First Advisor

Alexander Hunt

Term of Graduation

Fall 2022

Date of Publication

11-21-2022

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Mechanical Engineering

Department

Mechanical and Materials Engineering

Language

English

Subjects

Artificial legs -- Design, Biomimicry, Artificial joints -- Design, Mechanical movements, Quadrupedalism

DOI

10.15760/etd.8129

Physical Description

1 online resource (vii, 56 pages)

Abstract

The study of synthetic nervous systems is an emerging field within biomimetic robotics as an alternative to more classic control techniques. As the modeling of these nervous systems becomes more accurate, it is important to note that the nervous system and physical system co-evolved and continue to operate in an interdependent fashion. Many legged robots, including the existing quadruped in the AARL, have leg systems that may have similar geometrical properties to that of a mammal, but have significantly different dynamic properties. This paper presents a method for designing a limb so that the passive dynamics more accurately represent that of mammalian limbs. The desired limb dynamics were obtained by scaling kinematic rat leg data, and a gray-box optimization method was used to determine appropriate spring and damper properties, modeling the limb as a three-link pendulum with a spring-damper system at each joint. The new leg was designed with minimal changes to the current prototype, with the implementation of a modular spring and damper set, which allows the leg to achieve more biomimetic passive dynamics. This leg was built with the intent of comparing SNS control methods on legs with different dynamic scales (i.e. inertial vs overdamped). Future improvements to the spring/damper implementation will include increasing the modularity of the mechanical design in order to more easily change the leg dynamic properties.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Persistent Identifier

https://archives.pdx.edu/ds/psu/39206

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