초록

This paper studies a mobile platform system to provide a service for a large range of regions. The coverage of large service region is recently required while the service robot market is rapidly increased. Therefore, Regions of delivery/patrol/surveillance/inspection  services  started  to  include  outdoor  terrains  as  well  as  indoor  environments. Therefore, mobile robots have to adapt uneven terrains and overcome obstacles. In this paper, we introduce a rocker-bogie typed mobile robot which is able to provide this required capability. The robot has six active driving wheels, two degrees of freedom (DoFs) for active steering, and 2 DoFs for active bogie. The linear dynamic model was derived, and practically the values for normal and traction forces are calculated through the simple pseudo-inverse technique. The compensation algorithm is added to achieve minimal friction on the bogie axis, which leads to all wheel contact with the ground through the adaptation to uneven terrains. Also, the calculated traction force is distributed to ground contact wheels  based  on  sensor  estimation.  In  the  experiment,  upright-standing  and  climbing  a  curb  were  demonstrated. Especially, the upright posture of the robot was verified to be controlled based on Linear Quadratic Regulator (LQR) optimization controller using inverted pendulum model.

연관키워드

Mobile Robot, Rocker Bogie, Climbing a Curb, Upright Robot, LQR