Innovation and kinematics analysis of rice wide-narrow row pot seedlingtransplanting mechanism

摘要

Wide-narrow row pot seedling transplanting (WPST) could result in high grain yield and quality. To meet its requirements, a new type of mechanism for WPST is designed based on the analysis of recent advances at home and abroad. The WPST mechanism consists of planetary gear trains with seven noncircular bevel gears, which is used in automatic rice pot seedling transplanter. The working trajectory and attitude properties are analyzed according to the agronomy requirements of rice WPST. To establish itskinematics, non-uniform B-spline curve is used to fit and control the outer pitch curve of the noncircular bevel gears, and D-H transformation matrices are introduced to express the trajectory and attitude of the planting paw in the world frame. Computer aided analysis and optimization program for WPST mechanism are developed. Based on the program, the effects of various parameters on transplanting trajectory and attitude are analyzed. By human-machine interaction, the structural parameters which meetthe demands of WPST mechanism are optimized. Using these parameters, the 3D model of the mechanism is bui the virtual simulation and physical prototype test are carried out. Simulation and experimental results agree with the theoretical analysis, which validate the theoretical model of the WPST mechanism.