| In China,the use of pesticides to control pests and weeds is the main link in agricultural production.Due to the relatively backward development of plant protection machinery in China,the unscientific mode of application,the complexity of the type of plots and other factors,resulting in low utilization of pesticides,pesticide residues,serious environmental pollution and many other issues.In recent years,with the rapid development of precision agriculture,variable application technology is more and more applied to agricultural production.Aviation plant protection have the advantage of high operating efficiency,rising above geographical constraints,spraying equipment on the destruction of crops.In recent years,although the rapid growth of aircraft plant protection,there is still little research on the application of aviation variables.In this paper,the analysis of domestic and foreign variables in the application of technology analysis and summary,proposed to change the PWM duty cycle to change the plant protection UAV diaphragm pump motor turn-on and turn-off time to adjust the average voltage across the diaphragm pump motor,thus to achieve the control of the flow during the application process.In this paper,the combination of experimental and theoretical simulation methods,the main work is as follows:(1)According to the control requirements of the actual application of plant protection UAV,combined with the characteristics of plant protection UAV,the structure of the control system is designed theoretically,the corresponding control chip,hardware circuit,and software programming,The Design Scheme of Dosing Control System for Plant Protection Unmanned Aerial Vehicle.(2)Based on the DSP control technology,the TSM320F28335 control chip is introduced,and the characteristics of the chip are introduced.According to the structure of the chip,the hardware circuit diagram of the quantitative control system is designed,including the power supply circuit,the signal acquisition circuit,Output circuit,completed the control system hardware circuit design.(3)According to the CCS programming software selected by the control chip,the characteristics of CCS software programming are introduced.According to the input and output requirements of the quantitative control system,the input signal of the control system and the output of the PWM square wave signal are realized by software programming.The actual plant protection UAV application characteristics and quantitative application requirements,the preparation of quantitative control system required procedures.(4)As the PWM duty cycle technology to control the diaphragm power supply voltageto control the diaphragm pump outflow,in order to accurately control the spray flow,the need to establish a pump voltage and pump flow function model,the design and establishment of the spray flow test bench the corresponding pump flow and pump flow test data were measured,and the experimental data were fitted by polynomial fitting.The pump voltage and pump flow function model were obtained.(5)Based on the characteristics of plant protection and unmanned aerial vehicles(UAVs),the Simulink model of the application rate of plant protection unmanned aerial vehicles(UAVs)was established.According to the theoretical analysis of agricultural application operation,Drug speed and the application of the flow of the existence of a function of the relationship between the establishment of theoretical application rate and application flow function model.(6)In order to determine the reliability and stability of the control system,a simulation experiment of the application process of the quantitative control system was established.The speed of the collected technology of the plant protection UAV was taken as the input and application of the whole control system Flow as a control system sub-feedback,the establishment of closed-loop control system simulation test,through the simulation test,get the best parameters of quantitative control system. |
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