论文部分内容阅读
Aerial plant protection technology has grown rapidly in recent years and received many applications, due to its high working efficiency, and independency of terrain and growth situation of late crop.The technology, especially applied via large-fixed-wing agricultural aircraft, shows great competence in terms of fast working speed, large covering area and high working efficiency for large-scale cropping in the reclamation area of the Heilongjiang Province.The fixed-wing agricultural aircraft, however, usually flies at a relatively high altitude, e.g.5-10 meters and at a high speed.These can easily cause turbulence in both ends of the wings, leading to drift of pesticide sprays during its dropping.This further worsens the deposition rate of pesticides onto crops' surface, reduces the accuracy of the deposition and causes waste of pesticides.To deal with the problems aforementioned, we have developed an electrostatic spray equipment based on using a Y-5B type fixed-wing aircraft, which is composed of a high-voltage electrostatic powder source, a charging electrode, an insulation connection, ect.The equipment can charge the pesticides spray and the charge carried by the pesticide spray is opposite to the surface charge of crops.This will ensure that there is certain degree of inter-attraction between the preside and crop, which helps to reduce the drift of the pesticides spray, increase the deposition rate of pesticides onto crops and increase the possibility of the pesticide to fall onto crops rather than soil.This study first analyzed the electrostatic induction and the charging process of the pesticide dropping, and then designed a charging electrode to ensure that it can achieve its highest-possible charging property through a series of experimental tests on influencing factors.The interconnection part between the electrode and the nozzle was designed afterwards.An indoor electrostatic spray equipment was further set up to test our design in terms of its capability to charge the droppings of pesticide via measuring the charge-to-mass ratio.The study analyzed subsequently the dropping process well as the deposition process of the pesticide spray.Factors that affect the deposition ratio have been determined and they are: pressure of the spray, charging voltage of the induction electrode, electrical conductivity of the pesticide liquid, and the flight altitude and speed of the aircraft, ect.A database was therefore built up which will provide an theoretical basis for the future large-scale crop test.