Warning method for abnormal deflection of front wheel during turning

Abstract

The invention relates to a front wheel turning abnormal deflection warning method, which comprises the following steps of: (1) finishing power-on self-test of a front wheel turning control box, and starting turning / anti-swing control; (2) a front wheel turning control box judges whether the system is in a turning state or not, if not, the system enters an anti-swing state, front wheel abnormal deviation judgment is not carried out, and an electromagnetic valve in a combined hydraulic valve is powered off in the anti-swing state; if yes, front wheel abnormal deflection and over-limit logic judgment and disposal are carried out; (3) the front wheel turning control box reads the instruction sensor signal ZL, the feedback sensor signal FK and the inertial navigation ground speed DS, and the front wheel turning control box calculates the deflection angle of the front wheel at the current speed, namely the feedback sensor theoretical position signal FKL; (4) the front wheel turning control box outputs control current according to a servo valve control current algorithm according to the difference value between the feedback sensor theoretical position signal FKL and the feedback sensor signal FK; (5) front wheel abnormal deflection judgment and treatment; and (6) front wheel overrun judgment and treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft design and relates to an alarm method for abnormal deflection of a front wheel turn. Background Art

[0002] The front wheel turning system of a certain type of aircraft adopts an electro-hydraulic servo control system, which is mainly composed of a command sensor, a front wheel turning control box, a turning actuator (including a feedback sensor) and a combined hydraulic valve. The electro-hydraulic servo valve inside the combined hydraulic valve is a nozzle-flapper servo valve. This type of servo valve has a fast response and high control accuracy, but due to the lack of valve core position feedback and poor anti-pollution ability, there may be a servo valve jam failure during use, causing abnormal deflection of the front wheel, affecting safety. Therefore, it is necessary to optimize the system control strategy, identify the deflection trend of the front wheel in time, and switch the system to the anti-sway state in time when the front wheel shows an abnormal deflection trend, and send out an alarm signal.

[0003] According to the above design and usage background, on the basis of unchanged system hardware architecture, by optimizing the system software control strategy, a comprehensive judgment is made on the theoretical turning command signal and the feedback sensor signal. When the wrong deflection trend of the front wheel is identified, the system is switched to the anti-sway state in time, and the hydraulic source of the servo valve is closed to prevent abnormal deflection of the front wheel, so as to ensure the safety of aircraft taxiing. Summary of the invention

[0004] Purpose of the present invention:

[0005] The present invention provides an alarm method for abnormal deflection of a front wheel turn. On the basis of keeping the system architecture unchanged, the control logic of a front wheel turn control box is optimized, and the judgment logic of abnormal deflection of the front wheel turn and the corresponding disposal strategy and method are designed to ensure the taxiing safety of the aircraft.

[0006] The technical solution of the present invention:

[0007] A method for warning abnormal deflection of front wheel turning,

[0008] The front wheel turning control box collects the feedback sensor signal in real time to identify the front wheel deflection direction. It is defined that when the feedback sensor signal increases, the front wheel deflects to the right, and when the feedback sensor signal decreases, the front wheel deflects to the left;

[0009] When the front wheel turning anti-sway system is in the turning state, the front wheel turning control box control board is defined to output a negative current, and the front wheel deflects to the right; the front wheel turning control box control board outputs a positive current, and the front wheel deflects to the left;

[0010] The front wheel turning control box determines the deflection trend of the front wheel in real time. If the control board of the front wheel turning control box outputs a negative current and the feedback signal decreases, or the control board of the front wheel turning control box outputs a positive current and the feedback signal increases, it is determined that the front wheel has an abnormal deflection without command at this time, and the system switches to the anti-sway state and sends out an alarm signal;

[0011] In extreme cases, if the servo valve of the front wheel is stuck at the left or right extreme position, the front wheel will remain at the extreme position when the turning command returns to the center. At this time, when the front wheel is at the left or right extreme position, if the front wheel turning control box outputs the return current and the feedback sensor signal remains unchanged, it is determined that the front wheel has an abnormal non-command deflection, the system switches to the anti-sway state, and sends out an alarm signal;

[0012] If the front wheel deflection angle exceeds the limit deflection angle at the current aircraft speed, the front wheel turning anti-sway system switches to the anti-sway state and sends out an alarm signal.

[0013] Further, the method comprises the following steps:

[0014] (1) The front wheel turning control box completes the power-on self-test and starts turning / anti-sway control;

[0015] (2) The front wheel turning control box determines whether the system is in a turning state. If not, the system enters an anti-sway state and does not perform abnormal front wheel deflection judgment. The solenoid valve inside the combined hydraulic valve is powered off in the anti-sway state. If yes, the system performs abnormal front wheel deflection and over-limit logic judgment and disposal.

[0016] (3) The front wheel turning control box reads the command sensor signal ZL, the feedback sensor signal FK and the inertial navigation ground speed DS, and calculates the angle at which the front wheel should deflect at the current speed, that is, the feedback sensor theoretical position signal FKL;

[0017] (4) The front wheel turning control box outputs the control current according to the servo valve control current algorithm based on the difference between the feedback sensor theoretical position signal FKL and the feedback sensor signal FK;

[0018] (5) Determination and treatment of abnormal front wheel deflection;

[0019] (6) Determination and handling of front wheel overload.

[0020] Further, in step (4), the servo valve control current algorithm is:

[0021] When the absolute value of the difference is greater than 3.5mm, the output control current is the maximum current, i.e. 5mA;

[0022] When the absolute value of the difference is less than 0.4mm, the output control current is 0;

[0023] When the absolute value of the difference is 0.4mm-3.5mm, the output control current varies in the range of 0-5mA.

[0024] Further, step (5) includes the following three cases:

[0025] (5.1) When the inertial navigation ground speed DS received by the front wheel turning control box is less than or equal to 30km / h, the abnormal deflection of the front wheel turning is judged and handled;

[0026] (5.2) When the inertial navigation ground speed DS received by the front wheel turning control box is (30, 120] km / h, the abnormal deflection of the front wheel turning is judged and handled;

[0027] (5.3) When the front wheel is at the extreme position, judge and deal with the abnormal deflection of the front wheel.

[0028] Furthermore, in (5.1), when the inertial navigation ground speed DS received by the front wheel turning control box is less than or equal to 30km / h, the following logic is used for judgment and processing:

[0029] a) Is the feedback sensor signal FK in (-11mm, 11mm)? If so, do not judge the deflection trend of the front wheel and continue with the normal turning procedure. If not, go to step b);

[0030] b) If the feedback sensor signal FK is not in (-11mm, 11mm), the front wheel deflection trend is judged, that is, the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA, and the feedback sensor signal FK changes in the opposite direction, then the front wheel is judged to be abnormally deflected; when the feedback sensor signal FK moves in the opposite direction by more than 5mm and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

[0031] Furthermore, in (5.2), when the inertial navigation ground speed DS received by the front wheel turning control box is (30, 120] km / h, the following logic is used for judgment and processing:

[0032] When the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA and the feedback sensor signal FK changes in the opposite direction, the front wheel is judged to be abnormally deflected; when the displacement of the feedback sensor signal FK in the opposite direction exceeds 3mm and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

[0033] Furthermore, the opposite change direction of the feedback sensor signal FK means that the front wheel turning control box control board outputs a negative current and the feedback signal decreases, or the front wheel turning control box control board outputs a positive current and the feedback signal increases.

[0034] Furthermore, in (5.3), when the front wheel is in the extreme position, the following logic is used for judgment and disposal: in the turning state, the front wheel turning control box determines in real time whether the front wheel is in the extreme position, that is, whether the feedback sensor signal FK is within ±3mm of the maximum stroke allowed by the control law at the current aircraft speed; if not, the methods of (5.1) and (5.2) are used to determine whether the front wheel deflection trend is normal. If yes, the following method is used for judgment: when the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA, the feedback sensor signal FK remains unchanged and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

[0035] Furthermore, the front wheel over-limit judgment and disposal are as follows: in the turning state, the front wheel turning control box determines in real time whether the front wheel deflection angle exceeds the limit, that is, whether the feedback sensor signal FK is greater than the maximum stroke upper tolerance of 3mm allowed by the control law under the current aircraft speed and lasts for 0.1s. If so, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal

[0036] Beneficial effects of the present invention:

[0037] The present invention provides an alarm method for abnormal deflection of a front wheel turn. The present invention realizes the addition of an abnormal front wheel deflection alarm and an excessive front wheel deflection alarm by optimizing and changing the software of a front wheel turn control box on the basis of the original hardware of the system, thereby improving the safety of the system. The method has been applied to specific models and also provides a reference for the design of the front wheel turn alarm logic of subsequent models. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is the functional principle diagram of the front wheel turning system;

[0039] Figure 2 Method flow for warning abnormal deflection of front wheel turning Figure 1 ;

[0040] Figure 3 Method flow for warning abnormal deflection of front wheel turning Figure 2 . DETAILED DESCRIPTION

[0041] The present invention is a novel alarm method for abnormal deflection of front wheel turning, which involves the design of control software for the front wheel turning system of an aircraft and is put into use in a specific model. The present invention aims at the problem of abnormal deflection of the front wheel caused by the internal stagnation of the front wheel turning combined hydraulic valve. The software collects the front wheel position feedback information in real time to judge whether the deflection trend of the front wheel is correct. If the front wheel deflection is abnormal, the front wheel turning system is switched to the anti-sway state in time and an alarm signal is issued to ensure the taxiing safety of the aircraft.

[0042] One embodiment of the present invention is that the method comprises the following steps:

[0043] 1) The front wheel turning control box collects the feedback sensor signal in real time to identify the front wheel deflection direction. It is defined that when the feedback sensor signal increases, the front wheel deflects to the right, and when the feedback sensor signal decreases, the front wheel deflects to the left.

[0044] 2) When the front wheel turning anti-sway system is in the turning state, the front wheel turning control box control board is defined to output a negative current, and the front wheel deflects to the right; the front wheel turning control box control board outputs a positive current, and the front wheel deflects to the left.

[0045] 3) The front wheel turning control box determines the deflection trend of the front wheel in real time. If the control board of the front wheel turning control box outputs a negative current and the feedback signal decreases, or the control board of the front wheel turning control box outputs a positive current and the feedback signal increases, it is determined that the front wheel has an abnormal deflection without command. The system switches to the anti-sway state and sends out an alarm signal.

[0046] 4) In extreme cases, if the servo valve of the front wheel is stuck at the left or right extreme position (there are mechanical limits at the left or right extreme positions), the front wheel will remain at the extreme position when the turning command returns to the center. At this time, it is impossible to judge according to the front wheel deflection trend in 3). Therefore, when the front wheel is at the left or right extreme position, if the front wheel turning control box outputs the return current and the feedback sensor signal remains unchanged, it is determined that the front wheel has abnormal non-command deflection, the system switches to the anti-sway state, and sends out an alarm signal.

[0047] 5) To ensure the safety of aircraft taxiing, if the front wheel deflection angle exceeds the limit deflection angle under the current aircraft speed (inertial navigation ground speed), the front wheel turning anti-sway system will switch to the anti-sway state and send out an alarm signal to prevent the front wheel deflection angle from exceeding the boundary and causing safety hazards during the process of the front wheel turning control box judging the front wheel deflection trend.

[0048] A second embodiment of the present invention is:

[0049] 1) If Figure 1 As shown, the command sensor, the front wheel turning control box, the combined hydraulic valve, and the turning actuator (including the feedback sensor) are connected to form a system. The front wheel turning control box receives the inertial ground speed and navigation status on the receiver for turning / anti-sway control and control law solution.

[0050] 2) If Figure 2 As shown, the front wheel turning control box completes the power-on self-test and starts turning / anti-sway control.

[0051] 3) The front wheel turning control box determines whether the system is in a turning state. If not, the system enters the anti-sway state and does not perform abnormal front wheel deflection judgment (in the anti-sway state, the solenoid valve inside the combined hydraulic valve is powered off, and the servo valve is stuck and the front wheel will not deflect abnormally); if so, perform abnormal front wheel deflection and over-limit logic judgment and disposal.

[0052] 4) The front wheel turning control box reads the command sensor signal (ZL), feedback sensor signal (FK) and inertial ground speed (DS), and calculates the angle that the front wheel should deflect at the current speed, that is, the feedback sensor theoretical position signal (FKL).

[0053] 5) The front wheel turning control box outputs the control current according to the servo valve control current algorithm based on the difference between the feedback sensor theoretical position signal (FKL) and the feedback sensor signal (FK).

[0054] The servo valve control current algorithm is:

[0055] When the absolute value of the difference is greater than 3.5mm, the output control current is the maximum current, i.e. 5mA;

[0056] When the absolute value of the difference is less than 0.4mm, the output control current is 0;

[0057] When the absolute value of the difference is 0.4mm-3.5mm, the output control current varies in the range of 0-5mA.

[0058] 6) Judgment and handling logic of abnormal front wheel deflection

[0059] 6.1) When the inertial ground speed (DS) received by the front wheel turning control box is less than or equal to 30km / h, the following logic is used for judgment and handling:

[0060] a) Is the feedback sensor signal (FK) at (-11mm, 11mm)? If so, do not judge the deflection trend of the front wheel and continue with the normal turning procedure. If not, proceed to step b).

[0061] b) If the feedback sensor signal (FK) is not between (-11mm, 11mm), the front wheel deflection trend is judged, that is, the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA, and the feedback sensor signal (FK) changes in the opposite direction (negative current and the (FK) value is smaller than the previous cycle, positive current and the (FK) value is larger than the previous cycle), then the front wheel is judged to be abnormally deflected; when the feedback sensor signal (FK) is displaced in the opposite direction by more than 5mm and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

[0062] 6.2) When the inertial navigation ground speed (DS) received by the front wheel turning control box is (30, 120] km / h, the following logic is used for judgment and processing:

[0063] When the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA, and the feedback sensor signal (FK) changes in the opposite direction (negative current and the (FK) value is smaller than the previous cycle, positive current and the (FK) value is larger than the previous cycle), the front wheel is judged to be abnormally deflected; when the displacement of the feedback sensor signal (FK) in the opposite direction exceeds 3mm and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

[0064] 6.3) When the front wheel is at the extreme position, the judgment and handling are carried out according to the following logic:

[0065] In the turning state, the front wheel turning control box determines in real time whether the front wheel is at the extreme position, that is, whether the feedback sensor signal (FK) is within ±3mm of the maximum stroke allowed by the control law at the current aircraft speed; if not, judge whether the front wheel deflection trend is normal according to the methods in steps 6.1 and 6.2. If yes, judge according to the following method: when the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA, the feedback sensor signal (FK) remains unchanged and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

[0066] 7) Front wheel overrun judgment and handling logic

[0067] In the turning state, the front wheel turning control box determines in real time whether the front wheel deflection angle exceeds the limit, that is, whether the feedback sensor signal (FK) is greater than the maximum stroke tolerance of 3mm allowed by the control law at the current aircraft speed and lasts for 0.1s. If so, the front wheel turning control box cuts off the solenoid valve, servo valve and turn indication signal output, the system enters the anti-sway state, and sends out an alarm signal.

Claims

1. A method for warning of abnormal deflection of a front wheel turning, characterized in that: The front wheel turning control box collects the feedback sensor signal in real time to identify the front wheel deflection direction. It is defined that when the feedback sensor signal increases, the front wheel deflects to the right, and when the feedback sensor signal decreases, the front wheel deflects to the left; When the front wheel turning anti-sway system is in the turning state, the front wheel turning control box control board is defined to output a negative current, and the front wheel deflects to the right; the front wheel turning control box control board outputs a positive current, and the front wheel deflects to the left; The front wheel turning control box determines the deflection trend of the front wheel in real time. If the control board of the front wheel turning control box outputs a negative current and the feedback signal decreases, or the control board of the front wheel turning control box outputs a positive current and the feedback signal increases, it is determined that the front wheel has an abnormal deflection without command at this time, and the system switches to the anti-sway state and sends out an alarm signal; In extreme cases, if the servo valve of the front wheel is stuck at the left or right extreme position, the front wheel will remain at the extreme position when the turning command returns to the center. At this time, when the front wheel is at the left or right extreme position, if the front wheel turning control box outputs the return current and the feedback sensor signal remains unchanged, it is determined that the front wheel has an abnormal non-command deflection, the system switches to the anti-sway state, and sends out an alarm signal; If the front wheel deflection angle exceeds the limit deflection angle at the current aircraft speed, the front wheel turning anti-sway system switches to the anti-sway state and sends out an alarm signal.

2. The method for warning abnormal deflection of the front wheel turning according to claim 1, characterized in that: The method comprises the following steps: (1) The front wheel turning control box completes the power-on self-test and starts turning / anti-sway control; (2) The front wheel turning control box determines whether the system is in a turning state. If not, the system enters an anti-sway state and does not perform abnormal front wheel deflection judgment. The solenoid valve inside the combined hydraulic valve is powered off in the anti-sway state. If yes, the system performs abnormal front wheel deflection and over-limit logic judgment and disposal. (3) The front wheel turning control box reads the command sensor signal ZL, the feedback sensor signal FK and the inertial navigation ground speed DS, and calculates the angle at which the front wheel should deflect at the current speed, that is, the feedback sensor theoretical position signal FKL; (4) The front wheel turning control box outputs the control current according to the servo valve control current algorithm based on the difference between the feedback sensor theoretical position signal FKL and the feedback sensor signal FK; (5) Determination and treatment of abnormal front wheel deflection; (6) Determination and handling of front wheel overload.

3. The method for warning abnormal deflection of the front wheel turning according to claim 2, characterized in that: In step (4), the servo valve control current algorithm is: When the absolute value of the difference is greater than 3.5mm, the output control current is the maximum current, i.e. 5mA; When the absolute value of the difference is less than 0.4mm, the output control current is 0; When the absolute value of the difference is 0.4mm-3.5mm, the output control current varies in the range of 0-5mA.

4. The method for warning abnormal deflection of the front wheel turning according to claim 3 is characterized in that: Step (5) includes the following three cases: (5.1) When the inertial navigation ground speed DS received by the front wheel turning control box is less than or equal to 30km / h, the abnormal deflection of the front wheel turning is judged and handled; (5.2) When the inertial navigation ground speed DS received by the front wheel turning control box is (30, 120] km / h, the abnormal deflection of the front wheel turning is judged and handled; (5.3) When the front wheel is at the extreme position, judge and deal with the abnormal deflection of the front wheel.

5. The method for warning abnormal deflection of the front wheel turning according to claim 4, characterized in that: In (5.1), when the inertial navigation ground speed DS received by the front wheel turning control box is less than or equal to 30km / h, the following logic is used for judgment and handling: a) Is the feedback sensor signal FK in (-11mm, 11mm)? If so, do not judge the deflection trend of the front wheel and continue to execute according to the normal turning procedure. If not, execute step b); b) If the feedback sensor signal FK is not in (-11mm, 11mm), the front wheel deflection trend is judged, that is, the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA, and the feedback sensor signal FK changes in the opposite direction, then the front wheel is judged to be abnormally deflected; when the feedback sensor signal FK moves in the opposite direction by more than 5mm and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

6. The method for warning abnormal deflection of the front wheel turning according to claim 5, characterized in that: In (5.2), when the inertial navigation ground speed DS received by the front wheel turning control box is (30, 120] km / h, the following logic is used for judgment and processing: When the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA and the feedback sensor signal FK changes in the opposite direction, the front wheel is judged to be abnormally deflected; when the displacement of the feedback sensor signal FK in the opposite direction exceeds 3mm and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

7. The method for warning abnormal deflection of the front wheel turning according to claim 6, characterized in that: The opposite change direction of the feedback sensor signal FK means that the front wheel turning control box control board outputs a negative current and the feedback signal decreases, or the front wheel turning control box control board outputs a positive current and the feedback signal increases.

8. The method for warning abnormal deflection of the front wheel turning according to claim 6, characterized in that: In (5.3), when the front wheel is in the extreme position, the following logic is used for judgment and disposal: in the turning state, the front wheel turning control box determines in real time whether the front wheel is in the extreme position, that is, whether the feedback sensor signal FK is within ±3mm of the maximum stroke allowed by the control law at the current aircraft speed; if not, the front wheel deflection trend is judged to be normal according to the methods of (5.1) and (5.2). If yes, the following method is used for judgment: when the absolute value of the theoretical control current output by the front wheel turning control box is greater than 4mA, the feedback sensor signal FK remains unchanged and lasts for 0.3s, the front wheel turning control box cuts off the output of the solenoid valve, servo valve and turning indication signal, the system enters the anti-sway state, and sends out an alarm signal.

9. The method for warning abnormal deflection of the front wheel turning according to claim 7, characterized in that: The front wheel over-limit judgment and disposal are as follows: in the turning state, the front wheel turning control box determines in real time whether the front wheel deflection angle exceeds the limit, that is, whether the feedback sensor signal FK is greater than the maximum stroke upper tolerance of 3mm allowed by the control law under the current aircraft speed and lasts for 0.1s. If so, the front wheel turning control box cuts off the solenoid valve, servo valve and turn indication signal output, the system enters the anti-sway state, and sends out an alarm signal.

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