University of California
at Santa Barbara
Computer and Electrical Engineering Department
In the Control Lab, students get their first taste of the balkiness of real systems. The vertical pendulum will stay vertical only if the undercarriage moves to offset the pendulum's fall. It's like balancing a broom on your palm--but the feedback comes from electrical transducers Instead of nerves. The undercarriage is moved by a motor.
There are only two observed signals: the angle of the pendulum, and the position of the cart. The student must learn to model this real system and control it, first by building a control system out of capacitors, resistors, and operational amplifiers, to see how difficult it is to stabilize the pendulum using classical control methods. Students then learn to stabilize the pendulum with microprocessor-based controllers they design using modern state-space methods.
A visiting researcher investigates
hardware implementation of digital filter structures, using a microprocessor development system donated by the INTEL Corporation.
CURRENT RESEARCH PROJECTS IN SIGNALS AND SYSTEMS Decentralized Decision and Control Decentralized Network Problems Stochastic Systems
Digital Coding of Speech and Images Radar Signal/Image Processing Models Radar Imaging of Large Vehicles
Radar Target Simulation
Biomedical Studies of Human Performance Biomedical Instrumentation
Block Implementation of Digital Filters and its Applications
Digital Filters with Reduced Number of Multiplications
Switched-Capacitor Filter Design
ECE research projects on heterostructures, laser and electron beam annealing of ion-implanted semiconductors, computer-aided IC layout, and field effect transistor modeling for computer-aided design of very high speed integrated circuits are paving the way for the next gener¬ation of semiconductor devices. Among the most promising of the new technologies is the use of Molecular Beam Epitaxy (MBE) for the construction of compound semiconductor heterostructures. Most importantly, this technology allows the use of energy-gap variations as an independent design variable, which in bipolar devices may be used to control the flow of electrons and holes independently of each other. In devices involving only electrons, energy-gap variations may be used to counteract electric fields, resulting in devices with unprecedented speed capabilities. It is expected that the use of heterostructures will become one of the dominant themes of semiconductor technology in the 80's.
Another area of current research is the use of laser and electron beams to anneal the damage caused by heavy-ion implantation of silicon and various compound semiconductors. Unlike most current studies of "laser annealing," this work emphasizes the effects of annealing on the properties of minority-carriers,
so that minute concentrations of defects and damage centers may
be detected and investigated. Research in computer-aided IC layout and FET (transistor) modeling is making possible increased automation in the design of integrated circuits. Improved transistor modeling will allow the incorporation of very high speed
compound semiconductor devices into computer-aided design (CAD) techniques, and ongoing research in computer-aided IC layout will revolutionize currently time-consuming and expensive manual (custom) IC layout approaches. Research is also being conducted in the areas of integrated optics, thermophotovoltaic filters,
and quantum-well structures.
Research in Computer Engineering is geared toward the problems of processing real-time data, and toward the efficient use of ever more sophisticated hardware. Current projects in real-time computing include design and development of a microcomputer system for respiratory data, development of a problem-driven design method for real-time computing, and the development of linguistic and graphic aids for real-time systems. Design methodologies are being developed as theoretical tools, as models
and evaluation techniques for computer-based systems and computer systems components, and as firmware/hardware tools for micro-programming. Innovations in computer architecture include use and adaptation of Ethernet-type systems, high-throughput serial architectures, and VLSI-based generalized array processors to specific problem areas in computer network design.