NZ609869B - Method and devices for identifying a vehicle using a location - Google Patents
Method and devices for identifying a vehicle using a locationInfo
- Publication number
- NZ609869B NZ609869B NZ609869A NZ60986913A NZ609869B NZ 609869 B NZ609869 B NZ 609869B NZ 609869 A NZ609869 A NZ 609869A NZ 60986913 A NZ60986913 A NZ 60986913A NZ 609869 B NZ609869 B NZ 609869B
- Authority
- NZ
- New Zealand
- Prior art keywords
- radio
- onboard unit
- identifier
- beacon
- identification
- Prior art date
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- 238000004891 communication Methods 0.000 claims abstract description 7
- 238000001514 detection method Methods 0.000 claims description 9
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- 229940035295 Ting Drugs 0.000 claims description 2
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- 238000005259 measurement Methods 0.000 description 7
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- 101710017884 Segment-8 Proteins 0.000 description 4
- 238000010295 mobile communication Methods 0.000 description 4
- 101700009395 orf8 Proteins 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 102100014471 CALM2 Human genes 0.000 description 2
- 101700010927 CALM3 Proteins 0.000 description 2
- 102100014466 CALM3 Human genes 0.000 description 2
- 101710038036 CAMK2B Proteins 0.000 description 2
- 101700048718 EBP1 Proteins 0.000 description 2
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- 101700007087 PID1 Proteins 0.000 description 1
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- 238000011156 evaluation Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000003287 optical Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Abstract
609869 Disclosed is an onboard navigation unit (10) for a vehicle (9). The onboard unit (10) is comprised of a processor, a satellite navigation receiver for position determination, and a transceiver for radio communication. The onboard unit (10) is configured to, with the aid of the transceiver, repeatedly broadcast via radio status messages (16). Each status message (16) contains a radio identifier of the onboard unit (10) that changes after several status changes. The onboard unit (10) is also configured to indicate in each status message (16) the current relative distance from a predetermined location (5, 6, 7, 8), as determined by way of the satellite navigation receiver. The onboard unit (10) also receives, from a radio beacon (3), an identification request that is addressed to the current radio identifier of the onboard unit (10) and contains a cryptographic sender certificate. The onboard unit (10) can then validate the sender certificate and if it is valid, transmit a unique identification of the onboard unit (10) to the radio beacon (3). The identification remains the same over several changes of radio identifier. repeatedly broadcast via radio status messages (16). Each status message (16) contains a radio identifier of the onboard unit (10) that changes after several status changes. The onboard unit (10) is also configured to indicate in each status message (16) the current relative distance from a predetermined location (5, 6, 7, 8), as determined by way of the satellite navigation receiver. The onboard unit (10) also receives, from a radio beacon (3), an identification request that is addressed to the current radio identifier of the onboard unit (10) and contains a cryptographic sender certificate. The onboard unit (10) can then validate the sender certificate and if it is valid, transmit a unique identification of the onboard unit (10) to the radio beacon (3). The identification remains the same over several changes of radio identifier.
Description
Patents Form 5
N.Z. No. 609869
NEW ZEALAND
Patents Act 1953
COMPLETE SPECIFICATION
METHOD AND DEVICES FOR FYING A VEHICLE USING A LOCATION
We, KAPSCH TRAFFICCOM AG, an Austrian company of Am Europlatz 2, A-1120
Wien, Austria, do hereby declare the invention, for which we pray that a patent may
be granted to us, and the method by which it is to be performed, to be particularly
described in and by the ing statement:-
(Followed by 1A)
- 1A -
Method and Devices for Identifying a Vehicle Using a Location
The present invention relates to a method for identifying a vehicle
using a predetermined location. The invention further relates to a radio
beacon and to an onboard unit for use with this .
Methods for identifying vehicles are required, for example, so as
, monitor, authorize and/or impose tolls (charge fees) for the
usage of locations by vehicles. Such usages of locations can, for
example, include the entering of areas to which access is limited or that
are monitored, a fee-based stay at a particular on, for example a
parking lot that is subject to a charge, or the use of traffic routes subject
to tolls, such as highways or inner cities (city toll), and the like. In known
vehicle identification s, either license plate numbers (registration
plates) are read by way of optical character recognition (OCR), or the
vehicles are ed with onboard units (OBUs) having a unique
identification, which can be read out via a radio interface such as
dedicated short range communication (DSRC), radio frequency
identification (RFID), wireless local area network (WLAN), wireless
access for vehicular environments (WAVE) or the like.
So as to create a clear association of a wirelessly read OBU
identification with the location used by the vehicle, presently radio
beacons, which are used for wireless reading, are mounted on special
installations ("gantries) at the on to be monitored
and equipped with narrowly defined radio coverage ranges; or satellite
navigation-based d units are employed, which it the selflocated
position data via a mobile communication network to a back
office, which performs a map matching with the ons to be
monitored. All of these known methods require not only special, complex
lations, both in the vehicle and on the road, but also disclose the
identity of the OBU (in the form of a wirelessly read OBU identification),
even if no location usage requiring monitoring exists, which is
objectionable for data protection reasons.
It is the object of the invention to create methods and s of
type mentioned above, which allow vehicles using a location to be
identified in a simpler manner and with improved confidentiality for
uninvolved vehicles.
This object is ed in a first aspect of the invention by a
method of the type mentioned above, comprising:
carrying, on the vehicle, an onboard unit that via radio repeatedly
broadcasts status messages, which each indicate a current relative
distance of the onboard unit from the predetermined location and a radio
identifier that changes after each or several status messages;
receiving at least one status message in a radio beacon;
detecting a location usage of the vehicle by evaluating the at
least one status message based on the relative ce indicated
itting an identification request from the radio beacon to that
onboard unit which is addressed by way of the radio identifier from the
at least one status message;
receiving and conducting a legitimacy check of the fication
request in the onboard unit and, if the request is legitimate, transmitting
a unique fication of the onboard unit to the radio beacon, the
unique identification remaining the same over several s of radio
identifier.
The invention is based on a novel integration of onboard units
transmitting status messages, such as those known, for example, from
the ITS-G5 or WAVE (IEEE p) rds, in the form of common
awareness messages (CAM) or basic safety messages (BSM). The
messages are emitted as repeated broadcasts so as to warn or notify
neighboring onboard units or roadside infrastructure in order to avoid
collisions or provide the driver with an improved overview of the
situation. So as to render the creation of movement profiles of a vehicle
more difficult, the status messages are sent only under ary radio
identifiers, which change from time to time and are not known to the
system operators, so as to protect the privacy. The invention only
evaluates the temporary radio identifiers of at least one status message
of the onboard units. Only after the usage of the location has been
detected - anonymously as a result of the temporary radio identifiers - is
the onboard unit requested to reveal the "true" identity thereof, for
example payment, use or application identity. This ensures that in fact
only those onboard units are identified, which used the predetermined
location; onboard units of third-party vehicles, which merely pass the
location in the vicinity or turn around just before actual usage of the
location, and the like, are not identified, which is to say they remain
anonymous. Consequently, high data protection requirements in terms
of privacy can be satisfied, without itating complex ide
installations, OBU modifications or separate anonymization devices
such as proxy computers.
The measure according to the invention, according to which each
onboard unit itself calculates the relative distance f from the
predetermined location and transmits the finished calculation result to
the radio beacon, relieves the unit of the computationally intensive
calculation of the distance. All the radio beacon is now required to do is
to te the relative distances, for example check them to see
whether a drop below a predetermined m distance has occurred,
so as to detect the location usage based thereon.
According to a first embodiment of the invention, information
about the predetermined on is transmitted from the radio beacon to
the onboard unit, which then based thereon and based on its current
position calculates the relative ce.
As an alternative, information about the predetermined location
can be stored in the onboard unit, which based thereon and based on its
current position calculates the relative distance. For example, each
onboard unit can include lists of installation locations of radio beacons
as predetermined locations, have previously stored them, or received
them via radio, for example distributed by radio beacons, and can use
these lists so as to ine the relative distance from the respective
nearest radio beacon.
Another preferred embodiment of the invention is characterized in
that at least two status messages are received in a radio beacon and
are associated with each other based on the radio fiers ted
therein, and the location usage by the vehicle is ed by ting
the mutually associated status messages based on the relative
distances indicated therein.
By mutually associating and evaluating at least two status
messages, an d unit is tracked over a short period of time, which
is sufficient to be able to establish the usage of a particular on with
high certainty. Even two or just a few status messages that can be
associated with one and the same onboard unit may suffice for this
purpose to exclude ement errors and reliably detect a movement
that has occurred with respect to an increasing or decreasing relative
distance. In the simplest case, such a detected location usage can be
the crossing of a predetermined boundary around the predetermined
location, if the first status message indicates a relative distance outside
the boundary and the second status message tes a relative
distance inside the boundary, so as to detect a location usage.
ing to a further preferred embodiment of the invention, the
legitimacy check is carried out by checking a cryptographic sender
certificate of the radio beacon that is transmitted by the radio beacon
along with the identification request. The onboard unit thus ses the
identity thereof only to identified, legitimate inquirers, which further
improves the protection of privacy.
For the same reason, it is particularly advantageous for the
identification of the onboard unit to be transmitted to the radio beacon
via an encrypted channel. Direct (point-to-point) encrypted
communication can be established between the onboard unit and
inquiring radio beacon for this purpose. For example, the encrypted
communication l can be part of the protocol at the radio interface
n the onboard unit and the radio beacon, for example part of the
ITS-G5 or WAVE standard, but atively could also be established
separately via a 3G, 4G or 5G mobile communication network.
In a preferred application of the identification method of the
invention, the identification received in the radio beacon is recorded
together with a time stamp in a memory so as to log the location usage,
for example for monitoring purposes.
In an alternative application of the invention, the identification
received in the radio beacon is compared to at least one previously
stored legitimate identification so as to authorize the on usage, for
example so as to open gates, lower a wheel lock, deactivate an
enforcement system or the like.
In another application of the identification method of the
invention, the identification received in the radio beacon is used to
search for and debit a toll account ated with the identification, so
as to toll the on usage, for example so as to levy a location and/or
time toll, parking fees, road usage fees, city toll or the like.
In all three variants, the radio beacon can preferably transmit a
beacon identifier that is unique to the radio beacon to the onboard unit
after g, ization or tolling of the location usage, the onboard
unit storing this identifier and transmitting the same along with the next
broadcast of the status message(s) thereof or transmission of the
identification thereof, and the radio beacon can ignore a status message
or identification ed from an onboard unit, if the beacon identifier
received along therewith is identical to its own beacon identifier.
Inadvertent double logging, ization or tolling of one and the same
onboard unit in the radio coverage range of a radio beacon can thus be
prevented.
According to a further preferred characteristic of the invention,
more than two status messages can be received and associated with
each other, and a movement trend of the onboard unit can be calculated
based on the ve distances ted in these messages, the trend
being compared to the predetermined location so as to detect the
location usage. This allows the detection ility to be increased and,
for example, "measurement outliers" to be better suppressed.
It is particularly advantageous if the respective radio identifier is
changed after approximately 5 to 1000, preferably 20 to 100, status
messages. The more frequently the radio identifier changes, the greater
is the data protection in terms of the traceability of a particular onboard
unit; the less frequently the radio identifier changes, the lower is the risk
that the radio identifier around the location to be detected changes,
which would make detection more ult. The values indicated above
constitute a good compromise between these mutually opposing
requirements.
As an alternative, the change interval of the radio identifier of the
onboard unit can also be set so that the radio identifier is changed at the
earliest after expiration of a predetermined time period. Based on the
size of a ary radio coverage range of a radio beacon and an
average speed of d units, the predetermined time period can be
ed so that no radio identifier change takes place with high
certainty when an onboard unit passes a radio beacon.
Another preferred embodiment of the ion is to keep the
radio identifier the same while the onboard unit is located in the radio
coverage range of one and the same radio beacon. For this purpose, for
e, the onboard unit can directly measure the radio coverage
range of a radio beacon if the radio beacon periodically broadcasts
beacon identifiers, or can determine the same based on previously
stored lists or maps of radio coverage ranges of known radio beacons,
or be notified by a radio beacon as part of one of the broadcasts or the
identification request of the beacon.
The status messages can further also contain the current position
and/or a current movement vector of the onboard unit, which is or are
used along with the detection of the location usage so as to further
increase the detection reliability.
According to a further red characteristic of the invention, the
current position of the onboard unit can be determined by way of
satellite navigation and improved by referencing to a reference position
of the radio beacon that was determined by way of ite navigation,
in the manner of differential GPS (dGPS), wherein the radio beacon
forms the reference er so as to improve the ons of the
onboard units determined by way of satellite navigation.
As an alternative, the current position of the onboard unit can be
determined by way of satellite navigation and improved by referencing to
at least one further position of a oring onboard unit that was
determined by way of satellite tion. This embodiment is based on
the assumption that, given the proximity to each other, the d units
that are present in the radio coverage range of a radio beacon are each
subject to the same satellite navigation errors and neighboring OBUs
thus can be used as comparison receivers in the manner of dGPS.
In general, a radio beacon could be used to detect location
usages in the immediate or wider nment thereof, or even in
remote territories outside the radio coverage range thereof; however,
the radio coverage range of the radio beacon preferably ns the
predetermined location, so that each radio beacon is in charge of
location usages in the immediate surroundings thereof and thus
receives current and local measurement data from onboard units.
In a second aspect, the invention creates a radio beacon for
identifying a vehicle using a predetermined location, the vehicle carrying
an onboard unit that via radio repeatedly broadcasts status messages,
which each indicate a current relative distance of the d unit from
the indicated location and a radio identifier that changes after each or
several status messages, wherein the radio beacon is configured to,
with the aid of a processor and a transceiver ted thereto,
receive at least one status message;
detect a location usage by evaluating the at least one status
message based on the relative distance predetermined therein;
transmit an identification request to that onboard unit which is
addressed by way of the radio identifier from the at least one status
message; and then
receive a unique identification of the onboard unit that remains
the same over several radio identifier changes.
It is particularly advantageous if the radio beacon is configured to
receive at least two status messages and associate these with
each other based on the radio identifiers indicated therein, and
detect the location usage of the vehicle by evaluating the
mutually associated status messages based on the relative distances
ted therein.
The radio beacon preferably contains a cryptographic sender
certificate and is configured to it the same along with the
identification request.
In a third , the invention creates an onboard unit,
comprising a processor, a satellite navigation receiver for position
determination, and a transceiver for radio communication, n the
d unit is configured to edly broadcast status messages via
radio using the transceiver, each e ning a radio identifier
of the onboard unit that changes after several status messages,
wherein the onboard unit is further configured to indicate in each
status message the current relative distance thereof from a
predetermined location, as determined by way of the satellite tion
receiver,
receive an identification request from a radio beacon, the request
being addressed to the current radio identifier of the unit and containing
a cryptographic sender certificate;
to validate the sender certificate; and if the same is valid,
to transmit a unique identification of the onboard unit to the radio
beacon, the identification remaining the same over several radio
fier changes.
The status messages of the onboard unit are preferably modified
CAMs according to the ITS-G5 standard or modified BSMs according to
the WAVE standard.
With regard to onal characteristics and advantages of the
radio beacon and onboard unit of the invention, reference is made to the
above descriptions of the method, and the description below of preferred
ments, which is provided referencing the anying
drawings, in which:
shows a schematic overview of components acting within
the scope of the method of the invention, including the radio beacon and
l onboard units of the invention;
shows a block diagram and also a signal flow chart of the
method of the ion; and
shows a sequence diagram of the exchange of messages
at the radio interface between the radio beacon and onboard unit.
shows a road toll system 1 as an exemplary application of
the identification method of the invention, comprising a back office 2 and
a plurality of geographically distributed roadside radio beacons
(roadside entities, RSE) 3 that are connected thereto. Each of the radio
beacons 3 has a limited radio coverage range 4, for example a wireless
radius of 200 meters, within which predetermined locations such as
points 5 ("virtual toll plazas"), areas 6 (for example parking lots),
boundaries 7 (for example virtual gantries, inner city boundaries or the
like) or road segments 8 are defined, n the ons 5-8 can also
be entirely or partially located outside the radio coverage range 4. They
are preferably located (at least partially) inside the radio coverage range
, which fies the association of a radio beacon 3 with the locations
-8 for which the beacon is in charge.
The radio beacons 3 detect location usages of vehicles 9 that
pass the radio ge range 4 of the beacons, which is to say whether
- and optionally how long - these use one of the locations 5-8, and
identify such vehicles 9 that use the locations. Vehicles 9 that do not use
any of the locations 5-8 are not to be identified, which is to say remain
anonymous.
For the purposes mentioned above, all vehicles 9 are equipped
with onboard units (OBUs) 10, the uration of which will be
described in more detail based on
According to each OBU 10 comprises a satellite
tion er 11 for successively repeated determining the
respective current position ("position fix" P1, P2, ..., Pi in general, of the
unit in a global satellite navigation system (GNSS) such as GPS,
GLONASS, Galileo or the like. Moreover, the OBU 10 is equipped with a
processor 12 and a transceiver 13, wherein some of the data
tions between the satellite navigation receiver 11, processor 12
and transceiver 13 are not shown for clarity reasons.
Reference numeral 14 schematically s a service
application that can be executed by the processor 12, for example a toll
application, which can cooperate with the radio beacons 3 and the back
office 2 of the road toll system 1 in a manner that will be described
hereafter and for this purpose has an OBU identifier uID that is unique
("unique ID") in the road toll system 1. For e, the OBU
identification uID can be a unique tion identifier of the OBU 10,
the name of the owner thereof, the name of the owner of the vehicle on
which the OBU 10 is mounted, an account or credit card identifier of the
vehicle owner or the like. In the road toll system 1, the OBU
identification uID is known to the back office 2 and/or the radio beacons
3 and can be used there for identifying the vehicle 9 that carries the
OBU.
Reference numeral 15 s a security application which is
processed by the processor 12 and by way of which the OBU 10
successively and repeatedly, preferably periodically approximately every
100 ms, broadcasts a status message 16 via the transceiver 13. The
status message 16 is intended to be received by OBUs 10 of
neighboring vehicles 9 and/or roadside infrastructure, such as the radio
beacons 3, and es neither a confirmation of receipt nor actual
receipt; the application 15 transmits status es 16 via the
transceiver 13 regardless of r or not these are received by a
receiver, however optionally the application can also be requested to do
so by radio beacons 3 or other OBUs 10.
Each of the status messages 16 can include the last position Pi of
the OBU 10 as determined by way of the satellite navigation receiver 11,
and optionally additional data, for example the speed and direction of
movement (movement vector) M, height, ement accuracy, and
the like. Each status message 16 is provided with a temporary radio
identifier pID, so that neighboring OBUs or infrastructure can correlate,
which is to say associate, consecutive status messages 16 with each
other based on the temporary radio identifier pID, so as to be able to
determine, at least over a short period of time, the movement path
(trajectory) of an OBU 10 based on the positions Pi from consecutive
status messages 16.
d units 10 comprising safety applications 15 for sending
such status messages 16 are d in the ITS-G5 and WAVE (IEEE
802.11p) standards, for example. Status messages 16 of this type are
referred to as common awareness messages (CAM) in the ITS-G5
standard and as basic safety es (BSM) in the WAVE standard
(notable SAE J2735). The temporary radio fier pID of a status
message 16 can, for example, be a temporary IP6 address, a MAC
address or pseudo MAC address of the OBU 10, an exact or preferably
generalized geographical on (location coordinates) of the OBU 10,
or the like. In the simplest case, the temporary radio identifier pID can
thus even be identical to the position Pi of the OBU 10.
The radio identifier pID is not known in the road toll system 1 or to
the back office 2 and the radio beacons 3 and has no significance there;
for example, it can also be ly selected by an OBU 10. The radio
identifier pID is also "temporary" in the sense that the same changes
after a particular number of status messages 16 so as to suppress
tracking of a particular OBU 10 over an extended period. For example,
the radio identifier pID is changed after every fifth to thousandth,
preferably every twentieth to hundredth, status message 16. This
method is shown in more detail in the sequence diagram of
As an alternative, the radio identifier pID can be changed after a
predetermined time period, or the change can be selectively omitted,
which is to say ssed by the onboard unit 10, while the same is
present in the radio coverage range 4 of one and the same radio beacon
3. For this purpose, the onboard unit 10 can have previously stored
information about the position of a radio beacon and/or the size of the
radio coverage range 4, for example in the form of lists or maps, or have
been notified thereof by a radio beacon 3, be it in the form of period
broadcasts of a radio beacon 3 or as part of the messages 22, 27 and
27' described below.
For the purpose of the method that is described here, the status
messages 16 are modified as ed to conventional CAMs or BSMs
in that these - instead of or in addition to the current position Pi of the
OBU 10 - in each case include the current ve distance Ai of the
OBU 10 from a predetermined location 5 - 8. For this purpose, it is
necessary for the OBU 10 to have ation about the location
coordinates (geographical position) P0 of the predetermined location 5 -
8, for example of the point 5 or of the center or a nce point of the
area 6, the boundary 7, the road segment 8, and the like.
The on information P0 of the predetermined location 5 - 8
can, for example, have been previously stored in the OBU 10, for
example in the form of a list, and more particularly the same have been
stored during tion or delivery of the OBU 10 or "on the fly", for
example ed from one of the radio beacons 3, or distributed to the
OBUs 10 by the back office 2 via the network of radio beacons 3 or
another radio network, for example a mobile communication network. If
several predetermined locations 5 - 8 exist, the OBU 10 transmits, for
example in the status messages 16, the respective relative distance Ai
from the nearest location 5 - 8, ed the OBU does not receive an
order from a radio beacon 3, or in another manner, to calculate the
relative distance Ai from another than the nearest location 5 - 8.
Calculating the relative distance Ai between the current on
Pi of the OBU 10 and the position P0 of the predetermined on 5 - 8
is a standard calculation of the length of the vector from P0 to Pi
according to the ing equation
Ai = (X i − X 0 ) (2 + Y −) (Y 2 2
0 + Z)i − Z i 0 , (1)
where (Xi/Yi/Zi) are the nates of the current position Pi of
the OBU 10 and (X0/Y0/Z0) are the coordinates of the position P0 of the
predetermined location 5 - 8. The calculation can, of course, also be
carried out exclusively in the two-dimensional plane X/Y, which is to say
the Z coordinates can be disregarded.
According to the OBU 10 repeatedly its status
messages 16, here denoted by CAM1, CAM2, CAM3,..., or CAMi in
general. In the example shown, the radio identifier pIDn changes after
the first three status messages 16, or CAM1, CAM2, CAM3 from pID1 to
pID2, and so forth. At the ith status message CAMi, the nth radio
identifier pIDn is used (n << i).
As a result, it is statistically very likely that two consecutive status
messages 16 can be associated with each other based on the identical
radio identifier pIDi thereof; it is only during the change of the radio
fier from pIDn to pIDn+1 that a direct correlation of the status
message 16 before and after the change of the radio identifier is not
possible. In this case, a correlation of the status messages 16 is also
possible by tracking the movement y of the onboard unit 10, for
example by evaluating the speed thereof, directional vector f or
the like, be it that this information is provided ly by the OBU 10 in
the status messages 16 or measured by the radio beacon 3. It is also
possible to store properties of the vehicle 9 that carries the OBU 10,
such as the vehicle width, length, height or the like, in the OBU 10 and
for the same to be ed in the status messages 16 or measured by
the radio beacon 3, so as to increase the reliability of the correlation.
According to FIGS. 1 to 3, a radio beacon 3, which receives the
status messages 16 of all OBUs 10 passing in the radio coverage range
4 thereof, is thus able to associate the status messages 16 ating
from a particular OBU 10 with each other based on the radio identifiers
pID and thus track the nt trend of the OBU 10 based on the
relative distances Ai, optionally also the entire trajectory of the OBU 10
based on the positions Pi, if these are transmitted at the same time. For
this purpose, the radio beacon 3 according to comprises a
processor 17, a transceiver 18 and an association s 19, which the
processor 17 processes and which filters the flow of arriving status
messages 16 with regard to correlating radio identifiers
pID and feeds the relative distances Ai from mutually associated status
es 16 to a tracking process 20 that the processor 18 ses.
If the radio identifiers pID directly correspond to the
positions Pi or to geographical positions generalized therefrom, the
association process 19 can also carry out the mutual association of the
status messages 16 with each other based on a movement history
("tracking") of the OBU 10.
The tracking process 20 compares the relative distances Ai thus
obtained to a maximum distance am from a predetermined location 5 - 8,
so as to detect a location usage. Moreover, the movement trend of the
OBU 10 can be monitored for continually increasing or continually
decreasing relative distances Ai, so as to detect or suppress
measurement outliers and reliably detect any occurrence where the
distance limit am is ed.
In addition, the current positions Pi, if these are transmitted at the
same time, can be ted so as to further increase the detection
reliability. Because the distance calculation according to equation 1 is
d out in the OBU 10, the tracking process 20 in the radio beacon 3
can be kept very simple and reduced, for example, to the simple
ison "Ai < am?". ally, however, it is also possible to y
evaluate multiple relative distances Ai that are transmitted in
consecutive status messages 16, for e form the mean value
thereof and compare the same to the maximum distance am.
If the predetermined location P0 is a point 5, the location usage
detected based on the relative distances Ai can onally be validated
when a ermined number or a mean value of positions Pi drops
below a maximum distance am from the point 5. If the location is an area
6, the detection of the location usage can additionally be validated when
a predetermined number or a mean value of positions Pi is within the
area 6. If the location is a road segment 8, the detection of the location
usage can additionally be validated when, for e, the ons Pi
indicate travel on the entire road segment 8, from the beginning thereof
to the end thereof, or travel on a predetermined succession of multiple
consecutive road segments 8 or the like. If the location is a boundary 7
(which incidentally can also be used to delimit the scope around the
point 5, the area 6 or the road segment 8), the detection of the location
usage can additionally be validated as a crossing of the boundary.
In a simplified embodiment, the radio beacon 3 can detect a
location usage already from a single status message 16, so that the
association process 19 can be eliminated. In this case, for example, a
location usage can be detected when a single relative distance Ai drops
below the maximum distance am around the point 5. If the status
message 16 contains additional data, such as the speed and the
movement direction, notably a movement vector M, of the OBU 10,
usage of a location can also be detected when an extrapolation of the
movement of the OBU 10 in the past or future shows that the unit just a
moment ago used, is in the process of using, or will shortly use a
location, for example has dropped below the m distance am or
crossed or will cross the boundary 7.
As soon as the ng process 20 detects a location usage, the
process starts a service application 21 which is in charge of this location
usage and which the sor 17 will process. The application 21 can,
for example, be a logging, monitoring or authorization service, so as to
record the detected location usage - identified for the OBU 10 - or
monitor the same, or authorize additional steps such as the opening of
an access barrier, or the like. In the present example, the service
application 21 is a tolling e that has the service identification sID
and can impose tolls e fees) for the usage of the location by the
OBU 10.
The service application 21 now transmits an identification t
Id_Req 22, ally together with the service identification sID thereof,
via the transceiver 18 to the OBU 10 having the radio identifier pID that
was indicated in the status messages 16 associated by the association
process 19, refer also to The identification request 22 preferably
ns a graphic sender certificate "Cert" 23 of the radio beacon
3 so as to authenticate the same with respect to the onboard unit 10.
The OBU 10 addressed by way of the radio identifier pID
receives the identification request 22 and forwards the same to the
corresponding process, which here is the toll application 14. If the
fication request 22 contains a sender certificate 23, the OBU 10
can check the authenticity of the certificate 23 in an optional step 24
(; if this certificate is authentic or valid, the remaining steps are
carried out; if not, the identification request 22 is ignored.
The OBU 10 responds to the identification request 22 by
releasing (disclosing) the identification uID thereof, which is unique
throughout the system, which is to say consistently unique even over
multiple changes of the radio identifier pID, see the declaration message
Id_Rsp 25, which the unit returns to the transceiver 18 of the radio
beacon 3 via the eiver 13. The declaration message 25 may
contain the service identifier sID of the polling service application 21 of
the radio beacon 3, so that the declaration message can be supplied
there to the correct e application 21.
From now on, the OBU 10 is identified with the unique
identification uID thereof with respect to the service application 21, and
the latter is identified with the service identifier sID and the certificate 23
thereof with respect to the OBU 10 or the toll application 14. Additional
service-specific messages Svc_Msg 27 can now be exchanged between
the transceiver 13 of the OBU 10 and the transceiver 18 of the radio
beacon 3 via the radio interface 26. For e, the messages 27 can
be service packs of a conventional toll log for tolling the usage of the
location. The OBU identification uID can, for example, reference a toll
account in the radio beacon 3 or the back office 2, which is debited the
toll fees for the location usage. As an alternative, the identification uID
could be compared to (at least) one legitimate (reference) identification
uIDref that was previously stored in the radio beacon 3 or the back office
2, wherein if identical the identification uID is authorized, for example, to
access a location or receive a service.
As soon as the radio beacon 3 and the OBU 10 have been
authenticated with t to each other, in particular by evaluation of
the sender certificate 23 of the radio beacon 3, all subsequent
ication, such as the declaration message 25 and the ensuing
service es 27, can be transmitted in encrypted form via the radio
interface 26, for example as encrypted to-point communication.
Such an encrypted transmission channel could alternatively be
established via a mobile communication network (not shown), instead of
via the radio interface 26, for example directly with the back office 2.
In a simplified embodiment, in which the radio beacon 3 does not
perform a g on, but is merely used to identify the vehicles 9 or
OBUs 10, the determined identifications uID of the onboard units 10 can
also simply be recorded - ably in each case together with a current
time stamp t - in a memory 28 of the radio beacon 3 or back office 2 for
logging purposes.
Following successful logging, authorization or tolling of a location
usage, the radio beacon 3 can transmit a confirmation message "ok" to
the OBU 10 in an al step 27' and transmit in this message
nally again) a unique beacon identifier bID. The OBU 10 can store
beacon identifiers bID received from radio s 3 and transmit at
least the respective last beacon identifier bID received in one (or more)
of the status messages 16 and/or in the disclosure of the identification
uID thereof to a radio beacon 3 in step 25. The radio beacon 3 can thus
ignore or suppress status messages 16 and/or identification
transmissions 25, with which the same es a beacon identifier bID
that is identical to its own beacon identifier bID, so as to avoid double
processing of one and the same passing OBU 10.
During the ination of the current positions Pi and the
ve distances Ai, the positions Pi of an OBU 10 can be ed by
comparison to known reference positions - or at least to third-party
positions that are subject to the same measurement errors - as is known
from the field of ential GPS (dGPS). For example, the radio beacon
3 can have a dedicated satellite navigation receiver (not shown), which
measures reference positions Pref,i of the radio beacon 3 at
approximately the same times at which the positions Pi are generated
and makes these available, for example transmits these, to the OBU 10.
Having knowledge of the previously known position of a stationary radio
beacon 3, the positions Pi determined by way of satellite navigation can
then be placed in relation to the reference positions Pref,i - which are
subject to approximately equivalent measurement errors - and
measurement errors can thus be compensated for, refer to path 29 in
The respective positions Pi determined at similar times for
neighboring OBUs 10 could be used in the same manner to correct the
measurement errors of the positions Pi generated by an OBU 10 of
interest.
The invention is not limited to the shown embodiments, but
asses all variants and modifications that are covered by the
scope of the accompanying claims.
Claims (15)
1. A method for identifying a vehicle using a predetermined location, comprising: carrying, on the vehicle, an onboard unit that via radio repeatedly broadcasts status messages, which each indicate a current relative distance of the onboard unit from the predetermined location and a radio identifier that changes after each or several status messages; receiving at least one status message in a radio beacon; detecting a location usage of the vehicle by evaluating the at least one status message based on the relative distance indicated therein; transmitting an identification request from the radio beacon to that onboard unit which is sed by way of the radio identifier from the at least one status message; ing and conducting a legitimacy check of the fication request in the onboard unit and, if the request is legitimate, transmitting a unique identification of the onboard unit to the radio beacon, the unique identification remaining the same over several changes of radio identifier.
2. The method according to claim 1, characterized in that information about the ermined location is transmitted from the radio beacon to the onboard unit, which based thereon and based on the current position of the onboard unit calculates the relative distance.
3. The method according to claim 1, characterized in that information about the predetermined location is stored in the onboard unit, which based n and based on the t on of the d unit calculates the relative distance.
4. The method according to any one of claims 1 to 3, characterized in that at least two such status messages are received in the radio beacon and are ated with each other based on the radio identifiers indicated therein, and the location usage of the vehicle is detected by evaluating the mutually associated status messages based on the relative distances indicated therein.
5. The method according to any one of claims 1 to 4, characterized in that the legitimacy check is done by checking a cryptographic sender certificate of the radio beacon that is transmitted by the radio beacon along with the identification request.
6. The method according to any one of claims 1 to 5, terized in that the identification of the onboard unit is itted to the radio beacon via an encrypted channel.
7. The method according to any one of claims 1 to 6, characterized in that the fication received in the radio beacon is recorded together with a time stamp in a memory so as to log the location usage, or is compared to at least one usly stored legitimate identification so as to authorize the location usage, or is used to search for and debit a toll account associated with the identification so as to toll the location usage.
8. The method according to claim 7, characterized in that the radio beacon transmits a beacon identifier that is unique to the radio beacon to the onboard unit after logging, ization or tolling of the on usage, the onboard unit storing this identifier and transmitting the same at least along with a subsequent broadcast of the status message(s) thereof or transmission of the identification thereof, and the radio beacon ignores a status message or identification received from an onboard unit if the beacon identifier received along therewith is identical to its own beacon identifier.
9. The method according to any one of claims 1 to 8, characterized in that the radio fier is changed after every approximately 5 to 1000, preferably 20 to 100, status messages.
10. The method according to any one of claims 1 to 8, characterized in that the radio identifier is changed at the earliest after expiration of a predetermined time period.
11. The method ing to any one of claims 1 to 8, characterized in that the radio identifier is kept the same while the onboard unit is present in the radio coverage range of one and the same radio beacon.
12. The method according to any one of claims 1 to 11, characterized in that each status message also indicates the current position and/or a current movement vector of the onboard unit, which is or are also used during the detection of the location usage.
13. The method according to any one of claims 1 to 12, characterized in that the current on of the onboard unit is determined by way of satellite navigation and improved by referencing to a reference position of the radio beacon that was determined by way of ite navigation.
14. A radio beacon for identifying a vehicle using a predetermined location, the vehicle carrying an onboard unit that via radio repeatedly broadcasts status messages, which each indicate a current relative distance of the onboard unit from the predetermined location and a radio identifier that s after each or several status messages, characterized by being configured to, with the aid of a processor and a transceiver connected thereto, receive at least one status message; detect a location usage by ting the at least one status e based on the relative distance indicated therein; transmit an identification request to that onboard unit which is addressed by way of the radio identifier from the at least one status e; and then to receive a unique identification of the onboard unit that remains the same over several radio identifier changes.
15. An onboard unit, comprising a processor, a satellite navigation receiver for position determination, and a transceiver for radio communication, n the d unit is configured to, with the aid of the transceiver, repeatedly ast via radio status messages, which each contain a radio identifier of the onboard unit that changes after several status changes, characterized by further being configured to te in each status message the current relative distance from a ermined location, as determined by way of the satellite navigation receiver, e, from a radio beacon, an identification request that is addressed to the current radio identifier of the unit and contains a cryptographic sender certificate; validate the sender certificate; and if the same is valid, transmit a unique identification of the onboard unit to the radio beacon, the identification remaining the same over several changes of radio identifier. KAPSCH TRAFFICCOM AG By Their Attorneys HENRY HUGHES Per: 5-8 dGPS 29 28 21 20 TrackSrvc TollSrvc 3 µP 19 sID 22 25 17 CAM/BSM match sID uID RSE pID 23 18 RX/TX 6 2
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP12166502.0 | 2012-05-03 | ||
EP13158877.4 | 2013-03-13 |
Publications (1)
Publication Number | Publication Date |
---|---|
NZ609869B true NZ609869B (en) | 2014-01-07 |
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