Robust hybrid control of robot manipulators

The problem of hybrid (position and force) control of robot manipulators is studied as a control of a dynamical system whose mathematical model contains uncertainties. It is shown that robust control which renders the system globally practically stable can be designed. A simplification of the robust control can be made provided the uncertainty is cone-bounded. This occurs when the modeling error in the Coriolis and centrifugal forces is negligible. Further elaboration on the quadratically bounded uncertainty (which occurs as substantial modeling error in Coriolis and centrifugal forces arises) is investigated. The simplified robust control is shown to be applicable provided the control design parameters are chosen in a prescribed way. A control for a two-joint SCARA type robot is provided as an illustrative example. Excellent system performance is observed