Computer-aided Control Engineering Research Articles

A Study of the Use of Ontologies for Building Computer-Aided Control Engineering Self-Learning Educational Software

This paper describes research on the use of knowledge models (ontologies) for building computer-aided educational software in the field of control engineering. Ontologies are able to represent in the computer a very rich conceptual model of a given domain. This model can be used later for a number of purposes in different software applications. In this study, domain ontology about the field of lead–lag compensator design has been built and used for automatic exercise generation, graphical user interface population and interaction with the user at any level of detail, including explanations about why things occur. An application called Onto-CELE (ontology-based control engineering learning environment) uses the ontology for implementing a learning environment that can be used for self and lifelong learning purposes. The experience has shown that the use of knowledge models as the basis for educational software applications is capable of showing students the whole complexity of the analysis and design processes at any level of detail. A practical experience with postgraduate students has shown the mentioned benefits and possibilities of the approach.

Integrated Structural and Controller Optimization in Dynamic Mechatronic Systems

In order to take into account the interaction between the part, dynamic system, control system, and changing mechanical behavior with all its consequences for the optimization process, a simulation of the complete mechatronic system is integrated into the optimization process within the research work presented in this paper. A hybrid multibody system (MBS) simulation, that is a MBS containing flexible bodies, in conjunction with a cosimulation of the control system represented by tools of the computer aided control engineering, is integrated into the optimization process. By an inner optimization loop the controller parameters are adopted new in each of the iterations of the topology optimization in order to provide realistic load cases. The benefits will be illustrated by an example in conjunction with the humanoid robot ARMAR III of the Collaborative Research Centre 588 “Humanoid Robots-Learning and Cooperating Multimodal Robots” in Karlsruhe Germany. It will be shown how the new approach for the optimization of parts “within” their surrounding mechatronic system allows an efficient optimization of such structures.

Innovative integration techniques between Virtual Reality systems and CAx tools

The efficacy of virtual reality (VR) as a design support technique is widely recognised by industries. However, the efficiency of the routine employment of VR into the product development process (PDP) still finds an obstacle in the poor integration of the tools employed. The use of VR still needs long and quite hard procedures to work effectively; the models have to be converted into a format that is compatible with VR systems and each task requires an effort to prepare the virtual environment or to post-process the results that depend on the complexity of the task. This work analyses some VR applications into the PDP and describes some ideas to effectively support the operator that prepares the virtual environment. These ideas have been tested by developing four software interfaces, able to create an easy data exchange link between VR and other design tools like CAD, CAE and computer aided control engineering (CACE).

Real-time capable Finite Element Models with closed-loop control: a method for Hardware-in-the-Loop simulation of flexible systems

Modern simulation methods are increasingly applied in all areas of research and development in production engineering. Moreover, the application area can be extended by the combination of different simulation tools e.g. Finite Element Method (FEM) with Computer Aided Control Engineering (CACE). The dynamic behaviour of machine tools depends not only on their distribution of mass, damping and stiffness, but also on their applied control mechanisms. The following article presents a method for simulating the influence of the actual control system on the structural dynamics in real-time by using Hardware-in-the-Loop Simulation.

Overview of Coupling of Multibody and Control Engineering Tools

The role of Computer Aided Engineering in vehicle development has been significantly increased during the last decade. Specialised simulation tools became very complex, however, growing demands on complexity and particularly interdisciplinarity of vehicles and their simulation models have led to a number of approaches trying either to develop multidisciplinary simulation tools or to connect various specialised simulation tools by interfaces. This paper addresses some aspects of interconnection of the specialised simulation tools as one possibility for simulating complex mechatronic vehicle systems. It classifies the interfaces between specialised software packages in general, mentions some historical development of the interfacing and further discusses the examples of the implemented couplings between the Multibody System codes and Computer Aided Control Engineering tools. Finally, the performance of selected interfaces is compared on an example simulation of a controlled vehicle suspension.

Simulation environment for designing the dynamic motion behaviour of the mechatronic system machine tool

Machine tools consist of mechanical and electronic components and software, and thus constitute mechatronic systems. To make sure that they work reliably in the overall system these different components have to be designed in coordination. This process is complicated by the fact that virtual prototyping is becoming increasingly important in machine tool design and every development department employs different software tools, e.g. finite element method, multibody system simulation, computer aided control engineering software, etc. Moreover, every department has its own method of setting up models within these programs. The result is that various sets of data are produced that are mutually incompatible due to different modelling methods. This paper describes a new method for setting up a model for the mechatronic system machine tool, with special emphasis on the design of its motion dynamics. The main objective of the method is to standardize the model set-up within the different simulation tools with a view to producing reusable data. A concept for data management and provision is also presented.

The State of the Art in CACSD a Decade after Ecstasy

In the mid 1980s, the UK Science and Engineering Research Council funded a number of projects to develop computer-aided control system design (CACSD) environments. The flagship project was ECSTASY (Environment for Control System Theory and SYnthesis), a database-mediated framework for hosting a number of popular control systems design tools. As the ECSTASY project neared its completion, some of the most urgently requested features appeared in rival commercial packages, and the short-falls in tool provision that ECSTASY was designed to address apparently went away. Using as a benchmark the capabilities of the current generation of the popular CACSD package MATLAB, the prescience of the original ECSTASY proposal will be demonstrated. A couple of areas that the environment excelled in, the use of a common information model and common user interface, will be discussed in the context of recent work done in the University of Wales and elsewhere. Finally, two topics of particular interest to the authors, the proposed standard reference model for computer-aided control engineering and an Object-Oriented Unified Infonnation Model for CACSD will be revisited in the light of recent developments in internet computing.

The Development of Multilevel Control Education

Abstract This paper deals with the development of new control engineering education programmes at three different levels at the Faculty of Electrical Engineering in Ljubljana. A new form of continuing education for people from industry was prepared. Later, the courses were used as core material for new postgraduate specialisation programmes. A course in computer-aided control engineering was set up for University study. The current activities which are still running, will develop lectures, exercises and a laboratory for new undergraduate Engineering study. In addition to lectures and exercises with appropriate written materials as the basic results of the projects, some interesting common conclusions were made.

Computer Aided Control Engineering - Current Approaches to Design Methodologies

Current developments in the field of Computer Aided Control Engineering (CACE) have a visible impact on the design methodologies and the structure of the software tools supporting them. In this paper we try to define requirements on design methodologies used in CACE enhancing efficient flow of information between the tools supporting the following phases of the design process. The major conclusions of the paper are related to identification of the factors affecting the software tool integration in a way needed to facilitate design "interphase" communication. These are: standard application interfaces, dynamic data exchange mechanisms, code generation techniques and general software architecture requirements.

Towards a “Repository Service” for Computer-Aided Control Engineering

The integration of tools within a computer-aided control engineering environment has been the topic of research for many years. In much of this previous work, a database has been placed at the centre of the proposed designs. By examining the whole lifecycle of control systems design, a unified information model has been developed which allows tools to exchange information between any stage in the design process. The information model is used as the basis for a prototype information repository service for an integrated computer-aided control engineering environment. Use is made of the EXPRESS information modelling language to formally specify the data objects to be stored in the repository and in software wrappers that allow existing tools to make use of the information. Examples of use of the repository and directions for further work are given.

A Platform Neutral Computer Aided Control Engineering Environment

This paper proposes a computer aided control systems design environment based on an object-oriented component model. A document centered approach towards the process of computer-aided control systems design is taken. This paper examines current technologies for realizing such an environment which may be used platform neutrally, collaboratively and over a network.

An object-oriented information model for computer-aided control engineering

The aim of modern computer-aided engineering research is to create integrated sets of tools that support all stages of the control-systems design life-cycle. The most efficient way to achieve the exchange of data between the tools of the integrated environment is to define an information model that is shared by all tools and maintained by a common software environment. An object-oriented information model for life-cycle support of computer-aided control engineering is presented in this paper, and a possible architecture for its implementation is suggested. The model has been formally specified in the information modelling language EXPRESS. Object-oriented methods are also to be used for database support and inter-tool communications. The design is evaluated against previously published information models for computer-aided control engineering.

A New Approach to Generating Finite-State Control Programs for Hybrid Systems

We provide an abstract of a new approach for generating finite-state control programs for hybrid systems. We illustrate these ideas in the context of a cost-based Computer-Aided Control Engineering (CACE) environment. We discuss our methodology for ensuring that the environment should support automatic generation of automata which simultaneously comply with logic and evolution constraints. We argue that a declarative, hybrid systems approach to off-line design and online generation of reactive control automata is needed for achieving synchronization, scalability, integration, and incremental construction of large-scale, computer-controlled systems. The methodology supports a multiple-game strategy for distributed systems optimization whereby different components of the systems can employ different local optimization strategies. We conclude by comparing this constructive approach for on-line selection of actions that are near-optimal with respect to economic cost to the simulation-based approach for heuristic and exhaustive trade-off analysis.

An approach to project management in computer-aided control engineering

An integrated approach to the management of computer-aided control engineering projects is described. It is shown that to exploit the benefits of object-oriented modelling and design an object-oriented database is required. A dynamic system object model is developed for use in project management using an object-oriented database. A complete description of the project management facilities is given, and the graphical user interface is described. A case study is used for illustration. Open architectures are considered and it is concluded that, together with object-oriented methods, these provide the possibility for exploiting the work described.

A hybrid systems approach to computer-aided control engineering

In this article we provide a tutorial-style overview of ideas for a new computer-aided control engineering (CACE) environment. We discuss these ideas through repetition of two themes. The first theme is that the CACE environments should support a thread from requirements development to implementation. While some CACE environments come close to this today, none provides the end-to-end thread we envision. The second theme is that the environment should support automatic generation of automata that simultaneously comply with discrete and continuous constraints. Success in this theme would reduce the need to conduct extensive simulations and build prototypes in order to deliver and incrementally change computer-controlled systems. An example shows how such an environment can assist in addressing a recurring problem in manufacturing systems: repair of production schedules required by changes in logical or continuum constraints on factory operation. We argue that a declarative, hybrid-systems approach to off-line design and online generation of reactive control is needed for achieving synchronization, scalability, integration, and incremental construction of large-scale, computer-controlled systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The ANDECS CACE framework

Computer-aided control engineering (CACE) environments, in order to be reusable in a broad spectrum of applications, have to be based on an open software framework that provides seven classes of services: database services; model-definition services; algorithmic services; tool-control services; task-control services; user-interaction services; and process-communication services. This is detailed herein with the available CACE framework for the application system ANDECS. >

Open environments and object-oriented methods for computer-aided control system design

Two current trends in the computer industry are towards open systems and object-oriented methods. Both are important for computer-aided control system design. The success of computer-aided software engineering is attributed to its open environment, based on a reference model that involves a service-oriented framework serving a set of tools. An adaptation of this reference model is proposed for computer-aided engineering in general and computer-aided control engineering in particular. Object-oriented methods are described, and their roles in the framework services are considered. Their particular importance for the modelling services of a computer-aided control engineering environment is established. It is concluded that a combination of open environments and object-oriented methods provides a unique opportunity for progress in computer-aided control system design that needs to be grasped if the world-wide control community is to benefit.

248 A requirements analysis of future environments for computer-aided control engineering: H.A. Barker, C.P. Jobling, O. Ravn, M. Szymkat, pp 1201–1204

248 A requirements analysis of future environments for computer-aided control engineering: H.A. Barker, C.P. Jobling, O. Ravn, M. Szymkat, pp 1201–1204

250 Data-base management guidelines for computer-aided control engineering: J.H. Taylor, G. Grübel, pp 1209–1214

250 Data-base management guidelines for computer-aided control engineering: J.H. Taylor, G. Grübel, pp 1209–1214

146 Object-oriented data representation for computer aided control engineering

146 Object-oriented data representation for computer aided control engineering