This thesis describes work on the development of a `plug and play' communications system for ethernet designed to enable devices to automatically provide data logging and control services over a network. Examination of the current work in protocol design such as Common Object Request Broker Architecture (CORBA) suggests that there is scope for research in developing a simpler design. This view is supported by examining the factors that have led to the widespread adoption of the Internet and its protocols. The approach is to develop a protocol that is open systems based. The protocol will allow multiple applications to be served; one of these applications will be to enable numerical controllers to download programs over the Internet. The research carried out here involves developing a standard `plug and play' communications protocol for ethernet based on TCP/IP. A pre-requisite for developing such a `standard' protocol is that of universal interfacing. In view of the fact that devices do not share common interfaces a universal electronic connector box has been developed. The purpose is to provide connectivity to a wide range of devices. The development of the electronic box involved building successively complex prototypes. The prototypes are designed to control and transfer information to and from equipment such as printers, photocopiers, electronic door access and numerical controllers. By building such a diverse range of `real world' applications it is possible to show how a single technology can control dissimilar devices. The development of the technology has the potential to enable SME's to replace complex personal computer based control systems with simple Internet enabled `plug and play' controllers. By sharing common functions and data services the technology also creates new opportunities for SME's to develop supply chain management and enterprise resource planning systems. The results of the research have led to the design and implementation of photocopier and printer control management systems, as a test of the validity of the protocol and prototypes that have been developed. The printer and photocopier control management systems are now in daily use by staff at the University of Teesside. The numerical machine control system has attracted government funding for further development.

The Shaky Hand is a multi-input, multi-output laboratory demonstrator which is modelled on a village fete game. In the original, the aim is to guide, by hand, a wire loop along a wire which has been bent to form a meandering track, 'without touching the loop to the wire. In the original game, touching the hand-held loop against the wire track sets off a loud warning bell and the player loses. The thesis presents the research work associated with the quest for practical solutions to a generic problem: the correct operation of a fallible system. The work covers three distinct areas: modelling of the demonstrator, design and construction of a physical system, and evoiution of algorithms for control of the demonstrator in practice in the presence of sensor faults, using Cartesian Genetic Programming (CGP). The third area forms the core of the thesis. The key challenges in creating the virtual environment to train for generic sensor fault tolerant algorithms are considered and addressed. The evolved algorithms are analysed and then verified using the demonstrator in practice. The practical results showed that sensor fault tolerant control was successfully achieved.

A fundamental property of a robotic manipulator system is that it is capable of accurately following complex position trajectories in three-dimensional space. An essential component of the robotic control system is the solution of the inverse kinematics problem which allows determination of the joint angle trajectories from the desired trajectory in the Cartesian space. There are several traditional methods based on the known geometry of robotic manipulators to solve the inverse kinematics problem. These methods can become impractical in a robot-vision control system where the environmental parameters can alter. Artificial neural networks with their inherent learning ability can approximate the inverse kinematics function and do not require any knowledge of the manipulator geometry. This thesis concentrates on developing a practical solution using a radial basis function network to approximate the inverse kinematics of a robot manipulator. This approach is distinct from existing approaches as the centres of the hidden-layer units are regularly distributed in the workspace, constrained training data is used and the training phase is performed using either the strict interpolation or the least mean square algorithms. An online retraining approach is also proposed to modify the network function approximation to cope with the situation where the initial training and application environments are different. Simulation results for two and three-link manipulators verify the approach. A novel real-time visual measurement system, based on a video camera and image processing software, has been developed to measure the position of the robotic manipulator in the three-dimensional workspace. Practical experiments have been performed with a Mitsubishi PA10-6CE manipulator and this visual measurement system. The performance of the radial basis function network is analysed for the manipulator operating in two and three-dimensional space and the practical results are compared to the simulation results. Advantages and disadvantages of the proposed approach are discussed.

Programmable logic controllers have been widely used in real time discrete event control systems. Generally speaking, a programmable logic controller based discrete event dynamic system consists of two parts: control software and the controlled system. The design of a programmable logic controller based discrete event dynamic system involves the following phases: modelling, programming, implementation, testing and maintenance. This thesis only focuses on the software design, which corresponds to the first two phases. The current situation in the design of programmable logic controller software can be summarised as follows: a lack of a powerful design environment, in particular a lack of simulation tools; a lack of a powerful, yet simple, graphical modelling language; a lack of formal syntaxes and semantics of the existing graphical modelling languages and a lack of methodology to deal with the multi-language situation in PLC industry. In this thesis a graphical design environment, EXCES (Extended X-based Control Engineering workStation), has been developed for programmable logic controller based discrete event systems. This environment is based on two existing graphical modelling languages, the ladder diagram and Grafcet, and a new modelling language, PLCNet (programmable logic controller net). Based on the three languages three construction tools, three simulation tools, three compilers and the three transformation tools have been designed and implemented. The formal syntax and semantics have also been defined for each of the three graphical languages. These formal syntaxes and semantics allow the correctness of the designed compilers and simulation tools to be verified. Finally, a synthesis tool based on Petri net allows optimal controllers to be synthesised for discrete event dynamic systems.

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