Design And Experiment Of Large-width Fertilizer And Pesticide Application Vehicle For Rows

Fertilizer-pesticides application is an important part in agricultural production.At present,there are some problems in the fertilizer-pesticides application machines in China.Such as poor precision,low utilization rate,low efficiency and single function,which are difficult to meet the needs of agricultural modernization.In view of the existing problems.This paper puts forward a compound operation mode combining fertilization-pesticides application,designs a large-width fertilizer application vehicle,which is suitable for the fertilization-pesticides application of row crops.And trial produces a prototype and carries out field experiments.(1)The whole machine structure and key components of the large-width fertilizer and pesticides application vehicle for rows were designed.The working principle and design scheme of the operation width expansion,the adjustment of the distance between the lines,the adjustment of the working height and the mechanical weeding of the fertilizer applicator were determined.And the three-dimensional model of the machine was constructed.In order to improve the convenience and stability of machine control,the hydraulic control system and PLC based control system are designed.(2)The air flow field of the air delivery spray system and structural strength of middle main frame of fertilizer applicator were studied.It mainly includes 2 aspects:the wind spray system was designed based on the downward inclined air spray principle.Different design schemes of gas-distributing pipe for the manifold were proposed,and the flow field simulation analysis was carried out.It was found that the best comprehensive effect is to eliminate the cone cavity and distribute the air directly in the intake pipe.The static analysis and modal analysis of the main frame show that the structural strength and rigidity of the main frame meet the design requirements.(3)The algorithm of path planning was studied according to the operation characteristics of the large-width fertilizer-pesticides application vehicle for rows.Including two aspects:according to the machine parameters of the fertilizer-pesticides application,the mathematical model of the large-width fertilizer applicator was established.A new shuttle set path planning method suitable for the operation of the fertilizer-pesticides application vehicle in the flat field was proposed,and the path planning system was compiled by using MATLAB.(4)The basic functions of the prototype were debugged,including field walking,width expansion,height adjustment,row distance adjustment,etc.The prototype runs smoothly and normally.The wind power test of the wind conveying and spraying system of the prototype is carried out.The results show that the wind speed distribution at each nozzle is uniform and the average outlet wind speed is 18.42 m·s-1.A model of crop seedling was established,and water was used instead of the pesticides liquid.The experiment of the droplet spray to the target was carried out on the prototype.The results showed that the average coverage rate of the droplet was about 17.746%,which could meet the spraying requirements.Based on the satellite navigation,the precision test of the machine's moving alignment is carried out.The precision of straightness and the accuracy of connecting line spacing were 1.54 cm and 2.38 cm respectively.