Simulation of square cluster planting

Introduction. For cultivated crops, the optimal form of spacing is square form, which is provided by the square cluster method of planting. Currently, due to the high metal consumption and low productivity, this method of planting has been replaced with a single-seed planting one. But this does not solve the problem of rational distribution of seeds in the field, so the problem of plant spacing with the use of the optimal square form of spacing is relevant. The aim of the study is to develop and analyze a simulation model of square cluster planting based on an algorithm for controlling the executive mechanisms of the seeder sections using devices for local coordination of the seeding apparatus. Materials and Methods. A programmable square cluster planting using local coordination of the seeding apparatus and an algorithm for its realization are considered. The article describes the construction of a simulation model of sowing planting in Simulink Matlab with justification of its elements. The seed spreading in furrows and the seeder variable speed are taken into account. The number of pulses per revolution of the encoder shaft is theoretically justified. Results. The graphs of the distance traveled, positions coordinates of the flap opening and control signals depending on the time are constructed. The analysis of the encoder settings is carried out. When varied the plant spacing and the coordinates of the first flap opening, the dimension of the last seed cluster changes in the range from -2.6 ∙ 10-3 to 2.7 ∙ 10-3 m. With the increase in the seeder speed from 1.5 to 3.0 m/s, the mathematical expectation of the seed cluster dimensions increase from 0.054 to 0.218 m, and the coefficient of variation decreases from 61.2 to 15.0%. Discussion and Conclusion. The analysis of the simulation model of the square cluster planting showed that the algorithm for controlling executive mechanisms together with the local coordination system works adequately and provides high precision of placing seed clusters in the field. The dependences of the optimal number of pulses per an encoder shaft revolution on the specified seed spacing and radius of the track measuring wheel are determined. It was determined that the maximum dimension of the last seed cluster does not exceed 2.7 mm per 1 000 m (for x = 0.3 m and t = 0.7 m). It was found that the precision of the distribution of seed clusters in the field is determined more by the seeder speed than by the settings of the measuring device.