Control method for mobile robot system

• US 5,329,450 A
• Filed: 05/07/1992
• Issued: 07/12/1994
• Est. Priority Date: 05/10/1991
• Status: Expired due to Fees

• Current Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Original Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Inventors: Onishi, Masanori
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US07/879,883
• Time in Patent Office: 796 Days
• Field of Search: 364/424.02, 364/513, 364/468, 364/488, 364/478, 414/789, 180/167, 180/168, 180/169
• US Class Current: 701/24
• CPC Class Codes: G05B 19/41895 using automatic guided vehicles [AGV] control of position or course of AGV's G05D1/00
• CPC Class Codes: G05D 1/0297 by controlling means in a control room
• 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

When mobile robots having no task exist in the system and tasks not completed are remaining, a control station instructs the mobile robots to evaluate the remaining tasks. The mobile robots having no task then evaluate the remaining tasks and report corresponding evaluation values to the control station. The control station sequentially selects the combination of one of the mobile robots, having no task and one of the remaining tasks which are not assigned to the mobile robots so that the combination presenting the best evaluation value is selected, and assigns the task of the selected combination to the mobile robot of the selected combination.

Claims

1. A method of controlling a mobile robot system of the type having a control station and a plurality of mobile robots, wherein the control station transmits instructions to the robots to travel to and to perform tasks at a plurality of work points, the method comprising the steps of:

(a) storing at the control station tasks for the robot;

(b) assigning some of the tasks to the robots;

(c) identifying any of the robots not currently having any assigned tasks;

(d) identifying tasks not currently assigned to any of the robots;

(e) instructing the identified robots to evaluate the identified tasks, including the steps of each of the identified robots,

1) determining a best travel route to travel to each respective work point at which each unassigned task is to be performed, and

2) generating, for each unassigned task, an evaluation value depending on the best travel route to the work point at which the unassigned task is to be performed, and

3) transmitting the generated evaluation values to the control station;

(f) creating at the control station, an evaluation table containing the evaluation values transmitted to the control station;

(g) selecting an optimum evaluation value from the evaluation values in the evaluation table;

(h) determining the robot from which said optimum evaluation value was transmitted to the control station;

(i) determining the unassigned task for which said optimum evaluation value was generated;

(j) assigning the determined unassigned task to the determined robot;

(k) deleting from the evaluation table all of the evaluation values transmitted to the control station from the determined robot and all of the evaluation values generated for the determined unassigned task; and

(l) repeating steps (g) through (k) until all of the unassigned tasks have been assigned to the robots.

2. A method according to claim 1, further including the step of, the control station transmitting instructions substantially simultaneously to all of the identified robots to perform the identified tasks.