Protected cultivation systems such as greenhouses are becoming increasingly popular globally and have been adopted because of unpredictable climatic conditions and their ability to easily control micro- and macroenvironments. However, limitations such as hazardous work environments and shortages in labor are major concerns for agricultural production using these structures. This has led to the development and adoption of robotic systems. For the efficient use of robots in protected cultivation systems, we formulate the work efficiency problem and model a three-dimensional standard strawberry greenhouse to analyze the effectiveness of a strawberry-harvesting robot compared to different levels of human workforce (experienced, average, and beginner). Simulations are conducted using Quest software to compare the efficiency of different scenarios of robotics to humans. Different methods of improvement from battery capacity and charge rate to harvesting speed are investigated and optimal conditions are recommended. The average hourly production of the robot is about five times lower than that of skilled workers. However, robots are more productive due to their ability to work around the clock. Comparative analyses show that a reduction in harvesting time per strawberry from 3 to 1 s would result in an increase in daily production from 347.93 to 1021.30 kg. This would lead to a five-fold increase in comparison to present daily production. A 10% improvement in battery charge time would result in the battery capacity gaining two extra hours from the current 10 h and would cut the current 2 h needed for charge to 1 h. This paper proposes an operation process and suggestions for changes needed for improving the work efficiency of robots in a greenhouse. This could be extended to other crops and greenhouses.

Hydrogen tractors are being developed, necessitating consideration of the variation in the center of gravity depending on the arrangement of components such as power packs and cooling modules that replace traditional engines. This study analyzes the effects of component arrangement on stability and rollover angle in hydrogen tractors through simulations and proposes an optimal configuration. Stability is evaluated by analyzing rollover angles in various directions with rotations around the tractor’s midpoint. Based on the analysis of rollover angles for Type 1, Type 2, and Type 3 hydrogen tractors, Type 2 demonstrates superior stability compared to the other types. Specifically, when comparing lateral rollover angles at 0° rotation, Type 2 exhibits a 2% increase over Type 3. Upon rotations at 90° and 180°, Type 2 consistently displays the highest rollover angles, with differences ranging from approximately 6% to 12% compared to the other types. These results indicate that Type 2, with its specific component arrangement, offers the most stable configuration among the three types of tractors. It is confirmed that the rollover angle changes based on component arrangement, with a lower center of gravity resulting in greater stability. These findings serve as a crucial foundation for enhancing stability in the future design and manufacturing phases of hydrogen tractors.

A prototype for the remover of cherry tomato calyxes was designed and manufactured. The tap remover was designed and manufactured considering the conveyor transport speed, brush length and clearance, and diameter. These were adjusted in three levels to determine the optimal design factor. Performance tests were conducted using Icon 513, a circular-shaped cherry tomato variety, and Minimaru, a jujube-shaped cherry tomato variety. Conveyor transport speeds were set at 210, 280, and 350 mm/s; brush lengths at 70, 80, and 90 mm; brush clearances at 20, 22, and 24 mm; and brush diameters at 0.8, 1.0, and 1.2 mm. The two varieties showed a similar damage rate during calyx removal. However, Minimaru showed a higher calyx removal rate than Icon 513, indicating that it is most suitable for the calyx removal mechanization process.

In this study, the physical properties of garlic just before collection were investigated, and garlic-collecting conditions are presented as basic data of design factors that can be utilized during the development of garlic collectors. The physical properties were subdivided into geometrical properties and mechanical properties, and the ecotype of garlic was divided into CSG (cold-season garlic) and WSG (warm-season garlic). Geometrical properties were compared between CSG and WSG by measuring the average weight, length, width, number of kernels, volume, and density of each cultivar, and WSG showed higher geometrical properties in all geometrical properties. In addition, there was garlic on the incomplete side of WSG, and shape non-uniformity was higher than that of CSG. There was no significant difference in the average Poisson’s ratio of mechanical properties. In the case of the modulus of elasticity, Namdo cultivars showed the lowest value at 15.52 MPa. The average allowable compressive stress measured using Hooke’s law was the lowest in the Uiseong cultivar (204.33 kPa) and the highest in the Danyang cultivar (376.42 kPa). The static friction coefficients among the four different materials by cultivar exhibited a commonality of being highest in aluminum and generally lowest in plastic. It is expected that the design of the garlic collector will be carried out in consideration of garlic when developing it using up-to-date physical properties of garlic just before collection.

Tractor overturning accidents are a prominent safety concern in the field of agriculture. Many studies have been conducted to prevent tractor overturning accidents. Rollover protective structures and seat belts currently installed on tractors cannot prevent them from overturning. The posture of a tractor was controlled by installing individual actuators. The overturning angles of the tractor equipped with an actuator were compared with those of a tractor with no actuator. For the overturning angles in all directions of the tractor, it rotated 15° from 0° to 345°, and the actuator height suitable for the tractor posture was controlled by establishing an equation according to the tractor posture. Consequently, posture control using actuators was noticeably improved. This study proposes that tractors operating on irregular and sloping terrain be equipped with individual actuators. These results prevent tractor rollover accidents and improve safety and driving stability.

Manure distribution in soil creates a ground environment that is conducive to crop cultivation. However, the lumping and concentration of manure in the field can occur, hindering the fertilization of the soil for plant growth, and the randomization of nutrients under different soil depths accelerates it. To overcome the challenges associated with agricultural testing, such as high cost, inclement weather, and other constraints, computational analysis is often used. In this study, rotary operations are performed using the discrete element method (DEM) to ensure the uniform distribution of manure and four soil layers. DEM analysis was conducted with three experimental factors, and simulation sets were designed using the Box-Behnken central combination method. The DEM results were evaluated using the uniformity index (UI), and the field test of the rotary operation was performed with the set showing the most uniform distribution among the results. Due to undistinguishable particles in reality, the uniformity was validated by a comparison of the chemical characteristics of the L₁ and L₅ in terms of before and after the rotary operation. The DEM parameter of the soil was determined by performing field measurements at different soil depths (0–20 cm), and this parameter was calibrated by conducting a penetration test. The Box–Behnken central combination method was implemented using the following factors: tillage depth (X₁), PTO revolution speed (X₂), and forward machine velocity (X₃). These factors were obtained using the UI regression model and the response surface method. In the results, it was indicated that the UI was affected by the factors in the following order: X₁ > X₂ > X₃. The optimized factor values were X₁ = 25 cm, X₂ = 800 RPM, and X₃ = 1.8 km/h, leading to a UI of 6.07, which was consistent with the analysis results. The operating parameters were maintained throughout the field test, and the acquired data were input into the measurement system. The lowest UI value of 6.07 had the strongest effect on decreasing the disparity between L₁ and L₅, especially in terms of pH, organic matter, P, Ca, and Mg. In summary, the results indicated that soil distribution can be controlled by adjusting mechanical parameters to ensure uniform chemical characteristics across various soil depths.