INMATEH - Agricultural Engineering

4

Authors: Popa Gh., Buculei M.

In this paper are presented and analyzed the experimental test results for tractor U 650-braking system, in INMA Bucharest laboratory. We determined the torque for the drive wheels of the tractor (Mr), the hydrostatic motor shaft torque (MMh)tangential traction forces (Fm) and braking carriage thrust (Ft).

6

Authors: Dinu I, Popa C., David M.F.

In this paper is presented the press room of the MAC – 3 machine endowed with two pressing mechanisms, while also showing the advantages of the new system. Also the diagram of the two pressing mechanisms is given, while equations are established for determining the speed distribution by using the independent cycle method.

6

Authors: Vieru I., Petrache Gh., Nicolae V., Pârlac S., Neagu E.

This paper presents a first study on dynamic analysis done on a rear axle with torsion beam. The main purpose of this analysis is to establish the natural vibration modes with similar values which are likely to come into resonance. The CAD models of the parts were obtained using CATIA V5 application and the calculation was performed with FEM using MSC/NASTRAN software. The experimental determinations were performed in the vibration laboratory of the University of Pitesti.

8

Authors: Liu M., Wang H.

Agriculture survey and evaluation UAV is kind of advanced high-efficiency agriculture information equipment that can be used to farmland measurement, agricultural insurance assessments and other fields. BeiDou Navigation Satellite System is China’s global navigation satellite system which has been developed independently ， and currently it is rarely applied in agriculture survey and evaluation UAV. Since BeiDou navigation system can only provide location information, an integrated navigation system that composed by BeiDou Navigation Satellite System, Strapdown Inertial Navigation System and Air Data System is proposed to improve the navigation accuracy of UAV navigation system. Integrated navigation system model is established, and to improve the navigation system parameters solving speed, and also to overcome the filtering divergence phenomenon caused by the system model uncertainty, a modified two-step adaptive Kalman filter algorithm for navigation parameters solving is proposed. Simulation results show that the proposed integrated navigation system and parameters solving algorithm can effectively improve the UAV navigation accuracy and prevent divergence of the filter.

10

Authors: Manea I., Gîrnita I., Matache M., Muscalu A., Persu C., Voicea I.

The paper presents theoretical and experimental researches on the use of experimental modal analysis as an instrument of appreciation of fatigue state, as well as to identify the structural changes of the complex mechanical structures. The application is carried out on a railway bogie frame, performed at SC Softronic Craiova, being in course to be tested for static and fatigue stress at INMA Bucharest. Researches are in full progress, in the article being presented the results of initial tests as well as those performed after 6 millions of stress cycles at fatigue.

10

Authors: Xu L., You Z., Wu S., Zhao H., Wu L.

There is little equipment specially developed for grading kiwi fruit in both China and foreign countries. While the full automatic grading equipment often has complex mechanical structure and costs highly, it always grades kiwi fruit on the basis of singular feature such as size, weight, shape, color and surface defect such that it is hard for them to promote kiwi fruit’s market competitiveness. Therefore, this paper developed a set of practical automatic kiwi fruit grading equipment basing on technologies of mechanical separation and conveyance, image capture and processing as well as intelligent control. This set of equipment mainly consists of material storage bin, single-line positioning system, image capture system and grading executive system. And it also has programs of image capture, image processing, grade determination and human-machine interaction for the host computer as well as control programs for the slave computer. Its operating principle is that: firstly put a small amount of kiwi fruits or slowly put kiwi fruits into the storage bin and switch on, and then the host computer sends the startup command to the slave computer. Upon receiving such command, the slave computer starts grading equipment and initializes the camera. The camera will then get into the image capture state. Kiwi fruits are conveyed to the image capture system by the single-line positioning system in single row. Upon the slave computer receives the signal that kiwi-fruits are on position sent by the position sensor of the image capture system, it will immediately send such signal to the host computer. Then the host computer will store the images from the camera at this time and discard the images captured at other time. After the host computer carries out relevant operations such as image processing and grade determination to moving images, it will send grading results to the slave computer. At this time, the kiwi fruits will have been conveyed to the grading implementation area and the slave computer will control the implementation system at all levels to perform grading. Each kiwi fruit will be graded through the same grading flow. By testing, this equipment is capable of grading by three features of size, shape and surface defect and their grading accuracy can reach to 88.9%, 91% and 94% respectively. And the accuracy of integrated grading can reach to 86%. The output of this equipment can reach to 1.22kg/min which is much more than the efficiency of manual grading. With simple mechanical structure and low cost, this equipment reduces the processing cost of kiwi fruit and is suitable to vast middle and small users.

6

Authors: Stefan E.M., Voicu Gh., Constantin G., Ewemoje T.A.

In the paper are presented the theoretical and experimental researches results regarding the particle size characteristics variation of grist coming from breakage phase of wheat seeds on the milling plant technological flow of 100 t / 24h capacity, along with constructive parameters of grinding rolls. For determining the workflow parameters of grinding rolls the mathematical model is presented.

6

Authors: Yaschuk A., Kirchuk R., Dudarev I.

The results of theoretical researches of the process of aeration of bulk material in the cylindrical drying chamber of the dryer [1] are suggested in the article.

8

Authors: Stoica D., Voicu Gh., Plosceanu B., Carp-Ciocârdia C., Moise V., Kabas O.

The dynamical study of oscillatory motion in the horizontal plane of a conical sieve with vertical axis,suspended in three points, is presented in this paper. The sieve is suspended with three elastic cables, in three points, at the top and at the bottom. The differential equations of the sieve motion in polar coordinates have been determined with Lagrange’s equations. The trajectory of the sieve joint point to the acting mechanism was graphically drawn. Analyzing the trajectory of a point on the sieve, some qualitative assessments on material motion on the sieve, in separation process, can be done.

8

Authors: Wang G.

Demand prediction is a hot research field in markets management, especially for fresh agricultural products prediction based on supply chain management. Based on BP neural network, a new demand prediction algorithm for fresh agricultural products is presented in the paper. First, the structure and data indicators of BP neural network algorithm are redesigned and the training function is selected for the fresh agricultural products prediction algorithm. Second, the improvement of excitation function, (including trigonometric function and sigmoid function) and orthogonalizable design, are presented and analyzed to speed up the calculation and improve the prediction accuracy of ordinary BP algorithm. Finally, data from certain fresh agricultural product corporations are taken for example and the simulation results show that not only the problem of convergence speed has been solved, but also the prediction accuracy is ensured when the improved algorithm is used in demand prediction for fresh agricultural products .

8

Authors: Bulac I., Pandrea N.

Technological deviations determine in the intermediate couples of the cardan joint supplementary efforts due to restrained movement. This paper sets as goal the determination of dependency between the technological deviations and the size of these movements.

10

Authors: Lijia X., Chaolin L., Xianping Z., Nan J., Xinbao W.

As the present feeding devices used in the chicken farm are mostly simple and less automated, an intelligent feeding system is established in this paper by comprehensive technological means like sensor detection, data processing and remote monitoring to control the feeding quantity accurately and monitor the feed intake in real time. The system consists of upper computer, control center and mechanical hardware equipment, of which the mechanical hardware equipment is about 44.2kg. Upon testing, the system takes 15s in feeding; the accuracy of feeding quantity is 90-99%, compared with 70-85% of that of traditional machine; the feeding efficiency is 1.4-1.9 times higher than that of traditional machine. Users can set the feeding parameters based on the chicken age, type of chicken and other information through the interface of the upper computer, and monitor the epidemic situation of the chicken farm, to achieve the requirement of intelligent feeding.

6

Authors: Anghel St., Usenko M.

The paper presents theoretical research on modelling and simulation of U-650 M tractor power steering . Starting from developing of the model we realised its simulation following the evolution of main parameters in time. The results can be used to study the behaviour of power steering in operation

6

Authors: Filip Ilie

Nanoparticles have been widely used in polishing slurry such as chemical mechanical polishing (CMP) process. The movement of nanoparticles in polishing slurry and the interaction between nanoparticles and solid surface are very important to obtain an atomic smooth surface in CMP process. Nanoparticle’s behavior in the slurry with law viscosity has a great effect on the wafer surface in polishing process. Hydrodynamic pressure is periodically generated on the surface of asperity when nanoparticles are passing through the zone. Due to the periodical pressure, fatigue fracture occurs and begins from the top to the bottom of the asperity, then the material on the top is removed. Removal rate is calculated based of energy theory of balance fracture , and result shows a good agreement with experiment data. In this paper we present both experimental and theoretical studies on the movement of nanoparticles in polishing slurry and collision between nanoparticles, as well as between the nanoparticles and solid surfaces in time of process of CMP by exploring a model of microscopic friction based on the surface topography. Experimental results have proved that the nanoparticle size and slurry properties have great effects on the polishing results. The effects of the nanoparticle size and the slurry film thickness are, also discussed.

8

Authors: Dutu M.F., Maican E., Dutu I., David L., Rusănescu C.O.

This paper presents the two degrees of freedom of mathematical modelling of a tractor wheel. The tractor is a complex mechanical system that, while traveling, is subjected to vibrations that are transmitted from the running path to the driver. A modelling program was used in order to study the tractor movement on agricultural land. Useful charts were developed for: amplitude variation of the tractor’s mass center oscillation, with traveling speed; amplitude variation of the angle of rotation of the tractor around its center of mass; amplitude variation of the driven wheel with speed; driving wheel’s amplitude variation; amplitude variation of vertical force acting on driven wheel, with speed; amplitude variation of vertical force acting on driving wheel, with speed. There are also presented the study results for a tractor traveling on a country road. Interpretation of results is based on charts for amplitude variation of the tractor’s center of mass, amplitude variation of the angle of rotation of the tractor around its center of mass, amplitude variation of the driving and driven wheel when tractor is moving, amplitude variation of vertical force acting on driving and on driven wheel, with speed.

8

Authors: Constantin G.A., Voicu Gh., Stefan M.E., Paraschiv G.

In the paper it is presented the flow diagram of the wheat breakage phase in a milling plant with the capacity of 4.2 t/h, as well as the experimental results of the granulometric analysis of the grist from the plane sifter compartment of the Second Break. It is presented the particle size distribution of the grist that comes from the grinding rolls, but also the five grist fractions in which it is divided into plane sifter compartment of respective passage. Experimental data obtained for the particle size distributions of grist fractions were tested by computer regression analysis , with known distribution laws: Schuhman, Rosin-Rammler, Gauss and log-normal, determining the values for the equations coefficient and the correlation coefficient R2.

10

Authors: Moise V., Biris S.St., Kabas O., Ungureanu N., Vlădut V., Boureci Gh., Stroe I., Caba I.L.

To establish a machinery system and the optimal mechanization technologies for different types of agricultural farm and for various specific conditions it is necessary to use scientific methods of optimization. The success of a business, including agriculture, is determined by the amount of profit, which depends on the quality and quantity of the achieved product. To determine the minimum surfaces from which a certain power range of tractors becomes profitable, the income limit must be equal to the costs required to perform works in that area. In this paper is determined the optimal surfaces matrix for 20-65 HP tractors, used in family farms. For the determination of the minimum surfaces, incomes and necessary costs for the considered works must be taken into account. The optimal usage time of the tractors, the matrices of aggregates yields, as well as the matrix of equipment costs are also determined. Various methods of numerical optimization are used. After running numerical calculus and optimization programs, has been observed that, in case of family farms, the minimum surfaces from which a certain power range of tractors becomes profitable decreases if the work is performed by the farmer, with personal equipment. It has also been observed that the minimum surface required for the profit to be equal to zero at the limit, decreases with higher quality of the equipment.

10

Authors: Boja N., Boja F., Caba I., Gligoras D., Dărău P. A.

The present research displays the results obtained after the digging of holes for planting saplings in a previously unprepared soil, following the steps to carry them out according to some physical-mechanical properties of the soil. The research was carried out on a horizontal ground in the O.S. Iuliu Moldovan, in two arranged unities (parcels) 31 C and 32 A, in a previously unprepared ground, on two types of soil: gley-soil (the muddy subtype) and alluvial soil (the vertical-gleyed subtype), and in O.S. Radna, u.a. 74, on a brown typically luvic soil, using the Stihl BT 121 motto-borer with a 150 mm drill. The objectives of the research were to make a comparative determination, on different types of soil, of the qualitative parameters, among which the most important ones are: degree of loosening of the soil taken and left in the hole, resistance to penetration, resistance to shearing, timing of drilling holes, degree of scattering of the soil taken out from the hole, degree of evacuation of the soil from the hole, gas consumption for the drilling of the hole, using the Stihl BT 121 motto-borer in order to establish its technical efficiency. In order to observe the influence which the drilling of holes have on walls, we measured the resistance to penetration and resistance to shearing every 10 cm at a 30cm depth, the proper depth for planting small-sized saplings, on two opposite sides, so that we could get the most probable values of these physicalmechanical properties of the soil. After taking the measures in order to establish the compaction degree of the wall and of the bottom of the hole by the borer in that interval, it was judged that in conditions of normal humidity, if the borers have sharp knives and are well conceived and executed in technical terms speaking, there are no big values of the resistance to penetration which could affect the subsequent development of the saplings.