Nondeterministic assembly system and method

Patent metadata

Field	Value
Publication number	US-11059534-B2
Application number	US-201816223218-A
Country	US
Kind code	B2
Filing date	Dec 18, 2018
Priority date	Dec 18, 2018
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A method of assembling a manufactured item without a guide rail and an assembly system are provided. The method includes disposing a base item on an unmanned independent vehicle system, moving the unmanned independent vehicle system to an assembly station, and attaching an additional item to the base item. The assembly system includes a number of unmanned independent vehicle systems, each unmanned independent vehicle system having at least one wheel. Each unmanned independent vehicle system is configured to be loaded with a base item. A number of assembly stations are provided, each being configured to complete at least one assembly operation. Each unmanned independent vehicle system is configured to independently move to multiple of the assembly stations to have a different assembly operation performed at each assembly station, resulting in additional items being attached to each base item to form each manufactured item.

First claim

What is claimed is:

1. An assembly system for assembling a plurality of manufactured items without a guide rail, the assembly system comprising:
a plurality of unmanned independent vehicle systems, each unmanned independent vehicle system being configured to be loaded with a base item, wherein the plurality of unmanned independent vehicle systems corresponds to a desired number of unmanned independent vehicle systems;
a plurality of assembly stations, each being configured to complete at least one assembly operation; and
a control system in communication with each unmanned independent vehicle system of the plurality of unmanned independent vehicle systems,
wherein each unmanned independent vehicle system is configured to independently move to multiple of the assembly stations to have a different assembly operation performed at each assembly station resulting in a plurality of additional items being attached to each base item to form each manufactured item,
wherein the control system is configured to determine the desired number of unmanned independent vehicle systems for performing the assembly operations based on:
travel times of each unmanned independent vehicle system to each assembly station;
cycle times for each assembly operation; and
a number of buffer parts.

2. The assembly system of claim 1 , each unmanned independent vehicle system including one or more of the following: an automated guided vehicle (AGV), an automated guided cart (AGC), a laser guided vehicle (LGV), a vision guided vehicle (VGV), an autonomous vehicle, a drone, and a wheeled vehicle having at least one wheel.

3. The assembly system of claim 2 , wherein at least one assembly station is configured to perform a welding operation to attach an additional item to a base item, the welding operation including performing a plurality of spot welds.

4. The assembly system of claim 3 , wherein welding operation has no predetermined cycle time, the welding operation being configured to last for as long as needed to complete the plurality of spot welds so that additional spot welds are not needed to secure the additional item to the base item.

5. The assembly system of claim 3 , wherein a first assembly station is configured to weld a first additional item to the base item to form an intermediate item, and a second assembly station is configured to weld a second additional item to the intermediate item.

6. The assembly system of claim 5 , wherein the control system is further configured to:
determine a desired style penetration ratio;
monitor an actual style penetration ratio; determine a difference between the actual style penetration ratio and the desired style penetration ratio; and
load onto an unmanned independent vehicle system a base item having a style that will bring the actual style penetration ratio toward conformance with the desired style penetration ratio.

7. The assembly system of claim 3 , wherein the at least one assembly station includes at least one robot configured to perform the welding operation, the assembly system further comprising a loading station configured to dispose each base item onto an independent unmanned vehicle system in a location outside of an area of reach of the at least one robot.

8. The assembly system of claim 7 , wherein the at least one robot is disposed within an operation area, the operation area including a barrier that allows passage of at least one unmanned independent vehicle system of the plurality of unmanned independent vehicle systems, wherein the at least one robot is disabled when an object other than the at least one unmanned independent vehicle system passes the barrier.

9. The assembly system of claim 8 , wherein the barrier comprises a light curtain.

10. The assembly system of claim 1 , wherein the control system is further configured to:
determine whether an assembly station is available and tooled for a desired assembly operation;
if an assembly station is not available and tooled for the desired assembly operation, determine whether an assembly station is tooled for the desired operation;
if an assembly station is tooled for the desired operation, wait for the assembly station that is tooled for the desired operation to become available and when the assembly station that is tooled for the desired operation becomes available, cause an unmanned independent vehicle system bearing a part for which the desired assembly operation is desired to move to the assembly station that is tooled for the desired operation.

11. The assembly system of claim 10 , the control system being further configured to cause components of the assembly system to perform the following if no assembly station is tooled for the desired operation:
wait for an assembly station that has a shortest wait time to complete a current operation;
move the unmanned independent vehicle system to the assembly station that has the shortest wait time to complete the current operation; and
retool the assembly station having the shortest wait after the assembly station having the shortest wait time completes the current operation.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Gao Dalong
• Huang Ningjian
• Janis Richard C

Classifications

• B62D65/024 Primary

  Positioning of sub-units or components with respect to body shell or other sub-units or components · CPC title

• B23K11/115

  by means of two electrodes placed opposite one another on both sides of the welded parts · CPC title

• B23K37/047

  moving work to adjust its position between soldering, welding or cutting steps (B23K37/053 takes precedence) · CPC title

• B62D65/028

  by determining relative positions by measurement · CPC title

• B23P19/04

  for assembling or disassembling parts · CPC title