Greenhouse Climate Controller Using Fuzzy Logic Programming Anantharaman

Greenhouse Climate Controller Using Fuzzy Logic Programming Anantharaman Sriraman September 2, 2003 Green. House Climate Controller Fuzzy Logic Programing

Purpose of GHCC u It takes care of maintaining a protected environment despite fluctuations of external climate u It acts as a program memory, which can be operated by the grower as a tool to steer their cultivation Green. House Climate Controller Fuzzy Logic Programing

Advantages of GHCC u Energy Conservation u Better productivity of plants u Reduced human intervention Green. House Climate Controller Fuzzy Logic Programing

Environmental factors Major Factors u Temperature of the inside air u Relative humidity of the inside air u Sunlight Minor Factors u Wind speed u Wind direction u Rate of transpiration Green. House Climate Controller Fuzzy Logic Programing

Control Actuators u Thermal System u Humidification System u Lighting system u Thermal shade system u CO 2 generator u Performance of the system Green. House Climate Controller Fuzzy Logic Programing

Fuzzy Logic u an alternative design methodology u linear and non-linear systems for control u lower development costs u superior features u better end product performance u market faster u more cost-effectively Green. House Climate Controller Fuzzy Logic Programing

Fuzzification u Measure the values of input variables u Performs a scale mapping that transfers the range of values of input variables into corresponding universes of discourse, u Performs the function of fuzzification that converts input data into suitable linguistic values, which may be viewed as labels of fuzzy sets. Green. House 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: ” u The database provides necessary definitions, which are used to define linguistic control rules and fuzzy data manipulation in an FLC. u The rule base characterizes the control goals and control policy of the domain experts by means of a set of linguistic control rules. Green. House Climate Controller u Fuzzy Logic Programing

The decision-making logic u 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 Green. House Climate Controller Fuzzy Logic Programing

The defuzzification inference u Scale mapping, which converts the range of values of output variables into corresponding universe of discourse, u Defuzzification, which yields a nonfuzzy control action from an inferred control action. u A defuzzifier converts an inferred fuzzy control action into a crisp one Green. House Climate Controller Fuzzy Logic Programing

Comparison of Conventional & Fuzzy Design Green. House Climate Controller Fuzzy Logic Programing

Advantages u Reduces Design Development Cycle u Simplifies Design Complexities u Improve time to market u Better for non Linear system u Improve control performance u Reduces hardware cost Green. House Climate Controller Fuzzy Logic Programing

Greenhouse Layout Green. House Climate Controller Fuzzy Logic Programing

Function of Controller Green. House Climate Controller Fuzzy Logic Programing

Role of FLC in GHCC Green. House Climate Controller Fuzzy Logic Programing

Input Variables u u u u u 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/m 2] 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) Green. House Climate Controller Fuzzy Logic Programing

Output Variables u u u Thermal system (0 to 100 %) Ventilation & humidification system (0 to 100 %) Thermal shade system (0 to 100 %) CO 2 generation system (0 to 100 %) Forced ventilation system (0 to 100 %) Performance of the system (0 to 100 %) Green. House Climate Controller Fuzzy Logic Programing

FLC System Green. House Climate Controller Fuzzy Logic Programing

Input Membership Function Green. House Climate Controller Fuzzy Logic Programing

Input MFs Green. House Climate Controller Fuzzy Logic Programing

Input MFs Green. House Climate Controller Fuzzy Logic Programing

Output MFs Green. House Climate Controller Fuzzy Logic Programing

Output MFs Green. House Climate Controller Fuzzy Logic Programing

Rules-1 Green. House Climate Controller Fuzzy Logic Programing

Rules-2 Green. House Climate Controller Fuzzy Logic Programing

Rules-3 & 4 Green. House Climate Controller Fuzzy Logic Programing

Rules 5 & 6 Green. House Climate Controller Fuzzy Logic Programing

GUI Green. House Climate Controller Fuzzy Logic Programing

THANK YOU Questions? Green. House Climate Controller Fuzzy Logic Programing