中文摘要：

为了探究适合植保无人机药箱液位实时监测的可行方法,阐述了国内外常见的接触式和非接触式液位监测方法,包括差压式、浮体式、电极式、电容式、超声波式、激光式、光电式、流量计式、机器视觉式、雷达式等主要方法,指出了植保无人机作业过程中,其药箱存在的特点,包括液面波动剧烈、药液的理化特性各异、药箱空间小、防腐蚀要求高等,并对上述常见液位测量方法用于植保无人机药箱液位测量时存在的局限进行了分析,在此基础上,探讨了适合植保无人机质量轻、功耗小、精度高、耐腐蚀药箱液位监测方法及装置,并针对植保无人机药箱液位监测中需克服的难题,提出了气压式液位无线监测的解决方案,为进一步开发适用于植保无人机的药箱液位监测装置提供参考。

英文摘要：

The liquid-level data is one of the most important informations for flying operators of spaying UAV. During the operation, the liquid content in the pesticide tank is dynamic, the flying operators have always to pay attention to the liquid content so that they can make suitable decisions for the flight control according to the liquid content adjustment in the pesticide tank. Therefore, the liquid-level monitoring method for pesticide tank is important in the design of key components of spraying UAV. In order to explore the feasible method for liquid-level monitoring of pesticide tank in spraying UAV, several major methods about contact and non-contact liquid-level monitorings were reviewed, including differential pressure, floating electrode, capacitance, ultrasonic, laser, photoelectric, flowmeter, machine vision and radar. Spraying UAV has special requirements, such as liquid surface violent fluctuation, different physical and chemical properties of different pesticides, different shapes in different tanks and high anti- corrosion requirements and small size of tank. Lots of limitations of the above mentioned methods when they were used in spraying UAV were pointed out. And then solutions called air-pressure wireless liquid- level monitoring （APWLLM） , a kind of non-contact liquid-level monitoring method, which was suitable for use in spraying UAV, were proposed. It would provide a reference for the further development of liquid-level monitoring device for pesticide tank in spraving UAV.