A. Sharifi Malvajerdi; M. Younesi Alamouti; A. Mohsenimanesh
Abstract
Soil compaction can occur as a result of a number of factors. One of the most important factors is soil response to pressures imposed by wheels and soil engaging tools. This research investigated the effect of tyre load and inflation pressure on soil compaction-related factors. These factors include ...
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Soil compaction can occur as a result of a number of factors. One of the most important factors is soil response to pressures imposed by wheels and soil engaging tools. This research investigated the effect of tyre load and inflation pressure on soil compaction-related factors. These factors include rut width, rut depth, cone index and horizontal force in different layers of soil profile. In this research a stiff carcass tyre has been used and a soil compaction profile sensor in controlled soil bin laboratory conditions. This sensor consisted of eight flaps, each equipped with strain gauges, installed on a subsoiler leg face with working depth of 45 cm. Studies were conducted using a factorial experiment at two levels of axle load of 6.3 kN and 23.9 kN and three levels of inflation pressure of 324 kPa, 524 kPa and 724 kPa with three replications in a randomized complete design. Duncan test and F test were applied to compare the means of pressure and axle load, respectively. The soil compaction profile sensor measured soil compaction at different layers from soil surface to 45 cm depth at 5 cm interval. The results of experiments indicated that vertical load significantly affected the horizontal force at different tyre inflation pressures on the soil profile. The tyre inflation pressure exhibited greater effects on shallow depths than those of higher depths. The amount of rut width, rut depth and cone index increased with an increase in vertical load. Increasing of the inflation pressure decreased rut width and increased rut depth and cone index.
S. Kordi; A. Fadavi; M. Eskandari; M. Barari; M. Rafiee; A. Ashraf Mehrabi
Abstract
Mechanical properties of grain are influenced by various factors including soil nutrients and grain moisture content at harvest time. In order to reduce mechanical losses, the design of different processing operations should be performed based on the knowledge of factors influencing the mechanical properties. ...
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Mechanical properties of grain are influenced by various factors including soil nutrients and grain moisture content at harvest time. In order to reduce mechanical losses, the design of different processing operations should be performed based on the knowledge of factors influencing the mechanical properties. The effects of urea fertilization methods and grain moisture content at harvest time on mechanical properties of dried corn were investigated in a field experiment as a strip split plot with four replications based on randomized complete block design at Khorram Abad Agricultural Research Station in 2010. The investigated factors were urea fertilization methods (urea foliar application and urea side-dress application), grain moisture content at harvest time (20, 30 and 40%) and four corn hybrids (NS 640, Konsur 580, Jeta 600 and control SC 704). The moisture content of dried grains due to different absorption property of the treatments was about 7±1 percent. The results showed that the interaction of fertilization methods and hybrid was significant (P < 0.05) for grain toughness. However, the grain moisture content at harvest time had significant effect on all studied traits except on grain firmness. The highest maximum fracture force, displacement at the maximum rupture force, energy consumption at maximum force point, specific deformation, rupture power and toughness were obtained at 20% grain’s moisture content Also, the results showed that NS hybrid had the highest maximum rupture force (219 N), displacement at the maximum fracture force (0.37 mm), energy consumption at maximum force (42.51 mj), rupture power (3.89 . 10-3W) and toughness (0.33 mj mm-3).
R. Mohammadigol; M. H. Khoshtaghaza; R. Malekfar; M. Mirabolfathi; A. M. Nikbakht
Abstract
Pistachio contamination to aflatoxin has been known as a serious problem for pistachio exportation. With regards to the increasing demand for Raman spectroscopy to detect and classify different materials and also the current experimental and technical problems for measuring toxin (such as being expensive ...
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Pistachio contamination to aflatoxin has been known as a serious problem for pistachio exportation. With regards to the increasing demand for Raman spectroscopy to detect and classify different materials and also the current experimental and technical problems for measuring toxin (such as being expensive and time-consuming), the main objective of this study was to detect aflatoxin contamination in pistachio by using Raman spectroscopy technique and artificial neural networks. Three sets of samples were prepared: non-contaminated (healthy) and contaminated samples with 20 and 100 ppb of the total aflatoxins (B1+B2+G1+G2). After spectral acquisition, considering to the results, spectral data were normalized and then principal components (PCs) were extracted to reduce the data dimensions. For classification of the samples spectra, an artificial neural network was used with a feed forward back propagation algorithm for 4 inputs and 3 neurons in hidden layer. Mean overall accuracy was achieved to be 98 percent; therefore, non-liner Raman spectra data modeling by ANN for samples classification was successful.
Design and Construction
S. Dehghani; S. H. Karparvarfard; H. Rahmanian- Koushkaki
Abstract
Introduction: Automatic guidance of tractors in the mechanized farming practice has taken the attention of agricultural engineers in the last two decades. For this to be truly practical on the farm, it should be economical, simple to operate and entirely contained on the vehicle. Different types of steering ...
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Introduction: Automatic guidance of tractors in the mechanized farming practice has taken the attention of agricultural engineers in the last two decades. For this to be truly practical on the farm, it should be economical, simple to operate and entirely contained on the vehicle. Different types of steering systems such as leader- cable, laser- controlled, radio- operated and contactor- type have been developed for automatic guidance. The automatic leveling system is used on hillside machines to keep the separator level when operating on hillsides. This system has three parts: fluid level system, electrical system and hydraulic system. The fluid level system consists of fluid reservoir and a leveling control switch box. The fluid level system actuates the electrical system of the leveling unit. The electrical system which actuated by the fluid system consist of four micro switches in the leveling control switch box, two micro switches in the limit control box, a solenoid in the hydraulic control level, manual leveling control switch, and a leveling limit warning light. The hydraulic system maintains the level of the separator when the machine is operating on a hillside. The present study was aimed to develop a reliable, versatile and easy to maintain system to fit our economy and low technology level of farmers for hillside- range development or fallow farming. The automatic guidance system has been implemented successfully on agricultural vehicles on the basis of three components, i.e. sensors, processors and actuator elements. The study site (N, latitude; E, longitude; and 1810 m above sea level) was located at the Agricultural Research Center, Shiraz University, 15 km northwest of Shiraz, Fars Province, Iran. MF-399 agricultural tractor manufactured by ITMCO, Tabriz, Iran was used for doing the experiments.Materials and Methods:The Level Sensing System: The biaxial tilt industrial sensor (ZCT245AL- China) with digital output can be connected to the computer and received angular position in x and y coordinates. An assumed degree could be considered as basis degree and the measured frequency was adjustable. The tilt sensor located along the axial length of tractor and leads the angles which are created by longitudinal axle transverse axle of the tractor in related to horizontal level. It was used for contour lines detecting. The potentiometer located on the steering wheel of the tractor and pressure sensor which used with goniometer sensor used keeping uniformly of leveling points in tractor motion. The pressure sensor (SN-SCP1000- South Korea) which is used in leveling system can detect the elevation changes. In this way, by defining a limitation of altitude for system, it would be able to stop steering turning motor which was coupled to tractor steering rod automatically. By resetting, the tractor could be able to live in a new level position. To avoid excessive left and right steering wheels deviation and interfering with other lines of travel, potentiometer was used. The deviation degree for steering rod from center to left or right was selected 120 degrees. Accordingly, the wheels would not be able to move more than 10 degrees to each direction. The Processing System: The electrical circuit graphically designed and simulated by software (Altium Designer, 2009) and installed on the tractor. The components of this circuit are as follows: Electrical board, two relays which control the electrical pathway in both directions, a battery with 12 volts of electric potential as electrical power supply, ATmeGA32 microcontroller which was made by Atmel company as main core for information processing, RS232 protocol was used for making correlation between serial port (COM) and the microcontroller and two capacitors for reducing noises. The Actuator System: The output signals from the a processing system, were lead in the actuator system would order and indicative of left- turn or right- turn command, were introduced to actuator- units include an electric- gearbox motor that stimulate the steering wheel shaft of the tractor by chain and sprocket and conduct the tractor in leveling traces at the desired speed. Before hitching any implements such as row planter behind the tractor, the system was successfully tested on average slopes of 14.5% using a tracing powder. Results and Discussion: A plot of the average elevation of each 12 lines traced for a length of about 50 meters, H0, versus the actual elevation of 12 to 16 equally spaced points of each trace, H, produced the following relationship: H0= 0.142+ 0.990 H Indicating a reasonably acceptable performance with standard error and R2 0.048 and 99.3% respectively. Conclusions:The row planting in various slopes coincided with the contour lines of ground (Duncan’s Multiple Range Test p ≤ 0.05). Also, no significant difference was observed among the slopes and index of length and dry weight of root and shoot. The percentage of the emergence index in the high slopes (18-21%) showed significant differences. Hence by increasing slopes, the percentage of seed emergence was decreased.
Design and Construction
S. M. Nassiri; S. Samsami; M. Loghavi
Abstract
Introduction Iran is a frontier of pomegranate fruit production in the world (with almost 40 % of the world`s production). However due to traditional processing operations is not ranked as the largest pomegranate exporter. Saveh, Neyriz and Ferdows are the top pomegranate producing cities in Iran. Pomegranate ...
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Introduction Iran is a frontier of pomegranate fruit production in the world (with almost 40 % of the world`s production). However due to traditional processing operations is not ranked as the largest pomegranate exporter. Saveh, Neyriz and Ferdows are the top pomegranate producing cities in Iran. Pomegranate is consumed as a fresh fruit as well as processed product as food additive, paste, syrup, jelly, pectin, jam, beverage, essence, vinegar and concentrate. Aril extraction is the first and essential postharvest operation for pomegranate processing. Arils are mostly extracted manually even in large scales for fresh and processed consumption. This labor intensive operation is rational when aril quality is an important index for consumer. But whenever pomegranate juice is desired, the aril quality has no priority for consumer, and therefore arils can be extracted with less care. Sarig (1985) was the first inventor of a pomegranate aril extractor who employed air jet force to extract the arils. Later, other researchers employed the same method as well as water jet to extract fruit juice and sac. In the present study, fabrication and evaluation of vibratory aril extractor augmented with air system was conducted. Materials and Methods The study was conducted using Rabab cultivar samples which were manually harvested from an orchard in Neyriz town, Fars province. Samples were kept in refrigerator at 5 0C till experimental trials. Initial moisture content of fruit skin, arils and internal fleshes were measured by gravimetric method as 31.7±2.6 %, 61.5±1.8 % and 42.8±1.4 %, respectively and for a whole fruit was measured 45.3±11.5 % (w.b.). For conducting laboratory tests, an aril extraction unit was designed and fabricated. It comprised a steel main frame, a 746 W electric motor, drive mechanism (eccentric and shaft), sample retentive unit, air jet unit, aril tank, and an air compressor-tank assembly. Sample retentive unit was designed in such a manner to hold a halved fruit. This unit was made from four elements, a hemisphere bowel, four pressure (spring) arms to apply force on skin of the sample, and four tension (spring) arms for fixing the sample in the bowel by applying pressure on the edges of the halved sample. Such configuration helped sample to open more and more while extracting the arils to expose trapped aril for easier extraction. Sample retentive assembly was vibrated by the electric motor and drive mechanism. Electric motor was equipped with an electric convertor to create different levels of vibration frequency. Also, the drive mechanism was designed in such a manner to create different levels of vibration amplitudes. According to the previous studies, 2 nozzles with 3.5 mm diameter were selected for air jet unit. Nozzles were spaced at 8 cm apart according to the measured mean diameter of samples. Outlet air jet from nozzles covered the cross sectional area of the halved fruit. Nozzles assembly was rotated 180 degrees clockwise and counterclockwise with an electronically controlled stepper motor. Pressurized air (from air tank) was transferred to nozzles assembly by flexible pipes. Air pressure was controlled at 500 kPa level by air regulator. To conduct experimental trials, samples halved at three different cutting directions (horizontal (equatorial), vertical and oblique) by a sharp cutter and halved samples were used for tests. Halved sample was fixed in bowel and then the unit was excited by the electric motor. The assembly was vibrated for 60 seconds before blowing the air jet for extra 30 seconds. Tests for air jet alone were conducted for 90 seconds and percentage of detached and damaged arils were calculated. Damaged aril during cutting process was subtracted from total damaged arils for each trial. Collected data were analyzed according to factorial experiments based on completely randomized design, and means were compared by Duncan post-hoc test. Data of combined and air jet alone systems were analyzed by two independent sample t tests. Results and Discussion ANOVA results revealed that cutting type, frequency and amplitude, significantly influenced the percentage of aril extraction at 5 % level of significance. The highest amount of extraction was obtained at 30 Hz frequency and 4 mm amplitude for diagonal cutting by 87 %. At this condition, 13.9 % of arils were damaged by air jet pressure. A significant difference in percentage of extracted and damaged arils was observed between vibratory-air and air systems at 5 % level of significance. The highest amount of aril extraction as well as damage was observed for vibratory-air system with the means of 80.1 % and 9.9 %, respectively. Conclusion Maximum percentages of extraction and aril damage were achieved by applying the combined system with as compared to air jet system alone, so that combined system increased aril extraction by 7.1 % with 2.2 % extra damages.
M. Maharlooei; M. Loghavi; S. G. Bajwa; M. Berti
Abstract
Introduction Current study tries to find a new simple and practical real-time technique to estimate forage crop nutritional quality indices at field conditions. Estimating these indices help producers to have field quality variation layer to reach the goals of Precision Agriculture. Previous studies ...
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Introduction Current study tries to find a new simple and practical real-time technique to estimate forage crop nutritional quality indices at field conditions. Estimating these indices help producers to have field quality variation layer to reach the goals of Precision Agriculture. Previous studies have shown that standardized shear characteristics of crop stem would be a good indicator for some nutritional quality indices. In previous studies, laboratory tests were conducted at controlled conditions of crop moisture content, stem diameter and employing standard shear test procedure. Materials and Methods In order to simulate field conditions, a two-stage study was conducted in Iran and United States. In the first stage fresh and naturally sun dried alfalfa stems were used in evaluating four levels of crop growth stage and eight loading conditions (four loading rates and two stem conditions). In order to evaluate the effectiveness of shear technique with respect to the conventional harvest method in Iran, shear tests were conducted using fixed and moving knives of a standard square hay baler (John Deere-348). Special fixtures were constructed to attach these knives to a universal testing machine (SANTAM, STM-20). Since evaluation of the suggested method with regard to other quality related factor indices such as different varieties and seeding rates, was not practically feasible in Iran in the second stage of this research, five different varieties and three seeding rates were tested in United States. In this part of the study, shear tests were conducted using modified Varner-Bratzler shear test with universal testing machine (TESTRESOURCES-311). Based on the results of loading rate and stem condition in the first stage, shear tests were carried out using loading rate of 500 mm/min and multiple stem condition. In both stages Specific Shear Energy (shear energy per stem diameter, J mm-1) were calculated using trapezoidal method. In order to compare the shear energy results with crude fiber nutritional quality indices such as Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF) and Relative Feed Value (RFV), all alfalfa samples were analyzed using (Association of Official Agricultural Chemists) AOAC standard analytical laboratory methods. Statistical analyses were consisted of ANOVA mean comparison test at each level of factors and regression analysis to find the correlation between specific shear energy and nutritional quality indices. Results and Discussion Results of ANOVA analysis and mean comparisons showed a significant difference in specific shear energy at different levels of loading rates. The higher loading rates showed lower energy which was related to lower ability of knives to cut alfalfa stem thoroughly and shredding the stems at lower speed levels. Significant differences were found in different levels of annual growing cycle, harvest time and seeding rates. Alfalfa stem in fifth harvest year showed the highest shear energy due to higher lignification in plant stems. In the first year, harvested alfalfa stem did not have the lowest shear energy which might be due to existence of weeds in first year field. Results showed higher values of shear energy in fifth harvest of the season in comparison with the third harvest which was acceptable because of differences in plant received Degree Day in these harvest times. The lowest seeding rate (5 kg h-1) showed the highest shear energy respect to the other seeding rates. The reason for this significant difference could be due to lower competition to receive water and nutritions, also lower plant density helps the canopy to receive more sun light which causes higher lignification. Comparing the shear energy means in different varieties didn’t show significant differences which can be explained because of varieties adoptability to the region specific weather condition. The regression analysis showed good correlations between specific shear energy and crude fiber nutritional indices (ADF, NDF and RFV). The negative trends which were found in regression analyses were also reported in similar studies. Conclusion Two stage laboratory tests were conducted in order to evaluate the effect of alfalfa nutritional feed quality indices related factors on unitized shear energy. Results showed a significant difference of standardized shear energy mean at different levels of harvest time, annual growing cycle and seeding rates. The specific shear energy was not significantly different in different varieties because of varieties environmental adoptability. The unitized shear energy showed a good correlation with crude fiber related indices with similar trends in both stages of research and good agreements with previous studies.
Design and Construction
A. Rezahosseini; K. Jafari Naeimi; H. Mortezapour
Abstract
Introduction Harvesting is one of the most difficult steps in cabbage production that is usually a costly intensive operation. Cabbage harvesting is often done by human labors in Iran. According to customs administration’s statistics, more than 54000 tons of cabbages have been exported from Iran ...
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Introduction Harvesting is one of the most difficult steps in cabbage production that is usually a costly intensive operation. Cabbage harvesting is often done by human labors in Iran. According to customs administration’s statistics, more than 54000 tons of cabbages have been exported from Iran in 2015. Development of cabbage harvesting industry is necessary, because of the large cultivation area and the short available harvesting time. So far, a few studies have been done on cabbage mechanized harvesting in Iran. The harvesting machines can reduce harvesting time to one-eighth in comparison with manual harvesting. Design and manufacturing of a harvester unit suitable for small cabbage farms in Iran were conducted in the present study. So the paper was aimed to investigate the performance of the harvester at the different forward velocities, attack angles and distances between the plants. Materials and Methods The proposed machine consists of two major units; the soil looser and the unit for pulling out, crops from the soil. In this machine, the blades loose the soil around the cabbage root after penetrating into the soil. Next, cabbage is pulled out from the soil by puller belts. The belts move contrary to forward speed direction and take crop to the backward of the machine. Mechanical and physical properties of the cabbages should be measured, because the harvester is directly in touch with the crop. These properties are firstly measured and then selection of the different components and machine manufacturing are done. Two narrow legs (tillage tools) equipped with one-side blade with attack angles of 20 and 25 degrees are used for losing the soil around the cabbage’s root. The force exerted on the blade was 5.47 kN. Finally, the harvesting force is estimated to be 164.8 N by using mechanical and physical properties of the cabbages. Experiments were conducted at the different forward velocity levels (2, 3.5 and 5 km h-1), attack angle of the blades at three levels (20, 25 and 30 degree) and the distance between the crops in two levels (40 and 60 cm) in a completely randomized design with three replications. Results and Discussion The analysis of variance of the effect of different parameters on the harvested crop numbers showed, that the effects of forward velocity and attack angle on the number of harvested crops were significant in 5 percent probability. But distance between crops did not have significant effect on the number of harvested crops. Also the effects of interaction between forward velocity and attack angle, forward velocity and distance between crops, attack angle and distance between crops on the number of harvested crops were significant in 5 percent probability. According to the results, the number of harvested crops and machine performance were decreased by increasing forward velocity. Moreover, designed machine had the best performance (80 percent) at an attack angle of 25 degrees and forward velocity of 2 km h-1. Conclusion The results showed, with increasing the forward speed from 2 to 5 km h-1 the harvest success decreased by 20 to 25 percent. Also, the harvesting quality did not change at the different distances between the plants. The highest machine capacity was more than 5300 plants per hour, which was observed at the forward velocity of 3.5 km h-1 and the attack angle of 25 degrees.
Design and Construction
S. Rezaei; M. Dowlati; R. Abbaszadeh
Abstract
Non-chemical treatments are an approach for improving seed germination. In order to evaluate the effects of the magnetic field application on onion seed germination and seedling growth indices, a quadrupole magnetic field system was designed and fabricated. It was also compared with a dipole magnetic ...
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Non-chemical treatments are an approach for improving seed germination. In order to evaluate the effects of the magnetic field application on onion seed germination and seedling growth indices, a quadrupole magnetic field system was designed and fabricated. It was also compared with a dipole magnetic field system. In the quadrupole system, each coil consisted of three layers and the cores were moved inside the coils. These arrangements make it possible to change the magnetic field intensity in addition to input current setting. The experiments were conducted based on factors including the type of system (bipolar and quadrupole), magnetic flux density (75, 150, 300 and 600 μT) and duration of the field application (15, 30, 60 and 120 min). Germination percentage, germination rate, mean germination time, seedling vigor index, shoot length, root length, fresh weight of shoot and root, fresh weight of seedling, dry weight of shoot and root were measured. The results showed significant effects on seed germination and seedling growth of onion. In most germination characteristics, the quadrupole system had a better impact than the bipolar system. For many traits (except for weights), the increase in field intensity degraded the traits. Quadrupole system that applied the magnetic field of 600 μT for 15 minutes, yielded 63% increase in the total seedling weight. Most of the germination traits were not affected by exposure time. Further investigations are required for shorter exposure times compared to used durations in this study.
A. Heidari; J. Amiri Parian
Abstract
Repetitive and dangerous tasks such as harvesting and spraying have made robots usable in the greenhouses. The mechanical structure and navigation algorithm are two important parameters in the design and fabrication of mobile greenhouse robots. In this study, a four- wheel differential steering mobile ...
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Repetitive and dangerous tasks such as harvesting and spraying have made robots usable in the greenhouses. The mechanical structure and navigation algorithm are two important parameters in the design and fabrication of mobile greenhouse robots. In this study, a four- wheel differential steering mobile robot was designed and constructed to act as a greenhouse robot. Then, the navigation of the robot at different levels and actual greenhouses was evaluated. The robot navigation algorithm was based on the path learning, so that the route was stored in the robot memory using a remote control based on the pulses transmitted from the wheels encoders; then, the robot automatically traversed the path. Robot navigation accuracy was tested at different surfaces (ceramics, concrete, dense soil and loose soil) in a straight path 20 meters long and a square path, 4×4 m. Then, robot navigation accuracy was investigated in a greenhouse. Robot movement deviation value was calculated using root mean square error (RMSE) and standard deviation (SD). The results showed that the RMSE of deviation of autonomous method from manual control method in the straight path to the length of 20 meters in ceramic, concrete, dense soil and loose soil were 4.3, 2.8, 4.6 and 8 cm, and in the 4×4 m square route were 6.6, 5.5, 13.1 and 47.1 cm, respectively.
M. Rahmatian; S. H. Karparvarfard; M. A. Nematollahi; A. Sharifi Malvajerdi
Abstract
All over the world, farmers choose different implements for tillage, which depend on crop type, soil type, the amount of plant residue from the previous crop, etc. Tillage implement selection is also affected by the availability of implements, power consumption, labor costs, and fund. In this research, ...
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All over the world, farmers choose different implements for tillage, which depend on crop type, soil type, the amount of plant residue from the previous crop, etc. Tillage implement selection is also affected by the availability of implements, power consumption, labor costs, and fund. In this research, the draft force, soil disturbance area, soil cone index, and fuel consumption were considered. The effects of rake angle, forward speed, and soil moisture content on the above-mentioned parameters were investigated. In this research, a comparison between the performance of a Fiber Reinforced Polymer (FRP) composite blade and a conventional steel blade was carried out. Tests were based on the split-split plot in a completely randomized design. The factors of soil moisture content, rake angle, and forward speed were included in three levels. Three levels for the soil moisture content (9.3, 13, 16.7 %), rake angle (20°, 30°, 40°), and forward speed (3, 5, 7 km.h-1), were considered. The FRP composite blade (on average in the desired range for variables) has reduced the draft force, fuel consumption, and soil cone index, 14.97%, 16.63%, and 35.08%, respectively, than the steel blade. Also, the soil disturbance area created by the FRP composite blade was 4.93% higher than the steel blade. Based on the results of this study, it is clear that the FRP composite blade has better performance rather than the conventional steel blade for the aforementioned test variables. The FRP composite is inexpensive than the steel, this leads to remarkable save money in the production of the FRP composite blade used in the chisel and combined tillage tools that is economical for the farmer and manufacturer.
Agricultural systems engineering (greenhouse, fish farming, mushroom production)
M. Ghonimy; M. Morcos; A. Badr
Abstract
In this study a mathematical analysis for estimating the performance rate "RP" of wheel type trenching machine was studied. The mathematical analysis quantifies the analysis and resulted in an equation. This mathematical equation was checked under different operating conditions. The practical study of ...
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In this study a mathematical analysis for estimating the performance rate "RP" of wheel type trenching machine was studied. The mathematical analysis quantifies the analysis and resulted in an equation. This mathematical equation was checked under different operating conditions. The practical study of the performance rate showed that the deviation of the theoretical performance rate from the actual performance rate ranged from 5 to 7% for the 60.4 and 90.5 cm trench depth, respectively. The machine field efficiency also ranged between 43 and 50.1% for 90.5 cm and 60.4 cm trench depth respectively.
Design and Construction
S. M. R. Nazemsadat; M. Loghavi
Abstract
In grain yield monitoring system, the amount of clean grain mass flow rate to the storage bin is the most important yield property. In this research, an impact-plate type grain mass flow sensor was designed, developed and evaluated. After construction of the impact sensor, it was calibrated by loading ...
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In grain yield monitoring system, the amount of clean grain mass flow rate to the storage bin is the most important yield property. In this research, an impact-plate type grain mass flow sensor was designed, developed and evaluated. After construction of the impact sensor, it was calibrated by loading the impact plate with static weights ranging from 0.5 to 4.5 kg every 0.5 kg and its linear response to the applied loads was proved with a correlation coefficient of 0.99. Then, grain mass flow measurement tests and data collection were conducted according to the ASABE standard S587, developed for grain mass flow sensors. The tests were conducted in three phases: 1- constant and steady state flow, 2- linear variation of flow, 3- oscillating flow. The results showed that the output of impact plate sensor varies proportionally and linearly with increasing wheat grain (Rowshan cultivar) mass flow rate. The error in prediction of actual flow rate was decreased by increasing the mass flow rate such that the calculated errors at 25%, 50%, 75% and 100% of flow capacity (4.25 kg s-1) were 8.3%, 6.3%, 5.2% and 4.9%, respectively. The high coefficient of determination (R2 = 0.9975) between accumulated mass flow data of impact plate sensor and the reference scale data indicated high accuracy and sensitivity of impact plate sensor in prediction of mass flow variations. The average percent error of impact sensor in variable flow rate in “ramp-up-ramp-down”, “ramp-down-ramp-up” and oscillating flows were 7.4%, 8.6% and 8.3%, respectively.
S. I. Shariati; M. H. Aghkhani; M. R. Golzarian; A. A. Akbari
Abstract
IntroductionRobots have been used for material handling for many years, and their applications have greatly expanded with the integration of intelligent technologies. While numerous researchers have proposed various robots for this field, it is crucial to design customized configurations that are suitable ...
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IntroductionRobots have been used for material handling for many years, and their applications have greatly expanded with the integration of intelligent technologies. While numerous researchers have proposed various robots for this field, it is crucial to design customized configurations that are suitable for agricultural farms. However, research in our country has been limited to a few mobile agricultural robots. The main focus of this paper is to design and model workspaces and analyze the kinematics of manipulators in agricultural settings.Materials and MethodsThis article investigates the workspace and kinematics of a robot manipulator to design and manufacture a four-DOF manipulator for farming. This manipulator will be capable of performing a variety of tasks, but the goal of this project is to enable it to load and unload materials and products on the farm as an auxiliary force for the farmer.When designing and analyzing a manipulator, the first step is to determine the specific task that the robotic arm will perform. For example, consider a scenario where the task involves loading or unloading forage packages from a trailer at a designated location. This task specification forms the basis for further design and analysis, ensuring that the manipulator is appropriately designed to meet the requirements of the task.An intelligent robotic arm that is attached to a tractor can perform this operation in the shortest possible time without the intervention of human workers. Otherwise, a large number of laborers would be required to move boxes weighing 10 kg over distances of 3 to 4 meters and heights of 1 to 2 meters, which would require a great deal of torque.At this stage, the design of the arm kinematics model, direct kinematic equations, velocity kinematics, and Jacobian matrix solving were performed. The calculations were carried out using two methods: manual calculation and kinematic modeling in MATLAB software for three arm configurations in two simulation tests. The results of both methods were compared.The workspace analysis of the selected manipulator configurations, as well as the use of arm kinematic performance evaluation indices, were illustrated in graphs.Results and DiscussionThe issue of moving forage packages on the farm is described below. If a farmer were to move 48 packages of fodder weighing about 10 kg manually (using human workers) in the workspace modeled in Figure 10, each package would take an average of 30 seconds to be moved reciprocally along an unobstructed path. Hence, it would take approximately 24 minutes to move all the packages. However, the linear speed of the final operator of the robot arm during the first test was found to be 1 meter per second, which is 3.7 times faster than the manual work scenario, and the total movement of the packages can be completed in about 6.5 minutes.Upon analyzing the velocity diagrams of the final performer in both tests, it becomes evident that there is not much variation in speed and acceleration due to the change in configurations. The evaluation of robot workspace indicators was conducted using two methods: workspace index and structural length index. These indicators were calculated for all three configurations, and the results indicated that Configuration Type 1 was the most suitable option. Furthermore, the manipulability index of the robot arm was assessed based on the obtained diagrams for all three configurations in the two tests. It was observed that Configuration Type 1 outperformed the other two types in terms of score, indicating its superior performance. This aligns with the suggestion made by Yoshigawa for the first three joints of the Puma robot.Overall, the results suggest that Configuration Type 1 is one of the most favorable options, ensuring better performance for the final performer.ConclusionOne of the main considerations when using robots in agriculture is the appropriate kinematic design of joints and links for work operations. Using the example of robots assisting with moving products on the ground, it can be seen that using robots significantly reduces the time required compared to manual labor. Furthermore, in terms of energy consumption and cost within a certain period, the use of robots has economic justification.Based on the studies conducted, Configuration Type 1 passed the kinematic path in both tests with a higher manipulability index and a more suitable workspace index based on both calculated criteria. Therefore, this configuration is recommended for the design of robots for the operation of moving products on the ground.
Post-harvest technologies
S. Sharifi; M. H. Aghkhani; A. Rohani
Abstract
IntroductionOn the field and in the paddy milling factory dryer losses have always been challenging issues in the rice industry. Different forms of losses in brown rice may occur depending on the field and factory conditions. To reduce the losses, proper management during pre-harvest, harvesting, and ...
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IntroductionOn the field and in the paddy milling factory dryer losses have always been challenging issues in the rice industry. Different forms of losses in brown rice may occur depending on the field and factory conditions. To reduce the losses, proper management during pre-harvest, harvesting, and post-harvest operations is essential. In this study, different on-field drying and tempering methods were investigated to detect different forms of brown rice losses.Materials and MethodsThe present study was conducted on the most common Hashemi paddy variety during the 2019-2020 season in Talesh, Rezvanshahr, and Masal cities in the Guilan province, Iran with 0.2 hectares and 5 paddy milling factory dryers. On the fields, the method and date of tillage, irrigation, and transplanting used in all experimental units were the same. Moreover, the same amount of fertilizer and similar spraying methods were used across all experiments. For the pre-drying process on the fields, the following three pre-drying methods were applied on the harvest day: A1) The paddies were spread on the cut stems for insolating, A2) The paddies were stacked and stored after being placed on the cut stems for 5h, and A3) The paddies were covered with plastic wrap and stored after 5h of insolating. The first method (A1) is the most common in the area and was chosen as the control treatment. For the second step of the process, the time interval between the on-field pre-drying and threshing was considered: B1) 14 to 19h post-harvest; B2) 20 to 24h post-harvest, and B3) 25 to 29h post-harvest. Afterward, methods A1 to A3 were combined with methods B1 to B3 and feed into an axial flow-thresher at 10 kg min-1, 550 rpm PTO, and two levels of moisture content at 19 and 26 percent (% w.b). The third process was two-stage or three-stage tempering for 10 or 15 hours resulting in four levels (C1 to C4) and was done in the conventional batch type dryer under temperatures of 40 and 50 ˚C and airspeeds of 0.5 and 0.8 m s-1 in paddy milling factories. At the end of each process, a 100g sample was oven-dried for 48h and a microscope achromatic objective 40x was used to detect incomplete horizontal or vertical cracks, tortoise pattern cracks, and immature and chalky grains. The equilibrium moisture content was determined to be 7.3 percent. Losses properties were analyzed using a completely randomized factorial design with a randomized block followed by Tukey's HSD test at the 5% probability and comparisons among the three replications were made.Results and DiscussionResults demonstrated that the stack and plastic drying methods significantly increased the percentage of losses. In the plastic drying method, the percentage of chalky grains and tortoise pattern cracks was higher than other forms of loss. In the first process, irrespective of the pre-drying method, the losses were reduced at a lower level of moisture content. At the end of the first stage, losses in the spreading method were significantly lower at 19% moisture content. Threshing the plastic-wrapped paddies after 14 to 19 hours at 19% moisture content resulted in the maximum threshing loss of 8.446% and over half of the grains were chalky or had tortoise pattern cracks. The threshing loss was halved (4.443%) for paddies threshed 25 to 29h after spreading at a moisture content of 26%. The mean of losses in the second step of the process were 7.229, 5.585, and 5.156% for the time interval between the on-field pre-drying and threshing of 14 to 19h, 20 to 24h, and 25 to 29h, respectively. In the last step of the process in paddy milling factory dryers, there was no significant difference in the minimum percent of losses between 10 and 15 hours of three-stage tempering at 40 °C and with 0.5 m s-1 airspeed. Furthermore, maximum total losses with the most incomplete horizontal and vertical cracks occurred in the two-stage 10h tempering at 50 °C and with 0.5 and 0.8 m s-1 airspeed.ConclusionFood security has always been a critical matter in developing countries. Furthermore, identifying the source of losses in the fields and the factories is one way to reduce losses and achieve food security. Stacking or wrapping the paddies in plastic after pre-drying on the fields for 5h is not recommended in terms of its effect on increasing the percentage of brown rice losses. Additionally, due to the importance of factory dryer scheduling in the management of the losses, it is recommended to use a three-stage 10h tempering at 40 °C and with 0.5 m s-1 airspeed.
Image Processing
Z. Azizpour; H. Vahedi; A. N. Lorestani
Abstract
IntroductionPistachio or Green Gold is one of the most important agricultural crops and is especially important for Iranian exports. A group of pistachio's pests mainly feed on pistachio, among which Idiocerus stali is very important. Conventional methods for identifying insects using identification ...
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IntroductionPistachio or Green Gold is one of the most important agricultural crops and is especially important for Iranian exports. A group of pistachio's pests mainly feed on pistachio, among which Idiocerus stali is very important. Conventional methods for identifying insects using identification keys are time-consuming and costly. Due to the rapid development of the Pistachio industry, the use of artificial intelligence techniques such as image processing, for identification and population monitoring is highly recommended. On the other hand, little research was carried out on I. stali. Therefore, in this research, I. stali was selected as a target insect for the identification and counting on sticky yellow cards using image processing techniques and artificial neural networks. The purpose of this study was to determine the feasibility of I. stali identification algorithm by image processing, to determine the possibility of separation and counting of I. stali from other non-target insects by artificial neural network and to determine its accuracy in identification of I. Stali.Materials and MethodsIdiocerus stali was selected as the target insect for identification. Sticky yellow cards were used for collecting samples. Taking the photos with the help of a SONY Handycam Camera, which had a 12-megapixel resolution and G lens, was carried out (SONY, HDR-XR500, CMOS, SONY Lens G, Made in Japan). Then insects were counted on each card manually and the data was recorded. The data, which were digital images of yellow sticky cards, were imported into the MatLab R2017b software environment. A total of 357 color properties and 20 shape's features for the identification of I. stali were extracted by an image processing algorithm. Color properties were divided into two categories of mean and standard deviation and characteristics related to vegetation indices. An ANN-PSO (Artificial Neural Network hybrid method-Particle Swarm Optimization) algorithm was used to select the effective features. The selected effective characteristics for insect classification were: Color index for extra collective vegetation related to HSL color space, normalized difference index for LCH color space, gray channel for color space YCbCr, second component index minus third component for color space YCbCr, area and mean of the first, second and third components of color space Luv.Results and DiscussionComparing the results with the results of Qiao et al. (2008), we found that in his study, which divided the data into three categories, for medium and high-density groups, the detection rate was 95.2% and 94.6%, respectively. On the other hand, in low densities (less than 10 trapped insects); its detection rate was 72.9%, while the detection rate of the classifier system designed in this study for different densities of trapped insects, was identical and equal to 99.59%. Also, comparing the results of this study with Espinoza et al. (2016), we found that their algorithm in whiteflies detection had a high accuracy of about 0.96 on a sticky yellow card, while the Thrips identification algorithm accuracy was 0.92 on a sticky blue card. As stated above, the correct detection rate of I. stali by the algorithm designed in this study was 99.72%.ConclusionThe results showed the feasibility of the new method for identifying the pest insects without destroying them on the farm and in natural light conditions and in a short time and with very high accuracy. This suggests that this algorithm can be applied to the machine vision system and can be used in future in the construction of agricultural robots.
Design and Construction
J. Soleimani; M. H. Kianmehr; S. R. Hassan Beigi Bidgoli; S. M. Shariatmadari; K. Rezapoor
Abstract
Introduction The annually production of cattle manure is estimated around six million tons in Iran. Manure transportation with high moisture and low density recognized as crucial issue. The densification of dry or wet manure is the profound method for decreasing the manure volume which reduces the cost ...
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Introduction The annually production of cattle manure is estimated around six million tons in Iran. Manure transportation with high moisture and low density recognized as crucial issue. The densification of dry or wet manure is the profound method for decreasing the manure volume which reduces the cost of handling and storage. Besides, the particle size is one of the important factors in the pellet production. Ball mills, vibratory mills, hammer mills, knife mills, two roll mills, colloid mills, attrition mills, or extruders can be used for size reduction of biomass. Specific energy consumption for size reduction of biomass highly depends on moisture content, bulk and particle densities, feed rate of the material, particle size distribution (initial/final particle size) and machine variables. The present study is conducted for wet cattle manure size reduction machine. Furthermore, the relationship between moisture content (35, 40 and 45 %w.b) and drum of special size reduction machine in rotational speed (150, 200 and 250 rpm) considering geometric mean diameter of particle and size distribution of wet cattle manure were investigated. A factorial experiment under randomized complete design method was employed with three replications. Materials and Methods The main parts of machine include drum, concave, spring and adjusting screw. The main function of this thresher machine is to combine crushing and cutting in order to conduct the size reduction methods, i.e., to apply compressive and shear forces to the cattle manure particles. The drum is also equipped with several rows of sharp-edged milling segments. The spring constants were determined by evaluating the slope of the force vs. deflection curves. The rotational speed of drum was changed in the range of 100-700 rpm during these experiments. In the test of the machine physical properties of grinds such as geometric mean diameter of grind particles and particle size distribution were determined. One kg of cattle manure was grinded in each test and the particle size distribution of grinded cattle manure was determined according to ASAE standard S319.3. The moisture content of cattle manure was obtained according to ASAE standard S358.3. Results and Discussion The initial and final particle size of the materials are 20 millimeters and less than 5 millimeters, respectively and the angle of nip is 30 degrees (according to the installation space limitations), the diameter of the drum is 310 millimeters. The spring constant was equal to 24.371 N mm-1 and on the basis of the experiments a drum speed in the range of 150–250 rpm is considered to be optimal settings for the milling for cattle manure disintegration. The results of Table 4 show that for wet cattle manure with 35% (w.b) moisture content at 250 rpm rotational speed of drum (P > 0.05; Skewness = -0.056; Kurtosis = -2.15), 40% (w.b) moisture content at 250 rpm rotational speed of drum (P > 0.05; Skewness = 0.076; Kurtosis = -1.77), 45% (w.b) moisture content at 200 rpm rotational speed of drum (P > 0.05; Skewness = 0.095; Kurtosis = -1.72), in grinds that would potentially produce better compacts. The geometric mean particle size and standard deviation for each test are shown in Table 2. According to Table 2, the lowest geometric mean of particle size is related to rotational speed of 200 rpm and a moisture content of 45% (w.b), and the highest at rotational speed of 250 rpm and a moisture content of 45% (w.b) can be observed. Conclusion The use of cattle manure of thresher machine reduces the specific energy consumption of cattle manure by 92% compared to the conventional method (using drying and hammer mill) in the pellet production. The lowest geometric mean diameter of wet cattle manure was 1.02 millimeter for drum rotational speed of 200 rpm at 45% (w.b) moisture content and the highest was 1.38 at rotational speed of 250 rpm and a moisture content of 45% (w.b%). The best particle size distribution was observed for milling of wet cattle manure with 35% (w.b) moisture content at 250 rpm rotational speed of drum (P> 0.05; Skewness = -0.056; Kurtosis = -2.15), 40% (w.b) moisture content at 250 rpm rotational speed of drum (P> 0.05; Skewness = 0.076; Kurtosis = -1.77), 45% (w.b) moisture content at 200 rpm rotational speed of drum (P> 0.05; Skewness = 0.095; Kurtosis = -1.72)
Design and Construction
O. Esmand; S. R. Mousavi Seyedi; D. Kalantari
Abstract
Introduction The use of new technology in planters is one of the most important factors in the advancement of agricultural science. In the present study, an electronic warning system has been designed and implemented to prevent large seeds from falling from the fall pipe into the ground groove. In this ...
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Introduction The use of new technology in planters is one of the most important factors in the advancement of agricultural science. In the present study, an electronic warning system has been designed and implemented to prevent large seeds from falling from the fall pipe into the ground groove. In this study, three types of corn, bean and soybean seeds have been used, using two laser and microwave sensors. Viewing and comparison of the two sensors and their performance in two conditions of medium and high sensitivity in both laboratory and field conditions were conducted. In this case, the differences between the two sensors in different sensitivities have been evaluated and compared. The performance of the sensors in seed count has also been studied and compared. According to the results obtained in both cases, the sensors performance was acceptable, and especially in the maximum sensitivity of the sensors, they were able to handle well the clogs created in different situations (clogging down or above the fall pipe or emptying the seed tank). Detect and alert in a timely manner. Also, the count of seeds in all three seed types was recorded with high accuracy compared to the actual number. Materials and Methods Three types of coarse seeds (corn, beans and soybeans) as well as two types of sensors (laser and microwave) with two levels of medium sensitivity and high sensitivity were used for the experiments. Laser sensors are one of the most precise instrumentation and industrial automation tools that use laser light to detect objects or even precise distances. The function of the microwave sensor is that the high frequency waves are transmitted when the power supply is connected. These waves are reflected back to the module receiver if they hit objects. The open waves in the module are multiplied by the frequency of transmission by the mixer and a low-output (IF) signal is generated. The output frequency is equal to the difference between the frequency of the transmitted and reflected waves caused by the Doppler effect. Based on this frequency, the presence of a moving object and its speed are detected. Experiments were carried out at both laboratory and field levels and in both moderate and high sensitivity modes using variable resistance mounted on the controller. The equivalent distance for each seed test is 100 meters, so twice for each seed in the laboratory and field level for each of the laser and microwave sensors in both high and medium sensitivity modes. In this system, in case of falling pipe clogging due to seed accumulation or mud under the falling pipe or other factors, an alert system (warning beep), along with the corresponding LED light, indicates a problem in the seed fall system and the operator alerts paying attention to the LED light (green or red) will detect the problem. Results and Discussion The results indicated that by installing a variable resistance inside the circuit, different sensors can be created in the sensors. Increasing the sensitivity of the sensor as much as possible can cause higher the efficiency of the sensor. In the two cases of medium and high resistance, sensors work with medium and high sensitivity. It works since both modes have been tested and the results have been satisfactory. The accuracy of counting and seed detection accuracy between two laser sensors and microwave sensors in two medium and high sensitivity modes were calculated and evaluated. The experiments in the laboratory showed that the difference in the number of seed count by laser sensor compared to the actual number in maize seed at medium and high sensitivity were 87.4% and 94.3%, respectively, in bean seeds 89.1% and 94.2%, respectively. And in soybean seed were 89.4% and 92.3%, respectively. Conclusion The developed embedded system can successfully check and announce the instantaneous state of three types of grain tested (corn, beans and soybeans) in the seed delivery tube of a hand single-row planter with visual cues (on or off LED lights) and audible signals (on or off the alarm), whenever there is a grain flow or no grain flow. Likewise, the developed system can show the blockage at the end of the seed delivery tube with visual indications of the green and red lights on or off and the alarm sound described in detail. These warnings are indications of a fall pipe failure or lack of grain flow in the grain measuring mechanism toward the opening groove and then into the ground. This type of detection alerts the operator in a timely manner by monitoring the status of the grains in the measuring system and ensuring that the grains are located in the ground.
Design and Construction
F. Karimi; A. Fadavi
Abstract
The wild pistachio (Pistacia Atlantica Mutika) exists in 2.4 million hectares of Iranian forest. In spite of high nutritional and medical value of this fruit, its use and processing are still performed manually. The objectives of this research are to design, to construct and to evaluate the performance ...
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The wild pistachio (Pistacia Atlantica Mutika) exists in 2.4 million hectares of Iranian forest. In spite of high nutritional and medical value of this fruit, its use and processing are still performed manually. The objectives of this research are to design, to construct and to evaluate the performance of a pistachio hulling machine. The pistachio of Kerman province was chosen as the case of study. The mechanism of shelling was chosen based on the applied pressure force of two cylinders, driving and driven. The effects of input variables including revolution of driving cylinder (three levels), the gap between two cylinders (four levels) and moisture content (four levels) on the performance of machine (shelling efficiency, percentage of intact kernel, percentage of imperfective broken nut, percentage of dust, and percentage of unshelled nut) were analyzed. The results showed that the shelling efficiency decreases with increasing the gap of two cylinders and moisture content of wild pistachio. The maximum intact kernel was obtained at moisture content of 6.61 wb %. The best performance was observed with the following conditions: the cylinders’ gap of 0.48 mm, rotational speed of the driving cylinder of 25.84 rpm and moisture content of 4.31% w.b.
Design and Construction
D. Ghanbarian; A. Ghorbani-marghmaleki; M. A. Ghazavi; Sh. Besharati
Abstract
Introduction: Iran is one of the major producers of almonds. According to the statistics released by FAO (2011), Iran with more than 110000 tons of almonds is the third in rank throughout the world. However, most Iranian almonds are presented as an unsorted and unpackaged product. Some producers sort ...
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Introduction: Iran is one of the major producers of almonds. According to the statistics released by FAO (2011), Iran with more than 110000 tons of almonds is the third in rank throughout the world. However, most Iranian almonds are presented as an unsorted and unpackaged product. Some producers sort their products by hand which is very time-consuming and labor-intensive. So, there is an essential need for suitable grading and packaging machines especially for the export of almond kernels.Grading, which is sometimes called sorting, is basically separating the material in different homogenous groups according to its specific characteristics like size, shape, color and on the basis of quality. Weighing is one of the best methods for grading agricultural products based on size, but due to its high cost and complexity of operations, usage of weigh size sorting machines is practically limited. So, sizing of most agricultural products is accomplished based on their dimensional attributes such as diameter, length, thickness or a combination of them. Field study shows that recently vibrating sizing machines are used for grading almond kernels. This type of sizing machine is huge, expensive, noisy and it consumes a lot of energy. Thus, the main objective of the present study was the design, development and evaluation of a new prototype of an almond kernel sizing machine. Materials and methods: It is important that the machine could resolve defects of existing vibrating machines. It should provide efficient and cost effective sizing for a wide range of kernel sizes and shapes. Furthermore, it should be of simple construction and be able to accept manual feeding. Previously conducted experiments showed that the thickness of the kernel is the most appropriate dimension for its sizing. Among the different types of dimensional sizing machines, the divergent roller grader which grades the products based on their thickness is considered to be one of the simplest options. So, a divergent roller grader was developed and built in this research. The prototype consisted of two diverging rotating rollers which were made of mild steel with an outside diameter of 95 mm and a length of 700 mm. They were mounted to provide an adjustable slope towards the wide opening end. These roller beds were fixed on a box shaped frame of size 500×1000×1200 mm. The slope and counter-rotating action of the rollers encouraged the kernels to continue moving toward the end where the gap between the rollers was the widest. A tray was fixed at the feeding end of the machine for feeding the kernels. A provision was given to adjust the gap from a minimum to a maximum level. Based on the required activate torques of the rollers, an electric 74 W motor was selected to drive the machine. The power transmission mechanism consists of two pulleys 150 and 250 mm diameters and a V belt type A with a length of 1448 mm. The center distance of the pulleys is calculated to be 410 mm. Standard criterions of weighted sorting error index (C ̅_R), weighted sorting efficiencies index (EW) and operation capacity (Q) were used to evaluate the machine. Practical analysis showed that the machine’s performance is influenced mainly by the slope of the rollers, the rotation speed of the rollers, and the feeding rate of the product. In order to evaluate the performance of the prototype, a factorial experiment in a completely randomized design with three replications for each test was done. The performance evaluation was carried out for three levels of feeding rates (600, 1000, and 1400 kg 8h-1, three levels of slopes (2, 7, and 12 degree), and three rotation speeds of rollers (50, 80, and 110 rpm). Spreadsheet software MSTATC and SPSS were used to analyze the data and the Duncan's multiple range tests were used to compare the means.Results and discussion: Analysis of variance showed that all three studied factors have significant effects on evaluating standard criterions of C ̅_R, EW, and Q at the 1% level of confidence. In this work, an increase in the slope of rollers led to a decrease in C ̅_R, whereas at the same time an increase in EW and Q was observed. It may be because at a higher level of slope the almond kernels slip more effectively on rollers surface. This condition restrains the aggregation of kernels on the first part of the gap between the rollers. So, they have enough time to drop through all of the gap. Experimental results show that as the feeding rate increases, C ̅_R and Q increase, whereas EW decreases. Based on the results of the experiments, with an increase of rotation speed of rollers from 50 to 110 rpm, the C ̅_R decreases up to %6.5, and EW decreases about %6. Study of interactions showed effects among which only the interaction of slope and rotation speed of rollers significantly affects all standard criterions. The results also showed that the operation capacity (Q) was significantly affected (P≤0.01) by the interaction effects between the feeding rate and the slope of rollers, and the feeding rate and the rotation speed of the rollers. The mechanical damage to almond kernels in the form of external damage such as cracks and scuffing was almost zero, which is a very important advantage of this machine in comparison with the other sizing machines. Conclusions: In this research, a divergent roller sizer was designed, developed and evaluated for almond kernels.The results showed that the best machine operation is obtainedat a feeding rate of 1000 kg 8h-1, slope of 9 degrees and rotation speed of 110 rpm. In this situation, the prototype could reach weighted sorting efficiencies index of 80% and operation capacity of 830 kg in an 8 hour work shift with weighed sorting error index of 23%.
Design and Construction
S. Mollapour; D. Kalantari; M. Rajabi Vandechali
Abstract
Introduction Nowadays, the best method for fertilizing trees is spot treatment via hole-digger. Conventional mechanical hole-diggers have several drawbacks such as auger’s non-continuous and limited speeds due to using a mechanical gearbox, and risks of getting stuck inside the hole and motor reaction ...
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Introduction Nowadays, the best method for fertilizing trees is spot treatment via hole-digger. Conventional mechanical hole-diggers have several drawbacks such as auger’s non-continuous and limited speeds due to using a mechanical gearbox, and risks of getting stuck inside the hole and motor reaction force to the operator. On the other hand, a three-point hitch hole-digger has problems such as the lack of maneuverability in confined spaces and high prices. Meanwhile, preparation of these hole-diggers by most farmers and gardeners has no economic justification. Thus, in this research it has been aimed to handle the mentioned problems and to optimize the working quality of hole-diggers via designing and manufacturing a new hydraulic hole-digger. Materials and Methods To start design the machine, displacement volume and power requirement of the hydro-motor and consequently displacement volume requirement of a hydro-pump were calculated using the appropriate formulas (70.83 cm3, 2.3 kW & 7.5 cm3, respectively). According to available hydro-motors and hydro-pumps in the market and using obtained values of displacement volume, an orbital hydro-motor, BMR-80 model with the maximum torque of 220 N.m and an external gear pump REXPORT-2APF8 with displacement volume of 8 cm3 and flow rate of 12 L.min-1 were chosen. In the following, hydro-pump’s parameters were used to select the internal combustion engine. The engine power requirement was 2.875 kW (3.85 hp); thus according to the available engines in the market, a single cylinder gasoline engine, WX168F-1 model that made in Kato company of China with 6.5 hp power and maximum speed of 3600 rpm was chosen. To transmit the power from the engine to the hydro-pump, a coupling DK-42 model was used. Also, two pressure gauges, LB-250 model with maximum pressure of 250 bars were used in the entrance and the exit of the hydro-motor. An hydraulic oil tank with total volume of 24 liters was made from a sheet metal with thickness of 3 mm. The helical auger used in this research, was made in china by LIONS Company with cone tip, total diameter of 200 mm and pitch of 180 mm. The fabricated digger has a working depth and diameter of 30 cm & 20 cm, respectively; rotational speed between 100-160 rpm and maximum power equal to 6.5 hp. In order to evaluate the stress distribution in the auger set, the static analysis based on maximum dynamic torque exerting on auger’s axle and maximum dynamic force exerting on auger’s blades, was used in SOLIDWORKS 2013 software. The maximum force 214.07 kgf (2100 N) proportional to the maximum exerting torque (210 N.m) from soil to the edge of the auger’s blade were considered in the modelling. Farm experiments were carried out in two citrus gardens with silty-clay and sandy-loam texture based on factorial test in Completely Randomized Design with three replications. Soil moisture content as high and low humidity levels (24.85% and 16.12% in sandy-loam and 25.95% and 16.48% in silty-clay) as the first factor and soil depth as the second factor varied in three levels of low, medium, and high (10, 20 and 30 cm), respectively. The measured parameters consisted of specific fuel consumption, machine efficiency, auger torque, auger power and used energy. To determine the auger’s torque, the oil pressure measurement method with two manometers was used in the entrance and the exit of the hydro-motor. After measuring the time and power needed to dig pits, for determining the used energy, the area under the power-time graph was calculated in Excel software. Also, to determine the fuel consumption during the experiments, the filled fuel tank method was used. Data analysis including analysis of variance (Anova), mean comparisons and interaction between the parameters were performed using the SPSS 22 software. Results and Discussion The numerical stress analysis results of the auger showed that the maximum von - Mises stress is occurred in the position of the blade-auger axis connections, with a magnitude of 86 MPa. The obtained experimental results in this study indicated that influence of soil depth and moisture content on the measured parameters were significant. in both soil textures and the influence of soil moisture on machine efficiency was non-significant in the silty-clay texture. With increasing soil depth, measured parameters excluding machine efficiency were increased in both soil textures. In high depth and also in low moisture, regarding to the increasing soil bulk density and shear strength, more torque was needed for the rotating auger in the soil that this has led to an increasing in specific fuel consumption of the device. Regarding the results obtained in this study, minimum specific fuel consumption value of the device (0.0014 liter pit-1) was obtained at the low working depth (10 cm) and the high soil moisture (25.95%) in the silty-clay soil. The hole-digger working capacity at 30 cm working depth and soil moisture content as high and low humidity levels in silty- clay obtained equal to90 and 88 pits per hour and in sandy-loam obtained equal to 101 and 95 pits per hour, respectively. Also, the maximum device’s power (2.548 kW) occurred in deep soil (30 cm) and low soil moisture in silty-clay texture. Conclusion Stress analysis and field qualitative observations results indicated that the fabricated device has sufficient resistance and strength against maximum torque from tested soils. Field evaluation of the fabricated machine showed that pit digging operations in soil is not appropriate in low moisture content because of the high fuel consumption and environmental pollution issues.
Image Processing
S. Abdanan Mehdizadeh
Abstract
IntroductionAdopting new technologies for crop growth has the characteristics of improving disaster resistance and stress tolerance, ensuring stable yields, and improving product quality. Currently, the cultivation of seed trays relies on huge labor power, and further mechanization is needed to increase ...
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IntroductionAdopting new technologies for crop growth has the characteristics of improving disaster resistance and stress tolerance, ensuring stable yields, and improving product quality. Currently, the cultivation of seed trays relies on huge labor power, and further mechanization is needed to increase production. However, there are some problems in this operation, such as the difficulty of improving the speed of a single machine, seedling deficiency detection, automatic planting, and controlling the quality, which need to be solved urgently. To solve these problems, there are already some meaningful attempts. Si et al. (2012) applied a photoelectric sensor to a vegetable transplanter, which can measure the distance between seedlings and the movement speed of seedlings in a seedling guide tube, to prevent omission transplantation. Yang et al. (2018) designed a seedling separation device with reciprocating movement of the seedling cup for rice transplanting. Tests show that the structure of the mechanical parts of the seedling separation device meets the requirements of seed movement. The optimization of the control system can improve the positioning accuracy according to requirements and achieve the purpose of automatic seedling division. Chen et al. (2020) designed and tested of soft-pot-tray automatic embedding system for a light-economical pot seedling nursery machine. The experimental results showed that the embedded-hard-tray automatic lowering mechanism was reliable and stable as the tray placement success rate was greater than 99%. The successful tray embedding rate was 100% and the seed exposure rate was less than 1% with a linear velocity of the conveyor belt of 0.92 m s-1. The experiment findings agreed well with the analytical results.Despite the sharp decline in Iran's water resources and growing population, the need to produce food and agricultural products is greater than ever. In the past, most seeds were planted directly into the soil, and many water resources, especially groundwater, were used for direct seed sowing and plant germination. One way to reduce the consumption of water, fertilizers, and pesticides is to plant seedlings instead of direct seed sowing. Therefore, the purpose of this study was dynamic modeling and fabrication of seed planting systems in seedling trays.Material and MethodsIn this experiment, Flores sugar beet seeds (Maribo company, Denmark) were used. The seedling trays had dimensions of 29.5*60 cm with openings and holes of 5.5 and 4 cm, respectively. To plant seeds in seedling trays, first, a planter arm was modeled and its position was obtained at any time. Then, based on dynamic modeling, the arm was constructed and a capacitive proximity sensor (CR30-15AC, China) and IR infrared proximity sensor (E18-D80NK, China) were used to find the location of seedling trays on the input conveyor and position of discharging arm, respectively. To achieve a stable and effective control system, a micro-controller-based circuit was developed to signal the planting system. The seed planting operation was performed in the seedling tray according to the coordinates which were provided through the image processing method. The planting system was evaluated at two levels of forward speed (5 and 10 cm s-1). Moreover, a smartphone program was implemented to monitor the operation of the planting system.Results and DiscussionThe planting system was assessed for sugar beet seeds using two levels of forward speed (5 and 10 cm s-1). The nominal capacity of this planter ranged from 3579 to 4613 cells per hour, with a miss and multiple implantation indices of 0.03% and 8.17%, respectively, in 3000 cells. Due to its planting accuracy, speed, and low energy consumption (25.56 watt-hours), this system has the potential to replace manual seeding in seedling trays.ConclusionIn the present study, a seed-sowing system for planting seedling trays was designed, constructed, and evaluated based on dynamic modeling. In the developed system, unlike previous research, planting location detection was conducted through image processing. Additionally, a smartphone program was established to monitor the operation of the planting system without interfering with its performance. This study demonstrates that image processing can successfully detect planting locations and can effectively improve efficiency over time for major producers.
P. Fayyaz; S. S. Mohtasebi; A. Jafari; A. Masoudi
Abstract
Introduction Essences or essential oils are aromatic compounds that are found in different organs of the plants. Essences can be classified into three groups of natural, synthetic and natural like. Most of the methods that are used to detect and to distinguish essential oils are based on chromatographic ...
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Introduction Essences or essential oils are aromatic compounds that are found in different organs of the plants. Essences can be classified into three groups of natural, synthetic and natural like. Most of the methods that are used to detect and to distinguish essential oils are based on chromatographic methods. However, these analytical methods are time consuming and require expert operators to work with required devices. Moreover, it is necessary to prepare the samples. An electronic nose is known as a tool for mimicking the sense of smell. This tool usually consists of an array of sensors which are used to identify and to isolate a variety of complex odors at a low cost. Since there has been no research on the usage of an electronic nose system for detection and separation of essential oils, the purpose of this study is to develop and to evaluate an electronic nose system for identification and classification of various types of commercial lemon essential oils (synthetic types). Materials and Methods The proposed system consists of a sensor chamber, a sample chamber, an array of MOS sensors, electro valves, a pump, a data acquisition cart and, a processor. Essential oils used in this study includes eight types of synthetic commercial lemon essential oils that were prepared by ((Avishan Khane Tabiat Sabz)) Company located in chemistry and chemical engineering research center of Iran. One gram sample of each essential oil was prepared to be placed in the sample chamber. Each experiment was carried out in 9 replicates and in three stages of 1- Baseline correction (250 s) 2- Sample smell injection (400 s) and 3- Sensors chamber cleaning (200 s). Data received from the sensors signals were initially preprocessed and normalized and then three methods of principal component analyses (PCA), linear discriminant analyses (LDA) and artificial neural network (ANN) were used to process the data. Both PCA and LDA methods were run using the Unscramble x10.4 software and the artificial neural network was used with the help of NeuroSolution 5 software. In ANN, the classification was carried out using a multilayer perceptron (MLP) and Leave-one-out technique. Leave-one-out is an acceptable method for evaluating the performance of the classification algorithms when the number of samples is low. Results and Discussion In order to analyze the data obtained from the sensor array, first, the principal components analysis (PCA) method was used. In this method, the first two principal components of PC 1 and PC 2 totally covered 99% of the data variance. Another plot called as loading plot was used to determine the effects of each sensor responses in pattern recognition analyzes. According to this plot, all sensors had high loading coefficients. In case of distinguishing the lemon essential oils, the results of the linear discriminant analysis (LDA) method showed that this method can distinguish eight types of lemon essential oils with an accuracy of %98. The artificial neural network (ANN) also separated the essential oils with the accuracy of the above %91. Conclusion An Electronic nose system based on semiconductor metal oxide sensors is a powerful tool that can be used as a substitute for traditional methods. In general, this study showed that the electronic nose system based on MOS sensors has the ability to detect and to distinguish commercial lemon essential oils. Considering the wide ranges and economical nature of the essential oils, it is suggested that applications of the electronic nose can be more expanded in the subject of the essential oils of different products.
Agricultural waste management
M. Khoshdel; S. J. Hashemi; S. M. Zabihzadeh; R. Esmaeilzadeh Kenari
Abstract
IntroductionThe use of agricultural waste to produce biodegradable containers is an appropriate option to solve the problem of biomass accumulation resulting from the cultivation of crops such as rice. The highest amount of agricultural waste compared to the area under cultivation is related to wheat ...
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IntroductionThe use of agricultural waste to produce biodegradable containers is an appropriate option to solve the problem of biomass accumulation resulting from the cultivation of crops such as rice. The highest amount of agricultural waste compared to the area under cultivation is related to wheat straw and rice straw, respectively. After wheat, rice is the most important agricultural product in human nutrition. According to the World Food Organization, the area under rice cultivation in the world is about 150 million hectares. The use of rice straw as a raw material for disposable cellulosic dishes can prevent straw residues in paddy fields, improve the deficiency of cellulosic raw materials, and reduce the use of plastic containers and the dangers thereof. Rice straw is a significant source for making cellulosic containers, but after making containers, hydrophobicity and microbial hazards can be among the problems of making these types of containers. The coating technique is one of the best solutions for resolving hydrophobicity and microbial problems. Coverage is very important and necessary to increase the shelf life of agricultural products and maintain their quality. Waxes are the best preventative methods against moisture and water vapor loss, and beeswax is one of the best edible waxes with these properties. The antibacterial properties of coatings with natural antioxidants will help solve the cellulose containers' problem. The main objectives of this study were to evaluate the endurance, hydrophobicity and antimicrobial activity of rice straw degradable cellulosic dishes.Materials and MethodsIn order to obtain the raw material for the manufacture of cellulosic dishes, the straw was digested with 10% and 20% sodium hydroxide, and then to weigh the hydrophobicity tests, tensile strength index and brightness, 120 Gr paper was made. Concentrations of 1, 2, 5 and 10% of the wax solution in ethanol solution were prepared and used as the first coating to improve the hydrophobicity. The nettle extract encapsulated with royal seed gum as the second coating to improve the antibacterial activity. Hydrophobicity and antimicrobial properties of the samples were measured and compared. The cup mold specimen was made of 2-piece steel and made using appropriate rice straw paste and coating with the appropriate concentration of the sample in disposable cellulose.Results and DiscussionThe results showed that increasing the amount of sodium hydroxide in baking conditions increased the tensile strength and the degree of clarity, but it had no effect on hydrophobicity. As the concentration of baking soda (sodium hydroxide) increases, so does the brightness. Increasing the concentration of sodium hydroxide increases the tensile strength, and the increase in tensile strength due to the increase in the percentage of sodium hydroxide can be due to the increase in the ability to form bonds between fibers due to the release of lignin. Honey wax with a 5% concentration was the most optimal coating for hydrophobic cellulose containers. With increasing wax concentrations in ethanol solvents from 1 to 10 percent, water absorption by the paper made from rice straw has decreased by approximately 93 percent. Adding royal seed gum and nettle extract has a positive effect on the diameter of the halo and has antimicrobial properties. Honey wax with 5% and 10% concentration with nano-encapsulated nettle extract with royal seed gum was selected as the most suitable coating to improve antibacterial activity.ConclusionDue to the characteristics of rice straw and the experiments shown, rice straw can be considered as a suitable alternative to oil resources in the production and usage of disposable tableware. Rice straw has the potential to be used as a cellulose source for the production of disposable containers, and honey wax with a 5% concentration and nano-encapsulated nettle extract can improve the hydrophobic and antimicrobial properties as the airtight coating of the dishes.
Design and Construction
M. Tohri; D. Ghanbarian; O. Taki; M. Ghasemi-Varnamkhasti
Abstract
IntroductionIn recent years due to lack of water resources in our country, planting of bare root seedlings of onion has been welcomed by farmers. Considering the desired high dense planting of Iranian farmers, lack of proper transplanting machine has appeared as the main problem. To overcome this problem, ...
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IntroductionIn recent years due to lack of water resources in our country, planting of bare root seedlings of onion has been welcomed by farmers. Considering the desired high dense planting of Iranian farmers, lack of proper transplanting machine has appeared as the main problem. To overcome this problem, some researchers tested a few methods, but none of them reached to complete successfully. As the one of last efforts, Taki and Asadi (2012) developed a semi-automatic transplanting machine with 9 planting units. This machine requires to 9 men to separate and single out a bunch of seedlings. Usage of this machine is very time-consuming and labor intensive. In Iran, transplanting of bare root seedlings is practically performed by hand with a density of 700-800 thousand plants at hectare. The main purpose of this study was designed, manufacture, and evaluation of an automatic metering device that with the separation and singulars of bare root seedlings of onion could get a high density planting.Materials and MethodsFig. 1 shows the main employed idea of this research for separation and single out a bunch of seedlings.As shown in Fig. 1, the metering device consisted of two carrying and separating belts with different teeth forms. Placing seedling bunches between the two belts, the belts move at different speeds in opposite directions and separate seedlings from their bunch.For proper design of metering device system, measurement of some physical properties were necessary. The obtained information was used to select two belts form. A belt with flexible plastic teethes with a height of 6 mm and the distance of 4mm was selected as separator while for carrier, two types of belts were selected: the first was the same as a separator and the second was made of metal teethes. Based on the average thickness of seedling bunch and some pre-tests, the horizontal angle of separator belt determined as α=20 degrees. Theoretical calculations were done to computatingof the needed force of the system. In this section, seedlings were modeled as some solid cylinders with a length of 200 and a diameter of 10 mm. In the mentioned system, it was necessary that the speed of separator belt is more than the speed of carrier belt. Thus, ratio of two linear velocities ( ) of 1.67 and 2.32 were considered for evaluation of the system. For evaluation of manufactured metering device, the effects of three factors, i.e., carrier belt type, ratio of linear velocities of the belts, and number of seedlings in a bunch (n = 30 and n =60), on qualitative planting parameters were studied in a factorial experiment based on completely randomized design with three replications. The studied qualitative planting parameters were miss index, consumed seedlings, miss length, quality of feed index, multiple index, mean, and damaged seedlings.Results and DiscussionThe results of analysis of variance showed that, except of belt type, effects of the two studied factors and all interactions are statistically non-significant on consumed seedlings and miss length indexes. The results indicated significant differences between miss index (P<0.01), multiple index (P<0.05), and mean (P<0.05) as affected by belt type. None of the studied variable had a significant effect on damaged seedlings. Interactions of belt type and ratio of linear velocities significantly affected the quality of feed index (P < 0.01). An increase in ratio of linear velocities in plastic toothed belt lead to decrease of mean and miss indexes, whereas in case of metal toothed belt there is no significant effect on this two indexes. The results also showed that increase of linear velocities for the two types of carrier belt lead to increase of consumed seedlings and decrease of miss length. At the two ratios of linear velocities, miss length in metal toothed is less than plastic toothed belt. ConclusionsCommercial transplanting machines are not suitable for dense planting of onion. In this research an automatic metering device for separation and singularize of bare root seedlings of onion was manufactured and evaluated. The results indicated that the carrier belt with long and rigid teeth, having an angle of attack, could separate seedlings more efficiently. The results also showed a 80 percent increased in uniformity of plant seedlings distances is reachable using the metering system.
S. M. Hosseini; A. A. Jafari
Abstract
Introduction Great areas of the orchards in the world are dedicated to cultivation of the grapevine. Normally grape vineyards are pruned twice a year. Among the operations of grape production, winter pruning of the bushes is the only operation that still has not been fully mechanized while it is known ...
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Introduction Great areas of the orchards in the world are dedicated to cultivation of the grapevine. Normally grape vineyards are pruned twice a year. Among the operations of grape production, winter pruning of the bushes is the only operation that still has not been fully mechanized while it is known as the most laborious jobs in the farm. Some of the grape producing countries use various mechanical machines to prune the grapevines, but in most cases, these machines do not have a good performance. Therefore intelligent pruning machine seems to be necessary in this regard and this intelligent pruning machines can reduce the labor required to prune the vineyards. It this study in was attempted to develop an algorithm that uses image processing techniques to identify which parts of the grapevine should be cut. Stereo vision technique was used to obtain three dimensional images from the bare bushes whose leaves were fallen in autumn. Stereo vision systems are used to determine the depth from two images taken at the same time but from slightly different viewpoints using two cameras. Each pair of images of a common scene is related by a popular geometry, and corresponding points in the images pairs are constrained to lie on pairs of conjugate popular lines. Materials and Methods Photos were taken from gardens of the Research Center for Agriculture and Natural Resources of Fars province, Iran. At first, the distance between the plants and the cameras should be determined. The distance between the plants and cameras can be obtained by using the stereo vision techniques. Therefore, this method was used in this paper by two pictures taken from each plant with the left and right cameras. The algorithm was written in MATLAB. To facilitate the segmentation of the branches from the rows at the back, a blue plate with dimensions of 2×2 m2 were used at the background. After invoking the images, branches were segmented from the background to produce the binary image. Then, the plant distance from the cameras was calculated by using the stereo vision. In next stage, the main trunk and one year old branches were identified and branches with thicknesses less than 7 mm were removed from the image. To omit these branches consecutive dilation and erosion operations were applied with circular structures having radii of 2 and 4 pixels. Then, based on the branch diameter, one-year-old branches were detected and pruned through considering the pruning parameters. The branches were pruned so that only three buds were left on them. For this aim, the branches should be pruned to have a length of 15 cm. To truncate the branches to 15 cm, the length of the main stem was measured for each of the branches, and branches with length less than 15 cm were omitted from the images. Then the main skeleton of grapevine was determined. Using this skeleton, the attaching points of the branches as well as attachment points to the trunk were identified. Distance between the branches was maintained. At the last step, the cutting points on the branches were determined by labeling the removed branches at each step. Results and Discussion The results indicated that the color components in the texture of the branches could not be used to identify one year old branches and evaluation results of algorithm showed that the proposed algorithm had acceptable performance and in all photos, one year old branches were correctly identified and pruning point of the grapevines were correctly marked. Also among 254 cut off-points extracted from 20 images, just 7 pruning points were misdiagnosed. These results revealed that the accuracy of the algorithm was about 96.8 percent. Conclusion Based on the reasonable achievement of the algorithm it can be concluded that it is possible to use machine vision routines to determine the most suitable cut off points for pruning robots. By an intelligent pruning robot, the one year old branches are diagnosed properly and the cut off points of the plants are determined. This can reduce the required labor to perform winter pruning in vineyards which subsequently reduces the time required and the costs needed for pruning the vineyards.
