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Li M.,Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment | Li M.,Hunan Agricultural University | Zhang M.,Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment | Zhang M.,Hunan Agricultural University | He J.,HIGH-TECH
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

Precision breeding and a local position system (LPS) substitute GPS for field local positioning was proposed in this paper. The system mainly consisted of an omnidirectional vision sensor, artificial landmarks, PC and PC software operating vehicle. The artificial landmarks adopted a primary landmark and three subsidiary landmarks. The algorithm mainly included landmark color pixels beyond threshold which were extracted and divided as a small area based on the Euclid geometrical distance. The center of gravity of the extracted small area was calculated and represented as a position of one landmark. Omnidirectional vision sensor position was estimated according with circumferential theorem and geometric transformation formula based on the direction angles. Experiments were conducted on a level lawn under the sun in a 30 m×30 m rectangular area. Results showed that the distance RMS error between estimated position and test position was about 15 cm. The system is feasible for precision breeding such as field positioning, precision fertilizing and spaying and production mapping. Source


Tang C.,Hunan Agricultural University | Tang C.,Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment | Wang H.,Hunan Agricultural University | Li M.,Hunan Agricultural University | And 7 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

Breeding is an important process of hybrid rice production. Pollination is the key link of breeding, which effect the production and economical efficiency obviously. The status of pollination equipments and technologies at home and abroad were reviewed. There were two types of pollination techniques with collision type and slipstream type based on the working principle, the features and the shortcomings of which were summarized. The problems of pollination equipment, such as pollination nonuniformity, plant scathing, resulted into pollinating blindly and randomly. Hybrid rice production should be oriented toward mechanization and multifunction. The strategies of different kinds of pollinating scientifically and applicatively, and the methods of obtaining reasonable working parameters and avoiding interbreeding and developing applicable pollination machines were explored. Source


Wang H.,Hunan Agricultural University | Tang C.,Hunan Agricultural University | Tang C.,Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment | Li M.,Hunan Agricultural University | And 7 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

Effect of airflow speed (including natural wind) on pollens distribution for hybrid rice breeding pollination is very significant, which correlates with the yield of breeding seed closely. To study the effect of airflow speed on pollination, the basic principle of pneumatic pollination for hybrid rice breeding was analyzed. Then, tests were conducted to validate the effect of airflow speed on pollens distribution based on pollens density, horizontal distribution and vertical distribution. The results showed that pollens distribution was affected by airflow speed significantly, and pollens density, horizontal distribution and vertical distribution increased with the airflow speed increased. A distinct bimodal pattern appeared in horizontal distribution, and the second peak was far away from the pollen source with the airflow speed increased. Vertical distribution showed that pollens were close to the center of airflow with the airflow speed increased, which suggested that pollens could be spread in straight line with a certain speed and directional airflow. When the airflow speed was at 20 m/s, pollens were more in horizontal distribution, of which the vertical distribution could meet the demand of transmitting in the working area. It provides a scientific basis for further study of pollination machinery by airflow. Source


Luo H.,Hunan Agricultural University | Luo H.,Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment | Tang C.,Hunan Agricultural University | Zou D.,Hunan Agricultural University | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

In order to solve the problems of harvesting eulaliopsis binata by reciprocating cutter, the single factor test was carried out with the stem of eulaliopsis binata, which include the factors of cutting gap, cutting speed, cutting blade combination, the position and the number of stem cutting etc. Factors and levels of the orthogonal experiment were selected based on the single-factor test, then the stem maximum shear force orthogonal experiment was carried out. The results showed that the cutting gap and the cutting blade combination had greater effect on the shear force, while the cutting speed had less effect. Finally the field comparison tests were completed between the helical tooth-helical smoothing tool combination and the helical smoothing tool-helical smoothing tool traditional combination. The results showed that the helical tooth-helical smoothing tool combination increased 23% cuting rate and reduced 94% wrapping grass rate, which greatly improved the operation quality and efficiency of the eulaliopsis binata cutting.The results indicated that the helical tooth-helical smoothing tool combination for eulaliopsis binata harvest was feasible. Source


Liu D.,Hunan Agricultural University | Xie F.,Hunan Agricultural University | Xie F.,Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment | Li X.,Hunan Agricultural University | Wang X.,Hunan Agricultural University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

Lifting platform in orchard is of great importance to the fruit production, because it plays a vital role in the operation links: picking, flower thinning, etc. However, current mechanical devices are not suitable for orchard in the southern hillside area due to the complex terrain. It means low efficiency and the need for more farmers. Mechanization is the only way to change the present situation. Therefore, based on studying and analyzing the collected data of orchard in south China, a miniature self-propelled lifting platform was developed to increase the operation efficiency in orchard in the southern area. The lifting platform was mainly composed of the crawler, scissors elevating mechanism and a multi-function manned worktable. In particular, the manned worktable was designed to realize the real-time leveling through the means of azimuth adjustment, lifting and angle adjustment which were separately driven by revolving support and hydraulic cylinders. In order to maintain stability of the worktable and increase worker's comfort, the secondary leveling was crucial. In order to make the platform has the advantages of small external size, compact structure and easy to assemble, the dimensions of the mechanism and main technical parameters of key parts were optimized based on preliminary experiments. The prototype was made in a machine processing factory and driven directly by a 4.41 kW diesel engine. With the aim to evaluate the performance of the platform, tests of the prototype including climbing angle test, turning radius test, leveling performance test, and stable performance test were carried out in the simulated work environment. The experimental results indicated that the running speed of the prototype was 0.12-0.25 m/s, and the maximum lifting height was 1.2 m, and the turning radius was 0.75-1.34 m, which meet the design requirements and are suitable for the varied working environments. In addition, the simulation results revealed that the static tipping angle of the prototype was between 15°-30° when the platform was equipped with different loads and in various lifting height. Moreover, the mechanism can adjust the inclination angle of the manned worktable through the secondary leveling, which demonstrated that this mechanical platform can be used to work in difficult terrain. But because the distribution of weight is uneven and the chassis touches the ground in a small area, the stability of the whole machine is decreased. All the experiments concluded that the lifting platform met the needs of fruit production and fruit transportation. Meanwhile, with smaller outline size, it is easy to operate and suitable for orchard planting pattern and use requirements in the South. The study provides guidance for the practical production. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved. Source

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