JP3754504B2 - Conveying means control method and apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a conveying means control method and a conveying means control device for controlling conveying means such as a carriage that travels along a laid rail.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a factory, a warehouse, or the like, conveying means such as an automatic guided vehicle that travels on a certain transport route on a floor surface or a cart that travels along a laid rail has been used to transport articles. These transfer means are all provided with instructions for starting position and arrival position (referred to as tracking) and starting, stopping and transferring operations by a ground controller that centrally manages the distribution system.
[0003]
However, since these instructions cannot be performed unless each of the plurality of carriages returns to a predetermined position, the burden on the ground controller is increased only by performing this control (the program becomes very complicated). Further, since each cart cannot be instructed unless it returns to a predetermined position, the conveyance efficiency is not good.
Japanese Patent Laid-Open No. 4-41322, for example, solves this problem. In this system, the ground controller and all the trucks are connected by a wireless LAN so that instructions can be issued anywhere from the ground controller. This reduces the burden on the ground controller and improves the efficiency of the transfer work.
[0004]
[Problems to be solved by the invention]
However, such a conventional transport means control device has the following problems.
(B) Since radio waves are used, when other radio systems use the same carrier frequency in the vicinity, interference such as interference will be given or given to the radio systems.
(B) Since the ground controller obtains the movement position information of each carriage from the output of the reflection type photoelectric sensor provided at each station, there is a possibility that the carriage may be erroneously recognized.
[0005]
Therefore, the present invention does not cause interference such as interference to other wireless systems, or erroneously recognizes a carriage, and has a low burden on the ground controller and high transport efficiency and a transport means control method and It is an object of the present invention to provide a transport means control device.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the transport means control method of the present invention, a cable formed by covering a member that transmits an electromagnetic field is laid along a rail, and each of the plurality of transport means that travel on the rail has the cable. A coupler that is tightly coupled with each other, optical communication means is provided in each of the plurality of transport means and each of the plurality of stations arranged along the rail, and the cable and the coupler provided in each of the transport means; The position information is transmitted and received wirelessly between the cable and the coupler of each transport means, and when each transport means arrives at a station based on the position information, the optical communication means transports it from the station. The transfer information such as loading and unloading of articles is transmitted to and received from the means.
[0007]
The transport means control device according to the present invention is a transport means control device that controls the movement of a plurality of transport means with respect to a plurality of stations provided along the rail. A cable that covers a member that transmits the field; a transmission / reception unit that wirelessly transmits / receives position information via the cable; a coupler that is provided in each of the plurality of transport units and is tightly coupled to the cable; Transmission / reception means for transmitting and receiving position information wirelessly through this coupler, optical communication means for transmitting and receiving transmission information such as loading and unloading of articles by optical communication, and each of the plurality of stations, Optical communication means for transmitting / receiving transmission information by optical communication with each of a plurality of conveying means, and a position with respect to each conveying means via the cable When information that informs the arrival to the station based on the position information is received from each transport means, the article is loaded and unloaded from the optical communication means of the station to the optical communication means of the transport means. And a control means for performing transmission / reception transmission / reception of the transfer information.
[0008]
According to the above method and configuration, the cable laid along the rail and the coupler provided in each transport means are tightly coupled, and transmission / reception of position information is performed wirelessly between the cable and each coupler. In addition, transfer information such as loading / unloading of articles is transmitted / received between each station and each transport means by optical communication.
[0009]
Therefore, since the electromagnetic field level is very small at some distance from the cable, even if there is another wireless system using the same carrier frequency in the vicinity, it will not interfere with the wireless system. . In addition, since the position information can be transmitted and received at any position on the rail, each moving means can accurately grasp the moving position of the conveying means. In addition, since information can be transmitted and received at any position on the rail, the program for controlling the transport means can be simplified and the transport efficiency can be improved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a transfer system to which an embodiment of a transfer means control apparatus according to the present invention is applied. FIG. 2 is a block diagram showing the configuration of the transport means control apparatus.
The transport means control device of this embodiment divides the supply of instruction data from the ground controller 50 to each carriage 5 into instruction data relating to positions with a small amount of data and instruction data relating to transfer with a large amount of data, The instruction data relating to the position is supplied by tightly coupled wireless transmission, and the instruction data relating to the transfer is supplied by remote space transmission.
[0011]
In this case, the tightly coupled wireless transmission is, for example, a tightly coupled cable concealed by an object that transmits an electromagnetic field and an object opposite to the tightly coupled cable as disclosed in Japanese Patent Publication No. 5-80180. The coupler is tightly coupled, and information is exchanged wirelessly between the tightly coupled cable and the coupler. By adopting this tightly coupled wireless transmission system, the electromagnetic field level becomes small at some distance from the tightly coupled cable, so even if there is another wireless system using the same carrier frequency in the vicinity, No interference such as interference will be given to the wireless system. On the other hand, in remote space transmission, data is converted into an optical signal by a light projecting element and transmitted, and the optical signal is received by a light receiving element. Bidirectional transmission and mass data transmission enable real-time transmission / reception.
[0012]
(A) Configuration of Transfer System 1 In FIG. 1, the transfer system 1 includes an automatic warehouse 2, a plurality of stacker cranes 3, a plurality of stations 4, a plurality of carts 5, a rail 6, and a ground controller 50. It is configured. The rail 6 has a long oval shape as shown, and a plurality of carts 5 travel. Each station 4 is arranged along the rail 6. These stations 4 are dedicated for entry / exit, those dedicated for warehouse, and those for empty pallet processing. 4a in the figure is dedicated for storage, 4b is dedicated for delivery, 4c is dedicated for warehouse, 4d is for empty pallet processing. It is for. Each station 4 has a light projecting element (for example, a near-infrared light emitting diode) and a light receiving element (for example, a phototransistor) for remote space transmission as shown in FIG. An optical transmission module 10 is provided.
[0013]
Returning to FIG. 1, the automatic warehouse 2 stores articles carried by the stacker crane 3. The stacker crane 3 transports the articles carried to the warehouse dedicated station 4c to a designated place within the range of the automatic warehouse 2, takes out the articles stored in the automatic warehouse 2, and discharges them to the station 4c. Is. A tightly coupled cable 11 shown in FIG. 2 is laid along the rail 6 below the rail 6. A terminating resistor 12 is connected to one end of the tightly coupled cable 11, and a matching unit 13 for connecting to the ground controller 50 is connected to the other end. A repeater 14 for amplifying a signal propagating in the cable is inserted in the intermediate portion. Note that as many repeaters 14 as the number of the tightly coupled cables 11 are provided.
[0014]
The carriage 5 includes a coupler 14, an optical transmission module 15 similar to the optical transmission module 10 provided in each station 4 described above, a transmission / reception device 16, and a control device 17. The coupler 14 is a so-called antenna, and captures instruction data regarding the position transmitted from the ground controller 50 by being tightly coupled to the tightly coupled cable 11. The instruction data captured by the coupler 14 is demodulated by the transmission / reception device 16 and captured by the control device 17.
[0015]
The control device 17 includes a CPU (central processing unit) (not shown), a ROM that stores a control program, and a RAM that is used in the operation of the CPU. By capturing the instruction data relating to the demodulated position, the station 4 that is going to be recognized is recognized. Further, the control device 17 takes in instruction data relating to transfer from the ground controller 50 via the light transmission module 15 and recognizes start, deceleration, stop, transfer work, and the like. After finishing the operation based on the instruction data, the control device 17 deletes the instruction data and allows the next instruction data to be accepted.
[0016]
The ground controller 50 includes a transmission / reception device 51 used for transmission of instruction data relating to position and reception of a position data confirmation signal from each carriage 5, and a storage device 52 used for storing each instruction data relating to position and transfer. And a control device 53. The control device 53 includes a CPU (not shown), a ROM that stores a control program, and a RAM that is used in the operation of the CPU. The ground controller 50 is connected to an automatic warehouse remote panel (not shown), an operation panel, a personal computer, and the like. The ground controller 50 uses the tightly coupled cable 11 to inquire whether each carriage 5 can be instructed by polling. In this case, the wireless polling time is approximately 2.5 to 3.8 seconds when there are five carriages 5.
[0017]
In the control of each carriage 5, the order in which the instructions are generated is managed, and whether or not the destination station 4 can be accepted is checked to select a station 4 that can be processed. After selecting a station 4 that can be processed, an optimum cart 5 is selected for the station 4. In this case, with respect to the cart 5 in an empty state after completing the work of loading and unloading articles, the cart closest to the selected station 4 is a candidate. However, in the selection of the carriage 5, the one that can be stopped at the selected station 4 is selected in consideration of the traveling speed of the carriage 5 and the wireless polling time. By doing so, the movement position of the carriage 5 is not erroneously recognized.
[0018]
After selecting an empty cart 5 candidate, the cart 5 in a working state such as loading and unloading of goods is selected at the position closest to the selected station 4. This is because it may be faster to go to the target station 4 after the work is completed even if the work is currently being completed, rather than directing the empty cart 5 to the target station 4. The cart 5 is also taken into account. After selecting the empty cart 5 and the working cart 5, the most optimal one is selected. And it inquires whether the instruction | indication is possible with respect to the selected trolley | bogie 5, and if possible, instruction | indication data is supplied.
[0019]
When the instruction data confirmation signal notifying that the instruction data has been received is output from the cart 5 supplied with the instruction data, the ground controller 50 cannot receive the instruction confirmation signal within a predetermined time after the instruction data is transmitted. The instruction data is transmitted again. When the cart 5 that supplied the instruction data reaches the target station 4, the ground controller 50 supplies the instruction data regarding the transfer from the light transmission module 10. The cart 5 transfers articles and the like based on the instruction data. The ground controller 50 corrects the movement position of the carriage 5 using the optical transmission module 10 when the carriage 5 arrives at the station 4. When the carriage 5 travels over a long distance, a slight shift occurs in the movement position. Therefore, it is possible to always grasp the accurate movement position by correcting the movement position.
[0020]
(B) Operation of Ground Controller 50 FIG. 3 is a flowchart showing the operation of the ground controller 50.
First, in step S10, it is determined whether or not instruction data has been generated. In this determination, if it is determined that the instruction data is not generated, this step is repeated, and if it is determined that the instruction data is generated, the process proceeds to step S12 and the station 4 is selected. In step S14, it is determined whether or not the selected station 4 can be accepted. If it is determined that the selected station 4 cannot be accepted, the process returns to step S12 to make a new selection.
[0021]
On the other hand, if it is determined that it is acceptable, the process proceeds to step S16 to determine whether there is an empty state, that is, whether there is a cart 5 that is not being processed. In this determination, if it is determined that there is an empty carriage 5, the process proceeds to step S18, and the empty carriage 5 that is closest to the acceptable station 4 is selected. In this case, as described above, in selecting the carriage 5, the one that can be stopped at the selected station 4 is selected in consideration of the traveling speed of the carriage 5 and the wireless polling time.
[0022]
After selecting the closest cart 4 to the acceptable station 4 among the carts 5 in the empty state, it is determined whether or not there is a cart 5 being processed in step S20. In this determination, if it is determined that there is a cart 5 being processed, the process proceeds to step S22, and the cart 5 of the station closest to the acceptable station 4 is selected from the stations 4 having the cart 5 being processed.
Among the trolleys 5 in the empty state, the one closest to the acceptable station 4 is selected, and the trolley at the station closest to the acceptable station 4 among the stations 4 having the cart 5 being processed is selected. After selecting 5, the one closest to the most acceptable station 4 among these carts 5 is determined in step S24.
[0023]
After the optimum cart 5 is determined, the instruction data regarding the position is transmitted from the tightly coupled cable 11 and supplied to the determined cart 5 in step S26. Next, in step S28, it is confirmed whether or not instruction data has been received. That is, it is confirmed whether or not an instruction data confirmation signal is transmitted from the cart 5. If the instruction data confirmation signal is not transmitted within a predetermined time, the instruction data is transmitted again. If the instruction data confirmation signal has been transmitted, the process proceeds to step S30 to confirm that the carriage 5 has arrived at the acceptable station 4. When it is confirmed that the carriage 5 has arrived at the acceptable station 4, the instruction data relating to the transfer is output from the optical transmission module 10 of the station 4 and supplied to the carriage 5 in step S 32.
[0024]
The carriage 5 receives the optical signal output from the optical transmission module 10 by its own optical transmission module 15 and demodulates the instruction data. Then, an instruction data confirmation signal is output from the optical transmission module 15.
The operations from step S10 to step S32 are performed every time instruction data is generated. If there is no trolley 5 that is empty in the determination in step S16, the process directly proceeds to step S20. Further, if it is determined in step S20 that there is no cart 5 being processed, the process directly proceeds to step S24. Further, since there is no case where there is no trolley 5 in the empty state and there is no trolley 5 being processed, the processing is not performed in the order of steps S16, S20, S24.
[0025]
As described above, in the embodiment, the supply of the instruction data from the ground controller 50 to each carriage 5 is divided into the instruction data related to the position with a small amount of data and the instruction data related to the transfer with a large amount of data. The instruction data is supplied by tightly coupled wireless transmission, and the instruction data related to transfer is supplied by remote space transmission. Further, the moving position of the carriage 5 is recognized in consideration of the traveling speed of the carriage 5 and the wireless polling time.
[0026]
Therefore, since the electromagnetic field level becomes very small at a distance from the tightly coupled cable 11, even if there is another wireless system using the same carrier frequency in the vicinity, interference such as interference is given to the wireless system. There is nothing. In addition, since the position data on the position of each carriage 5 can be transmitted and received at any position on the rail 6, the movement position of the carriage 5 can be accurately recognized. Moreover, since the information can be transmitted / received at any position on the rail 6 on the rail 6, the burden on the ground controller 50 can be reduced, and the conveyance efficiency can be increased.
[0027]
【The invention's effect】
As described above, according to the present invention, the electromagnetic field level becomes small at a certain distance from the cable, so even if there is another wireless system using the same carrier frequency in the vicinity, the wireless system Will not interfere with interference. Further, since the position information can be transmitted and received at any position on the rail, each moving means can accurately grasp the moving position of the conveying means. In addition, since information can be transmitted and received at any position on the rail, the program for controlling the transport means can be simplified and the transport efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a plan view showing a transfer system to which an embodiment of a transfer means control apparatus according to the present invention is applied.
FIG. 2 is a block diagram illustrating a configuration of a transport unit control device according to the embodiment.
FIG. 3 is a flowchart showing the operation of the transport means control apparatus of the embodiment.
[Explanation of symbols]
4 stations 5 carts (transportation means)
6 rail 10 optical transmission module (optical communication means)
11 Tightly coupled cable (cable)
14 coupler 15 optical transmission module (optical communication means)
16 Transmission / reception device (transmission / reception means)
50 Ground controller 51 Transmission / reception device (transmission / reception means)
53 Control device (control means)

Claims (2)

A cable (11) formed by covering a member that transmits an electromagnetic field is laid along the rail (6), and each of the plurality of transport means (5) traveling on the rail (6) has the cable (11). Is coupled to each of the plurality of transport means (5) and each of the plurality of stations (4) arranged along the rail (6). 15), and the cable (11) and the coupler (14) provided in each transport means (5) are tightly coupled to each other between the cable (11) and the coupler (14) of each transport means. When the position information is transmitted and received wirelessly and each transport means (5) arrives at the station (4) based on the position information, the optical communication means (10, 15) sends the position information from the station (4) to the transport means (5). Information on loading and unloading of goods Conveying means controlling method characterized by sending and receiving transmissions. A transport means control device (1) for controlling movement of a plurality of transport means (5) with respect to a plurality of stations (4) provided along a rail (6),
A cable (11) provided along the rail (6) and covering a member that transmits an electromagnetic field; and
Transmission / reception means (51) for transmitting and receiving position information by tightly coupled radio via the cable (11);
A coupler (14) that is provided in each of the plurality of transport means and is tightly coupled to the cable (11), and a transmission / reception means (16) that transmits and receives position information wirelessly via the coupler (14); ,
An optical communication means (15) provided in each of the plurality of transport means (5), for performing transmission and reception transmission by optical communication of transfer information such as loading and unloading of articles;
An optical communication means (10) that is provided in each of the plurality of stations (4) and performs transmission / reception of each of the plurality of transport means (5) by optical communication of transfer information;
Position information is transmitted to each of the transport means (5) via the cable (11), and information notifying that the station (4) has arrived based on the position information is received from each of the transport means (5). Then, the control means (53) for transmitting and receiving transfer information such as loading and unloading of articles from the optical communication means (10) of the station to the optical communication means (15) of the transport means,
A conveying means control apparatus comprising:

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