What Is Fuzzy Logic?

Working in Simulink ® Environment
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
0 10 20 30 40 50 60 70 80 90 100
Time (second)
One interesting feature of the water tank system is that the tank empties
much more slowly than it fills up because of the specific valueoftheoutflow
diameter pipe. You can deal with this by setting the close_slow valve
membership function to be slightly different from the open_slow setting.
A PID controller does not have this capability. The valve command versus
thewaterlevelchangerate(depictedaswater) andtherelativewaterlevel
change (depicted as level) surface looks like this. If you look closely, you can
see a slight asymmetry to the plot.
2-89