0
Research Papers

Mobility Analysis of a Spoked Walking Machine With Variable Topologies

[+] Author and Article Information
Ping Ren1

Dennis Hong

 Department of Mechanical Engineering, RoMeLa: Robotics and Mechanisms Laboratory, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061dhong@vt.edu

Note that the term mobility referred in this paper has two types of definitions. One is defined as the quality of a mobile robot s free moving over all types of terrains. The other is defined as the continuous or instantaneous DOF of a mechanism.

1

Corresponding author.

J. Mechanisms Robotics 3(4), 041005 (Sep 26, 2011) (16 pages) doi:10.1115/1.4004892 History: Received September 09, 2010; Revised July 15, 2011; Published September 26, 2011; Online September 26, 2011

In this paper, the concept of the Intelligent Mobility Platform with Active Spoke System (IMPASS) is introduced in the first place as an alternative locomotive method that allows for multiple modes of motion. Based on this concept, a walking machine with two actuated spoke wheels and one tail is developed. Observations on the motion of this mobile robot indicate that it is able to change its topology by changing the contact scheme of its spokes with the ground. In order to investigate its transformable configuration, the robot is treated as a mechanism with variable topologies (MVTs) and the Modified Grübler–Kutzbach criterion is adopted to identify the degrees of freedom (DOF) for each case of its topological structures. The mobility analysis demonstrates that, with the assistance of Grassmann Line Geometry, the DOF in all possible configurations can be determined straightforward. The nature of the IMPASS’ locomotion is revealed through the mobility analysis and the theoretical results are validated with an experimental prototype.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

The prototype of IMPASS

Grahic Jump Location
Figure 2

Kinematic model of the IMPASS with two spokes and the tail in contact with the smooth ground

Grahic Jump Location
Figure 3

Topology transformations of the common contact cases of IMPASS

Grahic Jump Location
Figure 4

Spherical-prismatic dyad and its reciprocal screw system

Grahic Jump Location
Figure 5

Constraint screw system and DOF of: (a) the “1-1: parallel &unequal” case; (b) the “1-1: parallel & equal” case

Grahic Jump Location
Figure 6

Motion screw system of a RPPR mechanism with q11  ≠ q21 and q12 =q22  ≠ 90 deg

Grahic Jump Location
Figure 7

Motion screw system of a special RPPR mechanism with q11  = q21 and q12 =q22  = 90 deg

Grahic Jump Location
Figure 8

Constraint screw system of: (a) the “2-1: parallel & unequal” case; (b) the “1-2: parallel & unequal” case

Grahic Jump Location
Figure 9

Constraint screw system of: (a) the “2-1: parallel &equal” case; (b) the “1-2: parallel & equal” case

Grahic Jump Location
Figure 10

Constraint screw system of the “2-2: parallel & equal” case

Grahic Jump Location
Figure 11

2D Projection of the DOF in the “2-2: parallel & equal” case

Grahic Jump Location
Figure 12

Constraint screw system of the “2-2: parallel & unequal” case

Grahic Jump Location
Figure 13

Constraint screw system and DOF of the “1-1: skew” case

Grahic Jump Location
Figure 14

Constraint screw system of the “3-3: parallel & equal” case

Grahic Jump Location
Figure 15

Constraint screw system of: (a) the “1-2: parallel & equal” case; (b) the “2-2: parallel & equal” case

Grahic Jump Location
Figure 16

Constraint screw system of: (a) the “1-3: parallel & equal” case; (b) the “1-2: skew” case

Grahic Jump Location
Figure 17

Three examples of the contact cases with the axle’s DOF as zero

Grahic Jump Location
Figure 18

Constraint screw system of a special “2-2: parallel & unequal” case with four non-coplanar contact points

Grahic Jump Location
Figure 19

The internal mechanism of the hub

Grahic Jump Location
Figure 20

Straight-line walking using “1-1: parallel & equal” and “2-2: parallel & equal”

Grahic Jump Location
Figure 21

IMPASS’ climbing an 18-inch obstacle using “1-1: parallel & equal” and “2-2: parallel & equal”

Grahic Jump Location
Figure 22

Straight-line walking using “2-2: parallel & equal” and “3-3: parallel & equal”

Grahic Jump Location
Figure 23

Steady state turning

Grahic Jump Location
Figure 24

Turning gait transition

Grahic Jump Location
Figure 25

Lifting of the tail in the “3-3: parallel & equal” contact case

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In