Research Papers: Mechanisms and Robotics

Self-Collision Detection in Spatial Closed Chains

[+] Author and Article Information
John S. Ketchel, Pierre M. Larochelle

Robotics and Spatial Systems Laboratory, Department of Mechanical & Aerospace Engineering, Florida Institute of Technology, Melbourne, FL 32901

J. Mech. Des 130(9), 092305 (Aug 18, 2008) (9 pages) doi:10.1115/1.2965363 History: Received December 22, 2006; Revised June 05, 2008; Published August 18, 2008

A novel methodology for detecting self-collisions in spatial closed kinematic chains is presented. In general these chains generate complex three dimensional motions in which their own links will collide with each other (i.e., a self-collision) without effective motion planning. The self-collision detection is accomplished via a novel algorithm for definitively detecting collisions of right circular, cylindrically shaped, rigid bodies moving in three dimensions. The algorithm uses line geometry and dual number algebra to exploit the geometry of right circular cylindrical objects to facilitate the detection of collisions. In the first stage of the algorithm, cylindrically shaped rigid bodies are modeled by infinite length right circular cylinders. Sufficient and necessary conditions are then used to determine if a pair of infinite length cylinders collide. If the actual finite length rigid bodies collide, then it is necessary that their associate infinite length cylinder models collide, and we proceed to the next stage of the algorithm where the bodies are modeled with finite length cylinders and a definitive necessary and sufficient collision detection algorithm is employed. The result is an efficient approach of detecting collisions of cylindrically shaped bodies moving in three dimensions that has applications in spatial mechanism design and motion planning. A case study examining a spatial 4C mechanism for self-collisions is included.

Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 11

4C Case study 1: two hit collision

Grahic Jump Location
Figure 12

4C Case study 2: one hit collision

Grahic Jump Location
Figure 6

Cylinder testing

Grahic Jump Location
Figure 7

On testing notation

Grahic Jump Location
Figure 8

Off testing: projecting on

Grahic Jump Location
Figure 9

End testing: cylinder end overlap

Grahic Jump Location
Figure 10

4C mechanism point designation

Grahic Jump Location
Figure 1

A spatial 4C mechanism

Grahic Jump Location
Figure 2

Infinite cylinder notation

Grahic Jump Location
Figure 3

Flow chart: finite cylinder testing

Grahic Jump Location
Figure 4

Finite cylinder test: parallel projection and overlap

Grahic Jump Location
Figure 5

Finite cylinders notation



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