Robotica

  • Robotica (2007), 25 : pp 1-11
  • Copyright © 2006 Cambridge University Press
  • DOI: 10.1017/S0263574706002943 (About DOI)
  • Published online: 08 August 2006

Table of Contents - 2007 - Volume 25, Issue 01  


Article

On the construction of discretized configuration space of manipulators

X. J. Wu a1, J. Tang a2c1 and K. H. Heng a1
a1 School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
a2 Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Unit 3139, Storrs, CT 06269, USA

Article author query
wu xj   [Google Scholar] 
tang j   [Google Scholar] 
heng kh   [Google Scholar] 
 

Abstract

In this research, we study the construction of configuration space (C-space) of manipulators. The proposed approach is based upon precomputing the global topology of a robot's free space, and consists of an offline phase and an online phase. In the offline phase, a C-space obstacle database (COD) for a given robot is developed in which the C-space obstacle (C-obstacle) maps are stored and indexed by the cells of the workspace; in the online phase when the same robot is operated in a real environment, those maps whose indices match the real obstacle cells are identified and then extracted from the COD. The superposition of these maps forms forbidden region in operation. This proposed approach is a generic one and can be applied to manipulators with arbitrary kinematic structures and geometries. The construction of the COD, which is generally the most time-consuming step, is implemented in the offline phase, and the online computing only involves the identification of the components matching the COD indices. Therefore, this proposed approach for C-space construction can be realized in a real-time online fashion and is especially suitable for robot manipulation under dynamic operations. We carry out analyses on several types of manipulators to verify and demonstrate the feasibility and efficiency of the proposed approach.

(Received June 20 2006)
(Published Online August 8 2006)


Key Words: Robot manipulators; Configuration space obstacle; Bit maps; Motion planning; Dynamic environment.

Correspondence:
c1 Corresponding author. E-mail: jtang@engr.uconn.edu

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