The Applicationon On Cascade PID Controller With Combining A Fuzzy Logic Tunning

Silicone has a lot of great performance due to it's typical structure, and applies in quite a few area. It's foresee the most potential new"green material"in 21 century. The appearance of silicone micro emulsion is transparence or half-transparence, so the silicone micro emulsions is a liquid between of the emulsions and solution and named silicone micro emulsion. Nowadays ,there are many silicone micro emulsions have been developed in U.S. , Japan, Germany and other developed country, and the market margin is very good. It can solve some common issue like emulsion-broken, surface oil that normal particle size emulsions. The micro-emulsions has a quick polymerization speed, however the temperature control seems a little difficult to control, it's critical to maintain a steady temperature with very small fluctuation when load the surfactant to achieve a targeted small particle size. And temperature control is very fundamental but it's very important subject in the process control. With considering the characteristics of long dead time , time variance ,non-linear of temperature control, to fulfill the complex process requirement, there is a lot think on utilize the intellectual control theory and method on temperature control, fuzzy PID control is one example. The fuzzy logic thinking combines the advantages of traditional PID control algorithm and fuzzy control theory, the on-line PID tuning become realistic with rapid responding from the control system and the transitioning period is minimized, also the overshoot has been reduced with less fluctuation and strong robustness, therefore it's playing a very important role in fuzzy control.In order to optimize the micro-emulsion blender's temperature control performance especially under the disturbance and fulfill the requirement one control system for different product(with different specific heat), i.e. to minimize the temp. Fluctuation and avoid overshooting occasionally, A cascade PID controller with combining a Fuzzy logic on the PID tuning is developed. A Fuzzy control box is added in the typical cascade PID controller, the fuzzy logic will determine the PID parameters according to the temperature difference among the blender, the set point and the Jacket Temp., which also combines the experience from the field operators on the PID adjustment. The results of the implementation in real plant prove that the method is effective; the performance of the temperature control system for the blender is improved and result is satisfied.