Travelling vehicle system

• US 6,381,523 B2
• Filed: 05/24/2001
• Issued: 04/30/2002
• Est. Priority Date: 05/26/2000
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Sone, Hiroki
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US09/863,526
• Publication Number:
  US 20010049572A1
• Time in Patent Office: 341 Days
• Field of Search: 701/23, 701/24, 701/2, 701/300, 180/167, 180/168, 180/169, 342/455, 342/456, 342/451
• US Class Current: 701/23
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors

Abstract

A distribution computer 10 and a plurality of controllers 12˜15 are connected together via a LAN. One of the controllers acts as a main controller 12 to transmit control from the distribution controller 10 to the controllers 12˜15. The controllers 12˜15 are duplicated so as to back up one another, and a main programmable controller 16 monitors the controllers 12 to 15 to detect defects. Arc nets 19˜22 are connected together via an RS232C line to communicate the passage of a travelling vehicle between themselves. Even with an extended running path, the present invention hinders a delay in communication and thus a delay in control, thereby preventing system down caused by a defect in a controller.

Claims

1. A travelling vehicle system comprising a running path for travelling vehicles which is divided into a plurality of zones and a plurality of zone controllers for controlling the travelling vehicles in the corresponding zones, the system being characterized in that:

said plurality of zone controllers are divided into a plurality of groups, a plurality of group controllers are provided for controlling the corresponding groups, and each of the group controllers backs up at least one of the other group controllers.

2. A travelling vehicle system according to claim 1, characterized in that communication lines are provided to connect said groups together without using the group controllers.

3. A travelling vehicle system according to claim 1, characterized in that one of said group controllers acts as a main controller so that an upper controller and said plurality of group controllers communicate with one another via the main controller, and at least one of the other group controllers is configured to back up the main controller.

4. A travelling vehicle system according to claim 2, characterized in that one of said group controllers acts as a main controller so that an upper controller and said plurality of group controllers communicate with one another via the main controller, and at least one of the other group controllers is configured to back up the main controller.