Wire-Pulling Mechanism with Embedded Soft Tubes for Robot Tongue

Abstract

There do not exist enough physical models of human oral and laryngeal systems for human speech movement in both computer simulators and mechanical simulators. In particular, there is no robot tongue mechanism that completely reproduces the deformation motion of the human tongue. The human tongue has no skeleton inside and is an aggregate of tongue muscles. A driving mechanism that can drive and control the deformation of a soft body like the human tongue with multiple degrees-of-freedom and has an affinity for the soft body has not been realized. In order to solve this problem, this paper proposes a wire-pulling mechanism with embedded soft tubes. By using this, it is possible to realize a flexible tongue mechanism that can be deformed with multiple degrees-of-freedom without the wire breaking the flexible tongue. A two degrees-of-freedom input planar mechanism capable of contraction and bending was prototyped. The kinematic model under an assumption of piecewise constant curvature was formulated. An experiment confirmed that the durability was improved compared to the one without the soft tubes. A deformation test confirmed that the prototype was contracted and bent like the model. However, the tip angle error was not small enough. More accurate modeling and deformation sensors are the future work.