Plant protection unmanned aerial vehicle real-time variable spraying control system and control method thereof

Abstract

The invention discloses a plant protection unmanned aerial vehicle real-time variable spraying control system and a control method thereof, and the system employs a large Xinjiang T30 plant protection unmanned aerial vehicle as a system building platform, and comprises a power supply module, and a data collection module, a data processing module and an action execution module which are connected with the power supply module. The data acquisition module and the action execution module are both connected with the data processing module, the data acquisition module comprises a positioning device and a flowmeter, the data processing module comprises a man-machine interaction unit and a main controller unit, the man-machine interaction unit comprises a wireless data transmission device and a serial port screen, the main controller unit comprises an STM32F103ZET6 single-chip microcomputer, and the wireless data transmission device is connected with the wireless data transmission device. The action execution module comprises a diaphragm pump, a centrifugal nozzle, an electronic speed regulator and a motor driver; and the power supply module comprises a direct-current battery power supply and a power supply voltage-stabilizing and voltage-reducing plate. The problem that pesticide spraying is uneven due to the fact that real-time matching of the pesticide flow and the flight speed cannot be achieved when the pesticide flow and the flight speed of the plant protection machine are manually controlled is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural plant protection UAVs, and in particular to a real-time variable spraying control system and a control method thereof for a plant protection UAV. Background Art

[0003] Plant protection drones are a new type of agricultural plant protection equipment and a new product of modern agriculture. It is mainly composed of drones carrying spraying equipment, and is used for pesticide plant protection spraying tasks on farmland, woodland and urban green areas. Due to its advantages of high operating efficiency, good effect, water saving and pesticide saving, it has been rapidly developed in recent years. According to statistics, the working efficiency of agricultural plant protection drones exceeds the efficiency of traditional manual spraying by more than 60%, which greatly avoids the waste of pesticides, has an important impact on reducing environmental problems caused by the abuse of pesticides, and has a wide market value. Therefore, the combination of precise real-time variable spraying technology of pesticides and plant protection drones has become the best solution for modern agriculture to improve the utilization rate of pesticides. However, the plant protection drones currently on the market can only be operated manually when encountering small plots, unplanned plots and obstacles. During the manual operation process, the flight speed of the drone and the flow rate of pesticide spraying are manually controlled, which is prone to missed spraying, heavy spraying and uneven spraying.

[0004] In order to solve the above problems, it is necessary to propose a real-time variable pesticide spraying control system, which can achieve real-time matching of UAV flight speed and spraying flow rate according to the set per mu usage, so as to achieve the purpose of improving the utilization rate of pesticides. Summary of the invention

[0005] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a real-time variable spraying control system for plant protection drones and a control method thereof, which aims to solve the problem that the current plant protection drones need to manually control the pesticide flow rate and the flight speed of the plant protection drone during manual operation, and cannot achieve real-time matching of the pesticide flow rate and the flight speed, resulting in uneven pesticide spraying. The system of the present invention is mainly based on the STM32F103ZET6 single-chip microcomputer, collects speed and position information through the GPS Beidou positioning device, controls the rotation speed of the centrifugal nozzle and the liquid flow rate of the water pump based on the PWM technology, feeds back the real-time flow rate through the flowmeter, forms a closed-loop system, and uses the PID algorithm to accurately control the entire system.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a real-time variable spraying control system for a plant protection UAV, characterized in that the system comprises a data acquisition module, a data processing module, an action execution module and a power supply module, the power supply module is respectively connected to the data acquisition module, the data processing module and the action execution module, the power supply module is used to power the entire system, the data acquisition module and the action execution module are both connected to the data processing module, the parameter data collected by the data acquisition module is transmitted to the data processing module for processing, the data collected by the data acquisition module is processed by the data processing module, and a corresponding execution instruction is issued to the action execution; The data processing module includes a human-computer interaction unit and a main controller unit, the human-computer interaction unit includes a wireless data transmission device and a serial port screen, the main controller unit includes an STM32F103ZET6 single-chip microcomputer, the STM32F103ZET6 single-chip microcomputer is connected to the wireless data transmission device, and the wireless data transmission device is connected to the serial port screen; The action execution module includes a diaphragm pump, a centrifugal nozzle, an electronic speed regulator and a motor driver. The motor driver is connected to the diaphragm pump, and the centrifugal nozzle is connected to the electronic speed regulator. The action execution module executes the instructions issued by the data processing module to control the flow rate of the diaphragm pump, adjust the speed of the centrifugal nozzle, and transmit the information to be displayed to the serial port screen for display through a wireless data transmission device; The data acquisition module includes a positioning device and a flow meter. The data acquisition module is connected to the data processing module and is used to collect parameter data and transmit it to the data processing module for processing. The collected parameter data includes the flight speed of the plant protection UAV and the flow rate of the diaphragm pump.

[0007] Preferably, the configuration of the STM32F103ZET6 single-chip microcomputer includes 64kB SRAM, 512kB Flash, 2 basic timers, 4 general timers, 2 advanced timers, 2 DMA controllers, 3 SPIs, 2 IICs, 5 serial ports and 112 general IO ports. The STM32F103ZET6 single-chip microcomputer minimum system is used as the main control system, which includes a main control chip, a clock circuit, a reset circuit and a debugging circuit.

[0008] Preferably, the power supply module includes a DC battery power supply and a power supply voltage regulator and step-down board, the DC battery power supply includes a 54V 6000mAh lithium battery and a 124V2000mAh aircraft model lithium battery, the power supply voltage regulator and step-down board includes a primary step-down module and a secondary step-down module, the power supply module adopts a hierarchical step-down method, the primary step-down module reduces the voltage to 24V, which is used to power the centrifugal nozzle and the diaphragm pump, and the secondary step-down module reduces the voltage from 24V to 5V, which is used to power the STM32F103ZET6 single-chip microcomputer, the flow meter and the Beidou GPS positioning device; The 12 4V2000mAh model aircraft lithium batteries provide power to the human-computer interaction module through the power supply voltage regulator and step-down board including 5V.

[0009] Preferably, the wireless data transmission device is a 433MHz wireless communication module, the serial port screen is a USART HMI intelligent serial port screen, and the USART HMI intelligent serial port screen is provided with a variety of configuration controls, including button controls, progress bar controls, text controls, and pointer controls. When the plant protection UAV is operating, communication is carried out with the main controller unit on the plant protection UAV through the 433MHz wireless communication module.

[0010] Preferably, the positioning device and the flow meter are both connected to the main controller unit; The positioning device includes a Beidou GPS positioning device, the Beidou GPS positioning module is an ATK-S1216F8-BDGPS / Beidou module, the communication interface with the external device adopts UART (serial port) mode, the output GPS / Beidou positioning data adopts NMEA-0183 protocol, the control protocol is SkyTraq protocol, and the flight parameter information of the plant protection UAV is collected through the Beidou GPS module. The flight parameter information includes flight speed, longitude and latitude, and altitude, and the data is sent to the main controller unit in real time through serial port communication; The flow meter uses the YF-S201 flow meter sensor to collect the flow rate of the diaphragm pump outlet. The main controller unit reads the number of pulses generated through external interruption and obtains the real-time flow rate of the pesticide through internal calculation.

[0011] Preferably, the motor driver is connected to the diaphragm pump, and the motor driver is a 24V 7A L298N motor driver, which is used to control the flow rate of the diaphragm pump liquid medicine. The 24V 7A L298N motor driver changes the output voltage by receiving the PWM signal sent by the single-chip microcomputer, and the output voltage is linearly related to the input pulse duty cycle, thereby changing the flow rate; The electronic speed regulator is connected to the centrifugal nozzle. The electronic speed regulator is a brushless electronic speed regulator. The brushless electronic speed regulator changes the droplet size of the centrifugal nozzle by receiving a PWM signal from a single chip microcomputer.

[0012] Preferably, the USART HMI intelligent serial port screen is used as a host computer terminal and a ground handheld device to remotely control the centrifugal nozzle speed and pesticide flow rate in real time, and display flight parameters and other information on the LCD screen of the host computer. According to the set per mu usage, the UAV flight speed and spraying flow rate can be matched in real time to achieve the purpose of improving the utilization rate of pesticides.

[0013] The beneficial effects of the present invention are: (1) The system of the present invention provides a real-time pesticide variable control system based on STM32F103ZET6 single-chip microcomputer and a pesticide flow control method based on PWM technology combined with incremental PID algorithm. The Beidou GPS positioning module collects drone attitude parameters such as drone flight speed, and completes data transmission through wireless communication and serial communication protocol, so that the pesticide flow rate of the plant protection drone in manual operation mode can be matched in real time with the flight speed of the plant protection drone. The system response time performance and system flow control performance were tested. The test showed that the system startup initialization time was 3.5 s, and the system response time was between 1 m and 1 km away from the ground station to the main equipment. The average error between the actual flow and the theoretical flow of the pesticide flow control system was 2.2%. The system performance and pesticide control accuracy met the test expectations and completed the design requirements.

[0014] (2) The system of the present invention designs the host computer of the system based on the USART HMI serial port screen, displays the operating parameters of the system in real time through the screen, and realizes remote control through the 433MHz wireless communication module, meeting the actual operation requirements.

[0015] (3) In the system of the present invention, the nozzle is a centrifugal nozzle, which has better atomization effect than the pressure nozzle, and has a wider range of droplet coverage and droplet size. In addition, the nozzle speed can be directly set on the host computer to change the droplet size.

[0016] (4) According to the analysis of test data, the relative error of the system of the present invention is higher than 3% when the spraying flow rate is lower than 1 L / min and higher than 3.5 L / min. The design needs to be improved in the future by optimizing the PID algorithm and adopting a diaphragm pump with higher precision and greater power. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the structure of a plant protection UAV construction platform for the plant protection UAV real-time variable spraying control system provided by the present invention; Figure 2 A block diagram of a real-time variable spraying control system for a plant protection UAV real-time variable spraying control system provided by the present invention; Figure 3 This is a diagram of the host computer interface of the real-time variable spraying control system of the plant protection UAV provided by the present invention; Figure 4 This is a work flow diagram of the host computer of the real-time variable spraying control system of the plant protection UAV provided by the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In this embodiment, the present invention provides a real-time variable spraying control system for a plant protection UAV, which includes a data acquisition module, a data processing module, an action execution module and a power supply module, wherein the power supply module is respectively connected to the data acquisition module, the data processing module and the action execution module, and the entire system is powered by the power supply module. The data acquisition module and the action execution module are both connected to the data processing module, and parameter data collected by the data acquisition module is transmitted to the data processing module for processing, and the data collected by the data acquisition module is processed by the data processing module, and corresponding execution instructions are issued to the action execution; The data processing module includes a human-computer interaction unit and a main controller unit, the human-computer interaction unit includes a wireless data transmission device and a serial port screen, the main controller unit includes an STM32F103ZET6 single-chip microcomputer, the STM32F103ZET6 single-chip microcomputer is connected to the wireless data transmission device, and the wireless data transmission device is connected to the serial port screen; The action execution module includes a diaphragm pump, a centrifugal nozzle, an electronic speed regulator and a motor driver. The motor driver is connected to the diaphragm pump, and the centrifugal nozzle is connected to the electronic speed regulator. The action execution module executes the instructions issued by the data processing module to control the flow rate of the diaphragm pump, adjust the speed of the centrifugal nozzle, and transmit the information to be displayed to the serial port screen for display through a wireless data transmission device; The data acquisition module includes a positioning device and a flow meter. The data acquisition module is connected to the data processing module and is used to collect parameter data and transmit it to the data processing module for processing. The collected parameter data includes the flight speed of the plant protection UAV and the flow rate of the diaphragm pump.

[0021] Preferably, the configuration of the STM32F103ZET6 single-chip microcomputer includes 64kB SRAM, 512kB Flash, 2 basic timers, 4 general timers, 2 advanced timers, 2 DMA controllers, 3 SPIs, 2 IICs, 5 serial ports and 112 general IO ports. The STM32F103ZET6 single-chip microcomputer minimum system is used as the main control system, which includes a main control chip, a clock circuit, a reset circuit and a debugging circuit.

[0022] Preferably, the power supply module includes a DC battery power supply and a power supply voltage regulator and step-down board, the DC battery power supply includes a 54V 6000mAh lithium battery and a 124V2000mAh aircraft model lithium battery, the power supply voltage regulator and step-down board includes a primary step-down module and a secondary step-down module, the power supply module adopts a hierarchical step-down method, the primary step-down module reduces the voltage to 24V, which is used to power the centrifugal nozzle and the diaphragm pump, and the secondary step-down module reduces the voltage from 24V to 5V, which is used to power the STM32F103ZET6 single-chip microcomputer, the flow meter and the Beidou GPS positioning device; The 12 4V2000mAh model aircraft lithium batteries provide power to the human-computer interaction module through the power supply voltage regulator and step-down board including 5V.

[0023] Preferably, the wireless data transmission device is a 433MHz wireless communication module, the serial port screen is a USART HMI intelligent serial port screen, the USART HMI intelligent serial port screen is provided with a variety of configuration controls, the configuration controls include button controls, progress bar controls, text controls, pointer controls, and the USART HMI intelligent serial port screen is used as a host computer terminal, as a ground handheld device, for remotely and in real time controlling the speed of the centrifugal nozzle and the flow rate of pesticides, while displaying information such as flight parameters on the LCD screen of the host computer. When the plant protection UAV is operating, the 433MHz wireless communication module is used to communicate with the main controller unit on the plant protection UAV. Among them, the 433MHz wireless communication module has the characteristics of long transmission distance, simple communication protocol, stable transmission data, etc., which can fully meet the needs of this system.

[0024] Specifically, during operation, the system can modify and transmit data through serial communication according to the instruction set given by the manufacturer. At the same time, it has its own processor and flash, which will not occupy too many microcontroller resources. Its interface UI design is graphically programmed through the host computer software provided by the manufacturer, which greatly shortens the human-computer interaction development cycle.

[0025] Preferably, the positioning device and the flow meter are both connected to the main controller unit; The positioning device includes a Beidou GPS positioning device, the Beidou GPS positioning module is an ATK-S1216F8-BDGPS / Beidou module, the communication interface with the external device adopts UART (serial port) mode, the output GPS / Beidou positioning data adopts NMEA-0183 protocol, the control protocol is SkyTraq protocol, and the various flight parameter information of the plant protection UAV is collected through the Beidou GPS module. The flight parameter information includes flight speed, longitude and latitude, and altitude, and the data is sent to the main controller unit in real time through serial port communication; the NMEA 0183 used in this embodiment is a standard format formulated by the National Marine Electronics Association of the United States for marine electronic equipment, and has now become a unified RTCM (Radio Technical Commission for Maritime services) standard protocol for GPS / Beidou navigation equipment; The flow meter uses the YF-S201 flow meter sensor to collect the flow rate of the diaphragm pump outlet. The main controller unit reads the number of pulses generated through external interruption and obtains the real-time flow rate of the pesticide through internal calculation.

[0026] Preferably, the motor driver is connected to the diaphragm pump, and the motor driver is a 24V 7A L298N motor driver, which is used to control the flow rate of the diaphragm pump liquid medicine. The 24V 7A L298N motor driver changes the output voltage by receiving the PWM signal sent by the single-chip microcomputer, and the output voltage is linearly related to the input pulse duty cycle, thereby changing the flow rate; The electronic speed regulator is connected to the centrifugal nozzle. The electronic speed regulator is a brushless electronic speed regulator. The brushless electronic speed regulator changes the droplet size of the centrifugal nozzle by receiving a PWM signal from a single chip microcomputer.

[0027] It should be noted that the specific setting positions of the hardware parts of the data acquisition module, data processing module, action execution module and power supply module can be reasonably constructed by referring to the existing plant protection UAVs.

[0028] In this embodiment, the power supply interface of the entire system and the connection between each module adopts a plug-in interface design, which is simple and convenient to assemble and disassemble. The data processing module and the power supply module are waterproofed, and the download interface of the microcontroller is reserved to facilitate subsequent program debugging and upgrading.

[0029] In this embodiment, the real-time variable spraying control method of the plant protection UAV real-time variable spraying control system is: After the object of plant protection operation, the spraying width of the plant protection UAV, the operating height and the amount of pesticide used per mu are determined, the pesticide flow rate extracted from the medicine box by the diaphragm pump and the flight speed of the plant protection UAV are positively correlated.

[0030] The calculation formula for the spraying flow rate required by the plant protection UAV at different flight speeds is: (1) In the formula ——Theoretical flow rate, L / min; ——Amount of pesticide used per unit area, L / m 2 ; ——spray width, m; ——Flight speed, m / s.

[0031] In order to more accurately control the flow of pesticides, the PID algorithm is introduced. The controller compares the actual flow collected by the flow meter with the theoretical flow, calculates an output signal through PID, converts the output signal into a PWM signal, and outputs the PWM signal to the L298N motor driver to control the diaphragm pump, ultimately achieving precise control of the pesticide flow.

[0032] This time, the incremental PID algorithm is used. The incremental digital PID control expression is: （2） Where: is the adjustment amount for this time; It is the difference between the current actual flow rate and the theoretical flow rate; , is the difference between the actual flow rate and the theoretical flow rate for the first two times; is the proportionality coefficient; is the integration coefficient; is the differential coefficient.

[0033] Since incremental PID control is adopted, the actual output expression is: (3) In the formula is the current output, is the last output, so the current output is equal to the sum of the last output and this adjustment.

[0034] In this embodiment, the system software of the real-time variable spraying control system of the plant protection UAV includes a data acquisition part, an action execution part and a host computer part.

[0035] Specifically, the data acquisition part includes the Beidou GPS information acquisition part and the flowmeter data acquisition part. The Beidou GPS module communicates with the UART3 of the single-chip microcomputer. In the main program, the serial port is initialized first. During the initialization, the baud rate is set to 38400, and the positioning information update speed is set to 5 Hz to determine whether the GPS module is in place. When the serial port 3 receives the data, it is passed to the NMEA-0183 parsing function and parsed according to the NMEA-0183 protocol. After the data is parsed, it is stored and waits for other programs to call. The flowmeter is connected to the PE2 pin of the single-chip microcomputer, and the pin is multiplexed as an external interrupt 2. The external interrupt is configured as a falling edge trigger. The trigger pulse is accumulated in the interrupt service function. In the interrupt service function of the tick timer, the number of pulses accumulated in 1 second is converted into a frequency f, and the flow Q is calculated according to the formula.

[0036] Q = f / 7.5s (4) Where Q is the pump flow rate, L / min; f——pulse frequency, Hz; s——time, s.

[0037] Specifically, the action execution part program includes the diaphragm pump drive part and the centrifugal nozzle drive part. Channel 2 of the general timer 3 of the single-chip microcomputer is used to output a PWM signal to control the diaphragm pump. The PWM signal has a fixed frequency of 1 kHz, and the duty cycle is adjusted from 0% to 100%, with a step size of 1%. In the program, the TIM3_PWM_Init(arr,psc) function is first called to initialize the PWM configuration, and the duty cycle is changed by calling the TIM_SetCompare2(TIM_TypeDef*TIMx,uint16_t Compare2) function to adjust the pesticide flow.

[0038] In order to control the flow more accurately, an incremental PID algorithm is introduced. The code is as follows: float PID (float temp_val) / * Pass in the target value * / pid.target_val = temp_val; / *Calculate the error between the target value and the actual value* / pid.err=pid.target_val-pid.actual_val; / *PID algorithm implementation* / Float increment_val = pid.Kp*(pid.err - pid.err_next)+pid.Ki*pid.err+ pid.Kd*(pid.err-2 * pid.err_next + pid.err_last); / *Accumulate* / pid.actual_val += increment_val; / *Transmission error* / pid.err_last = pid.err_next; pid.err_next = pid.err; / *Return the current actual value* / return pid.actual_val; } Among them, channel 2 of the MCU general timer 2 outputs a PWM signal to control the centrifugal nozzle. Since it uses a brushless ESC control, its PWM signal frequency is 47.1965 Hz, the duty cycle is adjusted from 0% to 7.5%, and the step length is 0.75%. Since the DJI T30 is used as the development platform, 6 centrifugal nozzles are used. The PWM signal output by the MCU is divided into six ESCs using a breakout board to control the centrifugal nozzles.

[0039] Specifically, the host computer software uses the USART HMI serial port screen as the host computer, and the program is mainly divided into two aspects. On the one hand, the host computer UI design is performed by graphical programming through the USART HMI host computer software provided by the manufacturer; on the other hand, the corresponding data packet parsing program and data packet encoding program are written according to the instruction set given by the manufacturer to realize communication with the USART HMI serial port screen.

[0040] Among them, the present invention focuses on the upper computer UI design, the upper computer interface is as follows Figure 3 As shown, first, create a new project in the USART HMI host computer software, and create a new page through the page on the right side of the interface. The picture library in the lower left corner of the interface is used as the background. The left side of the interface is the corresponding control, which can be directly dragged to the page. The property box in the lower right corner of the interface modifies the control properties. The bottom side of the interface is the event, such as the button control before and after it is pressed. Program under the event, and you can run the code after the event occurs. The host computer workflow diagram is as follows Figure 4 shown.

[0041] In this embodiment, the real-time variable spraying control system of the plant protection UAV is also tested, and the test items are as follows: 1. System time response performance test The system response time is one of the important indicators to measure the performance of a device. This test is divided into the system startup initialization response time test and the serial port screen and main controller communication system time response test.

[0042] The system startup initialization response time test is the time required from turning on the main power to the normal operation of the system in an open outdoor environment. The number of tests is 10, and the average value is 3.5 s. The time response test of the serial port screen and the main controller communication system is that when the system is operating normally, the serial port screen is 1 m and 1 km away from the main device, the diaphragm pump flow and the speed of the centrifugal nozzle are set through the custom mode in the serial port screen, and the time from clicking the OK button on the serial port screen to the start of the main device is recorded; the number of tests is 10 times, when the serial port screen is 1 m away from the main device, the average response time is 10 ms; when the serial port screen is 1 km away from the main device, the average response time is 45 ms. That is, the test results of this system show that the real-time variable spraying control system of the plant protection drone is feasible, and the system startup initialization time is 3.5s; when the ground station is between 1m and 1km away from the main device, the system response time is between 10 and 45ms, and the average error between the actual flow and the theoretical flow of the pesticide flow control system is 2.2%.

[0043] 2. System flow control performance test In order to test the control performance of the system on the flow rate in the operation of the plant protection drone, the system pesticide flow rate changes in real time with the flight speed of the plant protection drone. According to the actual operation experience, the width is set to the common value of 5 m, and the pesticide dosage per hectare is set to the common values ​​of 22.5 L and 30 L. The actual flow rate and expected flow rate of the system per minute at 7 different flight speeds are tested. Since it is not feasible to test during the flight of the plant protection drone, the actual flow rate of the system is measured by manually inputting the flight speed through the serial port screen in an indoor windless environment. The theoretical flow rate is calculated by the formula. The test results are shown in Tables 1 and 2. It can be seen from Tables 1 and 2 that the minimum error between the expected flow rate and the actual flow rate is 1.2%, the maximum is 4.4%, and the overall error does not exceed 4.5%, which is within the error range. There may be two reasons for the large error in the maximum flow rate: one is that there is an error in the actual test; the other is that the diaphragm pump used has poor accuracy.

[0044] Table 1 Flow control performance test data of 22.5 L per hectare system

[0045] Table 2 Flow control performance test data of 30 L per hectare system

[0046] Working principle of the present invention: after the power switch is turned on, the system needs to wait for about 3 seconds to initialize the system; after the initialization is completed, the USART HMI serial port screen will display the current number of satellites, longitude and latitude, sea wave height and UAV flight speed and other information parameters. During specific work, the user selects the intelligent mode through the USART HMI serial port screen touch screen, then jumps to the page and enters the amount per mu; after waiting for the input to be completed, click the confirmation button, and the data will be sent to the STM32 single-chip microcomputer through the 433MHz wireless data transmission module. The STM32 single-chip microcomputer collects data according to the Beidou GPS positioning device and the flowmeter. After calculation, it outputs a suitable PWM signal to control the pesticide flow rate and centrifugal nozzle speed of the diaphragm pump, thereby achieving the purpose of real-time variable pesticide spraying. At the same time, you can also choose the custom mode, enter the required pesticide flow rate and the speed of the centrifugal nozzle, and achieve the purpose of custom pesticide spraying.

[0047] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. The real-time variable spraying control system for plant protection UAV is characterized by: The system includes a data acquisition module, a data processing module, an action execution module and a power supply module. The power supply module is connected to the data acquisition module, the data processing module and the action execution module respectively, and the entire system is powered by the power supply module. The data acquisition module and the action execution module are both connected to the data processing module. The data acquisition module collects parameter data and transmits it to the data processing module for processing. The data collected by the data acquisition module is processed by the data processing module, and corresponding execution instructions are issued to the action execution. The data processing module includes a human-computer interaction unit and a main controller unit, the human-computer interaction unit includes a wireless data transmission device and a serial port screen, the main controller unit includes an STM32F103ZET6 single-chip microcomputer, the STM32F103ZET6 single-chip microcomputer is connected to the wireless data transmission device, and the wireless data transmission device is connected to the serial port screen; The action execution module includes a diaphragm pump, a centrifugal nozzle, an electronic speed regulator and a motor driver. The motor driver is connected to the diaphragm pump, and the centrifugal nozzle is connected to the electronic speed regulator. The action execution module executes the instructions issued by the data processing module to control the flow rate of the diaphragm pump, adjust the speed of the centrifugal nozzle, and transmit the information to be displayed to the serial port screen for display through a wireless data transmission device; The data acquisition module includes a positioning device and a flow meter. The data acquisition module is connected to the data processing module and is used to collect parameter data and transmit it to the data processing module for processing. The collected parameter data includes the flight speed of the plant protection UAV and the flow rate of the diaphragm pump.

2. The real-time variable spraying control system for plant protection UAV according to claim 1 is characterized in that: The configuration of the STM32F103ZET6 single-chip microcomputer includes 64kB SRAM, 512kB Flash, 2 basic timers, 4 general timers, 2 advanced timers, 2 DMA controllers, 3 SPIs, 2 IICs, 5 serial ports and 112 general IO ports. The STM32F103ZET6 single-chip microcomputer minimum system is used as the main control system, which includes a main control chip, a clock circuit, a reset circuit and a debugging circuit.

3. The real-time variable spraying control system for plant protection UAV according to claim 1, characterized in that: The power supply module includes a DC battery power supply and a power supply voltage regulator and step-down board, the DC battery power supply includes a 54V 6000mAh lithium battery and a 124V2000mAh aircraft model lithium battery, the power supply voltage regulator and step-down board includes a primary step-down module and a secondary step-down module, the power supply module adopts a hierarchical step-down method, the primary step-down module reduces the voltage to 24V, which is used to power the centrifugal nozzle and the diaphragm pump, and the secondary step-down module reduces the voltage from 24V to 5V, which is used to power the STM32F103ZET6 single-chip microcomputer, the flow meter and the Beidou GPS positioning device; The 12 4V2000mAh model aircraft lithium batteries provide power to the human-computer interaction module through the power supply voltage regulator and step-down board including 5V.

4. The real-time variable spraying control system for plant protection UAV according to claim 1, characterized in that: The wireless data transmission device is a 433MHz wireless communication module, and the serial port screen is a USART HMI intelligent serial port screen. The USART HMI intelligent serial port screen is provided with a variety of configuration controls, including button controls, progress bar controls, text controls, and pointer controls. When the plant protection UAV is operating, communication is carried out with the main controller unit on the plant protection UAV through the 433MHz wireless communication module.

5. The real-time variable spraying control system for plant protection UAV according to claim 1 is characterized in that: The positioning device and the flow meter are both connected to the main controller unit; The positioning device includes a Beidou GPS positioning device, the Beidou GPS positioning module is an ATK-S1216F8-BD GPS / Beidou module, the communication interface with the external device adopts UART (serial port) mode, the output GPS / Beidou positioning data adopts NMEA-0183 protocol, the control protocol is SkyTraq protocol, and the flight parameter information of the plant protection UAV is collected through the Beidou GPS module. The flight parameter information includes flight speed, longitude and latitude, and altitude, and the data is sent to the main controller unit in real time through serial port communication; The flow meter uses the YF-S201 flow meter sensor to collect the flow rate of the diaphragm pump outlet. The main controller unit reads the number of pulses generated through external interruption and obtains the real-time flow rate of the pesticide through internal calculation.

6. The real-time variable spraying control system for plant protection UAV according to claim 1, characterized in that: The motor driver is connected to the diaphragm pump. The motor driver is a 24V 7A L298N motor driver, which is used to control the flow rate of the diaphragm pump. The 24V 7A L298N motor driver changes the output voltage by receiving the PWM signal sent by the single-chip microcomputer. The output voltage is linearly related to the input pulse duty cycle, thereby changing the flow rate; The electronic speed regulator is connected to the centrifugal nozzle. The electronic speed regulator is a brushless electronic speed regulator. The brushless electronic speed regulator changes the droplet size of the centrifugal nozzle by receiving a PWM signal from a single chip microcomputer.

7. The real-time variable spraying control system for plant protection UAV according to claim 1, characterized in that: The USARTHMI intelligent serial port screen is used as a host computer terminal and a ground handheld device to remotely control the rotation speed of the centrifugal nozzle and the pesticide flow rate in real time, and display information such as flight parameters on the LCD screen of the host computer.

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