• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.819-826
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• 2000

This study was performed to develop a measurement system of tractor field performance for plow and rotary operations. Measurement system for tractor consisted of torque sensors to measure torque of drive axles and PTO axle, speed sensors to measure rotational speed of drive axles and engine, microcomputer to control data logger, and data logger as I/O interface system. The measurement system was installed on four-wheel-drive tractor. Four-element full-bridge type strain gages were used for torque measurement of drive axles and optical encoders were used to measure speeds of drive axles and engine. Slip rings were mounted on the rotational axles. Signals from sensors were inputted to data logger that was controlled by microcomputer with parallel communication. Sensors were calibrated before the field tests. Regression equations were found on completion of the calibrations. The field experiment was performed at paddy fields and uplands. Rotary and plow were used when the tractor was operated in the field. Travelling speeds of the tractor were 1.9 km/h, 2.7 km/h, 3.7 km/h, 5.5 km/h, 8.2 km/h, and 11.8 km/h. Operating depths of implements were maintained approximately 20cm during the tests. Torque data of drive axles were different at each location during plow and rotary operations. Results showed that torque of rear axles were greater than those of front axles. Total torque were 6860 - 11064 Nm at the upland and 7360 - 14190 Nm at the paddy field for plow operations. It was found that torque at the paddy field were about 20% greater than those at the upland for plow operations. Torque data showed that rotary operations required less power than plow operation at the paddy field and the upland. Torque measurements at each axle for rotary operations were only 8 - 16% of plow operations in the upland and 15 - 20% in the paddy field.

• Journal of Biosystems Engineering
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• v.12 no.3
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• pp.30-41
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• 1987

The geometrical shape of a plow bottom may be the most important factor affecting the performance of a plow for a given soil and operating conditions. There are various designs of the Jaenggi (Korean plow) available commercially, which may be different from each other and from the plow (Western plow) in respect to the shape and performance. This study was intended to investigate the geometrical characteristics of Jaenggi. The coordinate digitizer equipped with 3 potentiometers was designed and manufactured for measurement of the shape of curved plane of moldboard and share. The digitizer was connected to a microcomputer having the data acquisition system. This device was used to analyze the plow bottoms of 5 differently-made Jaenggis and one cylindrical plow. The results of the study are summarized as follows: 1. It was possible to measure easily and quickly the curved plane of plow bottom and to plot the view on three major plans using the coordinate digitizer electrically connected to a microcomputer system. 2. The shape of five Jaenggi bottoms analyzed could be characterized by the cutting angle having the range of $33-42^{\circ}$, the maximum share-lift angle of $41-50^{\circ}$, and the setting angle of moldboard wing of $46-70^{\circ}$. The most critical difference of the shape factors between the Jaenggi and the plow was found in the maximum share-lift angle, the former was more than twice as much as the latter. 3. The analysis of the shape of Jaenggi bottoms showed that the share projections on 3 major plans had a varied triangle, which was quite different from that of plow bottom. Especially, it was analyzed that the shape of furrow slice for the Jaenggi had a skewed rectangle, leaving a considerable height of the ridge at the furrow bottom. 4. The dihedral angle was similar range of $30-85^{\circ}$ for the all bodies investigated, but the directional angle was somewhat different from each other. The difference in directional angle was $5^{\circ}$ for the plow, $20^{\circ}$ for the Jaenggi A and $30^{\circ}$ for the Jaenggi B. 5. Area of the spherical representation region was 0.0328 for the plow, 0.1194 for the Jaenggi A and 0.1716 for the Jaenggi B. This may indicate that the plow came close to a working surface and the Jaenggi A and the Jaenggi B departed from a working surface to a somewhat greater extent.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.383-394
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• 2023

In Korea, the U.S. Tier-4 Final emission standards have been applied to agricultural machinery since 2015. This study was conducted to analyze the emission characteristics of agricultural tractors during plow tillage operations using PEMS (portable emissions measurement systems). The tractor working speed was set as M2 (5.95 km/h) and M3 (7.60 km/h), which was the most used gear stage during plow tillage operation. An engine idling test was conducted before the plow tillage operation was conducted because the level of emissions differed depending on the temperature of the engine (cold and hot states). The estimated level of emissions for the regular area (660 m²), which was the typical area of cultivation, was based on an implement width of 2.15 m and distance from the work area of 2.2 m. As a result, average emission of CO (carbon monoxide), THC (total hydrocarbons), NOx (nitric oxides), and PM (particulate matter) were approximately 6.17×10-2, 3.36×10^-4, 2.01×10^-4, and 6.85×10^-6 g/s, respectively. Based on the regular area, the total emission of CO, THC, NOx, and PM was 2.62, 3.76×10^-2, 1.63, and 2.59×10^-4 g, respectively. The results of total emission during plow tillage were compared to Tier 4 emission regulation limits. Tier 4 emission regulation limits means maximum value of the emission per consumption power (g/kWh), calculated as ratio of the emission and consumption power. Therefore, the total emission was converted to the emission per power using the rated power of the tractor. The emission per power was found to be satisfied below Tier 4 emission regulation limits for each emission gas. It is necessary to measure data by applying various test modes in the future and utilize them to calculate emission because the emission depends on various variables such as measurement environment and test mode.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.723-735
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• 2019

The power-train is the most important component of an agricultural tractor. In this study, the strength of the driving gear transmission of an 82 kW-class tractor was analyzed using equivalent torque during plow tillage. The load measurement system consisted of an engine revolution speed sensor, torque-meters, revolution speed sensors for four axles, and pressure sensors for two hydraulic pumps. The load data were measured during plow tillage for four speed stages: F2 (2.78 km/h), F5 (5.35 km/h), F7 (7.98 km/h), and F8 (9.75 km/h). Aspects of the gear-strength such as bending stress, contact stress, and safety factors were analyzed under two torque conditions: the equivalent torque at the highest plow load for the F8 speed stage and the maximum engine torque. The simulation results using KISSsoft showed that the maximum engine torque conditions had a lower safety factor than did the highest equivalent torque condition. The bending safety factors were > 1 at all gear stages, indicating that gear breakage did not occur under actual measured operating conditions, nor under the maximum torque conditions. However, the equivalent torque condition in the contact stress safety factor was > 1, and the maximum torque condition was < 1 at the first gear pair. The method of analysis using the equivalent torque showed lower stress and higher safety factor than did the method using maximum torque. Therefore, when designing a tractor by applying actual working torque, equivalent torque method would support more reliable product development.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1135-1145
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• 2020

The purpose of this study was to compare and analyze the emissions of SOx and NH3 for a 78 kW class agricultural tractor during agricultural operations. A real-time monitoring system was constructed for measuring the load data. The field test was conducted during plow and rotary tillage. The working conditions were selected with the transmission gears in M3 Low and M2 High for the plow tillage and L3 High and L3 Low for the rotary tillage. The engine torque and fuel consumption were measured using controller area network (CAN) communication, and the emissions of SOx and NH3 were calculated based on the fuel consumption. As a result of the field tests, the engine torque was higher for the plow tillage than for the rotary tillage. As the gear stage was increased, the engine torque became higher. The emissions of SOx and NH3 were higher for the plow tillage than for the rotary tillage because the fuel consumption increased. Moreover, the emissions of SOx and NH3 tended to be more distributed for the rotary tillage than for the plow tillage. To develop an emission factor for agricultural machinery, it is important to measure reliable emission data during agricultural operations. In a future study, we will collect various emission data using a portable emission measurement system during agricultural operations.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.937-948
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• 2022

Agricultural operations are performed in uneven environments by attaching an implement on the 3-point hitch of a tractor. A high load is thus placed on the 3-point hitch, and fatigue and failure of the hitch may occur during agricultural operations. In this study, a dynamic simulation model was developed to predict the load occurring on the eyebolt of a 3-point hitch, which is the main damaged component. The simulation model was developed and validated using agricultural data as simulation input and validation data. The dynamics model was developed using the specifications of a 78 kW class tractor. A measurement system was constructed to measure the simulation input and validation data. The simulation model was validated using a traction load on an eye bolt, which was measured during plow tillage operation. The measurement results showed that the average traction load on the left and right lower link and the top link were 8,099.97, 4,943.06, and 636.11 N, respectively. The simulation results and the measured traction load on the left eyebolt were respectively 610.30 and 597.15 N. The simulation results and measured traction load on the left eyebolt were respectively 1,179.78, and 1,145.06 N. The error between the simulation and measurement data was roughly 2% on the left eyebolt and 3% on the right eyebolt.

• Korean Journal of Agricultural Science
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• v.42 no.1
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• pp.53-61
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• 2015

Development of highly efficient and energy-saving tractors has been one of the issues in agricultural machinery. For design of such tractors, measurement and analysis of load on major power transmission parts of the tractors are the most important pre-requisite tasks. Objective of this study was to perform pre-processing procedures before effective analysis of load data of agricultural tractors (30, 75, and 82 kW) during major field operations such as plow tillage, rotary tillage, baling, bale wrapping, and to select the suitable pre-processing method for the analysis. A load measurement systems, equipped in the tractors, were consisted of strain-gauge, encoder, hydraulic pressure, and radar speed sensors to measure torque and rotational speed levels of transmission input shaft, PTO shaft, and driving axle shafts, pressure of the hydraulic inlet line, and travel speed, respectively. The entire sensor data were collected at a 200-Hz rate. Plow tillage, rotary tillage, baling, wrapping, and loader operations were selected as major field operations of agricultural tractors. Same or different farm works and driving levels were set differently for each of the load measuring experiment. Before load data analysis, pre-processing procedures such as outlier removal, low-pass filtering, and data division were performed. Data beyond the scope of the measuring range of the sensors and the operating range of the power transmission parts were removed. Considering engine and PTO rotational speeds, frequency components greater than 90, 60, and 60 Hz cut off frequencies were low-pass filtered for plow tillage, rotary tillage, and baler operations, respectively. Measured load data were divided into five parts: driving, working, implement up, implement down, and turning. Results of the study would provide useful information for load characteristics of tractors on major field operations.

• Journal of Drive and Control
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• v.16 no.4
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• pp.23-31
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• 2019

The purpose of this study was to evaluate the PTO severeness for an agricultural tractor during disk plow and rotary tillage. The PTO load measurement system was constructed with data acquisition and a PTO torquemeter. Field experiments were conducted at a combination of traveling speed (L3 Low, L3 High) and PTO speed (P1, P2). The load spectrum was generated using the rain-flow counting method, and the SWT method was used to consider the range and mean of the PTO load. The damage sum was calculated by applying a modified miner rule, which is a cumulative damage law. The relative severeness was expressed as the ratio of the lowest damage sum. Relative severeness was higher with the lower PTO gear stage, and higher driving gear stage and it was approximately 40-102 times higher for rotary tillage than disk plow tillage in the same gear stages. The relative severeness was 1010.12 in the rotary tillage under L3 High P1 based on the disk plow tillage under L3 Low P2.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.9-9
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• 2003

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.665-669
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• 2016

Analysis of the load on the tractor during field operations is critical for the optimal design of the tractor. The purpose of this study was to do a load analysis of an agricultural tractor during plowing and harrowing. First, a load measurement system was developed and installed in a 71 kW agricultural tractor. Strain-gauges with a telemetry system were installed in the shaft located between the axles and the wheels, and used to measure the torque of the four driving axles. Second, field experiments were conducted for two types of field operations (plowing, harrowing), each at two gear levels (M2, M3). Third, load analysis was conducted according to field operation and gear level. At M2 gear selection for plowing, the maximum, minimum, and average (S. D.) torque values were 13,141 Nm; 4,381 Nm; and 6,971 Nm (${\pm}397.8Nm$, respectively). For harrowing, at M2 gear selection, torque values were, 14,504 Nm; 1,963 Nm; and 6,774 Nm (${\pm}459.4Nm$, respectively). At M3 gear selection for plowing, the maximum, minimum, and average (S. D.) torque values were,17,098 Nm; 6,275 Nm; and 8,509 Nm (${\pm}462.4Nm$, respectively). For harrowing at M3 gear selection, maximum, minimum, and average (S. D.) torque values were, 20,266 Nm; 2,745 Nm; and 9,968 Nm (${\pm}493.2$). The working speed of the tractor increased by approximately 143% when shifted from M2 (7.2 km/h) to M3 (10.3 km/h); while during plow tillage and harrowing, the load of the tractor increased approximately 1.2 times and 1.5 times, respectively.