טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentLejzerowicz Meir Zvi Yerem
SubjectGuidance for Rendezvous and Docking with Tumbling Space
Targets
DepartmentDepartment of Aerospace Engineering
Supervisor Professor Pinchas Gurfil


Abstract

This research focuses on a case of Distributed Space Systems technology: space- craft rendezvous missions. More specifically, the case of a two-phase maneuver is examined for rigid bodies instead of point-masses. Traditional linear Clohessy-Wiltshire models become invalid when the spacecraft shapes are considered.

The studied mission is considered non-cooperative in the sense that the target space- craft does not maneuver to facilitate the rendezvous with the chaser spacecraft. The target spacecraft has nevertheless constant non-zero linear and angular velocities.

The first part of this research considers a new guidance law based on the well-known Proportional Navigation (PN) guidance law, modified for the purpose of the studied mission. The required commanded accelerations are presented in the line-of-sight (LOS) reference frame (transverse and longitudinal components). Equations of motion for the relative motion between the target and the chaser are derived.

The second part of this thesis discusses the estimation of the line-of-sight rate and its higher derivatives in the case of imperfect information due to measurement imprecision. Different filters - Kalman-Bucy Filter, Extended Kalman Filter - are implemented, and results of the comparison are presented.

The main contribution of the thesis is the successful implementation of filtering methods on a spacecraft rendezvous guidance problem for rigid bodies and improvement of guidance performance in a scenario featuring measurement errors.