Seeding performance optimization on vibration-arranging type seeding device for potato micro-seed

The offspring potato grown by potato micro-seed has the characteristic of high yield, favorable quality, high commodity rate, and so on. Furthermore, enhancing the mechanical level of potato micro-seed planting is one of the key methods to promote the development of potato micro-seed. Therefore, a mechanical planting technology and the related seeding device were developed based on the principle of forced vibration to promote the mechanical level of potato micro-seed planting. The seeding device mainly includes a seed box, a frame assembly, driving unit, single row arranging and conveying mechanism, vibratory reseeding mechanism, and so on. Firstly, the working principle of the seeding device was introduced. Then, according to the operation characteristic of the seeding device, the kinematics and dynamic analysis was conducted to analyze the process of potato micro-seed planting, which included the process of seeds' single row sorting, vibratory reseeding, and conveying and dropping. Meanwhile, the main factors which influence the seeding performance and their test value range were determined, which were the eccentricity of eccentric wheel (EEW), revolving speed of driving shaft (RSDS) and linear speed of seed bed belt (LSSB). And then, EEW, RSDS and LSSB were chosen as experimental factors, and multiple-seeding rate (MUSI), miss-seeding rate (MISI) and qualified-seeding rate (QUSI) were chosen as evaluation indicators. Besides, the micro-seed variety Xisen 3 was selected as the material for test. Consequently, the quadratic regression orthogonal combination based on test bed was developed to test three levels of micro-seeds' seeding property. The regression mathematical models reflecting the relationship between experimental factors and evaluation indictors in each level of micro-seed seeding property were built. The related experimental factors influencing the seeding performance were analyzed. For level 1 micro-seed, the most significant of main effect factors reflecting MISI and QUSI both were RSDS, and for MUSI was EEW. For level 2 micro-seed, the most significant of main effect factors reflecting MUSI was EEW, MISI was LSSB and QUSI was RSDS. For level 3 micro-seed, the most significant of main effect factors reflecting MUSI and QUSI both were RSDS, and for MSI was RSDS. In order to obtain the good seeding operation parameters of seeding device, the optimization module of Design-Expert 8.0.6 was applied, and the theoretical value range of optimization results were calculated. Finally, the verification test in verifying the above theoretical optimization results was carried out by test bed. The results showed that for level 1 micro-seed, when EEW was 4.0 mm, RSDS was 815 r/min and LSSB was 0.56 m/s, the MUSI, MISI and QUSI was 1.35%, 3.26% and 95.39%, respectively. For level 2 micro-seed, when EEW was 4.0 mm, RSDS was 820 r/min and LSSB was 0.86 m/s, the MUSI, MISI and QUSI was 3.10%, 4.01% and 92.89%, respectively. For level 3 micro-seed, when EEW was 4.0 mm, RSDS was 840 r/min and LSSB was 1.08 m/s, the MUSI, MISI and QUSI was 4.19%, 1.54% and 94.27%, respectively. As it was seen from the verification test results, and in the suitable experimental combination parameters of three levels micro-seeds, both of the MUSI and MISI were all below 5%, the QUSI was all above 90%. In summary, this seeding device satisfied the performance requirements of potato planter. Furthermore, this research provides reference for researching, designing and optimizing the seeding device of micro-seed and other large size crop seeds, and finally promotes the seeding performance.