Marine organism imitating jet propulsion device and control method

Abstract

The invention discloses a marine organism imitating jet propulsion device and a control method. The marine organism imitating jet propulsion device comprises a plurality of jet devices, each jet device is installed on the tail propulsion section and comprises a jet device body, an ignition assembly and a piston, a jet pipe cavity is formed in the jet device body, the jet device piston is arranged in the jet pipe cavity, and the jet device piston is arranged in the jet pipe cavity. The jet device piston divides the jet pipe cavity into a liquid cavity and a mixed gas cavity, the jet device piston can move so as to adjust the volume of the liquid cavity and the volume of the mixed gas cavity, and a liquid outlet is formed in the jet device body; the high-pressure butane gas source assembly is arranged in the tail thrust section; the high-pressure oxygen source assembly is arranged in the tail pushing section; an output port of the high-pressure butane gas source assembly and an output port of the high-pressure oxygen gas source assembly are respectively communicated with an input port of the surge bin assembly, and an output port of the surge bin assembly is communicated with the mixed gas cavity.

Description

Technical Field

[0001] The present application relates to the field of biomimetic marine technology, and specifically relates to a biomimetic marine jet propulsion device and a control method for the biomimetic marine jet propulsion device. Background Art

[0002] Underwater thrusters are divided into various types according to different overall structural characteristics and working forms, mainly including propeller propulsion, pump-jet propulsion, gliding propulsion, and bionic propulsion. Propeller propulsion has a simple structure, small volume, mature development, and strong reliability, and is widely used in small underwater vehicles.

[0003] Propeller propulsion performs well at low speeds. However, as the blade rotation speed increases, its mechanical efficiency gradually decreases, and cavitation phenomena will occur due to the pressure difference between the blade back and the pressure, resulting in blade vibration erosion and noise problems. In addition, to achieve underwater steering, propeller propulsion needs to deploy multiple propeller thrusters for differential steering or use a steering rudder for cooperation, but this will bring problems such as a decrease in hydrodynamic performance, a large turning radius, slow turning, and poor maneuverability. Therefore, although propeller propulsion is reliable and effective, there are significant differences in performance between low-speed and high-speed scenarios, and it cannot achieve flexible underwater movement.

[0004] Pump-jet propulsion uses a combined hydrodynamic propulsion, which consists of an axisymmetric annular duct and a rotating cascade and a stationary cascade inside the duct. The rotating cascade (rotor) is usually located in an expanding duct, so that the water flow passing through the rotor blades decelerates to delay cavitation generation, improve its cavitation performance, and increase the quiet cruising speed. However, the structure of the pump-jet thruster is relatively complex, the volume is large, and the thrust vectoring degree is relatively low. Therefore, it is not suitable for underwater vehicles with high maneuverability requirements.

[0005] Gliding propulsion uses buoyancy for movement. After the carrier absorbs water, the net buoyancy decreases, resulting in sinking. When sinking, the relative vertical movement of the water above the wing generates a forward lift force. By discharging water at a given depth, the glider increases its net buoyancy and floats to the surface. This method has strong endurance and a long sailing cycle, but the sailing speed is low, it can only be applied to shallow water scenarios, and it is greatly affected by water flow.

[0006] Generally speaking, currently, small and medium-sized underwater submersibles generally adopt traditional propulsion forms such as propellers and pump-jets, lacking in maneuverability, and lacking solutions to improve the maneuverability of the vehicle in the face of complex mission scenarios. Summary of the Invention

[0007] The purpose of the present invention is to provide a biomimetic marine jet propulsion device to at least solve one of the above technical problems.

[0008] One aspect of the present invention provides a biomimetic marine jet propulsion device for an underwater drone, and the biomimetic marine jet propulsion device includes:

[0009] A plurality of ejectors, each ejector is installed on the tail propulsion section of the underwater drone, and each ejector includes an ejector body, an ignition assembly and a piston. A jet pipe cavity is arranged inside the ejector body, the ejector piston is arranged in the jet pipe cavity, the ejector piston divides the jet pipe cavity into a liquid cavity and a mixed gas cavity, and the mixed gas cavities communicate with each other. The ejector piston can move to adjust the volume of the liquid cavity and the volume of the mixed gas cavity. A liquid outlet is arranged on the ejector body;

[0010] A high-pressure butane gas source assembly, which is arranged inside the tail propulsion section;

[0011] A high-pressure oxygen gas source assembly, which is arranged inside the tail propulsion section;

[0012] A buffer tank assembly, the output ports of the high-pressure butane gas source assembly and the high-pressure oxygen gas source assembly are respectively communicated with the input port of the buffer tank assembly, and the output port of the buffer tank assembly is communicated with the mixed gas cavity; wherein,

[0013] The high-pressure butane gas source assembly is used to introduce high-pressure butane gas into the buffer tank assembly;

[0014] The high-pressure oxygen gas source assembly is used to introduce high-pressure oxygen into the buffer tank assembly;

[0015] The buffer tank assembly is used to introduce high-pressure butane gas into each mixed gas cavity after receiving high-pressure butane gas to a first preset pressure and to introduce high-pressure oxygen into each mixed gas cavity after receiving high-pressure oxygen to a second preset pressure;

[0016] The ignition assembly is used to generate an ignition spark in the mixed gas cavity, so that the mixed gas of oxygen and butane in each mixed gas cavity explodes, and the piston is pushed by the pressure gas generated by the explosion. The piston is pushed by the pressure gas to discharge the liquid in the liquid cavity from the liquid outlet to generate a thrust for pushing the underwater drone to move.

[0017] Optionally, the buffer tank assembly includes:

[0018] A buffer bin body, a buffer bin cavity is arranged inside the buffer bin body, a butane inlet, an oxygen inlet and a buffer bin gas outlet communicating with the buffer bin cavity are arranged on the buffer bin body, the high-pressure butane gas source assembly is communicated with the butane inlet, the high-pressure oxygen gas source assembly is communicated with the oxygen inlet, and the buffer bin gas outlet is communicated with the mixed gas cavity;

[0019] A pressure sensor, the pressure sensor is arranged inside the buffer bin cavity and is used for measuring the pressure inside the buffer bin cavity;

[0020] A buffer bin piston, the buffer bin piston is arranged inside the buffer bin cavity, and by controlling the movement of the buffer bin piston, the gas inside the buffer bin cavity can enter the mixed gas cavity.

[0021] Optionally, the marine organism imitating jet propulsion device further includes a vacuum pump, the vacuum pump is arranged inside the tail thrust section, the vacuum pump is communicated with the mixed gas cavity through a pipeline, and the vacuum pump can evacuate the mixed gas cavity.

[0022] The present application also provides a control method for a marine organism imitating jet propulsion device, and the control method for the marine organism imitating jet propulsion device includes:

[0023] Obtain control requirement information;

[0024] Obtain mixed gas requirement information and ignition strategy information according to a control instruction;

[0025] Control the high-pressure butane gas source assembly to fill the buffer bin body with butane gas to a first preset pressure value according to the mixed gas requirement information;

[0026] Control the butane gas inside the buffer bin body to be filled into the mixed gas cavity of one or more ejectors after reaching the first preset pressure value according to the ignition strategy information;

[0027] After the butane gas inside the buffer bin body is emptied, control the high-pressure oxygen gas source assembly to fill the buffer bin body with oxygen to a second preset pressure value according to the mixed gas requirement information;

[0028] Control the oxygen inside the buffer bin body to be filled into the mixed gas cavity of one or more of each ejector after reaching the second preset pressure value according to the ignition strategy information;

[0029] Control the gas in the mixed gas cavity with oxygen and butane gas to explode, so that one or more of each ejector generate propulsion force.

[0030] Optionally, the control requirement information includes a linear propulsion requirement. When the control requirement information is a linear propulsion requirement, the ignition strategy information is that the mixing gas chambers of all jet ejectors need to be filled with oxygen and butane gas, or the mixing gas chambers of two diagonally opposite jet ejectors need to be filled with oxygen and butane gas;

[0031] When the control requirement information is a linear propulsion requirement, the linear propulsion requirement includes demand thrust information;

[0032] Obtain the mixing gas demand information according to the demand thrust information.

[0033] Optionally, the obtaining the mixing gas demand information according to the demand thrust information includes:

[0034] Obtain the propulsion force information of each jet ejector that needs to work according to the demand thrust information;

[0035] Obtain a preset propulsion force and time database, where the propulsion force and time database includes at least one relationship curve of single-jet ejector propulsion force and time and the volume of the mixed gas of oxygen and butane gas corresponding to each relationship curve of single-jet ejector propulsion force and time;

[0036] Select the volume of the mixed gas of oxygen and butane gas corresponding to the relationship curve of single-jet ejector propulsion force and time that meets the propulsion force information according to the propulsion force information of each jet ejector that needs to work;

[0037] Obtain the mixing ratio of oxygen and butane gas;

[0038] Obtain the required volume of butane gas and the required volume of oxygen according to the volume of the mixed gas of oxygen and butane gas and the mixing ratio of oxygen and butane gas;

[0039] Obtain the pressure information that the pressure sensor needs to detect when the buffer tank body is filled with butane gas according to the required volume of butane gas;

[0040] Obtain the pressure information that the pressure sensor needs to detect when the buffer tank body is filled with oxygen according to the required volume of oxygen.

[0041] Optionally, the control method for the marine organism imitating jet propulsion device further includes:

[0042] Establish the preset propulsion force and time database.

[0043] Optionally, the establishing the preset propulsion force and time database includes:

[0044] Obtain each relationship curve of single-jet ejector propulsion force and time through the following simultaneous equations:

[0045]

[0046] Among them,

[0047] i is the time point, m P is the mass of the ejector piston, m J is the mass of a single ejector excluding the ejector piston part, and are the velocities of the ejector piston at the i-th time point and the (i - 1)-th time point respectively, v i and v i-1 are the velocities of a single ejector at the i-th time point and the (i - 1)-th time point respectively, ρ is the density of water, S N is the cross-sectional area of the liquid outlet, and are the liquid velocities passing through the liquid outlet at the i-th time point and the (i - 1)-th time point respectively, and are the liquid velocities in the cylindrical section of the liquid chamber at the i-th time point and the (i - 1)-th time point respectively, and are the total liquid momentum sums in the tail spray section of the liquid chamber at the i-th time point and the (i - 1)-th time point respectively, and are the liquid masses in the cylindrical section of the liquid chamber at the i-th time point and the (i - 1)-th time point respectively, and are the masses of the discharged water at the i-th time point and the (i - 1)-th time point respectively,, ∑W i is the total work done by the system between the (i - 1)-th time point and the i-th time point, and are the total kinetic energies of the system at the i-th time point and the (i - 1)-th time point respectively.

[0048] Optionally, the control requirement information includes a course deviation requirement. When the control requirement information is a course deviation requirement, the ignition strategy information is to select one or two of the mixed gas chambers of each ejector to fill with oxygen and butane gas according to the course deviation requirement;

[0049] When the control requirement information is a course deviation requirement, the course deviation requirement includes deviation angle information and deviation rate information;

[0050] Obtain the mixed gas requirement information according to the deviation angle information and the deviation rate information.

[0051] Optionally, the obtaining the mixed gas requirement information according to the deviation angle information and the deviation rate information includes:

[0052] Get the trained neural network;

[0053] The offset angle information and the offset rate information are input into a trained neural network to obtain a single ejector propulsion force and time relationship curve.

[0054] Beneficial Effects

[0055] The advantages of the marine life-imitation jet propulsion device of the present application are:

[0056] 1. A jet propulsion scheme imitating cephalopods is proposed. By optimizing the shape and physical size of the tail nozzle section, the pressure gradient is stabilized during the injection process, avoiding the violent interaction between the high-pressure fluid and the low-pressure water body. The method of using hydrocarbon and oxygen explosion to drive the piston to generate the jet is adopted to avoid the strong vortex and shear effect caused by traditional propellers and turbines, thereby effectively reducing the cavitation effect and cavitation caused by traditional propulsion forms.

[0057] 2. We designed and manufactured an underwater repeatable jet propulsion device based on butane-oxygen explosion. Through the design of the air pressure feedback buffer chamber, the flow rate of high-pressure gas entering the mixed gas cavity was reduced. Combined with the gas volume-air pressure calculation model, the constant gas fuel volume was accurately controlled to achieve stable impulse combustion jet propulsion. Butane-oxygen was selected as the explosive reactant, and the reaction products were easy to handle and discharge, which improved the sustainability of the explosive jet propulsion. The device configuration and material strength were determined through fluid-solid coupling analysis, ensuring the device's high temperature and high pressure resistance reliability while reducing weight.

[0058] 3. The method of the present application establishes a mathematical analysis model for explosive jets, which reduces the time cost and experimental cost of optimizing the physical parameters of the thruster through finite element simulation and actual experiments, and can be used as a method to quickly construct a data set of thruster jet propulsion results.

[0059] 4. The present application proposes a yaw and acceleration control strategy for a vehicle with four-tube linkage propulsion, which enhances the underwater thruster's ability to quickly change operating conditions. The four-tube layout generates a direction-controllable resultant force by adjusting the combination of nozzle opening (such as synchronous injection of single-side nozzles, alternating injection of diagonal nozzles, etc.), thereby achieving precise yaw control. Through the synchronization of multi-tube injection and rapid adjustment of the amount of gas injection, the vehicle can switch from cruising to high speed in an instant, thereby improving the ability to respond to changing operating conditions. At the same time, a neural network model is introduced for vehicle decision analysis, and the nozzle opening sequence, injection duration and thrust size are dynamically optimized based on real-time underwater sensor data (such as flow rate, depth, target position, etc.), to ensure that the thrust output accurately matches the navigation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1It is a schematic structural diagram of an ocean - organism - imitating jet propulsion device according to an embodiment of the present application.

[0061] Figure 2 It is another schematic diagram of a jet ejector according to an embodiment of the present application. Figure 3 It is a schematic structural diagram of a jet - ejector body according to an embodiment of the present application.

[0062] Reference numerals:

[0063] 1, jet ejector; 2, tail - propulsion section; 11, jet - ejector body, 12, ignition assembly; 13, jet - ejector piston; 111, liquid chamber; 112, mixed - gas chamber; 3, buffer - bin body; 4, vacuum pump; 5, high - pressure butane gas - source assembly; 6, high - pressure oxygen gas - source assembly. Detailed implementation manners

[0064] To make the purpose, technical solutions and advantages of the implementation of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The described embodiments are part of the embodiments of the present application, rather than all of them. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application. The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0065] As Figure 1 shown, the ocean - organism - imitating jet propulsion device is used for an underwater drone. The ocean - organism - imitating jet propulsion device includes a plurality of jet ejectors 1, a high - pressure butane gas - source assembly 5, a high - pressure oxygen gas - source assembly 6, and a buffer - bin assembly.

[0066] Refer to Figure 1 , each jet ejector 1 is installed outside the tail - propulsion section 2 of the underwater drone. There is a 90 - degree interval between each jet ejector and another adjacent jet ejector 1. Each jet ejector 1 includes a jet - ejector body 11, an ignition assembly 12, and a jet - ejector piston 13.

[0067] Refer to Figure 3, inside each injector body 11, there is a jet pipe cavity provided. The injector piston is arranged inside the jet pipe cavity. The injector piston divides the jet pipe cavity into a liquid cavity 111 and a mixed gas cavity 112. Each mixed gas cavity 112 is communicated through a multi-way valve. The injector piston 31 can move to adjust the volume of the liquid cavity 111 and the volume of the mixed gas cavity 112. A liquid outlet is arranged on the injector body; in this embodiment, through the control of the multi-way valve, the gas can enter the mixed gas cavity 112 of any injector as needed.

[0068] The high-pressure butane gas source assembly 5 is arranged inside the tail thrust section 2;

[0069] The high-pressure oxygen gas source assembly 6 is arranged inside the tail thrust section 2;

[0070] The output port of the high-pressure butane gas source assembly and the output port of the high-pressure oxygen gas source assembly are respectively communicated with the input port of the buffer bin assembly. The output port of the buffer bin assembly is communicated with the mixed gas cavity; wherein,

[0071] The high-pressure butane gas source assembly is used to introduce high-pressure butane gas into the buffer bin assembly;

[0072] The high-pressure oxygen gas source assembly is used to introduce high-pressure oxygen into the buffer bin assembly;

[0073] The buffer bin assembly is used to introduce the high-pressure butane gas into each mixed gas cavity after receiving the high-pressure butane gas to the first preset pressure and to introduce the high-pressure oxygen into each of the mixed gas cavities after receiving the high-pressure oxygen to the second preset pressure;

[0074] The ignition assembly is used to generate a spark for ignition inside the mixed gas cavity, so that the mixed gas of oxygen and butane in each mixed gas cavity 112 explodes. Thus, the pressure gas generated by the explosion pushes the piston. The piston is acted on by the pressure gas to push the liquid in the liquid cavity to discharge from the liquid outlet, so as to generate a thrust for pushing the underwater drone to move.

[0075] The advantages of the biomimetic marine organism jet propulsion device of the present application are as follows:

[0076] 1. A jet propulsion scheme imitating cephalopod organisms is proposed, with weak propulsion cavitation effect, strong fast-changing working condition ability, and high propulsion efficiency, which can fully make up for the disadvantages of poor maneuverability of existing underwater propulsion technologies and easy cavitation of propellers.

[0077] 2. We designed and manufactured an underwater repeatable jet propulsion device based on butane-oxygen explosion. Through the design of the air pressure feedback buffer tank, the constant amount of gas fuel is precisely controlled in combination with the simultaneous formula, thereby achieving stable impulse combustion jet propulsion. Butane-oxygen is selected as the explosive reactant, and the reaction products are easy to handle and discharge, which improves the sustainability of the explosion jet propulsion. The device configuration and material strength are determined through fluid-solid coupling analysis, and the high temperature and high pressure resistance reliability of the device are improved while reducing the weight.

[0078] 3. The method of the present application establishes a mathematical analysis model for explosive jets, which reduces the time cost and experimental cost of optimizing the physical parameters of the thruster through finite element simulation and actual experiments, and can be used as a method to quickly construct a data set of thruster jet propulsion results.

[0079] 4. This application proposes a yaw and acceleration control strategy for a four-tube linkage propulsion vehicle, introduces a neural network model for vehicle decision analysis, and achieves accurate underwater deflection and efficient acceleration of the vehicle.

[0080] See also Figure 2 In this embodiment, the buffer bin assembly includes a buffer bin body 3, a pressure sensor and a buffer bin piston, wherein:

[0081] A buffer bin cavity is provided in the buffer bin body 3, and a butane inlet, an oxygen inlet and a buffer bin gas outlet are provided on the buffer bin body 3, which are connected to the buffer bin cavity. The high-pressure butane gas source component is connected to the butane inlet through a solenoid valve, the high-pressure oxygen gas source component is connected to the oxygen inlet through a solenoid valve, and the buffer bin gas outlet is connected to the mixed gas cavity through a solenoid valve;

[0082] The pressure sensor is arranged in the buffer chamber, and is used to measure the pressure in the buffer chamber;

[0083] The buffer bin piston is arranged in the buffer bin cavity, and the gas in the buffer bin cavity can enter the mixed gas cavity by controlling the movement of the buffer bin piston.

[0084] In this embodiment, the marine life-simulating jet propulsion device further includes a vacuum pump 4, which is arranged in the tail thrust section. The vacuum pump 4 is connected to the mixed gas chamber through a pipeline, and the vacuum pump can vacuum the mixed gas chamber.

[0085] The present application also provides a control method for a marine life-simulating jet propulsion device, the control method for a marine life-simulating jet propulsion device comprising:

[0086] Obtain control requirement information;

[0087] Obtain the mixed gas demand information and the ignition strategy information according to the control instruction;

[0088] Control the high-pressure butane gas source assembly to fill the buffer bin body with butane gas to the first preset pressure value according to the mixed gas demand information;

[0089] Control the butane gas in the buffer bin body to be filled into one or more of the mixing gas cavities of each injector after reaching the first preset pressure value according to the ignition strategy information;

[0090] After the butane gas in the buffer bin body is emptied, control the high-pressure oxygen gas source assembly to fill the buffer bin body with oxygen to the second preset pressure value according to the mixed gas demand information;

[0091] Control the oxygen in the buffer bin body to be filled into one or more of the mixing gas cavities of each injector after reaching the second preset pressure value according to the ignition strategy information;

[0092] Control the gas in the mixing gas cavity with oxygen and butane gas to explode, so that one or more of each injector generate thrust.

[0093] In this embodiment, the control demand information includes a linear propulsion demand. When the control demand information is a linear propulsion demand, the ignition strategy information is that the mixing gas cavities of all injectors need to be filled with oxygen and butane gas, or the mixing gas cavities of two diagonally opposite injectors need to be filled with oxygen and butane gas;

[0094] When the control demand information is a linear propulsion demand, the linear propulsion demand includes demand thrust information;

[0095] Obtain the mixed gas demand information according to the demand thrust information.

[0096] In this embodiment, the obtaining the mixed gas demand information according to the demand thrust information includes:

[0097] Obtain the propulsion force information of each injector that needs to work according to the demand thrust information;

[0098] Obtain a preset propulsion force and time database, and the propulsion force and time database includes at least one single-injector propulsion force and time relationship curve and the volume of the mixed gas of oxygen and butane gas corresponding to each single-injector propulsion force and time relationship curve;

[0099] Select the volume of the mixed gas of oxygen and butane gas corresponding to the single-injector propulsion force and time relationship curve that meets the propulsion force information according to the propulsion force information of each injector that needs to work;

[0100] Obtain the mixing ratio of oxygen and butane gas;

[0101] Obtain the required volume of butane gas and the required volume of oxygen according to the volume of the mixed gas of oxygen and butane gas and the mixing ratio of oxygen and butane gas;

[0102] Obtain the pressure information that the pressure sensor needs to detect when the buffer tank body is filled with butane gas according to the required volume of the butane gas;

[0103] Obtain the pressure information that the pressure sensor needs to detect when the buffer tank body is filled with oxygen according to the required volume of the oxygen.

[0104] In this embodiment, the control method for the marine organism - imitating jet propulsion device further includes:

[0105] Establish the preset propulsion force and time database.

[0106] In this embodiment, establishing the preset propulsion force and time database includes:

[0107] Obtain the relationship curve of the propulsion force and time of each single injector through the following simultaneous equations:

[0108]

[0109] Where,

[0110] i is the time point, m P is the mass of the injector piston, m J is the mass of the part of a single injector except the injector piston, and are the velocities of the injector piston at the i - th time point and the (i - 1)-th time point respectively, v i and v i-1 are the velocities of a single injector at the i - th time point and the (i - 1)-th time point respectively, ρ is the density of water, S N is the cross - sectional area of the liquid outlet, and are the liquid velocities passing through the liquid outlet at the i - th time point and the (i - 1)-th time point respectively, and are the liquid velocities of the cylindrical section of the liquid cavity at the i - th time point and the (i - 1)-th time point respectively, and are the total liquid momentum of the tail - spray section of the liquid cavity at the i - th time point and the (i - 1)-th time point respectively, and are the liquid masses of the cylindrical section of the liquid cavity at the i - th time point and the (i - 1)-th time point respectively, and The mass of the discharged water at the i-th time point and the (i - 1)-th time point respectively, ∑W i is the total work done by the system between the (i - 1)-th time point and the i-th time point, and are the total kinetic energy of the system at the i-th time point and the (i - 1)-th time point respectively.

[0111] For the convenience of understanding, the relevant content of the simultaneous equations is described in detail below. It can be understood that this description does not constitute any limitation to this application.

[0112] Regard a single jet thruster as a whole. In a complete jet cycle t, the time period can be differentially divided into n units, namely 1, 2, 3, 4.....i.

[0113] Since the time scale of the deflagration process is smaller than that of the complete jet process, the initial state of the jet can be simplified as follows: The initial high pressure generated by the deflagration reaction is P. Assume that the temperature conduction in the water body by the thruster is rapid, and the reaction gas in the combustion chamber adiabatically expands to push the piston to move. In the i-th time period, the volume of gas expansion where is the volume of the discharged water, and the mass of the discharged water satisfies ρ is the density of water, S N is the area of the tail nozzle, S N = πr 2 , Δt is the time interval between two adjacent time points. At the time from t i-1 to t i moment, one of the simultaneous equations in this application is:

[0114]

[0115] In this formula, m J and v i are the mass of the thruster and the velocity at the i-th time point respectively, m P and are the mass of the piston and the velocity at the i-th time point respectively, is the liquid mass at the cylindrical end part of the thruster at the i-th time point, and this mass is equal to the liquid mass at the cylindrical end part at the previous time point minus the liquid mass discharged at the current time point, that is where the velocity of the piston is equal to the velocity of the liquid in the cylindrical section,

[0116] and are the total momentum of the liquid in the tail nozzle section at t i and t i-1 moments, and satisfy the following relationship:

[0117]

[0118] Where, cross-sectional area A(z) = πr(z) 2 , z is the distance from the starting position of the tail nozzle section along the tail nozzle section axis, and the radius r(z) of the tail nozzle section cross section changes linearly with the position, gradually decreasing from R to r, R is the inner radius of the cylindrical section, and r is the inner radius of the tail nozzle. Then we can get:

[0119]

[0120] is the velocity distribution of the liquid in the tail spray section with position. According to the incompressibility of water,

[0121]

[0122] The combined equations can simplify the expression of the tail nozzle momentum:

[0123]

[0124] Among them, L 2 is the length of the tail nozzle section.

[0125] The liquid velocity at the tail nozzle and the liquid velocity in the cylindrical section satisfy the following relationship:

[0126]

[0127] The system also satisfies the law of functional conversion, that is, another one of the simultaneous formulas of the present application is:

[0128]

[0129] ∑W i is the total work done by the system in time unit i, satisfying:

[0130]

[0131] in, The work done by gas combustion, explosion and expansion. From the i-1th time unit to the ith time unit, Resistance is the characteristic resistance of the piston in water, C D is the resistance coefficient, A is the piston cross-sectional area, and v is the piston velocity. The average force of gas expansion is converted through pressure and piston cross-sectional area. Assuming that gas expansion is an adiabatic process,

[0132]

[0133] P i V iγ = Pi-1 V i-1 γ ;

[0134]

[0135] wherein the volume of the gas satisfies is the average pressure, P i and P i-1 are the gas chamber pressures at the i-th time point and the (i - 1)-th time point respectively, γ is the adiabatic coefficient, R is the piston radius, V i and V i-1 are the volumes of the mixed gas chamber at the i-th time point and the (i - 1)-th time point respectively;

[0136] is the frictional force between the piston and the inner wall of the tube, S P = πR 2 , μ is the friction coefficient, F N is the pressure between the piston and the wall surface, d i is the piston displacement within the i-th time point.

[0137] is the sum of the head loss due to friction along the pipe and the local head loss.

[0138] h f is the head loss coefficient due to friction along the pipe and satisfies: f is a quantity related to the inner wall roughness and the Reynolds number, L i is the total length of the liquid in the cylindrical section at the i-th time point.

[0139] h l is the local head loss and satisfies: K is a quantity related to the ratio of the inner diameter change and the contraction angle.

[0140] In this embodiment, the control requirement information includes a course deviation requirement. When the control requirement information is the course deviation requirement, the ignition strategy information is to select one or two of the mixed gas chambers of each ejector to fill with oxygen and butane gas according to the course deviation requirement;

[0141] When the control requirement information is the course deviation requirement, the course deviation requirement includes deviation angle information and deviation rate information;

[0142] Obtain the mixed gas requirement information according to the deviation angle information and the deviation rate information.

[0143] In this embodiment, the obtaining the mixed gas requirement information according to the deviation angle information and the deviation rate information includes:

[0144] Obtain a trained neural network;

[0145] Input the offset angle information and the offset rate information into the trained neural network, so as to obtain the relationship curve between the single injector propulsion force and time.

[0146] In this embodiment, the neural network can be trained in the following manner:

[0147] Calculate the relationship curve between the single injector propulsion force and time for each offset angle information and each offset rate information respectively through formulas. Specifically, the relationship curve between the single injector propulsion force and time is obtained through the following formula:

[0148] where θ is the offset angle, d is the arm length of the propulsion force acting on the vehicle, I zz is the moment of inertia of the vehicle, and T is the offset time.

[0149] For each relationship curve between the single injector propulsion force and time obtained through the formula (multiple relationship curves between the single injector propulsion force and time can be obtained for each offset angle information and each offset rate information). For example, when the offset angle information is 30 degrees and the offset rate information is 1 degree per second, multiple relationship curves between the single injector propulsion force and time may be obtained through the above formula. When the offset angle information is 30 degrees and the offset rate information is 2 degrees per second, multiple relationship curves between the single injector propulsion force and time may also appear. Or when the offset angle information is 32 degrees and the offset rate information is 2 degrees per second, multiple relationship curves between the single injector propulsion force and time may also appear.

[0150] After obtaining these relationship curves between the single injector propulsion force and time, remove some unreasonable relationship curves between the single injector propulsion force and time through simulation or experimental simulation, and use the other relationship curves between the single injector propulsion force and time as the training relationship curves between the single injector propulsion force and time.

[0151] In this embodiment, each group of relationship curves between the single injector propulsion force and time corresponds to different gas volume inputs, and the initial pressure changes controllably. Under multiple groups of different relationship curves between the single injector propulsion force and time, pre-training can be performed through the neural network model and deployed in the control system of the bio-inspired ocean vehicle jet propulsion device to achieve precise control of the deflection pose.

[0152] In this embodiment, the index of the optimal relationship curve between the single injector propulsion force and time output by the neural network is i ＊ The corresponding propulsion force distribution meets the pose deflection target and has the lowest penalty in terms of fuel consumption and structural wear.

[0153] In this embodiment, the total penalty function of the neural network is defined as follows:

[0154] L(F i ) = w 1 ·L angle +w 2 ·L fuel +w 3 ·L struct ;

[0155] Deflection angle error loss of the neural network:

[0156]

[0157] Fuel loss loss function of the neural network:

[0158]

[0159] Structural safety threshold loss function of the neural network:

[0160] L struct = max(0, max(P initial ) - P threshold ) 2 .

[0161] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of the present invention claimed.

Claims

1. A marine life-like jet propulsion device for underwater drones, characterized in that: The marine life imitation jet propulsion device comprises: A plurality of ejectors (1), each ejector (1) being installed at the tail thrust section (2) of the underwater drone, each ejector (1) comprising an ejector body (11), an ignition assembly (12) and an ejector piston (13), a jet lumen being arranged inside the ejector body (11), the ejector piston being arranged in the jet lumen, the ejector piston dividing the jet lumen into a liquid lumen (111) and a mixed gas lumen (112), the mixed gas cavities (112) being connected via a multi-way valve, the ejector piston (31) being able to move so as to adjust the volume of the liquid lumen (111) and the volume of the mixed gas lumen (112), and a liquid outlet being arranged on the ejector body; A high-pressure butane gas source component (5), wherein the high-pressure butane gas source component (5) is arranged inside the tail thrust section (); A high-pressure oxygen gas source component (6), wherein the high-pressure oxygen gas source component (6) is arranged inside the tail thrust section (); A buffer bin assembly, the output port of the high-pressure butane gas source assembly and the output port of the high-pressure oxygen gas source assembly are respectively connected to the input port of the buffer bin assembly, and the output port of the buffer bin assembly is connected to the mixed gas chamber; wherein, The high-pressure butane gas source component is used to introduce high-pressure butane gas into the buffer bin component; The high-pressure oxygen gas source component is used to introduce high-pressure oxygen into the buffer bin component; The buffer bin assembly is used to pass the high-pressure butane gas into each mixed gas chamber after receiving the high-pressure butane gas to a first preset pressure, and is used to pass the high-pressure oxygen into each mixed gas chamber after receiving the high-pressure oxygen to a second preset pressure; The ignition assembly is used to generate an ignition spark in the mixed gas chamber, thereby causing the mixed gas of oxygen and butane in each mixed gas chamber (112) to explode, thereby pushing the ejector piston (13) through the pressurized gas generated by the explosion. The ejector piston (13) is acted upon by the pressurized gas to push the liquid in the liquid chamber to be discharged from the liquid outlet, thereby generating a thrust for driving the underwater drone to move.

2. The marine life imitation jet propulsion device according to claim 1, characterized in that: The buffer bin assembly comprises: A buffer bin body (3), wherein a buffer bin cavity is arranged in the buffer bin body (3), a butane inlet, an oxygen inlet and a buffer bin gas outlet are arranged on the buffer bin body (3) and are communicated with the buffer bin cavity, the high-pressure butane gas source component is communicated with the butane inlet, the high-pressure oxygen gas source component is communicated with the oxygen inlet, and the buffer bin gas outlet is communicated with the mixed gas cavity; A pressure sensor, the pressure sensor is arranged in the buffer chamber and is used to measure the pressure in the buffer chamber; A buffer bin piston is disposed in the buffer bin cavity, and the gas in the buffer bin cavity can enter the mixed gas cavity by controlling the movement of the buffer bin piston.

3. The marine life imitation jet propulsion device as claimed in claim 2, characterized in that: The marine life-simulating jet propulsion device further comprises a vacuum pump (4), wherein the vacuum pump (4) is arranged in the tail thrust section (2), and the vacuum pump (4) is connected to the mixed gas chamber (112) and the buffer chamber through pipelines, respectively, and the vacuum pump (4) can evacuate the mixed gas chamber (112) and the buffer chamber, respectively.

4. A control method for a marine life-simulating jet propulsion device, characterized in that: The control method for the marine life-imitating jet propulsion device comprises: Obtain control requirement information; Obtaining mixed gas demand information and ignition strategy information according to control instructions; Controlling the high-pressure butane gas source component to fill the buffer bin body with butane gas to a first preset pressure value according to the mixed gas demand information; Controlling the butane gas in the buffer bin body to be filled into the mixed gas chamber of one or more ejectors after reaching a first preset pressure value according to the ignition strategy information; After the butane gas in the buffer bin body is emptied, the high-pressure oxygen source assembly is controlled to fill the buffer bin body with oxygen to a second preset pressure value according to the mixed gas demand information; Controlling the oxygen in the buffer bin body to be filled into one or more mixed gas chambers in each ejector after reaching a second preset pressure value according to the ignition strategy information; The gas explosion in the mixed gas chamber having oxygen and butane gas is controlled so that one or more of the ejectors generate propulsion.

5. The control method for the marine life-simulating jet propulsion device according to claim 4, characterized in that: The control requirement information includes a linear propulsion requirement. When the control requirement information is a linear propulsion requirement, the ignition strategy information is that the mixed gas chamber of each ejector needs to be filled with oxygen and butane gas or the mixed gas chambers of two ejectors at diagonal angles need to be filled with oxygen and butane gas; When the control demand information is a linear propulsion demand, the linear propulsion demand includes demand thrust information; The mixed gas requirement information is acquired according to the required thrust information.

6. The control method for the marine life-simulating jet propulsion device according to claim 5, characterized in that: The acquiring the mixed gas requirement information according to the required thrust information comprises: Acquire the thrust information of each ejector that needs to work according to the required thrust information; Acquire a preset propulsion force and time database, wherein the propulsion force and time database includes at least one single ejector propulsion force and time relationship curve and a mixed gas volume of oxygen and butane gas corresponding to each single ejector propulsion force and time relationship curve; According to the propulsion force information of each ejector that needs to work, the mixed gas volume of oxygen and butane gas corresponding to the propulsion force and time relationship curve of a single ejector that meets the propulsion force information is selected; Obtain the mixing ratio of oxygen and butane gas; Obtaining the required volume of butane gas and the required volume of oxygen according to the volume of the mixed gas of oxygen and butane gas and the mixing ratio of oxygen to butane gas; According to the required volume of butane gas, the pressure information required to be detected by the pressure sensor of the buffer bin body when the butane gas is filled is obtained; The pressure information that the pressure sensor needs to detect when the buffer bin body is filled with oxygen is obtained according to the required volume of oxygen.

7. The control method for the marine life-simulating jet propulsion device according to claim 6, characterized in that: The control method for the marine life-simulating jet propulsion device further comprises: The preset propulsion force and time database is established.

8. The control method for the marine life-simulating jet propulsion device according to claim 7, characterized in that: The establishing of the preset propulsion force and time database comprises: The relationship curve between the propulsion force and time of each single ejector is obtained by the following simultaneous formula: in, i is the time point, m is P is the mass of the ejector piston, is the velocity of the ejector piston at the i-1th time point, m J is the mass of a single ejector excluding the ejector piston, v i is the velocity of a single ejector at the i-th time point, ρ is the density of water, s N is the area of ​​the liquid outlet, is the volume of liquid passing through the liquid outlet at the i-th time point, is the velocity of the ejector piston at the ith time point, is the velocity of the liquid in the cylindrical segment of the liquid chamber at the i-th time point, and are the sum of the liquid momentum of the tail jet section of the liquid chamber at the i-th time point and the i-1-th time point, is the liquid mass of the cylindrical segment of the liquid chamber at the i-th time point, is the mass of discharged water at the i-th time point, v i-1 is the velocity of a single ejector at the i-1th time point, is the liquid mass of the cylindrical segment of the liquid chamber at the i-1th time point, is the velocity of the liquid in the cylindrical segment of the liquid chamber at the i-1th time point, is the mass of discharged water at the i-1th time point, is the volume of liquid passing through the liquid outlet at the i-1th time point, ∑W i is the total work done by the system between time points 0 and i, It is the combustion, explosion and expansion of gases that do work.

9. The control method for the marine life-simulating jet propulsion device according to claim 8, characterized in that: The control requirement information includes a heading deviation requirement. When the control requirement information is a heading deviation requirement, the ignition strategy information is to select one or two mixed gas chambers of each ejector to be filled with oxygen and butane gas according to the heading deviation requirement. When the control requirement information is a heading deviation requirement, the heading deviation requirement includes deviation angle information and deviation rate information; The mixed gas demand information is acquired according to the deviation angle information and the deviation rate information.

10. The control method for the marine life-simulating jet propulsion device according to claim 9, characterized in that: The obtaining of mixed gas demand information according to the deviation angle information and the deviation rate information comprises: Get the trained neural network; The offset angle information and the offset rate information are input into a trained neural network to obtain a single ejector propulsion force and time relationship curve.

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