A gimbaled low noise momentum wheel
Abstract
The bus actuators are the heart and at the same time the Achilles' heel of accurate spacecraft stabilization systems, because both their performance and their perturbations can have a deciding influence on the achievable pointing accuracy of the mission. The main task of the attitude actuators, which are mostly wheels, is the generation of useful torques with sufficiently high bandwidth, resolution and accuracy. This is because the bandwidth of the whole attitude control loop and its disturbance rejection capability is dependent upon these factors. These useful torques shall be provided, without - as far as possible - parasitic noise like unbalance forces and torques and harmonics. This is because such variable frequency perturbations excite structural resonances which in turn disturb the operation of sensors and scientific instruments. High accuracy spacecraft will further require bus actuators for the three linear degrees of freedom (DOF) to damp structural oscillations excited by various sources. These actuators have to cover the dynamic range of these disturbances. Another interesting feature, which is not necessarily related to low noise performance, is a gimballing capability which enables, in a certain angular range, a three axis attitude control with only one wheel. The herein presented Teldix MWX, a five degree of freedom Magnetic Bearing Momentum Wheel, incorporates all the above required features. It is ideally suited to support, as a gyroscopic actuator in the attitude control system, all High Pointing Accuracy and Vibration Sensitive space missions.
- Publication:
-
27th Aerospace Mechanisms Symposium
- Pub Date:
- May 1993
- Bibcode:
- 1993aems.nasa..181B
- Keywords:
-
- Actuators;
- Angular Momentum;
- Attitude Control;
- Low Noise;
- Magnetic Bearings;
- Reaction Wheels;
- Spacecraft Stability;
- Attitude Stability;
- Oscillations;
- Resonance;
- Resonant Frequencies;
- Structural Vibration;
- Spacecraft Instrumentation