Seaplane water pumping structure, active wave compensation system and method

Abstract

This invention proposes a water-lifting structure, an active wave compensation system, and a method for seaplanes, relating to the field of seaplane technology. The water-lifting structure includes a shell, a lifting mechanism, a magnetorheological damper, a water-lifting hopper, a connecting pipe, and a one-way check valve. The shell is installed at the bottom of the seaplane's cabin and has two transfer boxes, each with a water inlet and outlet. The lifting mechanism is installed inside the shell. One end of the magnetorheological damper is connected to the lifting mechanism, and the other end is connected to the water-lifting hopper. The water-lifting hopper has an inlet, a throat, and an outlet. The inlet faces the seaplane's forward direction, and the throat connects both the inlet and outlet, with the cross-sectional area of ​​the throat gradually decreasing from the inlet end to the outlet end. The connecting pipe connects to the outlet. The one-way check valve is installed at the outlet. The magnetorheological damper generates significant impact resistance, effectively protecting the water-lifting hopper and greatly reducing fatigue loads transmitted to the fuselage. The one-way check valve prevents water backflow.

Description

Technical Field

[0001] This invention relates to the field of seaplane technology, and in particular to a water-drawing structure, active wave compensation system and method for seaplanes. Background Technology

[0002] Seaplanes can take off and land on water. They are used as firefighting aircraft and are characterized by high speed and high firefighting efficiency. They can scoop water from waters near the fire area by high-speed gliding and quickly fly to the fire area to carry out water drop firefighting missions. They are highly mobile and flexible and are currently widely used.

[0003] Existing water-drawing structures generally employ mechanical or hydraulic buffer devices. When faced with high-frequency, high-intensity water impacts, the response speed is often delayed, failing to provide adequate buffering for the water-drawing structure. This makes the water-drawing structure susceptible to damage under enormous impact forces, thereby reducing the stability of the device and shortening its service life. Summary of the Invention

[0004] In view of this, the present invention proposes a water-drawing structure, an active wave compensation system and method for seaplanes, to solve the technical problem mentioned in the background art that the water-drawing structure in the prior art often has a delayed response speed when facing high-frequency and high-intensity water impacts, which cannot provide a good buffer for the water-drawing structure, making the water-drawing structure easy to be damaged under huge impact forces, thereby reducing the stability of the device and having a short service life.

[0005] The technical solution of this invention is implemented as follows: In a first aspect, the present invention provides a water-lifting structure for a seaplane, comprising a shell, a lifting mechanism, a magnetorheological damper, a water-lifting hopper, a connecting pipe, and a one-way check valve, wherein: The hull is installed at the bottom of the seaplane cabin, and the hull is equipped with two transfer boxes, each with a water inlet and a water outlet. The lifting mechanism is installed inside the housing and connected to one end of the magnetorheological damper; The other end of the magnetorheological damper is connected to the water-drawing bucket; The water-drawing bucket has an inlet, a throat, and an outlet. The inlet faces the direction of travel of the seaplane. The throat connects the inlet and the outlet respectively. The cross-sectional area of ​​the throat gradually decreases from the inlet end to the outlet end. The connecting pipe is connected to the outlet and can move up and down along the inlet, and is sealed at the inlet; The one-way check valve is installed on the water outlet and connected to the water tank of the seaplane.

[0006] In some alternative implementations, preferably, the inlet is flat and shovel-shaped or rectangular, and the throat narrows and gradually turns upward to connect to the outlet to accelerate the water flow through the Venturi effect and guide the water flow to the tank.

[0007] In some optional embodiments, preferably, it further includes an inertial measurement unit and a controller. The inertial measurement unit is mounted on the side of the water hopper and is used to measure the acceleration value of the seaplane. The controller is connected to the inertial measurement unit and the magnetorheological damper respectively. It is used to calculate the control force vector of the magnetorheological damper based on the acceleration value of the seaplane, and to calculate the corresponding magnetic field strength of the magnetorheological damper through the control force vector. It is also used to control the current of the magnetorheological damper to meet the corresponding magnetic field strength.

[0008] In some alternative embodiments, preferably, a sealing assembly is also included, the sealing assembly comprising a packing tube, a sealing packing, and a gland, the packing tube being installed at the inlet, the sealing packing being installed between the inner wall of the packing tube and the outer wall of the connecting pipe, and the gland being installed on the end face of the packing tube and pressing against the sealing packing.

[0009] In some alternative implementations, preferably, the one-way check valve is a duckbill valve, which is opened by a strong ramming pressure when the water bucket is inserted into the water; once the water tank is detected to be full or the water bucket is retracted, the one-way check valve closes by elasticity and water pressure to prevent backflow or pressure loss.

[0010] In a second aspect, the present invention provides an active wave compensation system for a seaplane, comprising an inertial measurement unit, a wave sensor, a displacement sensor, a data processing unit, and a control unit, as well as a water-drawing structure for the seaplane as described in the first aspect, wherein: The inertial measurement unit is used to monitor the pitch, roll, heave speed and acceleration of the seaplane in real time. The wave sensor is used to detect the shape, height, and frequency of waves in front of the seaplane; The displacement sensor is installed on the float strut of the seaplane to monitor the current compression of the landing gear or float strut. The data processing unit is electrically connected to the inertial measurement unit, the wave sensor, the displacement sensor, and the control unit. It is used to calculate the compensation force output by the actuator based on the detected data and send the compensation force output by the actuator as a compensation command to the control unit. The control unit is used to control the actuator to output the corresponding compensation force according to the compensation command.

[0011] Thirdly, the present invention provides an active wave compensation method for seaplanes, using the active wave compensation system for seaplanes as described in the second aspect, the active wave compensation method for seaplanes comprising: A dynamic model is constructed based on the system state vector x(t), the compensation force μ(t) applied by the actuator, the wave disturbance term ω(t), and the matrices A, B, and G describing the physical characteristics of the aircraft. The feedforward compensation amount μ is calculated based on the aircraft's physical characteristics matrices B and G, and the wave disturbance term ω(t). ff (t); The expected compensation amount μ of feedback regulation is calculated by minimizing the cost function J and the algebraic Riccati equation. fb (t); By feeding forward compensation amount μ ff (t) and the expected compensation amount μ of feedback adjustment fb Adding (t) together yields the total expected compensation.

[0012] In some alternative implementations, preferably, the wave disturbance term ω(t) is an expected value derived from the observer based on a Kalman filter.

[0013] In some alternative implementations, preferably, the feedforward compensation amount μ is used. ff (t) and the expected compensation amount μ of feedback adjustment fb After adding (t) to obtain the total expected compensation, it also includes: Let the system transfer function be G(s), the controller be K(s), and from H ∞ Robust control of direction is achieved by defining the total expected compensation amount through a sensitivity function.

[0014] In some alternative implementations, preferably, the expected compensation amount μ for feedback adjustment is calculated by minimizing the cost function J and the algebraic Riccati equation. fb (t), including: The feedback adjustment parameters are updated based on the gradient descent method and learned through a neural network to output the optimal feedback adjustment parameters in real time.

[0015] The seaplane water-lifting structure, active wave compensation system, and method of the present invention have the following advantages over the prior art: (1) One end of the magnetorheological damper is connected to the lifting mechanism, and the other end of the magnetorheological damper is connected to the water hopper. By utilizing the millisecond-level viscosity change characteristics of the magnetorheological fluid under the action of the magnetic field, semi-active damping protection is provided for the water hopper. The magnetorheological damper generates huge impact resistance and absorbs more than 90% of the impact energy, which can better protect the water hopper and also greatly alleviate the fatigue load transmitted to the central structure of the fuselage. In addition, a powerful one-way check valve is provided at the interface of the water outlet into the water tank. When the probe is retracted or the aircraft leaves the water, the valve closes quickly by relying on the spring and internal water pressure to prevent several tons of water from flowing back along the pipe and improve the reliability of the device. (2) The inlet is flat and shovel-shaped or rectangular, the throat narrows and gradually turns upward to connect to the outlet, so as to accelerate the water flow through the Venturi effect and guide the water flow to the water tank, improve the water intake efficiency, and fill the water tank more quickly. This allows the seaplane to glide on the water surface for a shorter time, and the water intake point can be a smaller lake or river, thus increasing the scope of use of the seaplane. (3) The acceleration value of the seaplane is measured by the inertial measurement unit. The controller calculates the control force vector of the magnetorheological damper based on the acceleration value of the seaplane, and calculates the magnetic field strength of the corresponding magnetorheological damper through the control force vector. The current of the magnetorheological damper is controlled to meet the corresponding magnetic field strength. The control algorithm can increase the magnetic field at the moment of impact with the water surface, so that the magnetorheological damper generates huge impact resistance and absorbs more than 90% of the impact energy. (4) Calculate the feedforward compensation amount μ based on the aircraft's physical characteristics matrices B and G, and the wave disturbance term ω(t). ff (t), by minimizing the cost function J and the algebraic Riccati equation, the expected compensation amount μ of the feedback regulation is calculated. fb (t); by feeding forward compensation amount μ ff (t) and the expected compensation amount μ of feedback adjustment fb (t) are added together to obtain the total expected compensation amount. The disturbance is completely offset by the feedforward compensation amount, and then the correction is made by feedback adjustment to obtain the optimal expected compensation amount. This ensures that the depth of the water hopper in the water is uniform, ensuring water hopper efficiency while ensuring that the water hopper will not be damaged by large impact force due to being inserted into the water too deeply, thus improving reliability and stability. (5) The feedback adjustment parameters are updated based on the gradient descent method. The neural network is used to learn and output the optimal feedback adjustment parameters in real time. The neural network continuously observes whether the fuselage moves after compensation to fine-tune the PID feedback adjustment ratio and differential gain in real time to adapt to different sea states. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a perspective view of the seaplane water-lifting structure in an embodiment of the present invention from a bottom view. Figure 2 This is a perspective view of the seaplane water-lifting structure in an embodiment of the present invention from a top view. Figure 3 This is a perspective view of the housing in an embodiment of the present invention from a top view. Figure 4 This is a perspective view of the housing in an embodiment of the present invention from the bottom view. Figure 5 This is a schematic diagram of the water-drawing bucket in an embodiment of the present invention; Figure 6 This is a cross-sectional view of the sealing assembly in an embodiment of the present invention; Figure 7 This is a flowchart illustrating the active wave compensation method for seaplanes in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1-Housing, 2-Lifting mechanism, 3-Magnetorheological damper, 4-Water hopper, 5-Connecting pipe, 6-One-way check valve, 7-Adapter, 8-Sealing assembly; 11-Transfer box, 111-Inlet, 112-Outlet; 41-Inlet, 42-Throat, 43-Outlet, 44-Mounting shaft; 81-Stuffing tube, 82-Sealing packing, 83-Gland. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0025] The technical solution will now be explained in detail: Reference Figures 1-6As shown, a first aspect of the present invention provides a water-lifting structure for a seaplane, comprising a shell 1, a lifting mechanism 2, a magnetorheological damper 3, a water-lifting hopper 4, a connecting pipe 5, and a one-way check valve 6, wherein: The shell 1 is installed at the bottom of the cabin of the seaplane. The shell 1 is provided with two transfer boxes 11, and the transfer box 11 is provided with a water inlet 111 and a water outlet 112. The lifting mechanism 2, magnetorheological damper 3, water hopper 4, connecting pipe 5 and one-way check valve 6 are provided in two sets, each set corresponding to one transfer box 11. The lifting mechanism 2 is installed inside the housing 1 and is connected to one end of the magnetorheological damper 3; the lifting mechanism 2 can be a hydraulic cylinder, and its output end is connected to the magnetorheological damper 3 through the adapter 7. The other end of the magnetorheological damper 3 is connected to the water-drawing bucket 4. The working principle of the magnetorheological damper 3 is based on the rheological properties of magnetorheological fluid. The damping force is dynamically controlled by adjusting the magnetic field strength. Magnetorheological fluid is a suspension containing tiny magnetic particles. When no electricity is applied, the particles flow freely and the damping force is small. When electricity is applied, the magnetic field causes the particles to arrange into a chain or network structure, the liquid thickens, and the damping force increases significantly. The magnetorheological damper 3 is semi-actively controlled. It only requires a small current to adjust the damping force in real time, adapting to dynamic working conditions such as road bumps. The damping force is immediately restored after power is cut off, without the need for external energy. The water-drawing bucket 4 is provided with an inlet 41, a throat 42 and an outlet 43. The inlet 41 faces the direction of travel of the seaplane. The throat 42 connects the inlet 41 and the outlet 43 respectively. The cross-sectional area of ​​the throat 42 gradually decreases from one end of the inlet 41 to one end of the outlet 43. An installation shaft 44 is installed on the water-drawing bucket 4, and the installation shaft 44 is fixedly connected to the magnetorheological damper 3. The connecting pipe 5 is connected to the outlet 43 and can move up and down along the inlet 111, and is sealed at the inlet 111; The one-way check valve 6 is installed on the outlet 112 and connected to the water tank of the seaplane.

[0026] The seaplane water-lifting structure proposed in this embodiment connects one end of the magnetorheological damper 3 to the lifting mechanism 2, and the other end of the magnetorheological damper 3 to the water-lifting hopper 4. Utilizing the millisecond-level viscosity change characteristics of the magnetorheological fluid under the action of a magnetic field, it provides semi-active damping protection for the water-lifting hopper 4. The magnetorheological damper 3 generates a huge impact resistance force, absorbing more than 90% of the impact energy, which can effectively protect the water-lifting hopper 4 and significantly alleviate the fatigue load transmitted to the central structure of the fuselage. In addition, a powerful one-way check valve 6 is provided at the interface between the water outlet 112 and the water tank. When the probe is retracted or the aircraft leaves the water, the valve closes quickly by relying on the spring and internal water pressure, preventing several tons of water from flowing back along the pipe and improving the reliability of the device.

[0027] In some embodiments, the inlet 41 is flattened and shovel-shaped or rectangular, which increases the inlet area to maximize water flow capture during aircraft gliding while reducing impact on the water surface. The throat 42 narrows and gradually turns upward to connect to the outlet 43 to accelerate the water flow through the Venturi effect and guide it to the water tank. Viewed from the side, the hopper 4 resembles a hook. During operation, only the bottom tip of the hopper 4 is submerged in the water (typically a few centimeters to tens of centimeters, adjusted according to speed and water density) to reduce the seaplane's deceleration due to significant water resistance. This structure improves water-drawing efficiency, allowing the water tank to fill more quickly, thus reducing the seaplane's gliding time on the water surface. It also allows for water intake points in smaller lakes and rivers, expanding the seaplane's operational range.

[0028] In some embodiments, the system further includes an inertial measurement unit (IMU) and a controller. The IMU is mounted on the side of the water hopper 4 and is used to measure the acceleration value of the seaplane. The controller is connected to both the IMU and the magnetorheological damper 3. It calculates the control force vector of the magnetorheological damper 3 based on the seaplane's acceleration value, calculates the corresponding magnetic field strength of the magnetorheological damper 3 using the control force vector, and controls the current of the magnetorheological damper 3 to satisfy the corresponding magnetic field strength. The control algorithm can increase the magnetic field at the moment of impact with the water surface, enabling the magnetorheological damper 3 to generate a huge impact resistance force, absorbing up to 90% or more of the impact energy.

[0029] In this embodiment, the damping force of the magnetorheological damper 3 includes viscous damping force and Coulomb damping force. The viscous damping force is proportional to the relative motion speed of the damper piston. The Coulomb damping force (Fy·sgn(v)) is a force that is related to the velocity direction but whose magnitude is adjustable. The magnitude of Fy is directly determined by the applied current or magnetic field strength and is the "adjustment knob" of the entire control process.

[0030] In some embodiments, a sealing assembly 8 is further included. The sealing assembly 8 includes a packing tube 81, a sealing filler 82, and a gland 83. The packing tube 81 is installed at the water inlet 111. The sealing filler 82 is installed between the inner wall of the packing tube 81 and the outer wall of the connecting pipe 5. The gland 83 is installed on the end face of the packing tube 81 and presses against the sealing filler 82. The gland 83 is sleeved over the connecting pipe 5, and the gland 83 and the end face of the packing tube 81 are connected by bolts, so that the gland 83 is pressed into the packing tube, thereby tightly pressing the sealing filler 82 against the inner wall of the packing tube 81 and the outer wall of the connecting pipe 5, achieving a seal of the connecting pipe 5 at the water inlet 111. The connecting pipe 5 can move together with the water hopper 4.

[0031] In some embodiments, the one-way check valve 6 is a duckbill valve. When the water bucket 4 is submerged in water, a strong impact pressure forcibly opens the one-way check valve 6. Once the water tank is detected to be full or the water bucket 4 is retracted, the one-way check valve 6 closes using elasticity and water pressure to prevent backflow or pressure loss. The duckbill valve, having no moving parts, is a flexible rubber check valve. In sewage discharge systems, rainwater discharge systems, underground parking lot drainage systems, etc., it functions to block odors and prevent sewage backflow, preventing floods and sewage from flowing back into basements or municipal pipelines. In this embodiment, the use of a duckbill valve prevents backflow or pressure loss, thereby ensuring the water tank can be fully loaded and leave the water surface, improving the firefighting capability of the seaplane.

[0032] In some embodiments, the top of the seaplane fuselage has a large exhaust port to ensure that there is no pressure surge in the water tank, thus avoiding bursting the fuselage, and that the air in the water tank can be expelled at the same speed when several tons of water are poured into the cabin.

[0033] The working principle of the seaplane water-lifting structure proposed in this embodiment of the invention is as follows: When the seaplane reaches the water surface, the powerful ramming pressure forcibly opens the one-way check valve 6, and the lifting mechanism 2 quickly drives the water-lifting bucket 4 to descend to the designated height. During the seaplane's gliding on the water surface, the huge kinetic energy directly "push" the water into the inlet 41 of the water-lifting bucket 4, and then into the water tank through the connecting pipe 5. Once the water tank is detected to be full or the probe is retracted, the valve will close within milliseconds using elasticity and water pressure to prevent water backflow or pressure leakage.

[0034] Based on the same concept, a second aspect of the present invention provides an active wave compensation system for a seaplane, including an inertial measurement unit, a wave sensor, a displacement sensor, a data processing unit, and a control unit, as well as a seaplane water-drawing structure as described in the first aspect embodiment, wherein: The inertial measurement unit is used to monitor the pitch, roll, heave speed and acceleration of the seaplane in real time. The wave sensor is used to detect the shape, height, and frequency of waves in front of the seaplane; The displacement sensor is installed on the float strut of the seaplane to monitor the current compression of the landing gear or float strut. The data processing unit is electrically connected to the inertial measurement unit, the wave sensor, the displacement sensor, and the control unit. It is used to calculate the compensation force output by the actuator based on the detected data and send the compensation force output by the actuator as a compensation command to the control unit. The control unit is used to control the actuator to output the corresponding compensation force according to the compensation command.

[0035] The active wave compensation system for seaplanes proposed in this embodiment monitors the pitch, roll, heave speeds and accelerations of the seaplane in real time through the inertial measurement unit; the wave sensor detects the shape, height, and frequency of waves in front of the seaplane; the displacement sensor monitors the current compression of the landing gear or float struts; the data processing unit calculates the compensation force output by the actuator based on the detected data and sends the compensation force output by the actuator as a compensation command to the control unit; the control unit controls the actuator to output the corresponding compensation force according to the compensation command, thereby ensuring that the water hopper 4 is inserted into the water at a uniform depth, ensuring water intake efficiency while ensuring that the water hopper 4 will not be damaged by excessive impact force due to being inserted into the water too deeply, thus improving reliability and stability.

[0036] Based on the same concept, a third aspect of the present invention, combined with... Figure 7 As shown, an active wave compensation method for seaplanes is provided, using the active wave compensation system for seaplanes as described in the second aspect embodiment. The active wave compensation method for seaplanes includes: Step S1: Based on the system state vector x(t), the compensation force μ(t) applied by the actuator, the wave disturbance term ω(t), and the matrices A, B, and G describing the physical characteristics of the aircraft, construct a dynamic model; Specifically, in step S1, the float-landing gear-fuselage system is simplified into a single-degree-of-freedom vibration system, and the specific dynamic model formula is as follows: (1); In equation (1), x(t) is the system state vector. z represents the fuselage displacement state. The fuselage speed is represented by A, B, and G, which are matrices describing the aircraft's physical characteristics. μ(t) represents the compensating force applied by the actuators, and ω(t) represents the wave disturbance term. A in equation (1) is calculated using the following formula: (2); In equation (2), K represents the spring stiffness; M is the mass; and C is the damping coefficient. B in equation (1) is calculated using the following formula. (3); In equation (3), M represents mass; Step S2: Calculate the feedforward compensation amount μ based on the aircraft's physical characteristics matrices B and G, and the wave disturbance term ω(t). ff (t); In step S2, feedforward compensation can completely cancel out the disturbance. If we can predict the wave disturbance term ω(t) in advance through sensors, the ideal compensation formula should satisfy: (4); In equation (4), B and G are matrices representing the physical characteristics of the aircraft, ω(t) is the wave disturbance term, and μ ff (t) represents the feedforward compensation amount; μ can be calculated using equation (4). ff (t), the specific formula is as follows: (5); In equation (5), B + It is the pseudo-inverse of B; Step S3: Calculate the expected compensation amount μ of feedback regulation by minimizing the cost function J and the algebraic Riccati equation. fb (t); In step S3, the formula for minimizing the cost function J is: (6); In equation (6), x represents the displacement state of the system; x T Qx represents the state cost term; Q is an n×n positive semi-definite symmetric matrix; μ is the external control input applied to the system, which is an m×1 column vector; R is an m×m positive definite symmetric matrix; μ T Rμ is the control cost term, which measures the "energy consumption" or "cost" of using control quantities; By adjusting the weights of Q and R, a fast response (emphasizing x) can be achieved. T Qx) and energy saving (emphasizing μ) T To achieve balance between Rμ); According to the algebraic Riccati equation: (7); In equation (7), P is the Ricardi matrix; According to formula (7), the expected compensation amount μ of feedback regulation can be obtained. fb The formula for calculating (t) is as follows: (8); In equation (8), K is the optimal feedback gain matrix; The optimal feedback gain matrix K is calculated by formula (7), and μ is obtained by substituting it into formula (8). This minimizes the cost function mentioned earlier. In other words, solving P is equivalent to finding the "key" to optimal control. Step S4: By adjusting the feedforward compensation amount μ ff (t) and the expected compensation amount μ of feedback adjustment fb Adding (t) together yields the total expected compensation. The formula for calculating the total expected compensation is as follows: (9).

[0037] The active wave compensation method for seaplanes proposed in this embodiment completely cancels out disturbances through feedforward compensation and then corrects them through feedback adjustment, thereby obtaining the optimal expected compensation amount. This ensures that the depth of the water bucket 4 in the water is uniform, ensuring water-drawing efficiency while preventing the water bucket 4 from being damaged by excessive impact force due to excessive water depth, thus improving reliability and stability.

[0038] In some embodiments, because "wave force" is often not directly measurable, the algorithm needs to derive the expected value through an observer. The wave disturbance term ω(t) is the expected value derived through an observer based on a Kalman filter. The specific formula is as follows: (10); In equation (10), For all measurements up to time k (including Z) k The optimal estimate of the state; For all measurements up to time k-1 (including Z) k The optimal estimate of the state at time k; K k Here, H is the Kalman gain matrix; H is the measurement matrix, which maps the real state space to the measurement space; z k The actual measured value at time k; I is the identity matrix, with dimensions ... same; This method combines prior predictions and new observations to calculate the optimal posterior state estimate, yielding... (Including the predicted wave equivalence) is used as ω(t) in equation (5) to calculate μ. ff This makes the wave force more accurate.

[0039] In some embodiments, the feedforward compensation amount μ ff (t) and the expected compensation amount μ of feedback adjustment fb After adding (t) to obtain the total expected compensation, it also includes: Let the system transfer function be G(s), the controller be K(s), and from H ∞ Robust control direction is achieved by defining the total desired compensation amount using a sensitivity function. The formula for the sensitivity function is as follows: (11); In equation (11), G(s) is the controlled object, which is usually an n×m transfer function matrix, where n is the output dimension and m is the input dimension; I is the identity matrix; The optimization objective is: (12); In equation (12), W ω (s) is the performance weighting function; γ is the local minimum value; The core of the formula calculation is to design a controller K(s) such that the wave disturbance W ω The gain to the output error is suppressed below the minimum value γ.

[0040] In some embodiments, since the waves are time-series signals, a Long Short-Term Memory (LSTM) network is used to address the "time delay" problem and calculate the look-ahead compensation. Specifically, the neural network uses the input historical wave sequence H = {ω} t-n , ..., ω t}, output the expected position at the next moment, as shown in the formula below: (13); In equation (13), σ is the wave position predicted by the neural network at the next time step (time t+1); σ is the activation function of the output layer; W h0 W is the weight matrix of the output layer; tanh is the activation function of the hidden layer, hyperbolic tangent, which maps the input to the interval (-1, 1); ih is the weight matrix from the input layer to the hidden layer; H is the input historical wave sequence vector, containing wave values ​​from time tn to time t; b h b0 is the bias vector of the hidden layer; b0 is the bias scalar of the output layer. In this embodiment, by calculating the phase and height of the wave at time t+1, the hydraulic cylinder can act Δt time in advance, thereby reducing delay and improving reliability.

[0041] In some embodiments, the expected compensation amount μ for feedback regulation is calculated by minimizing the cost function J and the algebraic Riccati equation. fb (t), including: The feedback control parameters are updated using the gradient descent method, and learned through a neural network to output the optimal PID feedback control parameters in real time. The formula for updating the feedback control parameters using the gradient descent method is as follows: (14); In equation (14), Z represents the weight update amount, i.e., the amount of modification made to the weights connecting the j-th and k-th neurons in the neural network at step t (or time t); E is the system error function (the sum of squares of the fuselage's vertical displacement); η is the learning rate; z d -z represents the output error; z dz is the desired output; z is the actual system output; μ is an intermediate variable; K is the PID parameter, which is usually the proportional, integral, and derivative coefficients (possibly a vector).

[0042] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water-lifting structure for a seaplane, characterized in that, Includes a housing, lifting mechanism, magnetorheological damper, water hopper, connecting pipe, and one-way check valve, wherein: The hull is installed at the bottom of the seaplane cabin, and the hull is equipped with two transfer boxes, each with a water inlet and a water outlet. The lifting mechanism is installed inside the housing and connected to one end of the magnetorheological damper; The other end of the magnetorheological damper is connected to the water-drawing bucket; The water-drawing bucket has an inlet, a throat, and an outlet. The inlet faces the direction of travel of the seaplane. The throat connects the inlet and the outlet respectively. The cross-sectional area of ​​the throat gradually decreases from the inlet end to the outlet end. The connecting pipe is connected to the outlet and can move up and down along the inlet, and is sealed at the inlet; The one-way check valve is installed on the water outlet and connected to the water tank of the seaplane.

2. The seaplane water-drawing structure as described in claim 1, characterized in that, The inlet is flat and shovel-shaped or rectangular, and the throat narrows and gradually turns upward to connect to the outlet, so as to accelerate the water flow through the Venturi effect and guide the water flow to the water tank.

3. The seaplane water-drawing structure as described in claim 1, characterized in that, It also includes an inertial measurement unit and a controller. The inertial measurement unit is installed on the side of the water hopper and is used to measure the acceleration value of the seaplane. The controller is connected to the inertial measurement unit and the magnetorheological damper respectively. It is used to calculate the control force vector of the magnetorheological damper based on the acceleration value of the seaplane, and to calculate the magnetic field strength of the corresponding magnetorheological damper through the control force vector. It is also used to control the current of the magnetorheological damper to meet the corresponding magnetic field strength.

4. The seaplane water-drawing structure as described in claim 1, characterized in that, It also includes a sealing assembly, which includes a packing tube, a sealing packing, and a gland. The packing tube is installed at the water inlet, the sealing packing is installed between the inner wall of the packing tube and the outer wall of the connecting pipe, and the gland is installed on the end face of the packing tube and presses against the sealing packing.

5. The seaplane water-drawing structure as described in claim 1, characterized in that, The one-way check valve is a duckbill valve. When the water bucket is inserted into the water, the strong impact pressure forces the one-way check valve to open. Once the water tank is detected to be full or the water bucket is retracted, the one-way check valve closes using elasticity and water pressure to prevent backflow or pressure loss.

6. An active wave compensation system for seaplanes, characterized in that, It includes an inertial measurement unit, a wave sensor, a displacement sensor, a data processing unit, and a control unit, as well as a seaplane water-lifting structure as described in any one of claims 1 to 5, wherein: The inertial measurement unit is used to monitor the pitch, roll, heave speed and acceleration of the seaplane in real time. The wave sensor is used to detect the shape, height, and frequency of waves in front of the seaplane; The displacement sensor is installed on the float strut of the seaplane to monitor the current compression of the landing gear or float strut. The data processing unit is electrically connected to the inertial measurement unit, the wave sensor, the displacement sensor, and the control unit. It is used to calculate the compensation force output by the actuator based on the detected data and send the compensation force output by the actuator as a compensation command to the control unit. The control unit is used to control the actuator to output the corresponding compensation force according to the compensation command.

7. A method for active wave compensation for seaplanes, characterized in that, Using the active wave compensation system for seaplanes as described in claim 6, the active wave compensation method for seaplanes includes: A dynamic model is constructed based on the system state vector x(t), the compensation force μ(t) applied by the actuator, the wave disturbance term ω(t), and the matrices A, B, and G describing the physical characteristics of the aircraft. The feedforward compensation amount μ is calculated based on the aircraft's physical characteristics matrices B and G, and the wave disturbance term ω(t). ff (t); The expected compensation amount μ of feedback regulation is calculated by minimizing the cost function J and the algebraic Riccati equation. fb (t); By feeding forward compensation amount μ ff (t) and the expected compensation amount μ of feedback adjustment fb Adding (t) together yields the total expected compensation.

8. The active wave compensation method for seaplanes as described in claim 7, characterized in that, The wave disturbance term ω(t) is the expected value derived from the observer based on the Kalman filter.

9. The active wave compensation method for seaplanes as described in claim 7, characterized in that, The feedforward compensation amount μ ff (t) and the expected compensation amount μ of feedback adjustment fb After adding (t) to obtain the total expected compensation, it also includes: Let the system transfer function be G(s), the controller be K(s), and from H ∞ Robust control of direction is achieved by defining the total expected compensation amount through a sensitivity function.

10. The active wave compensation method for seaplanes as described in claim 7, characterized in that, The expected compensation amount μ of feedback regulation is calculated by minimizing the cost function J and the algebraic Riccati equation. fb (t), including: The feedback adjustment parameters are updated based on the gradient descent method and learned through a neural network to output the optimal feedback adjustment parameters in real time.

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