Fred J Robbins

US Patent:

58094571, Sep 15, 1998

Filed:

Mar 8, 1996

Appl. No.:

8/614784

Inventors:

Robert Yee - Mountain View CA
Fred Robbins - Santa Clara CA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

G05B 1918
H01Q 300

US Classification:

701220

Abstract:

An inertial pointing and control system and method for pointing to a designated target with known coordinates from a platform, to provide accurate position, steering, and command information. The system continuously receives GPS signals and corrects Inertial Navigation System (INS) dead reckoning or drift errors. An INS is mounted directly on a pointing instrument rather than in a remote location on the platform for monitoring the terrestrial position and instrument attitude, and for pointing the instrument at designated celestial targets or ground based landmarks. As a result, the pointing instrument and the INS move independently in inertial space from the platform since the INS is decoupled from the platform. Another important characteristic of the present system is that selected INS measurements are combined with predefined coordinate transformation equations and control logic algorithms under computer control in order to generate inertial pointing commands to the pointing instrument. More specifically, the computer calculates the desired instrument angles (Phi, Theta, Psi), which are then compared to the Euler angles measured by the instrument-mounted INS, and forms the pointing command error angles as a result of the compared difference.