JP3082441B2 - Response unit for mobile object identification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object, which moves when attached to a moving body and receives a writing signal in a communication area of a writing antenna unit, executes a writing process, and reads a reading signal in a communication area of a reading antenna unit. The present invention relates to a response unit for a mobile object identification device that performs a necessary data readout process upon reception and transmits the data.

[0002]

2. Description of the Related Art As this kind of moving object identification device, there is one applied to a system such as an automatic guided vehicle used in a factory, for example. That is, a tag unit as a response unit is attached to the automatic guided vehicle side, and a communication area of the antenna unit is set on the traveling path of the automatic guided vehicle so as to be able to communicate with the tag unit. . In this case, the tag unit stores, for example, various data such as the identification code and the number of articles to be conveyed by the automatic guided vehicle, the number of conveyed articles, and the like, and enables reading or writing of new data as necessary. I have.

Further, the antenna unit is configured to modulate a carrier wave of a predetermined frequency with an interrogation signal for transmission to a communication area, and to transmit an unmodulated carrier wave thereafter. When the tag unit attached to the automatic guided vehicle moves into the communication area due to the movement of the automatic guided vehicle and receives an interrogation signal, various data such as an identification code corresponding to the interrogation signal is generated as a response signal, and the uninterrupted reception is continued. The modulated carrier wave is transmitted by modulating it with the response signal.

On the antenna unit side, by receiving the response signal, the tag unit of the automatic guided vehicle passing through the communication area can be identified, and the contents of the mounted article can be determined and new data can be transmitted. To memorize,
Alternatively, the traveling of the automatic guided vehicle can be controlled.

By the way, in such a system,
Some response units are provided with a data memory using a non-volatile memory such as an EEPROM. However, in general, the non-volatile memory takes a long time to write data. When a write command signal is included, the time required to perform a write process to the data memory becomes longer. In this case, if the automatic guided vehicle is moving at a high speed,
Before reading the data written in the data memory and transmitting the data to the antenna unit, the tag unit may pass through the communication area and come out, and there is a problem that the communication cannot be performed reliably.

Conventionally, in order to solve such a problem, the antenna unit is divided into a writing antenna unit 10 and a reading antenna unit 12 as shown in FIG. 1
Some are placed before and after 6. That is, the writing signal is transmitted in the communication area 18 of the writing antenna unit 10 and the reading signal is transmitted in the communication area 20 of the reading antenna unit 12 set at a position farther away. Even when it takes time to write data to the data memory in the tag unit 22 attached to the automatic guided vehicle 14, the writing process can be completed before the tag unit 22 moves to the communication area 20 of the reading antenna unit 12. Therefore, even when the automatic guided vehicle 14 is moved at a high speed, the communication can be reliably performed and the identification can be performed.

[0007]

However, in the above-described conventional configuration, for example, if the automatic guided vehicle 14 stops in the communication area 18 of the writing antenna unit 10 for some reason, the unmanned transported vehicle 14 stops. Car 14
Will repeatedly receive the write signal transmitted from the write antenna unit 10. Then, for example, if the write signal is a command to write data such as the number of passes, the data of the number of passes is rewritten and updated every time a write signal is received. There is a problem that can not be done.

Therefore, the inventors have considered a configuration as shown in FIG. 5, for example, in order to solve such a problem. That is, object detectors 24a, 24b, which detect the presence or absence of an object before and after each of the antenna units 10, 12,
26a and 26b, and each antenna unit 10, 1
It is determined whether or not the tag unit 22 exists in the second communication areas 18 and 20. In this case, the object detectors 24a and 26
In the communication areas 18 and 20, the period between the detection of “a” and the detection of the object detectors 24 b and 26 b is
4 can be recognized as being present.
As a result, for example, the tag unit 22 that has entered the communication area 18 or 20 once is in the communication area 18 or 20.
In the case where the antenna is stopped inside, the above-mentioned problem can be solved by controlling the antenna unit 10 or 12 not to transmit the write signal.

However, in such a configuration, there is no problem when the automatic guided vehicles 14 provided with the tag units 22 pass through the communication areas 18 and 20 one by one. For example, FIG. As described above, when two or more AGVs 14 pass through the communication area 18 or 20 at the same time, when a write signal is transmitted to one of the tag units 22, the transmission of the write signal is stopped thereafter. Then, the writing signal is not transmitted to the tag unit 22 which has entered the communication areas 18 and 20 with a slight delay. On the other hand, the object detectors 24a and 26 indicate that two automatic guided vehicles 14 have entered.
When the write signal is transmitted twice by detecting by a
The tag unit 22 that has received the write signal first also receives the second write signal, and in this case, there is a problem that multiple writing occurs as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object a simple and inexpensive configuration that ensures that a write process is performed only once when a write signal is given in a communication area of a write antenna unit. The present invention provides a response unit for a mobile object identification device that can execute the following.

[0011]

According to a first aspect of the present invention , a writing process is executed when a mobile terminal is attached to a mobile body and receives a write signal in a communication area of a write antenna unit. The present invention is intended for a response unit for a mobile unit identification device that performs a necessary data read process when a read signal is received in a communication area of a read antenna unit and transmits the read data, and reads and writes the required data. Data writing means, control means for controlling the writing processing and reading processing to the data storage means, and a writing signal from the writing antenna unit is received, and the control means writes the data to the data storage means. And a state storage means for storing a write completion state when a write process is executed, wherein the state storage means writes the control means. In the state of storing completion state, when receiving a write signal from the write antenna unit has a feature where to disable the writing process corresponding to the write signal. The invention of claim 2 is
The response unit for a mobile object identification device according to claim 1
And the control means determines that the status storage means has completed writing.
The writing antenna unit in a state where the state is stored.
When receiving a write signal from, its write signal
Transmitted from the same writing antenna unit.
Judge whether they are the same or not.
Invalidate the write process corresponding to the write signal of
It has features in its configuration.

[0012]

According to the response unit for a mobile object identification device according to the first aspect of the present invention, when a write signal is received in the communication area of the write antenna unit, the control means executes a write process to execute the write processing. At this time, the state storage means stores the completion state of the write processing. Thereby, even after receiving the write signal from the write antenna unit, the control means invalidates the write processing corresponding to the write signal based on the fact that the state storage means stores the write completion state. It becomes to become.

Therefore, the moving speed of the moving body is slow,
Alternatively, in the case where the writing antenna unit is stopped in the communication area of the writing antenna unit due to some reason or the like, even if the writing signal transmitted from the writing antenna unit is repeatedly received, the writing process corresponding thereto is invalidated. Thus, the writing process can be surely executed only once. Further, even when other response units are present in the communication area at the same time, each response unit makes its own judgment and performs the write process, so that the write process can be executed only once in the same manner. Claim 2
According to the invention of (1), the write signal is the same by the control means.
Is it transmitted from the writing antenna unit?
Judge whether it is the same and respond to the write signal at the same time.
Since the writing process is invalidated, the same antenna unit
Simple and quick write process for write signals from
It can be executed only once with certain judgment
become.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a tag unit used in an automatic guided vehicle communication system will be described below with reference to FIGS. That is, first, in FIG. 2 showing the overall arrangement, an unmanned transport vehicle 30 as a moving body is controlled by a control device (not shown) so as to travel along a traveling path 32, and transported objects such as articles are transported. In the mounted state, the vehicle travels along the traveling path 32 as shown by an arrow to a target location.

At a predetermined position of the traveling path 32, a writing antenna unit 36 for setting a communication area 34 and a reading antenna unit 4 for setting a communication area 38.
0 are disposed adjacent to each other before and after in the traveling direction. Also,
At another predetermined position, a writing antenna unit 44 for setting a similar communication area 42 and a reading antenna unit 48 for setting a communication area 46 are also provided. When the automatic guided vehicle 30 travels on the travel path, the automatic guided vehicle 30 sequentially passes through the communication areas 34, 38, 42, and 46.

The automatic guided vehicle 30 is provided with a tag unit 50 as a response unit according to the present invention, and in each of the communication areas 34, 38, 42 and 46, the antenna units 36, 40, 44 and 4
8 as described later.

Each of the antenna units 36, 40, 44, and 48 is provided with, for example, a batch antenna formed by a microstrip line formed on a printed circuit board. It is configured as an array antenna in which a plurality of the batch antennas are arranged. Further, the frequency of the radio wave of the transmitted write signal or read signal is, for example, 2.45 GHz.
The quasi-microwave in the band is used as the carrier wave.

The radio waves transmitted from the antenna units 36, 40, 44, and 48 are obtained by modulating the above-described carrier radio waves during the transmission period of the write signal or the read signal, and are not used during other periods. It is configured to continuously transmit the modulated carrier wave, and during the transmission period of the unmodulated carrier wave, each communication area 3 is simultaneously transmitted.
4, 38, 42, and 46 are configured to receive radio waves transmitted from inside.

Next, in FIG. 3 showing the electrical configuration of the tag unit 50, a control circuit 52 as control means
It is configured to include a PU, a ROM, a RAM, and the like, and stores a control program described later in advance, controls communication, and has a function as a state storage unit described later. The antenna 54 uses, for example, a batch antenna using a microstrip line formed on a printed circuit board.

The antenna 54 is connected to the control circuit 52 via a radio wave detector 56 and to the control circuit 52 via a demodulation circuit 58. The antenna 54 is grounded via a switch circuit 60. The control terminal of the switch circuit 60 is connected to the control circuit 52 via the modulation circuit 62. The radio wave detector 56 detects a radio wave received by the antenna 54, and outputs the detection state to the control circuit 52. The demodulation circuit 58 similarly demodulates the radio wave received by the antenna 54 and outputs it to the control circuit 52 as a reception signal. The modulation circuit 62
The modulation operation is performed by turning on / off the switch circuit 60 according to the response signal given from the control circuit 52.

Data memory 64 as data storage means
Is composed of a nonvolatile memory such as an EEPROM, for example, and is connected to the control circuit 52. Control circuit 52
Executes a write process as needed to write various data into the data memory 64, and executes a read process to read various data from the data memory 64. Each of the above circuits is supplied with power from a battery (not shown).

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. Tag unit 5
When the power is supplied, the control circuit 52 starts executing the communication control program shown in FIG. 1, executes an initialization process (step S1), and then waits until a radio wave is received in step S2. Become. In this initialization processing, initialization is performed by clearing various registers and flags, and the completion flag F as the state storage means is also cleared (F ← “0”).

First, when the automatic guided vehicle 30 moves and enters the communication area 34 of the writing antenna unit 36, the writing signal transmitted from the writing antenna unit 36 is received by the antenna 54 of the tag unit 50. . Then, the radio wave detector 56 detects this and gives a detection signal to the control circuit 52. Accordingly, the control circuit 52 determines “YES” in step S2 and proceeds to step S3 to determine whether the received radio wave is a write signal. At this time, the control circuit 52 controls the demodulation circuit 5
8, a reception signal corresponding to the write signal is given, so that “YES” is determined in the step S3 and the step S3 is performed.
Move to 4.

The control circuit 52 determines in step S4
It is determined whether or not the completion flag F has been set. In this case, since the completion flag has not been set (F =
("0"), the judgment is "NO", and the routine goes to Step S5. In step S5, the control circuit 52 writes necessary data into the data memory 64, and sets the completion flag F in the following step S6 (F ←
"1") Return to step S2. Note that the above step S5
In this case, since it takes a longer time to write data in the data memory 64 than in other processing, the writing antenna is terminated at the time when the writing process is completed while the automatic guided vehicle 30 is traveling at a normal speed. It may pass through the communication area 34 of the unit 36.

Further, the moving speed of the automatic guided vehicle 30 is slow,
If the tag unit 50 is still present in the communication area 34 of the writing antenna unit 36 at the time when the writing process is completed, the writing signal is received again.
However, in this case, the control circuit 52 determines in step S
At step S4 after steps S2 and S3, the completion flag F has already been set (F = “1”).
O ”is determined, and the process proceeds to step S7. Control circuit 52
Determines "YES" in step S7 because it is received from the same antenna unit, and returns to step S2. That is, since the write processing has been executed once, the control circuit 52 invalidates the execution of the write processing by the second and subsequent write signals.

Next, when the automatic guided vehicle 30 enters the communication area 38 of the read antenna unit 40, the tag unit 50 operates as follows. That is, the control circuit 5
2 proceeds to step S2 through step S2 in the same manner as described above.
When the process proceeds to step S3, “NO” is determined here, and step S
8 is started. The control circuit 52 includes the demodulation circuit 5
8, since the read signal has been received from step S8.
In step S8, "YES" is determined, and the process proceeds to step S9. After the reading process is executed, the completion flag F is cleared (F ← "0") in step S10, and the process returns to step S2.

In this case, in the above-described reading process by the control circuit 52, for example, the data memory 6 is written by a writing process.
In order to check the data written in No. 4, the data is read and transmitted to the read antenna unit 40. In this transmission, the control circuit 52 gives the read data to the modulation circuit 62 as a response signal,
Performs a modulation operation according to the response signal to control on / off of the switch circuit 60. Thereby, the antenna 5
4 transmits the unmodulated carrier radio wave received from the read antenna unit 40 to the read antenna unit 40 by reflecting or absorbing it.
On the other hand, since the read antenna unit 40 receives the radio wave transmitted from the communication area 38 while transmitting the unmodulated carrier radio wave, it is possible to receive and demodulate this to obtain a response signal. it can.

If the control circuit 52 determines "NO" in step S8, that is, if the received radio wave is neither a write signal nor a read signal, the control circuit 52 outputs the signal from the antenna unit 36 or 40. It is determined that the received radio wave is not received, and the process returns to step S2.

When the automatic guided vehicle 30 stops in the communication area 34 of the writing antenna unit 36 for some reason, the writing signal is repeatedly transmitted to the tag unit 50, as described above. As described above, once the write processing is executed, the control circuit 52 invalidates the second and subsequent write signals and does not execute the write processing.
The problem of multiple writing is eliminated.

Further, even in a situation where a plurality of automatic guided vehicles 30 enter the communication area 34 at the same time, the writing process is executed only once as described above. Even if the write signal is continuously transmitted, all the tag units 50 can execute the write process only once without causing multiple writing.

Since the AGV 30 passes through the communication area 34 of the writing antenna unit 36 and then passes through the communication area 38 of the reading antenna unit 40, the control circuit 52 normally performs step The completion flag F set in S6 passes through the communication area 38 while being cleared in step S10. Therefore, when the automatic guided vehicle 30 enters the communication area 42 of another writing antenna unit 44 next,
In the same manner as described above, the writing process can be reliably executed only once.

However, when a plurality of AGVs 30 are moving in parallel as described above, for example, when passing through the communication area 38 of the readout antenna unit 40, other AGVs 30 Tag unit 5 in the shadow of
0 may pass without receiving a read signal from the read antenna unit 40.

In this case, when the automatic guided vehicle 30 enters the communication area 42 of the writing antenna unit 44 and the tag unit 50 receives the writing signal, the control circuit 52
Performs write processing by operating as follows. That is,
The control circuit 52 performs step S2 through steps S2 and S3.
At 4 the completion flag F has not been cleared (F = “1”), so that the determination is “YES” and the process proceeds to step S7. Here, the write antenna unit through which the write signal has already passed Not from 36,
Since it is from the writing antenna unit 44, it is determined to be "NO", so that the processing shifts to step 5 to execute the writing process in the same manner as described above.

According to this embodiment, the control circuit 5
2, when a write signal from the write antenna unit 36 or 44 is received, write processing is executed, and the completion flag F is set to invalidate the write processing by the second and subsequent write signals. Multiple writing to the memory 64 can be prevented, and
When a plurality of tag units 50 are simultaneously in the communication area 34 or 4
2, each tag unit 50
Can reliably execute the write process only once.

Further, according to the present embodiment, the control circuit 52 determines whether or not the write signal is from the same write antenna unit in step S7. Therefore, even when the read signal from the read antenna unit 40 or 48 cannot be received, the write process can be executed reliably.

In the above embodiment, the case where the data memory 64 using the EEPROM is provided as the data storage means is described. However, the present invention is not limited to this. For example, the case where the RAM backed up by a battery or the like is used, The present invention can be applied to a case where a memory called an IC card is used.

In the above embodiment, the case where the present invention is applied to a tag unit of an automatic guided vehicle has been described. However, the present invention is not limited to this, and for example, process control is performed on products flowing in a line in a factory. Applicable to all response units used in systems for identifying moving objects, such as being applied to a system or to a system using an ID card for managing entry and exit of a person into a room. It is.

[0038]

As described above, according to the response unit for a mobile object identification device of the first aspect, when the state storage means stores the write completion state by the control means, the write operation is completed. When a write signal from the antenna unit is received, a write signal corresponding to the write signal is received.
Since only the writing process is invalidated, the writing process can be executed only once when passing through the communication area of the writing antenna unit, and multiple writing can be prevented with a simple configuration. It has excellent effects. Further, according to the invention of claim 2, the above-mentioned invalidity
Processing is performed by writing from the same writing antenna unit.
Is performed by judging whether the signal is
Excellent effect that the above operation can be performed reliably
To play.

[Brief description of the drawings]

FIG. 1 is a flowchart of a control program showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an outline of an overall configuration.

FIG. 3 is a block diagram of an electrical configuration.

FIG. 4 is a diagram corresponding to FIG. 2 showing a conventional example.

FIG. 5 is a diagram corresponding to FIG. 2, showing a different conventional example.

FIG. 6 is a diagram corresponding to FIG. 2 for explaining a conventional problem.

[Description of Signs] 30 is an automatic guided vehicle (moving body), 32 is a traveling path, and 34 and 3
8, 42 and 46 are communication areas, 36 and 44 are write antenna units, 40 and 48 are read antenna units, 50 is a tag unit (response unit), 52 is a control circuit (control means, state storage means), 54 Is an antenna, 5
8 is a demodulation circuit, 60 is a switch circuit, 62 is a modulation circuit,
64 is a data memory (data storage means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 1/59 H04B 5/00 G06K 19/07

Claims (2)

(57) [Claims] When the mobile terminal moves on a moving body and receives a write signal in a communication area of a writing antenna unit, the mobile station performs a writing process. When a read signal is received in a communication area of the reading antenna unit, required data is transferred. In a response unit for a mobile object identification device that executes read processing and transmits the data, data storage means for reading and writing the necessary data, and control for controlling the write processing and read processing for the data storage means Means for receiving a write signal from the writing antenna unit, and a state storage means for storing a write completion state when a write process to the data storage means is executed by the control means. In the state where the state storage means stores the write completion state, the writing antenna unit is used. When receiving a et of the write signal, to the write signal
A response unit for a mobile object identification device, wherein a corresponding writing process is invalidated. 2. A response for a moving object identification device according to claim 1.
In the unit, the control means is the state storage means
When the memory for writing has been
When a write signal is received from the antenna unit,
Are sent from the same writing antenna unit.
Judgment of whether or not it was received, judgment that it is the same
The writing process non corresponding to the write signal when
Response unit for a mobile object identification device,
G.