A fault detection system and method for a multiple-redundancy aircraft wheel brake system

Abstract

This invention relates to the field of aircraft wheel braking technology, specifically to a fault detection system and method for an aircraft redundant wheel braking system. The method includes: determining whether the hydraulic power source of the current braking system is faulty; determining whether the braking function of the current braking system is faulty; determining whether the anti-slip switch is faulty; determining whether the anti-slip function of the current braking system is faulty; and determining whether the current braking system is faulty based on the results of the determinations regarding the hydraulic power source, braking function, anti-slip switch, and anti-slip function. This method achieves a comprehensive evaluation of whether the braking system is faulty, enabling accurate judgment of the braking system and providing a basis for the subsequent automatic intelligent switching of redundant braking systems.

Description

Technical Field

[0001] This invention relates to the field of aircraft wheel braking technology, and specifically to a fault detection system and method for an aircraft redundant wheel braking system. Background Technology

[0002] The aircraft wheel braking system is one of the most important systems on an aircraft, playing a crucial role in takeoff and landing. The probability of complete brake failure in a wheel braking system must be less than 1E-9FH. To meet this requirement, the wheel braking system design must consider redundancy, especially for large aircraft where additional redundancy is necessary.

[0003] Existing fault detection methods detect and isolate wheel speed sensor faults by adding an input switching unit. However, current technologies only collect wheel speed data and detect faults, without comprehensively assessing faults in the redundant braking system. Other existing technologies simply output three detection currents to the electro-hydraulic pressure servo valve via the auxiliary and main control boards of the aircraft's anti-skid control device to detect the servo valve's status. Furthermore, these methods only detect servo valve faults, or only detect servo motor or wheel speed individually, and cannot comprehensively reflect whether the entire system is faulty.

[0004] Therefore, there is a need to provide a fault detection system and method for aircraft redundant wheel braking systems to solve the above problems. Summary of the Invention

[0005] This invention provides a fault detection system and method for an aircraft redundant wheel braking system. By judging the faults of the hydraulic source, cut-off valve, braking function, anti-skid function, and anti-skid switch during the operation of the braking system, and then comprehensively judging whether the braking system is faulty based on the judgment results, it solves the problem that existing fault detection methods only detect the faults of servo valves, or detect the faults of individual servo motors or wheel speeds, which cannot comprehensively reflect whether the system is faulty.

[0006] The fault detection method for an aircraft redundant wheel braking system of the present invention adopts the following technical solution: including:

[0007] Based on the pressure of the hydraulic source in the current braking system and the braking pressure threshold of the current braking system, determine whether the hydraulic source is faulty when the current braking system is working.

[0008] Based on the target command signal corresponding to each command sensor of the current braking system, and the status of the control valve and shut-off valve of the hydraulic control channel of each wheel, determine whether the braking function of the current braking system is faulty, where the status is normal or faulty;

[0009] The three signals of each redundancy in the anti-slip switch are sorted into a target binary data according to the pin order of the anti-slip switch. A three-bit binary data is preset for each position of the anti-slip switch. Based on the target binary data of each redundancy of the anti-slip switch and the three-bit binary data corresponding to each position, it is determined whether the anti-slip switch is faulty when the braking system is working.

[0010] Obtain the rotational speed information of each wheel when the anti-slip switch is normal and in the open state, and determine whether the anti-slip function of the current braking system is malfunctioning based on the rotational speed information;

[0011] If any one of the following components of the current braking system—hydraulic power source, shut-off valve, braking function, anti-skid function, or anti-skid switch—fails, then the current braking system is faulty.

[0012] Preferably, the steps for determining whether the hydraulic power source of each brake module is faulty are as follows:

[0013] The pressure of the hydraulic source of each brake module is compared with the corresponding brake pressure threshold value of the brake module.

[0014] When the hydraulic power source pressure is greater than or equal to the brake pressure threshold, the hydraulic power source of the brake module is normal; when the hydraulic power source pressure is less than the brake pressure threshold, the hydraulic power source of the brake module is faulty.

[0015] Preferably, the steps for determining whether the braking function of the current braking system is malfunctioning are as follows:

[0016] The three command signals of the command sensor are the first command signal, the second command signal, and the third command signal;

[0017] Obtain the absolute value of the first difference between the first command signal and the second command signal from the command sensor;

[0018] Obtain the absolute value of the second difference between the first command signal and the third command signal from the command sensor;

[0019] Obtain the absolute value of the third difference between the second command signal and the third command signal from the command sensor;

[0020] Based on the absolute values ​​of the first, second, and third differences, and the magnitude of the foot pedal command tolerance, determine whether the target command signal of the command sensor is faulty.

[0021] If half or more of the control valves in the current braking system fail; or half or more of the shut-off valves in the current braking system fail; or 75% or more of the target command signals of the command sensors in the current braking system fail; or the corresponding target command signals of the command sensors of the driver's and passenger's pedals on the same side in the front braking system fail simultaneously.

[0022] This indicates a brake malfunction in the current braking system.

[0023] Preferably, the step of determining whether the target command signal of the command sensor is faulty is as follows:

[0024] If the target command signal is the first command signal:

[0025] If only the absolute values ​​of the second and third differences are less than or equal to the pedal command tolerance, then the first command signal of the command input module is faulty.

[0026] If only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, then the first command signal of the command input module is faulty.

[0027] If only the absolute value of the third difference is less than or equal to the pedal command tolerance, then the first command signal of the command input module is faulty.

[0028] If the target instruction signal is the second instruction signal:

[0029] If only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, then the second command signal of the command input module is faulty.

[0030] If only the absolute values ​​of the first and second differences are less than or equal to the pedal command tolerance, then the second command signal of the command input module is faulty.

[0031] If only the absolute value of the second difference is less than or equal to the pedal command tolerance, then the second command signal of the command input module is faulty.

[0032] If the target instruction signal is a third instruction signal:

[0033] If only the absolute values ​​of the second and third differences are less than or equal to the pedal command tolerance, then the third command signal of the command input module is faulty.

[0034] If only the absolute values ​​of the first and second differences are less than or equal to the pedal command tolerance, then the third command signal of the command input module is faulty.

[0035] If only the absolute value of the first difference is less than or equal to the pedal command tolerance, then the third command signal of the command input module is faulty.

[0036] Preferably, the steps for determining whether the anti-slip switch is faulty are as follows:

[0037] Among them, the three signals for each redundancy are the first signal, the second signal, and the third signal in the order of the pins of the anti-slip switch;

[0038] The target binary data corresponding to each redundancy is matched one by one with the three-bit binary data preset for each position of the anti-slip switch;

[0039] If one of the two target binary data does not match any of the three three-bit binary data, then the anti-slip switch is faulty.

[0040] If both target binary data match any one of the three three-bit binary data, the anti-slip switch is normal when the matching results corresponding to the two redundancies are consistent, and the anti-slip switch is faulty when the matching results corresponding to the two redundancies are inconsistent.

[0041] Preferably, the steps for determining whether the anti-skid function of the current braking system is malfunctioning are as follows:

[0042] When the current braking system is operating under the first braking control module, the first braking controller detects whether the four wheel speed sensors of the current braking system are faulty. If the first redundancy of three or more of the four wheel speed sensors fails, the anti-skid function of the current braking system fails.

[0043] When the current braking system is operating under the second or third braking control module, the second braking controller detects whether the four wheel speed sensors of the current braking system are faulty. If the secondary redundancy of three or more of the four wheel speed sensors fails, the anti-skid function of the current braking system is faulty.

[0044] The present invention provides a fault detection system for an aircraft redundant wheel braking system, which adopts the following technical solution, including:

[0045] The hydraulic power source fault diagnosis module is used to determine whether the hydraulic power source of the current braking system is faulty based on the pressure of the hydraulic power source in the current braking system and the braking pressure threshold value of the current braking system.

[0046] The brake function fault judgment module is used to determine whether the brake function of the current brake system is faulty based on the target command signal corresponding to each command sensor of the current brake system and the status of the control valve and shut-off valve of the hydraulic control channel of each wheel. The status is either normal or faulty.

[0047] The anti-slip switch fault diagnosis module is used to sort the three signals of each redundancy in the anti-slip switch into a target binary data according to the pin order of the anti-slip switch, and to preset a three-bit binary data for each position of the anti-slip switch. Based on the target binary data of each redundancy of the anti-slip switch and the three-bit binary data corresponding to each position, it determines whether the anti-slip switch is faulty when the braking system is working.

[0048] The anti-slip function fault judgment module is used to obtain the speed information of each wheel when the anti-slip switch is normal and in the open state, and to determine whether the anti-slip function of the current braking system is faulty based on the speed information.

[0049] The comprehensive fault diagnosis module is used to diagnose the current braking system fault if any one of the following is faulty: hydraulic power source, shut-off valve, braking function, anti-skid function, or anti-skid switch.

[0050] The present invention provides an aircraft redundant wheel brake control system, which adopts the following technical solution, including:

[0051] The system comprises a first brake control module, a second brake control module, a third brake control module, and a hydraulic power source module.

[0052] The first brake control module, the second brake control module, and the third brake control module all include a brake controller and a hydraulic control module, wherein a hydraulic control module is connected to the brake device of each wheel.

[0053] The hydraulic power module has its output end connected to three hydraulic control modules via output pipes.

[0054] The hydraulic control modules of the first brake control module and the second brake control module include: multiple hydraulic control channels connected to each output pipe of the hydraulic source module, a shut-off valve installed on each output pipe, a control valve and a hydraulic fuse installed sequentially on each hydraulic control channel, the outlet of the hydraulic control channel being connected to the oil inlet of the piston of the brake device on the wheel, and a switching valve installed on the output pipe between the control valve and the hydraulic fuse of one of the hydraulic control modules of the first brake control module and the second brake control module.

[0055] The hydraulic control module of the third brake control module includes: a third control valve and a third shut-off valve sequentially arranged on the third output pipe of the hydraulic source module, wherein the third control valve is connected to the switching valve;

[0056] The instruction input module is used to send instruction signals corresponding to braking instructions to the first braking module, the second braking module, and the third vehicle module.

[0057] Anti-slip switch, used to input control commands to prevent wheel lock-up when each brake control module is working;

[0058] And a fault detection system for an aircraft redundant wheel braking system.

[0059] Preferably, the hydraulic power source module includes:

[0060] First hydraulic source, second hydraulic source, and third hydraulic source;

[0061] The input end of the third hydraulic source is connected to the first hydraulic source and the second hydraulic source respectively, and a one-way valve is provided between the third hydraulic source and the first hydraulic source, and between the third hydraulic source and the second hydraulic source. The one-way valve is only used for the oil from the first hydraulic source or the second hydraulic source to flow to the third hydraulic source.

[0062] The first hydraulic source is connected to the control valve of the first brake control module, the second hydraulic source is connected to the control valve of the second brake control module, the output end of the third hydraulic source is connected to the third shut-off valve, and the output end of the first hydraulic source is connected to the shut-off valve of the first brake control module, and the output end of the second hydraulic source is connected to the shut-off valve of the second brake control module.

[0063] Preferably, the command input module includes four command sensors: a driver's left pedal command sensor, a driver's right pedal command sensor, a passenger's left pedal command sensor, and a passenger's right pedal command sensor. Each command sensor provides three command signals: a first command signal, a second command signal, and a third command signal. The first command signal is the input of the braking command from the first brake control module, the second command signal is the input of the braking command from the second brake control module, and the third command signal is the input of the braking command from the third brake control module.

[0064] The beneficial effects of this invention are:

[0065] This invention performs fault detection on the anti-skid switch, command sensor, hydraulic power source, shut-off valve, servo valve, and wheel speed sensor. Based on the detection results of these components, it determines whether the hydraulic power source, shut-off valve, braking function, anti-skid function, and anti-skid switch are malfunctioning during brake system operation. Furthermore, based on the detection results of these components, a comprehensive judgment is made regarding system malfunction, thus accurately identifying brake system failures. This facilitates subsequent automatic and intelligent switching between redundant systems, reducing the pilot's workload. Attached Figure Description

[0066] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0067] Figure 1 This is a flowchart of a fault detection method for an aircraft redundant wheel braking system according to the present invention;

[0068] Figure 2 This is a flowchart of the brake function fault detection of the first brake control module in a fault detection method for an aircraft redundant wheel brake system according to the present invention.

[0069] Figure 3 This is a flowchart of the brake function fault detection of the second brake control module in a fault detection method for an aircraft redundant wheel brake system according to the present invention.

[0070] Figure 4 This is a flowchart of the brake function fault detection of the third brake control module in a fault detection method for an aircraft redundant wheel brake system according to the present invention.

[0071] Figure 5 This is a schematic diagram of the structure of an aircraft redundant wheel braking system according to the present invention;

[0072] Figure 6 This is a control block diagram of an aircraft redundant wheel braking system according to the present invention;

[0073] Figure 7 This is a hydraulic control block diagram of an aircraft redundant wheel braking system according to the present invention.

[0074] In the diagram: 1. Anti-slip switch; 2. Command input module; 3. Second brake controller; 4. Second shut-off valve; 5. Second control valve; 6. Switching valve; 7. Second hydraulic fuse; 8. Second pressure sensor; 9. Second hydraulic source; 10. Second check valve; 11. Third brake controller; 12. Third shut-off valve; 13. Third control valve; 14. First hydraulic source; 15. First check valve; 16. Third hydraulic source; 17. Wheel speed sensor; 18. Wheel; 19. First pressure sensor; 20. First hydraulic fuse; 21. First control valve; 22. First shut-off valve; 23. First brake controller. Detailed Implementation

[0075] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0076] An embodiment of the fault detection method for an aircraft redundant wheel braking system according to the present invention is as follows: Figure 1 As shown, it includes:

[0077] S1. Determine if the hydraulic power source of the current braking system is faulty;

[0078] Specifically, based on the pressure of the hydraulic source in the current braking system and the braking pressure threshold of the current braking system, it is determined whether the hydraulic source is faulty when the braking system is working.

[0079] The steps for determining whether the hydraulic power source of each brake module is faulty are as follows: obtain the pressure of the hydraulic power source of each brake module, and compare the pressure of the hydraulic power source of each brake module with the corresponding brake pressure threshold value of the brake module; when the hydraulic power source pressure is greater than or equal to the brake pressure threshold value, the hydraulic power source of the brake module is normal; when the hydraulic power source pressure is less than the brake pressure threshold value, the hydraulic power source of the brake module is faulty.

[0080] Specifically, in step S1:

[0081] When the current braking system uses the first brake control module as the working module: the first brake controller 23 receives the pressure information of the first hydraulic source 14 detected by the first pressure sensor 19. When the pressure of the first hydraulic source 14 is less than the working pressure of the first control valve 21, the first brake controller 23 determines that the first hydraulic source 14 is faulty; when the pressure of the first hydraulic source 14 is greater than or equal to the working pressure of the first control valve 21, the first brake controller 23 determines that the first hydraulic source 14 is normal.

[0082] When the current braking system uses the second brake control module as the working module: the second brake controller 3 receives the pressure information of the second hydraulic source 9 detected by the second pressure sensor 8. When the pressure of the second hydraulic source 9 is less than the normal working pressure of the second control valve 5, the second brake controller 3 determines that the second hydraulic source 9 is faulty; when the pressure of the second hydraulic source 9 is greater than or equal to the normal working pressure of the second control valve 5, the second brake controller 3 determines that the second hydraulic source 9 is faulty or normal.

[0083] When the current braking system uses the third brake control module as the working module: the second brake controller 3 receives the pressure information of the third hydraulic source 16 detected by the first pressure sensor 19. When the pressure of the third hydraulic source 16 is less than the working pressure of the third control valve 13, the second brake controller 3 determines that the third hydraulic source 16 is faulty; when the pressure of the third hydraulic source 16 is greater than or equal to the working pressure of the third control valve 13, the second brake controller 3 determines that the third hydraulic source 16 is normal.

[0084] Specifically, the first brake controller 23 receives fault or normal information about the second hydraulic source 9 and the third hydraulic source 16 sent by the second brake controller 3; the second brake controller 3 receives fault or normal information about the first hydraulic source 14 sent by the first brake controller 23; and the third brake controller 11 receives fault or normal information about the first hydraulic source 14 sent by the first brake controller 23, receives fault or normal information about the second hydraulic source 9 sent by the second brake controller 3, and receives normal or fault information about the third hydraulic source 16.

[0085] It should be noted that the brake pressure threshold value in this embodiment is 1900 psi.

[0086] S2. Determine if the braking function of the current braking system is malfunctioning;

[0087] Specifically, based on the target command signal corresponding to each command sensor of the current braking system, and the status of the control valve and shut-off valve of the hydraulic control channel of each wheel 18, it is determined whether the braking function of the current braking system is faulty, where the status is normal or faulty.

[0088] The steps for determining whether the braking function of the current braking system is faulty are as follows: The three command signals from the command sensor are a first command signal, a second command signal, and a third command signal; the absolute value of the first difference between the first and second command signals from the command sensor is obtained; the absolute value of the second difference between the first and third command signals from the command sensor is obtained; the absolute value of the third difference between the second and third command signals from the command sensor is obtained; based on the absolute values ​​of the first, second, and third differences, and the size of the pedal command tolerance, it is determined whether the target command signal of the command sensor is faulty; if half or more of the control valves in the current braking system are faulty; or half or more of the shut-off valves in the current braking system are faulty; or 75% or more of the target command signals of the command sensors in the current braking system are faulty; or the corresponding target command signals of the command sensors on the same side of the driver's and passenger's pedals in the front braking system are simultaneously faulty; then the braking function of the current braking system is faulty.

[0089] In step S2, in this embodiment, the first brake controller 23 specifically determines whether the braking function is faulty. The first brake controller 23 receives a first command signal from the command sensor, the second brake controller 3 receives a second signal from the command sensor and sends it to the first brake controller 23, and the third brake controller 11 receives a third command signal from the command sensor and sends it to the first brake controller 23. The first brake controller 23 then determines whether the command sensor is faulty. Specifically:

[0090] |LVDT1-LVDT2|≤L T(1)

[0091] |LVDT1-LVDT3|≤L T (2)

[0092] |LVDT2-LVDT3|≤L T (3)

[0093] In the formula, LVDT1 is the first command signal received by the command sensor from the first brake controller 23;

[0094] LVDT2 is the second command signal received by the command sensor from the second brake controller 3;

[0095] LVDT3 is the third command signal received by the command sensor from the third brake controller 11;

[0096] LT represents the pedal command tolerance;

[0097] It should be noted that in this embodiment, the first brake controller 23 receives the first command signal LVDT1, the second command signal LVDT2, and the third command signal LVDT3 from the command sensor, all of which are between 0 and 100; the pedal command tolerance LT is 5.

[0098] Specifically, if the target command signal is the first command signal: if only the absolute values ​​of the second and third differences are less than or equal to the pedal command tolerance, then the first command signal of the command input module is faulty; if only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, then the first command signal of the command input module is faulty; if only the absolute value of the third difference is less than or equal to the pedal command tolerance, then the first command signal of the command input module is faulty.

[0099] Specifically, if the target command signal is the second command signal: if only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, then the second command signal of the command input module is faulty; if only the absolute values ​​of the first and second differences are less than or equal to the pedal command tolerance, then the second command signal of the command input module is faulty; if only the absolute value of the second difference is less than or equal to the pedal command tolerance, then the second command signal of the command input module is faulty.

[0100] Specifically, if the target command signal is a third command signal: if only the absolute values ​​of the second and third differences are less than or equal to the pedal command tolerance, then the third command signal of the command input module is faulty; if only the absolute values ​​of the first and second differences are less than or equal to the pedal command tolerance, then the third command signal of the command input module is faulty; if only the absolute value of the first difference is less than or equal to the pedal command tolerance, then the third command signal of the command input module is faulty.

[0101] Specifically, the table for judging whether the target command signal is faulty is shown in Table 1.

[0102] Table 1

[0103]

[0104] Specifically, since this invention takes four first control valves 21, two second control valves 5, two third control valves 13 and four command sensors as examples, it should be noted that the first control valves 21 and the second control valves 5 are both servo valves, and the third control valves 13 are direct-drive servo valves.

[0105] like Figure 2 As shown, if the current braking system is operated by the first brake control module, then in this embodiment, if two or more first control valves 21 fail, or one or more first shut-off valves 22 fail, or the first command signal of three or more command sensors fails, or the first command signal of the command sensor of the same side pedal of the driver and passenger in the front braking system fails simultaneously, then it is determined that the first brake control module of the current braking system has lost half or more of the braking function. In this embodiment, losing half or more of the braking function is considered as a braking function failure of the first brake control module of the current braking system. Conversely, if the first brake control module is not faulty or has lost less than half of the braking function, it is considered that the first brake control module has no fault or has lost less than half of the braking function.

[0106] like Figure 3 As shown, if the current braking system is operated by the second brake control module, then in this embodiment, if one or more second control valves 5 fail, or one or more second shut-off valves 4 fail, or the second command signals of three or more command sensors fail, or the second command signals of the command sensors of the driver's and passenger's side pedals in the front braking system fail simultaneously, then it is determined that the second brake control module of the current braking system has lost half or more of the braking function. In this embodiment, losing half or more of the braking function is considered a braking function failure of the second brake control module of the current braking system. Conversely, if the second brake control module has no fault or has lost less than half of the braking function, it is considered that the second brake control module has no fault.

[0107] like Figure 4As shown, if the current braking system is operated by the third braking control module, then in this embodiment, if one or more third control valves 13 fail, or one or more third shut-off valves 12 fail, or the third command signals of three or more command sensors fail, or the third command signals of the command sensors of the driver's and passenger's side pedals in the front braking system fail simultaneously, then it is determined that the third braking control module of the current braking system has lost half or more of the braking function. In this embodiment, losing half or more of the braking function is considered a braking function failure of the third braking control module of the current braking system. Conversely, if the third braking control module is not faulty or has lost less than half of the braking function, it is considered that the third braking control module has no fault or has lost less than half of the braking function.

[0108] S3. Determine if the anti-slip switch is faulty;

[0109] Specifically, the three signals of each redundancy in anti-slip switch 1 are sorted into a target binary data according to the pin order of anti-slip switch 1, and a three-bit binary data is preset for each gear of anti-slip switch 1. Based on the target binary data of each redundancy of anti-slip switch 1 and the three-bit binary data corresponding to each gear, it is determined whether anti-slip switch 1 is faulty when the current braking system is working.

[0110] In this configuration, the three signals for each redundancy are, in order of pin sequence of the anti-slip switch 1, the first signal, the second signal, and the third signal. The target binary data corresponding to each redundancy is matched one-to-one with the three-bit binary data preset for each gear position of the anti-slip switch 1. If one of the two target binary data sets does not match any of the three three-bit binary data sets, the anti-slip switch 1 is faulty. If both target binary data sets match any one of the three three-bit binary data sets, the anti-slip switch 1 is normal when the matching results for the two redundancy sets are consistent, and faulty when the matching results for the two redundancy sets are inconsistent. It should be noted that when both the first brake controller 23 and the second brake controller 3 determine that the anti-slip switch 1 is in a non-faulty state, it is necessary to determine whether the gear position of the anti-slip switch 1 obtained by the first brake controller 23 and the gear position obtained by the second brake controller 3 are consistent. If they are consistent, the first brake controller 23 determines that the anti-slip switch 1 is normal; if they are inconsistent, the first brake controller 23 determines that the anti-slip switch 1 is faulty.

[0111] When the current braking system is operating under the first brake control module, the first brake controller 23 receives three signals from the first redundancy in the anti-slip switch 1. It presets three-bit binary data corresponding to each position of the anti-slip switch 1. In this embodiment, the three-bit binary data of the anti-slip switch 1 in the ON position is denoted as 101, the three-bit binary data of the anti-slip switch 1 in the OFF position is denoted as 110, and the three-bit binary data of the anti-slip switch 1 in the AUTO position is denoted as 011. Therefore, the first brake controller 23 of the first brake control module first receives the three signals from the first redundancy in the anti-slip switch 1 and sorts these three signals in the order of the first signal, the second signal, and the third signal to obtain the target binary data. The result of the number is one of 101, 110, 011, 000, 001, 010, 111, and 100. The target binary number is compared with 101, 110, and 011 respectively. If it is the same as 101, the first brake controller 23 determines that the anti-slip switch 1 is in the ON position. If it is the same as 110, the first brake controller 23 determines that the anti-slip switch 1 is in the OFF position. If it is the same as 011, the first brake controller 23 determines that the anti-slip switch 1 is in the AUTO position. If the target binary data is any one of 000, 001, 010, 111, and 100, it cannot be matched, that is, the first brake controller 23 determines that the anti-slip switch 1 is faulty. Specifically, the state judgment of the anti-slip switch 1 is shown in Table 2.

[0112] Similarly, when the current braking system is operating under the second brake control module, the second brake controller 3 of the second brake control module first receives the three signals of the second redundancy in the anti-skid switch 1, and sorts the three signals of the second redundancy according to the numerical order of the first signal, the second signal, and the third signal to obtain the target binary data. The result of the target binary number is one of 101, 110, 011, 000, 001, 010, 111, and 100. The target binary number is compared with 101, 110, and 011 respectively. If it is the same as 101, the second brake controller 3 determines that the anti-skid switch 1 is in the ON position; if it is the same as 110, the second brake controller 3 determines that the anti-skid switch 1 is in the OFF position; if it is the same as 011, the second brake controller 3 determines that the anti-skid switch 1 is in the AUTO position; if the target binary data is any one of 000, 001, 010, 111, and 100, it cannot be matched, that is, the second brake controller 3 determines that the anti-skid switch 1 is faulty. The status judgment table of the anti-skid switch 1 is shown in Table 2.

[0113] Table 2

[0114]

[0115]

[0116] S4. Determine if the anti-skid function of the current braking system is malfunctioning;

[0117] Specifically, the rotational speed information of each wheel 18 is obtained when the anti-slip switch 1 is normal and in the open state. Based on the rotational speed information, it is determined whether the anti-slip function of the current braking system is faulty. Specifically, the determination of whether the anti-slip function of the current braking system is faulty is as follows: When the current braking system is operated by the first braking control module, the first braking controller 23 detects whether the four wheel speed sensors 17 of the current braking system are faulty. If the first redundancy of three or more of the four wheel speed sensors 17 is faulty, then the anti-slip function of the current braking system is faulty. When the current braking system is operated by the second braking control module or the third braking control module, the second braking controller 3 detects whether the four wheel speed sensors 17 of the current braking system are faulty. If the second redundancy of three or more of the four wheel speed sensors 17 is faulty, then the anti-slip function of the current braking system is faulty. In this embodiment, when the speed detected by the wheel speed sensor 17 is not within the range of 0-300km / h, it is determined that the redundancy of the corresponding wheel speed sensor 17 is faulty.

[0118] S5. Determine if the current braking system is malfunctioning;

[0119] Specifically, if any one of the following is faulty in the current braking system: hydraulic power source, braking function, anti-skid function, or anti-skid switch 1, then the current braking system is faulty.

[0120] This invention also discloses a fault detection system for an aircraft redundant wheel braking system, comprising: a hydraulic power source fault judgment module, a brake function fault judgment module, an anti-skid switch fault judgment module, an anti-skid function fault judgment module, and a comprehensive fault judgment module. The hydraulic power source fault judgment module is used to determine whether the hydraulic power source of the current braking system is faulty based on the pressure of the hydraulic power source in the current braking system and the brake pressure threshold value of the current braking system. The brake function fault judgment module is used to determine whether the braking function of the current braking system is faulty based on the target command signal corresponding to each command sensor of the current braking system, and the status of the control valve and shut-off valve of the hydraulic control channel of each wheel, wherein the status is normal or faulty. The anti-skid switch fault judgment module... The module is used to sort the three signals of each redundancy in anti-slip switch 1 into a target binary data according to the pin order of anti-slip switch 1, and to preset a three-bit binary data for each position of anti-slip switch 1. Based on the target binary data of each redundancy of anti-slip switch 1 and the three-bit binary data corresponding to each position, it is determined whether anti-slip switch 1 is faulty when the current braking system is working. The anti-slip function fault judgment module is used to obtain the rotational speed information of each wheel 18 when anti-slip switch 1 is normal and in the open state, and to determine whether the anti-slip function of the current braking system is faulty based on the rotational speed information. The comprehensive fault judgment module is used to determine the fault of the current braking system if any one of the hydraulic source, braking function, anti-slip function and anti-slip switch 1 is faulty when the current braking system is working.

[0121] This invention also discloses an aircraft redundant wheel brake control system, such as... Figure 5As shown, it includes: a first brake control module, a second brake control module, a third brake control module, a hydraulic power source module, a command input module 2, an anti-slip switch 1, and the fault detection system disclosed in this invention; the first brake control module, the second brake control module, and the third brake control module all include a brake controller and a hydraulic control module, wherein one hydraulic control module is connected to the brake device of each wheel 18; the output end of the hydraulic power source module is connected to the three hydraulic control modules respectively through output pipes; the hydraulic control modules of the first brake control module and the second brake control module include: multiple hydraulic control channels connected to each output pipe of the hydraulic power source module, a shut-off valve provided on each output pipe, and a control valve and a hydraulic valve sequentially provided on each hydraulic control channel. The hydraulic control channel outlet is connected to the oil inlet of the piston of the braking device on the wheel, and a switching valve 6 is also provided on the output pipe between the control valve of one of the hydraulic control modules in the first and second brake control modules and the hydraulic safety device; the hydraulic control module of the third brake control module includes: a third control valve 13 and a third shut-off valve 12 arranged sequentially on the third output pipe of the hydraulic source module, and the third control valve 13 is connected to the switching valve 6; the command input module 2 is used to send command signals corresponding to the braking commands to the first brake module, the second brake module and the third brake module; the anti-slip switch 1 is used to input control commands to prevent the wheel 18 from locking up when each brake control module is working; and the fault detection system disclosed in this invention, such as Figure 5 and Figure 6 As shown.

[0122] Specifically, the hydraulic power source module in this embodiment includes: a first hydraulic power source 14, a second hydraulic power source 9, and a third hydraulic power source 16; the input end of the third hydraulic power source 16 is connected to the first hydraulic power source 14 and the second hydraulic power source 9 respectively, and a one-way valve is provided between the third hydraulic power source 16 and the first hydraulic power source 14, and between the third hydraulic power source 16 and the second hydraulic power source 9. The one-way valve is only used for the flow of oil from the first hydraulic power source 14 or the second hydraulic power source 9 to the third hydraulic power source 16; wherein, the first hydraulic power source 14 is connected to the control valve of the first brake control module, the second hydraulic power source 9 is connected to the control valve of the second brake control module, the output end of the third hydraulic power source 16 is connected to the third shut-off valve 12, and the output end of the first hydraulic power source 14 is connected to the shut-off valve of the first brake control module, and the output end of the second hydraulic power source 9 is connected to the shut-off valve of the second brake control module.

[0123] Specifically, since the aircraft has four wheels 18, the command input module 2 in this embodiment includes four command sensors: a left pedal command sensor for the primary pilot, a right pedal command sensor for the primary pilot, a left pedal command sensor for the co-pilot, and a right pedal command sensor for the co-pilot. Each command sensor is correspondingly installed on each wheel 18, and each command sensor provides three command signals. The three command signals are: a first command signal, a second command signal, and a third command signal. The first command signal is used to control the first brake control module, the second command signal is used to control the second brake control module, and the third command signal is used to control the third brake control module.

[0124] Specifically, in this embodiment, the hydraulic control module of the first brake control module includes two first output pipes and four first hydraulic control channels. Each first output pipe is connected to two first hydraulic control channels, and each first hydraulic control channel controls one wheel 18. The second brake control module includes one second output pipe and two second hydraulic control channels. Each second output pipe is connected to two second hydraulic control channels, and each second hydraulic control channel controls two wheels 18. Specifically, as... Figure 7 As shown, taking the control of the two left wheels 18 of an aircraft as an example, the control of the two left wheels 18 by the first brake control module is controlled through two first hydraulic control channels. Specifically, the first hydraulic control module is powered by the first hydraulic source 14, then the first shut-off valve 22 of the first output pipe on the first hydraulic source 14 is opened, controlling the opening of the first control valve 21 on the first hydraulic control channel connecting to the first left wheel 18. Finally, the output is sent from the first hydraulic control channel to the piston in the brake device of the first left wheel 18 via the first hydraulic safety 20. When the hydraulic control channel after the first hydraulic safety 20 breaks, the first hydraulic safety 20 closes to prevent the hydraulic fluid from draining out, allowing the brake device to control the deceleration and braking of one left wheel 18. Each second hydraulic control module of the second brake control module controls two hydraulic channels, as shown in the diagram. Figure 7 As shown, the second control pipe of one of the second hydraulic control modules is connected to the first left wheel 18 and the second left wheel 18, thereby realizing simultaneous deceleration and braking control of the wheels 18 on the same side. When the third brake control module is working, as shown... Figure 7As shown, this embodiment takes the conversion valve as an example, which is set between the second control valve 5 and the second hydraulic fuse 7 of the second brake control module. At this time, the output end of the hydraulic control module of the third brake control module is opened to the first check valve 15 connected to the first hydraulic source 14 and the second check valve 10 connected to the second hydraulic source 9. That is, the first hydraulic source 14 and the second hydraulic source 9 supply oil to the third hydraulic source 16. Then the third shut-off valve 12 is opened and the third control valve 13 is opened. The oil flows through the third shut-off valve 12, the third control valve 13, and the conversion valve 6 in sequence into the hydraulic output pipeline of the second hydraulic control module, and is output to the wheel 18 on the same side to simultaneously control the deceleration and braking of the wheel 18 on the same side.

[0125] Working principle

[0126] When the system is powered on, the initial state of the anti-slip switch 1 is ON. The state of the anti-slip switch 1 is determined by the first brake controller 23 of the first brake control module. When the initial state of the anti-slip switch 1 is ON, the first brake controller 23 operates, and the second brake controller 3 is in standby mode, waiting for the instruction from the first brake controller 23, while the third brake controller 11 does not operate. When the first brake controller 23 determines that the initial state of the anti-slip switch 1 is AUTO, the first brake controller 23 operates, and the second brake controller 3 and the third brake controller 11 are in standby mode, waiting for the instruction from the first brake controller 23. When the first brake controller 23 determines that the anti-slip switch 1 is faulty, the first brake controller 23 operates, and the second brake controller 3 and the third brake controller 11 are in standby mode, waiting for the instruction from the first brake controller 23. That is, when the initial state of the anti-slip switch 1 is ON, the first brake controller 23 operates, and the second brake controller 3 and the third brake controller 11 are in standby mode, waiting for the instruction from the first brake controller 23. When the system is in AUTO mode or the anti-slip switch 1 is initially faulty, the first brake control module operates (it should be noted that this invention also assumes the first brake control module operates when the system is powered on). When the first brake control module operates, it detects whether the first hydraulic source 14, the braking function, the anti-slip function, and the anti-slip switch 1 are faulty. If any one of these components fails, the first brake control module of the current braking system is faulty, and the first brake control module will operate. If the first brake control module fails, when the second brake control module operates, it detects whether the second hydraulic source 9, the braking function, the anti-slip function, and the anti-slip switch 1 are faulty. If any one of these components fails, the first and second brake control modules of the current braking system are faulty, and the third brake control module will operate.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fault detection method for an aircraft redundant wheel braking system, characterized in that, include: Based on the pressure of the hydraulic source in the current braking system and the braking pressure threshold of the current braking system, determine whether the hydraulic source is faulty when the current braking system is working. Based on the target command signal corresponding to each command sensor of the current braking system, and the status of the control valve and shut-off valve of the hydraulic control channel of each wheel, determine whether the braking function of the current braking system is faulty, where the status is normal or faulty; The steps for determining whether the braking function of the current braking system is faulty are as follows: The three command signals of the command sensor are a first command signal, a second command signal, and a third command signal; obtain the first absolute value of the difference between the first command signal and the second command signal of the command sensor; obtain the second absolute value of the difference between the first command signal and the third command signal of the command sensor; obtain the third absolute value of the difference between the second command signal and the third command signal of the command sensor; based on the first absolute value, the second absolute value, and the third absolute value of the difference, and the size of the pedal command tolerance, determine whether the target command signal of the command sensor is faulty; if half or more of the control valves in the current braking system are faulty; or half or more of the shut-off valves in the current braking system are faulty; or 75% or more of the target command signals of the command sensors in the current braking system are faulty; or the corresponding target command signals of the command sensors of the driver's and passenger's pedals on the same side in the front braking system are simultaneously faulty; then the braking function of the current braking system is faulty. The steps to determine whether the target command signal of the command sensor is faulty are as follows: If the target command signal is the first command signal: when only the absolute values ​​of the second and third differences are less than or equal to the pedal command tolerance, the first command signal of the command input module is faulty; when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the first command signal of the command input module is faulty; when only the absolute value of the third difference is less than or equal to the pedal command tolerance, the first command signal of the command input module is faulty. If the target command signal is the second command signal: when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty. If the absolute values ​​of the differences are both less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; if only the absolute values ​​of the second difference are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; if the target command signal is a third command signal: if only the absolute values ​​of the second and third differences are both less than or equal to the pedal command tolerance, the third command signal of the command input module is faulty; if only the absolute values ​​of the first and second differences are both less than or equal to the pedal command tolerance, the third command signal of the command input module is faulty; if only the absolute value of the first difference is less than or equal to the pedal command tolerance, the third command signal of the command input module is faulty. The three signals of each redundancy in the anti-slip switch are sorted into a target binary data according to the pin order of the anti-slip switch. A three-bit binary data is preset for each position of the anti-slip switch. Based on the target binary data of each redundancy of the anti-slip switch and the three-bit binary data corresponding to each position, it is determined whether the anti-slip switch is faulty when the braking system is working. Obtain the rotational speed information of each wheel when the anti-slip switch is normal and in the open state, and determine whether the anti-slip function of the current braking system is malfunctioning based on the rotational speed information; If any one of the following is faulty in the current braking system: hydraulic power source, braking function, anti-skid function, or anti-skid switch, then the current braking system is faulty.

2. The fault detection method for an aircraft redundant wheel braking system according to claim 1, characterized in that, The steps to determine whether the hydraulic power source of each brake module is faulty are as follows: The pressure of the hydraulic source of each brake module is compared with the corresponding brake pressure threshold value of the brake module. When the hydraulic power source pressure is greater than or equal to the brake pressure threshold, the hydraulic power source of the brake module is normal; when the hydraulic power source pressure is less than the brake pressure threshold, the hydraulic power source of the brake module is faulty.

3. The fault detection method for an aircraft redundant wheel braking system according to claim 1, characterized in that, The steps to determine if an anti-slip switch is faulty are as follows: Among them, the three signals for each redundancy are the first signal, the second signal, and the third signal in the order of the pins of the anti-slip switch; The target binary data corresponding to each redundancy is matched one by one with the three-bit binary data preset for each position of the anti-slip switch; If one of the two target binary data does not match any of the three three-bit binary data, then the anti-slip switch is faulty. If both target binary data match any one of the three three-bit binary data, the anti-slip switch is normal when the matching results corresponding to the two redundancies are consistent, and the anti-slip switch is faulty when the matching results corresponding to the two redundancies are inconsistent.

4. The fault detection method for an aircraft redundant wheel braking system according to claim 1, characterized in that, The steps to determine if the anti-skid function of the current braking system is malfunctioning are as follows: When the current braking system is operating under the first braking control module, the first braking controller detects whether the four wheel speed sensors of the current braking system are faulty. If the first redundancy of three or more of the four wheel speed sensors fails, the anti-skid function of the current braking system fails. When the current braking system is operating under the second or third braking control module, the second braking controller detects whether the four wheel speed sensors of the current braking system are faulty. If the secondary redundancy of three or more of the four wheel speed sensors fails, the anti-skid function of the current braking system is faulty.

5. A fault detection system for an aircraft redundant wheel braking system, characterized in that, include: The hydraulic power source fault diagnosis module is used to determine whether the hydraulic power source of the current braking system is faulty based on the pressure of the hydraulic power source in the current braking system and the braking pressure threshold value of the current braking system. The brake function fault diagnosis module is used to determine whether the brake function of the current brake system is faulty, based on the target command signal corresponding to each command sensor of the current brake system and the status of the control valve and shut-off valve of the hydraulic control channel of each wheel, wherein the status is normal or faulty. The steps for determining whether the brake function of the current brake system is faulty are as follows: the three command signals of the command sensor are a first command signal, a second command signal, and a third command signal; the absolute value of the first difference between the first command signal and the second command signal of the command sensor is obtained; the absolute value of the second difference between the first command signal and the third command signal of the command sensor is obtained; the absolute value of the second command signal and the third command signal of the command sensor are obtained. The third absolute value of the difference; based on the absolute values ​​of the first, second, and third differences, and the size of the pedal command tolerance, determine whether the target command signal of the command sensor is faulty; if half or more of the control valves in the current braking system are faulty; or half or more of the shut-off valves in the current braking system are faulty; or 75% or more of the target command signals of the command sensors in the current braking system are faulty; or the corresponding target command signals of the command sensors of the driver's and passenger's pedals on the same side in the front braking system are simultaneously faulty; then the braking function of the current braking system is faulty; the steps to determine whether the target command signal of the command sensor is faulty are as follows: If the target command signal is the first command signal: when only the absolute values ​​of the second and third differences are less than or equal to the pedal command tolerance, the first command signal of the command input module is faulty; when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the first command signal of the command input module is faulty; when only the absolute value of the third difference is less than or equal to the pedal command tolerance, the first command signal of the command input module is faulty. If the target command signal is the second command signal: when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; when only the absolute values ​​of the first and third differences are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty. If the absolute values ​​of the differences are both less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; if only the absolute values ​​of the second difference are less than or equal to the pedal command tolerance, the second command signal of the command input module is faulty; if the target command signal is a third command signal: if only the absolute values ​​of the second and third differences are both less than or equal to the pedal command tolerance, the third command signal of the command input module is faulty; if only the absolute values ​​of the first and second differences are both less than or equal to the pedal command tolerance, the third command signal of the command input module is faulty; if only the absolute value of the first difference is less than or equal to the pedal command tolerance, the third command signal of the command input module is faulty. The anti-slip switch fault diagnosis module is used to sort the three signals of each redundancy in the anti-slip switch into a target binary data according to the pin order of the anti-slip switch, and to preset a three-bit binary data for each position of the anti-slip switch. Based on the target binary data of each redundancy of the anti-slip switch and the three-bit binary data corresponding to each position, it determines whether the anti-slip switch is faulty when the braking system is working. The anti-slip function fault judgment module is used to obtain the speed information of each wheel when the anti-slip switch is normal and in the open state, and to determine whether the anti-slip function of the current braking system is faulty based on the speed information. The comprehensive fault diagnosis module is used to diagnose the current braking system fault if any one of the following is faulty: hydraulic power source, braking function, anti-skid function, or anti-skid switch.

6. A redundant aircraft wheel brake control system, characterized in that, include: The system comprises a first brake control module, a second brake control module, a third brake control module, and a hydraulic power source module. The first brake control module, the second brake control module, and the third brake control module all include a brake controller and a hydraulic control module, wherein a hydraulic control module is connected to the brake device of each wheel; The hydraulic power module has its output end connected to three hydraulic control modules via output pipes. The hydraulic control modules of the first brake control module and the second brake control module include: multiple hydraulic control channels connected to each output pipe of the hydraulic source module, a shut-off valve installed on each output pipe, a control valve and a hydraulic fuse installed sequentially on each hydraulic control channel, the outlet of the hydraulic control channel being connected to the oil inlet of the piston of the brake device on the wheel, and a switching valve installed on the output pipe between the control valve and the hydraulic fuse of one of the hydraulic control modules of the first brake control module and the second brake control module. The hydraulic control module of the third brake control module includes: a third control valve and a third shut-off valve sequentially arranged on the third output pipe of the hydraulic source module, wherein the third control valve is connected to the switching valve; The command input module is used to send command signals corresponding to braking commands to the first braking module, the second braking module, and the third vehicle module; Anti-slip switch, used to input control commands to prevent wheel lock-up when each brake control module is working; And the fault detection system as described in claim 5.

7. The aircraft redundant wheel brake control system according to claim 6, characterized in that, The hydraulic power source module includes: First hydraulic source, second hydraulic source, and third hydraulic source; The input end of the third hydraulic source is connected to the first hydraulic source and the second hydraulic source respectively, and a one-way valve is provided between the third hydraulic source and the first hydraulic source, and between the third hydraulic source and the second hydraulic source. The one-way valve is only used for the oil from the first hydraulic source or the second hydraulic source to flow to the third hydraulic source. The first hydraulic source is connected to the control valve of the first brake control module, the second hydraulic source is connected to the control valve of the second brake control module, the output end of the third hydraulic source is connected to the third shut-off valve, and the output end of the first hydraulic source is connected to the shut-off valve of the first brake control module, and the output end of the second hydraulic source is connected to the shut-off valve of the second brake control module.

8. The aircraft redundant wheel brake control system according to claim 6, characterized in that, The command input module includes four command sensors: a driver's left pedal command sensor, a driver's right pedal command sensor, a passenger's left pedal command sensor, and a passenger's right pedal command sensor. Each command sensor provides three command signals: a first command signal, a second command signal, and a third command signal. The first command signal is the input of the braking command from the first brake control module, the second command signal is the input of the braking command from the second brake control module, and the third command signal is the input of the braking command from the third brake control module.

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