Switchable parallel elastic actuators in monopod and quadruped applications
Date
2019
Authors
Journal Title
Journal ISSN
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Publisher
University of Delaware
Abstract
Legged robotics have proven to be a viable approach to extending human reach
to various terrains that are unfit for conventional wheeled locomotion. While advances
have been made to further capacity of these robots through a variety of design approaches,
there are still difficulties in bridging compromise between energetic efficiency
and joint dexterity. Switchable Parallel Actuators (Sw-PEAs) have been proposed and
developed in legged robotics to address this trade-off by providing the benefits of both
control authority of the joint, and passive compliance, in a manner that is desired by
the overall objective of the application. ☐ This thesis begins by building upon the Sw-PEA concept, by first discussing a
two-link monopedal robot, SPEAR-II, which is the second design iteration of the robot
SPEAR (Switchable Parallel Elastic Actuator Robot). A mathematical model of the
monopod is created with a focus on understanding the internal system interactions
to use for simulation and controller design. Parameter identification experiments are
then conducted to improve the accuracy of the model by estimating previously unknown
variables. Using the refined monopod model, a simple controller is tuned and
implemented on the robot during hopping experiments. Lastly, a quadruped design
is proposed using SPEAR-II as a legged template. A quadruped model is derived to
perform analysis on key design parameters. Finally, the thesis concludes with results
for the quadruped simulation as a feasibility study for the proposed design using the
Sw-PEA.