A test signal simulation method based on virtual velocity superposition

Abstract

The application provides a test signal simulation method based on virtual velocity superposition, aiming at the simulation of the test signal of the trajectory of an aircraft which flies at high speed, tracks a target and has dramatic changes in the size and direction of the speed, first, a function description mode of the change of the size of the speed of the aircraft according to the engine acceleration is given according to the engine performance index and experimental data of the aircraft; second, the process of the trajectory acceleration turning is simplified by taking the circular motion as the tracking guide process; thus, the acceleration is divided into two parts of the virtual superposition of the engine acceleration and the tracking guide acceleration, the former is responsible for generating the speed and trajectory of the tangential motion, and the latter is responsible for generating the speed and trajectory of the radial motion, and then the two are decomposed into the direct coordinate system, through twice integration, the aircraft can track while the speed changes according to the preset mode of the engine, so as to realize the simulation of the test signal of the trajectory.

Description

Technical Field

[0001] This invention relates to the field of aircraft guidance and velocity-position signal simulation, and more specifically, to a test signal simulation method based on virtual velocity superposition. Background Technology

[0002] During aircraft testing, it is sometimes necessary to test the aircraft's altitude and lateral position signals. Since the trajectory of a real aircraft changes drastically with the target during flight, and it is impossible to use instruments such as real altimeters or inertial navigation systems for signal feedback, simulation methods are required to provide the necessary position test signals. Traditional proportional guidance or tracking guidance simulations consider the change in acceleration in the vertical velocity direction of the aircraft, thus not changing the magnitude of the aircraft's velocity. However, in reality, the velocity of short-range aircraft changes drastically after launch, and its flight process includes multiple acceleration processes; therefore, traditional simulation methods cannot solve this problem. Another method, using Newton's integral superposition simulation, inevitably encounters the problem of increasing velocity as altitude decreases. This is mainly because, in the physical process, gravitational potential energy is converted into kinetic energy, but the increase in velocity during simulation is not easy to control. Achieving the ideal velocity increase according to the engine's preset path or the ideal velocity increase obtained through multiple experiments is extremely difficult. Based on the aforementioned background, this invention proposes a method that uses ideal experimental data of the engine as virtual velocity, superimposed with the velocity data of the circular motion process formed by guidance. This superposition solves the target tracking simulation problem of guidance and avoids the problem of velocity magnitude remaining unchanged despite changes in velocity direction during guidance. Furthermore, since the superimposed velocity direction is perpendicular to the radial direction, it allows for control of velocity magnitude changes according to the ideal experimental data. This results in a highly realistic simulation of the entire aircraft's velocity and position changes, providing more accurate position test signals for the testing system and giving this invention significant engineering application value.

[0003] It should be noted that the information in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a test signal simulation method based on virtual velocity superposition, thereby overcoming the problems of insufficient accuracy in position signal simulation and inability of velocity to accurately change according to the acceleration process provided by engine performance due to the limitations and defects of related technologies.

[0005] According to one aspect of the present invention, a test signal simulation method based on virtual velocity superposition is provided, comprising the following steps:

[0006] Step S10: For a high-speed aircraft with drastic speed changes, select d typical speed nodes based on engine parameters, flight mission, and speed change; decompose the speed change into d-1 stages, then solve for the engine acceleration signal in each stage; and integrate to obtain the engine propulsion speed signal of the aircraft.

[0007] Step S20: Based on the longitudinal position signal of the target and the longitudinal position signal of the aircraft, solve for the longitudinal deviation signal; based on the vertical position signal of the target and the vertical position signal of the aircraft, solve for the vertical deviation signal; then, based on the longitudinal deviation signal and the vertical deviation signal, solve for the line-of-sight angle signal of the aircraft relative to the target; then, design a first-order differentiator to simulate the inertial process of line-of-sight angle measurement and obtain the line-of-sight angular rate signal.

[0008] Step S30: Based on the line-of-sight angle signal and line-of-sight angular rate signal of the aircraft relative to the target, and the propulsion speed of the aircraft's engine, the tracking and guidance acceleration signal of the aircraft is calculated; then, based on the ballistic angle signal of the aircraft, the tracking and guidance acceleration signal of the aircraft is decomposed to obtain the longitudinal tracking and guidance acceleration signal and the vertical tracking and guidance acceleration signal; then, the engine acceleration signal is decomposed based on the ballistic angle signal of the aircraft to obtain the longitudinal engine acceleration signal and the vertical engine acceleration signal.

[0009] Step S40: The longitudinal tracking and guidance acceleration signal and the engine longitudinal acceleration signal are superimposed to obtain the total longitudinal acceleration command signal of the aircraft. Then, a first-order simulation stage of the longitudinal structure of the aircraft is designed to obtain the total longitudinal acceleration output signal of the aircraft. The vertical tracking and guidance acceleration signal and the engine vertical acceleration signal are superimposed to obtain the total vertical acceleration command signal of the aircraft. Then, a first-order simulation stage of the vertical structure of the aircraft is designed to obtain the total vertical acceleration output signal of the aircraft.

[0010] Step S50: Integrate the longitudinal total acceleration output signal of the aircraft to obtain the longitudinal total velocity; then integrate the vertical total acceleration output signal of the aircraft to obtain the vertical total velocity; then solve for the resultant velocity signal and the trajectory angle signal of the aircraft based on the total velocity and the vertical total velocity; then integrate the longitudinal total velocity signal to obtain the longitudinal position signal of the aircraft; then integrate the vertical total velocity signal to obtain the vertical position signal of the aircraft; thus forming a closed-loop solution, completing the position signal calculation and simulation of the aircraft, and providing high-precision dynamic position information for the test system.

[0011] In one exemplary embodiment of the present invention, for a high-speed aircraft with rapidly changing speeds, d typical speed nodes are selected based on engine parameters, flight mission, and speed variation; the speed variation is decomposed into d-1 stages, and the engine acceleration signal for each stage is solved; and integration is performed to obtain the aircraft's engine propulsion speed signal, including:

[0012]

[0013] t = n * T;

[0014]

[0015] v c (n+1)=v c (n)+Ta a (n);

[0016] Where T represents the discrete sampling period of the data, which is a constant parameter, n is a positive integer, t represents the flight time, and v i The velocity node information of the aircraft, obtained from the aircraft engine model and experimental data, represents the velocity node information of the aircraft at t=t. i The engine calibration ideal speed at time point t; d is the number of velocity nodes, i is a positive integer, i≤d-1, t i For v i The corresponding point-in-time data; a i Let a be the engine acceleration value in the i-th stage; a For engine acceleration signal; v c This is the engine propulsion speed signal.

[0017] In one exemplary embodiment of the present invention, a longitudinal deviation signal is calculated based on the longitudinal position signal of the target and the longitudinal position signal of the aircraft; a vertical deviation signal is calculated based on the vertical position signal of the target and the vertical position signal of the aircraft; then, the line-of-sight angle signal of the aircraft relative to the target is calculated based on the longitudinal deviation signal and the vertical deviation signal; and a first-order differentiator is designed to simulate the inertial process of line-of-sight angle measurement, and the line-of-sight angular rate signal is obtained, including:

[0018] Δx = x2 - x1;

[0019] Δy = y2 - y1;

[0020]

[0021]

[0022] Where x1 is the longitudinal position signal of the aircraft, y1 is the vertical position signal of the aircraft; x2 is the longitudinal position signal of the target, y2 is the vertical position signal of the target; Δx is the longitudinal deviation signal, Δy is the vertical deviation signal; q is the line-of-sight angle signal of the aircraft relative to the target, tan -1 () represents the arctangent function; q d is the line-of-sight angular rate signal, s is the differential operator of the transfer function, and T1 is a constant time parameter used to simulate the inertial hysteresis characteristics of the measurement process.

[0023] In one exemplary embodiment of the present invention, the tracking and guidance acceleration signal of the aircraft is calculated based on the line-of-sight angle signal and line-of-sight angular rate signal of the aircraft relative to the target and the propulsion speed of the aircraft's engine; then, based on the ballistic angle signal of the aircraft, the tracking and guidance acceleration signal of the aircraft is decomposed to obtain a longitudinal tracking and guidance acceleration signal and a vertical tracking and guidance acceleration signal; furthermore, the engine acceleration signal is decomposed based on the ballistic angle signal of the aircraft to obtain a longitudinal engine acceleration signal and a vertical engine acceleration signal, including:

[0024] a b =k1q d v c +k2qv c ;

[0025] a bx =a b sinθ;

[0026] a by =-a b cosθ;

[0027] a ax =a a cosθ;

[0028] a ay =a a sinθ;

[0029] Where k1 and k2 are constant guiding parameters, a b For the tracking and guidance acceleration signal of the aircraft, a bx For longitudinal tracking and guidance acceleration signals, a by For vertical tracking and guidance of acceleration signals, a ax For the engine longitudinal acceleration signal, a ay θ represents the vertical acceleration signal of the engine, and θ represents the ballistic angle signal of the aircraft.

[0030] In one exemplary embodiment of the present invention, the longitudinal tracking and guidance acceleration signal is superimposed with the engine longitudinal acceleration signal to obtain the aircraft's total longitudinal acceleration command signal. Then, a first-order simulation stage for the aircraft's longitudinal structure is designed to obtain the aircraft's total longitudinal acceleration output signal. The vertical tracking and guidance acceleration signal is superimposed with the engine vertical acceleration signal to obtain the aircraft's total vertical acceleration command signal. Then, a first-order simulation stage for the aircraft's vertical structure is designed to obtain the aircraft's total vertical acceleration output signal, including:

[0031] a x =a ax +a bx ;

[0032]

[0033] a y =a ay +a by ;

[0034]

[0035] Where a x For the longitudinal total acceleration command signal of the aircraft, a x1 The longitudinal total acceleration output signal is T2, a constant time parameter used to simulate the turning inertial hysteresis characteristics of the aircraft body; a y For the vertical total acceleration command signal of the aircraft, a y1 This is the output signal for the total vertical acceleration of the aircraft.

[0036] In one exemplary embodiment of the present invention, the longitudinal total acceleration output signal of the aircraft is integrated to obtain the longitudinal total velocity of the aircraft; then, the vertical total acceleration output signal of the aircraft is integrated to obtain the vertical total velocity of the aircraft; then, the resultant velocity signal and the trajectory angle signal of the aircraft are calculated based on the total velocity and the vertical total velocity of the aircraft; then, the longitudinal position signal of the aircraft is obtained by integrating the longitudinal total velocity signal; the vertical position signal of the aircraft is obtained by integrating the vertical total velocity signal, including:

[0037] v x (n+1)=v x (n)+a x1 T;

[0038] v y (n+1)=v y (n)+a y1 T;

[0039]

[0040]

[0041] x1(n+1)=x1(n)+v x (n)T;

[0042] y1(n+1)=y1(n)+v y (n)T;

[0043] Where v x v is the total longitudinal velocity of the aircraft. y v is the total vertical velocity of the aircraft. a The vertical total velocity of the aircraft.

[0044] Beneficial effects

[0045] This invention presents a simulation method for test signals based on virtual velocity superposition, with three main innovations. First, it proposes a virtual velocity superposition method, resolving the contradiction that traditional simulations of aircraft velocity magnitude and direction changes during guidance cannot simultaneously account for both. Second, it proposes treating the acceleration during guidance as the radial acceleration of circular motion, changing only the velocity direction. This method and its transformation calculation significantly simplify the simulation calculations for guidance and improve simulation accuracy. Third, it treats the acceleration during engine acceleration as the vertical acceleration during guidance, changing only the velocity magnitude. This allows for separate simulations of velocity magnitude and direction control, enabling precise control of velocity magnitude changes during guidance. It also makes the entire calculation process physically clear, simple to implement, and provides highly accurate position test signals, making it suitable for simulating various complex target tracking processes involving dynamic changes at the end of an aircraft's trajectory.

[0046] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0048] Figure 1 This is a flowchart of a test signal simulation method based on virtual velocity superposition provided by the present invention;

[0049] Figure 2It is the engine propulsion speed signal (unit: meters per second) provided by the method in the embodiments of the present invention;

[0050] Figure 3 It is the line-of-sight angular rate signal (unit: radians per second) of the method provided in the embodiments of the present invention;

[0051] Figure 4 It is the longitudinal tracking guidance acceleration signal (unit: meters per second squared) provided by the embodiments of the present invention;

[0052] Figure 5 It is the vertical tracking and guidance acceleration signal (unit: meters per second squared) provided by the method in the embodiments of the present invention;

[0053] Figure 6 This is the longitudinal total acceleration output signal (unit: meters per second squared) provided by the embodiment of the present invention;

[0054] Figure 7 It is the vertical total acceleration output signal (unit: meters per second squared) of the method provided in the embodiments of the present invention;

[0055] Figure 8 This is the resultant velocity signal (unit: meters per second) of the aircraft provided by the method in the embodiments of the present invention;

[0056] Figure 9 This is the longitudinal position signal (unit: meters) of the aircraft provided by the method in the embodiments of the present invention;

[0057] Figure 10 It is the vertical position signal (unit: meters) of the aircraft provided by the method in the embodiments of the present invention;

[0058] Figure 11 This is the motion curve of the aircraft relative to the target (unit: meters) provided by the method in the embodiments of the present invention. Detailed Implementation

[0059] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of the invention. However, those skilled in the art will recognize that the technical solutions of the invention may be practiced with one or more of these specific details omitted, or other methods, components, apparatus, steps, etc., may be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the invention.

[0060] This invention provides a test signal simulation method based on virtual velocity superposition, addressing the trajectory simulation problem of high-speed aircraft tracking targets, especially the simulation of trajectory test signals for aircraft where both the magnitude and direction of the aircraft's velocity change drastically. First, based on the aircraft's engine performance indicators and experimental data, a functional description of the aircraft's velocity change according to engine acceleration is given. Second, the trajectory acceleration turning process is simplified by simulating circular motion during the tracking and guidance process. Thus, the acceleration is virtually superimposed into two parts: engine acceleration and tracking / guiding acceleration. The former generates the tangential velocity and trajectory, while the latter generates the radial velocity and trajectory. Both are then decomposed into a direct coordinate system, and through two integrations, the aircraft can achieve both tracking and velocity changes according to the engine's preset pattern, thereby realizing the simulation of the trajectory test signal.

[0061] The following will further explain and illustrate the test signal simulation method based on virtual velocity superposition according to the present invention, with reference to the accompanying drawings. (Reference) Figure 1 As shown, this test signal simulation method based on virtual velocity superposition may include the following steps:

[0062] Step S10: For a high-speed aircraft with drastic speed changes, firstly, based on engine parameters, flight mission, and speed changes, select d typical speed nodes; decompose the speed change into d-1 stages, then solve for the engine acceleration signal in each stage; and integrate to obtain the aircraft's engine propulsion speed signal.

[0063] Specifically, this can be broken down into the following three steps. The first step is to select d typical velocity nodes, denoted as v, based on engine parameters, flight mission, and speed variations. i , t iv i The velocity node information of the aircraft, obtained from the aircraft engine model and experimental data, represents the velocity node information of the aircraft at t=t. i The engine's ideal speed at time point t; i is a positive integer, i≤d-1, t i For v i The corresponding time point data; d is the number of velocity nodes.

[0064] The second step is to decompose the aircraft velocity change into d-1 stages, and then solve for the engine acceleration signal in each stage as follows:

[0065]

[0066] Where a i Let be the engine acceleration value for the i-th stage.

[0067] The third step is to summarize the engine acceleration values ​​at each stage to obtain the engine acceleration signal; then, perform integration to obtain the aircraft's engine propulsion speed signal as follows:

[0068] t = n * T;

[0069]

[0070] v c (n+1)=v c (n)+Ta a (n);

[0071] Where T represents the discrete sampling period of the data, is a constant parameter, n is a positive integer, t represents the flight time, and a a For engine acceleration signal; v c This is the engine propulsion speed signal.

[0072] Step S20: Based on the longitudinal position signal of the target and the longitudinal position signal of the aircraft, solve for the longitudinal deviation signal; based on the vertical position signal of the target and the vertical position signal of the aircraft, solve for the vertical deviation signal; then, based on the longitudinal deviation signal and the vertical deviation signal, solve for the line-of-sight angle signal of the aircraft relative to the target; then, design a first-order differentiator to simulate the inertial process of line-of-sight angle measurement and obtain the line-of-sight angular rate signal.

[0073] Specifically, this can be broken down into the following three steps. First, based on the target's longitudinal position signal and the aircraft's longitudinal position signal, calculate the longitudinal deviation signal; based on the target's vertical position signal and the aircraft's vertical position signal, calculate the vertical deviation signal as follows:

[0074] Δx = x2 - x1;

[0075] Δy = y2 - y1;

[0076] Where x1 is the longitudinal position signal of the aircraft, y1 is the vertical position signal of the aircraft; x2 is the longitudinal position signal of the target, y2 is the vertical position signal of the target; Δx is the longitudinal deviation signal, and Δy is the vertical deviation signal.

[0077] The second step is to calculate the line-of-sight angle signal of the aircraft relative to the target based on the longitudinal deviation signal and the vertical deviation signal, as follows:

[0078]

[0079] Where q is the line-of-sight angle signal of the aircraft relative to the target, tan -1 () represents the arctangent function.

[0080] The third step is to design a first-order differentiator to simulate the inertial process of line-of-sight angle measurement and obtain the line-of-sight angular rate signal as follows:

[0081]

[0082] Where q d is the line-of-sight angular rate signal, s is the differential operator of the transfer function, and T1 is a constant time parameter used to simulate the inertial hysteresis characteristics of the measurement process.

[0083] Step S30: Based on the line-of-sight angle signal and line-of-sight angular rate signal of the aircraft relative to the target, and the propulsion speed of the aircraft's engine, the tracking and guidance acceleration signal of the aircraft is calculated; then, based on the ballistic angle signal of the aircraft, the tracking and guidance acceleration signal of the aircraft is decomposed to obtain the longitudinal tracking and guidance acceleration signal and the vertical tracking and guidance acceleration signal; then, the engine acceleration signal is decomposed based on the ballistic angle signal of the aircraft to obtain the longitudinal engine acceleration signal and the vertical engine acceleration signal.

[0084] Specifically, this can be broken down into the following three steps. The first step is to calculate the aircraft's tracking and guidance acceleration signal based on the aircraft's line-of-sight angle signal and line-of-sight angular rate signal relative to the target, as well as the aircraft's engine propulsion speed:

[0085] a b =k1q d v c +k2qv c ;

[0086] Where k1 and k2 are constant guiding parameters, a b Acceleration signals for tracking and guidance of aircraft.

[0087] The second step is to decompose the tracking and guidance acceleration signal of the aircraft based on the aircraft's ballistic angle signal, obtaining the longitudinal tracking and guidance acceleration signal and the vertical tracking and guidance acceleration signal as follows:

[0088] a bx =a b sinθ;

[0089] a by =-a b cosθ;

[0090] Where a bx For longitudinal tracking and guidance acceleration signals, a by θ represents the vertical tracking and guidance acceleration signal, and θ represents the ballistic angle signal of the aircraft.

[0091] The third step is to decompose the engine acceleration signal based on the aircraft's ballistic angle signal to obtain the engine longitudinal acceleration signal and the engine vertical acceleration signal as follows:

[0092] a ax =a a cosθ;

[0093] a ay =a a sinθ;

[0094] Where a ax For the engine longitudinal acceleration signal, a ay This is the engine's vertical acceleration signal.

[0095] Step S40: The longitudinal tracking and guidance acceleration signal and the engine longitudinal acceleration signal are superimposed to obtain the total longitudinal acceleration command signal of the aircraft. Then, a first-order simulation stage of the longitudinal structure of the aircraft is designed to obtain the total longitudinal acceleration output signal of the aircraft. The vertical tracking and guidance acceleration signal and the engine vertical acceleration signal are superimposed to obtain the total vertical acceleration command signal of the aircraft. Then, a first-order simulation stage of the vertical structure of the aircraft is designed to obtain the total vertical acceleration output signal of the aircraft.

[0096] Specifically, it can be broken down into the following four steps. The first step is to superimpose the longitudinal tracking and guidance acceleration signal with the engine's longitudinal acceleration signal to obtain the aircraft's total longitudinal acceleration command signal as follows:

[0097] a x =a ax +a bx ;

[0098] Where a x This is the longitudinal total acceleration command signal for the aircraft.

[0099] The second step involves designing a first-order simulation of the longitudinal structure of the aircraft, resulting in the following longitudinal total acceleration output signal:

[0100]

[0101] Where a x1 T1 is the longitudinal total acceleration output signal of the aircraft, and T2 is a constant time parameter used to simulate the turning inertial hysteresis characteristics of the aircraft body.

[0102] The third step involves superimposing the vertical tracking and guidance acceleration signal with the engine's vertical acceleration signal to obtain the aircraft's total vertical acceleration command signal, as follows:

[0103] a y =a ay +a by ;

[0104] Where a y This is the command signal for the total vertical acceleration of the aircraft.

[0105] The fourth step involves designing a first-order simulation of the aircraft's vertical structure, resulting in the following total vertical acceleration output signal:

[0106]

[0107] Where a y1 This is the output signal for the total vertical acceleration of the aircraft.

[0108] Step S50: Integrate the longitudinal total acceleration output signal of the aircraft to obtain the longitudinal total velocity; then integrate the vertical total acceleration output signal of the aircraft to obtain the vertical total velocity; then solve for the resultant velocity signal and the trajectory angle signal of the aircraft based on the total velocity and the vertical total velocity; then integrate the longitudinal total velocity signal to obtain the longitudinal position signal of the aircraft; then integrate the vertical total velocity signal to obtain the vertical position signal of the aircraft; thus forming a closed-loop solution, completing the position signal calculation and simulation of the aircraft, and providing high-precision dynamic position information for the test system.

[0109] Specifically, this can be broken down into the following three steps. First, integrate the longitudinal total acceleration output signal of the aircraft to obtain the longitudinal total velocity; then integrate the vertical total acceleration output signal of the aircraft to obtain the vertical total velocity as follows:

[0110] v x (n+1)=v x (n)+a x1T;

[0111] v y (n+1)=v y (n)+a y1 T;

[0112] Where v x v is the total longitudinal velocity of the aircraft. y The vertical total velocity of the aircraft.

[0113] The second step is to calculate the resultant velocity signal and the ballistic angle signal of the aircraft based on the total velocity in the axial direction and the total velocity in the vertical direction, as follows:

[0114]

[0115]

[0116] Where v a Let θ be the total vertical velocity of the aircraft, and θ be the trajectory angle signal of the aircraft.

[0117] The third step involves integrating the longitudinal total velocity signal of the aircraft to obtain its longitudinal position signal; and integrating the vertical total velocity signal to obtain its vertical position signal. This forms a closed-loop solution, completing the aircraft's position signal calculation and simulation, and providing high-precision dynamic position information for the test system as follows:

[0118] x1(n+1)=x1(n)+v x (n)T;

[0119] y1(n+1)=y1(n)+v y (n)T;

[0120] Where x1 is the longitudinal position signal of the aircraft and y1 is the vertical position signal of the aircraft.

[0121] Case Implementation and Computer Simulation Results Analysis

[0122] In step S10, d=4 is selected, and four typical velocity nodes are set to obtain the engine propulsion speed signal as follows: Figure 2 As shown.

[0123] In step S20, the target is set to move in a straight line at a constant speed of 20 meters per second, and T1 = 0.1 is selected to obtain the line-of-sight angular rate signal as follows: Figure 3 As shown.

[0124] In step S30, k1 = 1.9 and k2 = 200 are selected to obtain the longitudinal tracking guidance acceleration signal as follows: Figure 4 As shown, the vertical tracking and guidance acceleration signal is as follows: Figure 5As shown.

[0125] In step S40, T2 = 0.15 is selected, and the longitudinal total acceleration output signal of the aircraft is obtained as follows: Figure 6 As shown, the vertical total acceleration output signal of the aircraft is obtained as follows: Figure 7 As shown.

[0126] In step S50, the resultant velocity signal of the aircraft is obtained as follows: Figure 8 As shown, the longitudinal position signal of the aircraft is obtained as follows: Figure 9 As shown; the vertical position signal of the aircraft is obtained as follows. Figure 10 As shown, the overall motion curve of the aircraft relative to the target is obtained as follows: Figure 11 As shown.

[0127] Depend on Figure 2 and Figure 8 The comparison shows that Figure 2 The velocity is generated by the ideal velocity point, therefore its change is linear, while Figure 8 The curve represents the actual velocity change, while the curve itself is a curve. However, the two are very similar, demonstrating excellent accuracy in simulating velocity changes. Figure 4 , Figure 5 , Figure 6 as well as Figure 7 The acceleration variation curves show that the changes are extremely drastic and complex throughout the entire target tracking process. Therefore, conventional simulation methods, if lacking sufficient accuracy, will produce significant deviations in the trajectory, making it difficult to meet the requirements. However, from... Figure 11 As can be seen, the aircraft is ultimately able to track the target. It is evident that the method provided by this invention not only fully reflects the trajectory changes during the tracking and guidance process, but also approximates the speed changes according to ideal engine data, thus possessing high accuracy in equivalent simulation of test signals and significant engineering practical value.

Claims

1. A test signal simulation method based on virtual velocity superposition, characterized by the following steps: Step S10: For a high-speed aircraft with rapidly changing speeds, firstly, based on engine parameters, flight mission, and speed variation, select d typical speed nodes; decompose the speed variation into d-1 stages, then solve for the engine acceleration signal in each stage; and integrate to obtain the aircraft's engine propulsion speed signal as follows: t = n * T; v c (n+1)=v c (n)+Ta a (n): Where T represents the discrete sampling period of the data, which is a constant parameter, n is a positive integer, t represents the flight time, and v i The velocity node information of the aircraft, obtained from the aircraft engine model and experimental data, represents the velocity node information of the aircraft at t=t. i The engine calibration ideal speed at time point t; d is the number of velocity nodes, i is a positive integer, i≤d-1, t i For v i The corresponding point-in-time data; a i Let a be the engine acceleration value in the i-th stage; a For engine acceleration signal; v c This is the engine propulsion speed signal; Step S20: Based on the longitudinal position signal of the target and the longitudinal position signal of the aircraft, solve for the longitudinal deviation signal; based on the vertical position signal of the target and the vertical position signal of the aircraft, solve for the vertical deviation signal; then, based on the longitudinal deviation signal and the vertical deviation signal, solve for the line-of-sight angle signal of the aircraft relative to the target; finally, design a first-order differentiator to simulate the inertial process of line-of-sight angle measurement, and obtain the line-of-sight angular rate signal as follows: Δx = x2 - x1; Δy = y2 - y1; Where x1 is the longitudinal position signal of the aircraft, y1 is the vertical position signal of the aircraft; x2 is the longitudinal position signal of the target, y2 is the vertical position signal of the target; Δx is the longitudinal deviation signal, Δy is the vertical deviation signal; q is the line-of-sight angle signal of the aircraft relative to the target, tan -1 () represents the arctangent function; q d is the line-of-sight angular rate signal, s is the differential operator of the transfer function, and T1 is a constant time parameter used to simulate the inertial hysteresis characteristics of the measurement process; Step S30: Based on the line-of-sight angle signal and line-of-sight angular rate signal of the aircraft relative to the target, and the engine thrust speed of the aircraft, the tracking and guidance acceleration signal of the aircraft is calculated; then, based on the ballistic angle signal of the aircraft, the tracking and guidance acceleration signal of the aircraft is decomposed to obtain the longitudinal tracking and guidance acceleration signal and the vertical tracking and guidance acceleration signal; then, the engine acceleration signal is decomposed based on the ballistic angle signal of the aircraft to obtain the longitudinal engine acceleration signal and the vertical engine acceleration signal as follows: a b =k1q d v c +k2qv c ; a bx =a b sinθ; a by =-a b cosθ; a ax =a a cosθ; a ay =a a sinθ; Where k1 and k2 are constant guiding parameters, a b For the tracking and guidance acceleration signal of the aircraft, a bx For longitudinal tracking and guidance acceleration signals, a by For vertical tracking and guidance of acceleration signals, a ax For the engine longitudinal acceleration signal, a ay θ represents the vertical acceleration signal of the engine, and θ represents the ballistic angle signal of the aircraft. Step S40: The longitudinal tracking and guidance acceleration signal is superimposed with the engine's longitudinal acceleration signal to obtain the aircraft's total longitudinal acceleration command signal. Then, a first-order simulation stage for the aircraft's longitudinal components is designed to obtain the aircraft's total longitudinal acceleration output signal. Similarly, the vertical tracking and guidance acceleration signal is superimposed with the engine's vertical acceleration signal to obtain the aircraft's total vertical acceleration command signal. Then, a first-order simulation stage for the aircraft's vertical components is designed to obtain the aircraft's total vertical acceleration output signal as follows: a x =a ax +a bx ; a y =a ay +a by ; Where a x For the longitudinal total acceleration command signal of the aircraft, a x1 The longitudinal total acceleration output signal is T2, a constant time parameter used to simulate the turning inertial hysteresis characteristics of the aircraft body; a y For the vertical total acceleration command signal of the aircraft, a y1 Output signal for the total vertical acceleration of the aircraft; Step S50: Integrate the longitudinal total acceleration output signal of the aircraft to obtain the longitudinal total velocity of the aircraft; then integrate the vertical total acceleration output signal of the aircraft to obtain the vertical total velocity of the aircraft. Then, the resultant velocity signal and the ballistic angle signal of the aircraft are obtained based on the total axial velocity and the total vertical velocity of the aircraft. The longitudinal position signal of the aircraft is obtained by integrating the longitudinal total velocity signal; the vertical position signal is obtained by integrating the vertical total velocity signal; thus forming a closed-loop solution, the position signal calculation and simulation of the aircraft are completed, providing high-precision dynamic position information for the test system as follows: v x (n+1)=v x (n)+a x1 T; v y (n+1)=v y (n)+a y1 T; x1(n+1)<x1(n)+v x (n)T; y1(n+1)=y1(n)+v y (n)T; Where v x v is the total longitudinal velocity of the aircraft. y v is the total vertical velocity of the aircraft. a The vertical total velocity of the aircraft.

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