Point-to-point control of elastic joint robots-dynamic output feedback passification approach

Motivated by the dynamic output feedback passification results, a point-to-point control law for an elastic joint robot is presented when only the position measurements are available. This provides an alternative way of replacing the role of the velocity measurements for the proportional-derivative (PD) feedback law. The proposed methodology makes a parallel connection of the robot system and an input-dimensional linear system which obtains the effect of the desired differentiators. It is shown that the closed-loop nonlinear robot system satisfies the sufficient conditions for passification and the regulation as well as the passivity of the system is achieved in the end. The performance of the proposed control law is illustrated in the simulation studies of a manipulator with three revolute elastic joints.