| Rice is an essential food in China.However,during its growth process,various pests,diseases and weeds occur frequently,which causes heavy pesticide application tasks.Traditional artificial pesticide application method is not only inefficient,but also pollutes the environment,wastes pesticides and endangers the health of farmers.Therefore,there is an emergency to develop mechanized pesticide application equipment.For the purpose of reducing the times of adding water and increase the spray efficiency,the present self-propelled boom sprayer always carrys oversize drug tank,so the entire unit is very heavy.What's worse,the contact area between wheels and soil is relatively small.Therefore,during working period in the rice fields,if the sprayer repeats the same path,it will be vulnerable to bogging,while each time takes a different path will lead to high injury rate.In order to overcome the difficult "unable to work in the paddy field" problem,considering the new agricultural stipulation that digging a ditch every fixed distance in paddy fields to drain flooded fields,this paper designed an online water collecting and pesticide premixing system.This system can intake water from the ditch in paddy fields and force the water to be filtered so as to obtain clean water for pesticide mixing.Then,through real-time measurement of liquid level,and take and mix pesticide quantitatively to realize precise mixture and decrease of the drug tank volume,which remarkably lightens the whole machine's weight.Online water collecting is very difficult,owing to the water layer in paddy fields is relatively thin,there are many weeds and impurities,and the machine tends to bumpy up and down during walking.Meanwhile,turbidity has influence on spray quality.In order to solve these problems,flowing researches were conducted:(1)Considering spray width of the existing self-propelled boom sprayer and the new regulation of agricultural ditch in paddy fields,determined the ditch's size,developed online water intake device and confirmed demand parameters and model number of spring,angle sensor,drive pusher,water pipe,electric ball valve,power adapter and tubidity meter through tests.(2)For the stability and purity of water absobtion,determined the thresholds of angel sensor by analysis to keep the online water intake device stay in the center of the ditch;analysed the requirements of control system to determine the working procedures of controlling water intaking and drug mixing timely and caculated keyparameters of liquid level sensor,actuating motor and so on;identified optimal sprayer working speed and electric pusher movement range by experiments.(3)Tested the influence of turbidity on the spray volume,and designed the cyclone desander,100 mesh stacked filter,and 120 mesh stacked filter combined3-level filter system.The cyclone desander of this system was developed based on work requirements,and this paper simulated its internal flow distribution through ANSYS as well as tested the actual filtering effect through field trail.(4)Assembled water collecting and pesticide mixing system with12m-spray-width self-propelled high-clearance boom sprayer and tested its performance.The results showed that the online water intake device can simulate the ditch's shape,offset skewing flexibly,and drive control horizontally.Besides,flow rate of sprayer and turbidity met actual working requirements.The combination of online water collecting and pesticide premixing can reduce the volume of the 1500 L water tank to less than 200 L.The total mass of the system is reduced by 56%,compared with the mainstream drug system in the market.Therefore,developing a new online water collecting and pesticide premixing system and integrating it into self-propelled high-clearance boom sprayer to reduce the dead-weight,solve the problem of “unable to work in the paddy fields”,and provide applicative mechanized pesticide application equipment for the large-scale cultivation of rice is of great significance in supporting the development of agricultural large-scale operations and safeguarding food security for our country. |
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