Fuzzy Logic Controlled Motor Speed in Rotating Aquaponics Based on Lactuca sativa Leaf Chlorosis and Necrosis and Environment Temperature

Abstract

Necrosis and chlorosis are some of the leaf conditions that contribute to losses in crop production, which is the browning and yellowing of leaves caused by improper irrigation and fertigation. A rotating aquaponics, crop cultivation conceptualized initially by NASA to save space and grow their food on space stations is the inspiration of application of this study. A fuzzy logic controlled (FLC) DC motor speed controller was developed using the Mamdani system to automate the rotating mechanism that is responsible for watering turns of lettuce crops. Using CIE L*, a*, color space, and environment temperature as input linguistic values, the motor speed will adjust depending on the status of the physical pigment condition of leaves as well as the intensity of temperature. The generated fuzzy logic controller has four triangular membership functions with 16 rules on each of the inputs. This resulted in four possible outputs of rotating aquaponics motor speed measured in rpm: very slow (0.25), slow (0.5), slightly fast (1.25), and fast (2). The modeled FLC was simulated in a Simulink environment in MATLABR2021 software and had a 10-step size and manifested essentially accurate results with 100% correct outputs based on input characteristics and rules developed. This developed FLC model is a substantial contribution to mitigating losses on lettuce crops grown under rotating aquaponics by automating the water absorption frequency depending on the status of the crop and the temperature of its environment.