High quality forage can be produced by using advanced drying equipment. As indispensable auxiliary equipment, the air heated furnace supply heat, generated by burning fuel, to dryer for the forage dried operation. Temperature is an important parameter, which has directly impact on the final quality and drying rate of forage. Therefore, it is very important to study on the temperature control of the air heated furnace.On the basis of the discussion of the production process of forage dryer, the rising temperature characteristics of an air heated furnace assigned a four-fold rotary hay dryer, a step response curve of the air heated furnace is obtained by fitting the experimental data and a mathematical model is established using the first order approximate method.The fuzzy PID control proposals are proposed by considering the advantages of PID control and fuzzy control. Simulations of PID control and fuzzy PID control, concerning their respective control quality and anti-interference ability, are conducted by means of Simulink and fuzzy logic tools in MATLAB software. The simulation results show that it can meet the control demands with shorter adjust time and smaller over value and strong anti-interference ability.A temperature controller is designed by using the STC89C58RD+. The experiment results show that the fuzzy PID control is a reasonable method for the interstate system of air heated furnace. |