Flexible sliding actuator using a flat tube and its application to the rescue operation
This paper proposes a novel flexible sliding actuator driven by fluid power. The actuator called Λ -drive is basically composed of a flat tube and a slider. In the slider the tube is bent, then the buckling point occurs, which helps to cut off the fluid passage in order to provide the driving force to the slider when pressurizing one side of the tube. The proposed actuator is applicable to not only the straight path but the spiral and the curved one as well. Moreover, the design method to drive stably and the analysis of the output force are discussed in this paper. Finally, “Fluid Ropeway” is also proposed as the application of Λ-drive aiming to search and rescue survivors in the half collapsed houses, and its feasibility is verified through the experiment.
MOBILE ROBOT BY A DRAWING-OUT TYPE ACTUATOR FOR SMOOTH LOCOMOTION INSHIDE NARROW AND CURVING PIPES
This study discusses the search and rescue mobile robot which is aimed to go through narrow and curving routes and pipes inside the collapsed houses. This robot is inspired by the action of the octopus drawing out its arms. Since it uses the part of the arm that was drawn out as support for its advancing motion, it is expected to carry a camera without depending on the size of pipes. To realize this action, this robot is composed of a flat tube and a slider named Λ-drive. In Λ-drive the tube is bent, forming a buckling point on it, which helps to cut off the fluid passage in order to provide the driving force to the slider when pressurizing one side of the tube. Finally, it is experimentally verified through experiments that this robot is able to go through some narrow and curving pipes.
Exponential stabilization of an axially moving string with geometrical nonlinearity by linear boundary feedback
This paper addresses the vibration suppression problem of an axially moving string using boundary control. Taking into account large transverse motion of the string via the second-order component of Lagrangian strain, a nonlinear oscillation equation is derived for the problem by employing the Hamilton's Principle. Direct Lyapunov method is then adopted to demonstrate that a linear boundary control of negative speed feedback ensures the vibration response of the moving string exponentially stable. The main contributions are a new stability condition in terms of controller gain parameter, and a detailed demonstration on the equilibrium condition at the boundary where the control is applied.