A brake system with an accumulator oil filling function and a control method

Abstract

A brake system and control method with accumulator oil charging function include a hydraulic source, an oil charging valve, a check valve, an accumulator, an oil charging button, a standby cut-off valve, a standby servo valve, a wheel, a switching valve, a brake controller, a normal servo valve and a normal cut-off valve.The accumulator and the hydraulic source are completely independent through the accumulator oil charging system, the opening and closing of the oil charging valve are controlled by detecting the state of the aircraft, the state of the accumulator and the working state of the brake system, when the oil charging valve is opened, the function of the hydraulic source charging the accumulator is realized, when the oil charging valve is closed, the isolation of the hydraulic source from the accumulator is realized, the risk of reverse connection of the oil in the accumulator caused by the jamming of the check valve is avoided through the accumulator oil charging system, the safety of the system is improved to 7.6E-10, the loss of hydraulic oil caused by the leakage of the accumulator is avoided, the probability of complete loss of the brake is reduced to 5.8E-9, and the probability of loss of the hydraulic system is also reduced.

Description

Technical Field

[0001] This invention relates to the field of aircraft wheel brake technology, specifically a brake system and control method with an accumulator oil filling function. Background Technology

[0002] The aircraft wheel braking system is one of the most critical systems on an aircraft, playing a vital role in takeoff and landing. Civil aircraft wheel braking systems require accumulators as backup energy sources to supply hydraulic fluid to the braking system, ensuring the aircraft can complete at least one anti-skid braking maneuver, six emergency braking maneuvers, and 12 hours of braking during a stop. Currently, wheel braking systems are equipped with accumulators as reserve energy sources. The accumulators are connected to a hydraulic power source, which continuously supplies hydraulic fluid to the accumulators.

[0003] The invention disclosed in publication number CN 217456341 U is an electronically controlled emergency and stop braking system for aircraft. In this invention, a local energy component and a hydraulic accumulator simultaneously provide hydraulic energy to an integrated valve. When the local energy component is closed, the hydraulic accumulator provides energy to the braking system, and the local energy component provides oil to the hydraulic accumulator. The local energy component and the hydraulic accumulator are connected, and the oil in the hydraulic accumulator can also flow back to the local energy component, resulting in bidirectional flow of oil between the hydraulic accumulator and the local energy component. This affects the normal operation of the local energy component and ultimately affects the use of other hydraulic systems.

[0004] The invention disclosed in publication number CN114802722A is a triple-redundant aircraft braking control system, which includes a normal braking system and an emergency braking system. The emergency braking system is powered by an accumulator. The main hydraulic power source and the emergency electro-hydraulic power source supply hydraulic oil to the accumulator. The main hydraulic power source, the emergency electro-hydraulic power source, and the accumulator are all connected by check valves to prevent oil from returning to the hydraulic power source. When the check valve is stuck in the normally open position, bidirectional flow occurs between the accumulator and the hydraulic power source, affecting the normal operation of the hydraulic power source and ultimately affecting the use of the emergency braking system.

[0005] The aforementioned accumulator serves as a reserve energy source for the wheel braking system. It is not completely independent of the hydraulic power source. When the one-way valve between the accumulator and the hydraulic power source is stuck in the normally open position, the accumulator and the hydraulic power source are interconnected, affecting the hydraulic fluid in the hydraulic power source. When the accumulator leaks, it causes the hydraulic power source to leak, resulting in the loss of function of other systems on the aircraft that use the hydraulic power source, as well as the complete loss of the braking system. Summary of the Invention

[0006] To overcome the problems in existing technologies where the hydraulic power source and accumulator are connected via a one-way valve, resulting in bidirectional flow between the accumulator and hydraulic power source when the one-way valve becomes stuck, and the loss of hydraulic power due to accumulator leakage leading to the malfunction of other aircraft systems, this invention proposes an accumulator-filled oil braking system and its control method.

[0007] The brake system with accumulator filling function proposed in this invention includes a hydraulic power source, a filling valve, a check valve, an accumulator, a filling button, a backup shut-off valve, a backup servo valve, a wheel, a switching valve, a brake controller, a normal servo valve, and a normal shut-off valve.

[0008] The hydraulic power source of the brake system with automatic accumulator filling function is hydraulically connected to the input of the filling valve, providing hydraulic pressure to the filling valve. The output of the filling valve is hydraulically connected to the input of the check valve, providing hydraulic pressure to the check valve. The output of the check valve is hydraulically connected to the output of the accumulator, providing hydraulic pressure to the accumulator. The output of the filling button is electrically connected to the input of the brake controller, sending an opening signal to the brake controller. The input of the standby shut-off valve is hydraulically connected to the output of the accumulator, providing hydraulic pressure to the standby shut-off valve. The hydraulic input of the accumulator pressure sensor is connected to the hydraulic pipeline between the accumulator and the standby shut-off valve, used to detect the hydraulic pressure output by the accumulator. The output of the accumulator pressure sensor is electrically connected to the input of the brake controller, used to send the detected output pressure signal of the accumulator to the brake controller. The input of the standby servo valve is hydraulically connected to the output of the standby shut-off valve, providing hydraulic pressure to the standby servo valve. The output of the hydraulic power source is hydraulically connected to the input of the normal shut-off valve, providing hydraulic pressure to the normal shut-off valve. The output of the normal shut-off valve is hydraulically connected to the input of the normal servo valve, providing hydraulic pressure to the normal servo valve. The output of the normal servo valve is hydraulically connected to the first input of the switching valve, providing hydraulic pressure to the switching valve. The output of the standby servo valve is hydraulically connected to the second input of the switching valve, providing hydraulic pressure to the switching valve. The output of the switching valve is hydraulically connected to the input of the wheel, providing hydraulic pressure to the wheel. The first output of the brake controller is electrically connected to the second input of the oil filling valve, providing a control signal to the oil filling valve; the second output of the brake controller is electrically connected to the electrical input of the normal shut-off valve, providing an open / close control signal to the normal shut-off valve; the third output of the brake controller is electrically connected to the electrical input of the normal servo valve, providing a pressure control signal to the normal servo valve; the fourth output of the brake controller is electrically connected to the electrical input of the standby shut-off valve, providing an open / close control signal to the standby shut-off valve; the fifth output of the brake controller is electrically connected to the electrical input of the standby servo valve, providing a pressure control signal to the standby servo valve.

[0009] The oil filling valve includes a pilot stage, a two-position two-way valve, and a valve body; the oil filling valve is a normally closed valve. When the pilot stage is energized, the two-position two-way valve is open and the oil filling valve is closed; when the pilot stage is not energized, the two-position two-way valve is closed and the oil filling valve is closed.

[0010] The control process of the braking system proposed in this invention is as follows:

[0011] Step 1: The brake controller receives the oil filling switch position signal.

[0012] The oil filling switch has two positions: an open position with oil filling function and a closed position without oil filling function; the brake controller receives the position signal of the oil filling switch.

[0013] Step 2: The brake controller determines whether the aircraft is in the air or on the ground.

[0014] The brake controller receives left and right landing gear wheel load signals from the landing gear system, as well as the aircraft airspeed signal from the inertial navigation system; it determines whether the aircraft is in the air or on the ground by receiving the left and right landing gear wheel load signals and the aircraft airspeed signal.

[0015] When the brake controller determines whether the aircraft is in the air or on the ground, it determines that the aircraft is on the ground if two of the following three conditions are met: the aircraft airspeed signal is less than or equal to the airspeed threshold, the left landing gear wheel load signal is on the ground, and the right landing gear wheel load signal is on the ground. Otherwise, if none of the three conditions are met, the brake controller determines that the aircraft is in the air.

[0016] The airspeed threshold is 100 km / h.

[0017] Step 3: The brake controller checks for accumulator filling malfunction.

[0018] The brake controller is used to determine if the accumulator pressure sensor is faulty. The accumulator pressure sensor fault can be an open circuit fault, a short circuit fault, or an out-of-range fault.

[0019] When the current value of the accumulator pressure sensor is 0, it is determined that the accumulator pressure sensor is open-circuit faulted.

[0020] When the voltage value of the accumulator pressure sensor is 0, it is determined that the accumulator pressure sensor has a short circuit fault.

[0021] When the pressure value detected by the accumulator pressure sensor exceeds the accumulator pressure threshold, the accumulator pressure sensor is determined to be out of range fault.

[0022] When the brake controller detects any of the three faults, it determines that the accumulator is faulty; otherwise, when the brake controller does not detect any of the three faults, it determines that the accumulator is not faulty.

[0023] Step 4: Determine if automatic oil filling is enabled.

[0024] The brake controller receives throttle signals from the engine system and hydraulic pressure signals from the hydraulic system to determine whether to perform accumulator charging. The decision to perform accumulator charging is based on the aircraft's operating status.

[0025] The operating states include two states: the aircraft is in the air or on the ground, and the fuel filling switch signal is on or off.

[0026] When determining whether to automatically refuel, whether the aircraft is in the air or on the ground, the brake controller determines whether to perform accumulator refueling on the ground:

[0027] When the signal from the filling switch received by the brake controller is in the open position, if the throttle lever signal received by the brake controller is in the slow position and the accumulator pressure signal is less than the accumulator filling threshold, the brake controller determines to perform accumulator filling; otherwise, the brake controller determines not to perform accumulator filling.

[0028] When the brake controller receives a signal from the charging switch in the off position, it determines whether to charge the accumulator on the ground based on the following three conditions: the throttle lever signal received by the brake controller is in the fast position, the accumulator pressure is less than or equal to the accumulator charging threshold, and the hydraulic power source pressure is greater than or equal to the hydraulic power source threshold. If all three conditions are met, the brake controller determines to charge the accumulator. Conversely, if any one of the three conditions is not met, the brake controller determines not to charge the accumulator.

[0029] The accumulator has an oil filling threshold of 16 MPa and a hydraulic power source threshold of 15 MPa.

[0030] When determining whether to automatically fill the oil tank, the brake controller determines whether to perform accumulator oil filling in the air when the oil filling switch signal is turned on or off:

[0031] When the brake controller determines that the aircraft is in the air, if the following three conditions are met simultaneously: the throttle lever signal received by the brake controller is in the fast position, the hydraulic source pressure is greater than or equal to the hydraulic source threshold, and the accumulator pressure is less than or equal to the accumulator filling threshold, the brake controller will determine to perform accumulator filling.

[0032] Conversely, if any of the three conditions is not met, the brake controller will not perform air accumulator charging.

[0033] The accumulator has an oil filling threshold of 16 MPa and a hydraulic power source threshold of 15 MPa.

[0034] Step 5: Perform oil filling of the accumulator:

[0035] After the brake controller determines that the accumulator needs to be filled with oil, it controls the filling valve to open, so that the hydraulic passage from the hydraulic source to the accumulator is unidirectional, and the hydraulic source provides hydraulic pressure to the accumulator to realize the filling of the accumulator.

[0036] Step 6: Stop the accumulator oil filling of the brake system.

[0037] The brake controller determines whether the accumulator is faulty when it is charging: the charging time exceeds the accumulator charging time threshold, and the accumulator pressure signal is less than the accumulator pressure threshold. If both conditions are met, the brake controller determines that the accumulator is faulty when it is charging. Otherwise, it determines that the accumulator is not faulty when it is charging.

[0038] The brake controller receives the accumulator pressure signal detected by the accumulator pressure sensor. When the detected accumulator pressure signal is greater than or equal to the accumulator pressure threshold, or when an accumulator filling fault is detected, the brake controller controls the filling valve to close, thereby shutting off the hydraulic passage between the hydraulic source and the accumulator.

[0039] The accumulator filling time threshold is 3s, the accumulator pressure threshold is 21MPa, and the accumulator out-of-range fault refers to the accumulator pressure signal not being between 0 and 25MPa.

[0040] Compared with existing technologies, this invention completely isolates the accumulator and hydraulic power source through an accumulator filling system. The opening and closing of the filling valve is controlled by detecting the aircraft status, accumulator status, and braking system operating status. When the filling valve is open, the hydraulic power source fills the accumulator; when the filling valve is closed, the hydraulic power source is isolated from the accumulator. The accumulator filling system avoids the risk of reverse oil flow in the accumulator due to check valve jamming, improving system safety to 7.6E-10. It also prevents hydraulic power source oil loss caused by accumulator leakage, reducing the probability of complete brake failure to 5.8E-9, and also reduces the probability of hydraulic system failure. Attached Figure Description

[0041] Figure 1 This is a block diagram of a brake system with accumulator filling function according to the present invention;

[0042] Figure 2 The present invention relates to an oil filling valve.

[0043] Figure 3 This is a flowchart of the present invention.

[0044] In the diagram: 1. Hydraulic source; 2. Filling valve; 3. Check valve; 4. Accumulator; 5. Filling button; 6. Backup shut-off valve; 7. Backup servo valve; 8. Wheel; 9. Switching valve; 10. Brake controller; 11. Normal servo valve; 12. Normal shut-off valve; 13. Pilot stage; 14. Two-position two-way valve; 15. Valve body. Detailed Implementation

[0045] Example 1

[0046] This embodiment is a brake system with accumulator oil filling function, including hydraulic source 1, filling valve 2, check valve 3, accumulator 4, filling button 5, backup shut-off valve 6, backup servo valve 7, wheel 8, switching valve 9, brake controller 10, normal servo valve 11, and normal shut-off valve 12.

[0047] The hydraulic power source of the brake system with automatic accumulator filling function is hydraulically connected to the input of the filling valve, providing hydraulic pressure to the filling valve. The output of the filling valve is hydraulically connected to the input of the check valve, providing hydraulic pressure to the check valve. The output of the check valve 3 is hydraulically connected to the output of the accumulator, providing hydraulic pressure to the accumulator. The output of the filling button 5 is electrically connected to the input of the brake controller, sending an opening signal to the brake controller. The input of the standby shut-off valve is hydraulically connected to the output of the accumulator, providing hydraulic pressure to the standby shut-off valve. The hydraulic input of the accumulator pressure sensor is connected to the hydraulic pipeline between the accumulator and the standby shut-off valve, used to detect the hydraulic pressure output by the accumulator. The output of the accumulator pressure sensor is electrically connected to the input of the brake controller, used to send the detected output pressure signal of the accumulator 4 to the brake controller 10. The input of the standby servo valve is hydraulically connected to the output of the standby shut-off valve, providing hydraulic pressure to the standby servo valve. The output of the hydraulic power source is hydraulically connected to the input of the normal shut-off valve, providing hydraulic pressure to the normal shut-off valve. The output of the normal shut-off valve 12 is hydraulically connected to the input of the normal servo valve 11, providing hydraulic pressure to the normal servo valve. The output of the normal servo valve is hydraulically connected to the first input of the switching valve 9, providing hydraulic pressure to the switching valve. The output of the standby servo valve is hydraulically connected to the second input of the switching valve, providing hydraulic pressure to the switching valve. The output of the switching valve is hydraulically connected to the input of the impeller 8, providing hydraulic pressure to the impeller. The first output terminal of the brake controller is electrically connected to the second input terminal of the oil filling valve, providing a control signal to the oil filling valve; the second output terminal of the brake controller is electrically connected to the electrical input terminal of the normal shut-off valve, providing an opening / closing control signal to the normal shut-off valve 12; the third output terminal of the brake controller 10 is electrically connected to the electrical input terminal of the normal servo valve, providing a pressure control signal to the normal servo valve 11; the fourth output terminal of the brake controller is electrically connected to the electrical input terminal of the backup shut-off valve 6, providing an opening / closing control signal to the backup shut-off valve; and the fifth output terminal of the brake controller is electrically connected to the electrical input terminal of the backup servo valve 7, providing a pressure control signal to the backup servo valve.

[0048] The oil filling valve mentioned above Figure 2 As shown, it includes a pilot stage 13, a two-position two-way valve 14, and a valve body 15.

[0049] Among them, the oil filling valve 2 is a normally closed valve. When the pilot stage is energized, the two-position two-way valve is open and the oil filling valve is closed; when the pilot stage is not energized, the two-position two-way valve is not open and the oil filling valve is closed.

[0050] Example 2

[0051] This embodiment provides a control method for automatic oil filling of an accumulator, the specific process of which is as follows:

[0052] Step 1: The brake controller receives the oil filling switch position signal.

[0053] The oil filling switch has two positions: an open position with oil filling function and a closed position without oil filling function; the brake controller receives the position signal of the oil filling switch.

[0054] Step 2: The brake controller determines whether the aircraft is in the air or on the ground.

[0055] The brake controller receives left and right landing gear wheel load signals from the landing gear system, as well as the aircraft airspeed signal from the inertial navigation system; it determines whether the aircraft is in the air or on the ground by receiving the left and right landing gear wheel load signals and the aircraft airspeed signal.

[0056] When the aircraft airspeed signal is less than or equal to the airspeed threshold, the left landing gear wheel load signal is on the ground, and the right landing gear wheel load signal is on the ground, the brake controller determines that the aircraft is on the ground if two of the above three conditions are met; otherwise, if none of the above three conditions are met, the brake controller determines that the aircraft is in the air.

[0057] The airspeed threshold is 100 km / h.

[0058] Step 3: The brake controller checks for accumulator filling malfunction.

[0059] The brake controller is used to determine if the accumulator pressure sensor is faulty. The accumulator pressure sensor fault can be an open circuit fault, a short circuit fault, or an out-of-range fault.

[0060] When the current value of the accumulator pressure sensor is 0, it is determined that the accumulator pressure sensor is open-circuit faulted.

[0061] When the voltage value of the accumulator pressure sensor is 0, it is determined that the accumulator pressure sensor has a short circuit fault.

[0062] When the pressure value detected by the accumulator pressure sensor exceeds the accumulator pressure threshold, the accumulator pressure sensor is determined to be out of range fault.

[0063] When the brake controller detects any of the three faults, it determines that the accumulator is faulty; otherwise, when the brake controller does not detect any of the three faults, it determines that the accumulator is not faulty.

[0064] Step 4: Determine if automatic oil filling is enabled.

[0065] The brake controller receives throttle signals from the engine system and hydraulic pressure signals from the hydraulic system to determine whether to perform accumulator charging. The decision to perform accumulator charging is based on the aircraft's operating status.

[0066] The operating states include the following two: the aircraft is in the air or on the ground, and the fuel filling switch signal is on or off. The specific process is as follows:

[0067] In the first operating state, the brake controller determines whether to perform accumulator charging on the ground:

[0068] When the signal from the filling switch received by the brake controller is in the open position, if the throttle lever signal received by the brake controller is in the slow position and the accumulator pressure signal is less than the accumulator filling threshold, the brake controller determines to perform accumulator filling; otherwise, the brake controller determines not to perform accumulator filling.

[0069] When the brake controller receives a signal from the charging switch in the off position, it determines whether to charge the accumulator on the ground based on the following three conditions: the throttle lever signal received by the brake controller is in the fast position, the accumulator pressure is less than or equal to the accumulator charging threshold, and the hydraulic power source pressure is greater than or equal to the hydraulic power source threshold. If all three conditions are met, the brake controller determines to charge the accumulator. Conversely, if any one of the three conditions is not met, the brake controller determines not to charge the accumulator.

[0070] The accumulator has an oil filling threshold of 16 MPa and a hydraulic power source threshold of 15 MPa.

[0071] In the second operating state, the brake controller determines whether to perform accumulator charging in mid-air:

[0072] When the brake controller determines that the aircraft is in the air, if the following three conditions are met simultaneously: the throttle lever signal received by the brake controller is in the fast position, the hydraulic source pressure is greater than or equal to the hydraulic source threshold, and the accumulator pressure is less than or equal to the accumulator filling threshold, the brake controller will determine to perform accumulator filling.

[0073] Conversely, if any of the three conditions is not met, the brake controller will not perform air accumulator charging.

[0074] The accumulator has an oil filling threshold of 16 MPa and a hydraulic power source threshold of 15 MPa.

[0075] Step 5: Perform oil filling of the accumulator:

[0076] After the brake controller determines that the accumulator needs to be filled with oil, it controls the filling valve to open, so that the hydraulic passage from the hydraulic source to the accumulator is unidirectional, and the hydraulic source provides hydraulic pressure to the accumulator to realize the filling of the accumulator.

[0077] Step 6: Stop the accumulator oil filling of the brake system.

[0078] The brake controller determines whether the accumulator is faulty when it is charging: the charging time exceeds the accumulator charging time threshold, and the accumulator pressure signal is less than the accumulator pressure threshold. If both conditions are met, the brake controller determines that the accumulator is faulty when it is charging. Otherwise, it determines that the accumulator is not faulty when it is charging.

[0079] The accumulator filling time threshold is 3s, the accumulator pressure threshold is 21MPa, and the accumulator out-of-range fault refers to the accumulator pressure signal not being between 0 and 25MPa.

[0080] The brake controller receives the accumulator pressure signal detected by the accumulator pressure sensor. When the detected accumulator pressure signal is greater than or equal to the accumulator pressure threshold, or when an accumulator filling fault is detected, the brake controller controls the filling valve to close, thereby shutting off the hydraulic passage between the hydraulic source and the accumulator.

[0081] The pressure threshold of the accumulator is 21 MPa.

Claims

1. A braking system with an accumulator oil filling function, characterized in that, The system includes a hydraulic power source (1), an oil filling valve (2), a check valve (3), an accumulator (4), an oil filling button (5), a backup shut-off valve (6), a backup servo valve (7), a wheel (8), a switching valve (9), a brake controller (10), a normal servo valve (11), and a normal shut-off valve (12). The output end of the hydraulic power source of the brake system with accumulator oil filling function is hydraulically connected to the input end of the oil filling valve, providing hydraulic pressure to the oil filling valve; the output end of the oil filling valve is hydraulically connected to the input end of the check valve, providing hydraulic pressure to the check valve; the output end of the check valve (3) is hydraulically connected to the output end of the accumulator, providing hydraulic pressure to the accumulator; the oil filling... The output of button (5) is electrically connected to the input of the brake controller, sending an opening signal to the brake controller; the input of the backup shut-off valve is hydraulically connected to the output of the accumulator, providing hydraulic pressure to the backup shut-off valve; the hydraulic input of the accumulator pressure sensor is connected to the hydraulic pipeline between the accumulator and the backup shut-off valve, used to detect the hydraulic pressure output by the accumulator; the output of the accumulator pressure sensor is electrically connected to the input of the brake controller, used to send the detected output pressure signal of the accumulator (4) to the brake controller (10); the input of the backup servo valve is hydraulically connected to the output of the backup shut-off valve, providing hydraulic pressure to the backup servo valve. Hydraulic; the output end of the hydraulic source is hydraulically connected to the input end of the normal shut-off valve to provide hydraulic pressure to the normal shut-off valve; the output end of the normal shut-off valve (12) is hydraulically connected to the input end of the normal servo valve (11) to provide hydraulic pressure to the normal servo valve; the output end of the normal servo valve is hydraulically connected to the first input end of the switching valve (9) to provide hydraulic pressure to the switching valve; the output end of the standby servo valve is hydraulically connected to the second input end of the switching valve to provide hydraulic pressure to the switching valve; the output end of the switching valve is hydraulically connected to the input end of the wheel (8) to provide hydraulic pressure to the wheel; the first output end of the brake controller is electrically connected to the second input end of the oil filling valve to provide control pressure to the oil filling valve. The brake controller provides a control signal for opening / closing the normal shut-off valve (12). The second output of the brake controller (10) is electrically connected to the electrical input of the normal servo valve (11). The brake controller provides a pressure control signal for the normal servo valve (11). The fourth output of the brake controller is electrically connected to the electrical input of the backup shut-off valve (6). The brake controller provides a control signal for opening / closing the backup shut-off valve. The fifth output of the brake controller is electrically connected to the electrical input of the backup servo valve (7). The brake controller provides a pressure control signal for the backup servo valve.

2. The braking system with accumulator filling function as described in claim 1, characterized in that, The oil filling valve includes a pilot stage (13), a two-position two-way valve (14), and a valve body (15); the oil filling valve (2) is a normally closed valve. When the pilot stage is energized, the two-position two-way valve is open and the oil filling valve is closed; when the pilot stage is not energized, the two-position two-way valve is not open and the oil filling valve is closed.

3. A control method using the braking system of claim 1, characterized in that: Step 1: The brake controller receives the oil filling switch position signal; Step 2: The brake controller determines whether the aircraft is in the air or on the ground. The brake controller receives left landing gear wheel load signals and right landing gear wheel load signals from the landing gear system, as well as aircraft airspeed signals from the inertial navigation system; it determines whether the aircraft is in the air or on the ground by receiving the left landing gear wheel load signals, right landing gear wheel load signals, and aircraft airspeed signals. Step 3: The brake controller checks for accumulator filling malfunction. The brake controller is used to determine whether the accumulator pressure sensor is faulty; the accumulator pressure sensor fault is an open circuit fault, a short circuit fault, or an out-of-range fault. Step 4: Determine if automatic oil filling is enabled. The brake controller receives the throttle lever signal from the engine system and the hydraulic pressure signal from the hydraulic system to determine whether to perform accumulator charging; and determines whether to perform accumulator charging based on the aircraft's operating status. The operating states include two states: the aircraft is in the air or on the ground, and the fuel filling switch signal is on or off. Step 5: Perform oil filling of the accumulator: After the brake controller determines that the accumulator needs to be filled with oil, the brake controller controls the filling valve to open, so that the hydraulic passage from the hydraulic source to the accumulator is unidirectional, and the hydraulic source provides hydraulic pressure to the accumulator to realize the filling of the accumulator with oil. Step 6: Stop the accumulator oil filling of the brake system. The brake controller determines whether the accumulator is faulty when it is charging: the accumulator charging time exceeds the accumulator charging time threshold and the accumulator pressure signal is less than the accumulator pressure threshold. If both conditions are met, the brake controller determines that the accumulator is faulty when it is charging; otherwise, it determines that the accumulator is not faulty when it is charging. The brake controller receives the accumulator pressure signal detected by the accumulator pressure sensor; when the detected accumulator pressure signal is greater than or equal to the accumulator pressure threshold, or when an accumulator filling failure is detected, the brake controller controls the filling valve to close, thereby shutting off the hydraulic passage between the hydraulic source and the accumulator.

4. The control method for the braking system as described in claim 3, characterized in that: The oil filling switch has two positions: an open position with oil filling function and a closed position without oil filling function; the brake controller receives the position signal of the oil filling switch.

5. The control method for the braking system as described in claim 3, characterized in that: When the brake controller determines whether the aircraft is in the air or on the ground, it determines that the aircraft is on the ground if two of the following three conditions are met: the aircraft airspeed signal is less than or equal to the airspeed threshold, the left landing gear wheel load signal is on the ground, and the right landing gear wheel load signal is on the ground. Otherwise, if none of the three conditions are met, the brake controller determines that the aircraft is in the air. The airspeed threshold is 100 km / h.

6. The control method for the braking system as described in claim 3, characterized in that: When the current value of the accumulator pressure sensor is 0, it is determined that the accumulator pressure sensor is open-circuit fault. When the voltage value of the accumulator pressure sensor is 0, it is determined that the accumulator pressure sensor has a short circuit fault. When the pressure value detected by the accumulator pressure sensor exceeds the accumulator pressure threshold, the accumulator pressure sensor is determined to be out of range fault. When the brake controller detects any of the three faults, it determines that the accumulator is faulty; otherwise, when the brake controller does not detect any of the three faults, it determines that the accumulator is not faulty.

7. The control method for the braking system as described in claim 3, characterized in that: When determining whether to automatically refuel, whether the aircraft is in the air or on the ground, the brake controller determines whether to perform accumulator refueling on the ground: When the signal from the filling switch received by the brake controller is in the open position, if the throttle lever signal received by the brake controller is in the slow position and the accumulator pressure signal is less than the accumulator filling threshold, the brake controller determines to perform accumulator filling; otherwise, the brake controller determines not to perform accumulator filling. When the signal from the charging switch received by the brake controller is in the closed position, the brake controller determines whether to charge the accumulator on the ground based on the following three conditions: the throttle lever signal received by the brake controller is in the fast position, the accumulator pressure is less than or equal to the accumulator charging threshold, and the hydraulic source pressure is greater than or equal to the hydraulic source threshold. When all three conditions are met, the brake controller determines to charge the accumulator; otherwise, if any of the three conditions are not met, the brake controller determines not to charge the accumulator. The accumulator has an oil filling threshold of 16 MPa and a hydraulic power source threshold of 15 MPa.

8. The control method for the braking system as described in claim 3, characterized in that: When determining whether to automatically refill oil, when the signal of the oil filling switch is open or closed, the brake controller determines whether to perform accumulator oil filling in the air: when the brake controller determines that the aircraft is in the air, if the following three conditions are met simultaneously: if the throttle lever signal received by the brake controller is in the fast position, the hydraulic source pressure is ≥ the hydraulic source threshold value, and the accumulator pressure is ≤ the accumulator oil filling threshold value, the brake controller determines to perform accumulator oil filling. Conversely, if any of the three conditions is not met, the brake controller will not perform air accumulator charging. The accumulator has an oil filling threshold of 16 MPa and a hydraulic power source threshold of 15 MPa.

9. The control method for the braking system as described in claim 3, characterized in that: The accumulator filling time threshold is 3s, the accumulator pressure threshold is 21MPa, and the accumulator out-of-range fault refers to the accumulator pressure signal not being between 0 and 25MPa.

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