Inverse orbit cooperative guidance method based on virtual target point

Abstract

The invention provides an inverse orbit cooperative guidance method based on a virtual target point. The method comprises the following steps: estimating a target speed direction according to target observation information; assuming that the target moves in the reverse direction of the missile with the maximum maneuverability, calculating the attack time required by each missile to hit the target according to the geometrical relationship and the motion relationship between the missile and the target, and taking the maximum value as the ideal attack time of the missile group; calculating a predicted hit point according to the target observation information, the target speed direction and the ideal attack time; according to the position relationship among the missile, the target and the predicted hit point, selecting a reverse orbit strike mode or a lateral strike mode, and determining a strike angle; virtual target points of all guided missiles are calculated according to the strike angles; and each missile is controlled to fly to the virtual target point to hit the target. By using the method, the target striking probability and the striking effect can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-aircraft cooperative guidance and control, and in particular to a reverse-track cooperative guidance method based on a virtual target point. Background Art

[0002] With the continuous development of near-space aircraft, especially near-space high-speed aircraft with the characteristics of fast speed, great maneuverability and strong penetration capability, it has become one of the most threatening weapons, bringing great challenges to the guidance mission. Single missile combat can no longer meet the combat needs. Multi-missile coordinated combat has become the current research trend. Various coordinated guidance strategies such as attack time coordination, attack angle coordination, multi-constraint coordination and coordinated guidance have been proposed one after another. Shi Heng and Zhu Jihong obtained the expected hit point as the virtual target point through iterative calculation to realize the transformation of large maneuvering targets to low-speed and small maneuvering targets. Wang designed the pitch acceleration to make the trajectory fall into the yaw plane, converted the three-dimensional problem into a plane problem, and then designed the yaw acceleration to achieve simultaneous attack on the target. Based on the sliding mode theory, You Hao et al. proposed a coordinated guidance law with dual constraints of time and angle. The error caused by the remaining time estimation was avoided through the consistency theory, and the high-precision attack on the maneuvering target was achieved. Wang designed a coordinated optimal guidance law for bang-bang maneuvering targets. Through the fast multi-model adaptive estimation of the target acceleration and the target acceleration switching time, the target acceleration was accurately tracked and the target was hit.

[0003] In addition, many scholars have proposed a coverage strategy that uses multiple missiles to cover the target's reachable domain. Su, based on a linear model, set a virtual aiming point for the missile to cover the target's maneuverable reachable domain, thus achieving collaborative guidance of a large maneuvering target. Xiao Wei and Chen applied the coverage strategy to nonlinear models in two-dimensional and three-dimensional scenarios, respectively, and added the concept of standard ballistics to dynamically adjust the bias term coefficient. On this basis, Liu considered the initial position of the missile and the optimal value of the number of missile groups, and the simulation verified that the method has good robustness to noise and error. Bai applied the coverage strategy to heterogeneous missile groups, and used numerical methods to solve the number of missile groups and the initial position required for coverage, thus achieving collaborative guidance of multiple missiles with less maneuverability than the target to a highly maneuverable target. Jiang Yong introduced the Apollonius circle in the coverage strategy to achieve collaborative guidance of targets with unknown maneuvers.

[0004] With the continuous development of communication jamming methods, cutting off the opponent's communication network can destroy its command and control functions and greatly weaken the opponent's coordination capabilities. Open-loop collaborative guidance has become an optional solution when inter-missile communication is restricted. Open-loop collaborative methods all require pre-setting the attack time, and the reasonable setting of the ideal attack time has always been a difficulty.

[0005] At the same time, the current collaborative guidance method is mainly aimed at at least one missile hitting the target. In the scenario where the speed and maneuverability of the attacking and defending sides are similar, even if there is a characteristic that the missile launch point is the target point of the incoming missile, the speed directions of the two sides are opposite in the initial guidance, so that a high missile-target intersection speed can be maintained. As the attack progresses, during the maneuvering process of the target, it is easy to change from a head-on attack to a side attack or even a pursuit, which reduces the intersection speed and reduces the success rate of the attack and the effect of hitting the target. The reverse-track guidance method can increase the missile-target intersection speed and reduce the requirements for missile speed. At the same time, the normal overload of the missile is perpendicular to the missile-target line of sight, and the maneuvering to change the line of sight angle change rate is the most efficient, which reduces the required overload of the missile. Summary of the invention

[0006] In view of this, the present invention provides a reverse-track collaborative guidance method based on a virtual target point, which can improve the probability and effect of hitting the target.

[0007] In order to solve the above technical problems, the present invention is implemented as follows.

[0008] A reverse track collaborative guidance method based on a virtual target point, comprising:

[0009] Step 1: Estimate the target speed and direction based on the target observation information;

[0010] Step 2: Assume that the target moves in the opposite direction of the missile with maximum maneuverability. According to the geometric relationship and motion relationship between the missile and the target, calculate the attack time required for each missile to hit the target, and take the maximum value as the ideal attack time T of the missile group. go ;

[0011] Step 3: Based on the target observation information, target speed direction and ideal attack time T go , calculate the predicted hit point P pre ;

[0012] Step 4: According to the missile, target, predicted impact point P pre The positional relationship between them is used to select the reverse-track strike method or the lateral strike method and determine the strike angle; according to the strike angle, the virtual target point P of each missile i is calculated. vir,i ;

[0013] Step 5: Control each missile to fly towards the virtual target point and hit the target.

[0014] Preferably, in step 1, the target speed direction is estimated based on the target observation information:

[0015] According to the target observation information, Kalman filter is used to estimate the target speed direction; in Kalman filter estimation, the constructed observation vector Z k The component V of the target velocity in the direction of the missile's sight line is added toLOS :

[0016] Z k =[x obs,k y obs,k z obs,k V LOS ] T

[0017] In the formula, x obs,k ,y obs,k ,z obs,k is the observed target position, and the subscript indicates the kth iteration;

[0018] Then the observation matrix H k for:

[0019]

[0020] Where: I is the unit matrix, u LOS is the unit vector in the direction of the missile's sight line.

[0021] Preferably, step 2 is:

[0022] Assume that when the target moves in the opposite direction of the missile with maximum maneuverability, the attack time required for missile i to strike the target is t go,i,max , M s,i , T s are the projection points of missile i and target initial position on the predicted strike surface S, respectively, then M s,i The y-axis and z-axis positions in the geodetic coordinate system are y M,i ,z M,i , T s The y-axis and z-axis positions in the geodetic coordinate system are y T ,z T .

[0023] Two projection points M s,i ,T s The distance between

[0024]

[0025] Target projection point T s and the predicted hit point P pre The distance between them is:

[0026]

[0027] Among them, V T is the target velocity estimate obtained based on the target observation information, a T,max is the target maximum maneuvering acceleration;

[0028] Target projection point T sThe distance from the target initial position T is

[0029]

[0030] As the target maneuvers away from the missile, M s,i , T s With P pre are on the same straight line, then the projection point M of missile i s,i and the predicted hit point P pre The distance is:

[0031]

[0032] Finally, the predicted hit point P is obtained pre =(x pre ,y pre ,z pre ) is:

[0033]

[0034] In the formula, (x T ,y T ,z T ) is the target position coordinate, β s It is the azimuth of the projection of the missile-target sight line on the predicted impact surface;

[0035] Assuming the missile flies directly to a stationary target at the predicted impact point, the remaining flight time is estimated to be

[0036]

[0037] Where V M,i is the speed of missile i, R M,i is the missile i and the predicted impact point P pre The distance between them, N is the proportional guidance coefficient; σ i is the angle between the velocity of missile i and the line connecting the missile and the target;

[0038] The attack time t go,i,max Substituting into the above formula, we can get missile i and predicted impact point P pre Distance between:

[0039]

[0040] Finally, we get the information about t go,i,max The equation

[0041]

[0042] Combine (III) to (VI) to find the required attack time t when the target is at maximum maneuverabilitygo,i,max ;

[0043] Take the maximum attack time required by each missile as the ideal attack time T of the missile group. go .

[0044] Preferably, the step 3 is:

[0045] When the target maneuvers in the same direction with maximum overload, the radius R of its circular reachable domain and the speed deflection angle δ of the circular motion are:

[0046]

[0047] In the formula, a T,max is the target maximum maneuvering acceleration, V T is the target flight speed obtained from the target observation information, T go is the ideal attack time;

[0048] The sphere formed by the maximum maneuver is approximated as a circular plane, and the distance between the center of the circular plane and the target is L = Rsinδ;

[0049] Combined with the target position P T =(x T ,y T ,z T ), the ballistic inclination angle θ in the target velocity direction T and ballistic angle The center position of the target's maximum maneuvering range at time t is obtained as:

[0050]

[0051] (x o ,y o ,z o ) is the predicted hit point P at time t pre .

[0052] Preferably, in step 4, the method according to the missile, the target, and the predicted hit point P pre The positional relationship between them, the choice of reverse track striking method or lateral striking method is:

[0053] When the angle between the missile and the target meets the set first angle condition, it has the advantage of reverse-track strike, and the strike method is reverse-track strike; otherwise, the strike method is lateral strike;

[0054] When a lateral strike is selected, two lateral strike methods are further determined based on the second angle condition: one is to perform a lateral strike without changing the current movement angle; the other is to calculate the strike angle based on the angle between the missile and the predicted impact point, and use the calculated strike angle to perform a measured strike.

[0055] Preferably, in step 4, the method according to the missile, the target, and the predicted hit point P pre According to the positional relationship between them, choose the reverse-track striking method or the lateral striking method, and determine the striking angle as:

[0056] Assume the virtual target point P of missile i vir,i and the predicted hit point P pre The line connecting the first connecting line and the reference direction on the predicted striking surface S is β s.i , the elevation angle between the predicted impact surface S is α s,i ; Similarly, the target and predicted hit point P pre The corresponding angle and elevation angle are defined as β s.T and α s,T ;

[0057] The attack mode is determined by formula (I) and formula (II):

[0058]

[0059] in, and is the azimuth and elevation of the expected missile-target line of sight projection for guided movement of missile i; n is the number of missiles; y M,i ,z M,i is the y-axis and z-axis position of the projection point of missile i on the predicted strike surface S in the geodetic coordinate system; pre ,z pre To predict the hit point P pre The y-axis and z-axis positions of the target; δ is the speed deflection angle of the target's circular motion when it moves in the same direction with maximum overload;

[0060] Preferably, in step 4, the virtual target point P of each missile i is calculated according to the attack angle. vir,i for:

[0061] according to Calculate the expected attack direction vector as:

[0062]

[0063] The farthest position of the virtual target point is obtained by the projectile-target distance r:

[0064]

[0065] In the formula, k 1 is the proportionality coefficient, let k 1 <1 ensures that the virtual target point is between the projectile and the target, and obtains the coordinates of the virtual target point:

[0066]

[0067] Where: k 2 is the adjustment parameter, T go The ideal attack time calculated in step 2, is the remaining flight time of missile i; t is the current time; P T is the target position coordinate.

[0068] Beneficial effects:

[0069] (1) All open-loop collaborative guidance methods require presetting of the attack time, and the reasonable setting of the ideal attack time has always been a difficulty. The current attack time is set manually, and there is no reasonable setting method. The present invention proposes a method for calculating the ideal attack time according to the target maneuvering range and the missile guidance characteristics, and uses the calculated ideal attack time to determine the predicted hit point, thereby improving the probability and effect of hitting the target.

[0070] (2) To achieve multi-constraint collaborative guidance, the present invention sets a virtual target point in combination with the target orientation and the predicted impact point to guide the missile to strike the target under the desired constraints.

[0071] (3) When determining the virtual target point, the present invention determines the strike mode as reverse-track strike or lateral strike according to the angle between the missile and the target. Based on the advantage of the missile's current position, the virtual target point is set to guide the missile to surround the target with the desired constraints, thereby improving the strike success rate.

[0072] (4) The current collaborative guidance method takes successful target capture as the only constraint. On this basis, the present invention adds a constraint on the attack angle, making the attack method reverse-track guidance, thereby improving the strike effect and reducing the requirement for missile speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 Schematic diagram of the target reachable domain.

[0074] Figure 2 Schematic diagram of the target reachable domain (Txy plane).

[0075] Figure 3 This is the terminal guidance scenario with ideal attack time.

[0076] Figure 4 Schematic diagram of the ideal attack time interval.

[0077] Figure 5 This is a schematic diagram of virtual target point guidance.

[0078] Figure 6 It is the straight line where the virtual target point is located and the predicted impact surface.

[0079] Figure 7It is the attack trajectory of the missile group on the C-type mobile target.

[0080] Figure 8 It is the attack angle of the missile group on the C-type maneuvering target.

[0081] Fig. 9 It is the overload instruction for the missile group to attack C-type mobile target.

[0082] Fig.10 It is the total miss rate of missile group on C-type mobile targets.

[0083] Fig.11 It is the minimum miss amount of a missile group attacking a C-type maneuvering target.

[0084] Fig.12 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0085] The present invention aims at the problem of high-speed maneuvering target guidance in near space under three-dimensional scenes, and proposes a reverse track collaborative guidance method based on virtual target points. By analyzing the maneuvering range of the target and combining the guidance characteristics of the missile, a method for calculating the ideal attack time of the missile group is proposed, thereby converting the guidance problem of high-speed maneuvering targets into the problem of hitting a point on a fixed plane in space at a specific time and a specific angle. Subsequently, in order to solve the problem of high missile speed requirements, virtual target points are selected in space according to the ideal attack time and attack angle to guide the missile, so that the hit angle meets the reverse track guidance requirements, thereby improving the probability and effect of hitting the target.

[0086] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0087] A flowchart of a reverse track collaborative guidance method based on a virtual target point in an embodiment of the present invention, the method comprising the following steps:

[0088] Step 1: Estimate the target speed and direction based on the target observation information.

[0089] The seeker equipped on a general missile can only detect the target's position information and the speed information in the direction of the missile's sight. The target velocity vector V T It can be obtained by Kalman filtering:

[0090]

[0091] Where: v k is the process noise, w k is the observation noise.

[0092] The target state vector X k Including the target position P T =[x k yk z k ],speed and acceleration In this step, because all parameters are target parameters and the subscript needs to reflect the number of iterations k, in order to simplify the expression, the subscript indicating the target is not added:

[0093]

[0094] Assuming the target is moving with uniform acceleration, the state transfer matrix F k for

[0095]

[0096] Where: Δt is the observation time interval, and I is the unit matrix.

[0097] The target observation information includes the target position and the component of the target velocity in the direction of the missile-target line of sight, so the observation vector Z k for

[0098] Z k =[x obs,k y obs,k z obs,k V LOS ] T (4)

[0099] The observation matrix H k for

[0100]

[0101] Where: u LOS =[u x,k u y,k u z,k ] is the unit vector of the sight line direction, which is obtained through the transformation matrix between the sight line coordinate system and the ground coordinate system:

[0102]

[0103] Where: is the azimuth angle, θ L It is the high and low angle.

[0104] Apply the Kalman filter formula

[0105]

[0106] Where G is the covariance matrix, Q is the prediction uncertainty, R is the sensor noise, K is the Kalman gain, and the subscript k|k-1 indicates the prediction of the state vector at time k in the k-1th iteration.

[0107] The estimated target speed is

[0108]

[0109] The target's ballistic inclination and ballistic deviation are further obtained as

[0110]

[0111] Step 2: Calculate the predicted hit point P pre .

[0112] Specifically, in the scenario of multi-missile coordinated guidance, like missiles, the target also has an approximately cone-shaped maximum maneuvering range, that is, the reachable domain of the target, such as Figure 1 , Figure 2 As shown:

[0113] The reachable domain is determined by the maneuver constraints of the target a T,max , Flight speed V T and flight time T go When the target maneuvers in the same direction with maximum overload, the radius and speed deflection angle of its circular motion are

[0114]

[0115] Where: V T V T The module length, T go Take the ideal attack time T calculated in step 3 go It should be noted that step 2 is written first here because it is smoother when performing logical interpretation. In the actual work process, step 3 is executed first to obtain T go , then execute step 2 to calculate the predicted hit point P pre .

[0116] Since the terminal guidance phase is short, the speed of the high-speed missile and the target is extremely large and the maneuverability is limited, the maneuvering angle δ is small, so the sphere formed by the maximum maneuver can be approximately regarded as a circular plane, and its diameter and distance from the target T are

[0117]

[0118] Combined with the target position P T =(x T ,y T ,z T ), the ballistic inclination angle θ in the target velocity direction obtained in step 1 T Ballistic angle The center position of the target's maximum maneuvering range at time t is obtained as

[0119]

[0120] Here, (x o ,y o ,z o ) is the predicted hit point P at time t pre As the distance between the projectile and the target decreases, the distance between the target and the predicted strike surface also decreases, causing the predicted hit point to gradually converge to the actual hit point.

[0121] Step 3: Calculate the ideal attack time T go .

[0122] In open-loop collaborative guidance, the reasonable setting of the ideal attack time has always been a difficult point. If the ideal attack time is set too long, it will exceed the missile's ability to adjust the attack time, resulting in a hit time less than the ideal attack time or off-target; if the time is set too short, it will exceed the missile's own flight capability and will not be able to hit the target at the ideal attack time.

[0123] In the interception scenario, when the terminal guidance begins, the target speed direction and the sight direction almost coincide. The target maneuvers itself to the side and longitudinal direction, resulting in a longer terminal guidance attack time. The attack time is longest when the target performs a C-type maneuver away from the missile with maximum overload. In order to reasonably design the ideal attack time, sufficient time is left for maneuvering while meeting the missile flight speed limit to meet the attack angle constraint. Calculate the attack time of each missile at the beginning of the terminal guidance. Suppose the attack time required for missile i to strike the target when the target moves in the opposite direction of the missile with maximum maneuverability is t. go,i,max , the predicted hit point is P pre , then the terminal guidance scene is as follows Figure 3 As shown in the figure, plane S is the predicted strike surface, M is the missile position point, and M s,i , T s are the projection points of missile i and target initial position on the predicted strike surface S, respectively, then M s,i The y-axis and z-axis positions in the geodetic coordinate system are y M,i ,z M,i , T s The y-axis and z-axis positions in the geodetic coordinate system are y T ,z T .

[0124] The distance between two projection points can be expressed as

[0125]

[0126] From equations (10) and (11), we can get the target projection point T s and the predicted hit point P pre The distance between

[0127]

[0128] Target projection point T s The distance from the target initial position T is

[0129]

[0130] As the target maneuvers away from the missile, M s,i , T s With P pre are on the same straight line, then the projection point M of missile i s,i and the predicted hit point P pre The distance is:

[0131]

[0132] Finally, the predicted hit point P is obtained pre =(x pre ,y pre ,z pre ) has coordinates of

[0133]

[0134] In the formula, (x T ,y T ,z T ) is the target position coordinate, β s is the azimuth of the projection of the missile-target line of sight on the predicted impact surface, that is,

[0135] βs=arctan[(z T -)z M,i / (y T -y M,i )] (18)

[0136] Here we use the position parameter of a missile i to calculate β s That is, the β calculated by each missile is s are consistent.

[0137] Assuming the missile flies directly to a stationary target at the predicted impact point, the remaining flight time t go for

[0138]

[0139] Where: r is the distance between the projectile and the target, When using proportional guidance to attack a target, the remaining flight time is estimated for

[0140]

[0141] Where: RM,i is the missile i and the predicted impact point P pre The distance between M,i is the speed of missile i, N is the guidance coefficient, σ i is the angle between the missile velocity and the missile-target line, which can be expressed as:

[0142]

[0143] Where: R M,i is the missile i and the predicted impact point P pre The distance vector between M,i is the velocity vector of missile i; To predict the hit point P pre The vector between the two points and the target point, is the vector between missile i and the target.

[0144] Set the attack time t go,max Substituting into formula (20) we get

[0145]

[0146] Finally, we get a go,i,max The equation

[0147]

[0148] The above formula indicates that the sum of the distances between the missile and the target and the predicted strike surface is equal to the missile-target distance.

[0149] By combining equations (15), (16), (22) and (23), we can obtain the attack time t by numerical method: go,i,max , and take the maximum value in the bullet group as the ideal attack time T of the bullet group go .

[0150] It should be noted that in the process of calculating the attack time of a single missile, the condition of "the missile approaches the target in the shortest time" is already implied, and the assumption of "the target maneuvers away from the missile" extends the attack time to cover all possible maneuvers of the target, which is actually the lower limit of the ideal attack time; the maximum attack time of the missile group is taken as the ideal attack time of the entire missile group in order to make this time meet the overload limit of each missile in the missile group. Let the maximum ideal attack time be T go,max , the attack time required for missile i to hit the target is

[0151] t go,i ∈[t go,i,min ,t go,i,max ](twenty four)

[0152] Then the minimum ideal attack time is tgo,max ,but

[0153] T go,i ∈[t go,i,max ,T go,max ](25)

[0154] Finally, the maximum value of the intersection of the ideal attack time of each missile is taken as the ideal attack time of the missile group:

[0155] T go =max(t go,i,max ) (26)

[0156] Step 4: Calculate the virtual target point P vir,i .

[0157] In this step, according to the missile, the target, and the predicted hit point P pre The positional relationship between them is used to select the reverse-track strike method or the lateral strike method and determine the strike angle; according to the strike angle, the virtual target point P of each missile i is calculated. vir,i .

[0158] The guidance situation of the missile group is mainly achieved through the guidance of virtual target points. By designing appropriate virtual target points, the missiles can exert their own maneuverability in the early stage of guidance, surround the target at a certain angle, and finally achieve a coordinated attack on the target. Figure 5 shown.

[0159] In order to achieve the encirclement of the target, missiles should be gradually gathered towards the target from all directions, and at least one missile should be in a state of attacking the target. At this time, no matter which direction the target escapes, there is at least one missile attacking in that direction, that is, the speed direction of the missile is opposite to that of the target. In simple terms, the classification control of missiles can be achieved by setting angle conditions. When the angle between the missile and the target meets the set first angle condition, it has the advantage of reverse track strike. For example, if the angle between the missile and the target is small, the reverse track strike is used as the strike method; otherwise, the side strike is used as the strike method.

[0160] When a lateral strike is selected, it can be further differentiated by setting a second angle condition to determine two lateral strike methods: one is to perform a lateral strike without changing the current attack angle; the other is to calculate the attack angle based on the angle between the missile and the predicted hit point, and use the calculated attack angle to perform a measured strike, thereby making full use of the advantages of missiles in different positions.

[0161] By setting a virtual target point in the corresponding direction, the missile can be guided to form an encirclement situation around the target. The positional relationship between the straight line where the virtual target point is located and the predicted strike surface is expressed by the angle β between the straight line and the reference direction on the plane S (set to the positive direction of the y axis). sand the elevation angle α between the line and plane S s To express, if Figure 6 Therefore, in this preferred embodiment, according to β s and α s Decide together on the method of attack.

[0162] Specifically, the strategy is as follows: since the missile whose own direction is opposite to the target's maneuvering direction has no advantage over the target's position and speed, its attack strategy changes from attacking the target in a head-on state to attacking the target as much as possible; among the missiles whose own direction is the same as the target's maneuvering direction, there is a missile with the smallest difference from the maneuvering direction, which has the greatest advantage in attacking the target, so the α of this missile is set s , β s The target speed direction is used to intercept the target, and the remaining missiles attack the target at the initial projection azimuth, that is:

[0163]

[0164] The attack mode is determined by equation (27) and equation (28). and is the azimuth and elevation of the expected missile-target line of sight projection for guided movement of missile i; n is the number of missiles; y M,i ,z M,i is the y-axis and z-axis position of the projection point of missile i on the predicted strike surface S in the geodetic coordinate system; pre ,z pre To predict the hit point P pre δ is the speed deflection angle of the target's circular motion when it maneuvers in the same direction with maximum overload.

[0165] when Satisfies the first condition of formula (28) and If the first condition of formula (27) is satisfied, then Conduct a counter-track attack;

[0166] when The second condition of formula (28) is satisfied, and If the second condition of equation (27) is satisfied, the missile angle becomes Perform a sideways strike;

[0167] when The second condition of formula (28) is satisfied, and If the third condition of equation (27) is met, the missile angle remains unchanged and a lateral strike is carried out.

[0168] according to The expected attack direction vector can be calculated as

[0169]

[0170] The farthest position of the virtual target point is further obtained from the missile-target distance r:

[0171]

[0172] Where k 1 is the proportional coefficient. In order to ensure that the virtual target point is located between the missile and the target, rather than guiding the missile to fly backwards, k must be satisfied. 1 <1. Finally, the coordinates of the virtual target point are obtained:

[0173]

[0174] Where: k 2 is the adjustment parameter, k 2 The larger the T go The ideal attack time calculated in the previous step, is the remaining flight time of missile i; the virtual target point is more sensitive to the error of the remaining attack time, but k 2 If the value is too large, the transition from the virtual target point to the target will not be smooth, resulting in an increase in the required overload of the missile. Finally, the missile flies to the virtual target point through three-dimensional proportional guidance and finally hits the target.

[0175] Based on the above analysis, the reverse track collaborative guidance method based on the virtual target point of the present invention is shown in Fig.12 , the process includes the following steps:

[0176] Step 1: Estimate the target speed and direction based on the target observation information;

[0177] Step 2: Assume that the target moves in the opposite direction of the missile with maximum maneuverability. According to the geometric relationship and motion relationship between the missile and the target, calculate the attack time required for each missile to hit the target, and take the maximum value as the ideal attack time T of the missile group. go ;

[0178] Step 3: Based on the target observation information, target speed direction and ideal attack time T go , calculate the predicted hit point P pre ;

[0179] Step 4: According to the missile, target, predicted impact point P pre The positional relationship between them is used to select the reverse-track strike method or the lateral strike method and determine the strike angle; according to the strike angle, the virtual target point P of each missile i is calculated. vir,i ;

[0180] Step 5: Control each missile to fly towards the virtual target point and hit the target.

[0181] The reverse track collaborative guidance method based on virtual target point is verified as follows.

[0182] (1) Simulation condition setting

[0183] The present invention takes near-space high-speed aircraft as the cooperative guidance object. Considering that the target often adopts C-type maneuvers and S-type maneuvers in the process of penetration to maximize the use of its own maneuverability to improve the penetration probability, the numerical analysis and verification of the proposed cooperative guidance method are carried out for two typical maneuver forms.

[0184] In the simulation, the missile group speed is set to 3000m / s, the maximum maneuvering overload is 5.6, the target speed is set to 2000m / s, the maximum maneuvering overload is 4, the initial distance between the missile and the target is about 50km, and the effective navigation ratio N is set to 4. The initial position of the missile is randomly generated according to the maximum boundary division angle of the predicted strike surface, as shown in Table 1; the initial position of the target is located at [0,0,30000]m.

[0185] Table 1 Initial position of missile

[0186]

[0187] (2) Comparative simulation analysis

[0188] When the target performs a C-type maneuver, the execution size is a T , direction is γ T The maneuverability, that is

[0189]

[0190] Where η is the ratio of the target overload to its maximum overload.

[0191] Taking the target with η=1 as an example, the attack trajectory of the missile group on the target is as follows: Figure 7 As shown in the figure, the solid line trajectory uses the method proposed in this paper (Virtual Aiming Point Guidance, VAPG), and the dotted line trajectory uses the true three-dimensional proportional guidance (TureProportion Navigation, TPN). Compared with the TPN method, VAPG achieves the attack on the target. The attack angle is as follows Figure 8 As shown, it can be seen that three missiles successfully hit the target, and the attack angle of one of the missiles is 179.4°, which improves the strike effect on the target compared with the TPN method.

[0192] The overload during the flight of the missile group is as follows: Fig. 9As shown, it can be seen that the yaw acceleration of the two missiles that missed the target was always in a saturated state during the flight, indicating that the attack on the target exceeded the attack capabilities of Missile 1 and Missile 5, while the overload saturation part of the three missiles that successfully hit the target was shorter, leaving sufficient maneuvering space for hitting the target and adjusting the attack angle.

[0193] In order to verify the strike effect of the proposed method on C-type maneuvering targets, the strikes on targets with different maneuvering sizes and directions are simulated, and the total miss amount of each missile on the C-type maneuvering target and the miss amount of the missile with the smallest miss amount in the missile group are obtained as follows: Fig.10 , Fig.11 As shown. It can be seen that when η≤0.7, the total miss amount of the missile group is small, that is, all missiles hit the target. When η>0.7, some missiles miss the target, but the minimum miss amount of the missile group is still less than 2m, and the target can be successfully hit. Each missile in the missile group has a miss phenomenon for targets maneuvering in different directions, and the collection of the non-miss parts of each missile can cover the entire maneuvering range of the target, thereby achieving the target hit.

[0194] The above specific embodiments only describe the design principle of the present invention. The shapes and names of the components in the description may be different and are not limited. Therefore, those skilled in the art in the field of the present invention may modify or replace the technical solutions recorded in the above embodiments; and these modifications and replacements do not deviate from the creative purpose and technical solutions of the present invention and should all fall within the protection scope of the present invention.

Claims

1. A reverse track collaborative guidance method based on a virtual target point, characterized in that: include: Step 1: Estimate the target speed direction based on the target observation information; Step 2: Assume that the target moves in the opposite direction of the missile with maximum maneuverability. According to the geometric relationship and motion relationship between the missile and the target, calculate the attack time required for each missile to hit the target, and take the maximum value as the ideal attack time T of the missile group. go ; Step 3: Based on the target observation information, target speed direction and ideal attack time T go , calculate the predicted hit point P pre ; Step 4: According to the missile, target, predicted impact point P pre The positional relationship between them is used to select the reverse-track strike method or the lateral strike method and determine the strike angle; according to the strike angle, the virtual target point P of each missile i is calculated. vir,i ; Step 5: Control each missile to fly towards the virtual target point and hit the target.

2. The method according to claim 1, characterized in that In step 1, the target speed direction is estimated based on the target observation information: According to the target observation information, Kalman filter is used to estimate the target speed direction; in Kalman filter estimation, the constructed observation vector Z k The component V of the target velocity in the direction of the missile's sight line is added to LOS : Z k =[x obs,k y obs,k z obs,k V LOS ] T In the formula, x obs,k ,y obs,k ,z obs,k is the observed target position, and the subscript indicates the kth iteration; Then the observation matrix H k for: Where: I is the unit matrix, u LOS is the unit vector in the direction of the missile's sight line.

3. The method according to claim 1, characterized in that Step 2 is: Assume that when the target moves in the opposite direction of the missile with maximum maneuverability, the attack time required for missile i to strike the target is t go,i,max , M s,i , T s are the projection points of missile i and target initial position on the predicted strike surface S, respectively, then M s,i The y-axis and z-axis positions in the geodetic coordinate system are y M,i ,z M,i , T s The y-axis and z-axis positions in the geodetic coordinate system are y T ,z T ; Two projection points M s,i ,T s The distance between Target projection point T s and the predicted hit point P pre The distance between them is: Among them, V T is the target velocity estimate obtained based on the target observation information, a T,max is the target maximum maneuvering acceleration; Target projection point T s The distance from the target initial position T is As the target maneuvers away from the missile, M s,i 、T s With P pre are on the same straight line, then the projection point M of missile i s,i and the predicted hit point P pre The distance is: Finally, the predicted hit point P is obtained pre =(x pre ,y pre ,z pre ) is: In the formula, (x T ,y T ,z T ) is the target position coordinate, β s It is the azimuth of the projection of the missile-target sight line on the predicted impact surface; Assuming the missile flies directly to a stationary target at the predicted impact point, the remaining flight time is estimated to be Where V M,i is the speed of missile i, R M,i is the missile i and the predicted impact point P pre The distance between them, N is the proportional guidance coefficient; σ i is the angle between the velocity of missile i and the line connecting the missile and the target; The attack time t go,i,max Substituting into the above formula, we can get missile i and predicted impact point P pre Distance between: Finally, we get the information about t go,i,max The equation Combine (III) to (VI) to find the required attack time t when the target is at maximum maneuverability go,i,max ; Take the maximum attack time required by each missile as the ideal attack time T of the missile group. go .

4. The method according to claim 1, characterized in that The step 3 is: When the target maneuvers in the same direction with maximum overload, the radius R of its circular reachable domain and the speed deflection angle δ of the circular motion are: In the formula, a T,max is the target maximum maneuvering acceleration, V T is the target flight speed obtained from the target observation information, T go is the ideal attack time; The sphere formed by the maximum maneuver is approximated as a circular plane, and the distance between the center of the circular plane and the target is L = Rsinδ; Combined with the target position P T =(x T ,y T ,z T ), the ballistic inclination angle θ in the target velocity direction T and ballistic angle The center position of the target's maximum maneuvering range at time t is obtained as: (x o ,y o ,z o ) is the predicted hit point P at time t pre .

5. The method according to claim 1, characterized in that In step 4, the missile, the target, and the predicted hit point P pre The positional relationship between them, the choice of reverse track striking method or lateral striking method is: When the angle between the missile and the target meets the set first angle condition, it has the advantage of reverse-track strike, and the strike method is reverse-track strike; otherwise, the strike method is lateral strike; When a lateral strike is selected, two lateral strike methods are further determined based on the second angle condition: one is to perform a lateral strike without changing the current movement angle; the other is to calculate the strike angle based on the angle between the missile and the predicted impact point, and use the calculated strike angle to perform a measured strike.

6. The method according to claim 1, characterized in that In step 4, the missile, the target, and the predicted hit point P pre According to the positional relationship between them, choose the reverse-track striking method or the lateral striking method, and determine the striking angle as: Assume the virtual target point P of missile i vir,i and the predicted hit point P pre The line connecting the first connecting line and the reference direction on the predicted striking surface S is β s.i , the elevation angle between the predicted impact surface S is α s,i ; Similarly, the target and predicted hit point P pre The corresponding angle is defined as β s.T ; The attack mode is determined by formula (I) and formula (II): in, and is the azimuth and elevation of the expected missile-target line of sight projection for guided movement of missile i; n is the number of missiles; y M,i ,z M,i is the y-axis and z-axis position of the projection point of missile i on the predicted strike surface S in the geodetic coordinate system; pre ,z pre To predict the hit point P pre δ is the speed deflection angle of the target's circular motion when it maneuvers in the same direction with maximum overload.

7. The method according to claim 6, characterized in that In step 4, the virtual target point P of each missile i is calculated according to the attack angle. vir,i for: according to Calculate the expected attack direction vector as: The farthest position of the virtual target point is obtained by the projectile-target distance r: Where k1 is the proportional coefficient. Let k1 < 1 to ensure that the virtual target point is between the projectile and the target, and get the coordinates of the virtual target point: Where: k2 is the adjustment parameter, T go The ideal attack time calculated in step 2, is the remaining flight time of missile i; t is the current time; P T is the target position coordinate.

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