Computed Torque Control of the Stewart platform with uncertainty for lower extremity robotic rehabilitation

Sahand Sabet, Arman Dabiri, David G Armstrong, Mohammad Poursina

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

2 Scopus citations

Abstract

Parallel manipulators play a key role in robotic rehabilitation. In reality, such systems operate under uncertainty due to the changes in the characteristics of the patients and lack of knowledge about the physical and geometrical properties of the system. In this paper, we present a robust control scheme to control a six-degree-of-freedom Stewart platform. In this application, it is aimed to follow a desired pure rotational motion required in the robotic rehabilitation of the foot for patients with diabetic neuropathy. It is assumed that uncertainty exists in the mass of the foot of the patients (the proposed approach can also be used when disturbance exists). To perform this, the method of polynomial chaos expansion (PCE) is extended and integrated with the computed torque control law (CTCL) to control the system. In PCE scheme, uncertainty is introduced to the system by compactly projecting each stochastic response output and random input onto the space of appropriate independent orthogonal polynomial basis functions. CTCL uses a feedback linearization technique which provides the necessary force/torque to enforce the system to follow a prescribed trajectory. This papers presents a successful implementation of the PCE-base CTCL on a Stewart platform. Finally, a comparison between the efficiency and accuracy of the Monte Carlo and PCE is conducted.

Original languageEnglish (US)
Title of host publication2017 American Control Conference, ACC 2017
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages5058-5064
Number of pages7
ISBN (Electronic)9781509059928
DOIs
StatePublished - Jun 29 2017
Event2017 American Control Conference, ACC 2017 - Seattle, United States
Duration: May 24 2017May 26 2017

Other

Other2017 American Control Conference, ACC 2017
CountryUnited States
CitySeattle
Period5/24/175/26/17

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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    Sabet, S., Dabiri, A., Armstrong, D. G., & Poursina, M. (2017). Computed Torque Control of the Stewart platform with uncertainty for lower extremity robotic rehabilitation. In 2017 American Control Conference, ACC 2017 (pp. 5058-5064). [7963739] Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.23919/ACC.2017.7963739