Technical Field
[0001] The present disclosure relates to the field of short range communications, in particular
to an Electronic Toll Collection (ETC) system, an On-Board Unit (OBU) and a data communication
method of the OBU.
Background
[0002] With the development of short range communication technology, an ETC system is used
more and more widely in order to improve efficiency of expressway toll operations.
[0003] The national standard of ETC belongs to device specifications in networking charge
technology standards of the Ministry of Communications and is a technology standard
applied to the expressway toll collection for implementing the ETC. The national standard
mainly prescribes two device specifications for OBU and Road Side Unit (RSU) respectively,
and prescribes a Dedicated Short Range Communication (DSRC) protocol. The RSU is arranged
at a toll lane. The OBU is installed inside a vehicle, and applies a double-chip label
solution of IC card plus controller (i.e., CPU). The IC card is configured to store
account number, account balance, transaction record, exit/entrance number, etc. The
controller is configured to store information such as vehicle physical parameters
including car owner and car type, and to guarantee communications between the OBU
and the RSU.
[0004] The RSU and the OBU in the existing ETC system are provided with antenna oscillators.
The OBU can communicate with the RSU initiatively, modulate and receive frequency
signals transmitted by the RSU. In this condition, the OBU should be equipped with
batteries. How to reduce power consumption of the OBU without affecting communication
service capability between the OBU and the RSU is always a research focus in this
technical field.
[0005] According to
US 5 621 412 A, a system and method is disclosed, which conserves energy in the operation of a transponder
or tag (14) by providing that the transponder (14) be enabled or awakened in multiple
stages. A threshold detector (62) is provided which measures the power level of received
RF energy. If the RF energy received by the detector (62) exceeds a pre-determined
level, the transponder (14) then employs a modulation detector (64) to ascertain whether
it has been awakened by a valid interrogation signal from an interrogator (12) or
whether the RF energy received was merely a spurious burst of RF energy from some
other source. If a pre-determined modulation is detected by the modulation detector
(64), the transponder (14) is then fully activated to its normal operational state.
Summary
[0006] Examples of the present disclosure provides an ETC system, an OBU and a data communication
method of the OBU, which realize lower power consumption and longer service life.
[0007] In an example, a data communication method of an OBU includes: an OBU receives an
awakening frequency signal; the OBU matches an awakening frequency of the awakening
frequency signal with a response frequency preset by the OBU; when the response frequency
of the OBU is matched with the awakening frequency of the awakening frequency signal,
the OBU establishes data communication with an RSU.
[0008] In order to reduce power consumption, a controller of the OBU may adopt a low main
frequency when performing the matching.
[0009] For the convenience of calculation of a period of the awakening frequency signal,
a clock source of a timer in the controller has a frequency which is the same as the
low main frequency of the controller when matching, wherein the timer may be configured
to calculate a square-wave period of the awakening frequency signal.
[0010] In order to further reduce power consumption, the controller may be in a low power
consumption mode during non-transaction, the controller may adopt the low main frequency
when performing the matching and adopt the high main frequency when the data communication
with the RSU for transaction is established. Thus, power consumption in the whole
operation may be further reduced.
[0011] In the implementation of the disclosure, the response frequency may have a range
from 12 KHz to 16 KHz. The process of matching may be: the controller of the OBU may
detect and calculate the square-wave period of the awakening frequency signal, when
the calculated square-wave period of the awakening frequency signal is in the range
of the square-wave period of the preset response frequency, the matching is successful.
[0012] In another example, an OBU is provided. The OBU is connected with an RSU, and the
OBU includes a signal receiving unit configured to receive an awakening frequency
signal; a data receiving link configured to establish data communication with the
RSU; and a controller connected with the signal receiving unit and the data receiving
link respectively, configured to match an awakening frequency of the awakening frequency
signal with a response frequency preset by the OBU, and configured to control the
data receiving link to establish data communication with the RSU when the response
frequency is matched with the awakening frequency of the awakening frequency signal.
[0013] The circuit layout of the OBU may be as follows: a radio-frequency power switch may
be connected between the controller and the data receiving link; the controller may
be further configured to: control the radio-frequency power switch to be turned on
when the response frequency is matched with the awakening frequency of the awakening
frequency signal, and control the radio-frequency power switch to be turned off when
the response frequency is not matched with the awakening frequency of the awakening
frequency signal.
[0014] Preferably, the controller may be in a low power consumption mode during non-transaction;
the controller may adopt the low main frequency when matching is performed and adopt
the high main frequency when the data communication with the RSU for transaction is
established.
[0015] Preferably, when the controller performs the matching, a clock source of a timer
in the controller may have a frequency which is the same as the main frequency of
the controller, wherein the timer may be configured to calculate the square-wave period
of the awakening frequency signal.
[0016] Preferably, the response frequency may have a range from 12 KHz to 16 KHz; the controller
may be further configured to: detect at least two square-wave periods of the awakening
frequency signal and calculate the square-wave period of the awakening frequency signal;
when the calculated square-wave period of the awakening frequency signal is in the
range of the square-wave period of the preset response frequency, the matching is
successful.
[0017] In yet another example, an ETC system is provided, which can reduce power consumption.
The ETC system includes an OBU and an RSU; the OBU establishes data communication
with the RSU when the awakening frequency of the received awakening frequency signal
is matched with the preset response frequency.
[0018] Compared with the prior art, the examples of the present disclosure may have the
following advantages: 1) the premise of the data communication method of the OBU is
that the controller of the OBU strictly limits the response frequency; only when the
awakening frequency of the received awakening frequency signal is matched with the
preset response frequency, can the controller of the OBU establish the data communication
with the RSU; therefore, other communication data signals and awakening frequency
signals which do not meet requirements can not trigger the controller to establish
data communication with the RSU, and thus error awakening rate of the OBU is greatly
reduced, and unnecessary power consumption is reduced and service life of the OBU
is prolonged; 2) in the data communication method of the OBU, the controller adopts
low main frequency such as 1MHz when performing the matching, wherein the clock source
of the timer has a frequency which is the same as the 1MHz low main frequency of the
controller; therefore, the controller also operates in the low main frequency so as
to further reduce the power consumption of the controller when performing the matching;
3) in the data communication method of the OBU, the controller is in a low power consumption
mode during non-transaction; when a data communication transaction with the RSU is
established, the controller adopts a normal operating higher main frequency such as
16MHz, so as to further reduce power consumption in the whole operation of the OBU;
4) in the data communication method of the OBU, when the controller performs the matching,
the clock source of the timer has a frequency which is the same as the low main frequency
of the controller, thus, on one hand, power consumption is reduced, on the other hand,
the square-wave period of the received frequency signal is conveniently calculated
and determined; 5) in the data communication method of the OBU of the disclosure,
the controller detects at least two square-wave periods of the awakening frequency
signal, so as to accurately calculate the detected square-wave period of the awakening
frequency signal.
Brief Description of the Drawings
[0019]
Fig. 1 shows a block diagram of hardware of an OBU according to an example of the
present disclosure; and
Fig. 2 shows a flowchart of a process of error awakening and matching at an OBU according
to an example of the present disclosure.
Detailed Description
[0020] The disclosure will be further illustrated below in detail in specific examples with
reference to accompanying drawings.
[0021] Through research, the main power consumption during practical applications of the
OBU does not occur in normal transaction, but in the error awakening of the OBU, as
well as in the discharging process of the battery under various conditions and the
like. The error awakening is one of main causes of the power consumption of the battery.
[0022] According to the national standard, the OBU is in a passive receiving mode, and it
is thus required that the OBU can be awakened at multiple frequency points designated
by the national standard. After being awakened, the OBU sets a response frequency
point according to data received from the RSU so as to communicate with the RSU. Because
the awakening of the OBU is broadband awakening, theoretically, error awakening of
the OBU is caused probably in places with stronger radio communication signals.
[0023] In laboratory tests, through continuously adjusting signal strength of signals transmitted
from a signal source, it is detected that the OBU can be awakened around frequency
points of 900MHz, 800MHz and 2.4GHz, and it is easier to awake the OBU by mistake
at a frequency point around 5GHz. As can be seen, for the OBU with broadband receiving,
the error awakening is common in long-term usage. Therefore, the service life of the
OBU can be prolonged by reduction of the OBU's power consumption caused by error awakening.
[0024] The ETC system for reducing error awakening in an example of the disclosure includes:
an OBU and an RSU. The OBU includes a signal receiving unit, a controller 10 and a
data receiving link 30. In this example, the signal receiving unit is an antenna 50,
and is configured to receive an awakening frequency signal; the data receiving link
30 is controlled by the controller 10 to start data communication with the RSU after
the OBU is awakened; the controller 10 has a preset response frequency, connected
with the signal receiving unit and the data receiving link 30 respectively, and is
configured to determine whether the awakening frequency of the awakening frequency
signal is matched with the preset response frequency of the OBU, and to control the
data receiving link 30 to establish data communication with the RSU when the response
frequency is matched with the awakening frequency.
[0025] Refer to Fig. 1, the OBU in this example of the disclosure includes an IC chip (not
shown), a controller 10 and an antenna 50 functioning as a signal receiving unit.
The controller 10 of the OBU presets response frequency. Circuit layout of the OBU
is as follows: the controller 10 is connected with an awakening link 20 and is also
connected with the data receiving link 30, and the data receiving link 30 is connected
with a radio-frequency power switch 40 controlled by the controller 10. When determining
that the awakening frequency signal is a modulation signal of 14KHz square wave, that
is, the awakening frequency is matched with the preset response frequency, the controller
10 controls the radio-frequency power switch 40 to be turned on; otherwise, the controller
10 controls the radio-frequency power switch 40 to be turned off. In detail, when
determining that the received awakening frequency signal is matched with the modulation
signal of 14KHz square wave required by the national standard, the controller 10 controls
the radio-frequency power switch 40 to be turned on to enable the OBU to establish
data communication with the RSU.
[0026] In this example, the response frequency ranges from 12KHz to 16KHz.
[0027] In this example, when a vehicle with an OBU is far away from a toll station equipped
with an RSU, the OBU is in a low power consumption mode. When the vehicle approaches
the toll station, the vehicle runs over an induction line configured to start the
RSU to transmit an awakening frequency signal and a data signal. The RSU transmits
the awakening frequency signal and the data signal, and the OBU first detects the
awakening frequency signal and checks whether it is a matched signal.
[0028] According to the national ETC technical requirement, the OBU can be awakened by a
modulation signal of 14KHz square wave, and also can be awakened by a modulated data
signal of radio communication. In order to meet the modulation requirement of the
received awakening frequency signal for the OBU, the modulation signal of 14KHz square
wave should be of 15 to 17 square-wave periods.
[0029] If it is strictly configured that the OBU can only be awakened by a 14KHz modulated
square-wave awakening frequency signal, and if power is reduced as much as possible
when matching a 14KHz modulated awakening frequency signal, reduction of the power
consumption caused by error awakening can be realized.
[0030] When matching the awakening frequency signal, the controller 10 adopts low main frequency
such as 1MHz. When matching the awakening frequency signal, a clock source of a timer
in the controller 10 has a frequency which is the same as 1MHz low main frequency
of the controller 10, and in this way, it is easier to calculate the awakening square-wave
periods. Therefore, the controller 10 also operates in low main frequency to further
reduce the power consumption of the controller during the matching. In addition, the
clock source of the timer of the controller has a frequency which is the same as the
low main frequency of the controller 10, and thus, on one hand, power consumption
is reduced; on the other hand, the square-wave periods of the received frequency signal
can be calculated and determined conveniently.
[0031] In order to achieve the reduction of error awakening rate and that of power consumption,
it should be guaranteed in hardware design that the 14KHz awakening frequency signal
can be received by the controller (single-chip microcomputer). In this example, the
controller is a single-chip microcomputer which can switch between the low power consumption
mode and the normal mode. The awakening frequency signals received by the controller
should reach a certain number so that the controller has enough time to perform modulating,
matching and processing. In this example, the circuit design of the OBU is: the awakening
link and the data receiving link are designed separately and are connected to the
controller respectively. The awakening response of the controller should be quick
enough so as to receive the awakening frequency signal in time. When the controller
performs matching for the awakening frequency signal in the example, no other elements
are needed except the controller, and thus the power consumption is reduced.
[0032] Based on the hardware design of the OBU above, the awakening power consumption of
the OBU mainly depends on the power consumption of the process of awakening and matching.
When determining whether it is the 14KHz awakening frequency signal by using the single-chip
microcomputer through software, the power consumption of the single-chip microcomputer
is the total power consumption of the OBU during the awakening process. In the example,
the total power consumption during the awakening process includes the power consumption
of the awakening link and the power consumption of the single-chip microcomputer,
i.e., the controller. The power consumption of the awakening link is very low and
thus may be ignored. Generally, the power consumption of the single-chip microcomputer
is in proportion to the operating main frequency. Therefore, the power consumption
can be reduced if the single-chip microcomputer operates at an extremely low frequency
matched with the 14KHz awakening frequency signal.
[0033] Through experiments, when the controller 10 operates at 1MHz main frequency, the
1MHz main frequency can handle the matching for the 14KHz awakening frequency signal.
Generally, the power consumption of the controller 10 working at 1MHz main frequency
is about hundreds of microamperes, wherein the power consumption is relatively low
and can greatly reduce the power consumption of the battery during error awakening.
In order to match with the 14KHz awakening frequency signal, a lower main frequency
may also be selected; however, the awakening and matching operations should not affect
the practical transaction, that is, the transaction range can not be limited and the
original transaction range should be kept unchanged even though the awakening and
matching operations are added. In addition, due to fluctuation of a radio signal when
the radio signal is received, the matching range can not be limited too strictly.
Moreover, if the main frequency is too low, the matching would be too strict. Therefore,
it is proved through experiments that 1MHz main frequency is quite appropriate.
[0034] In the example, the controller 10 is in the low power consumption mode during non-transaction
time (that is, when the OBU does not approach the RSU, the OBU is in a sleep state).
The controller 10 adopts higher main frequency for normal operating, such as 16MHz,
during data communication transaction with the RSU, so as to further reduce the power
consumption in the whole operating of the OBU.
[0035] The data communication method of the OBU in the present disclosure substantially
includes the following steps:
the controller of the OBU presets response frequency; and
the controller of the OBU establishes data communication with the RSU when the awakening
frequency of the received awakening frequency signal is matched with the preset response
frequency.
[0036] In the data communication method of the OBU in the example, the controller 10 of
the OBU strictly limits the response frequency; only when the awakening frequency
of the received awakening frequency signal is matched with the preset response frequency,
can the controller 10 of the OBU establish the data communication with the RSU. Therefore,
other communication data signals and the awakening frequency signals which do not
satisfy requirements can not trigger the controller to establish data communication
with the RSU, and thus the error awakening rate of the OBU is greatly reduced and
unnecessary power consumption is reduced.
[0037] The process of matching with the 14KHz awakening frequency signal is: calculating
the square-wave period of the awakening frequency signal by counting the clock width
of the square-wave period of the awakening frequency signal. When the awakening frequency
signal is matched with the response frequency, no matter which hop the period is calculated
from, the period should be the square-wave period of 14KHz awakening frequency signal
since there is no phase difference in a square wave, and thus the matching is relatively
simple.
[0038] Key points for implementing the matching are as follows:
- 1) Matching precision of the 14KHz awakening frequency signal: in order to have more
accurate matching, the time recorded by the timer after matching with two complete
square-wave periods is obtained, the time is divided by 2 and the division result
is taken as the square-wave period of the detected awakening frequency signal. If
the time meets the time condition of two square-wave periods of the 14KHz awakening
frequency signal, that is, if the square-wave period of the awakening frequency signal
calculated and obtained by the timer is around 73 microseconds, it is considered that
the matching is successful. In the example, when the calculated and obtained square-wave
period of the awakening frequency signal ranges from 63 microseconds to 83 microseconds,
it is considered that the matching is successful.
- 2) If the number of hops reaches four, it is indicated that two continuous square-wave
periods are detected.
- 3) After the OBU receives the awakening frequency signal, the controller 10 starts
to match the received awakening frequency signal with the preset response frequency.
Because the signal is subjected to air transmission and radio-frequency link modulation,
and the preciseness of other elements and the like, the obtained awakening square-wave
frequency has some errors. Therefore, in this example, it is considered that the matching
is successful when the preset response frequency is around 12-16KHz.
- 4) When the period of the received 14KHz awakening square-wave is matched, the controller
10 is firstly configured to work in a low main frequency (1MHz in the example). In
this way, the power consumption of the controller is saved as much as possible. In
practical application, the main frequency can be set according to complexity of software
algorithm, so as to avoid affecting the awakening sensitivity of the OBU, and so that
the operation of the OBU would not be affected by introducing this function. Then,
the clock source of the timer is set. The clock source of the timer is the running
clock 1MHz of the controller, i.e., the same as the main frequency of the controller.
The square-wave matching of the awakening frequency signal is then started.
- 5) Setting timeout in the matching process: since the square-wave period which is
matched with the 14KHz standard awakening frequency signal is about 73 microseconds,
the timeout may be set as hundreds of microseconds.
[0039] Refer to Fig. 2, the matching process at the OBU is as follows:
the signal receiving unit of the OBU, such as antenna 50, receives an awakening frequency
signal and transmits the awakening frequency signal to the controller 10 through the
awakening link 20.
[0040] Step 201: After receiving the awakening frequency signal, the controller 10 is awakened
and then operates in an active state. At this moment, only the controller 10 is in
a power-on state, other circuits are still kept in a power off state. The controller
10 is set to operate in the low main frequency operating mode (1MHz in this example).
Further, a timer is configured in the controller and the clock source of the timer
has a frequency which is the same as the main frequency of the controller.
[0041] Step 202: Repeatedly detect whether the electrical level of the signal pin connected
between the controller 10 and the awakening link 20 has a hop; if yes, start to count
the number of hops; otherwise, determine whether it is timeout. If it is timeout,
the matching process is terminated, that is, Step 207 is performed; otherwise, Step
202 is performed again. Because the square-wave time matched with the 14KHz standard
awakening signal is about 73 microseconds, the timeout period is set as hundreds of
microseconds.
[0042] Specifically, if a hop is detected, Step 203 is performed; if no hop is detected
during a preset period of time (200 microseconds in this example), it is indicated
that it is an error awakening, and then Step 207 is performed.
[0043] Step 203 to Step 204: If there is a hop, it is determined whether it is the first
hop. If it is the first hop, the timer is cleared when the first hop is detected,
and after the timer is cleared, the timer starts timing and the controller starts
to record the number of hops. Here, the first hop would not be recorded in the number
of hops. If it is not the first hop, the number of hops is recorded, that is, the
current number of hops is increased by 1.
[0044] Step 205: It is determined whether the number of hops reaches 4, if yes, go to Step
206; otherwise, return to Step 202. The number of hops reaching 4 indicates that the
timer has recorded two square-wave periods of the awakening frequency signal.
[0045] Step 206: It is determined whether two continuous square-wave periods of the awakening
frequency signal are matched with the square-wave period of the 14KHz response frequency,
if yes, it is indicated that the received awakening square-wave is the correct awakening
square-wave, then go to Step 207; otherwise, it is indicated that the matching process
fails, then go to Step 208.
[0046] Step 207: The controller 10 is set to work in the frequency of the normal operating
mode (16MHz in the example). The input/output state and the initial output electrical
level of each pin are also set. The clock source of the timer is also set and starts
to work after it is set. The power supply of the radio-frequency link is turned on
through the radio-frequency power switch 40. After those settings, the ODU starts
working normally.
[0047] Step 208: It is determined that the OBU is awakened by mistake. In order to save
power consumption, the controller 10 is immediately set as entering a sleep state,
and then works in a low power consumption mode.
[0048] At least the following two advantages can be achieved through the above examples.
[0049] On one hand, in the hardware circuit design, the data receiving link and the awakening
link of the OBU are set respectively. And it is thus possible for software to realize
the matching for the 14KHz awakening frequency signal in the case that only the awakening
link works. In this way, power consumption can be reduced. Because the data receiving
link has higher performance and should be power on to operate, the power consumption
caused by error awakening can be completely avoided in the way that the data receiving
is started only after correct awakening.
[0050] On the other hand, during the matching for the 14KHz awakening frequency signal,
a low main frequency (1MHz in this example) is used, and thus the power consumption
of the OBU is further reduced.
[0051] The foregoing is only the preferred examples of the present disclosure and is not
intended to limit the scope of the present invention. Any modification, equivalent
substitution, or improvement made without departing from the present invention should
be covered by the scope set forth in the appended claims.
1. A data communication method of an On-Board Unit (OBU), the method comprising:
receiving, by the OBU, an awakening frequency signal;
matching, by the OBU, an awakening frequency of the awakening frequency signal with
a response frequency preset by the OBU; and
establishing, by the OBU, data communication with a Road Side Unit (RSU) when the
response frequency preset by the OBU is matched with the awakening frequency of the
awakening frequency signal,
wherein the OBU comprises a controller (10); the controller (10) operates in a low
power consumption mode during non-transaction, characterized in that the controller (10) operates in a low main frequency when performing the matching,
and the controller (10) operates in a high main frequency when the data communication
with the RSU for transaction is established,
wherein a clock source of a timer in the controller (10) has a frequency which is
the same as the main frequency of the controller (10) when the controller (10) performs
the matching, wherein the timer is configured to calculate a square-wave period of
the awakening frequency signal.
2. The data communication method of the OBU according to claim 1, wherein a range of
the response frequency is 12 KHz to 16 KHz; and wherein the matching comprises: detecting
and calculating the square-wave period of the awakening frequency signal by the controller
(10) of the OBU, and determining that the matching is successful when the calculated
square-wave period of the awakening frequency signal is in the range of a square-wave
period of the response frequency.
3. An On-Board Unit (OBU) connected with a Road Side Unit (RSU), the OBU comprising:
a signal receiving unit (50), a data receiving link (30) and a controller (10); wherein
the signal receiving unit (50) is configured to receive an awakening frequency signal;
the data receiving link (30) is configured to establish data communication with the
RSU;
the controller (10) is connected with the signal receiving unit (50) and the data
receiving link (30) respectively, and is configured to match an awakening frequency
of the awakening frequency signal with a response frequency preset by the OBU, and
to control the data receiving link (30) to establish the data communication with the
RSU when the response frequency is matched with the awakening frequency of the awakening
frequency signal,
wherein the controller (10) is in a low power consumption mode during non-transaction;
characterized in that the controller (10) is in a low main frequency when matching is performed, and the
controller (10) is in a high main frequency when the data communication with the RSU
for transaction is established,
wherein a clock source of a timer in the controller (10) has a frequency which is
the same as the main frequency of the controller (10) when the controller (10) performs
the matching, wherein the timer is configured to calculate a square-wave period of
the awakening frequency signal.
4. The OBU according to claim 3, wherein a radio-frequency power switch (40) is connected
between the controller (10) and the data receiving link (30);
the controller (10) is further configured to: control the radio-frequency power switch
(40) to be turned on when the response frequency is matched with the awakening frequency
of the awakening frequency signal, and control the radio-frequency power switch (40)
to be turned off when the response frequency is not matched with the awakening frequency
of the awakening frequency signal.
5. The OBU according to claim 3, wherein a range of the response frequency is 12 KHz
to 16 KHz; and wherein the controller (10) is further configured to: detect at least
two square-wave periods of the awakening frequency signal and calculate the square-wave
period of the awakening frequency signal, and determine that the matching is successful
when the calculated square-wave period of the awakening frequency signal is in the
range of a square-wave period of the response frequency.
6. An Electronic Toll Collection (ETC) system, the system comprising an On-Board Unit
(OBU) and a Road Side Unit (RSU); wherein the OBU comprises: a signal receiving unit
(50), a data receiving link (30) and a controller (10);
the signal receiving unit (50) is configured to receive an awakening frequency signal;
the data receiving link (30) is configured to establish data communication with the
RSU;
the controller (10) is connected with the signal receiving unit (50) and the data
receiving link (30) respectively, and is configured to match an awakening frequency
of the awakening frequency signal with a response frequency preset by the OBU, and
to control the data receiving link (30) to establish the data communication with the
RSU when the response frequency is matched with the awakening frequency of the awakening
frequency signal,
wherein the controller (10) is in a low power consumption mode during non-transaction;
characterized in that the controller (10) is in a low main frequency when matching is performed, and the
controller (10) is in a high main frequency when the data communication with the RSU
for transaction is established,
wherein a clock source of a timer in the controller (10) has a frequency which is
the same as the main frequency of the controller (10) when the controller (10) performs
the matching, wherein the timer is configured to calculate a square-wave period of
the awakening frequency signal.
7. The ETC system according to claim 6, wherein a radio-frequency power switch (40) is
connected between the controller (10) and the data receiving link (30); the controller
(10) is further configured to: control the radio-frequency power switch (40) to be
turned on when the response frequency is matched with the awakening frequency of the
awakening frequency signal, and control the radio-frequency power switch (40) to be
turned off when the response frequency is not matched with the awakening frequency
of the awakening frequency signal.
8. The ETC system according to claim 6, wherein a range of the response frequency is
12 KHz to 16 KHz;
the controller (10) is further configured to: detect at least two square-wave periods
of the awakening frequency signal and calculate the square-wave period of the awakening
frequency signal, and determining that the matching is successful when the calculated
square-wave period of the awakening frequency signal is in the range of a square-wave
period of the response frequency.
1. Datenkommunikationsverfahren einer Bordeinheit (OBU), das Verfahren umfassend:
das Empfangen, durch die OBU, eines Aufwachfrequenzsignals;
das Angleichen, durch die OBU, einer Aufwachfrequenz des Aufwachfrequenzsignals an
eine Antwortfrequenz, voreingestellt von der OBU; und
das Herstellen, durch die OBU, von Datenkommunikation mit einer straßenseitigen Einheit
(RSU), wenn die von der OBU voreingestellte Antwortfrequenz an die Aufwachfrequenz
des Aufwachfrequenzsignals angeglichen wird,
wobei die OBU eine Steuerung (10) umfasst; die Steuerung (10) während Nicht-Transaktion
in einem Modus mit geringem Stromverbrauch arbeitet,
dadurch gekennzeichnet, dass die Steuerung (10) mit einer niedrigen Hauptfrequenz arbeitet, wenn die Angleichung
durchgeführt wird, und die Steuerung (10) mit einer hohen Hauptfrequenz arbeitet,
wenn die Datenkommunikation mit der RSU zur Transaktion hergestellt ist,
wobei eine Uhrquelle eines Timers in der Steuerung (10) eine Frequenz hat, die dieselbe
ist wie die Hauptfrequenz der Steuerung (10), wenn die Steuerung (10) die Angleichung
durchführt, wobei der Timer konfiguriert ist, eine Rechteckwellenperiode des Aufwachfrequenzsignals
zu berechnen.
2. Datenkommunikationsverfahren der OBU nach Anspruch 1, wobei ein Bereich der Antwortfrequenz
12 kHz bis 16 kHz ist; und wobei das Angleichen Folgendes umfasst: Erkennen und Berechnen
der Rechteckwellenperiode des Aufwachfrequenzsignals durch die Steuerung (10) der
OBU und Bestimmen, dass das Angleichen erfolgreich ist, wenn die berechnete Rechteckwellenperiode
des Aufwachfrequenzsignals im Bereich einer Rechteckwellenperiode der Antwortfrequenz
ist.
3. Bordeinheit (OBU), verbunden mit einer straßenseitigen Einheit (RSU), die OBU umfassend:
eine Signalempfangseinheit (50), eine Datenempfangsverbindung (30) und eine Steuerung
(10); wobei
die Signalempfangseinheit (50) konfiguriert ist, ein Aufwachfrequenzsignal zu empfangen;
die Datenempfangsverbindung (30) konfiguriert ist, Datenkommunikation mit der RSU
herzustellen;
die Steuerung (10) jeweils mit der Signalempfangseinheit (50) und der Datenempfangsverbindung
(30) verbunden ist und konfiguriert ist, eine Aufwachfrequenz des Aufwachfrequenzsignals
an eine von der OBU voreingestellte Antwortfrequenz anzugleichen und die Datenempfangsverbindung
(30) zu steuern, um die Datenkommunikation mit der RSU herzustellen, wenn die Antwortfrequenz
an die Aufwachfrequenz des Aufwachfrequenzsignals angeglichen ist,
wobei die Steuerung (10) während Nicht-Transaktion in einem Modus mit geringem Stromverbrauch
ist; dadurch gekennzeichnet, dass
die Steuerung (10) in einer niedrigen Hauptfrequenz ist, wenn die Angleichung durchgeführt
wird, und die Steuerung (10) in einer hohen Hauptfrequenz ist, wenn die Datenkommunikation
mit der RSU zur Transaktion hergestellt ist,
wobei eine Uhrquelle eines Timers in der Steuerung (10) eine Frequenz hat, die dieselbe
ist wie die Hauptfrequenz der Steuerung (10), wenn die Steuerung (10) die Angleichung
durchführt, wobei der Timer konfiguriert ist, eine Rechteckwellenperiode des Aufwachfrequenzsignals
zu berechnen.
4. OBU nach Anspruch 3, wobei ein Funkfrequenz-Leistungsschalter (40) zwischen der Steuerung
(10) und der Datenempfangsverbindung (30) angeschlossen ist;
die Steuerung (10) ferner konfiguriert ist, den Funkfrequenz-Leistungsschalter (40)
so zu steuern, dass er eingeschaltet wird, wenn die Antwortfrequenz an die Aufwachfrequenz
des Aufwachfrequenzsignals angeglichen ist, und den Funkfrequenz-Leistungsschalter
(40) so zu steuern, dass er ausgeschaltet wird, wenn die Antwortfrequenz mit der Aufwachfrequenz
des Aufwachfrequenzsignals nicht angeglichen ist.
5. OBU nach Anspruch 3, wobei ein Bereich der Antwortfrequenz 12 kHz bis 16 kHz ist und
wobei die Steuerung (10) ferner konfiguriert ist:
mindestens zwei Rechteckwellenperioden des Aufwachfrequenzsignals zu erkennen und
die Rechteckwellenperiode des Aufwachfrequenzsignals zu berechnen und zu bestimmen,
dass das Angleichen erfolgreich ist, wenn die berechnete Rechteckwellenperiode des
Aufwachfrequenzsignals im Bereich einer Rechteckwellenperiode der Antwortfrequenz
ist.
6. Elektronisches Mautsammelsystem (ETC), das System umfassend
eine Bordeinheit (OBU) und eine straßenseitige Einheit (RSU);
wobei die OBU Folgendes umfasst: eine Signalempfangseinheit (50), eine Datenempfangsverbindung
(30) und eine Steuerung (10);
die Signalempfangseinheit (50) konfiguriert ist, ein Aufwachfrequenzsignal zu empfangen;
die Datenempfangsverbindung (30) konfiguriert ist, eine Datenverbindung mit der RSU
herzustellen;
die Steuerung (10) jeweils mit der Signalempfangseinheit (50) und der Datenempfangsverbindung
(30) verbunden ist und konfiguriert ist, eine Aufwachfrequenz des Aufwachfrequenzsignals
an eine von der OBU voreingestellte Antwortfrequenz anzugleichen und die Datenempfangsverbindung
(30) zu steuern, die Datenkommunikation mit der RSU herzustellen, wenn die Antwortfrequenz
an die Aufwachfrequenz des Aufwachfrequenzsignals angeglichen ist,
wobei die Steuerung (10) während Nicht-Transaktion in einem Modus mit geringem Stromverbrauch
ist; dadurch gekennzeichnet, dass
die Steuerung (10) in einer niedrigen Hauptfrequenz ist, wenn das Angleichen durchgeführt
wird, und die Steuerung (10) in einer hohen Hauptfrequenz ist, wenn die Datenkommunikation
mit der RSU zur Transaktion hergestellt ist,
wobei eine Uhrquelle eines Timers in der Steuerung (10) eine Frequenz hat, die dieselbe
ist wie die Hauptfrequenz der Steuerung (10), wenn die Steuerung (10) die Angleichung
durchführt, wobei der Timer konfiguriert ist, eine Rechteckwellenperiode des Aufwachfrequenzsignals
zu berechnen.
7. ETC-System nach Anspruch 6, wobei ein Funkfrequenz-Leistungsschalter (40) zwischen
der Steuerung (10) und der Datenempfangsverbindung (30) angeschlossen ist; die Steuerung
(10) ferner konfiguriert ist: den Funkfrequenz-Leistungsschalter (40) so zu steuern,
dass er eingeschaltet wird, wenn die Antwortfrequenz an die Aufwachfrequenz des Aufwachfrequenzsignals
angeglichen ist, und den Funkfrequenz-Leistungsschalter (40) so zu steuern, dass er
ausgeschaltet wird, wenn die Antwortfrequenz nicht an die Aufwachfrequenz des Aufwachfrequenzsignals
angeglichen ist.
8. ETC-System nach Anspruch 6, wobei ein Bereich der Antwortfrequenz 12 kHz bis 16 kHz
ist;
die Steuerung (10) ferner konfiguriert ist: mindestens zwei Rechteckwellenperioden
des Aufwachfrequenzsignals zu erkennen und die Rechteckwellenperiode des Aufwachfrequenzsignals
zu berechnen und zu bestimmen, dass die Angleichung erfolgreich ist, wenn die berechnete
Rechteckwellenperiode des Aufwachfrequenzsignals im Bereich einer Rechteckwellenperiode
der Antwortfrequenz ist.
1. Méthode de communication de données d'une unité embarquée (OBU), la méthode comprenant
:
la réception, par l'OBU, d'un signal de fréquence de réveil ;
la mise en correspondance, par l'OBU, d'une fréquence de réveil du signal de fréquence
de réveil à une fréquence de réponse prédéfinie par l'OBU ; et
l'établissement, par l'OBU, d'une communication de données avec une unité de bord
de route (RSU) lorsque la fréquence de réponse prédéfinie par l'OBU correspond à la
fréquence de réveil du signal de fréquence de réveil,
dans laquelle l'OBU comprend un contrôleur (10) ; le contrôleur (10) fonctionne dans
un mode de faible consommation d'énergie en l'absence de transaction,
caractérisé en ce que
le contrôleur (10) fonctionne à une fréquence principale basse lors de la réalisation
de la mise en correspondance, et le contrôleur (10) fonctionne à une fréquence principale
haute lorsque la communication de données avec la RSU pour une transaction est établie,
dans laquelle une source d'horloge d'un minuteur dans le contrôleur (10) a une fréquence
qui est la même que la fréquence principale du contrôleur (10) lorsque le contrôleur
(10) réalise la mise en correspondance, dans laquelle le minuteur est configuré pour
calculer une période d'onde carrée du signal de fréquence de réveil.
2. Méthode de communication de données de l'OBU selon la revendication 1,
dans laquelle une plage de la fréquence de réponse est 12 kHz à 16 kHz ; et
dans laquelle la mise en correspondance comprend :
la détection et le calcul de la période d'onde carrée du signal de fréquence de réveil
par le contrôleur (10) de l'OBU, et le fait de déterminer que la mise en correspondance
est réussie lorsque la période d'onde carrée calculée du signal de fréquence de réveil
est dans la plage d'une période d'onde carrée de la fréquence de réponse.
3. Unité embarquée (OBU) connectée à une unité de bord de route (RSU), l'OBU comprenant
:
une unité de réception de signal (50), une liaison de réception de données (30) et
un contrôleur (10) ; dans laquelle
l'unité de réception de signal (50) est configurée pour recevoir un signal de fréquence
de réveil ;
la liaison de réception de données (30) est configurée pour établir une communication
de données avec la RSU ;
le contrôleur (10) est connecté à l'unité de réception de signal (50) et à la liaison
de réception de données (30), et est configuré pour mettre en correspondance une fréquence
de réveil du signal de fréquence de réveil à une fréquence de réponse prédéfinie par
l'OBU, et pour commander la liaison de réception de données (30) pour établir la communication
de données avec la RSU lorsque la fréquence de réponse correspond à la fréquence de
réveil du signal de fréquence de réveil,
dans laquelle le contrôleur (10) est dans un mode de faible consommation d'énergie
en l'absence de transaction ;
caractérisée en ce que le contrôleur (10) est à une fréquence principale basse lorsque la mise en correspondance
est réalisée, et le contrôleur (10) est à une fréquence principale haute lorsque la
communication de données avec la RSU pour une transaction est établie,
dans laquelle une source d'horloge d'un minuteur dans le contrôleur (10) a une fréquence
qui est la même que la fréquence principale du contrôleur (10) lorsque le contrôleur
(10) réalise la mise en correspondance, dans laquelle le minuteur est configuré pour
calculer une période d'onde carrée du signal de fréquence de réveil.
4. OBU selon la revendication 3, dans laquelle un commutateur de puissance radiofréquence
(40) est connecté entre le contrôleur (10) et la liaison de réception de données (30)
;
le contrôleur (10) est en outre configuré pour :
commander la mise en marche du commutateur de puissance radiofréquence (40) lorsque
la fréquence de réponse correspond à la fréquence de réveil du signal de fréquence
de réveil, et commander la mise à l'arrêt du commutateur de puissance radiofréquence
(40) lorsque la fréquence de réponse ne correspond pas à la fréquence de réveil du
signal de fréquence de réveil.
5. OBU selon la revendication 3, dans laquelle une plage de la fréquence de réponse est
12 kHz à 16 kHz ; et dans laquelle le contrôleur (10) est en outre configuré pour
: détecter au moins deux périodes d'onde carrée du signal de fréquence de réveil et
calculer la période d'onde carrée du signal de fréquence de réveil, et déterminer
que la mise en correspondance est réussie lorsque la période d'onde carrée calculée
du signal de fréquence de réveil est dans la plage d'une période d'onde carrée de
la fréquence de réponse.
6. Système de collecte de péage électronique (ETC), le système comprenant une unité embarquée
(OBU) et une unité de bord de route (RSU) ;
dans lequel l'OBU comprend : une unité de réception de signal (50), une liaison de
réception de données (30) et un contrôleur (10) ;
l'unité de réception de signal (50) est configurée pour recevoir un signal de fréquence
de réveil ;
la liaison de réception de données (30) est configurée pour établir une communication
de données avec la RSU ;
le contrôleur (10) est connecté respectivement à l'unité de réception de signal (50)
et à la liaison de réception de données (30), et est configuré pour mettre en correspondance
une fréquence de réveil du signal de fréquence de réveil à une fréquence de réponse
prédéfinie par l'OBU, et pour commander la liaison de réception de données (30) pour
établir la communication de données avec la RSU lorsque la fréquence de réponse correspond
à la fréquence de réveil du signal de fréquence de réveil,
dans lequel le contrôleur (10) est dans un mode de faible consommation d'énergie en
l'absence de transaction ;
caractérisé en ce que le contrôleur (10) est à une fréquence principale basse lorsque la mise en correspondance
est réalisée, et le contrôleur (10) est à une fréquence principale haute lorsque la
communication de données avec la RSU pour une transaction est établie,
dans lequel une source d'horloge d'un minuteur dans le contrôleur (10) a une fréquence
qui est la même que la fréquence principale du contrôleur (10) lorsque le contrôleur
(10) réalise la mise en correspondance, dans lequel le minuteur est configuré pour
calculer une période d'onde carrée du signal de fréquence de réveil.
7. Système ETC selon la revendication 6, dans lequel un commutateur de puissance radiofréquence
(40) est connecté entre le contrôleur (10) et la liaison de réception de données (30)
; le contrôleur (10) est en outre configuré pour : commander la mise en marche du
commutateur de puissance radiofréquence (40) lorsque la fréquence de réponse correspond
à la fréquence de réveil du signal de fréquence de réveil, et commander la mise à
l'arrêt du commutateur de puissance radiofréquence (40) lorsque la fréquence de réponse
ne correspond pas à la fréquence de réveil du signal de fréquence de réveil.
8. Système ETC selon la revendication 6, dans lequel une plage de la fréquence de réponse
est 12 kHz à 16 kHz ;
le contrôleur (10) est en outre configuré pour : détecter au moins deux périodes d'onde
carrée du signal de fréquence de réveil et calculer la période d'onde carrée du signal
de fréquence de réveil, et déterminer que la mise en correspondance est réussie lorsque
la période d'onde carrée calculée du signal de fréquence de réveil est dans la plage
d'une période d'onde carrée de la fréquence de réponse.