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Zhu L.,Nanjing Institute of Agricultural Mechanization | Li D.,Nanjing University of Science and Technology | Wu C.,Nanjing Institute of Agricultural Mechanization | Wu S.,Nanjing University of Science and Technology | Yuan Y.,Nanjing Sanai Industrial Co.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2017

At present, belt weigher has been widely used in various transportation and trade occasions of industry and agriculture. Belt deviation is one of the most important indicators of accuracy of belt weigher, and it is also one of the most common faults. In this paper, aiming at the problem of belt deviation, we obtained the real-time online detection of deviation by the data mining based on the existing original sensor data of belt weigher, instead of traditional hardware testing equipment in which CCD, PSD and array phototransistor are usually used as the specialized sensor for detecting deviation. At first, in order to reduce the dimension of existing original data and the complexity of the subsequent detection mode of belt deviation, the online features extraction models of belt deviation based on LTSA (Local Tangent Space Alignment) + GRNN (Generalized Regression Neural Networks), and CDBN(Continuous Deep Belief Networks) were proposed respectively, through introducing manifold learning and deep learning. GRNN was applied to construct the explicit nonlinear mapping from the original data of high dimension to the features of belt deviation extracted by LTSA. CDBN was proposed by introducing CRBM (Continuous Restricted Boltzmann Machine) and combining with the "dropout". Unlike LTSA, CDBN can be used to construct the explicit nonlinear mapping while extracting the deviation features from the original data, which needed more training time. Subsequently, the feature extraction experiments of belt deviation at different flow rates showed that the models based on LTSA+GRNN, and CDBN both had very good feature detection effect which meant that the two features extraction models could effectively reduce the redundancy of the original data while retaining enough features of belt deviation. And the experiments also revealed that, in case of belt deviation, the bigger the flow rate was, the greater the amount of belt deviation was, and vice versa. Further, SVM (Support Vector Machine), ELM (Extreme Learning Machine) and other regression analysis methods were used to build the online prediction models of belt deviation where the deviation features extracted by LTSA+GRNN and CDBN were taken as the input. Finally, the performances of two proposed online detection models of belt deviation based on LTSA+GRNN+ELM and CDBN+ELM respectively were verified through the experiments: the average prediction accuracy of deviation prediction model based on LTSA+GRNN+ELM was 93.33%, while its average prediction time of each group was 38.29 ms and its average training time was 18.91 s; the average prediction accuracy of deviation prediction model based on CDBN was as high as 98.61%, while its average prediction time of each group was as short as 1.47 ms and its average training time was 139.96 s. Besides, the experiments also showed that ELM was more suitable than SVM for the belt deviation, because ELM had almost the same prediction accuracy as SVM while the training and prediction time of ELM was far less than that of SVM. Both the prediction and real-time of the two models mentioned above showed that the two models could be a new approach for online detection of belt deviation and replaced traditional hardware detection device. Moreover, this study provided the necessary basis for the further online precision compensation and fault prediction of belt weigher. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.


Zhang M.,Nanjing University of Science and Technology | Zhang M.,Nanjing Institute of Agricultural Mechanization | Zhou C.,Nanjing University of Science and Technology | Wu C.,Nanjing Institute of Agricultural Mechanization | Zhang W.,Nanjing Institute of Agricultural Mechanization
International Journal of Simulation: Systems, Science and Technology | Year: 2016

The distribution of transmission ratio of a non-circular planetary-gear-train system is a very difficult problem in reverse design, involving structural parameters and non-circular gears parameters of transplanting mechanism based on a given trajectory. In this study, a turn-angle relation and transmission ratio between sun gear and planet gear are solved by using difference method and Newton-Simpson calculation method. A transmission ratio equation which only includes a radius vector of a sun gear is built by assuming the pitch curve of the sun gear and the planet gear are identical but have180° difference at the initial meshing position, and iteration calculation method to solve the transmission ratio is built by importing a correction factor. For a given trajectory of the hoe-shape, the transmission ratios of each pair of gears are solved under two different conditions: two groups of different parameters of a transplanting mechanism are obtained, and also the homologous virtual prototype models are built by using ADAMS software. The simulation analytical results indicate that the gear-train system can be designed by the proposed method to make its hoe-shape trace a given trajectory, and also proved that this method is valid and accurate. © 2016, UK Simulation Society. All rights reserved.


Yang F.,Nanjing Institute of Agricultural Mechanization | Ma D.,Nanjing University of Science and Technology | Xue X.,Nanjing Institute of Agricultural Mechanization | Cui L.,Nanjing Institute of Agricultural Mechanization
Baozha Yu Chongji/Explosion and Shock Waves | Year: 2016

In this work, by adopting dynamic mesh technology along with the spring based smoothing method and the laying based zone moving method, we have numerically solved the axisymmetric N-S equations, analyzed the flow field mechanism and thermal shock characteristics, identified the thermal environment evaluating and influencing factors that are essential for dealing with problems in decision making of the new land-based concentric canister launcher (CCL) under the high-speed thermal shock load condition, and determined the evaluation index of the thermal environment. The mathematic model was established by optimal Latin hypercube design and radial basis function neural network (RBFNN), thus greatly facilitating the automatic modeling and compensating for the large amount of calculation for CFD. The intelligent decision research of the influencing factors for the missile thermal environment was performed using the RBFNN training method. The numerical results show that the thermal environment of the internal canister and the external cylinder are improved by the cryogenic gas coming from the cylinder port; the approximate model is accurate enough to meet the engineering standards required; the influencing factors for the missile thermal environment load are, according to their ranking from high to low, are the following: The diameter of the cylinder bottom baffle plate, the length of the cylinder bottom baffle plate, the height of the deflector. The research of the influencing factors will lay a solid foundation for the multidisciplinary optimization of the thermal environment. © 2016, Explosion and Shock Waves. All right reserved.


Liang S.,Nanjing Institute of Agricultural Mechanization | Jin C.,Nanjing Institute of Agricultural Mechanization | Zhang F.,Xingguang Agricultural Ltd by Share Ltd | Kang D.,Nanjing Institute of Agricultural Mechanization | Hu M.,Nanjing Institute of Agricultural Mechanization
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

4LZG-3.0 millet combine harvester is developed to cope with the inadequacy in mechanized harvesting in millet. The major design is given in details. The header, conveyer, threshing system and cleaning system are designed, and their key parameters are calculated. The header dedicated for millet has a length of 580 mm. The crop dividers have their top points more than 1300 mm above the ground, and foremost point over 700 mm from the knife bar. Inner and outer divider bars are added to the left crop divider, which are located at a distance of 100-120 mm from the side of the crop divider. The height of the center of the reel is over 1100 mm, and has an adjustable region of 500-600 mm. The rotary speed of the reel is 30-34 r/min. The diameter of the feeder auger is 330 mm and the rotary speed 170 r/min. The original problems of crop stacking on the side of the header, ear dropping off and crop clinging to the reel are thus solved, and the header loss is significantly reduced. The threshing system has the structure of double transverse axial flow with D-type rasp bar. The entry clearance is 15-20 mm and the exit clearance is 2-4 mm. The concave is a grating one. The front conclave has a bar distance of 9 mm and the rear one 12 mm. The rotor speed is 850-970 r/min. By modifying the parameters mentioned above, the carry-on loss is reduced compared to other millet threshing systems while maintaining the grain breaking during the threshing procedure at a low level. Centrifugal fan with 3 kinds of available speeds and double-wire sieve is used in the cleaning system. The pore of the upper sieve is 14 mm × 14 mm and that of the lower sieve is 6 mm × 6 mm. The newly designed cleaning system has a drop in cleaning loss. A broken spike recycling device is developed to recollect capes and heavier broken stalk from the residual. This recycling device can be added to the machine as an attachment when required, as in some regions such materials are demanded as forage. Major parameters of the millet harvester are as follows. The engine power is 55 kW, the cutting width 2.0 m, the capacity ≥3.0 kg/s, the productivity 0.23-0.45 hm2/h, the rubber track 400 × 90 × 48 (mm × mm × segment), and the wheelbase 1080 mm. The field experiment and performance test results show that this harvesting machine has achieved a stable performance. The main indices tested in the standard working condition are as follows. The feeding amount is 3.30 kg/s, the total loss rate 6.89%, the impurity rate 1.8%, the broken rate 1.4%, the productivity 0.4 hm2/h, and the equipment reliability coefficient 95%. Each of the indices has reached or exceeded the designed technical specification. It is concluded that the millet combine harvester is suitable for harvesting small-grain crops like millet, with superiorities such as large capacity, low header and threshing loss rate and little impurity for the grain. It can save operation time by over 90% while reducing labor intensity, promoting efficiency and cutting cost compared to manual harvesting. This study has provided a reference for millet mechanical harvesting. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.


Zhang M.,Nanjing Institute of Agricultural Mechanization | Jin C.,Nanjing Institute of Agricultural Mechanization | Liang S.,Nanjing Institute of Agricultural Mechanization | Tang Q.,Nanjing Institute of Agricultural Mechanization | Wu C.,Nanjing Institute of Agricultural Mechanization
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

China is one of the major rapeseed production countries in the world, but the harvesting mechanization is still backward, and high mechanical harvest loss is a key inhibiting factor for rapeseed production. In order to reduce the harvest loss ratio, the effects of the parameters of air-screen cleaning device of rapeseed combine harvester on cleaning loss ratio and percentage of impurities in grain under the actual field harvest operating condition are needed to understand. In this paper, a Plackett-Burman test and a response surface test were designed to study the 4 parameters: vibration screen amplitude, crank revolving speed, fan revolving speed, and fan dip angle based on a two-roller and air-screen field mobile harvest testbed. The Plackett-Burman experiment results showed that the vibration screen amplitude and the crank revolving speed had significant influences on the cleaning loss ratio, and the effect of the amplitude was greater than that of the crank revolving speed, but the fan revolving speed and the fan dip angle had not significant impact; the results also showed that the fan revolving speed had significant influences on the percentage of impurities, while the other 3 parameters had not significant impact. The response surface regression variance analysis showed that the effects of the 4 parameters were not the linear relation but the interaction; the predicted values of quartic polynomial regression model were consistent with the measured values in the experiment, and the regression models of the cleaning loss ratio and the percentage of impurities were solved and the values of R2 were 0.9559 and 0.9660 respectively. The single factor and two-factor analysis results indicated that the vibration screen amplitude had a little impact on cleaning loss ratio near zero level, reducing the crank revolving speed could remarkably lower the cleaning loss ratio, and increasing the fan revolving speed could remarkably lower the percentage of impurities. A group of optimal parameter combinations under the constraint condition could be acquired by solving these regression equations, and a checking test was carried out by using an approximately optimal parameter combination: vibration screen amplitude of 35 mm, crank revolving speed of 392 r/min, fan revolving speed of 1 750 r/min, and fan dip angle of 29°. The cleaning loss ratio and the percentage of impurities were 0.90% and 0.45% respectively in the test, but when these parameters were applied into the regression mathematical models, the cleaning loss ratio was 0.38% and the percentage of impurities was 0.48%, and the absolute errors were 0.52% and -0.03% respectively. Compared with the field result that was based on the common parameters, the cleaning loss ratio dropped by 61% and the percentage of impurities dropped by 58%. The analysis results indicated that the relationship between the parameters of cleaning device and the cleaning loss ratio and grain percentage of impurities was correct and the precision of regression mathematical model could meet the need for optimizing the parameters of air-screen cleaning device. The results can provide theoretical basis and technical references for the parameter selection and optimization of air-screen cleaning device of rapeseed combine harvester. © 2015, Chinese Society of Agricultural Engineering. All right reserved.


Zhang S.,Nanjing Institute of Agricultural Mechanization | Xue X.,Nanjing Institute of Agricultural Mechanization | Qin W.,Nanjing Institute of Agricultural Mechanization | Sun Z.,Nanjing Institute of Agricultural Mechanization | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

In order to find out the safe buffer areas of pesticide drift during the aerial spraying by N-3 unmanned aerial vehicle (N-3 UAV), researches on pesticide drift were done, by simulations and experiments as flight speed was 3 m/s, crosswind velocities were 1 m/s, 2 m/s and 3 m/s, flight heights were 5 m, 6 m and 7 m. According to the parameters of the N-3 UAV and the aerial spraying operations, the whole equipment, atomizing surface and the entire computational domain were grid-processed first. A turbulence model by means of approximate solutions of N-S equations with appropriate boundary condition was developed and the two-phase flow of rotor wind field and pesticide-spraying was simulated. In the simulations, the equations were discretized by second-order upwind format based on the finite volume methods, the fluxes were calculated by the ROE scheme. Iterative calculations were processed using Gauss-Seidel method to analyze the droplets flow rate changes under the wind generated by the UAV's rotor until to the flow stability when the calculation converges residuals dropped more than three orders of magnitude, then liquid concentration and density of each grid were achieved, resulting droplet drift and deposition. And the model was verified by experiments. A solution of tracer (Rhodamine-B) mixed with water in a certain concentration was selected to replace the pesticide for aerial spraying, to monitor the wind velocity as well as the temperature and humidity. The N-3 UAV flight heights were changed in the experiments. The target area was a rectangle by 50 m×20 m, and the fly route was the centerline. Mylar cards with a diameter of 90 mm every 2 m downwind, 5 m along the flight direction out of the target area were sampled to collect the droplets drifted, forming a 50 m×10 m drift sample area. The drift amount at each sampling position was measured by means of a fluorescence spectrophotometer to obtain the regularities of droplets drifted by the wind. The simulations showed that the drift distance downwind (along positive Z-axis) and the maximum amount of drift position rear the UAV (along negative X-axis) were not significant with 5 m, 6 m, 7 m flight height under the same crosswind velocity, while which were relatively significant as crosswind velocity changed from 1 m/s to 3 m/s with the same flight height. The comparison results of amounts and trends of droplet drift (when flight height was 6 m, crosswind velocity was 1 m/s, 2 m/s, 3 m/s) showed that the simulated and measured curves were coincident, and the correlation determination (R2) were 0.7068, 0.8451 and 0.6859 respectively, which showed that the research had a significance for determining the buffers before aerial spraying to insure the safety. Also, the following conclusions can be drawn by the simulation and experiment results: the crosswind velocity is greater than the aerial spraying height as the droplet drift affecting factors; the droplet drift only occurs downwind of the spraying field, and as the crosswind velocity is 1-3 m, 8-10 m buffer zones should be considered downwind the spraying field for safe aerial spraying. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.


Guan C.,Jiangsu University | Guan C.,Nanjing Institute of Agricultural Mechanization | Wang S.,Jiangsu University | Hu H.,Nanjing Institute of Agricultural Mechanization | And 2 more authors.
Jiangsu Daxue Xuebao (Ziran Kexue Ban)/Journal of Jiangsu University (Natural Science Edition) | Year: 2016

To solve the problem that the existing tillage machine can't meet the ridging requirements for vegetable field, based on the tillage agronomic requirements of leaf vegetable cultivation, a bed former was designed according to the principles of double layered cutting and secondary fine soil breaking. The overall structure and the operating principle of bed former were described respectively. Two main affecting factors on working quality of forward velocity of machine and rotary speed of PTO were evaluated by the L9(32) orthogonal test. The test results show that the bed former can integrate multiple functions of deep tillage, secondary crushing, ridge forming and ridge shaping simultaneously, which meets the overall design requirements. The selected two factors have significant impact on working quality. The variance analysis results show that the suitable operation conditions are that the forward velocity of machine is 2.5 km·h-1, and the rotary speed of PTO is 1 000 r·min-1. Under the optizized conditions, ground-breaking rate and flatness of ridge surface can reach 92.58% and 2.24 cm, respectively. Compared with classical combined ridging machine, by the proposed implement, the tilling depth is increased by 2 cm with increased ground-breaking rate by 8.87%, and the flatness of ridge surface is reduced by 2.56 cm with obviously improved ridge quality. © 2016, Editorial Department of Journal of Jiangsu University. All right reserved.

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