JPH10123244A - Identification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure an accurate identification by employing a spread spectrum communication system in the modulation/demodulation system of transmitter and receiver in interrogator and responder thereby extracting a desired response signal surely at all times. SOLUTION: When a spread spectrum communication system is employed in the modulation/demodulation system of transmitter and receiver, a spread code containing an inherent code for identifying vehicles A, B, C, F, respectively, is employed in the modulation operation of the transmitters 7 in respective interrogators 1 of the vehicles A, F and of the transmitters 18 in respective interrogators 2 of the vehicles B, C. Even if the vehicle A delivering an interrogation signal to the vehicle B receives a response signal from the vehicle C simultaneously with a response signal from the vehicle B, the interrogators 1 of the vehicles A demodulates the identification code of the vehicle B in the spread code of response signal thereof while collating and thereby the response code of the vehicle C is not demodulated. Consequently, a plurality of vehicles from which response signals are received simultaneously can be discriminated according to the inventive vehicle identification system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle identification system using a secondary radar operating in conjunction with a laser telemeter, wherein a plurality of extremely close interrogators are simultaneously located at the same distance from each other. The present invention relates to a vehicle identification device capable of easily identifying a response signal from a desired target vehicle from among a plurality of response signals when an inquiry is made to a responder.

[0002]

2. Description of the Related Art Conventionally, a secondary radar which identifies a transponder by returning a response signal by radio wave from a transponder to an interrogation signal by radio wave from the interrogator interlocked with a distance measuring laser. 2. Description of the Related Art There is known a vehicle identification system that identifies a plurality of vehicles as friend or not using a plurality of vehicles. In the vehicle identification system, the interrogator is a laser telemeter that irradiates the laser signal to the transponder, a transmitter that outputs the interrogation signal, emits the interrogation signal to the transponder, and is returned from the transponder. Consisting of a directional antenna for an interrogator for receiving a response signal and a receiver for receiving the response signal,
On the other hand, the transponder is a laser detector that detects a laser signal from the interrogator, a directional antenna for the transponder that receives the interrogation signal, and radiates a response signal, and a beam direction of the directional antenna for the transponder. Controlling the antenna direction controller,
Generally, it is configured by a receiver for receiving the interrogation signal and a transmitter for outputting the response signal.

[0003] Regarding the conventional example of the vehicle identification system,
A description will be given based on FIG. 2 and FIG. FIG. 2 is a general operation conceptual diagram of a conventional vehicle identification system, and FIG.
FIG. 3 is a timing chart of operation signals in the vehicle identification system shown in FIG. 2. As shown in FIG. 2, in this case, an interrogator is mounted on each of the cars A and F, and a transponder is mounted on each of the cars B, C, D and E. First, as shown in FIG.
When the laser telescope of the interrogator of the car A is illuminated with a laser while aiming at the car B of which the response is desired, as shown in FIG. The detector detects the laser signal from the car A, and the transponder of the car B is ready to receive the interrogation signal, as shown in FIG. At the same time, the laser detector of the car B that has detected the laser signal detects the incident angle of the laser signal, and outputs this incident angle information to the antenna direction controller of the transponder of the car B. The above-mentioned antenna direction controller of the transponder controls the direction of the transponder directional antenna of the transponder based on the obtained incident angle information so that the direction of the laser is incident. As a result, the receiving direction of the transponder directional antenna of the transponder of the car B becomes the direction of the car A.
Next, as shown in FIG. 3 (g), the interrogator of the car A transmits an interrogation signal via the interrogator directional antenna. Then, the transponder of the car B receives the interrogation signal from the interrogator of the car A by the receiver via the transponder directional antenna, and determines whether the interrogation signal is a legitimate signal, As a result of the determination, when the interrogation signal is a normal signal, FIG.
As shown in (k), a response signal is transmitted via the transponder directional antenna. The response signal from the car B is received by the interrogator directional antenna of the interrogator of the car A, and is input to the receiver. On the other hand, the laser telemeter of the interrogator of the car A has already received the laser reflection signal from the car B, and applies a reception trigger to the interrogator of the car A. As shown in FIG. 3 (i), a reception gate is generated. The interrogator of the car A extracts a response signal corresponding to the reception gate from the response signals received after the reception trigger is applied, as shown in FIG. And outputs an identification result according to the content of the response signal. At this time, in FIG. 2, the transponders of car C and car D in the antenna beam of the interrogation signal of car A are A
Since the laser signal from the car is not detected, it is not ready to receive the interrogation signal of the car A.
The transponders of the car and car D ignore the interrogation signal. Also, for example, when the interrogator of the car F in FIG. 2 attempts to identify the car C, the laser from the car F's laser distance measuring device The laser detector detects this, so that only the answering machine of car C receives the interrogation signal of car F and sends out a response signal, and only the interrogator of car F receives the response signal. That is, the transponders of the cars B and E in the antenna beam of the interrogation signal of the car F ignore the interrogation signal of the car F. Therefore, the interrogation radio wave from the vehicle A emitted for the purpose of identifying the vehicle B is received only by the vehicle B, and the response signal from the vehicle B is received only by the vehicle A for which identification is desired.

[0005]

However, the above-described conventional vehicle identification system has a problem that identification becomes difficult in the following cases.
That is, as shown in FIG. 4, when the interrogator is mounted on each of the cars A and F and the answering machine is mounted on each of the cars B and C as shown in FIG. Is very close and car A and car B and car F and car C are equidistant, car A tries to identify car B, and car F identifies car C almost at the same time. It is time to try. The operation at the time of a problem will be described below with reference to FIGS. FIG. 4 is a conceptual diagram of the operation of the vehicle identification system in the related art at the time of a problem, and FIG. 5 is a timing chart of the operation signals at the time of the problem shown in FIG.
First, as shown in FIGS. 5 (a) and 5 (b), the laser telemeter of the interrogator of the car A in FIG. The laser telemeter of the interrogator irradiates the laser toward the car C. Then, as shown in FIGS. 5 (c) and 5 (d), the laser detectors of the transponders of the cars B and C detect the laser signals from the cars A and F, respectively.
As shown in (e) and (f), the transponders of car B and car C are ready to receive the interrogation signal. At the same time, the respective laser detectors of the car B and the car C that have detected the laser signal detect the incident angle of the laser signal with respect to each of them, and output this incident angle information to the responding machines of the car B and the car C.

Next, as shown in FIGS. 5 (g) and 5 (h),
Each of the interrogators A and F transmits an interrogation signal from the directional antenna. The laser telemeters of the interrogators A and F receive the laser reflection signals from the cars B and C, respectively, and apply reception triggers to the interrogators A and F. After the reception trigger is applied, the interrogators of the cars A and F open the reception gate as shown in FIGS. 5 (i) and 5 (j). The transponders of car B and car C respectively receive and decode the interrogation signals of car A and car F via the respective transponder directional antennas. As shown in (k) and (l), the response signals are transmitted almost simultaneously to the directional antennas in the laser incident direction based on the incident angle information from the laser detector. At this time, car A is very close to car F, so car B
As shown in FIG. 5 (m), both the response signals of the car B and the car C are received by the car A, because they are in the antenna beam of the response signal of the car and also in the antenna beam of the response signal of the car C. The signal is received as a reception signal corresponding to the gate. Therefore, there is a problem that it is difficult to extract only the desired response signal of the car B from the received signals. In addition, in the above state, if for some reason the car B did not transmit a response signal, or if the response signal did not reach the car A due to the appearance of an obstacle or the like,
There is also a problem that the response signal from the car C is determined to be the response signal of the car B. As a result, there is a high possibility that the car A is identified as a friend even though the car B is not a friend, or vice versa. The present invention
It was made in order to solve the above problems, even when a plurality of interrogators very close, almost simultaneously, each transmits an interrogation signal to the transponder at the same distance,
It is an object of the present invention to provide a vehicle identification system that reliably extracts and identifies a response signal from a desired transponder.

[0007]

In order to solve the above-mentioned problems, in the present invention, a response signal is returned from a transponder in response to an interrogation signal from an interrogator, so that the transponder is identified. In a vehicle identification system for identifying a plurality of vehicles by using a radar, the interrogator includes a laser irradiation unit that irradiates a laser signal to a transponder desired to be identified, and an interrogation signal transmission that transmits an interrogation signal after the laser irradiation. Means, and receiving means for receiving a response signal from the transponder, wherein the transponder receives a laser signal emitted from the interrogator, a laser detector, and receives an interrogation signal from the interrogator. And a response signal transmitting means for transmitting a response signal only when a laser is detected by the laser detecting means. And the response signal transmitting means of the transponder is a means configured by a modulation method based on a spread spectrum communication system. The response signal receiving means of the interrogator and the interrogation signal receiving means of the transponder are each a spread spectrum communication system. Means configured by a demodulation method based on

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. FIG. 1 is a configuration conceptual diagram showing an example of an embodiment of a vehicle identification system according to the present invention. This vehicle identification system uses a secondary radar system having an interrogator 1 and a transponder 2 as shown in FIG. 1. Usually, the interrogator 1 and the transponder 2 are mounted on a plurality of vehicles, respectively. Being used. The interrogator 1 includes a directional antenna for interrogator 3, a duplexer 4 connected to the directional antenna 3, a receiver 5 based on a spread spectrum communication system connected to the duplexer 4, and a receiver 5. A signal processing circuit 6 connected thereto, a transmitter 7 based on a spread spectrum communication system connected to the duplexer 4, an interrogation code generation circuit 8 connected to the transmitter 7 and the signal processing circuit 6, A laser telemeter 9 connected to the processing circuit 6. The transponder 2 includes a transponder directional antenna 10, an antenna direction controller 11 connected to the directional antenna 10, a laser detector 12 connected to the antenna direction controller 11, A duplexer 13 connected to the directional antenna 10 and a receiver 14 based on a spread spectrum communication system connected to the duplexer 13
And a video processing circuit 15 connected to the receiver 14.
And the video processing circuit 15 and the laser detector 1
2, a response code generation circuit 17 connected to the inquiry signal decryption circuit 16, the response code generation circuit 17 and the duplexer 13.
And a transmitter 18 based on a spread spectrum communication system. The feature of the vehicle identification system according to the present invention resides in the functions of the transmitters 7 and 18 and the receivers 5 and 14 based on the spread spectrum communication system, which form part of the interrogator 1 and the transponder 2.

Generally, in a transmitter based on the spread spectrum communication system, a carrier sine wave is first modulated by a spread code, and then a modulated signal to be transmitted thereon (in a vehicle identification system, an interrogator is used in an interrogator). Since the signal radio wave modulated by the interrogation code and the response code in the transponder is transmitted, the receiver cannot demodulate the received signal radio wave without knowing the spread code. In the present invention, the modulation and demodulation of the transmitter and the receiver in the above-mentioned vehicle identification system is performed by the above-mentioned spread spectrum communication system. The transmitters 7 of the interrogators 1 of the cars A and F, and the transponders 2 of the cars B and C
A, B, C, F
By using a spreading code including a unique identification code for identifying each car, even if the car A that has issued the interrogation signal to the car B receives the response signal of the car C at the same time as the response signal of the car B, The interrogator of the car A, in the spreading code of the response signal of the car B,
Since the identification code of the car B is collated and demodulated, the response code of the car C is not demodulated. Such an operation enables the vehicle identification system according to the present invention to identify a plurality of vehicles that have simultaneously received the response signal.

Next, the operation of the vehicle identification system having the above configuration will be described. Here, a description will be given with reference to the conceptual diagram of the operation at the time of the problem shown in FIG. 4 and the timing chart of the operation signal at the time of the problem shown in FIG. First, as shown in FIGS. 5 (a) and 5 (b), the laser telescope 9 of the interrogator 1 of the car A in FIG. The laser telemeter 9 of the car interrogator 1 irradiates the laser toward the car C. Then, as shown in FIGS. 5C and 5D, the laser signals from the A car and the F car are detected by the laser detectors 12 of the transponders 2 of the B car and the C car, respectively. As shown in (e) and (f), each of the transponders 2 of the car B and the car C is ready to receive the interrogation signal. At the same time, the laser detectors 12 of the cars B and C which have detected the laser signals detect the incident angles of the laser signals for the cars B and C, respectively, and transmit the incident angle information to each of the transponders of the cars B and C. 2 to the antenna direction controller 11. The antenna direction controller 11 of each transponder 2 controls the direction of the transponder directional antenna of each transponder 2 based on the obtained incident angle information so that the direction of the laser is incident. . As a result, the receiving direction of the transponder directional antenna 10 of the transponder 2 of the car B becomes the direction of the car A, and C
The receiving direction of the transponder directional antenna 10 of the transponder 2 of the car is the direction of the F car.

Next, the interrogator 1 for car A and car F is modulated with a spreading code including an identification code unique to each of car A and car F and an interrogation code in the car identification system. The interrogation signals shown in (g) and (h) are transmitted from the spread spectrum communication system transmitter 7 via the duplexer 4 and the interrogator directional antenna 3. The transponder 2 of the car B receives the interrogation signal from the interrogator 1 of the car A,
The interrogation signal is received by the directional antenna 10 for the transponder, passed through the duplexer 13 and received by the above-mentioned spread spectrum communication system receiver 14, and demodulated with the spreading code corresponding to the identification code of the car A. The demodulated interrogation signal is input to the interrogation signal decoding circuit 16 via the video processing circuit 15, and it is determined whether the interrogation signal is a legitimate signal. If the result of the above determination is that the interrogation signal is a legitimate signal, a response code is generated by the response code generation circuit 17 and the spread code including the identification code unique to the B-vehicle in the above-mentioned spread spectrum communication system transmitter 18. 5 through the duplexer 13 after being modulated by the
(K) As shown in FIG.
It is transmitted as a response signal.

On the other hand, the transponder 2 of the car C receives the interrogation signal from the car F by the spread spectrum communication system receiver 14 and responds to the identification code of the car F, as in the case of the car B described above. The interrogation signal is demodulated with the spread code thus obtained. When the interrogation signal is a legitimate signal, the signal is modulated by the spread code including the identification code unique to the car C and the response code in the spread spectrum communication system transmitter 18, and as shown in FIG. The response signal is transmitted from the directional antenna 10 for personal use. The two response signals from the cars B and C are
The signal is received by the interrogator directional antenna 3 of the interrogator 1 of the car A, and is input to the spread spectrum communication system receiver 5 via the duplexer 4. However, in the above-described spread spectrum communication system receiver 5 of the interrogator 1 of the car A, the received response signal is demodulated by the spread code corresponding to the identification code of the car B, so that the response signal of the car C is demodulated. Never. Therefore, since the response signal from the car B is demodulated only to the car A desired to be discriminated, and the response signal from the car C is demodulated only to the car F desired to be discriminated, the respective signals are decoded. The interrogators of the cars A and F do not mistake the response codes of the cars B and C. If there is no response signal from the transponder 2 of the car B, the interrogator 1 of the car A
However, the response signal from the transponder 2 of the car C is not confused with the response signal from the transponder 2 of the car B.

The above-described receiving operation of the interrogator 1 will be described in more detail. The laser telemeters 9 of the interrogators 1 of the cars A and F respectively transmit the laser reflected signals from the cars B and C, respectively. The reception trigger has already been applied to the signal processing circuits 6 of the interrogators 1 of the cars A and F, and the reception gate has been opened as shown in FIGS. 5 (i) and 5 (j). The signal processing circuit 6 of each of the interrogators 1 of the car A and the car F extracts a response signal corresponding to the reception gate responded after the application of the reception trigger, and the extracted signal is a normal response signal. , And outputs an identification result according to the content of the response signal. Although the embodiment of the present invention has been described as a vehicle identification system, the object of identification can naturally be applied to the identification of other moving objects.

[0014]

As described above, the present invention uses the spread spectrum communication system for the modulation and demodulation of the transmitter and the receiver in the interrogator and the transponder. When the interrogator is installed and the answering machine is installed in cars B and C, cars A and F are quite close, and the distance between cars A and B and between cars F and C are equidistant. At about the same time, the car A
When car F tries to identify car C, the interrogator of car A
Even when the response signals of the car B and the car C are output at the same timing, the interrogator of the car A extracts only the response signal of the car B and can reliably identify whether the car B is a friend. effective.

[Brief description of the drawings]

FIG. 1 is a configuration conceptual diagram showing one embodiment of a vehicle identification system according to the present invention;

FIG. 2 is a general operation conceptual diagram of a vehicle identification system in a conventional example.

3 (a) to 3 (m) are timing charts of operation signals in the vehicle identification system shown in FIG. 2;

FIG. 4 is an operation conceptual diagram of a conventional vehicle identification system when a problem occurs.

5 (a) to 5 (m) are timing charts of operation signals in the vehicle identification system shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 interrogator 2 transponder 3 directional antenna for interrogator 4 duplexer 5 spread spectrum communication system receiver 6 signal processing circuit 7 spread spectrum communication system transmitter 8 interrogation code generation circuit 9 laser telemeter 10 directional antenna for transponder DESCRIPTION OF SYMBOLS 11 Antenna direction controller 12 Laser detector 13 Duplexer 14 Spread spectrum communication system receiver 15 Video processing circuit 16 Interrogation signal decoding circuit 17 Response code generation circuit 18 Spread spectrum communication system transmitter

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[Procedure amendment]

[Submission date] February 17, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a configuration conceptual diagram showing an example of an embodiment of a vehicle identification system according to the present invention.

FIG. 2 is a general operation conceptual diagram of a vehicle identification system in a conventional example.

3 (a) to 3 (g) are timing charts of operation signals in the vehicle identification system shown in FIG. 2;

FIG. 4 is an operation conceptual diagram of a conventional vehicle identification system when a problem occurs.

5 (a) to 5 (m) are timing charts of operation signals in the vehicle identification system shown in FIG.

[Description of Signs] 1 Interrogator 2 Transponder 3 Directional antenna for interrogator 4 Duplexer 5 Spread spectrum communication system receiver 6 Signal processing circuit 7 Spread spectrum communication system transmitter 8 Interrogation code generation circuit 9 Laser telescope 10 Response Directional antenna for antenna 11 Antenna direction controller 12 Laser detector 13 Duplexer 14 Spread spectrum communication system receiver 15 Video processing circuit 16 Interrogation signal decoding circuit 17 Response code generation circuit 18 Spread spectrum communication system transmitter ────── ───────────────────────────────────────────────

[Procedure amendment]

[Submission date] March 10, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Identification system

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle identification system using a secondary radar operating in conjunction with a laser telemeter, wherein a plurality of extremely close interrogators are simultaneously located at the same distance from each other. The present invention relates to a vehicle identification device capable of easily identifying a response signal from a desired target vehicle from among a plurality of response signals when an inquiry is made to a responder.

[0002]

2. Description of the Related Art Conventionally, a secondary radar which identifies a transponder by returning a response signal by radio wave from a transponder to an interrogation signal by radio wave from the interrogator interlocked with a distance measuring laser. 2. Description of the Related Art There is known a vehicle identification system that identifies a plurality of vehicles as friend or not using a plurality of vehicles. In the vehicle identification system, the interrogator is a laser telemeter that irradiates a laser signal to the transponder, a transmitter that measures the interrogation signal, emits the interrogation signal to the transponder, and is returned from the transponder. The interrogator directional antenna for receiving the response signal and the receiver for receiving the response signal, while the transponder is a laser detector for detecting the laser signal from the interrogator, for receiving the interrogation signal And a transponder directional antenna that radiates a response signal, an antenna direction controller that controls the beam direction of the transponder directional antenna, a receiver that receives an interrogation signal, and a transmitter that outputs the response signal. It is generally composed.

[0003] Regarding the conventional example of the vehicle identification system,
A description will be given based on FIG. 2 and FIG. FIG. 2 is a general operation conceptual diagram of a conventional vehicle identification system, and FIG.
FIG. 3 is a timing chart of operation signals in the vehicle identification system shown in FIG. 2. As shown in FIG. 2, in this case, an interrogator is mounted on each of the cars A and F, and a transponder is mounted on each of the cars B, C, D and E. First, as shown in FIG.
3B, the laser telescope of the interrogator of the car A irradiates the laser with aiming at the car B of which the response is desired, and as shown in FIG. The detector detects the laser signal from the car A, and the transponder of the car B is ready to receive the interrogation signal, as shown in FIG. At the same time, the laser detector of the car B that has detected the laser signal detects the incident angle of the laser signal, and outputs this incident angle information to the antenna direction controller of the transponder of the car B. The above-mentioned antenna direction controller of the transponder controls the direction of the transponder directional antenna of the transponder based on the obtained incident angle information so that the direction of the laser is incident. As a result, the receiving direction of the transponder directional antenna of the transponder of the car B becomes the direction of the car A.
Next, as shown in FIG. 3 (d), the interrogator of the car A transmits an interrogation signal via the interrogator directional antenna. Then, the transponder of the car B receives the interrogation signal from the interrogator of the car A by the receiver via the transponder directional antenna, and determines whether the interrogation signal is a legitimate signal,
As a result of the determination, when the interrogation signal is a regular signal, FIG.
As shown in (2), a response signal is transmitted via the directional antenna for a transponder. The response signal from the car B is received by the interrogator directional antenna of the interrogator of the car A, and is input to the receiver. On the other hand, the laser telemeter of the interrogator of the car A has already received the laser reflection signal from the upper car, and applies a reception trigger to the interrogator of the car A. As shown in FIG. 3E, a reception gate is generated. The interrogator of the car A extracts a response signal corresponding to the reception gate from the response signals received after the application of the reception trigger as shown in FIG. 3 (g). And outputs an identification result according to the content of the response signal. At this time, in FIG. 2, the transponders of the car C and the car D in the antenna beam of the interrogation signal of the car A do not detect the laser signal from the car A, and are ready to receive the interrogation signal of the car A. Not so, C car and D
The transponder of the vehicle ignores the interrogation signal. Also, for example,
When the interrogator of the car F in FIG. 2 attempts to identify the car C, the laser detector of the car C uses the laser detector of the car F in the same manner as the car B identification operation of the car A described above. Accordingly, only the answering machine of the car C receives the interrogation signal of the car F and sends a response signal, and only the interrogator of the car F receives the response signal. That is, the transponders of the cars B and E in the antenna beam of the interrogation signal of the car F ignore the interrogation signal of the car F. Therefore, the interrogation radio wave from the vehicle A emitted for the purpose of identifying the vehicle B is received only by the vehicle B, and the response signal from the vehicle B is received only by the vehicle A for which identification is desired.

[0005]

However, the above-described conventional vehicle identification system has a problem that identification becomes difficult in the following cases.
That is, as shown in FIG. 4, when the interrogator is mounted on each of the cars A and F and the answering machine is mounted on each of the cars B and C as shown in FIG. Is very close and car A and car B and car F and car C are equidistant, car A tries to identify car B, and car F identifies car C almost at the same time. It is time to try. The operation at the time of a problem will be described below with reference to FIGS. FIG. 4 is a conceptual diagram of the operation of the vehicle identification system in the related art at the time of a problem, and FIG. 5 is a timing chart of the operation signals at the time of the problem shown in FIG. First, the laser telescope of the interrogator of the car A in FIG.
As shown in FIGS. 5 (a) and 5 (b), while irradiating the laser toward the car B, at about the same time, the laser telemeter of the interrogator of the car F applies the laser toward the car C. Irradiate.
Then, as shown in FIGS. 5 (c) and 5 (d), the laser detectors of the above-mentioned transponders of the car B and the car C are the cars A and F
Each of the laser signals from the car is detected, and FIG.
As shown in (f), the answering machines of car B and car C are ready to receive the interrogation signal. At the same time, each of the above laser detectors of car B and car C that detected the laser signal,
The angle of incidence of the laser signal for each is detected, and this angle-of-incidence information is output to the transponders of the cars B and C.

Next, as shown in FIGS. 5 (g) and 5 (h),
Each of the interrogators A and F transmits an interrogation signal from the directional antenna. The laser telemeters of the interrogators A and F receive the laser reflection signals from the cars B and C, respectively, and apply reception triggers to the interrogators A and F. After the reception trigger is applied, the interrogators of the cars A and F open the reception gate as shown in FIGS. 5 (i) and 5 (j). The transponders of car B and car C respectively receive and decode the interrogation signals of car A and car F via the respective transponder directional antennas. As shown in (k) and (l), the response signals are transmitted almost simultaneously to the directional antennas in the laser incident direction based on the incident angle information from the laser detector. At this time, car A is very close to car F, so car B
As shown in FIG. 5 (m), both the response signals of the car B and the car C are received by the car A, because they are in the antenna beam of the response signal of the car and also in the antenna beam of the response signal of the car C. The signal is received as a reception signal corresponding to the gate. Therefore, there is a problem that it is difficult to extract only the desired response signal of the car B from the received signals. In addition, in the above state, if for some reason the car B did not transmit a response signal, or if the response signal did not reach the car A due to the appearance of an obstacle or the like,
There is also a problem that the response signal from the car C is determined to be the response signal of the car B. As a result, there is a high possibility that the car A is identified as a friend even though the car B is not a friend, or vice versa. The present invention
It was made in order to solve the above problems, even when a plurality of interrogators very close, almost simultaneously, each transmits an interrogation signal to the transponder at the same distance,
An object of the present invention is to provide a vehicle identification system that reliably extracts and identifies a response signal from a desired transponder.

[0007]

In order to solve the above-mentioned problems, in the present invention, a response signal is returned from a transponder in response to an interrogation signal from an interrogator, so that the transponder is identified. In a vehicle identification system for identifying a plurality of vehicles by using a radar, the interrogator includes a laser irradiation unit that irradiates a laser signal to a transponder desired to be identified, and an interrogation signal transmission that transmits an interrogation signal after the laser irradiation. Means, and receiving means for receiving a response signal from the transponder, wherein the transponder receives a laser signal emitted from the interrogator, a laser detector, and receives an interrogation signal from the interrogator. And a response signal transmitting means for transmitting a response signal only when a laser is detected by the laser detecting means. And the response signal transmitting means of the transponder is a means configured by a modulation method based on a spread spectrum communication system. The response signal receiving means of the interrogator and the interrogation signal receiving means of the transponder are each a spread spectrum communication system. Means configured by a demodulation method based on

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. FIG. 1 is a configuration conceptual diagram showing an example of an embodiment of a vehicle identification system according to the present invention. This vehicle identification system uses a secondary radar system having an interrogator 1 and a transponder 2 as shown in FIG. 1, and the interrogator 1 and the transponder 2 are usually mounted on a plurality of vehicles, respectively. Used. The interrogator 1 includes a directional antenna 3 for an interrogator, a duplexer 4 connected to the directional antenna 3, a receiver 5 based on a spread spectrum communication system connected to the duplexer 4, 5, a signal processing circuit 6 connected to the duplexer 4, a transmitter 7 based on a spread spectrum communication system, and the transmitter 7 and the signal processing circuit 6.
And a laser telemeter 9 connected to the signal processing circuit 6. Also,
The transponder 2 includes a transponder directional antenna 10 and an antenna direction controller 11 connected to the directional antenna 10.
A laser detector 12 connected to the antenna direction controller 11, a duplexer 13 connected to the directional antenna 10, a receiver 14 based on a spread spectrum communication system connected to the duplexer 13, A video processing circuit 15 connected to the receiver 14, an interrogation signal decoding circuit 16 connected to the video processing circuit 15 and the laser detector 12, and a response code generation circuit 17 connected to the interrogation signal decoding circuit 16 And a transmitter 18 based on a spread spectrum communication system connected to the response code generation circuit 17 and the duplexer 13. The features of the vehicle identification system according to the present invention include:
The functions of the transmitters 7 and 18 and the receivers 5 and 14 based on the spread spectrum communication system forming a part of the interrogator 1 and the responder 2 are included.

Generally, in a transmitter based on the spread spectrum communication system, a carrier sine wave is first modulated by a spread code, and then a modulated signal to be transmitted thereon (in a vehicle identification system, an interrogator is used in an interrogator). Since the signal radio wave modulated by the interrogation code and the response code in the transponder is transmitted, the receiver cannot demodulate the received signal radio wave without knowing the spread code. In the present invention, the modulation and demodulation of the transmitter and the receiver in the above-mentioned vehicle identification system is performed by the above-mentioned spread spectrum communication system. The transmitters 7 of the interrogators 1 of the cars A and F, and the transponders 2 of the cars B and C
A, B, C, F
By using a spreading code including a unique identification code for identifying each car, even if the car A that has issued the interrogation signal to the car B receives the response signal of the car C at the same time as the response signal of the car B, The interrogator of the car A, in the spreading code of the response signal of the car B,
Since the identification code of the car B is collated and demodulated, the response code of the car C is not demodulated. Such an operation enables the vehicle identification system according to the present invention to identify a plurality of vehicles that have simultaneously received the response signal.

Next, the operation of the vehicle identification system having the above configuration will be described. Here, a description will be given with reference to the conceptual diagram of the operation at the time of the problem shown in FIG. 4 and the timing chart of the operation signal at the time of the problem shown in FIG. First, as shown in FIGS. 5 (a) and 5 (b), the laser telescope 9 of the interrogator 1 of the car A in FIG. The laser telemeter 9 of the car interrogator 1 irradiates the laser toward the car C. Then, as shown in FIGS. 5C and 5D, the laser signals from the A car and the F car are detected by the laser detectors 12 of the transponders 2 of the B car and the C car, respectively. As shown in (e) and (f), each of the transponders 2 of the car B and the car C is ready to receive the interrogation signal. At the same time, the laser detectors 12 of the cars B and C which have detected the laser signals detect the incident angles of the laser signals for the cars B and C, respectively, and transmit the incident angle information to each of the transponders of the cars B and C. 2 to the antenna direction controller 11. The antenna position controller 11 of each of the transponders 2 controls the direction of the transponder directional antenna of each transponder 2 based on the obtained incident angle information so that the direction of the laser is incident. I do. As a result, the receiving direction of the transponder directional antenna 10 of the transponder 2 of the car B becomes the direction of the car A, and C
The receiving direction of the transponder directional antenna 10 of the transponder 2 of the car is the direction of the F car.

Next, the interrogator 1 for car A and car F is modulated with a spreading code including an identification code unique to each of car A and car F and an interrogation code in the car identification system. The interrogation signals shown in (g) and (h) are transmitted from the spread spectrum communication system transmitter 7 via the duplexer 4 and the interrogator directional antenna 3. The transponder 2 of the car B receives the interrogation signal from the interrogator 1 of the car A,
The interrogation signal is received by the directional antenna 10 for the transponder, passed through the duplexer 13 and received by the above-mentioned spread spectrum communication system receiver 14, and demodulated with the spreading code corresponding to the identification code of the car A. The demodulated interrogation signal is input to the interrogation signal decoding circuit 16 via the video processing circuit 15, and it is determined whether the interrogation signal is a legitimate signal. If the result of the above determination is that the interrogation signal is a legitimate signal, a response code is generated by the response code generation circuit 17 and the spread code including the identification code unique to the B-vehicle in the above-mentioned spread spectrum communication system transmitter 18. 5 through the duplexer 13 after being modulated by the
(K) As shown in FIG.
It is transmitted as a response signal.

On the other hand, the answering machine 2 of the car C receives the interrogation signal from the getting off by the spread spectrum communication system receiver 14 and responds to the identification code of the car F in the same manner as in the case of the car B described above. The interrogation signal is demodulated with the spreading code. When the interrogation signal is a legitimate signal, the signal is modulated by the spread code including the identification code unique to the car C and the response code in the spread spectrum communication system transmitter 18, and the response signal is transmitted as shown in FIG. The response signal is transmitted from the directional antenna 10 for personal use. The two response signals from the cars B and C are
The signal is received by the interrogator directional antenna 3 of the interrogator 1 of the car A, and is input to the spread spectrum communication system receiver 5 via the duplexer 4. However, in the above-described spread spectrum communication system receiver 5 of the interrogator 1 of the car A, the received response signal is demodulated by the spread code corresponding to the identification code of the car B, so that the response signal of the car C is demodulated. Never. Therefore, since the response signal from the car B is demodulated only to the car A desired to be discriminated, and the response signal from the car C is demodulated only to the car F desired to be discriminated, the respective signals are decoded. The interrogators of the cars A and F do not mistake the response codes of the cars B and C. If there is no response signal from the transponder 2 of the car B, the interrogator 1 of the car A
However, the response signal from the transponder 2 of the car C is not confused with the response signal from the transponder 2 of the car B.

The above-described receiving operation of the interrogator 1 will be described in more detail. The laser telemeters 9 of the interrogators 1 of the cars A and F respectively transmit the laser reflected signals from the cars B and C, respectively. The reception trigger has already been applied to the signal processing circuits 6 of the interrogators 1 of the cars A and F, and the reception gate has been opened as shown in FIGS. 5 (i) and 5 (j). The signal processing circuit 6 of each of the interrogators 1 of the car A and the car F extracts a response signal corresponding to the reception gate responded after the application of the reception trigger, and the extracted signal is a normal response signal. , And outputs an identification result according to the content of the response signal. Although the embodiment of the present invention has been described as a vehicle identification system, the object of identification can naturally be applied to the identification of other moving objects.

[0014]

As described above, the present invention uses the spread spectrum communication system for the modulation and demodulation of the transmitter and the receiver in the interrogator and the transponder. When the interrogator is installed and the answering machine is installed in cars B and C, cars A and F are quite close, and the distance between cars A and B and between cars F and C are equidistant. At about the same time, the car A
When car F tries to identify car C, the interrogator of car A
Even when the response signals of the car B and the car C are output at the same timing, the interrogator of the car A extracts only the response signal of the car B and can reliably identify whether the car B is a friend. effective.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating an example of an embodiment of a vehicle identification system according to the present invention;

FIG. 2 is a general operation conceptual diagram of a vehicle identification system in a conventional example.

3 (a) to 3 (g) are timing charts of operation signals in the vehicle identification system shown in FIG. 2;

FIG. 4 is an operation conceptual diagram of a conventional vehicle identification system when a problem occurs.

5 (a) to 5 (m) are timing charts of operation signals in the vehicle identification system shown in FIG.

[Description of Signs] 1 Interrogator 2 Transponder 3 Directional antenna for interrogator 4 Duplexer 5 Spread spectrum communication system receiver 6 Signal processing circuit 7 Spread spectrum communication system transmitter 8 Interrogation code generation circuit 9 Laser telescope 10 Response Directional antenna 11 Antenna direction controller 12 Laser detector 13 Duplexer 14 Spread spectrum communication system receiver 15 Video processing circuit 16 Interrogation signal decoding circuit 17 Response code generation circuit 18 Spread spectrum communication system transmitter

Claims (1)

[Claims] 1. A secondary radar for identifying a transponder by returning a response signal by radio wave from a transponder to an interrogation signal by radio wave from the interrogator, wherein the interrogator desires the identification. A laser irradiating means for irradiating the transponder with a laser signal, an interrogation signal transmitting means for transmitting an interrogation signal after the laser irradiation, and a response signal receiving means for receiving a response signal from the transponder; However, a laser detecting means for detecting a laser signal emitted from the interrogator, an interrogation signal receiving means for receiving an interrogation signal from the interrogator, and a response signal is transmitted only when the laser is detected by the laser detecting means. And a response signal transmitting means of the interrogator, wherein the response signal transmitting means of the interrogator is a modulation method based on a spread spectrum communication system. Means comprising a formula, and
An identification system using a secondary radar, wherein the response signal receiving means of the interrogator and the interrogation signal receiving means of the transponder are means configured by a demodulation method based on a spread spectrum communication method.