微波加热钛精矿试验建模及温度控制器设计

微波加热物料是一个复杂的过程。在加热的过程中,物料温度会受到介质物理参量的温变等因素的影响。通过开展微波加热钛精矿试验,获取试验数据,并得到飞升曲线;结合Cohn Coon公式和温控对象的特点,建立微波加热钛精矿的对象模型。在此模型的基础上,分别采用经典PID和Smith预估两种控制策略,对微波加热过程中的温度进行控制;利用Matlab环境下的Simulink工具,对两种控制过程进行仿真分析研究,并对其结果进行比较分析。分析结果表明,经典PID策略有明显局限。它对具有大时滞、非线性、时变性,以及不确定性等复杂性特征的系统(微波加热等)的控制效果不理想。而采用具有鲁棒性的Smith预估策略,能够极大程度地减小微波加热过程中的超调量,使控制性能得到提升。

Experimental Modeling of Microwave Heating Titanium Concentrate and Design of Temperature Controller

Microwave heating of material is a complicated process,in which the material temperature will be affected by the variation of the physical parameters of the medium.The data and the ascending curve of microwave heating of ilmenite concentrate were obtained by experiments,and the object model of microwave heating of ilmenite concentrate was established according to Cohn-Coon formula and the characteristics of temperature-controlled object.On the basis of this model,two control strategies,namely classic PID and Smith prediction,were adopted to control the temperature during the microwave heating process.The two control processes were simulated and analyzed with Simulink in Matlab,and the results were compared and analyzed.The results showed that classic PID strategy had obvious limitations,as its control effect was unsatisfactory for systems(microwave heating,etc.)with complex features such as large dead time,nonlinearity,time variability,and uncertainty.However,the robust Smithprediction strategy could greatly reduce the overshoot in the microwave heating process and improve the control performance.