Closed Loop Static Control of Multi-Magnet Soft Continuum Robots

• Published in: IEEE robotics and automation letters 2023-07, Vol.8 (7), p.1-8
• Main Authors: Pittiglio, Giovanni, Orekhov, Andrew L., Veiga, Tomas da, Calo, Simone, Chandler, James H., Simaan, Nabil, Valdastri, Pietro
• Format: Article
• Language: English
• Subjects: Actuation; and Learning for Soft Robots; Bragg gratings; Closed loops; Computational modeling; Control; Controllers; Errors; Formal Methods in Robotics and Automation; Kinematics; Magnetic Actuation; Medical Robots and Systems; Modeling; Permanent magnets; Proportional integral derivative; Robot sensing systems; Robots; Sensors; Shape; Shape control; Three-dimensional displays; Tracking control
• ISSN: 2377-3766; 2377-3766
• DOI: 10.1109/LRA.2023.3274431

This paper discusses a novel static control approach applied to magnetic soft continuum robots (MSCRs). Our aim is to demonstrate the control of a multi-magnet soft continuum robot (SCR) in 3D. The proposed controller, based on a simplified yet accurate model of the robot, has a high update rate and is capable of real-time shape control. For the actuation of the MSCR, we employ the dual external permanent magnet (dEPM) platform and we sense the shape via fiber Bragg grating (FBG). The employed actuation system and sensing technique makes the proposed approach directly applicable to the medical context. We demonstrate that the proposed controller, running at approximately 300 Hz, is capable of shape tracking with a mean error of 8.5% and maximum error of 35.2% . We experimentally show that the static controller is 25.9% more accurate than a standard PID controller in shape tracking and is able to reduce the maximum error by 59.2%.