Transcript Greenhouse Climate Controller Using Fuzzy Logic Programming

Greenhouse Climate
Controller Using Fuzzy
Logic Programming
Anantharaman Sriraman
September 2, 2003
GreenHouse Climate Controller
Fuzzy Logic Programing
Purpose of GHCC
 It
takes care of maintaining a
protected environment despite
fluctuations of external climate
 It acts as a program memory, which
can be operated by the grower as a
tool to steer their cultivation
GreenHouse Climate Controller
Fuzzy Logic Programing
Advantages of GHCC
 Energy
Conservation
 Better productivity of plants
 Reduced human intervention
GreenHouse Climate Controller
Fuzzy Logic Programing
Environmental factors
Major Factors
 Temperature of the
inside air
 Relative humidity
of the inside air
 Sunlight
Minor Factors
 Wind speed
 Wind direction
 Rate of
transpiration
GreenHouse Climate Controller
Fuzzy Logic Programing
Control Actuators
 Thermal
System
 Humidification System
 Lighting system
 Thermal shade system
 CO2 generator
 Performance of the system
GreenHouse Climate Controller
Fuzzy Logic Programing
Fuzzy Logic
 an
alternative design methodology
 linear and non-linear systems for
control
 lower development costs
 superior features
 better end product performance
 market faster
 more cost-effectively
GreenHouse Climate Controller
Fuzzy Logic Programing
Fuzzification
 Measure
the values of input variables
 Performs a scale mapping that
transfers the range of values of input
variables into corresponding
universes of discourse,
 Performs the function of fuzzification
that converts input data into suitable
linguistic values, which may be
viewed as labels of fuzzy sets.
GreenHouse Climate Controller
Fuzzy Logic Programing
Knowledge Base
Comprises knowledge of the application
domain and the attendant control goals. It
consists of a “database” and a “linguistic
(fuzzy) control rule base:”
 The database provides necessary
definitions, which are used to define
linguistic control rules and fuzzy data
manipulation in an FLC.
 The rule base characterizes the control
goals and control policy of the domain
experts by means of a set of linguistic
control rules. GreenHouse Climate Controller

Fuzzy Logic Programing
The decision-making logic
 It
is the kernel of an FLC. It has the
capability of simulating human
decision-making based on fuzzy
concepts, implication and the rules of
inference in fuzzy logic
GreenHouse Climate Controller
Fuzzy Logic Programing
The defuzzification inference
 Scale
mapping, which converts the
range of values of output variables
into corresponding universe of
discourse,
 Defuzzification, which yields a nonfuzzy control action from an inferred
control action.
 A defuzzifier converts an inferred
fuzzy control action into a crisp one
GreenHouse Climate Controller
Fuzzy Logic Programing
Comparison of Conventional &
Fuzzy Design
GreenHouse Climate Controller
Fuzzy Logic Programing
Advantages
 Reduces
Design Development Cycle
 Simplifies Design Complexities
 Improve time to market
 Better for non Linear system
 Improve control performance
 Reduces hardware cost
GreenHouse Climate Controller
Fuzzy Logic Programing
Greenhouse Layout
GreenHouse Climate Controller
Fuzzy Logic Programing
Function of Controller
GreenHouse Climate Controller
Fuzzy Logic Programing
Role of FLC in GHCC
GreenHouse Climate Controller
Fuzzy Logic Programing
Input Variables

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Difference in temperature between inside greenhouse &
optimum must be maintained in greenhouse [-10 to +10 ºC]
Difference in temperature between outside greenhouse &
optimum must be maintained in greenhouse [-20 to +20 ºC]
Difference in R-Humidity between inside greenhouse & optimum
must be maintained in greenhouse [0 to 100 %]
Difference in R-Humidity between outside greenhouse &
optimum must be maintained in greenhouse [0 to 100 %]
Sunlight incident on the greenhouse roof [0 to 20 W/m2]
Seasonal Cloudiness which reduces the sun’s radiation [0 to 100
%]
Wind speed [0 to 100 mph]
Wind direction with respect to the direction of the ventilation
system of the greenhouse
Measurement error of the sensing system (-4 to 4)
Change in Error of the measurement of the sensing system (-1
to 1)
GreenHouse Climate Controller
Fuzzy Logic Programing
Output Variables
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Thermal system (0 to 100 %)
Ventilation & humidification system (0 to
100 %)
Thermal shade system (0 to 100 %)
CO2 generation system (0 to 100 %)
Forced ventilation system (0 to 100 %)
Performance of the system (0 to 100 %)
GreenHouse Climate Controller
Fuzzy Logic Programing
FLC System
GreenHouse Climate Controller
Fuzzy Logic Programing
Input Membership Function
GreenHouse Climate Controller
Fuzzy Logic Programing
Input MFs
GreenHouse Climate Controller
Fuzzy Logic Programing
Input MFs
GreenHouse Climate Controller
Fuzzy Logic Programing
Output MFs
GreenHouse Climate Controller
Fuzzy Logic Programing
Output MFs
GreenHouse Climate Controller
Fuzzy Logic Programing
Rules-1
GreenHouse Climate Controller
Fuzzy Logic Programing
Rules-2
GreenHouse Climate Controller
Fuzzy Logic Programing
Rules-3 & 4
GreenHouse Climate Controller
Fuzzy Logic Programing
Rules 5 & 6
GreenHouse Climate Controller
Fuzzy Logic Programing
GUI
GreenHouse Climate Controller
Fuzzy Logic Programing
THANK YOU
Questions?
GreenHouse Climate Controller
Fuzzy Logic Programing