Fuzzy Controller A conventional single loop control system adjusts controlled output temperature only by the feedback signal from a temperature sensor. Pressure changes in the reactor are regarded as noises to this system. To design a conventional controller for this kind of system is difficult and time consuming. To create a fuzzy controller for the above system, what we need to do is to write rules that contain not only temperature but also pressure in their antecedents. This design process is much easier compared with that of conventional controllers because we can write rules using commonsense knowledge and know-how from experts.
Rules are English like sentences and intuitive.
No mathematical model of the process is needed as in the case of conventional control. This process includes definition of labels and membership functions for each variable. Create rules that are represented as if-then English like sentences. Simulate and tune. Those of output variables are in Figure 5 .