Engineering topics

Napjus, G. A.

Publications and source records attributed to Napjus, G. A..

4 records

NASA NTRS1975

Recent advances in strapdown inertial navigation

The computational requirements and basic features of strapdown gyroscopes for inertial navigation are discussed. Strapdown navigators currently require 20 to 50% of the available time of a minicomputer with a capability of several hundred thousand operations per second; memory requirements are 2000 to 3000 16-bit words. A system in which these computational demands are met by three limited capability microcomputers is described. A technique using dedicated microprocessors in the place of analog electronics in the gyroscope control loops is discussed, and attention is given to applications of microprocessor technology in redundant strapdown navigation systems and associated flight control systems.

Napjus, G. A.↗

NASA NTRS1974

The application of microprocessors to strapdown inertial navigation

The fundamental concepts of inertial navigation are briefly examined. In a strapdown inertial navigator the accelerometers and gyros are mounted directly on the vehicle frame. The development of strapdown systems, which have important advantages over gimbal systems, has been mainly retarded by the computational requirements involved. However, the current availability of suitable minicomputers combined with other technological advances has now opened the way for a more widespread use of strapdown inertial navigators.

Napjus, G. A.↗

NASA NTRS1974

The application of microprocessors to strapdown inertial navigation

The paper describes the nature of strapdown navigators and the computational requirements associated with them. A current system design is then described in which three limited-capability microcomputers perform the tasks previously assigned to a powerful minicomputer. In addition, a technique employing dedicated microprocessors in place of conventional analog electronics in the gyroscope control loops is discussed.

Napjus, G. A.↗

NASA NTRS1971

Design of optimal probing signals for vector parameter estimation.

In the design of optimal inputs or probing signals for parameter estimation, it is more natural to consider functions of the Fisher information matrix as the criterion of optimality instead of some function of the error covariance matrix. The input which maximizes the Fisher information measure for efficient estimation of a scalar parameter also provides the minimum error variance. The information is thus a logical choice for the optimality criterion in scalar problems. No such obvious choice is apparent for vector parameter estimation. A number of performance measures are examined and compared in the present study, and a useful criterion is selected. The design of an optimal probing signal using this criterion is shown to be equivalent to an optimal control problem in which certain equality constraints must be satisfied. This problem may be solved by conventional techniques of deterministic or stochastic optimal control.

Nahi, N. E.↗