The effect of friction in transmission components on the dynamics of legged robots

Sim, Youngwoo

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https://hdl.handle.net/2142/122087 Copy

Description

Title

The effect of friction in transmission components on the dynamics of legged robots

Author(s)

Sim, Youngwoo

Issue Date

2023-07-28

Director of Research (if dissertation) or Advisor (if thesis)

Ramos, Joao

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Actuation system design
• robotic system design
• humanoid design

Abstract

The enduring stability of industrial manipulators, even when powered off, can be attributed to the joint friction, which prevents these systems from succumbing to their own weight. Although the friction-based mechanism provides effective stiff position control, specifically in pick-and-place applications, its suitability in legged robots is less ideal due to the necessity for rapid regulation of compliant interactions with environmental factors. There is, however, a dearth of metrics to measure a robot’s performance degradation due to mechanical losses in actuators and transmissions. This paper aims to bridge this gap by introducing a fundamental formulation that leverages the mechanical efficiency of transmissions to assess the impact of power losses in mechanical transmissions on the comprehensive dynamics of a robotic system. This paper presents quantitative evidence substantiating the intuitive fact that robots’ apparent inertia escalates with joint friction. Additionally, it illustrates that robots utilizing high gear ratio and low efficiency transmissions can statically bear more significant external loads. The provided framework, we hope, will serve as a key toolkit for designing future generations of legged robots capable of effectively interacting with their environment.

Graduation Semester

2023-12

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/122087

Copyright and License Information

Copyright 2023 Youngwoo Sim

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