A force simulation device and method for a floating platform carrying a drone payload

Abstract

This application provides a force simulation device and method for a floating platform carrying a drone payload. A first water tank with a first space containing a solution is placed on the platform, and a second water tank is placed within the first space and floats on the solution. By changing the draft of the second water tank, as well as the wave height, wave period, density, and viscosity of the solution, the force simulation of the floating platform under the influence of seawater wave load is achieved. Furthermore, the real-time position information of the payload collected by the data acquisition and transmission module guides the drone's landing. The simulation device proposed in this application is characterized by its simple structure, low cost, and ease of implementation. By achieving geometric similarity, Vlad number similarity, and Reynolds number similarity between the simulation device and the floating platform, the operating principle of the simulation device can closely approximate the actual situation, making the simulation method practical.

Description

Technical Field

[0001] This application relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a force simulation device and method for a floating platform carrying UAV payloads. Background Technology

[0002] Floating platforms at sea, such as ships, offshore oil drilling platforms, and floating wind power platforms, are subject to significant wave loads in the marine environment. These wave loads also affect the equipment mounted on the floating platforms to varying degrees. With the development of unmanned aerial vehicle (UAV) technology, the application of UAV systems on these floating platforms is becoming increasingly widespread. However, the wave loads significantly impact the takeoff, landing, and parking of UAVs, limiting the further deployment of UAV systems on these platforms. To ensure successful landing of UAVs on floating platforms at sea, most systems first conduct simulated landing experiments using motion simulation systems. However, current motion simulation systems are mostly designed for vehicles, ships, and aircraft, employing multi-degree-of-freedom parallel mechanisms as motion simulation devices. Existing multi-degree-of-freedom, multi-drive simulation motion platforms are too expensive and require customization based on the technical specifications of the load, resulting in a long customization cycle. Summary of the Invention

[0003] The purpose of this application is to address the above problems by providing a force simulation device and method for a floating platform carrying a drone payload.

[0004] In a first aspect, this application provides a force simulation device for a floating platform carrying a drone payload, comprising:

[0005] A vehicle capable of traveling at a set speed under different road conditions;

[0006] A first water tank is mounted on the vehicle and forms a first space inside, which is filled with a solution.

[0007] A second water tank is located within the first space and floats on the solution; a second space is formed inside the second water tank.

[0008] The payload is located in the second space and is equipped with a data acquisition and transmission module. The data acquisition and transmission module is used to acquire the real-time position information of the payload and transmit it to the UAV when the vehicle is traveling at a set speed, so that the UAV can land at a designated location.

[0009] According to the technical solutions provided in certain embodiments of this application, a plurality of elastic members are distributed on the outer periphery of the side wall of the second water tank, and the elastic extension and contraction directions of the plurality of elastic members are respectively perpendicular to the corresponding side wall of the second water tank.

[0010] According to the technical solutions provided in certain embodiments of this application, the second water tank has an upward-facing open end, and a mounting base is provided on the side of the second water tank away from the open end, and the load is fixed on the mounting base.

[0011] According to the technical solutions provided in some embodiments of this application, the simulation device further includes a plurality of counterweights, and the draft of the second water tank can be changed by setting different numbers of the counterweights in the second space.

[0012] Secondly, this application provides a method for simulating the force of a floating platform carrying a drone payload, using any one of the force simulation devices described above, the method comprising the following steps:

[0013] S1. Obtain actual data of the floating platform to be simulated and its surrounding area, including the length and draft of the floating platform, as well as the wave height, wave period, density, and viscosity of the seawater in the area where the floating platform is located;

[0014] S2. Adjust the draft of the second water tank and the wave height, wave period, density and viscosity of the solution according to the actual data, so that the simulation device and the floating platform achieve geometric similarity, Vlad number similarity and Reynolds number similarity; select the vehicle's driving speed and driving road conditions when Vlad number similarity and Reynolds number similarity are achieved;

[0015] S3. Control the vehicle to travel at a selected speed on a selected road condition, and collect the real-time position information of the payload through the data acquisition and transmission module and send it to the UAV so that the UAV can land according to the received real-time position information.

[0016] According to the technical solution provided in certain embodiments of this application, step S2 includes:

[0017] Depending on the density and viscosity of the seawater in the area where the floating platform is located, the type of solution is changed or solute is added to the solution to adjust the density and viscosity of the solution.

[0018] According to the technical solutions provided in certain embodiments of this application, step S2 further includes:

[0019] Based on the length and draft of the floating platform, the counterweights are added or removed in the second space to change the draft of the second water tank, so that the simulation device achieves geometric similarity with the floating platform.

[0020] According to the technical solutions provided in certain embodiments of this application, step S2 further includes:

[0021] The vehicle is controlled to travel at different speeds under different road conditions, and the wave height and wave period of the solution fluctuation in the second space are adjusted so that the simulation device and the floating platform achieve Vlad number similarity and Reynolds number similarity.

[0022] Compared with the prior art, the beneficial effects of this application are as follows: This application provides a force simulation device for a floating platform carrying a drone payload. A first water tank with a first space containing a solution is installed on the vehicle. A second water tank is placed within the first space and floats on the solution. The inertial force of the vehicle during travel causes the solution to fluctuate, simulating the fluctuation of seawater in the area where the floating platform is located. The floating platform is simulated by having the second water tank float on the solution. The payload, placed within the second space, simulates the mission payload used in conjunction with the drone on the floating platform. Real-time location information is collected during the simulation experiment via a data acquisition and transmission module and transmitted to the drone to guide its simulated landing. The simulation device proposed in this application is simple in structure, low in cost, and easy to implement. During the force simulation of the floating platform, the device remains on land throughout, and operators can intervene at any time based on the drone's flight trajectory, avoiding the risk of the drone crashing during the sea simulation, thus offering high safety.

[0023] This application also provides a method for simulating the force of a floating platform carrying a drone payload. By achieving geometric similarity, Vlad number similarity, and Reynolds number similarity between the simulation device and the floating platform, the operating principle of the simulation device can be made close to the actual situation. The simulation method has the characteristics of practicality.

[0024] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a structural schematic diagram of a force simulation device for a floating platform carrying a drone payload, provided in Embodiment 1 of this application.

[0027] The text labels in the image represent:

[0028] 1. Carrier; 2. First water tank; 3. Second water tank; 4. Load; 5. Data acquisition and transmission module; 6. Mounting base; 7. Elastic component; 8. Solution; 9. Counterweight. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The descriptions in this section are merely illustrative and explanatory, and should not be construed as limiting the scope of protection of this application. Specifically, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort should fall within the scope of protection of this invention.

[0030] It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0031] Example 1

[0032] As mentioned in the background section, in view of the problems in the prior art, this embodiment provides a force simulation device for a floating platform carrying a drone payload, comprising:

[0033] Vehicle 1, which can travel at a set speed under different road conditions;

[0034] A first water tank 2 is mounted on the carrier 1 and forms a first space inside, which is filled with a solution.

[0035] The second water tank 3 is located within the first space and floats on the solution 8; a second space is formed inside the second water tank 3.

[0036] The payload 4 is located in the second space and is equipped with a data acquisition and transmission module 5. The data acquisition and transmission module 5 is used to acquire the real-time position information of the payload 4 and transmit it to the drone when the vehicle 1 is traveling at a set speed, so that the drone can land at a designated location.

[0037] Please refer to Figure 1 In this embodiment, the vehicle 1 is a pickup truck, and the first water tank 2 is placed in the truck bed. The first water tank 2 is the same size as the inner circumference of the truck bed, which can keep the position of the first water tank and its corresponding truck bed relatively fixed, avoiding changes in the position of the first water tank during the experiment and ensuring a more realistic simulation of the floating platform to be simulated. The second water tank 3 is smaller than the first water tank 2. The second water tank 3 floats on the solution 8 and can move with the fluctuations of the solution 8. The load 4 is used in the simulation device in conjunction with the UAV. The load 4 can wirelessly communicate and transmit data with the UAV through the data acquisition and transmission module 5 mounted on it. The data acquisition and transmission module 5 can be replaced with different types of sensors according to actual needs, and has the characteristics of high interchangeability and flexibility in use. In this embodiment, the data acquisition module 5 mainly uses a photoelectric tracking measurement system (composed of laser rangefinder, photoelectric guidance, inertial navigation, etc.) to collect the real-time position information of the load.

[0038] Before conducting the simulation experiment, the simulation device is adjusted according to the actual data of the floating platform to be simulated and its sea area, and the driving speed and road conditions of the vehicle during the experiment are determined. During use, the vehicle is controlled to drive at the selected driving speed and under the selected road conditions. Under the influence of the inertial force generated when the vehicle is driving, the solution 8 forms a sinusoidal wave in the first space, generating a load on the second water tank 3, which can simulate the force situation of the floating platform under the load of the sea waves. The data acquisition and transmission module 5 is used to collect the real-time position information of the load 4 and send it to the UAV. After receiving the position information, the flight control module of the UAV controls the UAV to land.

[0039] This application provides a first water tank 2 on the vehicle 1, the first water tank 2 having a first space containing the solution 8, and a second water tank 3 floating on the solution 8 within the first space. The inertial force of the vehicle during travel causes the solution 8 to fluctuate, simulating the fluctuation of seawater in the area where the floating platform is located. The floating of the second water tank 3 on the solution 8 simulates the floating platform. The load 4 is placed within the second space, simulating the mission load used in conjunction with the UAV on the floating platform. A data acquisition and transmission module 5 collects real-time location information during the simulation and transmits it to the UAV, guiding the UAV to simulate a landing. The entire simulation is conducted on land, and operators can intervene at any time based on the UAV's flight trajectory, avoiding the risk of the UAV crashing during the sea simulation, thus offering high safety. Furthermore, the simulation device has a simple structure, low cost, requires no customization, and is easy to implement.

[0040] In a preferred embodiment, a plurality of elastic elements 7 are distributed on the outer periphery of the side wall of the second water tank 3, and the elastic extension and contraction directions of the plurality of elastic elements 7 are respectively perpendicular to the corresponding side wall of the second water tank 3.

[0041] like Figure 1 As shown, the elastic element 7 is distributed on the outer periphery of the side wall of the second water tank 3. When the second water tank 3 is displaced by the fluctuating load of the solution 8, it acts as a buffer between the second water tank 3 and the first water tank 2 to prevent the second water tank 3 from colliding with the first water tank 2. At the same time, when the second water tank 3 moves closer to the side wall of the first water tank 2, the elastic element 7 is compressed and rebounds, so that the second water tank 3 is subjected to a reaction force and moves away from the side wall of the first water tank 2, preventing the second water tank 3 from sticking tightly to the side wall of the first water tank 2 under inertia and being unable to move, thus interfering with the simulation process. In this embodiment, the elastic element is a spring seat.

[0042] In a preferred embodiment, the second water tank 3 has an upward-facing open end, and a mounting base 6 is provided on the side of the second water tank 3 away from the open end, and the load 4 is fixed on the mounting base 6.

[0043] like Figure 1 As shown, the mounting base 6 includes four support rods and a mounting plate. The two ends of the four support rods are respectively fixedly connected to the second water tank 3 and the mounting plate. The mounting plate is used to mount the load 4, so that there is a gap between the load 4 and the second water tank 3, to prevent the solution 8 from accidentally entering the second space during the use of the simulation device and causing damage to the load 4 and the data acquisition and transmission module 5.

[0044] In a preferred embodiment, the simulation device further includes a plurality of counterweights 9, and the draft of the second water tank 3 can be changed by setting different numbers of the counterweights 9 in the second space.

[0045] like Figure 1 As shown, the simulation device is equipped with multiple counterweights 9. By increasing or decreasing the number of counterweights 9 in the second space, the draft of the second water tank 3 in the solution 8 can be changed, thereby enabling a realistic simulation of the draft of the floating platform in the seawater. In this embodiment, the counterweights 9 are made of lead pellets.

[0046] Example 2

[0047] This embodiment provides a method for simulating the force of a floating platform carrying a drone payload, using the force simulation device for a floating platform carrying a drone payload described in Embodiment 1. The method includes the following steps:

[0048] S1. Obtain actual data of the floating platform to be simulated and its surrounding area, including the length and draft of the floating platform, as well as the wave height, wave period, density, and viscosity of the seawater in the area where the floating platform is located;

[0049] The draft of the floating platform can be measured using a liquid level sensor; the wave height and wave period of the seawater can be measured using a drifting wave buoy in the seawater in the area where the floating platform is located. To make the results more applicable, the measurements are usually taken in weather conditions that are suitable for UAV flight and where the wave height and wave period of the seawater are relatively stable; the viscosity of the seawater is usually measured using the filter paper method.

[0050] S2. Adjust the draft of the second water tank 3 and the wave height, wave period, density and viscosity of the solution 8 according to the actual data, so that the simulation device and the floating platform achieve geometric similarity, Vlad number similarity and Reynolds number similarity; select the driving speed and driving road conditions of the vehicle 1 when Vlad number similarity and Reynolds number similarity are achieved;

[0051] In a preferred embodiment, step S2 includes:

[0052] Depending on the density and viscosity of the seawater in the area where the floating platform is located, the type of solution 8 is changed or solute is added to solution 8 to adjust the density and viscosity of solution 8.

[0053] Based on the length and draft of the floating platform, the counterweight 9 is added or removed in the second space to change the draft of the second water tank 3, so that the simulation device achieves geometric similarity with the floating platform.

[0054] The vehicle 1 is controlled to travel at different speeds under different road conditions, and the wave height and wave period of the solution 8 in the second space are adjusted so that the simulation device and the floating platform achieve Vlad number similarity and Reynolds number similarity.

[0055] Specifically, the density and viscosity of the solution 8 affect the draft of the second water tank 3 and are also important parameters for calculating the Reynolds number of the solution 8.

[0056] First, the density and viscosity of the solution 8 should be adjusted by obtaining the density and viscosity of the seawater in the area where the floating platform is located, so that the ratio of the density to viscosity of the solution 8 is equal to the ratio of the density to viscosity of the seawater.

[0057] Secondly, adjust the draft of the second water tank 3; the method is: obtain the length and draft of the floating platform, and the length of the second water tank 3, and then adjust the draft according to the geometric similarity formula:

[0058]

[0059] Wherein, L1 is the length of the second water tank, L is the length of the floating platform, H1 is the draft of the second water tank, and H is the draft of the floating platform; thus, it can be seen that by increasing or decreasing the lead pellets in the second space to adjust the draft of the second water tank 3, geometric similarity between the second water tank 3 and the floating platform can be achieved.

[0060] Finally, it is necessary to achieve the similarity of the Vlad numbers and the similarity of the Reynolds numbers; the formula for the similarity of the Vlad numbers is:

[0061]

[0062] The formula for Reynolds number similarity is:

[0063]

[0064] Where g is the acceleration due to gravity, ρ1 is the solution density, μ1 is the solution viscosity, ρ is the seawater density, μ is the seawater viscosity, V1 is the fluid velocity of the solution, and V is the fluid velocity of the seawater; under the above conditions, achieving the similarity of the Vlad number and the similarity of the Reynolds number are only related to the fluid velocity; the floating platform simulated in this embodiment is a moored or anchored offshore platform. According to its motion characteristics, considering only the vertical direction, the fluid velocity can be regarded as the vertical relative velocity between the wave and the platform, and the vertical relative velocity is the ratio of the wave height to the wave period.

[0065] The vehicle is controlled to conduct a large number of simulation experiments at different speeds and on different road conditions. During the experiment, the real-time position information of the load 4 at different time points is collected through the data acquisition and transmission module 5, so as to obtain the wave height and wave period of the waves generated by the solution 8 in the simulation experiment.

[0066] The wave height and wave period of the seawater in the area where the floating platform is located are obtained. From the large amount of data obtained in the above simulation experiment, the vehicle's speed and road conditions are selected when the ratio of the wave height to wave period of the solution 8 and the ratio of the wave height to wave period of the seawater are equal. The selected vehicle speed and road conditions are the vehicle speed and operating conditions used by the UAV during the simulated landing.

[0067] It should be noted that the aforementioned large number of simulation experiments are not required before each drone landing simulation. After conducting a large number of simulation experiments, the experimental data can be organized into a corresponding database. The database stores various driving speeds, various driving conditions corresponding to various driving speeds, and the ratio of wave height to wave period corresponding to each driving condition. In this way, when a drone landing simulation experiment is needed, the driving speed and driving conditions corresponding to the experiment can be obtained by searching the database using the ratio of wave height to wave period of the sea area to be simulated.

[0068] Among them, driving road conditions can refer to the road conditions of road sections with potholes or undulations selected in actual roads, or the road conditions of roads arranged in a specific site for experimental purposes.

[0069] It should also be noted that, considering the force conditions of large floating platforms, the influence of inertial force is more significant than that of viscous force. Therefore, when the range to be adjusted is too large and the Reynolds number and Vlad number cannot be satisfied at the same time, the Vlad number should be satisfied first. Under this condition, it is still possible to obtain results that are close to the actual situation.

[0070] S3. Control the vehicle 1 to travel at the selected speed on the selected road conditions, and collect the real-time position information of the payload 4 through the data acquisition and transmission module 5 and send it to the UAV so that the UAV can land according to the received real-time position information.

[0071] The photoelectric tracking measurement system of the data acquisition and transmission module 5 collects real-time position information and converts it into electrical signals, which are then transmitted to the UAV. The flight control module of the UAV receives the electrical signals and controls the UAV to land at a designated location based on its own position information. Here, the designated location is not a specific fixed location set by humans, but refers to any location within a certain distance range of the moving load. When the UAV plans its own flight path based on the real-time position information of the load and flies to a certain distance range from the load according to the planned flight path, it means that the UAV can land successfully in the simulation experiment, which also means that the UAV can land successfully on the simulated floating platform at sea.

[0072] As can be seen from the above, geometric similarity, Vlad number similarity, and Reynolds number similarity between the simulation device and the floating platform can be achieved through relatively independent adjustment methods. Therefore, the simulation device provided in this application operates in a manner close to the actual situation and has the function of simulating a moored or anchored offshore floating platform.

[0073] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A floating platform load-carrying unmanned aerial vehicle stress simulation device, characterized in that, include: The vehicle (1) can travel at a set speed on different road conditions; The first water tank (2) is mounted on the vehicle (1) and forms a first space inside, which is filled with a solution; The second water tank (3) is located within the first space and floats on the solution (8); a second space is formed inside the second water tank (3); The load (4) is located in the second space. The load (4) is equipped with a data acquisition and transmission module (5). The data acquisition and transmission module (5) is used to collect the real-time position information of the load (4) and transmit it to the drone when the vehicle (1) travels at a set speed, so that the drone can land at a designated location. The second water tank (3) has multiple elastic elements (7) distributed on the outer periphery of its side wall, and the elastic extension and contraction directions of the multiple elastic elements (7) are perpendicular to the corresponding side wall of the second water tank (3); The simulation device also includes multiple counterweights (9), and the draft of the second water tank (3) can be changed by setting different numbers of the counterweights (9) in the second space.

2. The floating platform-mounted unmanned aerial vehicle load stress simulation device according to claim 1, wherein, The second water tank (3) has an upward-facing open end, and a mounting base (6) is provided on the side of the second water tank (3) away from the open end, and the load (4) is fixed on the mounting base (6).

3. A stress simulation method for a floating platform carrying a UAV load, characterized in that, The method employing the force simulation device for a floating platform carrying a UAV payload as described in any one of claims 1-2 includes the following steps: S1. Obtain actual data of the floating platform to be simulated and its surrounding area, including the length and draft of the floating platform, as well as the wave height, wave period, density, and viscosity of the seawater in the area where the floating platform is located; S2. Adjust the draft of the second water tank (3) and the wave height, wave period, density and viscosity of the solution (8) according to the actual data so that the simulation device and the floating platform achieve geometric similarity, Vlad number similarity and Reynolds number similarity; select the driving speed and driving conditions of the vehicle (1) when the Vlad number similarity and the Reynolds number similarity are achieved; S3. Control the vehicle (1) to travel at the selected speed on the selected road conditions, and collect the real-time position information of the load (4) through the data acquisition and transmission module (5) and send it to the UAV so that the UAV can land according to the received real-time position information.

4. The force simulation method for a floating platform carrying a UAV payload according to claim 3, characterized in that, Step S2 includes: Depending on the density and viscosity of the seawater in the area where the floating platform is located, the type of solution (8) is changed or solute is added to the solution (8) to adjust the density and viscosity of the solution (8).

5. The method for simulating the force on a floating platform carrying a UAV payload according to claim 4, characterized in that, Step S2 also includes: Based on the length and draft of the floating platform, the counterweight (9) is added or removed in the second space to change the draft of the second water tank (3), so that the simulation device and the floating platform achieve geometric similarity.

6. The method for simulating the force on a floating platform carrying a UAV payload according to claim 5, characterized in that, Step S2 also includes: Control the vehicle (1) to travel at different speeds under different road conditions, adjust the wave height and wave period of the solution (8) in the second space, so that the simulation device and the floating platform achieve Vlad number similarity and Reynolds number similarity.

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