The Application Research Of Fuzzy PID Optimization Control In Combined-Type Drying Experimental Equipment

Grain drying is the most important production link in process of agricultural production,and it will be of great significance to decrease the number of grain losses per year and promote technological level of grain drying as well as competitive force of food production in our country,if the process of grain drying can be automatically controlled.However,the process of grain drying is a typical kind of nonlinear and hysteresis process and it is hard to confirm its mathematical model,so the control effect of the traditional control methods is unsatisfactory.In order to study the drying effect and drying characteristics of different grain drying technology and explore the optimum drying process design parameters,a kind of combined-type drying experimental equipment is introduced,the control system and Fuzzy PID optimization controller is designed aiming at this experimental equipment.Main contributions are as follows:The control system is designed according to the actual structure and control requirements of the combined-type drying experimental equipment.On the hardware side,Siemens s7-300 series PLC is selected as the main controller,and the human-computer interaction interface is provided through the Weinview MT8101iE touch screen.After the determination of controlled variable and monitoring variable,the PLC modules is selected and the electric control cabinet is designed.On the software side,the PLC program is used to directly control experimental equipment and gather data signal from the sensors.At the same time,touch screen program is used to indirectly control experimental equipment and check the operation condition of the experimental equipment and real-time data of experimental variables.Aiming at the experimental equipment,the fuzzy PID controller optimized by genetic algorithm is designed.In consideration of the characteristics of the process of grain drying,such as non-linearity,Large lag and difficulty in establishing mathematical model,the fuzzy PID control is selected to design the controller.At the same time,the genetic algorithm is used to optimize the quantization factor and correction coefficient of fuzzy PID controller,and the advantage of the control algorithm is verified by MATLAB simulation.