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FP5

OCEAN Résumé de rapport

Project ID: IST-2001-37394
Financé au titre de: FP5-IST
Pays: Italy

Component-based open control reference architecture

The OCEAN project defined an extended component based open numerical control reference architecture for machine tools, not delivered as open source but whose standardised interfaces for motion control components are publicly available. In fact the results achieved within former research projects were not flexible and granular enough as the monolithic software blocks of the control system remained almost the same. In order to take advantage of open control systems it was necessary to extend the existing reference architecture and to decompose the monolithic blocks into components with clearly defined interfaces, described in standardised IDL format (e.g. for RT CORBA).

These specifications were published for further input and implementation by users in the field of control techniques. Thus it is now possible to integrate additional functionality and third party software just using the standardised interface description, without any need of adapting interfaces.

The key innovative features are:
- Non-ambiguous interfaces have been specified in a reference architecture that will enable an interoperability of control systems and additional components that can be supplied by third parties.

- Existing reference architecture have been extended with components which are not covered yet by any standard; the modelling of the single control components and the definition of their interfaces is for sure one of the most innovative aspects of the OCEAN project.

- Conventional monolithic control systems can now be opened for the integration of additional functionality.

- User interfaces for specific machining tasks or for an individual adaptation depending on the skills of the operator can be substituted in the control system on the basis of DCRF interfaces.

- The integration of third party software with standardised interfaces will now allow the reuse of software in different control systems which will result in shorter time to market periods, reduced software development costs and more stable software applications.

The project defined the reference architecture for the following motion control components:
- HMI (Human Machine Interface) server component: it distributes data from all active components to the client applications; it represents the entry point to gain access to the whole run-time machine functionality.

- PLC component: this is a general purpose tool, an application-independent logic sequencer which behaves in a different way according to the programmable logic code downloaded into it.

- Kinematics component: this component handles coordinate transformations from the user reference system to the physical axes reference system and vice versa..

- The Motion Control kernel itself can be defined as a component including the command generation for a single channel of a NC. Such a complex functionality includes: interpretation of the part program, motion preparation (look-ahead, tool compensation, etc.), path interpolation and axis control, while it excludes the above mentioned kinematics functionalities.

- Process Control component: This component provides different functionalities depending on the considered application and user needs, and offers standard interfaces for the control of specific processes.

- Safety Component: This component has to guarantee a fail-safe behaviour of the control system and the machine tool.

- Filter Component: The Filter Component includes a library of signal processing functions including standard frequency filters, path smoothing filters, control functions.
- Hardware Access Component: it is specifically dedicated to act as an interface among the other components and the hardware, in order to make other components compliant with hardware modules of different vendors and consequently hardware independent.

At the end of the project, the consortium published the standardised interfaces, in a public deliverable D4.9, a document giving all information about OCEAN compliant components and controls.

As clearly stated in the Consortium Agreement, All specifications of component or
other interfaces are distributed without any constraints that hinder their free and unconstrained distribution. All parties agree not to exercise any patent or other intellectual property rights they have about the subjects dealt with in the specifications. All partners agree that the specifications themselves are provided free of charge from the consortium webpage, and that they can be mirrored (without any changes) on other people's servers.

Therefore this result is clearly not directly exploitable, but is the basis for the implementation of the OCEAN compliant Numerical Controls. Also its existence and features has been and will be broadly disseminated.

Informations connexes

Contact

Fabrizio MEO, (Research Manager)
Tél.: +39-0112227111
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