As you will see in the next chapter, there are standard choices for the fuzzification and defuzzification interfaces moreover. most often the designer settles on an inference mechanism and may use this for many different processes. Hence the main part of the fuzzy controller that we focus on for design to the rule-base 21
21 As you will see in the next chapter, there are standard choices for the fuzzification and defuzzification interfaces. Moreover, most often the designer settles on an inference mechanism and may use this for many different processes. Hence, the main part of the fuzzy controller that we focus on for design to the rule-base
What is the main task in fuzzy controller design pI rocess The rule-base is constructed so that it represents a human expert in-the-loop Hence, the information that we load into the rules in the rule-base may come from an actual human expert who has spent a long time learning how best to control the process. In other situations there is no such human expert, and the control engineer will simply study the plant dynamics (perhaps using modeling and simulation) and write down a set of control rules that makes sense 22
22 What is the main task in fuzzy controller design process? The rule-base is constructed so that it represents a human expert "in-the-loop." Hence, the information that we load into the rules in the rule-base may come from an actual human expert who has spent a long time learning how best to control the process. In other situations there is no such human expert, and the control engineer will simply study the plant dynamics (perhaps using modeling and simulation) and write down a set of control rules that makes sense
It is clear that anyone who has experience driving a car can practice regulating the speed about a desired set-point and load this information into a rule-base. For instance. one rule that a human driver may use is"If the speed is lower than the set-point, then press down further on the accelerator pedal. "a rule that would represent even more detailed information about how to regulate the speed would be If the speed is lower than the set-point and the speed is approaching the set-point very fast, then release the accelerator pedal by a small amount. 23
23 It is clear that anyone who has experience driving a car can practice regulating the speed about a desired set-point and load this information into a rule-base. For instance, one rule that a human driver may use is "If the speed is lower than the set-point, then press down further on the accelerator pedal." A rule that would represent even more detailed information about how to regulate the speed would be "If the speed is lower than the set-point AND the speed is approaching the set-point very fast, then release the accelerator pedal by a small amount
This second rule characterizes our knowledge about how to make sure that we do not overshoot our desired goal(the set-point speed). Generally speaking, if we load very detailed expertise into the rule-base s we enhance our chances of obtaining better performance. 24
24 This second rule characterizes our knowledge about how to make sure that we do not overshoot our desired goal (the set-point speed). Generally speaking, if we load very detailed expertise into the rule-base, we enhance our chances of obtaining better performance
21.3 Performance Evaluation What are the performance evaluation of fuzzy control? Each and every idea on performance evaluation for conventional controllers applies here as well. The basic reason for this is that a fuzzy controller is a nonlinear controller--so many conventional modeling, analysis(via mathematics, simulation, or experimentation), and design ideas appl directly 25
25 2.1.3 Performance Evaluation What are the performance evaluation of fuzzy control? Each and every idea on performance evaluation for conventional controllers applies here as well. The basic reason for this is that a fuzzy controller is a nonlinear controller—so many conventional modeling, analysis (via mathematics, simulation, or experimentation), and design ideas apply directly