Establishment of the Interaction Simulation Model between Plug Seedlings and Soil

Abstract

Currently, the simulation parameters for the model of the interaction between the transplanter, the plug seedlings, the soil, and the pot damage mechanism still need to be clarified. The optimization design of the planters and the improvement of planting quality are still urgent issues that need to be solved. In this paper, the simulation parameters of the pot and the soil were calibrated based on the pressure distribution measurement technology. With the actual collision impact force and matrix loss rate as the targets, a four-factor, three-level orthogonal test was designed to obtain the optimal parameters. Through the optimization analysis of the experimental results, it could be concluded that the pot–soil restitution coefficient, the pot–soil static friction coefficient, the pot–soil rolling friction coefficient, and the surface energy were 0.31, 0.88, 0.35, and 1.07 J/m2, respectively. The experimental verification of the optimal parameter combination showed that the relative error of the collision impact force was 1.65% and that the relative error of the matrix loss rate was 2.32%, which verified the model’s reliability. Based on the optimal parameters, the movement law of the hole tray seedlings was studied at different positions during the transplanting process. The plug seedlings collided not only with the planter but also with the soil, which led to the breakage and looseness of the pot structure. The relative error between the matrix loss rate of the transplanter inserting soil, the matrix loss rate of the transplanter that did not enter the soil, and the simulated matrix loss rate was less than 10%, which further proved the accuracy of the simulation model.

Evaluation of the Functional Parameters for a Single-Row Seedling Transplanter Prototype

“…In the case of the prototype intended for micro-farms in Romania, the solution to eliminate complicated and error-prone seedling extraction and transport systems was the use of exclusively gravitational extraction and multistage transport of seedlings with nutrient substrate. Due to the limits to which the substrate can withstand different stresses [17], the verification of Jiffy substrates to transport shocks validates the choice of this simplifying solution.…”

“…It can be seen that the value obtained, which is the minimum real planting time of a seedling, calculated with the limited maximum working speed of the machine, follows a relation (17), where the theoretical planting time does not take into account the partial overlapping of some components of the planting and distribution times, an essential element in the machine functioning in different operating modes.…”