Proposed Steering Law Research Articles

A New Steering Law of a Single-Gimbal CMG System of Pyramid Configuration

A steering law is proposed for a pyramid type configuration single gimbal Control Moment Gyro system for attitude control of spacecrafts. Pyramid type CMG systems have the serious problem of complicated singular states. For the steering law, a function (gain) is introduced to the system. Gistribution of the gain, escapability from singular states, and symmetric characteristics of the system are discussed. The proposed steering law maximizes the gain of the system and avoids singular states by referring to the table which is obtained by off-line calculation and reduced to reasonably small size by using symmetric characteristics of the system.

Fixed-trim re-entry guidance analysis

The terminal guidance problem for a fixed-trim re-entry body is formulated with the objective of synthesizing a closed-loop steering law. A transformation of variables and subsequent linearization of the motion, with the sight-line to the target as a reference, reduces the order of the state system for the guidance problem. The reduced order system, although nonlinear and time-varying, is simple enough to lend itself to synthesis of a class of guidance laws. A generalization of the feedforward device of classical control theory is successfully employed for compensation of roll autopilot lags. The proposed steering law exhibits superior miss-distance performance in a computational comparison with existing fixed-trim guidance laws.

Steering law for roof type configuration control moment gyro system

A steering law is proposed for a roof type configuration Single Gimbal Control Moment Gyro (SGCMG) system for attitude control of the Large Space Telescope, a payload of the Space Shuttle. Although various steering laws have been developed for SGCMG systems, they have some drawbacks because of singular states of the system. The proposed steering law minimizes the effect of singular states by using a new momentum distribution scheme that makes all the singular states unstable. This scheme is formulated by treating the system as a sampled-data system.

A Steering Law for a Roof Type Configuration of Single Gimbal Control Moment Gyro System

A steering law is proposed for a roof type configuration Single Gimbal Control Moment Gyro (SGCMG) system for attitude control of the Large Space Telescope (a payload of the Space Shuttle). Although various steering laws have been developed for SGCMG systems, they have some drawbacks because of singular states of the system. The proposed steering law minimizes the effect of singular states by using a new momentum distribution scheme that makes all the singular states unstable. This scheme is formulated by treating the system as a sampled-data system.