Abstract:Existing rice pottedseedling transplanting mechanisms with compound planetary gear trains face difficulty in providing both the satisfactory trajectory and orientation during transplanting seedlings at the same time. Therefore, a design method based on the combination of forward design and reverse design was proposed to overcome the problem. The principles of the design method were discussed and illustrated by the design of a rice pottedseedling transplanting mechanism with a compound planetary gear train with a noncircular gear. The design requirements of rice pottedseedling transplanting mechanism with a compound planetary gear train with a noncircular gear were established, and its work principle was studied. On the basis of the previous forward design, fine tuning its static transplanting trajectory, and the reverse design was developed to further optimize the design of transplanting mechanism. The kinematics analysis of the transplanting mechanism in reverse design section was carried out and its kinematic model was set up. The computer aided analysis and design software of the transplanting mechanism based on Matlab was developed. A set of design parameters of the transplanting mechanism were obtained by using this software by means of humancomputer interaction. According to the final mechanism parameters, the transplanting mechanism structure was designed, a 3D model of the mechanism was created by using Pro/E software, and a virtual simulation test was performed by using ADAMS software. Finally, a physical prototype of the mechanism was developed for benchscale testing. The trajectory obtained by theoretical calculation was compared with trajectories obtained by virtual simulation and benchscale tests. The design parameters, including the trajectory criteria, takingseedling angle and pushingseedling angle, and the difference between the takingseedling angle and the pushingseedling angle were compared with the corresponding design requirements. The results met the specified design requirements, thus the transplanting mechanism designed with this method not only satisfied the orientation requirement, but also provided satisfactory transplanting trajectory.