基于非线性参数整定PI控制算法的激光淬火温度控制研究

Study on Laser Quenching Temperature Control Based on Nonlinear Adjusted Parameter for PI Control

为了解决恒功率激光淬火过程中材料基体预热时间长、材料表面温度不稳定、容易发生边界熔化等问题,设计基于非线性参数整定方法的PI控制器。首先使用了一阶惯性系统来描述激光淬火的温度模型,接着通过阶跃响应法来辨识温度系统的模型参数,然后提出了非线性参数整定的PI控制算法。结果表明,这种控制方法能够在控制过程中实时调节PI参数,并且能够准确控制激光作用区域的温度。同时,与传统PI控制相比,通过这种控制方法可以得到相对更好的快速性以及更小的超调量。此外,该控制系统还具有一定的鲁棒性,对于参数不断变化的非线性温度系统也能取得较好的控制效果。

In order to solve the problems of long preheating time of material, unstable temperature of material surface and boundary melting during laser quenching with constant power, a PI controller was designed based on non-linear parameter adjusting method. First, a first-order inertial system is used to describe the temperature model of laser quenching. Then, the model parameters of temperature system are identified by step response method. After that a PI control algorithm based on nonlinear setting parameter is proposed. The results show that this control method can adjust PI parameters in real time during the control process. And the temperature of the laser action area can be accurately controlled. At the same time, compared with traditional PI control, this control method can achieve relatively better rapidity and smaller overshoot. In addition, the control system has certain robustness. Good result can also be obtained for nonlinear temperature systems whose parameters are constantly changing parameters.