Laser semi-active rotating aircraft flight path pulse correction method
Through the combination of a fully strapdown laser semi-active detector and a pulse engine, the problem of large trajectory error of the spin-stabilized aircraft was solved, low-cost, high-precision aircraft trajectory correction was achieved, and the landing point error was reduced.
Patent Information
- Application Number
- CN202510719485.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-09-26
AI Technical Summary
Spin-stabilized aircraft have large trajectory errors when flying to the predetermined position. Existing trajectory error correction methods are costly, have complex actuators, and are difficult to match with the spinning motion, resulting in a large deviation between the landing point and the predetermined position.
A fully strapdown laser semi-active detector and a pulse engine are used as trajectory error detection and correction mechanisms. By establishing a six-degree-of-freedom mathematical model and spatial geometric relationships, the ignition timing and orientation of the pulse engine are determined to achieve aircraft trajectory correction.
It achieves low-cost, high-precision aircraft trajectory correction, reduces landing point error, and improves the aircraft's trajectory control accuracy and efficiency.
Smart Images
Figure CN120704382A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of aircraft trajectory correction, and in particular relates to a pulse correction method for the flight trajectory of a full-strapdown laser semi-active rotating aircraft. Background Art
[0002] Spin-stabilized aircraft have clear control objectives and advantages such as minimal impact of thrust deflection and eccentricity on attitude control. They also have a simplified structure and a concise control system, making them widely used in various fields. However, due to their special spinning motion, spin-stabilized aircraft experience large trajectory errors as they fly toward their intended location, resulting in a significant deviation between the final landing point and the intended location.
[0003] Currently, the commonly used flight trajectory error correction methods mainly include trajectory error correction methods based on pneumatic servos, trajectory error correction methods based on variable center of mass mechanisms, and trajectory error correction methods based on pulse control forces. The actuators of the former two are expensive and are mostly used for trajectory error correction of high-value aircraft, which are often cost-effective. Trajectory error correction mechanisms based on pulse forces, such as pulse engines, have low cost, simple structure, high efficiency, and good application prospects.
[0004] However, when using a pulse engine as an actuator for correcting the trajectory error of a spinning vehicle, the spinning motion of the vehicle will cause the detector measurement values and the vehicle motion state to change periodically over time. Therefore, there are problems such as complex spatial geometric modeling of the pulse engine, difficulty in matching the ignition timing and ignition orientation with the spinning motion, and difficulty in designing the ignition logic.
[0005] Therefore, this patent will take the spin-stabilized aircraft that uses a fully strapdown laser semi-active detector and a pulse engine as the trajectory error detection mechanism and trajectory error correction actuator respectively as the research object, and design a low-cost laser semi-active rotating aircraft flight trajectory pulse correction method that is convenient for practical engineering applications to improve the flight trajectory accuracy of the spin-stabilized aircraft. Summary of the Invention
[0006] The present invention aims to solve the problem of large trajectory errors in existing spin-stabilized aircraft during flight to a predetermined position. To this end, a low-cost fully strapdown laser semi-active rotating aircraft pulse trajectory correction method is provided. During the flight of the fully strapdown laser semi-active rotating aircraft, based on an established six-degree-of-freedom mathematical model of the rotating aircraft under wind interference, a fully strapdown laser semi-active detector detection model, and a pulse engine spatial geometric relationship model, the ignition timing and ignition azimuth of the pulse engine are determined according to the misalignment angle and azimuth angle information detected by the detector, and the pulse engine ignition working logic is given, thereby achieving trajectory correction of the rotating aircraft.
[0007] To achieve the above objectives, the technical solutions provided by the present invention are:
[0008] A method for pulse correction of a laser semi-active rotating aircraft flight trajectory, characterized by comprising the following steps:
[0009] Step 1: Based on the distance between the initial launch position of the rotating aircraft and the target point, the rotating aircraft is launched towards the target point at a certain initial angle, so that the rotating aircraft has an initial speed. After the rotating aircraft exits the launch port for a set time, the main engine of the rotating aircraft is ignited to accelerate the rotating aircraft until the main engine is shut down. The rotating aircraft moves freely under the interference of wind until the rotating aircraft is in the stage of descending altitude;
[0010] Step 2: Establish a full strapdown laser semi-active detector detection model and change the value range of the roll angle and the detector azimuth angle to determine whether the detector in the rotating aircraft detects the target point. If the detector detects the target point, proceed to step 3; otherwise, continue detection;
[0011] Step 3: Based on the six-degree-of-freedom mathematical model of the fully strapdown laser semi-active rotating aircraft under wind interference and the detection model of the fully strapdown laser semi-active detector, after changing the value range of the roll angle and the detector azimuth angle, the spatial geometric relationship of the rotating aircraft pulse engine is established and its angle correction capability is calculated. During the flight of the rotating aircraft, the control system determines whether the misalignment angle meets the ignition timing condition range at each simulation step. If it does and no pulse engine is working at this time, proceed to step 4; otherwise, return to step 2;
[0012] Step 4: Calculate the pulse engine ignition position, and determine whether there is an unignited pulse engine within the ignition range according to the pulse engine number from small to large. If so, control its ignition to correct the trajectory, and once this pulse engine is ignited, it will not be shut down. If not, continue to return to step 2;
[0013] Step 5: The pulse engine control system repeats steps 2-4 in each simulation step after start-up until the rotating aircraft reaches the predetermined position.
[0014] Furthermore, in step 1, a barrel-type launching device is used to launch the rotating aircraft, and the pulse engine does not work during the ascent of the rotating aircraft.
[0015] Furthermore, in step 2, the detection model of the full strapdown laser semi-active detector is:
[0016]
[0017] in,
[0018] OT is the line connecting the center of mass of the aircraft and the target point, OT' is the line connecting the center of mass of the aircraft and the projection of the target point on the plane Ox1z1, (x tb ,y tb ,z tb ) is the coordinate value of the target point in the rocket body coordinate system, q y is the elevation angle of the rotating vehicle’s body, q z is the azimuth angle of the line of sight of the rotating vehicle, δ is the misalignment angle and satisfies δ∈[0,π], λ is the azimuth angle and satisfies λ∈(π,π], and the four-quadrant arctan2(x,y) function is used to describe the azimuth angle, that is:
[0019]
[0020] Furthermore, in step 2, the roll angle and the detector azimuth angle are processed as follows:
[0021]
[0022]
[0023] in,
[0024] and are the converted γ and λ respectively, the function fmod(x,y) represents the modulus of x over y, the converted roll angle and detector azimuth angle are both in the range of [0,2π), and the 0° position coincides with the Y-axis of the quasi-rocket coordinate system, and the clockwise rotation direction is the increasing direction.
[0025] Furthermore, in step 3, the six-degree-of-freedom mathematical model of the fully strapdown laser semi-active rotating aircraft includes:
[0026] Center of mass dynamics equation:
[0027]
[0028] in,
[0029] m is the mass of the rotating vehicle, V is the velocity, θ is the velocity inclination, ψ v is the velocity deviation angle, P is the main engine thrust, F p is the thrust of the pulse engine, α + , β, and γ v+ is the quasi-angle of attack, quasi-sideslip angle and quasi-speed tilt angle, γ vw+ is the composite quasi-velocity tilt angle of the aircraft under wind speed interference, σ is the thrust action angle of the pulse engine, X w 、Y w and Z w are the drag, lift and lateral force under wind speed disturbance, g is the acceleration due to gravity;
[0030] The dynamic equations for rotation around the center of mass:
[0031]
[0032] in,
[0033] J x4 、J y4 and J z4 is the moment of inertia of the rotating vehicle about each axis of the rocket body coordinate system, ω x4 、ω y4 and ω z4 are the components of the vehicle's angular velocity on each axis of the quasi-rocket coordinate system, M xw4 、M yw4 and M zw4 are the components of the moments of all external forces acting on the rotating aircraft on the center of mass under wind speed interference on each axis of the quasi-rocket coordinate system, is the roll angular rate of the rotating aircraft.
[0034] Furthermore, in step 3,
[0035] The process of establishing the spatial geometric relationship of the pulse engine includes:
[0036] Looking forward from the tail of the aircraft along its axis, the engine at the top at the initial moment is numbered 0, and the numbers increase in a clockwise direction. Among the n pulse engines, the azimuth angle of the i-th engine is i Expressed as:
[0037]
[0038] Thrust action angle σ of engine No. i i Expressed as:
[0039]
[0040] Thrust action angle σ i As the vehicle rotates, it is converted to the range [0,2π] as follows:
[0041]
[0042] in,
[0043] is the transformed σ i ;
[0044] The pulse engine angle correction capability is:
[0045]
[0046] in,
[0047] Δθ is the angle correction of a single pulse engine, I is the total impulse of a single pulse engine, V t The speed of the rotating aircraft at the current moment;
[0048] The basis for judging whether the misalignment angle meets the ignition timing condition range is:
[0049] δ≥kΔθ
[0050] in,
[0051] k is a parameter to be designed, and k≥1. It is designed based on the different upper and lower positions of the line between the aircraft and the target point relative to the quasi-rocket coordinate system plane Oxz. When the line is located on the plane Oxz, k=k1, and in other cases k=k2. Both k1 and k2 are parameters to be designed.
[0052] Furthermore, the method for determining the vertical relationship between the line connecting the aircraft and the target point and the plane Oxz of the quasi-rocket coordinate system is as follows:
[0053] When the connecting line is below the quasi-rocket coordinate plane Oxz, the azimuth and roll angle satisfy:
[0054]
[0055] If the azimuth and roll angle If the relationship does not satisfy the above formula, the connecting line is located on the quasi-rocket coordinate system plane Oxz.
[0056] Furthermore, in step 4, the ignition position range is designed as follows:
[0057]
[0058] Among them, s1 and s2 are range boundary parameters, and their specific meanings are as follows:
[0059]
[0060] Among them, t on and t off is the start and end time of pulse engine ignition, k3 is the parameter to be designed and optimized, 1≤k3≤2,
[0061] Further,
[0062] If multiple pulse engines meet the ignition timing and ignition direction conditions at the same time, the pulse engine with a smaller number and not ignited will be ignited first;
[0063] Only one pulse engine is used for each trajectory correction and only one pulse engine is allowed to ignite at the same time, that is, during its ignition process, other pulse engines are not allowed to ignite.
[0064] In order to implement the above method, the present invention also provides a full strapdown laser semi-active rotating aircraft, which is characterized by comprising a full strapdown laser semi-active detector, an inertial group system, a pulse engine and its ignition control system, a main engine, a tail and a shell;
[0065] The fully strapdown laser semi-active detector and inertial group system are installed on the head of the aircraft to measure the line of sight angle information, aircraft motion and attitude information respectively;
[0066] A plurality of identical pulse engines are installed near the center of mass and are evenly arranged at equal angles in a ring-like form along the surface of the aircraft, with the thrust generated by the engine nozzles being perpendicular to the axis;
[0067] The main engine and tail fin are installed at the tail of the aircraft. During the flight of the rotating aircraft in the atmosphere, the offset tail fin at the tail generates a rotational torque, causing it to rotate continuously and maintain flight stability.
[0068] The beneficial effects of the present invention are:
[0069] The present invention is aimed at spin-stabilized aircraft and provides a full-strapdown laser pulse correction method for the flight trajectory of a semi-active rotating aircraft, which can achieve high-precision trajectory error correction of the rotating aircraft. Compared with existing trajectory correction methods based on other correction mechanisms, the present invention has the advantages of low cost, small size, light weight, simple structure, short response time, fast speed, high efficiency, etc., and the control parameters are simple, which is easy to apply in practical engineering. BRIEF DESCRIPTION OF THE DRAWINGS
[0070] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.
[0071] Figure 1 : Schematic diagram of the overall structure of the rotating aircraft;
[0072] Figure 2 : Schematic diagram of trajectory correction of rotating aircraft;
[0073] Figure 3 : Schematic diagram of misalignment angle and azimuth angle modeling;
[0074] Figure 4 : Pulse engine numbering diagram;
[0075] Figure 5 : Schematic diagram of single pulse engine correction capability;
[0076] Figure 6 : Pulse engine ignition logic flow chart;
[0077] Figure 7 : Uncontrolled Monte Carlo simulation landing point diagram corresponding to the embodiment;
[0078] Figure 8 : Controlled Monte Carlo simulation landing point diagram corresponding to the embodiment. DETAILED DESCRIPTION
[0079] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.
[0080] See attached Figure 1-6 The present invention proposes a low-cost full-strapdown laser semi-active rotating aircraft trajectory pulse correction method. To implement this method, a method is first proposed. Figure 1 The fully strapdown laser semi-active rotating aircraft shown in the figure is mainly composed of a fully strapdown laser semi-active detector, an inertial group system, a pulse engine and its ignition control system, a main engine, a tail and a shell from front to back. The fully strapdown laser semi-active detector and the inertial group system are installed at the head of the aircraft to measure the line of sight angle information, aircraft motion and attitude information respectively; multiple identical pulse engines are installed near the center of mass and are evenly arranged at equal angles in a ring form along the surface of the aircraft. The thrust generated by the engine nozzle is perpendicular to the axis; the main engine and tail are installed at the tail of the aircraft. During the atmospheric flight of the rotating aircraft, the offset tail generates a rotational torque to make it rotate continuously and maintain flight stability. Its working process is as follows Figure 2 As shown, the specific description is:
[0081] 1. Before launching, measure the distance between the aircraft and the target point, and launch the aircraft at a certain initial angle to give it a certain initial speed.
[0082] 2. After the rotating vehicle leaves the launch port for a specified period of time, the main engine ignites, accelerating the rotating vehicle until the main engine shuts down.
[0083] 3. When the rotating aircraft is in the stage of descending altitude, the pulse trajectory correction logic is started;
[0084] 4. When the detector detects that the trajectory error meets the engine ignition conditions, the pulse engine that meets the ignition conditions is selected according to the trajectory correction method to ignite the trajectory correction;
[0085] 5. Repeat steps 3 and 4 until the rotating aircraft reaches the desired position.
[0086] Then, based on the rotating aircraft and its workflow, a full strapdown laser semi-active rotating aircraft flight trajectory pulse correction method of the present invention is proposed. The specific steps of the present invention include:
[0087] Step 1: Based on the distance between the initial launch position of the rotating aircraft and the target point, the rotating aircraft is launched toward the target point at a certain initial angle using a barrel-type launch device to give the rotating aircraft an initial speed. After the rotating aircraft exits the launch port for a set time, the main engine of the rotating aircraft is ignited to accelerate the rotating aircraft until the main engine is shut down. The rotating aircraft moves freely under wind interference. During the rotating aircraft's ascent, the pulse engine does not work until the rotating aircraft is in a stage of descending altitude.
[0088] Step 2: Establish a full strapdown laser semi-active detector detection model and change the value range of the roll angle and the detector azimuth angle to determine whether the detector in the rotating aircraft detects the target point. If the detector detects the target point, proceed to step 3; otherwise, continue detection;
[0089] The pulse trajectory correction rotating aircraft uses a full strapdown laser semi-active detector. The optical axis of the detector coincides with the axis of the aircraft. The detector rotates with the rotation of the aircraft. The angles detected are the misalignment angle δ and the azimuth angle λ.
[0090] like Figure 3 As shown in the figure, the misalignment angle δ is the angle between the line between the aircraft and the target point and the aircraft axis, the azimuth angle λ is the angle between the perpendicular line of the optical image point on the photosensitive surface to the aircraft axis and the Y axis of the rocket body coordinate system, T is the target point, T' is the projection of the target point on the plane Ox1z1, (x tb ,y tb ,z tb ) is the coordinate value of the target point in the rocket body coordinate system, q y is the elevation angle of the rotating vehicle’s body, q z is the azimuth of the line of sight of the rotating aircraft body, and the coordinates of the target point in the body coordinate system are:
[0091]
[0092] in,
[0093] (x t ,y t ,z t) and (x m ,y m ,z m ) are the coordinates of the target point and the rotating vehicle in the ground coordinate system, and L1 is the transformation matrix from the ground coordinate system to the rocket body coordinate system;
[0094] According to the modeling diagram:
[0095]
[0096] The detection model of the full strapdown laser semi-active detector is:
[0097]
[0098] in,
[0099] OT is the line connecting the center of mass of the aircraft and the target point, OT' is the line connecting the center of mass of the aircraft and the projection of the target point on the plane Ox1z1, δ∈[0,π], λ∈(π,π], and in order to distinguish the azimuth quadrant, the four-quadrant arctan2(x,y) function is used to describe the azimuth, that is:
[0100]
[0101] It should be noted that the detector must meet the following two conditions at the same time for it to capture the target: the distance R between the aircraft's detector and the target is less than or equal to the detector's maximum detection distance R max ; The misalignment angle δ is less than or equal to the maximum misalignment angle δ detected by the detector max ;
[0102] The roll angle γ increases monotonically with the rotation of the aircraft, and its value range is [0, +∞). The roll angle and the azimuth angle measured by the detector are further processed as follows to convert the value range:
[0103]
[0104] in,
[0105] and are the converted γ and λ respectively, and the function fmod(x,y) represents the modulus of x to y;
[0106] The converted roll angle and azimuth angle have a value range of [0, 2π), and the 0° position coincides with the Y axis of the quasi-rocket coordinate system, and the clockwise rotation direction is the increasing direction.
[0107] Step 3: Based on the six-degree-of-freedom mathematical model of the fully strapdown laser semi-active rotating aircraft under wind interference and the detection model of the fully strapdown laser semi-active detector, after changing the value range of the roll angle and the detector azimuth angle, the spatial geometric relationship of the rotating aircraft pulse engine is established and its angle correction capability is calculated. During the flight of the rotating aircraft, the control system determines whether the misalignment angle meets the ignition timing condition range at each simulation step. If it does and no pulse engine is working at this time, proceed to step 4; otherwise, return to step 2;
[0108] The six-degree-of-freedom mathematical model of the fully strapdown laser semi-active rotating aircraft under wind interference includes:
[0109] Center of mass dynamics equation:
[0110]
[0111] in,
[0112] m is the mass of the rotating vehicle, V is the velocity, θ is the velocity inclination, ψ v is the velocity deviation angle, P is the main engine thrust, F p is the thrust of the pulse engine, α + , β, and γ v+ is the quasi-angle of attack, quasi-sideslip angle and quasi-speed tilt angle, γ vw+ is the composite quasi-velocity tilt angle of the aircraft under wind speed interference, σ is the thrust action angle of the pulse engine, X w 、Y w and Z w are the drag, lift and lateral force under wind speed disturbance, g is the acceleration due to gravity;
[0113] The dynamic equations for rotation around the center of mass:
[0114]
[0115] in,
[0116] J x4 、J y4 and J z4 is the moment of inertia of the rotating vehicle about each axis of the rocket body coordinate system, ω x4 、ω y4 and ω z4 are the components of the vehicle's angular velocity on each axis of the quasi-rocket coordinate system, M xw4 、M yw4 and M zw4 are the components of the moments of all external forces acting on the rotating aircraft on the center of mass under wind speed interference on each axis of the quasi-rocket coordinate system, is the roll angular rate of the rotating aircraft;
[0117] Pulse trajectory correction requires accurate description of the installation angle and position of the pulse engine on the rotating aircraft, so it is numbered, the specific number is as follows Figure 4 As shown in the figure, the engine at the top at the initial moment is numbered 0, and the numbers are incremented in a clockwise direction. The azimuth angle χ of the pulse engine is the clockwise angle between the perpendicular line of the pulse engine nozzle to the aircraft axis and the Y axis of the rocket body coordinate system.
[0118] Assuming that there are n pulse engines, and that the nozzle direction of engine 0 coincides with the Y axis of the rocket body coordinate system and is located in the vertical plane at the initial moment, the azimuth angle χ of engine No. i is i , which can be expressed as:
[0119]
[0120] At the initial moment, it is assumed that the rocket body coordinate system Ox1y1z1 and the quasi-rocket body coordinate system Ox4y4z4 coincide with each other. According to the definition of the pulse engine azimuth angle, the thrust action angle σ of the No. i engine is i It can be expressed as:
[0121]
[0122] Thrust action angle σ i As the aircraft rotates, σ i Convert to the range [0,2π] as follows:
[0123]
[0124] in,
[0125] is the transformed σ i .
[0126] During the motion of a rotating aircraft, a pulse engine is ignited at time t. The total impulse of a single pulse engine is I, the working time is Δt, and the average thrust is F. Then:
[0127] I=FΔt(12)
[0128] After the pulse engine is ignited at time t, the center of mass of the rotating aircraft will be affected by the lateral force F until the end of time t+Δt. The speed of the rotating aircraft at time t is recorded as V t At the moment t~t+Δt, the rotating aircraft will obtain a lateral velocity in the same direction as the lateral force F, which is recorded as ΔV. At this time, the movement speed of the rotating aircraft should be V t and ΔV synthesis, such as Figure 5 As shown, the composite speed V1 is obviously different from V t The direction of the velocity is inconsistent, and the direction variable is recorded as Δθ, then:
[0129]
[0130] On the other hand, according to the law of conservation of momentum, the rotating aircraft will produce a momentum change under the action of the pulse engine, the value of which is exactly equal to the impulse I of the pulse engine, that is:
[0131] I=FΔt=ΔmV t =mΔV (14)
[0132] In summary, the angle correction capability of the single-pulse engine is:
[0133]
[0134] When the pulse engine ignites is one of the two core issues in pulse trajectory correction. The corresponding ignition timing conditions are designed and judged by the value of the misalignment angle.
[0135] The basis for judging whether the misalignment angle meets the ignition timing condition range is:
[0136] δ≥kΔθ (16)
[0137] in,
[0138] k is the parameter to be designed, and k≥1;
[0139] In order to minimize the CEP of the landing point in the controlled Monte Carlo simulation, the parameter k will be classified and designed according to the different upper and lower positions of the line between the aircraft and the target point relative to the quasi-rocket coordinate system plane Oxz: when the line is located on the plane Oxz, k = k1, and in other cases k = k2, and k1 and k2 are parameters to be designed.
[0140] Because the detector is fixed to the head of the aircraft, the azimuth angle λ measured by it changes back and forth in the range of [0,2π] as the aircraft rotates. When judging the vertical relationship between the line between the aircraft and the target point and the plane of the quasi-rocket coordinate system Oxz, the roll angle is required. When the connecting line is below the plane Oxz of the quasi-rocket coordinate system, the azimuth and roll angle The relationship is as follows:
[0141]
[0142] If the azimuth and roll angle If the relationship does not satisfy the above formula, the connecting line is located on the quasi-rocket coordinate system plane Oxz.
[0143] Step 4: Calculate the pulse engine ignition position, and determine whether there is an unignited pulse engine within the ignition range according to the pulse engine number from small to large. If so, control its ignition to correct the trajectory, and once this pulse engine is ignited, it will not be shut down. If not, continue to return to step 2;
[0144] When to ignite the pulse engine is another core issue in pulse trajectory correction. The corresponding ignition azimuth condition design and ignition azimuth condition range must at least ensure that the thrust angle range after the pulse engine ignition includes the light spot formed by the target point on the detector sensor at the current moment. The boundary parameters s1 and s2 are designed as follows:
[0145]
[0146] in,
[0147] t on and t off is the start and end time of pulse engine ignition, k3 is the parameter to be designed and optimized, 1≤k3≤2,
[0148] The azimuth angle λ∈[0,2π] measured by the detector. To ensure that the ignition azimuth can be correctly represented within [0,2π] during the transition of s1 and s2 from 2π to 0, the ignition azimuth range is designed as follows:
[0149]
[0150] Step 5: Pulse engine ignition logic flow chart as shown below Figure 6 As shown, the pulse engine control system repeats steps 2-4 in each simulation step after start-up until the rotating aircraft reaches the predetermined position.
[0151] During the flight of the rotating aircraft, the control system determines whether the misalignment angle δ meets the ignition timing condition at each simulation step. If it does and no pulse engine is ignited at this moment, it determines whether there is an unignited engine within the ignition range according to the pulse engine number from small to large. If so, it controls the ignition to correct the trajectory. Once the pulse engine is ignited, it will not be shut down and will continue to work until it is extinguished.
[0152] In addition, it is also important to note that:
[0153] If multiple pulse engines meet the ignition timing and ignition direction conditions at the same time, the pulse engine with a smaller number and not ignited will be ignited first;
[0154] During the trajectory correction process, only one pulse engine is allowed to ignite at the same time, that is, during its ignition process, other pulse engines are not allowed to ignite.
[0155] The initial velocity of a certain parameter-disclosed rotating aircraft is 100m / s, the total impulse of the main engine is 448N·s, the thrust is 1900N, the ignition time is 0.35s after launch, the number of pulse engines is 6, the thrust of each is 3600N, the working time is 0.006s, and the laser semi-active detector detects R max and δ max 450m and 20° respectively.
[0156] The initial simulation scenario set in this embodiment is: the predetermined landing point position is (900, 0, 0) m, and the pulse control parameters k1 = 2.5, k2 = 4.5, and k3 = 1.2.
[0157] The simulation results are as follows:
[0158] Figure 7 The corresponding 500 uncontrolled Monte Carlo simulation results are given, taking into account various interference and error factors such as the inherent properties of the aircraft, launch parameters, aerodynamic interference, and wind field. The red closed curve represents the CEP circle, whose radius is 15.24m.
[0159] Figure 8 The corresponding 500 controlled trajectory correction Monte Carlo simulation results are given under the consideration of multiple interference and error factors such as the inherent properties of the aircraft, launch parameters, aerodynamic interference, wind field, etc. The radius of the CEP circle is 1.02m.
[0160] In summary, after the trajectory of the rotating aircraft is corrected using this design method, the CEP of the landing point is greatly reduced from 15.24m in uncontrolled flight to 1.02m, a reduction of 14.22m, and the accuracy of trajectory error correction is greatly improved.
[0161] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present invention, and these modifications or replacements should all be included in the scope of protection of the present invention.
Claims
1. A laser semi-active rotating aircraft flight trajectory pulse correction method, characterized in that: The following steps are involved: Step 1: Based on the distance between the initial launch position of the rotating aircraft and the target point, the rotating aircraft is launched towards the target point at a certain initial angle, so that the rotating aircraft has an initial speed. After the rotating aircraft exits the launch port for a set time, the main engine of the rotating aircraft is ignited to accelerate the rotating aircraft until the main engine is shut down. The rotating aircraft moves freely under the interference of wind until the rotating aircraft is in the stage of descending altitude; Step 2: Establish a full strapdown laser semi-active detector detection model and change the value range of the roll angle and the detector azimuth angle to determine whether the detector in the rotating aircraft detects the target point. If the detector detects the target point, proceed to step 3; otherwise, continue detection; Step 3: Based on the six-degree-of-freedom mathematical model of the fully strapdown laser semi-active rotating aircraft under wind interference and the detection model of the fully strapdown laser semi-active detector, after changing the value range of the roll angle and the detector azimuth angle, the spatial geometric relationship of the rotating aircraft pulse engine is established and its angle correction capability is calculated. During the flight of the rotating aircraft, the control system determines whether the misalignment angle meets the ignition timing condition range at each simulation step. If it does and no pulse engine is working at this time, proceed to step 4; otherwise, return to step 2; Step 4: Calculate the pulse engine ignition position, and determine whether there is an unignited pulse engine within the ignition range according to the pulse engine number from small to large. If so, control its ignition to correct the trajectory, and once this pulse engine is ignited, it will not be shut down. If not, continue to return to step 2; Step 5: The pulse engine control system repeats steps 2-4 in each simulation step after start-up until the rotating aircraft reaches the predetermined position.
2. The laser semi-active rotating aircraft flight trajectory pulse correction method according to claim 1, characterized in that: In step 1, a barrel-type launching device is used to launch the rotating aircraft, and the pulse engine does not work during the ascent of the rotating aircraft.
3. The laser semi-active rotating aircraft flight trajectory pulse correction method according to claim 1, characterized in that: In step 2, the detection model of the full strapdown laser semi-active detector is: in, OT is the line connecting the center of mass of the aircraft and the target point, OT' is the line connecting the center of mass of the aircraft and the projection of the target point on the plane Ox1z1, (x tb ,y tb ,z tb ) is the coordinate value of the target point in the rocket body coordinate system, q y is the elevation angle of the rotating vehicle’s body, q z is the azimuth angle of the line of sight of the rotating vehicle, δ is the misalignment angle and satisfies δ∈[0,π], λ is the azimuth angle and satisfies λ∈(-π,π], and the four-quadrant arctan2(x,y) function is used to describe the azimuth angle, that is:
4. The laser semi-active rotating aircraft flight trajectory pulse correction method according to claim 1, characterized in that: In step 2, the roll angle and the detector azimuth angle are processed as follows: in, and are the converted γ and λ respectively, the function fmod(x,y) represents the modulus of x over y, the converted roll angle and detector azimuth angle are both in the range of [0,2π), and the 0° position coincides with the Y-axis of the quasi-rocket coordinate system, and the clockwise rotation direction is the increasing direction.
5. The laser semi-active rotating aircraft flight trajectory pulse correction method according to claim 1, characterized in that: In step 3, the six-degree-of-freedom mathematical model of the fully strapdown laser semi-active rotating aircraft includes: Center of mass dynamics equation: in, m is the mass of the rotating vehicle, V is the velocity, θ is the velocity inclination, ψ v is the velocity deviation angle, P is the main engine thrust, F p is the thrust of the pulse engine, α + , β, and γ v+ is the quasi-angle of attack, quasi-sideslip angle and quasi-speed tilt angle, γ vw+ is the composite quasi-velocity tilt angle of the aircraft under wind speed interference, σ is the thrust action angle of the pulse engine, X w 、Y w and Z w are the drag, lift and lateral force under wind speed disturbance, g is the acceleration due to gravity; The dynamic equations for rotation around the center of mass: in, J x4 、J y4 and J z4 is the moment of inertia of the rotating vehicle about each axis of the rocket body coordinate system, ω x4 、ω y4 and ω z4 are the components of the vehicle's angular velocity on each axis of the quasi-rocket coordinate system, M xw4 、M yw4 and M zw4 are the components of the moments of all external forces acting on the rotating aircraft on the center of mass under wind speed interference on each axis of the quasi-rocket coordinate system, is the roll angular rate of the rotating aircraft.
6. The laser semi-active rotating aircraft flight trajectory pulse correction method according to claim 1, characterized in that: In step 3, The process of establishing the spatial geometric relationship of the pulse engine includes: Looking forward from the tail of the aircraft along its axis, the engine at the top at the initial moment is numbered 0, and the numbers increase in a clockwise direction. Among the n pulse engines, the azimuth angle of the i-th engine is i Expressed as: Thrust action angle σ of engine No. i i Expressed as: Thrust action angle σ i As the aircraft rotates, it is converted to [ 0,2 π] range: in, is the transformed σ i ; The pulse engine angle correction capability is: in, Δθ is the angle correction of a single pulse engine, I is the total impulse of a single pulse engine, V t The speed of the rotating aircraft at the current moment; The basis for judging whether the misalignment angle meets the ignition timing condition range is: δ≥kΔθ in, k is a parameter to be designed, and k≥1. It is designed based on the different upper and lower positions of the line between the aircraft and the target point relative to the quasi-rocket coordinate system plane Oxz. When the line is located on the plane Oxz, k=k1, and in other cases k=k2. Both k1 and k2 are parameters to be designed.
7. The laser semi-active rotating aircraft flight trajectory pulse correction method according to claim 6, characterized in that: The method for determining the vertical relationship between the line connecting the aircraft and the target point and the plane Oxz of the quasi-rocket coordinate system is as follows: When the connecting line is below the quasi-rocket coordinate plane Oxz, the azimuth and roll angle satisfy: If the azimuth and roll angle If the relationship does not satisfy the above formula, the connecting line is located on the quasi-rocket coordinate system plane Oxz.
8. The laser semi-active rotating aircraft flight trajectory pulse correction method according to claim 1, characterized in that: In step 4, the ignition position range is designed as follows: Among them, s1 and s2 are range boundary parameters, and their specific meanings are as follows: Among them, t on and t off is the start and end time of pulse engine ignition, k3 is the parameter to be designed and optimized, 1≤k3≤2, 9. The method for pulse correction of a laser semi-active rotating aircraft trajectory according to claim 1, characterized in that: If multiple pulse engines meet the ignition timing and ignition direction conditions at the same time, the pulse engine with a smaller number and not ignited will be ignited first; Only one pulse engine is used for each trajectory correction and only one pulse engine is allowed to ignite at the same time, that is, during its ignition process, other pulse engines are not allowed to ignite.
10. A fully strapdown laser semi-active rotating aircraft, characterized in that: It includes a full strapdown laser semi-active detector, an inertial group system, a pulse engine and its ignition control system, a main engine, a tail and a casing, and is used to implement the method described in any one of claims 1 to 9; The fully strapdown laser semi-active detector and inertial group system are installed on the head of the aircraft to measure the line of sight angle information, aircraft motion and attitude information respectively; A plurality of identical pulse engines are installed near the center of mass and are evenly arranged at equal angles in a ring-like form along the surface of the aircraft, with the thrust generated by the engine nozzles being perpendicular to the axis; The main engine and tail fin are installed at the tail of the aircraft. During the flight of the rotating aircraft in the atmosphere, the offset tail fin at the tail generates a rotational torque, causing it to rotate continuously and maintain flight stability.