ARTORG Center for Biomedical Engineering Research

Enforcing Virtual Dynamics with ARMin Exoskeleton Robot

Project Members:  Özhan Özen, Laura Marchal-Crespo
Project Start: 2018

Disturbance observers (DOBs) in robotic systems allow to control the acceleration, which simplifies and unifies the design of motion controllers. Usage of force sensor data as an input for the DOBs further simplifies the work: making it possible to directly enforce any motion dynamics for the robot (within practical limits), including transparent interactions, without the need for precise modelling of unwanted dynamics of the robot. The usage of DOBs is advantageous to many other popular control structures, since it allows that heavily-constructed robots might have a much lighter “effective dynamics” if desired.

Within this project, we focus on the implementation and usage of DOBs on the ARMin exoskeleton robot for enforcing virtual dynamics. ARMin is a 7 degree-of-freedom (DoF) robotic device for upper limb rehabilitation designed at ETH Zurich (Nef et al. 2009). The robot incorporates position and force/torque sensors to measure the interaction between human and robot.

The validity of the idea of enforcing virtual dynamics and its technical performance evaluation will be performed with the project.

Keywords: Robotics, haptics, motion control, disturbance observers

Publications: 

Nef, Tobias; Guidali, Marco; Riener, Robert (2009). ARMin III – arm therapy exoskeleton with an ergonomic shoulder actuation. Applied Bionics and Biomechanics, 6(2), pp. 127-142. I O S Press10.1080/11762320902840179