Faculty of Mechanical Engineering and Naval Architecture

2. The 14th International DAAAM Symposium "INTELLIGENT MANUFACTURING & AUTOMATION: FOCUS ON RECONSTRUCTION AND DEVELOPMENT“(DAAAM - 2003) 22-25th October 2003, Sarajevo, Bosnia and Herzegovina INTEGRATION OF CONTROL SYSTEMS OF AUTOMATIC ASSEMBLY CELL AND ROBOTS ASTRANSACTIONAL ANALYSIS ISSUE Davor ZORC Zoran KUNICA Božo VRANJEŠ Faculty of Mechanical Engineering and Naval Architecture University of Zagreb Croatia

3. INTRODUCTION Integration of equipment of different manufacturers - frequent task in design and realisation of automatic systems. Moreover, intensive technological development and manufacturing reality often imply that the mentioned task includes integration of different technological generations of equipment. “System integration” and “system integrators” are terms which usually mark that kind of engineering work. Integration implies several levels, both hardware and software, design and control. 3

4. The paper is based on the requirement of equipment integration in the Laboratory for Intelligent Production Systems (LIPS) of the Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb. The focus will be given to the integration of control systems of the equipment, which are due to their function and design entirely separated. 4

5. EQUIPMENT AND WORKING PROCESS Disassembled and assembled product Festo automatic assembly cell (1992) 5

6. Robot AdeptSix 300 (2002) Mobile robot Pioneer2 (2002) 6

7. The features of the equipment 7

8. INTEGRATION APPROACHES The integration of the equipment is possible in several ways. There are especially many possibilities in achieving connection between Festo station and Adept robot that should be addressed, because of the time/technology generation gap (older Festo vs. newer robots). 9

9. Manual integration. Human operator launches robot programs for loading/unloading of the base part and finished assembly. This kind of integration is sufficient for testing only. Integration based on timers incorporated into Adept's control programs. The robot waits the Festo station operations to be completed. Either this kind of integration is not sufficient for regular use. Namely, the robot does not 'know' whether Festo's operations are successfully completed. 10

10. Involving sensors into robot's control environment, by adding two sensors which monitor presence of the base part on the conveyor and finished assembly on the rotary table. The robot acts appropriately, however, the robot's and Festo's control systems are still entirely separated. Sharing of sensors' data between Festo station and robot. Robot's controller catches Festo's input signals. Additional electronic hardware is necessary to facilitate data collecting. Earlier duplication of sensors, is replaced by duplication of electronic circuits now. 11

11. General purpose bidirectional port-to-port connection between Festo's and Adept's controllers. Festo's controller does not have any free port connection. Ethernet based communication between PCs, where each of them controls station/robot. This solution requires appropriate control programs with instructions for reading/writing network messages. In the case of Festo's old PLC it is not supported. 12

12. The use of internet custom protocols. Adept supports such method, but only for communication with Adept's certified equipment. Internet-based communication through FTP protocol(standard on any newer operating system/platform). Since the Festo's controller is MS-DOS driven, the requirement for file transfer may be achieved by writing status file on local disk. Station's program should involve commands for writing status files, and robot's program should include commands for accessing and reading files on Festo's PC. However, there is no possibility for writing files in Festo's old software. 13

13. Acquiring new-generation PLC for Festo station. On the basis of the previous considerations, it may be finally concluded that the most effective solution is that given under 9., while the easiest and almost instantly achievable is that under 3 (duplication of sensors). Robot and mobile robot, as newer pieces of equipment, are ready to fully utilise TCP/IP protocol. After implementation of the TCP/IP protocol, the equipment will be fully integrated into single system in the sense of information flow – and as such, controllable through Internet from any location. 14

14. INTEGRATION AS TRANSACTIONAL ANALYSIS ISSUE Technical sciences are faced with emerging technologies and paradigms (including biological science, miniaturisation, ethics and uncovered aspects of human mind). Vast mankind's knowledge base calls for synthesis and compiling. Each domain cannot be self-centric any more – diversified knowledge is necessary: various engineering knowledge and knowledge from outside the traditional engineering domain and practice. Mentioned has inspired us to explore the possibilities of using Transactional Analysis (TA) in solving control issues in technical systems. 15

15. TA was introduced in the fifties years of the 20th century by Eric Berne. Transactional Analysis is (Steiner, 2003) : 1.) an easily understandable yet sophisticated psychological theory about people's thinking, feelings and behavior and, 2.) a contemporary and effective system of psychotherapy, education, organizational and socio-cultural analysis and social psychiatry. ... 3.) People's interactions are made up of transactions. Any one transactions has two parts: the stimulus and the response.... Stroking is the recognition that one person gives to another. ... are essential to a person's life. ... positive strokes like praise or expressions of appreciation, or negative strokes like negative judgements or put downs.... the exchange of strokes is one of the most important thing that people do in their daily lives. 16

16. Adept robot load unload unload load load unload Mobile robot Festo station table magazine conveyor pallet There is a clear analogy between the latter and any technical system. The “stroke” concept for our technical system is represented beneath. The strokes – transactions among equipment 17

17. The future work would try to identify other similarities in TA that could be useful for solving more and more complex transactions among incoming technical systems. • The further details & arguments on the possible use of TA: • - growing complexity of technical systems assumes that their behaviour should have several layers, as humans have, in the sense of efficiency, • TA offers a concept of ‘GAMES’ – structured behaviours and scenarios, • though that concept is not the paramount of the human capabilities and qualities, at the moment, it is very applicable in the effort to be imitated by a technical system. 18