Object-oriented programming in control system design: a survey

Some guiding principles for the design of open systems suitable for computer-aided control engineering are presented. Some possible architectures are considered, and an assessment is made of the available technologies that might be suitable for an open environment. An analogy is made with the requirements for computer-aided software engineering, for which a reference model has already been developed. It is concluded that such a model might well provide a clear definition of what is needed in computer-aided control engineering. >

Open architecture for computer-aided control engineering

Data structures and software tools for the computer aided design of control systems: a survey.

The GE multidisciplinary expert-aided analysis and design (MEAD) project, which involves the integration of several computer-aided control engineering (CACE) packages under a supervisor which coordinates the execution of these packages with a database manager, an expert system, and an advanced user interface, is discussed. The principal components are, in functional terms: a supervisor, which integrates the underlying CACE packages and coordinates all activity within the GE MEAD computer program (GMCP); an expert system shell and rule bases for expert aiding of specific procedures to relieve the user from unnecessary low-level detail; a database manager for tracking system models that evolve over time along with associated results; and a user interface that facilitates access to the CACE package capabilities by permitting the user to work in several modalities, i.e. menu/forms style, using GE MEAD commands, the core packages' native commands, or the GE MEAD macro facility. The operation of the GMCP, including the user interface, expert system, and database manager, is illustrated by examples. >

http://ieeexplore.ieee.org/iel2/872/2449/00069826.pdf

The GE MEAD computer-aided control engineering environment

The user interface (UI) of the MEAD computer-aided control engineering (CACE) program is presented. After a brief presentation of the MEAD computer program, the unifying philosophy behind the MEAD UI is discussed. Main features of this UI include a point-and-click-style interaction, a unifying grouping of similar functionality, and a graphical interface to its CACE database management system. A typical modeling, analysis, and design scenario is given to illustrate the interface. The use of a user interface management system (UIMS) in the design and implementation of the MEAD UI is discussed. The MEAD user interface is implemented using an experimental UIMS developed at GE which supports both a Tektronix terminal and X-window-based window systems. Some implementational features of the MEAD user interface are that it is implemented using an object-oriented database system; that it uses a state tree to specify the dialog control; and that it is created entirely by means of a graphical editor, thereby avoiding conventional programming. The architecture of the UIMS is described and the implications of creating a user interface with this UIMS are discussed. >

GE's MEAD user interface-a flexible menu- and forms-driven interface for engineering applications

There has been substantial progress made in the past decade in the development of analysis and design software for computer-aided control engineering (CACE). Engineering data-base management (EDBM) for support of CACE has not received much attention until recently, however. As CACE environments become more comprehensive and more powerful, the need for keeping track of the models, simulations, analysis results, control system designs, and validation study results over the control system design cycle becomes more pressing and the lack of EDBM support becomes more of an impediment to effective controls engineering. We have defined and implemented a CACE environment with EDBM as an integral part. The data base is organized in a hierarchical famework having the levels Project, Sub-project, Model, Attribute, and Element. The levels Project and Sub-project accommodate several control engineers working on a single project, with a project lead engineer having responsibility and control of the entire data base. Within a project, Models (plant models, control system models, etc.) are the main focus. Each model has two attributes, a Description and a Result_set. Fundamental properties plus component models (representations of a plant, compensator, sensor, etc.) comprise the elements of a Description; elements of a Result_set include any data generated with the model, such as a time-history, frequency response, etc. One factor that complicates the CACE DBM problem is that system models used for simulation, analysis, and design activity usually evolve as a project progresses.

http://ieeexplore.ieee.org/iel5/4789671/4789672/04789814.pdf

Ko-Haw Nieh

Papers

A Data-Base Management Scheme for Computer-Aided Control Engineering