Control System Reserch Of Variable Rate Fertilization Machine

Precision agriculture is the development of agriculture direction,variable fertilization precision agriculture is the one of the key research areas.Thumb of China's traditional uniform fertilizer has seriously can not meet the requirements of China's agricultural modernization,changes in the past backward fertilization manner fertilization changes in China it is imperative.At present,China's traditional way fertilization is in a region or the use of an average block fertilization, soil fertility due to the different plots in the larger regional differences,and the other in the production of low fertility traits of good regional often inadequate fertilization,and in a high-yield and high nutrient content in bad shape regional causing excessive fertilization,and the results not only a waste of resources,more importantly,resources environmental pollution,directly endanger human health.With the traditional fertilization fertilizer waste and unreasonable,and so on,did not consider inconsistencies soil fertility. Variable fertilization have higher technical efficiency,better access to income scale,variable fertilization technology itself can bring about good economic and social ecology.Variable rate application technology from the soil and crop nutrition data real-time data collection and analysis system for decision-making, variable control variable fertilization mechanical equipment and control technology components.Variable fertilization of the main tasks of the GPS(Global Positioning System),GIS(Geographic Information System),RS(Remote Sensing),and other technical support to achieve precision positioning and operating variables,first identified by GPS location and then use various types of sensors Acquisition of crops and environmental information,real-time information to be input comes with agronomic,soil,plants,data management,and other aspects of the Airborne decision-making system,Airborne decision-making system has been treated to make decisions and transmit to the implementing agencies,to achieve by implementing agencies fertilizer input variables or operating adjustments.Variable fertilizing machine to rely on objective data for decision-making and action aimed at a different area of crops,rather than homogeneous variable input agricultural resources,to the festival to improve efficiency,and reduce environmental pollution.At the same time avoiding the judgement due to different operational capabilities and the level of the differences will reduce operator fatigue as a result of errors of judgement.Traditional fertilization on a large piece of farmland or even connect to a soil testing and fertilization,is a rough-run.In fact,the distribution of soil nutrients in the field are different,this is the objective foundation of variable rate fertilization.The traditional method of fertilization in the same field within a homogeneous fertilization,therefore,in the traditional fertilization,the people in order to guarantee a regular individual nutrients(such as P) inputs,and other nutrients cause excessive application(such as K),which is a waste of fertilizer and one of the major causes of environmental pollution. Singlechip control variable fertilization,fertilization of an average reduction of 60 kg/ha,267 RMB fertilizer input/ha.And an average 500 kg/ha,more than 1350 RMB income/ha.Proceeds from the increased production and reduced fertilizer input to consider two aspects,through variable fertilization,in the equivalent per hectare was more than 1,400 yuan of income.Corn per-mu yield 694.8 to 733.5 kg,an increase of 6.2～10.1%,fertilizer and maize save 15.5～17.6%,while the use of machinery operations to ensure that the operating season,improve quality of operations,increasing agricultural output,and can save a large number of labor,engaged in the production of other industries,such as aquaculture industry,could increase productivity by more than 20%,and increase economic efficiency of 15.8%.Avoid the nutrients in some locations excessive accumulation,it inhibited chemical fertilizers and pesticides on agricultural pollution, reduce the waste of water resources,reducing groundwater pollution.The PFA field computer is imported computer equipment so the price is more expensive and not widely used.Singlechip instead of PFA field computer can not only good reading completed,the control function and to a large extent cost savings,reduce unnecessary spending,was widely used.In this paper,a large number of inspection on the basis of relevant information,integrated in all aspects of variable fertilizer requirements,determine the variable fertilization control system of hardware components, including the ARM7 processor LPC2220 series to replace the original field of computer PFA,the core of the control system,U disk,ZLG7290 I~2C interface keyboard,240128 A-21PIN liquid crystal displays,CPLD devices,RAM,SST39LF/VF160 FLASH,and so on.Hardware with a compilation of language development, software development process used in the ARM ADS AXD development tools and debug tools,using the C programming language.The series of experiments using ARM microprocessor LPC2220,RS232,conver the TTL-level and the GPS receiver to complete the reception work,thereby positioning tasks completed by the GIS and expert decision support system in the decision-making data storage USB session,the Working USB is a set of equipment and microcontroller interface connected to the completion of the GIS system and the SCM and experts connected equipment from the forward speed radar gun was the signal for the progress of equipment into pulse signal input to the single-chip microcomputer control system,as a single-chip microcomputer control system central processing chip,GPS positioning signal receiver,access stored in the USB after fertilization expert decision-making data,and read speed sensor feedback back fertilization of road speed. These data will be integrated to control motor speed,variable fertilization to achieve.In the laboratory through two variable fertilization controller comparative experiment shows that within the error allowed to LPC2220 microprocessors at the core of the control system to replace the computer field PFA conclusions.The emergence of experimental error of a few points,including GPS delay error,GPS errors,speed error,the algorithm error,error control delay. In a word,experimental study of the control variables fertilization system,designed to use the controller as the core ARM7 intelligent automatic control of the interface technology,and supporting the use of precision seeding,and reduce the use of fertilizer,improving fertilizer use efficiency and reducing excessive fertilizers on the pollution of the environment has obvious economic,environmental and ecological benefits,has currency.Single-chip microcomputer replace the PFA field computer reduce the funds of computer input,and the costs.