An elastic oblate axisymmetric reference gyro for attitude studies
Abstract
For real gyros deformations due to inertial forces are inevitable. If such deformations are small, one can often predict attitude drift and attitude stability of the gyro. This paper sets out to gain an understanding of the motion of a torquefree gyro, where the elastic deformations are not necessarily small. To that end, an elastic oblate axisymmetric gyro model has been devised. The model is as simple as possible, yet designed to have all characteristics required to study its behavior at any nutation angle. By studying the behavior of the reference gyro, it is concluded that the assumption of nearrigidity plays an important role in prediction of the motion of axisymmetric gyros. For large elastic deformations, the full nonlinear analysis shows that several equilibrium states exist. In an attempt to study the stability of the equilibrium states, comparisons were made of the value of the total energy of the system for a given nutation angle on different branches. It has been observed that depending on the oblateness of the gyro the total energy may attain its minimum on one branch or the other. This observation is based on numerical experiments.
 Publication:

Twelfth Canadian Congress of Applied Mechanics
 Pub Date:
 May 1989
 Bibcode:
 1989apme.proc..396S
 Keywords:

 Dynamic Characteristics;
 Elastic Deformation;
 Equilibrium Equations;
 Gyroscopes;
 Mathematical Models;
 Stiffness;
 Ellipticity;
 Modulus Of Elasticity;
 Moments Of Inertia;
 Nutation;
 Symmetry;
 Instrumentation and Photography