病理喉声源发声系统模型的非线性分析及其优化研究

发布时间：2018-01-12 07:35

本文关键词：病理喉声源发声系统模型的非线性分析及其优化研究　出处：《苏州大学》2015年硕士论文　论文类型：学位论文

【摘要】：嗓音的好坏直接影响着语言的表达,由于环境、职业等因素,声带疾病的患病率逐年增加,极大地影响了人们的健康和生活质量。声学检测用于病理嗓音识别还处于理论研究阶段,且对特征参数的研究仍存在不足,嗓音声学特征优化与实际声带生理结构缺乏联系。声带病变是导致嗓音异常的重要原因,近年来,关于声带的各类物理模型相继被提出,各类病理声带发声模型相关参数的研究为声带疾病分类提供了新的思路。本文针对声带疾病分类时参数选择存在的局限性,从发声系统建模的角度,提出对声带模型进行连续的非线性分析,优化模型参数匹配实际喉声源,并分析息肉和麻痹声带模型的连续非线性参数以及物理参数的差异性。首先对正常和病理发声系统振动进行分析,考虑声门下压对发声系统的影响,在不同声门下压条件下提取基频、振幅相关参数和非线性动力学参数,引入不同声门下压下的连续非线性参数并分析其差异性;其次采用优化算法对声带模型进行参数优化,实现实际喉声源的准确仿真,使所建模型能够准确反映声带的生理结构,并对优化得到的模型物理参数进行差异性分析。具体研究内容如下:(1)根据实际声带生理结构,分别建立正常和病理声带的发声模型,并耦合声门气流产生喉声源,求取喉声源基频和幅度相关参数;引入庞加莱截面,分岔图对模型振动进行非线性分析;改变声带病理参数及声门下压,分析频率参数和混沌参数李雅普诺夫指数的变化。仿真实验结果表明:声带麻痹减小了嗓音发声基频,并且只在一定压力范围内系统出现混沌,声带息肉引起的混沌则分布在整个发声压力范围内。(2)为了使声带模型参数和实际声带生理参数相匹配,采用模型结构或参数的变化描述声带病变所引起的喉生理参数的改变,提出用粒子群-拟牛顿算法(PSO-QN)优化声带生物力学模型参数,匹配正常和病理喉声源,得到反映实际喉参数的模型参数,并对优化得到的模型参数进行差异性分析。本文引入病理喉声源的声带物理模型,提出了连续声门下压下的最大李雅普诺夫指数,并进一步对声带模型参数进行了优化,结果表明,声带麻痹和声带息肉的最大李雅普诺夫指数随声门下压变化的分布存在明显差异性。本文提出的优化声带模型可以产生与实际喉声源一致的声门波形,且优化得到的正常、息肉和麻痹声带模型参数间存在显著差异。
[Abstract]:The quality of voice directly affects the expression of language, due to the environment, occupation and other factors, the prevalence of vocal cord diseases is increasing year by year. It has greatly affected people's health and quality of life. Acoustic detection for pathological voice recognition is still in the theoretical research stage, and the study of characteristic parameters is still insufficient. There is no relationship between the optimization of voice acoustic characteristics and the actual physiological structure of vocal cords. Vocal cord lesion is an important cause of voice abnormalities. In recent years, various physical models of vocal cords have been proposed one after another. The research on the relevant parameters of various pathological vocal cord vocal models provides a new way of thinking for vocal cord disease classification. This paper aims at the limitations of vocal cord disease classification parameters selection from the point of view of vocal system modeling. A continuous nonlinear analysis of the vocal cord model is proposed to optimize the parameters of the model to match the actual laryngeal sound source. The continuous nonlinear parameters and physical parameters of polyp and paralytic vocal cord models are analyzed. Firstly, the vibration of normal and pathological vocal system is analyzed, and the influence of pressure under glottis on the vocal system is considered. The fundamental frequency, amplitude correlation parameters and nonlinear dynamic parameters are extracted under different glottic pressure conditions. The continuous nonlinear parameters under different pressure are introduced and their differences are analyzed. Secondly, the optimal algorithm is used to optimize the parameters of the vocal cord model to realize the accurate simulation of the actual laryngeal sound source, so that the established model can accurately reflect the physiological structure of the vocal cord. And the physical parameters of the optimized model were analyzed. The specific research contents are as follows: 1) according to the actual physiological structure of vocal cords, the vocal models of normal and pathological vocal cords are established respectively. The throat sound source is generated by coupled glottic airflow, and the fundamental frequency and amplitude parameters of the throat sound source are obtained. The nonlinear analysis of the vibration of the model is carried out by introducing the Poincare section and bifurcation diagram. The changes of Lyapunov exponent and frequency parameters were analyzed by changing the pathological parameters of vocal cord and glottic pressure. The simulation results show that vocal cord paralysis reduces the pitch frequency of voice. And only in a certain pressure range system chaos, vocal polyps caused chaos is distributed in the whole vocal pressure range. 2) in order to make the vocal cord model parameters and actual vocal physiological parameters match. The changes of model structure or parameters are used to describe the changes of laryngeal physiological parameters caused by vocal cord disease. PSO-QN algorithm is used to optimize the parameters of vocal cord biomechanical model. Matching the normal and pathological laryngeal sound sources, the model parameters reflecting the actual laryngeal parameters are obtained, and the differences of the optimized model parameters are analyzed. In this paper, the vocal cord physical model of the pathological laryngeal sound source is introduced. The maximum Lyapunov exponent under continuous threshold pressure is proposed, and the parameters of the vocal cord model are further optimized. The results show that. The distribution of the maximum Lyapunov exponent of the vocal cord paralysis and polyp with the change of the pressure under the glottis is obviously different. The optimized vocal cord model proposed in this paper can produce the glottic waveform consistent with the actual laryngeal vocal source. The parameters of normal, polyp and paralytic vocal cord models obtained by optimization are significantly different.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R767.4

【参考文献】