Date of Award

Spring 1969

Document Type

Dissertation

Degree Name

Doctor of Engineering Science in Electrical Engineering

Department

Electrical Engineering

First Advisor

Joseph J. Padalino

Second Advisor

Frederick A. Russell

Third Advisor

Kenneth Sohn

Fourth Advisor

P. A. Fox

Abstract

This thesis deals with the engineering aspects of control electronics. It examines modern concepts of servo-control theory in the light of recent developments in the technology of monolithic circuits. Applicational considerations are slanted towards Aerospace standards of reliability and power-consumption economy.

Conclusions drawn from the discussion of fabrication constraints and performance requirements lead to a preference for digital implementations. Yield problems on one hand and aging effects on the other greatly reduce the feasibility rating of analog arrays.

Current practice in servo-control electronics revolves around purely analog implementations, sampled-data systems and Primitive on-off arrangements. The motivation behind the status quo and the justification of the proposed approach are discussed in detail.

The organization of digital systems is examined in order to demonstrate the feasibility of Large Scale Integration (LSI) in servo-control electronics. The questions of hardware versatility and power-dissipation economy are emphasized from technological, economical and applicational standpoints.

Self-Contained loops and Computer-Aided systems investigated within the ramifications of a functional division into Detectors, Compensators and Drivers. Differential Frequency Modulation is assumed to effect the information transfer from the Pick-Off coil of the transducer to tie input ports of the Ratemeter. Pulse Width-Frequency Modulation is employed at the Driver-Torquer interface.

The operation of the Ratameter conforms with classical logic, except for a slope-independent Level-Crossing-Discriminator (LCD), which is designed to provide a time-resolution gain of 3 db. over conventional frequency detectors. Circuit detais of the LCD are given in order to illustrate differences between integrated and discrete circuit configurations. Two types of compensators are discussed: canonic pole-zero arrangements with ROM multipliers and Kalman fiiters with stored-program implementations of covariance equations.

The concept of Pulse-Width-Frequency-Modulation (PWFM) is introduced co reconcile the dynamic-range requirements or servo-control drivers with the time-resolution limitations of power transistors. Simple means of implementation of PWFM are also given; they take the form. of a combination of logic-gates and DDA elements, a technique which could be used to advantage in other applications, especially digital detection and filtration.

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