Study on the Impact Damage Characteristics of Transplanting Seedlings Based on Pressure Distribution Measurement System

Abstract

Collision is one of the main causes of mechanical damage to the seedling during transplanting. To reveal the impact damage characteristics of plug seedlings, the kinetics equations of seedling collision were established based on Hertz’s contact theory, and the kinematic characteristics, elastoplastic deformation, and collision damage during seedling collision were analyzed using high-speed photography. Using the Tekscan pressure distribution measurement system, the significant levels of various factors that affect impact peak force (IPF) and damage of seedling pot (DSP) were studied, the change rule of contact pressure distribution of seedlings under significant factors was measured, and a regression model between IPF and DSP was established. The results showed that collision material, drop height and seedling pot size had significant effects on IPF and DSP. The contact pressure area of different collision materials from large to small was soil block, steel, and ABS plastic. The contact pressure area of seedlings of different pot sizes was big, medium, and small in descending order. At a dropping height of 50~350 mm, a contact pressure > 10 kPa accounted for the major contact pressure area, which is the main reason for collision damage of the seedling pot. Linear regression models between IPF and DSP under different factors were established, and the determination coefficients (R2) were 0.98 and 0.94, respectively. The results provided a theoretical basis for understanding the collision damage mechanism of the plug seedling and how to reduce damage during transplanting.

Study on Contact Stress Distribution Characteristics and Damage of Plug Seedlings Based on Flexible Pressure Sensor

“…Several factors are related to tray specification, such as the volume of the pot, the influence of the contact stress distribution, and the pot damage. We previously obtained through the vertical drop test that, with the increase of the tray specification, the contact stress area and the pot damage were reduced when the plug seedlings collided with the ground [22,32]. Although the posture and number of collisions of plug seedlings under actual transplanting conditions are variable, it is consistent with the rules obtained under the previous vertical drop conditions, so we only elaborated a little.…”

“…The 5250-type flexible film network tactile pressure sensor is used in this test, as shown in Figure 2. It has a matrix-shaped sensing area (245.9 mm × 245.9 mm), a resolution of 3.2 cm −2 , and a sampling frequency of 0-100 Hz [22,23]. The specific specifications are shown in Table 1.…”

“…The 5250-type flexible film network tactile pressu sensor is used in this test, as shown in Figure 2. It has a matrix-shaped sensing area (245 mm × 245.9 mm), a resolution of 3.2 cm −2 , and a sampling frequency of 0-100 Hz [22,23 The specific specifications are shown in Table 1. The experiment was carried out in the soil trench laboratory of Inner Mongolia Agr cultural University in Hohhot City, Inner Mongolia Autonomous Region.…”

Parameter Calibration and Optimization of a Discrete Element Model of Plug Seedling Pots Based on a Collision Impact Force

“…In this study, the pressure distribution measurement system of Tekscan Company in the United States is mainly composed of a flexible film network tactile pressure sensor, USB terminal, and I-Scan System data processing system. It can carry out static and dynamic measurements of contact stress and display the contact stress distribution in real-time through intuitive and vivid two-dimensional and three-dimensional images [30,31]. The 5250 model flexible film network tactile pressure sensor has a sensor size of 245.9 × 245.9 mm, a sensor spatial resolution of 3.2/cm 2 , a pressure measurement range of 0~0.179 MPa, and a scanning frequency of 0~100 Hz.…”