Design and Experiment of Automatic Adjustable Transplanting End-Effector Based on Double-Cam

Abstract

In view of the plugged-out end-effector that can adapt only to a specific size of the tray, the needle spacing and angle of the seedling needle are fixed. In this paper, a new type of plugged-out transplanting end-effector is proposed. The end-effector adopts a double-cam structure to automatically adjust the spacing and angle of the seedling needle, which solves the problem of picking seedlings for different sizes of trays. Firstly, the working principle of 72-hole, 128-hole, and 200-hole trays and a plugged-out end-effector was analyzed. The overall structure of the end-effector was designed. Subsequently, the EDEM software was used to construct the pot seedling model and conduct single-factor simulation experiments to identify the range of factors for the subsequent regression orthogonal experiment. Finally, a tray transplanting test platform was built. With the grasping acceleration, penetration angle, insertion depth, and insertion margin ratio as the test factors and the pot seedling breakage rate as the test evaluation indicators. A four-factor three-level orthogonal regression experiment was conducted to establish a regression model of the seedling breakage rate, and its parameters were optimized. The optimal combination is detailed as follows: a 72-hole tray grasping acceleration of 0.28 m/s2, a penetration angle of 13°, an insertion depth of 40 mm, and an insertion margin ratio of 15%; a 128-hole tray grasping acceleration of 0.28 m/s2, a penetration angle of 12°, an insertion depth of 36 mm, and an insertion margin ratio of 15%; a 200-hole tray grasping acceleration of 0.28 m/s2, a penetration angle of 11°, an insertion depth of 32 mm, and an insertion margin ratio of 10%. Under the optimal combination, the breakage rate of 72 holes reached 2.92%. The breakage rate of 128 holes was stable at 1.76%, while that of 200 holes was stable at 0.68%, which is conducive to the study of a general end-effector. The device developed in this study provides an effective solution to taking and throwing different sizes of cavitation trays, thus providing a practical reference for the study of a generic end-effector.

Design, Integration, and Experiment of Transplanting Robot for Early Plug Tray Seedling in a Plant Factory

“…To achieve the operations of removing and replanting seedlings, researchers have developed various forms of end effectors, mainly including the plug-in and clamping type [15][16][17], oblique insertion type [18][19][20][21], and deformed sliding needle type [22,23]. The current end effectors have found wide applications in transplanting seedlings at relatively advanced growth stages.…”

“…However, early-stage seedlings, characterized by underdeveloped root systems and loose substrate, especially for nongerminating holes, have no root system to consolidate the substrate, presenting challenges in effective grasping. The existing end effectors used in transplanting machines are primarily designed for well-developed root systems and compacted substrate blocks [21,[25][26][27] in greenhouses, so they may not be suitable for handling younger seedlings grown in loose substrate in plant factories.…”

Design and Experiment of Dual-Row Seedling Pick-Up Device for High-Speed Automatic Transplanting Machine

“…The end-effector of the seedling picking machine is mostly single, and the seedling picking efficiency is 50-60 plants/row•min −1 [7][8][9]. The method of inserting and gripping seedlings is stable and reliable and can adapt to the existing plug seedling cultivation techniques in China [10][11][12][13]. Han et al [14] developed a door-frame swing seedling pick-up device, which consists of a path manipulator and two end-effectors.…”