モード解析を用いた音声生成解析モデルの開発

抄録

Vocal cord vibration is self-excited vibration due to the interaction between structure and fluid. So far, several models have been proposed as analytical models for vocal cord vibration that represent the vocal cord by mass-spring systems. However, these models have a problem that it is difficult to determine the parameters of the analytical model (mass, spring constant, etc.). There are also studies that analyze vocal cord vibration using the Finite Element Method (FEM) or the Finite Volume Method (FVM), etc. However, large-scale Fluid-Structure Interaction (FSI) analysis has a problem of high computational cost. In order to solve these problems, we propose a vocal cord analysis model using modal analysis. Modes of the vocal cord are obtained by FEM, and vocal cord motion is represented as a superposition of modes. Fluid analysis is performed by one-dimensional Bernoulli's equation. The vocal cord vibration is calculated by coupling the vocal cord motion model and the fluid calculation model. In this method, since the mode obtained from structural analysis is used, analysis based on actual physical properties can be performed. The mode equation is a superposition of onedegree-of-freedom equations, and the fluid equation is a one-dimensional equation, therefore the calculation cost is low. The validation of the proposed method is performed by comparing the proposed method with ANSYS and the experiment. Moreover, the self-excited vibration condition of the vocal cords is mathematically derived. By applying the shooting method to the proposed method, the change of self-excited vibration due to the difference of conditions is examined.