JP4687501B2 - Position detection system and position detection method - Google Patents

Description

  The present invention relates to a position detection system and a position detection method, and in particular, the position of a transport device such as a forklift that travels along a traveling path and transports a load and transfers the load at a load storage area, and the position of the load at the load storage area. The present invention relates to a system and a method for detecting

  For example, in the position detection system disclosed in Patent Document 1, a traveling path for a forklift to travel and a luggage storage place for placing a luggage are partitioned in a warehouse. A plurality of RFIDs are embedded at regular intervals over the entire floor surface. Each identifier has position information indicating its position in the warehouse, and the position of the forklift is detected by reading the information of the position of each RFID with a reader mounted on the forklift. Further, when the forklift loads and unloads the load at the luggage storage, the position of the luggage is also detected based on the information on the RFID position read by the reading device.

Japanese Patent Laid-Open No. 2004-210429

  By the way, in the above-mentioned Patent Document 1, a plurality of luggage placement locations for placing luggage are formed in the luggage storage, and each luggage placement location is identified so that the position of each luggage placement location can be identified. One RFID is arranged. In this way, a plurality of RFIDs are also arranged on the travel path at the same intervals as the arrangement intervals of the plurality of RFIDs arranged in the luggage storage area.

  However, in the position detection system as described in Patent Document 1 described above, it is only necessary to be able to detect the route on which the forklift has traveled, and it is not necessary to detect the position in detail like each luggage placement location in the luggage storage area. On the traveling road, it is not necessary to arrange a plurality of RFIDs with a narrower arrangement interval than a plurality of RFIDs in the luggage storage area. In addition, since the RFID itself is expensive, and it takes time and cost to install a plurality of RFIDs on the floor of a warehouse, it is desired to reduce the number of RFIDs to be used.

Therefore, it is possible to reduce the number of RFIDs to be used by arranging a plurality of RFIDs at a wider interval than the luggage storage area on the traveling road, but when the arrangement interval of the RFIDs on the luggage storage area and the traveling road is different, It is necessary to mount two reading devices having different reading areas corresponding to the arrangement intervals of the RFID in the luggage storage area and the traveling path on the forklift, which not only increases the manufacturing cost of the entire system but also makes the configuration complicated. There was a problem of becoming.
The present invention has been made to solve such problems, and an object of the present invention is to provide a position detection system and a position detection method capable of detecting the positions of the transfer device and the load with a low cost and simple configuration. And

  A position detection system according to the present invention is a system that detects a position of a transport device and a load when the transport device reaches the luggage storage place through the travel route and transfers the load, and is arranged along the travel route. A plurality of first identifiers each having position information, and a plurality of second identifiers disposed in the luggage storage space at intervals narrower than an arrangement interval of the plurality of first identifiers and each having position information And a reading device that is mounted on the transport device and has a read area and detects the first and second identifiers present in the read area and reads the position information thereof, and the transport device has a luggage storage location. The reading device has a narrower reading area than when the conveying device is positioned on the travel path, so that only one second identifier exists in the reading area. In which and an adjusting means for adjusting the look out area.

  Preferably, the adjusting means adjusts the reading area of the reading device so that only one first identification body exists in the reading area of the reading device even when the transport device is positioned on the travel path.

  When a plurality of second identifiers are detected at a time by the reader, or immediately after the reader detects a first identifier located at a boundary portion with the luggage storage location on the travel route When the second discriminating body located at the boundary portion between the transfer device and the transfer device is detected by the transfer detection device attached to the transfer device, the adjustment device is operated by the transfer device. It can be configured that the reading area of the reading device is adjusted so that only one second identifier exists in the reading area of the reading device after determining that it is in the luggage storage area.

  The adjustment means stores in advance as a predetermined reading area a reading area in which only one second identification body exists in the reading area of the reading device in the baggage storage area, and when the transport device is located in the luggage storage area, the reading device The read-out area is set to a predetermined read-out area stored in advance, or the adjusting means gradually narrows the read-out area of the reading device when the transport device is located in the luggage storage area, and one read-out area is included in this read-out area. It is also possible to fix the reading area of the reader when only two identifiers are present.

The first identification body and the second identification body are composed of the same RFID, and the reading device transmits a signal to the first identification body and the second identification body, thereby the first identification body and the second identification body. The first identification body and the second identification body are detected by receiving signals respectively transmitted from the two identification bodies, and the intensity of the signal transmitted from the reading device is adjusted by the adjusting means. The reading area of the reading device can be adjusted.
Moreover, a forklift can be used as the transport device.

  The position detection method according to the present invention is a method for detecting a position of a transfer device and a load when the transfer device reaches a luggage storage place through a traveling path and performs load transfer. The first identification body is arranged along the traveling path, and a plurality of second identification bodies each having position information are arranged in the luggage storage space at an interval narrower than the arrangement interval of the plurality of first identification bodies, When a reading apparatus that has a reading area and detects the first and second identification bodies existing in the reading area and reads information on the position is mounted on the conveying apparatus, and the conveying apparatus is located in the luggage storage area In this method, the reading area of the reading device is narrower than when the transport device is positioned on the travel path, and the reading area is adjusted so that only one second identification object exists in the reading area.

  According to the present invention, it is possible to detect the position of the transfer device and the load with a low cost and simple configuration.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows a warehouse 1 to which a position detection system according to Embodiment 1 of the present invention is applied. In the warehouse 1, a traveling path 3 for the forklift 2 to travel and convey the load and a luggage storage place 4 for the forklift 2 to transfer the load are partitioned. A plurality of first identification bodies 5 are embedded in the floor surface of the travel path 3, and the plurality of first identification bodies 5 are arranged along the travel path 3 at intervals. In the luggage storage area 4, a plurality of luggage placement locations 6 for placing luggage are formed at regular intervals, and one second identification body 7 is arranged for each luggage placement location 6. Has been.
Here, the first identification body 5 arranged in the travel path 3 and the second identification body 7 arranged in the luggage storage area 4 are composed of the same RFID and store information on the corresponding positions in the warehouse 1 respectively. Have. In addition, the plurality of first identification bodies 5 are arranged at intervals wider than the arrangement interval of the plurality of second identification bodies 7.

  As shown in FIG. 2, the forklift 2 is equipped with one reading device 8, and this reading device 8 includes an antenna 9 and an output unit 10 and an input unit 11 connected to the antenna 9, respectively. Have. The forklift 2 has an input information determination unit 12, an output adjustment unit 13, and a position information conversion unit 14, and the input information determination unit 12 is connected to the input unit 11 of the reading device 8. In addition, the output unit 10 of the reading device 8 is connected to the input information determination unit 12 via the output adjustment unit 13. Further, a position information conversion unit 14 is connected to the input information determination unit 12.

  The output unit 10 of the reading device 8 outputs a signal composed of a radio wave or the like via the antenna 9, and when the signal from the reading device 8 is received by the first identification body 5 or the second identification body 7, The identification body 5 or the second identification body 7 emits a signal composed of a radio wave or the like, and the signal is received by the antenna 9 and taken into the input unit 11, whereby the first identification body 5 and the second identification body 7. The body 7 is configured to be detected by the reader 8 in a non-contact manner. The reading device 8 has a reading area that is an area where the first identification body 5 and the second identification body 7 can be detected in this way.

In addition, the signals of the first identification body 5 and the second identification body 7 received by the antenna 9 of the reading device 8 and taken into the input unit 11 are input to the input information determination unit 12. The input information determination unit 12 determines whether or not the forklift 2 is located in the luggage storage 4 based on a signal input from the input unit 11. The output adjustment unit 13 adjusts the intensity of the signal output from the output unit 10 of the reading device 8 via the antenna 9 based on the determination result of the input information determination unit 12, thereby reading the reading area of the reading device 8. Is configured to be enlarged and reduced.
The output adjusting unit 13 is narrower than the first reading area where only one first identification body 5 exists in the reading area of the reading device 8 in the traveling path 3 and the first reading area. In addition, a second reading area in which only one second identification body 7 exists in the reading area of the reading device 8 in the luggage storage 4 is stored in advance.
The input information determination unit 12 and the output adjustment unit 13 constitute the adjustment means of the present invention.

Next, the operation of the position detection system according to the first embodiment will be described.
When the forklift 2 is positioned on the travel path 3, the output adjustment unit 13 sets the reading area of the reading device 8 as the first reading area stored in advance. Therefore, only one first identification body 5 exists in the reading area of the reading device 8, and it is possible for the reading device 8 to reliably detect one first identification body 5 existing in the reading area. it can.

  When the forklift 2 reaches the luggage storage area 4 from the travel path 3, the reading area of the reading device 8 remains the first reading area, and therefore there are a plurality of second identification bodies 7 in the reading area. A plurality of second discriminators 7 are detected at a time by the reading device 8, and signals of the plural second discriminators 7 collide with each other so that information cannot be read correctly, or positions of the plural second discriminators 7 are detected. May be read out and the exact position of the forklift 2 may not be grasped.

  However, at this time, the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4 because there are a plurality of detectable second identifiers 7 present in the reading area of the reading device 8. The output adjusting unit 13 narrows the reading area of the reading device 8 based on the determination result that the forklift 2 is located in the luggage storage 4 by the input information determining unit 12 and stores it in the second reading area stored in advance. Set. Accordingly, only one second identification body 7 exists in the reading area of the reading device 8, and it is possible to reliably detect one second identification body 7 existing in the reading area by the reading device 8. it can.

  As described above, when one first discriminator 5 or one second discriminator 7 is detected by the reading device 8, the signal of the detected first discriminator 5 or second discriminator 7 is detected. Is sent from the reading device 8 to the position information conversion unit 14 via the input information determination unit 12 and converted into position information, and is displayed on a display unit (not shown) mounted on the forklift 2, for example, It is sent from a communication unit (not shown) installed to a management computer or the like arranged in the warehouse 1 and displayed on the display unit of this management computer. In this way, the position of the forklift 2 in the travel path 3 or the luggage storage area 4 is detected.

Further, the position of the forklift 2 at the time of transferring the load is detected to which of the plurality of baggage placement points 6 of the luggage storage 4 the forklift 2 transfers the load. can do. Thus, the position of the load is detected by specifying the load placement place 6 where the load is transferred. Similarly to the information on the position of the forklift 2, the information on the position of the load can be displayed on the display unit of the forklift 2 or the management computer.
Therefore, the operator can grasp the position of the forklift 2 and the position of the load by looking at the display unit of the forklift 2 or the management computer.

  As described above, even if the first identification bodies 5 are arranged on the travel path 3 at a wider interval than the second identification bodies 7 of the luggage storage place 4, the position and the load of the forklift 2 can be detected by one reading device 8. Each position can be detected with high accuracy. Therefore, it is possible to reduce the number of RFIDs used, thereby realizing a position detection system having a simple configuration at a low cost.

When the forklift 2 enters the luggage storage 4 from the travel path 3 and the reading device 8 detects a plurality of second identification bodies 7, the input information determination unit 12 determines that the forklift 2 is located in the luggage storage 4 and outputs it. Since the adjusting unit 13 automatically adjusts the reading area of the reading device 8 to the second reading area, it is not necessary for the operator to adjust the reading area of the reading device 8 when entering the luggage storage area 4. Operability is improved.
In addition, by detecting the position of the forklift 2 and the position of the load with this position detection system, the operating status of the travel path of the forklift 2 is grasped and analyzed, and the position of the load is managed to manage the load at the correct place. It can be confirmed whether or not the transfer is performed.

  If an adjustment button (not shown) that is connected to the output adjustment unit 13 and sets the reading area of the reading device 8 as the first reading area is provided, the work can be performed when the forlift 2 enters the travel path 3 from the luggage storage area 4. When the person presses the adjustment button, the reading area of the reading device 8 is changed from the second reading area to the first reading area, and one first identification body 5 existing in the reading area is read by the reading device 8. As a result, the position of the forklift 2 is detected. Therefore, the first identification body 7 is not skipped, and the position of the forklift 2 can be reliably detected even on the traveling path 3.

  Further, instead of providing the adjustment button as described above, when the reading area of the reading device 8 is the second reading area, both the first identification body 5 and the second identification body 7 are included in the reading area. When the non-existing state continues for a predetermined time or longer, the input information determination unit 12 determines that the forklift 2 is located on the travel path 3, and the output adjustment unit 13 sets the reading area of the reading device 8 to the first reading area. It can also be configured to set. With this configuration, the reading area of the reading device 8 is automatically adjusted even when entering the travel path 3 from the luggage storage area 4, and the position of the forklift 2 on the travel path 2 can be detected easily and reliably. Can do.

Embodiment 2. FIG.
Next, a position detection system according to Embodiment 2 will be described with reference to FIG. In Embodiment 1 described above, the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4 when there are a plurality of detectable identifiers in the reading area of the reading device 8. In the second embodiment, the input information determination unit 12 is disposed at the luggage placement locations 6A and 6B located at the boundary portion with the travel path 3 among the plurality of luggage placement locations 6 of the luggage storage location 4. The second identifiers 7A and 7B are stored in advance, and when the reading device 8 detects the second identifier 7A or 7B when the reading area of the reading device 8 is the first reading area, the forklift 2 It is determined that it is located in the luggage storage area 4.

  When the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4, the output adjustment unit 13 narrows the reading area of the reading device 8 by the output adjustment unit 13 as in the first embodiment, and performs the second reading. Set to area. Therefore, when the forklift 2 enters the luggage storage area 4 from the travel path 3, the reading area of the reading device 8 is automatically adjusted to the second reading area, and only one second identifier 7 is included in the reading area. Therefore, only one second identification body 7 existing in the reading area can be reliably detected by the reading device 8. Therefore, as in the first embodiment, the position of the forklift 2 and the position of the load can be detected with high accuracy while having a low cost and simple configuration.

  Further, the input information determination unit 12 includes a first identification body 5A located at a boundary portion with the luggage storage area 4 among the plurality of first identification bodies 5 arranged on the travel path 3 as shown in FIG. 5B is also stored in advance, and when the reading device 8 detects the first identifier 5A or 5B when the reading area of the reading device 8 is the second reading area, the input information determination unit 12 causes the forklift 2 to move the travel path 3. It is also possible to configure so that the output adjustment unit 13 sets the reading area of the reading device 8 to the first reading area when it is determined that the position is located in the first reading area. With this configuration, the reading area of the reading device 8 is automatically adjusted even when entering the travel path 3 from the luggage storage area 4, and the position of the forklift 2 on the travel path 3 can be detected easily and reliably. Can do.

In addition, when the input information determination unit 12 stores the second identifiers 7A and 7B of the luggage storage 4 and the first identifiers 5A and 5B of the travel path 3 in advance as described above, the reading device 8 detects the second discriminator 7A immediately after detecting the first discriminator 5A, or detects the second discriminator 7B immediately after the first discriminator 5B is detected. The unit 12 may be configured to determine that the forklift 2 is located in the luggage storage area 4 and set the reading area of the reading device 8 to the second reading area by the output adjustment unit 13. On the other hand, when the reader 8 detects the first identifier 5A immediately after detecting the second identifier 7A, or detects the first identifier 5B immediately after detecting the second identifier 7B. The input information determination unit 12 can also be configured to determine that the forklift 2 is located on the travel path 3 and set the reading area of the reading device 8 to the first reading area by the output adjustment unit 13.
According to this configuration, the reading area of the reading device 8 is automatically adjusted both when entering the luggage storage area 4 from the traveling path 3 and when entering the traveling path 3 from the luggage storage area 4. And the position of the load can be detected easily and reliably.

  As described above, instead of the input information determining unit 12 storing in advance the second identifiers 7A and 7B of the luggage storage area 4 and the first identifiers 5A and 5B of the traveling path 3, the input information determining unit 12 12 can recognize the position information of the respective identification bodies 5 and 7, and when the second identification body 7 is detected, it is determined that the forklift 2 is located in the luggage storage area 4, and the reading area of the reading device 8 is changed to the first area. When the first identification body 5 is detected, it is determined that the forklift 2 is located on the travel path 3 and the reading area of the reading device 8 is set as the first reading area. May be.

Embodiment 3 FIG.
Next, a position detection system according to Embodiment 3 will be described with reference to FIG. In the first embodiment, the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4 when there are a plurality of detectable identifiers present in the reading area of the reading device 8. Instead, the position detection system according to the third embodiment further includes transfer detection means 21 that is mounted on the forklift 2 and detects the transfer of the load by the forklift 2. When the transfer is detected, the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4. The transfer detection means 21 can be formed from a stock sensor such as a pallet sensor or a load sensor, and is connected to the input information determination unit 12, and the transfer detection means 21 detects the transfer of the load by the forklift 2. In this case, a signal is sent from the transfer detection means 21 to the input information determination unit 12.

  When the transfer detection means 21 detects the transfer of the load by the forklift 2 and sends a signal to the input information determination unit 12, the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4 based on this signal, and outputs it. The adjustment unit 13 narrows the reading area of the reading device 8 and sets it to the second reading area. Therefore, when the forklift 2 enters the luggage storage area 4 from the travel path 3 and transfers the load, the reading area of the reading device 8 is automatically adjusted to the second reading area, and one reading area is included in the reading area. Since only two discriminating bodies 7 are present, only one second discriminating body 7 existing in the reading area can be reliably detected by the reading device 8. Therefore, as in the first embodiment, the position of the forklift 2 and the position of the load can be detected with high accuracy while having a low cost and simple configuration.

  In addition, in the third embodiment, when there is no signal from the transfer detection means 21, the input information determination unit 12 determines that the forklift 2 is located on the travel path 3, and the output adjustment unit 13 reads out the reading device 8. If the area is set to be the first readout area, the position of the forklift 2 on the travel path 3 can be easily and reliably detected.

In the first to third embodiments described above, the output adjustment unit 13 stores the reading area of the reading device 8 in advance when the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4. However, the present invention is not limited to this. When the input information determination unit 12 determines that the forklift 2 is located in the luggage storage area 4, the output adjustment unit 13 reads the reading device. 8 is gradually narrowed, and when only one second discriminator 7 exists in the read area, the output adjustment unit 13 reads the read area at that time by the reading device 8. It can also be set as an area. According to this configuration, even when the second identification bodies 7 in the luggage storage 4 are not arranged at a constant interval, only one second identification body 7 in the luggage storage 4 can be obtained with the optimum accuracy by the reading device 8. Can be detected.
Similarly, when it is determined that the forklift 2 is located on the travel path 3, instead of setting the reading area of the reading device 8 to the first reading area stored in advance, the reading area of the reading device 8 is gradually set. When the first identification body 5 comes to exist in the reading area, the reading area at that time can be set as the reading area of the reading device 8.

In the first to third embodiments, a radio wave method is used in which a signal made up of radio waves is exchanged between the antenna 9 of the reading device 8 and the RFID constituting the first discriminator 5 and the second discriminator 7. Instead, an electromagnetic induction method is used in which signals are exchanged by magnetic flux coupling between the coil of the antenna 9 of the reader 8 and the RFID coil that constitutes the first discriminator 5 and the second discriminator 7. In this case as well, the first identification body 5 and the second identification body 7 can be detected by the reader 8 in a non-contact manner as in the radio wave system.
Further, the RFID constituting the first identification body 5 and the second identification body 7 can be either a passive type or an active type.

The luggage storage 4 is configured so that the luggage is laid flat in a plurality of luggage storage locations 6. However, a storage shelf having a plurality of shelves is arranged in the luggage storage 4, and a plurality of storages are placed on the storage shelf. There may be provided a luggage loading place. Also in this case, if one second identification body having information on the corresponding position is arranged for each load placement place provided on each shelf, one second identification body is provided by the position detection system of the present invention. Only the identifier is detected, and the position of the forklift 2 and the position of the load can be detected.
Further, the position detection system of the present invention can be applied not only to the indoor warehouse 1 but also to a work area where the traveling path 3 and the luggage storage area 4 are formed outdoors.

  It should be noted that this position detection system can be applied not only to the forklift 2 but also to a load transport device such as a self-propelled carriage or a handcart to detect the position of the transport device and the position of the load.

It is a top view which shows the structure in the warehouse where the position detection system which concerns on Embodiment 1 of this invention was applied. It is a block diagram which shows the position detection system which concerns on Embodiment 1 of this invention. It is a top view which shows the structure in the warehouse where the position detection system which concerns on Embodiment 2 of this invention was applied. It is a block diagram which shows the position detection system which concerns on Embodiment 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Warehouse, 2 Forklift, 3 Traveling route, 4 Luggage storage place, 5 1st identification body, 6 Luggage mounting location, 7 2nd identification body, 8 Reading apparatus, 9 Antenna, 10 Output part, 11 Input part, 12 Input information determination unit, 13 output adjustment unit, 14 position information conversion unit, 21 transfer detection means.

Claims (10)

In the system for detecting the position of the transfer device and the load when the transfer device reaches the luggage storage place through the traveling path and transfers the load,
A plurality of first identifiers arranged along the travel path and having position information respectively;
A plurality of second identifiers arranged in the luggage storage space at intervals narrower than the arrangement interval of the plurality of first identifiers, and each having position information;
A reading device mounted on a transport device and having a reading area and reading the information of the position by detecting the first identification body and the second identification body existing in the reading area;
When the transport device is located in the luggage storage area, the reading device has a narrower read area than when the transport device is located in the traveling path, and the reading device is such that only one second identification body exists in the read area. A position detecting system comprising: adjusting means for adjusting the reading area.   The adjustment unit adjusts the reading area of the reading device so that only one first identification body exists in the reading area of the reading device even when the transport device is positioned on a traveling path. The position detection system described in.   The adjustment means determines that the transport device is located in a luggage storage area when the reading device detects the plurality of second identification objects at a time, and one second identification is provided in a reading area of the reading device. The position detection system according to claim 1, wherein the reading area of the reading device is adjusted so that only the body exists.   The adjusting means may be configured such that immediately after the reading device detects the first identifier located at a boundary portion between the traveling path and the luggage storage area, the second identification unit is positioned at the boundary portion between the traveling area and the luggage storage area. When the identification object is detected, it is determined that the transport device is located in a luggage storage area, and the reading area of the reading device is adjusted so that only one second identification object exists in the reading area of the reading device. The position detection system according to 1 or 2.   A transfer detection means for detecting transfer of the load to the transfer apparatus and attached to the transfer apparatus is further provided, and when the adjustment means detects the transfer of the load to the transfer apparatus by the transfer detection means, 3. The reading area of the reading device is adjusted so that a transport device is determined to be in the luggage storage area and only one second identifier is present in the reading area of the reading device. Position detection system.   The adjustment means stores in advance a read area in which only one second identification body exists in the read area of the reading device in the luggage storage area as a predetermined reading area, and the transport device is located in the luggage storage area. The position detection system according to any one of claims 1 to 5, wherein the reading area of the reading device is set to a predetermined reading area stored in advance.   The adjusting means gradually narrows the reading area of the reading device when the transport device is located in the luggage storage area, and reads the reading when only one second identifier is present in the reading area. The position detection system according to any one of claims 1 to 5, wherein a reading area of the device is fixed.   The first identification body and the second identification body are composed of the same RFID, and the reading device transmits the signal to the first identification body and the second identification body, thereby the first identification body and the second identification body. And receiving signals respectively transmitted from the identification body and the second identification body to detect the first identification body and the second identification body, and the signal transmitted from the reader by the adjusting means. The position detection system according to any one of claims 1 to 7, wherein a reading area of the reading device is adjusted by adjusting the intensity.   The position detection system according to any one of claims 1 to 8, wherein the transport device is a forklift. In the method of detecting the position of the transfer device and the load when the transfer device reaches the luggage storage place through the traveling path and transfers the load,
A plurality of first discriminators each having position information are arranged along the traveling path, and a plurality of second discriminators each having position information are arranged more than the arrangement intervals of the plurality of first discriminators. Place it in the luggage storage space at a narrow interval
A reading device that has a reading area and detects the first identification body and the second identification body existing in the reading area and reads information on the position is mounted on the transport device,
When the transport device is located in the luggage storage area, the read area of the read device is narrower than when the transport device is located on the travel path, and the read area is such that only one second identifier exists in the read area. The position detection method characterized by adjusting to.

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