| Precision agriculture is an inevitable trend of modern agricultural development, and has been in our country has made a more significant economic and social benefits. Variable Precision fertilization is one of the focus of research in the field of agriculture, variable rate fertilization technology is based on different spatial units of the target yield and soil physical and chemical properties as the basis for a comprehensive measure analysis, combined with nutrition expert systems, crop growth models fertilizer making, direction variable fertilization machines field grid difference fertilization, and the variable is a variable rate fertilizer and fertilization technology based carrier, while variable control system of fertilizer fertilizing machines is an important part of the realization of variable rate fertilization system is the key to achieve precise variable fertilization.Therefore, considering the basis of domestic and variable rate fertilizer and fertilizer control system on the situation and development trend, it is proposed based on the IPC-bit micro-controller at an electronically controlled hydraulic drive closed-loop control system double variable rate fertilization,taking into account the reliability of the system and signal integrity, the paper will be divided from the hardware system for the hydraulic drive system, PC-based industrial computer host system based on lower level control system and GPS / DGPS positioning system four independent parts STC micro-controller design.Based on the STC micro-controller control system utilizes lower AD conversion will host a given amount of fertilizer information into Electra-hydraulic proportional control valve and the opening of the solenoid valve control signals required, and its main tasks are: realization of fertilizer shaft speed and the degree of opening data acquisition and transmission, control of fertilizer axis Electra-hydraulic proportional control valve opening threshold control of fertilizer shaft opening of the solenoid valve opening and closing,to communicate with the serial bus-based test systems as well as PC-based industrial computer systems.Drain fat shaft speed of acquisition and control system based on PCA speed variable fertilizing machine is mainly used for measuring the traveling speed, the use of PCA to capture the pulse of high speed and high reliability, real-time speed of the tractor through the serial bus based distributed IPC PC host system for real-time closed-loop control of fertilization.GPS /DGPS positioning system for the main research focuses on acquiring location information of the current equipment by GPS / DGPS positioning module, use the serial port to send location data to higher-level master control system, so that higher-level control system to obtain information about the location of the next prescription fertilization from the database.In order to make the decision-making system has been accurately fertilization fertilizer, paperestablishes a function of the amount of fertilizer and manure discharge opening of the shaft speed, the establishment of fertilizer outside sheaves Q displacement per revolution of the mathematical model, the hydraulic drive motor speed and to the mathematical model and variable rate fertilizer given signal Q = F(L, N, V) mathematical model, and primary and secondary factors come Fertilizer row fertilizer impact.Finally, in order to verify the performance of the bi-variate comprehensive article is designed fertilization control system of fertilizer trials conducted under dynamic test conditions. Experimental results show that the development of variable rate fertilizer reliable, easy to operate, with high control accuracy, to meet the system design requirement. This paper developed bi-variate fertilizing machine has been the acceptance by the Expert Group. |
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