基于控制参数化的注塑工业过程最优反馈控制方法

Control parameterization-based optimal feedback control for injection molding industry process

本文针对一类典型的注塑工业过程系统,研究了注塑填充过程中产生的熔体流动速度最优跟踪控制问题,提出了一种基于控制参数化的计算最优反馈控制器设计方法以实现注塑过程中熔融聚合物流动前沿位移的最优跟踪控制,进而达到改善注塑零件性能的高效生产目标.首先,面向注塑工艺复杂生产过程建立了动态过程系统数学模型,提出了注塑机内部熔融聚合物流动前沿位置的动态最优跟踪控制问题;其次,设计了一种多级反馈控制律,通过控制参数化方法将控制反馈核进行了参数化表示,将控制器设计问题转化为一序列最优参数决策问题;然后,通过状态灵敏度方程分析方法,求解出了目标函数及约束条件关于决策变量参数梯度信息的显式表达式,并基于所提供的梯度信息结合序列二次规划算法进行了高效优化迭代求解;最后,通过实验仿真验证了本文所提出的最优反馈控制器设计方法的可行性和有效性.

In this paper, an optimal tracking control problem of melt fiow velocity in the injection molding process is studied, and a design method of computational optimal feedback controller based on control parameterization is proposed to solve the optimal control problem arising in the injection molding process. Firstly, a mathematical model of a dynamic process system is established for the injection molding process, and the dynamic optimal tracking control problem of fiow front position of molten polymer in injection molding machine is proposed. Secondly, a multi-level feedback control law is designed, and the control feedback kernel is parameterized by the control parameterization method. The controller design problem is transformed into a sequential optimal parameter decision problem. Then, the explicit expression of the gradients of the objective function and constraints with respect to the parameters of the decision variables are obtained by using the state sensitivity analysis method, and then the nonlinear programming algorithm is used to solve the optimization problem efficiently. Finally, the feasibility and the effectiveness of the proposed design method of optimal feedback controller are verified by numerical experiments.