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.

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.

Straw returning has shown great advantages in residue management and soil protection in crop planting systems. Mechanized retention of straw is the primary straw returning method, which can reduce costs and improve efficiency. It is important to increase the chopping quality in the field of straw returning, because poor chopping quality will provoke a series of problems including seeding blockage. Straw chopping pass rate (CPR) is an important indicator to measure the chopping quality. Therefore, the CPR of straw should be improved during the chopping process. This paper introduced a novel maize straw chopping device. With the ground as the support, the maize straw was chopped rapidly in the vertical direction. The key parameters of the chopping device were determined by establishing mathematical models and kinematics simulation analysis methods via ADAMS. The effects of rotational velocity, installation positions of chopping units, and the tractor forward velocity on the CPR of maize straw and soil bulk density (SBD) were examined through the Box–Behnken design method. The test factors were the rotational velocities of the chopping units (RV, 550 rpm, 650 rpm, 750 rpm), the installation distance of the two chopping units (IDTCU, 480 mm, 600 mm, 720 mm), and the velocity of the tractor (VT, 3 km/h, 4 km/h, 5 km/h). The results showed that the maximum CPR value and better value of SBD were obtained under the RV of 610 rpm, the IDTCU of 526.8 mm, and the VT of 3.96 km/h. Finally, field validation experiments were conducted under the RV of 610 rpm, the IDTCU of 550 mm, and the VT of 4 km/h. The results showed that the CPR of maize straw was 92.0%, which was superior to the requirement as stipulated in the National Standards of China (CPR ≥ 85%). In addition, in 0–50 mm and 50–100 mm soil layers, the bulk density was decreased by 25.42% and 13.24%, respectively. These results become of considerable importance for crop production in China.

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.

To investigate the interaction mechanism between agricultural tillage machinery and soil, this study established a precise simulation model by integrating physical and numerical experiments using typical yellow cinnamon soil collected from western Henan Province, China. The discrete element parameters for soils with varying moisture contents were calibrated based on the Hertz–Mindlin (no slip) contact model. Through Plackett–Burman screening, steepest ascent optimization, and Box–Behnken response surface methodology, a predictive model correlating moisture content, parameters, and repose angle was developed, yielding the optimal contact parameter combination: interparticle static friction coefficient (0.6), soil–65Mn static friction coefficient (0.69), and interparticle rolling friction coefficient (0.358). For the Bonding model, orthogonal experiments coupled with NSGA-II multi-objective optimization determined the optimal cohesive parameters targeting maximum load (673.845 N) and displacement (9.765 mm): normal stiffness per unit area (8.8 × 10⁷ N/m³), tangential stiffness per unit area (6.85 × 10⁷ N/m³), critical normal stress (6 × 10⁴ Pa), critical tangential stress (3.15 × 10⁴ Pa), and bonding radius (5.2 mm). Field validation using rotary tillers and power harrows demonstrated less than 6% deviation in soil fragmentation rates between simulations and actual operations, confirming parameter reliability and providing theoretical foundations for constructing soil-tillage machinery interaction models.