Analysis and implementation of observers for robotic manipulators

Different solutions to the robot control problem by using only position measurements have been studied in literature. The performances of some linear and nonlinear observers previously proposed are discussed in this paper, on the basis of the experimental results obtained in the control of a SCARA two-link manipulator with two revolute joints. The comparison is carried out by using the observed velocities to implement a linear state feedback algorithm for the robot control. The obtained results show that different factors (e.g. the required task, the available knowledge of the robot dynamic model) may influence the choice of a particular observer