Generalized Proportional Integral observer–based force control in robot manipulators

Abstract

In this work the design of a linear observer–linear controller robust output feedback scheme is introduced for simultaneous trajectory tracking of position and force in fully actuated robot manipulators. The unknown state–dependent additive nonlinearity influencing the input–output description is modeled as an absolutely bounded “time–varying perturbation”. Generalized Proportional Integral (GPI) observers are shown to naturally estimate the unknown perturbation and a certain number of its time derivatives in an arbitrarily close manner. This information is used to advantage on the linear feedback controller design via a simple cancelation effort. To the best of the authors’ knowledge GPI observers have not been used before for robot force control. A comparison experimental analysis is presented to show the good performance of the proposed approach.

Keywords

• Control de fuerza
• Control de posición
• manipuladores robóticos
• observadores de estados
• control robusto