Self-stabilizing north-pointing meteorological unmanned aerial vehicle

Abstract

The utility model discloses a self-stabilizing north-pointing meteorological unmanned aerial vehicle which comprises an unmanned aerial vehicle body, a handheld three-axis self-stabilizing holder installed above the unmanned aerial vehicle body, meteorological equipment fixed to the top end of the handheld three-axis self-stabilizing holder, and a limiting mechanism used for fixing the handheld three-axis self-stabilizing holder to the unmanned aerial vehicle body. According to the self-stabilization north-pointing meteorological unmanned aerial vehicle, the problems that in the prior art, meteorological equipment is poor in perpendicularity, a stabilization platform is expensive, no damping measure exists between connection, and the endurance time of the unmanned aerial vehicle cannot meet the task requirement are solved.

Description

Technical Field

[0001] This utility model relates to the field of unmanned aerial vehicle (UAV) meteorological monitoring technology, specifically a gasoline-powered multi-rotor UAV that integrates an autonomous and stable platform, precise orientation pointing, and meteorological data acquisition functions. Background Technology

[0002] With their flexible and precise observation capabilities, drones are becoming an important tool in the field of meteorological monitoring, especially in monitoring extreme weather, local microclimates, and complex environments. Drones are playing an increasingly important role in meteorological monitoring, leveraging their advantages of flexibility, low cost, and high resolution to compensate for the shortcomings of traditional meteorological observation methods and improve the accuracy of weather forecasting and climate research.

[0003] Existing meteorological monitoring drones are divided into two main categories: fixed-wing and multi-rotor. Fixed-wing drones are mainly equipped with meteorological radar and atmospheric data collectors, which are used to monitor the location of cloud clusters and collect the content of various components in the atmosphere. Multi-rotor drones are mainly equipped with ultrasonic sensors and mechanical sensors, which are used to monitor wind speed, wind direction, temperature and humidity.

[0004] Currently, multi-rotor weather monitoring drones are mainly electric drones, which use batteries to directly power the motors and provide lift. The weather equipment of multi-rotor drones is primarily mounted on the fuselage or arms and directly fixed by linkages. Existing multi-rotor weather drones have the following problems:

[0005] First, the meteorological equipment installed on current multi-rotor meteorological monitoring drones is mostly connected to a single link, which is then connected to the drone. Due to the leverage effect of vibration transmission, when the drone vibrates during operation, the vibration will propagate to the sensor along the link, and the vibration amplitude will gradually amplify, which can easily lead to resonance. Therefore, the method of fixing the sensor with a single link is not suitable for fixing sensor equipment that has high requirements for vibration environment, and it is easy to cause error accumulation.

[0006] Secondly, existing meteorological equipment, especially anemometers, has strict requirements for ground verticality. When drones hover in the air, they are often tilted due to the wind, which will significantly affect the accuracy of meteorological equipment readings. For example, when ultrasonic anemometers are tilted, the measured airflow speed will be too high, resulting in the measured wind speed value being higher than the actual value and causing errors. Therefore, ensuring the verticality of the sensor is particularly important.

[0007] Third, there are currently two methods for maintaining the verticality of meteorological equipment: undermount three-axis self-stabilizing gimbals and six-degree-of-freedom (DOF) stabilizing platforms. Undermount three-axis self-stabilizing gimbals are the current mainstream solution, but this solution is strongly affected by the downdraft of the drone. Currently, this solution can only be installed in the middle of the drone body to minimize the impact of the downdraft. Six-degree-of-freedom (DOF) stabilizing platforms also have many problems. According to the driving method, six-degree-of-freedom (DOF) stabilizing platforms can be divided into three types: pneumatic platforms driven by air pressure, hydraulic platforms driven by hydraulic pressure, and electric platforms driven by electricity. Pneumatic and hydraulic platforms are difficult to install on drone platforms due to their large size, while electric platforms have too small a load capacity and can only rely on using higher-performance motors to shorten the response time and increase the load capacity. In addition, there is the problem of the high price of six-degree-of-freedom (DOF) stabilizing platforms, so they are rarely used in practical applications.

[0008] Fourth, existing multi-rotor weather monitoring drones are mainly electric drones. Because they need to carry lithium batteries, the flight time of multi-rotor electric drones is generally no more than 50 minutes. Therefore, most multi-rotor electric drones cannot operate continuously at an altitude of 1000m.

[0009] Fifth, directly connecting meteorological equipment and drones with a linkage will make the highly sensitive meteorological equipment susceptible to vibration, resulting in inaccurate readings or a significant reduction in service life. However, most drone manufacturers often neglect vibration reduction in their design and cost considerations, tending to ignore excessive measurement errors or use algorithms to compensate for and correct readings. Moreover, improper handling of vibration reduction may cause new resonant frequencies, which may amplify the vibration.

[0010] Sixth, the installation location of meteorological equipment in most existing multi-rotor meteorological monitoring drones is generally susceptible to environmental influences, which can lead to significant measurement errors or affect the flight safety of the drone. Problems such as airflow from the rotor, heat from the power unit, and shift of the drone's center of gravity are likely to occur. Utility Model Content

[0011] Purpose of the utility model: In order to overcome the shortcomings of the prior art, this utility model provides a self-stabilized north-pointing meteorological drone to solve the problems of poor verticality of meteorological equipment, expensive stabilization platform, lack of shock absorption measures between connections, and insufficient drone endurance to meet mission requirements in the prior art.

[0012] Technical solution: In order to achieve the above objectives, this utility model provides a self-stabilized north-pointing meteorological drone, which includes a drone, a handheld three-axis self-stabilizing gimbal mounted on the top of the drone, and meteorological equipment located on the top of the handheld three-axis self-stabilizing gimbal. It also includes a limiting mechanism for fixing the handheld three-axis self-stabilizing gimbal to the drone, and a buffer part located between the handheld three-axis self-stabilizing gimbal and the limiting mechanism.

[0013] The limiting mechanism includes a lower pipe clamp, an upper pipe clamp, and a mounting platform. One end of the upper pipe clamp is vertically installed below the mounting platform, and the other end of the upper pipe clamp is fixedly connected to the lower pipe clamp, thus fastening the lower pipe clamp, the upper pipe clamp, and the mounting platform together to lock the mounting platform, making the platform and the UAV rigidly connected and reducing the error value caused by unnecessary vibration.

[0014] The buffer consists of multiple stacked rubber pads, which are fixed to the bottom of the handheld three-axis self-stabilizing gimbal by screws passing through the mounting platform and the multiple rubber pads in sequence. The shock absorption effect of the rubber pads is used to reduce the error of meteorological equipment. While avoiding resonance, the transmission of vibration is weakened to meet safety requirements.

[0015] As a further preferred embodiment of this utility model, the lower and upper pipe clamps are fitted together and sleeved on the two arms at the front of the drone. The lower and upper pipe clamps are then vertically fixed to the bottom of the mounting platform to achieve a clamping state between the limiting mechanism and the drone. The lower and upper pipe clamps are arranged perpendicular to the axial direction of the two arms at the front of the drone, and there are two pairs in total. These two pairs of lower and upper pipe clamps can effectively lock the mounting platform, making the platform and the drone rigidly connected and reducing the error value caused by unnecessary vibration.

[0016] The platform uses high-strength carbon fiber, and the two pairs of lower and upper pipe clamps are made of stainless steel to withstand harsh environmental corrosion. The two pairs of upper and lower pipe clamps also have a hollow design to reduce weight while maintaining rigidity. Furthermore, due to its ease of design and manufacturing, it is helpful in selecting the installation location for meteorological equipment.

[0017] As a further preferred embodiment of this utility model, the lower pipe clamp, the upper pipe clamp, and the mounting platform are fixedly connected by threaded connections. This detachable connection method makes the maintenance of the entire structure more convenient. When a part of the structure needs to be replaced, it is only necessary to disassemble the threaded connection and replace the part of the structure, thereby reducing the later maintenance cost and improving the overall service life of the product.

[0018] As a further preferred embodiment of this utility model, the circular hole obtained by the cooperation of the lower and upper pipe clamps is connected to the two arms at the front end of the drone in a transitional fit. By making the circular hole obtained by the cooperation of the lower and upper pipe clamps match the size of the two arms at the front end of the drone, the transitional fit ensures that the limiting mechanism and the arms are not too tight and there is no gap, thus ensuring the stability of the connection between the two.

[0019] As a further preferred embodiment of this utility model, each arm is provided with multiple upper tube clamps. This arrangement of at least two pairs of lower tube clamps and upper tube clamps can effectively lock the mounting platform, making the platform and the drone rigidly connected, reducing the error value caused by unnecessary vibration, and ensuring the stability and reliability of the operation.

[0020] As a further preferred embodiment of this invention, the number of rubber pads is three. The rubber pads are made of Shore A material with a hardness range of 65HA to 75HA and a thickness of 8mm to 12mm. Three stacked rubber pads are placed between the mounting platform and each handheld three-axis self-stabilizing gimbal for vibration damping. Since most existing weather drones have rigid connections, parallel rubber pads are added to reduce the error of weather equipment and prevent resonance while weakening vibration transmission. The current power unit excitation frequency is 233Hz, which is reduced to 70Hz by the damping blocks between the power unit and the drone. The desired frequency to avoid resonance at 70Hz is:

[0021]

[0022] Taking a safety value of 25Hz, the weight supported by the parallel rubber pads is 3.1kg, including the gimbal and meteorological equipment, so the total stiffness requirement is 7648N / m, and the stiffness requirement of each rubber pad is 25496N / m. Due to the limitation of the installation diameter, a radius parameter of 15mm is used. Therefore, the rubber pad material is Shore A type, with a hardness range of 65HA~75HA, and the thickness of each rubber pad material is 8mm~12mm. The resulting natural frequency is 25Hz to meet the safety value requirement.

[0023] As a further preferred embodiment of this invention, the described drone is a gasoline-powered multi-rotor drone. Most existing electric multi-rotor drones generally have a flight time of no more than 40 minutes (hovering time), and if flying at maximum altitude while resisting strong winds, the flight time will be significantly reduced. For example, a round trip flight from 0m to 1000m takes 10 minutes, at a speed of approximately 3m / s; adding 10 minutes for mission operation time already reaches half of the conventional flight time. Therefore, compared to electric multi-rotor drones, gasoline-powered drones are more suitable in terms of flight time. Common gasoline-powered drones can fly for more than 90 minutes, and because of the high fuel energy storage utilization rate, carrying extra fuel can further extend the flight time without compromising flight safety due to short flight time.

[0024] The handheld three-axis gimbal selected in this invention has a similar market price to the under-mounted three-axis gimbal. However, the under-mounted three-axis gimbal is less practical because it is directly affected by the downwash airflow, which affects the accuracy of meteorological equipment. For six-degree-of-freedom (DOF) stabilization platforms, only electric platforms can be installed on drones. However, the load capacity of typical electric platforms is too small. If better motors and control units are installed to achieve the same performance as the handheld three-axis gimbal, the number of motors in the handheld gimbal (3) will always be far less than the number of motors in the six-DOF stabilization platform (6). Furthermore, the size of the handheld gimbal (220*200*75mm) is much smaller than that of the six-DOF platform (500*500*400mm). Combined with a more mature stabilization algorithm, the handheld three-axis gimbal is superior to the six-DOF stabilization platform.

[0025] As a further preferred embodiment of this utility model, the meteorological equipment is installed at least 0.5m away from the rotor plane of the UAV, at least 0.7m away from the silencer, and less than 1.49m away from the geometric center of the UAV. The installation position of the meteorological sensor is quite important for the reading accuracy of the meteorological sensor. Taking the ultrasonic anemometer as an example, if it is installed below the rotor plane, it will be severely affected by the downwash airflow, resulting in a large deviation between the reading of the ultrasonic anemometer and the actual reading. It has been experienced that when the horizontal distance from the rotor center is 1.2D (rotor diameter) and the vertical distance from the rotor center is 0.53D, the airflow generated by the rotor is hidden in the natural wind and no longer has a significant impact on the anemometer. The position of the meteorological sensor is also constrained by the power unit. The main heat sources of the power unit are the radiator, silencer and exhaust pipe. The heat of the radiator will be dissipated downwards due to the downwash airflow of the rotor. The heat sources closest to the sensor are the radiator and exhaust pipe, which are generally installed directly above the center of the UAV body. The selected model has its muffler and exhaust pipe located in the middle of the drone facing rearward. If the weather sensor is installed on the rear, left or right sides, or the upper middle of the drone, it will be affected by temperature. Therefore, the best installation position for the weather sensor is the front of the drone. Heat transfer at this position will be affected by the power unit itself. Moreover, a suitable distance of 0.7m from the muffler is selected, and this position will not be affected by heat.

[0026] As a further preferred embodiment of this invention, the center of gravity offset of the described nitro-powered multi-rotor UAV is less than 10% of its rotor pitch. Excessive center of gravity offset would prevent the power unit from correcting the excessive offset, leading to overturning during flight. The formula is as follows:

[0027] x_cg = Additional torque / Total mass;

[0028] The total weight is approximately 87 kg;

[0029] The center of gravity offset is less than 10% of the rotor spacing of 1.2m, which is ≤0.12m;

[0030] The total weight of the equipment, including the platform, is 7kg.

[0031] Therefore, the maximum installation location is calculated to be 1.49m from the geometric center;

[0032] Therefore, taking into account airflow, temperature and center of gravity, a mounting frame is set up between the two arms at the front of the fuselage. The handheld three-axis self-stabilizing gimbal is mounted on the mounting frame through shock-absorbing rubber. The meteorological equipment is mounted on the gimbal at a distance of at least 0.5m from the rotor plane, at least 0.7m from the silencer, and less than 1.49m from the geometric center of the UAV.

[0033] This invention uses the commercially available and mature DJI Ruibing SC handheld three-axis self-stabilizing gimbal to support meteorological equipment, thereby solving the stringent requirements of existing meteorological equipment for ground verticality.

[0034] Working principle

[0035] The mounting platform achieves stability by clamping the two forward-facing arms of the gasoline-powered multirotor UAV with offset lower and upper clamps. This keeps the platform stationary relative to the UAV, eliminating additional sway and reducing the error value of the meteorological equipment. A relatively inexpensive, fast-responding, highly stable handheld three-axis self-stabilizing gimbal is used, offering some shock absorption. This ensures the meteorological equipment remains perpendicular to the ground, further reducing its error value. The three parallel rubber pads connecting each handheld three-axis self-stabilizing gimbal to the mounting platform provide both rigidity and shock absorption without transmitting resonance, reducing vibrations from the rotor and power unit of the gasoline-powered multirotor UAV. Compared to most electric UAVs on the market, the gasoline-powered multirotor UAV used as the equipment platform offers a longer range, meeting the requirements for meteorological monitoring missions at an altitude of 1000m. The meteorological equipment also needs to be installed within a specific location range to ensure minimal error.

[0036] Beneficial effects: Compared with the prior art, the self-stabilized north-pointing meteorological drone of this utility model has the following advantages:

[0037] (1) The high rotational response speed and high stability of the handheld three-axis self-stabilizing gimbal meet the requirements of meteorological equipment within the same weight range. The gimbal itself is installed facing upwards. Choosing a suitable installation position can greatly reduce external interference to the meteorological equipment. By adjusting the height and installation position with the mounting platform, the meteorological equipment is placed in a position where it is least affected by airflow, heat and center of gravity shift.

[0038] (2) The mounting frame carries a handheld three-axis self-stabilizing gimbal and meteorological equipment. By using the upper and lower tube clamp structure, it locks the mounting platform, making the platform and the UAV rigidly connected, reducing the error value caused by unnecessary vibration, and reducing weight while maintaining rigidity.

[0039] (3) The handheld three-axis self-stabilizing gimbal itself has good stabilization function. The algorithm it is equipped with can accurately stabilize the work and also assist the whole system in shock absorption.

[0040] (4) By using an electric multi-rotor drone equipped with a handheld three-axis self-stabilizing gimbal and meteorological equipment, the fuel-powered characteristics make it more suitable for flight time. Common fuel-powered drones can fly for more than 90 minutes. Moreover, because the fuel energy storage utilization rate is high, extra fuel can be carried to further increase the flight time, and flight safety will not be affected by the short flight time.

[0041] (5) Three parallel rubber pads are added between the mounting platform and each handheld three-axis self-stabilizing gimbal for shock absorption, in order to reduce the error of meteorological equipment, and to reduce the transmission of vibration while avoiding resonance, thus meeting the safety requirements. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of this utility model;

[0043] Figure 2 The front view of a handheld three-axis self-stabilizing gimbal mounted on a limiting mechanism;

[0044] Figure 3 Left view of a handheld three-axis self-stabilizing gimbal mounted on a limiting mechanism;

[0045] Figure 4 This is a top view of a handheld three-axis self-stabilizing gimbal mounted on a limiting mechanism. Detailed Implementation

[0046] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0047] As shown in the attached figure, the self-stabilized north-pointing meteorological drone of this utility model includes a gasoline-powered multi-rotor drone 1, a lower tube clamp 2, an upper tube clamp 3, a mounting platform 4, a rubber pad 5, a handheld three-axis self-stabilizing gimbal 6, and meteorological equipment 7.

[0048] One end of the upper pipe clamp 3 is vertically installed below the mounting platform 4 by means of threaded connection. The other end of the upper pipe clamp 3 is connected with the lower pipe clamp 2 to form a circular hole that is locked on the outside of the two arms at the front end of the oil-powered multi-rotor UAV 1. Then, the lower pipe clamp 2 and the upper pipe clamp 3 are fastened by means of threaded connection, so as to realize the position limitation of the lower pipe clamp 2, the upper pipe clamp 3, the mounting platform 4 and the forearm of the oil-powered multi-rotor UAV 1, and achieve the clamping state.

[0049] After screws are passed through the mounting platform 4 and three rubber pads 5 in sequence, they are fixed to the bottom of the handheld three-axis self-stabilizing gimbal 6, so that the handheld three-axis self-stabilizing gimbal 6, the mounting platform 4 and the oil-powered multi-rotor UAV 1 are connected as a whole. A meteorological device 7 is installed on the top of the handheld three-axis self-stabilizing gimbal 6.

[0050] Example

[0051] When a mission is required, first fix the meteorological device 7 to the handheld three-axis self-stabilizing gimbal 6, turn on the power of the handheld three-axis self-stabilizing gimbal 6 and set it to self-stabilizing mode, then unfold the arms of the gasoline-powered multi-rotor drone 1, then start the gasoline-powered multi-rotor drone 1, shift gears to take off and execute the mission. During the mission, the gasoline-powered multi-rotor drone 1 will always keep its nose pointing north so that the meteorological device 7 points north through the drone's own flight path program. The handheld three-axis self-stabilizing gimbal 6 will always keep the meteorological device 7 perpendicular to the ground, and the handheld three-axis self-stabilizing gimbal 6, together with the rubber pads 5, will dampen the vibration of the meteorological device 7. After the mission is completed, control the gasoline-powered multi-rotor drone 1 to land, fold the arms, and remove the meteorological device 7.

[0052] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A self-stabilized north-seeking meteorological drone, comprising a drone (1), a handheld three-axis self-stabilized gimbal (6) mounted above the drone (1), and a meteorological device (7) located at the top end of the handheld three-axis self-stabilized gimbal (6), characterized in that: It also includes a limiting mechanism for fixing the handheld three-axis self-stabilizing holder (6) on the unmanned aerial vehicle (1), and a buffer part between the handheld three-axis self-stabilizing holder (6) and the limiting mechanism; The limiting mechanism comprises a lower pipe clamp (2), an upper pipe clamp (3) and a carrying platform (4), one end of the upper pipe clamp (3) is vertically installed below the carrying platform (4), and the other end of the upper pipe clamp (3) is fixedly connected with the lower pipe clamp (2). The buffer part is a plurality of rubber pads (5) stacked together, which are fixed below the handheld three-axis self-stabilizing holder (6) by being sequentially screwed through the carrying platform (4) and the plurality of rubber pads (5).

2. A self-stabilizing, north-seeking meteorological drone according to claim 1, characterized in that: After the lower pipe clamp (2) and the upper pipe clamp (3) are sleeved on the two arms at the front end of the unmanned aerial vehicle (1) in cooperation, the lower pipe clamp (2) and the upper pipe clamp (3) are vertically fixedly connected below the carrying platform (4) to realize the clamping state of the limiting mechanism and the unmanned aerial vehicle (1).

3. A self-stabilizing, north-seeking meteorological drone according to claim 2, characterized in that: The lower pipe clamp (2), the upper pipe clamp (3) and the carrying platform (4) are fixedly connected by screw connection respectively.

4. The self-stabilizing, north-seeking meteorological drone of claim 2, wherein: The circular hole obtained by cooperation and connection of the lower pipe clamp (2) and the upper pipe clamp (3) realizes transition fit connection with the two arms at the front end of the unmanned aerial vehicle (1).

5. A self-stabilizing, north-seeking meteorological drone according to claim 4, characterized in that: A plurality of upper pipe clamps (3) are arranged on each arm.

6. The self-stabilizing, north-seeking meteorological drone of claim 1, wherein: The material hardness of the rubber pad (5) is Shore A type, the hardness range is 65HA-75HA, and the thickness is 8mm-12mm.

7. The self-stabilizing, north-seeking meteorological drone of claim 1, wherein: The unmanned aerial vehicle (1) is an oil-driven multi-rotor unmanned aerial vehicle.

8. A self-stabilizing, north-seeking meteorological drone according to claim 7, characterized in that: The center of gravity offset of the oil-driven multi-rotor unmanned aerial vehicle (1) is less than 10% of the rotor spacing.

9. The self-stabilizing, north-seeking meteorological drone of claim 1, wherein: The installation position of the meteorological equipment (7) is at least 0.5m away from the rotor plane of the unmanned aerial vehicle (1), the installation position of the meteorological equipment (7) is at least 0.7m away from the muffler, and the installation position of the meteorological equipment (7) is less than 1.49m away from the geometric center of the unmanned aerial vehicle.

10. The self-stabilizing, north-seeking meteorological drone of claim 1, wherein: The number of rubber pads (5) is three.

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