title: Real-Time Estimation of Glenohumeral Joint Rotation Center With Cable-Driven Arm Exoskeleton (CAREX)-A Cable-Based Arm Exoskeleton.
abstract: In the past few years, the authors have proposed several prototypes of aCable-driven upperARmEXoskeleton (CAREX) for arm rehabilitation. One of the assumptions of CAREX was that the glenohumeral joint rotation center (GH-c) remains stationary in the inertial frame during motion, which leads to inaccuracy in the kinematic model and may hamper training performance. In this paper, we propose a novel approach to estimate GH-c using measurements of shoulder joint angles and cable lengths. This helps in locating the GH-c center appropriately within the kinematic model. As a result, more accurate kinematic model can be used to improve the training of human users. An estimation algorithm is presented to compute the GH-c in real-time. The algorithm was implemented on the latest prototype of CAREX. Simulations and preliminary experimental results are presented to validate the proposed GH-c estimation method.
authors.affiliation: GE Global Research , 1 Research Circle , Niskayuna, NY 12309 e-mail:  yingmao@ge.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Department of Mechanical Engineering, Columbia University , New York, NY 10027 e-mail:  xj2146@columbia.edu.
authors.forename: Xin
authors.initials: X
authors.lastname: Jin
authors.affiliation: Professor Department of Mechanical Engineering, Columbia University , New York, NY 10027 e-mail:  Sunil.Agrawal@columbia.edu.
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Agrawal