Operation control system for automated guide vehicles

• US 5,091,855 A
• Filed: 04/16/1990
• Issued: 02/25/1992
• Est. Priority Date: 04/17/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hori, Hideki, Umehara, Shigeru, Kato, Yoshito, Sunahara, Shuichi, Taga, Akira, Kohara, Ikumitsu, Kaseda, Satoshi, Kawase, Masao
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/509,874
• Time in Patent Office: 680 Days
• Field of Search: 364/424.02, 364/424.01, 318/587, 318/568.12, 318/568.17, 180/167-168
• US Class Current: 701/23
• CPC Class Codes: G05B 19/41895 using automatic guided vehicles [AGV] control of position or course of AGV's G05D1/00
• CPC Class Codes: G05B 2219/31002 Computer controlled agv conveys workpieces between buffer and cell
• CPC Class Codes: G05D 1/0265 using buried wires
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y02P 90/60 Electric or hybrid propulsion means for production processes

Abstract

An operation control system for automated guided vehicles conveying articles along an unmanned conveying system. This operational control system comprises a first travel path loop and a second travel path loop along which a first group and a second group of the automated guided vehicles are automatically travelled. A common travel path is provided along which the automated guided vehicles of both the first and the second group are travelled, to enable a transfer of articles between the groups of automated guided vehicles. Also a correlating unit for correlating one automated guided vehicle of the first group with another automated guided vehicle of the second group, and a transfer control unit for controlling the transfer of the articles between the automated guided vehicles are provided. The transfer control unit permits only a transfer of articles between automated guided vehicles correlated with each other by the correlating unit.

Claims

1. An operation control system for automated guided vehicles conveying articles along an unmanned conveying system comprising:

a first travel path loop along which only a first group of the automated guided vehicles are automatically travelled;

a second travel path loop along which only a second group of automated guided vehicles are automatically travelled;

a common travel path along which both the first group and the second group of automated guided vehicles are travelled, to transfer articles from the automated guided vehicles of one group to the automated guided vehicles of the other group;

a correlation means for correlating one automated guided vehicle of the first group with another automated guided vehicle of the second group;

a transfer control means for controlling said transfer of articles carried by said automated guided vehicles along the common travel path in such a manner that said transfer of articles is permitted only between the automated guided vehicles correlated by said correlation means.

2. An operation control system for automated guided vehicles according to claim 1, wherein a first assembly area for a first assembly of workpieces is located along said first travel path loop and a second assembly area for a main assembly of said workpieces is located along said second travel path loop,

said workpieces being conveyed by the first group of automated guided vehicles, and after said first assembly of said workpieces is completed, being transferred to corresponding correlated automated guided vehicles of the second group at a transfer loading station located along said common path.

3. An operation control system for automated guided vehicles according to claim 1, wherein:

said correlation means comprises;

a first recording means arranged on each automated guided vehicle of the first group, for storing information corresponding to the automated guided vehicle on which said recording means is arranged;

a second recording means arranged on each automated guided vehicle of the second group, to which information corresponding to the automated guided vehicle on which said second recording means is arranged can be written;

a first read out means for reading information stored in said first recording means, said first read out means being arranged along said first travel path loop at a position upstream of said common travel path;

an input means for writing information to said second recording means, said input means being arranged along said second travel path loop at a position upstream of said common travel path;

a means for controlling said first read out means and said input means to input information read out from said first recording means to said second recording means;

wherein said transfer control means comprises;

a second read out means arranged at an entrance of said common travel path for reading information from the first recording means of an automated guided vehicle of the first group entering said common travel path;

a third read out means disposed at the entrance to said common travel path for reading information from the second recording means of an automated guided vehicle of the second group before said vehicle enters said common travel path;

means for comparing said information acquired by the second and the third read out means to determine whether said automated guided vehicle of the first group entering the common travel path and said automated guided vehicle of the second group about to enter the common travel path have a predetermined relationship, and based on said determination, said means controls the travel of both of said automated guided vehicles.

4. An operation control system for automated guided vehicles according to claim 3,

wherein each of said first recording means and said second recording means comprises an erasable memory medium, a transmitter for sending microwave signals indicating the information stored in said memory medium, a signal receiver for receiving microwave signals from said input means, an input device for rewriting information stored in the erasable memory media with the information received by said receiver;

each of said read out means comprising an antenna and a signal receiver for receiving said microwave signals from the recording means;

said input means comprising an antenna and a signal transmitter for sending microwave signals to the recording means.

5. An operation control system for automated guided vehicles according to claim 1, which further comprises;

stop means for stopping automated guided vehicles upon arrival thereof at the entrance to at least one predetermined area of the travel path loops;

dispatch means for restarting said automated guided vehicles stopped by said stop means;

dispatch control means for controlling said dispatch means to dispatch the automated guided vehicles in such a manner that the respective automated guided vehicles travel in said predetermined area while maintaining a predetermined distance from the preceding automated guided vehicles.

6. An operation control system for automated guided vehicles according to claim 5,

wherein said dispatch control means includes a time counting means for counting time and a means for operating said dispatch means at predetermined time intervals to dispatch the automated guided vehicles.

7. An operation control system for automated guided vehicles according to claim 6,

wherein said dispatch means comprises a light signal emitting device for emitting a light signal to the automated guided vehicle and a photo sensor installed on each automated guided vehicle for receiving said emitted light signal.

8. An operation control system for automated guided vehicles according to claim 6,

wherein said stop means for stopping the automated guided vehicles comprises a position indicating mark disposed on the travel path at an entrance of said predetermined area and a proximity sensor for sensing said position indicating mark installed on each automated guided vehicle.

9. An operation control system for automated guided vehicles according to claim 5,

wherein said dispatch control means includes an automated guided vehicle detector arranged along the travel path in said area and at a predetermined distance from the entrance thereof for detecting the passing by thereof of the automated guided vehicles, and means for operating said dispatch means to dispatch an automated guided vehicle when another automated guided vehicle is detected by said detector.

10. An operation control system for automated guided vehicles according to claim 9,

wherein said automated guided vehicle detector comprises a magnetic reed switch detector disposed on the travel path and a magnet installed on each automated guided vehicle.

11. An operation control system for automated guided vehicles according to claim 9, wherein said dispatch means comprises a light signal emitting device for emitting a light signal to the automated guided vehicle and a photo sensor installed on each automated guided vehicle for receiving said emitted light signal.

12. An operation control system for automated guided vehicles according to claim 9, wherein said stop means for stopping the automated guided vehicles comprises a position indicating mark disposed on the travel path at an entrance of said predetermined area and a proximity sensor for sensing said position indicating mark installed on each automated guided vehicle.

13. An operational control system for automated guided vehicles according to claim 1, which further comprises:

power switch control means for generating a switch ON signal and a switch OFF signal;

signal transmission means for transmitting said switch ON signal and said switch OFF signal to the automated guided vehicles;

signal receiving means installed in each automated guided vehicle for receiving signals from said signal transmission means;

switching means installed in each automated guided vehicle for switching OFF a power supplied to a travel control devices of each of said automated guided vehicles when said switch OFF signal is received by said signal receiving means;

said switching means also switching ON the power supplied to said travel control devices when a switch ON signal is received by said signal receiving means.

14. An operation control system for automated guided vehicles according to claim 13,

wherein said signal transmission means comprises a transmitter for transmitting signals in the form of low frequency alternating current through guide wires laid along said travel paths, said signal receiving means comprising a pickup coil installed on each of said automated guided vehicle, said pickup coil being sensitive to said low frequency alternating current transmitted through said guide wires.