Codonopsis pilosula is cultivated mainly in sandy soils, especially in the Dingxi area of the Gansu province, northwest China. They are mainly planted in hilly areas, where large machines cannot reach easily. Codonopsis pilosula transplanting has been adopted with a conventional flat planting way, film mulching and seedling outcrops. While its planting requires opening a shallow ditch, short operation cycle, considerable labor intensity and is in large demand, a simulation analysis was performed according to specific tillage resistance, helpful in the optimization design in later stages and the improvement of a domestic ditching plow’s performance. This paper studies the simulation performance of an adjustable trench plough and analyzes the orthogonal test and Design-Expert response surface of the data. EDEM simulation software was used to analyze the traction resistance of the furrow ditching mechanism in the ditching process. The results show that the traction resistance increased from 1751.31 N to 2197.31 N as the simulation working speed increased from 0.9 m/s to 1.5 m/s, 1.25 times higher than the former. It indicates that speed had significant effects on traction resistance. With the increase in working speed, the furrow traction resistance and specific consumed power were increased considerably. Using the stability coefficient of the ditching depth and consistency coefficient of ditching bottom width as test indices, speed and angle of furrowing as impact factors, Box–Behnken orthogonal experiment design method, and establishing test indices and test factors, the regression model between the analysis of the influence of the test index, comprehensive agronomic requirements and MATLAB factor optimization of the experiment, the optimized operation parameter combination was obtained: the forward speed was 0.9 m/s, the angle of ditching was 35° and the stability coefficient of the ditching depth and consistency coefficient of ditch bottom width were 97.57% and 98.03%, respectively. The data after the simulation comparison test can provide a design reference for the domestic small trench operation.

To improve the accuracy of the Hami melon discrete element model, the parameters of the Hami melon seed discrete element model were calibrated by combining practical experiments and simulation tests. The basic physical parameters of Hami melon seeds were obtained through physical experiments, including triaxial size, 100-grain mass, moisture content, density, Poisson’s ratio, Young’s modulus, shear modulus, angle of repose, suspension speed and various contact parameters. Taking the repose angle of seed simulation as an index, the parameters of each simulation model were significantly screened by the Plackett-Burman test. The results showed that the recovery coefficient, static friction coefficient and rolling friction coefficient of Hami melon seeds had significant effects on repose angle. Based on the steepest climbing test and quadratic regression orthogonal rotation combination test, it was determined that the significant order of the influence of various contact parameters on the angle of repose was static friction coefficient, collision recovery coefficient, and rolling friction coefficient. The optimal parameter combination was obtained through the mathematical regression model between the angle of repose and various contact parameters, namely, the collision recovery coefficient of Hami melon seeds was 0.518, the static friction coefficient of Hami melon seeds was 0.585 and the rolling friction coefficient of Hami melon seeds was 0.337. Under this condition, three static seed-dropping experiments and dynamic rolling accumulation experiments were carried out. The average simulated angle of repose was 31.93°, and the relative error with the actual value was only 1.71%. The average simulated rolling accumulation angle was 51.98°, and the relative error with the actual value was only 1.92%.

To address the challenges of low efficiency and poor quality in the transplantation of the roots and stems of Chinese medicinal herbs, an electromechanical control system for Chinese medicinal herb transplantation was studied. The electronic control system employs an STM32 single-chip microcomputer as the main controller, utilizes a Hall sensor to capture the movement speed of the transplanter, employs an encoder to monitor the working speed of the DC drum motor and provide feedback to the system, and drives a belt conveyor for transplanter movement using a DC drum motor. The fuzzy PID algorithm is used to adjust the speed of the DC drum in real time based on the difference between the captured speed and the actual monitored speed, ensuring precise matching between the transplanting operation speed and the transplanter movement speed. The control system was simulated using Matlab/Simulink 2022b software. Compared to the traditional PID control algorithm, the steady-state error was reduced by 36.41%, the steady-state time was shortened by 47.26%, the response time was shorter, there was no overshoot, and the robustness was good. Based on the simulation test, a real machine-verification experiment was conducted. The test results indicated that, when operated at the forward speeds corresponding to the low-speed first gear (Low 1) and low-speed second gear (Low 2), the Codonopsis pilosula seedlings exhibited the following characteristics: the exposed seedling rate was 1.1% and 1.5%, the injured seedling rate was 0.5% and 0.7%, the unplanted rate was 1.6% and 2.2%, and the transplant qualification rate was 96.8% and 95.6%, respectively. Similarly, for Astragalus membranaceus seedlings at these speeds, the corresponding rates were as follows: the exposed seedling rate was 1.3% and 1.9%, the injured seedling rate was 0.4% and 0.5%, the unplanted rate was 0.8% and 1.2%, and the transplant qualification rate was 97.5% and 96.4%, respectively. Both results met the design requirements. This study lays a theoretical and technical foundation for controlling the transplanting speed, improving the transplanting accuracy, and promoting the mechanized development of transplantation in traditional Chinese medicine.

China’s small-arched shed-building machinery mostly adopts manual pole casting and mechanical planting, which have low building efficiency and mechanization. Therefore, we designed an automatic feeding device for shed poles to realize automatic single separation, orderly conveyance and timely dropping of poles. Considering shed pole-pitching pass rate as the evaluation index for the regression model, we adopted a three-factor, three-level experimental design and established the speed of the reclaiming ring, height of the falling shed poles and reclaiming ring spacing as the main influencing factors, obtaining 23.94 r/min, 408.799 mm and 1350 mm, respectively in experiments with a trellis qualification rate of 95.36%. Design-Expert 13 was used to perform analysis of variance and determine the optimal parameter combinations. The average measured trellis qualification rate in tests with the bench adjusted and the optimal parameter combination was 94.23%, with 1.13% relative error between test and theoretical optimization values. This confirmed the optimal parameter combination’s dependability. In field verification test results, pick-up card ring speed was 24 r/min; height of trellis pole drop, 410 mm; pick-up card ring spacing, 1350 mm; and pitching rate, 95.37%, obtaining 0.01% error compared with theoretically optimized values. The prototype operational performance was stable and satisfied design requirements.

This research investigates the physical and mechanical properties of Codonopsis pilosula seedlings to provide fundamental mechanical data to address issues like high damage rates and low efficiency in mechanized transplanting. After precise physical parameter measurements, we classified the seedlings into four types: l-type, Y-type, V-type, and W-type. The l-type was the most common, accounting for a large proportion (80.95%) of the total, with a median length of approximately 270 mm, a median diameter of around 5.0 mm, and an average individual weight of about 2.83 g. Freshly harvested seedlings had an average moisture content and density within the typical range for this species. Using the Box–Behnken design method, we determined that the primary and secondary factors affecting tensile force (F_N) and tensile strength (σ) were sample diameter (D), sample length (L), and loading speed (V). Sample diameter had a significant impact: F_N increased rapidly as the diameter grew, while tensile strength (σ) decreased. The tensile strength of different regions of the seedling (i.e., head, middle, and tail) showed distinct characteristics, with relatively small deviations between theoretical and experimental values. For the whole seedling, errors in tensile force (F_N) and strength (σ) between measured and theoretical values were below 5%. The average Young’s modulus, Poisson’s ratio, and shear modulus were also calculated. These mechanical property indices thus provide crucial references for future related research.

The discrete element method (DEM) is widely used in agricultural mechanization, but accurate parameter calibration for UAV seeding simulation of coated rice seeds remains challenging due to empirical parameter selection and single-stage optimization in existing studies. This study combined physical and simulation experiments to calibrate DEM parameters for coated rice seeds (CRS). Physical tests measured the intrinsic parameters and actual repose angle (18.84°). A three-stage progressive optimization strategy was then adopted: Plackett–Burman test to screen significant parameters, steepest ascent test to narrow the optimal range, and quadratic rotation orthogonal combination test to establish a regression model. Four significant parameters were identified: the CRS-CRS coefficient of restitution (C), the CRS-CRS coefficient of static friction (D), the CRS-CRS coefficient of rolling friction (E), and the CRS-stainless steel coefficient of static friction (G). The optimal combination was determined as 0.35, 0.22, 0.09, and 0.51, respectively. Verification using static repose angle, dynamic repose angle, and UAV total seeding rate showed average relative errors below 5% for all three indices. These results demonstrate that the calibrated parameters are reliable for DEM simulation of coated rice seeds, and the proposed multi-stage method effectively improves calibration accuracy and model applicability for UAV seeding operations.