Aircraft Braking Control Method, System and Aircraft

Abstract

The present invention provides an aircraft braking control method, system and aircraft. The method includes: obtaining a braking control command value based on the acquired aircraft speed, wheel speed and a preset target slip ratio; calculating an expected wheel speed according to the braking control command value, calculating an expected slip ratio according to the expected wheel speed, and obtaining a correction amount for correcting the braking control command value based on the expected slip ratio and the preset target slip ratio; determining a reference pressure value according to a preset slip ratio threshold and the acquired actual braking pressure value, and outputting a target braking control command value based on the reference pressure value, the braking control command value and the correction amount. The present invention can predict in advance the state after the system response delay to cope with the lag of the actual braking pressure relative to the braking control command, thereby achieving a good anti-skid braking control effect.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft brake control, and particularly to an aircraft brake control method, system and aircraft capable of coping with too low brake pressure. Background Art

[0002] The core of aircraft brake control is anti-skid brake control. Anti-skid brake control can play important roles such as adjusting brake pressure to prevent wheel skidding, locking and reducing braking distance, ensuring safe, reliable and efficient aircraft braking deceleration. And the aircraft anti-skid brake system is a complex non-linear system with uncertainty, and there are many non-linear factors in the system, which directly affect the performance of anti-skid braking.

[0003] In brake anti-skid control, once the anti-skid algorithm detects a low wheel speed, it will reduce the brake pressure to make the wheel speed start to rotate. However, due to system response delay or other reasons, usually it takes a certain time for the pressure to decrease. At this time, the wheel speed is still low, and the algorithm still judges skidding, so it continues to reduce the pressure, making the pressure lower than the pressure value that does not cause wheel skidding. That is to say, higher pressure could have been used for braking but was not. Therefore, due to too low release of brake anti-skid pressure, there is a problem of poor braking deceleration effect. Summary of the Invention

[0004] The present invention provides an aircraft brake control method, system and aircraft to solve the problem of poor braking deceleration effect caused by too low release of brake anti-skid pressure in the prior art.

[0005] In a first aspect, the present invention provides an aircraft brake control method, and the method includes:

[0006] Obtaining a brake control command value according to the obtained aircraft speed, wheel speed and a preset target slip ratio;

[0007] Calculating an expected wheel speed according to the brake control command value, calculating an expected slip ratio according to the expected wheel speed, and obtaining a correction amount for correcting the brake control command value according to the expected slip ratio and the preset target slip ratio;

[0008] Determining a reference pressure value according to a preset slip ratio threshold and the obtained actual brake pressure value, and outputting a target brake control command value according to the reference pressure value, the brake control command value and the correction amount.

[0009] In an embodiment of the present invention, the step of obtaining a brake control command value according to the obtained aircraft speed, wheel speed and a preset target slip ratio includes:

[0010] Obtaining the reference speed of the previous cycle;

[0011] Compare the magnitudes of the aircraft speed and the reference speed in the previous cycle, and use the one with the larger speed value as the reference speed for the current cycle;

[0012] Subtract the wheel speed from the reference speed for the current cycle, take the absolute value, and then divide by the reference speed for the current cycle to obtain the actual slip ratio;

[0013] Calculate the brake control command value based on the difference between the preset target slip ratio and the actual slip ratio, where the brake control command value is equal to the sum of the deviation term and the integral term of the difference.

[0014] In an embodiment of the present invention, the step of calculating the expected wheel speed based on the brake control command value includes:

[0015] Calculate the expected wheel speed according to the following formula:

[0016] W = a + ∫[k * N - b * μ * M * g)]dt;

[0017] Where, W is the expected wheel speed, N is the brake control command value, dt is the integral of the current cycle time t, and a, k, b, μ, M, g are all preset parameters.

[0018] In an embodiment of the present invention, the step of calculating the expected slip ratio based on the expected wheel speed includes:

[0019] Calculate the expected slip ratio according to the following formula:

[0020] H = (R - W) / (max(W, R));

[0021] Where, R = Va + c * t, c = 0.5 * r1 * r2 * [[dw(t) - dw(t - 1)] / dt] + [[dw(t - 1) - dw(t - 2)] / dt], H is the expected slip ratio, W is the expected wheel speed, Va is the aircraft speed, c is the aircraft acceleration correction value, w is the wheel speed, and r1 and r2 are all preset parameters.

[0022] In an embodiment of the present invention, the step of obtaining a correction amount for correcting the brake control command value based on the expected slip ratio and the preset target slip ratio includes:

[0023] Calculate the difference between the preset target slip ratio and the expected slip ratio;

[0024] Multiply the difference by a preset proportional coefficient to obtain the correction amount.

[0025] In an embodiment of the present invention, the step of obtaining a correction amount for correcting the brake control command value based on the expected slip ratio and the preset target slip ratio includes:

[0026] Calculate the correction amount according to the following formula:

[0027] D = k1 * (T - H) + k2 * (T - H) ^ 2;

[0028] Where D is the correction amount, T is the preset target slip ratio, H is the expected slip ratio, and k1 and k2 are both preset parameters.

[0029] In an embodiment of the present invention, the step of determining the reference pressure value according to the preset slip ratio threshold and the obtained actual brake pressure value includes:

[0030] If the actual slip ratio is less than or equal to the preset slip ratio threshold, increase the actual brake pressure value representing the current cycle to the candidate reference sequence, and the candidate reference sequence includes the actual brake pressure values of historical cycles;

[0031] Select the maximum actual brake pressure value from the candidate reference sequence and multiply it by a preset proportionality factor to be used as the reference pressure value.

[0032] In an embodiment of the present invention, the step of outputting the target brake control command value according to the reference pressure value, the brake control command value, and the correction amount includes:

[0033] Judge whether the corrected brake control command value is greater than the reference pressure value, where the corrected brake control command value is equal to the sum of the brake control command value and the correction amount;

[0034] If the corrected brake control command value is greater than the reference pressure value, output the corrected brake control command value as the target brake control command value;

[0035] If the corrected brake control command value is less than or equal to the reference pressure value, continue to judge whether the duration is less than the preset duration threshold;

[0036] If the duration is less than the preset duration threshold, output the reference pressure value as the target brake control command value;

[0037] If the duration is greater than or equal to the preset duration threshold, output the corrected brake control command value as the target brake control command value.

[0038] In a second aspect, the present invention further provides an aircraft brake control system, and the system includes:

[0039] A brake control command value calculation module, configured to obtain a brake control command value according to the obtained aircraft speed, wheel speed, and a preset target slip ratio;

[0040] A correction amount calculation module, configured to calculate an expected wheel speed according to the brake control command value, calculate an expected slip ratio according to the expected wheel speed, and obtain a correction amount for correcting the brake control command value according to the expected slip ratio and the preset target slip ratio;

[0041] A target brake command value calculation module, configured to determine a reference pressure value according to a preset slip ratio threshold and the obtained actual brake pressure value, and output a target brake control command value according to the reference pressure value, the brake control command value, and the correction amount.

[0042] In a third aspect, the present invention further provides an aircraft, which is configured to execute the aircraft brake control method according to any one of the first aspects.

[0043] In an embodiment of the present invention, the aircraft includes a wheel speed sensor, an aircraft speed measurement module, a brake control module, a brake control device, a brake actuator, and a brake pressure sensor;

[0044] Wherein, the wheel speed sensor is configured to measure the wheel speed of the aircraft, the aircraft speed measurement module is configured to measure the aircraft speed, the brake pressure sensor is configured to measure the actual brake pressure value output by the brake control device to the brake actuator, and the brake control module is configured to execute the aircraft brake control method according to the received aircraft speed, wheel speed, and actual brake pressure value and output a brake control command; the brake control device is configured to output a brake pressure according to the brake control command; the brake actuator is configured to receive the brake pressure and act on the aircraft wheels.

[0045] The aircraft brake control method, system, and aircraft provided by the present invention can correct the brake control command value by introducing an expected wheel speed, and at the same time determine a reference pressure value according to the actual brake pressure value to output a target brake control command value, so as to predict in advance the state after the system response delay to cope with the lag of the actual brake pressure relative to the brake control command, thereby achieving a good anti-skid brake control effect, effectively reducing brake skidding, avoiding releasing too much pressure at the same time, obtaining a high brake efficiency, and effectively improving the brake performance of the aircraft. Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0047] Figure 1 It is the module block diagram of the aircraft provided by the present invention;

[0048] Figure 2 It is the schematic flow chart of the aircraft brake control method provided by the present invention;

[0049] Figure 3 It is the schematic flow chart of the calculation of the brake control command value provided by the present invention;

[0050] Figure 4 It is the schematic flow chart of the calculation of the correction amount provided by the present invention;

[0051] Figure 5 It is the schematic flow chart of determining the reference pressure value provided by the present invention;

[0052] Figure 6 It is the schematic flow chart of the calculation of the target brake command value provided by the present invention;

[0053] Figure 7 It is the module block diagram of the aircraft brake control system provided by the present invention. Detailed implementation manners

[0054] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts fall within the scope of protection of the present invention.

[0055] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned accompanying drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in an order different from that shown or described herein.

[0056] The aircraft anti-skid brake control algorithm is the core of brake control, which plays an important role in adjusting the brake pressure to prevent tire skidding, locking and reducing the braking distance, ensuring safe, reliable and efficient braking deceleration of the aircraft.

[0057] To solve the problem in the prior art that the braking deceleration effect is poor due to too low release of anti-skid braking pressure, the present invention provides an aircraft braking control method, system and aircraft. By introducing an expected wheel speed to correct the braking control command value, and at the same time determining a reference pressure value according to the actual braking pressure value to output a target braking control command value, it is possible to predict in advance the state after the system response delay to cope with the lag of the actual braking pressure relative to the braking control command, thereby achieving a better anti-skid braking control effect, effectively reducing braking skidding, avoiding excessive pressure release at the same time, obtaining a higher braking efficiency, and effectively improving the braking performance of the aircraft.

[0058] The following will combine Figures 1-7 to describe the aircraft braking control method, system and aircraft of the present invention.

[0059] Please refer to Figure 1 , Figure 1 which is a block diagram of the modules of the aircraft provided by the present invention. An aircraft includes a wheel speed sensor 101, an aircraft speed measurement module 102, a braking control module 103, a braking pressure sensor 104, a braking control device 105 and a braking actuator 106.

[0060] Exemplarily, the wheel speed sensor 101 is connected to the braking control module 103 and is installed at the wheel axle of the landing gear wheel to measure the rolling speed of the aircraft landing gear wheel, that is, the wheel speed.

[0061] Exemplarily, the aircraft speed measurement module 102 is connected to the braking control module 103 and is used to measure the aircraft speed. The aircraft speed measurement module 102 can adopt an aircraft inertial navigation system.

[0062] Exemplarily, the braking control module 103 is respectively connected to the wheel speed sensor 101, the aircraft speed measurement module 102, the braking pressure sensor 104 and the braking control device 105, and is used to execute the aircraft braking control method of the present invention to output a braking control command according to the aircraft speed measured by the aircraft speed measurement module 102, the wheel speed measured by the wheel speed sensor 101 and the actual braking pressure value measured by the braking pressure sensor 104.

[0063] Exemplarily, the braking pressure sensor 104 is located at the output end of the braking control device 105 and is used to measure the actual braking pressure value output from the braking control device 15 to the braking actuator 106.

[0064] Exemplarily, the braking control device 105 is used to output a braking pressure to the braking actuator 106 according to the braking control command output by the braking control module 103.

[0065] Exemplarily, the brake actuator 106 is used to receive the brake pressure output by the brake control device 105, generate the torque of the brake, and then act it on the aircraft wheels to decelerate the aircraft wheels, so as to decelerate the aircraft.

[0066] Based on the above aircraft architecture, the aircraft brake control method and system provided by the present invention will be specifically described below.

[0067] Please refer to Figure 2 , Figure 2 is a schematic flow chart of the aircraft brake control method provided by the present invention. An aircraft brake control method, the method comprising:

[0068] Step 210, obtaining a brake control command value according to the obtained aircraft speed, wheel speed, and a preset target slip ratio.

[0069] Step 220, calculating an expected wheel speed according to the brake control command value, calculating an expected slip ratio according to the expected wheel speed, and obtaining a correction amount for correcting the brake control command value according to the expected slip ratio and the preset target slip ratio.

[0070] Step 230, determining a reference pressure value according to a preset slip ratio threshold and the obtained actual brake pressure value, and outputting a target brake control command value according to the reference pressure value, the brake control command value, and the correction amount.

[0071] It should be noted that the aircraft brake control method of the present invention can be executed periodically, that is, the above steps 210 to 240 are executed once in each period, completing the entire calculation process from input to output, and finally outputting a target brake control command value. The time of each period can be set according to actual needs, for example, each period is set to 5 ms.

[0072] The above steps 210 to 230 will be specifically described below by taking a certain period as an example.

[0073] Please refer to Figure 3 , Figure 3 is a schematic flow chart of the calculation of the brake control command value provided by the present invention. In the above step 210, the step of obtaining a brake control command value according to the obtained aircraft speed, wheel speed, and a preset target slip ratio includes:

[0074] Step 2101, obtaining the reference speed of the previous period.

[0075] Step 2102, comparing the magnitudes of the aircraft speed and the reference speed of the previous period, and taking the speed value with the larger magnitude as the reference speed of the current period.

[0076] Among them, the aircraft speed can be obtained by Figure 1The aircraft speed measurement module 102 in [specific context] measures that the reference speed is a reference speed for anti-skid braking control of the aircraft and can be calculated based on aircraft motion parameters. The aircraft motion parameters are, for example, the aircraft pitch angle, wheel speed, etc.

[0077] Step 2103: Subtract the wheel speed from the reference speed of the current cycle, take the absolute value, and then divide by the reference speed of the current cycle to obtain the actual slip ratio.

[0078] Exemplarily, the actual slip ratio H1 = |V0 - w| / V0, where V0 represents the reference speed of the current cycle and w represents the wheel speed.

[0079] Step 2104: Calculate the brake control command value according to the difference between the preset target slip ratio and the actual slip ratio, where the brake control command value is equal to the sum of the deviation term and the integral term of the difference.

[0080] Exemplarily, assume that the preset target slip ratio is H0. For example, the preset target slip ratio is 0.15, and the difference E = H0 - H1. Then the brake control command value N is equal to the sum of the deviation term and the integral term of the difference E, that is

[0081] N = K p *E + K i *∫E;

[0082] Where, K p 、K i are preset parameters and can be constants.

[0083] Please refer to Figure 4 , Figure 4 is a schematic flow diagram of the correction amount calculation provided by the present invention. In the above step 220, the steps of calculating the expected wheel speed according to the brake control command value, calculating the expected slip ratio according to the expected wheel speed, and obtaining the correction amount for correcting the brake control command value according to the expected slip ratio and the preset target slip ratio include:

[0084] Step 2201: Calculate the expected wheel speed according to the brake control command value.

[0085] Exemplarily, from the above step 2104, the brake control command value N can be obtained, and the expected wheel speed is calculated according to the following formula:

[0086] W = a + ∫[k * N - b * μ * M * g)]dt;

[0087] Where, W is the expected wheel speed, N is the brake control command value, dt is the integral of the current cycle time t, and a, k, b, μ, M, g are all preset parameters (can be constants).

[0088] Step 2202: Calculate the expected slip ratio based on the expected wheel speed.

[0089] Exemplarily, the expected slip ratio is calculated according to the following formula:

[0090] H = (R - W) / (max(W, R));

[0091] where R = Va + c * t, c = 0.5 * r1 * r2 * [[dw(t) - dw(t - 1)] / dt] + [[dw(t - 1) - dw(t - 2)] / dt], H is the expected slip ratio, W is the expected wheel speed, Va is the aircraft speed, c is the aircraft acceleration correction value, w is the wheel speed, and r1 and r2 are both preset parameters (which can be constants).

[0092] Step 2203: Calculate the difference between the preset target slip ratio and the expected slip ratio, and multiply the difference by a preset proportionality coefficient to obtain the correction amount.

[0093] That is, D = k * |T - H|, where D is the correction amount, T is the preset target slip ratio, H is the expected slip ratio, and k is a preset parameter (which can be a constant).

[0094] In some embodiments of the present invention, the correction amount in the above step 2203 can also be calculated according to the following formula:

[0095] D = k1 * (T - H) + k2 * (T - H) ^ 2;

[0096] where D is the correction amount, T is the preset target slip ratio, H is the expected slip ratio, and k1 and k2 are both preset parameters, which can be constants.

[0097] Please refer to Figure 5 , Figure 5 which is a schematic flow diagram of determining the reference pressure value provided by the present invention. In the above step 230, the steps of determining the reference pressure value according to the preset slip ratio threshold and the obtained actual brake pressure value include:

[0098] Step 2301: If the actual slip ratio is less than or equal to the preset slip ratio threshold, add the actual brake pressure value representing the current cycle to the candidate reference sequence, and the candidate reference sequence includes the actual brake pressure values of historical cycles.

[0099] It should be noted that the actual slip ratio H1 can be calculated by the above step 2103, and the preset slip ratio threshold can be set in advance. For example, the preset slip ratio threshold can be 0.2, and the slip ratio is a percentage, and its value ranges from 0 to 1.

[0100] For example, compare the size of the actual slip ratio H1 and 0.2. If H1 is less than or equal to 0.2, the actual brake pressure value P of the current cycle will be obtained. i Add it to the candidate reference sequence. Among them, the candidate reference sequence is a set of actual brake pressure values accumulated based on all cycles before this step.

[0101] Step 2302, select the maximum actual brake pressure value from the candidate reference sequence and multiply it by a preset proportionality coefficient to obtain the reference pressure value.

[0102] For example, assume the candidate reference sequence = {P1, P2, ……, P i}, then take the maximum value Pmax in this sequence, multiply it by a certain proportionality coefficient, such as 0.9, then the reference pressure value M = Pmax * 0.9.

[0103] Please refer to Figure 6 , Figure 6 is a schematic flow diagram of calculating the target brake command value provided by the present invention. In the above step 230, the step of outputting the target brake control command value according to the reference pressure value, the brake control command value, and the correction amount includes:

[0104] Step 2303, determine whether the corrected brake control command value is greater than the reference pressure value. Among them, the corrected brake control command value is equal to the sum of the brake control command value and the correction amount.

[0105] It should be noted that the brake control command value N is calculated by the above step 2104, and the correction amount D is calculated by the above step 2204. Then the corrected brake control command value Cb = N + D, and then compare the size of the corrected brake control command value Cb and the reference pressure value M.

[0106] Step 2304, if the corrected brake control command value is greater than the reference pressure value, output the corrected brake control command value as the target brake control command value.

[0107] That is to say, if Cb > M, the target brake control command value C i = Cb.

[0108] Step 2305, if the corrected brake control command value is less than or equal to the reference pressure value, continue to determine whether the duration is less than the preset duration threshold.

[0109] Step 2306, if the duration is less than the preset duration threshold, output the reference pressure value as the target brake control command value.

[0110] That is to say, if Cb ≤ M and the duration is less than the preset duration threshold, the target brake control command value C i= M.

[0111] Step 2307, if the duration is greater than or equal to the preset duration threshold, output the corrected brake control command value as the target brake control command value.

[0112] That is to say, if Cb ≤ M and the duration is greater than or equal to the preset duration threshold, the target brake control command value C i = Cb.

[0113] Exemplarily, the above steps 2305 and 2306 can be implemented by setting a parameter J for counting: when Cb is less than or equal to M, J is incremented by one, that is, J i = J i-1 + 1. If Cb is less than or equal to M and at the same time when J < 10, then C i = M; if Cb is less than or equal to M and at the same time when J is greater than or equal to 10, then C i = Cb.

[0114] In summary, the aircraft brake control method of the present invention corrects the brake control command value by introducing the expected wheel speed, and at the same time determines the reference pressure value according to the actual brake pressure value to output the target brake control command value, which can predict in advance the state after the system response delay to cope with the lag of the actual brake pressure relative to the brake control command, thereby achieving a better anti-skid brake control effect, effectively reducing brake slip, avoiding releasing too much pressure at the same time, obtaining a higher brake efficiency, and effectively improving the brake performance of the aircraft.

[0115] Next, the aircraft brake control system provided by the present invention will be described. The aircraft brake control system described below can be correspondingly referred to the aircraft brake control method described above.

[0116] Please refer to Figure 7 , Figure 7 which is a block diagram of the aircraft brake control system provided by the present invention. An aircraft brake control system 700 includes a brake control command value calculation module 710, a correction amount calculation module 720, and a target brake command value calculation module 730.

[0117] Exemplarily, the brake control command value calculation module 710 is used for:

[0118] Obtain the brake control command value according to the obtained aircraft speed, wheel speed, and preset target slip rate.

[0119] Exemplarily, the command correction amount calculation module 720 is used for:

[0120] Calculate the expected wheel speed according to the brake control command value, calculate the expected slip ratio according to the expected wheel speed, and obtain a correction amount for correcting the brake control command value according to the expected slip ratio and the preset target slip ratio.

[0121] Exemplarily, the target brake command value calculation module 730 is configured to:

[0122] Determine a reference pressure value according to a preset slip ratio threshold and the obtained actual brake pressure value, and output a target brake control command value according to the reference pressure value, the brake control command value, and the correction amount.

[0123] Exemplarily, the brake control command value calculation module 710 is further configured to:

[0124] Obtain the reference speed of the previous cycle;

[0125] Compare the magnitudes of the aircraft speed and the reference speed of the previous cycle, and use the larger speed value as the reference speed of the current cycle;

[0126] Subtract the wheel speed from the reference speed of the current cycle, take the absolute value, and divide by the reference speed of the current cycle to obtain the actual slip ratio;

[0127] Calculate the brake control command value according to the difference between the preset target slip ratio and the actual slip ratio, where the brake control command value is equal to the sum of the deviation term and the integral term of the difference.

[0128] Exemplarily, the instruction correction amount calculation module 720 is further configured to:

[0129] Calculate the expected wheel speed according to the following formula:

[0130] W = a + ∫[k*N - b*μ*M*g)]dt;

[0131] Where, W is the expected wheel speed, N is the brake control command value, dt is the integral of the current cycle time t, and a, k, b, μ, M, g are all preset parameters.

[0132] Exemplarily, the instruction correction amount calculation module 720 is further configured to:

[0133] Calculate the expected slip ratio according to the following formula:

[0134] H = (R - W) / (max(W, R));

[0135] Wherein, R = Va + c * t, c = 0.5 * r1 * r2 * [[dw(t) - dw(t - 1)] / dt] + [[dw(t - 1) - dw(t - 2)] / dt], H is the expected slip ratio, W is the expected wheel speed, Va is the aircraft speed, c is the aircraft acceleration correction value, w is the wheel speed, and r1 and r2 are both preset parameters.

[0136] Exemplarily, the instruction correction amount calculation module 720 is further configured to:

[0137] Calculate the difference between the preset target slip ratio and the expected slip ratio;

[0138] Multiply the difference by a preset proportionality coefficient to obtain the correction amount.

[0139] Exemplarily, the instruction correction amount calculation module 720 is further configured to:

[0140] Calculate the correction amount according to the following formula:

[0141] D = k1 * (T - H) + k2 * (T - H) ^ 2;

[0142] Wherein, D is the correction amount, T is the preset target slip ratio, H is the expected slip ratio, and k1 and k2 are both preset parameters.

[0143] Exemplarily, the target brake command value calculation module 730 is further configured to:

[0144] If the actual slip ratio is less than or equal to the preset slip ratio threshold, increase the actual brake pressure value representing the current cycle to the candidate reference sequence, where the candidate reference sequence includes the actual brake pressure values of historical cycles;

[0145] Select the maximum actual brake pressure value from the candidate reference sequence and multiply it by a preset proportionality coefficient to be used as the reference pressure value.

[0146] Exemplarily, the target brake command value calculation module 730 is further configured to:

[0147] Judge whether the corrected brake control command value is greater than the reference pressure value, where the corrected brake control command value is equal to the sum of the brake control command value and the correction amount;

[0148] If the corrected brake control command value is greater than the reference pressure value, output the corrected brake control command value as the target brake control command value;

[0149] If the corrected brake control command value is less than or equal to the reference pressure value, continue to judge whether the duration is less than the preset duration threshold;

[0150] If the duration is less than the preset duration threshold, output the reference pressure value as the target brake control command value;

[0151] If the duration is greater than or equal to the preset duration threshold, output the corrected brake control command value as the target brake control command value.

[0152] It should be noted here that the above aircraft brake control system provided by the embodiments of the present invention can implement all the method steps implemented by the above method embodiments, and can achieve the same technical effects. The same parts and beneficial effects as those in the method embodiments will not be specifically described in this embodiment.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aircraft braking control method, characterized in that, The method includes: Obtaining a brake control command value based on the acquired aircraft speed, wheel speed, and a preset target slip ratio; Calculating an expected wheel speed according to the brake control command value, calculating an expected slip ratio according to the expected wheel speed, and obtaining a correction amount for correcting the brake control command value based on the expected slip ratio and the preset target slip ratio; Determining a reference pressure value according to a preset slip ratio threshold and the acquired actual brake pressure value, and outputting a target brake control command value based on the reference pressure value, the brake control command value, and the correction amount.

2. The aircraft braking control method according to claim 1, wherein The step of obtaining a brake control command value based on the acquired aircraft speed, wheel speed, and a preset target slip ratio includes: Obtaining a reference speed of the previous cycle; Comparing the magnitudes of the aircraft speed and the reference speed of the previous cycle, and taking the larger speed value as the reference speed of the current cycle; Taking the absolute value of the difference between the reference speed of the current cycle and the wheel speed, and dividing it by the reference speed of the current cycle to obtain an actual slip ratio; Calculating the brake control command value according to the difference between the preset target slip ratio and the actual slip ratio, where the brake control command value is equal to the sum of the deviation term and the integral term of the difference.

3. The aircraft braking control method according to claim 2, characterized in that, The step of calculating an expected wheel speed according to the brake control command value includes: Calculating the expected wheel speed according to the following formula: W = a + ∫[k * N - b * μ * M * g)]dt; where, W is the expected wheel speed, N is the brake control command value, dt is the integration of the time t of the current cycle, and a, k, b, μ, M, and g are all preset parameters.

4. The aircraft braking control method according to claim 3, wherein, The step of calculating an expected slip ratio according to the expected wheel speed includes: Calculating the expected slip ratio according to the following formula: H = (R - W) / (max(W, R)); where, R = Va + c * t, c = 0.5 * r1 * r2 * [[dw(t) - dw(t - 1)] / dt] + [[dw(t - 1) - dw(t - 2)] / dt], H is the expected slip ratio, W is the expected wheel speed, Va is the aircraft speed, c is the aircraft acceleration correction value, w is the wheel speed, and r1 and r2 are both preset parameters.

5. The aircraft braking control method according to claim 4, characterized in that, The step of obtaining a correction amount for correcting the brake control command value based on the expected slip ratio and the preset target slip ratio includes: Calculating the difference between the preset target slip ratio and the expected slip ratio; Multiplying the difference by a preset proportionality coefficient to obtain the correction amount.

6. The aircraft braking control method according to claim 4, wherein, The step of obtaining a correction amount for correcting the brake control command value based on the expected slip ratio and the preset target slip ratio includes: Calculating the correction amount according to the following formula: D = k1*(T - H) + k2*(T - H) ^ 2; where, D is the correction amount, T is the preset target slip ratio, H is the expected slip ratio, and k1 and k2 are both preset parameters.

7. The aircraft braking control method according to claim 5 or 6, characterized in that The step of determining a reference pressure value according to a preset slip ratio threshold and the acquired actual brake pressure value includes: If the actual slip ratio is less than or equal to the preset slip ratio threshold, adding the actual brake pressure value representing the current cycle to a candidate reference sequence, where the candidate reference sequence includes the actual brake pressure values of historical cycles; Select the maximum actual brake pressure value from the candidate reference sequences and multiply it by a preset scale factor to obtain the reference pressure value.

8. The aircraft brake control method according to claim 7, wherein The step of outputting a target brake control command value based on the reference pressure value, the brake control command value, and the correction amount includes: Determine whether the corrected brake control command value is greater than the reference pressure value, where the corrected brake control command value is equal to the sum of the brake control command value and the correction amount; If the corrected brake control command value is greater than the reference pressure value, output the corrected brake control command value as the target brake control command value; If the corrected brake control command value is less than or equal to the reference pressure value, continue to determine whether the duration is less than a preset duration threshold; If the duration is less than the preset duration threshold, output the reference pressure value as the target brake control command value; If the duration is greater than or equal to the preset duration threshold, output the corrected brake control command value as the target brake control command value.

9. An aircraft brake control system, characterized in that, The system includes: A brake control command value calculation module for obtaining a brake control command value based on the acquired aircraft speed, wheel speed, and a preset target slip ratio; A correction amount calculation module for calculating an expected wheel speed based on the brake control command value, calculating an expected slip ratio based on the expected wheel speed, and obtaining a correction amount for correcting the brake control command value based on the expected slip ratio and the preset target slip ratio; A target brake command value calculation module for determining a reference pressure value based on a preset slip ratio threshold and the acquired actual brake pressure value, and outputting a target brake control command value based on the reference pressure value, the brake control command value, and the correction amount.

10. An aircraft, characterized in that, The aircraft is configured to execute the aircraft brake control method according to any one of claims 1 to 8.

11. The aircraft according to claim 10, characterized in that, The aircraft includes a wheel speed sensor, an aircraft speed measurement module, a brake control module, a brake control device, a brake actuator, and a brake pressure sensor; Wherein, the wheel speed sensor is configured to measure the wheel speed of the aircraft, the aircraft speed measurement module is configured to measure the aircraft speed, the brake pressure sensor is configured to measure the actual brake pressure value output from the brake control device to the brake actuator, the brake control module is configured to execute the aircraft brake control method based on the received aircraft speed, wheel speed, and actual brake pressure value and output a brake control command; the brake control device is configured to output a brake pressure according to the brake control command; the brake actuator is configured to receive the brake pressure and act on the aircraft wheels.

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