Design and Experimental Study on a New Horizontal Rotary Precision Seed Metering Device for Hybrid Rice

In order to meet the sowing demand of the hybrid rice plug seedling, a horizontal rotary precision seed metering device was proposed. The key structure parameters were designed, the kinematics analysis of the seed-filling process was carried out, and the main influencing factors of the seeding performance evaluation index were determined. Taking motor speed, the eccentric distance of the disk, and seed layer thickness as test factors, and the taking qualification rate, repetition rate, and miss-seeding rate as seeding performance test indexes, the quadratic regression orthogonal rotation combination test was carried out, and the relationship between the test factors and evaluation indexes was approached by a quadratic polynomial. On the basis of discussing the influence of the test factors on the performance index, the regression surrogate mathematical model between the main performance index and the influencing factors was established. The value of the evaluation index of correlation degree p between the model variables was less than 0.01. Based on the regression surrogate mathematical model, the response surface of the qualified rate of the seeding performance evaluation index was established, and the test data were analyzed by multiple regression analysis. The rapid prediction of qualified rates under the influence of test factors was realized, and the optimum test parameters were obtained as follows: motor speed 165 r/min, an eccentric distance of disk 22 mm, seed layer thickness 28 mm, qualification rate 98.55%, miss-seeding rate 1.45%, and repetition rate 0%. According to the best combination of test parameters, the performance evaluation index test of the prototype was carried out, and the qualification rate, miss-seeding rate, and repetition rate were 98.34%, 1.66%, and 0%. The experimental results were in good agreement with the theoretical analysis, indicating that the horizontal rotary precision seed metering device can meet the agronomic requirements of hybrid rice. The research results could provide some reference for the design of a precision seeding device for industrialized plug seedlings.