A tethered unmanned aerial firefighting system and intelligent control method

Abstract

The application provides a tethered unmanned flight fire extinguishing system and an intelligent control method, which is carried on an unmanned flight fire extinguishing system transport vehicle, the transport vehicle comprises a carrying chassis, a tethered power supply box, a generator set, a vehicle-mounted water tank, a first-stage booster pump and an unmanned aerial vehicle lifting platform, a water outlet of the vehicle-mounted water tank is communicated with a water inlet of the first-stage booster pump; the unmanned flight fire extinguishing system comprises a ducted unmanned aerial vehicle, a fire water cannon, a driving motor, a second-stage booster pump, a transition water tank and a fire hose, and the tethered power supply box is electrically connected with the aerial vehicle and the driving motor through an aviation cable. The second-stage booster structure is designed, the pressure loss of the high-altitude water hose conveying is effectively compensated, the spraying range of the fire cannon is improved, the long-range fire extinguishing demand of high-rise fire is met, the pressure water is stored in the transition water tank, the anti-flow-cut liquid level control strategy is matched, the uninterrupted water supply of the fire extinguishing operation is realized, the spraying flow-cut problem is effectively avoided, and the continuity of the fire extinguishing operation is ensured.

Description

Technical Field

[0001] This invention relates to the field of emergency fire protection technology, and in particular to a tethered unmanned aerial fire protection system and intelligent control method. Background Technology

[0002] With the increasing number of high-rise buildings in cities, fire rescue in high-rise fires has become a critical and challenging issue in emergency firefighting. Unmanned aerial vehicle (UAV) firefighting systems, due to their mobility, flexibility, and wide operating range, are widely used in high-rise fire suppression operations. Existing UAV firefighting systems generally employ a multi-rotor UAV carrying a jet cannon, delivering pressurized water from the ground to the cannon via a hose. However, this system has several technical drawbacks: First, multi-rotor UAVs have limited carrying capacity and cannot carry heavy-duty, high-flow-rate pressurized and jetting equipment. Second, the high flight altitude of the UAV results in significant pressure loss during the long-distance transport of pressurized water via hose to the cannon, leading to a short jetting distance (maximum only 25 meters) and low jet flow rate. Third, existing systems lack precise intelligent control strategies, making them prone to jet interruptions and pressure instability, hindering continuous firefighting operations, resulting in low firefighting efficiency and failing to meet the needs of high-rise fire rescue.

[0003] To address the aforementioned issues, there is an urgent need to develop an unmanned aerial firefighting system and control method with high load capacity, high pressure, long range, and intelligent closed-loop control to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to provide a tethered unmanned aerial firefighting system and intelligent control method, which solves the technical problems of existing unmanned aerial vehicle firefighting systems, such as low load-bearing capacity, high pressure loss, short spray distance, low flow rate, and lack of precise intelligent control. This invention enables high-load, high-pressure, long-range, and uninterrupted spraying for high-rise fire extinguishing operations, thereby improving fire extinguishing efficiency.

[0005] The present invention adopts the following technical solution: a tethered unmanned aerial vehicle (UAV) firefighting system, mounted on a UAV firefighting system transport vehicle, the transport vehicle including a transport chassis, a tethered power supply box, a generator set, a vehicle-mounted water tank, a primary booster pump, and a UAV lifting platform; the outlet of the vehicle-mounted water tank is connected to the inlet of the primary booster pump; the UAV lifting platform is used to carry the UAV firefighting system, the UAV firefighting system including a ducted UAV, a fire monitor, a drive motor, a secondary booster pump, a transition water tank, and a fire hose; the drive motor is connected to the secondary booster pump; the primary booster pump is connected to the inlet of the transition water tank via the fire hose; the outlet of the transition water tank is connected to the inlet of the secondary booster pump; the outlet of the secondary booster pump is connected to the inlet of the fire monitor; the tethered power supply box is electrically connected to the ducted UAV and the drive motor via an aviation cable.

[0006] Preferably, the transport chassis is a heavy-duty transport chassis, the primary booster pump is driven by the engine of the transport chassis, and the generator set is electrically connected to the tethered power supply box.

[0007] Preferably, the lifting force of the ducted unmanned aerial vehicle is 600 kg, which can meet the high-altitude heavy-load operation requirements of the unmanned aerial fire fighting system.

[0008] Preferably, the transport vehicle and the unmanned aerial fire-fighting system are also equipped with a centralized vehicle control system. The control system is equipped with a main loop PID controller and a secondary loop PID controller, which are connected to the generator set, the primary booster pump, the fire monitor, the drive motor, the secondary booster pump, and the level gauges built into the vehicle-mounted water tank and the transition water tank. The primary booster pump, the fire monitor, and the secondary booster pump are all equipped with pressure sensors and are all controlled collaboratively by the control system.

[0009] A control method for a tethered unmanned aerial firefighting system includes the following steps: S1. System Initialization: After the system starts up, it first performs a comprehensive self-check on detection equipment such as level sensors and pressure sensors, as well as actuators such as the primary booster pump, secondary booster pump, and water supply valve; at the same time, it reads the basic parameters before flight to determine whether they meet the requirements for flight and firefighting operations; if the self-check passes, the system enters the firefighting operation mode normally; if the self-check fails, the system immediately triggers a fault alarm to remind personnel to troubleshoot the problem and avoid equipment failure affecting the firefighting operation; S2. Operational Data Acquisition: During firefighting operations, the system collects core operational data in real time through various sensors, including: the flight altitude H of the ducted unmanned aerial vehicle and the liquid level L of the onboard water tank. 水罐 The liquid level L in the transition water tank of the unmanned aerial fire suppression system 过渡 The outlet pressure P of the first-stage booster pump 泵1 The outlet pressure P of the secondary booster pump 泵2 The spray pressure P of the fire monitor 炮 All collected data is transmitted to the control system in real time. S3. Altitude Compensation Calculation: As the flight altitude H of the ducted unmanned aerial vehicle increases, the frictional resistance of the fire hose changes significantly. Simultaneously, altitude difference and air back pressure also affect the jet. The system introduces an altitude compensation algorithm to calculate the theoretical jet pressure of the fire monitor: Theoretical P 炮 = P 泵1 -k*H, where k is the height compensation coefficient and H is the height of the fire monitor; S4. Anti-interruption liquid level control: The system controls the liquid level L in the transition water tank. 过渡 The real-time values ​​are used to divide the liquid level into four intervals, and corresponding interval adjustment rules are established to achieve precise liquid level control to prevent flow interruption. High liquid level (L) 过渡 >90%): At this point, the water volume in the transition water tank is sufficient. The system reduces the speed of the first-stage booster pump or directly closes the water supply valve to reduce the water supply flow. Medium liquid level (40%≤L) 过渡 ≤90%): At this time, the liquid level is in the normal operating range, and the system enters the normal adjustment mode. The speed of the secondary booster pump is adjusted by PID control to maintain the stable spray pressure of the fire monitor. Low liquid level (15%≤L) 过渡 <40%): At this point, the liquid level is low. The system first determines the liquid level L of the onboard water tank 24. 水罐 State, if L 水罐 If there is water and the water level is not below the threshold, fully activate the first-stage booster pump to replenish water; if L 水罐 If water is scarce, immediately issue an audible and visual alarm and control the ducted unmanned aerial vehicle to prepare to descend and return to base to avoid further water shortage; Ultra-low liquid level (L 过渡 <15%): At this point, the liquid level is in the danger zone. The system will forcibly reduce the output flow of the fire monitor (adjust the nozzle size) or enter the intermittent spray mode, while continuously monitoring the liquid level changes. S5. Jet Pressure Cascade PID Control: The system adopts a pressure-speed cascade PID control strategy, setting the primary booster pump and fire monitor as the main loop, with the fire monitor's jet pressure P... 炮 The main loop is the controlled variable, and the secondary booster pump and fire monitor are the secondary loops, with the outlet pressure P of the secondary booster pump as the controlled variable. 泵2 As a secondary loop feedback variable, it improves the system's response speed and anti-interference capability; simultaneously, the fire monitor's spray pressure satisfies the formula: P 炮 =P 泵1 -k*H, the system uses this formula to calibrate the effect of flight altitude on jet pressure in real time, ensuring the accuracy of pressure calculation; S6. Emergency Protection and Return Decision: The system continuously monitors the water level L in the vehicle's water tank during operation. 水罐 , Transition tank liquid level L 过渡 If the water level is below a preset extremely low threshold, emergency protection measures will be triggered immediately: the spray intensity of the fire monitor will be reduced or the pump will be stopped directly. Simultaneously, an audible and visual alarm will be triggered to alert personnel to take emergency measures, and a decision to return to base will be made based on the situation on site. If L... 水罐 L 过渡 If all values ​​are within the normal threshold range, the system will continuously cycle through steps S2-S5 to achieve continuous intelligent adjustment of the fire extinguishing operation until the fire extinguishing work is completed. After completion, the system will control the primary booster pump and the secondary booster pump to stop working and guide the ducted unmanned aerial vehicle to return smoothly to the drone landing platform.

[0010] Preferably, the PID control in step S5 includes the following steps: 5.1. Set the rated range of the fire monitor's spray pressure to [0.8, 1.0] MPa, take the median spray pressure of the range (0.9 MPa) as the setpoint of the main loop variable, and calculate the actual P in real time. 炮 With theoretical P 炮 Deviation rate e = (theoretical P) 炮 -Actual P 炮 ) / Theoretical P 炮 ; Actual P 炮 Calculation: The system introduces a pressure loss calculation model to calculate the pressure loss along the path. The friction loss caused by the vertical lifting height of the fire hose mainly includes: Static pressure loss (gravitational pressure drop caused by height difference): ; in: H represents the working height of the fire monitor; Friction loss along the pipe (related to flow rate, pipe diameter, pipe length, and coefficient of friction): ; Where D is the inner diameter of the fire hose (16mm), v is the water flow velocity, L is the equivalent length of the fire hose, and λ is the coefficient of friction. Total losses along the route: ; The calculated spray pressure of the fire monitor when the secondary booster pump is not activated is: Actual P 炮 =P 泵1 -△P total When the actual P 炮 When the pressure is less than 0.8 MPa, the system will activate the secondary booster pump for pressure compensation. When e ≤ 10%, the secondary booster pump maintains a stable output, and the outlet pressure is a stable P. 泵2 Fire monitor spray pressure: Actual P 炮 =P 泵1 -△P total +StableP 泵2 As the height increases, the actual spray pressure P of the fire monitor decreases. 炮 The pressure will decrease. When e > 10%, the speed of the drive motor needs to be adjusted to increase the outlet pressure of the pump in the secondary stage, thereby adjusting the spray pressure of the fire monitor so that the spray pressure of the fire monitor is within the theoretical pressure range, i.e., the actual pressure P. 炮 =P 泵1 -△P total +StableP 泵2 +compensation P 泵2 Within the range of [0.8, 1.0] MPa; 5.2 Compensation P 泵2Determination: When e > 10%, the main loop PID controller calculates and outputs the target pressure value P of the secondary booster pump in the auxiliary loop based on the deviation rate e. 泵2 The secondary loop PID controller uses the calculated outlet pressure of the secondary booster pump, i.e., the target pressure P, as its basis. 泵2 With stable P 泵2 To compensate for deviations, the speed of the drive motor is adjusted in real time, and the outlet pressure of the secondary booster pump is adjusted to stabilize P. 泵2 The deficiency, the compensating pressure value is the compensation P 泵2 This serves as the adjustment value for the secondary booster pump, enabling the outlet pressure of the secondary booster pump to quickly track the target P. 泵2 Ultimately, the actual P of the fire monitor's spray pressure was achieved. 炮 Precise adjustment; 5.3. Set up a pressure range locking mechanism; when P... 炮 Once the pressure stabilizes within the range of [0.8, 1.0] MPa for more than 5 seconds, the system locks the drive motor speed to maintain the current boosted state, preventing frequent motor speed adjustments from affecting equipment lifespan and system stability. If the pressure drops due to sudden changes in front-end pressure, significant changes in flight altitude, or other factors, the system will lock the drive motor speed to maintain the current boosted state and prevent frequent motor speed adjustments from affecting equipment lifespan and system stability. 炮 If the range is exceeded again, the system will automatically unlock and re-execute steps 5.1-5.2 until P. 炮 Return to the rated range.

[0011] Compared with the prior art, the advantages and positive effects of the present invention are as follows: 1. This invention features a two-stage pressurization structure. A ground-based primary pressurization pump performs initial pressurization, while a secondary pressurization pump on the unmanned aerial firefighting system performs secondary pressurization. This effectively compensates for the pressure loss during high-altitude water hose delivery, increasing the fire monitor's spray range by two times compared to existing technologies (from the current 25m to 50m), meeting the long-range firefighting requirements for high-rise fires. Simultaneously, by storing pressurized water in a transition tank and employing an anti-interruption liquid level control strategy, uninterrupted water supply for firefighting operations is achieved, effectively avoiding spray interruption problems and ensuring the continuity of firefighting operations. 2. The intelligent control method of the present invention integrates operation data acquisition, height compensation algorithm, anti-interruption liquid level control and jet pressure cascade PID control, realizing intelligent closed-loop control of fire monitor spraying operation, ensuring that the spray pressure, flow rate and range are always stable within the rated range, and solving the problems of unstable pressure and poor spraying effect in the existing system; 3. This invention provides a continuous power and water supply to the unmanned aerial firefighting system by transporting generator sets, water tanks, and other equipment on a transport vehicle. Combined with the power supply via aviation cables from the tethered power box, it enables long-range cruising and continuous firefighting operations for the unmanned aerial firefighting system, significantly improving the firefighting efficiency and emergency rescue capabilities for high-rise fires. At the same time, by using a ducted unmanned aerial vehicle as a carrier, it provides a super-large lift of 600kg, solving the problem of the small carrying capacity of existing multi-rotor drones. It can carry high-flow pressurization, spraying, and water storage equipment, providing hardware support for high-flow and long-range firefighting. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the unmanned aerial firefighting system in the takeoff and firefighting state of the present invention; Figure 2 This is a schematic diagram of the internal structure of the transport vehicle of the present invention; Figure 3 This is a schematic diagram of an unmanned aerial firefighting system. Figure 4 This is a schematic diagram of the control operation process for an unmanned aerial firefighting system.

[0013] Legend: 1-Unmanned aerial firefighting system, 2-Transport vehicle, 3-Aviation cable, 11-Culverted unmanned aerial vehicle, 12-Fire monitor, 13-Drive motor, 14-Secondary booster pump, 15-Transfer water tank, 16-Fire hose, 21-Transport chassis, 22-Tethered power supply box, 23-Generator set, 24-Vehicle-mounted water tank, 25-Primary booster pump, 26-UAV lifting platform. Detailed Implementation

[0014] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0015] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0016] Please see Figure 1-4 The invention provides a tethered unmanned aerial firefighting system 1, which is mounted on the drone lift platform 24 of the unmanned aerial firefighting system transport vehicle 2, and the two are connected by a fire hose 16 and an aviation cable 3.

[0017] The transport vehicle 2 mainly includes a transport chassis 21, a tethered power supply box 22, a generator set 23, a vehicle-mounted water tank 24, a primary booster pump 25, and a drone lift platform 26. The transport chassis 21 is a heavy-duty transport chassis. The tethered power supply box 22, generator set 23, vehicle-mounted water tank 24, primary booster pump 25, and drone lift platform 26 are all fixed on the transport chassis 21. The primary booster pump 25 is driven by the engine of the transport chassis 11 and can pressurize the water in the vehicle-mounted water tank 24. The generator set 23 is electrically connected to the tethered power supply box 22 and supplies power to the tethered power supply box 22 during operation. The vehicle-mounted water tank 24 provides water for firefighting operations, and the outlet of the vehicle-mounted water tank 24 is connected to the inlet of the primary booster pump 25. The drone lift platform 26 is used to carry the unmanned aerial firefighting system 1 and realize the smooth ascent, descent, and takeoff preparation of the unmanned aerial firefighting system 1.

[0018] The unmanned aerial firefighting system 1 includes a ducted unmanned aerial vehicle 11, a fire monitor 12, a drive motor 13, a secondary booster pump 14, a transition water tank 15, and a fire hose 16. The ducted unmanned aerial vehicle 11 has a lifting capacity of 600 kg, providing heavy load support for the unmanned aerial firefighting system 1. The fire monitor 12, drive motor 13, secondary booster pump 14, transition water tank 15, and fire hose 16 are all mounted on the ducted unmanned aerial vehicle 11. The drive motor 13 is connected to the secondary booster pump 14 to provide power for its operation. The primary booster pump 25 is connected to the inlet of the transition water tank 15 through the fire hose 16. The transition water tank 15 is used to store pressurized water after the first pressurization to ensure a continuous water supply to the fire monitor 12 and prevent flow interruption. The outlet of the transition water tank 15 is connected to the inlet of the secondary booster pump 14, and the outlet of the secondary booster pump 14 is connected to the inlet of the fire monitor 12. The primary booster pump 25 pressurizes the water in the water tank 24 once, and the secondary booster pump 14 pressurizes the water in the transition water tank 15 a second time, greatly increasing the water pressure and enabling the fire monitor 12 to spray fire extinguishing water with high pressure, large flow, and long range. The tethered power supply box 22 is electrically connected to the ducted unmanned aerial vehicle 11 and the drive motor 13 via the aviation cable 3, providing continuous power for the flight operation of the ducted unmanned aerial vehicle 11 and the operation of the drive motor 13.

[0019] The transport vehicle 2 and the unmanned aerial fire-fighting system 1 are also equipped with a centralized vehicle control system (not shown in the figure). The control system is equipped with a main loop PID controller and a secondary loop PID controller, which are connected to the generator set 23, the primary booster pump 25, the fire monitor 12, the drive motor 13, the secondary booster pump 14, and the level gauges built into the vehicle-mounted water tank 24 and the transition water tank 15. The primary booster pump 25, the fire monitor 12, and the secondary booster pump 14 are all equipped with pressure sensors and are all controlled collaboratively by the control system.

[0020] like Figure 4As shown, the present invention discloses a control method for a tethered unmanned aerial firefighting system, which integrates three core modules: operational data acquisition, anti-interruption liquid level control, and jet pressure cascade PID control. It also introduces an altitude compensation algorithm to achieve intelligent closed-loop control of fire monitor spraying operations. Specifically, the method includes the following steps: S1. System Initialization: After system startup, a comprehensive self-check is first performed on detection equipment such as level sensors and pressure sensors, as well as actuators such as the primary booster pump 25, the secondary booster pump 14, and the water supply valve. Simultaneously, pre-flight baseline parameters are read to determine if they meet flight and firefighting operation requirements. If the self-check passes, the system enters normal firefighting operation mode; if the self-check fails, the system immediately triggers a fault alarm, alerting personnel to troubleshoot the problem and prevent equipment malfunction from affecting firefighting operations. S2. Operation Data Collection: During firefighting operations, the system collects core operational data in real time through various sensors, including: the flight altitude H of the ducted unmanned aerial vehicle 11 and the liquid level L of the vehicle-mounted water tank 24. 水罐 The liquid level L in the transition water tank 15 of the unmanned aerial fire suppression system 1. 过渡 The outlet pressure P of the first-stage booster pump 25 泵1 The outlet pressure P of the secondary booster pump 14 泵2 The spray pressure P of fire monitor 12 炮 All collected data is transmitted to the control system in real time, providing data input for subsequent intelligent adjustments; S3, Height Compensation Calculation: As the flight altitude H of the ducted unmanned aerial vehicle increases, the frictional resistance of the fire hose 16 increases, and the altitude difference and air back pressure also affect the jet. To compensate for the pressure loss caused by these factors, the system introduces an altitude compensation algorithm to calculate the theoretical jet pressure of the fire monitor 12: Theoretical P 炮 = P 泵1 -k*H, where k is the altitude compensation coefficient and H is the height of the fire monitor, ensuring that the system can promptly increase the theoretical pressure to meet the pressure requirements for high-altitude fire extinguishing when the flight altitude increases. S4. Anti-interruption liquid level control: Maintaining a stable water level in the transition water tank 15 is crucial for the continuous spraying of the fire monitor 12. The system adjusts the water level L in the transition water tank 15 accordingly. 过渡 The real-time values ​​are used to divide the liquid level into four intervals, and corresponding interval adjustment rules are established to achieve precise liquid level control to prevent flow interruption. High liquid level (L) 过渡 >90%) At this time, the water volume in the transition water tank 15 is sufficient. In order to prevent the water from overflowing and increasing the useless load, the system reduces the speed of the first-stage booster pump 25 or directly closes the water supply valve to reduce the water supply flow. Medium liquid level (40%≤L) 过渡 ≤90%): At this time, the liquid level is in the normal operating range, and the system enters the normal adjustment mode. The speed of the secondary booster pump 14 is adjusted by PID control to maintain the stable spray pressure of the fire monitor 12. Low liquid level (15%≤L) 过渡 <40%): At this point, the liquid level is low. The system first determines the liquid level L of the onboard water tank 24. 水罐 State, if L 水罐 If there is water and the water level is not below the threshold, fully activate the first-stage booster pump 25 to replenish water; if L 水罐 In case of water shortage, immediately issue an audible and visual alarm and control the ducted unmanned aerial vehicle 11 to prepare to descend and return to base to avoid further water shortage; Ultra-low liquid level (L 过渡 <15%): At this time, the liquid level is in the danger zone. In order to prevent the primary booster pump 25 and the secondary booster pump 14 from running dry and causing equipment damage, the system forcibly reduces the output flow of the fire monitor 12 (adjusts the nozzle size) or enters the intermittent spray mode, while continuously monitoring the liquid level changes. S5, Injection pressure cascade PID control: To address the issue of poor pressure stability in single-loop control, the system employs a pressure-speed cascade PID control strategy, designating a primary booster pump and fire monitor as the main loop, with the fire monitor's jet pressure P as the control factor. 炮 The main loop is the controlled variable, and the secondary booster pump and fire monitor are the secondary loops, with the outlet pressure P of the secondary booster pump as the controlled variable. 泵2 As a feedback variable for the secondary loop, it improves the system's response speed and anti-interference capability; the specific process is as follows: 5.1. Set the rated range of the spray pressure of fire monitor 12 to [0.8, 1.0] MPa, and take the median spray pressure of 0.9 MPa as the set value of the main circuit variable, and calculate the actual P in real time. 炮 With theoretical P 炮 Deviation rate e = (theoretical P) 炮 -Actual P 炮 ) / Theoretical P 炮 ; Actual P 炮 Calculation: The system introduces a pressure loss calculation model to calculate the pressure loss along the path. The friction loss caused by the vertical lifting height of the fire hose mainly includes: Static pressure loss (gravitational pressure drop caused by height difference): ; in: H represents the working height of the fire monitor; Friction loss along the pipe (related to flow rate, pipe diameter, pipe length, and coefficient of friction): ; Where D is the inner diameter of the fire hose (16mm), v is the water flow velocity, L is the equivalent length of the fire hose, and λ is the coefficient of friction. Total losses along the route: ; The calculated spray pressure of the fire monitor when the secondary booster pump is not turned on is: Actual P 炮 =P 泵1 -△P total When the actual P 炮 When the pressure is less than 0.8 MPa, the system will activate the secondary booster pump 14 for pressure compensation. When e ≤ 10%, the secondary booster pump 14 maintains a stable output, and the outlet pressure is a stable P. 泵2 The spray pressure of fire monitor 12: actual P 炮 =P 泵1 -△P total +StableP 泵2 As the height increases, the actual spray pressure P of the fire monitor 12 increases. 炮 The pressure will decrease. When e > 10%, the speed of the drive motor 13 needs to be adjusted to increase the outlet pressure of the pump 14 in the second stage, thereby adjusting the spray pressure of the fire monitor 12 so that the spray pressure of the fire monitor 12 is within the theoretical pressure range, i.e., the actual pressure P. 炮 =P 泵1 -△P total +StableP 泵2 +compensation P 泵2 Within the range of [0.8, 1.0] MPa; 5.2 Compensation P 泵2 Determination: When e > 10%, the main loop PID controller calculates and outputs the target pressure value P of the secondary booster pump 14 in the auxiliary loop based on the deviation rate e. 泵2 The secondary loop PID controller calculates the target P... 泵2 With stable P 泵2 To compensate for deviations, the speed of the drive motor 13 is adjusted in real time, and the outlet pressure of the secondary booster pump 14 is adjusted to stabilize P. 泵2 The deficiency, the compensating pressure value is the compensation P 泵2 This serves as the adjustment value for the secondary booster pump 14, enabling the outlet pressure of the secondary booster pump 14 to quickly track the target P. 泵2 Ultimately, the actual spray pressure of the 12 fire monitors was achieved. 炮 Precise adjustment; 5.3. Set up a pressure range locking mechanism; when P... 炮 When the pressure stabilizes within the range of [0.8, 1.0] MPa for more than 5 seconds, the system locks the speed of drive motor 13 to maintain the current boosted state, preventing frequent motor speed adjustments from affecting equipment lifespan and system stability. If the pressure drops due to sudden changes in front-end pressure, significant changes in flight altitude, or other factors, the system will lock the speed of drive motor 13 to maintain the current boosted state and prevent frequent motor speed adjustments from affecting equipment lifespan and system stability. 炮If the range is exceeded again, the system will automatically unlock and re-execute steps 5.1-5.2 until P. 炮 Return to the nominal range; At the same time, the spray pressure of fire monitor 12 satisfies the formula: P 炮 =P 泵1 -k*H, the system uses this formula to calibrate the effect of flight altitude on jet pressure in real time, ensuring the accuracy of pressure calculation; S6. Emergency Protection and Return-to-Home Decision: The system monitors the water level L in the vehicle's water tank in real time during operation. 水罐 , Transition tank liquid level L 过渡 If the water level is below a preset extremely low threshold, emergency protection measures will be triggered immediately: the spray intensity of the fire monitor will be reduced or the pump will be stopped directly. Simultaneously, an audible and visual alarm will be triggered to alert personnel to take emergency measures, and a decision to return to base will be made based on the situation on site. If L... 水罐 L 过渡 If all values ​​are within the normal threshold range, the system will continuously cycle through steps S2-S5 to achieve continuous intelligent adjustment of the fire extinguishing operation until the fire extinguishing work is completed. After completion, the system will control the primary booster pump and the secondary booster pump to stop working and guide the ducted unmanned aerial vehicle to return smoothly to the drone landing platform.

[0021] Example: Calculating the spray pressure and control adjustment using a fire monitor with a working height of 50m as an example: ① Calculation of pressure loss along the friction line: Static pressure loss (gravitational pressure drop caused by height difference): ; ;

[0022] Friction loss along the pipe (related to flow rate, pipe diameter, pipe length, and coefficient of friction): ; In typical fire protection pipes (inner diameter) ,flow Flow rate equivalent length coefficient of friction Under the following conditions, the calculation yields: ; Total losses along the route: ; ② Initial system configuration: Ground-based primary booster pump outlet pressure P 泵1 =1.2MPa: Total friction loss along the pipeline: ; Fire monitor spray pressure: P 炮 =P 泵1-△P total =1.2-0.5=0.7MPa; Because P 炮 With the threshold set at [0.8, 1.0] MPa, the pressure loss caused by altitude cannot be compensated by the first-stage pressurization alone, so a second-stage pressurization must be introduced; ③ Cascade control structure: Pressure-speed cascade control is adopted to improve response speed and anti-interference capability: Main circuit: Fire monitor spray pressure P 炮 As the controlled variable, its set value is... (Midpoint of the interval); Secondary circuit: The outlet pressure P of the secondary booster pump or the pump or motor speed N is used as an intermediate variable.

[0023] Control process: The main controller (PI) is based on P 炮 The deviation from the set value is used to calculate the secondary circuit pressure set value P. 泵2； The secondary controller (PI) adjusts the speed of the secondary booster pump motor, so that P 泵2 Quickly track set values.

[0024] When P 炮 Once the pressure reaches [0.8, 1] MPa and remains stable for more than 5 seconds, the system locks the motor speed and maintains the current boost pressure.

[0025] In summary, under normal circumstances, the rated working pressure of the fire monitor 12 is 0.8 MPa, and its range is 50 m. If the rated pressure of the fire monitor 12 is less than 0.8 MPa, the range will be affected, failing to meet the needs of high-altitude firefighting. This invention combines a two-stage booster pump 14 with cascade pressure control to achieve adaptive compensation of the spray pressure of the high-altitude fire monitor 12, ensuring its stable operation within the rated pressure range under all working conditions. This ensures high-volume, long-range spraying operations.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A tethered unmanned aerial firefighting system, mounted on an unmanned aerial firefighting system transport vehicle, characterized in that: The transport vehicle includes a transport chassis, a tethered power supply box, a generator set, a vehicle-mounted water tank, a primary booster pump, and a drone lifting platform. The outlet of the vehicle-mounted water tank is connected to the inlet of the primary booster pump. The drone lifting platform is used to carry the unmanned aerial firefighting system, which includes a ducted drone, a fire monitor, a drive motor, a secondary booster pump, a transition water tank, and a fire hose. The drive motor is connected to the secondary booster pump. The primary booster pump is connected to the inlet of the transition water tank via the fire hose. The outlet of the transition water tank is connected to the inlet of the secondary booster pump. The outlet of the secondary booster pump is connected to the inlet of the fire monitor. The tethered power supply box is electrically connected to the ducted drone and the drive motor via an aviation cable.

2. The tethered unmanned aerial firefighting system according to claim 1, characterized in that: The transport chassis is a heavy-duty transport chassis, the primary booster pump is driven by the engine of the transport chassis, and the generator set is connected to the tethered power supply box.

3. The tethered unmanned aerial firefighting system according to claim 1, characterized in that: The ducted unmanned aerial vehicle has a lifting capacity of 600 kg, which can meet the high-altitude heavy-load operation requirements of the unmanned aerial fire fighting system.

4. The tethered unmanned aerial firefighting system according to claim 1, characterized in that: The transport vehicle and the unmanned aerial firefighting system are also equipped with a centralized vehicle control system. The control system has a main loop PID controller and a secondary loop PID controller, which are connected to the generator set, the primary booster pump, the fire monitor, the drive motor, the secondary booster pump, and the level gauges built into the vehicle-mounted water tank and the transition water tank. The primary booster pump, the fire monitor, and the secondary booster pump are all equipped with pressure sensors and are all controlled collaboratively by the control system.

5. An intelligent control method for a tethered unmanned aerial firefighting system as described in claim 4, comprising the following steps: S1. System Initialization: After the system starts up, it first performs a comprehensive self-check on detection devices such as level sensors and pressure sensors, as well as actuators such as the primary booster pump, secondary booster pump, and water supply valve; at the same time, it reads the basic parameters before flight to determine whether they meet the requirements for flight and firefighting operations. If the self-test passes, the system will enter the firefighting operation mode normally; if the self-test fails, the system will immediately trigger a fault alarm to remind staff to troubleshoot the problem and avoid equipment failure affecting the firefighting operation. S2. Operational Data Acquisition: During firefighting operations, the system collects core operational data in real time through various sensors, including: the flight altitude H of the ducted unmanned aerial vehicle and the liquid level L of the onboard water tank. 水罐 The liquid level L in the transition water tank of the unmanned aerial fire suppression system 过渡 The outlet pressure P of the first-stage booster pump 泵1 The outlet pressure P of the secondary booster pump 泵2 The spray pressure P of the fire monitor 炮 All collected data is transmitted to the control system in real time. S3. Altitude Compensation Calculation: As the flight altitude H of the ducted unmanned aerial vehicle increases, the system introduces an altitude compensation algorithm to calculate the theoretical jet pressure of the fire monitor: Theoretical P 炮 = P 泵1 -k*H, where P 泵1 Here, k is the outlet pressure of the primary booster pump, k is the height compensation coefficient, and H is the height of the fire monitor. S4. Anti-interruption liquid level control: The system controls the liquid level L in the transition water tank. 过渡 The real-time values ​​are used to divide the liquid level into four intervals, and corresponding interval adjustment rules are established to achieve precise liquid level control to prevent flow interruption. High liquid level (L) 过渡 >90%): At this point, the water volume in the transition water tank is sufficient. The system reduces the motor speed of the first-stage booster pump or directly closes the water supply valve to reduce the water supply flow. Medium liquid level (40%≤L) 过渡 ≤90%): At this time, the liquid level is in the normal operating range, and the system enters the normal adjustment mode. The speed of the drive motor is adjusted by PID control, the outlet pressure of the secondary booster pump is adjusted, and the spray pressure of the fire monitor is kept stable. Low liquid level (15%≤L) 过渡 <40%): At this point, the liquid level is low. The system first determines the liquid level L of the onboard water tank 24. 水罐 State, if L 水罐 If there is water and the water level is not below the threshold, fully activate the first-stage booster pump to replenish water; if L 水罐 If water is scarce, immediately issue an audible and visual alarm and control the ducted unmanned aerial vehicle to prepare to descend and return to base to avoid further water shortage; Ultra-low liquid level (L 过渡 <15%): At this point, the liquid level is in the danger zone. The system will forcibly reduce the output flow of the fire monitor (adjust the nozzle size) or enter the intermittent spray mode, while continuously monitoring the liquid level changes. S5. Jet Pressure Cascade PID Control: The system adopts a pressure-speed cascade PID control strategy, setting the primary booster pump and fire monitor as the main loop, with the fire monitor's jet pressure P... 炮 The main loop is the controlled variable, and the secondary booster pump and fire monitor are the secondary loops, with the outlet pressure P of the secondary booster pump as the controlled variable. 泵2 As a feedback variable in the secondary loop, it improves the system's response speed and anti-interference capability; simultaneously, the theoretical value of the fire monitor's jet pressure satisfies the formula: Theoretical P 炮 =P 泵1 -k*H, the system uses this formula to calibrate the effect of flight altitude on jet pressure in real time, ensuring the accuracy of pressure calculation; S6. Emergency Protection and Return Decision: The system continuously monitors the water level L in the vehicle's water tank during operation. 水罐 , Transition tank liquid level L 过渡 If the water level is below a preset extremely low threshold, emergency protection measures will be triggered immediately: the spray intensity of the fire monitor will be reduced or the pump will be stopped directly. Simultaneously, an audible and visual alarm will be triggered to alert personnel to take emergency measures, and a decision to return to base will be made based on the situation on site. If L... 水罐 L 过渡 If all values ​​are within the normal threshold range, the system will continuously cycle through steps S2-S5 to achieve continuous intelligent adjustment of the fire extinguishing operation until the fire extinguishing work is completed. After completion, the system will control the primary booster pump and the secondary booster pump to stop working and guide the ducted unmanned aerial vehicle to return smoothly to the drone landing platform.

6. The intelligent control method for the tethered unmanned aerial firefighting system according to claim 5, characterized in that: The PID control in step S5 includes the following steps: 5.

1. Set the rated range of fire monitor spray pressure to [0.8, 1.0] MPa, and take the median spray pressure of 0.9 MPa as the set value of the main circuit variable, and calculate the actual P in real time. 炮 With theoretical P 炮 Deviation rate e = (theoretical P) 炮 -Actual P 炮 ) / Theoretical P 炮 ; Actual P 炮 Calculation: The system introduces a pressure loss calculation model to calculate the pressure loss along the path. The friction loss caused by the vertical lifting height of the fire hose mainly includes: Static pressure loss (gravitational pressure drop caused by height difference): ; in: H represents the working height of the fire monitor; Friction loss along the pipe (related to flow rate, pipe diameter, pipe length, and coefficient of friction): ； Where D is the inner diameter of the fire hose (16mm), v is the water flow velocity, L is the equivalent length of the fire hose, and λ is the coefficient of friction. Total losses along the route: ; The calculated spray pressure of the fire monitor when the secondary booster pump is not activated is: Actual P 炮 =P 泵1 -△P total When the actual P 炮 When the pressure is less than 0.8 MPa, the system will activate the secondary booster pump for pressure compensation. When e ≤ 10%, the secondary booster pump maintains a stable output, and the outlet pressure is a stable P. 泵2 Fire monitor spray pressure: Actual P 炮 =P 泵1 -△P total +StableP 泵2 As the height increases, the actual spray pressure P of the fire monitor decreases. 炮 The pressure will decrease. When e > 10%, the speed of the drive motor needs to be adjusted to increase the outlet pressure of the pump in the secondary stage, thereby adjusting the spray pressure of the fire monitor so that the spray pressure of the fire monitor is within the theoretical pressure range, i.e., the actual pressure P. 炮 =P 泵1 -△P total +StableP 泵2 +compensation P 泵2 Within the range of [0.8, 1.0] MPa; 5.2 Compensation P 泵2 Determination: When e > 10%, the main loop PID controller calculates and outputs the target pressure value P of the secondary booster pump in the auxiliary loop based on the deviation rate e. 泵2 The secondary loop PID controller uses the calculated outlet pressure of the secondary booster pump, i.e., the target pressure P, as its basis. 泵2 With stable P 泵2 To compensate for deviations, the speed of the drive motor is adjusted in real time, and the outlet pressure of the secondary booster pump is adjusted to stabilize P. 泵2 The deficiency, the compensating pressure value is the compensation P 泵2 This serves as the adjustment value for the secondary booster pump, enabling the outlet pressure of the secondary booster pump to quickly track the target P. 泵2 Ultimately, the actual P of the fire monitor's spray pressure was achieved. 炮 Precise adjustment; 5.

3. Set up a pressure range locking mechanism; when P... 炮 Once the pressure stabilizes within the range of [0.8, 1.0] MPa for more than 5 seconds, the system locks the drive motor speed to maintain the current boosted state, preventing frequent motor speed adjustments from affecting equipment lifespan and system stability. If the pressure drops due to sudden changes in front-end pressure, significant changes in flight altitude, or other factors, the system will lock the drive motor speed to maintain the current boosted state and prevent frequent motor speed adjustments from affecting equipment lifespan and system stability. 炮 If the range is exceeded again, the system will automatically unlock and re-execute steps 5.1-5.2 until P. 炮 Return to the rated range.

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