| As an advanced carrier of air flight,UAV is used in the military field as early as possible.With the development of technology and the rapid progress of electronic devices and the decrease of cost,the application scope of UAV is gradually extended to the fields of scientific research,industry and agriculture,especially in these years,more and more applications have been used in the field of agricultural plant protection.Attention.The research on the agricultural unmanned aerial vehicle(UAV)in foreign countries started earlier than the fixed wing UAV,and the investment of the spraying equipment was great.The technology is relatively mature,and it has developed to the precise spraying operation for the local farmland,including pest control,weeding,and liquid fertilizer spraying,but it is also applied to the spraying application of the rotor unmanned aerial vehicle.In the stage of research and development.In recent years,some people have paid attention to the spraying technology and equipment of UAV in recent years.Preliminary experiments and experiments have been carried out on the application of rotary wing type UAV.The depth and breadth of the research need to be improved.There are many factors affecting the effect of the UAV spraying,such as the type of crop,the height of the plant,the speed of the flight,the wind speed and the wind direction,the temperature and humidity of the environment,the droplet characteristics,etc.In order to improve the efficiency,save the cost and avoid the environmental pollution caused by excessive spraying,two factors should be taken into consideration in the process of the UAV spraying operation:(1)the factors of the field conditions,such as plant characteristics,wind speed,temperature and humidity,the type of medicament,etc.;(2)the flying factors of UAV,such as the speed and course,the cruising altitude A gesture,etc.This paper analyzes the causes and relations of various factors affecting the spraying amount,as well as the correction and compensation methods.According to the operating conditions and requirements,the control parameters are adjusted in real time to ensure the effect of spraying.The main contents of the study include:(1)the research status and trend of UAV spraying at home and abroad,and the feasibility analysis of UAV application platform.(2)according to the requirements of the spraying operation and the factors affecting the effect,the airborne variable flow spraying technology scheme is formulated,including the structure and parameter selection of the rotor unmanned aerial vehicle,the configuration of the spray device,the configuration of the function control module,etc.(3)build the hardware platform of variable flow spray device for Rotor UAV,work out the circulation process of functional control software,integrate differential GPS positioning module,etc.(4)based on the analysis of the influence factors of the spray device of the nonlinear platform,the dynamic model of the flow control valve is constructed,and the analysis,research,the adjustment process and the dynamic response characteristics are analyzed.The fuzzy controller PID parameter self-tuning algorithm is proposed and the variable "domain" method is introduced to automatically adjust the set value according to the different levels of the set value.The output of fuzzy controller is used to realize the on-line tuning of PID control parameters,and the relevant parameters of fuzzy controller are designed.(5)the circuit test and computer simulation of the drive circuit of the solenoid valve,the flow displacement relation of the proportional valve and the effect of the fuzzy PID control of the proportional valve are carried out to verify,analyze,adjust and optimize some of the design parameters.(6)analyze and summarize the gains and losses in the implementation of the project,and put forward suggestions for improvement and improvement in the end. |
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