Acoustic Emissions in Air Conditioning and Refrigeration Systems
C. W. Bullard,* J. Bentsman,* W. Li, H. Zhao
National Science Foundation, EEC 96-12120

The broad objective of this project is to investigate the applicability of active control of acoustic emissions to air conditioning and refrigeration systems. The specific objectives of the proposed project are to: (1) identify the major sources and characteristics of acoustic emissions in air conditioning and refrigeration systems, (2) determine the techniques best suited for modeling and analysis of these emissions, and (3) determine which control strategies and sensor/actuator configurations are plausible for active noise control in these systems. Experimental work will be conducted to determine the noise sources and transmission paths in a typical air conditioning or refrigeration unit.

Active Control for Large-Scale Dynamic Systems
A. Alleyne,* Y. Zhang
National Science Foundation, 99-00116

The goal of this research is to develop a fundamentally sound approach to the active vibration control of large- scale dynamics systems. The motivation is to isolate large dynamic structures from external disturbances, particularly large, brief disturbances. The desire is to minimize the damage done to crucial components by actively isolating an internal structure from the external structure. This investigation will develop the overall control strategy but will also pay close attention to the actuation scheme used to carry out the control strategy. The potential benefits of this project are increased damage tolerance and survivability of the internal structure.

Adaptive Control and Identification of Distributed Parameter Systems
J. Bentsman,* Y. Orlov (Russian Acad. of Sciences)
National Science Foundation, CMS 96-12079; Electric Power Research Institute, WO-2710-32

A large number of processes require infinite dimensional state space for their adequate descriptions. The application of regular finite-dimensional adaptive control algorithms to such processes might result in poor convergence properties and inadequate performance of adaptive controllers. The purpose of this research is to explore the methods of improving controller adaptation capabilities and identification methods for systems described by partial differential and functional equations.

Advanced Nonlinear Analysis and Control Techniques for High-Performance Fluid Power Systems
A. G. Alleyne,* Y. Zheng
U.S. Office of Naval Research, N00014-96-1-0754

Fluid power systems, particularly hydraulics, have a very high power-to-weight ratio with a large dynamic bandwidth. The goal is to use advanced control methodology to increase the performance of fluid power systems in terms of force and motion control. Several linear and nonlinear control approaches are taken. Where appropriate, new methodologies are developed based on information gathered from experimental experience. The applications of these high-performance systems include active vibration isolation as well as manufacturing systems.

Complex Infrastructure Initiative-Identification of Disturbance Detection Mechanisms and Threshold-based Security Margin Monitors to Predict Onset of Catastrophic Failures in Power Networks
J. Bentsman,* A. F. Vakakis,* I. Rozhkov
Electrical Power Research Institute; U.S. Department of Defense

Techniques for fault detection, localization, and classification are developed for the purpose of the fault-on and post-fault controller selection. Once faults are diagnosed, techniques for damage localization are examined that prevent catastrophic failure in the networks. Mathematical techniques such as wavelets and orthogonal mode decomposition are employed.

Control Design of Complex Engineering Systems
G. E. Dullerud,* C. Pirie
National Science Foundation

The objectives of the program is the development of analytical and computational tools for (a) control of systems along trajectories, (b) validation of models in a control context, and (c) distributed control methods for emerging technologies.

Control of Complex Mechanical Systems under the Agility/Precision Response Objective
J. Bentsman,* B. Miller, Y. Orlov, N. Kuznetsov (Russian Acad. of Sciences)
National Science Foundation, NSFCMS 96-42079

This research attempts to lay the foundation of the optimal control and mathematical representation of discontinuous dynamical systems with impulsive impacts.

Control of Fluid Power Systems
A. G. Alleyne*
University of Illinois; Moog, Inc.

The modeling and control of fluid power systems includes electrical, mechanical, hydraulic, and pneumatic subsystems. Various types of advanced controllers are applied to these complex nonlinear systems. Applications of these systems range from automotive engine systems to earth-moving vehicles to high-speed machine tool drives.

Control of Nonlinear Systems
A. G. Alleyne*
University of Illinois

The control of various nonlinear mechanical and electromechanical devices is studied. The techniques applied vary from standard linearization (Jacobian) to gain scheduling to nonlinear transformations (feedback linearization). The structure of the particular systems being controlled is exploited to facilitate control. The application of this is directed to the control of vehicles and manufacturing systems.

Control of Nonstationary Acoustic Emissions in AC/R Systems
J. Bentsman,* W. Li, H. Zhao
Campus Research Board

This project aims at developing modeling, identification, and control methods for nonstationary acoustic emissions in air conditioning and refrigeration systems.

Control of Uncertain Time-varying Systems Based on Robust Predictive Control Technique and Localized Time-Frequency Concepts
J. Bentsman,* H. Zhao, W. Li
National Science Foundation, CMS 96-12079

The project focuses on the development of robust controllers for time-varying systems with uncertainties. The specific application is the control of startup and shutdown and transient dynamics of a boiler turbine power generation unit.

Convex Methods for Control Design of Complex Engineering Systems
G. E. Dullerud,* M. Farhood
Campus Research Board

This project is aimed at developing proof-of-concept testbed for recently constructed convex control design tools. Additionally, extensions to current tools are proposed.

Fault Detection and Diagnosis in Air Conditioners and Refrigerators
N. R. Miller,* C. W. Bullard,* S. McLevige
NSF I/UCRC Air Conditioning and Refrigeration Center

This project is developing diagnostic methods for identifying faults in air conditioners and refrigerators during normal cycling operation. Preliminary calculations suggest that many faults can be detected using only a small number of sensors. The approach involves first using numerical simulations, followed by laboratory experiments to verify the numerical results. It goes beyond the single-fault detection method based on statistical pattern recognition, which is already documented in the literature, testing other approaches, to quantify the amount of degradation in key physical process parameters. Several mathematical techniques are being used to extract the maximum amount of information from data obtained from a limited number of sensors.

Fluid Power Systems for Manufacturing Applications
A. G. Alleyne,* E. Erdem, D. Zheng
National Science Foundation, DMI 96-24837

Fluid power systems are able to achieve high forces and fast response. They also tend to be quite nonlinear in nature. Through modeling, simulation, and experiment, appropriate controllers are determined to enable fluid power drives to maintain their high force capability but with an increased bandwidth and accuracy. The application of this work is the development of high-speed machine tool drives for novel machine tools and other manufacturing equipment such as injection molding machines. Force and position control algorithms are developed and implemented along with hybrid force/position approaches.

Integrated Chassis Control for Vehicles
A. G. Alleyne,* S. Brennan, D. Lynch
University of Illinois

Presently, components of the vehicle act independently of one another to control various aspects of the vehicle's dynamics. In this research, the dynamics of a moving vehicle are controlled by coordinating and integrating the various subsystems of the chassis. ABS braking systems, traction control systems, lateral stability control systems, 4-wheel drive (4WD), and controllable suspensions (active or semiactive) are combined in a synergistic approach to achieve higher levels of vehicle performance. The benefits of this approach are increased vehicle performance and safety.

Robust Controller Design for Power Plant and Its Testing on EPRI Simulator
J. Bentsman,* H. Zhao, W. Li
Electric Power Research Institute, WO-2710-32

The goal of this project is to design an Ho controller for a coal-fired power plant, test it on an EPRI simulator, and compare its performance with existing control laws.

Self-tuning Robust Control of Multi-Input/Multi-Output Nonlinear Processes
J. Bentsman,* H. Zhao, W. Li
Electric Power Research Institute, WO-2710-32

This project aims at combining recently developed Ho predictive control techniques with the Ho predictive identification to synthesize robust controllers for several classes of MIMO uncertain nonlinear systems. The application is currently focused on the stream generation processes in the industrial and utility boilers.

Smart Mesoflaps for Aeroelastic Transpiration Control
A. Alleyne,* E. Loth* (Aero. & Astro. Engr.), D. Tortorelli,* P. Geubelle* (Aero. & Astro. Engr.), S. White* (Aero. & Astro. Engr.), J. C. Dutton,* P. Crisman
Defense Advanced Research Projects Agency

A multi-disciplinary research and development project is proposed to investigate the capability and performance of a novel concept termed Smart Mesoflaps for Aeroelastic Transpiration (SMAT) which will provide mass and momentum transfer to control shock/boundary-layer interactions (SBLIs). Such interactions are critical for supersonic mixed-compression inlets and on transonic external aerodynamic surfaces. The SMAT concept consists of a matrix of small flaps covering an enclosed cavity. These flaps are designed to undergo local aeroelastic deflection to achieve proper mass bleed or injection when subjected to shock loads.

Synthesis Methods for Distributed and Time-Varying Controlled Systems
R. D'Andrea* (Cornell Univ.), G. Dullerud*
U.S. Air Force Office of Scientific Research, F49620-98-1-0416

This project involves leveraging new semidefinite programming methods and functional analysis to achieve distributed and time-varying synthesis techniques.

Synthesis of Predictive Controllers with Guaranteed Stability and Robustness
J. Bentsman,* H. Zhao, W. Li
Electric Power Research Institute, WO-2710-32

The goal of this project is to synthesize stable and robust real-time predictive control algorithms with the tuning knobs which specify trade-off between performance and robustness for use in the self-tuning applications.