The stability investigation of variable viscosity control in the human‐robot interaction. Issue 5 (30th May 2022)

• Record Type: Journal Article
• Authors: Dong, Lin; Perrin, Nicolas; Richer, Florian; Roby‐Brami, Agnes; Morel, Guillaume
• Is Part Of: International journal of medical robotics and computer assisted surgery. Volume 18:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-30
• Subjects: co‐manipulation -- HRI -- human‐robot interaction -- impedance control -- stability -- viscosity control; Robotics in medicine -- Periodicals; Surgery -- Technological innovations -- Periodicals; Imaging systems in medicine -- Periodicals; 617.90285
• DOI: 10.1002/rcs.2416
• Languages: English
• ISSNs: 1478-5951

Abstract

Abstract: Background: For many co‐manipulative applications, variable damping is a valuable feature provided by robots. One approach is implementing a high viscosity at low velocities and a low viscosity at high velocities. This, however, is proven to have the possibility to alter human natural motion performance. Methods: We show that the distortion is caused by the viscosity drop resulting in robot's resistance to motion. To address this, a method for stably achieving the desired behaviour is presented. It involves leveraging a first‐order linear filter to slow the viscosity variation down. Results: The proposition is supported by a theoretical analysis using a robotic model. Meanwhile, the user performance in human‐robot experiments gets significantly improved, showing the practical efficiency in real applications. Conclusions: This paper discusses the variable viscosity control in the context of co‐manipulation. An instability problem and its solution were theoretically shown and experimentally evidenced through human‐robot experiments.