Accession Number : ADP003384

Title :   A Double Gimballed Momentum Wheel for Precision Three-Axis Attitude Control,


Personal Author(s) : Auer,W.

Report Date : JAN 1984

Pagination or Media Count : 8

Abstract : For precision three-axis attitude control of space vehicles, a Doubled Gimballed Momentum Wheel (DGMW) as attitude actuator is a favorable approach. A high reliability DGMW of modular design with two momentum wheels and two direct drive ultra high resolution stepper motors plus pick-offs per gimal axis (full redundancy; no caging during launch) was designed, built and qualification tested, together with an associated wheel and gimbal drive electronics. In addition, extensive system tests were performed on a three-axis air bearing table which proved the excellent control capabilities of this DGMW. Besides the measurement under stationary conditions with an accuracy of 18 sec of arc, also the transient behavior was studied. Due to the high torque capability (up to 0.2 Nm around the momentum wheel axis and up to 1 Nm around the gimbal axes) rapid and accurate pointing and repointing of spacecraft are possible. Therefore, the DGMW system can be designed into tracking loops and assure continuous pointing of spacecraft instruments with a rapid assignment capability. (Author)

Descriptors :   *Space systems, *Attitude control systems, *Gyro stabilizers, Satellite attitude, Spacecraft components, Gimbals, Momentum, Actuators, High reliability, Stabilization systems, Wheels, Degrees of freedom

Distribution Statement : APPROVED FOR PUBLIC RELEASE