Research On Car-type Resistance Furnace Temperature Control System

Because of its simple algorithm structure and the fast dynamic process, the conventionalPID control mode is widely used in the resistance furnace temperature control system. Butwith the unceasing expansion of production scale and unceasing enhancement of the qualityrequirement of production, the performance of PID control still needed to be further improved.But on the one hand, the conventional PID control can not keep the system tracking andanti-disturbance performance in good condition simultaneously; on the other hand, parameterregulation relies on precise mathematical model of the controlled process, the more accuratemathematical model is got, the more appropriate parameters are obtained, then the bettercontrol results are reached. Because the furnace temperature control is of very complexity,existing multitudinous disturbance factor, the great inertia, long time delay and very strongfeature of non-linear and time-varying, all above characteristics make it difficult to create anaccurate mathematical model. Aimed at these characteristics of furnace temperature controlprocess, two-degree-of-freedom PID control method and the way of two-degree-of-freedomPID control organically combining with fuzzy technology are introduced.In view of the disadvantages that conventional PID control can not keep the tracking onsetting point value of control system and can not possess the better anti-disturbanceperformance, this thesis proposes an adopt two-degree-of-freedom PID control technology infurnace temperature control system. At the same time, in order to realize the high demandunder uncertainty and complex condition, the fuzzy technology is combined withtwo-degree-of-freedom PID control. The condition and operation of control regulation wereexpressed by fuzzy sets through using the theory and method of fuzzy mathematics. Thefuzzy control regulation and relational information were put in computer knowledge base asknowledge. Then computer realizes the optimal adjustment of PID controller parameter bymaking use of fuzzy reasoning according to practical response of control system. Fuzzytwo-degree-of-freedom PID controller with the self-regulating of parameter realizesself-regulation on-line of PID parameters using fuzzy inference under the differencecircumstances. Then this controller is applied to furnace temperature control process and simulated. Thesimulation results show that this controller has strong adaptive ability and good robustness tothe model and the environment, and not only has the ability to track setting point value, butalso has good rejection of disturbances; it can be well applied to the furnace temperaturecontrol process. Finally, a resistance furnace temperature real-time control system isdeveloped based on fuzzy two-degree-of-freedom PID control with the self-regulating ofparameter.