Suspension type UAV (unmanned aerial vehicle) water sampler system

[0039] The present invention will be described in further detail below in conjunction with the drawings.

[0040] As shown in the figure, the device is composed of an unmanned aerial vehicle 1, a sampling control system 2 and a sampling cup 3. The sampling control system 2 is fixed to the bottom mounting plate of the UAV 1 through the motor fixing plate 4, and fixed to the feet of the UAV 1 through the return baffle 11. The sampling cup 3 is suspended on the reel 5 through the sampling cup drawstring 15 on. For the sampling control system 2, the reel 5, the self-locking motor 7, the coupling 8, the speed encoder 9, the sampling motor 10 and the self-locking gear 14 are fixed on the motor fixing plate 4, the central control board 6, the return buffer The device 12, the water level fixed height probe 13, the sampling cup drawstring 15 and the return switch 16 are fixed on the return baffle 11.

[0041] The power system of the present invention is an unmanned aerial vehicle 1. The basic requirement is that it can hover, the load is above 5Kg, and the endurance is above 15 minutes. This system adopts the M8A agricultural plant protection machine of Beijing Skyway Aviation, which is modified on the basis of the original model, and is equipped with our sampling control system and sampler. The total weight of the sampling control system and the empty bottle of the sampler is less than 1.5Kg. When the load is 10Kg, the M8A can hover for more than 15 minutes, the whole endurance time is more than 30 minutes, and the flight condition is good.

[0042] Sampling control system 2 is the core component of the system. The system is mainly composed of six parts: the fixed height subsystem, the retractable rope subsystem, the motor circle number calculation subsystem, the return subsystem, the central control subsystem and the assembly subsystem. The height-fixing subsystem is responsible for collecting the height information of the UAV from the water surface, the retractable rope subsystem is responsible for releasing and retracting the sampling cup pull rope 15, and the motor circle calculation subsystem is responsible for calculating the rotation circle of the sampling motor and then the sampling cup pull rope The release length of 15, the return subsystem is responsible for the accurate return of the sampling cup 3 to the position before the departure, the central control subsystem is responsible for the coordination and unity of the previous four subsystems and the communication with the UAV, and the assembly subsystem arranges all components reasonably Combined with unmanned aerial vehicles.

[0043] The components of the fixed-height subsystem include ultrasonic liquid level probes. This system uses 4-20SC- -WRTM series probes, the maximum range is 5 meters, the minimum range is 50cm, the resolution is 1.6mm, the data refresh rate is 0.6Hz, the power is supplied in the range of 10~32V, and the data interface is 4~20mA current signal.

[0044] The components of the rope retracting subsystem include a sampling motor 10, a coupling 8, a spool 5, and a sampling cup drawstring 15. Sampling motor 10 adopts Faulhaber2342L012 DC geared motor, working voltage 12V, no-load speed: 8100RPM, speed after deceleration 120RPM, output power: 17W. The shaft of the sampling motor 10 is connected to the central shaft of the reel 5 through a coupling 8, the sampling cup drawstring 15 is wound on the reel 5, and the sampling cup drawstring 15 adopts fishing line. The sampling motor 10 works to drive the reel 5 to rotate. When the sampling starts, the reel 5 unwinds, and the sampling cup 3 drops from a high altitude to below the water surface. After the sampling is completed, the sampling motor 10 rotates in the reverse direction, and the reel 5 takes up the wire. Rise below the water surface and return to the unmanned aerial vehicle 1.

[0045] The motor turns calculation subsystem includes a speed encoder 9. The speed encoder 9 is composed of a magnetic angle sensor AS5600 and a two-pole circular magnet. The magnetic encoder is small in size, cheap, and high in accuracy. It can be configured with analog voltage output or position angle PWM output, suitable for Calculate the demand for motor revolutions. AS5600 is symmetrical with the center of the magnet during installation, and AS5600 can output the voltage value corresponding to the angle of the magnet according to the position of the magnet. The number of rotations of the sampling motor can be obtained in real time through the speed encoder 9, and the number of rotations can be multiplied by the winding circumference of the reel to obtain the length of the pay-off, thereby controlling the descending height of the sampling cup 3.

[0046] The return subsystem includes a return buffer 12, a return switch 16, a self-locking gear 14 and a self-locking motor 7. The return buffer 12 is composed of a spring and disks on both sides of the spring, and the return switch 16 is a limit switch. When the sampling cup 3 rises and hits the lower disc of the return buffer 12, the lower disc presses the spring, the spring presses the upper disc, and the upper disc finally presses the limit switch. When the spring pressure reaches a certain level, The limit switch is closed, and the closing signal is transmitted to the central control subsystem. The central control subsystem knows that the sampling cup 3 has returned to its position, and stops the rising of the sampling cup 3. With the return buffer 12, the pressure impact of the rising of the sampling cup 3 on the bottom of the UAV 1 can be reduced, and the closing of the limit switch can be more reliable, and the shrapnel will not collide back and forth. After the sampling motor 10 stops running, in order to prevent the self-locking torque of the sampling motor 10 from being insufficient, the central control subsystem will control the self-locking motor 7 to push the self-locking head and the self-locking gear to engage, so that the self-locking gear cannot rotate. The gear is fixed on the rotating shaft of the sampling motor, so the rotating shaft of the sampling motor 10 is locked. The central control subsystem will control the self-locking motor 7 away from the self-locking gear 14 before the next sampling starts, and the self-locking head and the self-locking gear 14 are loose. Open, the shaft of the self-locking motor 7 can rotate freely.

[0047] The central control subsystem includes the central control board 6. The central control board 6 has electrical control interfaces for the height-fixing subsystem, the retractable rope subsystem, the motor coil number calculation subsystem, and the return subsystem. The MCU on the central control board uses STMicroelectronics' STM32F1 series of chips. This series has a CPU frequency of up to 72MHz, FLASH up to 1M capacity, RAM up to 96K, low power consumption, and a large number of common peripherals, which can meet the needs of system control.

[0048] The assembly subsystem includes a motor fixing plate 4 and a return baffle 11. The assembly subsystem is the link between the sampling control system 2 and the UAV 1. Reel 5, self-locking motor 7, coupling 8, speed encoder 9, sampling motor 10, self-locking gear 14 and other motor-related components are fixed on the motor fixing plate 4. The motor fixing plate 4 is connected to the unmanned motor through the top mounting plate. The bottom plate of the machine is connected together, the central control board 6, the return buffer 12, the water level fixed height probe 13, the sampling cup draw rope 15 and the return switch 16 are fixed on the return baffle 11, the return baffle 11 passes through the side The two mounting plates are connected to the feet of the UAV 1 together. Another function of the return baffle 11 is to limit the distance between the sampling cup 3 and the UAV 1. The sampling cup 3 will not directly touch the UAV 1, and the bottom of the sampling cup 3 should be higher than that of the unmanned aerial vehicle. The bottom of the feet of the aircraft 1, so that the UAV 1 will not be affected by the sampling cup 3 when it landed.

[0049] Its dynamic working process is: before sampling, first determine the specific location to be sampled on the map or on-site, and place the entire device within the voyage of the sampling point. If the unmanned aerial vehicle 1 uses automatic navigation, the unmanned aerial vehicle takes off to the sampling location according to the route plan; otherwise, the pilot controls the unmanned aerial vehicle 1 to the sampling location on the ground. When UAV 1 arrives above the sampling point, the pilot clicks "Start sampling" on the ground control software, and the sampling process begins. First, the UAV 1 reads the water surface height information from the sampling control system 2, and automatically adjusts the vertical height according to the current altitude until the UAV 1 stabilizes to the preset height, and then the UAV 1 informs the sampling control system 2 to fix the height. After completion, the sampling control system 2 first controls the self-locking motor 7 to unlock the self-locking gear 14, and then starts the sampling motor 10, the reel 5 starts to pay off, and the sampling control system 2 continuously reads the value of the speed encoder 9 and calculates the latest When it is calculated that the sampling cup 3 has been immersed to a certain depth under water, the sampling control system 2 stops the sampling motor 10 and waits for a period of time for the sampling cup 3 to be filled with water sample, and then the sampling control system 2 restarts the sampling motor 10 rotates in the reverse direction, and the reel 5 starts to take up the wire. When the sampling cup 3 reaches the return baffle 11, the sampling cup 3 abuts the return buffer 11 to close the return switch 16, and the closing signal is transmitted to the sampling control system 2. The control system 2 stops the sampling motor 10, and the self-locking motor 7 starts to lock the self-locking gear 14, and informs the UAV 1 to return home, the UAV 1 automatically returns to home or there is a flight crew to return home remotely on the ground.