| Woojin Chung Advanced
Robotics Research Center, Korea Institute of Science and Technology, 39-1
Hawolgok-dong, Sungbuk-ku, Seoul 136-791 Korea and Yoshihiko Nakamura
Dept. of Mechano-Informatics University of Tokyo 7-3-1, Hongo, Bunkyo-ku
Tokyo 113-8656 Japan |
| Exploiting unique features
of nonholonomic systems, innovative and advantageous mechanisms can be designed.
We have proposed a nonholonomic manipulator which is a controllable n
joint manipulator with only two actuators. In order to create its nonholonomic
constraint, a special type of velocity transmission, called the nonholonomic
gear, was developed. There are many possible alternatives for designing
underactuated manipulators using the nonholonomic gear. In this paper, the
chained form manipulator is designed not only to satisfy chained form convertibility,
but also to achieve control simplicity. Design requirements are clarified,
then we establish the mechanical design of the chained form manipulator.
The chained form manipulator is designed with an innovative main power train
as well as nonholonomic gears. For experimental verification, a prototype
is fabricated. So far, various control strategies for nonholonomic systems
have been proposed. In this paper, an efficient motion planning scheme for
the chained form is presented to approximate any holonomic path with the
feasible nonholonomic path. Furthermore, a new concept of motion planning
is proposed through the analysis of the initial-condition sensitivity. Combining
these two approaches, the motion planning scheme is constructed towards
practical applications. Presented experimental results show the usefulness
of the design and the applied control scheme. |
