93-142

High Thrust Rendezvous Via Feedback Linearization

S. Lee* and John E. Cochran, Jr**

Abstract

This paper deals with the development of two methods for obtaining optimal rendezvous trajectories of space vehicles. Geocentric, coplanar, orbital maneuvers with continuous finite thrust acceleration are studied. The elegance of Lambert's theorem and linearization using equinoctial variables are combined with feedback linearization and linear optimal control in the methods. The full nonlinear equations of motion are transformed exactly into 8 controllable linear set by using feedback linearization. First, these equations are used to pose a linear optimal tracking problem with a solution to Lambert's impulsive-thrust two-point boundary value problem as the reference orbit. Second, a similar procedure is used to force the system to follow an analytical solution to a linearized form of the continuous thrust problem. Limits on thrust magnitudes are enforced by adjusting the weights on the states in the performance indices.
*Graduate Student, Department of Aerospace Engineering, Auburn University, 211 Aerospace Engineering Building, Auburn University, Alabama 30849-5338. Student Member AIAA.

**Professor, Department of Aerospace Engineering, Auburn University, 211 Aerospace Engineering Building, Auburn University, Alabama 36849-5338. Fellow AAS; Associate Fellow AIAA.