Mohammad Loghavi

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...

Precision Agriculture is continuously trying to address the sources and factors affecting the in-field variability and taking appropriate managerial decisions. One of the popular research focuses in the recent three decades has been on the development of new approaches to making yield variability maps. Advancement in development of sensors and the importance of quality factor in high value crops has motivated scientists to investigate real-time and nondestructive testing methods. This study tried to introduce and evaluate a new approach to concurrent yield mapping and to estimate some nutritional qualitative factors of alfalfa production. In this study, yield quantity was determined by measurement of added hay slice in every hay compression cycle by employing a new star wheel and integrating its output with positioning data from Global Positioning System. To predict some nutritional quality properties, measurement of specific shear energy applied on the cutting blade and compressive...

Amygdales Scoparia, a species of wild almond native to the Middle East and South Asia is grown in calcic-rocky mountains of Iran. The conventional method of harvesting this fruit is by hand. For mechanized harvesting, a portable and light weight pneumatic branch-shaker system was designed and fabricated. For determining the effect of amplitude and frequency of vibration on fruit detachment rate an experiment was conducted in Kherameh region which is located in Fars province. The flow of pressurized air and electrical current necessary for operating the system are provided by a set of electric generator and an air compressor on a portable palette. For controlling the frequency of vibration and changing the amplitude of oscillation, the shaker was equipped with a programmable logic controller (PLC) and a pantograph system, respectively. The experiment was conducted by using a factorial design based on a completely randomized design with four replications. The effect of three levels of...

The most advanced part of precision agriculture technology is yield monitoring of grain and non-grain crops. In this study, the horizontal pressing force of baling plunger and the angular position of the plunger connecting rod were simultaneously measured by installing a load cell and a shaft encoder on the connecting rod and plunger flywheel of a small rectangular baler, respectively. The signals of these sensors were processed in an electronic board and the output data were recorded on a portable computer for monitoring and further analysis. Before baling the harvested alfalfa from the test field, random samples were collected and weighted to obtain a referenced measure of the yield variation along the entire field. Comparing the yield data with the pressing energy and angular position data indicated a good correlation between the throughput rate of the baler and the horizontal force imparted on the baler plunger. The estimated crop yield variations were geo-referenced by using a ...

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 ...

In this study an innovatively designed tractor-mounted, ground-wheel driven, triple unit, row crop precision planter capable of planting three rows of garlic (Allium sativum L.) cloves on each raised bed was designed, fabricated and tested. The major components of this planter include; chassis and transport wheels, lister-bedder unit, seed hopper, seed metering drum, sweeper, knocker, seed tube, furrow openers and seed coverers. The metering drums and sweepers are driven by two ground wheels through a chain drive system. Laboratory evaluation of the planter components, especially the seed metering mechanism revealed a satisfactory performance of the planter components, except a few modifications which were needed before conducting field tests. The performance parameters measured/calculated during the field tests included: seeding mass rate, seeding depth, seed spacing, miss index, multiple index and seed damage. The results showed that the new machine is capable of planting 220,000 ...

This paper communicates the prediction of required draft force of disk plow implement during tillage operations. The well-known mathematical model proposed by American Society of Agricultural and Biological Engineers (ASABE), multiple linear regression (MLR) and data mining model, based on artificial neural network (ANN), were employed for this purpose. The input variables of the models were considered as forward speed of 2-6 (km/h) and plowing depth of 10-30 (cm). The development details of the models are documented in the paper. On account of statistical performance criteria, the best ANN model with coefficient of determination of 0.971, root mean square error of 0.762 (kN), mean absolute percentage error of 1.886 (%) and mean value of absolute prediction residual errors of 0.968 (kN) was better performed than ASABE and MLR models for prediction of required draft force. The ANN modeling results also showed that the simultaneous or individual increment of forward speed and plowing ...

Scientific efforts for determination of instantaneous crop yield in recent decades have been mostly focused on cereal crops. Similar but more recent investigations have been initiated in order to prepare yield maps for silage crops due to its importance as a major feed stock. The main goal of this investigation was field evaluation and comparison of two newly developed silage corn yield monitoring sensors. The first sensor was based on using the momentum of chopped material impacting a pivoted plate installed at the chopper discharge spout and the other sensor was based on measuring the torque transmitted by the tractor PTO shaft driving the silage corn chopper. To accomplish this goal, a pivoted plate sensor equipped with a computer based data acquisition and processing system and a strain gauge type torque meter equipped with memory card data logger were designed and constructed. Results of calibration tests of the two sensors at specific mass flow rates of 6, 8 and 10 kg/s showed...

In this study an innovatively designed tractor-mounted, ground-wheel driven, triple unit, row crop precision planter capable of planting three rows of garlic (Allium sativum L.) cloves on each raised bed was designed, fabricated and tested. The major components of this planter include; chassis and transport wheels, lister-bedder unit, seed hopper, seed metering drum, sweeper, knocker, seed tube, furrow openers and seed coverers. The metering drums and sweepers are driven by two ground wheels through a chain drive system. Laboratory evaluation of the planter components, especially the seed metering mechanism revealed a satisfactory performance of the planter components, except a few modifications which were needed before conducting field tests. The performance parameters measured/calculated during the field tests included: seeding mass rate, seeding depth, seed spacing, miss index, multiple index and seed damage. The results showed that the new machine is capable of planting 220,000 ...

Yield monitors come with various technical designs and features. There is a growing need and interest for research-based information about the accuracy and performance of different brands of yield monitoring systems under varying crop yield and different field conditions such as varying terrain. Therefore, at the first step, a laboratory test stand facility was designed and developed. It is able to provide a wide range of grain mass flow rates and to simulate the hillside conditions. The system consisted of a supply and a receiving (reference) bin that is supported by three 5000-N load cells. A handling system (auger-elevator combination) is used to transfer grain between supply and receiving bins. The effects of grain flow rate and elevator tilt angle simulating pitch and roll on power consumption of the grain elevator was studied. The results showed that any increase in grain flow rate and elevator tilt angle in all positions, caused a significant and proportional increase (R 2 =0...

Iran produced 88,000 tonnes of dried figs in 2006 which ranked 4 th in the world. However, much of the production is downgraded due to traditional methods of harvesting and drying in which producers let the figs dry on trees until they fall down on the ground. This method of harvesting is laborious, time consuming, and somehow unhygienic. Using shakers would be a good option for mechanized fig harvesting, but with this method, harvested figs have different moisture contents. To dry the figs appropriately, a suitable sorter should be designed to sort the harvested figs based on their moisture content. The main objective of the study is to design and fabricate a moisture- based fig sorter. Based on some preliminary experiments on physical properties of fig which are affected by moisture content, the coefficient of friction and rolling resistance were introduced as the key characteristics in fig sorting. Considering the mentioned characteristics, a test rig was fabricated. The rig cons...

The aroma of honey is one of the important parameters in honey grading and that is depended on several factors, such as geographical origin, climate, botanical and environmental conditions. The aim of this study was the development and evaluation of an electronic nose as a new, fast and nondestructive method for detecting adulteration in honey. In this research, the ability of electronic nose as a non-destructive system for detecting honey adulteration with different percentages (pure, 20% syrup, 40% syrup, 60% syrup and 80% syrup) was investigated. The developed electronic nose consists of 8 metal oxide semiconductor sensors (MOS) to detect adultery in honey. After preprocessing the data obtained from the electronic nose the chemometric methods were utilized to classify different type of honey. Principle component analysis (PCA), hierarchical cluster analysis (HCA), linear discriminate analysis (LDA), were used to analyze the data obtained from electronic nose. Based on the results...

Abstract Required draft force of chisel plow implement during tillage operations was comprehensively apprised. Field experiments were carried out at three levels of plowing depth (PD) (10, 20 and 30 (cm)) and three levels of forward speed (FS) (2, 4 and 6 (km/h)) in a clay loam soil. An intelligent model based on soft computing technique, adaptive neuro-fuzzy inference system (ANFIS), was used to integrally predict draft force. The FS and PD were chosen as input variables and the draft force was considered as output parameter in the first order Takagi-Sugeno-Kang type of ANFIS model. A comparison was also performed between results of the best developed ANFIS model and those of the well-known mathematical model suggested by American Society of Agricultural and Biological Engineers (ASABE). To select the best model with the highest predictive ability, some statistical performance criteria (SPC) (coefficient of determination (R 2 ), root mean square error (RMSE), mean relative deviation modulus (MRDM), mean of absolute values of prediction residual errors (MAVPRE) and prediction error mean (PEM)) were used. The results demonstrated that the best ANFIS model with acceptable SPC values of R 2  = 0.994, RMSE = 0.722 (kN), MRDM = 3.172%, MAVPRE = 0.561 (kN) and PEM = −0.071% was more accurate than the ASABE model. The ANFIS modeling results also showed that the simultaneous or individual increment of FS and PD resulted in nonlinear increment of draft force. Additionally, the interaction of FS and PD on draft force was congruent. Application of physical perception obtained from developed ANFIS model results led to exposition of a new scientific window towards deep root understanding of draft force behavior. Thus, it is practically proposed to employ the ANFIS model for proper selection of tractor type for pulling chisel plow implement in the most efficient manner.

Abstract To optimize power and energy resources in field operations, there is an inevitable demand for attempts to be conducted regarding determination of performance parameters of tractor-implement. Computer simulation is a potential assistive tool for researchers concerned in this realm. This is the first investigation covering comparative ability of computer simulation frameworks, based on artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS), for neural prognostication of tractor tractive efficiency during tillage operations. In tillage operations, forward speed (2-6 km/h), plowing depth (10–30 cm), and tractor mode (two-wheel drive (2WD) and four-wheel drive (4WD)) were considered as main treatments affecting tractor tractive efficiency. Among several computer simulation frameworks developed in the investigation, the best ANFIS framework yielded coefficient of determination, root mean square error, mean absolute percentage error, and mean of absolute values of simulation residual errors of 0.987, 1.857%, 2.314% and 1.582%, respectively. On the account of obtained statistical parameters, the best ANFIS computer simulation framework was validated as the more distinguished framework than that of the ANN. The ANFIS simulation results revealed that increment of plowing depth and forward speed caused nonlinear decrement of tractor tractive efficiency in each tractor mode. Moreover, physical perception obtained from the integrated ANFIS simulation results indicated that application of the 4WD mode rather than the 2WD mode increased tractor tractive efficiency. Therefore, it can be asserted that the ANFIS simulation results improved state of the art in domain of studying tractor tractive efficiency.

The aim of this study was to determine the most suitable shaking frequency and amplitude for shake harvesting of lime fruit. A tractor mounted limb shaker receiving its rotating power from the tractor power-take-off shaft was designed and developed for this study. The rotating input power was transmitted to the shaker flywheel through a multiple sheave v-belt drive system, where it was converted to reciprocating motion by a slider-crank mechanism. The resulting vibrating motion was transmitted to tree limb through a telescoping boom and a special clamping device. In order to determine the mechanical and vibrational characteristics of lime fruits, a series of tests were conducted in which, the average pulling force required for detaching ripe and unripe fruits as well as fruit mass and geometric mean diameter were measured. A 3x3 factorial experiment with a completely randomized design with three replications was conducted to investigate the effects of shaking frequency and amplitude...