Semi-quantitative real-time monitoring unmanned aerial vehicle for wind power and wind quantity at middle

Abstract

The invention relates to a semi-quantitative real-time monitoring unmanned aerial vehicle for medium-low-altitude wind power and wind quantity. The semi-quantitative real-time monitoring unmanned aerial vehicle comprises a rotor unmanned aerial vehicle, a remote controller and a hanging swing belt The rotor unmanned aerial vehicle is connected with the hanging swing belt through the hanging ring below the belly, and a reliable indication platform can be provided for monitoring in any middle and low altitude airspace under a certain wind power condition; according to the hanging pendulum belt, wind power in different sizes and directions is correspondingly indicated through the variable density design, the situation that the hanging pendulum belt is drawn into a rotor wing of the unmanned aerial vehicle is avoided, real-time monitoring of the wind power in the airspace is guaranteed, and then the air volume in the corresponding time period of the airspace is estimated; in addition, the monitoring space-time range can be expanded by means of LED upgrading, image upgrading, multi-machine array and the like.

Description

Technical Field

[0001] The invention belongs to a special-function UAV, in particular to a rotor UAV for monitoring wind flow field data in a certain airspace and under certain meteorological conditions. Background Art

[0002] In the troposphere, the average eye can discern the outline of decimeter-level objects at a distance of about 200 to 300 meters, and the distance for discerning centimeter-level object features is within tens of meters, and can exceed kilometers with the help of optical telescopes. When the wind force is level 6, the maximum wind speed is less than 14 meters per second. According to the naked eye's discernible outline distance of 200 meters and the maximum wind speed of level 6, the "remote perception-origin perception" time of the airflow is about 14 seconds. In addition, the wind will also be affected by the nearby pressure field, temperature field, Coriolis force, and even obstacles during the process of flowing through the air flow field, and will undergo significant changes. Therefore, it is difficult for the meteorological department to obtain instantaneous data on wind force in various places, and only predicts a low-precision average value based on the measured data of each sampling point. Existing wind speed and direction instruments and wind pressure gauges can only monitor wind force and volume data at fixed coordinates near the surface. The use of sounding balloons is limited by high costs, large size, and poor flexibility. These devices are difficult to play a role in real-time monitoring of instantaneous wind force in special operations that require visual perception advantages in any airspace.

[0003] Compared with the above equipment, rotorcraft drones have more flexible maneuverability and good stability. As the mainstream model of consumer drones today, quad-rotor drones have main model parameters with a maximum wind resistance level of 5 to 8, a maximum flight speed of about 10 to 39 meters per second, a maximum take-off altitude of 2,500 to 7,000 meters, and a maximum flight time of about 20 minutes to 1 hour. These performance parameters will continue to improve with the emergence of new models and new technologies.

[0004] The common optional settings in the peripherals of rotary-wing UAVs include optical flow positioning, satellite positioning, imaging modules, and other electronic control and signal modules. The distribution of the air flow field generated by the rotary-wing UAV during its flight is roughly as follows: a cylindrical area with the rotating circle of each rotor blade as the cross section, downward along the axis of rotation, and the farther away from the blade, the lower the air flow field strength, and there are a large number of eddies in a small area near the blade surface. When the drone is blown by the external wind, its positioning and electronic control modules also have certain performance: the attitude change when the horizontal component of its own airflow field is offset by the external wind by changing the hovering inclination angle changes within the centimeter range, so it is not easy to identify at a long distance; the feedback electrical signal generated when the position change is detected by its positioning module has a step fluctuation state when forming a control closed loop with the motor drive circuit, and its fluctuation error is not easy to be recognized by the remote remote terminal after the signal delay is superimposed; the image signal change transmitted back to the remote control terminal through its imaging module is also difficult to accurately identify due to the image transmission bit rate and the delay of the image transmission system, and considering the accuracy error of the drone's flight altitude to the photographed object, it is even more difficult to perceive the external wind disturbance by the imaging system. Summary of the invention

[0005] In view of this, the present invention aims to provide a rotorcraft UAV for semi-quantitative real-time monitoring of wind force and volume in a certain airspace at medium and low altitudes under normal operating wind conditions, and to provide more accurate instantaneous wind force and volume monitoring data for special operations in nearby airspace.

[0006] In order to solve the above technical problems, the semi-quantitative real-time monitoring drone of low-altitude wind force and volume provided by the present invention comprises: a rotor drone and a remote controller, and a hanging swing belt.

[0007] The drone is remotely controlled by an operator, and its monitoring status can be seen by nearby workers including the operator.

[0008] The drone can be optionally equipped with an optical flow positioning function. When the optical flow positioning module is installed, the optical flow positioning can be turned off or the weight error in its code parameters can be adjusted to shield the interference when the hanging pendulum belt swings as much as possible.

[0009] The drone can be optionally equipped with an imaging module dedicated to monitoring the hanging pendulum belt below, which can assist in observation when the distance to the observer is far away and there is no telescope to assist observation, thereby serving as an imaging monitoring module to expand the monitoring range of the drone.

[0010] A hanging ring is arranged near the center of the belly of the rotary wing UAV for hanging a hanging swing belt.

[0011] The top of the hanging swing belt is equipped with a buckle, which can be buckled with the hanging ring on the belly of the drone to form a ring chain connection; the hanging swing belt is a variable density strip, the density of which decreases from top to bottom, and the overall density is small and the total weight is light; the hanging swing belt has a wide range, so it is easy to be blown by the wind.

[0012] Furthermore, the length of the higher-density section in the upper part of the hanging swing belt should match the length of the airflow field under the blades when the rotor UAV is flying in the air, so as to prevent it from falling into the vortex area and being entangled in the rotor when swinging in the wind; the middle and lower sections of the hanging swing belt should be set as longer medium-low density areas and lower density areas. The richer the density changes and the longer the sizes of each section, the more obvious the changes when affected by the wind, and the higher the accuracy of wind force monitoring.

[0013] When the monitoring UAV drifts due to the self-interference of the hanging pendulum belt in its optical flow positioning or due to the whole machine drifting due to the whole machine being blown by the side wind, in addition to actively correcting the drift through the operator's remote control, the different mechanical inertia time constants between the rigid fuselage connected up and down by the ring chain and the hanging pendulum belt can be used to eliminate interference and directly read and judge.

[0014] Furthermore, an LED series circuit can be embedded on the hanging pendulum belt and powered by a UAV power supply, so as to provide operation indications at night or in foggy and hazy weather with low visibility, thereby expanding the scope of use in different meteorological conditions; the color spectrum of the embedded LED can change according to the density changes of each section of the hanging pendulum belt, so as to achieve a clearer indication effect; at this time, it should be noted that the narrow-band spectrum of the selected LED should avoid the spectral band of the selected optical flow positioning.

[0015] The wind force and wind volume measured by the semi-quantitative real-time monitoring drone of wind force and wind volume are both vectors. The swing direction of the hanging pendulum belt at the lower end of the drone hovering in the air at a certain moment is the wind direction at that moment. The longer the swing section of the hanging pendulum belt from bottom to top and the greater the density of the blown section, the greater the wind force at that moment. In theory, observers calculate the algebraic sum of the size and direction of the wind force during the observed period to obtain the size and direction of the wind volume flowing through the location of the monitoring drone during that period.

[0016] Furthermore, a plurality of the monitoring drones are released at the same time, and are made to hover in an array in a certain airspace. The simultaneous swinging state of the hanging pendulum belts of each drone displays the distribution of wind field strength in the airspace. The sum of the displayed results of the windward surface units can be taken to obtain the wind volume flowing through the windward surface at that moment.

[0017] When the UAV receives a landing command or starts to land automatically due to low battery, the lower low-density section of the hanging swing belt touches the ground first, and the upper high-density section touches the ground later, until the entire machine lands and triggers the main shaft motor control circuit to cut off power; after the UAV is recovered, the buckle connection between the hanging swing belt and the UAV can be removed and folded for storage.

[0018] The beneficial effects of the present invention are: A. After low-cost modification, consumer-grade drones can be used to achieve semi-quantitative and intuitive monitoring of the magnitude and direction of instantaneous wind force and volume below level 6 strong winds in medium and low altitude areas on the ground; B. In the case where the downward optical flow positioning with the belly facing downward is necessary, the self-interference of the hanging swing belt of the monitoring drone can be reduced by software and hardware means during the design, the drift of the whole drone can be corrected by the operator's control means, or the error of the drift of the whole drone can be ignored directly by the observation means of fuzzy information processing; the latter two means are also applicable to the drift of the whole drone caused by the monitored wind; C. With the assistance of ordinary optical telescopes, semi-quantitative real-time monitoring of wind force and volume in airspace greater than 300 meters up to the restricted flight altitude can be obtained at only a small additional cost; by adding an image monitoring module and an LED series indication circuit, the monitoring time and space range of the drone can be expanded, and the scope of use under more meteorological conditions can be expanded; D. The hanging swing belt connected by buckle ring chain is easy to assemble and disassemble, and can respond to wind blowing from all directions on the horizontal plane; the hanging swing belt adopts variable density design to indicate the wind force vector while avoiding entanglement in the rotor, which is convenient for observers to make quick judgments and estimate the wind volume according to the observation time; after optimizing the density and length of each section of the hanging swing belt, higher-precision monitoring data can be obtained; E. A multi-machine monitoring array composed of multiple monitoring drones can achieve the vector field indication of wind force in a certain airspace at a relatively low cost, and then obtain the vector field data of wind volume, providing higher-precision reference data for special operations in the medium and low altitudes nearby that need to consider wind force and volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a hanging pendulum belt with step-change density.

[0020] Figure 2 This is a schematic diagram of a rotorcraft UAV for monitoring wind force and volume hovering in windless conditions.

[0021] Figure 3 This is a schematic diagram of a rotorcraft UAV for monitoring wind force and volume hovering under low wind conditions.

[0022] Figure 4 This is a schematic diagram of a rotorcraft UAV for monitoring wind force and volume hovering under strong wind conditions.

[0023] Figure 1 —— Figure 4 middle: 1 buckle, 2 vertical pendulum belt section A, 3 vertical pendulum belt section B, 4 vertical pendulum belt section C, 5 vertical pendulum belt section D, 6 vertical pendulum belt section chain; and in each section of the vertical pendulum belt: density of section A>density of section B>density of section C>density of section D 7 rotor UAV, 8 optical flow positioning module and probe, 9 imaging module and camera, 10 rotor, hanging ring 11. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with specific implementations verified by field experiments and accompanying drawings. Obviously, the described implementations are only part of the implementations of the present invention, rather than all of the implementations.

[0025] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 1 The vertical pendulum belt is a step-change density form, wherein the density of the four sections of the vertical pendulum belt section A 2, the vertical pendulum belt section B 3, the vertical pendulum belt section C 4, and the vertical pendulum belt section D 5 decreases in sequence, and the total weight of the vertical pendulum belt does not exceed the maximum load of the rotary-wing UAV 7; Figure 2 This is a schematic diagram of a rotor UAV for monitoring wind force and volume when hovering under windless conditions; Figure 3 , Figure 4 The following are schematic diagrams of the rotor UAV for monitoring wind force and volume when hovering under relatively small wind conditions and relatively large wind conditions, respectively.

[0026] In this specific embodiment, the present invention first sets a hanging ring 11 on the belly of a quad-rotor drone, and prepares a 4-section hanging swing belt. The sections of the hanging swing belt are arranged in sequence according to density and are pre-connected with a lightweight hanging swing belt section chain 6, and a lightweight buckle 1 is installed at the top with the highest density. The size of the buckle 1 matches the size of the hanging ring 11 to form a loose chain connection so that the buckle 1 can still swing freely after the hanging swing belt is buckled to the hanging ring 11 on the belly of the rotor drone 7.

[0027] In this specific implementation, before launching the UAV, the hanging swing belt is fastened to the belly of the rotor UAV 7 and spread flat on the ground before taking off. The flight altitude must not be lower than the total length of the hanging swing belt after it is extended. After flying to the designated altitude of the airspace where wind measurement is required, the drone will remain in a hovering state. At this time, the operator of the remote-controlled UAV controls the UAV while observing the state of the hanging swing belt, and reports the observation results to nearby operators while estimating the size and direction of the wind force and volume.

[0028] In this specific embodiment, the length, weight, width, and density distribution of each section of the hanging pendulum belt of the present invention are all numerical combinations that have been calculated multiple times and repeatedly verified by experiments. This array is not unique, and the array values ​​are related to factors such as the parameters of the rotorcraft UAV 7, the wind speed range to be monitored, and the ambient air pressure. When the hanging pendulum belt is embedded with an LED circuit, the weight of the circuit must also be included in this array for calculation, design, and experimental verification.

[0029] Furthermore, the number of sections of the hanging pendulum belt can also be divided into other numbers. When the number of sections tends to be extremely large and the length of each section tends to be extremely small, it becomes a hanging pendulum belt in the form of continuously changing density. The width, shape and thickness of each section of the pendulum belt can also be changed accordingly according to actual needs and flight control power limitations.

[0030] When observing the rotor UAV using the present invention to monitor wind force and volume: if all sections of the hanging pendulum belt are maintained vertically between the airflow fields of the cylindrical areas under the rotors of each axis of the UAV, it means that there is no wind at this moment; if only the lowest section D 5 of the hanging pendulum belt has an inclined swing, and the swing amplitude decreases from bottom to top until the uppermost section A 2 remains vertical, it means that there is a small soft wind, a light breeze, or a breeze at this moment; if the lowest section D 5 of the hanging pendulum belt is blown horizontally and the swing angles of the upper sections increase, it means that there is a large gentle breeze or a light breeze at this moment, and the entire rotor UAV 7 is also slightly tilted at this moment; if the entire section of the hanging pendulum belt is pulled by the wind and tends to be horizontal, the uppermost section A 2 is tilted significantly, and the last section D 5 also swings up and down with the horizontal plane as the centerline, and the inclination angle of the entire rotor UAV 7 is connected When it is close to 45 degrees, it means that the wind force at this position has reached the monitoring limit of the rotor drone monitoring wind force and wind volume. The drone should be retracted in time and the relevant operators in the nearby airspace should be notified to avoid safety accidents in strong wind environments. When the monitoring position is at a low altitude and close to the operator, the operator can use the wind direction sensed by the operator to verify whether the monitored wind direction indication is accurate. If the wind direction passes through the buckle 1-rotor 10, causing the hanging swing belt indication direction to be disturbed by the drone's own airflow field, the rotor drone 7 must be operated to turn left or right to make the hanging swing belt indication direction fall back to the cylindrical area under each axis rotor between its own airflow fields. At this time, the hanging swing belt has the largest swing amplitude under this wind force. When the monitoring position is high or far from the operator, it is also advisable to turn the fuselage left and right during monitoring to prevent inconsistent airflow in high and low wind fields. Whether it is the model verified by the experiment in this specific implementation method or the model of semi-quantitative real-time monitoring drone of wind force and wind volume that changes the parameters of the hanging swing belt or other verified wind force and wind volume, a more accurate reference indication can be obtained after subsequent wind tunnel calibration experiments.

[0031] For the situation where the optical flow positioning 8 under the belly of the aircraft must be activated, in addition to the control correction means and fuzzy information processing observation means during use, selecting transparent materials for the hanging pendulum belt during design and manufacturing can obtain good results in hardware design. When writing the code for the relevant light control module, using the Kanade-Lucas-Tomasi algorithm that expands the proportion of the global motion model, reducing the weight of the hanging pendulum belt to weaken the tracking effect of the hanging pendulum belt swinging into the perception range of the optical flow probe can also have a certain effect from the software level.

[0032] For the case where an image module 10 is installed to monitor the hanging swing belt, the lens 10 should maintain a vertical downward angle when in use. If a vertical rotor drone 7 is used, the downward angle of the fuselage should take into account the fuselage tilt factor when exposed to wind. Regardless of whether it is a single-lens or dual-lens configuration, when the hanging swing belt blows to the reverse angle or vertical angle of the fuselage lens and thus swings out of the field of view of the lens 10, the fuselage should be rotated remotely to make the "buckle 1-lens 10 position connection line" consistent with the swing direction of the swing belt.

[0033] For multi-machine monitoring arrays, they should be numbered in advance with three-dimensional position coordinates when in use, and the distance between each flying machine should be more than twice the total length of the hanging pendulum belt. When measuring the monitoring results, the coordinate values ​​of each machine during measurement should be added after the wind force and volume data. When the wind is strong, it is advisable for multiple people to jointly control, with each person controlling and monitoring one monitoring drone.

[0034] In this specific implementation, when the monitoring task is completed or the UAV is low on battery, it should be recovered in time. During recovery, the monitoring UAV will land vertically and land in the order of vertical pendulum belt section D 5, vertical pendulum belt section C 4, vertical pendulum belt section B 3, vertical pendulum belt section A 2, and the fuselage of the rotor UAV 7. When the feet of the rotor UAV 7 touch the ground first or the sections of the vertical pendulum belt are folded to pad the belly of the rotor UAV 7 until it cannot descend, the UAV rotor main shaft motor drive circuit is powered off, thereby completing the recovery of the monitoring UAV.

[0035] The above is a detailed introduction to the semi-quantitative real-time monitoring drone of medium and low altitude wind force and volume provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians who use the present invention in this technical field and other fields, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. Semi-quantitative real-time monitoring drone of medium and low altitude wind force and volume, including: Rotary-wing UAV, remote control and hanging pendulum belt.

2. The semi-quantitative real-time monitoring drone for medium and low altitude wind force and volume as claimed in claim 1 is characterized by: The pendulum belt is suspended under the drone, and when the drone is hovering, it can swing to different degrees in real time according to the instantaneous wind of different sizes and directions.

3. The semi-quantitative real-time monitoring drone for medium and low altitude wind force and volume as claimed in claim 1 is characterized by: The swing of the hanging pendulum belt during response monitoring allows for direct observation to determine wind force, thereby recording the size and direction of the semi-quantitative cumulative air output over a certain period of time.

4. The semi-quantitative real-time monitoring drone for medium and low altitude wind force and volume as claimed in claim 1 is characterized by: The hanging swing belt can be folded or released depending on whether the drone is in use or not, and will not be caught in the rotor blades due to turbulence interference when in use.

5. The semi-quantitative real-time monitoring drone for medium and low altitude wind force and volume as claimed in claim 1 is characterized by: Its monitoring range can be improved after LED and image upgrades.

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