The Research Of Methanol Rectifying Tower Variable Structure Control System Based On ARM

Due to the restrictions of various conditions,there will produce impurities in the process of methanol production.This requires rectification method to change the crude methanol into high purity methanol products.Controlling the temperature stability and precise for the production is essential.The traditional control method is based on the PLC and PID.However,it is difficult for the traditional control method to optimize the two dynamic performance indexes of the temperature regulation time in the real system and the overshoot quantity in the face of complicated nonlinear system.In order to solve this problem,the variable structure control algorithm is used to design the controller with ARM,so that the multi-performance index can be optimized.Firstly,the model of the methanol distillation tower is calculated and established from the data obtained in the real field.And build two simulation models based on algorithms in Simulink.The SMV algorithm can produce different functions according to the feedback and change,so it can make different operations at different stages of the temperature change,so that the adjustment time and the overshoot are optimized.Secondly,To solve the chattering problem of using sliding mode variable structure algorithm,the fuzzy algorithm is adopted to the algorithm,and generate the adjustment factor.The factors and the system feedback differences are taken as inputs of the SMV controller,which solves the phenomenon of using sliding variable structure algorithm.At last,the hardware simulation circuit is built.In the simulation,through the algorithm processing and calculation of controller,it outputs a measured to stepper motor control.The rotation of the stepper motor was used to simulate the change of valve opening,so that the top of temperature is adjusted.According to the two simulation platforms,the controlling strategy of the variable structure control algorithm is applied to the steady and dynamic characteristics of the methanol distillation column in the process of temperature control and the strong robustness requirement,which has a certain guiding significance for the methanol production process and a very broad application prospect.