A Framework to Design and Build a Height Controllable Eversion Robot

Eversion robots are used in many different environments for a variety of applications. However, the vast majority of these environments are land based and minimal work has been done on environments that are 3-dimensional (3D) such as in air or underwater. To be able to successfully operate in such environments, eversion robots need to be capable of operating in 3D, including adjusting their configuration along the vertical axis. This vertical motion for eversion robots has not been developed before. This paper proposes a design for an eversion robot that, when fully extended, is able to float in air, using varying amounts of helium to change its buoyancy and hence, the amount of lift force in the vertical direction. The robot in this paper consists of a fixed base, one main continuous everting chamber with a constriction at half its length to form two links and two actuation pouches, which are externally attached. Furthermore, the calculations for determining the quantity of helium required to generate a specific force to lift the robot a specified distance, for position changes is shown. Finally, a kinematic model of the robot shows how the robot's link tip positions affect the shape and position of the robot.