Active stabilization of a flexible antenna feed tower

Active stabilization logic is synthesized to hold a feed at the focus of a spacecraft antenna dish. The feed support structure is modeled as a tetrahedron made up of flexible bars and connected to the dish by six short legs containing force actuators. Using the symmetry of the structure, the model can be decomposed into four uncoupled subsystems: pitch/forward motions with four degrees of freedom (DOF) and two controls; roll/lateral motions with four DOF and two controls; vertical motions with three DOF and one control; and yaw motion with one DOF and one control. This greatly simplifies the synthesis of control logic.