Development of a Transformable Mobile Robot with a Variable Wheel Diameter

A demand of search and rescue operations using robotic technology increases to mitigate a natural disaster. In searching tasks with mobile robots, particularly in debris-covered environment, there is a trade-off between high-traversability on bumpy surfaces (likely to large robots) and exploration in limited areas (likely to small robots). With this in mind, we developed a small transformable mobile robot that uses a variable wheel diameter and stabilizer length. In its most compact form, the robot is deployable in limited areas and, in its fully expanded form, it traverses relatively large obstacles by expanding its wheel diameter. In this paper, development is detailed in the former sections, and geometric analysis and experiment of its step-climbing capabilities is introduced in the latter sections.