A method for maneuvering target angle constraint guidance considering the lag of the driving instrument

Abstract

The application discloses a kind of considering the angle restraint guidance method of maneuvering target of driving instrument lag, in this method, by setting fuzzy sliding mode backstepping guidance law, the guidance law can realize the interception of maneuvering target under the condition of existing automatic driving instrument lag, improve the guidance precision of interceptor, the method is also simultaneously with angle restraint, can improve the damage ability of interceptor, has important engineering significance.

Description

Technical Field

[0001] This invention relates to a control method for an aircraft intercepting a maneuvering target, specifically to a maneuvering target angle constraint guidance method that takes into account autopilot lag. Background Technology

[0002] In practical applications, with the development of the aerospace industry and precision guidance technology, various new types of aircraft possess extremely high flight altitudes, speeds, nonlinearities, and maneuverability, posing challenges to today's maneuvering interception missions. Traditional interceptor guidance laws offer high accuracy against non-maneuvering targets, but against highly maneuvering targets, the loss of speed and maneuverability leads to decreased accuracy, increased miss rates, and reduced damage capability. Therefore, traditional aircraft guidance laws can no longer meet current operational needs, necessitating the design of an interceptor guidance law with higher damage capability, maneuverability, versatility, and robustness to improve guidance accuracy and interception effectiveness against maneuvering targets.

[0003] To address this problem, this patent establishes a relative motion model between the missile and the target in the line-of-sight coordinate system. Based on fuzzy sliding mode control theory and backstepping control theory, a fuzzy sliding mode backstepping guidance law is proposed, with the aim of solving the above problem and improving the hit accuracy of interceptor aircraft through this guidance law. Summary of the Invention

[0004] To overcome the above problems, the inventors conducted intensive research and designed a maneuvering target angle constraint guidance method that considers autopilot lag. In this method, by setting a fuzzy sliding mode backstepping guidance law, the guidance law can intercept maneuvering targets even when autopilot lag exists, thereby improving the guidance accuracy of the interceptor aircraft. This method also incorporates angle constraints, which can improve the damage capability of the interceptor aircraft and has significant engineering implications, thus completing this invention.

[0005] Specifically, the purpose of this invention is to provide a maneuvering target angle constraint guidance method that takes into account the lag of the autopilot. In the line-of-sight coordinate system, the final required overload of the aircraft is obtained in real time through the fuzzy sliding mode backstepping guidance law. The final required overload is then input into the autopilot. When the autopilot has a lag, the autopilot performs rudder control on the aircraft based on the final required overload, so that the aircraft can accurately intercept and hit the maneuvering target.

[0006] Specifically, the required overload in the pitch direction and the required overload in the yaw direction are obtained in real time through the fuzzy sliding mode backstepping guidance law, and then the obtained required overload in the pitch direction and the required overload in the yaw direction are combined to obtain the final required overload.

[0007] The required overload for the pitch direction or yaw direction is obtained by the following formula (I):

[0008] (one)

[0009] in, Indicates the direction of the channel, including the pitch channel. and yaw channel ; This indicates that the pitch channel or yaw channel requires overload; when In for ,Right now When the pitch channel requires overload, all parameters in equation (1) are selected as pitch channel related parameters. In for ,Right now When overload is required for the yaw channel, all parameters in equation (1) are selected as yaw channel related parameters; This indicates the natural frequency of the pitch channel or the natural frequency of the yaw channel. This indicates the pitch channel damping ratio or the yaw channel damping ratio. Represents a state variable; the state variable Choose either pitch channel jerk or yaw channel jerk; This indicates the virtual control command for the second step of the backstepping method. The derivative; This indicates the virtual control command for the second step of the backstepping method. For state variables Tracking error; , and Each parameter represents the design parameters independently.

[0010] The beneficial effects of this invention include:

[0011] (1) According to the maneuvering target angle constraint guidance method considering the lag of the autopilot provided by the present invention, the fuzzy sliding mode backstepping guidance law provided in the method can intercept the maneuvering target in a finite time, has a certain robustness to the maneuvering action of the target and the uncertainty of the system and external disturbances, and can realize the interception considering the line of sight angle constraint to improve the damage capability of the interceptor aircraft.

[0012] (2) According to the maneuvering target angle constraint guidance method considering the lag of the autopilot provided by the present invention, in the actual consideration of the maneuvering interception process, the autopilot has a lag problem. The fuzzy sliding mode backstepping guidance law proposed in this method can effectively compensate for the second-order lag of the autopilot and has a certain robustness and universality. Attached Figure Description

[0013] Figure 1 The graph shows the membership function of the fuzzy input to the pitch channel. Figure 2 The graph shows the membership function of the fuzzy output of the pitch channel; Figure 3 The diagram shows the fuzzy input membership function of the yaw channel; Figure 4 The fuzzy output membership function graph of the yaw channel is shown; Figure 5 The relative distance curve between the projectile and the target is shown in Example 1; Figure 6 The overload curve of the aircraft in Example 1 is shown; Figure 7 The pitch channel line-of-sight curve is shown in Embodiment 1; Figure 8 The line-of-sight curve of the yaw channel in Example 1 is shown; Figure 9 The pitch channel acceleration curve is shown in Example 1; Figure 10 The yaw channel acceleration curve is shown in Example 1; Figure 11 The image shows a comparison curve of the pitch channel line-of-sight angle in Example 2; Figure 12 The comparison curves of the line-of-sight angle in the yaw channel are shown in Example 2; Figure 13 The pitch channel acceleration comparison curves are shown in Example 2; Figure 14 The comparison curves of yaw channel acceleration in Example 2 are shown. Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more apparent.

[0015] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0016] This application provides a maneuvering target angle constraint guidance method that considers autopilot lag. In the line-of-sight coordinate system, the method obtains the final required overload of the aircraft in real time through a fuzzy sliding mode backstepping guidance law, and then inputs the final required overload into the autopilot. When the autopilot has lag, the autopilot performs rudder control on the aircraft based on the final required overload, so that the aircraft can accurately intercept and hit the maneuvering target.

[0017] Preferably, the required overload in the pitch direction and the required overload in the yaw direction are obtained in real time through the fuzzy sliding mode backstepping guidance law, and then the obtained required overload in the pitch direction and the required overload in the yaw direction are combined to obtain the final required overload. The final required overload is output to the autopilot, so that the aircraft can finally intercept the target under the control of the autopilot.

[0018] The required overload for the pitch direction or yaw direction is obtained by the following formula (I):

[0019] (one)

[0020] in, Indicates the direction of the channel, including the pitch channel. and yaw channel ; This indicates that the pitch channel or yaw channel requires overload; when In for ,Right now When the pitch channel requires overload, all parameters in equation (1) are selected as pitch channel-related parameters, i.e., the parameters in subsequent related calculation formulas. All of them take values ​​of ;when In for ,Right now When overload is required for the yaw channel, all parameters in equation (I) are selected as yaw channel-related parameters; that is, the parameters in subsequent related calculation formulas... All of them take values ​​of ; This represents the natural frequency of the pitch channel or the natural frequency of the yaw channel; preferably, both the natural frequency of the pitch channel and the natural frequency of the yaw channel are 0.75 Hz. This indicates the pitch channel damping ratio or the yaw channel damping ratio; preferably, both the pitch channel damping ratio and the yaw channel damping ratio are 0.8.

[0021] Represents a state variable; the state variable The acceleration can be selected as either pitch channel jerk or yaw channel jerk; in this application, the jerk refers to the rate of change of acceleration obtained by differentiating the acceleration with respect to time.

[0022] This indicates the virtual control command for the second step of the backstepping method. The derivative; This indicates the virtual control command for the second step of the backstepping method. For state variables Tracking error; , and Each parameter represents a design parameter independently; preferably, the value is... , , .

[0023] Preferably, the We obtain it through the following formula (II):

[0024] (two)

[0025] This represents the virtual control command for the second step of the reverse stepping method; Represents a state variable; the state variable Choose either pitch channel jerk or yaw channel jerk.

[0026] Preferably, the We obtain it through the following formula (iii):

[0027] (three)

[0028] in, The virtual control command representing the first step of the backstepping method. The derivative; The virtual control command representing the first step of the backstepping method. For state variables Tracking error; , and Each parameter represents a design parameter independently, and the preferred values ​​are: , , .

[0029] Preferably, the We obtain it through the following formula (iv):

[0030] (Four)

[0031] in, Represents a state vector, the state variables Choose either pitch channel acceleration or yaw channel acceleration; This represents the virtual control command for the first step of the reverse stepping method.

[0032] Preferably, We obtain it through the following formula (5):

[0033] (five)

[0034] in, This represents the pitch channel command coefficient or the yaw channel command coefficient; the pitch channel command coefficient is... The yaw channel command coefficient is: ;

[0035] This indicates the pitch channel system status or yaw channel system status; the pitch channel system status is... The yaw channel system status is as follows: ; This represents the uncertainty of the pitch channel system or the uncertainty of the yaw channel system; the uncertainty of the pitch channel system is... The uncertainty of the yaw channel system is: ;in, The pitch angle represents the aircraft's angle relative to the line-of-sight coordinate system; it is obtained by measurement using a MEMS gyroscope located on the aircraft. The yaw angle represents the aircraft's yaw angle relative to the line-of-sight coordinate system; it is obtained by measurement using a MEMS gyroscope located on the aircraft. Indicates the relative distance between the aircraft and the target; obtained through measurements by infrared and radar seekers located on the aircraft; The relative velocity between the aircraft and the target is expressed by the following formula:

[0036] ;

[0037] in The target's speed is measured by infrared and radar seekers located on the aircraft. The missile's speed is measured by an IMU (Inertial Measurement Unit) located on the aircraft. The pitch angle represents the line-of-sight coordinate system relative to the ground coordinate system; it is calculated by coordinate transformation based on data measured by infrared and radar seekers and MEMS gyroscopes located on the aircraft. The pitch rate of the line-of-sight coordinate system relative to the ground coordinate system is expressed by the following formula:

[0038] ; The yaw rate, representing the line-of-sight coordinate system relative to the ground coordinate system, is obtained using the following formula:

[0039] ; The target's pitch angle is measured by infrared and radar seekers located on the aircraft. The target's yaw angle is measured by infrared and radar seekers located on the aircraft. This represents the target's acceleration in the pitch channel, which is calculated by measuring the target's velocity and differentiating it with respect to time. This represents the target's acceleration in the yaw path, which is calculated by measuring the target's velocity and differentiating it with respect to time. This indicates the acceleration of the aircraft in the pitch channel; The value is obtained in the previous time step. The initial value is 0.

[0040] , , , , , Each parameter represents a design parameter independently, and the preferred values ​​are: , , , , , ; This indicates the time-varying switching gain of the pitch channel or the time-varying switching gain of the yaw channel; This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. and Each state variable represents a state variable independently; the state variables Choose either the pitch channel line-of-sight error or the yaw channel line-of-sight error; the pitch channel line-of-sight error is... The line-of-sight error of the yaw channel is... ; This represents the yaw angle of the line-of-sight coordinate system relative to the ground coordinate system; Indicates the desired pitch line of sight, the stated This represents the expected line-of-sight angle for yaw, which is the expected line-of-sight angle when the aircraft hits the target.

[0041] The state variable Choose either the pitch channel line-of-sight rate or the yaw channel line-of-sight rate.

[0042] In a preferred embodiment, the Obtained through the following formula (VI):

[0043] (six)

[0044] This indicates the change in the time-varying switching gain of the pitch channel or the time-varying switching gain of the yaw channel. This represents the time-varying switching gain of the pitch channel or the time-varying switching gain of the yaw channel obtained at the previous moment; the initial value is 0.

[0045] The time-varying gain change of the pitch channel The following steps are used to obtain: Step 1, obtain the non-singular fast terminal sliding surface of the pitch channel. Approaching law of the sliding surface of the pitch channel The product of and use it as input, i.e. For input; Step 2, in such Figure 1In the pitch channel fuzzy input membership function graph shown, draw a vertical line with the input value as the horizontal axis. Find the input curve in the pitch channel fuzzy input membership function graph that intersects with this vertical line and record the vertical coordinate of the intersection point; record the name of the input curve. The corresponding intersection point's ordinate is , , Indicates the intersection number. Indicate the number of intersection points; Step 3, based on the fuzzy correspondence rule, obtain the output curve corresponding to the intersecting input curve in Step 2. Step 4, in such Figure 2 The output curve was found in the fuzzy output membership function graph of the pitch channel shown. And obtain each output curve x-coordinate of the center point Step 5, obtain the pitch channel. ,Right now The time-varying switching gain change of the yaw channel The following steps are used to obtain: Step a, obtain the non-singular fast terminal sliding surface of the yaw channel. Approaching law of yaw channel sliding surface The product of and use it as input, i.e. For input;

[0046] Step b, in such Figure 3 In the fuzzy input membership function graph of the yaw channel shown, draw a vertical line with the input value as the horizontal axis. Find the input curve that intersects this vertical line in the fuzzy input membership function graph of the yaw channel and record the vertical coordinate of the intersection point; record the name of the input curve. The corresponding intersection point's ordinate is , , Indicates the intersection number. Indicate the number of intersection points; Step c, based on the fuzzy correspondence rule, obtain the output curve corresponding to the intersection curve in step 2. Step d, in such Figure 4 Find the output curve in the fuzzy output membership function graph of the yaw channel shown. And obtain each output curve x-coordinate of the center point This application Figure 1 , Figure 2 , Figure 3 and Figure 4 The middle line contains 7 lines: NB represents negative large, NM represents negative medium, NS represents negative small, ZO represents zero, PS represents positive small, PM represents positive medium, and PB represents positive large.

[0047] Step e, obtain the yaw channel. ,Right now .

[0048] Preferably, the fuzzy correspondence rule is:

[0049] Both the pitch channel fuzzy input membership function graph and the yaw channel fuzzy input membership function graph include the following input curves: ;

[0050] Both the pitch channel fuzzy output membership function graph and the yaw channel fuzzy output membership function graph include the following output curves: ;

[0051] .

[0052] During the work process, the above work can be adjusted as needed, such as swapping the output curves of rule 3 and rule 4, or swapping more rule curves.

[0053] Preferably, the pitch channel is a non-singular fast terminal sliding surface. and yaw channel non-singular fast terminal sliding surface All are obtained through the following formula (VII):

[0054] (seven)

[0055] in, This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. Represents a state variable; the state variable Choose either the pitch channel line-of-sight angle error or the yaw channel line-of-sight angle error; Represents state variables The derivative of is the line-of-sight angular rate of the pitch channel or the line-of-sight angular rate of the yaw channel; , , Each parameter represents a design parameter independently, and the preferred values ​​are: , , .

[0056] Preferably, the pitch channel sliding surface approach law and the approach law of the sliding surface of the yaw channel All are obtained through the following formula (8):

[0057] (eight)

[0058] in, This represents the sliding surface approach law for the pitch channel or the sliding surface approach law for the yaw channel; This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. , , Each parameter represents a design parameter independently, and the preferred values ​​are: , , . Example 1

[0059] The basic operating parameters of the aircraft are set as follows:

[0060] The aircraft's cruising speed is 1000 m / s, and its maximum acceleration is 300 m / s². 2 The damping ratio of both the pitch and yaw channels is 0.8, and the natural frequency of both the pitch and yaw channels is 0.75 Hz. The launch point coordinates of the aircraft are (0, 0, 0); the initial launch angle of the aircraft is (45°, 0°).

[0061] Set the target to be detected at a distance of (10000, 10000, 0) m from the launch point and launch the aircraft.

[0062] Four flight conditions are set for the aircraft. The aircraft is controlled by a maneuvering target angle constraint guidance method that takes into account the lag of the autopilot, and the aircraft intercepts the targets in the following four flight conditions respectively.

[0063] Interception conditions Operating Condition 1 Operating Condition 2 Operating Condition 3 Operating Condition 4 Target flight speed 500 500 600 700 Target acceleration 15 sin2t 20 cos2t 30 cos2t 50 cos2t Target initial pitch angle -15 20 35 25 Target initial yaw angle 90 90 75 120 Pitch expected line of sight 30 40 50 40 Yaw expected line of sight 20 15 -15 10

[0064] Specifically, in the line-of-sight coordinate system, the aircraft is guided and controlled by a fuzzy sliding mode backstepping guidance law, so that the aircraft with a lagging autopilot can accurately intercept and hit maneuvering targets.

[0065] The required overload in the pitch direction and the required overload in the yaw direction are obtained in real time by the fuzzy sliding mode backstepping guidance law. The obtained required overload in the pitch direction and the required overload in the yaw direction are then combined to obtain the final required overload. The final required overload is then output to the autopilot, so that the aircraft can finally intercept the target under the control of the autopilot.

[0066] The required overload in the pitch direction and the required overload in the yaw direction are both obtained by the following formula (I):

[0067] (one)

[0068] in, Indicates the direction of the channel, including the pitch channel. and yaw channel ; This indicates that the pitch channel or yaw channel requires overload; when In for ,Right now When the pitch channel requires overload, all parameters in equation (1) are selected as pitch channel-related parameters, i.e., the parameters in subsequent related calculation formulas. All of them take values ​​of ;when In for ,Right now When overload is required to indicate the yaw channel, all parameters in equation (I) are selected as yaw channel-related parameters, i.e., the parameters in subsequent related calculation formulas. All of them take values ​​of ; This indicates the natural frequency of the pitch channel or the natural frequency of the yaw channel. This indicates the pitch channel damping ratio or the yaw channel damping ratio. Represents a state variable; the state variable Choose either pitch channel jerk or yaw channel jerk; This indicates the virtual control command for the second step of the backstepping method. The derivative;

[0069] This indicates the virtual control command for the second step of the backstepping method. For state variables The tracking error; the design parameters are set to, , , .

[0070] The We obtain it through the following formula (II):

[0071] (two)

[0072] This represents the virtual control command for the second step of the reverse stepping method;

[0073] The We obtain it through the following formula (iii):

[0074] (three)

[0075] in, The virtual control command representing the first step of the backstepping method. The derivative; The virtual control command representing the first step of the backstepping method. For state variables Tracking error;

[0076] The design parameter values ​​are: , , .

[0077] The We obtain it through the following formula (iv):

[0078] (Four)

[0079] in, Represents a state vector, the state variables Choose either pitch channel acceleration or yaw channel acceleration; This represents the virtual control command for the first step of the reverse stepping method.

[0080] We obtain it through the following formula (5):

[0081] (five)

[0082] in, This represents the pitch channel command coefficient or the yaw channel command coefficient; the pitch channel command coefficient is... The yaw channel command coefficient is: ; This indicates the pitch channel system status or yaw channel system status; the pitch channel system status is... The yaw channel system status is as follows: ; This represents the uncertainty of the pitch channel system or the uncertainty of the yaw channel system; the uncertainty of the pitch channel system is... The uncertainty of the yaw channel system is: ;in, This represents the pitch angle of the aircraft relative to the line-of-sight coordinate system; This represents the yaw angle of the aircraft relative to the line-of-sight coordinate system; Indicates the relative distance between the aircraft and the target; This indicates the relative speed between the aircraft and the target; This represents the pitch angle of the line-of-sight coordinate system relative to the ground coordinate system; This represents the pitch rate of the line-of-sight coordinate system relative to the ground coordinate system; This represents the yaw rate of the line-of-sight coordinate system relative to the ground coordinate system; Indicates the target's pitch angle: The yaw angle of the target: This represents the target's acceleration in the pitch channel: This represents the target's acceleration in the yaw channel: This represents the acceleration of the aircraft in the pitch channel; the design parameter values ​​are: , , , , , ; This indicates the time-varying switching gain of the pitch channel or the time-varying switching gain of the yaw channel; This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. and Each state variable represents a state variable independently; the state variables Choose either the pitch channel line-of-sight error or the yaw channel line-of-sight error; the pitch channel line-of-sight error is... The line-of-sight error of the yaw channel is... The Indicates the desired pitch line of sight, the stated Indicates the desired line-of-sight angle of yaw. The state variable represents the yaw angle of the line-of-sight coordinate system relative to the ground coordinate system. Choose either the pitch channel line-of-sight rate or the yaw channel line-of-sight rate.

[0083] In a preferred embodiment, the Obtained through the following formula (VI):

[0084] (six)

[0085] This indicates the change in the time-varying switching gain of the pitch channel or the time-varying switching gain of the yaw channel. This indicates the time-varying switching gain of the pitch channel obtained at the previous moment or the time-varying switching gain of the yaw channel obtained at the previous moment.

[0086] The time-varying gain change of the pitch channel The following steps are used to obtain: Step 1, obtain the non-singular fast terminal sliding surface of the pitch channel. Approaching law of the sliding surface of the pitch channel The product of and use it as input, i.e. For input; Step 2, in such Figure 1 In the pitch channel fuzzy input membership function graph shown, draw a vertical line with the input value as the horizontal axis. Find the input curve in the pitch channel fuzzy input membership function graph that intersects with this vertical line and record the vertical coordinate of the intersection point; record the name of the input curve. The corresponding intersection point's ordinate is , , Indicates the intersection number. Indicate the number of intersection points; Step 3, based on the fuzzy correspondence rule, obtain the output curve corresponding to the intersecting input curve in Step 2. Step 4, in such Figure 2 The output curve was found in the fuzzy output membership function graph of the pitch channel shown. And obtain each output curve x-coordinate of the center point Step 5, obtain the pitch channel. ,Right now ;

[0087] The time-varying switching gain change of the yaw channel The following steps are used to obtain: Step a, obtain the non-singular fast terminal sliding surface of the yaw channel. Approaching law of yaw channel sliding surface The product of and use it as input, i.e. For input; step b, in such Figure 3 In the fuzzy input membership function graph of the yaw channel shown, draw a vertical line with the input value as the horizontal axis. Find the input curve that intersects this vertical line in the fuzzy input membership function graph of the yaw channel and record the vertical coordinate of the intersection point; record the name of the input curve. The corresponding intersection point's ordinate is , , Indicates the intersection number. Indicate the number of intersection points; Step c, based on the fuzzy correspondence rule, obtain the output curve corresponding to the intersection curve in step 2. Step d, in such Figure 4 Find the output curve in the fuzzy output membership function graph of the yaw channel shown. And obtain each output curve x-coordinate of the center point Step e, obtain the yaw channel. ,Right now .

[0088] The fuzzy correspondence rule is as follows:

[0089] Both the pitch channel fuzzy input membership function graph and the yaw channel fuzzy input membership function graph include the following input curves: ;

[0090] Both the pitch channel fuzzy output membership function graph and the yaw channel fuzzy output membership function graph include the following output curves: ;

[0091] .

[0092] Pitch channel non-singular fast terminal sliding surface and yaw channel non-singular fast terminal sliding surface All are obtained through the following formula (VII):

[0093] (seven)

[0094] in, This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. Represents a state variable; the state variable Choose either the pitch channel line-of-sight angle error or the yaw channel line-of-sight angle error; Represents state variables The derivative of is the line-of-sight angular rate of the pitch channel or the line-of-sight angular rate of the yaw channel; the design parameter values ​​are: , , .

[0095] Pitch Channel Sliding Surface Approach Law and the approach law of the sliding surface of the yaw channel All are obtained through the following formula (8):

[0096] (eight)

[0097] in, This represents the sliding surface approach law for the pitch channel or the sliding surface approach law for the yaw channel; This indicates a non-singular fast terminal sliding surface for either the pitch or yaw channel; the design parameter values ​​are: , , .

[0098] Assuming the autopilot has no lag issues, the above control methods can be used to intercept targets under the four operating conditions described above.

[0099] Figures 5 to 10 The relative distance between the missile and the target, the line-of-sight angle, and the overload curve are given when intercepting under ideal interception conditions where the autopilot has no lag problem.

[0100] Depend on Figures 5 to 10 As can be seen, the maneuvering target angle constraint guidance method considering autopilot lag provided in this application can effectively intercept maneuvering targets under the above four working conditions and can achieve the desired line-of-sight angle constraint. This method has a certain degree of universality and robustness against the target's maneuvering motion, and at the same time, it incorporates angle constraints to improve damage capability.

[0101] Example 2

[0102] For the situation in condition 4 of Example 1, the control method in Example 1 is used to guide and control the interceptor aircraft, taking into account the second-order hysteresis of the autopilot. Such interception conditions are called actual interception conditions.

[0103] Accordingly, the interception result obtained in Example 1 can be considered as ideal interception conditions since the lag of the driving instrument is ignored.

[0104] Figures 11 to 14 The curves showing the comparison of the channel line-of-sight angle and acceleration under two interception conditions are presented.

[0105] Figures 11 to 14 It is known that autopilot lag does indeed affect interception performance. However, the maneuvering target angle constraint guidance method considering autopilot lag provided in this application can still achieve the desired line-of-sight angle constraint and intercept the target within a limited time. This shows that the maneuvering target angle constraint guidance method considering autopilot lag can effectively compensate for the autopilot lag problem and ensure the guidance accuracy of the interceptor aircraft in maneuvering interception.

[0106] The present invention has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present invention based on these embodiments, all of which fall within the scope of protection of the present invention.

Claims

1. A method for constraining the angle of a maneuvering target considering autopilot lag, characterized in that, This method, in a line-of-sight coordinate system, obtains the final required overload of the aircraft in real time through a fuzzy sliding mode backstepping guidance law. This final required overload is then input into the autopilot. In the event of autopilot lag, the autopilot performs rudder control on the aircraft based on the final required overload, enabling the aircraft to accurately intercept and hit the maneuvering target. The required overload in the pitch direction and the required overload in the yaw direction are obtained in real time by the fuzzy sliding mode backstepping guidance law, and then the obtained required overload in the pitch direction and the required overload in the yaw direction are combined to obtain the final required overload. The required overload for the pitch direction or yaw direction is obtained by the following formula (I): (one) in, Indicates the direction of the channel, including the pitch channel. and yaw channel ; This indicates that overload is required for either the pitch or yaw channel. when In for ,Right now When overload is required for the pitch channel, all parameters in equation (1) are selected as pitch channel-related parameters. when In for ,Right now When overload is required for the yaw channel, all parameters in equation (1) are selected as yaw channel related parameters; This indicates the natural frequency of the pitch channel or the natural frequency of the yaw channel. This indicates the pitch channel damping ratio or the yaw channel damping ratio. Represents a state variable; the state variable Choose either pitch channel jerk or yaw channel jerk; This indicates the virtual control command for the second step of the backstepping method. The derivative; This indicates the virtual control command for the second step of the backstepping method. For state variables Tracking error; , and Each parameter represents a design parameter independently; its value is... , , .

2. The maneuvering target angle constraint guidance method considering autopilot lag as described in claim 1, characterized in that, The We obtain it through the following formula (II): (two) This represents the virtual control command for the second step of the reverse stepping method; Represents a state variable; the state variable Choose either pitch channel jerk or yaw channel jerk.

3. The maneuvering target angle constraint guidance method considering autopilot lag according to claim 1 or 2, characterized in that, The We obtain it through the following formula (iii): (three) in, The virtual control command representing the first step of the backstepping method. The derivative; The virtual control command representing the first step of the backstepping method. For state variables Tracking error; , and Each parameter represents a design parameter independently, and its value is... , , .

4. The maneuvering target angle constraint guidance method considering autopilot lag as described in claim 3, characterized in that, The We obtain it through the following formula (iv): (Four) in, Represents a state vector, the state variables Choose either pitch channel acceleration or yaw channel acceleration; This represents the virtual control command for the first step of the reverse stepping method.

5. The maneuvering target angle constraint guidance method considering autopilot lag as described in claim 4, characterized in that, We obtain it through the following formula (5): (five) in, This indicates the pitch channel command coefficient or the yaw channel command coefficient; Indicates the status of the pitch channel system or the yaw channel system; This indicates uncertainty in the pitch channel system or uncertainty in the yaw channel system; , , , , , Each parameter represents a design parameter independently, and its value is... , , , , , ; This indicates the time-varying switching gain of the pitch channel or the time-varying switching gain of the yaw channel; This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. and Each represents a state variable independently; The state variable Choose either the pitch channel line-of-sight angle error or the yaw channel line-of-sight angle error; The state variable Choose either the pitch channel line-of-sight rate or the yaw channel line-of-sight rate.

6. The maneuvering target angle constraint guidance method considering autopilot lag as described in claim 5, characterized in that, The Obtained through the following formula (VI): (six) This indicates the change in the time-varying switching gain of the pitch channel or the time-varying switching gain of the yaw channel. This indicates the time-varying switching gain of the pitch channel obtained at the previous moment or the time-varying switching gain of the yaw channel obtained at the previous moment; The time-varying gain change of the pitch channel Obtained through the following steps: Step 1: Obtain the non-singular fast terminal sliding surface of the pitch channel. Approaching law of the sliding surface of the pitch channel The product of and use it as input, i.e. For input; Step 2: In the pitch channel fuzzy input membership function graph, draw a vertical line with the input value as the horizontal axis, find the input curve that intersects the vertical line in the pitch channel fuzzy input membership function graph and record the vertical coordinate of the intersection point; Record the input curve name The corresponding intersection point's ordinate is , , Indicates the intersection number. Indicates the number of intersections; Step 3: Based on the fuzzy correspondence rule, obtain the output curves corresponding to the intersecting input curves in Step 2. ; Step 4: Find the output curve in the fuzzy output membership function graph of the pitch channel. And obtain each output curve x-coordinate of the center point , Step 5, obtain the pitch channel. ,Right now ; The time-varying switching gain change of the yaw channel Obtained through the following steps: Step a, obtain the non-singular fast terminal sliding surface of the yaw channel. Approaching law of yaw channel sliding surface The product of and use it as input, i.e. For input; Step b: In the fuzzy input membership function graph of the yaw channel, draw a vertical line with the input value as the horizontal axis, find the input curve that intersects the vertical line in the fuzzy input membership function graph of the yaw channel and record the vertical coordinate of the intersection point; Record the input curve name The corresponding intersection point's ordinate is , , Indicates the intersection number. Indicates the number of intersections; Step c: Based on the fuzzy correspondence rule, obtain the output curve corresponding to the intersecting curve in step 2. ; Step d: Find the output curve in the fuzzy output membership function graph of the yaw channel. And obtain each output curve x-coordinate of the center point ; Step e, obtain the yaw channel. ,Right now .

7. The maneuvering target angle constraint guidance method considering autopilot lag as described in claim 6, characterized in that, The fuzzy correspondence rule is as follows: Both the pitch channel fuzzy input membership function graph and the yaw channel fuzzy input membership function graph include the following input curves: ; Both the pitch channel fuzzy output membership function graph and the yaw channel fuzzy output membership function graph include the following output curves: ; 。 8. The maneuvering target angle constraint guidance method considering autopilot lag as described in claim 6, characterized in that, Pitch channel non-singular fast terminal sliding surface and yaw channel non-singular fast terminal sliding surface All are obtained through the following formula (VII): (seven) in, This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. Represents a state variable; the state variable Choose either the pitch channel line-of-sight angle error or the yaw channel line-of-sight angle error; Represents state variables The derivative of is the line-of-sight angular rate of the pitch channel or the line-of-sight angular rate of the yaw channel; , , Each parameter represents a design parameter independently, and its value is... , , .

9. The maneuvering target angle constraint guidance method considering autopilot lag according to claim 6, characterized in that, Pitch Channel Sliding Surface Approach Law and the approach law of the sliding surface of the yaw channel All are obtained through the following formula (8): (eight) in, This represents the sliding surface approach law for the pitch channel or the sliding surface approach law for the yaw channel; This indicates a non-singular fast terminal sliding surface for the pitch channel or a non-singular fast terminal sliding surface for the yaw channel. , , Each parameter represents a design parameter independently, and its value is... , , .

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