SiC单晶片切割力建模与自适应控制
Modeling and Adaptive Control of the Cutting Force for SiC Monocrystal Wafer

SiC单晶因优良的物理和机械性能而大量用于大功率器件和IC行业。但由于材料的高硬度和高脆性，使其加工过程变得很困难。为此，分析了SiC单晶片切割过程，建立切割过程模型，通过F检验法进行系统阶次辨识，采用遗忘因子递推最小二乘算法在线估计模型参数，建立进给量与切割力的差分方程，设计基于最小方差自校正的切割力控制器，并进行实验验证。结果表明：控制器能够很好的跟踪不同信号，具有良好的鲁棒性，提高了SiC单晶片的加工效率和表面质量。
For having good physical and mechanical properties, SiC monocrystal is widely used in high-power devices and IC industry. However, the high hardness and brittleness make the cutting process of SiC monocrystal very difficultly. The single input and single output system consists of part feed rate and cutting force are analyzed; a minimum variance self-tuning controller is designed to make sure the process will be stable and more efficiency. Firstly, system order is determined through F-test. Then the system model parameters are estimated, the differential equation between the cutting force and the part feed rate is developed. The experiments with reference force (square wave and sine wave signal) are conducted and the results show that the proposed cutting force controller can control the feed rate well to track the different reference cutting forces, and the proposed controller has a robotic ability. The results indicate that the proposed cutting force controller can improve the surface integrity for SiC monocrystal wafer and keep the cutting process stable