An aerial refueling adjustment method and system based on active center of gravity control

Abstract

The application provides an airborne refueling adjustment method and system based on active gravity center control, which comprises the following steps: calculating the weight and gravity center of all external configurations of an airplane to obtain a remaining fuel limit value of the airplane and a corresponding fueling state of a rear fuselage tank of the airplane under the limit value, including two states that fuel in the rear fuselage tank is not allowed to be refueled when the fuel is less than the remaining fuel limit value and fuel in the rear fuselage tank is allowed to be refueled when the fuel is more than the remaining fuel limit value; and making a partner refueling pod have a low-speed fueling state and a high-speed fueling state, when the fuel in the rear fuselage tank is less than the limit value, the rear fuselage tank is not allowed to be refueled by making the fueling state of the partner refueling pod be the low-speed fueling state; and when the fuel in the rear fuselage tank is not less than the limit value, the rear fuselage tank is allowed to be refueled by making the fueling state of the partner refueling pod be the high-speed fueling state.

Description

Technical Field

[0001] This application belongs to the field of aircraft technology, and specifically relates to an aerial refueling adjustment method and system based on active center of gravity control. Background Technology

[0002] Buddy refueling refers to in-flight refueling between two aircraft. It can solve problems such as aircraft failing to land and needing to go around, and aircraft running low on fuel while waiting in the air, thus improving the aircraft's survivability and safety. In current technology, when aircraft refuel in the air using normal refueling control logic, the refueling sequence and control logic of each fuel tank are the same as for ground refueling. However, unlike ground refueling, when the aircraft has low remaining fuel, refueling from the rear fuselage fuel tanks can cause the aircraft's center of gravity to shift aft, potentially exceeding the aft limit, thus posing a significant safety hazard.

[0003] For the reasons mentioned above, there is a need for an in-flight refueling method and system capable of active center of gravity control, which can enable aircraft to refuel in the air while ensuring flight safety. Summary of the Invention

[0004] The purpose of this application is to provide an in-flight refueling adjustment method and system based on active center of gravity control, so as to solve or mitigate at least one of the problems in the prior art.

[0005] The technical solution of this application is: an in-flight refueling control method based on active center of gravity control, the method comprising:

[0006] By calculating the weight and center of gravity of all external stores configurations of the aircraft, the remaining fuel limit value of the aircraft and the refueling status of the aft fuselage fuel tank under the corresponding limit value are obtained. The refueling status includes two states: refueling is not allowed when the fuel in the aft fuselage fuel tank is lower than the remaining fuel limit value, and refueling is allowed when the fuel in the aft fuselage fuel tank is higher than the remaining fuel limit value.

[0007] The buddy refueling pod has two refueling states: low-speed refueling and high-speed refueling. When refueling in mid-air with less than the limit in the aircraft's rear fuselage fuel tank, the buddy refueling pod is set to low-speed refueling to prevent fuel from entering the rear fuselage fuel tank. When refueling in mid-air with more than the limit in the aircraft's rear fuselage fuel tank, the buddy refueling pod is set to high-speed refueling to allow fuel to enter the rear fuselage fuel tank.

[0008] In addition, this application also provides an air refueling control system for implementing the air refueling control method based on active center of gravity control as described above. The system includes: a refueling probe, a pressure regulator, a refueling control valve, a two-position valve, and a safety valve.

[0009] The receiving probe receives pressurized fuel from the refueling tanker's refueling compartment, and a pressure regulator is located on the rear side of the receiving probe to ensure that the refueling pipeline of the receiving tanker does not exceed the allowable pressure during the refueling process.

[0010] The refueling control valve is located on the refueling pipeline and is normally open, used to control the on / off state of the refueling pipeline;

[0011] The dual-position valve is installed on the control fuel line of the rear fuselage fuel tank, and is respectively connected to the power fuel line, the control line with the same pressure as the refueling line, and the connector for controlling the opening and closing of the refueling control valve.

[0012] The safety valve is installed in the aircraft's power fuel line and is used to regulate and protect the pressure of the aircraft's power fuel line.

[0013] When the pressure of the fuel output from the refueling pod reaching the double-position valve via the refueling line and control line is greater than the pressure in the power fuel line, the double-position valve does not output control fuel, the refueling control valve opens, and fuel is supplied to the aft fuselage fuel tank via the refueling line. When the pressure of the fuel output from the refueling pod reaching the double-position valve via the refueling line and control line is less than the pressure in the power fuel line, the double-position valve outputs control fuel, the refueling control valve closes, and fuel cannot be supplied to the aft fuselage fuel tank via the refueling line.

[0014] In a preferred embodiment of this application, the refueling control valve has a transverse channel, in which fuel in the refueling pipeline flows. The refueling control valve has a piston, one side of which is supported by a spring. The lower end of the refueling control valve has a connecting nozzle, which is connected to the control oil circuit of a two-position valve.

[0015] In a preferred embodiment of this application, the refueling control valve is normally open. When the double-position valve can output control fuel, the double-position valve provides pressurized fuel to the connector, thereby causing the piston inside the refueling control valve to move. At this time, the refueling control valve is in a closed state.

[0016] When the fuel pressure supplied by the dual-position valve to the inlet is less than a certain value, the spring returns to its initial state, and the refueling control valve opens.

[0017] In a preferred embodiment of this application, the dual-position valve has three fuel connection nozzles, namely a first nozzle, a second nozzle, and a third nozzle. The first nozzle is connected to the aircraft power fuel line, the third nozzle is connected to the aircraft control fuel line, the control fuel line is connected to the refueling line, and the two have the same pressure. The second nozzle is connected to the nozzle of the refueling control valve.

[0018] In a preferred embodiment of this application, the double-position valve has a diaphragm with different areas on both sides. When the fuel pressure at the third connector is greater than the fuel pressure at the first connector, the piston of the double-position valve is pressed against the bracket structure, thereby cutting off the control fuel passage to the second connector. At this time, there is no fuel pressure at the connector of the refueling control valve, and the refueling control valve is in the open state.

[0019] When the fuel pressure at the third connector is less than the combined force of the fuel pressure at the first connector and the spring force of the double-position valve, the double-position valve piston opens, and the aircraft's motive fuel enters the refueling control valve's connector pipe through the second connector, causing it to close.

[0020] In a preferred embodiment of this application, a one-way valve is provided on the refueling pipeline, and the one-way valve is located before the refueling control valve.

[0021] In a preferred embodiment of this application, there are two refueling control valves.

[0022] In a preferred embodiment of this application, an oil filter is provided in the control oil circuit for filtering the fuel in the refueling pipeline.

[0023] The refueling control adjustment method provided in this application solves the problems of slow in-flight refueling rate failing to meet the requirements of rapid in-flight refueling and the inability to fully refuel the aircraft due to low pressure preventing fuel from entering the fuselage fuel tanks, thus affecting the aircraft's range. It achieves the effects of increasing refueling rate, meeting full refueling requirements, and ensuring flight safety through active center of gravity control. Attached Figure Description

[0024] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0025] Figure 1 This is a schematic diagram of the aerial refueling adjustment system of this application.

[0026] Figure 2 This is a schematic diagram of the refueling control valve in this application.

[0027] Figure 3 This is a schematic diagram of the dual-position control valve of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0029] To address the issue of the center of gravity exceeding the rear limit during in-flight refueling when refueling according to normal control logic, this application proposes an in-flight refueling adjustment method and system based on active center of gravity control, which satisfies the aircraft's in-flight refueling capability while ensuring flight safety.

[0030] The in-flight refueling control method proposed in this application includes the following process:

[0031] Step 1: By calculating the weight and center of gravity of all external stores of the aircraft, the remaining fuel limit value of the aircraft and the refueling status of the corresponding rear fuselage fuel tank under the limit value are obtained. The refueling status includes two states: when the fuel in the rear fuselage fuel tank is lower than the remaining fuel limit value, refueling is not allowed; and when the fuel in the rear fuselage fuel tank is higher than the remaining fuel limit value, refueling is allowed.

[0032] For example, in one embodiment of this application, by calculating the weight and center of gravity of all external configurations of a certain type of aircraft, it is determined that when the remaining fuel of the aircraft is less than 6000 kg, fuel is not allowed to be added to a certain numbered aft fuselage fuel tank; when the remaining fuel of the aircraft is more than 6000 kg, fuel is allowed to be added to a certain numbered aft fuselage fuel tank. In the following embodiments, a certain numbered aft fuselage fuel tank will be used as an example for explanation.

[0033] Step 2: Set the buddy refueling pod to have two refueling states: low-speed refueling and high-speed refueling. When refueling in mid-air with less than the limit in the aircraft's rear fuselage fuel tank, set the buddy refueling pod to low-speed refueling to prevent fuel from entering the rear fuselage fuel tank. When refueling in mid-air with more than the limit in the aircraft's rear fuselage fuel tank, set the buddy refueling pod to high-speed refueling to allow fuel to enter the rear fuselage fuel tank.

[0034] The basis for achieving in-flight refueling adjustment is that the buddy refueling pod has two working states: refueling pod state I and refueling pod state II. Refueling pod state I has a lower pressurization pressure and is used for low-speed refueling before and after refueling docking. Refueling pod state II has a higher pressurization pressure and is used for high-speed refueling.

[0035] The purpose of preventing fuel from entering the rear fuselage fuel tank is achieved by using a lower refueling pressure in refueling pod I, and by using a higher refueling pressure in refueling pod II, the purpose of allowing fuel to enter the rear fuselage fuel tank.

[0036] like Figure 2 As shown, in order to realize the above-mentioned in-flight refueling adjustment method based on active center of gravity control, this application provides an in-flight refueling adjustment system 10, which mainly includes: a refueling probe 11, a pressure regulator 12, a one-way valve 13, an oil filter 14, a refueling control valve 15, a two-position valve 17, and a safety valve 16.

[0037] The receiving probe 11 receives pressurized fuel from the refueling tanker (not shown). The pressure regulator 12 is located on the rear side of the receiving probe 11 to ensure that the refueling pipeline P1 of the receiving tanker does not exceed the allowable pressure during the refueling process and thus does not burst.

[0038] A refueling control valve 15 is provided on the refueling pipeline P1. In a preferred embodiment of this application, two refueling control valves 15 are provided on the refueling pipeline P1.

[0039] like Figure 2 As shown, the refueling control valve 15 has a transverse channel within it, through which fuel in the refueling line P1 flows. The refueling control valve 15 contains a piston 151, supported on one side by a spring 152. The lower end of the refueling control valve 15 has a connector 153, which connects to the control oil circuit of the double-position valve 17. The refueling control valve 15 is normally open. When the double-position valve 17 can output high-pressure control fuel, it supplies pressurized fuel to the connector 153, causing the piston 151 within the refueling control valve 15 to move upwards, at which point the refueling control valve 15 is closed. When the fuel pressure supplied to the connector 153 is less than a certain value, the spring 152 returns to its initial state, and the refueling control valve 15 opens.

[0040] like Figure 3 As shown, the double-position valve 17 is installed on the control fuel line of the rear fuselage fuel tank. The double-position valve 17 has three fuel connection nozzles—nozzle A, nozzle B, and nozzle C. Nozzle A connects to the aircraft dynamite fuel line P3; nozzle C connects to the aircraft control fuel line P2, which is connected to the refueling line P1 at the same pressure; and nozzle B connects to nozzle 153. The double-position valve 17 contains a diaphragm. Due to the different areas on both sides of the diaphragm, when the fuel pressure at nozzle C is greater than that at nozzle A, the double-position valve piston 171 is pressed against the bracket structure above it, thus cutting off the control fuel passage to nozzle B. That is, there is no fuel pressure at nozzle B, and the refueling control valve 15 is in the open state. When the fuel pressure at nozzle C is less than the combined force of the fuel pressure at nozzle A and the spring, the double-position valve piston 171 opens, and aircraft dynamite fuel enters the refueling control valve's nozzle 153 through nozzle B, closing it.

[0041] Safety valve 16 is installed in aircraft power fuel line P3 to regulate and protect the pressure of aircraft power fuel line P3.

[0042] During in-flight refueling, fuel from the tanker aircraft passes through the refueling probe 11 and pressure regulator 12 before entering the refueling line P1. Whether the aft fuselage fuel tank can receive fuel depends on whether the refueling control valve 15 can open. The opening of the refueling control valve 15 is controlled by a safety valve 16 and a double-position valve 17. The safety valve 16 adjusts the pressure of the aircraft's power fuel line P3, and this pressure acts on the connector A of the double-position valve 17. The refueling line from the main refueling line through the pressure regulator 12 leads to a control fuel line P2, which acts on the connector B of the double-position valve 17. The pressure of connector A and connector B of the double-position valve 17 is compared to determine whether fuel can enter the connector 153 of the refueling control valve 15, thereby controlling the opening and closing of the refueling control valve 15, and ultimately controlling whether the refueling line P1 can refuel the aft fuselage fuel tank.

[0043] In a preferred embodiment of this application, a one-way valve 13 is provided on the refueling line P1, and the one-way valve 13 is located before the refueling control valve 15. Furthermore, an oil filter 14 is provided on the control oil line P2 for filtering the fuel on the refueling line P1.

[0044] In addition, the aerial refueling control system 10 also includes a ground refueling connector 18, which operates at the same refueling pressure as the refueling pod II – i.e., high-speed refueling. This allows for rapid refueling of the aft fuselage fuel tanks.

[0045] Taking a certain type of aircraft as an example, the pressure at the inlet A of the double-position valve 17 comes from the power fuel line P3. After the power fuel is regulated by the safety valve, its pressure range is relatively stable. The pressure of the control fuel line P2 is taken from the refueling line P1 after the pressure regulator 12. When the pressure of the control fuel line P2 at the inlet B of the double-position valve 17 is greater than 0.15 MPa, the double-position valve 17 does not output control fuel, the refueling control valve 15 is normally open, and the aft fuselage fuel tank can be filled with fuel. When the pressure of the control fuel line P2 at the inlet B of the double-position valve 17 is less than 0.14 MPa, the double-position valve 17 outputs control fuel (power fuel), the refueling control valve 17 is closed, and the aft fuselage fuel tank is not filled with fuel.

[0046] Through the above pressure matching, when the refueling pod is in state I, the pressure of the control oil circuit P2 is less than 0.14MPa, which can achieve the purpose of not allowing oil to enter the rear fuselage fuel tank; when the refueling pod is in state II, the pressure of the control oil circuit P2 is greater than 0.15MPa, which can achieve the purpose of allowing oil to enter the rear fuselage fuel tank.

[0047] The refueling control adjustment method provided in this application solves the problems of slow in-flight refueling rate failing to meet the requirements of rapid in-flight refueling and the inability to fully refuel the aircraft due to low pressure preventing fuel from entering the fuselage fuel tanks, thus affecting the aircraft's range. It achieves the effects of increasing refueling rate, meeting full refueling requirements, and ensuring flight safety through active center of gravity control.

[0048] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An air refueling control system for implementing an air refueling control method based on active center of gravity control, characterized in that, The in-flight refueling control system includes: a refueling probe, a pressure regulator, a refueling control valve, a two-position valve, and a safety valve; The receiving probe receives pressurized fuel from the refueling tanker's refueling compartment, and a pressure regulator is located on the rear side of the receiving probe to ensure that the refueling pipeline of the receiving tanker does not exceed the allowable pressure during the refueling process. The refueling control valve is located on the refueling pipeline and is normally open, used to control the on / off state of the refueling pipeline; The dual-position valve is installed on the control fuel line of the rear fuselage fuel tank, and is respectively connected to the power fuel line, the control line with the same pressure as the refueling line, and the connector for controlling the opening and closing of the refueling control valve. The safety valve is installed in the aircraft's power fuel line and is used to regulate and protect the pressure of the aircraft's power fuel line. When the pressure of the fuel output from the refueling pod reaching the double-position valve via the refueling line and control line is greater than the pressure in the power fuel line, the double-position valve does not output control fuel, the refueling control valve opens, and fuel is supplied to the aft fuselage fuel tank via the refueling line; when the pressure of the fuel output from the refueling pod reaching the double-position valve via the refueling line and control line is less than the pressure in the power fuel line, the double-position valve outputs control fuel, the refueling control valve closes, and fuel cannot be supplied to the aft fuselage fuel tank via the refueling line. The method includes: By calculating the weight and center of gravity of all external stores configurations of the aircraft, the remaining fuel limit value of the aircraft and the refueling status of the aft fuselage fuel tank under the corresponding limit value are obtained. The refueling status includes two states: refueling is not allowed when the fuel in the aft fuselage fuel tank is lower than the remaining fuel limit value, and refueling is allowed when the fuel in the aft fuselage fuel tank is higher than the remaining fuel limit value. The buddy refueling pod has two refueling states: low-speed refueling and high-speed refueling. When refueling in mid-air with less than the limit in the aircraft's rear fuselage fuel tank, the buddy refueling pod is set to low-speed refueling to prevent fuel from entering the rear fuselage fuel tank. When refueling in mid-air with more than the limit in the aircraft's rear fuselage fuel tank, the buddy refueling pod is set to high-speed refueling to allow fuel to enter the rear fuselage fuel tank.

2. The in-flight refueling and conditioning system as described in claim 1, characterized in that, The refueling control valve has a transverse channel in which fuel flows in the refueling pipeline. The refueling control valve has a piston, one side of which is supported by a spring. The lower end of the refueling control valve has a connecting nozzle, which is connected to the control oil circuit of the double-position valve.

3. The in-flight refueling and conditioning system as described in claim 2, characterized in that, The refueling control valve is normally open. When the double-position valve can output control fuel, the double-position valve provides pressurized fuel to the connector, thereby causing the piston inside the refueling control valve to move. At this time, the refueling control valve is in the closed state. When the fuel pressure supplied by the dual-position valve to the inlet is less than a certain value, the spring returns to its initial state, and the refueling control valve opens.

4. The in-flight refueling and conditioning system as described in claim 1, characterized in that, The dual-position valve has three fuel connection nozzles: a first nozzle, a second nozzle, and a third nozzle. The first nozzle connects to the aircraft's power fuel line, the third nozzle connects to the aircraft's control fuel line, and the control fuel line is connected to the refueling line, with both having the same pressure. The second nozzle connects to the nozzle of the refueling control valve.

5. The in-flight refueling and conditioning system as described in claim 4, characterized in that, The double-position valve has a diaphragm with different areas on both sides. When the fuel pressure at the third connector is greater than the fuel pressure at the first connector, the piston of the double-position valve is pressed against the bracket structure, thereby cutting off the control fuel passage to the second connector. At this time, there is no fuel pressure at the connector of the refueling control valve, and the refueling control valve is in the open state. When the fuel pressure at the third connector is less than the combined force of the fuel pressure at the first connector and the spring force of the double-position valve, the double-position valve piston opens, and the aircraft's motive fuel enters the refueling control valve's connector pipe through the second connector, causing it to close.

6. The in-flight refueling and conditioning system as described in claim 1, characterized in that, The refueling pipeline is equipped with a one-way valve, which is located before the refueling control valve.

7. The in-flight refueling and conditioning system as described in claim 1, characterized in that, There are two refueling control valves.

8. The in-flight refueling and conditioning system as described in claim 1, characterized in that, The control oil circuit is equipped with an oil filter for filtering the fuel in the refueling line.

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