The utility model content
In order to overcome the deficiency of above existence, the utility model provides a kind of board units signal screening system, can effectively reduce the mistake transaction rate of ETC system, with the raising success ratio that is open to traffic, thereby makes the ETC system to conclude the business more efficiently.
The utility model provides a kind of board units signal screening system, and said system comprises: signal receiving unit is used for receiving signal from board units, and is the simulating signal that is used for signal Processing with said conversion of signals; Amplify shaping unit, receive simulating signal, and simulating signal is amplified shaping, thereby generate first digital signal that is used to carry out data processing from signal receiving unit; The signal screening unit receives simulating signal and receives first digital signal from amplifying shaping unit from signal receiving unit, and through simulating signal being analyzed to determine whether the output of first digital signal to carry out data processing.
Preferably; The signal screening unit can comprise: screening signal generation unit; Receive simulating signal from signal receiving unit; And with the signal intensity of the simulating signal that receives and first predetermined threshold value relatively, confirming whether the signal that signal receiving unit receives is the useful signal that board units was sent that current needs are concluded the business, and the screening signal of comparative result is indicated in output; Selected cell receives first digital signal from amplifying shaping unit, and determines whether to export first digital signal to carry out data processing according to the screening signal that receives from screening signal generation unit.
Preferably; Screening signal generation unit can comprise: signal conversion unit; Be used for receiving said simulating signal from signal receiving unit; And the signal intensity of said simulating signal compared with first predetermined threshold value, when the signal intensity of simulating signal was greater than or equal to first predetermined threshold value, said signal conversion unit was three digital signal with said analog signal conversion and exports said three digital signal; When the signal intensity of simulating signal is lower than first predetermined threshold value, said signal conversion unit output low level signal; Detection unit; Be used for the signal of signal conversion unit output is carried out detection; When signal conversion unit receives three digital signal; Detection unit output has the rectified signal of first DC voltage, and when when signal conversion unit receives low level signal, detection unit output has the rectified signal of second DC voltage; Voltage comparison unit; Compare with reference voltage from detection unit reception rectified signal and with the voltage of the rectified signal that receives; Have the rectified signal of first DC voltage or have the rectified signal of second DC voltage with the rectified signal of confirming to receive, when the voltage of the rectified signal that receives was higher than reference voltage, voltage comparison unit confirmed to receive the rectified signal with first DC voltage; And the output high level signal is as the screening signal; When the voltage of the rectified signal that receives was lower than reference voltage, voltage comparison unit confirmed to receive the rectified signal with second DC voltage, and the output low level signal is as the screening signal.
Preferably, the signal screening unit can comprise: signal processing unit, receive simulating signal from signal receiving unit, and with second digital signal of the intensity that generates the said simulating signal of reflection, and said second digital signal outputed to the definite unit of signal output; The unit is confirmed in signal output, receives second digital signal and it is resolved from signal processing unit, to determine whether receiving first digital signal and the output of first digital signal to carry out data processing from amplifying shaping unit.
Preferably, signal processing unit can comprise: detection unit, the simulating signal that receives from signal receiving unit is carried out detection, and with the d. c. voltage signal of said analog signal conversion for the intensity of reflection simulating signal.AD conversion unit receives d. c. voltage signal from detection unit, and converts said d. c. voltage signal second digital signal of the magnitude of voltage of the said d. c. voltage signal of reflection into.
Preferably, signal output confirms that the unit can obtain the magnitude of voltage of the intensity of reflection simulating signal through second digital signal is resolved, and the magnitude of voltage that obtains is compared with predetermined threshold value.If said magnitude of voltage is more than or equal to second predetermined threshold value, then signal output confirms that the signal that the unit confirms that signal receiving unit receives is a useful signal, from amplify that shaping unit receives first digital signal and with the output of first digital signal to carry out data processing; If said magnitude of voltage is less than second predetermined threshold value, then signal output confirms that the signal that the unit confirms that signal receiving unit receives is not a useful signal, and does not receive first digital signal.
The utility model also provides a kind of roadside unit, and this roadside unit comprises the board units signal screening system with above-mentioned characteristic.
Utilize roadside unit, the signal screening system of the utility model; Can distinguish the signal that vehicle sent that to conclude the business apace; Get rid of the influence of monkey chatter and co-channel interference effectively, therefore can reduce the mistake transaction rate in the ETC system and improve the success ratio that is open to traffic.On the other hand; Because the application of the utility model makes the mistake transaction rate of ETC system significantly reduce; Therefore can reduce because extra cost of labor that the mistake transaction brings and time cost; And can improve the speed that is open to traffic in ETC track, therefore can make the user in ETC track obtain better user experience.
Embodiment
Below in conjunction with accompanying drawing embodiment is described in detail, then above-mentioned and other purpose, characteristics and the advantage of the utility model will become apparent.
Board units (OBU) signal screening system 100 can be installed on the roadside unit (RSU).Shown in Fig. 1 a, OBU signal screening system 100 comprises: signal receiving unit 110, signal screening unit 120, amplification shaping unit 130.
In the present embodiment, OBU that signal receiving unit 110 is installed from the vehicle through the track receives the OBU signal, and to said OBU signal carry out demodulation with said OBU conversion of signals for carrying out the simulating signal of signal Processing.
Signal receiving unit 110 can be signal receiving device commonly known in the art or circuit; Shown in Fig. 1 b, signal receiving unit 110 can comprise: low noise amplifier (LNA) 111, frequency mixer 112, BPF. (BPF) 113, amplifier 114 and carrier frequency produce circuit 115.When receiving the OBU signal through the antenna (not shown); The OBU signal can be imported into LNA 111 and amplify to carry out low noise; Frequency mixer 112 uses and produces the CF signal that circuit 115 produces by carrier frequency the OBU signal that amplifies through low noise is carried out frequency transformation, thereby is baseband signal with said OBU signal transformation.The baseband signal of 113 pairs of frequency mixer of BPF, 112 outputs is carried out filtering to remove the noise in the signal.Then, use 114 pairs of filtered signals of amplifier to amplify,, thereby obtain the RSSI simulating signal so that said signal can detect by signal processing apparatus thereafter and handle.
Amplify shaping unit 130 and receive the RSSI simulating signal from signal receiving unit 110; And thereby said signal is amplified shaping is the digital signal D that processor (for example, micro-control unit (MCU)) (not shown) can detect and can carry out data processing with the RSSI analog signal conversion that receives
1Thereby, can handle the information of carrying in the OBU signal.In addition; In the present embodiment; Amplifying shaping unit 130 can also be the amplification shaping unit 130 with delay function; The delay time of the signal that receives with adjustment as required makes in signal screening unit 120, from amplifying shaping unit 130 signal that receives and the signal Synchronization that receives from signal receiving unit 110.
Signal screening unit 120 is from signal receiving unit 110 reception RSSI simulating signals and from amplifying shaping unit 130 receiving digital signals D
1, and the RSSI simulating signal analyzed to determine whether digital signal D
1Output to processor to carry out data processing.To describe signal screening unit 120 in detail with reference to Fig. 1 c after a while.
Shown in Fig. 1 c, signal screening unit 120 can comprise screening signal generation unit 121 and selected cell 122.
Screening signal generation unit 121 receives the RSSI simulating signal from signal receiving unit 110; And the intensity of the RSSI simulating signal that receives compared with predetermined threshold value; The useful signal that OBU sent of the vehicle that thereby whether the signal of confirming to be received by signal receiving unit 110 is current needs concludes the business (below, be called useful signal).Should be appreciated that said predetermined threshold can be an intensity level that in OBU signal screening system 100, manually is provided with, also can be according to through the synchronous collaboration between a plurality of RSU, through repeatedly experiment and a definite intensity level.The setting of said predetermined threshold should make the signal that does not belong to the OBU that current needs conclude the business by filtering, thereby gets rid of the interference that the OBU signal of adjacent vehicle in OBU signal or the identical track of adjacent lane produces.
According to RSSI simulating signal that receives and predetermined threshold value comparative result relatively, screen signal generation unit 121 and will indicate the screening signal of comparative result to send to selected cell 122.For example, when the signal intensity of the RSSI simulating signal that receives during less than predetermined threshold value (that is, the signal that is received by signal receiving unit 110 is not a useful signal), screening signal generation unit 121 exportable low level signals are as the screening signal; When the signal intensity of the RSSI simulating signal that receives during more than or equal to predetermined threshold (that is, the signal that signal receiving unit 110 receives is a useful signal), screening signal generation unit 121 exportable high level signals are as the screening signal.
Fig. 1 d illustrates an example of screening signal generation unit 121.Screening signal generation unit 121 can include, but is not limited to: signal conversion unit 123, detection unit 124 and voltage comparison unit 125.
Signal conversion unit 123 can compare the signal intensity and the predetermined threshold value of the RSSI simulating signal that receives from signal receiving unit 110; When the signal intensity of said RSSI simulating signal was higher than predetermined threshold value, signal conversion unit 123 was digital signal S with the RSSI analog signal conversion
1And output digital signal S
1When the signal intensity of said RSSI simulating signal is lower than predetermined threshold value, signal conversion unit 123 will be exported a low level signal VL.
Although signal conversion unit 123 can be digital signal S with the RSSI analog signal conversion
1, when still hanging down owing to the signal power of the signal that receives when signal conversion unit 123, the digital signal S that signal conversion unit 123 is exported
1Dutycycle can variation, make that the MCU (not shown) among the RSU can't parse the entrained information of this digital signal, therefore be difficult to directly use the digital signal S of signal conversion unit 123 outputs in the present embodiment
1As the signal that in MCU, carries out data processing.
Detection unit 124 is used for the signal of signal conversion unit 123 outputs is carried out detection.In the present embodiment, be output as digital signal S when signal conversion unit 123
1The time, the DC voltage rectified signal U that detection unit 124 outputs have the specific voltage value
1(signal that for example, has the high level of appointment).When signal conversion unit 123 is output as low level V
LThe time, detection unit 124 outputs have the DC voltage rectified signal U of another magnitude of voltage
2(the low level voltage that for example, has appointment).
In the present embodiment; Because the voltage of the DC voltage rectified signal of detection unit 124 output possibly changed by circuit thereafter, therefore possibly be difficult to directly to use the rectified signal of detection unit 124 outputs to be input to selected cell 122 and carry out signal screening as the screening signal.Therefore, need convert the rectified signal of detection unit 124 outputs into signal with burning voltage.
In the present embodiment, voltage comparison unit 125 can receive rectified signal (that is U, from detection unit 124
1Or U
2).At voltage comparison unit 125, can be U with the rectified signal that said rectified signal and preset reference voltage compare to confirm detection unit 124 outputs
1Or U
2, and export the screening signal according to definite result, wherein, the magnitude of voltage of said reference voltage should satisfy: U
2Voltage<reference voltage<U
1Voltage.Specifically, when the voltage of the rectified signal that receives from detection unit 124 was higher than reference voltage, voltage comparison unit 125 can be confirmed detection unit 124 output U
1, and the output high level signal is as the screening signal; When the voltage of the rectified signal that receives from detection unit 124 was lower than reference voltage, voltage comparison unit 125 can be confirmed detection unit 124 output U
2, and the output low level signal is as the screening signal, thus screening signal generated with stable level.In other words, when the signal of signal receiving unit 110 receptions was useful signal, voltage comparison unit 125 output high level signals were as the screening signal; When the signal of signal receiving unit 110 receptions was not useful signal, voltage comparison unit 125 output low level signals were as the screening signal.
Should be appreciated that the screening signal of screening signal generation unit 121 outputs can be not limited to high level signal/low level signal.Selectively, the screening signal can also be the signal of other types, and for example, said screening signal can also be pulse signal/non-pulse signal.Specifically, when the signal of signal receiving unit 110 receptions was useful signal, screening signal generation unit 121 exportable pulse signals were as the screening signal; When the signal of signal receiving unit 110 receptions is not useful signal; Screening signal generation unit 121 exportable non-pulse signals (for example; Direct current signal) as the screening signal, thereby selected cell 122 can use pulse signal to trigger, and handles to accomplish signal screening.In addition, when the signal of signal receiving unit 110 receptions was not useful signal, screening signal generation unit 121 also can not exported any signal.
With reference to Fig. 1 c, selected cell 122 receives from amplifying the digital signal D of shaping unit 130 outputs once more
1, and according to the screening signal that receives from screening signal generation unit 121 to digital signal D
1Carry out Screening Treatment, to determine whether to export digital signal D
1Carry out data processing.Specifically, in the present embodiment, when the screening signal of screening signal generation unit 121 outputs is high level signal (that is, the OBU signal that signal receiving unit 110 receives is a useful signal), selected cell 122 will amplify shaping unit 130 output digital signal D
1Be input to the MCU (not shown) to carry out data processing; When the screening signal is low level signal (that is, the OBU signal that signal receiving unit 110 receives is not a useful signal), selected cell 122 exportable and digital signal D
1Different signal specific (for example, low level signal or high level signal etc.) is not perhaps exported signal.
In the present embodiment, said selected cell 122 can be to screening signal and digital signal D
1Carry out the logical and circuit of logical and operation, thereby when the screening signal of screening signal generation unit 121 outputs was the high level signal of indication 1, selected cell 122 can be operated through logical and will be from amplifying the digital signal D that shaping unit 130 receives
1Output to and carry out data processing in the MCU (not shown).When the screening signal of screening signal generation unit 121 outputs was the low level signal of indication 0, selected cell 122 can output to the MCU (not shown) with low level signal through the logical and operation, thereby can screen the OBU signal that receives effectively.
Embodiment 2
Embodiment 2 is that with the difference of embodiment 1 signal receiving unit 210 also has another kind of structural arrangements mode different.In the present embodiment, signal receiving unit 210 can also be receiving trap or the circuit shown in Fig. 2 b.In Fig. 2 b, when receiving the OBU signal through the antenna (not shown), said OBU signal can be imported into envelope detected unit 216.Envelope detected unit 216 detects the envelope of said OBU signal; And said envelope signal is input to voltage amplification unit 217; The faint envelope signal that receives with amplification, thus make said envelope signal become the RSSI simulating signal that device thereafter can detect and handle.
But other apparatus structure reference implementation examples 1.
Embodiment 3
Embodiment 3 is that with the difference of embodiment 1 structure of signal screening unit 320 is different with configuration mode.Fig. 3 c illustrates another implementation of signal screening unit 320.In this example, signal screening unit 320 can comprise signal processing unit 326 and the definite unit 327 of signal output.In conjunction with Fig. 1 a, signal processing unit 326 can receive the RSSI simulating signal from signal receiving unit 110, generates the digital signal S of the intensity of indication RSSI simulating signal, and said digital signal S is outputed to the definite unit 327 of signal output.Shown in Fig. 3 d, signal processing unit 326 can comprise: detection unit 328 and modulus (AD) converting unit 329.
Detection unit 328 can carry out detection to the RSSI simulating signal that receives from signal receiving unit 110; And be that d. c. voltage signal outputs to AD converting unit 329 with the RSSI analog signal conversion; Wherein, the magnitude of voltage V of said d. c. voltage signal can be the specific voltage value that is used to indicate the intensity of said RSSI simulating signal.
AD converting unit 329 receives from the d. c. voltage signal of detection unit 328 outputs, and converts said d. c. voltage signal into a digital signal S, and wherein, said digital signal S can indicate the magnitude of voltage V of said d. c. voltage signal.
Once more with reference to Fig. 1 a, Fig. 1 b and Fig. 3 c; The definite unit 327 of signal output can be resolved from the digital signal S of signal processing unit 326 reception outputs and to it; Whether the OBU signal to confirm signal receiving unit 110 receptions is useful signal, thereby further determines whether from amplifying shaping unit 130 receiving digital signals D
1And with digital signal D
1Output to the MCU (not shown) and carry out data processing.Say that at length signal output is confirmed unit 327 receiving digital signals S and it is resolved, thereby can obtain said magnitude of voltage V; Then; Signal output is confirmed unit 327 with the magnitude of voltage V and the predefined threshold that obtain, if magnitude of voltage V, confirms then that the OBU signal that signal receiving unit 110 receives is a useful signal more than or equal to predefined threshold value; Therefore, signal output confirms that unit 327 can be from amplifying shaping unit 130 receiving digital signals D
1, and with the digital signal D that receives
1Output to the MCU (not shown), to carry out data processing; If magnitude of voltage V, confirms then that the OBU signal that signal receiving unit 110 receives is not a useful signal less than predefined threshold value, not receiving digital signals D of unit 327 is confirmed in signal output
1Thereby the OBU signal of receiving that can achieve a butt joint effectively screens, and avoids the generation of mistake transaction.
Other apparatus structures are referring to embodiment 1.
The workflow of this OBU signal screening is provided below, three kinds of implementations can be arranged.
Embodiment 4
In conjunction with Fig. 1 a, shown in Figure 4, the OBU signal screening workflow of present embodiment, at step S401, signal receiving unit 110 receives the OBU signal that the OBU from be installed in vehicle sends, and is converted into the RSSI simulating signal that can be used for signal Processing.
At step S403; Amplify shaping unit 130 and receive the RSSI simulating signal of signal receiving unit 110 outputs and it is amplified shaping, can in MCU, be used for carrying out the digital signal D of data processing with the entrained information of the OBU signal of picked up signal receiving element 110 receptions to generate
1
At step S405, signal screening unit 120 receives the RSSI simulating signal and receives first digital signal from amplifying shaping unit 130 from signal receiving unit 110, then through simulating signal being analyzed to determine whether digital signal D
1Output to processor to carry out data processing.
Embodiment 5
In conjunction with Fig. 1 a, shown in Figure 5,, the OBU signal screening workflow of present embodiment, at step S501, signal receiving unit 110 receives the OBU signal that the OBU from be installed in vehicle sends, and is converted into the RSSI simulating signal that can be used for signal Processing.
At step S503; Amplify shaping unit 130 and receive the RSSI simulating signal of signal receiving unit 110 outputs and it is amplified shaping, can in MCU, be used for carrying out the digital signal D of data processing with the entrained information of the OBU signal of picked up signal receiving element 110 receptions to generate
1
In addition; In conjunction with Fig. 1 b, shown in Figure 5; At step S503, screening signal generation unit 121 also receives the RSSI simulating signals from signal receiving unit 110, and with the signal intensity and the predefined threshold of said signal; Whether the OBU signal to confirm signal receiving unit 110 receptions is the OBU signal that vehicle was sent that current needs are concluded the business, thereby obtains and export the screening signal of indication comparative result.Combined Fig. 1 a and Fig. 1 d to describe the process that produces the screening signal in detail, therefore will not be described in detail at this.
At step S505, selected cell 122 can confirm whether the signal that signal receiving unit 110 receives is useful signal according to the screening signal that receives from screening signal generation unit 121, thereby determines whether the digital signal D that generates among the step S503
1Output to the MCU (not shown) to carry out further data processing.
If the OBU signal that said screening signal indicator signal receiving element 110 receives is a useful signal, then at step S507, selected cell 122 is with digital signal D
1Output to MCU to carry out data processing.If the OBU signal that said screening signal indicator signal receiving element 110 receives is not a useful signal, then at step S509, selected cell 122 can with low level signal (or with digital signal D
1Other different signals, for example, high level signal) output to MCU, perhaps at step S509, selected cell 122 can not exported any signal.Handle through aforesaid signal screening, can avoid the OBU signal of current vehicle of not concluding the business with this RSU is input to MCU, and then avoid the generation of mistake transaction.
Embodiment 6
In conjunction with Fig. 1 a, shown in Figure 6,, the OBU signal screening workflow of present embodiment, at step S601, the OBU of signal receiving unit 110 from be installed in vehicle receives the OBU signal, and is converted into the RSSI simulating signal that can be used for signal Processing.
At step S603, signal processing unit 326 can receive the RSSI simulating signal from signal receiving unit 110, indicates the digital signal S of the intensity of RSSI simulating signal with generation, and said digital signal S is outputed to the definite unit 327 of signal output.
In addition,, amplify shaping unit 130 and receive the RSSI simulating signal and it is amplified shaping, be used to carry out the digital signal D of data processing with generation from signal receiving unit 110 at step S603
1
At step S605, signal output confirms that unit 327 resolves from signal processing unit 326 receiving digital signals S and to it, confirming whether the signal that signal receiving unit 110 receives is useful signal, thereby and further determines whether receiving digital signals D
1And with digital signal D
1Output to the MCU (not shown) to carry out further data processing.Specifically; Resolve from signal processing unit 326 receiving digital signals S and to it the definite unit 327 of signal output; Thereby obtain the magnitude of voltage V of the intensity of indication RSSI simulating signal, then said magnitude of voltage V and predefined threshold value are compared to judge whether the OBU signal that signal receiving unit 110 receives is useful signal.If magnitude of voltage V is more than or equal to predefined threshold value, then the definite unit 327 of signal output can confirm that the OBU signal that receives is a useful signal, and subsequently at step S607, signal output confirms that unit 327 is from amplifying shaping unit 130 receiving digital signals D
1, and with digital signal D
1Output to the MCU (not shown) to carry out further data processing.If magnitude of voltage V is less than predefined threshold value, then the definite unit 327 of signal output can confirm that the OBU signal that receives is not a useful signal, and at step S609, not receiving digital signals D of unit 327 is confirmed in signal output
1
Through as above process, can avoid the OBU signal of current vehicle of not concluding the business with this RSU is input to MCU, and then avoid the generation of mistake transaction.
Although specifically shown and described the utility model with reference to its exemplary embodiment; But it should be appreciated by those skilled in the art; Under the situation of the spirit of the utility model that does not break away from claim and limited and scope, can carry out the various changes on form and the details to it.