Under-Actuated Kinematic Structures for Miniature Climbing Robots

This paper presents two biped designs for miniature climbing robots. The designs use under-actuation to satisfy space and weight constraints. In the first design, one actuator provides steering and another two propel the robot in a cartwheel style gait. The cartwheel gait is quite effective but space required for the maneuver precludes certain applications. The limitation is overcome in the second design, which uses under-actuation to provide two different forms of locomotion. It uses a crawling stride in confined environments and a faster pivoting gait in open environments. Such adaptability is achieved without increasing the number of actuators. Both robots have been built and have successfully demonstrated their mobility and maneuverability.