|M.Sc Student||Dov Ofir|
|Subject||Optimal Trajectories and Optimal Guidance for Maneuvering|
|Department||Department of Aerospace Engineering||Supervisors||Professor Yoseph Ben-Asher|
|Dr. Isaac Yaesh|
|Full Thesis text - in Hebrew|
A closed-loop guidance system for extending rocket range or auto-correcting rocket trajectory is presented. In this research we propose using Pseudo Spectral methods for finding open-loop guidance and trajectories, and designing closed-loop guidance by using the Neighboring Extremals (NE) method. This method finds the optimal neighboring solutions by linearizing the governing (state and co-state) equations. For large deviations from the nominal trajectory this linearization is not sufficiently accurate. A novel approach is proposed whereby a Fuzzy Logic method is employed. The combination of the Fuzzy logic with NE is termed "Fuzzy Neighboring Externals". Fusing neighboring-extremals and fuzzy control concepts in order to deal with large uncertainties and external disturbances develops a new sub-optimal rocket guidance methodology. The methodology is shown to produce near-optimal implementable closed-loop guidance for maneuvering rockets. Simulations of a case study demonstrate performance under large uncertainties.