An omni-directional mobility platform design concept using two active split offset castors (ASOC) and one or more conventional castors is presented. An ASOC module consists of two coaxial conventional wheels driven independently and connected to the platform via an offset link. The kinematics and implementation of the omni-directional platform is described and analyzed. Particular attention is paid to the system performance on uneven floors. The fundamental mechanics of the ASOC wheel scrubbing, which is critical to system wear and energy use, is analyzed and compared to conventional active castor designs. The effectiveness of the design is shown experimentally using an intelligent mobility aid for the elderly.

Issue Section:
Technical Papers
Keywords:
mobile robots, collision avoidance, motion control, robot kinematics, handicapped aids
Topics:
Mechanical admittance, Wheels, Design, Kinematics
1.
West
,
M.
, and
Asada
,
H.
,
1997
, “
Design of Ball Wheel Mechanisms for Omnidirectional Vehicles with Full Mobility and Invariant Kinematics
,”
ASME J. Mech. Des.
,
119
(
2
), pp.
153
–
161
.
2.
Fujisawa, S., Ohkubo, K., Yoshida, T., Satonaka, N., Shidama, Y., and Yamaura, H., 1997, “Improved Moving Properties of an Omnidirectional Vehicle Using Stepping Motor,” Proc. of the 36th Conference on Decision & Control, pp. 3654–3657.
3.
Ferriere, L., and Raucent, B., 1998, “ROLLMOBS, a New Universal Wheel Concept,” Proc. of the IEEE International Conference on Robotics and Automation, 3, pp. 1877–1882.
4.
Muir, P., and Neuman, C. P., 1987, “Kinematic Modeling for Feedback Control of an Omnidirectional Wheeled Mobile Robot,” Proc. of IEEE International Conference on Robotics and Automation, 4, pp. 1772–1778.
5.
Killough
,
S. M.
, and
Pin
,
F. G.
,
1994
, “
A New Family of Omnidirectional and Holonomic Wheeled Platforms for Mobile Robots
,”
IEEE Trans. Rob. Autom.
,
10
(
4
), pp.
480
–
489
.
6.
Boreinstein, J., Everett, H. R., and Feng, L., 1996, Navigating Mobile Robots, AK Peters, Wellesley, Massachusetts.
7.
Wada, M., and Mori, S., 1996, “Holonomic and Omnidirectional Vehicle with Conventional Tires,” Proc. of the IEEE International Conference on Robotics and Automation, 4, pp. 3671–3676.
8.
Holmberg, R., and Khatib O., 1999, “Development of a Holonomic Mobile Robot for Mobile Manipulation Tasks,” Proc. of the Conference on Field and Service Robotics, pp. 268–273.
9.
Dubowsky, S., Genot, F., Godding, S., Kozono, H., Skwersky, A., Yu, L., and Yu, H., 2000, “PAMM—A Robotic Aid to the Elderly for Mobility Assistance and Monitoring: A Helping-Hand for the Elderly,” Proc. of the IEEE International Conference on Robotics and Automation, 1, pp. 570–576.
10.
Hertz, H. 1895, Gesammelte Werke, 1, Leigzig.
11.
Slocum, A., 1992, Precision Machine Design, Prentice Hall, Englewood Cliffs, New Jersey.
12.
Moore, D. F., 1975, The Friction of Pneumatic Tires, Elsevier Scientific Publishing Company, New York.
13.
Spenko, Matthew, 2001, “Design and Analysis of the SmartWalker, a Mobility Aid for the Elderly” Master Thesis, Massachusetts Institute of Technology, Cambridge, MA.
14.
Yu, H., 2002, “Mobility Design and Control of Personal Mobility Aids for the Elderly,” Ph.D Thesis, Massachusetts Institute of Technology, Cambridge, MA.
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 by ASME
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