Accession Number:

AD0262926

Title:

ANALYSIS OF A NONLINEAR DRIVE FOR A GIMBALLED PLATFORM

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE INSTRUMENTATION LAB

Personal Author(s):

Report Date:

1958-08-01

Pagination or Media Count:

1.0

Abstract:

Studies are made of the control of a single axis gimbal employing a nonsynchronous or synchronous relay type power amplifier. The techniques presented can be readily extended and applied to other systems employing relay type power amplifiers. First, conventional servo design techniques are used to study a linear control scheme so that comparisons can be made with the methods to be presented. For the nonlinear case the analysis utilizes a similar linear compensation approach. Relations for steady state angular error and characteristics of transient responses are given for step inputs. Since the nonlinear systems presented inevitably exhibit limit cycle operation, the describing function method is used to minimize periodic error. One primary objective is to illustrate that a limit cycle in a closed loop control system is not necessarily undesirable. In fact, the analysis demonstrates that the limit cycle behavior can be used to increase the stiffness of the loop, which yields lower steady state angular error and faster responses. An analog computer is used to simulate typical examples to verify developed techniques. The results can be generally interpreted, however, to fit the designers needs, and demonstrate that the suggested methods are of sufficient accuracy for engineering purposes. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE