Example Greenhouse control

1
Example Greenhouse control
2
Fuzzy model and controller
desired temperature
heating
Controller
Process Greenhouse
moistening
ventilation
desired humidity
temperature
humidity
3
Fuzzy Sets
heating
moistening
very little
very much
closed
low
middle
hard
full
little
middle
much
0
25
50
75
100
0
25
50
75
100
ventilation
low
middle
high
0
25
50
75
100
4
Fuzzy sets II
temperature
humidity
very cold
luke- warm
cold
warm
hot
soft
middle
hard
0C
15C
30C
45C
60C
0
0,5
1
5
The fuzzy model
if heating is hard, then temperature is high if
moistening is very much, then humidity is high if
heating is low and moistening is little and
ventilation is low, then temperature is lukewarm
and humidity is middle if heating is hard and
moistening is much and ventilation is high, then
temperature is hot and humidity is middle if
heating is middle and moistening is middle and
ventilation is middle, then temperature is
lukewarm and humidity is middle
6
The fuzzy controller
Suppose et desired temperature -
temperature Suppose ev desired humidity -
humidity
et
ev
NB
ZE
PB
NB
NS
ZE
PS
PB
0
1
0
1
7
Fuzzy rules of the controller
if et is NB, then heating is hard if ev is NB,
then moistening is very much if et is ZE and ev
is ZE, then heating is middle and moistening is
middle if et is NB and ev is PB, then heating is
hard and moistening is little and ventilation is
high if et is ZE and ev is PB, then heating is
middle and moistening is little and ventilation
is high