Thesis (Ph.D.)--University of Central Florida, 2009. / Adviser: Chengying Xu. Includes bibliographical references (p. 118-126).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 114-118). Also available via the Internet.

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Prasad, JVR; Committee Member: Costello, Mark; Committee Member: Johnson, Eric; Committee Member: Schrage, Daniel; Committee Member: Vela, Patricio. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Mark Costello; Committee Member: Eric Johnson; Committee Member: Frank Fresconi; Committee Member: Olivier Bauchau; Committee Member: Peter Plostins. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004. / Cover title. Includes bibliographical references (p. 129-134). Also available online from the MIT website (http://www.mit.edu/).

Thesis (M.S.)--University of Iowa, 2007. / Supervisor: Thomas Schnell. Includes bibliographical references (leaf 115).

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The problem of optimal guidance design for the low altitude, subsonic, vertical plane approach maneuver of an air vehicle constrained to maintain view of a fixed final position is studied using a nonlinear, constrained, optimal control problem formulation. Multiple, competing optimization criteria are included separately as performance goals and in combination as state equality constraints for design tradeoff analysis. In conjunction with vehicle flight constraints, a sensor line-of -sight (LOS) angle limit is imposed as a control variable inequality constraint to provide a sensor field of regard influence on the guidance design. Numerical results are provided that illustrate the optimal guidance for different performance criteria, the sensor LOS profile along the optimal maneuvers, and the influence of the sensor limit on the guidance law design. A near-optimal, closed-loop feedback guidance law that incorporates the sensor constraint is developed based on neighboring extremals. / Ph. D.

A design method for a multi-loop mixed discrete/continuous trajectory following pitch control algorithm for a generic aerospace vehicle is presented. This design methodology is facilitated by a time scale separation observed in the dynamical system. Two variations of this algorithm are considered, with features and drawbacks of both evaluated. The algorithm is then tested by simulations with two vehicles flying arbitrary trajectories. Results are presented for a thrust-vector controlled high-performance missile without atmospheric effects, and for a single-stage-to-orbit hypersonic vehicle with both elevator and thrust-vector control. It is shown that the control algorithm results in a pitch loop feedback controller that is robust and very stable, and is at least near optimal for the class of trajectories considered. No claims of optimality are made for the outer loop, but it is shown in the simulations that the outer loop tracker can do a reasonable job of following the prescribed nominal trajectory. / Ph. D.

Optimal intercept trajectories for a boost-sustain-coast medium-range air-to-air missile are synthesized using optimal control theory. Optimality in time/range/energy at intercept of a target is the main objective. Attainable sets and their boundaries are obtained and used to generate optimal intercept points in a three-dimensional scenario. A three-phase closed-loop guidance scheme is used to generate an efficient guidance law against a maneuvering target. In the present study, target maneuvers are restricted to the horizontal plane. An initial boost-phase with near-optimal guidance in the presence of active control constraints and thrust switches is simulated. Target maneuvers are neglected during this phase. A new method of gain evaluation is detailed. A midcourse guidance scheme with neighboring guidance, transversal comparisons, and chasing center-of-attainability of target to augment performance is studied. Modifications in terminal guidance using proportional navigation, such as chasing the center-of-attainability of target, altitude shaping, and drag-resolution schemes are used to attempt better performance at intercept. A composite guidance strategy using a combination of neighboring guidance and proportional navigation for the midcourse guidance is introduced. The excellent performance of this guidance strategy and the improvement in storage requirements for on-board use make it a very special scheme. / Ph. D.