Compensation of time delay in a network-based gait rehabilitation system with a discrete-time communication disturbance observer

Wenlong Zhang, Masayoshi Tomizuka

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

5 Scopus citations

Abstract

In this paper, a network-based gait rehabilitation system is proposed for enhanced mobility and tele-rehabilitation. In the proposed rehabilitation system, a compact rotary elastic actuator (cRSEA) is employed to provide assistive torque to the patients and it is controlled over a local wireless network. However, time delay exists in both sensor-controller and controller-actuator channels, which leads to performance degradation and even destabilization. Moreover, the amount of time delay is time-varying and it is difficult to measure accurately. In order to compensate the time delay and guarantee stability of the system, a communication disturbance observer (CDOB) is designed in the discrete-time domain. Parameters are tuned based on the linear quadratic regulator (LQR) design technique and compared to other parameter choices in the frequency domain in terms of closed-loop stability, tracking performance, disturbance attenuation, and noise cancellation. Simulation and experimental results are shown to validate the performance of the proposed controller.

Original languageEnglish (US)
Title of host publication6th IFAC Symposium on Mechatronic Systems, MECH 2013
PublisherIFAC Secretariat
Pages555-562
Number of pages8
Edition5
ISBN (Print)9783902823311
DOIs
StatePublished - 2013
Externally publishedYes
Event6th IFAC Symposium on Mechatronic Systems, MECH 2013 - Hangzhou, China
Duration: Apr 10 2013Apr 12 2013

Publication series

NameIFAC Proceedings Volumes (IFAC-PapersOnline)
Number5
Volume46
ISSN (Print)1474-6670

Other

Other6th IFAC Symposium on Mechatronic Systems, MECH 2013
Country/TerritoryChina
CityHangzhou
Period4/10/134/12/13

Keywords

  • Communication disturbance observer (CDOB)
  • Gait rehabilitation
  • Networked control
  • Time delay
  • Wireless communication

ASJC Scopus subject areas

  • Control and Systems Engineering

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