Roberto A. Pileggi

A Three-Axis Rate Table Control System Model

July 15, 1998
9:00 AM
422 Snell Building

Abstract

This thesis documents the development and application of a detailed computer model that describes the dynamics and tracking ability of a three-axis motion simulator (rate table). The computer model is used to simulate how the rate table affects a test, with the intention of getting a more accurate prediction of the data collected from a device under test.

In order to create an accurate model, the rate table dynamics are expressed in sets of empirical and analytical equations. Detailed equations are derived to describe the non-linear behavior associated with the dynamics of non-spherical gimbals of the rate table. Measurements are used to verify the moments of inertia and plant parameters for a particular rate table.

The model is exercised with a circular angular rate trajectory and with a simulated missile trajectory to study its behavior and to predict the performance of the rate table, particularly when the rate table approaches a gimbal lock condition, and during the upper stage maneuvers of the missile trajectory. The goal of this is to show the usefulness of the computer model to predict a rate table's performance and limitations for a given angular rate trajectory, as well as using the model to determine the appropriate initial conditions of a test setup.

Thesis Committee:
Prof. G. Tadmor (advisor)
Prof. B. Shafai
Dr. H. Musoff (Draper Lab)