Design And Test Of The Tri-wheel High Frame Precision Fertilizer Applicator

Wheat-corn double cropping is the main planting pattern of grain crops in Huanghuaihai region.The growth and development period of corn is short,and additional fertilizer has a very important effect on its yield.However,due to the height of corn stalk and the lack of special dressing machinery for corn,leading to only applying base fertilizer,overuse of fertilizer and environmental pollution.Therefore,this paper designed a special precision fertilization applicator cultivator for corn.It was composed of mechanical structure,hydraulic system and electronic speed control system,could realize top dressing for corn precisely,and ensure the demand of nutrient during growth and development process of corn,with reducing environment pollution at the same time.In this paper,the research content is roughly divided into the following several aspects:According to the structure of tri-wheel high frame operation vehicle,the application of mechanical structure designed a fertilizing 6 lines of the mechanical structure,and the core is rising whereabouts institutions,and the simulation analysis and experiments showed that it can work with wheel base adjustment(1.8 m to 2.4 m).Setting up soil model in discrete element analysis software EDEM and simulating the operation process of under different operation speed to get soil resistance of under different conditions,so calculating the maximum consumption power of colter was 464.8 W.The hydraulic system was designed Using hydraulic motor to drive the feeder through chain transmission in order to achieve that the fertilizing amount is adjustable from150 to 750 kg/hm2.The control of fertilizer application was realized by the technology of electro-hydraulic proportional control and electronic speed control system.The rotating speed of hydraulic motor was changed to control the speed of feeder.using closed-loop control and the microprocessor STM32F103R8T6 core,combining the setting parameters such as fertilizing amount,the speed signals of tri-wheel high frame precision Fertilizer applicator and actual rotational speed of feeder being detected,adopting the incremental PID algorithm to control electro-hydraulic proportional flow valve.The fertilizer parameters were displayed.Setting the PID parameters by trial method and the critical ratio method,and determining that the proportional coefficient was 1.2,the integral coefficient was 0.04,the differential coefficient was 0.2.The results showed that the maximum average error of fertilizer feeder speed was 3.37%.Different geneva wheel working length of the relationship between fertilizer consumption and speed were calibrated.The research showed that under 10 mm the opening function relation q=12.976n+94.301(q for fertilizer,n for speed)with the decision coefficient R squared 0.9792 and under 20 mm opening function relation q=29.345n+268.49,with the decision coefficient R squared 0.9963.A field experiment for fertilizer applicator was done,the results proved that the fertilizing amount from150 to 750 kg/hm2 could be achieved,the consistency variation coefficient of tilling depth was 6.37%,the variation coefficient of total fertilizing amount was 2.01%,the consistency variation coefficient of fertilizing amount under different rows was 4.63%,and conforming to the requirements of national standards.