• Journal of Biosystems Engineering
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• v.27 no.6
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• pp.521-528
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• 2002

Rotary and plow implements are mainly utilized for the tillage operation in Korea, and a implement control system for agricultural tractors was designed and fabricated to improve the working accuracy and efficiency. The control system was composed of three units: 1) sensors fur detection of angle of liftarm, draft force, engine rpm, tillage depth and so on, 2) a controller, and 3) hydraulic circuits, which included solenoid valves and so on, for operation of three point linkage and implements. The control system can control the speed(high and low speed) of implements by adjusting input flow rates of the hydraulic cylinder which was controled by two speed valve, which was composed of a solenoid valve and a orifice. Indoor experiments were conducted to evaluate response characteristics of the designed implement control system under experimental conditions of various engine nm, two kinds of input flow rates of the cylinder and some input frequency. The results of experiments showed the response characteristics sufficient to use as the implement control system fur agricultural tractors.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.292-293
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• 2004

• Proceedings of the Korean Society of Crop Science Conference
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• 1997.10a
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• pp.94-95
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• 1997

• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.233-239
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• 2020

The aims of this paper is to develop a modular agricultural robot and its autonomous driving algorithm that can be used in field farming. Actually, it is difficult to develop a controller for autonomous agricultural robot that transforming their dynamic characteristics by installation of machine modules. So we develop for the model based control algorithm of rotary machine connected to agricultural robot. Autonomous control algorithm of agricultural robot consists of the path control, velocity control, orientation control. To verify the developed algorithm, we used to analytical techniques that have the advantage of reducing development time and risks. The model is formulated based on the multibody dynamics methods for high accuracy. Their model parameters get from the design parameter and real constructed data. Then we developed the co-simulation that is combined between the multibody dynamics model and control model using the ADAMS and Matlab simulink programs. Using the developed model, we carried out various dynamics simulation in the several rotation speed of blades.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.280-284
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• 2012

No-tillage direct seeding of rice is consumed less labor and oil energy by no plowing and rotary tillage. And it has other advantages of soil and water conservation and accumulation of organic matter on paddy surface due to crowded water foxtail (Alopecurus aequalis var. amurensis). When no-tillage seeding of rice, many water foxtail occurred in winter paddy field. In this experiment their covering degrees were 97.6% and 95.2% in clay loam and sandy loam paddy soils, respectively. Because of this, Stellaria alsine var. undulata, Cardamine flexuosa, Rorippa indica and Ixeris chinensis etc. annual and perennial wintering weeds occurrence was reduced. And annual weeds Chenopodium serotinum and Polygonum hydropiper that occurred early in spring were also reduced. As well as Echinochloa crusgalli var. praticola, Cyperus difformis, Monochoria vaginalis and Lindernia procumbens etc. summer annual weeds that occurred after irrigation were also reduced. In conclusion, no-tillage direct seeding of rice has another advantages of weed management by water foxtail.

• Journal of Drive and Control
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• v.21 no.2
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• pp.44-52
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• 2024

In this study, we predicted PTO power requirements based on torque predicted by the discrete element method and the multi-body dynamics coupling method. Six different scenarios were simulated to predict PTO power requirements in different soil conditions. The first scenario was a tillage operation on cohesionless soil, and the field was modeled using the Hertz-Mindlin contact model. In the second through sixth scenarios, tillage operations were performed on viscous soils, and the field was represented by the Hertz-Mindlin + JKR model for cohesion. To check the influence of surface energy, a parameter to reproduce cohesion, on the power requirement, a simple regression analysis was performed. The significance and appropriateness of the regression model were checked and found to be acceptable. The study findings are expected to be used in design optimization studies of agricultural machinery by predicting power requirements using the discrete element method and the multi-body dynamics coupling method and analyzing the effect of soil cohesion on the power requirement.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.322-326
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• 2013

This study was tried to control the weedy rice using minimum tillage direct seeding of rice on dry paddy. Minimum tillage direct seeding on dry paddy is tilled with 4 cm in width at 27 cm intervals by 1-shaped rotary blade. Using this cultivation method can control weedy rice effectively by minimizing the soil disturbance. In this study, weedy rice was firstly emerged at April 28 in 2012. After 11 days emergence rate of weedy rice at May 9 was 61.9%. At this time rice was sown and then herbicides was treated at 10 and 15 days after sowing. When herbicides was treated at 10 days after sowing the control effect was 89-96%, and when treated at 15 days the control effect was 97-99%. However emergence of weedy rice differ according to the year and year. It was thought to be affected by April average temperature and total precipitation. So, for effective weedy rice control and stable rice yield, it was considered that irrigation at April 15-20 to induce the emergence of weedy rice is required.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.160-175
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• 1984

This study was carried out to analyze the effects of the revolution and forwarding speed of the rotary blade and the edge curves which were $30^{\circ}$ and $40^{\circ}$, on the power requirement of rotary tillage. In this study, the revolutions of the rotary blade considered were 204, 243, 285, 360 rpm, and the forwarding speeds of the rotary system considered were 29.40cm/sec, 46.93em/sec. The power requirements of rotary blade were measured by a dynamic strain gage systems at the soil bin which was filled with artificial soil. The results of the study were summarized as follows: 1. The response surface analysis showed that the revolution and forwarding speed of the rotary shaft had an interacting influence on the torque requirement of the rotary blade. The mathematical model developed by the above was repersented as follow. $$T=a_0+a_1V+a_2R +a_3VR+a_4VR^2$$ where, $a_0=constant$ $a_1,\;a_2,\;a_3,\;a_4=coefficients$ V=forwarding speed of the rotary system. (em/sec) R=revolution of the rotary shaft. (rpm) T=tilling torque requirement. (kg-m) 2. When the maximum tilling torque requirement was analyzed, ${\partial}T/{\partial}R$ was decreased with the increasing revolution of rotary shaft, while ${\partial}T/{\partial}V$ was increased, which was minimum at 200~220 rpm. When the forwarding speeds were increased, ${\partial}T/{\partial}R$ was decreased with increasing rate. 3. When the mean tilling torque requirement was analyzed, ${\partial}T/{\partial}V$ was constant at 320~360 rpm and ${\partial}T/{\partial}R$ was decreased with increasing rate along with the increasing revolution of rotary shaft. 4. When the mean tilling torgue requirement per unit volume of soil was analyzed, ${\partial}T/{\partial}V$ was minimum at 270~300 rpm. ${\partial}T/{\partial}R$ for the forwarding speeds of 29.40cm/sec and 46.93cm/sec was same as that for 280~290 rpm. 5. Increasing the edge curves of the rotary blades, the tilling torque requirement was increased. But other studies showed that the smaller the edge curve, the more straw could be wrapped on blades which resulted in increasing torque requirements. Therefore, the edge curve of rotary blade should be considered for the future study.

• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.120-127
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• 2018

The rural labor force has gradually been decreasing due to the decrement of the farm population and the increment of the aging population. To solve these problems, it is necessary to develop and study autonomous agricultural machinery. Therefore, analyzing the dynamic behavior of vehicles in an autonomous agricultural environment is important. Until now, most studies on agricultural machinery, especially on ground vehicle dynamics, have been done by field tests. However, these field test methods are time consuming and costly with seasonal restrictions. A research method that can replace existing field test methods by using simulations is needed. In this study, we did basic research analyzing the effect of the travelling speed of a tractor on tire slip using simulation software. A tractor simulation model was developed based on field conditions following a straight path. The simulation was done for three ranges of speed: 20 - 30 km/h (considered the normal travelling speed range), 6 - 8 km/h (considered the plow tillage speed range) and 2 - 4 km/h (considered the rotary tillage speed range). The results of the simulation show that the slip ratio and slip angle values tended to increase as the traveling speed range of the tractor decreased. From the simulation results, it can be concluded that at low tractor speeds, it becomes more difficult to control the vehicle path. In future research, simulations will be done with various work environments such as a curved path as well as with various friction coefficient conditions, and the simulation results will be experimentally verified by applying them to an agricultural tractor.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.548-554
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• 2016

Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.