The design of robust phase oscillator for wearable robotic systems

Juan de la Fuente, Susheelkumar C. Subramanian, Prudhvi Tej Chinimilli, Sangram Redkar, Thomas Sugar

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents the design of a phase-based robust oscillator for wearable robots that assists the human performing periodic or repetitive tasks. The robustness of the phase oscillator controller is evaluated by finding bounds for perturbations that guaranteed the stability of the output. Then, the Lyapunov redesign method is applied to construct a robust controller using a bounding function which can handle the uncertainties such as noise and perturbations in the overall human-robot system. The robust controller produces a bounded control signal to modify the amplitude and frequency of the resulting second-order oscillator to modulate the stiffness and damping properties. In this paper, the focus is put on the wearable robot that assists human hip joint while performing periodic activities such as walking. The proposed approach is verified through a simple pendulum experiment. The results show that a better limit cycle can be obtained with Lyapunov redesigned phase oscillator which controls the radial spread of the steady state. Finally, the potential of the proposed approach for hip assistance in a healthy subject wearing HeSa (Hip Exoskeleton for Superior Assistance) during periodic activities are discussed.

Original languageEnglish (US)
Title of host publication43rd Mechanisms and Robotics Conference
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791859230
DOIs
StatePublished - Jan 1 2019
EventASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC-CIE 2019 - Anaheim, United States
Duration: Aug 18 2019Aug 21 2019

Publication series

NameProceedings of the ASME Design Engineering Technical Conference
Volume5A-2019

Conference

ConferenceASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC-CIE 2019
CountryUnited States
CityAnaheim
Period8/18/198/21/19

Keywords

  • Periodic activity
  • Phase oscillator
  • Wearable robot

ASJC Scopus subject areas

  • Mechanical Engineering
  • Computer Graphics and Computer-Aided Design
  • Computer Science Applications
  • Modeling and Simulation

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  • Cite this

    de la Fuente, J., Subramanian, S. C., Chinimilli, P. T., Redkar, S., & Sugar, T. (2019). The design of robust phase oscillator for wearable robotic systems. In 43rd Mechanisms and Robotics Conference (Proceedings of the ASME Design Engineering Technical Conference; Vol. 5A-2019). American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/DETC2019-97453