Drift prediction for a rollstabilized inertial measurement system
Abstract
This system measures three orthogonal body angular rates and three orthogonal body accelerations and calculates three Euler angles for attitude control of small rocket systems and/or large rocket payloads in flight. An analysis of the predicted drift in the Euler angles was undertaken to aid in the definition of computational hardware characteristics (such as gyro resolution and gyro sample frequency) and to assess the performance of the system over typical trajectories. The method of analysis uses two different techniques to calculate Euler angles and to compare the results. The first technique results in a true Euler angle which is calculated by a Bortz equation (a method to relate vehicle body coordinates to Earth coordinates.) The second technique simulates the inflight calculations by including effects of drift from the truncated Bortz algorithm, quantization, and random gyro drift. The comparison results in drift as a function of time for the three Euler angles, roll, pitch, and yaw. Examples of predicted drift over typical trajectories are presented.
 Publication:

Presented at the 12th Transducer Workshop
 Pub Date:
 1983
 Bibcode:
 1983tran.work.....B
 Keywords:

 Attitude Control;
 Drift Rate;
 Inertial Guidance;
 Lateral Control;
 Rocket Vehicles;
 Attitude Gyros;
 Hardware;
 Prototypes;
 Launch Vehicles and Space Vehicles