Agricultural mechanization
Mehdi Anafche; nasim monjezi
Abstract
Introduction: Considering the high use of agricultural machines in sugarcane Agro-industry company; management of maintenance and repairs is necessary. The application of agricultural mechanization and the management of machines in agriculture is responsible for improving the way of working and correct ...
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Introduction: Considering the high use of agricultural machines in sugarcane Agro-industry company; management of maintenance and repairs is necessary. The application of agricultural mechanization and the management of machines in agriculture is responsible for improving the way of working and correct use of machines. Today, with the mechanization of agricultural systems, the timely performance of activities requires correct machine planning. For proper planning, one must know the reliability of the machines. Increasing efficiency and reliability of machines is an economic necessity. Any scheduled program to increase the reliability of machines can be effective in reducing time loss due to repairs and cause repairs to be completed on time. Therefore, in this research, according to the nature of the project of annual repairs of MF 399 tractors, in which the activities and the time of their completion are possible, the graphic evaluation and review technique (GRET) method was used. GERT's method is one of the possible network programming methods. In GERT's method, the occurrence of activities is considered possible and a percentage of probability is assigned for the occurrence of each activity.Materials and Methods: This research was conducted in the Dehkhoda Sugarcane Agro-industry Company in the crop year of 2023-2024. Dehkhoda Sugarcane Agro-industry Company has 42 Messi Ferguson 399 double differential tractors. In this research, in order to schedule annual repairs, statistics and data related to the repairs of 22 MF 399 tractors were collected and the data of other machines were used to compare the actual repair time with the calculated schedule. The 13 repair items of MF 399 tractors used in the company include: engine, clutch, gearbox, differential and rear axle, brake, rear hub, body, front axle, hydraulics, electricity and battery, wheels, service and greasing. The work breakdown structure diagram and network model of annual MF 399 tractor repairs were drawn. To extract the time distribution density function of each activity, first the available information was collected for each activity, then the time distribution density function was determined for each activity. The time to perform the activities is fuzzy and they are expressed by triangular fuzzy numbers. In this research, after scheduling, the results obtained from GERT's method were compared with the actual time spent to perform annual MF 399 tractor repairs and the appropriateness of the estimates was determined. For this purpose, in order to determine the actual time of annual MF 399 tractor repairs, among the tractors available in the mechanical equipment department of Dehkhoda Sugarcane Agro-industry Company, in the crop year 2023-2024, a sample was randomly selected and the actual duration of repairs was determined. Then the actual time to complete the operation was compared with the expected time.Results and Discussion: The time to complete the annual repairs of MF 399 tractors was estimated to be 225.93 hours using the classic GERT method. But in GERT's Fuzzy method, the time calculated for annual MF 399 tractor repairs was (295.30, 232.07, 168.73) hours. The actual duration of annual repairs for 20 tractors (out of a total of 42 tractors) in Dehkhoda Sugarcane Agro-industry Company, which were repaired during the 2023-2024 crop year, according to the information available in the technical office of the company's mechanical equipment, was determined. 29.12% of the real times for completing MF 399 tractor repairs were estimated outside the fuzzy time. Therefore, the manager of the repair unit can reduce the cost of time loss and manage the time to complete the operation in the optimal time frame by using correct planning and reducing the reasons for the delay in the operation.Conclusion: Therefore, GERT F Fuzzy's method provides the possibility to the manager of the repair unit to set the completion time in the estimated range appropriately, taking into account other effective factors involved in the operation, so that there is no disruption in the implementation of activities and on the other hand, the costs to minimize when the work is not done. It also provides the possibility to create cuts at different times and control the operation process and modify it if needed. In the real world, due to existing uncertainties, there is not enough confidence in the duration of the annual maintenance of tractors, but nevertheless, the results obtained from GERT's method in this research are close to the actual time of completion of operations and make the estimates more appropriate.
H. Mehregan; Sh. Ghavami Jolandan; M. E. Khorasani Ferdavani
Abstract
Introduction Today, in modern agriculture, the use of agricultural machines is inevitable. the tire is the last part of the power transmission system, which plays an essential role in controlling the tractor and transferring the tractor's reaction to the soil. Tires used in agricultural implements and ...
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Introduction Today, in modern agriculture, the use of agricultural machines is inevitable. the tire is the last part of the power transmission system, which plays an essential role in controlling the tractor and transferring the tractor's reaction to the soil. Tires used in agricultural implements and tractors should be able to transport appropriately and have sufficient adhesion and slip. Several parameters affect these abilities, including tire diameter and width, tire shape, tire tread modulus, tire pressure and load on the tire, with the last two parameters, tire pressure and load on the tire two very important factor is the tire and surface contact, the tire's contact between the tire and the ground, the tire's involvement in the direction of travel, as well as the tensile and fuel consumption of cars and motor vehicles. Given the fact that the tire pressures/load of agricultural machinery are less attractive to the users, Due to the many benefits that the use of electronic control systems. Due to the many benefits that the use of electronic control systems, Today, the use of electronic control technologies is considered as an innovation. the automatic tire pressure control system could ensure the pressure stability. Tire pressure drop is detected, and the system automatically refills the tire according to the tire pressure requirements. Therefore, the main aim of this paper is to set the tire pressure at the optimal value by designing an electronic control system for measuring and controlling tire pressure and evaluating the response speed of the system. Materials and Methods This research work is mainly aimed at designing a tire pressure control the tire pressure. BD pressure sensor, Arduino board, voltage/pressure regulator, 5-volt double-channel relay module was utilized. Moreover, Solenoid valve, rotary joint along with compressor and reservoir was employed for controlling tire pressure. In this paper, a laboratory tire pressure control system was designed which can operate in both manual and automatic modes. In automatic mode, a series of ideal pressure (P1) is defined as the soil type, and the driver selects an ideal pressure for the system. If the tire pressure (P0) differs from the set pressure point (P1), then the control unit determines a time duration (T1) for the decrease/increase the pressure level to achieve the optimal setpoint. Besides, a manual mode allows the system to provide a wide range of pressure for the driver depending on the terrain encountered. It is worthy of mentioning that the operation of the system in manual mode is the same as that of automatic mode. In this work, experiments were performed at three levels of output pressure (43.5, 65.2, 87 psi), two tire pressure reduction levels (20- 16 and 16 -12 psi), and two tire pressure increase levels (8 -12 and 12 -16 psi). The tests were laid out as a factorial in a completely randomized design with three replicates. Results and Discussion The ANOVA results indicated that the effect of reservoir outlet pressure on the timing function and tire pressure was significant at the level of 1% (p-value <0.01), while the dual and triple impacts of the factors were not significant. The results also illustrated an increase in the speed of the system response at the output pressure of the reservoir of 87 psi. Also, two different scheduling functions were conducted to evaluate the speed of the system response to reduce the tire two levels of 20 to 16 and 16 to 12 psi. For this reason, two different scheduling functions were used. The ANOVA results indicate that the timing function and tire pressure level had a significant effect on the output parameters at the level of 1%. Furthermore, an increase in the speed of the system response in the second-order scheduling function was observed. Comparison of system performance with first and second time estimation functions at different reservoir pressures, as shown in Fig. 9, showed that the use of the second-order estimation function in all cases reduced the number of steps to reaching the desired pressure significantly. Conclusion According to the obtained results, it can be concluded that the replacement of the second-order scheduling function to control tire pressure, increased the speed of the system’s response, which results in keeping the right pressure at all times very accurately.
Fatemeh Afsharnia; Mohammad Asoodar; Abbas Abdeshahi
Volume 36, Issue 2 , March 2014, , Pages 49-58
Abstract
Effective operation of a system is related to acceptable programming of repair and service activities. Efficient managerial programming is associated with accurate estimation of maintenance system parameters. In this study, four tractors failure rate was investigated by completing 300 questionnaires ...
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Effective operation of a system is related to acceptable programming of repair and service activities. Efficient managerial programming is associated with accurate estimation of maintenance system parameters. In this study, four tractors failure rate was investigated by completing 300 questionnaires from tractor operators in Khuzestan Province. The operators were interviewed in four regions of the province. Under study variables included driver experience, level of education, driving license, skill training course, work location (region and city), type of service and maintenance, storage conditions, distance to first workshop, distance from shelter to farm, machine age, annual use hours and number of failure. Regression analysis by estimating an exponential function showed that the variables such as age of tractor, annual hours used and type of service and maintenance affected the failure rate of each four type tractors. For one percent increase in age of tractor and annual use hours, failure rate increased about 0.6% and 0.24%, respectively. Also, failure rate in MF285, MF399 and U650 tractors was about 0.383, 0.453 and 0.143 percent more than JD3140 tractor, respectively. The preventive maintenance causes 0.252 percent decrease in failure rate.
Abbas Rohani; Hasan Masoudi
Volume 36, Issue 2 , March 2014, , Pages 59-68
Abstract
Replacement of tractors is a very difficult task. Farm managers often need to make such economic decisions about their machines. Repair and maintenance expenditures can have significant impacts on these economic decisions and forecasts. The purpose of this research was to identify a regression model ...
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Replacement of tractors is a very difficult task. Farm managers often need to make such economic decisions about their machines. Repair and maintenance expenditures can have significant impacts on these economic decisions and forecasts. The purpose of this research was to identify a regression model that can determine economic life of two-wheel drive tractors. The study was conducted using empirical data on 60 two-wheel drive tractors from Astan Ghodse Razavi agro-industry during the years 1988 to 2005. A power model was selected as the best model for prediction of repair and maintenance costs. Based on the power model, the cumulative cost model (CCM) was used to predict the tractors economic life. 29025 hours was predicted as the economic life of the tractor by the CCM model, while according to cost minimization model (CMM) this parameter was equal to 27773 hours.
