Research on the constitutive model of low-damage corn threshing based on DEM

Design, development, and field evaluation of a rubber tapping robot

YOLO5-spear: A robust and real-time spear tips locator by improving image augmentation and lightweight network for selective harvesting robot of white asparagus

Weed seed burial as affected by mouldboard design parameters, ploughing depth and speed: DEM simulations and experimental validation

To date, mechanized picking of famous tea (bud, one bud one leaf) causes a lot of damage. Manual picking results in high-quality tea but the process is inefficient. Therefore, in order to improve the quality of mechanically harvested tea buds, the study of bionic picking is beneficial to reduce the damage rate of mechanical picking. In this paper, the manual flexible picking process is studied, and a bionic bladeless mechanical picking mechanics model is developed. The relationship between the mechanical properties and structural deformation of tea stalks is obtained by microstructural observation and mechanical experimental analysis and determination of the bud bionic picking mechanics flow by combined loading tests is carried out. The results show that the key factor for low damage in tea picking is the precise flexible force applied to different parts of the shoot tip during pinching, upward, and picking. The biological force of tea stalks is closely related to the stalk diameter and maturity of stalk tissue development. The larger the xylem of the tea stalk, the stronger its resistance to bending, stretching, and deformation. The stalks at the tender end of the tea are more resilient than the lower stalks and will not break under the action of large angle bending. Additionally, the stalks at the shoot tip have significantly lower pull-off force than the stalks at other places. By simulating the manual picking process, the mechanical picking mechanical parameters were determined to be a clamping pressure of 340 kPa, bending force of 0.134 N, and pull-off force of 5.1 N. These findings help the design of low-damage pickers for famous tea and provide a reference for low-damage bionic picking of tea.

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Biomechanical Characterization of Bionic Mechanical Harvesting of Tea Buds

Analysis of the interaction between end-effectors, soil and asparagus during a harvesting process based on discrete element method

Burgers viscoelastic model-based variable stiffness design of compliant clamping mechanism for leafy greens harvesting

The subsoiling technique in conservation tillage can effectively break the bottom plow layer and improve the tillage structure. But the wear problem of subsoiler is an important obstacle to the popularization of subsoiling. In this paper, the surface of the subsoiler is defined, and the subsoiling process of the curved-surface subsoiler with different speeds is simulate by discrete element method. By comparing with the actual subsoiler that wears heavily, the results shows that the main wear surfaces of the subsoiler are the upper surface and the front surface of the subsoiler tip, the front surface of the subsoiler-surface and the front surface of the subsoiler handle; the wear degree of subsoilers has a positive correlation with the work speed, wherein subsoiler handle has the greatest correlated with the speed.

Wear Mechanism of Curved-Surface Subsoiler Based on Discrete Element Method

The invention provides a method for calibrating parameters of a proportional variable fertilization discrete element model based on a correlation vector machine. The method comprises the following steps: 1, according to the fertilizer discharging process of a specific type of proportional variable fertilization machine, establishing a proportional variable fertilization discrete element model; 2,analyzing that sensitivity of the parameters of the discrete element model; 3, generating a training sample and a test sample by use that discrete element simulation; 4, establishing a regression model of fertilizer blende uniformity; 5, constructing a principal factor parameter fitness function; 6, establishing a mathematical model for calculating that optimal principal factor parameter value andsolving the mathematical model. The parameter calibration method of proportional variable fertilization discrete element model based on correlation vector machine effectively avoids the simulation distortion phenomenon caused by the model parameter values obtained by experimental measurement, and effectively overcomes the blindness and complexity of manual simultaneous adjustment of multiple parameter values for calibration.

Parameter calibration method of discrete element model for proportional variable fertilization based on correlation vector machine

This paper designed a novel subsoiler named spiral subsoiling shovel, in order to solve the problems that arrow-shaped subsoiling shovel has little disturbance to the deep soil and looseness of soil is not obvious, and improved the amount of medium and deep soil disturbance in the process of subsoiling operation. Discrete element method is used to simulate the real soil environment. Spiral subsoiling shovel was established by 3D modeling software. The subsoiling process was modeled and simulated with discrete elements software. After the simulation, analysis of the disturbance and calculate the looseness of soil and soil disturbance coefficient. Compared with the existing literature data, the results show that the soil disturbance coefficient of the soil was 64.05% and the looseness of soil reached 24.46% by using the spiral subsoiling shovel.

Li Jinguang

Papers

Analysis of the interaction between end-effectors, soil and asparagus during a harvesting process based on discrete element method

Burgers viscoelastic model-based variable stiffness design of compliant clamping mechanism for leafy greens harvesting

Wear Mechanism of Curved-Surface Subsoiler Based on Discrete Element Method

Parameter calibration method of discrete element model for proportional variable fertilization based on correlation vector machine

Analysis of Soil Disturbance Process and Effect by Novel Subsoiler Based on Discrete Element Method