Hydrogen energy unmanned aerial vehicle and control method thereof

Abstract

The invention relates to the technical field of unmanned aerial vehicles, in particular to a hydrogen energy unmanned aerial vehicle and a control method thereof.According to the unmanned aerial vehicle, a hydrogen fuel cell serves as a power source, a hydrogen storage tank is arranged at the top of an inner cavity of an unmanned aerial vehicle body, the hydrogen fuel cell is arranged at the bottom of the inner cavity, and then long-time-efficiency driving of rotors is achieved; therefore, the unmanned aerial vehicle can meet the requirements of long-endurance and large-range task scenes, and a stable triangular supporting structure is formed through the unique layout of the three two-fork wing arms. Two brushless motors are installed at the tail end of each binary wing arm to form a power system with six rotors in total, the layout remarkably improves power redundancy, that is, when any rotor or even one rotor on a single binary wing arm breaks down, the other rotors can provide higher asymmetric torque compensation capacity, and by combining a specific control algorithm, the power redundancy can be greatly improved. The basic flight attitude and controllability of the unmanned aerial vehicle can be effectively maintained, and the flight safety and reliability are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and particularly to a hydrogen energy unmanned aerial vehicle and a control method thereof. Background Art

[0002] With the rapid development of unmanned aerial vehicle technology, its applications in fields such as aerial photography, surveying and mapping, inspection, and logistics are becoming increasingly widespread. Traditional lithium battery-powered unmanned aerial vehicles are limited by the battery energy density and generally have the problem of short endurance time, which severely restricts their ability to perform long-endurance and large-scale tasks. Hydrogen fuel cells, with their advantages of high energy density and zero emissions, are regarded as one of the effective solutions to solve the endurance bottleneck of unmanned aerial vehicles. Therefore, hydrogen energy unmanned aerial vehicle technology has emerged.

[0003] However, hydrogen energy unmanned aerial vehicles still face many challenges in practical applications. For example, hydrogen fuel cells have relatively high requirements for the stability of hydrogen supply pressure. During the cruise of existing unmanned aerial vehicles, especially when performing flight tasks including different altitudes (such as mountainous areas and hilly areas), the significant change in external atmospheric pressure will directly affect the effective supply pressure of the hydrogen storage tank. If the hydrogen supply pressure is unstable or insufficient, it will lead to fluctuations or even a decrease in the output power of the fuel cell, making it difficult to meet the continuous and stable power demand under complex flight routes and affecting flight performance and endurance mileage. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydrogen energy unmanned aerial vehicle and a control method thereof, which are used to solve the technical problem of short endurance time caused by the limitation of the battery energy density of existing lithium battery-powered unmanned aerial vehicles.

[0005] To solve the above technical problem, on the one hand, the present invention provides a hydrogen energy unmanned aerial vehicle, including: a drone body and three binary wing arms provided on the drone body. Among them, two binary wing arms are symmetrically provided on both sides of the front end of the drone body, and the other binary wing arm is provided at the rear end of the drone body. Brushless motors are provided at both ends of the binary wing arm; a hydrogen storage tank is provided at the top of the inner cavity of the drone body, and a hydrogen fuel cell is provided at the bottom of the inner cavity. The gas outlet of the hydrogen storage tank is connected to the hydrogen inlet of the hydrogen fuel cell through an adjustable pressure supply solenoid valve; a camera is provided on the lower side of the front end of the drone body.

[0006] Secondly, the drone body is provided with a control module, and the control module includes an IMU sensor and a super capacitor.

[0007] The hydrogen energy unmanned aerial vehicle is not only equipped with a hydrogen fuel cell, but also configured with a small lithium battery to supply power to the control circuit. That is, high-power devices such as rotors are powered by the hydrogen fuel cell, and low-power devices such as the control circuit are powered by the small lithium battery. Secondly, a super capacitor is also provided to compensate for the power of the hydrogen fuel cell when the hydrogen energy unmanned aerial vehicle performs instantaneous high-maneuver flight actions.

[0008] On the other hand, the present invention provides a control method for a hydrogen energy drone. The drone body is provided with a control module, and the control module includes an IMU sensor and a super capacitor. The control method includes: Obtain the cruise path information of the hydrogen energy drone, and perform cruise flight based on the cruise path information. During this period, adjust the opening degree of the adjustable pressure supply solenoid valve in real time based on the altitude fluctuation parameter in the cruise path information, and then dynamically adjust the hydrogen supply pressure value of the hydrogen fuel cell. At the same time, detect the current flight attitude in real time through the IMU sensor. When the flight attitude exceeds the threshold, calculate the compensation power of the super capacitor based on the current flight attitude and the real-time power of the hydrogen fuel cell, so that the hydrogen energy drone flies according to the cruise path.

[0009] Among them, dynamically adjusting the hydrogen supply pressure value of the hydrogen fuel cell based on the altitude fluctuation parameter includes: ; Among them, is the hydrogen supply pressure value, is the membrane characteristic sensitivity coefficient, = 0.03; ; is the standard temperature value, which is obtained by the feedback of the temperature sensor set at the standard point; is the standard pressure value, which corresponds to the standard temperature value ; is the altitude; is the natural constant; is the sea level temperature; is the sea level relative humidity; is the temperature fluctuation compensation caused by the altitude, that is, the temperature compensation; is the humidity fluctuation compensation caused by the altitude, that is, the humidity compensation.

[0010] Secondly, when the flight attitude exceeds the threshold, calculating the compensation power of the super capacitor based on the current flight attitude and the real-time power of the hydrogen fuel cell includes: When the IMU sensor detects that the pitch angle rate of the hydrogen energy drone is greater than 15° / s and the yaw angle rate is greater than 20° / s, it is determined as the high maneuvering state. At this time, the super capacitor is used to compensate the power of the hydrogen fuel cell. The calculation method of the power compensation is: ; Among them, is the climbing rate (m / s), is the turning angular velocity (rad / s), is the current mass of the hydrogen energy drone, which changes dynamically with the flight duration of the hydrogen energy drone, is the propeller efficiency, which varies dynamically with the altitude H. is the starting resistance coefficient is the relative air density at sea level, and H is the altitude. is the flight speed of the current hydrogen energy UAV. is the acceleration due to gravity, and t is the time. is the moment of inertia of the hydrogen energy UAV in the vertical direction. is the angular acceleration coefficient. is the output power of the current hydrogen fuel cell. Secondly, is used to simulate and calculate the climbing power of the hydrogen energy UAV. is used to simulate and calculate the turning power of the hydrogen energy UAV. is the climbing coefficient, which varies dynamically with the altitude H of the flight of the hydrogen energy UAV and the current mass of the hydrogen energy UAV and changes dynamically.

[0011] The beneficial effects of the present invention are as follows: The UAV described in the present invention uses a hydrogen fuel cell as a power source. By arranging a hydrogen storage tank at the top of the inner cavity of the UAV body and a hydrogen fuel cell at the bottom of the inner cavity, the long-term driving of the rotor is realized, so that the UAV can adapt to the requirements of long endurance and large range mission scenarios. Secondly, a stable triangular support structure is formed by a unique layout of three binary wing arms (two symmetrically on both sides at the front end and one at the rear end). Two brushless motors are installed at the end of each binary wing arm to form a power system with a total of six rotors. This layout significantly improves the power redundancy, that is, when any rotor or even one rotor on a single binary wing arm fails, the remaining rotors can provide a stronger asymmetric torque compensation ability. Combined with a specific control algorithm, the basic flight attitude and controllability of the UAV can be effectively maintained, greatly improving the flight safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 is a schematic structural diagram of the hydrogen energy UAV; Figure 2 is a perspective view of the hydrogen energy UAV; Figure 3 is a cross-sectional view of the central axis of the hydrogen energy UAV.

[0014] Reference numerals in the drawings: 1 - UAV body; 2 - binary wing arms; 3 - brushless motor; 4 - antenna; 5 - camera; 6 - hydrogen storage tank; 7 - hydrogen fuel cell; 8 - adjustable pressure supply solenoid valve. Detailed implementation manner

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0016] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0017] Embodiment 1: As Figures 1 - 3 shown, this embodiment provides a hydrogen energy UAV, including: a UAV body 1 and three binary wing arms 2 provided on the UAV body 1. Among them, two binary wing arms 2 are symmetrically provided on both sides of the front end of the UAV body 1, and the other binary wing arm 2 is provided at the rear end of the UAV body 1. Brushless motors 3 are provided at both ends of the binary wing arm 2; A hydrogen storage tank 6 is provided at the top of the inner cavity of the UAV body 1, and a hydrogen fuel cell 7 is provided at the bottom of the inner cavity. The gas outlet of the hydrogen storage tank 6 is connected to the hydrogen inlet of the hydrogen fuel cell 7 through an adjustable pressure supply solenoid valve 8; A camera 5 is provided on the lower side of the front end of the UAV body 1.

[0018] Secondly, the UAV body 1 is provided with a control module, and the control module includes an IMU sensor and a super capacitor. The super capacitor is used to compensate for the instantaneous pressure supply shortage of the hydrogen fuel cell during high-maneuver flight.

[0019] The drone described in this embodiment uses a hydrogen fuel cell as the power source. By arranging a hydrogen storage tank 6 at the top of the inner cavity of the drone body 1 and a hydrogen fuel cell 7 at the bottom of the inner cavity, the long-term driving of the rotor is realized, so that the drone can meet the requirements of long endurance and large-range mission scenarios. Secondly, a unique three-binary wing arm layout with two symmetrically arranged on both sides at the front end and one at the rear end forms a stable triangular support structure. Two brushless motors are installed at the end of each binary wing arm, forming a total of six-rotor power system. This layout significantly improves the power redundancy. That is, when any rotor or even one rotor on a single binary wing arm fails, the remaining rotors can provide a stronger asymmetric torque compensation ability. Combined with a specific control algorithm, the basic flight attitude and controllability of the drone can be effectively maintained, greatly improving the flight safety and reliability.

[0020] Embodiment 2: Hydrogen energy drones still face many challenges in practical applications. For example, hydrogen fuel cells have relatively high requirements for the stability of hydrogen supply pressure. During the cruise of existing drones, especially when performing flight tasks including different altitudes (such as mountainous areas and hilly areas), the significant change of the external atmospheric pressure will directly affect the effective supply pressure of the hydrogen storage tank. If the hydrogen supply pressure is unstable or insufficient, it will cause fluctuations or even a decrease in the output power of the fuel cell. To overcome the above technical problems, on the basis of Embodiment 1, this embodiment provides a control method for a hydrogen energy drone. The control method includes: Step S100: Obtain the cruise path information of the hydrogen energy drone, and perform cruise flight based on the cruise path information. During this period, adjust the opening and closing degree of the adjustable pressure supply solenoid valve 8 in real time based on the altitude fluctuation parameter in the cruise path information, and then dynamically adjust the hydrogen supply pressure value of the hydrogen fuel cell 7. At the same time, use the IMU sensor to detect the current flight attitude in real time. When the flight attitude exceeds the threshold, calculate the compensation power of the super capacitor based on the current flight attitude value and the real-time power of the hydrogen fuel cell, so that the hydrogen energy drone can fly according to the cruise path. Specifically, the hydrogen energy drone will obtain the current altitude according to the GPS and cruise path information, calculate the current hydrogen supply pressure value based on a preset algorithm model, and then fine-tune the adjustable pressure supply solenoid valve 8 based on the hydrogen supply pressure value. Secondly, only when the fluctuation of the hydrogen supply pressure value is greater than the minimum adjustment amount of the adjustable pressure supply solenoid valve 8, the adjustment will be triggered, that is, the calculation accuracy of the model is greater than the minimum adjustment accuracy of the adjustable pressure supply solenoid valve 8.

[0021] Secondly, it should be noted that the main purpose of adjusting the hydrogen supply pressure value is to stabilize the supply pressure value of the hydrogen fuel cell, thereby eliminating the drawback of unstable supply pressure of the hydrogen fuel cell caused by altitude fluctuations, rather than adjusting the instantaneous power of the hydrogen fuel cell. Usually during cruise, the output power of the hydrogen fuel cell generally does not fluctuate greatly, which is determined by its physical characteristics. As a result, when the UAV performs some instantaneous high-maneuver flight actions, it is impossible to adjust the output power of the hydrogen fuel cell instantaneously, but a supercapacitor is used for power compensation. The specific compensation method is described in detail below.

[0022] Among them, dynamically adjusting the hydrogen supply pressure value of the hydrogen fuel cell 7 based on altitude fluctuation parameters includes: ; Among them, is the hydrogen supply pressure value, is the membrane characteristic sensitivity coefficient, = 0.03; ; is the standard temperature value, which is obtained by the feedback of the temperature sensor set at the standard position. The hydrogen energy UAV updates this data regularly through the wireless communication module; is the standard pressure value, which corresponds to the standard temperature value and the corresponding relationship is obtained by querying the comparison table; is the altitude; is the natural constant; is the sea level temperature; is the sea level relative humidity; is the temperature fluctuation compensation due to altitude, that is, temperature compensation; is the humidity fluctuation compensation due to altitude, that is, humidity compensation, which is used to compensate for the conductivity fluctuation of the proton exchange membrane (PEM) caused by environmental humidity changes, so as to maintain the voltage output stability. Specifically, by increasing the hydrogen pressure, the water molecules on the anode side are forced to penetrate into the membrane to delay dehydration.

[0023] The above model stabilizes the stack internal resistance → smooths the output voltage → extends the fuel cell life. At the same time, this model connects the environmental parameters → material characteristics → system control in series as a causal chain, which is one of the core technologies for stable power supply of mountain hydrogen energy UAVs.

[0024] Among them, when the flight attitude exceeds the threshold, calculating the compensation power of the supercapacitor based on the current flight attitude and the real-time power of the hydrogen fuel cell includes: When the IMU sensor detects that the pitch rate of the hydrogen energy UAV is greater than 15° / s and the yaw rate is greater than 20° / s, it is determined to be in a high-maneuver state. At this time, the supercapacitor is used to compensate the power of the hydrogen fuel cell, and the calculation method of the power compensation is: ; wherein, is the climbing rate (m / s), is the turning angular velocity (rad / s), is the current mass of the hydrogen energy UAV, which changes dynamically with the flight duration of the hydrogen energy UAV, is the propeller efficiency, which changes dynamically with the altitude H, is the starting resistance coefficient is the relative air density at sea level, H is the altitude, is the current flight speed of the hydrogen energy UAV, is the acceleration due to gravity, t is the time, is the moment of inertia of the hydrogen energy UAV in the vertical direction, is the angular acceleration coefficient, is the current output power of the hydrogen fuel cell; this model roughly splits the power into climbing power and turning power. Among them, the climbing power is greatly affected by the self-weight of the hydrogen energy UAV, so the dynamic mass of the hydrogen energy UAV is introduced , the mass of the hydrogen energy UAV The relationship between the mass of the hydrogen energy UAV and the change of time can be obtained by calculating the power consumption, that is, the cumulative sum of the dynamic power, and then loading the preset hydrogen energy loss coefficient, the approximate hydrogen consumption can be obtained. However, this calculation method is relatively rough and does not consider the hydrogen loss fluctuations caused by altitude fluctuations, etc. But the overall impact of this fluctuation on the mass is small, and considering the model calculation amount, the hydrogen energy loss coefficient is a fixed value.

[0025] Secondly, the moment of inertia of the hydrogen energy UAV in the vertical direction is less affected by the mass, so a fixed value is adopted, ignoring the influence brought by the weight change of the hydrogen energy UAV.

[0026] Secondly, is used to simulate and calculate the climbing power of the hydrogen energy UAV, is used to simulate and calculate the turning power of the hydrogen energy UAV, is the climbing coefficient, which changes dynamically with the altitude H of the flight of the hydrogen energy UAV and the current mass of the hydrogen energy UAV.

[0027] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A hydrogen energy drone, characterized in that, Comprising: A drone body (1) and three bifurcated wing arms (2) provided on the drone body (1), wherein two bifurcated wing arms (2) are symmetrically provided on both sides of the front end of the drone body (1), and the other bifurcated wing arm (2) is provided at the rear end of the drone body (1), and brushless motors (3) are provided at both ends of the bifurcated wing arm (2); A hydrogen storage tank (6) is provided at the top of the inner cavity of the drone body (1), and a hydrogen fuel cell (7) is provided at the bottom of the inner cavity. The gas outlet of the hydrogen storage tank (6) is connected to the hydrogen inlet of the hydrogen fuel cell (7) through an adjustable pressure supply solenoid valve (8); A camera (5) is provided on the lower side of the front end of the drone body (1).

2. A control method for a hydrogen energy unmanned aerial vehicle according to claim 1, characterized in that, The drone body (1) is provided with a control module, and the control module includes an IMU sensor and a super capacitor. The control method includes: Obtaining the cruise path information of the hydrogen energy drone, and performing cruise flight based on the cruise path information. During this period, the opening degree of the adjustable pressure supply solenoid valve (8) is adjusted in real time based on the altitude fluctuation parameter in the cruise path information, so as to dynamically adjust the hydrogen supply pressure value of the hydrogen fuel cell (7), and the current flight attitude is detected in real time through the IMU sensor. When the flight attitude exceeds the threshold, the compensation power of the super capacitor is calculated based on the current flight attitude and the real-time power of the hydrogen fuel cell, so that the hydrogen energy drone flies according to the cruise path.

3. The control method according to claim 2, wherein Dynamically adjusting the hydrogen supply pressure value of the hydrogen fuel cell (7) based on the altitude fluctuation parameter, including: ； Among them, is the hydrogen supply pressure value, is the membrane characteristic sensitivity coefficient, = 0.03; ; is the standard temperature value, obtained by the feedback of the temperature sensor set at the standard position; is the standard pressure value, which corresponds to the standard temperature value ; is the altitude; is the natural constant; is the sea level temperature; is the sea level relative humidity; is the temperature fluctuation compensation caused by the altitude, i.e., the temperature compensation; is the humidity fluctuation compensation caused by the altitude, i.e., the humidity compensation.

4. The control method according to claim 3, characterized in that Calculating the compensation power of the super capacitor based on the current flight attitude and the real-time power of the hydrogen fuel cell when the flight attitude exceeds the threshold, including: When the IMU sensor detects that the pitch angle rate of the hydrogen energy drone is greater than 15° / s and the yaw angle rate is greater than 20° / s, it is determined to be in a high maneuver state. At this time, the super capacitor is used to compensate the power of the hydrogen fuel cell. The calculation method of the power compensation is: ； Among them, is the climbing rate (m / s), is the turning angular velocity (rad / s), is the current mass of the hydrogen energy UAV, which changes dynamically with the flight duration of the hydrogen energy UAV, is the propeller efficiency, which changes dynamically with the altitude H, is the starting resistance coefficient is the relative air density at sea level, and H is the altitude, is the current flight speed of the hydrogen energy UAV, is the acceleration due to gravity, and t is the time, is the moment of inertia of the hydrogen energy UAV in the vertical direction, is the angular acceleration coefficient, is the current output power of the hydrogen fuel cell; Secondly, used to simulate and calculate the climbing power of the hydrogen energy drone, used to simulate and calculate the turning power of the hydrogen energy drone, is the climbing coefficient, which changes dynamically with the altitude H at which the hydrogen energy drone flies and the current mass of the hydrogen energy drone changing.

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