To address problems encountered in current potato harvesting machines, such as potato damage, poor adaptability, and low operational efficiency, a new towed potato picking and bagging machine (4UJ-180A) equipped with a soil-digging axis, flexible conveying device, and hydraulic control system was developed. The digging mechanism of the harvester can reduce soil blockage and minimize damage to potato skins. The rubber biomimetic finger can maintain stable transportation of potatoes and minimize collisions. The hydraulic control system, the buffering components, and the bagging device work together to flexibly and continuously collect potatoes, reducing skin damage during the harvesting process. Based on the structure of the whole machine, the harvesting process, and the working principle, the soil picking, lifting buffer, and potato collection process were analyzed. Theoretical calculations were used to determine the structure and operational parameters of the potato picking, lifting buffering, and bagging segments. An experiment utilizing the orthogonal method was conducted. The experiment consisted of three factors and three levels, with the test indicators being the potato skin damage rate, potato injury rate, loss rate, and impurity rate. The factors considered in the experiment were the forward speed, conveyor speed, and soil-digging shaft speed. Field experiments demonstrate that at a forward speed of 1 m/s, soil digging shaft speed of 35 rpm, and conveyor speed of 28 rpm, the rate of potato skin damage is 2.8%, the potato injury rate is 1.3%, the loss rate is 0.4%, and the impurity rate is 0.7%. These experiments verify that all indicators adhere to national industry standards, providing a valuable reference for equipment research, development, optimization, and improvement.

In China, potatoes are predominantly cultivated using the tuber piece planting method. During the cutting process, it is essential to divide seed potatoes into tuber pieces based on the distribution of their bud eyes, ensuring that each tuber piece contains one to two bud eyes. These tuber pieces are subsequently sown into the soil. Currently, the preparation of potato tuber pieces relies heavily on manual labor, which presents challenges such as inefficiency and high operational costs. To address these issues, a seed potato cutting machine capable of posture adjustment, cutting, and spraying was designed. Three types of seed potato cutters were developed based on the distribution patterns of bud eyes. The movement mechanism of the posture adjustment process was analyzed, and a mathematical model was established. The key factors influencing the posture adjustment effectiveness were identified through discrete element simulation analysis. Using the qualified rate of potato cutting and the blind eye rate as evaluation metrics, a three-factor, three-level, orthogonal experimental design was implemented. The experimental factors included the rotational speed of the conical roller, the number of conical rollers, and the cutting angle. For the straight-shaped cutter, the optimal combination was determined as follows: a conical roller speed of 12 r/min, 44 conical rollers, and a cutting angle of 0°, yielding a qualified rate of 90.3% and a blind eye rate of 1.86%. For the Y-shaped cutter, the optimal parameters were 14 r/min, 44 conical rollers, and a 5° cutting angle, achieving a qualified rate of 87.9% and a blind eye rate of 2.86%. The cross-shaped cutter performed best at 14 r/min, 44 conical rollers, and a 0° cutting angle, with a qualified rate of 87.1% and a blind eye rate of 3.80%. All optimal configurations met agronomic requirements, demonstrating the efficacy of the designed machine and cutters.

Aiming to solve the problems of the large harvesting loss and low harvesting efficiency of wide- and narrow-row corn harvesting header in China, a method for the side installation of a header is proposed. A wide–narrow-row corn harvesting header with high working efficiency and low harvesting loss was designed. The collision energy balance equation of corn ears was established. The analysis shows that the kinetic energy change before and after the collision between the ear and the picking plate is the main cause of the shedding of and damage to corn kernels. Based on this, the main structural parameters of the corn harvesting header were designed. Based on the principle of Box–Behnken test, the response surface test was designed. The effects of the plant feeding speed, feeding angle, and rotation speed of a stem pulling roller on harvesting performance were analyzed. The best combination of working parameters was determined: The plant feeding speed was 1.08 m/s, the feeding angle was 52.46°, and the rotation speed of the stem pulling roller was 835.25 r/min. At this time, the grain damage rate was 1.09% and the grain loss rate was 0.14%. The corresponding parameters are verified by experiments. The results show that the grain damage rate was 1.12% and the grain loss rate was 0.14%. The optimization results are essentially consistent with the verification results, which meet the requirements of corn harvesting performance.

Traditional fluted roller seed metering devices exhibit unstable seeding rates during forage seed mixed sowing. To address this issue, a new seed metering device was designed based on the agronomic requirements of forage seed mixing and the structural characteristics of fluted roller mechanisms. The discrete element method (DEM) was employed to numerically simulate the movement of particles within the seed metering device. Single-factor experiments identified optimal parameter ranges for the seed metering device: a metering shaft speed of 10–20 r/min, a seed inlet width of 8–24 mm, and a seed outlet height of 10–20 mm. A response surface methodology (RSM) experiment was then designed using Design-Expert 13 software. The results yielded optimal operating parameters: a metering shaft speed of 18.9 r/min, a seed inlet width of 9.3 mm, and a seed outlet height of 14.4 mm. The field experiment validated the seeding performance with the optimal parameter combination. The coefficient of variation (CV) for the first-class seed (CV₁) was 4.16%, and for the second-class seed (CV₂) it was 2.98%, both of which met the requirements for mixed sowing of forage.

The study of Leymus chinensis seed cleaning has been hindered by the lack of accurate discrete-element contact parameters for seed–straw interactions, thereby limiting, to some extent, the optimization of cleaning equipment. To address this issue, the present study analyzed a mixture of L. chinensis seeds and straw, and determined their fundamental physical and contact parameters via laboratory experiments. The Hertz–Mindlin (no slip) discrete element simulation model was employed to calibrate the parameters of the seed–straw mixture. A Plackett–Burman test was used to identify key factors significantly affecting the repose angle, including the seed–seed static friction coefficient and the seed–straw static and dynamic friction coefficients. These factors’ optimal ranges were further refined using steepest ascent experiments. A Box–Behnken design was used to optimize contact parameters, resulting in the following values: a seed–seed static friction coefficient of 0.709, a seed–straw static friction coefficient of 0.281, and a seed–straw dynamic friction coefficient of 0.085. Validation experiments demonstrated an error of less than 2.14%, confirming the reliability of the calibrated parameters. This study offers a theoretical foundation for discrete element simulations in L. chinensis seed cleaning applications.