To address the problem in single-planetary-wheelset transplanter mechanisms where the seedling picking and placing motions cannot be simultaneously optimized—thereby degrading transplanting quality—we propose a segmented variable gear-ratio wheelset mechanism whose rotation direction is opposite to that of conventional transplanting mechanisms and whose input and output periods are unequal.
First, we derived the continuous meshing angular condition equation for a segmented incomplete-gear set and solved for the motion parameters required for the segmented incomplete gear set to achieve continuous meshing. Next, by combining the non-uniform transmission ratio of an oval (non-circular) gear with the cubic high-amplitude fluctuation transmission ratio of the segmented incomplete gear, we obtained the multi-step unequal-amplitude transmission ratios required for the ring-loop (ankle-shaped) seedling-transplanting trajectory. We then established a kinematic model of a non-circular gear planetary wheelset transplanting mechanism that includes incomplete gear sets and developed a MATLAB-based auxiliary design program for the transplanter. At the same time, in accordance with rice seedling transplanting agronomic requirements and using a human-machine interactive selection process, we selected a set of mechanism parameters that realize a ring-loop transplanting trajectory capable of large pick displacement with slow picking (pick loop 47 mm) and a large planting angle (planting angle 80.6°).
Finally, we compared simulation results with theoretical calculations. The results show that the parameters of the incomplete gear set meet the requirements, and that the mechanism's motion trajectory and posture are in substantial agreement with theory.
Prototype tests measured a picking angle of 20.95° and a planting angle of 80.3°, validating the feasibility of the combined-variable transmission-ratio transplanting mechanism design.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |