Abstract:The shape of the work trajectory and the pose requirements of the transplanting arm in a specific position are the primary problems to be considered in the design process of the transplanting mechanism. A noncircular gear planetary gear train transplanting mechanism based on approximate multipose was presented in order to obtain multiple desired positions and take into account the specific shape of the work trajectory. The information matrices of eight expected poses were transformed into threedimensional space by quaternion using kinematics mapping theory, and the general solution space was expanded by introducing eigenvectors after the singular value decomposition of the matrix. A fourbar mechanism was formed by selecting two sets of suitable twobar groups, whose coupler trajectory can approximately go through all the prescribed poses. The transmission ratio of noncircular gear was solved based on the kinematic characteristics of the selected twobar group. Moreover, after establishing the circurity function and determining the design parameters, the shape of the noncircular gears was optimized by using the genetic algorithm. Finally, the prototype of the transplanting mechanism was manufactured for the primary test. A testing result that had an identical shape and operating poses with that of theoretical calculation was obtained, as well as the qualified picking success rate, which effectively verified the correctness of the motion synthesis and design method. This method can be used for reference in the design of transplanting mechanism with multipose requirement.