The FESTO MPS Case-Study

                                       Live demo at ETFA'07     Video

Introduction
FESTO MPS

The control application

FESTO MPS Simulator

References

The Festo MPS control application Download

This is a CORFU project for the Festo MPS.

Copy the MyFesto directory (that is under library and contains the FB types) to the Corfu/library directory. Copy the FestoMPS directory (that contains the Corfu project) under Corfu/projects.

Introduction
To demonstrate the applicability of the IEC61499 Function Block model and prove the effectiveness and usability of our:

1. IEC61499 compliant FB execution environment (RTSJ-AXE) [1],

2. tool infrastructure (CORFU ESS and Archimedes System Platform) [2][3] and

3. development process,

the FESTO MPS example application was developed.

The first prototype implementation of the FESTO MPS control application was developed by Evagelia Mpogiatzi in the context of her Diploma thesis [4]. CORFU Engineering Support System (CORFU ESS) was utilized to apply the hybrid approach described in the paper entitled “Using UML in Control and Automation: A Model Driven Approach” by K. Thramboulidis 2^nd IEEE International Conference on Industrial Informatics, (INDIN’04), June 2004, Berlin [5].

This case study is also used as a running example in the paper entitled  "Design Alternatives in the IEC 61499 Function Block Model" by K. Thramboulidis [ETFA06] [6].

FESTO Modular Production System
According to [6] “FESTO MPS is a well documented system used by many universities for research and education purposes [7][8][9]. It is also used by other research groups to demonstrate the applicability of the IEC61499 model.” Figure 1 presents the schematic diagram of FESTO MPS. The class diagram of Fig. 2 taken from [6] represents the structural information of this system. Each one of the three units that constitute the system i.e., distribution unit, test unit and processing unit, is further defined as an aggregation of other mechanical units.

Fig. 1. FESTO Modular Production System (schematic diagram) [6].

“The distribution unit, which is composed of a pneumatic feeder and a converter, forwards cylindrical work pieces from the Stack to the Testing unit. The testing unit is composed of the detector, the elevator and the shift out cylinder. The detection unit performs checks on work pieces for height, material type and colour. Work pieces that successfully pass this check are forwarded to the rotating disk of the processing unit, where the drilling of the work piece is performed as the primary processing of this MPS. The result of the drilling operation is next checked by the checking machine and the work piece is forwarded for further processing to another mechanical unit. A detailed description of FESTO MPS can be found in [7] and [8].” [6].

Sensors and actuators list

The control application
For the development of the control application the hybrid approach presented in [5] was utilized. A UML analysis model was created using Rational Rose.  This model was next transformed using the Corfu Transformation facility manager (TFM) to a Function Block based design document. The design was next refined to get the final function block design diagram that was transformed using the Archimedes RTSJ-AXE package to get the execution model of the application.

In the following selected diagrams from the development of the prototype control application of FESTO MPS that is described in [4] are given.

Actors (Initiating IPTs) :

1. Operator

2. Converter

3. Elevator

4. DetectionModule

5. Rotating disc       

Use case list

Example use case

Use case No: 2         Use case name: Supply  next workpiece

Initiating IPT: Converter

Involved IPTs: push-out cylinder

Precondition: Push-out cylinder is in its back stop position

Description

The converter notifies the system (through S4) that it has reached its right position. The controller sends a MOVE FORWARD (A1) message to the feeders push-out cylinder (POC) . The push-out cylinder reaches its front position and sends a FRONT POSITION REACHED (S2)  message to system and the controller sends a STOP message to POC. The use case is terminated.

Postcondition: next workpiece has been supplied  

Example Object Interaction (sequence) diagrams

The object interaction diagram for the “testing properties” use case.

The The object interaction diagram for the “testing properties” use case.

Example class diagram

A draft class diagram produced in Rose

Function block types used

Feeder Function Block type: Graphical representation, ECC.

Converter Function Block type: Graphical representation, ECC, XML representation.

Detector Function Block type: Graphical representation, ECC.

Checking Machine FB Type: Corfu ESS snapshot.

Example Function Block network diagrams

Distribution unit Function block network diagram   distributionUnitFND

Testing unit Function block network diagram        testingUnitFND

Processing unit Function block network diagram    processingUnitFND

A snapshot of the final function Block network diagram in Corfu ESS

Verifying the design

Snapshot from the built in environment of CORFU ESS for the verification of Function Block network diagrams.

FESTO MPS simulator

A simulator for the FESTO MPS was developed to allow for the execution of the control application. The simulator was developed by Nikolaos Papakonstantinou.

A snapshot of the simulator screen.

To get a copy of the simulator’s user’s guide please contact Nikolaos Papakonstantinou.

References

1. K. Thramboulidis, A. Zoupas, “Real-Time Java in Control and Automation: A Model Driven Development Approach”, 10^th IEEE International Conference on Emerging Technologies and Factory Automation, (ETFA’05), Catania, Italy, September 2005.

2. K. Thramboulidis and C. Tranoris, “Developing a CASE Tool for Distributed Control Applications”, The International Journal of Advanced Manufacturing Technology, Volume 24, Number 1-2, July 2004, pages 24-31, Springer-Verlag.

3. K. Thramboulidis, D. Perdikis, S. Kantas, “Model Driven Development of Distributed Control Applications”, The International Journal of Advanced Manufacturing Technology, Springer-Verlag, (forthcoming).

4. Mpogiatzi, E. “Using IEC61499 in control and automation: The FESTO MPS case study” Diploma thesis, April 2006. (in Greek)

5. K. Thramboulidis, “Using UML in Control and Automation: A Model Driven Approach”, 2^nd IEEE International Conference on Industrial Informatics, 24-26 June, Berlin, Germany, (INDIN04).

6. K. Thramboulidis, “Design Alternatives in the IEC 61499 Function Block Model”, 11^th IEEE Int. Conf. on Emerging Technologies and Factory Automation, (ETFA’06) Sept 2006, Prague.

7. Martin-Luther-Universit�, http://at.iw.uni-halle.de/~testbeds/index.htm

8. University of Stuttgart, Institute of Industrial Automation and Software Engineering, http://www.ias.uni-stuttgart.de/forschung/demonstration sanlagen /mpsanlage.en.html

9. http://alice.stup.ac.ru/~dvn/fb61499/festo/visual_simulation_fbdk/