By Axier Ugartemendia, Daniel Rosquete, Jorge Juan Gil, Iñaki Díaz, and Diego Borro R obotic rehabilitation for poststroke therapies is an emerging new domain of application for robotics with proven success stories and clinical studies. New robotic devices and software applications are hitting the market, with the aim of assisting specialists carrying out physical therapies and even patients exercising at home. Rehabilitation robots are designed to assist patients performing repetitive movements with their hemiparetic limbs to regain motion. A successful robotic device for rehabilitation demands high workspace and force Machine Learning for Active Gravity Compensation in Robotics ©ISTOCKPHOTO.COM/ANDRESR Application to Neurological Rehabilitation Systems Digital Object Identifier 10.1109/MRA.2020.2978484 Date of current version: 3 April 2020 78 * IEEE ROBOTICS & AUTOMATION MAGAZINE * JUNE 2020 1070-9932/20©2020IEEEhttp://www.ISTOCKPHOTO.COM/ANDRESR