Collision estimation-based automatic ground collision prevention control method for training plane and training plane

Abstract

The embodiment of the invention discloses an automatic anti-ground-collision control method for a coach plane based on collision estimation and the coach plane, and the method comprises the steps: 1, predicting the prediction trajectory of the plane after a preset time based on the current flight state of the plane; step 2, scanning the aircraft prediction trajectory in the elevation digital map to obtain corresponding regional ground range data, that is, obtaining the relative position of the aircraft prediction trajectory and the terrain, and processing the regional ground range data into a two-dimensional terrain profile; step 3, comparing the aircraft predicted trajectory with the two-dimensional terrain profile data to obtain the height of the aircraft predicted trajectory and the relative height of the aircraft predicted trajectory to the corresponding terrain height in the two-dimensional terrain profile data, and comparing the relative height with a set vertical minimum safety distance in advance to estimate whether there is a collision; step 4, on the basis of the collision estimation result, a longitudinal change-out branch and a transverse change-out branch of the aircraft are controlled according to a preset automatic anti-collision maneuvering change-out control logic, and a normal overload instruction and a roll angle rate instruction are generated; and step 5, adding the normal overload instruction and the roll angle rate instruction into a main flight control law so as to realize automatic anti-collision maneuvering change. According to the technical scheme provided by the embodiment of the invention, a controllable flight ground collision accident caused by space loss due to the fact that a pilot loses consciousness due to large overload or the pilot misjudges the spatial position and the attitude of the aircraft in a complex flight environment during large maneuvering flight of a modern high-performance aircraft is solved, and the last defense line is provided for safe flight of the aircraft.

Description

Technical Field

[0001] The present invention relates to the field of flight control system technology, but is not limited to it, and in particular to an automatic collision avoidance control method for a trainer aircraft based on collision prediction and a trainer aircraft. Background Art

[0002] When modern high-performance aircraft are performing large maneuvers or missions in complex environments, a "Controlled Flight into Terrain (CFTI)" accident may occur if the pilot loses consciousness due to high overload or misjudges the aircraft's position and attitude in space. In severe cases, it may cause the aircraft to be destroyed and people to die.

[0003] In order to prevent such accidents from happening, the traditional method is to issue warnings in advance through visual, voice, etc. on the aircraft. However, this warning method requires the pilot to have enough time to correct the aircraft, and the warning system warns frequently and distractingly, which may be ignored by the pilot; or when the pilot loses consciousness, he or she may not be aware of these warning signals. Summary of the invention

[0004] Purpose of the present invention: The embodiment of the present invention provides a method for automatic ground collision avoidance control of a trainer aircraft based on collision prediction and a trainer aircraft to solve controlled ground collision accidents that may be caused during large maneuvering flight or when the pilot is lost in space.

[0005] Technical solution of the present invention: An embodiment of the present invention provides a method for automatically avoiding collisions of a trainer aircraft based on collision prediction, comprising:

[0006] Step 1, based on the current flight status of the aircraft, predict the aircraft's predicted trajectory after a preset time;

[0007] Step 2, scanning the predicted trajectory of the aircraft in the elevation digital map to obtain the corresponding regional terrain data, that is, obtaining the relative position of the predicted trajectory of the aircraft and the terrain, and processing the regional terrain data into a two-dimensional terrain profile;

[0008] Step 3, compare the predicted trajectory of the aircraft with the two-dimensional terrain profile data, obtain the relative height of the predicted trajectory of the aircraft and the corresponding terrain height in the two-dimensional terrain profile data, compare the relative height with the set vertical minimum safety distance in advance, and estimate whether there is a collision;

[0009] Step 4, based on the collision prediction result, the longitudinal recovery branch and the lateral recovery branch of the aircraft are controlled respectively according to the preset automatic collision avoidance maneuver recovery control logic to generate a normal overload instruction and a roll angular rate instruction;

[0010] Step 5: Add the normal overload command and the roll rate command to the main flight control law to achieve automatic anti-collision maneuver recovery.

[0011] Optionally, in the above-mentioned method for automatic collision avoidance control of a trainer aircraft based on collision prediction, step 1 comprises:

[0012] According to the current flight position, speed, acceleration, attitude and energy state of the aircraft, the Kalman filter method is used to estimate the aircraft state variables based on the aircraft position estimate, speed estimate, acceleration estimate at the previous moment and the observed value at the current moment, thereby completing the prediction of the aircraft's motion trajectory at the next moment.

[0013] Optionally, in the above-mentioned method for automatic collision avoidance control of a trainer aircraft based on collision prediction, in step 1, the state equation and observation equation for predicting the predicted trajectory of the aircraft are:

[0014]

[0015] Among them, X(k+1) represents the state value at time k+1, X(k) represents the state value at time k, A(k) is the state transfer matrix at time k, T(k) is the interference transfer matrix at time k, W(k) represents the system state noise of the motion model at time k, Z(k) represents the observation vector at time k, H(k) is the observation matrix at time k, and V(k) is the observation noise at time k.

[0016] Optionally, in the above-mentioned method for automatic collision avoidance control of a trainer aircraft based on collision prediction, step 2 comprises:

[0017] According to the predicted trajectory of the aircraft, the corresponding elevation digital map is scanned to realize the positioning of the aircraft in the current terrain, and the regional terrain data corresponding to the predicted trajectory of the aircraft in the elevation digital map is obtained; in order to reduce the complexity of map digital calculation, the regional terrain data corresponding to the predicted trajectory of the aircraft is processed into a two-dimensional terrain profile; wherein, the shape and size of the scanning area (i.e., the regional terrain data) depends on the current speed of the aircraft, the movement heading of the aircraft and the attitude angle of the aircraft.

[0018] Optionally, in the above-mentioned method for automatically avoiding collisions of a trainer aircraft based on collision prediction, the method for judging whether a collision occurs in step 3 includes:

[0019] Compare the predicted trajectory of the aircraft with the two-dimensional terrain profile. If the minimum vertical distance between the height of each trajectory point of the predicted trajectory of the aircraft and the height of the corresponding point in the two-dimensional terrain profile data is less than or equal to the preset safety distance, it is estimated that a collision will occur, and the automatic collision avoidance maneuver recovery control logic is turned on;

[0020] After the automatic collision avoidance maneuvering recovery control logic is turned on, the minimum vertical distance between the height of each trajectory point of the aircraft's predicted trajectory and the height of the corresponding point in the two-dimensional terrain profile data is continuously judged to be greater than the preset safety distance, and when it exceeds a certain threshold, the automatic collision avoidance maneuvering recovery control logic is exited.

[0021] Optionally, in the above-mentioned method for automatic collision avoidance control of a trainer aircraft based on collision prediction, step 4 comprises:

[0022] After the automatic anti-collision maneuver recovery control logic is turned on, a corresponding control strategy is used to recover according to the current attitude of the aircraft; wherein the automatic anti-collision maneuver recovery control logic is used to realize that the aircraft automatically recovers from various attitudes quickly and gently to a safe flight state with wings level and slightly climbing;

[0023] Optionally, in the above-mentioned automatic collision avoidance control method for a trainer aircraft based on collision prediction, the longitudinal recovery branch of the aircraft includes: a track angle control branch and a positive overload pull-up control branch; the lateral recovery branch of the aircraft includes: a roll angle control branch;

[0024] Among them, the track angle control branch uses the track angle command, angle of attack, pitch angle and pitch angle rate to generate the track angle control command. The positive overload pull-up control branch forms the normal overload command according to the current attitude and energy state of the aircraft. The roll angle control branch generates the roll angle rate command through the roll angle and the automatic recovery roll angle command.

[0025] After the automatic collision avoidance maneuver recovery control logic is turned on, the connection forms of the longitudinal recovery branch and the lateral recovery branch of the aircraft are controlled respectively according to the current attitude of the aircraft.

[0026] Optionally, in the above-mentioned automatic collision avoidance control method for a trainer aircraft based on collision prediction, in step 4, a corresponding control strategy is used for recovery according to the current attitude of the aircraft; including the following three control strategies:

[0027] Control strategy 1: When the aircraft is in a vertical dive when the automatic collision avoidance maneuver recovery control logic is turned on, first, the aircraft longitudinal recovery branch is connected to the positive overload pull-up control branch, and the aircraft is pulled up with positive overload, and the lateral recovery branch is not connected; during the longitudinal recovery process, when the aircraft pitch angle is greater than the set pitch angle threshold, the roll angle control branch in the lateral recovery branch is connected to control the aircraft roll angle and stabilize it to 0°, and the aircraft is still pulled up with positive overload in the longitudinal recovery branch;

[0028] Control strategy 2: When the aircraft is in a large-angle dive when the automatic collision avoidance maneuver recovery control logic is turned on, first, the lateral recovery branch of the aircraft is connected to the roll angle control branch, and the roll angle of the aircraft is controlled to stabilize to 0° through the automatic recovery roll angle command. During the roll leveling process, when the aircraft roll angle is less than the set roll angle threshold, the longitudinal recovery branch of the aircraft is connected to the positive overload pull-up control branch;

[0029] Otherwise, control strategy 3 is executed, the longitudinal recovery branch of the aircraft is connected to the track angle control branch, and the track angle control command generated by the command is used as the normal overload command; wherein, the track angle command FPAC is calculated based on the terrain information, the aircraft maneuvering constraints and the current aircraft state parameters; the lateral recovery branch is connected to the roll angle control branch to control the aircraft roll angle and stabilize it to 0°.

[0030] Optionally, in the above-mentioned method for automatic collision avoidance control of a trainer aircraft based on collision prediction, step 5 comprises:

[0031] The control command generated by the control stick after the command gradient and command shaping is superimposed on the normal overload command, and the horizontal tail movement is controlled through proportional integral to achieve longitudinal maneuver recovery control;

[0032] The control command generated by the control stick after the command gradient is superimposed on the roll angle rate command, and the aileron movement is proportionally controlled to achieve lateral maneuver recovery control.

[0033] In a second aspect, an embodiment of the present invention further provides a trainer aircraft based on collision prediction, wherein the flight control system of the trainer aircraft includes: a memory and a processor;

[0034] Wherein, the memory is configured to store executable instructions;

[0035] The processor is specifically configured to implement any of the above-mentioned methods for automatic collision avoidance control of a trainer aircraft based on collision prediction when executing the executable instructions stored in the memory.

[0036] Beneficial effects of the present invention: The embodiment of the present invention provides a method for automatically avoiding ground collisions of a trainer aircraft based on collision prediction and a trainer aircraft. The trainer aircraft based on collision prediction is equipped with an automatic ground collision avoidance system. The predicted trajectory of the aircraft after a preset time is predicted according to the current flight state of the aircraft. The predicted trajectory of the aircraft is scanned in an elevation digital map to obtain corresponding regional terrain data, that is, the relative position of the predicted trajectory of the aircraft and the terrain is obtained, and the regional terrain data is processed into a two-dimensional terrain profile. In addition, by comparing the predicted trajectory of the aircraft with the two-dimensional terrain profile data, the relative height of the predicted trajectory of the aircraft and the corresponding terrain height in the two-dimensional terrain profile data is obtained, and the relative height is compared with the set vertical minimum safety distance in advance to estimate whether there is a collision. According to the collision prediction result, the longitudinal recovery branch and the lateral recovery branch of the aircraft are controlled respectively according to the preset automatic collision avoidance maneuver recovery control logic, and a normal overload instruction and a roll angular rate instruction are generated. Finally, the normal overload instruction and the roll angular rate instruction are added to the main flight control law to achieve automatic collision avoidance maneuver recovery. The technical solution provided by the embodiment of the present invention has the following beneficial effects: on the one hand, the automatic ground collision avoidance system configured in the training aircraft will not harm the pilot or the aircraft, and will not interfere with the normal execution of the flight mission; on the other hand, when the pilot loses consciousness due to large overload during large maneuvering flight, or loses spatial disorientation in a complex flight environment and loses control of the aircraft, the automatic collision avoidance system can prevent the aircraft from crashing into the ground and causing a controlled flight-to-ground accident; on the other hand, the technical solution provided by the embodiment of the present invention can be used to save the lives and costs of pilots in combat and training missions, thereby avoiding the loss of talent and property for the country. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0038] Figure 1 A schematic diagram of the principle of an automatic collision avoidance control method based on collision prediction provided by an embodiment of the present invention;

[0039] Figure 2 A logic diagram of automatic recovery from collision avoidance of an automatic collision avoidance control method based on collision prediction provided by an embodiment of the present invention;

[0040] Figure 3 As shown, it is a schematic diagram of the control principle of the longitudinal maneuvering branch in an embodiment of the present invention;

[0041] Figure 4 As shown, it is a schematic diagram of the control principle of the lateral maneuvering diversion branch in an embodiment of the present invention;

[0042] Figure 5 Schematic diagram of the simulation result of the height change trajectory of the dive avoidance terrain obtained by executing the automatic avoidance terrain control method in Example 1 of the present invention;

[0043] Figure 6 It is a schematic diagram of simulation curves of various state quantities of the aircraft in the dive ground avoidance control obtained by executing the automatic ground avoidance control method in Embodiment 1 of the present invention;

[0044] Figure 7 It is a schematic diagram of the simulation result of the height change trajectory with rolling and diving collision obtained by executing the automatic collision avoidance control method in Example 2 of the present invention;

[0045] Figure 8 It is a schematic diagram of simulation curves of various state quantities of an aircraft in rolling and diving collision control obtained by executing the automatic collision avoidance control method in Example 2 of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0047] The above background technology has already explained that in modern high-performance large maneuvering flights and complex mission scenario flights, controlled flight collisions caused by pilots' loss of consciousness or spatial disorientation are likely to cause aircraft crashes and fatalities, resulting in pilot sacrifices and huge property losses. In view of this, it is necessary to develop a system with automatic ground collision avoidance warning and recovery functions to effectively avoid controlled flight collision accidents and save pilots' lives and expensive aircraft.

[0048] In response to the above problems and needs, an embodiment of the present invention provides an automatic anti-collision control method for a trainer aircraft based on collision prediction and a trainer aircraft. The trainer aircraft equipped with the method can timely predict the trajectory of the aircraft and automatically maneuver out of possible controllable flight collision events without interfering with the normal flight of the aircraft or affecting the normal performance of the pilot's mission, thereby providing the last guarantee for safe flight.

[0049] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0050] Figure 1 A schematic diagram of the principle of an automatic collision avoidance control method based on collision prediction provided by an embodiment of the present invention, Figure 2 A collision logic determination flow chart of an automatic collision avoidance control method based on collision estimation provided by an embodiment of the present invention. Figure 3 and Figure 4The automatic maneuvering recovery control structure diagram of an automatic anti-collision control method based on collision prediction provided by an embodiment of the present invention. Figure 1 As shown, the automatic anti-collision system for executing the automatic anti-collision control method has a collision estimation module and an automatic maneuvering recovery module, see Figure 1 to Figure 4 As shown, the automatic anti-collision control method and system provided by the embodiment of the present invention may include the following implementation steps:

[0051] Step 1: Based on the flight status information such as the aircraft's current flight position, speed, acceleration, attitude and energy status, predict the aircraft's predicted trajectory after a preset time in the future.

[0052] In the embodiment of the present invention, the implementation method of step 1 is: based on the Kalman filter method, the aircraft position estimation value, velocity estimation value, acceleration estimation value and the observation value at the previous moment are used to estimate the aircraft state quantity, and then the aircraft motion trajectory at the next moment is predicted. The state equation and observation equation for trajectory prediction are as follows:

[0053]

[0054] Among them, X(k+1) represents the state value at time k+1, X(k) represents the state value at time k, A(k) is the state transfer matrix at time k, T(k) is the interference transfer matrix at time k, W(k) represents the system state noise of the motion model at time k, Z(k) represents the observation vector at time k, H(k) is the observation matrix at time k, and V(k) is the observation noise at time k.

[0055] With the minimum mean square error J = E[(x k+1 -x' k+1 )(x k+1 -x' k+1 ) T ] is the criterion, and the optimal state estimation value is obtained according to the following filtering equation:

[0056] X(k+1,k+1)=X(k+1,k)+K(k+1)[Z(k+1)-X(k+1,k)];

[0057] Among them, x′ k+1 represents the optimal state estimate at time k+1, K(k+1) is the gain matrix at time k+1; the gain matrix K(k+1) is derived based on the state noise covariance and the observation noise covariance; X(k+1,k) represents the estimate of time k for time k+1; Z(k+1) represents the observation vector at time k+1.

[0058] According to the above formula, the optimal state estimation value at the next step can be obtained to complete the single-step prediction process. If the prediction is n steps, the calculation can be iterated n times to complete the n-step prediction.

[0059] Step 2, based on the elevation digital map, scan the predicted trajectory of the aircraft in the elevation digital map to obtain the corresponding regional terrain data, that is, obtain the relative position of the predicted trajectory of the aircraft and the terrain, and process the regional terrain data into a two-dimensional terrain profile. In the embodiment of the present invention, the specific implementation process of step 2 is:

[0060] According to the predicted trajectory of the aircraft, the corresponding elevation digital map is scanned to realize the positioning of the aircraft in the current terrain, and the regional terrain data corresponding to the predicted trajectory of the aircraft in the elevation digital map are obtained; in order to reduce the complexity of map digital calculation, the regional terrain data corresponding to the predicted trajectory of the aircraft is processed into a two-dimensional terrain profile, and the two-dimensional terrain profile is formed specifically through the forward and altitude information of the predicted trajectory of the aircraft in the regional terrain data; wherein, the shape and size of the scanning area (i.e., the regional terrain data) depend on the current speed of the aircraft, the movement heading of the aircraft and the attitude angle of the aircraft.

[0061] Step 3, compare the predicted trajectory of the aircraft with the two-dimensional terrain profile data, obtain the relative height of the predicted trajectory of the aircraft and its corresponding terrain height in the two-dimensional terrain profile data, compare the relative height with the set vertical minimum safety distance in advance, and estimate whether there is a collision.

[0062] The method for estimating whether there is a collision in step 3 includes:

[0063] The predicted trajectory of the aircraft is compared with the two-dimensional terrain profile. If the minimum vertical distance between the height of each trajectory point of the predicted trajectory of the aircraft and the height of the corresponding point in the two-dimensional terrain profile data is less than or equal to the preset safety distance, it is predicted that a collision will occur. The collision prediction module sends an automatic collision avoidance maneuver recovery request to the automatic collision avoidance maneuver recovery module, thereby connecting the automatic collision avoidance maneuver recovery control logic.

[0064] After the automatic collision avoidance maneuvering recovery control logic is turned on, the minimum vertical distance between the height of each trajectory point of the aircraft's predicted trajectory and the height of the corresponding point in the two-dimensional terrain profile data is continuously judged to be greater than the preset safety distance, and when it exceeds a certain threshold, the collision prediction module sends an automatic collision avoidance exit request to the automatic collision avoidance maneuvering recovery module, thereby exiting the execution of the automatic collision avoidance maneuvering recovery control strategy.

[0065] Step 4: Based on the collision prediction result, the automatic maneuvering recovery module of the flight control system responds, controls the longitudinal recovery branch and the lateral recovery branch of the aircraft respectively according to the preset automatic maneuvering logic and control law, and generates normal overload instructions and roll rate instructions to control the aircraft maneuvering recovery. Figure 2As shown, the processing method after the automatic collision avoidance maneuver recovery control logic is turned on in the automatic collision avoidance control method for a trainer aircraft based on collision prediction provided by an embodiment of the present invention. In the embodiment of the present invention, the implementation process of step 4 may include:

[0066] After the automatic collision avoidance maneuver recovery control logic is turned on, different methods are used to recover when the aircraft is in different attitudes; among them, the automatic collision avoidance maneuver recovery control logic enables the aircraft to automatically and quickly and gently recover from any attitude to a safe flight state with wings level and slightly climbing; in addition, the design of the automatic collision avoidance maneuver recovery control logic requires full consideration of the pilot's psychological and physiological tolerance to the automatic recovery action.

[0067] like Figure 3 FIG. 1 is a schematic diagram of the control principle of the longitudinal maneuvering branch diversion in an embodiment of the present invention. Figure 4 FIG. 1 is a schematic diagram of the control principle of the lateral maneuvering branch diversion in an embodiment of the present invention. Figure 3 and Figure 4 As shown, the longitudinal recovery branch of the aircraft includes: a track angle control branch and a positive overload pull-up control branch; the lateral recovery branch of the aircraft includes: a roll angle control branch.

[0068] Among them, the track angle control branch uses the track angle instruction, angle of attack, pitch angle and pitch angle rate to comprehensively generate the track angle control instruction. The positive overload pull-up control branch forms the normal overload instruction according to the current attitude and energy state of the aircraft. The roll angle control branch generates the roll angle rate instruction through the roll angle and the automatic correction roll angle instruction.

[0069] After the automatic collision avoidance maneuver recovery control logic is turned on, the connection form of the aircraft's longitudinal recovery branch and lateral recovery branch is controlled according to the aircraft's current attitude.

[0070] The following three different maneuver recovery strategies are used when the aircraft is in different flight attitudes:

[0071] (1) When the aircraft is in a vertical dive when the automatic collision avoidance maneuver recovery control logic is turned on, first, the aircraft longitudinal recovery branch is connected to the positive overload pull-up control branch, and the aircraft is forcibly pulled up with positive overload, and the lateral recovery branch is not connected; during the longitudinal recovery process, when the aircraft pitch angle is greater than the set pitch angle threshold, the roll angle control branch in the lateral recovery branch is connected to control the aircraft roll angle and stabilize it to 0°, and the aircraft is still pulled up with positive overload in the longitudinal recovery branch.

[0072] (2) When the aircraft is in a large-angle dive when the automatic collision avoidance maneuver recovery control logic is turned on, first, the aircraft's lateral recovery branch is connected to the roll angle control branch, and the aircraft's roll angle is controlled to stabilize to 0° through the automatic recovery roll angle command. During the roll leveling process, when the aircraft's roll angle is less than the set roll angle threshold, the aircraft's longitudinal recovery branch is connected to the positive overload pull-up control branch.

[0073] (3) Otherwise, the longitudinal recovery branch of the aircraft is connected to the track angle control branch, and the track angle control command generated by the command is used as the normal overload command; wherein, the track angle command FPAC is calculated based on the terrain information, the aircraft maneuvering constraints and the current aircraft state parameters; the lateral recovery branch is connected to the roll angle control branch, and the aircraft roll angle is controlled and stabilized to 0°.

[0074] Step 5: Add the normal overload command and the roll rate command to the main flight control law to achieve automatic anti-collision maneuver recovery.

[0075] like Figure 3 and Figure 4 As shown, the implementation method of step 5 is: on the one hand, the control command generated by the control stick after the command gradient and command shaping are superimposed on the normal overload command, and the horizontal tail movement is controlled through proportional integral to achieve longitudinal maneuver recovery control; on the other hand, the control command generated by the control stick after the command gradient is superimposed on the roll angle rate command, and the aileron movement is proportionally controlled to achieve lateral maneuver recovery control.

[0076] Based on the automatic collision avoidance control method for a trainer aircraft based on collision prediction provided by the above embodiment of the present invention, an embodiment of the present invention further provides a trainer aircraft based on collision prediction, characterized in that the flight control system of the trainer aircraft includes: a memory and a processor;

[0077] Wherein, the memory is configured to store executable instructions;

[0078] The processor is specifically configured to implement the automatic collision avoidance control method for a trainer aircraft based on collision prediction as provided in any of the above embodiments when executing the executable instructions stored in the memory.

[0079] The embodiment of the present invention provides an automatic ground collision avoidance control method for a trainer aircraft based on collision prediction and a trainer aircraft. The trainer aircraft based on collision prediction is equipped with an automatic ground collision avoidance system. The predicted trajectory of the aircraft after a preset time is predicted according to the current flight state of the aircraft. The predicted trajectory of the aircraft is scanned in an elevation digital map to obtain corresponding regional terrain data, that is, the relative position of the predicted trajectory of the aircraft and the terrain is obtained, and the regional terrain data is processed into a two-dimensional terrain profile. In addition, by comparing the predicted trajectory of the aircraft with the two-dimensional terrain profile data, the relative height of the predicted trajectory of the aircraft and the corresponding terrain height in the two-dimensional terrain profile data is obtained, and the relative height is compared with the set vertical minimum safety distance in advance to estimate whether there is a collision. According to the collision prediction result, the longitudinal recovery branch and the lateral recovery branch of the aircraft are controlled respectively according to the preset automatic collision avoidance maneuver recovery control logic, and a normal overload instruction and a roll angular rate instruction are generated. Finally, the normal overload instruction and the roll angular rate instruction are added to the main flight control law to achieve automatic collision avoidance maneuver recovery. The technical solution provided by the embodiment of the present invention has the following beneficial effects: on the one hand, the automatic ground collision avoidance system configured in the training aircraft will not harm the pilot or the aircraft, and will not interfere with the normal execution of the flight mission; on the other hand, when the pilot loses consciousness due to large overload during large maneuvering flight, or loses spatial disorientation in a complex flight environment and loses control of the aircraft, the automatic collision avoidance system can prevent the aircraft from crashing into the ground and causing a controlled flight-to-ground accident; on the other hand, the technical solution provided by the embodiment of the present invention can be used to save the lives and costs of pilots in combat and training missions, thereby avoiding the loss of talent and property for the country.

[0080] The following two embodiments are used to schematically illustrate the implementation of the automatic collision avoidance control method for a training aircraft based on collision prediction provided by the present invention.

[0081] Embodiment 1:

[0082] Step 1: Trajectory prediction

[0083] In the specific implementation, a low-altitude high speed state point is selected, and the total simulation time is set to 50s. Within 0 to 5s, the aircraft maintains level flight; within 5 to 10s, the vertical stick is fully pushed. According to the current position, speed, acceleration, attitude and energy state of the aircraft, the predicted trajectory of the aircraft after the prediction time T is determined.

[0084] Step 2: Determine the location of the aircraft's predicted trajectory on the elevation digital map

[0085] During specific implementation, according to the current speed and attitude of the aircraft, an elevation digital map area is selected for scanning to determine the relative position of the aircraft's predicted trajectory and the terrain.

[0086] Step 3: Determine whether there is a collision

[0087] In specific implementation, the minimum safety altitude threshold is set to 100m, the aircraft predicted trajectory is compared with the terrain profile data, and the relative distance is judged against the minimum safety altitude. If the minimum distance between the aircraft predicted trajectory altitude and the terrain profile is less than 100m, an automatic collision avoidance recovery request is issued.

[0088] Step 4: Automatic maneuver recovery

[0089] In the specific implementation of 401, when the aircraft is in a vertical dive, first the aircraft is pulled up longitudinally with a maximum overload of 5g according to the aircraft dynamic pressure, and the lateral heading is not controlled; when the aircraft pitch angle is greater than -81°, the aircraft roll angle is controlled and stabilized to 0°, and the longitudinal pull-up is still carried out with positive overload. The longitudinal pull-up overload command change rule is designed as follows:

[0090] Dynamic Pressure 0 800 1200 10000 Overload 2.0 2.0 5.0 5.0

[0091] In the specific implementation of 402, when it is predicted that no collision will occur during the pull-up process, the track angle control is turned on, and when the climbing altitude is greater than the safe altitude of 500m, the altitude holding is turned on.

[0092] Step 5: Instruction Synthesis

[0093] 501 In the specific implementation, the normal overload command is integrated with the control command of the joystick after the command gradient and command shaping to obtain the automatic collision avoidance simulation diagram. The specific results are shown in Figure 5 and Figure 6 , is a schematic diagram of simulation results of the automatic anti-collision control method in Embodiment 1 of the present invention, Figure 5 is a schematic diagram of a simulation result of a dive avoidance terrain height change trajectory obtained by executing the automatic avoidance terrain control method in Embodiment 1 of the present invention, Figure 6 Schematic diagram of simulation curves of various state quantities of the aircraft in the dive ground avoidance control obtained by executing the automatic ground avoidance control method in Example 1 of the present invention. It can be seen that the automatic ground avoidance function is successfully implemented in Example 1.

[0094] 502. Implementation completed.

[0095] Embodiment 2

[0096] The present invention will be further described below in conjunction with embodiments:

[0097] Step 1: Trajectory prediction

[0098] In the specific implementation, a low-altitude high speed state point is selected, and the total simulation time is set to 50s. Within 0-5s, the aircraft maintains level flight; within 5-10s, the longitudinal lever is fully pushed and the lateral lever is fully pressed. According to the current position, speed, acceleration, attitude and energy state of the aircraft, the prediction time T and the predicted trajectory of the aircraft are determined.

[0099] Step 2: Determine the location of the aircraft's predicted trajectory on the elevation digital map

[0100] During specific implementation, according to the current speed and attitude of the aircraft, an elevation digital map area is selected for scanning to determine the relative position of the aircraft's predicted trajectory and the terrain.

[0101] Step 3: Determine whether there is a collision

[0102] In specific implementation, the minimum safety altitude threshold is set to 100m, the aircraft predicted trajectory is compared with the terrain profile data, and the relative distance is judged against the minimum safety altitude. If the minimum distance between the aircraft predicted trajectory altitude and the terrain profile is less than 100m, an automatic collision avoidance recovery request is issued.

[0103] Step 4: Automatic maneuver recovery

[0104] In the specific implementation of 401, when the aircraft is in a vertical dive, first the aircraft is pulled up longitudinally with a maximum overload of 5g according to the aircraft dynamic pressure, and the lateral heading is not controlled; when the aircraft pitch angle is greater than -81°, the aircraft roll angle is controlled and stabilized to 0°, and the longitudinal pull-up is still carried out with positive overload. The longitudinal pull-up overload command change rule is designed as follows:

[0105] Dynamic Pressure 0 800 1200 10000 Overload 2.0 2.0 5.0 5.0

[0106] 402. In specific implementation, when the aircraft is in a dive with a large roll angle, first control the aircraft's roll angle to stabilize to 0°. During the roll leveling process, when the absolute value of the aircraft's roll angle is less than 60°, connect the longitudinal pull-up mode.

[0107] 403. In specific implementation, when no collision is predicted during the pull-up process, track angle control is turned on, and when the climbing altitude is greater than the safe altitude of 500m, altitude holding is turned on.

[0108] Step 5: Instruction Synthesis

[0109] 501 In the specific implementation, the normal overload command is integrated with the control command of the joystick after the command gradient and command shaping to obtain the automatic collision avoidance simulation diagram. The specific results are shown in Figure 7 and Figure 8 , is a schematic diagram of simulation results of the automatic anti-collision control method in Embodiment 2 of the present invention, Figure 7 Schematic diagram of simulation results of height change trajectory with rolling and diving collision obtained by executing the automatic collision avoidance control method in Example 2 of the present invention, Figure 8 Schematic diagram of simulation curves of various state quantities of an aircraft in rolling and diving ground collision control obtained by executing the automatic ground collision avoidance control method in Example 2 of the present invention. It can be seen that the automatic ground collision avoidance function is successfully implemented in Example 2.

[0110] 502. Implementation completed.

[0111] According to the simulation schematic diagram of Example 1, it is explained that in the case of an aircraft diving and hitting the ground, it is predicted that the aircraft may collide in about 15 seconds, and the aircraft maneuvers are carried out in time according to the automatic collision avoidance maneuver recovery strategy, so that the aircraft completes the automatic pull-up maneuver above the preset safety altitude of 1,100 meters, realizing the automatic collision avoidance function.

[0112] According to the simulation diagram of Example 2, it is explained that in the case of an aircraft rolling dive into the ground, it is predicted that the aircraft may collide around 15.5s, and the aircraft maneuvered in time according to the automatic collision avoidance maneuver recovery strategy, so that the aircraft completed the automatic pull-up maneuver above the preset safety altitude of 1100 meters, realizing the automatic collision avoidance function.

[0113] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for automatic collision avoidance control of a trainer aircraft based on collision prediction, comprising: Step 1, based on the current flight status of the aircraft, predict the aircraft's predicted trajectory after a preset time; Step 2, scanning the predicted trajectory of the aircraft in the elevation digital map to obtain the corresponding regional terrain data, that is, obtaining the relative position of the predicted trajectory of the aircraft and the terrain, and processing the regional terrain data into a two-dimensional terrain profile; Step 3, compare the predicted trajectory of the aircraft with the two-dimensional terrain profile data, obtain the relative height of the predicted trajectory of the aircraft and the corresponding terrain height in the two-dimensional terrain profile data, compare the relative height with the set vertical minimum safety distance in advance, and estimate whether there is a collision; Step 4, based on the collision prediction result, the longitudinal recovery branch and the lateral recovery branch of the aircraft are controlled respectively according to the preset automatic collision avoidance maneuver recovery control logic to generate a normal overload instruction and a roll angular rate instruction; Step 5, add the normal overload command and the roll rate command to the main flight control law to achieve automatic collision avoidance maneuver recovery.

2. The automatic collision avoidance control method for a trainer aircraft based on collision prediction according to claim 1, characterized in that: The step 1 comprises: According to the current flight position, speed, acceleration, attitude and energy state of the aircraft, the Kalman filter method is used to estimate the aircraft state variables based on the aircraft position estimate, speed estimate, acceleration estimate at the previous moment and the observed value at the current moment, thereby completing the prediction of the aircraft's motion trajectory at the next moment.

3. The automatic collision avoidance control method for a trainer aircraft based on collision prediction according to claim 1, characterized in that: In step 1, the state equation and observation equation used to predict the predicted trajectory of the aircraft are: in, X(k+1) represents the state value at time k+1, X(k) represents the state value at time k, A(k) is the state transfer matrix at time k, T(k) is the interference transfer matrix at time k, W(k) represents the system state noise of the motion model at time k, Z(k) represents the observation vector at time k, H(k) is the observation matrix at time k, and V(k) is the observation noise at time k.

4. The automatic collision avoidance control method for a trainer aircraft based on collision prediction according to claim 1, characterized in that: The step 2 comprises: According to the predicted trajectory of the aircraft, the corresponding elevation digital map is scanned to realize the positioning of the aircraft in the current terrain, and the regional terrain data corresponding to the predicted trajectory of the aircraft in the elevation digital map is obtained; in order to reduce the complexity of map digital calculation, the regional terrain data corresponding to the predicted trajectory of the aircraft is processed into a two-dimensional terrain profile; wherein, the shape and size of the scanning area (i.e., the regional terrain data) depends on the current speed of the aircraft, the movement heading of the aircraft and the attitude angle of the aircraft.

5. The automatic collision avoidance control method for a training aircraft based on collision prediction according to claim 1 is characterized in that: The method for determining whether a collision exists in step 3 includes: Compare the predicted trajectory of the aircraft with the two-dimensional terrain profile. If the minimum vertical distance between the height of each trajectory point of the predicted trajectory of the aircraft and the height of the corresponding point in the two-dimensional terrain profile data is less than or equal to the preset safety distance, it is estimated that a collision will occur, and the automatic collision avoidance maneuver recovery control logic is turned on; After the automatic collision avoidance maneuvering recovery control logic is turned on, the minimum vertical distance between the height of each trajectory point of the aircraft's predicted trajectory and the height of the corresponding point in the two-dimensional terrain profile data is continuously judged to be greater than the preset safety distance, and when it exceeds a certain threshold, the automatic collision avoidance maneuvering recovery control logic is exited.

6. The automatic collision avoidance control method for a training aircraft based on collision prediction according to claim 1 is characterized in that: The step 4 comprises: After the automatic anti-collision maneuver recovery control logic is turned on, the corresponding control strategy is adopted to recover according to the current attitude of the aircraft; wherein, the automatic anti-collision maneuver recovery control logic is used to enable the aircraft to automatically and quickly and gently recover from a variety of attitudes to a safe flight state with wings level and slightly climbing.

7. The automatic collision avoidance control method for a training aircraft based on collision prediction according to claim 6 is characterized in that: The longitudinal recovery branch of the aircraft includes: track angle control branch, positive overload pull-up control branch; the lateral recovery branch of the aircraft includes: roll angle control branch; Among them, the track angle control branch uses the track angle command, angle of attack, pitch angle and pitch angle rate to generate the track angle control command. The positive overload pull-up control branch forms the normal overload command according to the current attitude and energy state of the aircraft. The roll angle control branch generates the roll angle rate command through the roll angle and the automatic recovery roll angle command. After the automatic collision avoidance maneuver recovery control logic is turned on, the connection forms of the longitudinal recovery branch and the lateral recovery branch of the aircraft are controlled respectively according to the current attitude of the aircraft.

8. The automatic collision avoidance control method for a training aircraft based on collision prediction according to claim 7 is characterized in that: In step 4, according to the current attitude of the aircraft, a corresponding control strategy is used to recover; It includes the following three control strategies: Control strategy 1: When the aircraft is in a vertical dive when the automatic collision avoidance maneuver recovery control logic is turned on, first, the aircraft longitudinal recovery branch is connected to the positive overload pull-up control branch, and the aircraft is pulled up with positive overload, and the lateral recovery branch is not connected; during the longitudinal recovery process, when the aircraft pitch angle is greater than the set pitch angle threshold, the roll angle control branch in the lateral recovery branch is connected to control the aircraft roll angle and stabilize it to 0°, and the aircraft is still pulled up with positive overload in the longitudinal recovery branch; Control strategy 2: When the aircraft is in a large-angle dive when the automatic collision avoidance maneuver recovery control logic is turned on, first, the lateral recovery branch of the aircraft is connected to the roll angle control branch, and the roll angle of the aircraft is controlled to stabilize to 0° through the automatic recovery roll angle command. During the roll leveling process, when the aircraft roll angle is less than the set roll angle threshold, the longitudinal recovery branch of the aircraft is connected to the positive overload pull-up control branch; Otherwise, control strategy 3 is executed, the longitudinal recovery branch of the aircraft is connected to the track angle control branch, and the track angle control command generated by the command is used as the normal overload command; wherein, the track angle command FPAC is calculated based on the terrain information, the aircraft maneuvering constraints and the current aircraft state parameters; the lateral recovery branch is connected to the roll angle control branch to control the aircraft roll angle and stabilize it to 0°.

9. The automatic collision avoidance control method for a training aircraft based on collision prediction according to any one of claims 1 to 8, characterized in that: The step 5 comprises: The control command generated by the control stick after the command gradient and command shaping is superimposed on the normal overload command, and the horizontal tail movement is controlled through proportional integral to achieve longitudinal maneuver recovery control; The control command generated by the control stick after the command gradient is superimposed on the roll angle rate command, and the aileron movement is proportionally controlled to achieve lateral maneuver recovery control.

10. A training aircraft based on collision prediction, characterized in that: The flight control system of the trainer aircraft includes: a memory and a processor; Wherein, the memory is configured to store executable instructions; The processor is specifically configured to implement the automatic collision avoidance control method for a training aircraft based on collision prediction as described in any one of claims 1 to 9 when executing the executable instructions stored in the memory.

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