Closed-Loop Variable Stiffness Control of Dynamical Systems

In this paper, we present an approach to encode variable stiffness behaviors into Dynamical Systems (DS), controlled in a closed-loop configuration. Given a desired robot motion represented as a first order DS, as well as a desired stiffness profile, our approach generates a new DS, called Variable Stiffness DS (VSDS), that controls the robot motion and impedance simultaneously. The robot shows a symmetric spring-like attraction behavior around a reference path described by one of the integral curves of the DS with an interactive behavior prescribed by the desired stiffness. Our approach is validated in simulations and in real robot experiments, displaying a safe and compliant interaction in the face of disturbances or possible collisions. Furthermore, we validate our approach in a contact task that requires continuously varying stiffness levels.     «

In this paper, we present an approach to encode variable stiffness behaviors into Dynamical Systems (DS), controlled in a closed-loop configuration. Given a desired robot motion represented as a first order DS, as well as a desired stiffness profile, our approach generates a new DS, called Variable Stiffness DS (VSDS), that controls the robot motion and impedance simultaneously. The robot shows a symmetric spring-like attraction behavior around a reference path described by one of the integral c...     »