Tracking control of manipulators with active inertias by using sliding Lagrangian

A method to increase the versatility of manipulators is of using links with active inertias, and the paper examines how one can design the tracking control of such mechanical systems. Basically, two approaches are suggested. In the first one, the theory of variable structure is applied, after suitable appropriate alterations. In the second one, the author uses a sliding equation for the error which is exactly the dynamical equation of the system close to its equilibrium position but subject to external Raleigh forces. While the first design via Liapunov function provides robust control, robustness can be achieved in the second method by a combination with variable structure.