Record Details
Field | Value |
---|---|
Title | Digital simulation of a vertical reference system incorporating random error sources |
Names |
Rover, Jack Terry
(creator) Stone, Solon A. (advisor) |
Date Issued | 1968-05-01 (iso8601) |
Note | Graduation date: 1968 |
Abstract | The vertical reference system being considered utilizes a two-degree-of-freedom gyroscope configured as a vertical gyro. Each gimbal erection circuit forms a second-order feedback control system. Gyros are susceptable to a number of error sources. In view of the closed loop application being considered, all error sources are of negligible consequence with the exception of friction. With friction included in the gyro model, the inner and outer gimbal erection circuits cease to exist as independent second-order systems. Friction couples the gimbal erection circuits together in a type of algebraic loop. Bearing friction is a random phenomenon best described by a Gaussian distribution. Slip-ring friction is best categorized as a sliding friction. For simulation purposes, slip-ring friction is conveniently handled using the Amontons-Coulomb description. The digital technique is better suited to this simulation problem primarily because of the many decision making elements required. The Gaussian distribution needed to produce the random bearing torques is generated by sampling from the more easily produced uniform distribution. The simulation program is written in the FORTRAN IV programming language. Because of the special features required in simulating the vertical reference system, it was more feasible to develop the simulation program as a self-contained package complete with an integration routine. A second-order Runge-Kutta integration routine was selected. Using an integration interval of 0.02 seconds, the simulation program produces excellent results when compared with the response characteristic of an actual vertical reference system. |
Genre | Thesis/Dissertation |
Topic | Gyroscopic instruments |
Identifier | http://hdl.handle.net/1957/47119 |