Design of a control system for a mini-automatic transplanting machine of plug seedling

•The size of the machine is 1.5*1.2*1.1 m. It is smaller than the common transplanter. It is suitable for transplanting in narrow space greenhouse.•The mechanism of variable-pitch seedling extracting was adopted to realize the technology of small distance row seedling picking and large distance static seedling throwing.•The direct and reciprocating cup type seedling separation mechanism was adopted to realize the static seedling catching and separating.