Attitude Guidance for Spinning Vehicles with Independent Pitch and Yaw Control

Abstract

The design and simulation of an attitude guidance and control scheme for a spinning aerospace vehicle is detailed. The basis for the guidance law is the projection of the angular-velocity vector onto a plane normal to the desired heading. The result of the projection is an attitude error that can be converted to pitch-and yaw-rate commands for an autopilot. Two single-input/single-output controllers are used in this paper, which in turn issue flap defiection commands. An asymmetrical vehicle spinning at 1.5 Hz with independent pitch-and yaw-flap sets is simulated in a six-degree-of-freedom simulation. It is shown to perform successful attitude maneuvers for two different cases. In one case, the basic guidance law is used. This results in a settling time of approximately 1.0 s. The next case performs the maneuver with a modified guidance law that includes decoupling terms. This case results in a settling time of 0.6 s. The guidance law has a number of possible applications. These include stability augmentation and redundancy, alternatives in fin Configurations for vehicles, and reduction in number of necessary control surfaces. Copyright © 2009.