Guy O. Beale

Integration Operator Design for Real-Time Digital Simulation

This paper presents a design technique for integration operators which allows the simulation time step to be chosen independent of the system eigenvalues while guaranteeing stability of the simulation. The technique is particularly useful for the real-time simulation of stiff systems where critical constraints are often imposed on the simulation increment. A significant savings in computation time can be realized with this technique when compared with conventional methods for simulating stiff systems. Examples are presented which illustrate the stability and accuracy properties of this design method.

Robust temperature control for microwave heating of ceramics

This paper presents results on the development of an automatic feedback control system for controlling the temperature of ceramic samples being heated by microwave energy. Design of the temperature controller is presented, and experimental results from heating experiments are given. The temperature control system is evaluated in terms of its robustness to parameter variations in the linearized model and in terms of its performance in actual experiments.

A Robust Approach to Reconfigurable Control

Abstract Reconfigurable control is an approach used to provide stability and adequate performance for a system that is subject to major perturbations to its model. This paper describes research into the application of robust control techniques to reconfigurable control. The motivation for this work is the belief that, as far as possible, each controller should provide stability for each of the system models. Therefore, the controllers should be robust as well as reconfigurable. An example using the 250,000 DWT tanker model is used to illustrate this approach.

Modeling and control for microwave heating of ceramics

This paper presents results to date on the development of an automatic feedback control system for controlling the temperature of ceramic samples being heated by microwave energy. The paper discusses three major topics: mathematical modeling of the microwave cavity, design and evaluation of the temperature control system, and design of the plunger/iris control system.

Fisher discriminant analysis and the T/sup 2/ statistic for process fault detection and classification

This paper describes the application of Fisher discriminant analysis and the hotelling T/sup 2/ statistic to the detection and classification of major failures that can occur in underwater vehicles. Simulation results are presented that demonstrate that rapid detection and reliable classification can be obtained with these methods.

Stability Considerations: Numerical Methods and Control Theory Equivalences

Stability of difference equations is discussed from the viewpoints of control theory and numerical analysis. Several definitions used by numerical analysts are introduced and explained. A number of points of similarity and one of contrast between the two fields are presented.

Matrix Integrators For Real-Time Simulation

This paper contains a discussion of numerical integration methods with regression coefficients that are matrices rather than the usual scalars. Methods of this type will be shown to be particularly useful for real-time simulations as they allow arbitrary placement of the simulation closed loop poles. This property is generally very useful, but especially so for the real-time simulation of stiff systems. Linear systems will be considered initially, followed by obvious extensions to nonlinear systems. Adaptive integration using these methods will also be introduced.

Evaluation of Parallel Algorithms for the Real-Time Simulation of a Stiff Nonlinear System

Yen-Cook, Miranker-Liniger, and Stability Region Placement (SRP) methods are evaluated on the basis of their applicability to real-time simulation using the VU68K-HDG parallel processing system as the target machine. Because of stability-computation time trade-offs, the SRP method, which allows selection of step size independent of the system eigenvalue, is shown to be the only one of the three methods applicable to the real-time simulation of a particular stiff, nonlinear, third-order test system.

Detection and classification of faults affecting maneuverability of underwater vehicles

This paper describes the application of Fisher Discriminant Analysis and the Hotelling T/sup 2/ statistic to the detection and classification of major failures that can occur in underwater vehicles. Simulation results are presented that demonstrate that rapid detection and reliable classification can be obtained with these methods.

Fuzzy depth control for a submersible vehicle

The design of a fuzzy depth control algorithm for a submersible vehicle is presented. The equivalence of the fuzzy depth control algorithm to an existing time-varying gain, nonfuzzy control algorithm (i.e., proportional-plus-derivative) is illustrated. The stability of the closed-loop system of the submersible model and fuzzy depth controller over all allowed values of the controller is proven using approaches based on Kharitonov theory and Lyapunov theory.