Anti-Disturbance Switching Control for Silicon Single Crystal Growth Systems Under Unmeasured States
针对硅单晶生长系统中存在未测量状态和内外干扰的问题，提出了一种结合输出反馈和扰动观测器的抗干扰切换控制方法，通过设置多个平衡点提高系统精度，并利用Lyapunov函数和线性矩阵不等式保证指数稳定性。
In this article, the anti-disturbance switching control approach is proposed for silicon single crystal growth systems with unmeasured states. Initially, the silicon single crystal growth systems are modeled by using the geometrical models of meniscus section, hydrodynamic and heat transfer process of silicon single crystal growth. Since numerous unmeasurable state variables exist in systems and the growth equipments are affected by external and internal disturbances, consideration is given to employing the output feedback control scheme and disturbance observer method in the construction of the anti-disturbance switching controller. Meanwhile, considering the high accuracy of linear systems at equilibrium points, the silicon single crystal growth systems are divided into multiple subsystems using switching control method, that is, multiple equilibrium points are set to enable the systems to switch between different subsystem models, thereby the precision of silicon single crystal growth systems has been improved. Then, using the multiple Lyapunov function method and linear matrix inequality technique, the exponential stability of silicon single crystal growth systems is ensured with the $\boldsymbol {H_{\infty }}$ performance. Finally, the feasibility of designed switching anti-disturbance output feedback control method is verified through actual parameters of silicon single crystal growth systems.