Design and test of a pneumatic type of high-speed maize precision seed metering device

This study proposed a pneumatic type of high-speed maize precision seed metering device and analysed the motion mechanism of maize seeds during the filling, cleaning, and seed dropping processes of the device. Singlefactor test methods were used to explore the influence of forward velocity, negative pressure of the seed metering device, and positive pressure of the seed guide tube on seeding performance separately. Additionally, based on high-speed camera technology, trajectory analysis was performed on continuously dropping maize seeds under different positive pressures of the seed guide tube. Results showed that an increase in positive pressure of the seed guide tube shortened the seed dropping time of maize seeds and made the time interval between adjacent maize seeds leaving the seed guide tube more uniform. Furthermore, a three-factor five-level orthogonal rotation combination test was used to explore the optimal working parameters of the pneumatic type of high-speed maize precision seed metering device. The results indicated that the optimal parameters were a forward velocity of 10 km/h, negative pressure of the seed metering device of 4.5 kPa, and positive pressure of the seed guide tube of 3 kPa. Verification tests demonstrated that the qualified index was 98.31% and the coefficient variation was 9.26%.