Search Results (15)

The foot structure plays a decisive role in the trafficability of legged robots on granular media. Traditional foot-ends (spherical, cylindrical, flat-bottomed) are prone to sinkage and slippage, resulting in unstable locomotion. To solve this problem, a novel bionic-inspired reconfigurable foot with active opening and closing adjustment capability is designed based on bionics, combining the stable phalangeal contour of goat hoof capsules and the high-adhesion feature of beetle foot-end spines. A coupled EDEM–Adams simulation model is established, and physical experiments combined with simulation inversion are used to calibrate contact parameters between particles and between particles and the foot, including the coefficient of restitution, static friction and rolling friction. A high-fidelity numerical platform for foot–ground dynamic interaction is thus constructed. By comparing and analyzing the differences in anti-sinkage and traction performance between the bionic-inspired foot and traditional foot-ends, this study systematically revealed the influence law of bionic morphology on the mechanical behavior of the foot, and clarified the intrinsic mechanism through which bionic design improves foot–ground interaction. The results demonstrate that the spine structures of the bionic-inspired foot reshape the mechanical constitutive relationship of granular media. By expanding the ground contact area and optimizing contact pressure distribution, the maximum reduction in foot sinkage depth reaches 70.11%, and the traction coefficient is increased by up to 37.13%. Full article

Aiming at the problems of inter-row straw congestion, soil accumulation, and consequent uneven seeding depth during high-speed sowing with narrow row spacing under the summer maize no-tillage sowing mode in the Huang-Huai-Hai region, this study proposed a maize seedling belt pre-sowing treatment device suitable for narrow row spacing operation by analyzing the physical properties of straw and soil in the region. Dynamic analysis of the mechanical device was carried out, and the key factors affecting the straw removal effect of the seedling belt and the degree of soil disturbance were identified as machine offset distance, traction speed, and straw-cleaning wheel angle. Discrete element method simulation experiments were conducted via EDEM-ADAMS coupling; the key factors were simulated and optimized, and the optimal parameter combination of the device was determined as follows: machine offset distance of 165 cm (the relative distance between the front and rear positions of the right wheel of adjacent unit cleaning components), traction speed of 11 km/h, and straw-cleaning wheel angle of 44°. Field validation tests of the prototype were performed. The test results showed that the overall straw removal rate of the seedling belt reached 95%, and no large-scale straw and soil accumulation caused by pushing was observed between rows. Compared with the simulation results, the error of straw removal rate was only 0.5%. Sowing comparison tests were conducted, and the results indicated that the device could significantly improve the uniformity of seeding depth and meet the seedling belt quality requirements for high-speed sowing with narrow row spacing of summer maize. This study provides new ideas and methods for the design of straw-cleaning mechanisms in no-till seeding systems. Full article

The mechanized transplanting of sweet potato slips onto mulched raised beds in China’s Huang-Huai-Hai region faces significant challenges due to fragmented smallholder farms and the specific agronomic requirement of “boat-shaped” horizontal planting. To address this gap, this study aimed to develop a compact, cost-effective transplanter that meets the “boat-shaped” planting agronomy and adapts to small plots. We designed the 2CGX-1 mini wheel-driven transplanter coupled with a tractor. This machine features a compact chassis (<1.5 m length) for enhanced maneuverability on small plots, a novel five-bar taking-planting mechanism optimized for boat-shaped placement (achieving a stem-soil angle of 56.2° and planting depth of 110 mm), and an integrated spring buffer system. Transmission design ensures precise synchronization between the dual-chain seedling feeding mechanism and planting actions, allowing plant spacing adjustment from 18 to 30 cm. Coupled Adams–EDEM simulations demonstrated that the buffer system reduces maximum resistance on the clip fingers by 37.8% when encountering obstacles. Field validation under optimal parameters (0.55 km/h operating speed, 30 plants/min transplanting frequency) showed high consistency: average planting depth 101.3 mm (SD 1.38), plant spacing 330.3 mm (SD 11.24), seedling length under the film 185 mm (SD 3.65), and stem-soil angle 47.9° (SD 3.41), with qualification rates exceeding 91.9% for all key parameters except submerged length (82.5%). Compared with manual planting (≤0.1 ha/day per person, labor cost > ¥800/ha), this transplanter achieves a daily operational efficiency of ~0.35 ha/day (calculated by 0.55 km/h speed × 0.8 m working width × 8 h daily working time). Meanwhile, the consistency of its key planting indicators and the planting qualification rate are significantly superior to those of manual planting, while improving operational quality and significantly reducing labor cost input. Deviations in individual indicators mainly stem from planting positioning deviations induced by terrain undulations in hilly test areas, and sweet potato seedlings’ tendency to fall off during clamping due to mechanical vibration. However, these errors are within the acceptable agricultural operation range and do not compromise the machine’s overall compliance with agronomic requirements. The transplanter effectively meets agronomic requirements while offering a cost-effective, adapted solution for small-scale sweet potato production systems, significantly advancing mechanization capabilities for mulched cultivation. Full article

In traditional scallion cultivation, the bare-root transplanting method—which involves direct seeding, seedling raising in the field, and lifting—is commonly adopted to minimize seedling production costs. However, during the mechanized transplanting of bare-root scallion seedlings, practical problems such as severe seedling damage and poor planting uprightness exist. In this paper, the Hertz–Mindlin with Bonding contact model was used to establish the scallion seedling model. Combined with the Plackett–Burman experiment, steepest ascent experiment, and Box–Behnken experiment, the bonding parameters of scallion seedlings were calibrated. Furthermore, the accuracy of the scallion seedling model parameters was verified through the stress–strain characteristics observed during the actual loading and compression process of the scallion seedlings. The results indicate that the scallion seedling normal/tangential contact stiffness, scallion seedling normal/tangential ultimate stress, and scallion Poisson’s ratio significantly influence the mechanical properties of scallion seedlings. Through optimization experiments, the optimal combination of the above parameters was determined to be 4.84 × 10⁹ N/m, 5.64 × 10⁷ Pa, and 0.38. In this paper, the flexible planting components of scallion seedlings were taken as the research object. Flexible protrusions were added to the planting disc to reduce the damage rate of scallion seedlings, and an EDEM-ADAMS coupling interaction model between the planting components and scallion seedlings was established. Based on this model, optimization and verification were carried out on the key components of the planting components. Orthogonal experiments were conducted with the contact area between scallion seedlings and the disc, rotational speed of the flexible disc, furrow depth, and clamping force on scallion seedlings as experimental factors, and with the uprightness and damage status of scallion seedlings as evaluation criteria. The experimental results showed that when the contact area between scallion seedlings and the disc was 255 mm², the angular velocity was 0.278 rad/s, and the furrow depth was 102.15 mm, the performance of the scallion planting mechanism was optimal. At this point, the uprightness of the scallion seedlings was 94.80% and the damage rate was 3%. Field experiments were carried out based on the above parameters. The results indicated that the average uprightness of transplanted scallion seedlings was 93.86% and the damage rate was 2.76%, with an error of less than 2% compared with the simulation prediction values. Therefore, the parameter model constructed in this paper is reliable and effective, and the designed and improved transplanting mechanism can realize the upright and low-damage planting of scallion seedlings, providing a reference for the low-damage and high-uprightness transplanting operation of scallions. Full article

In response to the challenges of low fertilizer utilization rates, excessive application amounts, and difficulties in precise targeted fertilization during the middle tillage and top-dressing period for corn, a targeted deep fertilization device is designed, integrating mechanical structure design and automatic control technology. The device mainly includes a strong discharge fertilization device and a targeted fertilization control system. The fertilization device has been designed, and the main factors affecting the performance of the fertilization wheel have been identified. Based on the structure, a strong discharge fertilization plate mechanism has been added, and a mechanical model for the fertilization wheel during the refilling and discharging processes has been constructed. A targeted fertilization control system for corn has been developed that utilizes a photoelectric sensor to detect the position of the corn plants. A microcontroller combines the plant position information and the device moving speed to adjust the intermittent rotation of the stepper motor in real time, achieving targeted deep fertilization for corn. Coupled simulation analysis was conducted using discrete element software EDEM and dynamic software Adams. Through single-factor and multi-factor experiments, the main factors affecting fertilization performance were analyzed, and the optimal structural parameters for the fertilization wheel were determined. Bench validation tests were conducted, and the results demonstrated that under forward speeds of 0.4 to 1.2 m/s, the coefficient of variation of the fertilizer application rate per hole of the discharge device ranged from 2.02% to 4.46%, the error in fertilizer application rate per hole ranged from 7.12% to 12.18%, the average length of fertilizer application holes ranged from 72.5 mm to 130.2 mm, and the coefficient of variation of hole length stability ranged from 1.94% to 3.54%. These parameters were consistent with the results from the simulation tests, and the operational performance met the requirements. Finally, field tests validated the overall operational performance of the device. When the device’s speed ranged from 0.4 m/s to 1.2 m/s, the coefficient of variation of the fertilizer application rate per hole, the error in fertilizer application rate per hole, the average length of fertilizer application holes, the coefficient of variation of hole length stability, and the qualification rate of fertilization position were 3.63%, 10.46%, 108.8 mm, 2.96%, and 87.16%, respectively. The overall performance of the device is stable and meets the requirements for targeted deep fertilization in corn cultivation. Full article

The scraper conveyor, essential for mechanized mining, operates in harsh underground environments and is subjected to severe impact loads from coal and rock falls. Such conditions can cause chain jamming, breakage, and other malfunctions, necessitating a detailed study of the system’s dynamic behavior under impact conditions. This study investigates the dynamic characteristics of a scraper conveyor’s chain drive system using a coupled ADAMS-EDEM simulation model. The model analyzes the effects of loaded coal piles on the conveyor’s dynamics during normal and impact conditions. Simulations show that loaded coal piles excite the scraper’s acceleration and sprocket rotation, with the greatest impact in the scraper’s running direction. Longitudinal impact and contact forces on the chain ring are more significant than in other directions under both no-load and loaded conditions. A strong linear relationship exists between the falling coal mass and longitudinal impact force. The coal pile causes prominent longitudinal vibration excitation while inhibiting the overall vibration of the chain drive system to some extent. The findings provide insights for identifying failure-prone areas under impact conditions and offer theoretical guidance for optimizing scraper conveyor design. This enhances mining efficiency and safety in coal operations. Full article

In response to the significant challenge posed by the trade-off between the efficiency of separating potato soil and minimizing potato peel damage in the 4SW-170 potato excavator, this study focused on enhancing the design of the swing separation sieve. The objective was to develop a novel separation sieve comprising three distinct orders of sieve surfaces. Building upon this foundation, the EDEM-Adams coupled simulation method was employed to explore the fragmentation and separation attributes of potato–soil aggregates. This investigation aimed to elucidate the behavior of potato–soil aggregates within the operational scope of the novel swing separation sieve. Subsequently, the optimized parameters were validated through field tests. The findings indicate a direct correlation between the fracture ratio of the cohesive bond and the crank speed, illustrating an increase in the former with higher crank speeds. Conversely, an inverse relationship exists between the fracture ratio and the sieve inclination angle, demonstrating a decrease in the ratio as the sieve inclination increases. At a machine speed of 1.9 km/h, the fracture ratio of the cohesive bond attains its peak value. The force exerted on potatoes at their maximum point escalates with rising crank speed but diminishes with increasing machine speed. Conversely, the effect of sieve inclination on the peak force applied to the potatoes is deemed inconsequential. The most effective parameter configuration for the separation sieve comprises a crank speed of 180 revolutions per minute (r/min), a machine speed of 1.9 km per hour (km/h), and a sieve inclination of 14.4°. Field trials have confirmed that the parameter combination yielded a potato detection rate of 98.01% and a mere 0.68% rate of potato skin breakage, meeting the stipulated technical specifications of the potato harvester. Full article

We have combined the theory of bulk dynamics and the agronomic requirements of precision sowing with the aim of resolving the technical problems of poor seed mobility and the difficulty in controlling suction posture, which leads to an increase in the leakage rate and a reduction in seed qualification index scores. In this study, a vibrationally tuned directional seed supply method and system are proposed. We carried out a force analysis of seeds, constructed kinematic equations for seeds and seed boxes to specify the state of the seed motion, and determined the structural parameters and the range of structural parameters that affect the seed suction posture. In addition, we coupled the ADAMS-EDEM simulation of the motion process of the seed and seed boxes and analyzed the vibrational tuning process of the seeds and the angle of inclination of the bottom surface of the seed box. The speed of the eccentric wheel and the eccentric distance were used as test factors. Three-factor and three-level Box–Behnken central combination testing with a single-grain rate, multiple-grain rate, and cavity rate were used as response indicators. Mathematical models were obtained between the experimental factors and the response indicators. Multi-objective optimization of mathematical regression models was carried out with Design-Expert 10.0.4 software. The optimal parameter combination obtained was a tilt angle of 14.27°, an eccentric wheel speed of 4.48 rad/s, and an eccentricity of 1.94 mm. The rate of single grains was 90.75%, the rate of multiple grains was 3.63%, and the rate of cavities was 5.62%. In bench performance tests, using an angle of inclination of 14°, the speed of the eccentric wheel was 4.50 rad/s and the eccentricity was 2 mm. The mean value of the single-grain rate was 89.28%, the mean value of the multiple-grain rate was 3.89%, and the mean value of the cavity rate was 6.83%. The test error was within permissible limits, and reliable results were achieved for parameter optimization. The results met the technical requirements for precision sowing. The results of the study can provide academic references for theoretical research on the methodology of posturing and directional seed supply. They can also provide ideas for the design and development of seed supply systems for precision sowing machinery. Full article

Because the operating speed of current mechanical maize hole seeders is low and their ability to adapt to the seed is poor, an active clamping-type precision hole planter for corn was designed. Here, we explain its structural composition and working principle. According to the maize kernel size, the combination of hole parameters is based on the principle of virtual work on analyzing the seed extraction disc assembly’s static mechanical model. The model was imported into the ADAMS simulation for validation and the parameters and ranges affecting the seed-filling performance were identified. By further analyzing the results of the coupled ADAMS–EDEM simulation, the “arching” process of the seeds during leakage charging was revealed, and an arch-breaking method was proposed with the help of a swinging seed-collecting slider. The speed of the hole planter, the diameter of the outer edge of the gravity ring, and the angle of the block installation were used as test factors. The Box–Behnken center-combination simulation test was conducted using the sowing pass index, re-seeding index, and missed sowing index as evaluation indices. The experimental results show that the optimal parameter combination was as follows: gravity ring = 174.3 mm, stopper installation angle = 131.9°, and hole seeder speed = 85.2 rpm. At this time, the qualified seeding index was 94.53%, the multiple indices were 4.30%, and the leakage index was 1.18%. Under these conditions, the row seeding performance bench test was conducted to obtain the qualified seeding index of the hole seeder, which was 93.36%, while the multiple indices were 5.20% and the leakage index was 1.44%, which satisfied the agronomic requirements of precision seeding. This provides a theoretical reference for mechanical seeding methods for irregular seeds, as well as a basis for the research and development of maize precision sowing machinery and equipment. Full article

No-tillage seeding is of great significance for adjusting and improving soil structure in Northeast China. The conventional no-tillage seeder faces several issues with its row cleaner, such as a low straw cleaning rate and a high working resistance. To address these problems, this paper utilizes the bionic design method and develops a bionic elastic row cleaner inspired by the motion behavior of mole excavation. The bionic structure includes bent teeth and a torsion spring for lateral throwing. The MBD–DEM coupled simulation technology is proposed as the experimental optimization method, and it analyzes the interactions between different row cleaners, straw, and soil. The results indicate that a bionic elastic row cleaner with curved teeth and a torsion spring for lateral throwing (BA-T) had a higher straw cleaning rate and total kinetic energy of straw. It also had lower working resistance. The field test results indicate that the BA-T improved the straw cleaning rate by 13.04% and reduced the working resistance by 39.24% compared to a flat row cleaner. This outcome also validates the accuracy of the simulation experiments. This study contributes to the design of new and efficient row cleaners suitable for maize straw mulching and no-tillage conditions, thereby promoting the adoption of conservation agriculture practices. Full article

To improve wheel trafficability in soft and muddy soils such as paddy fields, a bionic walking wheel is designed based on the structural morphology and movement mode of the feet of waders living in marshes and mudflats, similar to the muddy soil of paddy fields. The bionic walking wheel adopts the arrangement of double-row wheel legs and staggered arrays to imitate the walking posture of waders. The two legs move alternately, cooperate with each other, and improve the smoothness of movement. The cam inside the bionic walking wheel is used to control the movement mode of the feet. The flippers open before touching the ground to increase the contact area and reduce sinking, and the toes bend and grip the ground while touching the ground to increase traction. Multi-rigid-body dynamics software (Adams View 2020) is used to simulate the movement of the wheel during the wading process, and the movement coordination and interference between the wheel legs are analyzed. The simulation results show that there is no interference between the parts and that the movement smoothness is good. The interaction between the bionic walking wheel and muddy soil was analyzed via coupled EDEM–ADAMS simulation, and the simulation analysis and experiments were conducted and compared with those for a common paddy wheel. The results showed that the bionic walking wheel designed in this paper improved the drawbar pull by 113.56% compared with that of a common paddy wheel and had better anti-sinking performance. By analyzing the effect of toe grip on traction, it was found that the soil under the feet can be disturbed to provide greater traction when the toe is bent downward. This study provides a reference for improving the trafficability of walking mechanisms in soft and muddy soils, such as paddy fields. Full article

In the context of cutting grass in orchards, the practice of leaving cut weeds in the orchard rows hinders the decomposition of the weeds and the absorption of nutrients by the fruit trees. To address this issue, a grass-cutting machine with an integrated sweeping disc was designed to remove weeds from orchard rows and sweep them to the roots of the trees to promote their absorption of nutrients. A coupled simulation platform was established using multi-body dynamics ADAMS and the discrete element method EDEM. The weed-shedding and sweeping device was dynamically analyzed through an ADAMS–EDEM collaborative simulation that enabled the use of a second-order regression orthogonal rotation experiment and response surface methodology. The optimal parameters for the cutting tools, cutter shaft speed, and the number of cutting tools included 23 cutting tools arranged in a single helical pattern for the cutting device, a cutter shaft speed of 728 rpm, and claw-shaped blades as the cutting tools. A prototype machine was built based on the optimized parameters and tested in the field. The results indicated that, when there were 250 m² of weeds, the cutting rate reached 92.96%. The machine was highly maneuverable, and the average remaining weed height in the orchard was 110 mm, which met the national standards and local agricultural requirements. The new orchard grass-cutting and sweeping device meets the technical demands of orchard grass operations in the Xinjiang region of China. Full article

In this study, a dynamic–discrete element-finite element coupling method is proposed to investigate the influence of structural parameters on the excavation performance and stress deformation of the bucket. The main research work is as follows: through ADAMS-EDEM co-simulation of the digging process of the bucket, the digging resistance and the loose force of each part of the bucket are obtained. The influence law of the change of the structural parameters of the excavator bucket on the digging resistance, filling rate and energy consumption is revealed. Through the coupling simulation of EDEM-ANSYS, the loose force is introduced into the finite element model of the bucket to enable the coupling of ADAMS-EDEM-ANSYS. The influence of the change of the bucket structure parameters on the stress and deformation of the bucket components is explored. The results show that the cutting angle and angle of throat of the bucket has a major influence on the digging performance of the bucket. While the angle of the throat and the thickness of the ear plate have a minor influence on the digging performance of the bucket. In the process of excavation, the teeth of the bucket are subjected to the largest digging resistance, resulting in relatively large deformation. All of the components of the bucket are subjected to different degrees of excavation resistance, but the stress concentration at the ear plate is the most obvious. The deformation and stress of the whole bucket can be reduced, to some extent, by reducing the thickness of the ear plate along with increasing the thickness of the stiffening plate. The results can be used to improve the digging performance of the bucket and reduce the stress and deformation of the bucket. Full article

As a component directly in contact with materials in the excavation process of the excavator, the structure and performance of the bucket directly affect the efficiency of the excavator. With the increasingly prominent environmental and energy problems, it has become a research difficulty to optimize the bucket structure of excavators so as to reduce the digging resistance and energy consumption of excavators. Therefore, an orthogonal optimization method of bucket structure that couples Adams with EDEM was proposed to explore the excavation performance of buckets with different structures under different geological conditions. The particle size distribution and mass proportion of various ores under different geological conditions were obtained through geological investigation, and particle models with different shapes and sizes were constructed. The friction coefficient and collision recovery coefficient between bucket and ore and between ore and ore were measured using a self-made testing device. The results show that the excavation resistance of the bucket teeth during the excavation process is much greater than that of other components, and optimizing the bucket structure can effectively reduce the excavation resistance of the bucket teeth. Under different geological conditions, the optimization parameter combinations of bucket structure obtained through orthogonal experiments are different. In addition, after structural optimization, the excavation resistance and energy consumption of the bucket were reduced, and the filling rate was also improved. Full article

A vibration ditching machine is a machine that can effectively reduce ditching resistance and energy consumption. In this paper, taking a self-developed, self-excited vibration ditching machine as the research object, we explore its internal dynamic vibration characteristics upon excitement when ditching, which reduces its resistance and energy consumption. The vibration characteristics of a ditching machine with three degrees of freedom (Y, Ry, and Rx directions), which are generated by the vibration of the self-excited ditching machine, are evaluated; the rotating speed, spring stiffness, spring damping coefficient, and blade weight are taken as factors, and their effects on the vibration characteristics are analyzed by an Adams–Edem coupling simulation model and a theoretical dynamics model of the self-excited ditching machine. Finally, a comparative analysis of the ditching machine of self-excited and nonself-excited ditching machines is conducted. The results of the analysis show that the rotating speed, spring stiffness, spring damping coefficient, and blade weight are important factors affecting the vibration characteristics. The theoretical dynamics model and the Adams–Edem coupling simulation model can represent the internal vibration mechanism of the self-excited ditching machine during ditching. The self-excited vibrating ditching machine is helpful in reducing the energy consumption of ditching. Full article