The modelling of radar systems is a complex process that has evolved over many years with the development of computer based technology. During this evolution some modelling techniques have been successful and others h...
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The modelling of radar systems is a complex process that has evolved over many years with the development of computer based technology. During this evolution some modelling techniques have been successful and others have failed. The author looks at what modelling frameworks are, why they are now being considered in the assessment of radar systems, what benefits they offer, and the pitfalls that can occur if they are not managed or planned correctly. Based on this assessment a strategy is put forward for the implementation of modelling frameworks that should yield both short term modelling goals and long term economy in software development. In particular the author discusses the objectoriented approach.< >
This paper outlines the results of a project concerned with investigating engineering techniques for real-time expert systems, and includes work concerned with parallel processing, formal specification, quality assura...
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This paper outlines the results of a project concerned with investigating engineering techniques for real-time expert systems, and includes work concerned with parallel processing, formal specification, quality assurance and safety-critical systems. The authors seek to evalutate the utility of object-oriented programming languages for implementing an experimental real-time blackboard expert system for data fusion in naval command and control systems. The evaluation has taken the form of implementing the data-fusion model in two object-oriented programming languages, Smalltalk-80 and Lingo, and two conventional languages, Ada and C. The implementations are compared with regard to quantitative run-time performance and qualitative software engineering properties.< >
ANDECS belongs to the new generation of open CAE systems for computational experimenting in controlled dynamics systems simulation, analysis, and multi-objective optimization. Strict databased function modularization ...
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ANDECS belongs to the new generation of open CAE systems for computational experimenting in controlled dynamics systems simulation, analysis, and multi-objective optimization. Strict databased function modularization with neutral object-oriented data- and model interfaces allows a flexible configuration of computational chains and loops. Function modules are available for basic mathematical methods, control methods, simulation, parameter- and trajectory optimization and interactive visualisation for result- and algorithm animation. ANDECS supports interoperability by exchanging both commands and data via interprocess communication with: MATLAB and Xmath for system dynamics analysis and synthesis; KHOROS and Data Explorer for versatile result visualisation; KISMET as robot animation package; and the like.
The author proposes the development of qualitative models of the individual components commonly found in automation, i.e. robots, controllers, computers etc. These can then be configured into a given specific architec...
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The author proposes the development of qualitative models of the individual components commonly found in automation, i.e. robots, controllers, computers etc. These can then be configured into a given specific architecture at the design stage to undertake diagnostic analysis and fault reporting. The final design is an optimised architecture that incorporates an inherent fault reporting system. This piece of work builds upon work on the production of diagnosis systems from qualitative models. This work offers a direct comparison between model-based diagnosis and the more traditional approach of using an expert system shell. The model representation uses an object-oriented approach, and includes a basic temporal capability through sequencing of messages.< >
Acumen is a collaborative research project whose goal is to define the requirements of an applications platform which will support the integration of software products in process and manufacturing industry thereby enh...
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Acumen is a collaborative research project whose goal is to define the requirements of an applications platform which will support the integration of software products in process and manufacturing industry thereby enhancing the useability and effectiveness of such products. A prototype applications platform is produced and demonstrated. The objectoriented paradigm has been adopted throughout the project, with P. Cood and E. Yourdon's (1991) methodology being used for analysis and design. The applications platform itself is implemented in C/sub ++/ in a Unix environment. The authors described the basic architecture of the applications platform and discuss some of the constraints upon its design.< >
Summary form only given. The paper describes a qualitative modelling toolbox for designing and developing application independent architectures. The domain chosen to demonstrate the versatility of the work is an advan...
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Summary form only given. The paper describes a qualitative modelling toolbox for designing and developing application independent architectures. The domain chosen to demonstrate the versatility of the work is an advanced robotics workcell that is part of a knowledge-based automation laboratory. Developed out of a remote monitoring application, the toolbox uses object-oriented software and encapsulates knowledge-based information from a human expert to construct the model. Being object-oriented there is full inheritance between individual objects. It was considered feasible that the original work could be the basis of a design tool for automation architectures.< >
Speed-sensorless control of induction motor drives has attracted considerable attention in recent past, with a vast amount of effort directed towards providing an accurate speed estimate in vicinity of zero speed. The...
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Speed-sensorless control of induction motor drives has attracted considerable attention in recent past, with a vast amount of effort directed towards providing an accurate speed estimate in vicinity of zero speed. The problem of speed estimation in the field weakening region has stayed to a large extent beyond the scope of interest. While some of the speed estimation algorithms completely fail in this region, the others exhibit a substantial speed estimation error, caused by de-fluxing of the machine and consequent variation in the magnetising inductance. This paper at first examines by simulation the speed estimation error that takes place in the field weakening region when a MRAS based speed estimator, of rotor flux type, is applied. Next, a possible solution to the problem of speed estimation under varying flux conditions is proposed. The speed estimator is modified in such a way that the variation in the instantaneous level of the flux during operation in the field weakening is recognised and properly adapted to at all times. Verification of the proposed scheme is provided by experimentation on an indirect feed-forward rotor flux oriented induction machine.
The central concept of the work described is that a database can be created which contains all the information about a complex engineering system, specifically a building management system (BMS). This database will be...
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The central concept of the work described is that a database can be created which contains all the information about a complex engineering system, specifically a building management system (BMS). This database will be updated and modified throughout the system lifecycle. Due to the large amount of information required to be entered into these databases, all data entry is done through graphical interfaces according to the maxim 'a picture is worth ten thousand words'. The user draws a picture of what is required, and this is then compiled into the desired database form. BMSs are used to control intelligent buildings. A BMS usually consists of a number of universal network controllers (outstations) which are connected together in a local area network (LAN), or wide area network (WAN). A number of PCs (terminals) can be connected to allow user access to the system for supervisory purposes. An outstation is connected to the hardware components which it controls and from where it gets its operating information. These components are called points; examples being sensors such as temperature, humidity, wind and solar effect, and actuators such as pumps, fans, valves, heating and cooling coils and humidifiers.< >
The design of a rotor time constant optimiser for a rotor flux oriented vector controlled drive has been shown. The SIMULINK simulation tool has been used to verify and test the initial design before producing code fo...
The design of a rotor time constant optimiser for a rotor flux oriented vector controlled drive has been shown. The SIMULINK simulation tool has been used to verify and test the initial design before producing code for the drive. This reduces the development time because the algorithm can be tested in an environment where unwanted secondary effects can be ignored and changes can be made quickly and easily.
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