An aircraft anti-skid braking system and anti-yaw control method based on anti-skid synchronization

Abstract

The present invention provides an aircraft anti-skid braking system and a yaw prevention control method based on anti-skid synchronization, including: Step 1, generating an aircraft heading correction command by collecting in real time the braking command stroke output by the pilot and the wheel speed signal output by the wheel speed sensor; Step 2, performing anti-skid treatment on the wheels on one side indicated by the aircraft heading correction command, and triggering anti-skid treatment on the wheels on the other side by assigning the speed of the wheels on this side before anti-skid treatment to the wheels on the other side, so as to achieve synchronous correction treatment of the wheels on both sides. The technical solution of the embodiment of the present invention solves the problems of the existing yaw prevention control function, which can only correct the heading after the aircraft yaws, and has a long response time, slow response speed, and a large offset heading angle, thus bringing potential safety hazards to the aircraft landing.

Description

Technical Field

[0001] The present invention relates to, but is not limited to, the technical field of aircraft brake control, and particularly to an aircraft anti-skid brake system and a yaw prevention control method based on anti-skid synchronization. Background Art

[0002] The aircraft anti-skid brake system is an important airborne device of an aircraft. By adjusting the brake pressure, it makes full use of the adhesion coefficient between the wheels and the ground, prevents the wheels from jamming and locking, and ensures the landing safety of the aircraft under various runway conditions.

[0003] After the aircraft lands, the pilot determines the brake pressure by stepping on the pedal. The controller receives the wheel speed signal transmitted by the wheel speed sensor, and based on this, generates a corresponding brake current through closed-loop control, thereby controlling the hydraulic servo valve to adjust the brake pressure acting on the brake device to achieve aircraft braking. During the braking process, when the brake torque of the wheel is greater than the ground adhesion torque, it will cause the aircraft to skid. Therefore, in addition to the braking function, the brake system of modern aircraft usually also has an anti-skid control function. The anti-skid control function can automatically adjust the brake pressure according to the current state of the runway surface, make the brake torque adapt to the current state of the runway surface, prevent the wheels from jamming (locking) or even bursting due to skidding, and obtain a higher braking efficiency.

[0004] The aircraft anti-skid control function is often configured with a corresponding yaw prevention control function to correct the heading deviation during the aircraft braking process. Obviously, the yaw prevention control function is crucial for the landing safety of the aircraft. Although the existing yaw prevention control function can effectively correct the yaw problem caused by the excessive speed difference between the left and right wheels during the aircraft anti-skid braking process, due to its slow response and relatively large heading deviation angle generated after correction. The above existing yaw prevention control function has the following disadvantages. First, it can only correct the heading after the aircraft yaws, and does not have an advanced correction function, that is, it cannot predict the possible heading deviation in advance based on the wheel conditions during the aircraft taxiing and perform manual intervention to correct it in advance. Second, the generation time of the correction command is long and the response is slow. Since the aircraft has a high speed in the initial stage of landing, the response of using this control method is slow, so the generated deviation heading angle is relatively large, posing a certain safety hazard. Summary of the Invention

[0005] The object of the present invention: The embodiments of the present invention provide an aircraft anti-skid brake system and a yaw prevention control method based on anti-skid synchronization to solve the problems of the existing yaw prevention control function, which can only correct the heading after the aircraft yaws, and has a long response time, slow response speed, and a relatively large deviation heading angle, thus bringing safety hazards to the aircraft landing.

[0006] The technical solution of the present invention is as follows: An anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization provided by an embodiment of the present invention includes:

[0007] Step 1: Generate an aircraft heading correction command based on the real-time collected brake command stroke output by the pilot and the wheel speed signal output by the wheel speed sensor.

[0008] Step 2: Perform anti-skid treatment on the wheels on one side indicated by the aircraft heading correction command, and trigger the anti-skid treatment on the wheels on the other side by assigning the speed of the wheels on this side before anti-skid treatment to the wheels on the other side, so as to achieve synchronous correction treatment of the wheels on both sides.

[0009] Optionally, in the anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization as described above, the aircraft heading correction command in Step 1 is a digital signal, where "1" indicates performing anti-yaw correction treatment, and "0" indicates not performing anti-yaw correction treatment.

[0010] Optionally, in the anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization as described above, the method for generating the aircraft heading correction command in Step 1 is as follows:

[0011] After the aircraft lands and enters the anti-skid braking state, when the brake command stroke output by the pilot is greater than or equal to a preset ratio of the full brake stroke, and the change amount of the unilateral wheel speed per unit time is greater than or equal to the speed change threshold, and the wheels on this side show a skidding phenomenon, the aircraft heading correction command is set to "1", and the anti-skid braking control system performs aircraft heading correction treatment;

[0012] After the aircraft lands and enters the anti-skid braking state, in other cases except the above, the aircraft heading correction command is set to "0", and no aircraft heading correction treatment is performed.

[0013] Optionally, in the anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization as described above, Step 2 includes:

[0014] After the aircraft lands and enters the anti-skid braking state, when the skidding of the unilateral wheels causes the aircraft heading correction command to be set to "1", the state of the wheels on this side triggers the anti-skid braking system to perform anti-skid treatment on the wheels on this side, release the brake pressure on the skidding side, and change the state of the wheels on this side from sliding to rolling;

[0015] Assign the speed of the wheels on this side to the speed of the wheels on the other side, trigger the anti-skid function of the wheels on the other side, and actively release the brake pressure on the other side to achieve synchronous correction treatment of the wheels on both sides.

[0016] An embodiment of the present invention also provides an aircraft anti-skid braking system based on anti-skid synchronization, including: a wheel speed sensor, a brake command sensor, and an anti-skid braking control box;

[0017] Wheel speed sensors are respectively installed on the left and right wheels of the aircraft, which are used to collect the wheel speed signals of the corresponding wheels in real time and transmit the wheel speed signals to the anti-skid brake control box;

[0018] A brake command sensor is installed on the aircraft brake pedal, which is used to collect the brake command stroke signal sent by the pilot stepping on the pedal in real time and transmit the brake command stroke signal to the anti-skid brake control box;

[0019] The anti-skid brake control box is respectively connected to the wheel speed sensor and the brake command sensor, and is used to generate an aircraft heading correction command according to the brake command stroke signal and the wheel speed signal collected in real time;

[0020] The anti-skid brake control box is also used to perform anti-skid treatment on the wheels on one side indicated by the aircraft heading correction command, and trigger the anti-skid treatment on the wheels on the other side by assigning the speed of the wheels on this side before anti-skid treatment to the wheels on the other side, so as to realize the synchronous correction treatment of the wheels on both sides.

[0021] Optionally, in the aircraft anti-skid brake system based on anti-skid synchronization as described above, the method for the anti-skid brake control box to generate an aircraft heading correction command is as follows:

[0022] After the aircraft lands and enters the anti-skid brake state, when the brake command stroke output by the pilot is greater than or equal to the preset ratio of the full brake stroke, and the change amount of the unilateral wheel speed per unit time is greater than or equal to the speed change threshold, and the wheels on this side show a skidding phenomenon, the aircraft heading correction command is set to "1", and the anti-skid brake control system performs aircraft heading correction processing;

[0023] After the aircraft lands and enters the anti-skid brake state, in other cases except the above, the aircraft heading correction command is set to "0", and no aircraft heading correction processing is performed.

[0024] Optionally, in the aircraft anti-skid brake system based on anti-skid synchronization as described above, the brake execution components of the aircraft anti-skid brake system include: an electro-hydraulic pressure servo valve and an electromagnetic hydraulic lock respectively connected to the anti-skid brake control box, and a brake device connected to the electro-hydraulic pressure servo valve;

[0025] The method for the anti-skid brake control box to perform anti-skid treatment on the unilateral wheels is as follows:

[0026] The anti-skid brake control box calculates the corresponding anti-skid amount according to the aircraft heading deviation correction instruction, sends a locking control signal to the electromagnetic hydraulic lock to open the electromagnetic hydraulic lock, and sends the difference between the digital quantity corresponding to the command stroke signal and the anti-skid amount to the electro-hydraulic pressure servo valve corresponding to the brake current value, so that the electro-hydraulic pressure servo valve outputs the corresponding brake pressure to the brake device to generate a braking torque.

[0027] Optionally, in the aircraft anti-skid brake system based on anti-skid synchronization as described above, the method for synchronously correcting the deviation of the two-side wheels by the anti-skid brake control box is as follows:

[0028] After the aircraft lands and enters the anti-skid brake state, when the aircraft heading deviation correction instruction is set to "1" due to the skidding of a single-side wheel, the state of the wheel on this side triggers the anti-skid brake system to perform anti-skid treatment on the wheel on this side, releases the brake pressure on the skidding side, and changes the state of the wheel on this side from sliding to rolling;

[0029] Assign the speed of the wheel on this side to the speed of the wheel on the other side, trigger the anti-skid function of the wheel on the other side, and actively release the brake pressure on the other side to achieve synchronous deviation correction of the two-side wheels.

[0030] The beneficial effects of the present invention are as follows: The embodiment of the present invention provides an aircraft anti-skid brake system and a yaw prevention control method based on anti-skid synchronization. Since it takes about 300 ms for the aircraft anti-skid brake system to respond to the command signal from the circuit to the hydraulic system after sending the aircraft heading deviation correction instruction; in the initial stage of aircraft landing, the speed is relatively high. If there is a lag in the time of sending the aircraft heading deviation correction instruction itself, a large deviation heading angle will be generated, which is likely to cause the aircraft to approach the edge of the runway. The existing yaw prevention control method issues a deviation correction instruction only when the speed difference between the left and right wheels reaches 30%, which requires a long wheel speed judgment time, resulting in a lag in the time of sending the deviation correction instruction, easily generating a large deviation heading angle, having the risk of running out of the runway, and there are potential safety hazards. By using the yaw prevention control method of the present invention, it is possible to monitor whether the aircraft yaws according to the wheel conditions during aircraft taxiing and by changing the input conditions of the anti-skid brake system. Once yaw occurs, the aircraft heading is corrected in real time, and the result is consistent with the expectation, achieving the goal of correcting the aircraft heading; the embodiment of the present invention adopts the technical means of correcting the aircraft heading in real time, which can effectively shorten the response time of yaw control, thereby effectively reducing the risk of the aircraft running out of the runway and improving the reliability and safety of the anti-skid brake system.

[0031] Furthermore, the yaw prevention control method of the aircraft anti-skid brake system provided by the embodiment of the present invention has the advantages of fast response, no lag, and small deviation heading angle, solves the defect that the conventional yaw control method cannot correct the aircraft heading in real time, effectively reduces the risk of the aircraft running out of the runway, and improves the reliability and safety of the system. There are no reports and cases of using the control method of the present invention in domestic and foreign anti-skid brake systems. Brief Description of the Drawings

[0032] The drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

[0033] Figure 1 It is a schematic structural diagram of an aircraft anti-skid braking system provided by an embodiment of the present invention;

[0034] Figure 2 It is a flowchart of a method for controlling yaw prevention of an aircraft anti-skid braking system based on anti-skid synchronization provided by an embodiment of the present invention. Detailed Embodiments

[0035] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the embodiments of the present invention will be described in detail below with reference to the drawings. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily.

[0036] As described in the above background art, the function of controlling yaw prevention is crucial for the safety of aircraft landing. Therefore, in various types of aircraft braking systems, emphasis is placed on setting a method for controlling yaw prevention. The control logic of the existing function of controlling yaw prevention is usually as follows: during the aircraft braking process, the CPU of the anti-skid braking control panel judges according to the collected wheel speed signals (the two left wheels and the two right wheels are protected in pairs). When the speed difference between the wheel speeds on one side and the wheel speeds on the other side reaches the threshold value Vdt1, the function of controlling yaw prevention is used to reduce the servo valve voltage on the low-speed side, release the braking pressure on that side, and make the wheel speed on the low-speed side rise rapidly, so as to avoid the aircraft from deviating; when the above speed difference is less than the threshold value Vdt2, the function of controlling yaw prevention automatically fails. It takes about 50 ms to 80 ms for the formation of the yaw correction instruction in the above method for controlling yaw prevention.

[0037] According to the control logic of the existing function of controlling yaw prevention as described above, it can be seen that although the function of controlling yaw prevention can effectively correct the yaw problem during the aircraft braking process, it has the following disadvantages:

[0038] (1) It can only correct the heading after the aircraft yaws, and does not have the function of advanced correction;

[0039] (2) The response time is long and the response speed is slow;

[0040] (3) Based on the feature of slow response speed, when the aircraft is at a relatively high speed in the initial stage of landing, the offset heading angle will be relatively large, posing a safety hazard.

[0041] In view of the various problems existing in the above-mentioned existing anti-yaw control functions, an embodiment of the present invention provides an anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization.

[0042] The present invention provides the following specific embodiments that can be combined with each other, and the same or similar concepts or processes may not be described in some embodiments.

[0043] In order to shorten the response time of the conventional aircraft anti-yaw control method and improve the reliability and safety of the conventional aircraft anti-yaw control method, an embodiment of the present invention proposes an anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization. As Figure 1 shown, it is a schematic structural diagram of an aircraft anti-skid braking system provided by an embodiment of the present invention. In the anti-yaw control method for the aircraft anti-skid braking system provided by the embodiment of the present invention, an electro-hydraulic anti-skid braking system is adopted. The execution components involved in the electro-hydraulic anti-skid braking system are: a wheel speed sensor (installed on the wheel to collect the wheel speed signal and transmit it to the control box); an anti-skid braking control box (collecting the above-mentioned wheel speed signal, brake command signal and brake pressure signal, and respectively outputting brake pressure signals to the electro-hydraulic pressure servo valve and the electromagnetic hydraulic lock); a brake command sensor (collecting the brake command signal according to the voltage value output by the pilot stepping on the pedal stroke); a brake pressure sensor (collecting the brake pressure signal output by the servo valve); an electro-hydraulic pressure servo valve and an electromagnetic hydraulic lock, etc.

[0044] As Figure 2 shown, it is a flowchart of the anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization provided by an embodiment of the present invention. The anti-yaw control method for the aircraft anti-skid braking system based on anti-skid synchronization may include the following steps:

[0045] Step 1, generate an aircraft heading correction command through the brake command stroke output by the pilot collected in real time and the wheel speed signal output by the wheel speed sensor.

[0046] Step 2, perform anti-skid treatment on the wheels on one side indicated by the aircraft heading correction command, and trigger the anti-skid treatment on the wheels on the other side by assigning the speed of the wheels on this side before anti-skid treatment to the wheels on the other side, so as to achieve synchronous correction treatment of the wheels on both sides.

[0047] In an embodiment of the present invention, a control method for preventing the aircraft landing gear from causing aircraft heading deviation due to excessive speed difference between the left and right wheels after landing is specifically provided. The aircraft heading correction command generated in the above step 1 is a digital signal, where "1" indicates performing anti-yaw correction processing, and "0" indicates not performing anti-yaw correction processing.

[0048] In an embodiment of the present invention, the specific manner of generating the aircraft heading correction command in the above step 1 is:

[0049] After the aircraft lands and enters the anti-skid braking state, when the stroke of the braking command output by the pilot is greater than or equal to the preset ratio of the full braking stroke, and the change amount of the unilateral wheel speed per unit time is greater than or equal to the speed change threshold, and the wheel on this side shows a skidding phenomenon, the aircraft heading correction command is set to "1", and the anti-skid braking control system performs aircraft heading correction processing;

[0050] After the aircraft lands and enters the anti-skid braking state, in other cases except the above, the aircraft heading correction command is set to "0", and no aircraft heading correction processing is performed.

[0051] In the embodiment of the present invention, the specific implementation manner of the above step 2 includes:

[0052] After the aircraft lands and enters the anti-skid braking state, when the skidding of the unilateral wheel causes the aircraft heading correction command to be set to "1", the state of the wheel on this side triggers the anti-skid braking system to perform anti-skid processing on the wheel on this side, releases the braking pressure on the skidding side, and makes the wheel on this side change from a sliding state to a rolling state;

[0053] Assign the speed of the wheel on this side to the speed of the wheel on the other side, trigger the anti-skid function of the wheel on the other side, and actively release the braking pressure on the other side to achieve synchronous correction processing of the two sides of the wheels.

[0054] As Figure 1 shown, the embodiment of the present invention also provides an aircraft anti-skid braking system based on anti-skid synchronization. The aircraft anti-skid braking system may adopt an electric anti-skid braking system, for example, and may include: a wheel speed sensor, a braking command sensor, and an anti-skid braking control box.

[0055] In the specific implementation of the embodiment of the present invention, wheel speed sensors are respectively installed on the left and right wheels of the aircraft, which are used to collect the wheel speed signals of the corresponding wheels in real time and transmit the wheel speed signals to the anti-skid braking control box.

[0056] In the embodiment of the present invention, a braking command sensor is installed on the aircraft brake pedal, which is used to collect the braking command stroke signal sent by the pilot by stepping on the pedal in real time and transmit the braking command stroke signal to the anti-skid braking control box; the above braking command stroke signal is actually the stroke corresponding to the voltage value.

[0057] In the embodiment of the present invention, the anti-skid braking control box is respectively connected to the wheel speed sensor and the braking command sensor, and is used to generate an aircraft heading correction command according to the braking command stroke signal and the wheel speed signal collected in real time.

[0058] In the embodiment of the present invention, the anti-skid brake control box is further configured to perform anti-skid processing on the wheels on one side indicated by the aircraft heading correction command, and trigger the anti-skid processing of the wheels on the other side by assigning the speed of the wheels on this side before anti-skid processing to the wheels on the other side, so as to achieve synchronous correction processing of the wheels on both sides.

[0059] In an implementation manner of the embodiment of the present invention, the implementation manner in which the anti-skid brake control box generates the aircraft heading correction command is as follows:

[0060] After the aircraft lands and enters the anti-skid brake state, when the stroke of the brake command output by the pilot is greater than or equal to a preset ratio of the full brake stroke, and the change amount of the speed of the wheels on one side per unit time is greater than or equal to the speed change threshold, and the wheels on this side show a skidding phenomenon, the aircraft heading correction command is set to "1", and the anti-skid brake control system performs aircraft heading correction processing;

[0061] After the aircraft lands and enters the anti-skid brake state, in other cases except the above, the aircraft heading correction command is set to "0", and no aircraft heading correction processing is performed.

[0062] In the practical application of the embodiment of the present invention, the brake execution components of the aircraft anti-skid brake system include: an electro-hydraulic pressure servo valve and an electromagnetic hydraulic lock respectively connected to the anti-skid brake control box, and a brake device connected to the electro-hydraulic pressure servo valve.

[0063] In an implementation scheme of the embodiment of the present invention, the manner in which the anti-skid brake control box performs anti-skid processing on the wheels on one side is as follows:

[0064] The anti-skid brake control box calculates the corresponding anti-skid amount according to the aircraft heading correction command, sends a lock control signal to the electromagnetic hydraulic lock to open the electromagnetic hydraulic lock, and sends the difference between the digital quantity corresponding to the command stroke signal and the anti-skid amount to the electro-hydraulic pressure servo valve corresponding to the brake current value, so that the electro-hydraulic pressure servo valve outputs the corresponding brake pressure to the brake device to generate a braking torque.

[0065] In another implementation scheme of the embodiment of the present invention, the manner in which the anti-skid brake control box performs synchronous correction processing on the wheels on both sides is as follows:

[0066] After the aircraft lands and enters the anti-skid brake state, when the skidding of the wheels on one side causes the aircraft heading correction command to be set to "1", the state of the wheels on this side triggers the anti-skid brake system to perform anti-skid processing on the wheels on this side, releases the brake pressure on the skidding side, and changes the state of the wheels on this side from sliding to rolling;

[0067] Assign the speed of the wheels on this side to the speed of the wheels on the other side, trigger the anti-skid function of the wheels on the other side, and actively release the brake pressure on the other side to achieve synchronous correction processing of the wheels on both sides.

[0068] The anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization provided by the embodiments of the present invention. After the aircraft anti-skid braking system issues an aircraft heading correction command, it takes about 300 ms for the circuit to the hydraulic system to start responding to the command signal. In the initial stage of aircraft landing, the speed is relatively high. If the time to issue the aircraft heading correction command itself has a lag, a large offset heading angle will be generated, which is likely to cause the aircraft to approach the runway edge. The existing anti-yaw control method issues a correction command only when the speed difference between the left and right wheels is 30%. It requires a long wheel speed judgment time, which will cause a lag in the time to issue the correction command, easily generate a large offset heading angle, have the risk of running out of the runway, and there are potential safety hazards. By using the anti-yaw control method of the present invention, it is possible to monitor whether the aircraft is yawing based on the wheel conditions during aircraft taxiing and by changing the input conditions of the anti-skid braking system. Once yawing occurs, the aircraft heading is corrected in real time, and the result is consistent with the expectation, achieving the goal of correcting the aircraft heading. The embodiments of the present invention adopt the technical means of correcting the aircraft heading in real time, which can effectively shorten the response time of yaw control, thereby effectively reducing the risk of the aircraft running out of the runway and improving the reliability and safety of the anti-skid braking system.

[0069] Furthermore, the anti-yaw control method for an aircraft anti-skid braking system provided by the embodiments of the present invention has the advantages of fast response, no lag, and small offset heading angle. It solves the defect that the conventional yaw control method cannot correct the aircraft heading in real time, effectively reduces the risk of the aircraft running out of the runway, and improves the reliability and safety of the system. There are no reports and cases of using the control method of the present invention in domestic and foreign anti-skid braking systems. The comparison between the anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization provided by the embodiments of the present invention and the conventional anti-yaw control method is shown in Table 1 below.

[0070] Table 1 Comparison table between the control method of the present invention and the conventional control method

[0071] Project description The control method of the present invention Conventional control method Hysteresis None Yes Deviation course angle Smaller Larger Safety High Low

[0072] The implementation manner of the anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization provided by the embodiments of the present invention is described in detail below through a specific embodiment.

[0073] This specific embodiment is the actual application of the anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization provided by the present invention on a certain type of aircraft anti-skid braking system. The main function of a certain type of aircraft anti-skid braking system is to perform anti-skid braking control on the aircraft after landing. During the anti-skid braking process of the aircraft, the aircraft heading may shift due to reasons such as tire skidding. Therefore, the anti-yaw control technology is crucial for the safe landing of the aircraft.

[0074] The anti-yaw control method of the aircraft anti-skid braking system is implemented through the following steps 1, 2, and 3. Step 1: Determine the system status. Only when the anti-skid braking system is working properly can the anti-yaw control work. Step 2: Generate a course correction command. After the aircraft anti-skid braking system is initially powered on, the aircraft anti-skid braking system generates a course correction command based on the current pilot command stroke and the wheel speed sensor signal. When this command is set to "1", the anti-yaw control works. Step 3: Correction. When the course correction command in Step 2 is "1", the aircraft course is corrected and controlled.

[0075] This specific embodiment is based on an FBW anti-skid braking system, and the control period of the anti-skid braking system is 20 ms. This specific embodiment realizes the anti-yaw control by controlling the anti-skid brake controller in the aircraft anti-skid braking system, and realizes the anti-yaw control function of the aircraft by judging the hardware signals collected by the anti-skid brake controller.

[0076] This specific embodiment includes the following implementation steps:

[0077] Step 1: Determine whether the aircraft anti-skid braking system is in a normal working state. Through BIT fault detection, ensure that the braking system is free of faults. The specific implementation method is as follows:

[0078] The anti-skid brake controller in the anti-skid braking system issues a BIT fault detection signal, and each component in the anti-skid braking system responds to the BIT fault detection signal and generates a feedback signal; the anti-skid brake controller receives the feedback signal. If the anti-skid braking system is free of faults, the anti-yaw control function responds and works; if the anti-skid braking system has faults, the anti-yaw control function does not respond and work.

[0079] Step 2: The aircraft anti-skid braking system generates a course correction command;

[0080] The aircraft anti-skid braking system generates an aircraft course correction command according to the pilot command stroke signal and the wheel speed signal of the wheel speed sensor. The course correction command is used to determine whether to perform course correction processing on the aircraft. The course correction command is a digital signal, "1" indicates performing anti-yaw correction processing, and "0" indicates not performing anti-yaw correction processing. The range of the wheel speed signal of the wheel speed sensor is 0 - 300 km / h, and the range of the pilot's brake command stroke signal is 0 - 7 V. The process of generating the aircraft course correction command is as follows:

[0081] After the aircraft lands and enters the anti-skid braking state, when the braking command stroke signal output by the pilot is greater than or equal to the preset ratio of the full braking stroke (for example, 85% - 95% of the full braking), that is, the pilot has no intention of changing the aircraft's heading, and the change amount of the left wheel speed per unit time is greater than or equal to the speed change threshold, and the left wheel shows a skidding phenomenon, the aircraft heading deviation correction command is set to "1", and the anti-skid braking control system performs aircraft heading deviation correction processing. Or,

[0082] After the aircraft lands and enters the anti-skid braking state, when the braking command stroke signal output by the pilot is greater than or equal to the preset ratio of the full braking stroke (for example, 85% - 95% of the full braking), that is, the pilot has no intention of changing the aircraft's heading, and the change amount of the right wheel speed per unit time is greater than or equal to the speed change threshold, and the right wheel shows a skidding phenomenon, the aircraft heading deviation correction command is set to "1", and the anti-skid braking control system performs aircraft heading deviation correction processing.

[0083] After the aircraft lands and enters the anti-skid braking state, in other cases except the above, if the pilot has no intention of correcting the heading, the aircraft heading deviation correction command is set to "0", and no aircraft heading deviation correction processing is performed.

[0084] In this specific embodiment, the various situations in response to the deviation correction command are as follows:

[0085] 1) When the left and right wheel speeds are both set to 200 km / h, and 6.3 V braking pressure (maximum braking pressure) is injected into the left and right channels of the anti-skid braking controller at the same time, and neither the left nor the right wheel shows a skidding phenomenon, the hydraulic servo valve outputs the corresponding braking current value according to the given braking command. The current I of the left hydraulic servo valve f1 = 46 mA, and the current I of the right hydraulic servo valve f2 = 46 mA, and there will be no heading deviation, and the deviation correction command is set to "0".

[0086] 2) When the left and right wheel speeds are both set to 200 km / h, and 6.3 V braking pressure (maximum braking pressure) is injected into the left and right channels of the anti-skid braking controller at the same time, when the left wheel skids due to the change of the runway adhesion coefficient, and the left wheel speed drops to 30 km / h, the anti-skid braking system is forcibly triggered to perform anti-skid processing on the wheels on this side. At this time, the current of the left hydraulic servo valve drops to I f1 = 4 mA, and the current I of the right hydraulic servo valve f2 = 46 mA. At this time, the aircraft's heading will deviate to the left, the deviation correction command is set to "1", and the anti-yaw control function works.

[0087] 3) Set the left and right wheel speeds to 200 km / h simultaneously, and inject 6.3 V brake pressure (maximum brake pressure) into the left and right channels of the anti-skid brake controller at the same time. When the right wheel slips due to the change in the runway adhesion coefficient and the right wheel speed drops to 30 km / h, forcefully trigger the anti-skid brake system to perform anti-skid treatment on the wheel on this side. At this time, the current I of the left hydraulic servo valve f1 = 46 mA, and the current of the right hydraulic servo valve drops to I f2 = 4 mA. At this time, the aircraft heading will deviate to the right. Set the deviation correction command to "1", and the anti-yaw control function works.

[0088] 4) Set the left and right wheel speeds to 200 km / h simultaneously, and inject 6.3 V brake pressure (maximum brake pressure) into the left and right channels of the anti-skid brake controller at the same time. When the left and right wheels slip simultaneously due to the change in the runway adhesion coefficient, forcefully trigger the anti-skid brake system on the left and right sides to perform anti-skid treatment on the wheels on their respective sides. There is no need to actively correct the aircraft heading, and the deviation correction command is set to "0".

[0089] Step 3: Deviation correction;

[0090] After the aircraft lands and enters the anti-skid brake state, when the left wheel slips and causes the aircraft heading deviation correction command to be set to "1", the left wheel state will forcefully trigger the anti-skid brake system to perform anti-skid treatment on the left wheel, release the brake pressure on the slipping side, and change the wheel on that side from a sliding state to a rolling state to avoid wheel skidding and bursting; at the same time, assign the left wheel speed to the right wheel speed to trigger the anti-skid function of the right wheel (after assignment, compare the right speed with the reference speed, which is to trigger anti-skid), and actively release the right brake pressure; finally, the brake pressures of the left and right wheels rise slowly to the output pressure value corresponding to the brake command stroke before deviation correction at the same time to ensure the synchronization of the left and right wheel speeds and correct the aircraft heading.

[0091] After the aircraft lands and enters the anti-skid brake state, when the right wheel slips and causes the aircraft heading deviation correction command to be set to "1", the right wheel state will forcefully trigger the anti-skid brake system to perform anti-skid treatment on the right wheel, release the brake pressure on the slipping side, and change the wheel on that side from a sliding state to a rolling state to avoid wheel skidding and bursting; at the same time, assign the right wheel speed to the left wheel speed to trigger the anti-skid function of the left wheel, and actively release the left brake pressure; finally, the brake pressures of the left and right wheels rise slowly to the output pressure value corresponding to the command at the same time to ensure the synchronization of the left and right wheel speeds and correct the aircraft heading.

[0092] The control cycle of the above process is usually 20 ms to 40 ms.

[0093] In this embodiment, the various situations of the heading deviation correction response are as follows:

[0094] 1) The left and right wheel speeds are set to 200 km / h at the same time, and 6.3 V brake pressure is injected into the left and right channels of the anti-skid brake controller at the same time. There is no slippage on the left and right wheels. When the correction command is set to "0", the aircraft does not deviate in heading and does not need active correction.

[0095] 2) The left and right wheel speeds are set to 200km / h at the same time, and 6.3V brake pressure is injected into the left and right channels of the anti-skid brake controller at the same time. The left wheel slips due to the change in the runway engagement coefficient. The correction command is set to "1". When the left wheel speed drops to 30km / h, the anti-skid brake controller will forcibly trigger the anti-skid brake system to perform anti-skid treatment on the wheel on this side and release the skidding state. The current of the left hydraulic servo valve drops to I f1 =4mA, right hydraulic servo valve current I f2 =46mA, at this time, the left wheel speed is assigned to the right wheel speed, triggering the right wheel anti-skid function, and the right hydraulic servo valve current drops to I f2 =4mA, causing the right wheel to actively reduce the brake pressure on this side; then the left and right brake currents slowly return to I f1 =46mA, I f2 =46mA.

[0096] 3) The left and right wheel speeds are set to 200km / h at the same time, and 6.3V brake pressure is injected into the left and right channels of the anti-skid brake controller at the same time. The right wheel slips due to the change in the runway engagement coefficient. The deviation correction command is set to "1". When the right wheel speed drops to 30km / h, the anti-skid brake controller will forcibly trigger the anti-skid brake system to perform anti-skid treatment on the wheel on this side and release the slipping state. The current of the right hydraulic servo valve drops to I f2 =4mA, left hydraulic servo valve current I f1 =46mA, at this time, the right wheel speed is assigned to the left wheel speed, triggering the left wheel anti-skid function, and the left hydraulic servo valve current drops to I f1 =4mA, the left wheel will actively reduce the brake pressure on this side; then the left and right sides will simultaneously recover to I at the same boost speed f1 =46mA, I f2 =46mA.

[0097] 4) The speed of the left and right wheels is set to 200km / h at the same time, and 6.3V brake pressure is injected into the left and right channels of the anti-skid brake controller at the same time. When the left and right wheels slip at the same time due to the change of the runway engagement coefficient, the correction command is set to "0", and the left and right wheels forcefully trigger the anti-skid brake system at the same time to perform anti-skid treatment on the wheels on this side. There is no need to actively correct the aircraft heading.

[0098] In this specific embodiment, by changing the input conditions of the anti-skid braking system, it is monitored whether the aircraft yaws. Once yaw occurs, the aircraft heading is corrected in real time, and the result is consistent with the expectation, achieving the goal of correcting the aircraft heading. The test results show that the anti-yaw control method of the aircraft anti-skid braking system based on anti-skid synchronization provided by the embodiment of the present invention can effectively shorten the response time of yaw control and improve the reliability and safety of the anti-skid braking system.

[0099] Although the disclosed embodiments of the present invention are as above, the described content is only an embodiment adopted for facilitating the understanding of the present invention and is not used to limit the present invention. Any person skilled in the art within the scope of the present invention can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the patent protection scope of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A yaw prevention control method for an aircraft anti-skid braking system based on anti-skid synchronization, characterized in that Including: Step 1: Generate an aircraft heading deviation correction command based on the brake command stroke output by the pilot collected in real time and the wheel speed signal output by the wheel speed sensor. Step 2: Perform anti-skid treatment on the wheels on one side indicated by the aircraft heading deviation correction command, and trigger the anti-skid treatment on the wheels on the other side by assigning the speed of the wheels on this side before anti-skid treatment to the wheels on the other side, so as to achieve synchronous deviation correction treatment for the wheels on both sides. The aircraft heading deviation correction command in Step 1 is a digital signal. "1" indicates performing anti-yaw deviation correction treatment, and "0" indicates not performing anti-yaw deviation correction treatment. Among them, the method of generating the aircraft heading deviation correction command in Step 1 is as follows: After the aircraft lands and enters the anti-skid braking state, when the brake command stroke output by the pilot is greater than or equal to a preset ratio of the full brake stroke, and the change amount of the unilateral wheel speed per unit time is greater than or equal to the speed change threshold, and the wheels on this side show a skidding phenomenon, the aircraft heading deviation correction command is set to "1", and the anti-skid braking control system performs aircraft heading deviation correction treatment. After the aircraft lands and enters the anti-skid braking state, in other cases except the above, the aircraft heading deviation correction command is set to "0", and no aircraft heading deviation correction treatment is performed. Among them, the brake execution components of the aircraft anti-skid braking system include: an electro-hydraulic pressure servo valve and an electromagnetic hydraulic lock, and a braking device connected to the electro-hydraulic pressure servo valve. In Step 2, the method of performing anti-skid treatment on the wheels on one side indicated by the aircraft heading deviation correction command is as follows: Calculate the corresponding anti-skid amount according to the aircraft heading deviation correction command, send the lock control signal to the electromagnetic hydraulic lock to open the electromagnetic hydraulic lock, and send the difference between the digital quantity corresponding to the command stroke signal and the anti-skid amount to the electro-hydraulic pressure servo valve corresponding to the brake current value, so that the electro-hydraulic pressure servo valve outputs the corresponding brake pressure to the braking device to generate a braking torque.

2. The anti-yaw control method for an aircraft anti-skid braking system based on anti-skid synchronization according to claim 1, characterized in that Step 2 includes: After the aircraft lands and enters the anti-skid braking state, when the skidding of the unilateral wheels causes the aircraft heading deviation correction command to be set to "1", the state of the wheels on this side triggers the anti-skid braking system to perform anti-skid treatment on the wheels on this side, release the brake pressure on the skidding side, and change the state of the wheels on this side from sliding to rolling. Assign the speed of the wheels on this side to the speed of the wheels on the other side, trigger the anti-skid function of the wheels on the other side, and actively release the brake pressure on the other side to achieve synchronous deviation correction treatment for the wheels on both sides.

3. An aircraft anti-skid braking system based on anti-skid synchronization, characterized in that, Including: Wheel speed sensors, brake command sensors, and anti-skid braking control boxes; Wheel speed sensors are respectively installed on the left and right wheels of the aircraft to collect the wheel speed signals of the corresponding wheels in real time and transmit the wheel speed signals to the anti-skid braking control box; A brake command sensor is installed on the aircraft brake pedal to collect the brake command stroke signal sent by the pilot stepping on the pedal in real time and transmit the brake command stroke signal to the anti-skid braking control box; The anti-skid braking control box is respectively connected to the wheel speed sensor and the brake command sensor, and is used to generate an aircraft heading deviation correction command according to the brake command stroke signal and the wheel speed signal collected in real time. The anti-skid brake control box is also used to perform anti-skid treatment on the wheels on one side indicated by the aircraft heading correction command, and trigger the anti-skid treatment of the wheels on the other side by assigning the speed of the wheels on this side before anti-skid treatment to the wheels on the other side, so as to achieve synchronous correction treatment of the wheels on both sides; Among them, the method for the anti-skid brake control box to generate the aircraft heading correction command is: After the aircraft lands and enters the anti-skid brake state, when the stroke of the brake command output by the pilot is greater than or equal to the preset ratio of the full brake stroke, and the change amount of the speed of the single-side wheels per unit time is greater than or equal to the speed change threshold, and the wheels on this side show a skidding phenomenon, the aircraft heading correction command is set to "1", and the anti-skid brake control system performs aircraft heading correction processing; After the aircraft lands and enters the anti-skid brake state, in other cases except the above, the aircraft heading correction command is set to "0", and no aircraft heading correction processing is performed; Among them, the brake execution components of the aircraft anti-skid brake system include: an electro-hydraulic pressure servo valve and an electromagnetic hydraulic lock respectively connected to the anti-skid brake control box, and a brake device connected to the electro-hydraulic pressure servo valve; The method for the anti-skid brake control box to perform anti-skid treatment on the single-side wheels is: The anti-skid brake control box calculates the corresponding anti-skid amount according to the aircraft heading correction command, sends a lock control signal to the electromagnetic hydraulic lock to open the electromagnetic hydraulic lock, and sends the difference between the digital quantity corresponding to the command stroke signal and the anti-skid amount to the electro-hydraulic pressure servo valve corresponding to the brake current value, so that the electro-hydraulic pressure servo valve outputs the corresponding brake pressure to the brake device to generate a braking torque.

4. The aircraft anti-skid brake system based on anti-skid synchronization according to claim 3, characterized in that The method for the anti-skid brake control box to perform synchronous correction treatment on the wheels on both sides is: After the aircraft lands and enters the anti-skid brake state, when the skidding of the single-side wheels causes the aircraft heading correction command to be set to "1", the state of the wheels on this side triggers the anti-skid brake system to perform anti-skid treatment on the wheels on this side, releases the brake pressure on the skidding side, and makes the wheels on this side change from the sliding state to the rolling state; Assign the speed of the wheels on this side to the speed of the wheels on the other side, trigger the anti-skid function of the wheels on the other side, and actively release the brake pressure on the other side to achieve synchronous correction treatment of the wheels on both sides.

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