Unmanned aerial vehicle applied to fire fighting and use method

Abstract

The invention relates to the technical field of fire-fighting unmanned aerial vehicles, in particular to an unmanned aerial vehicle applied to fire fighting and a using method. The unmanned aerial vehicle comprises a vehicle body, a rotor wing assembly, a pressure water gun, a detector and a control unit; the top of the pressure water gun is provided with a transparent window, the detector is provided with a plurality of detection units, and the detection units are located right above the transparent window; and the control unit is used for transmitting the flow velocity to a flight control system, so that the flight control system determines the magnitude of recoil force according to the flow velocity, and further adjusts flight parameters of the unmanned aerial vehicle according to the magnitude of the recoil force. The detector is arranged above the pressure water gun, the speed of water flow during spraying is calculated according to the distance between the detection units, and then the recoil force applied to the unmanned aerial vehicle when the pressure water gun sprays water is calculated, so that a flight control system adjusts the flight attitude of the unmanned aerial vehicle according to the recoil force; therefore, stable flight and efficient fire extinguishing of the unmanned aerial vehicle are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of fire-fighting unmanned aerial vehicles, and in particular to a unmanned aerial vehicle used for firefighting and a use method thereof. Background Art

[0002] As a new type of high-tech fire-fighting equipment, firefighting drones have received extensive attention and application in the field of firefighting in recent years. By using drones equipped with water guns to hover in the air to extinguish fires, firefighters can be effectively prevented from directly entering the fire scene, improving firefighting efficiency and safety. However, during the process of water gun spraying, the drone will be affected by the recoil generated by the water gun spray, resulting in unstable flight. During the process of water gun spraying, the water flow is sprayed out at high speed through the nozzle, and the water gun will generate a reaction force opposite to the spraying direction, that is, recoil. The recoil will interfere with the drone, resulting in unstable flight posture. Especially when extinguishing fires at high altitudes, the impact of recoil is more obvious due to the small air resistance. When the drone is disturbed by the recoil, it is easy to deviate from the predetermined trajectory, resulting in the water gun being unable to accurately aim at the fire source. In addition, the recoil may also cause the drone to lose balance or even crash, seriously threatening the safety of the operator and the surrounding environment.

[0003] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in the field of this technology. Summary of the invention

[0004] The technical problem to be solved by the present invention is that when a UAV is equipped with a water gun for fire extinguishing, the recoil force generated by the water gun spraying on the UAV makes the UAV flight unstable.

[0005] The present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a UAV for firefighting, comprising: a fuselage 1, a rotor assembly 2, a pressure water gun 3, a detector 4 and a control unit 5; the rotor assembly 2 is arranged on the side wall of the fuselage 1, the rotor assembly 2 is fixedly connected to the fuselage 1, the pressure water gun 3 is fixed below the fuselage 1, and the detector 4 is fixedly arranged between the fuselage 1 and the pressure water gun 3;

[0007] A transparent window 30 is provided on the top of the pressure water gun 3, and a plurality of detection units 40 are provided on the detector 4. The detection unit 40 is located directly above the transparent window 30. The detection unit 40 is used to send feedback information to the control unit 5 when detecting that the water flow in the pressure water gun 3 arrives directly below it, so that the control unit 5 records the moment when the water flow arrives at the corresponding detection unit 40, and then calculates the flow rate of the water flow in the pressure water gun 3;

[0008] The control unit 5 is used to transmit the flow velocity to the flight control system, so that the flight control system determines the size of the recoil according to the flow velocity, and then adjusts the flight parameters of the drone according to the size of the recoil.

[0009] Preferably, a fixing component 10 is provided at the bottom of the fuselage 1 , the fixing component 10 is fixedly connected to the bottom of the fuselage 1 , and the pressure water gun 3 is fixed on the fixing component 10 .

[0010] Preferably, the fixing assembly 10 includes two suspension frames 100, a fixing base 101 and a water gun fixing frame 102; both ends of the two suspension frames 100 are fixedly connected to the bottom of the fuselage 1, the middle part of the suspension frame 100 is fixedly connected to the fixing base 101, the bottom of the fixing base 101 is fixedly connected to the top of the water gun fixing frame 102, and the pressure water gun 3 is fixed on the water gun fixing frame 102.

[0011] Preferably, a water gun hanger 31 is provided on the top of the pressure water gun 3, an I-shaped groove 1020 is provided on the water gun fixing frame 102, and the detector 4 is fixedly arranged at the bottom of the I-shaped groove 1020;

[0012] A pin shaft 1021 is disposed in the I-shaped groove 1020 . The pin shaft 1021 is fixedly connected to the side wall of the I-shaped groove 1020 . The water gun hanger 31 is fixedly connected to the pin shaft 1021 .

[0013] Preferably, both ends of the water gun hanger 31 are provided with receiving grooves 310 , a clamp 311 is hung in the receiving groove 310 , and the water gun head of the pressure water gun 3 is sleeved on the clamp 311 .

[0014] Preferably, a water hose buckle 32 is provided at the bottom of the pressure water gun 3 , and the water hose buckle 32 is fixedly connected to the pressure water gun 3 .

[0015] Preferably, a plurality of connecting rods 33 are provided between the water hose buckle 32 and the water gun fixing bracket 102 , and two ends of the connecting rods 33 are fixedly connected to the water hose buckle 32 and the water gun fixing bracket 102 , respectively.

[0016] In a second aspect, the present invention provides a method for using a drone for firefighting, which is applicable to the drone for firefighting described in the first aspect, comprising:

[0017] When each of the detection units 40 detects that the water flow has arrived directly below it, it sends feedback information to the control unit 5, so that the control unit 5 records the moment when the water flow arrives at the corresponding detection unit 40, and then calculates the flow rate of the water flow in the pressure water gun 3;

[0018] The control unit 5 transmits the flow rate to the flight control system;

[0019] The flight control system calculates the recoil force exerted on the drone when water rushes out of the pressure water gun 3 based on the flow rate and pre-set related data;

[0020] The flight control system adjusts the flight parameters of the UAV according to the recoil force to keep the UAV flying stably.

[0021] Preferably, the flight control system includes a PID controller and a feedforward controller;

[0022] The flight control system adjusts the flight parameters of the UAV according to the recoil force to keep the UAV flying smoothly, specifically including:

[0023] When the drone is used for the first time to perform a firefighting mission, the feedforward controller adjusts the first flight parameter of the drone according to the size of the recoil force, and integrates the size of the recoil force and the corresponding first flight parameter into historical data, and uploads the historical data to the cloud platform; the PID controller determines the second flight parameter of the drone based on the data transmitted back by various sensors set by the drone itself, so as to adjust the attitude of the drone according to the first flight parameter and the second flight parameter;

[0024] When the drone is subsequently used to perform firefighting tasks, the current flow rate of the water flow in the pressure water gun 3 is obtained, and the current recoil force applied to the drone is calculated according to the current flow rate. The feedforward controller traverses the historical data on the cloud platform according to the current recoil force to determine whether there is historical data that matches the current recoil force;

[0025] If it exists, the flight parameter in the matching historical data is used as the first flight parameter, and the PID controller determines the second flight parameter of the drone based on the data transmitted back by the various sensors set by the drone itself; if it does not exist, the feedforward controller determines the first flight parameter according to the current recoil, and the PID controller determines the second flight parameter of the drone based on the data transmitted back by the various sensors set by the drone itself;

[0026] The attitude of the UAV is adjusted according to the first flight parameter and the second flight parameter, and the current recoil and the first flight parameter are integrated into historical data, and the historical data is uploaded to the cloud platform.

[0027] Preferably, the pre-set related data include the distance between each of the detection units 40, the water flow rate, the water pressure at the water inlet, and the height of the water inlet and the height of the water outlet.

[0028] Compared with the prior art, the beneficial effect of the present invention lies in that: by arranging multiple detection units 40 above the pressure water gun 3, each detection unit 40 records the moment when the water flow in the transparent window 30 reaches directly below the detection unit 40, so as to calculate the speed of the water flow when spraying in combination with the distance between each detection unit 40, and then calculate the recoil force exerted by the pressure water gun 3 on the drone when spraying water, so that the flight control system adjusts the flight attitude of the drone according to the recoil, and compensates for the speed of the drone accordingly, so as to ensure the stable flight of the drone and efficient fire extinguishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 1 is a schematic diagram of the overall structure of a UAV used for firefighting provided by an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram of a detector of a drone used for firefighting provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of a fixing component of a drone used for firefighting provided by an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of a water gun mount for a UAV used for firefighting provided by an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of a water belt buckle of a drone used for firefighting provided by an embodiment of the present invention;

[0035] Figure 6 is a schematic diagram of an arm of a drone used for firefighting provided by an embodiment of the present invention;

[0036] Figure 7 It is a flowchart of a method for using a drone for firefighting provided by an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of water flow detected by a detector of a drone used for firefighting provided by an embodiment of the present invention;

[0038] Fig. 9 The present invention provides a drone for firefighting. Figure 7 Schematic diagram of step 4 in .

[0039] Wherein, the accompanying drawings are marked as follows:

[0040] 1-fuselage, 10-fixed assembly, 100-suspension bracket, 101-fixed base, 102-water gun fixing bracket, 1020-I-slot, 1021-pin, 11-landing gear, 2-rotor assembly, 20-arm, 200-ventilation hole, 21-motor, 22-propeller, 3-pressure water gun, 30-transparent window, 31-water gun bracket, 310-receiving slot, 311-clamp, 32-water hose buckle, 33-connecting rod, 4-detector, 40-detection unit, 5-control unit. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as open inclusion, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner, that is, although they may be carried in the embodiments or examples of the above terms due to reasons such as the order and position of appearance, it is not limited to that they can be carried in combination by one embodiment or example.

[0043] In the description of the present invention, it is necessary to understand that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present disclosure.

[0044] In the description of the present invention, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "multiple" is two or more. In addition, for example, the same type of nouns may be described as two independent individuals by adding "A" and "B" at the end. In this case, the corresponding features defined as "A" and "B" are only used to distinguish the same type of individuals for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

[0045] When describing some embodiments, the expressions "coupling", "coupling" and "connection" and their derivatives may be used. For example, when describing some embodiments, the term "connection" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupling" may be used to indicate that two or more components are in direct physical or electrical contact. However, the terms "connection" or "coupling" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other, such as "optical path coupling", "wireless connection", etc. The embodiments disclosed herein are not necessarily limited to the contents of the present invention.

[0046] In the description of the present invention, the expression "A and / or B" (where A and B are used to formally represent specific characteristic contents) will be involved, and the corresponding expressions include the following three combinations: only A, only B, and a combination of A and B.

[0047] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0048] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] Embodiment 1:

[0050] Embodiment 1 of the present invention provides a drone used for firefighting, such as Figure 1As shown, it includes: a fuselage 1, a plurality of rotor assemblies 2, a pressure water gun 3, a detector 4 and a control unit 5; the rotor assembly 2 is arranged on the side wall of the fuselage 1, the rotor assembly 2 is fixedly connected to the fuselage 1, the pressure water gun 3 is fixed below the fuselage 1, and the detector 4 is fixedly arranged between the fuselage 1 and the pressure water gun 3; the top of the pressure water gun 3 is provided with a transparent window 30, as shown in FIG. Figure 2 As shown, the detector 4 is provided with a plurality of detection units 40, and the detection unit 40 is located directly above the transparent window 30. When the detection unit 40 detects that the water flow in the pressure water gun arrives directly below it, it sends feedback information to the control unit 5, so that the control unit 5 records the moment when the water flow arrives at the corresponding detection unit 40, and then calculates the flow rate of the water flow in the pressure water gun 3; the control unit 5 is used to transmit the flow rate to the flight control system, so that the flight control system determines the size of the recoil according to the flow rate, and then adjusts the flight parameters of the UAV according to the size of the recoil.

[0051] In practical application scenarios, the number of the detection units 40 is at least 3. In one embodiment, Figure 2 As shown in the figure as an example, the number of detection units 40 on the detector 4 is 4. Taking the orientation shown in the figure as an example, the four detection units 40 are numbered from right to left as detection unit No. 1 400, detection unit No. 2 401, detection unit No. 3 402 and detection unit No. 4 403, wherein, when detection unit No. 1 400 detects water flow, it sends feedback information to the control unit 5, and the control unit 5 records the current time t1; when detection unit No. 2 401 detects water flow, it sends feedback information to the control unit 5, and the control unit 5 records the current recording time t2; when detection unit No. 3 402 detects water flow, it sends feedback information to the control unit 5, and the control unit 5 records the current recording time t3; when detection unit No. 4 403 detects water flow, it sends feedback information to the control unit 5, and the control unit 5 records the current recording time t4. Each detection unit 40 transmits the recorded time to the control unit 5.

[0052] In one embodiment, the control unit 5 calculates the average value δt of δt1, δt2 and δt3 based on the difference δt1 between time t1 and time t2, the difference δt2 between time t3 and time t2, and the difference δt3 between time t4 and time t3, where δt=(δt1+δt2+δt3) / 3, and then calculates the average value δt based on the formula Where d is the distance between two adjacent detection units 40, and the velocity of the water flow when it is about to be sprayed out from the water gun is calculated.

[0053] In one embodiment, the control unit 5 transmits the recorded time and the distance d between two adjacent detection units 40 to the flight control system, and the flight control system calculates the flow rate

[0054] In one embodiment, the detection unit 40 may be an infrared detector or other detectors that can achieve the same purpose, and no specific limitation is made herein.

[0055] In order to enable the drone to carry the pressure water gun 3 to rise to a high altitude, such as Figure 1 As shown, a fixing assembly 10 is provided at the bottom of the fuselage 1, the fixing assembly 10 is fixedly connected to the bottom of the fuselage 1, and the pressure water gun 3 is fixed on the fixing assembly 10. Specifically, as Figure 3 As shown, the fixing assembly 10 includes two relatively arranged suspension frames 100, a fixing base 101 and a water gun fixing frame 102; the two ends of the two suspension frames 100 are fixedly connected to the bottom of the fuselage 1, the middle part of the suspension frame 100 is fixedly connected to the fixing base 101, the bottom of the fixing base 101 is fixedly connected to the top of the water gun fixing frame 102, and the pressure water gun 3 is fixed on the water gun fixing frame 102.

[0056] The pressure water gun 3 is fixed on the water gun fixing frame 102, and specifically includes: Figure 4 As shown, a water gun hanger 31 is provided on the top of the pressure water gun 3, an I-shaped groove 1020 is provided on the water gun fixing frame 102, and the detector 4 is fixedly provided at the bottom of the I-shaped groove 1020; a pin 1021 is provided in the I-shaped groove 1020, and the pin 1021 is fixedly connected to the side wall of the I-shaped groove 1020, and the water gun hanger 31 is fixedly connected to the pin 1021. Receiving grooves 310 are provided at both ends of the water gun hanger 31, and a clamp 311 is hung in the receiving groove 310, and the water gun head of the pressure water gun 3 is sleeved on the clamp 311. Among them, a through hole 312 is provided on the water gun hanger 31, and the through hole 312 is fixedly connected to the pin 1021.

[0057] In order to be able to connect the water hose to the pressure water gun 3, as Figure 5 As shown, a water hose buckle 32 is provided at the bottom of the pressure water gun 3, and the water hose buckle 32 is fixedly connected to the pressure water gun 3. Since the distance between the water hose buckle 32 and the water gun fixing frame 102 is relatively far, when the water hose buckle 32 is connected to the water hose, in order to prevent the excessive shaking amplitude of the water hose buckle 32 from affecting the flight stability of the drone, a plurality of connecting rods 33 are provided between the water hose buckle 32 and the water gun fixing frame 102, and the two ends of the connecting rod 33 are fixedly connected to the water hose buckle 32 and the water gun fixing frame 102 respectively.

[0058] In the embodiment of the present invention, in addition to the above structure, Figure 6 As shown, the rotor assembly 2 includes an arm 20, a motor 21 and a propeller 22. One end of the arm 20 is fixedly connected to the fuselage 1, and the motor 21 is fixed to the other end of the arm 20. The motor 21 is used to drive the propeller 22 to rotate. Secondly, in order to reduce the influence of wind resistance on the drone during hovering and flying, a plurality of ventilation holes 200 are provided on the arm 20 to reduce wind resistance when the drone is flying and ensure the stability of the drone's flight posture. The drone also includes two landing gears 11, which are fixedly arranged at the bottom of the fuselage 1.

[0059] Embodiment 2:

[0060] The embodiment of the present invention provides a method for using a drone for firefighting based on the embodiment 1, which is applicable to the drone for firefighting described in the embodiment 1, such as Figure 7 As shown, including:

[0061] In step S1 , when each detection unit 40 detects that the water flow arrives directly below it, it sends feedback information to the control unit 5 so that the control unit 5 records the moment when the water flow arrives at the corresponding detection unit 40 , and then calculates the flow rate of the water flow in the pressure water gun 3 .

[0062] The calculation method of the flow rate is shown in Example 1 and will not be repeated here.

[0063] In step S2 , the control unit 5 transmits the flow rate to the flight control system.

[0064] In step S3, the flight control system calculates the recoil force exerted on the drone when water rushes out of the pressure water gun 3 according to the flow rate and pre-set related data.

[0065] In step S4, the flight control system adjusts the flight parameters of the UAV according to the recoil force to keep the UAV flying smoothly.

[0066] Among them, the flight control system adjusts the flight parameters of the drone according to the recoil, mainly adjusting the rotation speed of the propeller. The flight parameters also include navigation and positioning parameters, camera and shooting parameters, communication and image transmission parameters, etc.

[0067] like Figure 8 As shown, the flow rate calculated above is is the water flow velocity at the point indicated by the arrow in the figure. In actual application scenarios, when the water flow fills the entire water gun, the water flow velocity at the water hose inlet is equal to the water flow velocity at the point indicated by the arrow in the figure. Therefore, the water flow velocity at the water inlet is defined as v1 (i.e., the flow rate calculated above). ), the speed of water spraying out of the pressure water gun 3 is defined as v2. After v1 is determined, v2 can be obtained according to the Bernoulli equation, and then the impulse force of water spraying out of the pressure water gun 3 is obtained, which is defined as F. According to the formula (where Δp is impulse), the force F when water is sprayed out from the pressure water gun 3 is calculated.

[0068] In the above step S3, the preset related data include the distance d between each of the detection units 40, the water flow Q, the water pressure P1 of the water inlet, the height h1 of the water inlet and the height h2 of the water outlet.

[0069] Among them, the water pressure P1 at the water inlet can be obtained by the pressure gauge at the water inlet. In the actual application scenario, according to the fire water consumption standard: for high-rise buildings, factories, warehouses and civil buildings with an indoor clearance height of more than 8 meters, the dynamic pressure at the fire hydrant outlet should not be less than 0.35MPa, and the water column filled by the fire hose should be calculated as 13 meters; for other places, the dynamic pressure at the fire hydrant outlet should not be less than 0.25MPa, and the water column filled by the fire hose should be calculated as 10 meters; the minimum fire water supply pressure in the indoor fire hydrant system pipeline should not be less than 0.30MPa. When the water outlet pressure at the fire hydrant outlet exceeds 0.70MPa, a pressure relief facility is also required; for high-rise buildings with a building height not exceeding 100 meters, the maximum unfavorable point fire hydrant static water pressure should not be less than 0.07MPa; for high-rise buildings with a building height exceeding 100 meters, the maximum unfavorable point fire hydrant static water pressure should not be less than 0.15MPa. At the same time, the static water pressure at the fire hydrant outlet should not be greater than 1.0MPa. When it is greater than 1.0MPa, a zoned water supply system should be adopted. When the water outlet pressure of the fire hydrant outlet is greater than 0.5MPa, pressure relief measures should be taken. The water flow rate Q is based on the fire water volume standard: when the building height is less than 54 meters, the design flow rate of outdoor fire hydrants shall not exceed 20L / s, and the design flow rate of indoor fire water supply shall not exceed 10L / s; when the building height is greater than 54 meters, the design flow rate of outdoor fire hydrants shall not exceed 25L / s; the temporary outdoor fire water consumption is 20L / s, and the temporary indoor fire water consumption is 10L / s.

[0070] According to Bernoulli's equation Where ΔP loss is the pressure loss due to friction and other resistances, which is a known quantity obtained in advance. lossIt is extremely small and can be ignored here. P2 is the pressure at the outlet. From the known conditions and scenarios, we know that the pressure P2 at the outlet is atmospheric pressure and can be regarded as 0. ρ is the density of water. Based on the above known quantities, the Bernoulli equation can be simplified to Thus we can solve: According to the velocity v2 obtained from the above formula, since we know the water flow rate Q, in a very short time Δt, the mass m of the water flowing out of the water pipe is: m = ρQΔt, and the momentum of this water at the outlet is p = mv2 = ρQΔtv2, so the impulse Substituting the expression of v2 into the formula of impulse F, we obtain According to Newton's third law, the impulse F is equal to the recoil F on the drone. recoil .

[0071] In the traditional scheme, the recoil force F is obtained recoil After that, the flight control system usually uses a proportional-integral-derivative controller (PID) to balance the fuselage 1 of the drone. In the solution provided in the embodiment of the present invention, a PID controller is also provided in the flight control system. The output formula of the PID controller is: Among them, u PID is the output of the PID controller (e.g., the speed of the propeller), e is the deviation between the current attitude and the target attitude, and K p , K i , K d are the gain coefficients of proportion, integration and differentiation respectively. However, if only the control method of the PID controller mentioned above is adopted, when the UAV is equipped with a pressure water gun 3 to spray water, the differential term Can help reduce the recoil F recoil However, its differential term can only be predicted based on the current rate of change of deviation, and cannot take into account the specific disturbance source (such as recoil F recoil )’s size and direction.

[0072] Based on this, in the preferred embodiment, if the recoil force F recoil The size and direction of the recoil force F are predicted, and the corresponding flight parameter adjustment plan is generated accordingly. recoil When the recoil force F is applied, the flight control system can respond more quickly and adjust the flight parameters of the drone in the shortest possible time, further avoiding the recoil F recoilThe possibility of the drone falling at the moment of being applied specifically includes that in the above step 4, the flight control system includes a PID controller and a feedforward controller; the flight control system adjusts the flight parameters of the drone according to the recoil force to keep the drone flying smoothly, such as Fig. 9 As shown, specifically including:

[0073] In step S40, when the drone is used for the first time to perform a firefighting mission, the feedforward controller adjusts the first flight parameter of the drone according to the size of the recoil, and integrates the size of the recoil and the corresponding first flight parameter into historical data, and uploads the historical data to the cloud platform; the PID controller determines the second flight parameter of the drone based on the data transmitted back by various sensors set by the drone itself, so as to adjust the posture of the drone according to the first flight parameter and the second flight parameter.

[0074] In step S41, when the drone is subsequently used to perform firefighting tasks, the current flow rate of the water in the pressure water gun 3 is obtained, and the current recoil applied to the drone is calculated based on the current flow rate. The feedforward controller traverses the historical data on the cloud platform based on the current recoil to determine whether there is historical data that matches the current recoil.

[0075] Specifically, when the current recoil matches the historical recoil in the historical data, a certain error range is allowed between the current recoil and the historical recoil, such as 0N-5N. The specific data range can be determined according to actual mission requirements and experimental tests. If the current recoil size is consistent with the historical recoil size or within the allowable error range, the historical data can be retrieved from the cloud platform to obtain the first flight parameter, which greatly reduces the calculation amount of the flight control system and responds more quickly.

[0076] In step S42, if it exists, the flight parameters in the matching historical data are used as the first flight parameters, and the PID controller determines the second flight parameters of the UAV based on the data transmitted back by the various sensors set by the UAV itself; if it does not exist, the feedforward controller determines the first flight parameters based on the current recoil, and the PID controller determines the second flight parameters of the UAV based on the data transmitted back by the various sensors set by the UAV itself.

[0077] In step S43, the attitude of the UAV is adjusted according to the first flight parameter and the second flight parameter, and the current recoil and the first flight parameter are integrated into historical data, and the historical data is uploaded to the cloud platform.

[0078] When performing firefighting tasks, the UAV is not only disturbed by the recoil of the water flow, but in actual application scenarios, the UAV may also be affected by strong winds, rain, snow and other weather conditions. Therefore, the feedforward controller needs to be combined with the PID controller to jointly determine the flight parameters of the UAV.

[0079] In actual application scenarios, the above steps S40 to S43 can be regarded as a training process for the UAV flight control system. After the above training process, the UAV can be directly used to perform firefighting tasks.

[0080] In the previous content, it has been mentioned that the output formula of the PID controller is u PID This is the second flight parameter mentioned in the above step. When there is no historical data matching the current recoil in the historical data, the output u of the feedforward controller is FF According to the recoil F recoil The calculation result directly determines that u FF This is the first flight parameter mentioned in the above steps. First, according to the recoil F recoil Determine the recoil F recoil Impact on the pitch attitude of the drone: where θ recoil is the pitch attitude change caused by the recoil, l is the distance from the recoil point to the center of gravity of the drone (moment arm), I is the pitch moment of inertia of the drone around its center of gravity, and the moment of inertia I can be monitored and obtained by a gyroscope or an accelerometer. In the preferred embodiment, an inertial measurement unit (IMU) can also be set on the drone to obtain the pitch attitude change θ through the inertial measurement unit. recoil .

[0081] After obtaining the pitch attitude change θ recoil After that, the output of the feedforward controller can be expressed as: FF =-K FF ·θ recoil , where u FF is the output of the feedforward controller (e.g., propeller speed), K FF is the feedforward gain coefficient, which is used to adjust the strength of the feedforward control.

[0082] Finally, the second flight parameter output by the PID controller and the first flight parameter output by the feedforward controller are combined to obtain the comprehensive flight parameter: u total =u PID +u FF , the integrated flight parameters are used to adjust the propeller speed of the drone to compensate for the recoil F recoilThe parameters of the PID controller and the feedforward controller (such as K p , K i , K d , K FF ) need to be adjusted according to the specific characteristics and mission requirements of the UAV, and the optimal parameter values ​​can be determined through experiments and debugging.

[0083] In the drone provided in the embodiment of the present invention, in order to accurately obtain the flight status and surrounding environment conditions of the drone during flight, the drone also includes a variety of sensors, specifically including air pressure sensors, load and hoisting sensors, inertial measurement units, global positioning system (Global Positioning System, abbreviated as GPS) modules, ultrasonic sensors, lidars, optical flow sensors, visual sensors, current sensors and magnetic sensors.

[0084] Air pressure sensor, used to calculate the height of the drone by measuring atmospheric pressure; load and hoisting sensors, used to monitor the weight of the drone and the weight of the objects carried to ensure flight balance and controllability; Inertial Measurement Unit (IMU) is the core sensor of the drone, including a three-axis gyroscope, a three-axis accelerometer and a three-axis geomagnetic sensor, used to measure the attitude, angular velocity and position information of the drone; GPS module, used to provide accurate location information, such as longitude, latitude, altitude and speed, which is the key to drone navigation and positioning; Ultrasonic sensor, which measures the distance between the drone and obstacles by emitting and receiving ultrasonic waves, and is often used for obstacle avoidance; LiDAR, which acquires the surrounding information by emitting lasers and receiving echo time. High-precision three-dimensional data of the environment is used for terrain mapping, obstacle avoidance, navigation and positioning; optical flow sensors use image changes to detect the movement speed and direction of the drone, which helps provide auxiliary positioning when the GPS signal is poor; visual sensors, including cameras and other equipment, are used for image acquisition and target recognition, and are often used for visual navigation and task execution; current sensors are used to monitor and optimize power consumption, ensure the safety of the drone's internal battery charging and motor status inspection system, and measure current (bidirectional) to ideally provide electrical isolation to reduce power loss and eliminate the chance of electric shock damaging the user's system; magnetic sensors provide information for inertial navigation and direction positioning systems, and are sensors based on anisotropic magnetoresistance (AMR) technology. Each of the above-mentioned sensors is a sensor that is well known and commonly used by those skilled in the art, and is not the key innovative content in the embodiments of the present invention, so they will not be repeated here.

[0085] In the technical solutions provided in Examples 1 and 2 of the present invention, multiple detection units 40 are arranged above the pressure water gun 3, and each detection unit 40 records the moment when the water flow in the transparent window 30 reaches directly below the detection unit 40, so that the speed of the water flow when spraying is calculated in combination with the distance between each detection unit 40, and then the recoil force exerted by the pressure water gun 3 on the drone when spraying water is calculated, so that the flight control system adjusts the flight attitude of the drone according to the recoil force, and compensates for the speed of the drone accordingly, so as to ensure the stable flight and efficient fire extinguishing of the drone, and effectively overcomes the influence of the recoil force generated on the drone during the water spraying process of the water gun on the flight stability of the drone.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A UAV used for firefighting, characterized in that: include: A fuselage (1), a rotor assembly (2), a pressure water gun (3), a detector (4) and a control unit (5); the rotor assembly (2) is arranged on the side wall of the fuselage (1), the rotor assembly (2) is fixedly connected to the fuselage (1), the pressure water gun (3) is fixed below the fuselage (1), and the detector (4) is fixedly arranged between the fuselage (1) and the pressure water gun (3); The top of the pressure water gun (3) is provided with a transparent window (30), and the detector (4) is provided with a plurality of detection units (40), wherein the detection units (40) are located directly above the transparent window (30), and the detection units (40) are used to send feedback information to the control unit (5) when detecting that the water flow in the pressure water gun (3) arrives directly below it, so that the control unit (5) can record the moment when the water flow arrives at the corresponding detection unit (40), and further calculate the flow rate of the water flow in the pressure water gun (3); The control unit (5) is used to transmit the flow velocity to a flight control system, so that the flight control system determines the magnitude of the recoil force according to the flow velocity, and further adjusts the flight parameters of the drone according to the magnitude of the recoil force.

2. The unmanned aerial vehicle used for firefighting according to claim 1, characterized in that: A fixing component (10) is provided at the bottom of the fuselage (1), the fixing component (10) is fixedly connected to the bottom of the fuselage (1), and the pressure water gun (3) is fixed on the fixing component (10).

3. The unmanned aerial vehicle used for firefighting according to claim 2, characterized in that: The fixing assembly (10) comprises two hanging frames (100), a fixing base (101) and a water gun fixing frame (102); the two ends of the two hanging frames (100) are fixedly connected to the bottom of the fuselage (1), the middle of the hanging frames (100) is fixedly connected to the fixing base (101), the bottom of the fixing base (101) is fixedly connected to the top of the water gun fixing frame (102), and the pressure water gun (3) is fixed on the water gun fixing frame (102).

4. The unmanned aerial vehicle used for firefighting according to claim 3, characterized in that: A water gun hanger (31) is provided on the top of the pressure water gun (3), an I-shaped groove (1020) is provided on the water gun fixing frame (102), and the detector (4) is fixedly arranged at the bottom of the I-shaped groove (1020); A pin shaft (1021) is arranged in the I-shaped groove (1020), the pin shaft (1021) is fixedly connected to the side wall of the I-shaped groove (1020), and the water gun hanger (31) is fixedly connected to the pin shaft (1021).

5. The unmanned aerial vehicle used for firefighting according to claim 4, characterized in that: Both ends of the water gun hanger (31) are provided with receiving grooves (310), a clamp (311) is hung in the receiving groove (310), and the water gun head of the pressure water gun (3) is sleeved on the clamp (311).

6. The unmanned aerial vehicle used for firefighting according to claim 3, characterized in that: A water hose buckle (32) is provided at the bottom of the pressure water gun (3), and the water hose buckle (32) is fixedly connected to the pressure water gun (3).

7. The unmanned aerial vehicle used for firefighting according to claim 6, characterized in that: A plurality of connecting rods (33) are arranged between the water hose buckle (32) and the water gun fixing frame (102), and two ends of the connecting rods (33) are fixedly connected to the water hose buckle (32) and the water gun fixing frame (102) respectively.

8. A method for using a UAV for firefighting, applicable to the UAV for firefighting according to any one of claims 1 to 7, characterized in that: include: When each of the detection units (40) detects that the water flow has arrived directly below it, it sends feedback information to the control unit (5), so that the control unit (5) can record the moment when the water flow arrives at the corresponding detection unit (40), and then calculate the flow rate of the water flow in the pressure water gun (3); The control unit (5) transmits the flow rate to the flight control system; The flight control system calculates the recoil force exerted on the drone when water rushes out of the pressure water gun (3) based on the flow rate and pre-set related data; The flight control system adjusts the flight parameters of the UAV according to the recoil force to keep the UAV flying stably.

9. The method for using a drone for firefighting according to claim 8, characterized in that: The flight control system includes a PID controller and a feedforward controller; The flight control system adjusts the flight parameters of the UAV according to the recoil force to keep the UAV flying smoothly, specifically including: When the drone is used for the first time to perform a firefighting mission, the feedforward controller adjusts the first flight parameter of the drone according to the size of the recoil force, and integrates the size of the recoil force and the corresponding first flight parameter into historical data, and uploads the historical data to the cloud platform; the PID controller determines the second flight parameter of the drone based on the data transmitted back by various sensors set by the drone itself, so as to adjust the attitude of the drone according to the first flight parameter and the second flight parameter; When the drone is subsequently used to perform firefighting tasks, the current flow rate of the water flow in the pressure water gun (3) is obtained, and the current recoil force applied to the drone is calculated according to the current flow rate. The feedforward controller traverses the historical data on the cloud platform according to the current recoil force to determine whether there is historical data that matches the current recoil force; If it exists, the flight parameter in the matching historical data is used as the first flight parameter, and the PID controller determines the second flight parameter of the drone based on the data transmitted back by the various sensors set by the drone itself; if it does not exist, the feedforward controller determines the first flight parameter according to the current recoil, and the PID controller determines the second flight parameter of the drone based on the data transmitted back by the various sensors set by the drone itself; The attitude of the UAV is adjusted according to the first flight parameter and the second flight parameter, and the current recoil and the first flight parameter are integrated into historical data, and the historical data is uploaded to the cloud platform.

10. The method for using a drone for firefighting according to claim 8, characterized in that: The preset related data include the distance between each of the detection units (40), water flow, water pressure at the water inlet, height of the water inlet and height of the water outlet.

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