Luís Ribeiro ( ldr@uninova.pt ) José Barata ( jab@uninova.pt )

1. MAS and SOA: A Case Study Exploring Principles and Technologies to SupportSelf-Properties in Assembly Systems Luís Ribeiro (ldr@uninova.pt) José Barata (jab@uninova.pt) Armando Comlombo(awcolombo@ieee.org)

2. Presentation Outline • Motivation • Systems, Paradigms and IT • MAS and SOA • System Componentization • Building Blocks • NOVAFLEX Cell • Architecture • A skill based approach • Generic Services • Device Level • System Level • Implementation • A generic communication Interface • Interaction Patterns • Test Scenario • Conclusions and Outlook

3. Motivation • Flexible, Bionic, Holonic and Reconfigurable Manufacturing Systems; Evolvable Assembly Systems, Evolvable Production Systems... • MAS • SOA • Market Turbulence • Profitable but volatile opportunities • Mass Customization • Safety and Environment • Sustainable Development • … • Internet • Web Services • Agent Platforms • Web Standards • Neural Networks • Prospective Reasoning • …

4. Systems, Paradigms and IT (1) • Current approaches will soon be insufficient • The Systems advocated by modern production paradigms are increasingly powerful, full featured and COMPLEX

5. Systems, Paradigms and IT (2) • Existing IT/AI are no adequate in the present • Software • Hardware • There is a lack of support tools • Development • Analysis • Is a new paradigm required? • Understand existing paradigms and technologies • Attempt to integrate/adequate them to fulfill emerging requirements

6. MAS and SOA: Brief Comparative Analysis

7. Componentization - Concept • Each device is provided an IT frontend • Harmonizes the devices with the infrastructure • Improves Flexibility and Scalability • Enables (re)composition of the system using building blocks • Encapsulates complexity

8. Componentization - Concept • Each type of service (CLS, MDS and SMI) is generic for a given family of hardware. • Each service provides generic processing and information flow • Each service has a typical interaction pattern

9. Componentization – Building Blocks • Service to Machine Interface (SMI): wraps legacy devices harmonizing them with the remaining infrastructure • Manufacturing Device Service (MDS): abstracts a manufacturing component: gripper, robot, conveyor, … • Coalition Leader Service (CLS): aggregates and orchestrates MDSs

10. Componentization – NOVAFLEX Cell

11. Componentization – NOVAFLEX Cell

12. Architecture – A skill based approach • A skill is a action a that a given service knows how to execute and therefore is able to offer to the remaining system. • MDS offers simple skills – atomic skills • CLS offers complex skills – skills that are composed of other skills

13. Architecture – Skills available in NOVAFLEX’s Generic Services

14. Architecture – Device Level • Each device performs self-analysis

15. Architecture – System Level • Interaction and Orchestration

16. Architecture – A plug and play reconfigurable environment • To accomodate changing requirements the building blocks (SMI, MDS and CLS) can be (re)combined.

17. Implementation - A Generic Communication Interface for Web Services (1) • Harmonizes the IT infrastructure • Supports Generic Ochestration • Supports Structured Interaction • Supports Runtime Changes • Minimizes Code Explosion and Complexity

18. Implementation - A Generic Communication Interface for Web Services (2) • It is essential as services take diferent roles during functionning

19. Implementation - A Generic Communication Interface for Web Services (3) • Implements: • Generic message structure • Generic types of interaction

20. Implementation – Service to Machine Interface (SMI) Interaction Pattern NOVAFLEX Interoperates the Bosch SCARA controller privding acess to the robot, grippers and tool warehous

21. Implementation – Manufacturing Device Service (MDS) Interaction Patterns with/out SMI NOVAFLEX Abstracts each device harmonizing them with the infrastructure

22. Implementation – Coalition Leader Service NOVAFLEX • The pallet is the main Coalition Leader and ochestrates its way around the system • Each station has its own ochestrator (CLS) that according to the devices under the coalition offers diferent complex skils. For instance Stattion 2 provides pick and place and swicth gripper operations under the presence of the following MDS: robot, gripper and toolwarehouse

23. Test Scenario – Re-Orchestration as a recovery action • Failure Scenario: • The pallet orchestrates its way until Station 2 where it requests the CLS a pick and place operation. • When attempting to open the active gripper detects that is unable to perform the operation. Upon diagnosing the fault and acknowledging that there is no possible recovery within its scope, the gripper MDS reports it to the CLS. • The CLS checks in its diagnosis and recovery knowledge base if there a specific handler for that fault and eventually identifies one. • For that specific gripper, a fault in step 2 of a pick and place operation can be recovered by switching gripper. A conversation is initiated with the tool warehouse. • The Gripper is replaced • The Pick and Place Restarts

24. Test Scenario – Gripper Reports the Failure

25. Conclusions • Despite the theoretical prospects and expectations, in practice technology requires further improvements to meet the IT requirements of modern production systems • Computational power is still a constraint in embedded tiny devices • SOA and MAS paradigms individually provide an incomplete solution • Experience shows that there are benefits in merging both concepts and technologies

26. Outlook Currently NOVAFLEX Future DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service DPWS Service

27. Thanks for your attention