目前，石英砂粒度检测采用人工筛分法或比表面积法，这两种方法测量精度差、耗时长、成本高、无法及时跟踪产品质量，导致生产中无法自动调整分级设备工作参数、生产效率低。为了解决上述问题，对石英砂湿法生产中粒度检测技术和系统进行研究。 根据石英砂湿法生产要求，重点探究了Mie散射理论的应用难点反演算法。独立模式反演算法抗干扰能力差、多峰适应性弱，基于该算法的粒度检测系统性能受到很大限制。通过对病态方程反问题研究发现，采用不同正则算子可改善P-T法性能，运用与散射角有关的预处理技术可提高反演算法的稳定性和噪声适应能力。在反演算法改进的基础上，设计了一种基于Mie散射理论的石英砂粒度检测系统。该系统分为信号产生和采集模块、信号处理模块、数据处理和显示模块。信号产生和采集模块包括激光器、扩束准直器、样品池、傅立叶透镜和CCD相机，该模块利用扩束准直器提高激光束的平行性、滤除高频分量、减小艾里斑尺寸、增大检测上限；确定了傅立叶透镜参数选择公式，根据待测粒度范围和光源光斑尺寸即可直接选取透镜；采用CCD相机代替硅光二极管阵列实现光电转换，降低了系统维护难度、提高了系统稳定性、减小了成本。信号处理模块利用图像分环和灰度处理方式得到散射光强曲线，并对该曲线做了平滑处理。数据处理和显示模块根据提出改进的反演算法编程实现，并将检测的粒度分布结果图形化输出。 通过仿真分析，改进的反演算法兼顾了光能残差和平滑程度，提升了抗噪声能力。通过搭建的实验系统测试，设计的基于改进反演算法的石英砂粒度检测系统达到了技术要求。

ABSTRACT At present, the artificial macrogrits or BET techniques are mainly used in the measurement method of quartz sand particles distribution. The methods are poor in measuring precision, inefficiency with a high cost and can not be tracking production quality timely, making it impossible to adjust operating parameters of grading equipment in the production, the production efficiency is low. In order to solve these problems, the research of particle size detecting technology and system of quartz sand production. With the characteristics of quartz sand wet production environment, the analysis for inversion algorithm was made, which is applied difficulty, based on Mie scattering theory. The weak anti-interference ability and multi peak adaptability, which belong to the independent mode inversion algorithm, have been the main obstructions on the further development of particle size distribution measurement system. In basis of inverse problem of ill posed equation, there proposed a different regularization operator to improve the performance of P-T algorithm and added pretreatment technology for the stability and noise adaptability of inversion calculation. In the research of Mie scattering theory, there designed a quartz sand size distribution measurement system based on improved inversion algorithm. This system consists of signal generation and acquisition module, signal processing module, data processing and display module. Signal generation and acquisition module includes laser, beam expander collimator, sample pool, Fourier lens and CCD camera. In this module, it improved the parallelism of the laser beam, filtered the high-frequency components, reduced the size of the Airy disk and increased the upper limit of measurement range through beam expander collimator. The parameters selection formulas established can select a Fourier lens directly through quartz sand size range and light spot size. Instead of silicon photodiode array, there applied a CCD camera, it can reduce maintenance difficulty, improve stability and decrease cost. The signal processing module in view of ring division and gray image processing got scattering intensity curve, which was smoothed. According to improved inversion algorithm, data processing and display module obtained the Particle Size distribution and graphical output. Through simulation, the improved inversion algorithm takes into account light residuals and smoothness, it enhances the noise adaptability. The experimental system test shows that quartz sand particle distribution measurement system proposed can satisfy the technical requirements totally.