Impedance Space Method: Time-Independent Parametric Ellipses for Robot Compliant Control

Authors

Keywords:

Impedance control, Force control, Human-robot interaction

Abstract

This paper proposes a novel 3D graphical representation for impedance control, called the impedance space, to foster the analysis of the dynamic behavior of robotic compliant controllers. The method overcomes limitations of existing 2D graphical approaches by incorporating mass, stiffness, and damping dynamics, and associates the impedance control parameters with linear transformations to plot a parametric 3D ellipse and its projections in 2D for a mass-spring-damper impedance under sinusoidal reference. Experimental evaluation demonstrates the effectiveness of the proposed representation for analysis of impedance control. The method applies to various compliant control topologies and can be extended to other model-based control approaches.

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Author Biographies

Leonardo F. Dos Santos, Sao Carlos School of Engineering, University of Sao Paulo

Leonardo F. dos Santos holds a degree in Mechatronics Engineering from the Sao Carlos School of Engineering at the University of Sao Paulo (2021). His interests lie in robotics, systems modeling and control, both in academia and industry. Leonardo is currently a member of the Legged Robotics Group and is pursuing is PhD within the FAPESP Young Researcher Project entitled "Impedance control of hydraulic actuators for robots with legs and arms". He is also a member of SENAI CIMATEC's robotics division, where he contributes to initiatives focusing on robotic manipulation for underwater inspection, maintenance, and repair.

Cícero Zanette, Sao Carlos School of Engineering, University of Sao Paulo

Cícero Zanette received his B.Sc degree in Mechanical Engineering from the Federal University of Sao Carlos, Brazil, in 2021. During his undergraduate studies, he worked with computational simulations in the area of induced cracks in high-hardness ceramics during laser-assisted machining processes utilizing FEM. He received his M.Sc degree in Dynamics and Mechatronics from the Sao Carlos School of Engineering of the University of Sao Paulo, Brazil, where he worked with the Legged Robotics Group in the development of metrics for comparison of hybrid impedance and admittance controllers. He is currently pursuing his D.Sc. degree in the same research group.

Elisa G. Vergamini, Sao Carlos School of Engineering, University of Sao Paulo

Elisa G. Vergamini graduated in Mechanical Engineering from the Federal University of Sao Carlos, Brazil, in 2020. In 2018, Elisa studied for a year at the Ecole Nationale Superieure de Techniques Avancees, in the undergraduate course in Mechanical Engineering with an emphasis on Intelligent Systems. In 2022, she carried out a research internship abroad for six months (BEPE - FAPESP) at the Altair Robotics Lab at the University of Verona. In 2024, Elisa completed her master's degree at the Robotics Laboratory of the Department of Mechanical Engineering of the Sao Carlos School of Engineering of the University of Sao Paulo, at the Legged Robots Group. She is currently pursuing her PhD in the same Research Group.

Lucca Maitan, Sao Carlos School of Engineering, University of Sao Paulo

Lucca Maitan holds a degree in Mechatronics Engineering from the University of Sao Paulo (2021). He has experience in the areas of Robotics, Mechatronics, Automation, and software development. During his undergraduate studies, he worked on scientific initiation projects and his final thesis at the Robotic Rehabilitation Laboratory of the Department of Mechanical Engineering at EESC - USP, focusing on exoskeleton control. Since the second semester of 2023, he has been pursuing a Master's degree in the legged robots laboratory at EESC - USP, specializing in control of electric and hydraulic actuators and impedance control for robotic legs.

Thiago Boaventura, Sao Carlos School of Engineering, University of Sao Paulo

Thiago Boaventura received his B.Sc. and M.Sc. degrees in Mechatronics Engineering from the Federal University of Santa Catarina, Brazil, in 2009. He received his Ph.D. degree in Robotics from a partnership between the Italian Institute of Technology and the University of Genoa in Italy in 2013. Then, he joined as a post-doctoral researcher at the Agile Dexterous Robotics Lab at ETH Zurich in Switzerland. There, he was mainly involved in the EU FP7 BALANCE project with a focus on the collaborative impedance control of exoskeleton robots. Thiago is an Assistant Professor at the Sao Carlos School of Engineering of the University of Sao Paulo. He is the founder and director of the Legged Robotics Group, a branch of the Robotics Laboratory. He has a strong background in model-based force and impedance control, as well as in hydraulic actuation.

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Published

2025-10-01

How to Cite

Dos Santos, L. F., Zanette, C., Vergamini, E. G., Maitan, L., & Boaventura, T. (2025). Impedance Space Method: Time-Independent Parametric Ellipses for Robot Compliant Control. IEEE Latin America Transactions, 23(11), 1081–1089. Retrieved from https://latamt.ieeer9.org/index.php/transactions/article/view/9874

Issue

Vol. 23 No. 11 (2025): Ordinary Issue

Section

Electronics