This dissertation presents a comprehensive and systematic investigation of some fundamental issues relating to creating an autonomous wheeled mobile robot (WMR). The forms of WMRs with various structures developed in the past are first classified into four groups according to the method of steering and powering. The four groups are: a. ordinary car-like robots (including passenger cars, single trucks, single unit buses and articulated trucks); b. dual drive robots (dual drive motors with various casters); c. synchro drive and steering robots; and d. omnidirectional robots. The concepts of inverse and direct kinematics widely used in non-mobile manipulators are, for the first time, introduced to WMRs, and a unified treatment of the kinematics for the four kinds of WMRs is presented. A motion feasibility and smoothness analysis for each of them is carried out, revealing the motion characteristics resulting from each of the different mechanical structures. This provides a better understanding of their motion characteristics and forms the basis for discussing the path planning problem. The concept of deviation angle interval is defined and used to explain the strange phenomenon of a pirouette. The conditions and formula for pure translation, pure rotation, straight line motion and circular motion are developed. In order to verify the correctness and to illustrate the advantages of the developed kinematic model, the simulation results from the present model are compared with the existing standards from other kinematic models. Path planning is essential for creating an autonomous robot. Various methods for dealing with the find-path problem have been developed in the past. Based on the motion analysis of the four kinds of WMRs, a critical review of the presently available algorithms for moving a WMR among known static obstacles from a given start location to a given goal location is presented, and the suitability of the existing algorithms to each of the four kinds of WMRs is examined.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:663459 |
| Date | January 1995 |
| Creators | Wang, Yongji |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13201 |
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