A control method, device and system for sea landing of a liquid oxygen-methane rocket

Abstract

This invention provides a control method, equipment, and system for the sea landing of a liquid oxygen-methane rocket. During the landing process, gas cylinders are used to purge the rocket's pipelines and provide positive pressure protection at each pipeline outlet to prevent ambient gases from entering the engine due to the cold suction effect, thus avoiding pipeline blockage or valve jamming. After the rocket lands on the deck, a stabilizing robot secures the rocket to the deck to prevent it from shifting or tipping due to wind, waves, or ship movement. Liquid methane is released, and the sea breeze allows the methane to diffuse fully, preventing methane accumulation and the risk of explosion. After the methane is released and the landing platform reaches a safe area, liquid oxygen is released to prevent the mixture of methane and high-concentration oxygen from causing an explosion. After the rocket warms up, the high-pressure gas in the gas cylinders is released until the pressure in the gas cylinders reaches the protective pressure, reducing the risk of gas cylinder explosion and improving the safety of the rocket recovery process.

Description

Technical Field

[0001] This application relates to the field of rocket recovery technology, and in particular to a control method and system for the sea landing of a liquid oxygen methane rocket. Background Technology

[0002] Liquid oxygen / methane propellants have advantages such as readily available raw materials, low cost, high specific impulse, and low combustion residue. Therefore, most research institutions and enterprises are currently developing reusable launch vehicles using liquid oxygen / methane dual-component propellants as the next generation of launch vehicles.

[0003] Post-landing processing is a key technology for reusable rockets, and its breakthrough directly affects the rocket's reusability, especially ensuring high safety and harmless post-recovery processing. Considering the limitations of rocket carrying capacity and the environmental impact on land-based residents, some reusable launch vehicles have designated sea landing sites.

[0004] Compared to land environments, marine environments are characterized by high humidity, high wind speeds, and difficulties in ensuring safety. Furthermore, since reusable launch vehicles often employ VTVL (vertical takeoff and vertical landing) operating modes, during the recovery process, situations such as residual propellant vaporization and mixing when the rocket uses cryogenic propellants, as well as cold suction effects in pipelines, can occur, reducing the safety of the rocket recovery process. Summary of the Invention

[0005] To address the problems existing in the prior art, embodiments of the present invention provide a control method, equipment, and system for the sea landing of liquid oxygen methane rockets, in order to solve or partially solve the technical problems in the prior art where the recovery risk is high and affects the safety of the rocket recovery process during sea recovery of liquid oxygen methane rockets.

[0006] A first aspect of the present invention provides a control method for sea landing of a liquid oxygen-methane rocket, the method comprising:

[0007] If it is determined that the rocket's engine meets the conditions for shutting down during guided landing, the engine is controlled to shut down.

[0008] Open the gas cylinders installed on the arrow body to purge the tubes on the arrow;

[0009] After the on-rocket pipeline purging stops, control the nitrogen fire suppression equipment to purge the space below the rocket body;

[0010] The robot is controlled to secure the rocket body to the landing platform.

[0011] Once it is confirmed that there are no abnormalities on the landing platform, methane emissions are controlled;

[0012] Control the landing platform to leave the methane emission area, and control the release of liquid oxygen when it is determined that the landing platform has reached a safe area;

[0013] When it is determined that the temperature of the rocket body is consistent with the ambient temperature, the gas cylinder is controlled to release gas until the pressure inside the gas cylinder reaches the protection pressure.

[0014] In the above scheme, determining that the rocket body's engine meets the guidance and landing shutdown conditions includes:

[0015] If it is determined that the height between the tail of the rocket body and the landing platform is less than a preset height threshold, and the speed of the rocket body is determined to be less than a preset speed threshold, then it is determined that the engine meets the guided landing shutdown conditions.

[0016] In the above scheme, purging the rocket's onboard tubing includes:

[0017] If the two pumps of the engine are separate pumps, the gas in the gas cylinder is controlled to blow air into the internal pipeline along the main valve of the engine pump.

[0018] If the two pump bodies of the engine are coaxial pumps, the gas in the gas cylinder is controlled to blow into the internal pipeline along the main valve of the engine pump, and the gas cylinder is controlled to blow into the isolation chamber of the coaxial pump.

[0019] In the above scheme, before the controlled nitrogen fire suppression equipment purges the space below the rocket body, the method further includes:

[0020] When the rocket body lands, video data is acquired on the landing platform;

[0021] If the video data determines that there is an open flame on the landing platform, then control the water fire-fighting equipment to spray water at the point of the open flame.

[0022] In the above scheme, controlling the fixing robot to fix the rocket body to the landing platform includes:

[0023] After the rocket lands on the deck, a movement command is sent to the stationary robot to move the stationary robot to the area below the rocket.

[0024] The fixed robot is controlled to connect the rocket body to the landing platform by gripping, welding, or electromagnetic attraction.

[0025] The method in the above scheme further includes:

[0026] During the methane emission process, the initial pressure inside the methane storage tank is obtained;

[0027] The gas cylinder is controlled to fill the methane storage tank with a corresponding amount of gas according to the first pressure, so that the pressure in the methane storage tank is greater than a preset first minimum pressure threshold.

[0028] The method in the above scheme further includes:

[0029] During the liquid oxygen discharge process, the second pressure inside the liquid oxygen storage tank is obtained;

[0030] The gas cylinder is controlled to fill the liquid oxygen storage tank with a corresponding amount of gas according to the second pressure, so that the pressure in the liquid oxygen storage tank is greater than the preset second minimum pressure threshold.

[0031] In the above scheme, before determining that the temperature of the rocket body is consistent with the ambient temperature, the method further includes:

[0032] The nitrogen fire suppression system is used to purge the space below the rocket body.

[0033] A second aspect of the present invention provides a control device for sea landing of a liquid oxygen-methane rocket, the control device comprising:

[0034] The first control unit is configured to control the engine to shut down if it is determined that the engine of the rocket body meets the conditions for shutdown during guided landing.

[0035] The second control unit is used to control the opening of the gas cylinder installed on the rocket body to purge the pipeline on the rocket; after the pipeline purging on the rocket body stops, it controls the nitrogen fire extinguishing equipment to purge the space below the rocket body.

[0036] The third control unit is used to control the fixing robot to fix the rocket body to the landing platform;

[0037] The fourth control unit is used to control methane emissions when it is determined that there is no abnormality in the landing platform; to control the landing platform to leave the methane emission area; and to control liquid oxygen emissions when it is determined that the landing platform has reached a safe area.

[0038] The fifth control unit is used to control the gas cylinder to release gas when it is determined that the temperature of the rocket body is consistent with the ambient temperature, until the pressure inside the gas cylinder reaches the protection pressure.

[0039] A third aspect of the present invention provides a control system for a liquid oxygen methane rocket to land at sea, the system comprising: a landing platform placed on the sea surface for providing a landing site for the rocket;

[0040] The control device described in the second aspect is used to control the engine to shut down if it is determined that the engine of the rocket body meets the conditions for shutdown during guided landing.

[0041] Open the gas cylinders installed on the arrow body to purge the tubes on the arrow;

[0042] After the on-rocket pipeline purging stops, control the nitrogen fire suppression equipment to purge the space below the rocket body;

[0043] The robot is controlled to secure the rocket body to the landing platform.

[0044] Once it is confirmed that there are no abnormalities on the landing platform, methane emissions are controlled;

[0045] Control the landing platform to leave the methane emission area, and control the release of liquid oxygen when it is determined that the landing platform has reached a safe area;

[0046] When it is determined that the temperature of the rocket body is consistent with the ambient temperature, the gas cylinder is controlled to release gas until the pressure inside the gas cylinder reaches the protection pressure.

[0047] This invention provides a control method, equipment, and system for the sea landing of a liquid oxygen-methane rocket. The method includes: if it is determined that the rocket's engine meets the conditions for guided landing shutdown, controlling the engine to shut down; controlling the opening of gas cylinders installed on the rocket to purge the rocket's pipelines; after the pipeline purging stops, controlling nitrogen fire suppression equipment to purge the space below the rocket; controlling a fixing robot to fix the rocket to a landing platform; if it is determined that the landing platform is normal, controlling methane emission; controlling the landing platform to move away from the methane emission area; when it is determined that the landing platform has reached a safe area, controlling liquid oxygen emission; when it is determined that the temperature of the rocket is consistent with the ambient temperature, controlling the gas cylinders to release gas until the pressure inside the gas cylinders reaches the protection pressure; thus, during the rocket's landing process, the pre-set gas cylinders are used to purge the rocket's pipelines, blowing out residual propellant from the engine and auxiliary pipelines, preventing engine failure. The system prevents residual propellant from igniting during accidental firing, while simultaneously preventing ambient gases from entering the engine through the exhaust nozzle and auxiliary pipelines connected to the external environment due to the cold suction effect, thus avoiding engine pipeline blockage or valve jamming. After the rocket lands on the deck, a securing robot is used to fix the rocket to the deck, preventing it from shifting or tipping due to wind, waves, or ship movement. Then, liquid methane is released, and the sea breeze is used to fully disperse the methane, preventing it from accumulating near the rocket or along the ship's route and causing an explosion risk. After the methane is released, the landing platform is controlled to move away from the methane release area. Once in a safe area, liquid oxygen is released to prevent the methane and liquid oxygen from mixing and exploding. After the rocket warms up, the high-pressure gas in the gas cylinders is released until the pressure in the gas cylinders reaches the protective pressure, reducing the risk of gas cylinder explosion. It can be seen that this application, through the above measures, can reduce the risk of sea recovery of liquid oxygen methane rockets and improve the safety of the rocket recovery process. Attached Figure Description

[0048] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0049] Figure 1 A schematic diagram of the control system structure for a liquid oxygen-methane rocket landing at sea is shown according to an embodiment of the present invention;

[0050] Figure 2 A schematic diagram of the landing area of ​​a landing vessel for a liquid oxygen-methane rocket landing at sea, according to an embodiment of the present invention, is shown.

[0051] Figure 3 A schematic flowchart of a control method for sea landing of a liquid oxygen methane rocket according to an embodiment of the present invention is shown;

[0052] Figure 4 A schematic diagram of the control device for sea landing of a liquid oxygen methane rocket according to an embodiment of the present invention is shown. Detailed Implementation

[0053] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0054] To better understand the technical solution of this invention, the control system for sea landing of a liquid oxygen-methane rocket will be introduced first, such as... Figure 1 As shown, the system includes: a landing vessel 1 and ground control equipment 2; wherein,

[0055] Landing vessel 1, placed on the sea surface, is mainly used to provide a landing site for rockets;

[0056] Control device 2, specifically, can be understood as all the equipment in the ground control center used for rocket recovery. Its main functions include: shutting down the engine when it is determined that the rocket's engine meets the conditions for guided landing shutdown; opening the gas cylinders on the rocket to purge the rocket's pipelines; after the pipeline purging stops, controlling the nitrogen fire suppression system to purge the space below the rocket; controlling the securing robot to fix the rocket to the landing platform; controlling methane emission when the landing platform is confirmed to be normal; controlling the landing platform to move away from the methane emission area, and controlling liquid oxygen emission when the landing platform reaches a safe area; and releasing gas from the gas cylinders when the rocket's temperature matches the ambient temperature, until the pressure inside the gas cylinders reaches the protective pressure.

[0057] Specifically, when landing a liquid oxygen-methane rocket at sea, both the rocket and the landing vessel should meet the following conditions:

[0058] For liquid rockets, the structure, from bottom to top, generally includes: a tail section, propellant tanks, attitude control module, and instrument module; among which...

[0059] The rear compartment is used to load the engine;

[0060] The propellant tanks are bicomponent propellant tanks, consisting of a methane tank and a liquid oxygen tank from bottom to top. To improve safety and reduce the risk of explosion caused by the mixing of methane and liquid oxygen, an inter-tank section is also provided between the methane tank and the liquid oxygen tank.

[0061] The attitude control cabin mainly houses small engines used to control the rocket's flight attitude, while the instrument cabin mainly houses instruments and equipment, such as control computers and communication equipment.

[0062] To improve the safety of rockets landing at sea, rockets should be equipped with special gas cylinders required after landing. The number and capacity of the gas cylinders can be determined based on the actual situation, and the gas contained in the cylinders is generally nitrogen.

[0063] Gas cylinders can be installed in the attitude control cabin, the inter-cabin section, or the instrument compartment. Considering space issues, gas cylinders are generally placed in the attitude control cabin or the inter-cabin section.

[0064] All valves involving gas and liquid discharge, such as the safety valve of the propellant storage tank, the propellant filling valve, and the pre-cooling discharge control valve, are solenoid valves or electric pneumatic valves.

[0065] The solenoid valves on the rocket have wireless command control capability when the electrical connector is not connected. After the rocket lands, the rocket control system needs to be able to receive control commands from the ground control equipment for the various valves of the rocket.

[0066] Among them, different on-arrow solenoid valves are used for the on-off control of various gas and liquid channels on the rocket in the power system, such as engine start / stop control, engine pre-cooling emission control, on-arrow pneumatic valve control, engine pipeline purging control, and power system pipeline outlet gas seal control.

[0067] The propellant tank's exhaust pipe and pre-cooling discharge pipe are equipped with two-way filters, which mainly prevent impurities (such as dust) from the external environment from entering the engine pipeline.

[0068] The pre-cooling discharge pipe is located within the rear transition and tail sections of the rocket body. Since liquid oxygen-methane rockets use liquid oxygen and methane as propellants, both of which are cryogenic, a large amount of propellant will evaporate from the rocket body (at room temperature) when unfueled. Without any treatment, the mass and temperature of the propellant entering the engine at the moment of ignition cannot be controlled. Therefore, it is necessary to pre-cool the rocket's piping before ignition. This involves using some means to allow the liquid propellant to flow through the engine, exchange heat with the engine piping, and then flow out of the engine, thus lowering the piping temperature. The high-temperature propellant or vaporized propellant flowing out of the engine has two possible fates: either it is discharged from the rocket body, or it flows back into the propellant tank. The pre-cooling discharge pipe serves as the channel for discharging the pre-cooled propellant from the rocket body.

[0069] In addition, a methane concentration sensor can be installed on the rocket body, specifically near the engine exhaust port, to collect the methane concentration near the engine.

[0070] For ships landing, the following conditions must be met:

[0071] The landing vessel must be a non-powered vessel (barge) or an electrically powered vessel to avoid using internal combustion engine vessels and reduce the risk of methane emissions.

[0072] The landing vessel includes a flat deck made of refractory materials and coated with refractory materials to ensure that the rocket can withstand the high temperature of the rocket body at the moment of landing and to prevent the landing platform area from being burned through.

[0073] For details, please refer to [link / reference]. Figure 2 The deck of the landing vessel serves as the landing pad, and is marked with the landing area boundary 21, the aiming landing point 22, the ideal landing area 23, the quadrant number, and the reference quadrant line; so as to provide markers for rocket landing.

[0074] To improve the safety of the landing process, the minimum width of the landing platform should be greater than or equal to four times the outer radius of the rocket body after the rocket's outriggers are deployed, and there should be no obstructions such as ships within the upward space extending a certain angle outward from the landing zone boundary 21. The landing platform should be able to adapt to deviations in the rocket's landing position.

[0075] In addition, the landing vessel also includes: anti-roll devices, nitrogen fire suppression equipment, freshwater fire suppression equipment, a stationary robot, and a methane concentration sensor; among which,

[0076] Roll reduction devices are used to reduce the rolling of landing vessels caused by marine environmental disturbances such as rocket impact, waves, sea winds, and ocean currents.

[0077] Nitrogen fire suppression equipment is used to purge the space beneath the rocket body to reduce the water vapor content in the air below the rocket body.

[0078] Freshwater firefighting equipment, including freshwater supply tanks and sprinkler systems, is used to extinguish open flames on landing platforms.

[0079] A methane concentration sensor is used to collect the methane concentration near the rocket body.

[0080] The landing vessel is also equipped with: a 24-meter forecastle;

[0081] The forecastle 24 is located at one end of the landing vessel. The forecastle can serve as a control area and can be equipped with navigation equipment (if the landing vessel is a powered vessel, it can be equipped with both remote control and manual control systems; if the landing vessel is a barge, it can be unequipped), navigation and communication equipment, fire control equipment, fixed robot control equipment, and personnel living quarters (personnel are not allowed to remain on board during missions).

[0082] There are also fixed camera positions outside the landing area on the deck, and the cameras can rotate at an angle of 120° or more.

[0083] Based on this system, after the rocket lands at sea, the ground control equipment can send corresponding instructions to the rocket and the recovery vessel. For example, during the landing process, the rocket's pipelines can be purged using pre-set gas cylinders to blow out the propellant remaining inside the engine and auxiliary pipelines, preventing the engine from accidentally igniting the residual propellant. At the same time, it prevents ambient gas from entering the engine from the rocket's pipelines (such as the engine's tail nozzle and auxiliary pipelines that communicate with the external environment) due to the cold suction effect, thereby avoiding engine pipeline blockage or valve jamming. After the rocket lands on the deck, a securing robot is used to hold it in place, preventing it from shifting or tipping due to wind, waves, or ship movement. Liquid methane is then released, and the sea breeze helps it disperse, preventing accumulation near the rocket or along the ship's path that could cause an explosion. After the methane is released, the landing platform is guided away from the methane release area to a safe zone, where liquid oxygen is released to prevent a possible explosion from the mixture of methane and liquid oxygen. Once the rocket has warmed up, the high-pressure gas in the cylinders is released until the pressure reaches the protective level, reducing the risk of cylinder explosion. It can be seen that this application, through the above measures, can reduce the risks of sea recovery of liquid oxygen / methane rockets and improve the safety of the rocket recovery process.

[0084] The specific control method for the hydraulic methane rocket after landing at sea can be found in the detailed description of the subsequent control method section, and will not be repeated here.

[0085] Based on the same inventive concept as the foregoing embodiments, this embodiment also provides a control method for sea landing of a liquid oxygen-methane rocket, such as... Figure 3 As shown, the method mainly includes the following steps:

[0086] S310, if it is determined that the rocket body's engine meets the conditions for shutting down during guided landing, control the engine to shut down;

[0087] In one implementation, determining that the rocket body's engine meets the guided landing shutdown conditions includes:

[0088] If it is determined that the height between the tail of the rocket body and the landing platform is less than a preset height threshold, and the speed of the rocket body is determined to be less than a preset speed threshold, then the engine is determined to meet the guided landing shutdown conditions.

[0089] Generally speaking, during landing, in order to reduce the impact of the rocket body on the landing ship and improve the stability during landing, it is necessary to ensure the rocket's altitude and speed.

[0090] When the rocket's speed is less than a certain speed threshold and its height is less than a certain height threshold, an engine shutdown command can be sent to the rocket's control system. The rocket's control system will then shut down the rocket's engine based on the engine shutdown command, allowing it to land on the landing vessel by gravity.

[0091] S311 controls the opening of the gas cylinder installed on the arrow body to purge the pipeline on the arrow;

[0092] Because the rocket engine in this embodiment uses cryogenic propellant, after the rocket lands, the cryogenic propellant acts as a cold source, absorbing heat from the rocket's piping through conduction, convection, and thermal radiation. This lowers the pipe wall temperature and consequently reduces the gas pressure. If the gas pressure inside the piping is lower than the ambient atmospheric pressure, ambient air will enter the piping, which is known as the cold suction effect. However, the marine environment has a high salt and water content. If ambient air enters these piping systems, the high humidity and salinity of the gas will enter the engine, causing corrosion and potentially leading to pipe blockage or valve jamming.

[0093] To prevent high-humidity, high-salt gases from the external environment from entering the pipelines, this embodiment implements positive pressure protection for these pipelines. This means controlling the opening of the gas cylinders installed on the rocket body to purge the pipelines on the rocket, ensuring that the gas inside the pipelines flows towards the external environment, thus preventing high-humidity, high-salt gases from entering the pipelines.

[0094] It should be noted that if the rocket itself carries a gas cylinder with sufficient gas volume, then there is no need to install an additional gas cylinder for the rocket; if the gas cylinder carried by the rocket itself cannot provide sufficient gas volume, then a separate gas cylinder for the rocket is required.

[0095] In one embodiment, an engine of the present invention includes two pump bodies, namely an oxygen pump and a methane pump, for purging the rocket's piping, including:

[0096] If the two pumps of the engine are separate pumps, the gas in the gas cylinder is blown into the internal pipeline along the main valve of the engine pump;

[0097] If the two pumps of the engine are coaxial pumps, control the gas in the gas cylinder to blow gas along the main and auxiliary valves of the engine to the pipeline after the valve, and control the gas cylinder to blow gas into the isolation chamber of the coaxial pump.

[0098] Specifically, the two pumps of the engine can be connected in series, i.e., using a coaxial pump solution; or they can be set separately, i.e., using a split pump solution. If the two pumps of the engine are split pumps, air needs to be blown into the main and auxiliary valve downstream pipelines of the engine separately.

[0099] If the two pump bodies of the engine are coaxial pumps, an isolation chamber will be formed between the two pump bodies. Therefore, in addition to blowing air into the main and auxiliary valve downstream pipelines, air also needs to be blown into the pump isolation chamber.

[0100] Specifically, the engine propellant delivery channel can be simplified as follows: "Engine inlet → Pump pre-pump duct → Pump → Pump post-pump, main / auxiliary valve pre-pump duct → Main / auxiliary valve → Main / auxiliary valve post-duct → Thrust chamber / gas generator → Thrust chamber nozzle / turbine exhaust pipe → Engine outlet". Therefore, when the control gas cylinder blows gas into the engine pump's main valve and post-pump pipeline, the purging range is "Main / auxiliary valve post-duct → Thrust chamber / gas generator → Thrust chamber nozzle / turbine exhaust pipe → Engine outlet", meaning that gas is introduced starting from after the main / auxiliary valve, purging all downstream pipelines and cavities.

[0101] This allows residual propellant inside the engine to be blown out, preventing the engine from igniting the residual propellant during malfunction; and it also prevents external ambient gases from entering the engine due to the cold suction effect, which could cause blockages in the engine's internal pipes or valves.

[0102] Furthermore, since the engine is also connected to other pipelines on the rocket, such as the propellant loading pipeline, it is also necessary to purge the engine's auxiliary pipelines to prevent external ambient gases from entering the engine through these pipelines, which could cause blockages in the engine's internal pipelines or valve malfunctions.

[0103] During purging, specific purging parameters (such as purging flow rate, velocity, purging cycle, and purging duration) can be determined based on these parameters. Specifically, the optimal purging scheme can be determined by simulating these parameters.

[0104] S312, After the purging of the on-rocket pipeline stops, control the nitrogen fire suppression equipment to purge the space below the rocket body;

[0105] Upon landing, the rocket body reaches temperatures of approximately 2000 degrees Celsius, making it highly likely to ignite upon impact. Therefore, before using nitrogen smothering equipment to purge the space beneath the rocket body, the method further includes:

[0106] When the rocket body lands, acquire video data on the landing platform;

[0107] If video data confirms the presence of an open flame on the landing platform, then control the water fire suppression equipment to spray water at the source of the flame.

[0108] After the open flames are extinguished and the internal piping of the engine is purged, the nitrogen septic tank is controlled to purge nitrogen into the space below the rocket body to reduce the water vapor content in the air below the rocket body. The purging principle is as follows: purging is stopped when the average atmospheric water vapor content near the engine nozzle and turbine exhaust pipe outlet is determined to be less than 50% of the local atmospheric water vapor content.

[0109] This step, by promptly extinguishing open flames and reducing the rocket's temperature, provides the necessary environment for the subsequent fixation operation of the robot, thus improving the reliability of the robot's operation. Furthermore, by purging nitrogen into the space below the rocket, it prevents ambient gases from entering the engine due to the cold suction effect, which could cause pipe blockages or valve malfunctions.

[0110] S313, Control the fixing robot to fix the rocket body to the landing platform;

[0111] After the rocket lands, to prevent it from shifting or tipping over due to wind, waves, or the rocking of the landing vessel, a robot is needed to secure the rocket to the landing platform.

[0112] In one embodiment, controlling the anchoring robot to anchor the rocket body to the landing platform includes:

[0113] Once the rocket lands on the deck, a movement command is sent to the stationary robot, causing the stationary robot to move under the rocket.

[0114] The robot is controlled to connect the rocket body to the landing platform by gripping, welding, or electromagnetic attraction.

[0115] The type of stationary robot can be selected based on the actual situation. When the stationary robot is a welding robot, after receiving the movement command, the stationary robot moves from its current position to the rocket's outriggers and welds the rocket outriggers to the landing platform using the pre-set welding parameters.

[0116] When the stationary robot is an electromagnetic attraction robot, after receiving the movement command, the stationary robot moves from its current position to the support leg of the rocket body, hangs the hook it carries at the preset position of the support leg, and then uses magnets to attract itself to the deck.

[0117] In practical applications, other fixing methods can also be used to fix the arrow body, and there are no restrictions here.

[0118] S314, when it is determined that there is no abnormality in the landing platform, methane emissions are controlled;

[0119] If video data from the landing platform is obtained and it is determined from the video data that there is no open flame on the deck, then it is determined that there is no abnormality on the landing platform at this time, and the valve of the methane storage tank can be opened to release liquid methane.

[0120] To improve safety during methane emission processes, the method also includes:

[0121] During the methane emission process, the initial pressure inside the methane storage tank is obtained;

[0122] The gas cylinder is charged into the methane storage tank according to the first pressure control, so that the pressure in the methane storage tank is greater than the preset first minimum pressure threshold.

[0123] The first minimum pressure threshold can be determined based on the actual situation and is not restricted.

[0124] This allows for the rapid release of one of the two propellant components (methane and liquid oxygen), preventing large amounts of flammable propellant from being stored inside the rocket and improving safety. Furthermore, the methane can be dispersed by sea breezes, reducing the risk of explosion caused by methane accumulating on the rocket body or in nearby shipping lanes.

[0125] S315, control the landing platform to leave the methane emission area, and when it is determined that the landing platform has reached a safe area, control the emission of liquid oxygen;

[0126] Once methane emissions are confirmed to be complete, the landing platform can be controlled to move away from the methane emission area. Once the landing platform is confirmed to have reached a safe area, liquid oxygen emissions can be controlled.

[0127] Since both methane and liquid oxygen are flammable, a mixture of methane and liquid oxygen will explode upon contact with an open flame. Therefore, after the methane is discharged, this embodiment will control the landing vessel to leave the methane discharge area and discharge liquid oxygen only after reaching a safe area.

[0128] Generally, a landing vessel can reach a safe area after traveling about 10km. Since the landing vessel may be either a non-powered or electric vessel, when the landing vessel is non-powered, it needs to be towed away from the methane emission area by a tugboat; if the landing vessel is electric, it can be remotely controlled to leave the methane emission area.

[0129] Once the landing vessel reaches a safe area and is at a safe distance from the coast or nearby vessels, it adjusts its course to be against the wind or crosswind, controls the liquid oxygen discharge valve to open, and releases the liquid oxygen.

[0130] Similarly, to improve the safety of liquid oxygen emissions, the methods also include:

[0131] During the liquid oxygen discharge process, the second pressure inside the liquid oxygen storage tank is obtained;

[0132] The second pressure control cylinder fills the liquid oxygen storage tank with the corresponding amount of gas so that the pressure in the liquid oxygen storage tank is greater than the preset second minimum pressure threshold.

[0133] The second minimum pressure threshold can be determined based on actual conditions and is not restricted.

[0134] Then, when it is determined through video data that there is no visible liquid oxygen at the liquid oxygen discharge port, the liquid oxygen discharge valve is closed.

[0135] In this way, the rapid vaporization of liquid oxygen can be used to effectively dilute and remove trace amounts of methane gas near the rocket body. Specifically, after liquid oxygen vaporizes, its mass increases while the mass of other gases in the surrounding atmosphere remains constant. Consequently, the volume fraction of methane decreases, thus diluting the methane.

[0136] S316, when it is determined that the temperature of the rocket body is consistent with the ambient temperature, the gas cylinder is controlled to release gas until the pressure inside the gas cylinder reaches the protection pressure.

[0137] The rocket body then naturally warms up. During this process, the vent valve of the propellant tank is opened, releasing the propellant gas into the external environment. Before the rocket body warms up and before its temperature matches the ambient temperature, the nitrogen septic tank must be used to purge the space beneath the rocket body at preset intervals.

[0138] In this way, the air flowing through the rocket body is used to draw propellant gas from the propellant tank, reducing the probability of a cold suction effect during the warm-up process.

[0139] After the rocket body has warmed up and its temperature is confirmed to be the same as the ambient temperature, the gas cylinder is released until the pressure inside the gas cylinder reaches the protection pressure.

[0140] This prevents the presence of high-pressure gas on the rocket after it has warmed up, reducing the risk of the gas cylinder exploding.

[0141] As can be seen, during the landing process, this invention uses pre-set gas cylinders to purge the rocket's pipelines, blowing out residual propellant from the engine and auxiliary pipelines. This prevents accidental engine ignition of residual propellant and also prevents ambient gases from entering the engine through the engine's exhaust nozzle and auxiliary pipelines connected to the external environment due to the cold suction effect, thus avoiding engine pipeline blockage or valve jamming. After the rocket lands on the deck, a fixing robot secures it to the deck, preventing it from shifting or tipping due to wind, waves, or ship movement. Liquid methane is then released, and the sea breeze is used to fully disperse the methane, preventing it from accumulating near the rocket body or along the ship's route and causing an explosion risk. After the methane is released, the landing platform is controlled to move away from the methane release area. Once in a safe area, liquid oxygen is released to prevent the methane and liquid oxygen from mixing and causing an explosion. After the rocket body warms up, the high-pressure gas in the gas cylinders is released until the pressure in the gas cylinders reaches the protective pressure, reducing the risk of gas cylinder explosion. It can be seen that this application can reduce the risk of sea recovery of liquid oxygen methane rockets and improve the safety of the rocket recovery process through the above measures.

[0142] Based on the same inventive concept as the foregoing embodiments, this embodiment also provides a control device for sea landing of a liquid oxygen-methane rocket, such as... Figure 4 As shown, the control device includes:

[0143] The first control unit 41 is used to control the engine to shut down if it is determined that the engine of the rocket body meets the conditions for shutdown during guided landing.

[0144] The second control unit 42 is used to control the opening of the gas cylinder installed on the rocket body to purge the pipeline on the rocket; after the pipeline purging on the rocket body stops, it controls the nitrogen fire extinguishing equipment to purge the space below the rocket body.

[0145] The third control unit 43 is used to control the fixing robot to fix the rocket body to the landing platform;

[0146] The fourth control unit 44 is used to control methane emissions when it is determined that there is no abnormality in the landing platform; control the landing platform to leave the methane emission area; and control liquid oxygen emissions when it is determined that the landing platform has reached a safe area.

[0147] The fifth control unit 45 is used to control the gas cylinder to release gas when it is determined that the temperature of the rocket body is consistent with the ambient temperature, until the pressure inside the gas cylinder reaches the protection pressure.

[0148] Since the apparatus described in the embodiments of this invention is used for implementing the control method for sea landing of a liquid oxygen-methane rocket according to the embodiments of this invention, those skilled in the art can understand the specific structure and variations of the apparatus based on the method described in the embodiments of this invention, and therefore will not be described in detail here. All apparatuses used in the methods of the embodiments of this invention fall within the scope of protection of this invention.

[0149] The beneficial effects of the control method, equipment, and system for sea landing of liquid oxygen methane rockets provided by this invention are at least as follows:

[0150] This invention provides a control method, equipment, and system for the sea landing of a liquid oxygen-methane rocket. The method includes: controlling the engine to shut down when it is determined that the rocket's engine meets the conditions for guided landing shutdown; controlling the opening of gas cylinders installed on the rocket to purge the rocket's pipelines; controlling nitrogen fire suppression equipment to purge the space below the rocket after the pipeline purging stops; controlling a fixing robot to fix the rocket to a landing platform; controlling methane emission when it is determined that the landing platform is free of abnormalities; controlling the landing platform to move away from the methane emission area; controlling liquid oxygen emission when it is determined that the landing platform has reached a safe area; controlling the gas cylinders to release gas when it is determined that the temperature of the rocket is consistent with the ambient temperature, until the pressure inside the gas cylinders reaches the protection pressure; thus, during the rocket landing process, the internal pipelines of the engine and auxiliary pipelines are purged using preset gas cylinders to blow out residual propellant from the engine and auxiliary pipelines, preventing... To prevent the engine from igniting residual propellant due to accidental firing, and to prevent ambient gases from entering the engine through the exhaust nozzle and auxiliary pipelines connected to the external environment due to the cold suction effect, thus avoiding engine pipeline blockage or valve jamming; after the rocket lands on the deck, a fixing robot is used to secure the rocket to the deck to prevent it from shifting or tipping due to wind, waves, or ship rolling; then liquid methane is released, and the sea breeze is used to fully disperse the methane, avoiding accumulation near the rocket or along the ship's route that could cause an explosion risk; after the methane is released, the landing platform is controlled to move away from the methane release area, and after reaching a safe area, liquid oxygen is released to avoid the risk of explosion caused by the mixing of methane and liquid oxygen; after the rocket body warms up, the high-pressure gas in the gas cylinders is released until the pressure in the gas cylinders reaches the protective pressure, reducing the risk of gas cylinder explosion; it can be seen that, through the above measures, this application can reduce the risk of sea recovery of liquid oxygen methane rockets and improve the safety of the rocket recovery process.

[0151] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0152] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for sea landing of a liquid oxygen-methane rocket, characterized in that, The method includes: S310, if it is determined that the rocket body's engine meets the conditions for shutting down during guided landing, control the engine to shut down; S311 controls the opening of the gas cylinder installed on the arrow body to purge the pipeline on the arrow; S312, After the purging of the on-rocket pipeline stops, control the nitrogen fire suppression equipment to purge the space below the rocket body; Before the controlled nitrogen fire suppression equipment purges the space below the rocket body, the method further includes: When the rocket body lands, video data is acquired on the landing platform; If the video data indicates that there is an open flame on the landing platform, the water fire-fighting equipment is controlled to spray the open flame. After the open flame is extinguished and the internal pipelines of the engine are purged, the nitrogen fire-fighting equipment is controlled to purge nitrogen into the space below the rocket body to reduce the water vapor content in the air below the rocket body. S313, Control the fixing robot to fix the rocket body to the landing platform; S314, when it is determined that there is no abnormality in the landing platform, methane emissions are controlled; Acquire video data from the landing platform. If the video data indicates that there is no open flame on the deck, then the landing platform is deemed to be functioning normally. Control the valve of the methane storage tank to open and release liquid methane. S315, control the landing platform to leave the methane emission area, and when it is determined that the landing platform has reached a safe area, control the emission of liquid oxygen; Once the landing vessel reaches a safe area and is at a safe distance from the coast or nearby vessels, it adjusts its course to be against the wind or crosswind, controls the liquid oxygen discharge valve to open, and releases liquid oxygen; taking advantage of the rapid vaporization of liquid oxygen, it dilutes and removes trace amounts of methane gas near the rocket body. S316, when it is determined that the temperature of the arrow body is consistent with the ambient temperature, the gas cylinder is controlled to release gas until the pressure inside the gas cylinder reaches the protective pressure; wherein... Controlling the fixing robot to fix the rocket body to the landing platform includes: After the rocket lands on the deck, a movement command is sent to the stationary robot to move the stationary robot to the area below the rocket. The fixed robot is controlled to connect the rocket body to the landing platform by gripping, welding, or electromagnetic attraction.

2. The method as described in claim 1, characterized in that, The determination that the rocket body's engine meets the guidance and landing shutdown conditions includes: If it is determined that the height between the tail of the rocket body and the landing platform is less than a preset height threshold, and it is determined that the speed of the rocket body is less than a preset speed threshold, then it is determined that the engine meets the guided landing shutdown conditions.

3. The method as described in claim 1, characterized in that, The purging of the rocket's tubing includes: If the two pumps of the engine are separate pumps, the gas in the gas cylinder is controlled to blow air into the internal pipeline along the main valve of the engine pump. If the two pump bodies of the engine are coaxial pumps, the gas in the gas cylinder is controlled to blow into the internal pipeline along the main valve of the engine pump, and the gas cylinder is controlled to blow into the isolation chamber of the coaxial pump.

4. The method as described in claim 1, characterized in that, The method further includes: During the methane emission process, the initial pressure inside the methane storage tank is obtained; The gas cylinder is controlled to fill the methane storage tank with a corresponding amount of gas according to the first pressure, so that the pressure in the methane storage tank is greater than a preset first minimum pressure threshold.

5. The method as described in claim 1, characterized in that, The method further includes: During the liquid oxygen discharge process, the second pressure inside the liquid oxygen storage tank is obtained; The gas cylinder is controlled to fill the liquid oxygen storage tank with a corresponding amount of gas according to the second pressure, so that the pressure in the liquid oxygen storage tank is greater than the preset second minimum pressure threshold.

6. The method as described in claim 1, characterized in that, Before determining that the temperature of the rocket body is consistent with the ambient temperature, the method further includes: The nitrogen fire suppression system is used to purge the space below the rocket body.

7. A control device for sea landing of a liquid oxygen-methane rocket, characterized in that, The control device includes: The first control unit is configured to control the engine to shut down if it is determined that the engine of the rocket body meets the conditions for shutdown during guided landing. The second control unit is used to control the opening of the gas cylinder installed on the rocket body to purge the pipeline on the rocket; after the pipeline purging on the rocket body stops, it controls the nitrogen fire extinguishing equipment to purge the space below the rocket body. Before the controlled nitrogen fire suppression equipment purges the space below the rocket body, video data is acquired on the landing platform as the rocket body lands; If the video data indicates that there is an open flame on the landing platform, the water fire-fighting equipment is controlled to spray the open flame. After the open flame is extinguished and the internal pipelines of the engine are purged, the nitrogen fire-fighting equipment is controlled to purge nitrogen into the space below the rocket body to reduce the water vapor content in the air below the rocket body. The third control unit is used to control the fixing robot to fix the rocket body to the landing platform; The fourth control unit is used to control methane emissions when the landing platform is confirmed to be normal; control the landing platform to leave the methane emission area; control liquid oxygen emissions when the landing platform reaches a safe area; acquire video data on the landing platform; if the video data determines that there is no open flame on the deck, then the landing platform is confirmed to be normal, and the valve of the methane storage tank is opened to release liquid methane; when the landing vessel reaches a safe area and is at a safe distance from the coast or nearby vessels, the course is adjusted to headwind or crosswind, and the liquid oxygen emission valve is opened to release liquid oxygen; and the trace amounts of methane gas near the rocket body are diluted and blown away by the rapid vaporization of liquid oxygen. The fifth control unit is used to control the gas cylinder to release gas when it is determined that the temperature of the rocket body is consistent with the ambient temperature, until the pressure inside the gas cylinder reaches the protective pressure; wherein, Controlling the fixing robot to fix the rocket body to the landing platform includes: After the rocket lands on the deck, a movement command is sent to the stationary robot to move the stationary robot to the area below the rocket. The fixed robot is controlled to connect the rocket body to the landing platform by gripping, welding, or electromagnetic attraction.

8. A control system for a liquid oxygen-methane rocket landing at sea, characterized in that, The system includes: a landing platform, placed on the sea surface, for providing a landing site for the rocket; The control device for sea landing of a liquid oxygen methane rocket as described in claim 7 is used to control the engine to shut down when it is determined that the engine of the rocket body meets the guidance landing shutdown conditions; Open the gas cylinders installed on the arrow body to purge the tubes on the arrow; After the on-rocket pipeline purging stops, control the nitrogen fire suppression equipment to purge the space below the rocket body; The robot is controlled to secure the rocket body to the landing platform. Once it is confirmed that there are no abnormalities on the landing platform, methane emissions are controlled; Control the landing platform to leave the methane emission area, and control the release of liquid oxygen when it is determined that the landing platform has reached a safe area; When it is determined that the temperature of the rocket body is consistent with the ambient temperature, the gas cylinder is depressurized until the pressure inside the gas cylinder reaches the protective pressure; wherein, controlling the fixing robot to fix the rocket body to the landing platform includes: After the rocket lands on the deck, a movement command is sent to the stationary robot to move the stationary robot to the area below the rocket. The fixed robot is controlled to connect the rocket body to the landing platform by gripping, welding, or electromagnetic attraction.

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