Search Results (52)

Selecting an appropriate disc coulter is crucial for reducing the power consumption of no-till seeders, preventing straw from being pressed into seed furrows, improving the soil penetration performance of the disc coulter, and thus minimizing the weight of no-till seeders. This study utilized the quadratic regression orthogonal rotation central composite approach. With the application of EDEM and RecurDyn software, a virtual simulation model of the interaction between a toothed disc coulter and soil was developed. The angle of front serration δ, the angle of rear serration θ, and the number of serrations n were taken as experimental factors. The draft F_v and penetration resistance F_N were selected as performance evaluation indicators for parameter combination optimization simulation tests. The results indicated that δ, θ, and n have significant influences on F_v and F_N (p < 0.05). When the optimized parameter combinations δ, θ, and n were respectively determined as 16°, 39.1°, and 13, both F_v and F_N reached their minimum values. A comparative experimental study was conducted with the optimized toothed disc coulter and six existing disc coulters; under the working conditions of 14.4 km·h⁻¹, both the draft and penetration resistance of the toothed disc coulter are minimized. The draft was 227.5 ± 8.9 N and the penetration resistance was 415.9 ± 5.3 N. Meanwhile, the toothed disc coulter had the highest ratio of soil disturbance area to draft, indicating better soil loosening effects. Full article

Weed control is crucial for safeguarding the yield and quality of fresh maize. To achieve comprehensive, low-damage removal of weeds in fresh maize fields, an intelligent mechanical weeding system was developed. Based on the spatial distribution of maize seedling roots and agronomic requirements, a three-dimensional protection zone was established and a dedicated intra-row weeding knife was designed. An EDEM–RecurDyn co-simulation was then performed; single-factor and orthogonal experiments were used to evaluate the effects of operating speed, hydraulic cylinder extension–retraction speed, and knife bending angle on the coverage rate and intrusion rate, and to determine the optimal parameter combination. Seedling detection and field weeding trials were subsequently conducted. The detection accuracies under good and low illumination were 95.82% and 93.32%, respectively. Under the optimal settings (operating speed 1.5 km/h, hydraulic cylinder extension–retraction speed 0.22 m/s, and knife bending angle 20°), the system achieved a mean weeding rate of 90.79% and a mean seedling damage rate of 2.27%. The results demonstrate stable performance and confirm that the proposed system meets the requirements for comprehensive, low-damage weeding in fresh maize fields, providing a reference for the design of intelligent mechanical weeding equipment. Full article

The operational reliability of the elastic wheel, essential for specialized vehicle mobility on complex terrain, is critically constrained by fatigue failure under multi-axis ground loads. While high-fidelity physics-based simulation provides an accurate assessment, its “one-simulation-per-test” paradigm is inefficient for exploring multi-condition, multi-parameter designs. Conversely, purely data-driven methods are hindered by the scarcity of high-quality fatigue data. This paper proposes LightGBM-CH, an integrated framework that couples Discrete Element Method–Multi-Body Dynamics (DEM-MBD) simulation with an enhanced LightGBM model to overcome these limitations. The framework first converts high-fidelity simulations into a configurable data generator, producing batches of dynamic load–stress response data. A physics-informed feature engineering scheme then extracts 122 discriminative features characterizing six-dimensional loads, fatigue damage metrics, and load–stress coupling. To address the “small-sample, high-dimensional” challenge, a tailored training strategy incorporating robust scaling, correlation-based feature selection, and stability-constrained hyperparameter optimization is developed. Simulation experiments demonstrate that the LightGBM-CH model achieves a determination coefficient of 0.9251 and a root mean square error of 67.06, significantly outperforming benchmark models in accuracy and generalization. The study validates the framework’s engineering efficacy, identifies key influencing factors such as peak–stress ratio, and provides an intelligent, data-informed pathway for fatigue-resistant elastic wheel design. Full article

Potato combine harvesters often face the challenge of balancing efficient potato–soil separation with minimizing tuber mechanical damage, which significantly affects harvest quality and economic returns. To address this issue, a dual-vibration potato–soil separation conveyor was designed based on agronomic planting parameters and soil physical characteristics. A high-fidelity DEM-MBD coupling simulation model was developed to analyze soil clod breakage behavior and potato collision-induced jumping dynamics, and to identify key operational factors influencing separation performance. The porosity was verified using computer vision combined with CT technology to ensure the model’s fidelity. Single-factor simulations and a central composite design (CCD) response surface experiment were conducted using potato damage rate and soil removal efficiency as evaluation indices. The results showed that the inclination angle α, conveying line speed V_f, and vibration frequency f were the dominant factors affecting separation efficiency and tuber integrity. Multi-objective optimization determined optimal operating parameters of α = 18.51°, V_f = 1.995 km·h⁻¹, and f = 6.22 Hz, under which soil removal efficiency reached 98.43% and the minimum damage rate was 1.60%. Field experiments using a 4U-1000 combine harvester verified the simulation results, with an average soil removal efficiency of 97.8% and an average damage rate of 1.62%. These findings confirm the accuracy of the DEM-MBD simulation model and provide theoretical guidance for optimizing separation devices in large-scale potato harvesting equipment. Full article

Rotary tillage blades are critical soil-engaging components in conservation tillage systems but are prone to adhesion of soil particles under cohesive soil conditions, which increases tillage resistance, degrades tillage quality, and lowers operational efficiency. To address these issues, this study proposed a collaborative strategy that combines parameter optimization of rotary tillage blades with a bionic microtexture design to reduce adhesion and resistance and improve operation performance. A coupled soil–wheat straw–rotary tillage blade model based on the Discrete Element Method (DEM) and Multibody Dynamics (MBD) was established in loessial soil environment. The structure and working parameters of the rotary tillage blade were optimized using a Box–Behnken experimental design. On this basis, a bionic microtexture design was introduced on regions prone to adhesion of the rotary tillage blade, inspired by the non-smooth convex hull microstructure on the head surface of the dung beetle. The results indicated that the optimal parameter combination (rotational speed 244 r·min⁻¹, tillage depth 110 mm, and bending angle 122°) reduced soil adhesion mass and tillage resistance by 74.47% and 23.44%, respectively. After applying the bionic microtexture, the corresponding reductions further increased to 82.93% and 28.35%. Moreover, the bionic-optimized rotary tillage blade outperformed the original design in disturbance depth and range and exhibited improved energy consumption performance. Overall, the results demonstrated that coupling parameter optimization with bionic microtexture design substantially enhanced adhesion and resistance reduction and improved soil-disturbance performance, thereby providing theoretical support for the development of high-performance rotary tillage blades. Full article

This study investigates a duckbill-type hole seeder to elucidate the kinematic and force characteristics of hole formation under the dry sowing–wet emergence regime and to provide theoretical support for the optimization of key structural parameters. A bidirectional coupling simulation model based on the discrete element method (DEM) and multibody dynamics (MBD) was established to analyze the motion trajectories of the fixed and movable duckbills, the evolution of three-directional forces, and the associated soil–plastic film disturbance under different combinations of front and rear angles. The results indicate that soil disturbance during hole formation is dominated by vertical penetration and uplift, accompanied by forward cutting and lateral redistribution. The three-directional forces acting on the fixed duckbill exhibit a non-monotonic response with respect to the front angle, decreasing first and then increasing, while the force level during the expansion stage of the movable duckbill generally increases with the rear angle. Within the investigated parameter range, a front angle of 18° combined with a rear angle of 38° resulted in a relatively lower overall force level during penetration and expansion, which is favorable for stable hole formation. Field experiments conducted with this configuration showed an average seed placement deviation of 0.50 cm, satisfying the requirements for precision cotton planting under plastic mulch. The findings provide theoretical insight and methodological support for the structural optimization and engineering design of cotton hole seeders operating under the dry sowing–wet emergence regime. Full article

To address the challenges of the lack of specialized machinery adapted to traditional agronomic requirements, high labor intensity, and low efficiency in the planting of Ligusticum chuanxiong stalk segments (commonly known as Chuanxiong seed stalk or Lingzhong), a planting mechanism for the cutting of Chuanxiong seed stalk was developed in accordance with traditional agronomic requirements. A kinematic model of the gripping point was established, from which a plant spacing formula was derived. Based on the zero-speed planting principle, a cuttage planting scheme for Chuanxiong seed stalks was proposed, in which the gripper trajectory as well as the forward-tilt x_t and correction x_c were defined, and the decisive role of installation height on planting depth and the influence of driven-sprocket motion parameters on planting uprightness were elucidated. A 3D model and a DEM-MBD coupled simulation model were constructed to analyze planter–soil–seed interaction. A three-factor, three-level Box–Behnken experiment was conducted, and a response surface model was built and optimized using ‘Design-Expert’ software. The optimal parameters were a driven sprocket angular velocity of 0.654 rad/s, a rotation radius of 100.787 mm, and a release angle of 90.647°, yielding an average planting uprightness of 85.264°, with the corresponding x_t and x_c of 5.18 mm and 2.69 mm, respectively; the factor influence ranked as angular velocity > rotation radius > release angle. Seed–soil interaction analysis verified the mechanism’s feasibility and the accuracy of the theoretical models. Field tests showed average qualification rates of 87.13% for plant spacing, 96.01% for planting depth, and 90.41% for uprightness, with corresponding coefficients of variation of 4.37%, 2.95%, and 3.73%, indicating stable and reliable field performance. Full article

With the continuous increase in high-speed train operating speeds, effective vibration suppression of the car body is critical for ensuring passenger comfort. This study proposes a composite damping device based on particle damping technology, featuring a variable cavity structure incorporating spring components designed for space-constrained areas. The primary aim of this work is to elucidate the energy dissipation mechanism of granular media under adaptive boundary conditions and to establish a novel method for overcoming the saturation limitations of traditional fixed-cavity dampers. The energy dissipation characteristics were investigated using coupled Discrete Element Method (DEM) and Multibody Dynamics (MBD) numerical simulations. Parametric analysis quantitatively demonstrated significant performance variations: 2 mm particles outperformed larger diameters by maximizing collision frequency, and cast iron particles (29.497 J) achieved approximately five times the energy dissipation of steel particles (5.909 J). Furthermore, the filling rate exhibited a non-linear relationship with damping performance, peaking at a 98% filling rate (57.251 J)—a nearly 9-fold increase compared to a 90% filling rate. Most notably, quantitative comparison confirms that the introduction of the spring-adaptive mechanism enhanced the total energy dissipation to approximately 2 times that of the traditional fixed-cavity design. Simulation results reveal that the flexible cavity significantly enhances performance by preventing particle packing and stagnation. The dynamic deformation continuously “recruits” particles into high-energy collision regimes, ensuring sustained broadband attenuation. These findings establish the spring-based variable volume design as a high-efficiency strategy for high-speed rail applications. Full article

To address the low efficiency of corn straw collection, this study aims to optimize the design of the straw shredding mechanism of corn straw harvesters. A multi-blade arrangement shredding mechanism was designed, with ANSYS 2022 employed for gas-phase flow field simulation of the pick-up and fan conveying chambers, and a multi-field coupled simulation was conducted to evaluate performance using pick-up rate and qualified cutting length rate as metrics. Field tests were carried out to validate the simulation results. The results show that the DC-type pick-up (symmetrically arranged Y-shaped and hammer claw blades) exhibited optimal performance. At a travel speed of 1.2 m/s and rotational speed of 2100 r/min, the pick-up rate and qualified cutting length rate reached 93.62% and 93.94%, respectively, in field tests (81.34% pick-up rate in simulation); its maximum collection efficiency reached 92.98% under the conditions of fan 1 speed of 2300 r/min, fan 2 speed of 4600 r/min, and single feed rate of 9.4 kg. All pick-up types had maximum forces below the stress limit (348 MPa), meeting operational requirements. This research provides reliable references for the design and optimization of corn straw returning machines and verifies the accuracy of the simulation method. Full article

To solve the problems of high resistance and blockage in stubble-breaking operations, it is necessary to reveal the interaction mechanism between disc coulters and crop root–soil composites. This study developed a discrete element method–multi-body dynamics (DEM-MBD) coupling model of the stubble-breaking operation and verified the accuracy of the model through soil bin tests (error < 20%) and field experiments (error < 32%). The model was used to investigate the effects of different design parameters (coulter type and disc radius) and operating parameters (tillage speed and depth) on the stubble-breaking operation. The results showed that due to the significant strengthening effect of roots on soil, the resistance of disc coulter stubble-breaking operation was high; the number of roots in contact with the blade edge and the amount of root deformation significantly affected the resistance of the disc coulter; irreversible deformation of roots and soil could easily lead to the holes and root hairpin effects in the seeding furrow; compared to plain disc coulters, the difference in the time of deformation and fracture of the roots made the resistance of the notched coulter lower. The wavy disc coulter with a longer edge curve made its resistance higher; the disc coulter with a greater radius, higher tillage speed, and deeper tillage depth significantly increased the tillage resistance. However, the disc coulter with a greater radius or a higher tillage speed was beneficial for improving stubble-breaking performance. This study revealed the interaction mechanism between disc coulters and maize root-soil composites, providing a theoretical basis for the optimization design of no-till stubble-breaking devices. Full article

Under the condition of high-speed maize seeding, the collision between the seeds and the restraint seeding guide device, as well as the excessively high seeding speed, will lead to a sharp increase in the coefficient of variation in the seed spacing during seeding. To address these problems, this study designed a brush-belt-type seed-guiding device incorporating an auxiliary seed-receiving mechanism (ASRM). The aim of this device is to improve the stability of the brush tube in receiving seeds through the ASRM and to stabilize the seed spacing during seeding under the constraint of the brush belt and the seeding tube. Finally, the seeding speed is balanced by adjusting the rotational speed of the brush belt to achieve zero-speed seeding. A multi-body dynamics model of the seeding machine and a discrete element model of the soil were constructed. The seeding process of the device was simulated and analyzed using the discrete element method and multi-body dynamics (DEM-MBD) coupling simulation method. The seeding height and seeding angle were used as experimental factors, and a two-factor five-level orthogonal simulation experiment was conducted. The qualified rate of seed spacing, the re-seeding rate, and the missed seeding rate were used as experimental indicators. The results show that the optimal operating parameters of this device are as follows: seeding height of 46.8 mm, seeding angle of 25.5°, qualified coefficient of seed spacing of 96.03%, missed seeding rate of 1.76%, and re-seeding rate of 3.48%. Under the optimal working parameters of the device, speed performance verification tests were conducted. The research results show that when the operating speed is 12–16 km h⁻¹, the qualified rate of grain spacing is not less than 94.3%, the re-seeding rate does not exceed 3.92%, the missed seeding rate does not exceed 3.19%, and the damage rate does not exceed 0.19%. This study can provide a reference for the design and optimization of high-speed maize seeding devices. Full article

To address issues in traditional vegetable transplanter planting mechanisms such as poor hole-forming quality and low seedling uprightness, a seven-bar linkage planting mechanism with posture compensation of seedling entering soil was designed. By establishing a mathematical model of the planting mechanism and developing visual auxiliary optimization software, the optimal mechanism parameters for the best planting trajectory were determined. A DEM–MBD (Discrete Element Method and Multibody Dynamics) coupling simulation model of planting mechanism-soil-seedlings was established. The planting frequency, opening width, and opening time of the planter were used as factors, and the soil backflow and seedling uprightness were used as evaluation indicators. A quadratic regression orthogonal rotation combination simulation test was carried out. The regression model was established using Design-Expert 12.0 software to analyze the influence of various factors on the indicators. Response surface methodology was simultaneously applied for comprehensive optimization of the influencing factors. The optimal parameter combination obtained was as follows: planting frequency 57 plants/min, opening width 48.5 mm, opening time 0.76 s, corresponding to a soil backflow of 0.67 and seedling uprightness of 80.35°. Field tests were conducted to verify the following mechanism: the soil backflow was 0.64, and the seedling uprightness was 78.49°, which were 4.47% and 2.31% different from the regression model optimization results, respectively. The error variation was small, indicating that the simulation results were effective and the mechanism design was reasonable. This study provides a reference for the development of high-quality and efficient vegetable transplanters. Full article

To solve the problems of large root damage and incomplete seedling blocks (SBs) in rice machine transplanting, this study numerically optimized the root blanket-cutting device for rice blanket seedling cutting and throwing transplanters based on the discrete element method (DEM) and multi-body dynamics (MBD) coupling method. A longitudinal sliding cutter (LSC)–substrate–root interaction model was established. Based on the simulation tests of Center Composite Design and response surface analysis, the sliding angle and cutter shaft speed of the LSCs arranged at the circumferential angles (CAs) of 0°, 30°, and 60° were optimized. The simulation results indicated that the LSC arrangement CA significantly affected the cutting performance, with the optimal configuration achieved at a CA of 60°. Under the optimal parameters (sliding angle of 57°, cutter shaft speed of 65.3 r/min), the average deviation between the simulated and physical tests was less than 11%, and the reliability of the parameters was verified. A seedling needle–substrate–root interaction model was established. The Box–Behnken Design method was applied to conduct simulation tests and response surface optimization, focusing on the picking angle, needle width, and rotary gearbox speed. The simulation results showed that the picking angle was the key influencing factor. Under the optimal parameters (picking angle of 20°, seedling needle width of 15 mm, rotary gearbox speed of 209 r/min), the average deviation between the simulated and physical tests was less than 10%, which met the design requirements. This study provides a new solution for reducing root injury, improving SB integrity, and reducing energy consumption in rice transplanting, and provides theoretical and technical references for optimizing transplanting machinery structure and selecting working parameters. Full article

Improving sowing quality is crucial for ensuring wheat emergence and healthy growth. To address issues of poor wheat sowing quality, such as uneven sowing depth and inadequate soil coverage, in the Yangtze River Delta region of China, this study systematically analyzed the effects of the implement’s structural and operational parameters on sowing quality. Based on this analysis, a double-shaft rotary tillage and double-press seeder was designed. Protrusions on the grooving press roller are used to form seed furrows, rotary tiller blades cover the seeds with soil, and the rear press roller compacts the soil. DEM-MBD (discrete element method–multibody dynamics) coupled simulations, combined with single-factor and central composite design (CCD) experiments, were conducted with seeding depth as the evaluation index and four experimental factors: the protrusion height on the press grooving roller, forward speed, seed mass in the seed box, and straw mulching amount. The optimal protrusion height was 29 mm. The effects of rotary tiller blade working depth, rotational speed, and forward speed on soil-covering mass and its coefficient of variation were evaluated through discrete element method (DEM) simulations. The optimal working depth and rotational speed were found to be 55 mm and 350 r·min⁻¹, respectively, based on single-factor and Box–Behnken Design experiments. Field experiments based on optimized parameters showed results consistent with the simulations. The qualified rate of seeding depth decreased as forward speed increased. The optimal forward speed was 4.5 km·h⁻¹, at which the average seeding depth was 25.7 mm, the qualified seeding depth rate was 90%, the soil-covering mass within a 50 cm² area was 143.2 g, and the coefficient of variation was 13.21%, meeting the requirements for wheat sowing operations. Full article

To address the problem of unstable seed filling and low seeding accuracy caused by poor seed flow in conventional peanut seed metering devices, a novel precision metering device based on a cam-swing link was developed. Using EDEM simulations, the capacity of different type hole installation positions to induce seed cluster disturbance was analyzed. A single-factor test and MBD–DEM coupled simulation were conducted to analyze the seeding performance. The simulation results indicate that when the type hole protrusion height was set to half the thickness of the seeding disc, seed cluster kinetic energy remained relatively stable, enhancing the capability to disturb seeds. As the seeding disc rotational speed increased from 10 to 40 rpm, the qualified index initially increased and then declined. Increasing the cluster wrap angle from 20° to 70° similarly led to a peak in the qualified index and a steady decrease in the missed index. Using the JPS-12 computer vision-based test platform, a second-order rotary orthogonal design was applied to evaluate the seeding performance. The experimental results show that when the seeding disc rotational speed was set at 26 rpm and the seed cluster wrap angle at 46°, the qualified index reached 89.95%, and the missed index was 4.04%. The average plant spacing of peanuts in field experiments was 137.82 mm. These results meet the operational requirements for precision peanut planting. Full article