An underwater three-dimensional cooperative guidance method based on angle constraint

Abstract

The application relates to an underwater three-dimensional cooperative guidance method based on angle constraint, and belongs to the technical field of underwater vehicle control. The leading missile adopts an optimal guidance method with angle constraint, and an additional maneuvering instruction is added to the state of the missile based on proportional guidance to control the state of the missile. On the basis of the dynamics and kinematics model of the vehicle, the required rudder angle is designed through three-channel decoupling control to control the attitude of the vehicle, and finally the cooperative guidance is realized. The key of the application lies in the design of the additional maneuvering instruction of the missile, which needs to design a nonlinear state tracking controller based on the dynamic inverse control principle. In order to solve the singularity problem of the angle in the navigation process, the design of the additional maneuvering instruction considers two attack conditions, and the multiple vehicles can hit the target on both sides of the target motion.

Description

Technical Field

[0001] This invention belongs to the field of underwater vehicle control technology and relates to an underwater three-dimensional cooperative guidance method based on angle constraints. More specifically, in a "leader-follower" guidance architecture, the leader missile adopts optimal guidance based on angle constraints, and controls the attitude of the follower missiles by calculating additional maneuver commands, so as to enable multiple autonomous underwater vehicles to simultaneously reach a dynamic target at a desired angle, which can be applied in the field of navigation. Background Technology

[0002] Autonomous underwater vehicles (AUVs) are among the most important platforms for underwater operations, playing a crucial role in various application scenarios. With the rapid development of underwater intelligent technology, the defense systems of warships and AUVs are constantly being updated and improved. The efficiency and success rate of a single AUV performing underwater missions are relatively low. Multi-AUV cooperative guidance technology can overcome the weakness of a single AUV in completing complex tasks, offering higher efficiency and applicability. Simultaneously, with the development of precision guidance technology, multi-AUV cooperative guidance not only aims to simultaneously hit targets but also to strike targets at the desired angle of attack. For example, when intercepting targets, it is best to collide directly with the target at a small angle of attack; when attacking targets such as ships, it is best to destroy them with a large angle of attack or a vertical hit. This requires the designed guidance law to not only have the smallest possible miss distance but also meet the constraints of the terminal attack angle.

[0003] Many existing cooperative guidance methods are based on two-layer cooperative guidance architectures and "leader-follower" cooperative guidance architectures. The "leader-follower" architecture, in particular, can effectively combine different vehicles, reducing operational costs and enhancing attack effectiveness. Furthermore, it is easier to implement in engineering due to the use of relatively mature control methods. In traditional cooperative guidance methods based on the "leader-follower" architecture, all vehicles converge their line-of-sight angles to the same value and strike the target in the same direction. This requires the vehicle's velocity direction and line-of-sight angle to change within the same quadrant, which has limitations in actual battlefield situations and low attack efficiency, failing to fully reflect the significance of cooperative attacks. Therefore, it is necessary to divide the target into different quadrants, allowing multiple vehicles to attack simultaneously from both sides. Considering the effectiveness of cooperative attacks, incorporating attack angle constraints into this method is also of practical significance. Summary of the Invention

[0004] The technical problem to be solved by this invention is:

[0005] To avoid the shortcomings of existing technologies, this invention provides an underwater three-dimensional cooperative guidance method based on angle constraints: the attack scenario consists of a dynamic target, a "leader missile" and multiple "slave missiles". The slave missiles track the "leader missile" based on its state, so that the states of each vehicle are consistent to achieve the goal of simultaneous arrival.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] An underwater three-dimensional cooperative guidance method based on angle constraints, characterized by the following steps:

[0008] Step 1: Establish a relative motion model between the vehicle and the target in the plane to obtain the relative motion relationship between velocity, normal acceleration, trajectory tilt angle, line-of-sight elevation angle, lead angle and the relative distance between the missile and the target;

[0009] Step 2: Design a multi-vehicle cooperative guidance strategy. The leader vehicle adopts optimal guidance with angle constraints, and the follower vehicles add an additional maneuver command A2 to the proportional guidance, resulting in the guidance law as follows:

[0010]

[0011] Where σ is the vehicle's yaw angle, q is the vehicle's line-of-sight angle to the target, and the subscripts l and fi represent the leader and follower missiles, respectively. d For the final desired line-of-sight angle, N is the proportional guidance coefficient from the projectile. p and N q It is the constant proportional guidance coefficient of the missile leader, t go Remaining sailing time;

[0012] Step 3: Define two tracking errors E R and E η , representing the distance tracking error and velocity lead angle tracking error of the lead missile and follower missile, respectively. Depending on whether the aircraft attacks the target from the same side or different sides, there are two cases: Case 1 is: E R =R l -R fi E η =η l -η fi Case 2 is: E R =R l -R fi E η =-η l -η fi Using this as the input to the feedback linearization controller, we obtain control design models for two cases; where R l and R fiη represents the target distance of the lead missile and the i-th follower missile, respectively; l and η fi Let represent the angles between the velocity vectors of the lead missile and the i-th follower missile and the target's line of sight, respectively; these are the leading angles.

[0013] Step 4: The controller can be viewed as two subsystems, a slow one and a fast one, and the desired value is defined. and pseudo-control quantity The design employs a dynamic inverse approach, with the desired slow subsystem dynamics being: The desired fast subsystem dynamics are The calculation results of the additional maneuver command A2 in two cases are obtained;

[0014] Step 5: The required rudder angle of the aircraft is obtained through three-channel decoupling control. The obtained additional maneuver command A2 is applied to the heading control. The vertical and differential rudder angles are calculated using the traditional PID method. In pitch control, the horizontal rudder angle is obtained by adopting the depth-pitch angle dual-loop depth control method.

[0015] A further technical solution of the present invention: the vertical rudder angle δ mentioned in step 5 r Differential rudder angle δ d and horizontal rudder angle δ e They are respectively:

[0016]

[0017]

[0018]

[0019] Where Δσ is the difference between the current yaw angle and the yaw angle at the previous moment, y e Let Δθ be the depth difference between the vehicle and the target, and Δφ be the difference between the vehicle's pitch angle and roll angle and the expected value, respectively, with the expected value being 0. This is calculated from the guidance law in step 2 using additional control command A2.

[0020] A further technical solution of the present invention: q in step 2 d Set to 90°.

[0021] A computer system is characterized by comprising: one or more processors, and a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the method described above.

[0022] A computer-readable storage medium is characterized by storing computer-executable instructions, which, when executed, are used to implement the above-described method.

[0023] The beneficial effects of this invention are as follows:

[0024] The present invention provides an underwater three-dimensional cooperative guidance method based on angle constraints, which has the following significant advantages compared with traditional cooperative guidance technology:

[0025] 1. In the process of coordination, this invention takes into account the final attack angle, increases the damage effect, avoids all vehicles hitting the target with their tails, and makes the guidance effect better.

[0026] 2. Taking into account the situation where the advance angle exceeds the limit during navigation and the system cannot operate normally, this invention designs a strategy that can reach the target simultaneously from both sides of the target's motion, making the guidance process more reasonable.

[0027] 3. This invention not only considers the ideal guidance law, but also verifies the feasibility of cooperative guidance based on the vehicle model and the underlying control, making the simulation process more realistic and feasible.

[0028] Furthermore, traditional simulation methods do not consider the dynamics and kinematics of the aircraft, resulting in a guidance law simulation under an ideal state. In this invention, the kinematics and dynamics of the aircraft are added to the simulation, and a control law is designed using a decoupled three-channel attitude controller. The simulation experiment is completed by combining the control law and the cooperative guidance law, making it more practically significant. Attached Figure Description

[0029] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0030] Figure 1 The relative motion relationship between the lead missile, the i-th follower missile, and the target;

[0031] Figure 2 Diagrams illustrating same-side and opposite-side strikes: (a) Same-side strike; (b) Opposite-side strike;

[0032] Figure 3 Cooperative guidance architecture;

[0033] Figure 4 Multi-vehicle cooperative guidance effect;

[0034] Figure 5 Graph showing the change in distance between the vehicle and the target. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0036] This invention provides an underwater cooperative guidance method capable of attacking targets at large angles or vertically: the "leader missile" employs an optimal guidance method with angle constraints, while the "follower missile," based on proportional guidance, receives an additional maneuver command to control its state. Based on the vehicle's dynamics and kinematics model, the required rudder angle is designed through a three-channel decoupled control system to control the vehicle's attitude, ultimately achieving cooperative guidance. The key to this invention lies in the design of the additional maneuver command for the "follower missile," requiring a nonlinear state tracking controller designed based on the dynamic inverse control principle. To address the singularity issue arising during navigation, the additional maneuver command design considers two attack scenarios, enabling multiple vehicles to simultaneously strike the target from both sides of its trajectory.

[0037] The implementation steps of this invention are as follows:

[0038] Step 1: Establish a relative motion model between the vehicle and the target in the plane to obtain the relative motion relationship between velocity, normal acceleration, trajectory tilt angle, line-of-sight elevation angle, lead angle and the relative distance between the missile and the target.

[0039] Step 2: Design a multi-vehicle cooperative guidance strategy. The leader vehicle adopts optimal guidance with angle constraints, and the follower vehicles add an additional maneuver command A2 to the proportional guidance, resulting in the guidance law as follows:

[0040]

[0041] In the above formula, σ is the yaw angle of the aircraft, q is the line-of-sight angle from the aircraft to the target, and the subscripts l and fi represent the leader and follower missiles, respectively. d For the final desired line-of-sight angle, N is the proportional guidance coefficient from the projectile. p and N q It is the constant proportional guidance coefficient of the missile leader, t go This represents the remaining sailing time.

[0042] Step 3: Define two tracking errors E R and E η , representing the distance tracking error and velocity lead angle tracking error of the lead and follower missiles, respectively. Depending on whether the aircraft attacks the target from the same side or different sides, there are two cases. Case 1 is: E R =R l -Rfi E η =η l -η fi Case 2 is: E R =R l -R fi E η =-η l -η fi Using this as the input to the feedback linearization controller, two control design models can be obtained.

[0043] Step 4: The controller can be viewed as two subsystems, a slow one and a fast one, and the desired value is defined. and pseudo-control quantity The design employs a dynamic inverse approach, with the desired slow subsystem dynamics being: The desired fast subsystem dynamics are The calculation results of the additional maneuver command A2 in two cases are obtained.

[0044] Step 5: The required rudder angle of the aircraft is obtained through three-channel decoupling control. The obtained additional maneuver command A2 is applied to the heading control. The vertical and differential rudder angles are calculated using the traditional PID method. In pitch control, the horizontal rudder angle is obtained by adopting the depth-pitch angle dual-loop depth control method.

[0045] In step 1, the relative motion model between the vehicle and the target is established, such as... Figure 1 As shown.

[0046] Among them, M l For the lead ammunition, M fi Let R be the i-th missile, T be the target; l and R fi q represents the target distance of the lead missile and the i-th follower missile, respectively; l and q fi σ represents the line-of-sight angle of the lead bullet and the i-th follower bullet, respectively; l and σ fi Let σ represent the trajectory deflection angles of the lead missile and the i-th follower missile, respectively. When the attack plane is horizontal, σ l and σ fi σ is the yaw angle of the aircraft. t It is the target's yaw angle; η l and η fi Let η represent the angles between the velocity vectors of the leading projectile and the i-th follower projectile and the target's line of sight, respectively, which are the leading angles. tl η is the angle between the target velocity vector and the line of sight of the missile leader; tfi A is the angle between the target's velocity vector and the line of sight from the projectile; l and A fi Let represent the normal accelerations of the lead missile and the i-th follower missile, respectively.

[0047] according to Figure 1 The relative motion relationship shown can be used to obtain the motion equations (1) and (2) of the lead projectile and the follower projectile relative to the target.

[0048]

[0049]

[0050] The entire underwater cooperative guidance architecture is as follows Figure 3 As shown, the state of the lead missile is used as the reference state, and compared with the state of the follower missile to obtain E under the two attack scenarios. R and E η These values ​​are then input into the dynamic inverse controller. The dynamic inverse controller calculates the additional control command A2 for the follower missile, which is used to control the follower missile's attitude. The PID controller then calculates the rudder values ​​required by the aircraft and inputs them into the aircraft model for attitude update.

[0051] In step 2, to simplify the calculation process, the remaining flight time t of the missile is used. go The calculation method is as follows Among them, dR l It is the rate of change of the distance between the missile leader and the target. The proportional guidance coefficient used in this invention is N. p =6,N q =6, N=4. Meanwhile, to ensure a perpendicular hit to the target, the desired final line-of-sight angle q is set. d It is -90°.

[0052] In step 3, the two guidance strategies of the aircraft are as follows: Figure 2 As shown, this allows the vehicle to reach the target from both sides of the target's direction of motion. The cooperative and target initialization data are shown in Table 1, and the cooperative effect and distance changes in the designed simulation experiment are shown in... Figure 4 and 5 As shown, the distances between the vehicles at different initial positions and the target can be quickly converged to a consistent value, and ultimately all four vehicles can reach the target at the desired line-of-sight angle. This fully verifies the advancement and effectiveness of this invention in vehicle cooperative guidance.

[0053] The specific calculation process in step 3 is as follows:

[0054] Based on the guidance law and the set of motion equations (1) and (2) in step 2, equation (3) can be obtained.

[0055]

[0056] For case 1, we can obtain equation (4) as follows:

[0057]

[0058] Combine equations (3) and (4), and make the velocities of the lead and follower projectiles the same, i.e., V fi =V l =V, we can obtain equation (5):

[0059]

[0060] The calculation process for case 2 is the same as that for case 1, so in case 2 we can obtain equation (6):

[0061]

[0062] In step 4, the controller can be considered as two subsystems: a slow system and a fast system. The desired value is defined. and pseudo-control quantity The design employs a dynamic inverse approach, with the desired slow subsystem dynamics being: The desired fast subsystem dynamics are The calculation results of the additional maneuver command A2 in two cases are obtained.

[0063] The specific calculation process for additional maneuver command A2 is as follows:

[0064] Taking case 1 as an example, the dynamic equation of the slow subsystem is:

[0065]

[0066] Where, ω R Let be the bandwidth of the slow subsystem. Based on equations (5) and (7), we can obtain equation (8):

[0067]

[0068] in, It is E η The control commands have

[0069]

[0070] in, It is η l The expected value.

[0071] When the i-th missile is at its initial forward angle η fi (0) In the range of 0 to π, the expected value is It also varies within this range, and we can obtain from equation (9) Therefore, the inverse solution (8) yields...

[0072]

[0073] Similarly, when the i-th bullet starts from the initial pre-angle η... fi (0) In the range of -π to 0, it is expected that we can obtain Solving equation (8) inversely yields...

[0074]

[0075] Therefore, for control orders Ultimately, it can be concluded that

[0076]

[0077] In order to make E R To achieve the desired dynamic equation (7), E must be such that... η Fast convergence to Therefore, the desired fast subsystem dynamics can be designed as follows:

[0078]

[0079] Differentiating equation (12) and substituting it into equation (7) yields...

[0080]

[0081] Combining equations (5), (12), (13), and (14), we can finally obtain the additional maneuver command A2 designed in case 1.

[0082]

[0083] in,

[0084]

[0085]

[0086]

[0087] The control design scheme for case 2 is similar to that for case 1. The final calculated A2 for case 2 is...

[0088]

[0089] in

[0090]

[0091]

[0092]

[0093]

[0094] To prevent singularities from occurring during the calculation, the parameter ω... R There exists a range. The process of determining the range is as follows:

[0095] Since 0 ≤ cosη ≤ 1, and Therefore, it can be obtained

[0096] 0≤V t / E R ≤ω R ≤(VV t ) / E R (17)

[0097] Let ω R =c1 / [c2+E R / (VV t )], where c1 and c2 are constants. And 0 < c1, c2 < 1. Since ω R Satisfying the above inequalities, and when E R When →0, ω R →c1 / c2, this makes it easier to adjust E R The convergence speed is determined by the parameters used in this invention: c1 = 0.7; c2 = 0.9.

[0098] In step five, based on the design control laws of underactuated aircraft, a three-channel decoupled attitude controller for yaw, pitch, and roll is adopted.

[0099] For ease of calculation, the aircraft controller employs a proportional-integral-derivative (PID) controller. Specifically, the guidance law from step 2 can be used to calculate the value σ via additional control command A2, which is then applied to the heading control to obtain the vertical rudder angle δ. r In pitch control, a dual-loop depth control method based on depth and pitch angle is adopted to obtain the horizontal rudder angle δ. e In roll control, PD control is used to calculate the differential rudder angle δ. d The PID control law used in this invention is:

[0100]

[0101]

[0102]

[0103] Where Δσ is the difference between the current yaw angle and the yaw angle at the previous moment, y e Let Δθ represent the depth difference between the vehicle and the target, and Δφ represent the differences between the vehicle's pitch angle and roll angle and their expected values, respectively, with the expected values ​​being 0 for both.

[0104] Table 1 Initial conditions for simulation examples

[0105]

[0106] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. An underwater three-dimensional cooperative guidance method based on angle constraints, characterized in that... The steps are as follows: Step 1: Establish a relative motion model between the vehicle and the target in the plane to obtain the relative motion relationship between velocity, normal acceleration, trajectory tilt angle, line-of-sight elevation angle, lead angle and the relative distance between the missile and the target; Step 2: Design a multi-vehicle cooperative guidance strategy. The leader vehicle adopts optimal guidance with angle constraints, and the follower vehicles add an additional maneuver command A2 to the proportional guidance, resulting in the guidance law as follows: Where σ is the vehicle's yaw angle, q is the vehicle's line-of-sight angle to the target, and the subscripts l and fi represent the leader and follower missiles, respectively. d For the final desired line-of-sight angle, N is the proportional guidance coefficient from the projectile. p and N q It is the constant proportional guidance coefficient of the missile leader, t go Remaining sailing time; Step 3: Define two tracking errors E R and E η , representing the distance tracking error and velocity lead angle tracking error of the lead missile and follower missile, respectively. Depending on whether the aircraft attacks the target from the same side or different sides, there are two cases: Case 1 is: E R =R l -R fi E η =η l -η fi Case 2 is: E R =R l -R fi E η =-η l -η fi Using this as the input to the feedback linearization controller, we obtain control design models for two cases; where R l and R fi η represents the target distance of the lead missile and the i-th follower missile, respectively; l and η fi Let represent the angles between the velocity vectors of the lead missile and the i-th follower missile and the target's line of sight, respectively; these are the leading angles. Step 4: The controller can be viewed as two subsystems, a slow one and a fast one, and the desired value is defined. and pseudo-control quantity The design employs a dynamic inverse approach, with the desired slow subsystem dynamics being: The desired fast subsystem dynamics are The calculation results of the additional maneuver command A2 in two cases are obtained; Step 5: The required rudder angle of the aircraft is obtained through three-channel decoupling control. The obtained additional maneuver command A2 is applied to the heading control. The vertical and differential rudder angles are calculated using the traditional PID method. In pitch control, the horizontal rudder angle is obtained by adopting the depth-pitch angle dual-loop depth control method.

2. The underwater three-dimensional cooperative guidance method based on angle constraints according to claim 1, characterized in that: The vertical rudder angle δ mentioned in step 5 r Differential rudder angle δ d and horizontal rudder angle δ e They are respectively: Where Δσ is the difference between the current yaw angle and the yaw angle at the previous moment, y e Let Δθ be the depth difference between the vehicle and the target, and Δφ be the difference between the vehicle's pitch angle and roll angle and the expected value, respectively, with the expected value being 0. This is calculated from the guidance law in step 2 using additional control command A2.

3. The underwater three-dimensional cooperative guidance method based on angle constraints according to claim 1, characterized in that: The q mentioned in step 2 d Set to 90°.

4. A computer system, characterized in that... include: One or more processors, a computer-readable storage medium for storing one or more programs, wherein, when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the method of claim 1.

5. A computer-readable storage medium, characterized in that... The device stores computer-executable instructions, which, when executed, are used to implement the method of claim 1.

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