In such a situation there is no need for a formal model of the process however is this type of control problem really so challenging that fuzzy control is even needed? Could a conventional approach (such as Pid control or a table look-up scheme work just as well or better especially considering implementation complexity? 16
16 In such a situation there is no need for a formal model of the process; however, is this type of control problem really so challenging that fuzzy control is even needed? Could a conventional approach (such as PID control) or a "table look-up" scheme work just as well or better, especially considering implementation complexity?
Overall. when you carefully consider the possibility of ignoring the information that is frequently available in a mathematical model. it is clear that it wil often be unwise to do so. Basically, then, the role of modeling in fuzzy control design is quite similar to its role in conventional control system design. In fuzzy control there is a more significant emphasis on the use of heuristics, but in many control approaches(e.g, PID control for process control) there is a similar emphasis
17 Overall, when you carefully consider the possibility of ignoring the information that is frequently available in a mathematical model, it is clear that it will often be unwise to do so. Basically, then, the role of modeling in fuzzy control design is quite similar to its role in conventional control system design. In fuzzy control there is a more significant emphasis on the use of heuristics, but in many control approaches (e.g, PID control for process control) there is a similar emphasis
Basically, in fuzzy control there is a focus on the use of rules to represent how to control the plant rather than ordinary differential equations (ODE). This approach can offer some advantages in that the representation of knowledge in rules seems more lucid and natural to some people. For others, though, the use of differential equations is more clear and natural. basicall lly, there is simply a"language differencebetween fuzzy and conventional control: odes are the language of conventional control, and rules are the language of fuzzy control 18
18 Basically, in fuzzy control there is a focus on the use of rules to represent how to control the plant rather than ordinary differential equations (ODE). This approach can offer some advantages in that the representation of knowledge in rules seems more lucid and natural to some people. For others, though, the use of differential equations is more clear and natural. Basically, there is simply a "language difference" between fuzzy and conventional control: ODEs are the language of conventional control, and rules are the language of fuzzy control
The performance objectives and design constraints are the same as the ones for conventional control that we summarized above. since we still want to meet the same types of closed-loop specifications. The fundamental limitations that the plant provides affect our ability to achieve high- performance control, and these are still present just as they were for conventional control(eg, nonminimum phase or unstable behavior still presents challenges for fuzzy control). 19
19 The performance objectives and design constraints are the same as the ones for conventional control that we summarized above, since we still want to meet the same types of closed-loop specifications. The fundamental limitations that the plant provides affect our ability to achieve highperformance control, and these are still present just as they were for conventional control (e.g, nonminimum phase or unstable behavior still presents challenges for fuzzy control)
2.1.2 Fuzzy Controller Design How do we design a fuzzy controller? Fuzyy control system design essentially amounts to (1) choosing the fuzzy controller inputs and outputs,() choosing the preprocessing that is needed for the controller inputs and possibly postprocessing that is needed for the outputs, and (3)designing each of the four components of the fuzzy controller shown in Figure 1.2 20
20 2.1.2 Fuzzy Controller Design How do we design a fuzzy controller? Fuzzy control system design essentially amounts to (1) choosing the fuzzy controller inputs and outputs, (2) choosing the preprocessing that is needed for the controller inputs and possibly postprocessing that is needed for the outputs, and (3) designing each of the four components of the fuzzy controller shown in Figure 1.2