Aiming at the potato cropping pattern in the hilly area of southwest China, a small digging device for potato harvester was designed. First, the overall structure of the harvester was determined according to the soil physical characteristic and cropping pattern of the test site. Then, the digging shovel, the key components of harvester were designed and was analyzed the relationship between the inclination of the digging shovel and the power loss under the conditions of different digging speed, digging depth and soil bulk density by MATLAB software, and the mathematical models were established. Finally, the three-dimensional model of the whole machine was established by SolidWorks, and the simulation experiment was carried out with the model of soil particles, potato particles and potato ridges created by the discrete element (DEM) software. The simulation results show that when the working speed of the harvester is 1 m/s, the digging depth is 170 mm, and the potato expose rate is 87.3%. Under normal working conditions of the digging device, appropriately reducing the digging depth can reduce the resistance and wear of the digging shovels.

In view of the problems of the output power and operation, when the multi-function machine in hilly and mountainous areas driving in the field, the hydraulic control drive system of small multi-function agricultural hydraulic chassis is designed. The key components of the hydraulic drive system were selected and matched. The hydraulic system simulation model was established in AMESim simulation analysis software, and the dynamic analysis of the hydraulic system operation under different conditions is carried out. The simulation analysis results show that the hydraulic system has a large impact and vibration when it is started instantaneously, and the hydraulic system has smaller impact and vibration when it is started stably. It is consistent with the actual working state of the hydraulic chassis. Under the two starting controls, the maximum flow of the hydraulic pump is 50L/min, the motor torque is about 440N • m, and the motor stable pressure is 6Mpa, the motor speed is 96 r/min, which is within the bearing range of the hydraulic components. The simulation output parameters are basically consistent with the theoretical calculation results, and meeting the design requirements. The chassis performance test results show that the maximum crossing height of the chassis is 200mm, the crossing width is 300mm, the maximum deviation of high-speed straight driving is 2.57m, it can stably pass 20° slope, and the operation is stable and the steering is flexible. All performance parameters can better meet the requirements of chassis operation in hilly and mountainous areas.

At present, the speed of the reel of soybean combine harvester is mainly adjusted manually, and basically does not have the ability to automatically adjust the speed of the reel according to changes in crops or working speed. In the maize-soybean strip intercropping mode, soybean plants are densely planted. During harvesting, the feeding rate increases, making it even more necessary to adjust the reel speed according to the growth status of the crops. This article uses PLC as the main control platform to design a reel speed control system for the existing combine harvester. Tests have shown that the control system can meet the requirements for reel speed control. The relative error of the reel control system’s speed test is 2.6%, the relative error of the operating speed is 6.77%, and the maximum relative error of the automatic control of the reel speed is 5.38%. Compared with traditional reel, it reduces header loss by 2.12%. The soybean combine harvester reel speed control system designed in this article can realize automatic adjustment of the reel speed, reduce feeding losses caused by changes in crop height, changes in feed volume, and untimely adjustment of the reel, and can reduce header loss, increased crop yield.

This paper addresses the issues caused by traditional tractors during seeding operations, such as soil compaction, decreased soil fertility, use of unclean fuel leading to environmental pollution, and the disruption of sustainable development. In response, the study designs a compact and lightweight electric four-wheel-drive chassis for a seeding robot suitable for strip planting of soybeans and corn. Using RecurDyn(V9R2) software and MATLAB/Simulink(2020a) modules, the paper conducts simulation and analysis of the straight-line driving process of the electric four-wheel-drive chassis on hilly terrain in field conditions. The simulation results demonstrate that when the suspension stiffness is 14.4 kN/m and the damping is 900 N·s/m, the chassis achieves optimal vibration reduction and straight-line driving performance. Experimental results based on the simulation findings indicate a high consistency between the simulation and actual models, confirming that optimizing the suspension damping parameters effectively improves chassis smoothness and enhances operational quality.

This design uses three point convergence type suspension system，The upper pull rod adopts the hydraulic oil cylinder to adjust the buried angle, and use rope winding device connection the lower pull rod，It can independently adjust the working condition of the equipment. Small multi-function chassis suspension device is designed for small agricultural power equipment design, especially solve suspend ploughshare problem of the buried angle adjustment, realize the real-time adjustment of the buried angle, thus limiting the depth of the plow and improve the quality of cultivated land.

Based on a photoelectric sensor and a single-chip microcomputer, a kind of automatic reseeding system is designed.