ABSTRACT In the process of rice harvesting, the passability of the track combine harvester is often limited by the state of the soil. Meanwhile, wet and soft paddy soil is compacted under the rolling of harvesting machinery, which also affects the soil function and the ecological environment. Therefore, the relationship between the physical and mechanical properties of wet and soft paddy soil was studied in this paper. In addition, compaction from a track combine harvester on field soil with and without rice stubble was studied. The density and gradation of wet and soft paddy soil were positively correlated with cohesion and negatively correlated with the internal friction angle. In paddy soil with a moisture content of 16–36%, the soil moisture content was negatively correlated with cohesion and internal friction angle. Additionally, the plastic deformation of soil with rice stubble under compaction was greater than that without rice stubble, and the plastic deformation of the field with rice stubble mainly occurred in the second rolling stage. Increasing the speed of the track combine harvester effectively reduced the compaction risk of rice stubble soil.

ABSTRACT In view of the fact that the design of the cab structure of wheeled combine harvesters in China lacks ergonomic design parameters exclusive for Chinese drivers, there are generally problems such as high vibration and poor comfort of the whole machine structure during the harvesting process. Firstly, this paper designed the cab structure of a wheeled grain combine harvester based on ergonomics. Then, the driver's handling comfort and visibility were simulated and analyzed using Creo. Finally, the relevant dimensions of the driver's control device were optimized. The results show that the wheeled grain combine harvester cab based on ergonomic design better meets their driving comfort needs. In addition, it is found that the operating frequencies of the key components, such as the main shaft of the conveyor spindle, the vibrating screen, the threshing drum, and the intermediate shaft of the engine, partially overlap with the frequency of human discomfort. Therefore, modal planning is also needed for this harvester to meet human comfort requirements better. This paper provides the basic parameters for the design of the cab structure of the combine harvester with high comfort for the Chinese harvesting machinery driver.