Design and Construction
A. Akbarnia
Abstract
Introduction Sugarcane, a plant which sugar is extracted from, is planted in vast areas with hot and humid climate. Brazil is the largest producer of sugarcane in the world. The next five major producers, in decreasing order, are India, China, Thailand, Pakistan and Mexico. Sugarcane is a tropical, perennial ...
Read More
Introduction Sugarcane, a plant which sugar is extracted from, is planted in vast areas with hot and humid climate. Brazil is the largest producer of sugarcane in the world. The next five major producers, in decreasing order, are India, China, Thailand, Pakistan and Mexico. Sugarcane is a tropical, perennial grass that forms lateral shoots at the base to produce multiple stems, typically three to four meters high and about 5 cm in diameter. The total area under sugarcane plantation in Iran (Khozestan Province) is about 80,000 hectares with an average yield of 100 tons per hectare. To increase the yield per unit of land and reduce production costs and move toward sustainable agriculture, mechanization of agricultural operations seems inevitable. Planters are the most important of farm machinery among the mechanization equipment. Sugarcane cultivation is done both by hand and machine. Hand planting operations is laborious and painstaking work and work efficiency is so low and culture costs are so high. In Iran farms, the sugarcane plantation process is carried out manually by the farmers. Considering the climatic conditions, the agricultural soil composition and constitution, and the different plantation pattern used in Iran, the imported planting machines are not suitable for the farming conditions in the country. Moreover, the domestically produced machines, which are mostly based on the imported versions, do not provide adequate performance. Therefore, fabrication of a machine, capable of continuously lifting the sugarcane scions from a container and sending them to a dropper pipe, uniformly and in conformance with the climatic conditions of the sugarcane farms in the country, is of great importance. Materials and Methods In this research, initially, a field study was carried out to identify the problems and shortcomings of imported and copied planting machines in sugarcane farms, such as jamming of the scions conveying mechanism and the existence of unplanted sections in the farm. Subsequently, a new compound seeding unit with unique capabilities for solving the above mentioned problems was fabricated, with the aim of application in sugarcane planting machines. The various components of the system include: 1- Tank split in two pieces and connected to each other by two hinges through the middle and it can adjust to different angles. 2- Tube fall for cuttings scions. 3- Two rows of chain on a conveyor screwed on belt. 4- Number of 9 cups (channels) to receive and transmit cutting scions from the tank and guided them to the falls duct. 5- 18 pcs of metal preservative, the chain screwed to conveyor. 6- Four Number of gears on two shafts in order to drive the conveyor chain. 7- Two shafts, one on top and one another on the bottom of the anchor-conveyors chain. 8- The mechanism of driven Endless belt as a mobile bed to showing the steady rate of falling the scions from the fallen channel. 9- Two variable speeds electromotor to provide the movement of complex distributer and planter’s mobile bed belt. 10- Controlling mechanism of falling number of scion. After preparing and manufacturing the different machine’s pieces, they were installed on the chassis and then different units were prepared and the machine are run. Results and Discussion Therefore, fabrication of a mechanism, capable of continuously lifting the sugarcane scions from a container and sending them to a dropper pipe, uniformly and in conformance with the conditions of the sugarcane farms is of great importance. In the new mechanism, as opposed to the existing seeding units in which the seeding operation is performed lengthwise, planting of the scions is performed in a widthwise pattern. Using the manufactured machine had a great effect on method of tillage and planting. The farm field was changed to a smooth surface in tillage then in planting the scions with installing the two diagonal plate the soil putted on scions and the made furrows for irrigating. Conclusion This mechanism reduces the number of planted scions per hectare, results in a more uniform planting and growth of the scions, and reduces the number of machine trips in the farm, increasing the planter productivity. The seeding unit was fabricated and is presently ready for use in the sugarcane planters.
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, ...
Read More
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.
Design and Construction
A. Mondani; S. H. Karparvarfard
Abstract
IntroductionMaximum efficiency of natural resources, reduced risk of production, improved fertility of soil, and increased production per area enjoyment have made intercropping a preferential practice compared with cropping. One of the fundamental problems in this kind of cropping is non-existence of ...
Read More
IntroductionMaximum efficiency of natural resources, reduced risk of production, improved fertility of soil, and increased production per area enjoyment have made intercropping a preferential practice compared with cropping. One of the fundamental problems in this kind of cropping is non-existence of suitable machines. In this research, a new intercropping machine has been designed and built for intercropping of corn and bean with precise ratios and different planting patterns. Materials and MethodsThe experiments were conducted at the Badjgah Research Station, Shiraz University, located in NW Shiraz, Iran. The soil texture was clay loam (16% sand, 48% silt, and 35% clay). The plot size was 9 m wide and 12 m long. The total number of the plots were 9. The basic components of intercropping machine were an adjustable frame to adjust row spacing for each unit planter about 550 mm horizontally independently (the row spacing between corn and bean planting lines was considered 375 mm), a hinged frame for adjustment of seeding depth and possible poor emergence of plants due to very deep or shallow planting, metering case frames for installing the vacuum metering disk units around which the seed drums have a row of 36 holes of 4.5 and 5.5 mm diameter for corn and bean, respectively, seed delivery tubes, a suction fan, shovel openers used for bedder planting for corn and lister planting for bean, a knife covering attachment, seed-firming wheels, interchangeable gears which are mechanical chain drives for 43 varying seeding rates driven by carrying wheel drives, two metal seed hoppers whose lower side walls’ slope can be adjust at a maximum level of 45 . A front wheel assist, Massey Ferguson tractor (MF-399) (ITM, Tabriz, Iran) with a maximum engine power of 81 kW was used for field test of intercropping machine. Moldboard plow was used for primary tillage and the depth of plowing was 25 cm. Next, by an offset disk harrow, the field was disked twice for pulverizing lumps, mulching the surface and firming the underneath soil to provide a smooth uniform seedbed. In this study, the common bean seed (var. Derakhshan) and corn hybrid seed (SC-704) with 93 and 83 percent of germination and 97 and 98 percent of purity, respectively, were used. This machine was operated in five different distance patterns between corn and bean seeds on each row: 55 mm and 215 mm in the first pattern, 85 mm and 185 mm in the second pattern, 110 mm and 150 mm in the third pattern, 130 mm and 120 mm in the fourth pattern, and 160 mm and 100 mm in the fifth pattern for corn and bean, respectively. For all patterns, the depth of planting for corn and bean seeds was chosen as 20, 40, and 60 mm. In addition, the forward speed was assumed to be constant (4 km h-1). By using split plots with three replicates and SAS software (2002), the results were analyzed. Results and DiscussionThe multiple index, miss index, precision index, and quality of feed index was evaluated. The analysis of variance for bean planting unit showed that difference distance between seeds and various planting depth were significantly higher for multiple index (P< 0.01), but their interactions were not significant (P 0.05). Also, with decreasing the seeds distances, the multiple index was increased (P< 0.05). Moreover, comparing the results of the average multiple index in different levels of planting depth indicated that the multiple index was decreased when at higher depths of planting (P< 0.05). The seeds distance and planting depth were significantly higher for miss index and quality of feed index (P< 0.01), but their interactions were not significant for either index (P> 0.05). The precision index was significant was affected by different levels of seeds distance (P< 0.05) and was higher for different levels of seeds planting depths (P< 0.01), but their interactions were not significant. In corn planting unit, the results showed that the different distances between seeds and planting depths were significantly higher for multiple index, miss index, quality of feed index, and precision index (P< 0.01). Also their interactions were significant for multiple index (P< 0.05), but the other indices showed no significant interactions (P> 0.05). ConclusionsThe data suggested a higher quality index once corn and bean were respectively plated at 160 and 215 mm seed distance with a planting depth of 60 mm being optimum for each corn and bean.
Design and Construction
I. Eskandari; N. Sartipi
Abstract
IntroductionResearchers frequently include multiple cultivars and fertility levels in field experiments. Therefore, the experiments sowing operation must represent a considerable saving in time and labor, compared to hand sowing. Greater flexibility in experimental design and setup could be achieved ...
Read More
IntroductionResearchers frequently include multiple cultivars and fertility levels in field experiments. Therefore, the experiments sowing operation must represent a considerable saving in time and labor, compared to hand sowing. Greater flexibility in experimental design and setup could be achieved by equipment that enables quick changes in the cultivar and fertilizer rates from one plot to the next. A satisfactory seed drill must distribute a given quantity of seed evenly over a predetermined length of coulter row, the coulters must be spaced at exact intervals and depth of sowing must be uniform. In a self-propelled type of plot seeder, no coulter should run in a wheel track as the compaction of the soil can cause observable differences in vigor between plants in such a row and those in un-compacted rows. The machine should sow in succession from a try in which a series of seed pocket separated clearly and must be put into distributer funnel by an assistant operator. The length of gap being varied according to the nature and purpose of the plot.The objectives of this experiment were 1- to design and construct a local self-propelled plot seeder and 2- To compare it with the imported (Wintersteiger) plot seeder in cereal breeding programs.Materials and MethodsA small-plot seeder was designed and constructed to meet this objective. The unit consists of the following basic components: a toolbar for pulling a set of six blade coulter, an air compressor for lifting and putting down the openers and metering transmission drive wheel, an operators chair and work rack, one belt seed distribution. A cone-celled and rotor seed distributor is used for seed distribution to the openers. The cone system is connected to the gearbox and allows for great flexibility in changing cultivars, crop species, and plot length. This is driven by the separate drive wheel. The cone-celled distributor sows all the seed of the sample in making one complete turn. The spinner can be equipped with a 4 or 6 outlet delivery head, depending on row spacing. The planter is fitted with hoe openers. Alternatively, spear-point openers have sometimes been used under conventional tillage systems. Seeding depth control was achieved by an adjustment screw handle. The plot seeder is being moved by a 9.6 kW engine, and has been successfully used in applications. Field experiment established by using 4 plot length (2, 3, 4 and 6) with 4 replication by the constructed plot seeder and imported plot seeder. Crop measurements were planted height, spike m-2, seeds/spike, Thousand kernel weight, Biological and grain yield, harvest index and drill measurements were seeding depth, uniformity of row spacing in action, seed counter performance, power requirement, slippage evenly of rows after planting.Results and DiscussionResults showed that there were significant differences between the plant emergences. The emergencies were higher in plots, which planted by the new plot seeder. The differences between seed distribution of openers were insignificant, but the variances of new plot seeder and imported plot seeder were 0.267 and 1.05 respectively. Mean planting depth of plots planted by the Wintersteiger plot seeder was 0.8 cm shallower than the adjusted planting depth while mean planting depth in plots planted by constructing machine had only 0.01 cm variation.Results of variance analysis revealed that effect of treatments on wheat grain yield and yield components was significant. So that, highest grain yield (4216 kgha-1), biological yield (8704 kgha-1), number of spikes per square meter (649spike), obtained from a plot which planted by constructed plot seeder. Increasing yield of treatments which planted by constructed plot seeder might be because of increasing the number of spikes per square meter in those treatments. The mean of spike per square meter in plots of new planter was 691 spikes which were116 spike more than plots planted by imported plot seeder.ConclusionsThe constructed plot seeder had up to 18500$ cost reduction. The seeder was able to distribute the different type of seed to the seed tubes uniformly in laboratory tests, nevertheless it is necessary to test the constructed plot seeder in field condition by using different seed type and conducting new research project. Advantages of this planter include less variation of seed fall down in different coulters, perfect planting depth control, separate wheel for adjusting planting length, minimize the slippage of planter driven wheel and proper utility in different field condition. According to effects on crop parameters the constructed plot seeder had relative priority to imported one. In addition easily accessories supply and cheaper prime cost are profit of the designed and constructed plot seeder.
Design and Construction
M. A. Rostami
Abstract
IntroductionNowadays, in a lot of farm land due to reasons such as high density, heavy textured soils, steep terrain and a large body of water at each irrigation, rapid and complete absorption of water in the soil does not happen and runoff will be accrued. Improvement of infiltration reduces runoff ...
Read More
IntroductionNowadays, in a lot of farm land due to reasons such as high density, heavy textured soils, steep terrain and a large body of water at each irrigation, rapid and complete absorption of water in the soil does not happen and runoff will be accrued. Improvement of infiltration reduces runoff and thus increases available water capacity. The main methods used to increase the infiltration area: The use of soil amendments, soil management by tillage and conservation farming. These methods may be used separately or together. Reservoir tillage is the process by which small holes or depressions are punched in the soil to prevent runoff of water from irrigation or rainfall. The objective of this study was to develop and evaluate a new reservoir tillage machine for runoff control in the fields. Materials and MethodsFabricated machine has four main units include three-point hitch, toolbar, frame and tillage unit. Tillage unit was a spider wheel with 6 arms that has 6 Wedge-shaped blades, mounted on them. Each tillage unit mounted on a frame and the frame is attached to the toolbar with a yoke. The toolbar was attached to the tractor by three-point hitch. The movement of tractor caused blades impact soil and spider wheel was rotating. Spider wheel rotation speed was depended on the forward speed of the tractor. Blades were created mini-reservoirs on the soil surface for "In situ" irrigation water or rainwater harvesting. Theoretically distance between basins, created by reservoir tillage machine, fabricated in this study was 57 and 68 cm for Arm's length of 30 and 40 cm respectively.For the construction of machine, first the plan was drawn with SolidWorks software and then the parts of the machine were built based on technical drawings. First tillage unit was constructed and its shaft was based in two bearings. Six of the arms were positioned at 60 degrees from each other around tillage units and connected by welding. For evaluation of machine performance, two factors contain of machine speed (in three levels of 5, 7.5 and 10 km h-1) and Arm's length (in two levels of 30 and 40 cm) were evaluated. The machine was evaluated based on a completely randomized block factorial design with three replications. Effects of these factors on depth, distance and volume of basins and runoff were evaluated. Results and DiscussionMean comparisons of depth, distance and size of reservoirs in different machine forward speed and different Arm's length are summarized in Table 1 and 2. The results showed that the effect of arm length and forward speed on changes in the depth and volume of the reservoirs were significant at the probability level of one percent but changes of the distance between the reservoirs was only affected by Arm's length. The results also showed that increasing the forward speed from 5 to 10 km h-1 and increase the Arm's length from 30 to 40 cm increased depth, distance and volume of reservoirs. Reservoir tillage practices were control runoff in all plots.ConclusionsIn this research project, a reservoir tillage machine was built and assessed. Tillage unit of this machine is similar to the spider wheel. By this machine the small holes generated in the ground periodically. For evaluation of machine performance, effect of two factors, including machine speed and arm's length on depth, distance and volume of the basins were evaluated. The results showed that increasing the ground speed from 5 to 10 km h-1 and increase the arm's length from 30 to 40 cm increased depth, distance and volume of reservoirs. Reservoir tillage practices were controlled runoff in all plots.
Design and Construction
M. Zamani; M. Aboonajmi; S. R. Hassan Beigi Bidgoli
Abstract
IntroductionOne of the ways used for minimizing the cost of maintenance and repairs of rotating industrial equipment is condition monitoring using acoustic analysis. One of the most important problems which always have been under consideration in industrial equipment application is confidence possibility. ...
Read More
IntroductionOne of the ways used for minimizing the cost of maintenance and repairs of rotating industrial equipment is condition monitoring using acoustic analysis. One of the most important problems which always have been under consideration in industrial equipment application is confidence possibility. Each dynamic, electrical, hydraulic or thermal system has certain characteristics which show the normal condition of the machine during function. Any changes of the characteristics can be a signal of a problem in the machine. The aim of condition monitoring is system condition determination using measurements of the signals of characteristics and using this information for system impairment prognostication. There are a lot of ways for condition monitoring of different systems, but sound analysis is accepted and used extensively as a method for condition investigation of rotating machines. The aim of this research is the design and construction of considered gearbox and using of obtaining data in frequency and time spectrum in order to analyze the sound and diagnosis.Materials and MethodsThis research was conducted at the department of mechanical biosystem workshop at Aboureihan College at Tehran University in February 15th.2015. In this research, in order to investigate the trend of diagnosis and gearbox condition, a system was designed and then constructed. The sound of correct and damaged gearbox was investigated by audiometer and stored in computer for data analysis. Sound measurement was done in three pinions speed of 749, 1050 and 1496 rpm and for correct gearboxes, damage of the fracture of a tooth and a tooth wear.Gearbox design and construction: In order to conduct the research, a gearbox with simple gearwheels was designed according to current needs. Then mentioned gearbox and its accessories were modeled in CATIA V5-R20 software and then the system was constructed.Gearbox is a machine that is used for mechanical power transition from a productive source of power to a consumer, for torque meeting and for rotating speed needed for the consumer. In fact, gearbox is an interfere between power source and power consumer which produces a flexible communication between power source and power consumer. Needing to a gearbox as a machine which can generate harmony as an interface is unavoidable due to lack of harmony of torque and rotating speed of production source of power. So necessary calculations in order to attain to technical characteristics of gearwheels, bearings, shaft dimensions and other accessories of gearbox were done. This gearbox is from kinds of simple gearwheel which its input and output shaft are parallel to each other. Main accessories of gearbox are: 1.crust 2.shaft 3.gearwheel 4.thorn 5.bearing 6.cover. All of the design parameters were calculated and considered in designing of all of the accessories of gearbox.Electromotor rotating calibration: For this aim, a light-contact telemeter in model of Lutron was used as contact.Acoustic module of electro motor: A module was constructed in order to prevent from sound waves interaction resulting from an electromotor function with waves of gearbox function. Three layers of sound absorbent including common felt with 1mm width, polyethylene foam with 15 mm width and shoulder foam egg with 35 mm width were used for the module insulation. Material used for the body of this module was MDF. Based on field measurement, level of electromotor sound decrement using the acoustic module was 20dB. Investigated malfunctions in this research are relevant to gearwheel with one tooth fracture, one worn tooth and one tooth fracture and other worn tooth.Collection and storage of acoustic data: In this research, an audiometer in model of HT-157 made in Italy in order to obtain acoustic data and a laptop with a model of Lenovo-G550 for data storage and processing was used. Cool Edit Pro 2.0 software was used for data processing. Data storage was in PCM format and MATLAB R2014a software used for data processing.Data processing: Signal processing method in the frequency domain is used in order to reveal the defects. Fast Fourier Transform: Fast Fourier Transform FFT for application in electronic equipment specially analyzers have great importance. In this condition, sampling number is chosen exponentially as 2N which decreases the calculation volume significantly. Determination of defect kind of gearwheel using frequency spectrum analysis: In mentioned gearwheel, errors were generated synthetically. Defect kind of these errors was generated in separate gearwheels in order to investigate the defects more precisely and a gearwheel was considered as control gearwheel. Despite of this, the sound of all of the gearwheels in correct condition was stored. Results and DiscussionComparison of processed acoustic signals from gearwheels of gearbox in two correct and incorrect conditions was indicative of gearwheel involvement, frequency, their harmony and the changes resulted from defects. Gearwheel defect detection tests showed that at the speeds of 1496, 1050 and 749 rpm, investigated defects are recognizable with a comparison of the frequency spectrum of obtained signals in correct and incorrect conditions and according to the involvement frequency of gearwheel, its harmony and sided spectrum. Results of the frequency spectrum of signal analysis in speed of 1496 rpm pinion showed the defect of one tooth fracture in involvement frequency of gearwheels by 489, 350 and 249 Hz respectively which became apparent with a mentioned frequency domain increment. A worn tooth defect in a gearwheel was completely determinable as sided bands with equal distance around gearwheel involvement frequency in the signal frequency determination of the speeds of 1496 and 105 rpm pinion, but became a bit harder in less speeds. Investigation of frequency spectrum of acoustic signal resulted from gearwheel, is indicative of the ability of this method in gearbox condition investigation with high precision and minimum time. So the gearbox condition investigation is reached by investigation of the frequency spectrum of acoustic signal resulted from gearwheel.ConclusionsIn current research, acquisitive signals resulted from produced sound waves of constructed gearwheel were used for investigation and diagnosis. Recorded signal in time domain and processed frequency and exploited characteristics of signal in frequency domain for diagnosis were analyzed. Obtained results of this research can be summarized as follow:1. Precision level in the diagnosis decreased by increasing in pinion speed.2. There will be a decrement in gearwheel diagnosis after defects integration and signal behavior won’t be completely similar to the defect as individual. 3. Proper placement of audiometer is effective in diagnosis trend.4. In frequency spectrum of obtained signals, particle velocity level is more efficient in diagnosis than the sound pressure level.
Design and Construction
I. Ahmadi
Abstract
IntroductionMeasurement of the draft force exerted from agricultural machineries to the tractor and the calculation of the implement power requirements is important for agriculturalists in terms of machine design and tractor-machine matching . Therefore, studies about this issue have been started from ...
Read More
IntroductionMeasurement of the draft force exerted from agricultural machineries to the tractor and the calculation of the implement power requirements is important for agriculturalists in terms of machine design and tractor-machine matching . Therefore, studies about this issue have been started from the 1950’s. Zoerbet al.,(1983) claimed that the first dynamometers have been made of spring and in reality, users had difficulties reading these dynamometers gauge due to the quick variations of the gauge pointer. Therefore the second stage was the development of the hydraulic-type dynamometers in which the oil pressure inside the hydraulic cylinder-piston set installed between machine and tractor that can be readable with a bourdontube gauge was considered as its indicator. From the first years of the 1960’s development of the strain-gauge pull-type dynamometers started. In this study, design, fabrication and evaluation of a pull-type tractor dynamometer is considered that can be used to measure and store tractor forward velocity, and horizontal component of draft force exerted from wheel-type towed implements to the tractor. Therefore, drawbar power needed to pull the machine through the soil can be calculated. This dynamometer can also be utilized to measure three-point-hitch implement’s draft force and power requirements in condition that the RNAM (1983) method was used. In addition to measure the tractor velocity with a GPS receiver instead of a fifth wheel, the other particular issue about this dynamometer is that a remote controller is used to order data acquisition commands such as starting, ending, pausing and time zeroing in the process of data gathering. Materials and MethodsIn this study an S-type strain gauge load cell (model: SS300) and a GPS receiver (model: Micro GPS antenna AGM-10 + NEO-6-M-0-001 ublox AG board) were utilized to measure the draft force and forward velocity, respectively. To calibrate the load cell sensor, in an iron material selling store, the load cell was placed between an external force with a known value and roof-type load lifter by steel cables, and external loads with the value of 1-5 ton applied to the load cell in ascending and descending order. In each loading stage, the system and measuring apparatus outputs were booked. After drawing the x-y scatter chart of paired values (system output, measuring apparatus output), regression equation between these two variables were obtained that can be utilized to calibrate this part of the system. Above-mentioned method was used to calibrate the velocity measuring part of the dynamometer with a difference that real velocity was used instead of external load and velocity output was used instead of the load cell output. After performing the calibration of the system, the developed dynamometer was utilized to measure the draft force and power requirements of a three-point-hitch moldboard plow using the RNAM method. Finally, the obtained results were compared with the other researcher’s results, and the ASAE prediction of the draft force of a moldboard plow.Results and DiscussionAccording to the results of this study, the estimated equation and its coefficient of determination for the calibration of the load cell sensor were , and respectively, and the estimated equation and its coefficient of determination for the calibration of the velocity were , and respectively. Moreover, according to the results of the field tests, draft force and the power requirements of a three-bottom moldboard plow in a silty clay loam soil with the forward velocity of was measured to be , and , respectively, that were in agreement with other studies. Furthermore, the draft force results of this study, and other studies were in the range of of the which is the moldboard plow draft prediction according to the ASAE standard.ConclusionsThis study suggests that with the aid of the RNAM method, and the developed dynamometer, the draft force and power requirements of the tillage implements can be calculated. These results can further be utilized to match the implements with the tractor or to design new tillage implements.
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 ...
Read More
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
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 ...
Read More
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
J. Ghezavati; D. Mohammad Zamani; M. Abbasgholipour; B. Mohammadi Alasti; A. Ranji
Abstract
Introduction: From an economic viewpoint, tomato is considered as the second most valuable crop after potato. It is also preceded by the potato in terms of per capita consumption in the world. In 2008, the cultivation area used for the tomato as equal to 163,539 hectares in Iran and the production of ...
Read More
Introduction: From an economic viewpoint, tomato is considered as the second most valuable crop after potato. It is also preceded by the potato in terms of per capita consumption in the world. In 2008, the cultivation area used for the tomato as equal to 163,539 hectares in Iran and the production of it was equal to 5,887,715 tons with an average production of 117,887 tons in 4352 hectares in the provinces, respectively. Having high production volume and quality, costly hybrid seeds are currently used for the major planting areas of vegetable in Iran. Most of the used transplanted seedlings are 83%. Since the seeds are expensive, the percentage of seedlings and healthy and disease-free seeds should be used for maximized germination and be transferred to the fields of open space. Preparing seedlings in transplanting trays is a technology to respond to this need. Trays are covered with a layer of Peat and Miculite fertilizers. Then, one seed is manually placed in each cell after gauging and preparing a suitable field. However, manually placing seeds is time-consuming and requires hard labor. Sixteen working labors per hour are required for 15 × 7 cell in order to have 10200 seedlings grown in 100 trays. Due to lack of adequate labor, production capacity of greenhouses is reduced, especially in the farming season when finding labor for planting vegetable sprouts is laborious. Therefore, mechanizing tray seeding operations is essential to increase the capacity of the growing industry of greenhouses in Iran.Materials and Methods: Initially, the tomato seeds were examined in the laboratory. The most important parameters of the study included size, shape, weight, the speed of getting out of the tank and the minimum carrying speed. Then, a vacuum-based single seed picking unit was prepared to investigate the factors influencing the design, so that a single tomato seed can be harvested from the masses. The most important factors considered in the design and construction included: cost, ease of performance, portability, use of local equipment, the planter’s capacity as well as the style of picking single seeds (In Fig.1, the original scheme of the device is presented). The planter consists of several parts operating harmoniously to yield the desired results. These parts include a chassis and conveyor belt mechanism, primary and secondary fertilizer tanks, squashing unit, seed metering device and vibrating reservoir of the seed (The main text of modeling the device with SolidWorks software is shown in Fig.2). This device is designed in such a way that the position of the nozzle, the suction pressure, the height of removing seeds and the vibration frequency of the seeding tray are adjustable. Evaluation of the device was carried out by single seeding of tomato seeds in trays with 105 cells (7 × 15). Suction pressure and nozzle size were calculated for tomato seeds. Scaling distances were considered equal, based on the 30.5-mm intervals of the cells. Single seed picking efficiency of seeds was calculated by the system, as the single percentage of seeding and the total percentage of seeded cells. Seed consumption efficiency is the ratio of the total seeded cells to the total number of existing seeds in the cells. Seeding efficiency also refers to single, dual, and multiple harvested seeds. Furthermore, the device capacity is defined as the number of seeded tray cells per hour. In order to design and build a precise robot planter, an experiment including the designed planter and planting speed of workers in 10 repetitions was designed and implemented to estimate the seeding time and compare with automated and manual planting methods. Seedling trays with four replications were cultivated by the designed robot and the number of cultivated seeds per tray at each stage were correctly counted. After that, the spent planting time by a worker was determined with four replications.Results and Discussion: The planting rate of tomato seeds is different when comparing mechanized and manual methods. As it is known, the time required for cultivation in the mechanized method is at least one-tenth of the time required for cultivation in the conventional and manual method, which causes the planting rate to increase, and this robot is one of the components of cultivation in the mechanized method in cultivation and production of tomatoes. By assessing planting time using the mechanized method it was revealed that an average of 26.3 seconds is needed to fill a 7 × 15 centimeter tray of tomato seeds with 105 cells. The same planting procedure in the manual method takes an average of 357 seconds which is indicative of the high rate of the designed device. The planter capacity experimented using a seedling tray with the size of 15×7 cells, was calculated to be 17750 cells per hour showing that the suction pressure increases by a reduction in seed size. Thus, while working with small-sized seeds, fluctuations of the suction pressure must be carefully considered to be minimized and the seed being dual was only affected by the opening diameter. Therefore, the opening diameter should become the same in size in order to minimize the dual seed instances. In case of the tomato, the opening diameter had a great influence on the seeds being bulky.Conclusions: Manual planting takes a considerable time in comparison with the mechanized planting. Furthermore, using the designed device in addition to speeding up the planting process, caused regular and accurate cultivation of tomato seeds in order to produce seedlings. The results indicate that utilizing the device over time is highly economical for the major producers of tomatoes, and it is recommended to be used in agro-industry companies, and in the mechanized method of planting in large scales.
Design and Construction
A. Damirchi; M. H. Aghkhani; M. Khojastehpour; J. Baradaran Motie
Abstract
Introduction: In conventional farming, the soil and crop are considered uniform in different locations of the farm and the fertilizers are applied according to the average of soil needs with an additional percentage for safety (Loghavi, 2003). Non-essential chemical fertilizers in the field have harmful ...
Read More
Introduction: In conventional farming, the soil and crop are considered uniform in different locations of the farm and the fertilizers are applied according to the average of soil needs with an additional percentage for safety (Loghavi, 2003). Non-essential chemical fertilizers in the field have harmful effects and social, economic and environmental concerns will increase. Many fertilizers go into the surface waters and ground waters and cause poisoning and environmental pollution without being absorbed by the plants. In variable rate technology, the soil fertilizer needs a map of all parts of the farm which is prepared with the GIS system. This map is uploaded on the computer before variable rate fertilizer machine starts. The computer continually controls the fertilizing rate for each part of the farm using a fertilizing map and global positioning system. The purpose of this study is to construct and evaluate a map-based variable rate fertilizer system that can be installed on a common fertilizer in Iran to be used as a variable rate system.Materials and methods: In common variable rate fertilizers, the rotational speed change of the distributor shaft is used to apply fertilizers. In this way, a DC motor is assembled on the main shaft of all distributors, which reduces the fertilizing accuracy. The reason for this is that there is no separation for units along the width of the fertilizer. Therefore, we used one DC motor for each distributor and another motor to rotate the agitator in the tank.System Set up: To design and select a suitable engine, the required torque for the rotation distributor shaft was measured by a torque meter and the amount of 2.1 Nm was acquired for that. With regard to the maximum rate of nitrogen fertilizer for land and tractor speed at the time of fertilizing, the order of 350 kg per hectare and 8 km per hour, the maximum distributor shaft speed and power required to rotate distributor shaft were calculated to be 55 rpm and 6.9 watts, respectively. The selected motor was rated 27.5 watts, 24 volts and 7.5 amperes (Since there were no 6.9 watts motors in the market, a more powerful motor was selected). According to the gear ratio and motor speed, the speed of the distributor shaft was adjustable in the range of 0 to 65 rpm. To determine the speed and position with respect to the direction, a central encoder (E50S8-600-6-L-5 model manufactured by Autonix Korea) was used on the ground wheel. The encoder had 600 pulses per revolution of the axis.Performance evaluation of the system: Performance evaluation of the system consists of two parts; static and moving tests. In static tests, the purpose was the determination of the fertilizer loss (in grams), due to changes in distributor speed as well as the accuracy of the electromechanical control system according to the command values sent to the device. Results of this part were used for the calibration of the device.In motion tests: In motion tests, the assessment of fertilizer loss was due to values set in a given situation and the accuracy of planted fertilizer in place (delay and acceleration) is reviewed. The delay is found by the determination of the distance that the fertilizer was placed after the desired location on the ground and the acceleration is found by the determination of the distance that the fertilizer is placed before the desired location on the ground.Results and discussion: The distributor flow rate on F0 valve position was measured for different rotation speeds. The correlation (linear regression) between the planted fertilizer and rotation speed of distributor shaft (rpm) were 0.99 for y=71.636x+75.182. So, it can be deduced that these two parameters have a good linear correlation. The results achieved from diagrams and regression model were used in the programming of the system control unit. Thus, by reading the distributors motor speed, the amount of fertilizer can be calculated and the amount of used fertilizer according to the need of the farm in each part is controlled. The effect of plot length on the amount of fertilizing on 25% need level was not significant, but it was significant on 50% need level. This is due to stopping and starting fertilizer flow during the test, changes in motors speed and error of these on fertilizer output at a certain amount of fertilizing so that at the 25% need level, the error resulting from these factors had less share on the amount of plant fertilizer and the effect of plot length was not significant according to the system default. On the other hand, the effect of forward speed was significant on the 50% need level and insignificant on the 25% need level.Conclusions: In order to calculate the accuracy of the system, the error from the application amount of fertilizer was measured at different fertilizing rates. The correlation between the adjusted fertilizing rate and the measured fertilizing rate was 0.98 with regression model of y=1.0475x which shows the good accuracy of the system.
Design and Construction
S. Khalili; B. Mohammadi Alasti; M. Abbasgholipour
Abstract
Introduction: Grading agricultural products always has a particular important position for submission to domestic and overseas markets. The grading causes more profitable product ranges and customer satisfaction. Grading treatment is carried out based on various parameters such as color, ripeness level, ...
Read More
Introduction: Grading agricultural products always has a particular important position for submission to domestic and overseas markets. The grading causes more profitable product ranges and customer satisfaction. Grading treatment is carried out based on various parameters such as color, ripeness level, dimensions and weight. Product weight is one of the most effective parameters in grading operation. Egg weight is directly related to the smallness and coarseness of eggs. In egg grading, the largeness value is very important in marketing. This research aimed to design, fabricate and evaluate the egg weighing system based on its dielectric properties.Materials and Methods: To perform this research, the stages of work are divided into several sections including, design and construction of the hardware section, writing code for the software section to collect data, conducting nondestructive tests and data collection, analysis of obtained data using artificial intelligence, and giving the results of analysis for device calibration of the system as the software code. The large eggs as dielectric substances cause more increase in the capacity of the capacitive sensor. Furthermore, by derivation of a relation between capacity of capacitive sensor and egg weight, one can predict the weight of the sample. A prototype unit of weighing system was designed and fabricated. The designed unit was composed of a chassis, a voltage source, a sinusoidal signal generator, a voltage measurement unit, an AVR micro controller, a COM port, a capacitive sensor, and an LCD and a keyboard. Neural network technique was used for egg weight prediction. The designed net receives 16 voltage values at different frequencies as inputs and its output is the egg weight. In order to calibrate and evaluate the weighing unit, 150 fresh egg samples were provided on egg laying day from a local poultry farm. Experiments were divided into three groups. The experiments were carried out on egg-laying day, and the second and fourth day after laying.Results and Discussion: In this study, two networks were built and evaluated. In the first series, two-layer networks and in the second series, three-layer networks were developed. In the two-layer neural networks, the number of neurons in the hidden layer was changed from 2 to 10.According to the given results for two-layer networks, two layer networks with 10 neurons offer the best results (the highest R-value and minimum RMSE) and it can be chosen as the most effective two-layer network. Three-layer neural networks have been composed of two hidden layers. The number of neurons in the first hidden layer was 10 and in the second layer it was changed from 1 to 20. Between three-layer networks, the network with 7 neurons with the highest R-value and the lowest error is the most appropriate network. It is even more efficient than the two-layer network with 10 neurons. So, the most appropriate structure is 1-7-10-16 and it has been selected for calibration of the weighing device. To evaluate and assess the accuracy of the weighing machine, weights of 24 samples of fresh eggs were predicted and compared with the actual values obtained using a digital scale with the accuracy of 0.01 gr. The paired t-test has been used to compare the measured and predicted values and the Bland-Altman method has been used for charting the accordance between the measured and predicted values. Based on the findings, the difference between the measured and predicted values was observed up to 5.4 gr that is related to a very large sample. The mean absolute error is equal to 2.21 gr and the mean absolute percentage error is equal to 3.75 %. According to the findings, 95% of the actual and approximate matching range to compare the two weighing methods is between -5.3 gr and 3.36 gr. Thus, the dielectric technique may underestimate the egg weight up to 5.3 gr or it may overestimate it up to 3.36 gr more than the actual prediction.Conclusions: The best results were obtained with a 3 layers net having 10 and 7 neurons, respectively in the first and the second hidden layers with the highest R-value, 0.983 and the lowest error, 0.502. Therefore, this net was applied for egg weight prediction. To evaluate the device, the weights of 24 fresh eggs were estimated using the device and were compared with actual values and the maximum error was observed to be equal to 5.4 gr.
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 ...
Read More
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
E. Chaligar; M. H. Raoufat; S. M. R. Khadem; E. Chaligar
Abstract
In conventional cultivation of sugar beet the weeding and crust breaking are mostly performed manually. The objectives of this research were to design, fabricate and evaluate a soil crust breaker and weeding implement equipped with a detecting sensor. Each unit consisted of a distance detecting sensor ...
Read More
In conventional cultivation of sugar beet the weeding and crust breaking are mostly performed manually. The objectives of this research were to design, fabricate and evaluate a soil crust breaker and weeding implement equipped with a detecting sensor. Each unit consisted of a distance detecting sensor and a hydro-motor for driving the blades and pneumatic valves for moving the blades. The hydro-motor was activated by the sensors. To avoid damaging the plants, a command signal was sent to the pneumatic valves to move the blades up and down and pass safely. Three configurations of cutting blades were considered which could be mounted to the crust breaker. The field evaluation was conducted with two tractor forward speeds (0.4 and 1 km h-1) and four plant-to-plant spacings within rows (20, 25, 30 and 40 cm) all with three different blade shapes. For field evaluation split plot experiments arranged in a completely randomized block design with three replications. The number of plants damaged (evaluated only for four-lobe blades) and size of broken crusts (evaluated for all blade shapes) for various treatments were recorded and compared. The results of analysis indicated that the higher the inter-row spacing the lower the injury to the plant. The highest and the least damage to the plants occurred for within-row plant spacings of 20 and 40 cm, respectively. The forward speed was also significantly affected the percent of plant damaged. The forward speed of 1 km h-1 at 20 cm spacing had the most (59%) and the speed of 0.40 km h-1 at 40 cm spacing had the least effect (3.3%) on the percent of plant damage. The two-lobe blade could result in the maximum surface area broken.
Design and Construction
E. Movahedi; M. Rezvani; A. Hemmat
Abstract
For planting fine seeds in cellular trays, an automatic pneumatic seeder was designed, constructed and evaluated. CATIA software was used to design and analysis the system parts of the seeder. Different parts of the seeder, including vibrating seed hopper, vacuum boom, seed picking nozzles, seed tube, ...
Read More
For planting fine seeds in cellular trays, an automatic pneumatic seeder was designed, constructed and evaluated. CATIA software was used to design and analysis the system parts of the seeder. Different parts of the seeder, including vibrating seed hopper, vacuum boom, seed picking nozzles, seed tube, pneumatic system and electronic control unit for automation of the seeder, were designed and constructed. The area of nozzle orifice was used to calculate the required pressure of nozzle tip. The seeder was evaluated using two sizes of trays. Experiments were performed with five replications and the error of planting the seeds in the 105 and 390-cellular trays were 1.9 and 0.46 percent, respectively. The time of planting for 105 and 390 cellular trays reduced from 20 min (for manual seeding) to 35 s and from 90 min to 160 s, respectively.
Design and Construction
A. Zeinali; A. Farzad; M. H. Aghkhani
Abstract
Torque, speed, and power as mechanical variables are associated with the functional performance of any rotating machinery. The real-time performance and the efficiency of a machine can be determined with on-line measurement of these parameters. In this investigation a rotary torque meter (transducer) ...
Read More
Torque, speed, and power as mechanical variables are associated with the functional performance of any rotating machinery. The real-time performance and the efficiency of a machine can be determined with on-line measurement of these parameters. In this investigation a rotary torque meter (transducer) was constructed from strain gauge sensors for measuring the torque of rotating shafts. The system converts the torque of rotating shaft into voltage signals, based on the principle of strain gauge resistance. The signals are then amplified and converted into digital signals. These digital signals are sent to a RF receiver circuit for displaying and storage. Results of static calibration and a series of dynamic tests confirmed a satisfactory operation of the designed apparatus in various conditions. Also, the torque measuring range, resolution and the accuracy were from 3 to 700 N m, 3 N m and 1%, respectively.
Design and Construction
M. Gol Mohammadi; Sh. Abdollahpour; A. Mahmoudi; S. H. Fattahi
Abstract
Equipment availability is necessary in the development of Agriculture mechanization. Crop thinning is one of the most important stages in row crop production which is laborious and costly. The objective of this project is design and construction of a row crop thinning machine. Four main system units ...
Read More
Equipment availability is necessary in the development of Agriculture mechanization. Crop thinning is one of the most important stages in row crop production which is laborious and costly. The objective of this project is design and construction of a row crop thinning machine. Four main system units are plant sensors, ground sensors, control and thinning platforms. In this machine the unwanted plants on the rows are randomly removed by employing a pneumatically system. A blade on a vertical arm with pendulum motion removes the plant from the rows. The machine control system consists of an arm and a blade which is activated by a double acting cylinder and equipped with a relay and a timer. The pneumatic cylinder is controlled via a solenoid valve. Laboratory tests were conducted to validate the machine performance. Some other preliminary tests also were performed for optimization of parameters such as cinematic index and cutting length of blades. The laboratory tests (totally 9 tests) were performed with a constant forward speed and three levels of plant density, using artificial plants. The data were analyzed using SPSS software. The results show that satisfactory performance of the machine is achieved when the plant density is moderate i.e. the thinning performance reduces with higher plant distance in the row. The other effective variable on machine performance is the adjustment of sensor sensitivity, which is used to distinguish between week and strong plants. In general the machine performance is sensitive to plant shape and morphology, plant distribution pattern in the field, growing stage of the plants, time of thinning and the effectiveness of previous weeding operations
Design and Construction
R. Loni; M. Loghavi
Abstract
Farmers are now more interested in application of weed control methods and tools with less environmental side effects. Flame weeding using propane gas is an approach with almost no any chemical residue on the soil and plant surfaces or underground water. In this research, a flame weeding machine with ...
Read More
Farmers are now more interested in application of weed control methods and tools with less environmental side effects. Flame weeding using propane gas is an approach with almost no any chemical residue on the soil and plant surfaces or underground water. In this research, a flame weeding machine with the ability of uniform and also discrete flaming was developed and evaluated in laboratory and field scales. In this apparatus, machine vision technology successfully discriminates between soil and weeds (plants grown in between the corn rows are considered as weeds) under natural illumination. In the laboratory tests, the effect of three forward speeds (0.5, 0.7 and 0.9 m s-1) on flam leading or lagging was investigated. The feasibility of using this technology for site-specific weed control of a corn field in comparison with conventional continuous flaming was investigated. The field trials were conducted with both continuous and discrete flaming approaches. The system performance and weed response to flaming treatments were evaluated by measuring the fuel consumption, counting the number of and weighting the survived and dead weeds one and three days after each flaming treatment. The results of laboratory tests showed that the effect of forward speed on system accuracy was significant and the system performance was more accurate at forward speeds of 0.5 and 0.7 m s-1 than 0.9 m s-1. According to the field experiments, continuous and discrete flaming methods exhibited similar results in eradication of weeds (both number and weight-based), while the fuel consumption of the discrete flaming was lower than the continuous one. The results also showed that discrete flaming by employing machine vision technology could be an efficient substitute for continuous flaming due to its lower fuel consumption and potential reduction of air pollution as well as other benefits of flame weeding.
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 ...
Read More
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.
Design and Construction
R. Meamar Dastjerdi; S. Minaei; M. H. Khoshtaghaza
Abstract
Non-destructive ultrasonic testing is one of the methods utilized to evaluate quality of agricultural produce. Transducers used in this method are made for basically industrial applications. Since ultrasonic attenuation of waves in agricultural produce is very high, industrial transducers cannot be used ...
Read More
Non-destructive ultrasonic testing is one of the methods utilized to evaluate quality of agricultural produce. Transducers used in this method are made for basically industrial applications. Since ultrasonic attenuation of waves in agricultural produce is very high, industrial transducers cannot be used in agriculture and needs to be modified. This is done with horns that concentrate energy on a small area at a certain distance from the transducer. In this paper, an exponential horn was designed, fabricated and tested using theoretical and computer-aided methods. Results showed that highly sophisticated horns can be designed using computer-aided method with a high accuracy. Analysis of the number of elements on the natural frequency of horn proved that the analysis was not precise at the low number of elements. Therefore, the number of elements should be increased when natural frequency of horn is almost fixed. The minimum number of elements was obtained to be 300. A comparison between theoretical and computer-aided methods showed a desirable performance of the computer-aided method with an error less than 1% without solving very complicated equations. Based on statistical analysis of the data, the effect of produce thickness (potato and carrot) on the velocity of ultrasonic waves in the horned probe was not significant. However, for the un-horned probe, velocity changed significantly with the sample thickness which is not desirable. Therefore, horned probe is more suitable for non-destructive ultrasonic tests than the un-horned probe.
Design and Construction
M. Khosravi; M. H. Abbaspour-Fard; M. H. Aghkhani
Abstract
The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has ...
Read More
The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has been designed. Furthermore, it has been assessed after construction. To measure actual and theoretical ground speed, four rotary encoders for sensing the rotation of front and rear wheels have been utilized. Slip and ground speed were measured by means of software which has been developed in an ATmega16PU microprocessor. The measured slip and speed are digitally displayed on tractor dashboard. To evaluate the performance of the system, the measured values of ground speed and slip were compared with their calculated values obtained from conventional method. The Micro-controller has been programmed in such a way that the effect of front wheel sliding on slip is eliminated. In all evaluation conditions (in field and on asphalt), the maximum difference between system measurements for slip and speed and calculated slip and speed via conventional method was 2.4% and 0.2 km h-1, respectively. With slight alteration this system can be fitted on any kind of exiting two wheel drive tractors in the country.
Design and Construction
M. Askari; M. H. Komarizade; N. Nobakht
Abstract
For measuring the draft forces exerted by implements into tractor, we use the dynamometers that are divided into pull type or three-point hitch type. For measuring the forces between the tractor and the mounted implements, three-point hitch dynamometers are used. In this research, an adjustable three-point ...
Read More
For measuring the draft forces exerted by implements into tractor, we use the dynamometers that are divided into pull type or three-point hitch type. For measuring the forces between the tractor and the mounted implements, three-point hitch dynamometers are used. In this research, an adjustable three-point hitch dynamometer with a draft capacity of 25 kN was designed and built which is made up from two frames that one of them placed inside the other. The force sensing elements were comprised of a loadcell that was installed between the frames. All mounted tillage implements were able to be tested by this measuring device excluding mounted implements which are powered by PTO and by using this dynamometer, the variations of implements draft force in the different tillage conditions consist of the various work depths and different forward speeds would be studied. After design and construction steps, dynamometer was calibrated, tested and evaluated. Field tests were done by using of four mounted tillage implements and obtained data were compared by obtained data from ASAE D497.5 standard formula. So with these data, the design of tines, their stems, equipment frames and the selection of the optimal size of the tillage equipments in regard of the soil type of the region and the power of the available tractors will be more scientific and reasonable.
Design and Construction
J. Baradaran Motie; M. H. Aghkhani; M. H. Abbaspour-Fard; A. Lakziyan
Abstract
The issue of soil salinity is one of the snags for increasing agricultural productivity, which must be inhibited by appropriate devise and scientific management. One way to identify salty areas of farm lands is to prepare salinity maps. In this study, a prototype soil apparent electrical conductivity ...
Read More
The issue of soil salinity is one of the snags for increasing agricultural productivity, which must be inhibited by appropriate devise and scientific management. One way to identify salty areas of farm lands is to prepare salinity maps. In this study, a prototype soil apparent electrical conductivity measuring and mapping device, was designed and built. This device employs direct contact method of electrodes with soil (Also called Wenner method). The system inputs include power supply voltage, location signal from a GPS receiver and signal of voltage between the electrodes. The outputs include the apparent electrical conductivity with respective to geographical coordinate that created in a TEXT file, and then transmitted through a RS-232 serial port to a PC. Electrical conductivity data calibrated and mapped using ESAP-95 software package. To evaluate the device, electrical conductivity map of a land with area of 0.8 Ha surveyed in two ways: using the on the go EC mapper and capturing soil samples manually. The results of these two methods were then compared. Assessment of the device in a clay-loamy soil with low salt level, showed a good correlation with the laboratory EC, having mean error (ME) of -15.27μS.cm-1. Point to point comparison between surveyed data and laboratory EC’s shown that in 67 percent of measurements the errors were under 10 percent. These errors are acceptable mainly due to unknown soil variables and in comparison with other research findings.
