Design of a flight control architecture using a non-convex bundle method

We design a feedback control architecture for longitudinal flight of an aircraft. The multi-level architecture includes the flight control loop to govern the short term dynamics of the aircraft, and the autopilot to control the long term modes. Using H1 performance and robustness criteria, the problem is cast as a non-convex and non-smooth optimization program. We present a non-convex bundle method, prove its convergence, and show that it is apt to solve the longitudinal flight control problem

Minimizing transients via the Kreiss system norm

We consider norms which assess transient behavior of stable LTI systems. Minimizing such a norm in closed loop may enhance stability and performance of a nonlinear system by mitigating transients and enlarging its region of attraction around a locally stable steady state.Comment: 31 pages, 11 figure

Antenna Analysis and Design Using Stored Energies and Physical Limitations

A method to estimate Q and QZ' of antennas from single-frequency current distributions is described. This single-frequency method and the concepts of physical bounds on antenna parameters and optimum current distributions are applied to different analysis and design situations of two-dimensional and three-dimensional radiating structures (i.e., antennas). The situations considered are: antenna optimization using a genetic algorithm and the single-frequency Q computation for single or multi-band operation, antenna placement optimization in a wireless device using physical bounds, and antenna optimization that includes QZ' in the objective function. Antenna performance is compared with physical bounds or optimum-current performance in the situations studied. The results presented in this thesis suggest that single-frequency methods may reduce the time necessary to optimize automatically, e.g., using a computer, some antenna parameters such as bandwidth. Furthermore, physical bounds and optimum current distributions are tools that provide valuable information for the processes of antenna analysis and design