Analysis on Transporting Methods of Cultivation Unit for Vertical Cultivation in Plant Factory

Automatic transport can improve the operational efficiency in plant factory production and reduce the use of labor. However, a determination of a plant factory automation operation mode should comprehensively consider the economic strength of the enterprise, operation objects and operation mode, production scale, technical strength, labor costs, and other factors. In this study, a logistics transport system comprising a set of cultivation units was developed for plant factories, using a mode based on shelf-end delivery without power inside the shelf. Moreover, an analysis was conducted on four modes of common transportation methods for the cultivation units for vertical cultivation in plant factories. The results showed that, when comparing the progressive transport type and warehousing/reciprocating transport type for cultivation units, the transport productivity of the former is higher than that of the latter, and the difference in the two transport productivities is proportional to the capacity for cultivation units in each layer. When the capacities for cultivation units in each layer are 20 and 40, the transport productivity of the former is 115-200% and 130-250% higher than that of the latter, respectively. Moreover, the logistics transport system developed herein reaches an input (output) transport productivity of 330 (270) cultivation units h(-1).