COMMENTS ON HAMILTONIAN ADAPTIVE-CONTROL OF SPACECRAFT

In the adaptive scheme presented by Slotine and Benedetto [1] for atti tude tracking control of rigid spacecraft, the spacecraft is parameter ized in terms of the inertial frame. This note shows how a parameteriz ation in body coordinates considerably simplifies the representation o f the adaptation scheme. The new symbolic expression for the regressor matrix is easy to find even for 6 degrees of freedom (DOF) Hamiltonia n systems with a large number of unknown parameters. If the symbolic e xpression for the regressor matrix is known in advance, the computatio nal complexity is approximately equal for both representations. In the scheme presented by Slotine and Benedetto [1] this is not trivial bec ause the transformation matrix between the inertial frame and the body coordinates is included in the expression for the regressor matrix. H ence, implementation for higher DOF systems is strongly complicated. A n example illustrates the advantage of the new representation when mod eling a simple 3 DOF model of the lateral motion of a space shuttle.