Design and experiments of a seed clearing, reseeding and elevating type seed metering device for sugarcane

Sugarcane is prone to disorder in the process of transversal elevating sowing. A high missed-seeding index and a low qualified index can result in low germination rates for the total yield of sugarcane. In this study, an elevating type sugarcane seed metering device was designed with the function of seed clearing and reseeding. The device shared multiple functions, including cane separation, sorting, dynamic elastic seed clearing, and automatic grading adjustment in the process of elevating transportation. Firstly, the key structural and operating parameters of the seeding device were determined the impact on the seeding performance using dynamic analysis in the processes of cane separation, clearing, and reseeding during the elevating and sowing of transversal sugarcane. Then, the collision between sugarcane and elastic board was simulated using the EDEM-RecurDyn coupling platform. The force acting on the sugarcane was calculated in the process of seeding and clearing. A series of push and compression tests were carried out to determine the parameters of the elastic plate. The deformation mechanism of the elastic board was used to clarify the force on the sugarcane. A blocking test was conducted on the sugarcane collection box. The gap was determined between the seed guide plate of the cane collecting box and the bottom of the seed separating and cleaning board, in order to ensure smooth and unobstructed movement of the sugarcane and unobstructed falling of sugarcane. A PVC seed planting platform was selected to launch a single-factor experiment. The optimal solution range was narrowed down in the experiments. A quadratic regression orthogonal rotation combination experiment was conducted on a single-factor experiment, in order to obtain the optimal performance parameters of the seed metering device. A regression mathematical model was established to analyze the effects of the length of the first and second clearing and reseeding area and the seeding belt speed on the miss-seeding index, multiple-seeding index and qualified index. The test results showed that the significant coefficients of the length of the first and second seed clearing and reseeding area were less than 0.01, indicating a significant impact on the miss-seeding index, multiple-seeding index and qualified index. The speed of the seeding belt shared a significant impact on the miss-seeding index, with a significance coefficient of less than 0.01. However, there was no significant impact on the multiple-seeding index and qualified index, with significance coefficients greater than 0.05. After multi-objective optimization, the optimal parameter combination was determined to be: the length of the first-level seed cleaning and reseeding area was 13 cm, the length of the second-level seed clearing and reseeding area was 16 cm, and the speed of the seed metering belt was 97 mm/s. The validation test showed that the miss-seeding index was only 1.7%, the multiple-seeding index was 3.5%, and the qualified index was 94.8% under this optimal combination. The miss-seeding index of the metering device was reduced by 75%, and both the multiple-seeding index and the qualified index were improved significantly, compared with the 6.9% miss-seeding index of the conventional elevating type seed metering device. This device can be expected to achieve a reduction in the miss-seeding index and an improvement in the qualified-seeding index of sugarcane. This finding can lead to promoting accurate planting and high yield in sugarcane planting.