Unmanned aerial vehicle for ocean rescue

Abstract

The invention relates to an unmanned aerial vehicle for ocean rescue, and belongs to the technical field of ocean rescue, a dynamic balance mechanism is introduced, the mechanism is formed by hinging first to fourth connecting rods in a crossed mode, the first and third connecting rods are located on different horizontal planes and form a multi-degree-of-freedom linkage system with a rack, and the second and fourth connecting rods are hinged to the two ends of a supporting block respectively; when the gravity center shifts due to fire extinguishing agent consumption, the supporting block drives the connecting rod system to conduct linkage under the gravity effect, a first connecting rod and a third connecting rod rotate around the hinge point of the rack, the two ends of the supporting block are pushed and pulled through a fourth connecting rod and a second connecting rod correspondingly, and the supporting block slides in a self-adaptive mode in the parallel direction of the rack; the motion trail of the supporting block is in a hyperbolic curve shape and is accurately matched with the gravity center shift characteristic caused by non-linear consumption of the fire extinguishing agent, and therefore sliding displacement of the supporting block is converted into non-linear torque compensation, and unbalance torque is effectively offset.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine rescue, and particularly relates to an unmanned aerial vehicle for marine rescue. Background Art

[0002] In recent years, rescue unmanned aerial vehicles have been increasingly used in the field of marine fire fighting to perform fire extinguishing tasks because of their fast response, strong mobility, and the ability to accurately deliver fire extinguishing agents. However, in existing unmanned aerial vehicles, the fire extinguisher is usually directly fixed on the unmanned aerial vehicle bracket. This design has some shortcomings: it cannot "dynamically adjust the position". During the fire extinguishing process, as the fire extinguishing agent is continuously ejected, the weight distribution of the entire unmanned aerial vehicle will gradually become unbalanced. This center-of-gravity shift will cause the unmanned aerial vehicle to fly unstably. Especially in complex environments such as high temperatures at the fire site and strong marine winds, it may cause severe shaking or even loss of control, seriously affecting rescue safety. Moreover, the remaining liquid in the fire extinguisher may slosh during flight, further exacerbating the center-of-gravity drift. It is very difficult for traditional control systems to accurately respond to such irregular changes.

[0003] Therefore, at present, some rescue unmanned aerial vehicles have also tried the "rail sliding" scheme, that is, to let the fire extinguisher automatically move its position as it is consumed to maintain balance. However, such a scheme relies on a motor drive and a sensor feedback system and has obvious limitations: there are obvious defects. One is that the motor response has a delay, and with the frictional resistance of the rail, it cannot keep up with the rapid consumption speed of the fire extinguishing agent. The second is that the high temperature and dust at the fire site are likely to cause electronic devices to malfunction. The most crucial point is that the rail sliding can only achieve linear displacement, while the physical relationship between the consumption of the fire extinguishing agent and the center-of-gravity shift has non-linear characteristics. Simple linear adjustment cannot completely offset the moment imbalance. Therefore, there is an urgent need for an unmanned aerial vehicle for marine rescue with a dynamic balance mechanism that does not require external energy, can adapt to complex environments, and can autonomously match non-linear center-of-gravity changes, so as to fundamentally improve the stability and adaptability of the rescue unmanned aerial vehicle. Summary of the Invention

[0004] To solve the above problems existing in the prior art, the present invention provides an unmanned aerial vehicle for marine rescue, which solves the problem that the physical relationship between the consumption of the fire extinguishing agent and the center-of-gravity shift in the prior art has non-linear characteristics, and simple linear adjustment cannot completely offset the moment imbalance.

[0005] The object of the present invention can be achieved through the following technical solutions: A marine rescue drone, comprising a drone body, a frame arranged below the drone, a dynamic balancing mechanism arranged on the frame, and a fire extinguishing device arranged on the dynamic balancing mechanism, wherein the fire extinguishing device is arranged on the dynamic balancing mechanism through a support block, and the dynamic balancing mechanism comprises a first connecting rod, a second connecting rod, a third connecting rod and a fourth connecting rod, wherein the two ends of the first connecting rod are respectively hinged to one end of the second connecting rod and the frame, the two ends of the third connecting rod are respectively hinged to the other end of the second connecting rod and the frame, the first connecting rod and the third connecting rod are cross-arranged and the first connecting rod is connected to the third connecting rod. The rod and the third link are located in different horizontal planes, the midpoint of the second link is hinged to one end of the support block, the midpoint of the first link is hinged to one end of the fourth link, and the other end of the fourth link is hinged to the other end of the support block. When the fire extinguishing agent in the fire extinguishing device is consumed and the center of gravity shifts, the first link, the second link, the third link and the fourth link are linked by gravity drive, so that the support block adaptively slides to the center of gravity position of the drone in a direction parallel to the frame to offset the nonlinear torque imbalance, and after the sliding is completed, it is self-locking and fixed between the first link, the second link, the third link and the fourth link.

[0006] As a further solution of the present invention, an L-shaped connecting rod is provided at one end of the support block, one end of the L-shaped connecting rod is perpendicularly arranged to the other end of the support block, the other end of the L-shaped connecting rod is hinged to the midpoint of the second connecting rod, and a vertical connecting rod is perpendicularly arranged at the other end of the support block, and the vertical connecting rod is hinged to the other end of the fourth connecting rod.

[0007] As a further solution of the present invention, the vertical rod of the L-shaped connecting rod is equal to the vertical connecting rod.

[0008] As a further solution of the present invention, the frame is provided with a limiting groove matching the vertical connecting rod, and a roller is vertically arranged on the vertical connecting rod. When the support block slides to the center of gravity position, the roller is embedded in the groove.

[0009] As a further solution of the present invention, there are two dynamic balancing mechanisms, and the two dynamic balancing mechanisms are symmetrically arranged on both sides of the support block.

[0010] As a further solution of the present invention, the support block is an elastic support block, an arc-shaped groove is provided on the elastic support block, an arc-shaped frame is provided on the frame, the fire extinguishing device is a fire extinguisher, the arc-shaped groove and the fire extinguisher are snap-fitted and locked, a guide wheel is provided on the arc-shaped frame, and the guide wheel is in contact with the outer wall of the fire extinguisher.

[0011] As a further solution of the present invention, the third connecting rod and the fourth connecting rod are arranged in parallel.

[0012] As a further solution of the present invention, the length of the fourth link is half of the length of the first link.

[0013] As a further solution of the present invention, the first link and the third link have the same length.

[0014] As a further solution of the present invention, the first link is hinged to the frame through a first hinge block, and the third link is hinged to the frame through a second hinge block. The first hinge block and the second hinge block are respectively located at both ends of the frame, and the first hinge block and the second hinge block are in different planes.

[0015] The beneficial effects of the present invention are as follows: By introducing a dynamic balance mechanism, the problem of unstable flight caused by the center of gravity shift due to the consumption of fire extinguishing agent in the background art of the drone is fundamentally solved. This mechanism is composed of the first to fourth links cross-hinged. Among them, the first and third links are located in different horizontal planes and form a multi-degree-of-freedom linkage system with the frame. The second and fourth links are respectively hinged to both ends of the support block. When the center of gravity shifts due to the consumption of the fire extinguishing agent, the support block drives the linkage system under the action of gravity: the first and third links rotate around the hinge points of the frame, and respectively push and pull both ends of the support block through the fourth link and the second link, so that it slides adaptively along the parallel direction of the frame. Since the first and third links are equal in length and cross-arranged, their movement trajectories are hyperbolic, which exactly matches the characteristic of the center of gravity shift caused by the non-linear consumption of the fire extinguishing agent. Thus, the sliding displacement of the support block is converted into a non-linear torque compensation to effectively offset the unbalanced torque. When the support block slides to the equilibrium position, the fourth link forms a dead center passing through the center with the first and third links, and the reaction force and friction force at the hinge point cooperate to achieve self-locking and fixation, and the position can be stabilized without relying on motors or sensors. This design realizes passive drive, non-linear adjustment and self-locking through a pure mechanical structure, completely avoiding the problems in the traditional scheme that electronic devices are easily interfered by high temperature and dust, and linear adjustment cannot match non-linear torque, and significantly improving the stability and reliability of the drone in a complex fire field environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 It is an axonometric view of the overall structure of the rescue drone of the present invention; Figure 2 It is a front view of the overall structure of the rescue drone of the present invention; Figure 3 It is a side view of the overall structure of the rescue drone of the present invention; Figure 4 It is a front view of the dynamic balance mechanism of the present invention; Figure 5It is an axial side view of the dynamic balancing mechanism of the present invention; Figure 6 It is a schematic diagram of the cooperation between the dynamic balancing mechanism and the support block of the present invention.

[0018] Description of main component symbols: In the figure: 1. UAV body; 2. frame; 3. dynamic balancing mechanism; 31. first connecting rod; 32. second connecting rod; 33. third connecting rod; 34. fourth connecting rod; 35. L-shaped connecting rod; 36. vertical connecting rod; 4. fire extinguishing device; 5. camera; 6. support block. DETAILED DESCRIPTION

[0019] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0020] See also Figures 1 - 6 As shown, this embodiment provides a marine rescue drone, including a drone body 1, a frame 2 arranged below the drone, a dynamic balancing mechanism 3 arranged on the frame 2, and a fire extinguishing device 4 arranged on the dynamic balancing mechanism 3, the fire extinguishing device 4 is arranged on the dynamic balancing mechanism 3 through a support block 6, the dynamic balancing mechanism 3 includes a first connecting rod 31, a second connecting rod 32, a third connecting rod 33 and a fourth connecting rod 34, the two ends of the first connecting rod 31 are respectively hinged to one end of the second connecting rod 32 and the frame 2, the two ends of the third connecting rod 33 are respectively hinged to the other end of the second connecting rod 32 and the frame 2, the first connecting rod 31 and the third connecting rod 33 are cross-arranged and the first connecting rod 31 and the third connecting rod 33 are located at different The second link 32 is hinged to one end of the support block 6 at its midpoint, the first link 31 is hinged to one end of the fourth link 34 at its midpoint, and the other end of the fourth link 34 is hinged to the other end of the support block 6. When the fire extinguishing agent in the fire extinguishing device 4 is consumed and the center of gravity is shifted, the first link 31, the second link 32, the third link 33 and the fourth link 34 are linked by gravity drive, so that the support block 6 slides adaptively to the center of gravity position of the UAV in a direction parallel to the frame 2 to offset the nonlinear moment imbalance, and after the sliding is completed, it is fixed by self-locking between the first link 31, the second link 32, the third link 33 and the fourth link 34. In addition, a camera 5 is also installed on the UAV body 1, such as Figure 1 shown.

[0021] It should be noted that the core structure of the dynamic balancing mechanism 3 is composed of a first link 31, a second link 32, a third link 33 and a fourth link 34, which are cross-hinged to the frame 2 to form a multi-degree-of-freedom linkage system. Figure 4As shown, the support block 6 is connected to the fire extinguishing device 4 and realizes adaptive sliding through the gravity drive of the connecting rod. After the sliding is completed, the position is automatically locked through the geometric constraint of the connecting rod. When the center of gravity shifts due to the consumption of the fire extinguishing agent, the support block 6 is out of balance, causing the first connecting rod 31 and the third connecting rod 33 to rotate around the hinge points of the frame 2; the midpoint of the first connecting rod 31 pushes one end of the support block 6 through the fourth connecting rod 34, and the third connecting rod 33 pulls the other end of the support block 6 through the second connecting rod 32, forming a bidirectional driving force; the geometric relationship of the cross connecting rod converts the gravitational potential energy into the horizontal sliding kinetic energy of the support block 6. Since the first connecting rod 31 and the third connecting rod 33 are of equal length and cross each other, their movement trajectories are hyperbolic, matching the non-linear center of gravity shift caused by the consumption of the fire extinguishing agent; the sliding displacement of the support block 6 has a non-linear proportional relationship with the center of gravity shift amount, precisely offsetting the moment imbalance. When the support block 6 slides to the equilibrium position, the fourth connecting rod 34 and the first connecting rod 31, the third connecting rod 33 form a dead center passing through the center. At this time, the internal force direction of the connecting rod system changes, and the friction force and the reaction force at the hinge point jointly lock the position of the support block 6. Without external energy, this design completely relies on gravity and mechanical linkage, avoiding the risk of failure of electronic devices such as motors and sensors, adapting to high-temperature and dust environments. The geometric design of the cross connecting rod makes the displacement of the support block 6 non-linearly correspond to the center of gravity shift, precisely offsetting the moment imbalance. The dead center passing through the center design ensures automatic locking of the equilibrium position and prevents secondary offset during flight.

[0022] In recent years, rescue drones have been increasingly used in the field of marine fire fighting to perform fire extinguishing tasks because they are fast in response, highly maneuverable, and can accurately drop fire extinguishing agents. However, existing drones usually directly fix the fire extinguisher on the drone bracket. This design has some shortcomings: it cannot "dynamically adjust the position". During the fire extinguishing process, as the fire extinguishing agent is continuously ejected, the weight distribution of the entire drone will gradually become unbalanced. This shift in the center of gravity will cause the drone to fly unsteadily. Especially in complex environments such as high temperatures at the fire scene and strong winds in the ocean, it may cause violent shaking or even loss of control, seriously affecting rescue safety. What's more troublesome is that the remaining liquid in the fire extinguisher may slosh during flight, further exacerbating the center of gravity drift. Traditional control systems are very difficult to accurately handle such irregular changes. Currently, some rescue drones on the market try to use the "rail sliding" scheme, that is, let the fire extinguisher automatically move its position as it is consumed to maintain balance. However, such a scheme relies on a motor drive and a sensor feedback system and has obvious limitations: there are obvious defects. One is that the motor reaction is delayed, and combined with the frictional resistance of the rail, it cannot keep up with the rapid consumption speed of the fire extinguishing agent. The second is that the high temperature and dust at the fire scene easily cause electronic devices to malfunction. The most crucial thing is that the rail sliding can only achieve linear displacement, while the physical relationship between the consumption of the fire extinguishing agent and the center of gravity shift has non-linear characteristics, and simple linear adjustment cannot completely offset the moment imbalance.

[0023] To solve the above problems, in this embodiment, by introducing a dynamic balance mechanism 3, the problem of unstable flight caused by the center of gravity deviation of the drone in the background art due to the consumption of the fire extinguishing agent is fundamentally solved. The mechanism is composed of a first connecting rod 31, a second connecting rod 32, a third connecting rod 33 and a fourth connecting rod 34 which are cross-hinged. Among them, the first connecting rod 31 and the third connecting rod 33 are located in different horizontal planes and form a multi-degree-of-freedom linkage system with the frame 2. The second connecting rod 32 and the fourth connecting rod 34 are respectively hinged to both ends of the support block 6. When the center of gravity deviates due to the consumption of the fire extinguishing agent, the support block 6 drives the linkage of the connecting rod system under the action of gravity: the first connecting rod 31 and the third connecting rod 33 rotate around the hinge points of the frame 2, and respectively push and pull both ends of the support block 6 through the fourth connecting rod 34 and the second connecting rod 32, so that it slides adaptively along the parallel direction of the frame 2. Since the lengths of the first connecting rod 31 and the third connecting rod 33 are equal and cross-arranged, their movement trajectories are hyperbolic, which precisely matches the characteristics of the center of gravity deviation caused by the non-linear consumption of the fire extinguishing agent. Thus, the sliding displacement of the support block 6 is converted into a non-linear moment compensation, effectively offsetting the unbalanced moment. When the support block 6 slides to the equilibrium position, the fourth connecting rod 34 forms a dead center passing through the center with the first connecting rod 31 and the third connecting rod 33, and the reaction force and friction force at the hinge point cooperate to achieve self-locking fixation, and the position can be stabilized without relying on motors or sensors. This design realizes passive drive, non-linear adjustment and self-locking through a pure mechanical structure, completely avoiding the problems in the traditional scheme that electronic devices are vulnerable to high-temperature dust interference and linear adjustment cannot match non-linear moments, and significantly improving the stability and reliability of the drone in complex fire scenes and in strong wind environments at sea.

[0024] When this rescue drone is in use, if the support block 6 only transmits the driving force through a single connecting rod, the acting direction of the force may deviate from the center of gravity of the support block 6, resulting in uneven torque distribution. For example, when the first connecting rod 31 pushes one end of the support block 6 through the fourth connecting rod 34, if there is no symmetric pulling or supporting structure, the support block 6 will be affected by the lateral component force during sliding and generate a rotational tendency; at the same time, the single-point force will exacerbate local friction, resulting in jitter caused by fluctuations in friction force during the sliding process. This design defect will destroy the stability of the support block 6 sliding along the parallel direction of the frame 2 and affect the accuracy of dynamic balance. To solve the above problems, in one embodiment, an L-shaped connecting rod 35 is provided at one end of the support block 6. One end of the L-shaped connecting rod 35 is perpendicularly arranged with the other end of the support block 6. The other end of the L-shaped connecting rod 35 is hinged to the midpoint of the second connecting rod 32. A vertical connecting rod 36 is perpendicularly arranged at the other end of the support block 6. The vertical connecting rod 36 is hinged to the other end of the fourth connecting rod 34. The L-shaped connecting rod 35 and the vertical connecting rod 36 form a double-point hinge, dispersing the force and restricting the sliding direction of the support block 6 to ensure parallel movement along the frame 2, improving the linear accuracy of the sliding path, and avoiding trajectory deviation caused by single-point drive.

[0025] In addition, if the lengths of the L-shaped connecting rod 35 and the vertical connecting rod 36 are not equal, the force transmission path will be asymmetric. For example, the longer L-shaped connecting rod 35 will amplify the driving force arm of the second connecting rod 32, while the shorter vertical connecting rod 36 will limit the reaction force of the fourth connecting rod 34, resulting in uneven forces on both ends of the support block 6. This unbalanced couple will force the support block 6 to rotate around its geometric center, causing tilting, thus deviating the sliding trajectory from the expected direction and unable to accurately compensate for the non-linear moment imbalance. In this regard, in one embodiment, the vertical rod of the L-shaped connecting rod 35 is equal in length to the vertical connecting rod 36. The equal-length design ensures the symmetry of force transmission, avoids generating a rotational moment during the sliding of the support block 6, maintains the geometric symmetry of the dynamic balance mechanism 3, and improves the accuracy of balance adjustment.

[0026] Although the connecting rod system achieves self-locking through the dead center, if the clearance between the limiting groove and the roller is too large, or the friction coefficient at the hinge point is insufficient, external vibrations, such as the airflow disturbance during the flight of the drone, may cause the support block 6 to disengage from the locked state. In addition, the inertia effect will cause the support block 6 to have a small rebound due to the incomplete dissipation of kinetic energy after rapid sliding, destroying the established equilibrium position and resulting in the failure of moment compensation. To avoid this problem, in one embodiment, the frame 2 is provided with a limiting groove matching the vertical connecting rod 36, and a roller is vertically arranged on the vertical connecting rod 36. When the support block 6 slides to the center of gravity position, the roller is embedded in the groove. The roller embedded in the limiting groove forms a mechanical lock, fixing the position of the support block 6 through physical limitation, enhancing the self-locking stability of the equilibrium position, and preventing accidental displacement.

[0027] Since the movement range of a single dynamic balance mechanism 3 is limited by the geometric dimensions of the connecting rods and the hinge angles. For example, when the fire extinguishing agent is rapidly consumed on one side of the drone, the support block 6 needs to slide significantly to offset the asymmetric moment, but the connecting rod length and swing angle of a single mechanism cannot cover the extreme offset. In addition, a single mechanism can only adjust in a fixed direction and cannot cope with multi-axis moments, resulting in insufficient balance ability under complex loads. Therefore, in one embodiment, the number of dynamic balance mechanisms 3 is two, and the two dynamic balance mechanisms 3 are symmetrically arranged on both sides of the support block 6. The symmetrical arrangement of the double mechanisms expands the adjustment freedom, can offset the moment imbalance in different directions simultaneously, improves the overall balance ability of the system, and adapts to the requirements of multiple scenarios.

[0028] Furthermore, based on the lack of elastic deformation ability of the rigid connection, when the UAV is impacted or vibrated during flight, the contact surface between the fire extinguisher and the support block 6 will generate local high pressure due to the direct transfer of stress, aggravating the friction resistance. During long-term operation, metal fatigue or surface wear will form burrs, further increasing the sliding resistance or even getting stuck. In addition, the rigid structure cannot absorb high-frequency vibration energy, which can easily lead to cracks or fractures at the connection. In one embodiment, the support block 6 is an elastic support block 6, an arc-shaped groove is provided on the elastic support block 6, an arc-shaped frame is provided on the frame 2, and the fire extinguishing device 4 is a fire extinguisher. The arc-shaped groove is engaged and locked with the fire extinguisher, and a guide wheel is provided on the arc-shaped frame. The guide wheel is in contact with the outer wall of the fire extinguisher. The elastic support block 6 engages and locks the fire extinguisher through the arc-shaped groove to reduce rigid impact. The guide wheel is in contact with the outer wall of the fire extinguisher to reduce sliding resistance, ensure smooth sliding of the fire extinguisher, and protect the device from mechanical damage.

[0029] Furthermore, if the third link 33 and the fourth link 34 are not arranged in parallel, their movement directions will be uncoordinated. For example, the swing of the third link 33 may generate a component force perpendicular to the frame 2, while the thrust direction of the fourth link 34 deviates from the expected path, causing the support block 6 to be subjected to lateral tension when sliding. The superposition of such multi-directional forces will cause the actual trajectory of the support block 6 to deviate from the theoretical straight line, forming an irregular serpentine motion, which cannot effectively offset the nonlinear torque imbalance. In one embodiment, the third link 33 and the fourth link 34 are arranged in parallel. The parallel link design ensures that the force transmission direction is consistent, optimizes the linearity of the motion trajectory, and improves the motion stability of the dynamic balancing mechanism 3.

[0030] It is worth mentioning that if the length of the fourth connecting rod 34 is twice that of the first connecting rod 31 instead of half, its lever effect will excessively amplify the sliding distance of the support block 6, resulting in a small center of gravity offset causing excessive displacement, exceeding the actual compensation requirements; on the contrary, if the fourth connecting rod 34 is too short, a larger center of gravity offset is required to trigger effective sliding, and the response speed is delayed. Improper proportions will destroy the matching relationship between force and displacement, and reduce the adjustment sensitivity and efficiency. Therefore, in one embodiment, the length of the fourth connecting rod 34 is half the length of the first connecting rod 31. The specific ratio optimizes the lever effect, so that the sliding distance of the support block 6 is accurately matched with the center of gravity offset, thereby improving the sensitivity and effectiveness of torque compensation.

[0031] In addition, if the lengths of the first link 31 and the third link 33 are different, the radii of the movement trajectories of their hinge points are inconsistent. For example, the swing amplitude of the longer link is larger, and the driving force transmitted to the support block 6 is stronger, while the reverse force of the shorter link is weaker, resulting in unbalanced forces at both ends of the support block 6. This asymmetric force distribution will distort the geometric relationship of the dynamic balance mechanism 3, causing the moment compensation to deviate from the theoretical value, and ultimately affecting the flight stability of the drone. In one embodiment, the lengths of the first link 31 and the third link 33 are the same. The equal-length links ensure symmetric force application, avoid stress concentration inside the dynamic balance mechanism 3, maintain the mechanical balance of the system, and extend the service life of the mechanism.

[0032] Continuing from the previous embodiment, when the hinge blocks of the first link 31 and the third link 33 are in the same plane, their swing trajectories may overlap in space. For example, when the first link 31 swings upward, it may collide with the downward swing path of the third link 33, forcing the link system to deviate from the designed movement range. In addition, the dense hinge points in the same plane will increase the local frictional heat, accelerate the lubrication failure, resulting in an increase in the movement resistance or even jamming. In one embodiment, the first link 31 is hinged to the frame 2 through the first hinge block, and the third link 33 is hinged to the frame 2 through the second hinge block. The first hinge block and the second hinge block are respectively located at both ends of the frame 2, and the first hinge block and the second hinge block are in different planes. The design of hinge blocks in different planes reduces the movement interference, improves the flexibility and durability of the mechanism, optimizes the smoothness of the multi-link cooperative movement, and reduces the mechanical wear.

[0033] Finally, it should be added that the dynamic balance mechanism 3 is a pure mechanical structure and does not require the intervention of the flight control system. Its adaptive sliding completely depends on gravity and geometric constraints and operates independently of the original attitude control module of the drone. The hinge axis of the hinge point between the fourth link 34 and the frame 2 at the dead center passes through a high-hardness steel needle roller bearing, and a rubber buffer pad is embedded in the limit groove to ensure that additional frictional force is generated through deformation after the roller is embedded. The material of the first link 31 is aerospace aluminum alloy, and the surface of the sliding track of the support block 6 is coated with a polytetrafluoroethylene coating to reduce the friction coefficient.

[0034] The working principle and process of the present invention: The center of gravity of the drone during the fire extinguishing process is adaptively adjusted through the dynamic balance mechanism 3. When the center of gravity shifts due to the consumption of the fire extinguishing agent, the support block 6 drives the linkage of the four-bar system under the action of gravity: the first link 31 and the third link 33 rotate around the hinge points on the frame 2, and respectively push and pull the two ends of the support block 6 through the fourth link 34 and the second link 32, so that it slides along the parallel direction of the frame 2. Since the first and third links 33 are of equal length and cross-arranged, their hyperbolic motion trajectories precisely match the center of gravity offset characteristics of the non-linear consumption of the fire extinguishing agent. The sliding displacement of the support block 6 is converted into non-linear torque compensation, effectively counteracting the unbalanced torque. During the whole process, the pure mechanical structure is driven by gravitational potential energy without external energy or electronic control. When the support block 6 slides to the equilibrium position, the fourth link 34 forms a dead center passing through the center with the first link 31 and the third link 33. At this time, the reaction force and friction force at the hinge point work together to achieve self-locking fixation. This design ensures the stability of the equilibrium state through geometric constraints and physical limits, such as the roller being embedded in the groove of the frame 2 to avoid secondary offsets caused by flight vibration or inertial rebound. The double-symmetry dynamic balance mechanism 3 further expands the adjustment freedom. The elastic support block 6 cooperates with the guide wheel to reduce the sliding resistance, and the parallel link design optimizes the force transmission direction. Finally, the flight stability and reliability of the drone in the complex environment of the fire scene are significantly improved.

[0035] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to make equivalent embodiments with equivalent changes, but as long as it does not depart from the technical content of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An unmanned aerial vehicle for marine rescue, characterized in that, The invention comprises a drone body, a frame arranged below the drone, a dynamic balancing mechanism arranged on the frame, and a fire extinguishing device arranged on the dynamic balancing mechanism, wherein the fire extinguishing device is arranged on the dynamic balancing mechanism through a supporting block, and the dynamic balancing mechanism comprises a first connecting rod, a second connecting rod, a third connecting rod, and a fourth connecting rod, wherein the two ends of the first connecting rod are respectively hinged to one end of the second connecting rod and the frame, the two ends of the third connecting rod are respectively hinged to the other end of the second connecting rod and the frame, the first connecting rod and the third connecting rod are cross-arranged, and the first connecting rod and the third connecting rod are located in different horizontal planes, The midpoint of the second connecting rod is hinged to one end of the support block, the midpoint of the first connecting rod is hinged to one end of the fourth connecting rod, and the other end of the fourth connecting rod is hinged to the other end of the support block. When the fire extinguishing agent in the fire extinguishing device is consumed and causes the center of gravity to shift, the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod are linked by gravity drive, so that the support block adaptively slides to the center of gravity position of the drone in a direction parallel to the frame to offset the nonlinear torque imbalance, and after the sliding is completed, it is self-locking and fixed between the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod.

2. The marine rescue drone according to claim 1, characterized in that, An L-shaped connecting rod is arranged at one end of the support block, one end of the L-shaped connecting rod is arranged perpendicularly to the other end of the support block, the other end of the L-shaped connecting rod is hinged to the midpoint of the second connecting rod, and a vertical connecting rod is arranged perpendicularly at the other end of the support block, and the vertical connecting rod is hinged to the other end of the fourth connecting rod.

3. The marine rescue drone according to claim 2, characterized in that, The vertical rod of the L-shaped connecting rod is equal to the vertical connecting rod.

4. The unmanned aerial vehicle for marine rescue according to claim 2, characterized in that, The frame is provided with a limiting groove matching the vertical connecting rod, and a roller is vertically arranged on the vertical connecting rod. When the support block slides to the center of gravity position, the roller is embedded in the groove.

5. The marine rescue drone according to claim 1, wherein, The number of the dynamic balancing mechanisms is two, and the two dynamic balancing mechanisms are symmetrically arranged on both sides of the support block.

6. The marine rescue drone according to claim 1, characterized in that, The support block is an elastic support block, an arc-shaped groove is provided on the elastic support block, an arc-shaped frame is provided on the frame, the fire extinguishing device is a fire extinguisher, the arc-shaped groove and the fire extinguisher are locked together, a guide wheel is provided on the arc-shaped frame, and the guide wheel is in contact with the outer wall of the fire extinguisher.

7. The marine rescue drone according to claim 1, characterized in that, The third connecting rod and the fourth connecting rod are arranged in parallel.

8. The unmanned aerial vehicle for marine rescue according to claim 1, wherein, The length of the fourth connecting rod is half of the length of the first connecting rod.

9. The marine rescue drone according to claim 1, wherein, The first connecting rod and the third connecting rod have the same length.

10. The marine rescue drone according to claim 9, characterized in that, The first connecting rod is hinged to the frame through a first hinge block, the third connecting rod is hinged to the frame through a second hinge block, the first hinge block and the second hinge block are respectively located at two ends of the frame, and the first hinge block and the second hinge block are located in different planes.

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