@article{5524f7a33aa54655a55c1bbd71e45d92,
title = "Continuous-Phase Control of a Powered Knee-Ankle Prosthesis: Amputee Experiments Across Speeds and Inclines",
abstract = "Control systems for powered prosthetic legs typically divide the gait cycle into several periods with distinct controllers, resulting in dozens of control parameters that must be tuned across users and activities. To address this challenge, this paper presents a control approach that unifies the gait cycle of a powered knee-ankle prosthesis using a continuous, user-synchronized sense of phase. Virtual constraints characterize the desired periodic joint trajectories as functions of a phase variable across the entire stride. The phase variable is computed from residual thigh motion, giving the amputee control over the timing of the prosthetic joint patterns. This continuous sense of phase enabled three transfemoral amputee subjects to walk at speeds from 0.67 to 1.21 m/s and slopes from -2.5° to +9.0°. Virtual constraints based on task-specific kinematics facilitated normative adjustments in joint work across walking speeds. A fixed set of control gains generalized across these activities and users, which minimized the configuration time of the prosthesis.",
keywords = "Legged locomotion, prosthetics, rehabilitation robotics, robot control, virtual constraints",
author = "David Quintero and Villarreal, {Dario J.} and Lambert, {Daniel J.} and Susan Kapp and Gregg, {Robert D.}",
note = "Funding Information: Manuscript received October 17, 2017; accepted January 3, 2018. Date of publication February 27, 2018; date of current version June 6, 2018. This paper was recommended for publication by Associate Editor H. Vallery and Editor P. Dupont upon evaluation of the reviewers{\textquoteright} comments. This work was supported in part by the National Institute of Child Health and Human Development of the National Institutes of Health under Award DP2HD080349 and in part by National Science Foundation Award CMMI-1637704. The work of R. D. Gregg was supported by a Career Award at the Scientific Interface from the Burroughs Wellcome Fund. The work of D. J. Villarreal was supported by a Graduate Fellowship from the National Council of Science and Technology from Mexico. The content of this paper is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or National Science Foundation. (Corresponding author: Robert D. Gregg.) D. Quintero and R. D. Gregg are with the Department of Bioengineering and the Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX 75080 USA (e-mail: dxq130330@utdallas.edu; rgregg@ieee.org). Publisher Copyright: {\textcopyright} 2004-2012 IEEE.",
year = "2018",
month = jun,
doi = "10.1109/TRO.2018.2794536",
language = "English (US)",
volume = "34",
pages = "686--701",
journal = "IEEE Transactions on Robotics",
issn = "1552-3098",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "3",
}