Fractal impedance for passive controllers: a framework for interaction robotics

Babarahmati, Keyhan Kouhkiloui, Tiseo, Carlo, Smith, Joshua, Lin, Hsiu Chin, Erden, Mustafa Suphi and Mistry, Michael (2022) Fractal impedance for passive controllers: a framework for interaction robotics. Nonlinear Dynamics. pp. 1-17. ISSN 0924-090X

[img] PDF - Accepted Version
Restricted to SRO admin only

Download (3MB)
[img] PDF - Published Version
Available under License Creative Commons Attribution.

Download (1MB)


There is increasing interest in control frameworks capable of moving robots from industrial cages to unstructured environments and coexisting with humans. Despite significant improvement in some specific applications (e.g., medical robotics), there is still the need for a general control framework that improves interaction robustness and motion dynamics. Passive controllers show promising results in this direction; however, they often rely on virtual energy tanks that can guarantee passivity as long as they do not run out of energy. In this paper, a Fractal Attractor is proposed to implement a variable impedance controller that can retain passivity without relying on energy tanks. The controller generates a Fractal Attractor around the desired state using an asymptotic stable potential field, making the controller robust to discretization and numerical integration errors. The results prove that it can accurately track both trajectories and end-effector forces during interaction. Therefore, these properties make the controller ideal for applications requiring robust dynamic interaction at the end-effector.

Item Type: Article
Schools and Departments: School of Engineering and Informatics > Informatics
SWORD Depositor: Mx Elements Account
Depositing User: Mx Elements Account
Date Deposited: 28 Jul 2022 13:01
Last Modified: 22 Sep 2022 14:16

View download statistics for this item

📧 Request an update