2019/09/19 by Namita Anil Kumar, Kumar, Namita Anil, Woolim Hong +3 · 1 citation
Engineering · #FOS: Computer and information sciences #Fuel Cells and Related Materials #Muscle activation and electromyography studies #Prosthetics and Rehabilitation Robotics #Robotics (cs.RO)
paper · pdf · doi:10.48550/arxiv.1909.09299
openalex publication_date 2019/09/19 · openalex created_date 2022/07/24 · openalex updated_date 2026/07/28
Impedance controllers are popularly used in the field of lower limb\nprostheses and exoskeleton development. Such controllers assume the joint to be\na spring-damper system described by a discrete set of equilibria and impedance\nparameters. Said parameters are estimated via a least squares optimization that\nminimizes the difference between the controller's output torque and human joint\ntorque. Other researchers have used perturbation studies to determine empirical\nvalues for ankle impedance. The resulting values vary greatly from the prior\nleast squares estimates. While perturbation studies are more credible, they\nrequire immense investment. This paper extended the least squares approach to\nreproduce the results of perturbation studies. The resulting impedance\nparameters were successfully tested on a powered transfemoral prosthesis, AMPRO\nII. Further, the paper investigated the effect of multiple equilibria on the\nleast square estimation and the performance of the impedance controller.\nFinally, the paper uses the proposed least squares optimization method to\nestimate knee impedance.\n