Fire-fighting unmanned aerial vehicle flight attitude instability control device and control method thereof

Abstract

The invention relates to the technical field of unmanned aerial vehicle control, and discloses a fire-fighting unmanned aerial vehicle flight attitude instability control device and a control method thereof. The device at least comprises a control module which is configured to estimate an equivalent disturbance torque vector generated by throwing a fire extinguishing bomb in real time by utilizing an expansion state observer according to an attitude state quantity, a load state parameter and a current motor control instruction, a self-adaptive sliding mode controller fuses the equivalent disturbance torque vector and a feedback control quantity obtained through sliding mode control based on the current attitude error, a total compensation torque instruction needed by the fire-fighting unmanned aerial vehicle to recover stability is generated, and the total compensation torque instruction is decomposed into a target displacement instruction and a differential speed adjusting instruction; and the execution module is configured to execute the target displacement instruction by using the movable counterweight mechanism to drive the counterweight block to move, and execute the differential speed adjustment instruction through the power fine adjustment mechanism to adjust the rotating speed of the motor. The problem of attitude instability after bomb dropping of the fire-fighting unmanned aerial vehicle is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) control technology, and in particular to a flight attitude instability control device and control method for firefighting UAVs. Background Technology

[0002] In fire emergency rescue scenarios, fire-fighting drones equipped with fire extinguishing bombs can quickly overcome terrain and spatial limitations, accurately deliver fire extinguishing bombs for targeted fire suppression, effectively filling the gaps in ground-based fire-fighting equipment for high-altitude and long-distance fire response, and significantly improving emergency rescue efficiency. However, as a crucial payload, the fire extinguishing bomb typically accounts for 10%-30% of the drone's total mass, and this proportion is even higher for some small fire-fighting drones. After the fire extinguishing bomb is deployed, the drone's total mass undergoes a drastic change in a very short time, directly causing a sharp shift in the center of gravity; simultaneously, the separation of the fire extinguishing bomb from the mounting mechanism at the moment of deployment generates instantaneous impact disturbances, and the combined effect can easily lead to severe fluctuations in the drone's attitude.

[0003] Currently, mainstream UAV attitude control algorithms (such as traditional PID control and LQR control) are mostly designed with a fixed center of mass and stable load as premises, and lack robustness against sudden load changes and center of mass shifts. Under extreme conditions such as the deployment of fire extinguishing bombs, existing algorithms struggle to respond quickly and compensate for disturbances, often resulting in excessive overshoot in pitch and roll angles. In severe cases, this can lead to UAV attitude instability and crashes, not only interrupting firefighting operations but also potentially damaging equipment and even posing secondary safety risks.

[0004] To address the control challenges posed by sudden load changes, existing technologies have proposed several improvement solutions: one is to employ adaptive control algorithms, but these algorithms largely rely on precise mathematical models of the system and are ill-suited to effectively handle unmodeled dynamics such as aerodynamic disturbances and elastic deformations of mechanical structures during deployment; another approach is to increase control redundancy by adding redundant actuators, but these additional mechanisms significantly increase the drone's weight and energy consumption, directly reducing its endurance and operating radius, which conflicts with the practical needs of firefighting drones. Summary of the Invention

[0005] To address the attitude stability issue of firefighting drones after dropping fire extinguishing bombs, this invention provides a flight attitude instability control device and method for firefighting drones, which can quickly and directly compensate for changes in the center of mass while also ensuring lightweight flight attitude instability control.

[0006] In a first aspect, embodiments of the present invention provide a flight attitude instability control device for a fire-fighting drone, which is built into the middle of the fuselage of a fire-fighting drone carrying fire extinguishing bombs. The device includes a sensing module, a control module, and an execution module. The control module includes an extended state observer and an adaptive sliding mode controller. The execution module includes a movable counterweight mechanism and a power fine-tuning mechanism. The sensing module is configured to collect the attitude state variables and load state parameters of the fire-fighting drone in response to the fire extinguishing bomb deployment command. The control module is communicatively connected to the sensing module, and the control module is configured to use the extended state observer to estimate the equivalent disturbance torque vector generated by the deployment of fire extinguishing bombs in real time based on the attitude state quantity, the load state parameter and the current motor control command, and to fuse the equivalent disturbance torque vector with the feedback control quantity obtained by sliding mode control based on the current attitude error through the adaptive sliding mode controller to generate the total compensation torque command required for the fire-fighting drone to restore stability, and to decompose the total compensation torque command into target displacement command and differential speed adjustment command; The execution module is communicatively connected to the control module, and the execution module is configured to use the movable counterweight mechanism to execute the target displacement command to drive the counterweight block to move, and to use the power fine-tuning mechanism to execute the differential speed adjustment command to adjust the motor speed.

[0007] Preferably, the sensing module includes an inertial measurement unit and a load sensor; The inertial measurement unit is configured to collect the pitch angle and its corresponding angular velocity, roll angle and its corresponding angular velocity, and yaw angle and its corresponding angular velocity of the firefighting drone. The load sensor is installed at the fire extinguishing projectile mounting mechanism of the fire-fighting drone, and the load sensor is configured to detect the mounting status of the fire extinguishing projectile and the real-time load mass.

[0008] Preferably, the extended state observer is configured to reconstruct the extended state based on the received attitude state quantity, the load state parameter and the current motor control command, and estimate the equivalent disturbance torque vector generated by the deployment of the fire extinguishing bomb in real time.

[0009] Preferably, the adaptive sliding mode controller is configured as follows: The equivalent disturbance torque vector is introduced as a feedforward control quantity; Based on the current attitude error of the firefighting drone fed back by the sensing module, the feedback control quantity is calculated through a sliding mode control law; The feedforward control quantity and the feedback control quantity are fused to generate the total compensation torque command required for the firefighting drone to restore stability. The total compensation torque command is decomposed into target displacement command and differential speed adjustment command according to different torque components.

[0010] Preferably, the step of decomposing the total compensation torque command into target displacement command and differential speed adjustment command according to different torque components includes: The torque component used to offset the steady-state centroid shift in the total compensation torque command is calculated into a target displacement command; The torque component used to suppress transient high-frequency disturbances in the total compensation torque command is calculated into a differential speed adjustment command.

[0011] Preferably, the movable counterweight mechanism includes a counterweight block, an X-axis drive motor, a Y-axis drive motor, and a displacement sensor; The process by which the movable counterweight mechanism executes the target displacement command includes: The X-axis drive motor and the Y-axis drive motor are used to drive the counterweight to move in a two-dimensional plane in which the X-axis guide rail and the Y-axis guide rail are orthogonal to each other according to the target displacement command, and the position of the counterweight is detected in real time by the displacement sensor.

[0012] Preferably, the power fine-tuning mechanism is configured to differentially adjust each rotor motor of the firefighting drone based on the differential adjustment command.

[0013] Preferably, the system further includes a power supply module, which is a combination of a lithium battery pack and a DC-DC voltage regulator module, and is configured to provide DC power to the sensing module, the control module, and the execution module.

[0014] Secondly, embodiments of the present invention provide a method for controlling the flight attitude instability of a fire-fighting drone, applied to the fire-fighting drone flight attitude instability control device described above, the method comprising: In response to the fire extinguishing bomb release command, the attitude and load status parameters of the firefighting drone are collected; Based on the attitude state quantity, the load state parameter and the current motor control command, the equivalent disturbance torque vector generated by the deployment of the fire extinguishing bomb is estimated in real time. By fusing the equivalent disturbance torque vector with the feedback control quantity obtained through sliding mode control based on the current attitude error, the total compensation torque command required for the firefighting drone to restore stability is generated. The total compensation torque command is decomposed into a target displacement command and a differential speed adjustment command; The target displacement command is executed to drive the counterweight to move, and the differential speed adjustment command is executed to adjust the motor speed.

[0015] Preferably, the step of estimating the equivalent disturbance torque vector generated by the deployment of the fire extinguishing bomb in real time based on the attitude state quantity, the load state parameter, and the current motor control command includes: The attitude state variables, load state parameters, and current motor control commands are reconstructed using an extended state method to estimate the equivalent disturbance torque vector generated by the deployment of fire extinguishing bombs in real time.

[0016] Compared with the prior art, the flight attitude instability control device and control method for firefighting drones according to embodiments of the present invention have at least the following advantages: (1) Through the collaborative architecture of extended state observer and adaptive sliding mode controller, the seamless connection between disturbance estimation and compensation control is realized. The extended state observer does not need to rely on an accurate system model and can quickly integrate attitude state variables, load state parameters and current motor control commands to estimate the equivalent disturbance vectors such as centroid offset torque and instantaneous impact torque caused by the release of fire extinguishing bombs in milliseconds. The adaptive sliding mode controller uses this disturbance vector as a feedforward control quantity and generates a feedback control quantity through sliding mode control in combination with attitude error, forming a composite control of "feedforward cancellation + feedback correction", which completely solves the problem of lag in response to sudden load changes in traditional algorithms and greatly improves the real-time performance and robustness of control. (2) A two-dimensional movable counterweight mechanism is used as the core component for center of mass compensation. Unlike the traditional method that relies on indirect adjustment through aerodynamic torque, the counterweight is precisely driven to move by the X-axis drive motor and the Y-axis drive motor, directly reconstructing the mass distribution of the UAV to correct the center of mass position. This physical balancing method can specifically offset the steady-state center of mass shift after the fire extinguishing bomb is dropped. The compensation accuracy is not affected by factors such as flight speed and aerodynamic environment. Even in complex firefighting operation conditions such as hovering and low speed, it can ensure that the center of mass quickly returns to the equilibrium position and avoids continuous attitude fluctuations. (3) A collaborative execution mechanism of "steady-state compensation + transient fine-tuning" is designed. The movable counterweight mechanism undertakes the main low-frequency steady-state interference compensation, while the original power system of the UAV is only responsible for suppressing high-frequency transient disturbances. This division of labor avoids the weight redundancy and energy consumption surge caused by simply adding redundant actuators, and also reduces the compensation load on the power system, preventing it from failing due to overload saturation. It maximizes the effective payload and endurance of the fire-fighting UAV, effectively meeting the practical needs of fire emergency rescue. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a fire-fighting drone carrying fire extinguishing bombs according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a fire-fighting drone flight attitude instability control device according to an embodiment of the present invention; Figure 3This is a flowchart illustrating a method for controlling flight attitude instability of a firefighting drone according to an embodiment of the present invention; Figure label: 1. UAV body; 2. Mounting mechanism; 3. Landing frame; 4. Fire extinguishing bomb; 5. Electromagnetic adsorption structure; 6. Propeller; 7. Sensing module; 8. Control module; 9. Extended state observer; 10. Adaptive sliding mode controller; 11. Inertial measurement unit; 12. Load sensor; 13. Binocular camera; 14. Counterweight; 15. X-axis drive motor; 16. Y-axis drive motor; 17. Displacement sensor; 18. Power supply module; 19. UAV connecting support; 20. Battery; 21. X-axis motor motion guide rail; 22. Y-axis motor motion guide rail; 23. X-axis counterweight motion guide rail; 24. Y-axis counterweight motion guide rail. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] In the description of this invention, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by those skilled in the art. The terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] like Figure 1 The diagram shown is a structural schematic of a fire-fighting drone carrying fire-extinguishing bombs according to an embodiment of the present invention. (Refer to...) Figure 1 The fire-fighting drone of this invention includes a drone body 1, a mounting mechanism 2, a landing gear 3, a fire extinguishing bomb 4, an electromagnetic adsorption structure 5, and a propeller 6.

[0021] The mounting mechanism is fixed to the bottom of the drone body and can be detachably connected to the fire extinguishing bomb via an electromagnetic adsorption structure; the landing gear is symmetrically arranged at the bottom of the drone body for ground support; the propellers are set corresponding to the rotor motors, forming the power base of the drone.

[0022] This invention provides a flight attitude instability control device for a fire-fighting drone, which is built into the middle of the fuselage of the drone carrying fire extinguishing bombs. Figure 2 The diagram shown is a structural schematic of a fire-fighting drone flight attitude instability control device according to an embodiment of the present invention. (Refer to...) Figure 2This invention discloses a flight attitude instability control device for a firefighting drone, comprising a sensing module 7, a control module 8, and an execution module, all connected via a serial communication interface. The control module includes an extended state observer 9 and an adaptive sliding mode controller 10, while the execution module includes a movable counterweight mechanism and a power fine-tuning mechanism.

[0023] Each module will be explained in detail below: 1) Perception Module: The sensing module is configured to collect the attitude state variables and load state parameters of the fire-fighting drone in response to the fire extinguishing bomb release command.

[0024] Specifically, refer to Figure 2 The sensing module in this embodiment of the invention includes an inertial measurement unit 11 and a load sensor 12.

[0025] The inertial measurement unit (IMU) is configured to collect the pitch angle and its corresponding angular velocity, roll angle and its corresponding angular velocity, and yaw angle and its corresponding angular velocity of the firefighting drone. In this embodiment, the IMU uses an integrated module of a six-axis gyroscope and accelerometer, with a sampling frequency of not less than 1000Hz.

[0026] The load sensor is installed at the fire extinguishing projectile mounting mechanism of the firefighting drone, and is configured to detect the projectile mounting status (mounting / deployment) and real-time load mass. In this embodiment, the load sensor adopts a combination of a pressure sensor and a Hall effect sensor.

[0027] Furthermore, referring to Figure 2 The perception module in this embodiment of the invention also includes a binocular camera 13, which is used to assist in identifying the attitude of the drone and the surrounding environmental interference.

[0028] 2) Control module: The control module is communicatively connected to the sensing module, and the control module is configured to use an extended state observer to estimate the equivalent disturbance torque vector generated by the deployment of fire extinguishing bombs in real time based on attitude state variables, load state parameters, and current motor control commands. The control module then uses an adaptive sliding mode controller to fuse the equivalent disturbance torque vector with the feedback control quantity obtained by sliding mode control based on the current attitude error, and generates the total compensation torque command required for the fire-fighting drone to restore stability. The total compensation torque command is then decomposed into target displacement command and differential speed adjustment command.

[0029] The extended state observer is configured to reconstruct the extended state from the received attitude state variables, load state parameters, and current motor control commands, and estimate the equivalent disturbance torque vector generated by the deployment of the fire extinguishing projectile in real time. Specifically, the extended state observer receives attitude state variables from the inertial measurement unit, load state parameters from the load sensors, and the current motor control commands issued by the UAV flight control system to the power system (each rotor motor) at the moment of fire extinguishing projectile deployment. Within a millisecond-level control cycle, it estimates an equivalent disturbance torque vector in real time. This vector includes all unmodeled dynamic disturbances, such as the gravitational torque caused by the center of mass shift due to the fire extinguishing projectile detachment and the instantaneous impact torque generated during deployment.

[0030] The adaptive sliding mode controller is configured as follows: a) Introduce an equivalent disturbance torque vector as a feedforward control quantity; b) Based on the current attitude error of the firefighting drone fed back by the sensing module, the feedback control quantity is calculated using a sliding mode control law; c) Integrate the feedforward control quantity and the feedback control quantity to generate the total compensation torque command required for the firefighting drone to restore stability; d) Decompose the total compensation torque command into target displacement command and differential speed adjustment command according to different torque components.

[0031] Specifically, the torque component in the total compensation torque command used to offset the steady-state centroid offset is calculated as the target displacement command; the torque component in the total compensation torque command used to suppress transient high-frequency disturbances is calculated as the differential speed adjustment command.

[0032] 3) Execution module: The execution module is communicatively connected to the control module, and the execution module is configured to use a movable counterweight mechanism to execute target displacement commands to drive the counterweight block to move, and to execute differential speed adjustment commands through a power fine-tuning mechanism to adjust the motor speed.

[0033] Reference Figure 2 The movable counterweight mechanism in this embodiment of the invention includes a counterweight block 14, an X-axis drive motor 15, a Y-axis drive motor 16, and a displacement sensor 17.

[0034] The process by which the movable counterweight mechanism executes the target displacement command includes: Using X-axis and Y-axis drive motors, the counterweight is moved according to the target displacement command within a two-dimensional plane where the X-axis and Y-axis guide rails are orthogonal. The position of the counterweight is detected in real time by a displacement sensor. It should be noted that the movable counterweight mechanism is a two-dimensional movable counterweight system. By driving the counterweight to move within a two-dimensional plane according to the target displacement command, it can actively adjust the mass distribution of the UAV and directly correct the position of its center of gravity physically.

[0035] The power fine-tuning mechanism is configured to differentially adjust the speed of each rotor motor of the firefighting drone based on differential adjustment commands. It should be noted that the power fine-tuning mechanism is the original multi-rotor power system of the drone. By differentially adjusting the speed of each rotor motor, it can quickly change the lift distribution to generate auxiliary aerodynamic torque.

[0036] like Figure 2 As shown in the figure, an embodiment of the present invention provides a flight attitude instability control device for a fire-fighting drone, which further includes a power supply module 18. The power supply module adopts a combination of a lithium battery pack and a DC-DC voltage regulator module, and is configured to provide DC power to the sensing module, the control module, and the execution module. In this embodiment, the power supply module provides 5V / 3A power to the control module and 12V / 10A power to the execution module, and has overcurrent, overvoltage, and undervoltage protection functions.

[0037] To verify the effectiveness of the flight attitude instability control device for a fire-fighting drone according to an embodiment of the present invention, in another embodiment, a six-rotor fire-fighting drone with an empty weight of 50 kg is used as a platform, and a fire extinguishing bomb with a weight of 10 kg is carried for illustration: After the fire extinguishing bomb is released, the mechanical lock is unlocked, and the fire extinguishing bomb quickly detaches from the mounting mechanism. The load sensor installed at the mounting point detects the pressure returning to zero and the state change within milliseconds, and simultaneously outputs the "released" signal and the load change data of "mass reduced by 10kg". At the same time, the inertial measurement unit captures the initial angular acceleration of the body caused by the sudden change in the center of mass.

[0038] The extended state observer of the control module is then activated, fusing load change data, current motor control commands, and initial angular velocity feedback from the inertial measurement unit. Within a 1ms control cycle, it accurately estimates the equivalent disturbance torque vector, which includes the gravitational torque of the center of mass shift and the instantaneous impact torque. The adaptive sliding mode controller uses this vector as the feedforward control quantity, and combines it with the real-time attitude error feedback from the inertial measurement unit to solve the feedback control quantity through the sliding mode control law. The two are then fused to generate the total compensation torque command. Subsequently, the total compensation torque command is decomposed into two types of execution commands (target displacement command and differential speed adjustment command).

[0039] The X-axis and Y-axis drive motors of the movable counterweight mechanism receive target displacement commands. Under the closed-loop feedback of the displacement sensor, the drive counterweight block moves precisely to the target position within 100 milliseconds along mutually orthogonal guide rails, completing the physical reconstruction of the center of mass to offset the steady-state offset. The power fine-tuning mechanism receives differential speed adjustment commands simultaneously and generates aerodynamic torque to suppress transient oscillations by adjusting the speed of each rotor motor in milliseconds. Under the synergistic effect of the two types of mechanisms, the attitude fluctuations of the UAV decay rapidly. Within 500 milliseconds after the drop event, the pitch and roll angle errors converge to within ±0.5°, and the UAV smoothly recovers to a stable flight state.

[0040] This invention discloses a flight attitude instability control device for firefighting drones. Through a collaborative architecture of an extended state observer and an adaptive sliding mode controller, it achieves seamless integration of disturbance estimation and compensation control. The extended state observer, without relying on a precise system model, can quickly fuse attitude state variables, load state parameters, and current motor control commands, estimating the equivalent disturbance vectors such as the center-of-gravity offset torque and instantaneous impact torque caused by the deployment of fire extinguishing projectiles within milliseconds. The adaptive sliding mode controller uses this disturbance vector as a feedforward control variable, combining it with attitude errors to generate feedback control variables through sliding mode control, forming a composite control of "feedforward cancellation + feedback correction." This completely solves the problem of lag in response to sudden load changes in traditional algorithms, significantly improving the real-time performance and robustness of the control. A two-dimensional movable counterweight mechanism is used as the core component for center-of-gravity compensation. Unlike traditional methods that rely on indirect adjustment using aerodynamic torque, this device precisely drives the counterweight block through X-axis and Y-axis drive motors, directly reconstructing the drone's mass distribution to correct the center-of-gravity position. This physical balancing method can specifically offset the steady-state center of mass shift after the fire extinguishing bomb is deployed. The compensation accuracy is unaffected by factors such as flight speed and aerodynamic environment. Even in complex firefighting operation conditions such as hovering and low speed, it can ensure that the center of mass quickly returns to the equilibrium position, avoiding continuous attitude fluctuations. A collaborative execution mechanism of "steady-state compensation + transient fine-tuning" is designed, with the movable counterweight mechanism undertaking the main low-frequency steady-state interference compensation, while the original power system of the UAV is only responsible for suppressing high-frequency transient disturbances. This division of labor avoids the weight redundancy and energy consumption surge caused by simply adding redundant actuators, and reduces the compensation load on the power system, preventing it from failing due to overload saturation. It maximizes the effective payload and endurance of the firefighting UAV, effectively meeting the practical needs of fire emergency rescue.

[0041] like Figure 3 The diagram shown is a flowchart illustrating a method for controlling flight attitude instability of a fire-fighting drone according to an embodiment of the present invention. This method is applied to the aforementioned flight attitude instability control device for fire-fighting drones. (Refer to...) Figure 3 An embodiment of the present invention provides a method for controlling flight attitude instability of a firefighting drone, comprising the following steps: S1. In response to the fire extinguishing bomb release command, collect the attitude state variables and load state parameters of the fire-fighting drone; S2. Based on the attitude state variables, load state parameters and current motor control commands, estimate the equivalent disturbance torque vector generated by the deployment of the fire extinguishing bomb in real time; Specifically, the attitude state variables, load state parameters, and current motor control commands are expanded and reconstructed to estimate the equivalent disturbance torque vector generated by the deployment of fire extinguishing bombs in real time.

[0042] S3. By fusing the equivalent disturbance torque vector with the feedback control quantity obtained through sliding mode control based on the current attitude error, the total compensation torque command required for the firefighting drone to restore stability is generated. S4. Decompose the total compensation torque command into the target displacement command and the differential speed adjustment command; S5. Execute the target displacement command to drive the counterweight to move, and execute the differential speed adjustment command to adjust the motor speed.

[0043] It should be noted that the specific limitations of the flight attitude instability control method for a fire-fighting drone are the same as those for the flight attitude instability control device for a fire-fighting drone mentioned above. The two have the same function and role, and will not be repeated here.

[0044] In summary, the present invention provides a flight attitude instability control device and method for firefighting drones. Through a collaborative architecture of an extended state observer and an adaptive sliding mode controller, it achieves seamless integration of disturbance estimation and compensation control. The extended state observer does not rely on a precise system model and can quickly fuse attitude state variables, load state parameters, and current motor control commands to estimate the equivalent disturbance vectors such as the center of mass offset torque and instantaneous impact torque caused by the deployment of fire extinguishing bombs in milliseconds. The adaptive sliding mode controller uses this disturbance vector as a feedforward control variable and combines it with the attitude error to generate a feedback control variable through sliding mode control, forming a composite control of "feedforward cancellation + feedback correction". This completely solves the problem of lag in response to sudden load changes in traditional algorithms and significantly improves the real-time performance and robustness of the control. A two-dimensional movable counterweight mechanism is used as the core component for center of mass compensation. Unlike the traditional method that relies on indirect adjustment using aerodynamic torque, this method precisely drives the counterweight block to move through X-axis and Y-axis drive motors, directly reconstructing the mass distribution of the drone to correct the center of mass position. This physical balancing method can specifically offset the steady-state center of mass shift after the fire extinguishing bomb is deployed. The compensation accuracy is unaffected by factors such as flight speed and aerodynamic environment. Even in complex firefighting operation conditions such as hovering and low speed, it can ensure that the center of mass quickly returns to the equilibrium position, avoiding continuous attitude fluctuations. A collaborative execution mechanism of "steady-state compensation + transient fine-tuning" is designed, with the movable counterweight mechanism undertaking the main low-frequency steady-state interference compensation, while the original power system of the UAV is only responsible for suppressing high-frequency transient disturbances. This division of labor avoids the weight redundancy and energy consumption surge caused by simply adding redundant actuators, and reduces the compensation load on the power system, preventing it from failing due to overload saturation. It maximizes the effective payload and endurance of the firefighting UAV, effectively meeting the practical needs of fire emergency rescue.

[0045] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts of the embodiments, refer to each other. Each embodiment focuses on describing the differences from other embodiments. In particular, the method embodiments are basically similar to the device embodiments, so the description is relatively simple; relevant parts can be referred to the description of the device embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A device for controlling flight attitude instability of a firefighting drone, characterized in that, Built into the middle of the fuselage of a fire-fighting drone carrying fire extinguishing bombs, the device includes a sensing module, a control module, and an execution module. The control module includes an extended state observer and an adaptive sliding mode controller, and the execution module includes a movable counterweight mechanism and a power fine-tuning mechanism. The sensing module is configured to collect the attitude state variables and load state parameters of the fire-fighting drone in response to the fire extinguishing bomb deployment command. The control module is communicatively connected to the sensing module, and the control module is configured to use the extended state observer to estimate the equivalent disturbance torque vector generated by the deployment of fire extinguishing bombs in real time based on the attitude state quantity, the load state parameter and the current motor control command, and to fuse the equivalent disturbance torque vector with the feedback control quantity obtained by sliding mode control based on the current attitude error through the adaptive sliding mode controller to generate the total compensation torque command required for the fire-fighting drone to restore stability, and to decompose the total compensation torque command into target displacement command and differential speed adjustment command; The execution module is communicatively connected to the control module, and the execution module is configured to use the movable counterweight mechanism to execute the target displacement command to drive the counterweight block to move, and to use the power fine-tuning mechanism to execute the differential speed adjustment command to adjust the motor speed.

2. The fire-fighting drone flight attitude instability control device according to claim 1, characterized in that, The sensing module includes an inertial measurement unit and a load sensor; The inertial measurement unit is configured to collect the pitch angle and its corresponding angular velocity, roll angle and its corresponding angular velocity, and yaw angle and its corresponding angular velocity of the firefighting drone. The load sensor is installed at the fire extinguishing projectile mounting mechanism of the fire-fighting drone, and the load sensor is configured to detect the mounting status of the fire extinguishing projectile and the real-time load mass.

3. The fire-fighting drone flight attitude instability control device according to claim 1, characterized in that, The extended state observer is configured to reconstruct the extended state based on the received attitude state quantities, load state parameters, and current motor control commands, and to estimate the equivalent disturbance torque vector generated by the deployment of fire extinguishing bombs in real time.

4. The fire-fighting drone flight attitude instability control device according to claim 1, characterized in that, The adaptive sliding mode controller is configured as follows: The equivalent disturbance torque vector is introduced as a feedforward control quantity; Based on the current attitude error of the firefighting drone fed back by the sensing module, the feedback control quantity is calculated through a sliding mode control law; The feedforward control quantity and the feedback control quantity are fused to generate the total compensation torque command required for the firefighting drone to restore stability. The total compensation torque command is decomposed into target displacement command and differential speed adjustment command according to different torque components.

5. The fire-fighting drone flight attitude instability control device according to claim 4, characterized in that, The step of decomposing the total compensation torque command into target displacement command and differential speed adjustment command according to different torque components includes: The torque component used to offset the steady-state centroid shift in the total compensation torque command is calculated into a target displacement command; The torque component used to suppress transient high-frequency disturbances in the total compensation torque command is calculated into a differential speed adjustment command.

6. The fire-fighting drone flight attitude instability control device according to claim 1, characterized in that, The movable counterweight mechanism includes a counterweight block, an X-axis drive motor, a Y-axis drive motor, and a displacement sensor. The process by which the movable counterweight mechanism executes the target displacement command includes: The X-axis drive motor and the Y-axis drive motor are used to drive the counterweight to move in a two-dimensional plane in which the X-axis guide rail and the Y-axis guide rail are orthogonal to each other according to the target displacement command, and the position of the counterweight is detected in real time by the displacement sensor.

7. The fire-fighting drone flight attitude instability control device according to claim 1, characterized in that, The power fine-tuning mechanism is configured to differentially adjust each rotor motor of the firefighting drone based on the differential adjustment command.

8. The fire-fighting drone flight attitude instability control device according to claim 1, characterized in that, It also includes a power supply module, which is a combination of a lithium battery pack and a DC-DC voltage regulator module, and is configured to provide DC power to the sensing module, the control module and the execution module.

9. A method for controlling flight attitude instability of a firefighting drone, characterized in that, The method, applied to the firefighting drone flight attitude instability control device as described in any one of claims 1 to 8, comprises: In response to the fire extinguishing bomb release command, the attitude and load status parameters of the firefighting drone are collected; Based on the attitude state quantity, the load state parameter and the current motor control command, the equivalent disturbance torque vector generated by the deployment of the fire extinguishing bomb is estimated in real time. By fusing the equivalent disturbance torque vector with the feedback control quantity obtained through sliding mode control based on the current attitude error, the total compensation torque command required for the firefighting drone to restore stability is generated. The total compensation torque command is decomposed into a target displacement command and a differential speed adjustment command; The target displacement command is executed to drive the counterweight to move, and the differential speed adjustment command is executed to adjust the motor speed.

10. The method for controlling flight attitude instability of a firefighting drone according to claim 9, characterized in that, The step of estimating the equivalent disturbance torque vector generated by the deployment of the fire extinguishing bomb in real time based on the attitude state variables, the load state parameters, and the current motor control command includes: The attitude state variables, load state parameters, and current motor control commands are reconstructed using an extended state method to estimate the equivalent disturbance torque vector generated by the deployment of fire extinguishing bombs in real time.

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