Some remarks on two quasi-velocities approaches in PD joint space control

This paper presents some remarks on PD control in joint space for serial manipulators whose dynamics is expressed in terms of two different kind of quasi-velocities. Robot dynamics algorithms in terms of so called normalized quasi- velocities are recursive in nature and consists of two recursions: one starts from a base of the manipulator towards its tip and the second in opposite direction. Both recursions are described by making use of vector-matrix notation. In the second work authors introduce an instantaneous eigenstructure quasi-velocity formulation as a result of numerical mass matrix factorization. Both PD controls were tested on a model of manipulator with two degrees of freedom. In this paper we adopt standard PD control known in robotic literature to a case when robot dynamics is formulated in terms of quasi-velocities.