Papers by Keyword: Mckibben Muscle

Abstract: In this paper, a robotic fin was idealized with three rays, which are serially connected by thin flexible rubber membranes. Each ray consists a two chamber braided soft actuator operated by pneumatic pressure at the maximum of 20 kPa. The bending of the ray is achieved by alternating the supply of air to the chamber. The soft actuator bends to the right when the left chamber is pressurized and moves to the left when the right chamber is pressurized. The propulsive wave motion along the fin is thus achieved by oscillating the rays at the same frequency but in different phases. The finite element (FE) analysis was conducted in MARC^®, nonlinear FE software, from which the lateral displacements of the rays and the corresponding effect on the membranes were measured. The wave amplitude of the fin was computed from the simulation results. The wave motion of the robotic fin and its corresponding pressure distributions were also observed and presented.

Abstract: Several types of artificial muscles are actually able to mimic the active spring-like behaviour characterizing the tension-length diagram of the skeletal muscle but the natural damping expressed by the typical tension-velocity Hill’s relationship is not so easy to integrate in a simple way into the artificial muscle functioning. We discussed the use of a textile braided sheath, particularly in the case of the so-called McKibben structure to obtain a Hill’s model-like dynamic behaviour of the artificial muscle. Experiments are reported to compare “quick-release” experiments – as defined in muscular physiology – between artificial muscles whose braided weave is made of metallic strands and of rayon textile strands. It is shown that only in the second case a typical hyperbolic tension-velocity is highlighted with a curvature close to this of human skeletal muscle. It is also shown how the typical laws of friction in textile can explain this analogical behaviour with the Hill’s-model interpreted as a force model including a typical non-linear viscous component. An original interpretation of Hill’s model in terms of natural load-variations adaptation is given and so the advantage for an artificial muscle to get this biomimetic character.

Abstract: A humanoid robot arm with both shoulder joint and elbow joint is built. It is actuated by pieces of Mckibben muscles. Its skeleton-muscle formation is similar to the anatomical structure of the human arm. A pneumatic experiment system is established for supporting and testing the robot arm. The relationship between the robot arm actions and the Mckibben muscles is studied. Some main actions of the robot arm including the elbow bending, the whole arm arising and the rotating around the arm axis are realized.