Reconfigurable manufacturing system having a production capacity method for designing same and method for changing its production capacity

• US 6,349,237 B1
• Filed: 05/27/1998
• Issued: 02/19/2002
• Est. Priority Date: 12/23/1997
• Status: Expired due to Fees

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Ulsoy, A. Galip, Koren, Yoram
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Backer, Firmin
• Application Number:
  US09/085,562
• Time in Patent Office: 1,364 Days
• Field of Search: 700/96, 700/94, 700/39, 700/78, 700/47, 700/99, 700/103, 700/105, 700/116, 700/112, 700/121, 700/230, 708/100, 708/230, 708/231, 715/313, 712/20, 714/712, 714/821, 714/714, 714/708, 705/7
• US Class Current: 700/96
• CPC Class Codes: B23Q 37/00 Metal-working machines, or constructional combinations thereof, built-up from units designed so that at least some of the units can form parts of different machines or combinations; Units therefor in so far as the feature of interchangeability is important features relating to particular metal-working operations, see the relevant subclass, e.g. B23P23/00
• CPC Class Codes: B23Q 39/02 the sub-assemblies being capable of being brought to act at a single operating station
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: G06Q 10/06315 Needs-based resource requirements planning or analysis

Abstract

A reconfigurable manufacturing system (RMS) having an adjustable structure is designed based upon market demand and can be readily changed from a first desired production capacity to a second desired production capacity to manufacture a desired amount of products from a family of products. The RMS includes a plurality of workstations with reconfigurable machines and computerized numerically controlled (CNC) machines, a control system including a plurality of reconfigurable controllers, as well as a reconfigurable material handling system. The reconfigurable machines may be reconfigurable machine tools having reconfigurable hardware that enables conversion of the machines by, for example, relocating their spindle units. The RMS production capacity is quickly adjusted to market fluctuations in product demand. The RMS functionality is easily adapted to fabrication of new products of the same product family. The RMS possesses certain key characteristics (i.e., modularity, integrability, customization, convertability, and diagnosability) that are needed for rapid and cost-effective reconfiguration. A methodology for the design of an RMS, and a complementary methodology for changing the production capacity including reconfiguration and ramp-up of the RMS are also provided.

Claims

1. A reconfigurable manufacturing system (RMS) having an adjustable structure to quickly change from a first desired production capacity to a second desired production capacity to manufacture a desired mix of products from a family of products, the system comprising:

a plurality of work stations including reconfigurable machines;

a control system including a plurality of reconfigurable controllers for controlling the reconfigurable machines; and

a reconfigurable material handling system in communication with the control system for transporting material or parts between the work stations, wherein the reconfigurable machines and controllers are modular to permit rapid and reliable integration of the machines and controllers during a change in the structure of the RMS so that the RMS will have the second desired production capacity.

2. The RMS as claimed in claim 1 wherein the adjustable structure of the RMS also allows the RMS to quickly change from a first functionality to a second functionality.

3. The RMS as claimed in claim 1 wherein the material handling system includes a plurality of conveyor modules for moving parts or materials between the work stations.

4. The RMS as claimed in claim 1 wherein the material handling system includes a plurality of wireless-controlled transport vehicles for moving parts or materials between the work stations.

5. The RMS as claimed in claim 1 wherein the machines include modular machine tools.

6. The RMS as claimed in claim 1 wherein the controllers include open-architecture controls.

7. The RMS as claimed in claim 1 wherein the machines, the controllers and the material transport system all obey an open standard so that the machines, the controllers and the material transport system can be improved and upgraded rather than replaced.

8. The RMS as claimed in claim 1 wherein at least one of the machines is a CNC machine.

9. The RMS as claimed in claim 1 wherein at least one of the machines is a machine having reconfigurable hardware components.

10. The RMS as claimed in claim 1 wherein at least one of the controllers is a controller having reconfigurable software components or modules.

11. The RMS as claimed in claim 1 wherein each of the controllers, the machines and the material transport system has an interface to permit rapid and reliable mechanical and electrical integration with the rest of the RMS.

12. The RMS as claimed in claim 1 wherein the family of products has at least one dominant feature and wherein the controllers and the machines are customized to fit the at least one dominant feature.

13. The RMS as claimed in claim 12 wherein the machines are configured to fit the at least one dominant feature.

14. The RMS as claimed in claim 12 wherein each of the controllers includes control modules integrated into an open controller platform.

15. The RMS as claimed in claim 1 further comprising a communication system for communicating with the machines, the controllers and the material handling system.

16. The RMS as claimed in claim 15 further comprising a quality measurement system in communication with the communication system for measuring part or product quality after a change in the structure of the RMS.

17. The RMS as claimed in claim 1 wherein the work stations are configured in parallel.

18. The RMS as claimed in claim 1 wherein the work stations are configured in series.

19. The RMS as claimed in claim 1 wherein the work stations have a hybrid configuration of serial-parallel.

20. The RMS as claimed in claim 16 wherein the quality measurement system includes a plurality of sensor modules, each of the sensor modules being associated with the part being produced, or with one or more of the machines, to provide corresponding sensor information to identify errors or faults via a test or calibration part.

21. The RMS as claimed in claim 1 wherein at least one of the machines includes a plurality of single axis drive modules.

22. The RMS as claimed in claim 21 wherein a controller for the at least one machine is a distributed controller having high bandwidth communication.

23. The RMS as claimed in claim 1 wherein at least one of the machines is capable of performing machining or other manufacturing operations.

24. The RMS as claimed in claim 1 further comprising a reconfigurable system diagnostics network coupled to the controllers and the material handling system to diagnose errors or faults in the RMS for calibration of the RMS.

25. A computer-implemented method for designing the reconfigurable manufacturing system (RMS) of claim 1 to have the first desired production capacity, the method comprising the steps of:

storing a life cycle economic analysis program in a computer to obtain a programmed computer;

utilizing the programmed computer to determine whether an RMS is needed based on product information and market forecasts;

performing a system level design for the RMS if the RMS is needed to obtain requirements; and

performing a machine level design for the RMS based on the requirements to obtain a final design for the RMS.

26. The method as claimed in claim 25 wherein the step of performing the system level design includes the step of designing the RMS to include subsystems that can be readily re-integrated into different RMS configurations.

27. The method as claimed in claim 25 wherein the step of performing the machine level design includes the step of designing each subsystem to be modular, integratable, customized, convertable, and diagnosable.

28. A computer-implemented method for changing the production capacity of the RMS of claim 1, the method comprising the steps of:

monitoring market conditions for the family of products to obtain market information;

determining if it is desirable to reconfigure the RMS;

if it is desirable to reconfigure the RMS, reconfiguring the RMS at system and machine levels, and

ramping up the reconfigured RMS to obtain the second desired production capacity.

29. The method as claimed in claim 28, wherein the step of ramping up includes the steps of:

measuring the reconfigured RMS at the machine level to obtain at least one machine measurement signal;

processing the at least one machine measurement signal to obtain a diagnostic signal; and

modifying the reconfigured RMS based on the diagnostic signal.

30. The method as claimed in claim 29 wherein the step of ramping up further includes the steps of:

operating the reconfigured RMS to obtain a product;

measuring the product to obtain at least one product measurement signal;

processing the at least one product measurement signal to obtain a second diagnostic signal; and

modifying the reconfigured RMS based on the second diagnostic signal.