WO1995034057A1

WO1995034057A1 - Apparatus for transmitting-receiving vehicle information and processing method thereof

Info

Publication number: WO1995034057A1
Application number: PCT/KR1995/000069
Authority: WO
Inventors: Sok Koon Kang; Jung Ok An
Original assignee: Sok Koon Kang; Jung Ok An
Priority date: 1994-06-02
Filing date: 1995-06-01
Publication date: 1995-12-14
Also published as: AU2577995A; KR960002103A

Abstract

The invention is about the remote data transmission transmitter/receiver and its processing method to transmit/receive the digital information between many transmitters (T1, T2, ... Tn) and several receivers (R0, R1, ... Rn) using frequency sharing method. The same number of Fn communication frequencies f0 ... fn and one shunt channel fs are assigned to Tn transmitters. While continue to change the frequency and transmit according to the stored inherent information, during idle period, use the shunt channel fs or make transmission output off to minimize the interference ratio. Many transmitters (Tn) transmit a small quantity of information using several frequency bands jointly to several receivers with great concentration in order to process the targeted information fast.

Description

Apparatus for Transmitting-Receiving vehicle Information and Processing Method thereof

TECHNICAL FIELD

This invention relates to an apparatus for transmitting and receiving vehicle information and processing method thereof to enable a number of receivers to transmit and receive digital information using frequency sharing by a number of transmitters.

BACKGROUND ART In establishing the automatic fee collecting system and comprehensive traffic control system for the fee post payment system in highways, the unmanned remote control system for future driverless vehicles or the people access control system in restricted areas requires the transmitter/receiver to transmit remotely the inherent information of specific object.

For example, the vehicle information such as registration number or other vehicle driving data should be transmitted in digital codes on a wanted transmission medium to a designated control center for controlling the input/output of vehicles.

Light beam (infrared rays) , ultrasonic wave and radio wave have been used as transmission media so far. The light beam may be affected by external light, and can not penetrate the obstacles. The ultrasonic wave is incapable of high-speed transmission, and it takes long time to transmit the signal because of its sonic wave characteristic.

On the contrary, the radio wave is capable of high-speed transmission and penetrating the obstacles (non-conductor) . Also the radio wave is considered the best transmission media, because it is not affected by external light. But, due to its limited resources available, it is realistically impossible to assign different frequencies to each vehicle.

In addition, the information transmission using a single frequency may cause an interference problem. To solve this problem, MCA (Multi Channel Access) method has been used as a frequency sharing method. However, it has the following problems.

The MCA method assigns first the transmitter and receiver as a pair, and selects a control channel out of several communication frequencies channels. At this moment, a receiver is always in the state of waiting for receiving the control channel.

Accordingly, a transmitter which is going to communicate searches for an unoccupied channel by other transmitters. If there is no vacant channel, it returns to a waiting state, and if any, lets an empty channel know to other side to communicate through the control channel.

But to communicate in such ways, transmitter/receiver must be matched by a pair. In that case, transmission timing and time may get restrictions, and equipment may be complicated. In particular, it is realistically difficult for many transmitters to transmit with great concentration a small quantity of information for short period to several receivers. Thus, MCA method cannot be applied to the automatic fee collecting system and unmanned remote control system. DISCLOSURE OF INVENTION

An object of the invention is to provide an apparatus for transmitting-receiving vehicle information and processing method thereof which is capable of transmitting with great concentration a small quantity of information through many transmitters without interference to several receivers. Other purpose of the invention is to provide an apparatus for transmitting-receiving vehicle information and processing method thereof which can use properly the establishment of the unmanned fee collecting system for paid highways and the comprehensive traffic control system in order to transmit a small quantity of information without interference by a simple circuit structure.

According to this invention, there is provided an apparatus for transmitting-receiving vehicle information comprising: transmitters assigning a number of communication frequency channel and one shunt channel among them and repeating the transmission of radio wave in pulse, after modulating data to be transmitted in high frequency, in which the communication frequency channels are changed sequentially in the order of the inherent vehicle information stored in memory according to the date to be transmitted, and in order to delay transmitting time for a pre-determined period, a high-frequency switching means is switched on or off, or the communication channel is changed to said shunt channel; receivers with fixed frequencies corresponding to each of the number of communication frequency channels and installed within receiving range of transmitters; and main computer to receive the information sent from each receiver RO, Rl...Rn. According to this invention, there is further provided a method for transmitting-receiving vehicle information comprising the step of : assigning a number of communication frequencies and one shunt channel to a number of transmitters respectively; transmitting data in pulse while changing said communication frequencies sequentially according to the inherent vehicle information; converting frequency to the shunt frequency fs or switching on/off the transmission output after data transmission during idle period ; transmitting data by changing said shunt channel or by delaying for a certain period with the operated value according to the inherent vehicle information after transmitting the converted frequency in pulse; and receiving the transmitted data occurred by the above processes in reverse order.

The apparatus according this invention assigns the same number of fn communication frequencies EX: fO - f9 as the number of Tn transmitters and one shunt channel fs to the Tn transmitters, determines the transmitter channel CH according to the input inherent vehicle information data, and changes the frequency continuously to avoid the interference. Such method helps avoid the interference by changing the frequency continuously and the transmitting time according to the inherent vehicle information data in transmitting.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be described in greater detail with reference to the drawings in which:

FIGURE 1 is diagram of the all structure to show an embodiment of the invention; FIGURE 2 is block diagram to show the transmitter of the embodiment of the invention;

FIGURE 3 is constitutional graph of being modulated and frequency conversion with regard to time change;

FIGURE 4a shows the data stored in the memory map; FIGURE 4b is a flow chart of transmitter execution of the invention with regard to vehicle information memory map used in the invention and data stored in the memory map there of.

FIGURE 5 is diagram to show the state of frequency change by Fn frequencies assigned to each transmitter Tn according to the order of the stored inherent data;

FIGURE 6 is block diagram of receiver of an embodiment of the invention; and

Figure 7. is flow chart of receiver execution of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The detailed explanation about drawings attached to an embodiment of the invention is given below.

Figure 1 is a diagram for the overall structure to show an embodiment of the invention. The an apparatus for transmitting and receiving vehicle information is consisted of a number of transmitters Tl, T2...Tn with the same fO, fl...fn communication frequency channels and one shunt channel fs, a number of receivers RO, Rl...Rn with fixed frequencies corresponding to the number of respective communication frequency channels within receivable distance, and main computer HC.

Figure 2 is a block diagram of transmitter of an embodiment of the invention to^' show the construction of each transmitters Tl, T2...Tn. That is to say, it is consisted of power supply 10, crystal oscillator 11, microprocessor 12, PLL 13, Voltage Controlled Oscillator VCO to produce high frequency, high frequency switching means 15 to switch on and switch off the output of VCO 13, RF amplifier 16, and antenna 17.

Here, power supply 10 is a constant-voltage power supply to apply power to each part. Crystal oscillator 11 is to produce the precise clock which microprocessor 12 needs. Microprocessor 12 is to store and determine information storage and to convert parallel data to serial data. In addition, it determines and provides the frequency to assign to PLL 13. PLL 13 enables VCO 14 to change the frequency according to data assigned by the microprocessor.

VCO 14 converts the frequency according to an instruction from the PLL 13, and makes the high-frequency modulation of the inherent data to transmit. High-frequency switching means 15 performs switching on/off functions to transmit the high frequency in pulse. RF amplifier 16 provides the necessary high-frequency power to antenna 17, therefore radiates the radio wave in the air.

Figure 3 shows the state of frequency conversion instructed from the PLL 13 to VOC 14 according to binary data output by microprocessor, and the modulated state of high frequency. That is to say, in transmitting, if data Dl, D2 and D3 from the microprocessor 12 are binary 000, frequency channel CH becomes frequency fO. If 001, CH becomes fl. If 010, CH becomes f2. If 011, CH becomes f3. If 100, CH becomes shunt channel fs not modulated or is switched on/off by high-frequency switching means 15 and high-frequency modulated according to data DO from the microprocessor 12. In the apparatus consisted as above, data are transmitted from transmitter in the following ways.

First of all, transmitters Tl, T2...Tn have the same fO..fn communication frequency channels and one shunt channel fs. A transmitter should be installed in each vehicle. In transmitting the inherent vehicle information from each vehicle, the output frequency channel is determined by the inherent vehicle information consisted of character and number in vehicle plate number.

Accordingly, because each vehicle plate has the different number combinat- . n, the different transmitting frequency channels can be input into receivers R0.Rl,...Rn. However, although the transmitters exist as many number as vehicles, the number of receivers is limited. Thus the same frequency channel may be received. But the invention solves this problem by differentiating the transmitting time according to the vehicle information (character and number) produced by different vehicle number in transmitting the inherent.vehicle number.

Even when last digit of vehicle information (character and number) is different, different channels as many as repetitions and difference in transmitting time are produced by transmitting repeatedly for short period (twice for 1 sec. in the invention) as long as the number of inherent vehicle information (frame length) . Thus data of the inherent vehicle number of each vehicle can be received accurately. It can be explained by the example of an embodiment.

In transmitting, microprocessor 12 is executed by the order of flow chart in Figure 4. Namely, Figure 4a shows the data stored in memory, Figure 4b is a flow chart to show the flow of transmitter execution of the invention, and is a application example to vehicle information transmitter. Firstly, suppose (SI) that there is a vehicle number

[SEOUL 2GA 1234] , 'SEOUL' is 2 bytes, '2' is 1 byte, 'GA' is

2 bytes, '12' is 1 byte, and '34' is assigned as a data length of 1 byte (S2) . That is to say, SEOUL (character) = ABCD, 2 = EF, GA

(character) = GHIJ, 1 = K, 2 = L, 3 = M, and 4 = N are stored in non-volatile memory. Accordingly the inherent vehicle information is stored in non-volatile memory of transmitter inside vehicle. Here A,B...N are BCD (Binary Coded Decimal System) ; A=0, B=l, C=2, D=3, E=0, F=2, G=6, H=7, 1=8, J=9, K=l, L=2, M=3 and N=4.

Vehicle number[SEOUL(character) GA(character) 1234] defined as Z. SI...S3 in figure 4a show data about vehicle information stored in memory chip of electronic chip inside each vehicle. Of course, this is an example for Korean vehicle number system. However, this invention can be applied to any vehicle number system of any country with different inherent vehicle numbering system.

After the first starting step, in step S4, microprocessor 12 chooses A (A is 0) , namely 0 CH (fO) according to the stored inherent vehicle information data (in figure 3, frequency whose data is 000 because A is 0), and sends a command to PLL 13. In step S5, the process to insert A and B (A is BCD 10th digit and B is single digit) out of inherent vehicle information data into the formula ' (AB x 2) + 300' is done.

That is to say, make RF switching means 15 on S6 by delaying for (01x2) +300=302 (mS) .

In step S7, convert the inherent vehicle number data Z (01230267891234) to serial data. VCO 14 receives the output which microprocessor 12 output port DO produces, and makes a high-frequency modulation to provide the output to RF amplifier 16.

In step S8, just after the execution of step S7 finishes, microprocessor 12 makes high-frequency switching 5 means 15 off or convert it to shunt channel fs. Thus transmit as fO frequency during step S5 period.

The inherent vehicle number data Z stored as 0 channel is modulated as high frequency and is transmitted in the air. The first frame is finished, and the next frame starts. 10 In step S9 , microprocessor chooses B(B is 1) , namely, 1 CH(fl) (data 001 in Figure 3) , out of the stored inherent vehicle information data, and instruct this chosen frequency to PLL 13.

In step S10, microprocessor S10 delays B and C (B is 15 10th digit and C is single digit) out of the stored inherent vehicle information data for (12x2) + 300 = 324 mS, and makes RF switching means 15 on Sll.

In step S12, microprocessor converts the stored inherent vehicle number data Z (01230267891234) to serial data, and

20 VCO 14 receives the output which microprocessor 12 output port DO produces, and makes a high-frequency modulation to provide the output to RF amplifier 16.

In step S13, just after the execution of step S12 finishes, microprocessor 12 makes high-frequency switching 25 means DS 15 off or converts it to shunt channel fs.

The inherent vehicle number data Z stored as 1 channel is modulated as high frequency and is transmitted in the air. The second frame is finished, and the next frame starts.

Here, step S14 skips the above processes. In the

30 transmission frame of next frames 3,4...13, only channel selection variable and delay variable for making RF switching means DS 15 off are changed like the above example, and others are the same S14.

In the next step S15, according to the stored inherent vehicle information data, microprocessor 12 chooses N (N is

5 4) namely, 4, and selects the corresponding fn frequency in

Figure 3 (f3 is omitted in Figure 3) in the same way as above. Send a instruction to PLL 13.

In step S16, microprocessor 12 delays the stored inherent data N and A (N is BCD 10th digit and A is single 10 digit) for (40 x 2) + 300 = 380 (mS) .

Make RF switching means 15 on S17.

In the next step S18, microprocessor 12 converts the stored inherent vehicle number data Z (01230267891234) to serial data. VCO 14 receives the output which microprocessor

15 12 output port DO produces, and makes a high-frequency modulation to provide the output to RF amplifier 16.

In step 19, just after the execution of step 18 finishes, microprocessor 12 makes high-frequency switching means 15 off or convert it to shunt channel fs. 20 The inherent vehicle number data Z stored as a chosen channel frequency is modulated as high frequency to transmit in the air. The 14th (last) frame is finished, and return to the first frame to repeat the above processes.

At last, because the inherent vehicle number such as

25 vehicle registration number can not have exactly the same number, during transmission of 14 frames, the frequency channel of each vehicle is different from each other to avoid the interference.

Also according to the formula of step S5, delay the

30 transmission time to transmit during a certain period to on/off the radio wave, or convert to the shunt channel fs to transmit the high frequency in pulse in order to minimize the interference. That is to say, 1/12800 bps (communication speed) x 256 bit (transmission data quantity) = 2 mS (transmission time) , and the maximum delay time is (99 x 2 ) + 300 = 498 mS. Here since 2 mS + 498 mS = 500 S, it is possible to transmit at least twice for 1 sec. Even though the transmission fails twice for 1 sec, time goes on. So there are a plenty of opportunities.

In Figure 5, during unit time t, Tn transmitters continue to change the frequency to transmit the frequency in pulse. According to the stored inherent data, delay the frequency transmission for a certain period, and repeat transmission in order to minimize the interference ratio. reference 20 shows that Tn transmitter transmits on the transmission channel fO according to the stored inherent vehicle information data. According to the stored inherent vehicle information data, delay during a certain period or convert to the shunt channel fs. Transmit on the transmission channel fn 21. reference 22 shows that T(n-l) transmitter 20 is transmitting during the same time with Tn transmitter 20 or that it is avoiding the interference due to different frequency. reference 23 with the same frequency as 22 shows that according to the stored inherent vehicle information data, differentiate the transmission time to avoid the interference.

Figure 6 is a block diagram of transmitter of an embodiment of the invention. This transmitter does not have any big difference with general RF receiver, but its receiving frequency is fixed. Also to raise the transmission speed, bandwidth is widened, and microprocessor instead of speaker is added. The detailed explanation is omitted.

Figure 7 is a flow chart of execution flow of transmitter (shown in Figure 6) of the invention. After starting step S20, in step S21, determine whether it is the beginning of transmission. If not, return to step S20. If it is, receive n bit data in step S22 and store them in memory. After receiving S24 again, in comparison step S25, determine whether it matches with the stored data. If not, determine as error(interference) and return to step S20. If it does, determine whether accurate data are received, and proceed to the next step.

In step S26, determine whether the same data exist in the memory. If yes, return to step S20. If no, store S27 in memory and repeat the execution of transmission process to main computer at the same time.

According to the inherent vehicle information data, continue to change the assigned frequency of the invention, and transmit the radio wave in pulse. At this moment, delay the transmission of the next pulse during a certain period, and repeat the transmission.

Although no delay is made during a certain period, due to other causes such part error, the transmission time phase can be later wrong. But because of delay during a certain period and transmitting, the better results can be obtained.

By repeating transmitting and receiving, non-interfered parts are received. Transmit the information to main computer to obtain the targeted results. A small quantity of information can be transmitted with great concentration using several frequency channels ' without errors from many transmitters to several receivers. Accordingly, since several shared frequencies by many transmitters can transmit information without interference, these processes are considered suitable for paid roads or the establishment of unmanned automatic fee collecting system and comprehensive traffic control system to detect the traffic flow.

In an embodiment of the invention, Korean vehicle number was described as an example, but as described above, the invention can be easily applied to different vehicle number system of each country. Also the invent: :.n differentiates the frequency channel and transmission time occurred by the inherent vehicle information based upon the inherent vehicle number(character and number) of each vehicle.

INDUSTRIAL APPLICABILITY

The invention can transmit data of the inherent vehicle number without interference. But because of the limited number of receivers used, in selecting the frequency channel according to the inherent vehicle information, the sequential data according to character and number do not choose the frequency channel, but use random circuit. Therefore, it is possible to select the frequency channel randomly.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. Apparatus for transmitting-receiving vehicle information comprising: transmitters assigning a number of communication frequency channel and one shunt channel among them and repeating the transmission of radio wave in pulse, after modulating data to be transmitted in high frequency, in which the communication frequency channels are changed sequentially in the order of the inherent vehicle information stored in memory according to the date to be transmitted, and in order to delay transmitting time for a pre-determined period, a high-frequency switching means is switched on or off, or the communication channel is changed to said shunt channel; receivers with fixed frequencies corresponding to each of the number of communication frequency channels and installed within receiving range of transmitters; and main computer to receive the information sent from each receiver RO, Rl...Rn.

2. Method for transmitting-receiving vehicle information comprising the steps of: assigning a number of communication frequencies and one shunt channel to a number of transmitters respectively; transmitting data in pulse while changing said communication frequencies sequentially according to the inherent vehicle information; converting frequency to the shunt frequency fs or switching on/off the transmission output after data transmission during idle period ; transmitting data by changing said shunt channel or by delaying for a certain period with the operated value according to the inherent vehicle information after transmitting the converted frequency in pulse; and receiving the transmitted data occurred by the above processes in reverse order.