Comparison Between Some Nonlinear Controllers for the Position Control of Lagrangian-type Robotic Systems

Abstract

This work addresses the set-point control problem of the position of fully-actuated Lagrangian-type robotic systems by means of some nonlinear control laws. We adopt four different nonlinear control laws: the PD plus gravity compensation controller, the PD plus desired gravity compensation controller, the computed-torque controller and the augmented PD plus gravity compensation controller. An in-depth comparison between these control laws and their application is achieved. Indeed, using some properties, we design some conditions on the feedback gains of the nonlinear controllers ensuring the stability in the closed loop of the zero-equilibrium point and its uniqueness. At the end of this work, we adopt a planar two-degree-of-freedom manipulator robot to illustrate via simulation the difference between and the efficiency of the adopted nonlinear controllers.