The Design and Test of the Chassis of a Triangular Crawler-Type Ratooning Rice Harvester

Self Cite

To promote the germination of rice panicles during the regeneration season, it is necessary to ensure a stubble height of 300–450 mm when mechanically harvesting the first-season rice. However, due to variations in the depth of the paddy soil and fluctuations in the height of the header during harvesting, maintaining the desired stubble height becomes challenging, resulting in a significant impact on the yield during the regeneration season. This study presents the design of an adaptive profiling header capable of adjusting the height and level of the header adaptively. Based on the theoretical analysis of the profiling mechanism, a quadratic regression orthogonal rotation combination experiment is designed. Considering the actual field conditions, the range of each factor is determined, and simulation experiments are conducted based on the MBD-DEM coupling to establish a mathematical regression model between each factor and indicator. In the case of the profiling wheel linkage length of 562 mm, profiling wheel width of 20 mm, and profiling wheel mass of 3.6 kg, the supporting force of the header on the profiling wheel would be greater than zero, the supporting force of soil on the profiling wheel and the depth of soil subsidence represent the smallest values, and the highest sensitivity and accuracy of the profiling wheel are achieved. Bench tests demonstrated that the header exerts a force on the profiling wheel, confirming the normal functioning of the profiling. The average magnitudes of forces exerted by the soil on the profiling wheel are obtained to be 31.98 N, 31.63 N, and 30.86 N, whereas the corresponding average soil subsidence depths are obtained as 3.4 mm, 5.6 mm, and 8.3 mm, aligning closely with the simulation values. The results indicate that the profiling mechanism achieves high accuracy in ground profiling and that the structural design is reasonable. By employing fuzzy PID control to adjust the height of the header, the average error in adjustment is obtained as 6.75 mm, while the average error in the horizontal adjustment is derived as 0.64°. The header adjustment is fast, offering high positioning accuracy, thereby meeting the harvesting requirements of the first season of ratooning rice.

Section: Introductionmentioning

confidence: 99%

“…Figure 1. Adaptive profiling header: (1) header support frame, (2) elevation oil cylinder, (3) conveyor groove, (4) rotating disc, (5) profiling mechanism, (6) header, (7) inclination sensor, (8) leveling oil cylinder, (9) the angle sensor,(10) four-link mechanism,(11) the linkage of the profiling wheel,(12) …”

mentioning

confidence: 99%

Design and Experiment of Adaptive Profiling Header Based on Multi-Body Dynamics–Discrete Element Method Coupling

Liu,

Zeng,

Chen

2024

Self Cite

“…On the other hand, scholars such as Fu and Zeng tackled the issue from a different perspective by improving the design of the harvester. They developed a specialized harvester for ratoon rice through adjustments to the cutting table width and optimization of the chassis form [14][15][16][17][18]. This approach achieved notable success in reducing the straight-line compaction rate and significantly contributed to increasing the yield of the second-season rice.…”

Section: Introductionmentioning

confidence: 99%

Design and Parametric Optimization Study of an Eccentric Parallelogram-Type Uprighting Device for Ratoon Rice Stubbles

Xing,

Yu,

Cao

et al. 2024

To address the issue of reduced yield in the second season caused by damaged stubbles resulting from being compressed during the harvesting process of the first season’s ratoon rice, a device for rectifying the compressed stubbles was designed. Utilizing the DEM-MBD coupling simulation method, a simulation analysis was conducted to determine the range of key parameters and verify the feasibility of the solution. Using rotational speed, forward speed, and stubble entry angle as experimental factors and stubble rectification rate and second-season yield as evaluation metrics, a three-factor, three-level Box–Behnken response surface field trial was conducted. The theoretically optimal working parameter combination was found to be a forward speed of 1.4 m/s, device rotational speed of 75 rpm, and stubble entry angle of 39°. Under these conditions, three parallel experiments were performed, resulting in a rectification rate of 90.35% in the mechanically harvested and compressed area and a second-season yield of 2202.64 ± 35 kg/hm². The deviation from the numerical simulation results of parameter optimization was less than 5%. These findings suggest that the designed stubble rectification device for ratoon rice can meet the requirements of stubble rectification during the first-season harvest of ratoon rice. Furthermore, it provides valuable insights for reducing harvest losses in the first season and further improving the level of mechanized harvesting for ratoon rice.

“…The rice growing area in China is about 30 million hectares, with an annual output of more than 210 million tons [1,2]. Ratooning rice has the advantages of planting once and harvesting twice, making full use of light and temperature resources, increasing grain production and income, and good rice quality, etc., which has been rapidly promoted in recent years in suitable areas in the middle and lower reaches of the Yangtze River [3,4]. Cleaning is a key link in the harvesting operation of the ratooning rice [5].…”

Section: Introductionmentioning

confidence: 99%

Vortex Cleaning Device for Rice Harvester: Design and Bench Test

Liu,

Zeng,

Chen

2024

Self Cite

To solve the problem of increased grain impurity rate and grain loss rate caused by clogging of sieve holes during the cleaning process of ratooning rice, a spiral step cleaning device was designed, which disturbed the flow field at the sieve holes through vortex in the slot and disrupted the force balance of the blockages at the sieve holes. The device mainly includes a cleaning separation core and a cleaning separation core shell. Firstly, the main parameters of the cleaning separation core were determined, and the critical shear airflow velocity was obtained through theoretical analysis. Through energy loss analysis, the fan wind speed was determined to be 11.5 m/s. Secondly, the CFD-DEM coupling method was used to analyze the flow patterns inside the slot and the movement patterns of blockages on the sieve surface, confirming the effectiveness of vortex guided blockage removal. Finally, a prototype was designed and built for testing, and the results showed that when the wind speed of the fan was 11.5 m/s, the grain impurity rate was 1.35%, the grain loss rate was 2.13%, and the average sieve blockage rate was ≤0.1%. All indicators were better than traditional cleaning devices and could meet the cleaning requirements. During the continuous operation of the spiral step cleaning device, performance indicators such as sieve hole blockage rate remained basically unchanged.