Characterization of a series viscous actuator for use in rehabilitative robotics

Abstract

In this thesis, a series viscous actuator, composed of a viscous rotary damper connected to the output of a geared electric motor, is proposed as a novel solution to the high actuator impedances encountered when using such a motor. High impedances can be undesirable when interacting with the environment or animal subjects as unexpected forces may damage already-compromised joints. A state space model for the series viscous actuator was derived and verified by measurements upon a physical system. Physical design considerations for implementing a series viscous actuator, such as the appropriate gearing ratio and damper selection, are discussed and supported using the derived model.