基于专家PID控制的微波加热功率主动控制方法

Active control on microwave heating power based on expert-PID control

摘要:

针对现有微波功率控制方法存在的过渡时间长，稳定性差等问题，提出微波源功率专家比例积分微分(PID)主动控制法，在防止出现“热失控”的前提下，根据物料的介电特性、反射功率等先验知识，建立专家控制规则库，将控制规则预存于控制器，解决微波加热过程实时控制难，控制精确度差等问题。仿真实验结果证明，专家PID控制比经典PID控制达到稳态的用时节约70%，效率提高89%，精确度提高87%。

Abstract:

It is difficult to describe the microwave heating procedure with accurate mathematical modeling since it is nonlinear and time-delayed. The existing microwave power control methods generally adjust and control parameters according to the results identified by the system. Because those methods feature a long transition time and low stability, a method of expert-Proportion Integration Differentiation (PID) active control on the source power of microwave is proposed. When 'thermal runaway' is prevented, the database of experts’ control rules is set up in line with such prior knowledge as dielectric properties and reflected power of materials. The control rules are in advance stored in the controller, so the problems of hard real-time control and low accuracy of control in the microwave heating procedure can be solved. Compared with the classical PID control, the simulation findings show that the expert-PID control saves about 70% of time taken to reach the state of being stable, improves the efficiency by 89% and increases the accuracy by 87%.