泡生法生长大尺寸蓝宝石单晶的等径控制方法

Diameter Controlling Method of Large Size Sapphire Single Crystal Grown by Kyropoulos Method

在泡生法生长大尺寸蓝宝石单晶的过程中,为了获得高质量的晶体,精确等径控制至关重要。本文根据晶体的重量变化率来控制热场,实现晶体等径生长。设计了应用在线整定多项式权值的广义最小方差(OAPW_GMV)控制方法,并建立了系统模型。该方法的主要思想是根据在线估计的被控对象参数及OAPW_GMV的输出,调整多项式的权值,实现炉内的热场控制。仿真和实验结果表明该控制方法实现了蓝宝石单晶的精确等径控制,有效地提高了蓝宝石单晶的质量。

To obtain high quality crystals,a precision diameter-constant controlling method was required in the growth process of large size sapphire single crystal by Kyropoulos method.Based on the weight of the crystal to control the thermal field,and to achieve diameter-constant growth of crystals.a generalized minimum variance principle base on online adjusting polynomial weights（RAPW_GMV） control method is introduced,and establishing model of system.Its main idea is based on the online estimation of the parameters of controlled object and RAPW_GMV output,online adjusting polynomial weights,fulfill the controlling of thermal field and diameter-constant growth of crystals.The emulator and experimental results confirm that the controlling method achieve precision diameter-constant controlling of Sapphire Single Crystal and effectively improve the quality of sapphire single crystal.