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An aircraft formation autopilot is designed for flight test to demonstrate autonomous aerial refueling. The controller requirements are stated, and models for the lead and wing aircraft are outlined and stabilized. Control laws are developed for the model, and four frames of reference are investigated for optimal control. Next, a simulation is constructed with modeled disturbances to produce the real-time...
The minimal controller synthesis (MCS) is an extension of hyperstable model reference adaptive control (MRAC) algorithm. The aim of MCS is to achieve excellent closed-loop control despite the presence of plant parameter variations, external disturbances, dynamic coupling within the plant and plant nonlinearities. A modification on the MCS algorithm is proposed in this paper to highly enhance the robustness...
The ability to coordinate sets of rovers in an unknown environment is critical to the long-term success of many of NASA's exploration missions. Such coordination policies must have the ability to adapt in unmodeled or partially modeled domains and must be robust against environmental noise and rover failures. In addition such coordination policies must accommodate a large number of rovers, without...
The design of robust tracking control for a nonlinear MIMO system having modeling uncertainty and unknown disturbance is one of the most complicated control problems. In this paper two new algorithms for tracking control are presented which guarantee the satellite attitude during small maneuvers having desired attitude angle. The amplitude of the control signal and consumed energy is less than the...
Control of a class of uncertain nonlinear systems which estimates unavailable state variables is considered. A new approach for robust tracking control problem of satellite for large rotational maneuvers is presented in this paper. The features of this approach include - a strong algorithm to estimate attitude, based on discrete extended Kalman filter combined with a continuous extended Kalman filter...
Space exploration applications can benefit greatly from autonomous systems. Great distances, limited communications and high costs make direct operations impossible while mandating operations reliability and efficiency beyond what traditional commanding can provide. Autonomous systems can improve reliability and enhance spacecraft capability significantly. However, there is reluctance to utilizing...
The application of a stochastic optimizer to the problem of the control of a highly flexible space structure, and its robustness, is examined. The optimized fuzzy logic controller is used to perform a certain maneuver. A model of the flexible space structure was developed in a rigid multi-body dynamics software package called Odessa, and this model was used as a basis for deriving a number of other...
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