M. Mohammadi; S. H. Karparvarfard; S. Kamgar; M. Rahmatian
Abstract
Introduction Due to problems such as water resources constraints, poor soil and soil organic matter, and the problems related conventional tillage, the attention paid to protective tillage equipment should be taken into consideration by farmers. Today, agricultural machinery designers and manufacturers ...
Read More
Introduction Due to problems such as water resources constraints, poor soil and soil organic matter, and the problems related conventional tillage, the attention paid to protective tillage equipment should be taken into consideration by farmers. Today, agricultural machinery designers and manufacturers are looking for ways to resolve the problems due to the lack of water and soil resources and the reduction in fuel resources. One of these solutions is the optimization of agricultural machinery. The blade is one of the most important consumed components of tillage tools, which is very important for how it is adjusted and its effect on soil. According to research conducted on the importance of optimizing tillage implements, this study was carried out with the aim of optimizing the operating conditions for combined tillage with a new narrow blade. Materials and Methods The tests were taken place in the 10th section of farms in Agriculture school (Bajgah zone) of Shiraz University. Those tests were arranged as the split-split plot based on a completely randomized design. The treatments included the tillage depth, tilt angle and forward speed. The levels for the tillage depth, tilt angle and forward speed were 15, 20 cm and 0, 10, 15, 20, 25 degree and 3, 4, 5 km h-1 respectively. The experiments were performed in three replications. The test variables were draft, soil upheaving and disturbance areas, specific draft, fuel consumption and tractor wheel slippage. The CK 45 steel was used to make blades. The blades were made of the same dimensions and the difference between the blades was only at their tilt angle. Before starting the field tests, some properties of soil such as soil moisture content, soil texture and soil bulk density were measured. The RNAM test code was then used for measuring the draft force. The encoder and the fifth wheel were also employed to measure the slippage. For measuring the fuel consumption, two flow meters were used in the round way. The profilometer was applied for measuring the soil upheaving and disturbance areas. The specific draft was also computed. The data analysis was performed by SAS software (9.4 edition). Multiple regression method was used for modeling the desired treatments. Results and Discussion The results of multivariate regression method for optimizing forward speed, tillage depth and tilt angle for the blades including winged were 3.3 km h-1, 20 cm and 25°, respectively, and for the non-winged, 3.5 km h-1, 20 cm and 24.8°. Providing the tilt angle on the blade surface is considered as an innovation in this research, therefore, it can be seen from the results that with increasing this angle, the draft of the tillage was decreased. This could be due to the increased surface of the blade in the face of the soil on the diagonal surface. This increase was proportional to the cosine tilt angle at the initial surface of the blade. Therefore, the shear strength of the soil was decreased with increasing of this surface and ultimately decreased the amount of draft of the tillage. This variable had a significant difference with the depth of tillage and the forward speed of tractor and fuel consumption for the winged new narrow blade. Although the interactions of the above mentioned variables on the fuel consumption for the new blade condition were not significantly different, the minimum fuel consumption for the non-winged blade condition was also obtained at the same tilt angle as the winged new blade. In general, considering all of factors, the 25 degree inclination angle was proposed for both conditions. The interaction of this factor (tilt angle) on the wheel slip rate was also significant. The effect of the angle of inclination for both blades was significant on the slip of the wheel drive, so that the increase in the tilt angle reduced the amount of wheel slip. However, if the amount of slip of the tractor's wheel for an optimum angle of 25° was considered, according to the graph which representing the relationship between tractive efficiency vs. wheel slip and for Cn = 50, the tractive efficiency will be determined by calculation. It should be noted that the tractor's tractive efficiency was equivalent to 82%. This value reflects the effect of the tilt angle on the amount of tractor output power according to the definition of the tractive efficiency of the tractor. Conclusion Considering the increasing growth of using combined tillage tools in dry soil and its low moisture content, and considering the necessity of replacing the custom chisel blades with new blades which resistance to the soil reaction forces upon them, the non- winged blades with the tilt angle about 25° for working depth of 20 cm and forward speed of 3.5 km h-1 can increase the tractive efficiency of tractors to 82% and also decrease the fuel consumption by 34% compared to conventional tillage blades.
F. Akhavan; S. Kamgar; A. A. Golneshan
Abstract
Introduction Pollinating elevated date palms has been a challenging problem for many years. A few types of equipment have been designed and manufactured in the last fifty years, using either low pressure or compressed air to overcome this problem. However traditional pollination is still the most popular ...
Read More
Introduction Pollinating elevated date palms has been a challenging problem for many years. A few types of equipment have been designed and manufactured in the last fifty years, using either low pressure or compressed air to overcome this problem. However traditional pollination is still the most popular method in none-mechanized and small date farms. In the present research, a light portable electrical pollen-duster has been developed and tested. Materials and Methods A powerful ducted fan, equipped with a speed controller and a servo tester was made and installed on the top of a 6 -7.7m long carbon fiber boom, to provide a high volume rate of air flow for pollination. A small part of air flow is conducted through a by-pass tube to hit the pollen/pollen-flour blend in the pollen bin and suspend it. The rest of air flow, passing through a venturi, is responsible to provide a relative vacuum at the opening of pollen bin to pull up the suspended pollen and throw it toward the date palm crown. Although plain flour is traditionally used as filler in mechanical pollinators, however, SEM imaging showed that pasta flour particles are bigger than plain flour particles and are closer in size to pollen particles. Also, Repose angle of date pollen was measured as 38º where plain flour and pasta flour showed 44.9º and 40.7º respectively (figures 6 and 7). So, Pasta flour was used instead of plain flour to make a blend. To provide a low-weight pollen-duster, wires extending from ducted fan to its actuating equipment (battery, servo tester, and speed controller) were selected to be a combination of 2.5mm2 (3 meters) and 1.5mm2 (3 meters) types in the standard boom. This lowered the applied force on the operator’s hand by 33% (Figure 5 and equations 4 and 5). Evaluation of the pollen-duster has been performed in Khoor town in Isfahan province of Iran. Eighteen trees of Kabkab variety were pollinated in a completely random test with 6 treatments (five mechanical treatments compared with traditional treatment). Mechanical treatments were using 0.5, 1.5 and 2.5g pure pollen and 2 and 6g pollen-flour blend (in 1:3 ratio) in each of the three weekly repetitions. After 8 weeks, in kimri stage, normal, abnormal (non- pollinated), and dropped fruits on some randomly selected strands were counted to determine pollination as well as fruit setting efficiencies. Fruits weight in each treatment was measured on some random fruits in the Tamar stage. A new index; called "pollen consumption index", was introduced to provide a measure of pollen consumption rate in order to prevent redundant pollen consumption which has no sensible effect on the yield. Results and Discussion Calculated pollination and fruit setting efficiencies did not show a significant difference in all treatments, convincing that the traditional method could be replaced by pollen-duster without any yield difference. It offers benefits of lower pollen consumption; more trees pollinated in a day and also safer pollination due to reducing number of trees climbing. It was also shown that a tree could be pollinated properly with 0.5g pollen, so each hectare of date farm (120 trees) needs almost 180g pollen for all three replications, almost 1/4 of Perkins consumption report and 1/3 of Mostaan for three replications. Fruits weights of two pollen-flour treatments were significantly lower than others. As there is not any report available on the effect of the presence of flour or concentration of pollen on date fruits weights, so with the available data no definite reasoning can be made. Conclusion The developed pollen-duster could be used instead of the traditional date palm pollination method with the same fruit set and lower pollen consumption. The weight of the fruits in pollen-flour treatments `was lower than pure pollen and traditional treatments.
A. Bakhshipour Ziaratgahi; A. A. Jafari; Y. Emam; S. M. Nassiri; S. Kamgar; D. Zare
Abstract
Introduction Sugar beet (Beta vulgaris L.) as the second most important world’s sugar source after sugarcane is one of the major industrial crops. The presence of weeds in sugar beet fields, especially at early growth stages, results in a substantial decrease in the crop yield. It is very important ...
Read More
Introduction Sugar beet (Beta vulgaris L.) as the second most important world’s sugar source after sugarcane is one of the major industrial crops. The presence of weeds in sugar beet fields, especially at early growth stages, results in a substantial decrease in the crop yield. It is very important to efficiently eliminate weeds at early growing stages. The first step of precision weed control is accurate detection of weeds location in the field. This operation can be performed by machine vision techniques. Hough transform is one of the shape feature extraction methods for object tracking in image processing which is basically used to identify lines or other geometrical shapes in an image. Generalized Hough transform (GHT) is a modified version of the Hough transform used not only for geometrical forms, but also for detecting any arbitrary shape. This method is based on a pattern matching principle that uses a set of vectors of feature points (usually object edge points) to a reference point to construct a pattern. By comparing this pattern with a set pattern, the desired shape is detected. The aim of this study was to identify the sugar beet plant from some common weeds in a field using the GHT. Materials and Methods Images required for this study were taken at the four-leaf stage of sugar beet as the beginning of the critical period of weed control. A shelter was used to avoid direct sunlight and prevent leaf shadows on each other. The obtained images were then introduced to the Image Processing Toolbox of MATLAB programming software for further processing. Green and Red color components were extracted from primary RGB images. In the first step, binary images were obtained by applying the optimal threshold on the G-R images. A comprehensive study of several sugar beet images revealed that there is a unique feature in sugar beet leaves which makes them differentiable from the weeds. The feature observed in all sugar beet plants at the four-leaf stage was a stretched S-shaped curve at the junction of the leaf and petiole. This unique shape characteristic was used as the pattern for sugar beet detection using GHT. To implement the Hough transform in the images, a 50-member group of samples was prepared from S-shaped curve to build appropriate patterns. Desired features for the Hough transformation were extracted from the patterns. In the next step, the attempts were made to find the images for the shapes similar to each of the patterns. Results and Discussion Plants were thoroughly separated from soil and residues. The accuracy of segmentation algorithm was achieved by almost 100%. The accuracy of the generalized Hough algorithm was evaluated in two stages. In the first stage, the algorithm accuracy was assessed in detecting patterns in the images. Results showed that the accuracy of the algorithm was 96.21%. In the second stage, the algorithm was evaluated for some other test images, whereas the algorithm achieved an overall accuracy of 91.65%. In some cases, the presence of a large overlap between objects in the image reduced the detection accuracy. This was because of two main reasons; 1) high interference and ambiguity in the object edges, so that Hough transform was not able to detect the predefined patterns in the objects and, 2) weeds highly overlapped with sugar beet plants and thereby they were wrongly detected as sugar beet. However, since there is no or little interference between plants at the four-leaf stage, this interference can be eliminated by morphological operations. Due to this fact, it can be said that the results of GHT algorithm are acceptable for the detection of sugar beet in the plants close to four-leaf stage. Conclusion A special feature in the shape of sugar beet leaves was used as a criterion to distinguish between sugar beet and weeds. The results showed that by quantifying this special feature, which is an S-shaped curve near the petioles connection of beet leaves, sugar beet can be discriminated from weeds with an accuracy of 91.65 %. Recalled that this feature is a shape characteristic, therefore, the generalized Hough algorithm must be applied prior to plant canopy development, which is consistent with the critical period of weed control in sugar beet fields.
S. Kamgar; F. Noori Gushki; H. Mustafavand
Abstract
Introduction
The main producers of lentil are Canada, India, Nepal and China, respectively and Iran is the ninth producer in the world. The hand pulling is the usual method of lentil harvesting. Use of conventional combine because of short leg varieties, wide combine head in dry land and grain losses ...
Read More
Introduction
The main producers of lentil are Canada, India, Nepal and China, respectively and Iran is the ninth producer in the world. The hand pulling is the usual method of lentil harvesting. Use of conventional combine because of short leg varieties, wide combine head in dry land and grain losses by cutter bar vibrations is impossible. So a mechanism should be designed to harvest the lentil plants with minimum damage. This mechanism should be evaluated under different tests of crop and machines such as forward speed (FS), grain moisture content (GMC), different varieties and other parameters. Some researchers studied the effects of GMC (Andrews and et al., 1993; Huitink, 2005; Adisa, 2009; Abdi and Jalali, 2013) and FS on grain losses (Geng et al., 1984; Swapan et al., 2001; Mostafavand and Kamgar, 2014; Hunt, 1995). Field tests were conducted at three levels of FS 1.5, 3 and 4.5 km.h-1; three levels of cutting height (CH) 4, 8 and 13 cm and two levels of GMC, 8 and 14% on two varieties of lentils including Flip and Shiraz with three replications.
Materials and Methods
The feeder and cutter mechanism for chickpea harvesting that was the base design of device which is notched wheel and counter shear, was used. The other components of device were dividers, slat and chain feeders, belt and pulleys, chassis, elevator conveyor and storage. Two split plot design based on a randomized complete design was used to determine the effects of above treatments on lentil losses.
Results and Discussion
The ANOVA results indicated that the all studied factors; FS of feeder and cutter mechanism, CH and GMC had significant effect on losses of Shiraz variety (P0.05). The ranges of losses of Flip variety at 8% GMC were 8.6 to 10% for FS of 1.5 km.h-1, 9.1 to 10.4% for FS of 3 km.h-1and 10.4 to 11.4% for FS of 4.5 km h-1. These ranges at 14% GMC were 7.9 to 8.9% for FS of 1.5 km.h-1, 8.4 to 9.2% for FS of 3 km.h-1and 8.5 to 10% for FS of 4.5 km h-1. The ranges of losses of Shiraz variety at 8% GMC were 8.3 to 10.9% for FS of 1.5 km.h-1, 9 to 12.4% for FS of 3 km h-1and 10.7 to 13.6% for FS of 4.5 km h-1. These ranges at 14% GMC were 8.3 to 9.1% for FS of 1.5 km h-1, 8.3 to 9.9% for FS of 3 km h-1and 9.2 to 11.5% for FS of 4.5 km h-1. The comparison between two varieties at different levels of FS, GMC and CH indicated that the lentil losses of Shiraz variety were more than the other variety at 8 cm CH at 8 and 14% GMC. The difference of losses between two varieties was 0.8% at FS of 4.5 km.h-1 at 14% GMC where this value was 2% at 8% GMC and same FS and at 14% GMC and 8 cm CH from FS of 3 to 4.5 km h-1 was 0.3% and 1% for Flip and Shiraz varieties, respectively. Also at 14% GMC and 13 cm CH, the differences within group were 0.8 and 1.4% where at 8% GMC and 13 cm CH were 1 and 1.2% for Flip and Shiraz varieties, respectively. The results of the study of field evaluation of cutter and feeder mechanism of chickpea harvester for lentil harvesting showed that FS, CH and GMC at 1% probability for Shiraz variety and FS and GMC at 1% probability had significant effect on lentil losses but CH at 5% probability for Flip variety had no significant effect. The lentil losses were increased by increase in FS, CH and decreasing of GMC for both varieties. There was no significant difference from 1.5 to 3 km.h-1 and 4 to 8 cm CH in Flip variety while significant difference was at all levels of FS and CH in Shiraz variety.
Conclusions
At studied varieties, Flip variety because of more performance and minimum of losses was better than Shiraz variety. Also to achieve the lowest of losses by feeder and cutter mechanism, FS of 3 km h-1, GMC of 14%, CH of 8 cm and variety of Flip was recommended.
A. Rezaei; M. Loghavi; S. Kamgar; Y. Mehdipour
Abstract
Introduction
Olive (Oleo europaea) includes about 20 species of small trees from Oleaceae family. This point should be considered that Iran has allocated only a small universal market to its olive products in spite of having high production potentials; so that about 23 provinces of this country can ...
Read More
Introduction
Olive (Oleo europaea) includes about 20 species of small trees from Oleaceae family. This point should be considered that Iran has allocated only a small universal market to its olive products in spite of having high production potentials; so that about 23 provinces of this country can produce olive products. Therefore mechanizing of olive production and encouraging to develop olive trade are among the effective methods for development of this market. On the basis of IOOC report, the production of olive oil in 2008-2009 in Iran and all over the world has been 3 and 2866.5 thousand tons, respectively. Currently, harvesting olive product is done by hand in Iran. The expensiveness of work force and providing the needed workers are considered as the biggest problem in olive harvesting. While harvesting the tall trees, the workers use beating method by wood sticks which causes the fruits to be damaged and their quality to be decreased. The harvesting method which the quality and quantity of the olive final products is under its effect and also high expenses of harvesting by hand are considered as the two important factors in developing the mechanical harvesting of olive. For this purpose, the mechanized harvesting of olive should be considered for producing olive conserve and olive oil and decreasing expenses of harvesting. Considering the conducted studies on one hand and shortage of informational resources in the country on the other hand, a research was designed and performed with the following purposes:
Designing and fabricating of a portable pneumatic branch shaking system.
Determining the best frequency and oscillation duration for harvesting olive by the constructed system.
Materials and Methods
The branch shaking system is made of two general parts:
(a) The set of branch shaker driving unit.
(b) The portable vibration arm.
For constructing the set of vibrating arm, two experiments “elasticity and inflectionˮ of tree branches were conducted and the maximum force of 362.40 N was registered and it was considered as the base of computations. Then a double-action pneumatic jack with the internal diameter of 32 mm and the rod diameter of 12mm with the stroke length of 200 mm was selected. An electronic circuit was designed and developed for ordering the solenoid valve to control the flow. The system was transferred to one of the olive garden’s located in kilometer 5 of Sarvestan – Fasa road in Fars province in order to be evaluated. The effects of three oscillation frequencies of 12, 16 and 20 Hz and three oscillation durations of 5, 10 and 15 seconds at constant amplitude of 5 cm on detachment percentage of olive fruit was investigated through a factorial 3×3 experiment based on completely randomized design with four replications. Then the most suitable frequency and vibration duration was selected for harvesting olive by this system.
For measuring the static detachment force of the fruits, a tensile force dynamometer system model FG-5100 made by Lutron Company was used with the accuracy of 0.1 N and a maximum capacity of 980 N.
Results and Discussion
The variance analysis of the investigated features on the basis of the factorial experiment based on completely randomized designs was conducted through using SPSS software. The results showed that both frequency of vibration and oscillation duration had significant effect on the shaker performance; with no significant interaction effects which implies the independence of the debated variables. Comparing the means by using Duncan test at 1% significance level for features of oscillation frequency and duration of shaking showed that at any constant duration of oscillation, increasing of oscillation frequency significantly increases the percentage of the olive fruit detachment. This increase is due to the increase of dynamic force with the second power of oscillation frequency compared to the static separating force (Murphy, 1950).
It was observed that the calculated dynamic force is larger than the static force for separating the fruit in frequencies of 16 and 20 Hz, but since the dynamic force is variable at each point of the branch, 84.50 percent of fruits are separated from branches at frequency of 16 Hz and 87.25 percent of the fruits are separated from branches at frequency of 20 Hz.
Conclusions
At the end, the frequency of 20 Hz with 5 second duration of oscillation was selected as the most suitable treatment for this branch– shaker in harvesting oil-type olives.
H. Izadi; S. Kamgar; M. H. Raoufat
Abstract
Introduction: The quality of agricultural products is associated with their color, size and health, grading of fruits is regarded as an important step in post-harvest processing. In most cases, manual sorting inspections depends on available manpower, time consuming and their accuracy could not be guaranteed. ...
Read More
Introduction: The quality of agricultural products is associated with their color, size and health, grading of fruits is regarded as an important step in post-harvest processing. In most cases, manual sorting inspections depends on available manpower, time consuming and their accuracy could not be guaranteed. Machine Vision is known to be a useful tool for external features measurement (e.g. size, shape, color and defects) and in recent century, Machine Vision technology has been used for shape sorting.
The main purpose of this study was to develop new method for tomato grading and sorting using Neuro-fuzzy system (ANFIS) and to compare the accuracies of the ANFIS predicted results with those suggested by a human expert.
Materials and Methods: In this study, a total of 300 image of tomatoes (Rev ground) was randomly harvested, classified in 3 ripeness stage, 3 sizes and 2 health.
The grading and sorting mechanism consisted of a lighting chamber (cloudy sky), lighting source and a digital camera connected to a computer.
The images were recorded in a special chamber with an indirect radiation (cloudy sky) with four florescent lampson each sides and camera lens was entire to lighting chamber by a hole which was only entranced to outer and covered by a camera lens.
Three types of features were extracted from final images; Shap, color and texture. To receive these features, we need to have images both in color and binary format in procedure shown in Figure 1.
For the first group; characteristics of the images were analysis that could offer information an surface area (S.A.), maximum diameter (Dmax), minimum diameter (Dmin) and average diameters. Considering to the importance of the color in acceptance of food quality by consumers, the following classification was conducted to estimate the apparent color of the tomato;
1. Classified as red (red > 90%)
2. Classified as red light (red or bold pink 60-90%)
3. Classified as pink (red 30-60%)
4. Classified as Turning (red 10-30%, It showed the color green change to pink)
5. Classified as Breakers (red < 10%, It showed the color green change to yellow)
6. Classified as green (The whole fruit area was green)
To estimate the quality of tomato, we need to estimate background of the images. For this purpose we should follow the preocedure as shown in Fig.2.
According to flowcharts shown in Fig.1, our samples will be in the following stages: (Fig.3.)
Fig.4 shows that during the ripening of tomato red color is increased and green color is decreased. Indicating chlorophyll degradation while lycopen started to be produced.
According to figure 6 we utilize the R and G value of tomato for ripening decision. As ripening data we utilize the mean of red and green values of pixels that are used for this goal. For correct processing of last group, edge of images were removed that had incompletely understood of the fruit color and determine color coefficients, the system with slight error could detect all parts of the damage. Quantity of damage area reported in the proportion of the total area of tomato.
In the present work, 5 factors were considered and the linguistic variables corresponding to the values were created in 4 levels: size, color or ripening, a healthy and final level that classified tomatoes in 8 classes. In size level input values were minimum diameter and surface area. These values classified the tomatoes into 3 groups. In color level input values were Red and Green component values. These values were used to classify the tomatoes in 3 group, too. In healthy and unhealthy level, input value was proportion of damage area to tomato total area. This value were used to classify the tomatoes in 2 group. In final level, outputs of previous levels are our inputs now. This values going to classify the tomatoes into 8 final groups.
Results and Discussion: This system can classify the tomatoes in 8 groups just with rules. For this reason we measured the accuracy of the system before training. This values were 70.7, 82.0, 95.7 and 75.5% for size, color, health and final system respectively. For achieving all ability of ANFIS in classifing we done the above measuring after training of machine. The results were 80.9, 89.5, 95.7 and 81% for size, color, health and final system respectively, that indicate the accuracy of the system is raised by 10%. A validation step is done in this study. The accuracy of the system is measured versus a human expert. The classification was done with 60 samples. The accuracies of machine were 75.9, 83.8, 94.2 and 76.5%. Analysis of results with qui-square test indicated that there is no significant difference between machine results and human expert choices.The validation process proved that system is useful in this purpose.
Conclusions: This research was about evaluating of using machine vision and ANFIS in grading machines and done in off-line mode. The research was redirected to the following general conclusions:
1. To obtain an estimate of tomatoes, sample sizes were measured by using calipers and machine vision, the results showed that this system can be used to obtain dimensions.
2. For the purpose of size grading, the small diameter and the surface area of the image was used whichyielded 67% and 62% accuracy for determining the mass, in comparison the ANFIS system performance was precisely 81%.
3. For the purpose of color grading, red and green were used which is a better description of quality. For this the ANFIS system was used for color grading and it performed at 89.5%.
4. For the purpose of sample selection grading (dividing the rotten from the good), optical robot was used. The outcome of system ANFIS and the optical robots had the same results of selection at 95%.
5. In an aggregate or globally, the criteria from the above was used as an input for the grading and classification. Based on these inputs, the ultimate output was consequently categorized into 8 groups. The precision of the division or the selection was determined to be 81.5%.
6. With respect to the testing based on chi-square, it can be determined that this system can replace human workers. In addition, based on the performance and necessary adjustments to the system and its grading criteria better system can be built to replace human workers.
