Hanyu Yang’s research while affiliated with China Agricultural University and other places

The shape of particles is a critical determinant that significantly influences the accuracy of discrete element simulations. To reduce the discrepancies between the discrete element model of wheat seeds and the actual particle shapes, and to enhance the accuracy of Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) coupling simulations in gas–solid two-phase flow studies, We employed laser scanning and inverse modeling techniques to develop a three-dimensional (3D) reconstruction of the wheat seed. Subsequently, we employed Rocky DEM simulation software to develop a polyhedron model and an Angle of Repose (AOR) test model. The interval range of material parameters was determined through a series of physical experiments and subsequently employed to delineate the high and low levels of parameters for the simulation tests. The simulation parameters were calibrated using data from AOR simulation tests. The Plackett–Burman test, Steepest-Ascent test, and Box–Behnken test were conducted sequentially to determine the optimal parameter configuration. A test bench for wheat gas-assisted seeding was constructed, and a semi-resolved CFD-DEM coupling simulation model was developed to perform comparative analysis. The results demonstrated that the optimal parameters were as follows: the static friction coefficient of wheat seed was 0.15, the dynamic friction coefficient of wheat seed was 0.11694, and the dynamic friction coefficient between wheat seed and resin was 0.0797. In this scenario, the relative error of AOR was 2.3% and the maximum relative error of ejection velocity observed was 4.1%. The reliability of the polyhedron model and its calibration parameters was rigorously validated, thereby providing a robust reference for studies on gas–solid two-phase flows.

As the focus of the development of mechanized tillage and sowing, combined tillage and sowing machines have a variety of functions, such as seedbed preparation, fertilizer sowing, and pressing. Compared with the traditional single-function planter, these machines effectively shorten the operation cycle, reduce production costs, and promote increased production and income. This paper categorizes the machines into these combined rotary tillage and sowing machine, the combined disk harrow and sowing machine, and the combined multi-link tillage and sowing machine according to the form of the tillage and operation. It also systematically elaborates on the technical characteristics, application scenarios, and operational requirements of different types of combined tillage and sowing machines. Additionally, this paper outlines key technologies, such as seedbed preparation and precision sowing. Considering the current state of scientific and technological advancements and the practical needs of agricultural production, it also suggests future research directions and trends, offering valuable insights for subsequent studies in this field.

Straw incorporation offers significant advantages in agricultural crop cultivation systems. Mechanized methods constitute the predominant approach, potentially reducing yield costs and enhancing operational efficiency. The imperative to enhance the quality of straw chopping within the field is of particular significance, as suboptimal chopping quality can engender a cascade of issues, particularly seeding blockages. The straw chopping pass rate (CPR) is a pivotal metric for assessing the quality of straw chopping. Therefore, enhancing the CPR during the straw chopping process is necessary. This study introduces a novel maize-straw-chopping device with the ground as its supporting base. This device facilitates the rapid vertical chopping of maize straw through a constant breath cam transmission mechanism. Critical parameters were determined to optimize the performance of the chopping device by establishing mathematical models and kinematic simulation analysis methods. With the help of Rocky 2022.R2 software, the influence of the rotational velocity of the draft, tractor velocity, and blade edge angles on the CPR during the operation of the device was analyzed. The Box–Behnken test methodology was used to carry out a three-factor, three-level orthogonal rotation test to obtain the optimal working parameter combination. The results indicated that the maximum CPR value was achieved with a draft rotational velocity of 245 rpm, a tractor velocity of 3.8 km/h, and a blade edge angle of 20.75°. Finally, field validation experiments were conducted under these optimized conditions, with the average CPR of maize straw reaching an impressive 91.45%. These findings have significant implications for enhancing crop production practices.

Ultrasonic detection is one of the main methods for information detection and has advantages in soil detection. Ultrasonic signals attenuate in soil, resulting in unique propagation laws. This paper studies the propagation laws of ultrasound in soil, focusing on the propagation characteristics of ultrasonic continuous signals at the transducer–soil interface. This study uses excitation frequency and amplitude as experimental factors and employs the discrete element simulation method to analyze the vibration characteristics of soil particles. It reveals the relationship between changes in soil pressure at the interface and the movement of the transducer. The results show that the motion curve of the transmitting transducer lags behind the soil pressure changes, and the energy of the ultrasonic signal increases with higher excitation frequency and amplitude. Specifically, the peak value of the first wave |H0| at 40 kHz and 60 kHz is 210% and 263% of that at 20 kHz, respectively. When the excitation amplitude increases from 0.005 mm to 0.015 mm, the value of the peak value of other waves |H| increases by 323%. This paper preliminarily reveals the propagation laws of ultrasonic continuous signals at the transducer–soil interface, providing theoretical support for the development of ultrasonic soil property detection instruments.

Different agronomic requirements, production conditions, and crop species result in varying row spacings. To address the issue of seedling damage caused by pressure when a fixed track width sprayer operates in different row spacings and enhance the accuracy of track width adjustment, this study designed a track width adjustment system for a sprayer based on the agronomic requirements for field management during the early and mid-stages of corn growth and the entire growth period of wheat in Henan Province, China. The designed track width adjustment system for the sprayer comprised transmission mechanisms, telescopic track width adjustment mechanisms, and an electro-hydraulic control system. The control system achieved a precise track width adjustment by controlling the movement of the hydraulic cylinders through electrical signals, forming a closed-loop adjustment system with the aid of sensors. Four control schemes are proposed: classical PID, integral separated PID, fuzzy adaptive PID, and integral separated fuzzy PID. Simulation experiments were conducted using MATLAB to compare these schemes. The results indicated that the integral separated fuzzy PID exhibited the fastest response and highest steady-state accuracy. The performance of the track width adjustment system was validated through field experiments. The results demonstrate that the stability coefficient of variation for the track width adjustment was 3.04%, which is below the 10% threshold required by agricultural machinery standards. Additionally, the average error of the track width adjustment was 13.42 mm, indicating high precision and effectively reducing seedling compression damage during plant protection operations.

The article briefly describes the importance of furrowing depth stability for seed germination and growth under precision seeding conditions. By analyzing the application status of furrowing depth control technology of the planter globally, the research method, technical characteristics, and development of furrowing depth stability control technology are reviewed from three key aspects, namely, profiling adjustment device, furrowing depth detection technology, and automatic control system. In this paper, (1) two types of profiling adjustments, active and passive, are described based on the difference in the downforce adjustment method; (2) three furrowing depth detection methods are described based on different sensors; (3) and three ways of regulating the furrowing depth system are summarized based on the different ways of evaluating the stability of furrowing depth. In addition, the characteristics and application requirements of global furrow depth control technology are summarized. It is proposed that the future planter should be developed in the direction of automatic navigation, automatic monitoring and evaluation of seeding quality, variable seeding, high-speed seeding, and other intelligent precision seeding techniques. The summary and outlook of this paper aim to promote the overall development of furrowing depth control technology.

Pneumatic seed metering devices are widely used in high-speed and precise corn seeding operations. The objective of this study was to analysis the high-speed seeding performance of a pneumatic precision seed metering device at seeding speed ≥12 km/h. In this study, full-factor experiments were conducted of an air-suction rotary-hub corn precision seed metering device at the early stage of development. Seed leaking was the primary failure mode, and the experimental factors had no evident regular influence on the repeat index. The negative pressure of 3-7 kPa had significantly positive and negative correlations with the qualified index and the leak index, whereas the seeding speed of 12-20 km/h was significantly negatively and positively correlated with the qualified index and the leak index, respectively. The leak index reached its greatest value of 32.48%, 15.61% and 66.77% when the negative pressure was 3 kPa, and it was always less than 10% when the negative pressure was greater than 6 kPa for the three corn seed varieties. The corn seed varieties with smaller sizes and regular shapes were more suitable for high-speed precision seeding operations above 12 km/h, and the negative pressure could be increased to improve the qualified index and reduce the leak index. corn; seed meter device; high-speed seeding; precision seeding; experiment

This paper provides a review of path-tracking strategies used in autonomous agricultural vehicles, mainly from two aspects: vehicle model construction and the development and improvement of path-tracking algorithms. Vehicle models are grouped into numerous types based on the structural characteristics and working conditions, including wheeled tractors, tracked tractors, rice transplanters, high clearance sprays, agricultural robots, agricultural tractor–trailers, etc. The application and improvement of path-tracking control methods are summarized based on the different working scenes and types of agricultural machinery. This study explores each of these methods in terms of accuracy, stability, robustness, and disadvantages/advantages. The main challenges in the field of agricultural vehicle path tracking control are defined, and future research directions are offered based on critical reviews. This review aims to provide a reference for determining which controllers to use in path-tracking control development for an autonomous agricultural vehicle.

Precision seeding is an effective technical way to improve quality and reduce material costs. However, certain factors limit the development and promotion of precision seeding technology, among which the main factor is that the agronomic requirements of sowing vary significantly in different areas, and there is a lack of suitable implements; at the same time, each link among the parts interact, which brings specific difficulties to improving the operational effect. This paper summarizes the precision seeding technology from the perspective of precision seeding realization and the consistency of seed spacing and use of consistent sowing depth control technology. A detailed description is included of the precision seed-discharge technology, the smooth seed-dropping technology, and the seed falling into the seed bed with precision. The need for regulation technology for consistent sowing depth is explained from a developmental perspective. The research status of compatible sowing depth control technology is described, as used in soil covering and compacting. This paper presents the problems and future development directions of soil-covering and compacting technology under precision-seeding conditions, including developing adaptable regional soil-covering and compacting devices, improving the processing and equipment technology of enterprises, strengthening the structural optimization design of soil-covering and compacting devices, conducting research into soil-covering and compacting control methods, and promoting the intellectual development of agricultural equipment.

The cover image is based on the Research Article Soil hydrologic properties in permanent raised beds—A field study experiment on wheat–maize cropping systems by Han Lin et al., https://doi.org/10.1002/ldr.4487.