Neural network for positioning Space Station solar arrays
Abstract
As a shuttle approaches the Space Station Freedom for a rendezvous, the shuttle's reaction control jet firings pose a risk of excessive plume impingement loads on Freedom solar arrays. The current solution to this problem, in which the arrays are locked in a feathered position prior to the approach, may be neither accurate nor robust, and is also expensive. An alternative solution is proposed here: the active control of Freedom's beta gimbals during the approach, positioning the arrays dynamically in such a way that they remain feathered relative to the shuttle jet most likely to cause an impingement load. An artificial neural network is proposed as a means of determining the gimbal angles that would drive plume angle of attack to zero. Such a network would be both accurate and robust, and could be less expensive to implement than the current solution. A network was trained via backpropagation, and results, which compare favorably to the current solution as well as to some other alternatives, are presented. Other training options are currently being evaluated.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- June 1994
- Bibcode:
- 1994STIN...9436943G
- Keywords:
-
- Active Control;
- Earth Orbital Rendezvous;
- Jet Impingement;
- Neural Nets;
- Pointing Control Systems;
- Solar Arrays;
- Space Station Power Supplies;
- Spacecraft Control;
- Angle Of Attack;
- Gimbals;
- Positioning;
- Space Station Freedom;
- Engineering (General)