Control of a planar arm by nonlinear feedback gains

Abstract

Abstract The control of a three‐link planar robot, whose parameters roughly match a small commercially available arm, is considered. The end effector of the arm moves along a specified trajectory on a surface with dry friction while maintaining a prespecified constant pressure against the surface both with and without force sensors at the tip. A control strategy is presented with nonlinear position and velocity error feedback gains which are state dependent. Digital computer simulations of the motion are provided for comparison purposes and for demonstrating the effectiveness of this strategy.