Initialized Model Reference Adaptive Control for Lower Limb Exoskeleton

Mohammad Soleimani Amiri, Rizauddin Ramli, Mohd Faisal Ibrahim

Research output: Contribution to journalArticle

Abstract

In this paper, a Proportional-Integral-Derivative (PID) controller tuning scheme by Initialized Model Reference Adaptive Control (IMRAC) for a Lower Limb Exoskeleton (LLE) is presented. Mathematical expression of the LLE structure is determined using Lagrangian and Kirchoff's equations. The transfer function of the structure based on the physical features of the links, and actuators is established under Range of Motion (RoM) condition. The PID controller of the LLE is tuned in a closed-loop control system using Ziegler-Nichols (Z-N) for initializing parameters of IMRAC. Adjustment mechanism is a gradient based method for real-time adaptation of tuned PID controller. A Lyapunov function has been applied to confirm the stability of IMRAC. The proposed IMRAC shows faster convergence in comparison with conventional non-initialized model reference adaptive control. It can be ascertained the proposed tuning scheme is applicable for real-time tuning of PID controller of LLE.

Original languageEnglish
Article number8906124
Pages (from-to)167210-167220
Number of pages11
JournalIEEE Access
Volume7
DOIs
Publication statusPublished - 1 Jan 2019

Fingerprint

Model reference adaptive control
Derivatives
Controllers
Tuning
Closed loop control systems
Lyapunov functions
Transfer functions
Actuators

Keywords

  • lower limb exoskeleton
  • Lyapunov method
  • model reference adaptive control
  • Proportional-integral-derivative controller

ASJC Scopus subject areas

  • Computer Science(all)
  • Materials Science(all)
  • Engineering(all)

Cite this

Initialized Model Reference Adaptive Control for Lower Limb Exoskeleton. / Amiri, Mohammad Soleimani; Ramli, Rizauddin; Ibrahim, Mohd Faisal.

In: IEEE Access, Vol. 7, 8906124, 01.01.2019, p. 167210-167220.

Research output: Contribution to journalArticle

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