【作者】 马云峰；

【导师】 葛宝臻；

【作者基本信息】 天津大学 ， 光学工程， 2010， 硕士

【摘要】 基于衍射原理的激光粒度仪是在颗粒测量领域应用最为广泛的仪器之一。在激光粒度测试中,反演算法各有其适用条件和适用范围,对于不同粒径和粒度分布宽度的粒子群进行反演,求解结果可能出现较大偏差。本文在研究不同粒子群光能分布特点的基础上,使用相似度原理预测了粒子群的粒度分布,并根据预测结果自适应选取步长调整因子,将得到的最优步长调整因子应用于Projection算法求解粒子群粒度分布。本文的主要工作及创新性如下:1、在分析粒子群的粒径、分布宽度及混合粒子群与光能分布关系的基础上,借鉴基于测距相似度原理的粒度分布预测方法,预测粒子群的粒度分布。2、在分析基于Projection算法的几种反演方法优缺点的基础上,提出根据粒子群的预测粒度分布计算步长调整因子的自适应Projection算法,并对该算法的收敛阈值的选取进行了讨论。3、采用自适应Projection算法对标准粒子板和国家标准物质进行测量实验,并与已有的改进下降因子的Projection算法、引入渐变下降因子的Projection算法的实验结果进行了比对。通过对实验结果的分析,验证了自适应Projection算法的有效性。更多还原

【Abstract】 Laser particle sizer which based on the principle of laser diffraction is one of the most widely used in particle size measurement.In laser particle size analyzing,each algorithm has its inversion condition and application scope.The results may have been solved deviation when measuring different size and different width of the particles.According to the characteristics of particle light distribution,this paper has used of similarity theory to predict the distribution of particle size.The adaptive step adjustment coefficient has been calculated based on the predicted distribution which will be used in Projection algorithm to measure the distribution of particle size.Main work and innovation are as follows:1. This paper has researched the relationship of particle size, particle width and hybrid particle to the light distribution .Using a method to predict the distribution of particle size which based on similatity.2. Research the advantages and disadvantages of Projection algorithm and some other non-mode inversion algorithms which based on Projection algorithm. The adaptive Projection algorithm which calculate the step adjustment coefficient based on the predicted distribution has been proposed. Finally, the algorithm threshold for convergence is discussed.3. Using adaptive Projection algorithm to measure the standard particle board and national standard material, compared the result with improved Projection algorithm which introducing an increasing fine coefficient and Projection algorithm which introducing an improved fall coefficient. The results show that the adaptive Projection algorithm is effective.更多还原