HIERARCHICAL CROP FLOW STRATEGY FOR VARIABLE INTER-ROW SPACING BY MULTI-MANIPULATOR MOBILE ROBOT AND VERTICAL ARRAY PLANT TOWER DESIGN

Optimal space utilization is an underlying goal in indoor cultivation systems where soilless hydroponic culture with row-based layout is to be applied. However, a problem in conventional hydroponic systems when using individual hydroponic channels, is fixed inter-row crop spacing for entire duration of growth. To make more efficient use of the given space, while benefiting from variable inter-row crop spacing, novel concept of vertical farming can be implemented by introducing movable plant beds with an automatic spacing system in a multi-layer cultivation array. A hierarchical crop flow strategy has been characterized. In addition, conceptual design and operational principles of a mechatronic design including an autonomous multi-manipulator wheeled robot and a rack structure with multiple cultivation layers, so called a plant tower, have been described. Flexible inter-row crop spacing will be possible as a result of stepwise relocations of hydroponic channels among different layers via the cooperation of plant tower’s spacing mechanism and pull-push efforts of robot arms end-effectors. Interdependent sequenced actions of robot working units and the plant tower will create a time-based discrete flow of hydroponic channels, oriented from higher to lower layers. A primary design for a six storey plant tower with three distinct growth stages has been described.