2020/04/02 by Chunpeng Wang, Wang, Chunpeng, John P. Whitney +1
Computer Science · Engineering · #FOS: Computer and information sciences #Prosthetics and Rehabilitation Robotics #Robot Manipulation and Learning #Robotics (cs.RO) #Soft Robotics and Applications #cs.RO
paper · pdf · doi:10.48550/arxiv.2004.01269
8 pages, 8 figures
openalex publication_date 2020/04/02 · arxiv created 2020/04/06 · arxiv updated 2020/04/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Fluid-based soft actuators are an attractive option for lightweight and human-safe robots. These actuators, combined with fluid pressure force feedback, are in principle a form of series-elastic actuation (SEA), in which nearly all driving-point (e.g. motor/gearbox) friction can be eliminated. Fiber-elastomer soft actuators offer unique low-friction and low-hysteresis mechanical properties which are particularly suited to force-control based on internal pressure force feedback, rather than traditional external force feedback using force/tactile sensing, since discontinuous (Coulomb) endpoint friction is unobservable to internal fluid pressure. However, compensation of endpoint smooth hysteresis through a model-based feedforward term is possible. We report on internal-pressure force feedback through a disturbance observer (DOB) and model-based feedforward compensation of endpoint friction and nonlinear hysteresis for a 2-DOF lightweight robotic gripper driven by rolling-diaphragm linear actuators coupled to direct-drive brushless motors, achieving an active low-frequency endpoint impedance range ("Z-width") of 50dB.