U.S. patent application number 16/447918 was filed with the patent office on 2019-12-26 for system and method of calibrating an optical sensor mounted on board of a vehicle.
The applicant listed for this patent is Mahle Aftermarket Italy S.p.A.. Invention is credited to Andrea Cantadori, Paolo Gandolfi.
Application Number | 20190392610 16/447918 |
Document ID | / |
Family ID | 62874554 |
Filed Date | 2019-12-26 |
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United States Patent
Application |
20190392610 |
Kind Code |
A1 |
Cantadori; Andrea ; et
al. |
December 26, 2019 |
SYSTEM AND METHOD OF CALIBRATING AN OPTICAL SENSOR MOUNTED ON BOARD
OF A VEHICLE
Abstract
One embodiment provides a method for calibrating an optical
sensor mounted on board of a vehicle, including the steps of:
positioning the vehicle in a test station; arranging a projection
surface for images or videos opposite the test station; identifying
the type of optical sensor; selecting in a memory an image or video
associated with the type of optical sensor; projecting the image or
video selected onto the projection surface; and adjusting the
position of the optical axis of the optical sensor starting from
the projected image or video. Other aspects are described and
claimed.
Inventors: |
Cantadori; Andrea; (Parma,
IT) ; Gandolfi; Paolo; (Parma, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mahle Aftermarket Italy S.p.A. |
Parma |
|
IT |
|
|
Family ID: |
62874554 |
Appl. No.: |
16/447918 |
Filed: |
June 20, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01S 17/931 20200101;
B60R 2300/402 20130101; B60R 11/04 20130101; G01B 11/272 20130101;
G06T 2207/30252 20130101; H04N 9/3185 20130101; G01S 13/931
20130101; G01M 17/00 20130101; G06T 7/80 20170101; G01S 7/4021
20130101; G07C 5/0841 20130101; G07C 5/0808 20130101; G01S 7/4972
20130101 |
International
Class: |
G06T 7/80 20060101
G06T007/80; H04N 9/31 20060101 H04N009/31; G01S 17/93 20060101
G01S017/93; G01S 13/93 20060101 G01S013/93; G01S 7/497 20060101
G01S007/497; G01S 7/40 20060101 G01S007/40; G07C 5/08 20060101
G07C005/08; B60R 11/04 20060101 B60R011/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 21, 2018 |
EP |
18178983.5 |
Claims
1. A calibration system that calibrates an optical sensor mounted
on board of a vehicle, comprising: a test station consisting of a
horizontal or inclined support zone for supporting the vehicle; a
projection surface for images or videos, said projection surface
being located in front of said test station; at least one memory
containing a plurality of images and/or videos archived by type of
optical sensor; a calibration unit for calibrating the optical
sensor configured to adjust the position of the optical axis of
said optical sensor; and a control unit which, in response to a
signal representing the type of said optical sensor, is configured
to: search in said memory for at least one image or video archived
in association with the type of said optical sensor; command the
projection onto said projection surface of the image or video found
in said memory or a processed version of said image or said video;
interface with said calibration unit; and adapt or deform the image
or video found in said memory to the size of the projection
surface.
2. The calibration system according to claim 1, further comprising
a screen or monitor located in front of said test station, said
projection surface being the display of said monitor.
3. The calibration system according to claim 2, further comprising
a television set, said monitor being the monitor of said television
set.
4. The calibration system according to claim 2, further comprising
a multimedia interactive board, said monitor being the monitor of
the multimedia interactive board.
5. The calibration system according to claim 2, further comprising
a computer, said monitor being the monitor of the computer.
6. The calibration system according to claim 1, wherein said
projection surface is obtained from a sheet made of PVC.
7. The calibration system according to claim 1, further comprising
a projector or a luminous board, said control unit being configured
to command the projector or luminous board to project the image or
video found in said memory onto said projection surface.
8. The calibration system according to claim 1 wherein, in response
to the signal representing the type of said optical sensor, said
control unit is configured to project a set of parameters or
initial calibration conditions onto said projection surface.
9. The calibration system according to claim 8, further comprising
a projector or a luminous board, said control unit being configured
to command the projector or luminous board to project the image or
video found in said memory onto said projection surface.
10. A method of calibrating an optical sensor mounted on board of a
vehicle, comprising the steps of: positioning the vehicle in a test
station consisting of a horizontal or inclined support zone for
supporting the vehicle; arranging a projection surface for images
or videos in front of said test station; identifying the type of
said optical sensor; selecting in a memory an image or video
associated with the type of said optical sensor; adapting or
deforming the image or video selected in said memory (6) to the
size of the projection surface; projecting the image or video
selected or the adapted or deformed version thereof onto said
projection surface; and adjusting the position of the optical axis
of said optical sensor starting from said projected image or video.
Description
CLAIM FOR PRIORITY
[0001] This application claims priority to European Application No.
18178983.5, which was filed on Jun. 21, 2018, the contents of which
are fully incorporated by reference herein.
FIELD
[0002] The subject matter described herein relates to a system and
method of calibrating an optical sensor mounted on board of a
vehicle.
BACKGROUND
[0003] Over recent years, the attention of those developing the
safety of motor vehicles has extended from the traditional passive
safety systems (airbags, seat belts, impact resistance, etc.) to
advanced active safety systems, known to specialists as ADAS
(Advanced Driver Assistance Systems).
[0004] ADAS systems are electronic driving assistance systems for
vehicles that support the driver for the purpose of increasing
safety and/or driving comfort. Such systems have been classified
into six levels according to the degree of autonomy, as indicated
below: [0005] Level 0 (no automation): the driver is in charge of
all the driving aspects, even when he/she is facilitated by the
systems installed on board of the vehicle. [0006] Level 1 (driver
assistance): in some situations the vehicle can accelerate, brake
or steer autonomously, but the driver must be ready at all times to
regain control of the vehicle. [0007] Level 2 (partial automation):
the vehicle has full control of the accelerator, brake and
steering, but the driver must still monitor the surrounding
environment. [0008] Level 3 (conditioned automation): the vehicle
has full control of the accelerator, brake, steering and monitoring
of the environment, but the driver must be ready to intervene if
required by the system. [0009] Level 4 (high automation): the
automatic system is able to handle any event, but must not be
activated in extreme driving conditions such as in bad weather.
[0010] Level 5 (complete automation): the automatic driving system
is able to handle all driving situations; there is no longer any
need for intervention by a human driver.
[0011] Currently, the most advanced vehicles are equipped with
level 3 systems. The objective over coming years is to reach level
5 in most of the vehicles on the roads.
[0012] By way of example, ADAS systems that are already widespread
include adaptive cruise control, automatic full-beam headlamp
adjustment, automatic headlamp orientation, automatic parking
system, navigation system with traffic information, night vision
system, blind spot monitor, frontal collision warning system,
automatic emergency braking, etc.
[0013] At technological level, ADAS systems are based on a
plurality of sensors (television cameras, radar, Lidar, etc.) able
to detect different information that can possibly be used as the
input data for a smart algorithm that oversees the degree of
autonomy of the vehicle.
[0014] Before the vehicle is placed on the market, the sensors are
calibrated directly by the manufacturer. For example, the initial
calibration of a television camera is performed through a
simulation environment specifically provided by the manufacturer in
which the television camera is placed opposite a monitor onto which
settable dynamic scenarios are projected (e.g. a pedestrian
crossing the road).
[0015] After the vehicle has been placed on the market, the sensors
are calibrated periodically (e.g. when the vehicle is serviced) or
after exceptional events (e.g. replacement of the sensor following
a defect, damage or breakdown warning).
BRIEF SUMMARY
[0016] In summary, one aspect provides a calibration system that
calibrates an optical sensor mounted on board of a vehicle,
comprising: a test station consisting of a horizontal or inclined
support zone for supporting the vehicle; a projection surface for
images or videos, said projection surface being located in front of
said test station; at least one memory containing a plurality of
images and/or videos archived by type of optical sensor; a
calibration unit for calibrating the optical sensor configured to
adjust the position of the optical axis of said optical sensor; and
a control unit which, in response to a signal representing the type
of said optical sensor, is configured to: search in said memory for
at least one image or video archived in association with the type
of said optical sensor; command the projection onto said projection
surface of the image or video found in said memory or a processed
version of said image or said video; interface with said
calibration unit; and adapt or deform the image or video found in
said memory to the size of the projection surface.
[0017] Another aspect provides a method of calibrating an optical
sensor mounted on board of a vehicle, comprising the steps of:
positioning the vehicle in a test station consisting of a
horizontal or inclined support zone for supporting the vehicle;
arranging a projection surface for images or videos in front of
said test station; identifying the type of said optical sensor;
selecting in a memory an image or video associated with the type of
said optical sensor; adapting or deforming the image or video
selected in said memory (6) to the size of the projection surface;
projecting the image or video selected or the adapted or deformed
version thereof onto said projection surface; and adjusting the
position of the optical axis of said optical sensor starting from
said projected image or video.
[0018] The foregoing is a summary and thus may contain
simplifications, generalizations, and omissions of detail;
consequently, those skilled in the art will appreciate that the
summary is illustrative only and is not intended to be in any way
limiting.
[0019] For a better understanding of the embodiments, together with
other and further features and advantages thereof, reference is
made to the following description, taken in conjunction with the
accompanying drawings. The scope of the invention will be pointed
out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIG. 1 schematically illustrates a system of calibrating an
optical sensor mounted on board of a vehicle, according to an
embodiment;
[0021] FIG. 2 and FIG. 3 illustrate the reciprocal arrangement of a
vehicle in the test station and a projection surface of the
calibration system of FIG. 1, in a perspective view, in which the
projection surface projects a pattern and a video,
respectively;
[0022] FIG. 4 schematically illustrates the communication between a
scan tool and a calibration unit of the calibration system of FIG.
1.
DETAILED DESCRIPTION
[0023] It will be readily understood that the components of the
embodiments, as generally described and illustrated in the figures
herein, may be arranged and designed in a wide variety of different
configurations in addition to the described example embodiments.
Thus, the following more detailed description of the example
embodiments, as represented in the figures, is not intended to
limit the scope of the embodiments, as claimed, but is merely
representative of example embodiments.
[0024] Reference throughout this specification to "one embodiment"
or "an embodiment" (or the like) means that a particular feature,
structure, or characteristic described in connection with the
embodiment is included in at least one embodiment. Thus, the
appearance of the phrases "in one embodiment" or "in an embodiment"
or the like in various places throughout this specification are not
necessarily all referring to the same embodiment.
[0025] Furthermore, the described features, structures, or
characteristics may be combined in any suitable manner in one or
more embodiments. In the following description, numerous specific
details are provided to give a thorough understanding of
embodiments. One skilled in the relevant art will recognize,
however, that the various embodiments can be practiced without one
or more of the specific details, or with other methods, components,
materials, et cetera. In other instances, well known structures,
materials, or operations are not shown or described in detail to
avoid obfuscation.
[0026] Two types of calibration are currently performed in the
aftermarket: static and dynamic.
[0027] Static calibration is performed in a closed environment
(generally the workshop) through a portable device--known in the
sector as a "scan tool"--connected to the vehicle's EOBD (European
On Board Diagnostic) diagnostic socket and using specific target
panels for each type of sensor (e.g. photo camera, radar, Lidar,
etc.) usually placed on the front of the stationary vehicle (they
can also be positioned on the side or the rear of the vehicle). An
example of such a calibration method is proposed in patent US
2013/0325252.
[0028] The main criticality of the static calibration methods known
to date is connected with the wide variety of parameters at stake.
As every manufacturer requires ad hoc calibration settings for each
vehicle model and for each type of sensor, workshops are generally
affiliated to only some manufacturers, for which they must be
equipped with the related target panels (numerous ones as they
differ in terms of shape, size and pattern).
[0029] Furthermore, to guarantee reliable calibration, it is
essential to guarantee the correct transverse and longitudinal
alignment of the target panels with respect to the vehicle. At each
calibration, the panel alignment step takes a long time.
[0030] The movement of the panels also requires special care to
prevent damage and breakages. In fact, the panels are made of
plastic material, generally forex, and have a significant extension
with respect to the thickness, which is reduced (usually max 5
mm).
[0031] Furthermore, static calibration cannot take place outdoors
as there must be a well defined contrast of the panels.
[0032] For some types of vehicles, static calibration is not
sufficient but an on-road test is required.
[0033] In that case, dynamic calibration methods are applied, i.e.
performed while driving the vehicle. Two scenarios are possible:
[0034] dynamic calibration performed automatically by the vehicle
systems while a generic driver is driving, [0035] dynamic
calibration using a scan tool connected to the vehicle's EOBD
diagnostic socket for performing specific calibration procedures
established by the manufacturer, performed by an authorized
repairer.
[0036] A first limit of dynamic calibration is connected with the
fact that it must be performed under good weather conditions, with
the clear planning difficulties of the time scales. A second limit
is connected with the need to provide paths with determined
characteristics (horizontal signage, vertical signage, etc.) for
performing the calibration.
[0037] Furthermore, during dynamic calibration the vehicle could
have unexpected reactions (precisely due to calibration errors),
which put the driver's safety at risk.
[0038] The aftermarket calibration methods known to date (static
and dynamic) require long performance times to guarantee the
reliability of the results.
[0039] From US 2018/100783 it is already known a calibration system
for optical sensors using a screen or other projection surface
disposed within the field of view of an optical sensor system
onboard a vehicle.
[0040] From WO 2018/067354 it is disclosed an ADAS calibration
support structure in which it is possible to project indicia on a
screen and to correct parallax distortion by means of mechanical
rotation of a laser emitter.
[0041] From WO 2014/192347 it is also known an inspection system
for an optical sensor.
[0042] In U.S. Pat. No. 9,247,222 a projection display for images
is disclosed, that may be applied to a vehicle.
[0043] In DE 10 2006060 553 there is disclosed a method for testing
a motor vehicle driver assistance system.
[0044] In this context, the technical task underpinning an
embodiment is to provide a system and method of calibrating an
optical sensor mounted on board of a vehicle, that obviate the
above-cited drawbacks.
[0045] In particular, it an embodiment provides a universal system
of calibrating an optical sensor mounted on board of a vehicle,
i.e. that can be used for the sensors of any vehicle, regardless of
the manufacturer, the specific model and the ADAS system being
implemented and, at the same time, more reliable and compact with
respect to known solutions.
[0046] An embodiment provides a method for calibrating an optical
sensor mounted on board of a vehicle that can be performed in a
shorter time and more easily with respect to the calibration
methods known to date.
[0047] A further embodiment provides a system and method of
calibrating an optical sensor mounted on board of a vehicle, which
are reliably applicable also to vehicles that normally require an
on-road test, i.e. dynamic calibration.
[0048] The stated technical task are substantially achieved by a
system of calibrating an optical sensor mounted on board of a
vehicle, comprising: [0049] a test station for the stationary
vehicle; [0050] a projection surface for images or videos, which is
located in front of the test station; [0051] at least one memory
containing a plurality of images and/or videos archived by type of
optical sensor; [0052] a calibration unit for calibrating the
optical sensor configured to adjust the position of the optical
axis of the optical sensor; [0053] a control unit which, in
response to a signal representing the type of the optical sensor,
is configured to: [0054] search in the memory for at least one
image or video archived in association with the type of optical
sensor; [0055] command the projection onto the projection surface
of the image or video found in the memory or a processed version of
the image or video; [0056] interface with the calibration unit.
[0057] In accordance with one embodiment, the control unit is also
configured to determine, in response to the signal representing the
type of optical sensor, a spatial position of the projection
surface with respect to the optical sensor mounted on board of the
vehicle arranged in the test station.
[0058] In accordance with one embodiment, the control unit is also
configured to adapt or deform the image or video found in the
memory to the dimensions of the projection surface, in response to
the signal representing the type of optical sensor.
[0059] In accordance with one embodiment, the calibration system
further comprises a screen or monitor located in front of the test
station, the projection surface being the display of said
monitor.
[0060] In accordance with one embodiment, the calibration system
further comprises a television set, said monitor being the monitor
of said television set.
[0061] In accordance with one embodiment, the calibration system
further comprises a multimedia interactive board, said monitor
being the monitor of the multimedia interactive board.
[0062] In accordance with one embodiment, the calibration system
further comprises a computer, said monitor being the monitor of the
computer.
[0063] In accordance with one embodiment, the projection surface is
obtained from a sheet made of PVC.
[0064] In accordance with one embodiment, the calibration system
further comprises a projector or a luminous board, said control
unit being configured to command the projector or luminous board to
project the image or video found in the memory onto the projection
surface.
[0065] Preferably, in response to the signal representing the type
of optical sensor, the control unit is configured to project a set
of parameters or initial calibration conditions onto said
projection surface.
[0066] Preferably, the calibration system also comprises an
automatic means for adjusting the spatial position of the
projection surface with respect to the test station.
[0067] The stated technical task and specified objects are
substantially achieved by a method of calibrating an optical sensor
mounted on board of a vehicle, comprising the steps of: [0068]
positioning the vehicle in a test station; [0069] arranging a
projection surface for images or videos in front of said test
station; [0070] identifying the type of optical sensor; [0071]
selecting in a memory an image or video associated with the type of
said optical sensor; [0072] projecting the image or video selected
or a processed version thereof onto the projection surface; [0073]
adjusting the position of the optical axis of the optical sensor
starting from said projected image or video.
[0074] In accordance with one embodiment, the calibration method
further comprises a step of determining, according to the type of
optical sensor, a spatial measurement position that the projection
surface must assume with respect to the optical sensor during
calibration.
[0075] In accordance with one embodiment, the calibration method
further comprises a step of adapting or deforming the image or
video selected based on the size of the projection surface and the
distance from the optical sensor.
[0076] Further characteristics and advantages will become more
apparent from the indicative and thus non-limiting description of a
preferred, but not exclusive, embodiment of a system and method of
calibrating an optical sensor mounted on board of a vehicle, as
illustrated in the accompanying drawings.
[0077] With reference to the figures, the number 1 indicates a
system of calibrating an optical sensor 2 mounted on board of a
vehicle 100, in particular a motor vehicle such as an automobile, a
bus, a lorry, a road tractor, a tractor trailer, an articulated
lorry, a farm machinery, a working vehicle, a self-propelled
vehicle, etc.
[0078] For example, the optical sensor 2 is a CMOS or CCD type
sensor of a television camera installed on the vehicle 100.
[0079] The calibration system 1 preferably comprises: [0080] a test
station 3 for the stationary vehicle 100; [0081] a projection
surface 4 for projecting images or videos.
[0082] In particular, the test station 3 consists of a horizontal
or inclined support zone for supporting the vehicle 100.
[0083] The stationary vehicle 100 is arranged in the test station 3
according to techniques and with means of the known type, which are
not the subject matter this disclosure.
[0084] The projection surface 4 is arranged in front of the test
station 3 so that the optical sensor 2 can acquire images or videos
projected onto such projection surface 4.
[0085] Preferably, the projection surface 4 is rectangular
shaped.
[0086] Preferably, the calibration system 1 comprises a screen or
monitor, whose display constitutes the projection surface 4.
[0087] The monitor comprising the projection surface 4 may be a
monitor of a television set 40, as illustrated in FIGS. 2 and
3.
[0088] For example, the monitor of the television set 40 may be
plasma, liquid crystal, OLED.
[0089] For example, a television set 40 can be used with a 65'' or
greater anti-glare monitor.
[0090] Alternatively, the monitor comprising the projection surface
4 is the monitor of a multimedia interactive whiteboard (often
indicated by the acronym IWB), or the monitor of a computer.
[0091] In accordance with another embodiment, the calibration
system 1 comprises a projector or a video projector or a luminous
board that projects images or videos onto the projection surface 4,
preferably made of (polarised or lenticular) high-contrast PVC
fabric.
[0092] For example, the projection surface 4 is the surface of a
fabric sheet which when unrolled and taut, must have a planarity of
+/-2 millimetres per linear metre. Preferably, the fabric is opaque
white so as to have a good contrast.
[0093] The calibration system 1 comprises a control unit 5 which
receives at least one input signal (indicated as S1) representing
the type of optical sensor 2. In response to such signal S1, the
control unit 5 is configured for: [0094] selecting an image or a
video in a memory 6; [0095] commanding the projection onto the
projection surface 4 of the image or video selected or a processed
version thereof.
[0096] In particular, the memory 6 is part of the calibration
system 1 and contains a plurality of images and/or videos archived
by type of optical sensor.
[0097] In fact, on board of the vehicle 100, different television
cameras, stereo pairs etc. can be installed. Each of such devices
has optical sensors of different types that together form an ADAS
system. Above all, according to the manufacturer and the model, the
vehicle 100 has its own ADAS system, therefore each optical sensor
requires ad hoc calibration.
[0098] The selection of the image or video by the control unit 5 is
performed by searching in the memory 6 for at least one image or
video that is archived in association with the type of that
particular optical sensor 2 subject to calibration.
[0099] For example, the image projected onto the projection surface
4 can reproduce the shape, size and pattern of a target panel for
the calibration of a specific optical sensor.
[0100] In the case of a video, it is possible to display a real
dynamic scenario or a simulated one, which reproduces an on-road
test of the vehicle.
[0101] For example, the control unit 5 is housed in a portable
device 20 (generally known in the sector as a scan tool) which can
be connected to the vehicle's 100 EOBD diagnostic socket 31.
[0102] The memory 6 can be housed in the same portable device
20.
[0103] Alternatively, it may be the computer memory, or an external
memory (e.g. USB memory connectible directly to the television set
40).
[0104] If the projection surface 4 is composed of the fabric sheet,
then the control unit 5 is configured to command the projector or
video projector or luminous board to project the image or video
onto such projection surface 4.
[0105] Preferably, in a preliminary step it is necessary to
configure the calibration system 1. For this reason, the control
unit 5 is configured to project onto the projection surface 4 a set
of parameters or initial calibration conditions, in response to the
signal S1 representing the type of optical sensor 2.
[0106] The calibration of the optical sensor 2, meaning the
adjustment of the position of the optical axis, takes place by a
calibration unit 30 that interfaces with the control unit 5. The
calibration unit 30 is preferably part of the vehicle's 100
electronic control unit and it interfaces with the control unit 5
of the scan tool 20 through the connection to the EOBD diagnostic
socket 31.
[0107] In accordance with one embodiment, the control unit 5 is
also configured to determine a spatial position of the projection
surface 4 with respect to the optical sensor 2 mounted on board of
the vehicle 100 arranged in the test station 3. Such determination
is performed based on the signal S1 representing the type of
optical sensor 2.
[0108] Preferably, the calibration system 1 also comprises an
automatic means for adjusting (i.e. regulating) the spatial
position of the projection surface 4 with respect to the test
station 3. Said adjusting means is of the known type and will not
be described further.
[0109] This position adjustment of the projection surface 4 is
usually used in the event in which the vehicle 100 is placed on a
horizontal support surface.
[0110] In accordance with another embodiment, the control unit 5 is
also configured to process the images or videos resident in the
memory 6. In particular, the control unit 5 is configured to adapt
or deform the selected image or video to the size of the projection
surface 4. Such adaptation is performed in response to the signal
S1 representing the type of optical sensor 2.
[0111] For example, if the vehicle 100 in the test station 3 is
placed on an inclined plane, the image or video is to be deformed
rather than adjusting the spatial position of the projection
surface 4 with respect to the optical sensor 2.
[0112] For example, the vehicle's 100 support plane is inclined
forwards by a maximum of 1.degree. with respect to the
horizontal.
[0113] Or, the vehicle's 100 support plane is inclined backwards by
a maximum of 3.degree. with respect to the horizontal.
[0114] It is also envisaged that the control unit 5 is configured
to perform both a determination of the spatial position of the
projection surface 4 with respect to the optical sensor 2 mounted
on board of the vehicle 100 in the test station 3 and a deformation
of the selected images or videos.
[0115] In that case, the determination of the spatial position is
rough, and is performed from a deformed projection of the image or
video.
[0116] The method of calibrating an optical sensor mounted on board
of a vehicle, according to an embodiment, is described below.
[0117] First of all, the vehicle 100 is parked in the test station
3, according to known techniques, as already mentioned above.
[0118] The projection surface 4, e.g. the display of a monitor, is
arranged in front of the test station 3, in particular transverse
to the longitudinal axis AA of the vehicle 100.
[0119] The operator then connects the portable device 20 (scan
tool) to the EOBD diagnostic socket 31 of the vehicle 100.
[0120] The portable device 20 has a screen 21 on which a graphical
interface is displayed, configured to allow text or instructions to
be entered by an operator.
[0121] In particular, the operator can select the vehicle 100 to be
calibrated, by choosing from different types of vehicles split into
brands (manufacturers) and models.
[0122] Alternatively, the portable device 20 performs such
selection automatically or semi-automatically, asking the operator
to confirm that the vehicle 100 detected is the correct one.
[0123] The operator also selects the ADAS system to be calibrated,
specifically the optical sensor 2 to be calibrated. Also in this
case, the selection can take place manually, automatically or
semi-automatically.
[0124] These detection or selection steps of the vehicle 100 and of
the type of optical sensor 2 to be calibrated are known in
themselves and therefore are not the subject matter of this
disclosure.
[0125] Once the type of optical sensor 2 has been identified, the
control unit 5 (in the scan tool 20) can determine the spatial
measurement position that the monitor must assume with respect to
the optical sensor 2 during calibration.
[0126] Such determination takes place, for example, in the case of
a vehicle 100 placed on a horizontal support surface.
[0127] The spatial measurement position is preferably displayed in
the form of instructions on the projection surface 4.
[0128] It is known that the mutual position of the optical sensor
and its target (in this case the display or, in general, the
projection surface) must be adjusted according to the type of
optical sensor and the position that it occupies in the vehicle
2.
[0129] Preferably, other parameters or initial calibration
conditions are also projected onto the projection surface 4.
[0130] The operator then manually adjusts the projection surface 4
until the latter assumes the spatial measurement position.
Alternatively, the adjustment of the position of the projection
surface 4 takes place automatically.
[0131] Once this adjustment has been performed, the operator
confirms to the portable device 20 (still through the graphical
interface that can be loaded onto its screen 21) that the
preliminary step has been performed and the actual calibration can
take place. The operator can choose whether to perform a
calibration with a static image or a dynamic video.
[0132] The control unit 5 searches inside the memory 6 for the
image (in the former case) or the video (in the latter case)
associated with the type of optical sensor 2 to be calibrated.
[0133] The image or video selected can then be displayed on the
projection surface 4.
[0134] Once the target (which in this case is the projection
surface 4) has been adjusted and the image or video has been
projected, the calibration is performed by the calibration unit 30
which communicates with the scan tool 20. The actual calibration,
meaning the adjustment of the position of the optical axis of the
optical sensor 2, takes place according to an algorithm of the
known type.
[0135] Once the optical sensor 2 has been calibrated, the operator
can easily repeat the aforesaid method for other optical sensors
located on board of the vehicle 100.
[0136] Alternatively to the determination of the spatial position
that the projection surface 4 must have and its subsequent
adjustment, it is possible to project a deformed image or video
onto the projection surface 4. Such solution, used in particular
when the vehicle 100 is on a horizontal support surface, is
particularly advantageous because it prevents having to adjust the
position of the projection surface 4.
[0137] Finally, it is also possible to adopt a combined solution,
in which the spatial adjustment is performed on both the position
of the projection surface 4 and a projection of the deformed
image/video.
[0138] A similar calibration system may also be applied for the
calibration of a radar mounted on board of a vehicle, i.e. a
frontal radar.
[0139] According to prior art solutions, the calibration of the
frontal radar is achieved by means of a plane reflector arranged at
a certain distance D from the radar and perpendicular to the axis
of the radar.
[0140] Usually, the manufacturers declare a certain tolerance
.DELTA.D range for the distance D, i.e. D.+-..DELTA.D, in the
arrangement of the plane reflector with respect to the radar.
[0141] Nevertheless, it is well-known in this field that a
deviation, even of a few degrees, in the orthogonal arrangement of
the plane reflector with respect to the radar results in failure of
the calibration.
[0142] Applying to the frontal radar a system and the method
similar proposed herewith for the optical sensor, the user simply
place the plane reflector in front of the radar at the distance D
recommended by the manufacturer, then he inserts the relevant
distances obtained by means of laser meters, and the system
calculates the magnitude of the angle that the plane reflector
needs to be rotated. Furthermore, the system indicates to the user
whether and of which amount the plane reflector shall slide right
or left in order to be centred with respect to the radar.
[0143] In practice, in the calibration of a radar, the radar
substitutes the optical sensor 2, while the plane reflector
substitutes the projection surface 4.
[0144] The characteristics and the advantages of the system and
method of calibrating an optical sensor mounted on board of a
vehicle, according to an embodiment, are clear, as are the
advantages.
[0145] In particular, the use of a surface onto which the images
are projected prevents the storage or delicate handling in the
workshop of numerous target panels having different shapes, sizes
and patterns.
[0146] In the solution using a screen, e.g. of a television set,
the calibration system proposed herein further allows a contrast to
be achieved that is also compatible with use in an open
environment.
[0147] Furthermore, the screen also allows videos that reproduce
real dynamic or simulated scenarios to be projected. Therefore,
even for static calibration (i.e. with the vehicle stationary),
comparable performance levels are obtained to those of dynamic
calibration, which can therefore be prevented for vehicles which
usually required an on-road test. Preventing the on-road test
simplifies planning (connected with weather and road conditions)
and prevents risks for the driver.
[0148] The method and system proposed can also be used in the event
of inclination of the vehicle (within certain limits) because it is
sufficient to suitably deform the image/video to be projected onto
the screen instead of performing the spatial adjustment of the
screen with respect to the vehicle.
[0149] In addition, in case of calibration of the radar, the user
may save up to 20 minutes times for each vehicle.
[0150] As will be appreciated by one skilled in the art, various
aspects may be embodied as a system, method or device program
product. Accordingly, aspects may take the form of an entirely
hardware embodiment or an embodiment including software that may
all generally be referred to herein as a "circuit," "module" or
"system." Furthermore, aspects may take the form of a device
program product embodied in one or more device readable medium(s)
having device readable program code embodied therewith.
[0151] It should be noted that the various functions described
herein may be implemented using instructions stored on a device
readable storage medium such as a non-signal storage device that
are executed by a processor. A storage device may be, for example,
a system, apparatus, or device (e.g., an electronic, magnetic,
optical, electromagnetic, infrared, or semiconductor system,
apparatus, or device) or any suitable combination of the foregoing.
More specific examples of a storage device/medium include the
following: a portable computer diskette, a hard disk, a random
access memory (RAM), a read-only memory (ROM), an erasable
programmable read-only memory (EPROM or Flash memory), an optical
fiber, a portable compact disc read-only memory (CD-ROM), an
optical storage device, a magnetic storage device, or any suitable
combination of the foregoing. In the context of this document, a
storage device is not a signal and "non-transitory" includes all
media except signal media.
[0152] Program code embodied on a storage medium may be transmitted
using any appropriate medium, including but not limited to
wireless, wireline, optical fiber cable, RF, et cetera, or any
suitable combination of the foregoing.
[0153] Program code for carrying out operations may be written in
any combination of one or more programming languages. The program
code may execute entirely on a single device, partly on a single
device, as a stand-alone software package, partly on single device
and partly on another device, or entirely on the other device. In
some cases, the devices may be connected through any type of
connection or network, including a local area network (LAN) or a
wide area network (WAN), or the connection may be made through
other devices (for example, through the Internet using an Internet
Service Provider), through wireless connections, e.g., near-field
communication, or through a hard wire connection, such as over a
USB connection.
[0154] Example embodiments are described herein with reference to
the figures, which illustrate example methods, devices and program
products according to various example embodiments. It will be
understood that the actions and functionality may be implemented at
least in part by program instructions. These program instructions
may be provided to a processor of a device, a special purpose
information handling device, or other programmable data processing
device to produce a machine, such that the instructions, which
execute via a processor of the device implement the functions/acts
specified.
[0155] It is worth noting that while specific blocks are used in
the figures, and a particular ordering of blocks has been
illustrated, these are non-limiting examples. In certain contexts,
two or more blocks may be combined, a block may be split into two
or more blocks, or certain blocks may be re-ordered or re-organized
as appropriate, as the explicit illustrated examples are used only
for descriptive purposes and are not to be construed as
limiting.
[0156] As used herein, the singular "a" and "an" may be construed
as including the plural "one or more" unless clearly indicated
otherwise.
[0157] This disclosure has been presented for purposes of
illustration and description but is not intended to be exhaustive
or limiting. Many modifications and variations will be apparent to
those of ordinary skill in the art. The example embodiments were
chosen and described in order to explain principles and practical
application, and to enable others of ordinary skill in the art to
understand the disclosure for various embodiments with various
modifications as are suited to the particular use contemplated.
[0158] Thus, although illustrative example embodiments have been
described herein with reference to the accompanying figures, it is
to be understood that this description is not limiting and that
various other changes and modifications may be affected therein by
one skilled in the art without departing from the scope or spirit
of the disclosure.
* * * * *