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Linear And Nonlinear Adaptive Attitude Control Of Asteroid-Orbiting Spacecraft Using State Feedback And Output Feedback, Nicholas Moya
Linear And Nonlinear Adaptive Attitude Control Of Asteroid-Orbiting Spacecraft Using State Feedback And Output Feedback, Nicholas Moya
UNLV Theses, Dissertations, Professional Papers, and Capstones
This thesis presents the derivation of both a linear and nonlinear adaptive control law for the attitude states of a spacecraft in orbit around rotating asteroids. The asteroid is assumed to be irregularly shaped and in an elliptical orbit around the sun. The linearized, time-varying spacecraft model will assume to include unknown parameters and will have external disturbances present. The objective is to control the roll, pitch, and yaw angle trajectories of the spacecraft such that they track desired reference trajectories. To achieve this, the control law will be composed of (1) a feedback controller, sufficiently robust to disturbance such …
Closed Loop Control Of A Cylindrical Tube Type Ionic Polymer Metal Composite (Ipmc), Benjamin Mead
Closed Loop Control Of A Cylindrical Tube Type Ionic Polymer Metal Composite (Ipmc), Benjamin Mead
UNLV Theses, Dissertations, Professional Papers, and Capstones
The goal of this research is to provide a framework for the integration of tube type, cylindrical Ionic Polymer Metal-Composite (IPMC) into conventional devices. IPMCs are one of the most widely used types of electro-active polymer actuator, due to their low electric driving potential and large deformation range. For this research a tube type IPMC was investigated. This IPMC has a circular cross section with four separate electrodes on its surface and a hole through the middle. The four electrodes allow for biaxial bending and accurate control of the tip location. One of the main advantages of using this type …