A First Course in FUZZY and NEURAL CONTROL

148 CHAPTER 4. FUZZY CONTROL

(c) Engine force

Figure 4.3. Prototype membership functions for automobile cruise control

With the fuzzy sets defined, it is now possible to associate the fuzzy sets in
the form of fuzzy rules. When there are two inputs and one output, it is easy
to visualize the associations in the form of a table, called afuzzy associative
memoryordecision table. For this system, we can obtain such a table as
showninFigure4.4.

Figure 4.4. Fuzzy associative memory table for automobile cruise control

Theassociativememoryisasetofninerulesoftheform:

1. If velocity error is NE and acceleration is NA, then engine force is Min.


2. If velocity error is NE and acceleration is ZE, then engine force is Min.


3. If velocity error is NE and acceleration is PA, then engine force is Min.


4. If velocity error is ZE and acceleration is NA, then engine force is Normal.


5. If velocity error is ZE and acceleration is ZA, then engine force is Normal.


6. If velocity error is ZE and acceleration is PA, then engine force is Normal.