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This thesis is concerned with the dissipative control and filtering problems of singular systems. Four classes of singular systems are considered: delay-free singular systems, singular systems with constant time-delay, uncertain singular systems with time-varying delay and sensor failures, and singular Markovian jump systems with actuator failures. For delay-free singular systems, the system augmentation approach is employed to study the dissipative control and filtering problems. First, the approach is used to solve the dissipative control problem by static output-feedback for standard state-space systems which are the special cases of singular systems. For a continuous-time standard state-space system, the closed-loop system is represented in an augmented system form. Based on the augmented system, a necessary and sufficient dissipativity condition is proposed, which decouples the Lyapunov matrix and controller matrix. To further separate the Lyapunov matrix and the system matrices, an equivalent condition is obtained by introducing some slack matrices. Then, a necessary and sufficient condition for the existence of a static output-feedback controller is proposed, and an iterative algorithm is given to solve the condition. For discrete-time singular systems, by giving an equivalent representation of the solution set, a necessary and sufficient dissipativity condition is proposed in terms of strict linear matrix inequality (LMI) which can be easily solved by standard commercial software. Then a state-feedback controller design method is given based on the augmentation system approach. The method is extended to the static output-feedback control problem and the reduced-order dissipative filtering problem. For continuous-time singular time-delay systems, the problem of state-feedback dissipative control is considered. An improved delay-dependent dissipativity condition in terms of LMIs is established by employing the delay-partitioning technique, which guarantees a singular system to be admissible and dissipative. Based on this, a delay-dependent sufficient condition for the existence of a state-feedback controller is proposed to guarantee the admissibility and dissipativity of the closed-loop system. In addition to delay-dependence, the obtained results are also dependent on the level of dissipativity. Moreover, the results obtained unify existing results on H∞ performance analysis and passivity analysis for singular systems. For discrete-time singular systems with polytopic uncertainties, time-varying delay and sensor failures, the problem of robust reliable dissipative filtering is considered. The filter is designed by the reciprocally convex approach such that the filtering error singular system is admissible and strictly (Q, S, R)-dissipative. For singular systems with time-varying delay and sensor failures, a sufficient condition of reliable dissipative analysis is obtained in terms of LMIs. Then the result is extended to the uncertain case by introducing some variables to decouple the Lyapunov matrices and the filtering error system matrices. Moreover, a desired filter for uncertain singular systems with time-varying delay and sensor failures is obtained by solving a set of LMIs. For continuous-time singular Markovian jump systems with actuator failures, the problem of reliable dissipative control is addressed. Attention is focused on the state-feedback controller design method such that the closed-loop system is admissible and strictly (Q, S, R)-dissipative. A sufficient condition is obtained in terms of strict LMIs. Moreover, the results obtained unify existing results on H∞control and passive control on singular Markovian jump systems. / published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

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The aims of the current research programme were, first, to examine expertise effects with regard to anticipation skill and the perception of deceptive movement, and, second, to examine how knowledge of the probability of behavioural events influences anticipation performance and visual search behaviour. In addition, this thesis sought to test the predictions of attentional control theory (ACT) in examining how anxiety affects the influence of top-down probability information on anticipation skill and visual search behaviour. In Chapter 3, skill-based differences in anticipation and decision making were examined using judgement accuracy and confidence ratings. High-skilled soccer players demonstrated superior anticipatory performance and were less susceptible to deception compared with low-skilled players. In Chapters 4 and 5 Posner’s spatial cueing paradigm was adapted to examine the influence of top-down probability information on anticipation skill and visual search behaviour. High-skilled participants were found to be more accurate and demonstrate more efficient visual search behaviour compared to low-skilled participants. However, findings demonstrated that both groups benefited from the provision of probability information, and performance was moderated by the degree of certainty conveyed through the probability information. In Chapter 6, the same anticipation task and process tracing measures were used to examine the effects of heightened anxiety on the processing of probability and visual information. The findings supported the predictions of ACT, as the influence of top-down information was suppressed during high-pressure conditions, owing to an increased influence of the stimulus-driven attentional control system. The series of studies in this thesis are the first to explore the influence of top-down probability information on anticipation performance and the perception of deception. Study 4 is also the first to test the predictions of ACT regarding the processing of (top-down) explicit knowledge and (bottom-up) visual information under pressure during a simulated soccer anticipation task. The use of probability information through performance analysis feedback plays a prominent role across a number of sports, and the present findings highlight the importance of understanding the costs and benefits associated with such information. It is concluded that future perceptual training interventions should incorporate context-specific information that mimics the real-life demands of competitive sport, and should be directed towards enhancing players' ability to detect deception rather than training players to become attuned to non-deceptive movement.

This thesis examines the present methods of centre less bearing grinding, with a view to applying IIDderncontrol nethods in order to reduce the distribution of output size variations and improve the quality of surface finish. Established rrodels of the grinding process shew that various inportant parameters describing the process can be derived, providing that the grinding power can be accurately rronitored. Several alternative control strategies based on paNer rronitoring are considered. The drive systems of a typical grinding machine are rrodelled as they react through the non-linear grinding wheel/work interface. A simplified computer simulation of the process is demonstrated. Suitable rrethods of instrumentation are evaluated including the optical shaft encoder as a source of high resolution data for the estimation of drive shaft dynamics. A method is devised for on line pararreter estimation of the drive system transfer functions. This enables the important grinding power to be estimated fran shaft dynamics and also al loes the rronitoring of the drive system parameters. The cpt.ica l shaft encoder is also assessed as the source of data for vibration detection. A development conputer with real tine multi-tasking operating system software and specialised shaft encoder interfacing has been established as a basis for an expandable control and rronitoring system. A plan for fee<l:>ackcontrol of the grinding, involving several separate control algorithms cormunicating with an expert system executive controller, is outlined.

The aim of this thesis is to investigate relay feedback process identification and some controller design methods. Using an exact analysis method, namely the state space method, a set of conditions for the prediction of oscillations in relay control systems has been developed. Since the exact solution for the limit cycle is found it becomes possible to assess the stability of these oscillations using an eigenvalue criterion. A correction factor has been introduced to overcome the limitations of the Balasubramanian's eigenvalue criterion. Relay feedback identification in process control can lead to erroneous results if the system parameters are estimated from the approximate describing function approach. Exact analytical expressions are derived and on the basis of these expressions an identification procedure is suggested which is capable of estimating the parameters of a class of process transfer functions. Analytical expressions are presented for quantifying the approximate estimation errors in the presence of measurement noise and load disturbance. The performance limitations of the conventional PID controller have been clearly shown in the context of controlling resonant, unstable or integrating processes. It has been shown that a PI-PD controller with the PD in the inner loop not only avoids the derivative kick but also a better performance is achieved than with a P or D controller in the inner loop. Further, the same controller provides good disturbance rejection and its performance is often near to that of an optimum controller for disturbance rejection and is significantly better than the results of other design methods based on setpoint response. Simple tuning methods based on standard forms for a PI-PD controller controlling time delay processes have been presented which are particularly effective for integrating and unstable plants. Automatic tuning formulae for PI, PID and PI-PD controllers have been proposed for controlling stable and unstable processes. The problem of controlling integrating and unstable processes incorporating time delay has been tackled by proposing a new Smith predictor. It is shown that the predictor is capable of successfully controlling stable, integrating and unstable processes. Controller parameters leading to robust performance for various levels of uncertainty in the model parameters particularly in the unstable time constant and time delay have been presented. Also, simple and effective automatic tuning formulae are derived for the new Smith predictor structure when the plant model is not available assuming first order model with time delay for stable, unstable and integrating processes. The plant model blocks in the control structure, as well as all the controllers, are designed from a single symmetrical relay test.

published_or_final_version / abstract / toc / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Mathematics / Master / Master of Philosophy

No description available.

No description available.