorithm is contained within
the radar controller.
[0005] In other instances, the FOV can be divided into a plurality
of zones by the radar controller and the beam density optimizer
algorithm has a weighting function that provides a weight or a
weighted value to a first subset of the plurality of zones that is
higher than a weight applied or assigned to a second subset of the
plurality of zones. In addition, the executed beam density curve
can be a function of the weighted value of first subset of FOV
zones. Finally, the first subset of field zones can have a target
identified by the radar apparatus.
[0006] The radar controller executes a beam density curve and the
phased array transmitter transmits a first subset of transmit beams
evenly across the FOV and a second subset of transmit beams
directed only to the first subset of FOV zones. In the alternative,
the phased array transmitter transmits a first subset of transmit
beams directed to the first subset of FOV zones and a second subset
of transmit beams evenly across the FOV. In some instances, the
first subset of FOV zones cover a curved portion of a road that the
motor vehicle is traveling on, the curved portion located in front
of the motor vehicle at an angle, not equal to zero, from a
projected longitudinal center line of the motor vehicle. In
addition, the radar controller executes the particular beam density
curve as a function of a yaw rate of the motor vehicle. Also, the
pre-calculated beam density curves can correspond to different
radii curved roads that the motor vehicle can or is traveling
on.
[0007] A process for operating a motor vehicle radar apparatus in
order to focus radar beams on a forward area of a curved road that
the motor vehicle is traveling on is also provided. The process
includes determining a yaw rate of the motor vehicle traveling
along the curved road and executing a beam density curve as a
function of the determined yaw rate. Thereafter, a plurality of
transmit beams corresponding to the executed beam density curve is
transmitted with a first subset of the transmitted beams directed
evenly across a FOV of the radar apparatus and a second subset of
the transmitted beams directed to a selected sub-area of the FOV
that is not directly in front of the motor vehicle.
[0008] The process can also include the radar apparatus detecting a
target within one or more sub-areas of the radar FOV and executing
a beam density curve as a function of the one or more sub-areas
where the target is located. Thereafter, a first subset of transmit
beams is directed evenly across the radar FOV and a second subset
of transmitted beams is directed to the one or more sub-areas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1A is a schematic illustration of a prior art radar
apparatus;
[0010] FIG. 1B is a schematic illustration of the prior art radar
apparatus shown in FIG. 1A when a motor vehicle is traveling along
a curved road;
[0011] FIG. 2 is a graphical representation of: (A) a radar
resolution map for a field of view (FOV) of a radar apparatus; and
(B) a beam distribution as a function of angle within the FOV;
[0012] FIG. 3 is a graphical representation of: (A) a radar
resolution map with increased resolution along a straight road; and
(B) a beam distribution versus angle that provides the increased
resolution shown in (A);
[0013] FIG. 4 is a schematic diagram of a radar apparatus according
to an embodiment of the present invention;
[0014] FIG. 5 is a graphical illustration of: (A) a resolution map
for a radar apparatus according to an embodiment of the present
invention in which increased resolution is shown for a portion of a
curved road; and (B) beam distribution as a function of angle that
provides for the increased resolution shown in (A);
[0015] FIG. 6 is a graphical representation of: (A) a target map;
and (B) a weight map for a radar apparatus according to an
embodiment of the present invention;
[0016] FIG. 7 is a schematic illustration of a motor vehicle with a
radar apparatus according to an embodiment of the present invention
and traveling on a curved road;
[0017] FIG. 8 is a schematic illustration of an enclosed area with
an entry and/or exit that is monitored by a radar apparatus
according to an embodiment of the present invention; and
[0018] FIG. 9 is a schematic illustration of an airfield being
monitored by a radar apparatus according to an embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] A radar apparatus for focusing and/or steering radar beams
towards a sub-area of a field of view (FOV) of the radar apparatus
is provided. As such, the apparatus has utility as a safety
component for a motor vehicle, security system, and the like.
[0020] The radar apparatus has a phased array transmitter and a
phased array receiver. The phased array transmitter is operable to
generate and/or propagate a transmit beam within the FOV and the
phased array receiver is operable to receive a receive beam
reflected from within the FOV.
[0021] A radar controller is also included and has an electronic
circuit and an electronic memory. In some instances, the electronic
memory has a plurality of pre-calculated beam density curves.
Furthermore, the radar controller is operable to execute each of
the plurality of pre-calculated beam density curves and steer at
least one transmit beam generated from a particular executed beam
density curve towards a sub-area of the FOV. It is appreciated that
with the stored pre-calculated beam density curves, computation
time is reduced and computational efficiency is increased for the
radar apparatus.
[0022] A beam density optimizer may or may not be included as part
of the radar apparatus, the beam density optimizer operable to
calculate a beam density distribution for the FOV in which a
desired sub-area has a relatively high transmit beam density with
respect to the remaining FOV. The beam density optimizer may or may
not have a weighting function that is operable to assign a weight
or weight value to a first subset of sub-areas or zones of the FOV
that is higher or greater than a weight or weight value that the
weighting functions assigns to a second subset of sub-areas or
zones of the FOV. Furthermore, a particular beam density curve is
executed by the radar controller as a function of the weighting of
the first and/or second subset of FOV zones.
[0023] The radar apparatus can be part of and/or attach to a motor
vehicle and provide for greatly improved resolution for particular
areas in proximity of the motor vehicle that are not currently
available with prior art radar systems. For example and for
illustrative purposes only, the radar apparatus steers a plurality
of transmit beams to cover a portion of a curved road that is in
front of a motor vehicle and located at an angle from a projected
longitudinal center line of the vehicle. In this manner, low radar
resolution for curved portions of roads, highways, etc. that are in
front of a traveling vehicle is replaced by a high resolution
"viewing".
[0024] Turning now to FIG. 1, FIG. 1A schematically illustrates a
motor vehicle 10 traveling along a straight portion of a road 106.
The vehicle 10 has a prior art radar apparatus 100 that provides a
wide angle, low resolution FOV 102 in combination with a low angle,
high resolution FOV 104 in front of the vehicle 10 as it travels
along the road 106. As shown in FIG. 1B, when the motor vehicle 10
travels along a curved portion of the road 106, a sub-area 108 in
front of the vehicle 10 is not subjected or covered by the low
angle, high resolution FOV 104. As such, the radar apparatus 100 is
not capable of providing high radar resolution within the sub-area
108 located at an angle in front of the vehicle 10 as it travels
along the road 106.
[0025] Turning now to FIG. 2, FIG. 2A a resolution map with a FOV
superimposed onto a straight portion of the road 106. Also shown
within the resolution map is a high resolution area 110. Such a
resolution map is provided by a beam distribution as shown in FIG.
2B in which the location of transmit beams as a function of angle
in front of the radar apparatus is shown at 120. It is appreciated
that, the density of beams as a function of angle is linear as
represented by the beam distribution curve 120. Also shown in FIG.
2B is a beam distribution curve 122 for a single beam at 0 degrees
and an overall beam distribution profile 124 over the entire
FOV.
[0026] In contrast to the resolution map and beam density profile
124 shown in FIG. 2, FIGS. 3A and 3B illustrate a resolution map
and beam density profile 124 for a radar apparatus according to an
embodiment of the present invention. As stated above, the radar
apparatus can steer one or more transmit beams and provide a
relatively high density of transmit beams directed to a desired
sub-area of the FOV. In particular, the high resolution area 110 is
projected along the straight portion of road 106 to a greater
length when compared to FIG. 2A, which is accomplished by steering
an increased number of transmit beams within +/-10 degrees from 0.
With respect to the beam distribution curve 120 shown on FIG. 3B,
the region 120a has a greater slope compared to the remainder of
the curve 120 and thus graphically illustrates the higher density
of transmit beams within the +/-10 degree region. In addition, the
corresponding overall beam distribution profile 124 reflects the
increased transmit beam density within this region.
[0027] With reference to FIG. 4, a schematic illustration of a
radar apparatus according to an embodiment of the present invention
is shown generally at reference numeral 15. The apparatus 15 has a
transmit phased array 50 with one or more phase shifters 52 in
electrical communication with one or more antenna elements 53.
Similarly, the apparatus 15 has a receive phased array 54 with one
or more phase shifters 55 in electrical communication with one or
more antenna receiving elements 56. Although not shown, one or more
amplifier elements can be located between each phase shifter 52, 55
and an associated transmit antenna element 53 or receiving antenna
element 56. A local oscillator 60 that provides a local oscillator
signal which is fed to a mixer 58 can also be included.
[0028] The exact electrical connection pattern is not shown in the
figure; however, the local oscillator distribution network is
typically configured such that the local oscillation signal
arriving at each mixer 58 has the same phase and amplitude. In the
alternative, a software adjustment in digital processing for phase
offsets between the local oscillation signals can be provided. An
electronic control circuit 62 can generate a plurality of beam
density curves that are subsequently transmitted with the transmit
phased array 50. In the alternative, the electronic control circuit
62 can have memory 64 which has a plurality of pre-calculated beam
density curves. The electronic control circuit 62 can select one or
more of the pre-calculated beam density curves and afford for a
beam distribution to be transmitted through the one or more
transmit antenna elements 52.
[0029] The electronic control circuit 62 may or may not have a beam
density optimizer 66, e.g. in the form of an algorithm, that can
calculate the beam density distribution for a particular sub-area
within the FOV. In addition, the beam density optimizer 66 may or
may not be stored in the memory 64. The beam density optimizer 66
can have a weighting function that is operable to weight, assign a
weight and/or assign a weighted value to a first subset and/or
second subset of sub-areas or zones within the FOV. The electronic
control circuit 62 can also divide the FOV into the grid of
sub-areas or zones 114 illustrated in FIGS. 2A and 3A.
[0030] Turning now to FIGS. 5 and 6, FIG. 5A provides a graphical
representation of a resolution map for a curved portion of road
106, e.g. a portion of the road 106 that has a radius of curvature
less than 10,000 feet. Also shown in FIG. 5A is high resolution
area 110 that has been steered along or onto the curved portion of
the road 106. Stated differently, the high resolution area 110 is
located at an angle from an imaginary line extending perpendicular
from the y-axis at the 0 degree point, which corresponds to the
projected longitudinal center line 12 shown in FIG. 1B.
[0031] FIG. 5B illustrates the beam distribution and beam density
for the resolution map shown in 5A. As shown by the graph, a
relatively high beam density is provided in the region 120a which
is approximately 5 to 30 degrees off center. In this manner, high
resolution for one or more sub-areas within the radar FOV, but not
located directly in front of motor vehicle 10 can be provided. In
addition, FIGS. 6A and 6B illustrate a target map and weight map,
respectively, in which beam density optimizer 66 provides weighting
to sub-areas or zones that cover the curved portion of road 106 and
affords for in the electronic control circuit 62 providing a
relatively high density of steered transmit beams within the high
resolution area 110. For example, FIG. 6B illustrates higher
weighted zones 116 and lower weighted zones 118, the higher
weighted zones 116 being targeted in FIG. 6A. In addition, the
higher weighted zones 116 have a relatively high transmit beam
density steered thereto as illustrated by beam distribution curve
portion 120a shown in FIG. 5A.
[0032] In operation, FIG. 7 illustrates the motor vehicle 10
traveling along the road 106, the road 106 being a curved road. The
motor vehicle 10 can have a yaw rate sensor 14 that provides a yaw
rate to the radar apparatus 15. The radar apparatus 15 then
generates a beam density curve as a function of the yaw rate with a
plurality of transmit beams transmitted from antennas 53 such that
a high density of beams are provided within sub-area(s) 108. As
such, high resolution is provided for a portion of a curved road
that the motor vehicle 10 is traveling upon, the curved road
portion being at an angle not equal to zero from the vehicle
projected center line 12. In the alternative, the electronic
control circuit 62 with memory 64 has a plurality of pre-calculated
beam density curves, one or more of which are selected as a
function of the yaw rate and used to generate and transmit the
plurality of transmit beams that afford for the high resolution
area 108.
[0033] Turning now to FIG. 8, the radar apparatus 15 of the instant
invention can also be used to monitor an area as shown generally at
reference numeral 20. The area 20 may or may not be partially or
totally enclosed by a boarder 250, wall, fence and the like. The
area 20 has a radar apparatus 200 as discussed above, the apparatus
200 having a FOV defined by dotted lines 210. The area 20 also has
an entry or exit 252 and the radar apparatus 200 provides an
increased beam density 204 directed to the exit or entry area 252
in comparison with the remainder of the FOV. It is appreciated that
the increased beam density 204 can be continuously directed towards
the sub-area 252 or, in the alternative, directed to the area 252
upon detection of a target, e.g. an individual, entering or leaving
the area 20.
[0034] Finally, another embodiment of the radar apparatus is shown
in FIG. 9 at reference numeral 30 which illustrates an airfield
having a pair of runways 306. A radar apparatus 300 can have a FOV
defined within the lines 310 in which portions 302 of the runways
306 are covered/monitored. Upon detection of a target 305, e.g.
debris, the radar apparatus 300 can steer an increased beam density
304 to the target 305 for improved or higher resolution of the
target. In this manner, it can be determined if the target 305
should be removed before the runway 306 is used by an aircraft. In
the alternative, the radar apparatus 300 can provide uniform
coverage of the FOV during nonuse time periods and then focus or
steer a high density of beams along a particular runway prior to
arrival of an aircraft 320. In this manner, increased safety,
maintenance, and the like can be provided.
[0035] It is understood that various modifications can be readily
made to the embodiments of the present invention described herein
without departing from the scope and spirit thereof. Accordingly,
it is understood that the invention is not to be limited by the
specific illustrated embodiments but by the scope of the appended
claims.
* * * * *