阅读说明：本技术 一种防止飞机着陆冲出跑道的预防系统及预防方法 (Prevention system and prevention method for preventing airplane from rushing out of runway during landing ) 是由 刘劲松 陈国慧 马晓军 邓伟林 刘珊 张宏艳 于 2021-08-23 设计创作，主要内容包括：一种防止飞机着陆冲出跑道的预防系统及预防方法,通过机轮刹车系统、机翼扰流板控制器、冲出跑道预防控制器、告警模块、显示模块、记录模块、地面跑道数据模块、发动机控制器、地面环境模块、速度传感器和定位模块实现对飞机着陆过程防冲出跑道的预警。本发明在飞机进入下滑道开始预计飞机的下降轨迹,判断是否偏离下滑道；同时在决断高度预计飞机的接地点,减速到滑行速度所需的正常距离以及最严苛距离,对飞机复飞进行判断；同时在飞机减速过程中,预计飞机的减速距离,对飞机偏离跑道进行判断,实现了飞机在着陆过程中的风险预警,降低了飞机冲出跑道的概率。(A prevention system and a prevention method for preventing an airplane from rushing out of a runway during landing are used for realizing early warning of the airplane from rushing out of the runway during the landing process through an airplane wheel braking system, a wing spoiler controller, a rushing-out runway prevention controller, an alarm module, a display module, a recording module, a ground runway data module, an engine controller, a ground environment module, a speed sensor and a positioning module. The method comprises the steps of predicting the descending track of the airplane when the airplane enters the glidepath, and judging whether the airplane deviates from the glidepath; meanwhile, the grounding point of the airplane is predicted at the decision height, and the airplane is decelerated to the normal distance and the severest distance required by the sliding speed, so that the repeated flight of the airplane is judged; meanwhile, in the process of airplane deceleration, the deceleration distance of the airplane is predicted, and the deviation of the airplane from the runway is judged, so that the risk early warning of the airplane in the landing process is realized, and the probability of the airplane rushing out of the runway is reduced.)

1. A prevention system for preventing an airplane from rushing out of a runway during landing is characterized by comprising an airplane wheel braking system, a wing spoiler controller, a rushing-out runway prevention controller, an alarm module, a display module, a recording module, a ground runway data module, an engine controller, a ground environment module, a speed sensor and a positioning module; the first input port to the seventh input port of the rush-out runway prevention controller are sequentially communicated with the output end of a brake controller of a wheel brake system, the output end of a wing spoiler controller, the output end of a ground runway data module, the output end of an engine controller, the output end of a ground environment module, the output end of a speed sensor and the output end of a positioning module; the first output port to the seventh output port of the rush-out runway prevention controller are respectively communicated with the input end of the warning module, the input end of the display module, the input end of the recording module, the input end of the ground runway data module, the input end of the brake controller of the airplane wheel braking system, the input end of the wing spoiler controller and the input end of the engine controller.

2. A prevention system for preventing an aircraft from landing on a thrust runway according to claim 1, wherein the thrust runway prevention controller receives the following information: the airplane wheel braking system fault state information is sent by the airplane wheel braking system, the wing spoiler fault state is sent by the wing spoiler controller, the runway information is sent by the ground runway data module, the deceleration rate provided by the wing spoiler, the engine thrust reverser and the airplane wheel braking system, the engine controller fault state information, the wind direction and the wind speed of the airplane predicted landing runway, the speed information detected by the speed sensor and the airplane real-time position information sent by the positioning module; and processing the information received by the rush runway prevention controller through an AD module.

3. The system of claim 1, wherein the shoot runway prevention controller outputs an audible warning message to an alert module; the position information of the airplane relative to the runway is output to the display module, and the distance of the runway, the distance of the severest runway and the distance of the departure runway required by the deceleration to the taxi speed are used for displaying the ground information of the airplane; outputting system information including a runway rushing-out prevention system state, an airplane deviation runway distance, an airplane wheel speed, airplane information, runway information and fault information to a recording module; and sending the fault state information of the airplane wheel braking system, the wing spoilers and the engine to a ground runway data module.

4. A prevention system for preventing an aircraft from landing on a runway according to claim 3, wherein the ground runway data module matches the deceleration rate of the aircraft that the wheel brake system, wing spoilers and engine thrust reversals can provide via fault status information.

5. A prevention system for preventing an aircraft landing on a runway overrun as claimed in claim 1, wherein said overrun runway prevention controller controls braking by brake current to effect braking of the aircraft wheels; the runway rushing-out prevention controller controls the opening of the wing spoilers through switching value signals; through the engine controller, the airplane is decelerated through reverse thrust of the engine.

6. A method for preventing an aircraft from rushing out of a runway during landing by using the prevention system of claim 1, wherein the method comprises the following specific steps:

step 1, displaying the deviation track of airplane glide:

when the aircraft begins to descend, the shoot runway prevention system is activated; predicting the descending track of the airplane according to the landing information of the airplane, comparing the predicted descending track of the airplane with the set position of the glidepath of the airport, judging whether the airplane deviates from the glidepath, and when the predicted descending track is consistent with the set position of the glidepath, judging that the airplane does not deviate; when the predicted descending track is inconsistent with the set position of the lower slideway, the deviation is considered to occur; if the airplane deviates from the glide slope, displaying deviated position information; if the aircraft does not deviate from the glideslope, displaying an expected glide track;

step 2, determining whether the alarm is required to go back to the flight:

the runway rushing-out prevention system respectively receives the fault states of the airplane wheel braking system, the engine reverse thrust and the wing spoiler of the airplane, and determines that the airplane decelerates to the taxiing speed through the following second stepThe required normal runway distance and the most severe runway distance; if the length of the normal runway distance and the length of the severest runway distance are both smaller than the severest distance, providing warning information of missed approach; otherwise, displaying the braking distance required by the airplane;

step 3, implementing the maximum deceleration capacity of the airplane:

the runway rushing-out prevention system activates the airplane wheel braking system, the engine reverse thrust and the wing spoiler to decelerate the airplane by controlling the airplane wheel braking system, the engine reverse thrust and the wing spoiler after the airplane is grounded;

the specific process of decelerating the aircraft is as follows:

the method comprises the following steps of firstly, respectively obtaining the control capacities of an airplane wheel braking system, an engine thrust reverser and a wing spoiler:

and secondly, respectively activating an engine reverse thrust system, a wing spoiler system and an airplane wheel braking system:

after the airplane is grounded, an engine controller is used for activating the engine to perform reverse thrust so as to enable the reverse thrust capacity of the engine to reach the maximum, after the airplane wheels rotate fully, a brake controller of the airplane wheel brake system is used for enabling the airplane wheel brake system to output the maximum brake capacity under the antiskid working condition, and a wing spoiler is opened through a wing spoiler controller to decelerate;

step 4, determining the runway distance required by the distance between the runway and the taxiing speed when the airplane decelerates to the taxiing speed:

determining the runway distance required by the airplane to decelerate to the taxi speed in the landing deceleration process of the airplane, and displaying the remaining runway distance in real time;

the specific process of the step 4 is as follows:

firstly, acquiring aircraft landing information:

when the required runway distance is determined, the speed, deceleration and position information of the aircraft after being grounded are obtained through the airspeed head and the positioning module;

secondly, determining the runway distance x required by the aircraft to decelerate to the taxi speed_n：

According to the current aircraft speedAnd accelerationCalculating the deceleration to taxiing speed v of an aircraft_mtThe required runway distance, wherein the runway remaining distance is the distance from the current position of the airplane to the origin of the ground inertial coordinate system;

thirdly, displaying the runway distance required by the aircraft to decelerate to the taxi speed:

determining a runway distance required for decelerating the aircraft to a taxi speed and a runway remaining distance x_lAnd (3) comparison:

if x_l≥x_nIf the airplane can stop the airplane in the preset runway, displaying the distance of the runway and the residual distance of the runway required by the deceleration of the airplane to the taxi speed;

if x_l＜x_nIf the airplane cannot stop in the preset runway, providing an alarm for the pilot to rush out of the runway, and displaying the distance of the runway required by the deceleration of the airplane to the taxi speed and the residual distance of the runway;

fourthly, displaying the deviation of the airplane:

if the aircraft is in the ground coordinate system Y_gAbsolute value of displacement in direction y_nIf greater than threshold value y_cDisplaying the deviation of the airplane from the runway, providing warning information for the pilot and prompting the pilot to deviate from the course;

step 5, exit/end:

the specific process of exiting/ending is as follows:

the first step, receiving the aircraft ground speed and the aircraft wheel speed:

when the runway rushing-out prevention system is judged to be exited, the speed of the airplane is obtained through the airspeed head, and the speed of the front airplane wheel of the airplane and the speed of each main airplane wheel are respectively obtained through the airplane wheel braking system;

second, the rush-out runway prevention system exits/ends

When the ground speed of the airplane is less than or equal to the sliding speed, or the speed of the front airplane wheel is less than or equal to the sliding speed, or the speed of each main engine wheel is less than or equal to the sliding speed, the runway rushing-out prevention system exits; during the operation of the shoot-off runway prevention system, the pilot terminates the shoot-off runway prevention system via the operator.

7. The method for preventing the runway from being washed away during the landing process of the airplane as claimed in claim 6, wherein the specific process of the step 2 is as follows:

the method comprises the following steps of firstly, respectively obtaining the deceleration capacity of an aircraft engine, an aircraft wheel braking system and a wing spoiler: the runway rushing-out prevention system receives a fault state of an engine, a fault state of a wheel braking system and a fault state of a wing spoiler; the fault state comprises: whether the engine can be opened to the maximum position of the reverse thrust or not; whether the wing spoilers can be fully opened; whether all channels of the airplane wheel braking system can brake normally or not;

secondly, defining an aircraft grounding point position vector and a grounding speed vector:

before the airplane descends to the decision altitude, the runway rushing-out prevention system calculates the grounding position, the grounding speed and the acceleration of the airplane;

calculating the aircraft grounding position, grounding speed and acceleration through the formulas (6), (7) and (8):

wherein the content of the first and second substances,which is indicative of the speed of the aircraft at the current time,which is indicative of the wind speed at the present moment,indicating the aircraft acceleration at the present moment, t indicating the time required to land to ground,is the speed of the aircraft at the point of grounding,information of the position of the aircraft grounding point;

the ground runway data module matches a normal deceleration rate and a maximum deceleration rate which can be provided by the engine reverse thrust, the airplane wheel braking system and the wing spoiler respectively through a runway and a ground environment according to the fault states of the airplane wheel braking system, the engine reverse thrust and the wing spoiler respectively received in the first step; calculating the normal runway distance and the severest runway distance required by the deceleration of the airplane to the taxi speed according to the information of the grounding position, the grounding speed and the acceleration of the airplane;

the normal runway distance and the most severe runway distance required for the aircraft to decelerate to taxi speed are calculated by equations (9) and (10):

wherein the content of the first and second substances,the deceleration rate provided by the ground runway data module for the reverse thrust of the engine matched with the airplane and the deceleration rate provided by the wing spoiler correspond to the sum of the deceleration rates provided by the wheel brake system on the runway;representing the sum of the maximum deceleration rate provided by the reverse thrust of the engine, the maximum deceleration rate provided by the wing spoilers, and the maximum deceleration rate that the runway can provide to the braking system of the airplane wheels;representing the normal runway distance required for the aircraft to slow down to taxi speed;representing the harshest runway distance required for the aircraft to slow down to taxi speed;

thirdly, determining a missed approach warning:

the rush-out runway prevention system calculates the normal runway distance, the severest runway distance and the runway length x obtained in the second step_tMaking a comparison, e.g.The length of the fruit track is more than or equal to the distance of the normal track, x_t≥x_nWhen the airplane can stop in the preset runway, the display module displays that the airplane decelerates to the taxi speed v_mtThe required runway distance; if the runway length is less than the normal runway distance and greater than or equal to the severest runway distance, x_s≤x_t＜x_nAnd when the airplane needs to implement the maximum deceleration capacity, the airplane can be stopped in the preset runway by considering that the airplane can be decelerated to the taxi speed v_mtThe required runway distance; if the runway length is less than the harshest runway distance, x_t＜x_sWhen, the display aircraft decelerates to the taxi speed v_mtAnd the required runway distance is obtained, and information is sent to an alarm system to prompt the system to fly back.

8. The method for preventing a shoot away runway prevention during an aircraft landing as in claim 7, wherein the aircraft ground contact location, ground contact velocity and acceleration are calculated by equations (6), (7) and (8):

wherein the content of the first and second substances,which is indicative of the speed of the aircraft at the current time,which is indicative of the wind speed at the present moment,indicating the aircraft acceleration at the present moment, t indicating the time required to land to ground,is the speed of the aircraft at the point of grounding,information of the position of the aircraft grounding point; the ground runway data module matches normal deceleration rate and maximum deceleration rate which can be provided by the engine reverse thrust, the airplane wheel braking system and the wing spoiler through a runway and a ground environment according to the fault states of the airplane wheel braking system, the engine reverse thrust and the wing spoiler received in the first step; and calculating the normal distance and the severest distance required by the airplane to decelerate to the taxi speed according to the information of the grounding position, the grounding speed and the acceleration of the airplane.

9. A method for preventing a shoot-off runway prevention during landing of an aircraft according to claim 7, characterized by calculating the severest distance required for the aircraft to slow down to taxiing speed by means of equations (9) and (10):

wherein the content of the first and second substances,the deceleration rate provided by the ground runway data module for the reverse thrust of the engine matched with the airplane and the deceleration rate provided by the wing spoiler correspond to the sum of the deceleration rates provided by the wheel brake system on the runway;representing the sum of the maximum deceleration rate provided by the reverse thrust of the engine, the maximum deceleration rate provided by the wing spoilers, and the maximum deceleration rate that the runway can provide to the braking system of the airplane wheels;represents the normal distance required for the aircraft to slow down to taxi speed;representing the harshest distance required for the aircraft to slow down to taxi speed.

10. A method for preventing a runway overrun prevention during an aircraft landing as claimed in claim 6, wherein step 4 calculates the runway distance required for the aircraft to decelerate to taxi speed by equations (11) and (12) when determining the required runway distance:

wherein t is the time required for the aircraft to decelerate to the taxi speed, x_nRunway distance, y, required for the aircraft to slow down to taxi speed_nThe distance from the heading when the aircraft decelerates to taxi speed.

Technical Field

The invention relates to the field of civil aircrafts, in particular to a method and a system for preventing an aircraft from rushing out of a runway, providing information of runway deviation for a pilot from an approach to a taxi speed stage, and implementing the maximum deceleration capacity of the aircraft.

Background

The rush-out runway is listed as one of three accidents of commercial airplanes all over the world. Many of these accidents occur on runways where the braking effect is reduced due to contamination. Statistics of accidents show that rush out of the runway resulted in 35% overall loss accidents and 14% fatal accidents between 1998 and 2017.

The invention of publication number CN 107944701 a discloses a method and a device for detecting a risk of rushing out of a runway during an aircraft landing process, the method and the device obtain a landing environment after matching the runway according to a geographical position, and calculate a critical line of rushing out of the runway according to aircraft landing data, but the method and the device do not consider the state of an aircraft deceleration system and the operation of immediate real-time maximum deceleration after the aircraft continues to land, and the runway may be rushed out when the aircraft deceleration system fails.

The invention of US 10214300B2 discloses a method and system for displaying information of rushing out runway, which determines the braking distance required by an aircraft and displays it on a display system by receiving runway information and aircraft state information, but does not consider the deviation of the aircraft descent process and the prediction of the landing site, does not consider the state of the aircraft deceleration system and the maximum deceleration immediately after the aircraft continues to land, reduces the reflection and operating time of the pilot, and may rush out the runway when the aircraft deceleration system fails.

Disclosure of Invention

The invention provides a prevention system and a prevention method for preventing an airplane from rushing out of a runway, which aims to overcome the defects that the normal runway distance and the severest runway distance required by the stop of the airplane after landing cannot be determined, the required runway distance is provided for a pilot, and the airplane is automatically controlled to decelerate according to the state of a deceleration system after landing.

The invention provides a prevention system for preventing an airplane from rushing out of a runway during landing, which comprises an airplane wheel braking system, a wing spoiler controller, a rushing out runway prevention controller, an alarm module, a display module, a recording module, a ground runway data module, an engine controller, a ground environment module, a speed sensor and a positioning module. The first input port to the seventh input port of the rush-out runway prevention controller are sequentially communicated with the output end of a brake controller of a wheel brake system, the output end of a wing spoiler controller, the output end of a ground runway data module, the output end of an engine controller, the output end of a ground environment module, the output end of a speed sensor and the output end of a positioning module; the first output port to the seventh output port of the rush-out runway prevention controller are respectively communicated with the input end of the warning module, the input end of the display module, the input end of the recording module, the input end of the ground runway data module, the input end of the brake controller of the airplane wheel braking system, the input end of the wing spoiler controller and the input end of the engine controller.

The rush-out runway prevention controller receives the following information, respectively: the airplane wheel braking system fault state information is sent by the airplane wheel braking system, the wing spoiler fault state is sent by the wing spoiler controller, the runway information is sent by the ground runway data module, the deceleration rate provided by the wing spoiler, the engine thrust reverser and the airplane wheel braking system, the engine controller fault state information, the wind direction and the wind speed of the airplane predicted landing runway, the speed information detected by the speed sensor and the airplane real-time position information sent by the positioning module; and processing the information received by the rush runway prevention controller through an AD module.

The rush-out runway prevention controller outputs audible warning information to a warning module; the position information of the airplane relative to the runway is output to the display module, and the distance of the runway, the distance of the severest runway and the distance of the departure runway required by the deceleration to the taxi speed are used for displaying the ground information of the airplane; outputting system information including a runway rushing-out prevention system state, an airplane deviation runway distance, an airplane wheel speed, airplane information, runway information and fault information to a recording module; sending the fault state information of the airplane wheel braking system, the wing spoilers and the engine to a ground runway data module;

the ground runway data module matches an airplane deceleration rate that can be provided by an airplane wheel brake system, a wing spoiler and engine back thrust through fault state information.

The runway rushing-out prevention controller controls braking through braking current to realize braking of the airplane wheel; the runway rushing-out prevention controller controls the opening of the wing spoilers through switching value signals; through the engine controller, the airplane is decelerated through reverse thrust of the engine.

The invention provides a specific process for preventing the airplane from rushing out of the runway in the landing process by using the prevention system, which comprises the following steps:

step 1, displaying the deviation track of airplane glide:

when the aircraft begins to descend, the shoot runway prevention system is activated; predicting the descending track of the airplane according to the landing information of the airplane, comparing the predicted descending track of the airplane with the set position of the glidepath of the airport, judging whether the airplane deviates from the glidepath, and when the predicted descending track is consistent with the set position of the glidepath, judging that the airplane does not deviate; when the predicted descending track is inconsistent with the set lower slideway position, the deviation is considered to occur. If the airplane deviates from the glide slope, displaying deviated position information; if the aircraft does not deviate from the glideslope, the expected glide trajectory is displayed.

Step 2, determining whether the alarm is required to go back to the flight:

the runway rushing-out prevention system respectively receives the fault states of the airplane wheel braking system, the engine reverse thrust and the wing spoiler of the airplane, and determines that the airplane decelerates to the taxiing speed through the following second stepThe method comprises the steps that a normal runway distance and a severest runway distance are needed, and if the length of the normal runway distance and the length of the severest runway distance are both smaller than the severest runway distance, warning information of missed flyings is provided; and otherwise, displaying the braking distance required by the airplane.

The specific process for determining whether the alarm is required to go back to the flight is as follows:

the method comprises the following steps of firstly, respectively obtaining the deceleration capacity of an aircraft engine, an aircraft wheel braking system and a wing spoiler:

the runway overrun prevention system receives a fault condition of the engine, a fault condition of the wheel braking system, and a fault condition of the wing spoiler. The fault state comprises: whether the engine can be opened to the maximum position of the reverse thrust or not; whether the wing spoilers can be fully opened; and whether all channels of the wheel braking system can brake normally or not.

Secondly, defining an aircraft grounding point position vector and a grounding speed vector:

the thrust out runway prevention system will calculate the aircraft ground position, ground speed and acceleration before the aircraft descends to the decision altitude.

Calculating the aircraft grounding position, grounding speed and acceleration through the formulas (6), (7) and (8):

wherein the content of the first and second substances,which is indicative of the speed of the aircraft at the current time,which is indicative of the wind speed at the present moment,indicating the current time of flightThe mechanical acceleration, t represents the time required to land to ground,is the speed of the aircraft at the point of grounding,is the information of the position of the aircraft grounding point. And the ground runway data module is used for respectively matching a normal deceleration rate and a maximum deceleration rate which can be provided by the engine reverse thrust, the airplane wheel braking system and the wing spoiler through a runway and a ground environment according to the fault states of the airplane wheel braking system, the engine reverse thrust and the wing spoiler respectively received in the first step. And calculating the normal runway distance and the severest runway distance required by the deceleration of the airplane to the taxi speed according to the information of the grounding position, the grounding speed and the acceleration of the airplane.

The normal runway distance and the most severe runway distance required for the aircraft to decelerate to taxi speed are calculated by equations (9) and (10):

wherein the content of the first and second substances,the representative ground runway data module provides a deceleration rate for the reverse thrust of an engine matched with the airplane, and the deceleration rate provided by the wing spoiler corresponds to the sum of the deceleration rates provided by the braking systems of the wheels on the runway;representing the sum of the maximum deceleration rate provided by the reverse thrust of the engine, the maximum deceleration rate provided by the wing spoilers, and the maximum deceleration rate that the runway can provide to the braking system of the airplane wheels;represents the normal distance required for the aircraft to slow down to taxi speed;representing the harshest distance required for the aircraft to slow down to taxi speed.

Thirdly, determining a missed approach warning:

acquiring runway information through a ground runway data module; the runway information includes a runway length x_t。

The rush-out runway prevention system calculates the normal runway distance, the severest runway distance and the runway length x obtained in the second step_tComparing, if the length of the runway is larger than or equal to the normal distance of the runway, x_t≥x_nWhen the airplane can stop in the preset runway, the display module displays that the airplane decelerates to the taxi speed v_mtThe required runway distance. If the runway length is less than the normal runway distance and greater than or equal to the severest runway distance, x_s≤x_t＜x_nAnd when the airplane needs to implement the maximum deceleration capacity, the airplane can be stopped in the preset runway by considering that the airplane can be decelerated to the taxi speed v_mtThe required runway distance. If the runway length is less than the harshest runway distance, x_t＜x_sWhen, the display aircraft decelerates to the taxi speed v_mtAnd the required runway distance is obtained, and information is sent to an alarm system to prompt the system to fly back.

Step 3, implementing the maximum deceleration capacity of the airplane:

the runway rushing prevention system controls the airplane wheel braking system, the engine reverse thrust system and the wing spoiler, and activates the airplane wheel braking system, the engine reverse thrust system and the wing spoiler to decelerate the airplane after the airplane is grounded.

The specific process of decelerating the aircraft is as follows:

the method comprises the following steps of firstly, respectively obtaining the control capacities of an airplane wheel braking system, an engine thrust reverser and a wing spoiler:

and secondly, respectively activating an engine reverse thrust system, a wing spoiler system and an airplane wheel braking system:

after the airplane is grounded, the engine is activated by the engine controller to perform reverse thrust so that the reverse thrust capacity of the airplane is maximized, after the airplane wheels rotate fully, the brake controller of the airplane wheel brake system enables the airplane wheel brake system to output the maximum brake capacity under the antiskid working condition, and the wing spoiler controller opens the wing spoiler to decelerate.

Step 4, determining the runway distance required by the aircraft to decelerate to the taxi speed:

and in the process of landing and decelerating the airplane, determining the runway distance required by the deceleration of the airplane to the taxi speed, and displaying the remaining runway distance in real time.

The specific process is as follows:

firstly, acquiring aircraft landing information:

when the required runway distance is determined, the speed, the deceleration and the position information of the aircraft after the ground contact are obtained through the airspeed head and the positioning module.

Calculating the aircraft ground contact position, ground contact velocity and deceleration by equations (6), (7) and (8):

wherein the content of the first and second substances,which is indicative of the speed of the aircraft at the current time,indicating the wind speed at the present moment，Indicating the aircraft acceleration at the present moment, t indicating the time required to land to ground,is the speed of the aircraft at the point of grounding,is the information of the position of the aircraft grounding point. And the ground runway data module matches normal deceleration rate and maximum deceleration rate which can be provided by the engine reverse thrust, the airplane wheel braking system and the wing spoiler through the runway and the ground environment according to the fault states of the airplane wheel braking system, the engine reverse thrust and the wing spoiler received in the first step. And calculating the normal runway distance and the severest runway distance required by the deceleration of the airplane to the taxi speed according to the information of the grounding position, the grounding speed and the acceleration of the airplane.

Calculating the harshest runway distance required for the aircraft to slow down to taxi speed by equations (9) and (10):

wherein the content of the first and second substances,the deceleration rate provided by the ground runway data module for the reverse thrust of the engine matched with the airplane and the deceleration rate provided by the wing spoiler correspond to the sum of the deceleration rates provided by the wheel brake system on the runway;representing the maximum deceleration rate provided by the reverse thrust of the engine, the maximum deceleration rate provided by the spoilers of the wingA large deceleration rate, the sum of the maximum deceleration rates that the runway can provide to the wheel braking systems;representing the normal runway distance required for the aircraft to slow down to taxi speed;representing the harshest runway distance required for the aircraft to slow down to taxi speed.

Secondly, determining the runway distance x required by the aircraft to decelerate to the taxi speed_n：

According to the current aircraft speedAnd accelerationCalculating the deceleration to taxiing speed v of an aircraft_mtAnd the required runway distance, wherein the runway remaining distance is the distance from the current position of the airplane to the origin of the ground inertial coordinate system.

In determining the desired runway distance, the runway distance required for the aircraft to slow down to taxi speed is calculated by equations (11) and (12):

wherein t is the time required for the aircraft to decelerate to the taxi speed, x_nRunway distance, y, required for the aircraft to slow down to taxi speed_nThe distance from the heading when the aircraft decelerates to taxi speed.

Thirdly, displaying the runway distance required when the airplane decelerates to the taxi speed:

determining a runway distance required for decelerating the aircraft to a taxi speed and a runway remaining distance x_lAnd (3) comparison:

if x_l≥x_nThe aircraft is considered to be able to stop within the predetermined runway, and the runway distance required for the aircraft to slow down to taxi speed and the runway remaining distance are displayed.

If x_l＜x_nAnd if the airplane cannot stop in the preset runway, providing an alarm for rushing out of the runway for the pilot, and displaying the distance of the runway required by the airplane to decelerate to the taxi speed and the residual distance of the runway.

Fourthly, displaying the deviation of the airplane:

if the aircraft is in the ground coordinate system Y_gAbsolute value of displacement in direction y_nThreshold value y for | > deviation from runway_cAnd displaying the deviation of the airplane from the runway, and providing warning information for the pilot to prompt the pilot to deviate from the runway.

Step 5, exit/end:

the specific process of exiting/ending is as follows:

the first step, receiving the aircraft ground speed and the aircraft wheel speed:

when the runway rushing-out prevention system is judged to be quitted, the speed of the airplane is obtained through the airspeed head, and the speed of the front airplane wheel of the airplane and the speed of each main airplane wheel are respectively obtained through the airplane wheel braking system.

Second, the rush-out runway prevention system exits/ends

And when the ground speed of the airplane is less than or equal to the sliding speed, or the speed of the front airplane wheel is less than or equal to the sliding speed, or the speed of each main engine wheel is less than or equal to the sliding speed, the runway rushing-out prevention system exits. During the operation of the shoot-off runway prevention system, the pilot terminates the shoot-off runway prevention system via the operator.

Thus, the prevention of the airplane rushing out of the runway in the landing process is completed.

The invention provides a method and a system for preventing an airplane from rushing out of a runway in the landing process, aiming at the situation that whether the distance provided by the runway meets the requirement of the airplane sliding out and whether the airplane deviates from the runway exists or not and the situation that measures cannot be taken to deal with the situation in time and aiming at the situation that the accident that the airplane rushes out of the runway can only be analyzed after the accident occurs, and realizing the accident that the airplane rushes out of the runway in the landing process.

The method comprises the steps of predicting the descending track of the airplane when the airplane enters the glidepath, and judging whether the airplane deviates from the glidepath; meanwhile, the grounding point of the airplane is predicted at the decision height, and the airplane is decelerated to the normal runway distance and the severest runway distance required by the sliding speed, so that the airplane re-flight is judged; meanwhile, in the process of airplane deceleration, the deceleration distance of the airplane is predicted, and the deviation of the airplane from the runway is judged.

Compared with the prior art, the invention has the advantages that:

1. the invention is activated when the airplane enters the glideslope, predicts the flight track of the airplane in the descending process of the airplane, compares the flight track with the glideslope, and provides deviation position information and warning for a pilot if deviation occurs.

2. The invention provides a method for predicting the landing point information of an airplane, the normal runway distance and the severest runway distance required by the deceleration to the taxi speed when the airplane descends to the decision altitude, judging whether the airplane can land safely or not and prompting a pilot to fly back.

3. The invention provides a method for predicting the deceleration distance and the runway remaining distance of an airplane in real time in the process of grounding deceleration of the airplane, determining whether the airplane deviates from the runway, and displaying and giving an alarm when the airplane deviates from the runway.

In the descending process of the airplane, whether the airplane can decelerate to the sliding speed on the runway of the airport is determined, the distance of the required runway is determined and displayed when the airplane does not land, the visual prompt is given to the pilot, the airplane flies again when the airplane does not land, and the fifteen percent risk that the airplane rushes out of the runway is reduced. After the aircraft lands, if the required harshest runway distance is greater than the length of the runway, the maximum deceleration capacity is implemented immediately after the aircraft is connected, the aircraft is decelerated by automatically operating the deceleration system after the aircraft lands, the deceleration distance of the aircraft is shortened by 200m, the probability that the aircraft rushes out of the runway is reduced, the operation time and the reflection time of a pilot are saved, and the burden of the pilot is relieved.

Drawings

FIG. 1 is a schematic diagram of the technical solution of the present invention.

Fig. 2 is a block diagram of a shoot runway prevention system.

FIG. 3 is an approach trajectory diagram of an aircraft; wherein FIG. 3-A is a representation of a flying trajectory and a predicted flying trajectory of an aircraft; figure 3-B is the flight path of the deviated glideslope.

FIG. 4 is a diagram of an aircraft deceleration trajectory; wherein, fig. 4-a is the deceleration trajectory of the airplane when the runway length is greater than or equal to the normal runway distance, fig. 4-B is the deceleration trajectory of the airplane when the runway length is less than the normal runway distance and greater than or equal to the severest runway distance, and fig. 4-C is the deceleration trajectory of the airplane when the runway length is less than the severest runway distance.

FIG. 5 is a graph of an aircraft landing deceleration trajectory; wherein, FIG. 5-A is the deceleration trajectory for landing the airplane when the runway remaining distance is greater than or equal to the required runway distance, FIG. 5-B is the deceleration trajectory for landing the airplane when the required runway distance is greater than the runway remaining distance, and FIG. 5-C is the deceleration trajectory for landing the airplane in the ground coordinate system Y_gAbsolute value of displacement in direction y_n| is greater than deviation heading threshold value y_cWhen the aircraft deviates from the runway's land deceleration trajectory.

FIG. 6 is a rush runway prevention system exit logic diagram;

fig. 7 is a flow chart of the present invention.

In fig. 1: 1. a wheel braking system; 2. a wing spoiler controller; 3. rush out of the runway prevention controller; 4. an alarm module; 5. a display module; 6. a recording module; 7. a ground track data module; 8. an engine controller; 9. a ground environment module; 10. a speed sensor; 11. and a positioning module. 12. A flying trajectory; 13. a predicted flight trajectory; 14. deviation from the trajectory; 15. a deviation distance; 16. the most severe runway distance; 17. normal runway distance; 18. runway distance; 19. the runway distance required by the airplane to decelerate to the taxi speed; 20. the runway remaining distance;

Detailed Description

Example one

The airplane wheel braking system comprises an airplane wheel braking system 1, a wing spoiler controller 2, a rush runway prevention controller 3, an alarm module 4, a display module 5, a recording module 6, a ground runway data module 7, an engine controller 8, a ground environment module 9, a speed sensor 10 and a positioning module 11.

The output end of the brake controller of the airplane wheel brake system 1 is communicated with the first input port of the outburst runway prevention controller 3, the outburst runway prevention controller receives the airplane wheel brake system fault state information sent by the airplane wheel brake system, and the first input port of the outburst runway prevention controller 3 receives the information and then processes the information through the AD module. The output end of the wing spoiler controller is communicated with a second input port of the rushing-out runway prevention controller, the rushing-out runway prevention controller receives the fault state of the wing spoiler sent by the wing spoiler controller, and the second input port of the rushing-out runway prevention controller receives information and then processes the information through an AD module. The output end of the ground runway data module is communicated with a third input port of the rushing runway prevention controller, the rushing runway prevention controller receives runway information, a wing spoiler, an engine thrust reverser and a deceleration rate provided by an airplane wheel braking system, which are sent by the ground runway data module, and the runway information comprises: the third input port of the outburst runway prevention controller receives the information and then processes the information through the AD module. The output end of the engine controller is communicated with a fourth input port of the runway rushing-out prevention controller, the runway rushing-out prevention controller receives engine controller fault state information sent by the engine controller, and the information received by the fourth input port of the runway rushing-out prevention controller is processed through an AD module. The output end of the ground environment module is communicated with a fifth input port of the rushing-out runway prevention controller, the ground environment module sends the detected wind direction and wind speed of the airplane to be predicted to land on the runway to the rushing-out runway prevention controller, and the fifth input port of the rushing-out runway prevention controller receives information and then processes the information through the AD module. The output end of the speed sensor is communicated with a sixth input port of the rush-out runway prevention controller, the rush-out runway prevention controller receives speed information detected by the speed sensor, and the speed information comprises: the speed of the main airplane wheel, the speed of the front airplane wheel, the speed of the airplane and the acceleration are processed through the FPGA module after the sixth input port of the runway rushing-out prevention controller receives information. The output end of the positioning module is communicated with the seventh input port of the rushing-out runway prevention controller, the rushing-out runway prevention controller receives the airplane real-time position information sent by the positioning module, and the seventh input port of the rushing-out runway prevention controller receives the information and then processes the information through the AD module.

And audible warning information output by the runway prevention controller, including alarms and voice alarms. The input end of the display module is communicated with a second output port of the runway rushing-out prevention controller; the display module receives the position information of the airplane relative to the runway, which is output by the rushing-out runway prevention controller, and the distance of the runway, the distance of the severest runway and the distance of the departure runway, which are required by the deceleration to the sliding speed, are used for displaying the ground information of the airplane. The input end of the recording module is communicated with the third output port of the runway rushing-out prevention controller, and system information sent by the runway rushing-out prevention controller is received and recorded through the recording module; the system information includes a runway overrun prevention system status, an aircraft departure runway distance, an aircraft wheel speed, aircraft information, runway information, and fault information.

The input end of the ground runway data module is communicated with the fourth output port of the rushing-out runway controller, and the ground runway data module receives the fault state information of the airplane wheel braking system, the wing spoiler and the engine, which is sent by the rushing-out runway prevention controller; the ground runway data module matches an airplane deceleration rate that can be provided by an airplane wheel brake system, a wing spoiler and engine back thrust through fault state information.

And a fifth output port of the runway rushing-out prevention controller is communicated with the input end of a brake controller of the airplane wheel brake system. And the runway rushing-out prevention controller controls braking through braking current to realize braking of the airplane wheel.

And a sixth output port of the rushing-out runway prevention controller is communicated with an input end of the wing spoiler controller, and the rushing-out runway prevention controller controls the opening of the wing spoiler through a switching value signal.

And a seventh output port of the runway rushing-out prevention controller is communicated with an input end of the engine controller, and the runway rushing-out prevention controller controls the engine controller through a switching value signal to realize the deceleration of the airplane through the reverse thrust of the engine.

The runway rushing-out prevention controller adopts the prior art, comprises an FPGA (field programmable gate array), a DA (digital-to-analog) module and an AD (analog-to-digital) module, receives/transmits information through the FPGA, the DA module and the AD module, and processes acquired information through a CPU (central processing unit) or a DSP (digital signal processor).

The positioning module adopts a GPS system or a Beidou satellite system; the ground runway data module is used for storing runway information of an airport, performing data matching on deceleration rates provided by airplane wheel braking systems, wing spoilers and engine reverse thrust of airplanes in different fault states on a selected landing runway, and sending the runway information of airplane landing, the deceleration rate information provided by the airplane wheel braking systems, the wing spoilers and the engine reverse thrust to the rushing-out runway prevention controller; the ground environment module is used to send the wind speed and direction of the airport runway to the rush-out runway prevention controller.

The airplane wheel brake system, the wing spoiler controller and the engine controller are in the prior art.

Example two

The embodiment provides a method for preventing an airplane from rushing out of a runway in a landing process, which comprises the following specific steps:

step 1, displaying the deviation track of airplane glide:

when the aircraft begins to descend, the shoot runway prevention system is activated; predicting the descending track of the airplane according to the landing information of the airplane, comparing the predicted descending track of the airplane with the set position of the glidepath of the airport, judging whether the airplane deviates from the glidepath, and when the predicted descending track is consistent with the set position of the glidepath, judging that the airplane does not deviate; when the predicted descending track is inconsistent with the set lower slideway position, the deviation is considered to occur. If the airplane deviates from the glide slope, displaying deviated position information; if the aircraft does not deviate from the glideslope, the expected glide trajectory is displayed.

The specific process of the step 1 is as follows:

firstly, acquiring airplane glidepath information:

and acquiring the information of the airplane glidepath by a ground runway data module according to a conventional method.

The aircraft glideslope information refers to data when the aircraft starts to descend, and the data when the aircraft descends comprises glideslope position information in a ground inertia coordinate system. Obtaining the information of the airplane glide slope through a ground runway data module; the aircraft glidepath information is recorded asWherein g is a ground inertia coordinate system,is the aircraft glidepath position.

And the origin of the coordinates of the ground inertia coordinate system is the starting point of the airplane sliding. In the ground inertial coordinate system, X_gAxis opposite to direction of movement of aircraft, Z_gWith axis vertically downwards, Y_gThe axis orientation conforms to the right hand rule.

Secondly, determining the predicted aircraft descent track information:

determining the predicted aircraft descent trajectory information by a conventional method:

when the aircraft descent height reaches 1500ft, the runway overrun prevention system is activated.

The runway rushing-out prevention system obtains the real-time speed of the airplane of the body coordinate system through the speed sensor, and the real-time speed of the airplane is recorded asCalculating aircraft acceleration by real-time velocityWherein the content of the first and second substances,is the velocity vector of the aircraft and,is the speed of the airplane in the x-axis direction in the body coordinate system,the speed of the airplane in the y-axis direction in the body coordinate system,the speed of the airplane in the z-axis direction in the body coordinate system,is the acceleration vector of the aircraft, a_xAcceleration of the aircraft in the x-axis direction in the body coordinate system, a_yIs the acceleration of the plane in the y-axis direction in a plane body coordinate system, a_zB represents an aircraft body coordinate system, namely the acceleration of the aircraft in the z-axis direction in the aircraft body coordinate system.

The runway overrun prevention system obtains real-time position information of the aircraft through a position sensor, and records the information asWherein the content of the first and second substances,is real-time position information of the airplane in a body coordinate system,

the rush-out runway prevention system acquires the wind speed and the wind direction in the ground inertial coordinate system through the ground environment module and records the wind speed and the wind direction asWherein the content of the first and second substances,is the velocity vector of the wind and,is the speed of the wind in the x-axis direction in the ground coordinate system,is groundThe velocity of the wind in the y-axis direction in the planar coordinate system,is the velocity of the wind in the z-axis direction in the ground coordinate system.

The origin of coordinates of the aircraft body coordinate system is the mass center O of the aircraft_b(ii) a In the coordinate system of the aircraft body, X_bThe direction of the axis being in line with the aircraft nose direction, Z_bThe axis being oriented vertically and pointing downwards, Y, of the aircraft_bThe axis orientation conforms to the right hand rule.

Converting the body coordinate system to the ground inertia coordinate system by formula (1):

wherein the content of the first and second substances,is the aircraft roll angle, theta is the pitch angle,is the yaw angle, M_gbThe coordinate system of the machine body is converted into the inertial coordinate system of the ground.

Determining a descent trajectory of the aircraft by equations (2) and (3):

wherein X is the predicted descending track of the airplane in the ground inertial coordinate system X_gPosition information of the axis, Y being the predicted trajectory of the aircraft in the ground inertial frame Y_gInformation on the position of the shaft is obtained,for obtaining the aircraft glideslope in the ground inertial frame X_gInformation on the position of the shaft is obtained,for obtaining aircraft glideslopes in the ground inertial frame Y_gPosition information of the shaft.

Thirdly, judging whether the predicted descending track of the airplane deviates from the glide slope:

and judging whether the predicted descending track of the airplane deviates from the glide slope by a conventional method.

The conventional method is adopted to judge whether the predicted descending trajectory of the airplane deviates from the glide slope, and the flying trajectory and the predicted flying trajectory of the airplane are displayed through the display module 5, as shown in fig. 3-a, wherein the flying trajectory 12 and the predicted flying trajectory 13 of the airplane are respectively displayed.

Judging whether the predicted descending trajectory of the airplane deviates from the glide slope through the formulas (4) and (5):

wherein the content of the first and second substances,the position of the glidepath obtained in the first step; x and y are predicted descending tracks of the airplane calculated in the second step; r is_XC、r_YCIs a constant value;

and displaying the deviation track, sending information to an alarm system to prompt the deviation from the glide-slope, and displaying the distance of the deviation from the glide-slope through a display module according to the predicted landing point track of the second step, as shown in fig. 3-B. In fig. 3-B, the flown trajectory 12, the predicted flight trajectory 13, the deviated trajectory 14 and the deviated distance 15 are shown.

And if the descending track of the airplane deviates from the glide slope, displaying the deviation position of the airplane and giving an alarm.

In this example, r_XCIs 5m, said r_YCIs 3 m.

Step 2, determining whether the alarm is required to go back to the flight:

the runway rushing-out prevention system respectively receives the fault states of the airplane wheel braking system, the engine reverse thrust and the wing spoiler of the airplane, and determines that the airplane decelerates to the taxiing speed through the following second stepThe method comprises the steps that a normal runway distance and a severest runway distance are needed, and if the length of the normal runway distance and the length of the severest runway distance are both smaller than the severest runway distance, warning information of missed flyings is provided; and otherwise, displaying the braking distance required by the airplane.

The specific process of the step 2 is as follows:

the method comprises the following steps of firstly, respectively obtaining the deceleration capacity of whether the reverse thrust of the aircraft engine works normally, the braking system of the aircraft wheel and the spoiler of the aircraft wing:

the runway rushing-out prevention system respectively acquires the fault state of an engine, the fault state of a wheel braking system and the fault state of a wing spoiler according to a conventional method. The fault state comprises: whether the engine can be opened to a maximum position for reverse thrust; whether the wing spoilers can be fully opened; and whether all channels of the wheel braking system can brake normally or not.

Secondly, defining an aircraft grounding point position vector and a grounding speed vector:

the thrust out runway prevention system will calculate the aircraft ground position, ground speed and acceleration before the aircraft descends to the decision altitude. The decision height is defined as 200ft in this embodiment.

Calculating the aircraft grounding position, grounding speed and acceleration through the formulas (6), (7) and (8):

wherein the content of the first and second substances,which is indicative of the speed of the aircraft at the current time,which is indicative of the wind speed at the present moment,indicating the aircraft acceleration at the present moment, t indicating the time required to land to ground,is the speed of the aircraft at the point of grounding,is the information of the position of the aircraft grounding point. And the ground runway data module is used for respectively matching a normal deceleration rate and a maximum deceleration rate which can be provided by the engine reverse-thrust system, the airplane wheel braking system and the wing spoiler through a runway and a ground environment according to the fault states of the airplane wheel braking system, the engine reverse-thrust system and the wing spoiler respectively received in the first step. And calculating the normal runway distance and the severest runway distance required by the deceleration of the airplane to the taxi speed according to the information of the grounding position, the grounding speed and the acceleration of the airplane.

The normal runway distance and the most severe runway distance required for the aircraft to decelerate to taxi speed are calculated by equations (9) and (10):

wherein the content of the first and second substances,representing the sum of a deceleration rate provided by a ground runway data module for the reverse thrust of an engine matched with the airplane, a deceleration rate provided by a wing spoiler and a deceleration rate provided by a corresponding airplane brake system on the runway;the sum of the maximum deceleration rate provided by the reverse thrust of the engine, the maximum deceleration rate provided by the wing spoilers and the maximum deceleration rate provided by the airplane wheel braking system;a normal runway distance required for the aircraft to slow down to taxi speed;the harshest runway distance required for the aircraft to slow down to taxi speed.

Thirdly, determining a missed approach warning:

acquiring runway information through a ground runway data module; the runway information includes a runway distance x_t。

The rush-out runway prevention system calculates the normal runway distance, the severest runway distance and the runway length x obtained in the second step_tComparing, if the length of the runway is larger than or equal to the normal distance of the runway, x_t≥x_nWhen the airplane can stop in the preset runway, the display module displays that the airplane decelerates to the taxi speed v_mtThe required runway distance is shown in fig. 4-a. In fig. 4-a, normal runway distance 17, harshest runway distance 16, and runway length 18 are shown. If the runway length is less than the normal runway distance and greater than or equal to the severest runway distance, x_s≤x_t＜x_nAnd when the airplane needs to implement the maximum deceleration capacity, the airplane can be stopped in the preset runway by considering that the airplane can be decelerated to the taxi speed v_mtThe required runway distance is shown in fig. 4-B. In fig. 4-B, normal runway distance 17, harshest runway distance 16, and runway length 18 are shown. If the runway length is less than the harshest runway distance, x_t＜x_sWhen, the display aircraft decelerates to the taxi speed v_mtThe required runway distance is shown in fig. 4-C and a message is sent to the warning system prompting it to fly back. In fig. 4-C, normal runway distance 17, harshest runway distance 16, and runway length 18 are shown.

Said coasting speed v_mtThe setting is carried out according to different models, and the setting is 60km/h in the embodiment.

If the airplane rushes out of the runway prevention system in the step 2 and the third step prompts the flyover, the pilot carries out the flyover operation and quits the runway prevention system; if the pilot does not take the missed approach, continue landing and go to step 3. And if the airplane rushes out of the runway, the prevention system does not prompt the missed approach in the step 2 and the third step, performing the step 4.

Step 3, implementing the maximum deceleration capacity of the airplane:

the runway rushing-out prevention system respectively controls the airplane wheel braking system, the engine reverse thrust system and the wing spoiler, and respectively activates the airplane wheel braking system, the engine reverse thrust system and the wing spoiler to decelerate the airplane after the airplane is grounded.

The specific process of decelerating the aircraft is as follows:

the method comprises the following steps of firstly, respectively obtaining the control capacities of an airplane wheel braking system, an engine thrust reverser and a wing spoiler:

and secondly, respectively activating an engine reverse thrust system, a wing spoiler system and an airplane wheel braking system:

after the airplane is grounded, the engine is activated by the engine controller to perform reverse thrust so that the reverse thrust capacity of the airplane is maximized, after the airplane wheels rotate fully, the brake controller of the airplane wheel brake system enables the airplane wheel brake system to output the maximum brake capacity under the antiskid working condition, and the wing spoiler controller opens the wing spoiler to decelerate.

Step 4, determining the runway distance required by the aircraft to decelerate to the taxi speed:

and in the process of landing and decelerating the airplane, determining the runway distance required by the deceleration of the airplane to the taxi speed, and displaying the remaining runway distance in real time.

The specific process of the step 4 is as follows:

firstly, acquiring aircraft landing information:

when the required runway distance is determined, the speed, the deceleration and the position information of the aircraft after the ground contact are obtained through the airspeed head and the positioning module.

Secondly, determining the runway distance required by the aircraft to decelerate to the taxi speed:

according to the current aircraft speedAnd accelerationCalculating the deceleration to taxiing speed v of an aircraft_mtAnd the required runway distance, wherein the runway remaining distance is the distance from the current position of the airplane to the origin of the ground inertial coordinate system.

Calculating the runway distance required by the airplane to decelerate to the taxiing speed through equations (11) and (12):

wherein t is the time required for the aircraft to decelerate to the taxi speed, x_nRunway distance, y, required for the aircraft to slow down to taxi speed_nThe distance from the heading when the aircraft decelerates to taxi speed.

Thirdly, displaying the runway distance x required by the aircraft to decelerate to the taxi speed_n：

The runway distance required by the airplane to be decelerated to the taxi speed and the residual runway distance x obtained in the second step_lA comparison is made. If the runway remaining distance is more than or equal to the runway distance x required by the airplane to decelerate to the taxiing speed_n，x_l≥x_nThen, the airplane is considered to be able to stop the airplane within the predetermined runway, and the required runway distance is displayed through the display module, as shown in fig. 5-a. In fig. 5-a, runway distance 19 and runway remaining distance 20 required for the aircraft to slow down to taxi speed are shown.

If the required runway distance obtained in the second step is larger than the remaining distance of the runway, x_l＜x_nIf so, the aircraft is considered to be unable to stop within the predetermined runway, a runway overrun warning is provided to the pilot, and the desired runway distance is displayed via the display module, as shown in fig. 5-B. In fig. 5-B, runway distance 19 and runway remaining distance 20 required for the aircraft to slow down to taxi speed are shown.

Fourthly, judging whether to provide a course deviation alarm

If the aircraft is in the ground coordinate system Y_gAbsolute value of displacement in direction y_n| is greater than deviation heading threshold value y_c，|y_n|＞y_cAnd meanwhile, displaying the distance of the airplane deviating from the course through the display module, as shown in the figure 5-C, and providing warning information for the pilot to prompt the pilot to deviate from the course. In fig. 5-C, the departure distance 15, the runway remaining distance 20, and the runway distance 19 required for the aircraft to slow down to taxi speed are shown.

Displaying the deceleration of the airplane to the taxiing speed v through the display module_mtThe required runway distance is shown in fig. 4-a. In fig. 4-a, normal runway distance 17, harshest runway distance 16, and runway length 18 are shown.

Step 5, exit/end:

the specific process of the step 5 is as follows:

the first step, receiving the aircraft ground speed and the aircraft wheel speed:

and when the airplane exits the runway rushing-out prevention system, acquiring the speed of the airplane through the flight control system, and respectively acquiring the speed of the front airplane wheel of the airplane and the speed of each main airplane wheel through the airplane wheel braking system.

And step two, the rushing-out runway prevention system quits/ends:

and when the ground speed of the airplane is less than or equal to the taxiing speed, or the speed of the front airplane wheel is less than or equal to the taxiing speed, or the speeds of all the main airplane wheels are less than or equal to the taxiing speed, exiting the runway rushing-out prevention system. During the operation of the shoot-off runway prevention system, the pilot terminates the shoot-off runway prevention system via the operator.

Thus, the prevention of the airplane rushing out of the runway in the landing process is completed.