Anti-disturbance attitude control device and method of near-surface cross-medium platform in complex sea state

Abstract

The application discloses a kind of complex sea conditions near water surface trans-medium platform's anti-disturbance attitude control device and method, using the active fluid dynamic control of cross type tail rudder, can real-time generate reverse rectification torque, effectively offset near water surface sea wave, surge and shear flow to the lateral drift and attitude disturbance caused to platform, the device realizes the closed-loop correction of the floating trajectory, ensure that platform can converge to the predetermined area accurate water, effectively solve the problem of large drop point dispersion range under complex sea conditions, greatly improve the precision of operation deployment;Device is calculated by internal control unit, drive four rudder blades to carry out independent differential or linkage deflection, can complete fine adjustment to platform pitch angle, yaw angle and roll angle under water, which makes platform not need to change hardware configuration, can be independently selected according to actual operation instruction Vertical water, fixed angle water or near horizontal attitude water three modes, greatly expand the single platform's scientific research and engineering application scene.

Description

Technical Field

[0001] This invention belongs to the field of overall design technology for cross-medium aircraft, specifically relating to an anti-disturbance attitude control device and method for a near-water surface cross-medium platform under complex sea conditions. Background Technology

[0002] Transmedium-based aircraft or prefabricated platforms possess significant application value in fields such as marine environmental observation, geological exploration, and emergency communication relay due to their advantages including long-term underwater loitering capability, extremely fast cross-domain response speed, relatively low cost, and adaptability to various operational payloads. These platforms typically need to be deployed underwater and then cross the water-air interface to enter aerial flight. However, when the platform operates in the near-water surface region, its hydrodynamic environment becomes extremely complex. The immersion depth ratio is usually defined as... (in For the operating depth of the aircraft, (for the diameter of the aircraft), when At this point, the platform is located in a typical water-air interface interference zone. Within this region, cross-medium platforms are highly susceptible to strong nonlinear coupling interference from wave forces, near-surface shear currents, and turbulence. In existing technologies, cross-medium platforms primarily employ uncontrolled ascent, relying on inertial velocity to break through the water surface. While some solutions utilize passive drag reduction mechanisms such as deceleration fins to control ascent speed, they generally lack effective active end-effector attitude correction mechanisms. This passive stabilization method makes the platform highly susceptible to deflection by environmental torques near the water surface, resulting in an uncontrollable ascent trajectory.

[0003] In summary, existing passive surfacing methods suffer from two major technical drawbacks: First, the surfacing point is widely dispersed. Due to the lack of active disturbance resistance, the surfacing point often deviates significantly from the predetermined surfacing point, severely impacting the timeliness and success rate of operational deployment. Second, the surfacing attitude is limited and lacks application flexibility. Existing devices cannot flexibly adjust the surfacing angle according to actual operational needs, making it difficult to switch between various operational modes such as vertical surfacing, constant tilt surfacing, or near-horizontal surfacing. Therefore, there is an urgent need to develop a highly reliable and versatile disturbance-resistant attitude control device to address the technical challenges of near-surface attitude instability and uncontrollable trajectory of cross-medium platforms under complex sea conditions. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an anti-disturbance attitude control device and method for a near-surface cross-medium platform under complex sea conditions, aiming to solve the following technical problems:

[0005] The wide distribution range and unpredictable trajectory of water outlets result in low deployment accuracy in the task area and low positioning accuracy in the operation area, making it difficult to meet the requirements for high-precision point-to-point delivery. Limited water output mode and insufficient operational adaptability: Existing devices cannot flexibly switch between various water output postures such as vertical, inclined or horizontal without changing the hardware structure, which limits the multi-functional application of the platform. Poor resistance to disturbances and easy to lose attitude: Especially in high sea state environments, wave moment can easily cause the platform to tilt excessively or even capsize, which seriously reduces the success rate of cross-medium processes. The surfacing process results in significant energy loss: Traditional passive deceleration methods increase fluid resistance, which not only prolongs underwater travel time but also leads to insufficient kinetic energy upon surfacing, affecting the efficiency and continuity of cross-medium conversion.

[0006] An anti-disturbance attitude control device for a near-water surface cross-medium platform under complex sea conditions, which is coaxially connected to the tail of the cross-medium platform 20 as an independent attitude control module; including: servo motor mounting assembly (11), servo motor drive assembly (12), rudder surface actuation assembly (13) and electronic control assembly (14); The servo mounting assembly (11) is fixedly connected to the inner wall of the cross-medium platform compartment, used to fix the servo drive assembly (12) and the servo surface actuator assembly (13) to the tail of the cross-medium platform, and to provide support and sealing for the internal transmission; The servo drive assembly (12) is fixedly installed inside the servo mounting assembly (11), and its power output is transmitted to the rudder blade (131) of the rudder surface actuator assembly (13); The control surface actuation component (13) is symmetrically distributed in a cross shape, including four control blades (131). Each control blade (131) is connected to the servo drive component (12) through the control shaft (132) and is driven by the servo motor (121) to perform bidirectional independent deflection, generating hydrodynamic control torque. The electronic control component (14) includes a main control module (142), a depth sensor (144), and an inertial measurement unit, which is used to calculate control quantities and drive the servo motor (121) based on the real-time sensed depth, attitude, and disturbance information.

[0007] Preferably, the servo mounting assembly (11) includes: The servo mounting base (112) has a disc structure with four servo receiving slots evenly distributed around the circumference on its disc surface. The servo receiving slots are adapted to the servo drive assembly (12) for embedded installation and fixing of the servo (121). The transmission support frame (113) is located below the servo mounting base (112) and has a cross-shaped column structure. It is axially locked and rigidly connected to the servo mounting base (112) through countersunk bolts (116) located on the central axis, thereby forming a complete internal support frame. The first sealing ring (111) and the second sealing ring (114) are respectively set at the upper and lower ends of the outer cylindrical surface of the servo mount (112) to achieve sealing with the inner wall of the platform and the electronic sealing chamber (141); The transmission support frame (113) integrates multiple sets of bearings to achieve longitudinal output support and lateral transmission support; at the bottom center hole of the transmission support frame (113), four longitudinal transmission bearings (115) are installed to connect and support the rudder shaft (132) in the rudder drive assembly (12). On the four symmetrically distributed horizontal extension arms of the transmission support frame (113), a pair of transverse transmission bearings (117) are respectively provided, and the servo drive shafts (123) of the four sets of servo drive assemblies (12) are correspondingly installed in each pair of transverse transmission bearings (117). The servo drive assembly (12) has a drive bevel gear 124 installed at the output end of the servo drive shaft (123) of the servo (121); One end of the rudder shaft (132) extending out of the transmedia platform body is connected to the end rudder blade 131, and the other end is located inside the housing, where a driven bevel gear (136) is installed; the driven bevel gear (136) and the driving bevel gear (124) form a 90-degree meshing transmission pair; through this meshing relationship, the longitudinal rotational motion output by the servo motor (121) is converted into the lateral deflection motion of the rudder shaft (132), thereby driving the rudder blade (131) to move.

[0008] Preferably, the servo drive shaft (123) of the servo drive assembly (12) is connected to the output shaft of the servo (121) via the servo disc (122) and the cylindrical head bolt (127), and one end of the servo drive shaft (124) is locked by a set screw (125); the servo drive shaft (123) is provided with an elastic retaining ring (128) for axial positioning.

[0009] Preferably, the control surface actuation component (13) includes: At the middle section of the rudder shaft (132), a support bearing (134) is installed with an interference fit or clearance fit to bear the radial load transmitted from the rudder blade (131). A rudder shaft sealing end cap (138) is provided, which is fastened to the housing by a cross countersunk bolt (139); a bearing limiting groove is provided on the inner side of the rudder shaft sealing end cap (138); when the end cap is locked, the limiting groove presses against the outer ring of the supporting bearing (134); The cylindrical pin (133) passes through the radial through hole on the rudder shaft (132) and is engaged in the pre-set positioning groove at the root of the rudder blade (131); the countersunk bolt (135) is screwed into the threaded hole on the end face of the rudder shaft (132) to axially press the rudder blade (131) onto the rudder shaft (132).

[0010] Preferably, the electronic control component (14) includes: The electronic sealed compartment (141) is piston-type inserted into the servo mounting base (112) and sealed by the second sealing ring (114). Its side wall is provided with a through hole for the servo shaft (132) to pass through. The through hole is dynamically sealed by the third sealing ring (149). The main control module (142) is fixedly installed at the bottom of the electronic sealed chamber (141); The power module (143) is mounted on top of the main control module (142) via a battery mounting plate (147) and support bolts (148); A depth sensor (144) is installed at the bottom of the electronic sealed chamber (141) to obtain the depth of the platform; And a vent bolt (145) and an external switch (146).

[0011] A control method for the above-mentioned anti-disturbance attitude control device includes the following steps: Step S1: Acquire basic data in real time, including water pressure data collected by the depth sensor and the current attitude angle, angular velocity and linear acceleration of the platform collected by the inertial measurement unit (IMU); Step S2: Calculate the current depth h and dimensionless parameter Q value based on the water pressure data; Step S3: The main control module divides the buoyancy process into three stages based on the Q value and executes the corresponding control strategies: When Q > the first set threshold Q1, it enters the deep water standby stage, controlling the four rudder blades to maintain the zero-degree neutral state or to execute low-gain attitude damping control. When the second set threshold Q2 < Q ≤ the first set threshold Q1, the active disturbance rejection and attitude adjustment stage is entered. The target attitude is generated according to the task, and the total control torque required to maintain the stability of the platform is calculated. When Q≤Q2, the pre-exit lock-in phase is entered, freezing the current target attitude command and keeping the control surface deflection angle unchanged until the cross-medium conversion is completed. Step S4: In the active disturbance rejection and attitude adjustment stage, the total control torque is distributed to the four rudder blades based on the rudder effect weight matrix, generating the target deflection angle vector and outputting it to the four rudder surface actuators (13).

[0012] Preferably, in the active disturbance rejection and attitude adjustment stage of step S3, the total control torque The calculation formula is: ;in, For feedforward compensation torque, The feedback control torque; the feedforward compensation torque It is achieved by fusing recent attitude and depth change data and using a perturbation observer or Kalman filter algorithm to estimate and predict the thrust and yaw torque exerted on the platform by the external environment, thereby generating a counterforce; the feedback control torque It compares the set target attitude with the current actual attitude measured by the IMU to find the attitude deviation, and uses the control law to calculate the torque used to correct the deviation.

[0013] Preferably, the calculation method of the rudder effect weight matrix includes: the main control module calculates the equivalent submersion degree of the four rudder blades arranged in a cross shape in real time according to the current depth, platform attitude and geometric position of each rudder blade; and assigns weights according to the equivalent submersion degree: the control weight is reduced for rudder blades that are close to the water surface or have partially emerged from the water, and the control weight is increased for rudder blades that are completely submerged in the water, in order to cope with the hydrodynamic attenuation caused by local ventilation or partial water emergence.

[0014] Preferably, in step S4, the target deflection angle vector is generated. The weighted allocation formula is: ;in, The rudder effect weight matrix is... To control the generalized inverse of the allocation matrix, The total control torque is given.

[0015] Preferably, in the deep-water standby phase of step S3: the low-gain attitude damping control specifically means: only when the platform is detected to be swaying beyond a preset threshold, a small-amplitude rudder surface adjustment is made to maintain a basically vertical state, and the rudder blade does not deflect at other times. In the active disturbance rejection and attitude adjustment stage of step S3: for vertical water exit missions, the target attitude is set to keep the platform's longitudinal axis vertical; for missions with winged payloads, the target attitude is set to a preset tilt angle or horizontal attitude, and the control system drives the platform to smoothly transition from a vertical floating state to the preset attitude.

[0016] The present invention has the following beneficial effects: 1. Active trajectory convergence significantly improves water output accuracy. This invention utilizes the active hydrodynamic control of a cruciform tail rudder to generate a real-time counter-yawing torque, effectively counteracting the lateral drift and attitude disturbances caused to the platform by near-surface waves, currents, and shear flows. Compared to traditional uncontrolled or passively stabilized surfacing schemes, this device achieves closed-loop correction of the surfacing trajectory, ensuring the platform converges to a predetermined area for precise water emergence. This effectively solves the problem of large impact point dispersion under complex sea conditions, significantly improving the accuracy of operational deployment. 2. Possesses multi-mode posture operation capability, expanding application scenarios. This invention breaks through the technical limitations of traditional cross-medium platforms with fixed water exit angles. The device, through internal control unit calculations, drives four rudder blades to perform independent differential or coordinated deflections, enabling precise adjustment of the platform's pitch, yaw, and roll angles underwater. This allows the platform to autonomously select between three modes—vertical water exit, constant tilt water exit, or near-horizontal attitude water exit—based on actual operational commands without altering its hardware configuration, greatly expanding the research and engineering application scenarios for a single platform.

[0017] 3. Optimize fluid layout and center of gravity configuration to improve cross-medium efficiency. This device, installed at the stern of the platform, acts as a "counterweight section" in terms of physical structure. It effectively lowers the platform's center of gravity, creating a better static stability margin and making it easier to maintain a vertical or preset balanced state near the water surface. Meanwhile, compared to traditional deployable deceleration fins or drag chute, the cruciform rudder of this invention adopts a streamlined cross-section design, significantly reducing fluid resistance and effectively minimizing kinetic energy loss during ascent. This allows the platform to cross the water surface at a higher speed, improving the speed and safety of cross-domain transitions.

[0018] 4. Compact structure and strong compatibility, facilitating upgrades and maintenance. This invention features a simple and reliable structure, employing standardized modular interfaces for easy piston-type or flange-type connection to the tail of existing cross-medium platforms. Without altering the original platform's aerodynamic shape, the device fully utilizes the tail space to integrate attitude control functions, facilitating low-cost upgrades and rapid installations of existing equipment.

[0019] 5. Improve control feedforward compensation capability by introducing external inflow and wave disturbance estimation and short-term forecasting. This invention does not rely solely on attitude error feedback for passive correction. Instead, it estimates and predicts the equivalent disturbance force and / or disturbance torque caused by wave moment, lateral flow and shear flow based on the near-surface disturbance state, and outputs the compensation rudder amount in advance, thereby reducing the phase lag and overshoot correction of feedback control and improving the response speed and robustness under complex sea conditions.

[0020] 6. Improve near-surface control continuity by weighted allocation of rudder effectiveness based on rudder blade immersion degree. During the near-surface phase, different rudder blades may experience inconsistent submersion levels, partial aeration, or partial water exposure due to attitude changes and wave surface fluctuations, leading to asymmetrical attenuation of rudder effectiveness. This invention dynamically adjusts the control allocation weights based on the submersion level of each rudder blade, allowing the rudder blades that remain submerged to undertake more control functions, thereby avoiding control distortion or instability that occurs with traditional uniform allocation methods during the near-surface phase. Attached Figure Description

[0021] Figure 1A schematic diagram of the overall structure of an anti-disturbance attitude control device for a near-water surface cross-medium platform under complex sea conditions, provided for an embodiment of the present invention; Figure 2 This is a schematic diagram of the servo motor mounting assembly in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the servo motor mounting assembly in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the servo drive assembly in an embodiment of the present invention; Figure 5 This is a schematic diagram of the rudder blade assembly assembly in an embodiment of the present invention; Figure 6 This is a schematic diagram of the electronic control component in an embodiment of the present invention; Figure 7 This is a three-dimensional structural diagram of the attitude control device in operation according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the installation structure of the attitude control device in an embodiment of the present invention; Figure 9 This is a schematic diagram of the force acting on the rudder blade of the attitude control device in an embodiment of the present invention. Figure 10 This is a comparison diagram of the working process of the attitude control device in the embodiments of the present invention; Figure 11 This is a schematic diagram of the attitude control device operating at multiple angles in an embodiment of the present invention.

[0022] In the diagram: 10-Attitude control device; 20-Transmedia platform; 11-Servo mounting assembly; 12-Servo drive assembly; 13-Control surface actuator assembly; 14-Electronic control assembly; 111-First sealing ring; 112-Servo mount; 113-Transmission support frame; 114-Second sealing ring; 115-Longitudinal drive bearing; 116-Counterhead bolt; 117-Transverse drive bearing; 121-Servo motor; 122-Servo disc; 123-Servo motor drive shaft; 124-Drive bevel gear; 125-Setting screw; 126-Spring washer; 127-Cylindrical head bolt; 128-Elastic retaining ring; 131-Rudder blade; 132-Rudder shaft; 133-Cylindrical pin; 134-Support bearing; 135-Counterhead bolt; 136-Driven bevel gear; 137-Setting screw; 138-Rudder shaft seal cover; 139-Phillips head countersunk bolt; 141-Electronic sealed chamber; 142-Main control module; 143-Power supply module; 144-Depth sensor; 145-Ventilation bolt; 146-External switch; 147-Power supply mounting plate; 148-Support bolt; 149-Third sealing ring. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] This invention proposes an anti-disturbance attitude control device and method suitable for near-water surface cross-medium platforms under complex sea conditions. The invention constructs an active hydrodynamic control system by configuring a cross-shaped all-moving rudder, electronic control components, and an attitude sensing unit at the platform's stern. During near-water surface surfacing, the main control module calculates the dimensionless immersion depth ratio Q based on data from depth and attitude sensors, and executes pre-control, active disturbance rejection, attitude reconstruction, and pre-surface attitude locking according to the control stages corresponding to Q. Simultaneously, by combining the estimation or short-term prediction of the equivalent disturbance force and / or disturbance torque of external currents and / or wave disturbances, the total control torque required by the platform is calculated. Based on the immersion degree of each rudder, a rudder effect weight is constructed, and weighted control allocation is performed on the four rudder surface actuators. This achieves real-time correction of the near-water surface surfacing trajectory and active reconstruction of the surface attitude, significantly improving the stability, surface accuracy, and operational flexibility of the cross-medium process under complex sea conditions.

[0025] like Figure 1 The present invention provides an anti-disturbance attitude control device for a near-water surface cross-medium platform under complex sea conditions, comprising: a servo motor mounting assembly 11, a servo motor drive assembly 12, a servo surface actuation assembly 13, and an electronic control assembly 14.

[0026] Specifically, the servo mounting assembly 11 is fixedly connected to the inner wall of the cross-medium platform compartment to fix the servo drive assembly 12 and the servo surface actuation assembly 13; The control surface actuators 13 are symmetrically distributed in a cross shape on the outside of the platform hull. The control shaft passes through the hull wall and is connected to the internal transmission components. Driven by the servo drive assembly 12, the control blades can deflect in both directions. The electronic control assembly 14 is located at the bottom of the hull, and its low center of gravity layout improves the overall static stability. This assembly mainly includes a main control module 142, a power module 143, and a depth sensor 144. It is electrically connected to the servo drive assembly 12 through internal wiring harnesses and is used to calculate attitude data in real time and issue control commands.

[0027] like Figures 2-3 As shown in the figure, the specific structure of the servo mounting assembly 11 is described in detail in this embodiment. As the core carrier of power transmission, this assembly mainly consists of the servo mounting base 112, the transmission support frame 113, and the matching seals and bearings.

[0028] Specifically, the servo mount 112 has a disc-like structure with four servo receiving slots evenly distributed circumferentially on its surface. These slots are adapted to the servo drive assembly 12 for embedded mounting and securing of four independent servos, ensuring the stability of the power source. The transmission support frame 113, located below the servo mount 112, has a cross-shaped column structure. The two are axially locked and rigidly connected by countersunk bolts 116 located on the central axis, forming a complete internal support frame.

[0029] Specifically, to adapt to the high-pressure underwater environment, the outer cylindrical surface of the servo mount 112 is provided with two annular sealing grooves, one upper and one lower. The upper sealing groove is fitted with a first sealing ring 111, which is used to form a static seal between the device and the inner wall of the platform to prevent external water from seeping in; the lower sealing groove is fitted with a second sealing ring 114, which is used to form a sealed connection between the device and the housing of the rear electronic control component 14.

[0030] Furthermore, the transmission support frame 113 integrates multiple sets of precision bearings to ensure efficient and stable transmission; specifically, it includes: longitudinal output support and lateral transmission support. At the bottom center hole of the transmission support frame 113, four longitudinal transmission bearings 115 are installed. These bearings are used to connect the rudder shaft (132) in the servo drive assembly (12) to ensure rotational accuracy during power transmission.

[0031] On each of the four horizontal extension arms of the transmission support frame 113, there is a pair of transverse transmission bearings 117. The entire unit is equipped with a total of eight transverse transmission bearings 117. The servo drive shafts 123 of the four sets of servo drive assemblies 12 are correspondingly installed in each pair of transverse transmission bearings 117, meaning each servo drive shaft 123 is supported at two points by two spaced-apart bearings. This dual-bearing support structure not only ensures high coaxiality of the rudder stock rotation but also effectively withstands the radial load and bending moment generated when the rudder blades move in water, significantly improving the smoothness and shock resistance of the transmission.

[0032] like Figure 4 As shown in the figure, this embodiment provides a detailed description of the specific structure and assembly relationship of the servo drive assembly 12. This assembly, as an independent power unit, is responsible for converting electrical energy into mechanical rotational torque and transmitting it to the next stage of the transmission mechanism.

[0033] Specifically, the servo motor 121, as a power source, is fixedly mounted on the aforementioned servo motor mounting base 112 using fastening bolts. To achieve efficient power output, the output shaft of the servo motor 121 is connected to a servo disc 122. The bottom end of the servo motor drive shaft 123 is designed with an enlarged flange, which is rigidly connected to the servo disc 122 via cylindrical head bolts 127. At this connection, a spring washer 126 is preferably used to prevent bolt loosening under high-frequency vibration or frequent forward and reverse rotation conditions, ensuring the reliability of the connection.

[0034] Furthermore, the servo drive shaft 123 is provided with two spaced-apart annular grooves. During assembly, elastic retaining rings 128 are respectively embedded in these two grooves. The function of these two elastic retaining rings 128 is to cooperate with the aforementioned transmission support frame 113 and transverse transmission bearing 117 to form axial limiting. Specifically, the elastic retaining rings 128 restrict the axial movement of the servo drive shaft 123, ensuring that the transverse transmission bearing 117 is always in the correct working position, thereby ensuring the stability of transmission accuracy. At the output end of the servo drive shaft 123, a drive bevel gear 124 is installed. In order to ensure that the transmission of high torque does not slip, the drive bevel gear 124 is connected to the drive shaft 123 by a set screw 125 to prevent relative rotation between the gear and the shaft, ensuring that the commands issued by the servo can be accurately converted into the rotational action of the gear.

[0035] like Figure 5 As shown in the illustration, this embodiment provides a detailed description of the specific structure and assembly logic of the control surface actuator component 13. This component serves as the actuator terminal for the device's interaction with external fluids, responsible for converting mechanical torque into hydrodynamic control force.

[0036] Specifically, the rudder shaft 132, as the core rotating component, penetrates the housing wall of the device. A support bearing 134 is installed in the middle section of the rudder shaft 132 with an interference fit or clearance fit. This bearing bears the radial load transmitted from the rudder blade 131 and reduces frictional resistance during rudder shaft rotation, ensuring smooth transmission. To achieve isolation and sealing between the inside and outside of the device, a rudder shaft sealing end cap 138 is provided. This end cap is fastened to the outer housing of the main body of the device by countersunk bolts 139. In particular, a bearing limiting groove is formed on the inner side of the rudder shaft sealing end cap 138. When the end cap is locked, this limiting groove presses against the outer ring of the support bearing 134, thereby achieving radial fixation and axial preload of the bearing, effectively preventing bearing displacement in a vibrating environment.

[0037] Specifically, the rudder blade 131 is mounted on the extended end of the rudder shaft 132. To ensure the reliability of the connection under hydrodynamic impact, a connection design of "torque transmission and anti-slippage separation" is adopted. First, the cylindrical pin 133 passes through the radial through hole on the rudder shaft 132 and is engaged in the pre-set positioning groove at the root of the rudder blade 131. This pin connection method can withstand huge shear forces, ensuring that the rudder blade can follow synchronously with zero clearance when the rudder shaft rotates, preventing relative slippage. Second, the countersunk bolt 135 is screwed into the threaded hole on the end face of the rudder shaft 132, axially pressing the rudder blade 131 onto the rudder shaft to prevent the rudder blade from falling off during operation.

[0038] Furthermore, a driven bevel gear 136 is installed at the inner end of the rudder shaft 132. This gear is screwed into the side of the hub via a set screw 137 and pressed against the surface of the rudder shaft 132 to achieve axial fixation. In terms of assembly relationship, the driven bevel gear 136 is related to the aforementioned... Figure 4 The driving bevel gear 124 forms a 90-degree meshing transmission pair. Through this meshing relationship, the longitudinal rotational motion output by the servo drive assembly 12 is precisely converted into the lateral deflection motion of the rudder surface actuator assembly 13, thereby driving the rudder blade to move.

[0039] like Figure 6 As shown in the illustration, this embodiment provides a detailed description of the internal architecture and external interfaces of the electronic control component 14. This component is the control core and energy center of the entire device, and it adopts an independent sealed compartment design.

[0040] Specifically, the electronic sealing chamber 141 has a cylindrical shell structure and serves as the physical carrier of the electronic system. In terms of connection, the upper opening of the electronic sealing chamber 141 and the lower mating surface of the aforementioned servo mount 112 adopt a piston-type insertion structure. This is achieved through the aforementioned second sealing ring 114 (see...). Figure 2 (Description) A radial static seal is achieved, ensuring the watertightness of the compartment joint. Four symmetrical rudder shaft through-holes are provided around the sidewalls of the sealed compartment 141. The aforementioned rudder shaft 132 extends out of the compartment through these holes. To achieve a rotational seal, each through-hole has a raised bearing seat, which, together with the third sealing ring 149, forms a dynamic sealing interface. Furthermore, the outer wall of the compartment has countersunk grooves around the through-holes that match the shape of the rudder shaft sealing end cap 138. This embedded design ensures that the sealing end cap is flush with the outer surface of the compartment after installation, guaranteeing a streamlined overall appearance of the device and minimizing fluid resistance during underwater navigation.

[0041] Specifically, the main control module 142 is fixedly installed at the bottom inner part of the electronic sealed compartment 141. This location is chosen to shorten the distance between the sensor and the outside environment, while also facilitating heat dissipation. Above the main control module 142, a battery mounting plate 147 is mounted via support bolts 148. The power module 143 is mounted on the battery mounting plate 147 to provide power to the servo motor and control system.

[0042] like Figure 6 As shown, the electronic control component 14 will be described in detail in this embodiment.

[0043] Specifically, the electronic sealing chamber 141 is connected to the lower end of the aforementioned servo mounting base 112 via a piston-like O-ring. In addition, a rudder shaft 132 is provided around the electronic sealing chamber 141, extending out of the chamber to control the rudder blades. The aforementioned rudder shaft 132 has a protruding frustum that dynamically seals with the electronic sealing chamber 141 via an O-ring 149. An adapter groove for the rudder shaft sealing cover 138 is also provided to ensure a streamlined appearance.

[0044] Furthermore, the control module 142 is fixed to the bottom of the electronic sealed chamber 141, and the battery mounting plate 147 is mounted on the control module 142 by means of cylindrical head bolts 148. The power module 143 is also mounted on the battery mounting plate 147.

[0045] A depth sensor 144 is installed at the bottom of the device to calculate the water pressure and determine the depth, thus adjusting the attitude. A vent bolt 145 is used for venting during piston installation, balancing the pressure inside and outside the chamber for easy installation. Additionally, the vent bolt is used to reduce internal pressure using a vacuum device, serving as a basic airtightness check. An external switch 146 is used for switching the entire control unit on and off.

[0046] Furthermore, three key functional components are integrated on the bottom end face of the electronic sealing chamber 141: 1. Depth sensor 144: Installed at the bottom through hole, it is used to sense the external water pressure in real time and calculate the current depth information, providing data support for the control system to determine the "near water surface" state and start the attitude adjustment.

[0047] 2. Waterproof switch 146: Used to control the power supply of the entire device from the outside without disassembling the sealed compartment, improving ease of use.

[0048] 3. Vent Bolt 145: Located in a dedicated threaded hole in the bilge. This component serves a dual purpose: firstly, during assembly and connection, removing this bolt balances the air pressure inside and outside the bilge, preventing installation difficulties caused by the "piston effect" of air compression; secondly, after final assembly, this interface can be connected to a vacuum pump to perform non-destructive airtightness checks by monitoring the negative pressure inside the bilge, ensuring the reliability of the device before launch.

[0049] like Figure 7 and Figure 8 The diagram illustrates the integration of the anti-disturbance attitude control device 10 provided by this invention with a prior art cross-medium platform 20. In practical applications, this device 10 serves as an independent attitude control module, coaxially docked to the tail of the cross-medium platform 20. The servo drive assembly 12 and the electronic control assembly 14 are encapsulated within a streamlined housing, with only the cross-shaped control surface actuators 13 extending outside the housing, forming the hydrodynamic control surfaces of the aircraft.

[0050] In this embodiment, the core control concept of the electronic control component 14 is as follows: A dimensionless immersion depth ratio Q is constructed using the ratio of the current depth h to the platform diameter D as the trigger condition, forming a control flow of "input-state judgment-solution-weighted allocation-output". This scheme solves the technical problem of platform instability under complex near-surface sea conditions by introducing feedforward compensation for predicting wave forces and dynamic weights based on immersion degree to address the problem of partial rudder blade failure at the moment of emergence. The specific working process is as follows: 1. Input The electronic control component 14 includes an inertial measurement unit (IMU) and a main control module 142. The system acquires two types of basic data in real time: first, water pressure data collected by the depth sensor 144 (used to calculate depth h and Q value); second, the platform's current attitude angle, angular velocity, and linear acceleration collected by the IMU.

[0051] 2. Status Judgment The main control module 142 calculates the Q value according to the control cycle and divides the entire buoyancy process into three stages: Deep-water standby phase (Q > first set threshold Q1): At this time, the platform is far from the water surface and is less affected by waves. In order to save energy and reduce drag, the system is in a neutral standby state with the four rudder blades maintaining zero deflection, or only performs low-gain attitude damping control, that is, only performs small-amplitude rudder surface fine-tuning to maintain a basically vertical state when the platform experiences large swaying.

[0052] Active disturbance rejection and attitude adjustment phase (second set threshold Q2 < Q ≤ first set threshold Q1): The platform enters a strong interference zone near the water surface, and the control system intervenes. The main control module 142 generates the target attitude according to the task. For vertical water exit tasks, the target attitude is to keep the longitudinal axis vertical; for tasks requiring a fixed tilt angle or horizontal water exit, such as those with wing loads, the system will actively change the target parameters to drive the platform to smoothly transition from vertical ascent to the preset tilt angle.

[0053] Pre-emergence locking phase (Q≤Q2): As the platform is about to break through the water surface, the main control module 142 freezes the current target attitude command, and the control surfaces maintain a constant deflection angle to suppress the shock waves and transient impacts at the moment of emergence, relying on the platform's inertia to complete the cross-medium transition.

[0054] 3. Solution During the aforementioned active disturbance rejection and attitude adjustment phase, the main control module 142 needs to calculate the total control torque required to maintain platform stability. This torque is composed of two superimposed parts: Feedforward compensation torque The main control module integrates recent attitude and depth change data and uses algorithms such as disturbance observers or Kalman filters to estimate and predict the thrust and deflection torque that external environments such as waves and shear flows will cause to the platform, thereby providing the reverse resistance force in advance.

[0055] Feedback control torque The main control module compares the set target attitude with the current actual attitude measured by the IMU to calculate the attitude deviation, and then uses the control law to calculate the torque used to correct this deviation. The final formula for calculating the total control torque required is as follows: .

[0056] 4. Weighted Allocation In the near-water area, due to the platform's tilt and wave undulations, the four cross-shaped rudder blades are often submerged to different depths, easily leading to localized airflow or partial water exposure, causing a sharp decrease in the hydrodynamic performance of the rudder blades exposed to air. To address this, the main control module 142 further calculates the equivalent submersion degree of the four rudder blades in real time based on the current depth, platform attitude, and the geometric position of each rudder blade, and constructs a rudder effect weight matrix W accordingly. The allocation principle is: reduce the control weight for rudder blades close to the water surface or partially above water, and increase the control weight for rudder blades fully submerged in water.

[0057] 5. Output The main control module 142 uses the generalized inverse of the rudder effect weight matrix W and the control allocation matrix. The total control torque Transformed into specific target deflection angle vectors of the four rudder blades The specific weighted allocation formula can be expressed as: .

[0058] The generalized inverse formula for the control allocation matrix is: By introducing generalized inverse The main control module 142 can meet the total control torque. In the redundant solution space, the optimal target deflection angle vector that minimizes the overall deflection amplitude of the four rudder blades is found. This vector is then compared with the rudder effect weight matrix. By combining these methods, a control allocation strategy can be achieved that can accurately output corrective torque while avoiding excessive deflection of local outboard rudders under complex liquid surface disturbances near the water surface. The control allocation matrix B is a physical constant matrix determined by the hydrodynamic coefficient of the tail rudder and its geometric installation position relative to the platform's center of mass. It is used to represent the linear mapping relationship between the deflection angles of the four independent rudders and the three-axis control torques of the platform (roll, pitch, and yaw).

[0059] Subsequently, regarding the target deflection angle vector After applying maximum deflection amplitude and rate limits, the output is sent to the four control surface actuators to achieve independent differential deflection of the four rudder blades. This dynamic weighted allocation based on the degree of physical immersion effectively ensures the continuity of control at the waterfront.

[0060] Through this integration method, this device can provide active attitude intervention capabilities for traditional uncontrolled or weakly controlled platforms, specifically achieving the following two core technical effects and their working principles: The first technical effect: actively suppressing fluid interference, significantly reducing the dispersion range of water outlets near the water surface, thus improving water output accuracy. For example... Figure 9 , 10 As shown, its specific working principle and process are as follows.

[0061] First, during the sensing and activation phase, as the cross-medium platform 20 releases and ascends from a preset underwater depth (surfacing point), the depth sensor 144 at the bottom of the device collects external water pressure in real time and calculates depth data. When the depth data indicates that the platform has entered a near-surface wave interference zone (e.g., an area where Q=h / D<1.5), the main control module 142 automatically activates the attitude stabilization control algorithm, and the system enters "active anti-disturbance mode." Second, in the near-surface area, the platform will be subjected to irregular impact forces from lateral ocean currents or waves, causing attitude deviation. At this time, the main control module 142, based on the real-time attitude deviation fed back by the internal attitude sensor (IMU), performs differential deflection by independently controlling the four control surface actuators 13. Figure 9As shown, when the incoming flow acts on the platform, by precisely adjusting the deflection angle (angle of attack) of the rudder blades, the rudder blades generate a reverse hydrodynamic lift or lateral force. This force creates a corrective torque on the platform's center of gravity, thereby counteracting the overturning torque or drift caused by the waves within the control cycle, forcing the platform's attitude back to the preset vertical state. Finally, Figure 10 The demonstration compares the ascent trajectories before and after device activation. Without this device's intervention, the platform's ascent trajectory exhibits significant non-linear drift due to lateral currents, resulting in a large deviation between the actual water exit point and the predetermined target point. Furthermore, the lateral drift consumes kinetic energy, reducing the water exit velocity. With the active intervention of this device, through continuous fine-tuning of attitude, the platform can overcome lateral current interference and maintain a predetermined straight trajectory for ascent. Figure 10 As shown in the top view, after activating this device, the distribution range of the water outlet points shrinks from a wide area to a very small target circle. This not only significantly improves the predictability of the water outlet location, but also reduces ineffective lateral displacement, allowing the platform to reach the water surface with less kinetic energy loss and in a shorter time, thereby significantly improving the penetration capability and deployment timeliness of the mission payload.

[0062] The second technical effect is: it possesses the ability to adaptively reconfigure multiple modes of water output attitude, achieving operational adaptability across media platforms. For example... Figure 9 As shown, in addition to the aforementioned anti-disturbance stabilization function, the anti-disturbance attitude control device of this invention can also actively control the cross-medium platform 20 to establish a specific water exit attitude in the near-water surface stage according to different operational load requirements. Its specific working principle and application mode are as follows: Attitude reconstruction principle: as... Figure 9 As shown, the main control module 142 (see...) Figure 6 The system has multiple preset motion trajectory models or receives operational commands from a host computer. When the water outlet angle needs to be changed, the control system no longer uses "vertical attitude" as the sole closed-loop target, but instead sets the target pitch angle to a specific non-zero value. For example... Figure 9 As indicated by the "Attitude Change" arrow, the main control module 142 calculates the required control torque and drives the rudder surface actuator 13 to perform asymmetric differential deflection. At this time, the water flow through the rudder blades generates a hydrodynamic lift difference, and this torque forms a pitching moment at the tail of the platform. This moment drives the platform to rotate around its center of mass, changing its angle of attack, thereby actively changing the tangential direction of its ascent trajectory under hydrodynamic action, achieving a smooth transition from a vertical to an inclined or horizontal attitude.

[0063] Based on the above principles, this device can support three typical water exit and operation modes for cross-medium platforms, thereby greatly expanding the application efficiency of a single platform. Specifically, the first mode is the vertical water exit mode, which is suitable for high-speed sounding payloads or vertical climbing aircraft that seek the shortest cross-medium path and the fastest response speed. Its operating logic lies in controlling the rudder blades to fine-tune the system, always keeping the platform axis aligned with the vertical line of gravity to maintain a zero angle of attack, thereby breaking through the water surface vertically with minimal fluid resistance and reducing energy loss. The second mode is the constant tilt angle water exit mode, which is suitable for winged payloads such as folding-wing UAVs or gliding probes. Given that such payloads require a certain initial angle of attack at the moment of water exit to obtain aerodynamic lift and prevent altitude drop, its dynamic... The operating logic is as follows: when the device approaches the water surface, it controls the deflection of the rudder blades to establish and lock the platform at a preset tilt angle, such as 45° or 60°, ensuring that the payload has the initial attitude required for aerodynamic gliding upon exiting the water; the third is the near-water-surface horizontal exit mode, suitable for the deployment of environmental monitoring buoys or the release of surface cruisers. Its operating logic is to use the control lift generated by the device's tail rudder to smoothly transition the platform's attitude to a near-horizontal state, turning it to a horizontal attitude before exiting the water, thus enabling horizontal cruising at depths close to the water surface or smooth entry into the water at tangential speed, minimizing the impact load at the moment of exiting the water. In summary, by means of... Figure 9 The active control mechanism of the rudder blade shown in this invention not only solves the problem of "inaccurate water outlet point", but also fundamentally overcomes the technical bottleneck of "single water outlet attitude" of existing cross-media platforms. This allows the same platform to be adapted to various types of scientific research or engineering loads without hardware modification, significantly improving the equipment's versatility and application flexibility.

[0064] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A disturbance-resistant attitude control device for a near-surface cross-medium platform under complex sea conditions, characterized in that, As an independent attitude control section, it is coaxially docked to the tail of the cross-medium platform 20; including: servo mounting assembly (11), servo drive assembly (12), control surface actuation assembly (13) and electronic control assembly (14); The servo mounting assembly (11) is fixedly connected to the inner wall of the cross-medium platform compartment, used to fix the servo drive assembly (12) and the servo surface actuator assembly (13) to the tail of the cross-medium platform, and to provide support and sealing for the internal transmission; The servo drive assembly (12) is fixedly installed inside the servo mounting assembly (11), and its power output is transmitted to the rudder blade (131) of the rudder surface actuator assembly (13); The control surface actuation component (13) is symmetrically distributed in a cross shape, including four control blades (131). Each control blade (131) is connected to the servo drive component (12) through the control shaft (132) and is driven by the servo motor (121) to perform bidirectional independent deflection, generating hydrodynamic control torque. The electronic control component (14) includes a main control module (142), a depth sensor (144), and an inertial measurement unit, which is used to calculate control quantities and drive the servo motor (121) based on the real-time sensed depth, attitude, and disturbance information.

2. The anti-disturbance attitude control device according to claim 1, characterized in that, The servo mounting assembly (11) includes: The servo mounting base (112) has a disc structure with four servo receiving slots evenly distributed around the circumference on its disc surface. The servo receiving slots are adapted to the servo drive assembly (12) for embedded installation and fixing of the servo (121). The transmission support frame (113) is located below the servo mounting base (112) and has a cross-shaped column structure. It is axially locked and rigidly connected to the servo mounting base (112) through countersunk bolts (116) located on the central axis, thereby forming a complete internal support frame. The first sealing ring (111) and the second sealing ring (114) are respectively set at the upper and lower ends of the outer cylindrical surface of the servo mount (112) to achieve sealing with the inner wall of the platform and the electronic sealing chamber (141); The transmission support frame (113) integrates multiple sets of bearings to achieve longitudinal output support and lateral transmission support; at the bottom center hole of the transmission support frame (113), four longitudinal transmission bearings (115) are installed to connect and support the rudder shaft (132) in the rudder drive assembly (12). On the four symmetrically distributed horizontal extension arms of the transmission support frame (113), a pair of transverse transmission bearings (117) are respectively provided, and the servo drive shafts (123) of the four sets of servo drive assemblies (12) are correspondingly installed in each pair of transverse transmission bearings (117). The servo drive assembly (12) has a drive bevel gear 124 installed at the output end of the servo drive shaft (123) of the servo (121); One end of the rudder shaft (132) extending out of the transmedia platform body is connected to the end rudder blade 131, and the other end is located inside the housing, where a driven bevel gear (136) is installed; the driven bevel gear (136) and the driving bevel gear (124) form a 90-degree meshing transmission pair; through this meshing relationship, the longitudinal rotational motion output by the servo motor (121) is converted into the lateral deflection motion of the rudder shaft (132), thereby driving the rudder blade (131) to move.

3. The anti-disturbance attitude control device according to claim 2, characterized in that, The servo drive shaft (123) of the servo drive assembly (12) is connected to the output shaft of the servo (121) via the servo disc (122) and the cylindrical head bolt (127). One end of the servo drive shaft (123) is locked by a set screw (125). The servo drive shaft (123) is provided with an elastic retaining ring (128) for axial positioning.

4. The anti-disturbance attitude control device according to claim 2, characterized in that, The control surface actuation component (13) includes: At the middle section of the rudder shaft (132), a support bearing (134) is installed with an interference fit or clearance fit to bear the radial load transmitted from the rudder blade (131). A rudder shaft sealing end cap (138) is provided, which is fastened to the housing by a cross countersunk bolt (139); a bearing limiting groove is provided on the inner side of the rudder shaft sealing end cap (138); when the end cap is locked, the limiting groove presses against the outer ring of the supporting bearing (134); The cylindrical pin (133) passes through the radial through hole on the rudder shaft (132) and is engaged in the pre-set positioning groove at the root of the rudder blade (131); the countersunk bolt (135) is screwed into the threaded hole on the end face of the rudder shaft (132) to axially press the rudder blade (131) onto the rudder shaft (132).

5. The anti-disturbance attitude control device according to claim 2, characterized in that, The electronic control component (14) includes: The electronic sealed compartment (141) is piston-type inserted into the servo mounting base (112) and sealed by the second sealing ring (114). Its side wall is provided with a through hole for the servo shaft (132) to pass through. The through hole is dynamically sealed by the third sealing ring (149). The main control module (142) is fixedly installed at the bottom of the electronic sealed chamber (141); The power module (143) is mounted on top of the main control module (142) via a battery mounting plate (147) and support bolts (148); A depth sensor (144) is installed at the bottom of the electronic sealed chamber (141) to obtain the depth of the platform; And a vent bolt (145) and an external switch (146).

6. A control method based on the anti-disturbance attitude control device according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step S1: Acquire basic data in real time, including water pressure data collected by the depth sensor and the current attitude angle, angular velocity and linear acceleration of the platform collected by the inertial measurement unit (IMU); Step S2: Calculate the current depth h and dimensionless parameter Q value based on the water pressure data; Step S3: The main control module divides the buoyancy process into three stages based on the Q value and executes the corresponding control strategies: When Q > the first set threshold Q1, it enters the deep water standby stage, controlling the four rudder blades to maintain the zero-degree neutral state or to execute low-gain attitude damping control. When the second set threshold Q2 < Q ≤ the first set threshold Q1, the active disturbance rejection and attitude adjustment stage is entered. The target attitude is generated according to the task, and the total control torque required to maintain the stability of the platform is calculated. When Q≤Q2, the pre-exit lock-in phase is entered, freezing the current target attitude command and keeping the control surface deflection angle unchanged until the cross-medium conversion is completed. Step S4: In the active disturbance rejection and attitude adjustment stage, the total control torque is distributed to the four rudder blades based on the rudder effect weight matrix, and the target deflection angle vector is generated and output to the four rudder surface execution components (13).

7. The control method according to claim 6, characterized in that, In the active disturbance rejection and attitude adjustment stage of step S3, the total control torque The calculation formula is: ;in, For feedforward compensation torque, The feedback control torque; the feedforward compensation torque It is achieved by fusing recent attitude and depth change data and using a perturbation observer or Kalman filter algorithm to estimate and predict the thrust and yaw torque exerted on the platform by the external environment, thereby generating a counterforce; the feedback control torque It compares the set target attitude with the current actual attitude measured by the IMU to find the attitude deviation, and uses the control law to calculate the torque used to correct the deviation.

8. The control method according to claim 7, characterized in that, The calculation method of the rudder effect weight matrix includes: the main control module calculates the equivalent submersion degree of the four rudder blades arranged in a cross shape in real time according to the current depth, platform attitude and geometric position of each rudder blade; and assigns weights according to the equivalent submersion degree: the control weight is reduced for rudder blades that are close to the water surface or have partially emerged from the water, and the control weight is increased for rudder blades that are completely submerged in the water, in order to cope with the hydrodynamic attenuation caused by local ventilation or partial water emergence.

9. The control method according to claim 8, characterized in that, In step S4, the target deflection angle vector is generated. The weighted allocation formula is: ;in, The rudder effect weight matrix is... To control the generalized inverse of the allocation matrix, The total control torque is given.

10. The control method according to claim 6, characterized in that: In the deep-water standby phase of step S3: the low-gain attitude damping control specifically means: only when the platform is detected to be swaying beyond a preset threshold, a small-amplitude rudder surface adjustment is made to maintain a basically vertical state, and the rudder blade does not deflect at other times. In the active disturbance rejection and attitude adjustment stage of step S3: for vertical water exit missions, the target attitude is set to keep the platform's longitudinal axis vertical; for missions with winged payloads, the target attitude is set to a preset tilt angle or horizontal attitude, and the control system drives the platform to smoothly transition from a vertical floating state to the preset attitude.

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