A two pendulums driven spherical robot is designed for pipe inspection tasks in this paper and a circular trajectory motion control method is proposed. Compared with the traditional pendulum driven spherical robot, the improved two pendulums drive unit offers novel motion principle of circular trajectory motion which is studied by force analysis. Considering the motion characters, the circular trajectory motion is decomposed into forward roll and lateral roll, and the dynamics model is built based on the theorem of moment of momentum. In order to acquire the controllable velocity and radius of circular trajectory motion, a circular trajectory motion control strategy is proposed, by which the motion of one pendulum is planned according to the sine function to control the angle between the outer shell of the robot and the ground, and the motion of the other pendulum is controlled by position servo control to maintain the forward velocity of the robot. The controller of circular trajectory motion is designed for accurate tracking of the tile angle of the two pendulums, and the control strategy is validated by both numerical simulation and prototype experiment.

Date Published: 31 January 2013
PDF: 7 pages
Proc. SPIE 8759, Eighth International Symposium on Precision Engineering Measurement and Instrumentation, 875916 (31 January 2013); doi: 10.1117/12.2014556

Published in SPIE Proceedings Vol. 8759:
Eighth International Symposium on Precision Engineering Measurement and Instrumentation
Jie Lin, Editor(s)