Design of a mixed seed tape knitting machine based on the vibrating disk for seed feeding

A mixed seed tape knitting machine has been used to form the landscape pattern of cultivated crops in industrial and agricultural production. In this study, a new mixed seed-tape knitting machine was proposed to realize the fully automatic operation using a vibrating disk for the seed's continuous feeding. The principle of vibration conveying was theoretically established using numerical analysis. A systematic optimization was carried out to determine the key structure parameters of the vibrating plate for the seed supply, according to the agronomic requirement of specific flower seeds. Theoretical analysis and structural design were also performed on the opposite rubber-roller feeding device in the feeding system. As such, a prototype was built to optimize the layout of each part of the whole machine and the work flow of seed tape weaving during operation. After that, a slip rate test was conducted to evaluate the slip rate of the feeding device under the alternative woven seed-tape efficiency. The three-factor orthogonal test and the range analysis of the test data were utilized to determine the optimal working parameters of the seed metering system. The marking accuracy of the marking device was also measured to evaluate the performance of the prototype at different speeds. The coefficients of variation of the key/relative points of the pattern, and the weaving area were selected to evaluate the reduction degree of the pattern, after the outline of the pattern was formed in the field. Finally, the seed tape was placed in the pattern for the plants using the new mixed knitting machine. The pattern was collected using the photographing equipment. The restoration degree of the pattern was then evaluated by a specific algorithm. The test results showed that the factor "the time of filling the study tape by the seed metering system" presented the greatest influence on the qualified rate of seed metering, followed by the factor "the flow rate of the seed supply by the vibrating seed supply tray", whereas, the factor with the least influence was the "switching speed of the guide plate" among the seed metering system. The state switching speed the seed metering system was 7 r/s in the state of the oscillating seed guide device, the seed replenishment time was 200 ms, and the vibration when the seed supply flow was 40 grains/s, indicating the mixed seed tape weaving machine reached the best working condition, and the qualified rate of seed filling to the tape reached 87.8%. The test showed that the marking accuracy error of the prototype marking device was between 0.1% and 1.1%, where the tape slip rate was 5.62% and below. The indoor spreading test showed that the relative position variation coefficient of the weaving pattern, area, and the key points of each row were less than 10%, 10%, and 5%, respectively. The developed pattern cosine value comparison algorithm was used to evaluate the similarity between the collected and the target pattern after the pattern collection of the field planting experiment. The reduction degrees of the pattern were 86.58% and 72.39% in the seedling and flowering stage, respectively, fully meeting the needs of landscape modeling. The finding can provide a strong reference for the mechanization level of mixed seed tape knitting machines in modern agriculture.