Development Of An Intelligent Machine For Planting Fruit Trees With Self-propelled Pit Digging Mixed Fertilizer Backfill

In recent years,the accumulation of toxins,the depletion of trace elements and the increase of harmful fungus eggs caused by successive years of soil cultivation have seriously damaged the soil structure and seriously restricted the development of forest fruit industry in China.In view of the growing soil-borne diseases,complex planting process and great labor intensity in fruit tree cultivation,a self-propelled in-situ fruit tree planting machine with functions of digging,discharging fertilizer,mixing fertilizer,backfilling and watering was developed.Field test results show that the machine can achieve uniform mixing,improve the utilization rate of fertilizer,solve the obstacle of continuous cropping,improved soil structure,and promote the survival rate and planting efficiency of fruit trees.The specific research contents of this paper are as follows:(1)Design and selection of machine structure and key componentsWhole structure and key components developed by the design and type selection of selfpropelled combined rig for digging holes in situ mixed fertilizer backfilling fruit tree planting is mainly composed of digging holes mixed fertilizer backfill device,double quadrilateral lifting device,power transmission system and planting operation control system,which can realize single digging holes in the process of fruit tree planting,fertilizer,mixed fertilizer,backfilling and irrigation automation,machine key components for the design and selection.(2)Modeling and discrete element simulation analysis of compost mixture.Based on Hertz-Mindlin with JKR contact model for joint rig for inner and outer sleeve,trenching and mixed fertilizer joint operation bit loam mixed model of object,simulates the bacterial manure under different rotational speed and mixing time and soil particles in the mixing process of mixed area,and expounds the loam mixing mechanism of the mixing chamber in the loam mixture backfill simulation,through the RSD method analyzes the fertile soil of different depth in foxholes mixture mixing evenness variation coefficient.(3)Design and implementation of plant operation control systemDesign based on architecture Cortex-M3 kernel planting operation control system,including automatic plant operation subsystem,the human-computer interaction feedback subsystem,data acquisition subsystem,pressure subsystem,through various sensors to realize automatic machine plant assignment,the machine automatically by using human-computer interaction subsystem,travel to plant operation and control,data acquisition subsystem implementation of speed,oil pressure,oil temperature,such as data collection,can be directly on the OLED display real-time display,hydraulic control pressure feedback subsystem according to the vertical drop relay execution cycle PWM duty ratio feed real-time adjustment.(4)Prototype processing and field performance testThe prototype processing was completed in Linyi city,and the operation performance of the machine was verified by the operation performance test of the machine.The fastest planting operation time of the machine was about 2 minutes and 20 seconds,and the machine performance was good.In Tai’an City according to the optimum working parameters for the fat soil mixing performance test,in 150,250 and 350 mm,the depth of the three fertilizer of backfill soil mixture grid sampling and statistical researches grain number,finally obtained the mixing uniformity coefficient of variation are below 16%,bacterial manure and soil mixing quality accord with standard of the prevention and control of fruit tree planting.