Exploring the Just Noticeable Interaction Stiffness Differences of an Impedance-Controlled Series Elastic Actuator

Velasco Guillen RJ, Schofer F, Bliek A, Beckerle P (2023)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2023

Journal

Actuators MDPI

Book Volume: 12

Journal Issue: 10

URI: https://www.mdpi.com/2076-0825/12/10/378

DOI: 10.3390/act12100378

Open Access Link: https://www.mdpi.com/2076-0825/12/10/378

Abstract

The integration of a passive elastic element in series between a motor and its load is popular in many human–robot interaction scenarios. By virtually imposing elastic behavior on the motor, an impedance control can act as a second stiffness to such an actuator. In this study, we investigated how participants perceived the different stiffness settings in a series elastic actuator by measuring the Just Noticeable Difference (JND) of the real stiffness of the elastic element and the virtual stiffness introduced by impedance control. We conducted a user study during which participants interacted with an impedance-controlled Series Elastic Actuator through a lever. During the user study, we varied the real stiffness of the elastic element and the virtual stiffness. We found that participants seem to perceive both the virtual stiffness and the real stiffness in the same way and in accordance to Weber’s law, which states that the stiffness JND is always equal to a fraction of the initial stiffness. Following these findings, we concluded that the impedance controller can implement an effective virtual stiffness with a behavior comparable to a real torsional spring. Therefore, a system combining real and virtual stiffness can simulate a single combined stiffness for a user interacting with it.

Authors with CRIS profile

Rodrigo Jose Velasco Guillen Lehrstuhl für Autonome Systeme und Mechatronik Adna Bliek Lehrstuhl für Autonome Systeme und Mechatronik Philipp Beckerle Lehrstuhl für Autonome Systeme und Mechatronik

Involved external institutions

Karlsruhe Institute of Technology (KIT) DE Germany (DE)

How to cite

APA:

Velasco Guillen, R.J., Schofer, F., Bliek, A., & Beckerle, P. (2023). Exploring the Just Noticeable Interaction Stiffness Differences of an Impedance-Controlled Series Elastic Actuator. Actuators, 12(10). https://dx.doi.org/10.3390/act12100378

MLA:

Velasco Guillen, Rodrigo Jose, et al. "Exploring the Just Noticeable Interaction Stiffness Differences of an Impedance-Controlled Series Elastic Actuator." Actuators 12.10 (2023).

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