Abstract
Light-emitting diodes (LEDs) are broadly used in smart agriculture especially in plant factories because of energy efficiency and variable spectrum characteristics. LEDs can promote plant growth and photomorphogenesis that improves plant yield and quality in the control environment. The objectives of this paper were to review the advantages of LEDs on phototrophic plants, different light detection systems, and intelligent control systems of LED illumination on plants inside plant factories. The typical LEDs supplement light devices and intelligent control systems that are regulated by various control models. The narrowband LEDs with the simplest combination of wavelengths can optimize light and promote photosynthesis. Blue light is advantageous for chloroplast improvement and can increase the amount of chlorophyll in algal cells. Red light is the best light source to keep short-lived plants from blooming and sometimes helps plants bloom in dark times when distant red light can counter the effects of red light. The review demonstrated that fuzzy logic control systems are more reliable compared to other intelligent control methods such as intelligent machine vision, wireless intelligent control systems, and PID control. The future development direction and application prospects of LEDs with intelligent control are addressed for ensuring the quality and productivity of cultivating plans inside the plant factories.
Figures & Tables
Fig. 1. Plant factory facility (Saya et al, 2018)
