To solve the problem that there are many human factors, great difficulty, and low efficiency in distinguishing quinoa seeds from weed seeds and distinguishing the quality of quinoa seeds by appearance, a method of quinoa seed detection and classification based on computer vision is proposed. In this study, convolutional neural network and Vision Transformer (ViT) were used to quickly and nondestructively classify different quinoa seeds and weed seeds. The dataset used in this experiment was 1440 sample images containing quinoa seeds and weed seeds, which were divided into training set, test set, and validation set at a ratio of 8:1:1. The training set was 1152 pieces, test set was 144, and the validation set was 144 pieces. The convolutional neural network model and ViT model based on deep learning were established. The results show that the average classification accuracies of MobileNet, VGG16, ResNet50, and ViT models used in the experiment are 93.75%, 90.97%, 93.75%, and 98.61% respectively. The accuracy of ViT classification is much higher than that of convolutional neural networks, establishing a benchmark for quinoa seed classification. This study provides a reproducible dataset construction method and a dual-imaging strategy, and demonstrates practical deployment value for automated seed grading and purity testing.

In order to ensure the most reasonable distribution of wheat seeds in the field to improve seeding quality and uniformity, a set of negative pressure precision seed-metering device was designed, which shares a hollow shaft. Every seed-metering device can sow two rows of wheat. By the STAR-CCM+, the analysis of nephogram, vectogram and streamline graph showed that more ideal structural parameters of the seed-metering device are 0.5 mm width of the slit sucking seed (WSS), 150-200 mm diameter of the seed-metering disc (DSD), 2.0 mm axial depth of air chamber in the seed-metering disc (ADS), and arc-shaped cross-section shape of the ring groove sucking seed (CSGS). Single-factor test on the JPS-12 test-bed analyzed the influence of the CSGS, WSS, DSD, and ADS on the qualified index (I_q), multiple index (I_mul), miss index (I_miss) and coefficient of variation of qualified seed spacing (CV). Through the orthogonal on the JPS-12 test-bed, it is found that the influence of vacuum negative pressure and seed-metering device shaft speed is significant on the I_q, I_miss and I_mul. Based on these, the structural parameters of the seed-metering device were optimized. The DSD is 180 mm, the WSS is 0.7 mm, the ADS is 2.5 mm, and the CSGS is arc-shaped. The optimization seed-metering device was tested on the JPS-12 test-bed. The I_q is 86.66%, the I_miss is 5.09%, the I_mul is 8.25%, and the CV is 24.50%. These testing results fully coincide with the standard JB/T 10293-2013 Specifications of single seed drill (precision drill). The seed-metering device meets fully the requirements for wheat precision seeding.

Aiming at the problem of poor uniformity of maize sowing caused by ground wheel slip, an electronic control seed-metering system (ECSMS) for maize single seed precision sowing was designed and a mathematical model for motor control of the ECSMS was determined. The PID parameters were set by Z-N method and fuzzy control. The fuzzy PID control design and Simulink simulation were completed by MATLAB, which reduced response time of the system by 0.23 s and improved the control accuracy. Experiments on the JPS-12 test bench show that the qualification index (QI) of maize seed-metering device with the ECSMS increases by 4.47%, the multiples index (MI) decreases by 1.96%, the miss index (MIX) decreases by 2.81%, and the coefficient of variation (CV) of qualified seed spacing decreases by 5.06%, and the sowing uniformity has been greatly improved. Test results of the soil-tank test bench show that the system has good sowing uniformity and stability. And the QI is 96.74%, the MI is 2.15%, the MIX is 1.10%, and the CV of qualified seed spacing is 16.24%. Under different setting seed spacing and different sowing operation speed, the change range of seeding quality index was within 10%. The results of field sowing test show that the QI was 84.21%, the MI was 2.63%, the MIX was 7.89%, and the CV of qualified seed spacing was 22.15%, which meet the requirements of JB/T 10293-2013 ‘Specification for single seed planters (precision planters)’ and the agronomic requirements for maize precision sowing. The system runs stably and reliably in practical operation and has good operation performance.

Aiming at the problem of difficulties in seed filling and seed cleaning caused by the small specific gravity, small size, and irregularity of quinoa seeds, a positive-negative pressure precision seed-metering device for quinoa seeds with a disturbed seed-filling mechanism was designed. The disturbed seed-filling mechanism can improve the seed-filling performance of the precision seed-metering device and reduce the power consumption required by the forced-draught fan. Positive pressure seed cleaning can solve the problem of pore blockage caused by small and light quinoa seeds and improve work stability. Taking Jili No. 3 seed as the research object, simulation analysis of the flow field in the air chamber of the precision seed-metering device was carried out by the Fluent 2021 R1 software. The influence of seed-sucking hole structure parameters (shape and number of seed-sucking holes, inclination angle of seed-sucking holes, and diameter of seed-sucking holes) on the flow field was analyzed by a pressure nephogram and a velocity vectogram. The optimal parameter combination was obtained as follows: a circular-cone-type shape of the seed-sucking hole, a number of 20 seed-sucking holes, a 70° inclination angle of the seed-sucking hole, and a 1 mm diameter of the seed-sucking hole. EDEM 2020 software and orthogonal test were used to optimize the design of the disturbed seed-filling mechanism. The influence of structural parameters of the disturbed seed-filling mechanism (groove radius of the disturbed seed-filling mechanism (GRDSM), arc of the disturbed seed-filling mechanism (ADSM), and position angle of the disturbed seed-filling mechanism (PADSM)) on the qualified index (I_q) of scooping seeds was analyzed. The optimal parameter combination was obtained: 1.3 mm GRDSM, 140° ADSM, and 25° PADSM. With the help of the JPS-12 test-bench, a response surface test was carried out with the qualified index (I_q), the miss index (I_miss), and the multiple index (I_mul) as test indices, and the seed-sucking negative pressure, the seed-metering device rotation speed, and the seed-falling height as test factors. The optimal working parameter combination was obtained: –3.0 kPa seed-sucking negative pressure, 15 r/min seed-metering device rotation speed, 100 mm seed-falling height. Validation tests were carried out on the optimized seed-metering device, and the results showed that the I_q was 82.5%, the I_miss was 6.5%, and the I_mul was 11%, which met the index requirements in JB/T 10293-2013 Technical conditions of single seed (precision) seeder. The results of this study can provide a reference for the design of machinery for the precision seeding of small seeds such as quinoa.