Hierarchical control system for automatically guided vehicles

• US 5,367,456 A
• Filed: 01/24/1991
• Issued: 11/22/1994
• Est. Priority Date: 08/30/1985
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Summerville, David F., Williston, John P., Doty, Thomas J., Wand, Martin A.
• Primary Examiner(s): Trans, Vincent N.
• Application Number:
  US07/647,671
• Time in Patent Office: 1,398 Days
• Field of Search: 364/424.02, 364/200, 364/900, 395/650, 395/800
• US Class Current: 701/24
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G05D 1/0297 by controlling means in a control room

Abstract

The invention is a modular and hierarchically organized set of computer programs which comprise methods for controlling a system of semi-autonomous automatically guided vehicles, such as mobile robots. The methods include control programs which: execute in stationary control computers; communicate between the stationary control computer programs and corresponding programs which execute in mobile control computers aboard the vehicles; operate independently in mobile control computers aboard the vehicles. The invention allows the system executive program to command the mobile vehicles to start, to stop, to transfer material to or from the vehicles, to change batteries in the vehicles, to park the vehicles at specific points in a factory, to move the vehicles from point to point in a factory, and to remove the vehicles from the factory. The invention improves the performance of conventional automatically guided vehicle systems by maximizing the autonomy of individual vehicles while retaining sufficient supervisory control at the system executive level to provide the maximum flexibility in routing and scheduling the activity of the vehicles. The invention "closes the loop" in an automatically guided vehicle system by providing the highest level of control between mobile vehicles and stationary control computers.

Claims

1. A hierarchical control method for communicating with and controlling a plurality of AGVs, comprising:

(a) providing a system controller (2) to communicate with a plurality of AGVs;

(b) running a plurality of vehicle-application-task computer programs independently and concurrently by said system controller, each of said vehicle-application-task computer program is associated with each AGV;

(c) generating commands, using said vehicle-application-task computer programs, for each associated AGV;

(d) running, by said system controller, a system-controller-task computer program independently and concurrently with said vehicle-application-task computer programs to generate communicating commands for a selected AGV to the vehicle-application-task program associated with said selected AGV; and

(e) communicating and controlling a plurality of AGVs using the generated commands.

2. The hierarchical control method of claim 1, further comprising:

running a visual-navigatin-task computer program concurrently with other computer programs; and

using said visual-navigation-task computer program to determine the position of each of said AGVs.

3. The hierarchical control method of claim 1, further comprising:

providing a vehicle controller on board each AGV.

4. The hierarchical control method of claim 3, further comprising:

providing a communication link from said system controller to said vehicle controller; and

communicating commands from said system controller to said vehicle controller.

5. The hierarchical control method of claim 1, further comprising:

running a scheduler-task computer program concurrently with said other computer program; and

using said scheduler-task computer program to generate routes for said AGVs.

6. A hierarchical control system for communicating with and controlling a plurality of AGVs, comprising:

(a) a system controller (2) for communicating with and controlling a plurality of AGVs;

(b) vehicle-application-task controllers (9-12 and 18-19) running a plurality of programs each of said vehicle-application-task controllers is associated with each AGVs, wherein;

(i) said vehicle-application-task controllers run programs independently and concurrently by said system controller, and

(ii) each of said vehicle-application-task controllers runs programs for generating commands for its associated AGV; and

(c) a system-controller-task controller (21) for running a program for communicating commands for a selected AGV to the vehicle-application-task controller which runs a program associated with said selected AGV, wherein;

said system-controller-task controller and its program is run independently and concurrently with said vehicle-application-task controller and program by said system controller.

7. The hierarchical control system of claim 6, further comprising:

(a) a visual-navigation-task controller and program for determining the position of each of said AGVs, wherein;

said visual-navigation-task controller and program is run concurrently with said other computer programs by said system controller.

8. The hierarchical control system of claim 6, further comprising:

a vehicle controller (6) on board each AGV.

9. The hierarchical control system of claim 8, further comprising:

a communication link for communicating commands from said system controller to said vehicle controllers.

10. The hierarchical control system of claim 6, further comprising:

(a) a scheduler-task controller for generating routes for said AGV'"'"'s, wherein;

said scheduler-task controller runs a scheduler-task program which is run concurrently with said other computer programs by said system controller.