JP3235264B2 - Operation control device for automatic guided vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an article transport system in a production line or the like, and allows a plurality of automatic guided vehicles to travel along a predetermined travel path and a transfer station arranged along the travel path. The present invention relates to an operation control device of an automatic guided vehicle for loading and unloading articles by circulating between them.

[0002]

2. Description of the Related Art As an automatic guided vehicle operation control device of this type, conventionally, a central computer, which is a fixed station, controls each automatic guided vehicle based on an operation information signal from a transfer station arranged along a traveling path. Creates operation data necessary for traveling, sends the operation data to each AGV via multiple controllers installed along the traveling path, and the AGV travels along the traveling path according to the operation data and gives instructions. There is proposed an apparatus configured to load and unload articles at a transfer station.

[0003]

However, in this automatic guided vehicle operation control device, the central computer uses the current position of each carrier, the loading state of articles, the destination at the time of traveling, and the dispatch from each transfer station. Since all information, such as requests, is stored and managed, the system becomes complicated and various arithmetic processes become complicated, and there is a case where the central computer cannot quickly send out proper operation data to each automatic guided vehicle.

[0004] In addition, since the operation data from the central computer is sent to the automatic guided vehicle via a controller installed near the traveling path, the operation data may be transmitted until the automatic guided vehicle reaches a specific point. Since it is impossible to transmit operation data in real time, there is a problem that it is difficult to control the automatic guided vehicle quickly.

[0005] The present invention has been made in view of the above points, and when a transfer request for articles is issued at a transfer station,
To provide an operation control device for an automatic guided vehicle that can quickly transmit and receive transport information and the like between a transfer station and a plurality of automatic guided vehicles and efficiently control the operation of the multiple automated guided vehicles. With the goal.

[0006]

In order to achieve the above object, an operation control apparatus for an automatic guided vehicle according to the present invention is provided with a plurality of transfer stations along a traveling path, and a plurality of unmanned conveyances on the traveling path. car traveling visited該移mounting station, the operation control device of the automatic guided vehicle to perform loading and unloading of goods, it is installed in a plurality of transfer stations, corresponding to
A call signal or the like is transmitted by radio communication to mobile stations of a plurality of automatic guided vehicles for the transfer of articles from a transfer station, and a response signal or the like transmitted from the mobile station is received. Station, installed in the AGV, receives call signals and the like transmitted from the fixed station, and wirelessly communicates a response signal containing the current position information and loading information of the AGV to the fixed station of the transfer station. and a mobile station for transmitting a result, the solid
Wireless communication between fixed station and mobile station is time-division bidirectional communication.
And the fixed station is in one time-divided frame.
Transmitting the paging signal to each of the plurality of mobile stations
It is characterized by the following.

[0007] In the operation control device of the automatic guided vehicle configured as described above, when the transport information of the article is input to the transfer station, the fixed station installed therein transmits the information to the mobile station of each automatic guided vehicle. Time-division bidirectional calling signal by wireless communication
At this time, the fixed station transmits a call signal to each of the plurality of mobile stations in one time-divided frame. Upon receiving the call signal, the mobile station of each unmanned guided vehicle on the travel path transmits a response signal including the current position information and the loaded information of the guided vehicle in a time-division bidirectional manner by wireless communication.
Transmit by communication . Based on the current position information and the loading information of each unmanned carrier, the fixed station that receives these response signals determines a carrier that is located at the shortest distance and can load articles, and issues a carrier command signal to the carrier. Is transmitted to instruct the conveyance of the article.

As described above, no matter where the automatic guided vehicle is traveling on the traveling path, a call signal is immediately transmitted via wireless communication from the transfer station at which the article transport request has been issued, and the article can be transported. It is possible to determine an unmanned transport vehicle, issue a transport command, quickly turn the transport vehicle to the transfer station, and efficiently transport articles. In addition, since the transport information is transmitted between the transfer station and each of the automatic guided vehicles using wireless communication, it is not necessary to lay signal lines along the traveling path as in the related art, thereby simplifying the construction. Ma
In addition, time-division bidirectional communication is performed between fixed and mobile stations.
The fixed station uses multiple frames in one time-divided frame.
Sends a paging signal to each mobile station and receives a response signal
A very small number of communications to multiple mobile stations
Signals can be transmitted and received on channels.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an unmanned transfer system in a production line to which the present invention is applied. In order to transfer various parts and other goods to this production site,
A plurality of transfer stations 1 are installed at a plurality of locations, and an endless (annular) running path 3 is laid so as to connect the transferring stations 1.
Runs.

An electromagnetic induction line for guidance is laid on the traveling path 3, and a pickup coil for detecting the electromagnetic induction line is attached to the automatic guided vehicle 2. Each of the automatic guided vehicles 2 has an electromagnetic induction line, that is, the traveling path 3. Traveling in one direction along each of the transfer stations 1.

In the transfer station 1, for example, conveyors for loading and unloading are arranged, and a fixed station 10 is provided. The fixed station 10 receives transfer information (transportation information) from an external computer or the like, and Operation information is transmitted to the carrier 2 and a response from the carrier is received.

As shown in FIG. 2, the fixed station 10 includes a control unit 11 for processing information such as transfer information input and output, a memory 12 for storing various data, and an operation provided with various switches and displays. It comprises a board 13 and a wireless communication unit 14. The control unit 11 includes a CPU as a main unit, outputs a paging signal to the wireless communication unit 14 based on the transfer information sent from an external computer or the like, and outputs the current position information and the load information sent from the mobile station described later. Based on this, processing for determining an automatic guided vehicle is performed.

For wireless communication between the fixed station 10 and a mobile station on the side of each of the automatic guided vehicles 2 described later, TDMA / TDD (Time
Division Multiple Access-Time Division Duplex)
A method (time division multiplex / full duplex digital communication) is used. This TDMA / TDD system, as shown in FIG.
A single carrier is time-divided into, for example, 5 msec frames, each frame is divided into two for reception and transmission, and each is divided into, for example, four slots (R1 to R4, T1 to 14),
In each slot, time-division two-way communication is performed between the fixed station 10 as the parent machine and the mobile station of the automatic guided vehicle 2 as the child machine.

For example, when there are four automatic guided vehicles 2, the first guided vehicle has slots R1 and T1, the second guided vehicle has slots R2 and T2, and the third guided vehicle has slots R3 and T3. The fourth carrier is assigned the R4 and T4 slots as one channel, and the mobile station of each unmanned carrier 2 performs transmission and reception with the fixed station 10 of the transfer station 1 at the timing of each slot.

As a modulation method of data transmitted and received, for example, QPSK (Quadrture Phase Shift Keying) method (4
A phase shift keying method is used to modulate the carrier so as to shift the phase of the carrier by π / 4 in accordance with the digital signal to be transmitted.

As shown in FIG. 2, the radio communication unit 14 of the fixed station 10 for performing such radio communication includes a transmission timing / encoding control unit 15a for controlling transmission timing and channel encoding, and a reception timing and channel encoding. Receiving timing / encoding control unit 1
5b, a modulator 16a for QPSK-modulating a transmission signal, a demodulator 16b for demodulating a received signal, a transmitter 17a for amplifying and transmitting a modulated carrier, a receiver 17b for receiving and amplifying a signal, and a transmitting / receiving antenna 18a And a changeover switch 18b for switching an antenna in transmission and reception.

On the other hand, a mobile station 20 for performing wireless communication with the fixed station 10 is installed in the automatic guided vehicle 2. As shown in FIG. 3, the mobile station 20 processes the transfer information and the like sent from the fixed station 10 and controls the traveling motor 24,
It comprises a memory 22 for storing various data, a display 13 for displaying work instructions and the like sent from the fixed station 10, and a wireless communication unit 14. The control unit 21 is configured with a CPU as a main unit, outputs a response signal including current position information and loading information to the wireless communication unit 26 in response to a call signal sent from the transfer station, and controls the traveling motor 24. Then, the traveling of the automatic guided vehicle 2 is controlled.

Further, a position sensor 25 such as a photoelectric sensor or a proximity switch for optically or magnetically detecting each transfer point of the transfer station 1 is attached to the automatic guided vehicle 2 so that the transfer vehicle is running. , The current position is detected, and the current position data is stored in the memory 22.

As shown in FIG. 3, the radio communication section 26 of the mobile station 20 includes a transmission timing / encoding control section 27a for controlling transmission timing and channel encoding, and a reception timing / encoding control section for controlling reception timing and channel encoding. 27b, QPSK transmission signal
Modulating section 28a for modulating, demodulating section 28 for demodulating a received signal
b, a transmitter 29 for amplifying and transmitting the modulated carrier wave
a, a receiving unit 29b for receiving and amplifying a signal, an antenna 30a for transmission and reception, and a changeover switch 30b for switching an antenna in transmission and reception.

Next, the transfer station 1 and the automatic guided vehicle 2
Will be described with reference to the flowchart of FIG.

Each automatic guided vehicle 2 travels on the traveling path 3 and travels around each transfer station 1. During this time, each time the vehicle passes through each transfer point, the position sensor 25 detects it, and the control unit 20 And current position data indicating which transfer station is running between which transfer station,
Write to 2.

In the meantime, when article transport information is input to the fixed station 10 of any of the transfer stations 1 from an external computer (not shown) (step 100), the control unit 11 sends the unmanned Mobile station 20 of carrier 2
To send a call signal to the user. The radio communication unit 14 includes slots R1 to R as shown in FIG.
At timing 4 (reception timing as viewed from the mobile station side), a call signal is transmitted to each mobile station 20 of, for example, four automatic guided vehicles 2 (step 110).

The mobile station 20 of each automatic guided vehicle 2 receives the calling signal by the radio communication unit 26 and sends it to the control unit 21 (step 200).
Then, it is determined whether the received signal is a calling signal or a transport command signal. And if the signal is a call signal,
Next, in step 220, the current position data of the transport vehicle and the loading data indicating the loading state of the articles are read from the memory 22, and in the next step 240, the current position data and the loading data are loaded on the response signal and transferred. It is transmitted to the fixed station 10 of the loading station 1. The transmission from each mobile station 20 is performed at a predetermined transmission timing assigned in slots T1 to T4 as shown in FIG.

On the other hand, in the radio communication section 14 of the fixed station 10 of the transfer station 1, the radio communication section 2 of each mobile station 20 of the four automatic guided vehicles 2 is operated at the timing of the slots T1 to T4.
6 is received (step 1).
20) The current position data and the loading data of each AGV 2 included in the signal are temporarily stored in the memory 12. Then, the control unit 11 of the fixed station 10 determines in step 130 whether or not there is an unmanned guided vehicle capable of newly loading and transporting articles based on the current position of each unmanned guided vehicle 2 and the data of the loading state. If there are unmanned guided vehicles that can be transported, the process proceeds to step 150, where the unmanned guided vehicle 2 that can be loaded and is located at the shortest distance from the transfer station is determined from the current position data of each of the guided vehicles.

Then, in the next step 160, the fixed station 1
0 indicates a transfer command signal (only the transfer station for transferring articles and the transfer destination between the transfer destination and the transfer destination) via the wireless communication unit 14 at the timing of the slot Rn corresponding to the automatic guided vehicle 2 only for the determined automatic guided vehicle 2. (A signal including a code indicating the loading station).

In step 130, if the loading state of all the vehicles is full and loading is not possible, in step 140, after delay processing, the process returns to step 110, and returns to step 110 in the same manner as described above. Perform a transmission operation.

On the other hand, the transfer command signal transmitted from the fixed station 10 is received by the mobile station 20 of the automatic guided vehicle whose transfer is determined (step 200).
It is determined whether the received signal is a call signal or a transport command signal.
With the transfer station 1 that has transmitted the transfer command signal as the destination, the operation of the automatic guided vehicle 2 is controlled and the unmanned transfer vehicle 2 is caused to travel to the transfer station 1. Thereafter, the automatic guided vehicle 2 arriving at the transfer station 1 is loaded with the articles there, travels to the transfer station 1 at the destination, and unloads the articles at the transfer station 1.

When a call signal is transmitted from a plurality of transfer stations 1 at substantially the same time, communication is possible only with the station that has started transmission the earliest by the contention method, and communication with other transfer stations is busy. What is necessary is just to wait until the channel is opened as a state.

As described above, regardless of the position on the traveling path where the automatic guided vehicle 2 is traveling, the transfer signal is immediately transmitted from the transfer station 1 from which the article is requested to be transmitted through the wireless communication, and the conveyance is performed. A possible unmanned transport vehicle can be determined, a transport command can be issued, the transport vehicle can be quickly directed to the transfer station 1, and articles can be transported efficiently. In addition, since the transport information is transmitted between the transfer station and each of the automatic guided vehicles using wireless communication, it is not necessary to lay signal lines along the traveling path as in the related art, thereby simplifying the construction.

The above transfer system 1 is provided at each work site in the production line, and the above system is used at a production site where a large number of parts are sequentially transferred to each transfer station 1 by the automatic guided vehicle 2 to manufacture products. You can also.

In this case, work instruction information is sent from the external computer to each transfer station 1 together with the transfer information of the parts, and the fixed station 10 of the transfer station 1 transfers the work instructions to the mobile station 20 of the automatic guided vehicle 2. Send information and work instruction information. Then, the transmitted work instruction information is displayed on a display 23 provided in the automatic guided vehicle 2.

In this way, when the automatic guided vehicle 2 arrives at the transfer station 1 at the destination, the worker at that place, that is, the worker at the work site, looks at the work instruction information displayed on the display 23. And assembling of parts. Therefore, the paper or the LAN system, which conventionally sends the work instruction information to each work site, becomes unnecessary, and the equipment can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an operation system of an automatic guided vehicle showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a fixed station of the transfer station.

FIG. 3 is a block diagram showing a configuration of a mobile station of the automatic guided vehicle.

FIG. 4 is an explanatory diagram showing a wireless communication system.

FIG. 5 is a flowchart showing the operation of the operation control system.

[Explanation of symbols]

1-transfer station, 2-automated guided vehicle, 3-travel path,
10-fixed station, 14-wireless communication unit, 20-mobile station, 26
A wireless communication unit.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuya Ohashi 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-64-9508 (JP, A) JP-A-63- 204418 (JP, A) JP-A-63-282508 (JP, A) JP-A-60-238908 (JP, A) JP-A-3-241409 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05D 1/02

Claims (3)

(57) [Claims] A plurality of transfer stations are provided along a traveling path, and a plurality of automatic guided vehicles travel on the traveling path to circulate around the transfer stations and load and unload articles. in operation control unit, installed in the plurality of transfer stations, the corresponding transfer ɽ
Transmitting a call signal or the like to the mobile stations of the plurality of automatic guided vehicles by wireless communication for the transfer of articles from the station,
A fixed station that receives a response signal and the like transmitted from the mobile station; and a fixed station that is installed in the automatic guided vehicle and receives a call signal and the like that is transmitted from the fixed station. A mobile station that transmits a response signal including the current position information and the loading information of the automatic guided vehicle by wireless communication, and wherein the wireless communication between the fixed station and the mobile station is performed in a
The fixed station is a two-way communication, and the fixed station
In each of the plurality of mobile stations in the frame.
An operation control device for an automatic guided vehicle, which transmits a signal . 2. The fixed station according to claim 1 , wherein said fixed station responds to said paging signal.
And receiving a response signal from each of the plurality of mobile stations.
Based on the current position information and loading information contained in the answer signal
From the transfer station with the fixed station
2. A transport vehicle for transporting a vehicle is determined.
An operation control device for an automatic guided vehicle according to the above. 3. A fixed station of the plurality of transfer stations
When the call signal is transmitted substantially simultaneously from the
The mobile station of the carrier is the transfer station where communication was started fastest.
Communication only at fixed stations
The operation control device for an automatic guided vehicle according to claim 1 or 2 .