The goal of this research was to analyze the load and safety of the transplanting device of the 4-bar link type semi-automatic vegetable transplanter under different workload conditions. To measure the strain at the transplanting device, a load measurement system was developed using 15 strain gauges. Field tests were conducted at 4 levels of engine speeds (750, 1000, 1250, and 1500 rpm) and 10 levels of the planting distance (0.29–0.47 m). The static safety factor was defined as the ratio between the strength of the material and the maximum stress in the transplanting device. The calculated stress data were converted from the time domain to the frequency domain using the rain-flow counting methods and Goodman’s Equation. The sum of fatigue damage was acquired based on the Palmgren–Miner’s rule. It was observed that the stresses increased with increasing engine speed and planting distance. The results show the higher engine speed and the longer planting distance will decrease the static safety factor and fatigue life. The static safety factor value was more than 1.0 for all locations and all working conditions. The minimum fatigue life was 49,153.3 h at link A (S_14), under the working condition of engine speed 750 rpm and planting distance of 0.35 m.

The consumed power and safety of cam and four-bar-link semi-automatic vegetable transplanters were analyzed and compared according to the engine speed and planting distances. A measurement system was constructed to obtain the torque, rotational speed, and strain at the corresponding locations of both transplanters. Field tests were conducted at three engine speeds and three planting distances for each type of transplanter. The torque and rotational speed data of the input shaft of the transplanting devices were used to calculate the power consumed during transplanting. The strain data were converted into stress values to calculate the static safety factor and fatigue life. The results show that the torque and consumed power of the cam transplanter were greater than those of the four-bar-link transplanter under similar operational conditions, owing to its rigid and heavier design. The consumed power increased as the engine speed increased for both types. The static safety factor and fatigue life exhibited different values depending on the measurement location with a sufficient safety margin. Although more skill is required in planting distance control owing to its manual adjustment, the four-bar-link type is more economical under similar operating conditions because of its smaller power requirement.

The aim of this study is to analyze the stress exerted on a four-bar link-type transplanting device using two distinct methods: stress measurement performed during a field test and stress simulation. A field test is conducted to measure stress using a strain gauge positioned at 15 specific points on the transplanting device. Subsequently, the measured strain data are converted into calculated stress data. In another method, stress is simulated using specialized multibody dynamic simulation software. The simulation results are compared with the stress measured during field tests to verify the simulation model. Based on the results, the maximum stress derived from the simulation correlates with the measured results, although notable discrepancies are shown, particularly at strain gauge positions 11 and 13. The maximum stress derived from the simulation is used to calculate the static safety factor of the transplanting device. The peak stress derived from the simulation aligns with the measured results, although significant discrepancies are observed at positions corresponding to strain gauges 4 and 10. The maximum stress (150.82 MPa) is observed on the link of the transplanting device, and the static safety factor determined via the simulation is 1.39.

In this study, the static safety factor and fatigue life of fastening devices of an agricultural by-product collector were evaluated under hard flat ground driving conditions. The strain gage-based measurement system was constructed, and the strain gage was attached on the highest stress spot of the fastening devices derived from structural analysis. The static safety factor and fatigue life of the fastening devices were calculated using the measured strain values and by converting it into stress data. The two operating conditions are considered to be the loading part of the by-product collector, lifted and non-lifted. The results for all fastening devices showed that the static safety factor was larger than 1.0 and the fatigue life was much greater than the expected lifetime under both operating conditions. Therefore, it can be concluded that the fastening devices of the by-product collector can be operated reliably under hard flat ground driving conditions. In future work, we plan to evaluate the safety of the fastening devices in various actual orchard farm environments.

In this study, to evaluate the safety of the fastening device, which is a vulnerable part of the agricultural by-product collector, the stress in fastening devices was measured, and the operational and driving safety were analyzed by deriving the static safety factor and fatigue life. The position with the maximum stress in fastening devices was identified through structural analysis simulation, and a stress measurement system was constructed using strain gauges. Test conditions for stress measurement were classified into three operating conditions (collection operation, driving with the loading part lifted to the highest point, and driving with the loading part lifted to the lowest point) and three soil conditions (even pavement, sloped pavement, and farmland). A process for deriving the fatigue life based on the measured stress was constructed by applying the rain-flow counting method, Goodman equation, and Palmgren–Miner’s rule via commercial software. From the stress measurement results, the collection operation exhibited the highest maximum stress, followed by driving with the loading part lifted to the highest point and driving with the loading part lifted to the lowest point. Under all conditions, the static safety factor of the fastening devices was found to be higher than 1.0 (1.16–1.33). The fatigue life of the fastening devices was also found to be longer than the service life of Korean agricultural machinery under all operating conditions. Therefore, the fastening devices are expected to operate safely under generated static and dynamic loads. The agricultural by-product collector can perform agricultural work and drive stably and is expected to contribute to reducing unnecessary labor force for Korean farms.

Stress measurements play a crucial role in safety analyses of transplanting devices. Strain gauges for stress measurements during field tests can be expensive and time-consuming. The aim of this study was to investigate the stress on the transplanting device of a cam-type semiautomatic vegetable transplanter using a simulation method. A three-dimensional simulation model was established, considering the dimensions and material properties of the transplanting device. The stress distribution and maximum stress values were obtained through simulations. The maximum stress values at 15 points within the transplanting device determined via the simulation were compared with the experimental stress data to verify the stress simulation model. The results show that the maximum stress obtained from the simulation correlated with that of the measured results, although differences were observed at different locations, particularly at strain gauge positions 11 and 13. Based on the simulation results, the maximum stress occurs at the upper link of the cam-type transplanting device, reaching a magnitude of 201.21 MPa, and the static safety factor is 1.04.