Underwater autonomous vehicle control method and device, electronic equipment and storage medium

Abstract

The invention discloses an autonomous underwater vehicle control method and device, electronic equipment and a storage medium. The method comprises the following steps: constructing an AUV kinematic model; a virtual target point is distributed to each AUV, the virtual target point is the center of a tangent plane circle formed by the track where the AUV is located, and the AUV forms a surrounding situation with the virtual target point as the center of the circle and the distance between the virtual target point and the AUV is the radius of the tangent plane circle where the AUV is located; when the AUV loses the target information, generating a virtual target point based on projection mapping of neighbor AUV position information; and based on a kinematics controller, according to the AUV kinematics model and the virtual target point, driving the multiple AUVs to move cooperatively. According to the embodiment of the invention, the problem of efficient and stable multi-AUV cooperative hunting control under the conditions of ocean current disturbance and lack of target information by part of AUVs is solved.

Description

Technical Field

[0001] The present application relates to a method, device, electronic equipment and storage medium for controlling an underwater autonomous vehicle, and belongs to the field of three-dimensional collaborative surround capture control of multiple AUVs. Background Art

[0002] With the growing demand for marine resource development, marine environmental exploration and resource utilization have become key areas of scientific, technological and economic development. Autonomous underwater vehicles (AUVs) play a key role in tasks such as marine exploration and environmental monitoring, thanks to their autonomous navigation, obstacle avoidance and target detection capabilities. However, a single AUV system has obvious limitations in operating for a long time, over a large area or in complex environments: the detection range is limited, and single-point failures can easily lead to mission interruption, which seriously restricts system reliability. Therefore, multi-AUV collaborative control technology has become a current research hotspot. This technology has shown great application potential in tasks such as marine exploration and target search. However, existing research methods have obvious shortcomings: it is usually assumed that all AUVs can obtain complete target information, and the impact of some missing information on the system is not fully considered, resulting in reduced efficiency of collaborative tasks in practical applications. Summary of the Invention

[0003] In view of this, the present application provides an underwater autonomous vehicle control method, device, electronic device and storage medium. The embodiments of the present application solve the problem of efficient and stable multi-AUV collaborative capture control under conditions of ocean current disturbances and lack of target information for some AUVs.

[0004] In a first aspect, an embodiment of the present application discloses a method for controlling an underwater autonomous vehicle, the method comprising:

[0005] Construct AUV kinematic model;

[0006] Assign a virtual target point to each AUV. The virtual target point is the center of the tangent circle formed by the AUV's track. The AUV forms a surrounding capture posture with the virtual target point as the center and the distance from the virtual target point as the radius of the tangent circle where the AUV is located.

[0007] When the AUV loses target information, it generates a virtual target point based on the projection mapping of the neighboring AUV position information;

[0008] Based on the kinematic controller, multiple AUVs are driven to move in coordination according to the AUV kinematic model and the virtual target point.

[0009] Furthermore, the construction of the AUV kinematic model includes:

[0010] The disturbed ocean current velocity of each axis of the inertial coordinate system is introduced into the AUV kinematic model to obtain the AUV kinematic model with ocean current disturbance.

[0011] Furthermore, allocating a virtual target point to each AUV includes:

[0012] For each AUV, the longitude angle and polar angle are calculated using the spherical coordinate grid method and are evenly distributed on the spherical surface;

[0013] A corresponding virtual target point is obtained based on the coordinates of the actual target in the inertial coordinate system and the longitude angle and polar angle.

[0014] Furthermore, the projecting mapping based on the neighboring AUV position information to generate a virtual target point includes:

[0015] Construct a neighbor relationship graph for the multi-AUV system, where the neighbor AUV of the i-th AUV is the i+1-th AUV, where i does not include N; the neighbor AUV of the N-th AUV is the 1st AUV; i represents the i-th AUV, i=1,2,…,N, where N is the total number of AUVs participating in the collaborative capture;

[0016] If the i-th AUV cannot detect the target, the three-dimensional coordinates of the neighbor AUV are mapped to the orbit where the i-th AUV is located to form the virtual target point coordinates.

[0017] Furthermore, the method further comprises:

[0018] Define the extended state observer as follows:

[0019]

[0020] in, represents the rate of change of the position estimate, represents the rate of change of the ocean current disturbance estimate, are the estimated positions of the current i-th AUV in the x, y, and z directions in the inertial coordinate system, are the estimated ocean current velocities of the current i-th AUV in the x, y, and z directions in the inertial coordinate system, λ1 and λ2 are the observation gains, and λ2>λ1 is satisfied. [x i ,y i ,z i ] is the coordinate of the i-th AUV in the inertial coordinate system; θ i is the heading angle of the i-th AUV in the inertial coordinate system; ψ i is the pitch angle of the i-th AUV in the inertial coordinate system; v i The designed forward speed for the i-th AUV;

[0021] Adjusting the control gain k based on the adaptive law p The current position of the AUV is made to approach the virtual target point, and the distance to the target point is ensured to be the spherical radius.

[0022] Furthermore, the kinematic controller is as follows:

[0023]

[0024] Among them, k v >0,k ω >0,k μ >0 is the controller parameter, a i Indicates relative position and The previous weight, 0 i <1; [v i ,ω i ,μ i ] T is the kinematic controller input, v i ,ω i ,μ i represent the forward speed, yaw rate, and pitch rate of the i-th AUV design respectively;

[0025]

[0026] in, is the rotation matrix, [x0, y0, z0] is the coordinate of the target in the inertial coordinate system, [x' n ,y' n ,z' n ] is to use the three-dimensional coordinates of the neighbor AUV to map to the orbit where the i-th AUV is located to form the virtual target point coordinates;

[0027] Flag=[f1,f2,f3…f N ]

[0028] Among them, f N The state of whether the Nth AUV can observe the target. The elements in Flag are not all 0.

[0029] Furthermore, the gain k p As follows:

[0030]

[0031] Where η is the learning rate;

[0032] e r =||[x0-x i ;y0-y i ;z0-z i ]||-R

[0033] Here, ||·|| represents the Euclidean distance, and R represents the radius of the sphere.​

[0034] A second aspect of the present application discloses a control device for an underwater autonomous vehicle, the device comprising:

[0035] Building module for constructing AUV kinematic model;

[0036] An allocation module is used to allocate a virtual target point to each AUV. The virtual target point is the center of the tangent circle formed by the AUV's track. The AUV forms a surrounding capture posture with the virtual target point as the center and the distance from the virtual target point as the radius of the tangent circle where the AUV is located;

[0037] A generation module is used to generate a virtual target point based on the projection mapping of the neighboring AUV position information when the AUV loses the target information;

[0038] The driving module is used to drive the coordinated movement of multiple AUVs based on the AUV kinematic model and the virtual target point based on a kinematic controller.

[0039] A third aspect of an embodiment of the present application discloses a computer-readable storage medium, which includes a stored program, wherein when the program is run, the underwater autonomous vehicle control method of the above embodiment is executed in a processor of the device where the program is located.

[0040] The fourth aspect of an embodiment of the present application discloses an electronic device, which includes one or more processors; a storage device for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors execute the underwater autonomous vehicle control method of the above embodiment.

[0041] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0042] Under the premise of fully considering ocean current disturbances and incomplete local information, stable three-dimensional capture control of the multi-AUV system is achieved, significantly reducing the dependence on global precise positioning and high-bandwidth communication; through adaptive observation and gain adjustment mechanism, the robustness of the controller to changes in ocean current disturbances is improved; the use of relative information for distributed control strategy design avoids mission failure caused by single point failure; relative information and ESO current compensation method are used to realize three-dimensional collaborative capture control of multiple AUVs under ocean current disturbances, ensuring the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without any creative work.

[0044] Figure 1 、 Figure 8 、 Figure 15 Schematic diagrams of the three-dimensional trajectories of each AUV in the three-dimensional collaborative capture of multiple AUVs (0-200s) in embodiments 1, 2, and 3 of the present invention;

[0045] Figure 2 、 Figure 9 、 Figure 16 Schematic diagrams of the trajectories of each AUV in the three-dimensional collaborative capture (0-200s) of multiple AUVs in embodiments 1, 2, and 3 of the present invention from the XY plane perspective;

[0046] Figure 3 、 Figure 10 、 Figure 17 Schematic diagrams of the trajectories of each AUV in the three-dimensional collaborative capture (0-200s) of multiple AUVs in embodiments 1, 2, and 3 of the present invention from the XZ plane perspective;

[0047] Figure 4 、 Figure 11 、 Figure 18 These are respectively graphs showing the difference between the distance between each AUV and the target and the radius R of the sphere formed during the spherical capture in embodiments 1, 2, and 3 of the present invention for the three-dimensional collaborative capture of multiple AUVs (0-200s);

[0048] Figure 5 、 Figure 12 、 Figure 19 These are respectively diagrams showing the change of the separation angle β of each adjacent AUV relative to the target during the multi-AUV three-dimensional collaborative capture (0-200s) in embodiments 1, 2, and 3 of the present invention;

[0049] Figure 6 、 Figure 13 、 Figure 20 The ESO parameters of each AUV in the three-dimensional collaborative capture (0-200s) of multiple AUVs in embodiments 1, 2, and 3 of the present invention are respectively Change graph;

[0050] Figure 7 is a schematic diagram of three-dimensional ocean current distribution in embodiments 2 and 3 of the present invention;

[0051] Figure 14 、 Figure 21They are the ESO parameters of the first and fifth AUVs in the multi-AUV three-dimensional collaborative capture (0-200s) in embodiments 2 and 3 of the present invention, respectively. Change graph;

[0052] Figure 22 This is a flow chart of a method for controlling an underwater autonomous vehicle provided by the present invention. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0054] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0055] The technical concept of the present invention is: by dynamically allocating virtual target points, multiple AUVs are ensured to form a stable and evenly distributed spherical capture structure in three-dimensional space. The kinematic controller of the multi-AUV system is divided into two parts. The first part is to address the situation where some AUVs cannot obtain target information due to detection distance or sensor limitations. A method of calculating virtual target points by projecting and mapping neighbor position information is introduced to obtain the relative position of the virtual coordinates calculated based on the position information of the neighbors in the local coordinate system and the relative position control part with the target in the local coordinate system in the controller, so that all AUVs can also achieve spherical capture of the target under limited measurement and communication conditions; the second part is to add the use of extended state observer (ESO) and adaptive gain adjustment strategy to estimate and compensate for the ocean current online, ensuring that the AUV can still accurately track and capture the target when disturbed by uncertain ocean currents; this method significantly reduces the dependence on global positioning and communication, improves the robustness of the system under ocean current disturbances, and provides reliable technical support for marine environment monitoring and confrontation tasks.

[0056] Based on the relative position of virtual coordinates calculated with the position information of neighbors in the local coordinate system and the relative position with the target in the local coordinate system, the present invention aims to solve the problems of uncertain ocean current disturbances and missing target information of some AUVs in the three-dimensional ocean environment. A kinematic controller is obtained by designing a real-time observation and compensation mechanism for ocean current disturbances and a local neighbor information mapping strategy. This method realizes stable spherical capture control of multiple AUVs in three-dimensional space. This method significantly reduces the dependence on global positioning and communication, improves the robustness of the system under asymmetric ocean current disturbances, and provides reliable technical support for marine environment monitoring and confrontation tasks.

[0057] Example 1:

[0058] refer to Figure 1-Figure 22 The three-dimensional collaborative capture control method of multiple AUVs under ocean current disturbance includes the following steps:

[0059] Step 1: Establish the AUV kinematic model and the kinematic model with ocean current disturbance, and initialize the system state;

[0060] 1.1 The kinematic model of AUV is expressed as

[0061]

[0062] Where, the subscript i represents the i-th AUV, i = 1, 2, ..., N, N is the total number of AUVs participating in the collaborative capture; [x i ,y i ,z i ] is the coordinate of the i-th AUV in the inertial coordinate system (x i is the horizontal axis, y i is the vertical coordinate, z i is the vertical coordinate); θ i is the heading angle of the i-th AUV in the inertial coordinate system; ψ i is the pitch angle of the i-th AUV in the inertial coordinate system; [v i ,ω i ,μ i ] T is the kinematic controller input, v i ,ω i ,μ i Respectively represent the forward speed, yaw angular velocity and pitch angular velocity of the i-th AUV design; [C x ,C y ,C z ] T is the disturbance current velocity, C x ,C y ,C z represent the disturbed ocean current velocities of the x, y, and z axes of the inertial coordinate system, respectively;

[0063] 1.2 The AUV target capture method in this control method is a virtual target pursuit method, that is, a virtual coordinate is set for each AUV, and the AUV moves with the virtual coordinate as the target, so that the AUV forms a spherical surround capture with the target as the center and the distance to the target as the radius of the sphere. For a sphere with the actual target as the center, given the longitude angle (horizontal rotation around the z-axis, ranging from 0 to 2π) and the polar angle φ i (measured downward from the positive z-axis, ranging from 0 to π), using the spherical coordinate grid to calculate the longitude angle and polar angle φ i Make it evenly distributed on the sphere, the longitude angle and polar angle φ i The expression is:

[0064]

[0065] Where t is the orbiting time, at the polar angle φ i A small offset is introduced in the setting of , so that the calculated φ i It will not fall exactly on the poles (i.e. the North Pole and the South Pole), ensuring that all AUVs are evenly distributed on the sphere, starting from the North Pole (φ i =0) to the South Pole (φ i =π). The longitude angle The time-varying rotation angle is added to the setting so that the azimuth angle of each AUV is not fixed, but changes dynamically around the center of the sphere, ensuring that the AUV rotates around the Z axis along the sphere at a uniform angular velocity over time, completing a full 2π rotation every 50 time units.

[0066] 1.3 Using the Longitude Angle Obtained from the Spherical Coordinate Grid Method and polar angle φ i Calculate the virtual target point of each AUV. The virtual target point of each AUV is

[0067]

[0068] where [x t ,y t ,z t ] is the coordinate of the virtual target point pursued by the i-th AUV (x t is the horizontal axis, y t is the vertical coordinate, z t is the vertical coordinate), [x0, y0, z0] is the coordinate of the target in the inertial coordinate system (x0 is the horizontal coordinate, y0 is the vertical coordinate, and z0 is the vertical coordinate), and R represents the radius of the sphere formed when the AUV forms a spherical capture of the target.

[0069] Step 2: Considering the situation where some AUVs are unable to obtain target information during the actual movement of the multi-AUV system, this situation may occur due to: limited sensor sensitivity and detection range; some AUVs are equipped with advanced sensors; and information measurement loss caused by obstacles. A projection mapping method based on neighbor position information is proposed to achieve target capture control of the multi-AUV system when some AUVs lack target information.

[0070] 2.1 Define the neighbor AUVn of the i-th AUV as the i+1-th AUV, where the neighbor AUVn of the N-th AUV is the 1st AUV. The neighbor relationship graph of the entire multi-AUV system forms a one-way cycle;

[0071] 2.2 If the i-th AUV cannot detect the target, the 3D coordinates [x n ,y n ,z n ](x n is the horizontal axis, y n is the vertical coordinate, z n is the vertical coordinate) is mapped to the orbit where the i-th AUV is located to form the virtual target point coordinate [x' n ,y' n ,z' n ].

[0072] Specifically, for the vertical coordinate of the neighbor AUV, if it is the Nth AUV, then its neighbor n is the 1st AUV. If the i-th AUV is not the Nth AUV, then its neighbor n is the i+1th AUV. The vertical coordinate z' of the virtual coordinate point n The calculation formula is as follows:

[0073]

[0074] where z' n is the vertical coordinate of the virtual target point, z n is the vertical coordinate of the nth AUV. Polar angle

[0075] For the horizontal coordinate x' of the virtual target point n and the vertical coordinate y' n , the horizontal coordinate x of the neighbor AUVn can be n and the vertical coordinate y n Perform polar coordinate transformation to obtain the radius coordinate r n With angular coordinate θ n

[0076]

[0077] Calculate x' through the conversion relationship n and y' n The specific formula is as follows

[0078]

[0079] where [r' n ,θ' n ] is the polar coordinate of the virtual target point (r' n is the radius coordinate, θ' n is the angular coordinate), [x N-i+1 ,y N-i+1 ] represents the rectangular coordinates (x N-i+1 is the horizontal axis, y N-i+1 is the vertical axis), which means that when When , the circling radius of the i-th AUV relative to the target [x0, y0] is the same as the circling radius of the N-i+1-th AUV. When N is an odd number and When the i-th AUV is surrounded by a sphere, the radius R of the sphere formed by the AUV is the radius R of the sphere formed when the AUV forms a spherical capture of the target. In addition, r' n You can also use r' n =Rsinφ i Directly derived.

[0080] The polar coordinates of the virtual target point [r' n ,θ' n ] is converted to rectangular coordinates [x' n ,y' n ]

[0081]

[0082] Combining formulas (7) and (12), we can get the virtual coordinate point [x' n ,y' n ,z' n ].

[0083] Step 3: To address the asymmetric disturbance problem caused by time-varying ocean currents in a three-dimensional ocean environment on the coordinated capture of multiple AUVs, an adaptive dynamic compensation strategy based on the extended state observer (ESO) is proposed. The ocean current disturbance is coupled to the x, y, and z direction velocity components of the AUVs through the kinematic equations, resulting in formation instability and target tracking deviation. To this end, the ESO introduces a dynamic compensation strategy for each AUV in the x, y, and z directions. Used to estimate the position of the i-th AUV in the x, y, and z directions. This approach estimates the impact of ocean current disturbances by transforming the disturbed dynamic system into an extended state model. It estimates the x, y, and z components of the ocean current velocity in real time and incorporates them as feedforward terms into the backstepping control law design. This approach combines adaptive gain adjustment to achieve ocean current disturbance suppression. This solution relies solely on observations of the AUV's own motion state, eliminating the need for precise preset ocean current model parameters. It dynamically offsets unsteady flow field disturbances through online adjustment of compensation gains.

[0084] 3.1 For each AUV’s motion in three-dimensional space affected by ocean currents, the extended state observer (ESO) is defined as follows:

[0085]

[0086] in In ESO, it represents the rate of change of position estimate, which is calculated through kinematic model, disturbance compensation and observation error correction. It represents the rate of change of the ocean current disturbance estimate, which is driven by the observation error and adjusts the convergence speed of the disturbance estimate through the gain β2. are the estimated positions of the current i-th AUV in the x, y, and z directions in the inertial coordinate system, are the estimated velocities of the ocean current experienced by the i-th AUV in the x, y, and z directions in the inertial coordinate system, respectively. λ1 and λ2 are the observation gains of the ESO, respectively. Usually, γ2>>λ1 is satisfied to improve the accurate estimation of the disturbance.

[0087] 3.2 Adjusting the control gain k through adaptive law p , so that the kinematic controller can automatically adapt to the intensity and direction disturbance of the ocean current, and adopts an error-based adaptive law to update the gain. The goal is to make the current position of the AUV close to the virtual target point position [x t ,y t ,z t ], and the position of the target point is maintained at a spherical radius R.

[0088] Define the deviation e between the current distance from the AUV to the target point and the expected capture radius r for

[0089] e r =||[x0-x i ;y0-y i ;z0-z i ]||-R (11)

[0090] Here, ||·|| represents the Euclidean distance, which is the distance between the AUV and the target point in three-dimensional space.

[0091] Next, the gain is dynamically adjusted based on the error. The rate of change of the adaptive gain is Given by the following formula

[0092]

[0093] Where η is the learning rate, which controls the rate at which the gain changes. When the error is large, the gain changes more rapidly, making the control system more responsive. When the error decreases, the gain adjustment is gradually reduced to avoid over-adjustment.

[0094] Based on the rate of change Adaptive gain k p The update formula can be expressed as

[0095]

[0096] in is the adaptive gain k obtained at time t p , To calculate the adaptive gain k at time t+1 p .

[0097] The velocity estimation of ocean currents and the adaptive gain k are achieved by using the extended state observer (ESO). p The setting can make the system automatically adjust the control input according to the current environmental state as the error between the AUV and the target changes, thereby improving the robustness of the system.

[0098] Step 4: Considering the inaccurate underwater GPS positioning and the limited detection range during motion, a multi-AUV kinematic controller based on local information is proposed. The controller is designed by utilizing the relative position information between neighboring AUVs and the relative position information between the AUV that can detect the target and the target, making it more suitable for underwater working environments.

[0099] 4.1 Define the relative position of the virtual coordinate points calculated in step 2 between the i-th AUV and its neighbor n-th AUV in the local coordinate system and the relative position between the i-th AUV and the target in the local coordinate system They are

[0100]

[0101] in is the rotation matrix, and the separation angle β of two adjacent AUVs relative to the target on the XY plane is defined as arctan2(y i+1 -y0,x i+1 -x0)-arctan2(y i -y0,x i -x0), where arctan2 is the inverse tangent function;

[0102] 4.2 Define the requirements that the target capture mission needs to meet:

[0103]

[0104] in, is a constant, R is the distance to the target in the i-th AUV target capture mission, and is also the radius of the sphere formed by the AUV around the target;

[0105] 4.3 Design the state of whether the i-th AUV can observe the target as f i , when f i = 0, it means that the i-th AUV cannot observe the target. When f i = 1, it means that the i-th AUV can observe the target, and the determinant Flag is set to indicate whether all AUVs can observe the target.

[0106] Flag=[f1,f2,f3…f N ] (17)

[0107] Where N is the total number of AUVs participating in the target capture mission, f1, f2, and f3 are the states of whether the first, second, and third AUVs can observe the target, respectively. In the application, at least one AUV can observe the target, that is, the elements in Flag are not all 0.

[0108] 4.4 Design the kinematic controller of the multi-AUV system, which is expressed as

[0109]

[0110] where k v >0,k ω >0,k μ >0 is the controller parameter, a i Indicates relative position and The previous weight, 0 i <1,k p Adaptive gain for the extended state observer (ESO) compensation control part.

[0111] Step 5: To simulate the effect of ocean currents on autonomous underwater vehicles (AUVs) in real ocean environments, a spatially distributed ocean current disturbance model is established. This model assumes that the velocity field of the ocean current is non-uniform in three-dimensional space and changes with position. Since the AUV has a short time to capture the target, the ocean current does not change significantly over time, so the ocean current is set to remain constant over time. [C x ,C y ,C​z ] T It represents the velocity of the ocean current in the x, y, and z directions, and its expression is as follows

[0112]

[0113] Where A represents the maximum velocity amplitude of the current, keeping the velocity range between [-A, A]. α, β, and γ are the spatially varying wave numbers used to control the spatial distribution characteristics of the current in different directions. x, y, and z are the positions of the AUV in the inertial coordinate system. Phase offsets π / 3 and π / 4 simulate the asymmetry of the current, resulting in different distribution patterns in different regions. This current field modeling approach can be used to test the adaptability of AUVs in complex water environments and provide a foundation for subsequent control algorithm design.

[0114] In step 6, the kinematic controller designed in step 4 is used to act on the AUVs to perform three-dimensional collaborative capture control of the target (taking 5 AUVs as an example), with the purpose of performing a spherical capture of the target to meet the requirements of the capture mission, in order to verify the effectiveness of the present invention.

[0115] In some embodiments, the dynamic orbit radius cyclic iteration method designed in step 2 is aimed at the dynamic changes of the detection target information. Once the target detection information changes, steps 2.1 and 2.2 are used to perform cyclic iterations to re-determine the orbit radius of each AUV.

[0116] In order to more effectively illustrate the effectiveness of the method of the present invention, all parameter settings are consistent. The system parameters and controller parameters are initialized as shown in Table 1. In addition, the initial positions of the N AUVs performing the roundup mission are set to random positions.

[0117] Table 1 Parameter initialization

[0118]

[0119] Implementation method 1: Three-dimensional collaborative capture control of multiple AUVs without current disturbance and with all AUVs able to detect the target.

[0120] In this example, the ocean current speed is set to 0, that is, the AUV is not affected by the ocean current, and all AUVs can detect the target. The determinant Flag is set to [1,1,1,1,1]. Figure 1 The figure shows the three-dimensional collaborative capture process of multiple AUVs on a target in three-dimensional space. Different line types are used to distinguish the orbital trajectories of each AUV. The solid circle represents the initial position of the AUV, the * represents the final position of the AUV at t = 200s, that is, the end of the simulation time, and the triangle represents the target position [x0, y0, z0]. Figure 1It can be seen intuitively that multiple AUVs can complete the spherical capture task of the target from any initial position. Figure 2 and Figure 3 The following are the capture process diagrams of multiple AUVs in the XY plane and XZ plane perspectives, respectively. Figure 2 Each AUV in the XY plane takes the target as the center of the circle, Rsinφ i N concentric circles are formed with radius, Figure 3 This indicates that the distances between the orbits of each AUV are relatively uniform, and the x-coordinate of the midpoint of the line segment formed by the trajectory in the XZ plane is the same as the horizontal coordinate x0 of the target. Figure 4 The error value change diagram of the distance between AUV and target and the capture radius R is shown in the figure. Figure 5 The figure shows the change of the separation angle β between two adjacent AUVs relative to the target on the XY plane. Figure 4 It can be seen from the figure that the error between the distance between each AUV and the target and the capture radius R basically reaches stability at t=45s, and the stable value is 0, which is consistent with The capture target requirements; from Figure 5 It can be seen that the separation angle β reaches a stable value of 72° at t = 25s, which is consistent with roundup requirements. Figure 6 Represents the estimated speed of the ocean current in the ESO estimator From the graph of the change in , we can see that the ESO estimator accurately estimates the velocity of the ocean current. In summary, the present invention provides a three-dimensional collaborative capture control method for multiple AUVs in the absence of ocean current disturbances and in which all AUVs can detect the target.

[0121] Implementation 2: Adding ocean current disturbances and enabling all AUVs to detect targets in three-dimensional collaborative capture control of multiple AUVs.

[0122] In order to verify the effectiveness of the present invention, without changing the control parameters, the influence of the current disturbance is added, that is, the current that varies with the position set in step 5. The results are as follows: Figures 7 to 14 As shown, Figure 7 It represents the distribution of ocean currents in three-dimensional space, where the direction of the arrow indicates the direction of the ocean current, and the length of the arrow indicates the size of the ocean current. The longer the arrow, the faster the ocean current. Figure 8 、 Figure 9 、 Figure 10 The three-dimensional collaborative capture process diagram of multiple AUVs on the target in three-dimensional space under the influence of ocean current disturbance, the capture process diagram of multiple AUVs in the XY plane and the XZ plane respectively show the process. It can be seen that although there is the influence of ocean current, the trajectory of AUV is still basically the same as the trajectory diagram of AUV in Example 1, indicating that the ESO state observer’s estimation and compensation of ocean current are accurate and timely. Figure 11It can be seen that when t = 20s, the error between the distance between each AUV and the target and the capture radius R is stable at around 0, but there are still fluctuations after stabilization, with the maximum offset being 0.2m. Figure 12 It can be seen that the separation angle β reaches a stable value of 72° at t = 25s, which is consistent with roundup requirements. Figure 13 Represents the estimated speed of the ocean current in the ESO estimator The change diagram shows that the estimated speed of the ocean current obtained by each AUV is different due to the different orbits. Not the same, Figure 14 The estimated speed of the ocean current for the first and fifth AUVs The change diagram, combined with the calculation of formula (19) in step 5, can find the estimated ocean current speed The same as the set ocean current, it is proved that the ESO state observer estimates the ocean current accurately.

[0123] Implementation 3: Three-dimensional collaborative capture control of multiple AUVs with current disturbance added and only the first AUV able to detect the target.

[0124] In this example, the ocean current parameters are the same as those in Example 2. The determinant Flag is modified to [1, 1, 1, 1, 1], which means that only the first AUV can detect the target. Figure 15-17 The three-dimensional collaborative capture process diagram of multiple AUVs on the target, the capture process diagram of multiple AUVs in the XY plane, and the XZ plane respectively show the capture process of multiple AUVs. It can be found that compared with Example 2, the motion trajectory of the AUV is more scattered, that is, the AUV takes longer to complete the spherical capture of the target, and the trajectory of the AUV in the XY plane is not a regular circle, but is still a concentric circle with the target coordinates as the center. The x coordinate of the midpoint of the line segment formed by the trajectory in the XY plane is basically the same as the horizontal coordinate x0 of the target, indicating that the capture control is still effective. Figure 18 The error value changes between the distance between each AUV and the target and the capture radius R. It can be seen that the error value is basically stable at t = 50s, but the stable value of each AUV is not 0, but close to 0. The fluctuation after stabilization is more obvious, and the maximum offset is 0.6m. Figure 19 Indicates the change of separation angle between adjacent AUVs. At t=80s, the separation angle β basically reaches a stable value. However, the separation angles calculated for the first and second AUVs deviate greatly from those of other adjacent AUVs. The reason may be that the average value of all separation angles is set. The calculation results in . Figure 20 and Figure 21 Estimated speed of the mid-ocean current It is still the same as in Example 2, which shows that the ESO state observer still accurately estimates the ocean current. Only the first AUV can detect the target. The multi-AUV three-dimensional collaborative capture basically meets the control requirements.

[0125] The various embodiments and simulation results described above fully verify that the multi-AUV three-dimensional collaborative capture control method proposed in the present invention can still show good capture performance under complex ocean current disturbance conditions and in environments where some AUVs cannot obtain target information. However, it should be pointed out that in embodiment 3, when only one AUV can directly observe the target, although the capture task is finally achieved, the capture trajectory has certain irregularities and stability errors compared to when all AUVs can observe the target. This phenomenon is mainly due to the fact that insufficient information leads to a decrease in the accuracy of virtual target point mapping, thereby affecting the overall capture efficiency and accuracy. Therefore, in practical applications, the method can be further improved by increasing information interaction between AUVs, optimizing the neighbor information mapping algorithm, or improving sensor performance. Obviously, the present invention is not limited to the specific details of the above embodiments. Without departing from the basic spirit and protection scope of the present invention, those skilled in the art can make further improvements and adjustments to the present invention according to actual conditions, and these adjustments and improvements should also be considered to fall within the protection scope of the present invention.

[0126] Example 2:

[0127] An embodiment of the present application provides a control device for an underwater autonomous vehicle, which may include the following modules:

[0128] Building module for constructing AUV kinematic model;

[0129] An allocation module is used to allocate a virtual target point to each AUV. The virtual target point is the center of the tangent circle formed by the AUV's track. The AUV forms a surrounding capture posture with the virtual target point as the center and the distance from the virtual target point as the radius of the tangent circle where the AUV is located;

[0130] A generation module is used to generate a virtual target point based on the projection mapping of the neighboring AUV position information when the AUV loses the target information;

[0131] The driving module is used to drive the coordinated movement of multiple AUVs based on the AUV kinematic model and the virtual target point based on a kinematic controller.

[0132] Example 3:

[0133] An embodiment of the present application further provides an electronic device, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods of various embodiments of the present invention when running.

[0134] The above-mentioned memory may refer to a device inside a computer for storing data and programs, and may include memory, hard disk, etc., wherein the memory may be used to temporarily store running programs and data, the hard disk may be used to store programs and data for a long time, and the memory may be used to enable the computer to read and write data, as well as execute programs; the above-mentioned processor may be responsible for executing instructions in computer programs and performing data processing, and may be responsible for controlling and executing various operations, including arithmetic operations, logical operations, data transmission, etc.

[0135] Example 4:

[0136] An embodiment of the present application further provides a computer-readable storage medium, which includes a stored executable program, wherein when the executable program is running, the device where the computer-readable storage medium is located is controlled to execute the methods in various embodiments of the present invention.

[0137] The above-mentioned computer storage medium may refer to a medium in a computer memory used to store certain discontinuous physical quantities. Computer storage media mainly include semiconductors, magnetic cores, magnetic drums, magnetic tapes, laser disks, etc. The stored program included in the computer-readable storage medium may be a set of instructions that can be recognized and executed by a computer, running on an electronic computer, and serving as an information tool to meet certain needs of people.

[0138] Example 5:

[0139] An embodiment of the present application further provides a computer program product, including a computer program, which implements the methods in various embodiments of the present invention when executed by a processor.

[0140] The above-mentioned computer program product may refer to a software program that has been written, tested and released, which can be run on a computer or other device. The computer program product may include an application, an operating system, tool software, etc., which is used to implement specific functions or solve specific problems.

[0141] Example 6:

[0142] An embodiment of the present application further provides a computer program product, including a non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium is used to store a computer program, and when the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0143] The above-mentioned non-volatile computer-readable storage medium may refer to a medium for storing data. The non-volatile computer-readable storage medium can keep the data from being lost when the power is off, and can be used to store long-term data, such as operating systems, applications and user files. The non-volatile storage medium may include hard disk drives, solid-state drives, optical disks and flash memory storage devices, etc.

[0144] Example 7:

[0145] The embodiments of the present application further provide a computer program, which implements the methods in the above-mentioned embodiments of the present invention when executed by a processor.

[0146] The above-mentioned computer program may refer to a collection of instructions used to tell a computer to perform a specific task or operation. A computer program may be written by a programmer using a specific programming language and may include algorithms, data structures, logic, and control flows. Computer programs may be used for a variety of purposes, including application software, operating systems, and the like.

[0147] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0148] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0149] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0150] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0151] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, etc. Various media that can store program codes.

[0152] In summary, in order to overcome the technical difficulties of the existing multi-AUV system in inaccurate underwater positioning, limited measurement and communication distance, and insufficient target capture capability under complex conditions such as ocean current disturbances or some AUVs being unable to obtain target information, the present invention provides a three-dimensional collaborative capture control method for multiple AUVs under ocean current disturbances. This method takes into account the influence of ocean current disturbances in the AUV kinematic model, and for different situations of observable targets and unobservable targets, the information used by the controller only includes the relative position of the virtual coordinates calculated from the position information of the neighbors in the local coordinate system and the relative position with the target in the local coordinate system. This realizes the spherical capture task of multiple AUVs in three-dimensional space in the presence of ocean current disturbances, ensures the stability of the system, and provides new technical means and theoretical basis for the fields of marine environment monitoring, resource development, marine confrontation and disaster relief.

[0153] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for controlling an underwater autonomous vehicle, characterized in that: include: Construct AUV kinematic model; Assign a virtual target point to each AUV. The virtual target point is the center of the tangent circle formed by the AUV's track. The AUV forms a surrounding capture posture with the virtual target point as the center and the distance from the virtual target point as the radius of the tangent circle where the AUV is located. When the AUV loses target information, it generates a virtual target point based on the projection mapping of the neighboring AUV position information; Based on the kinematic controller, multiple AUVs are driven to move in coordination according to the AUV kinematic model and the virtual target point.

2. The underwater autonomous vehicle control method according to claim 1, characterized in that: The AUV kinematic model is constructed, including: The disturbed ocean current velocity of each axis of the inertial coordinate system is introduced into the AUV kinematic model to obtain the AUV kinematic model with ocean current disturbance.

3. The underwater autonomous vehicle control method according to claim 1, characterized in that: The method of allocating a virtual target point to each AUV includes: For each AUV, the longitude angle and polar angle are calculated using the spherical coordinate grid method and are evenly distributed on the spherical surface; A corresponding virtual target point is obtained based on the coordinates of the actual target in the inertial coordinate system and the longitude angle and polar angle.

4. The underwater autonomous vehicle control method according to claim 1, characterized in that: The projecting mapping based on the neighbor AUV position information to generate a virtual target point includes: Construct a neighbor relationship graph for the multi-AUV system, where the neighbor AUV of the i-th AUV is the i+1-th AUV, where i does not include N; the neighbor AUV of the N-th AUV is the 1st AUV; i represents the i-th AUV, i=1,2,…,N, where N is the total number of AUVs participating in the collaborative capture; If the i-th AUV cannot detect the target, the three-dimensional coordinates of the neighbor AUV are mapped to the orbit where the i-th AUV is located to form the virtual target point coordinates.

5. The underwater autonomous vehicle control method according to claim 1, characterized in that: The method further comprises: Define the extended state observer as follows: in, represents the rate of change of the position estimate, represents the rate of change of the ocean current disturbance estimate, are the estimated positions of the current i-th AUV in the x, y, and z directions in the inertial coordinate system, are the estimated ocean current velocities of the current i-th AUV in the x, y, and z directions in the inertial coordinate system, λ1 and λ2 are the observation gains, and λ2>λ1 is satisfied. [x i ,y i ,z i ] is the coordinate of the i-th AUV in the inertial coordinate system; θ i is the heading angle of the i-th AUV in the inertial coordinate system; ψ i is the pitch angle of the i-th AUV in the inertial coordinate system; v i The designed forward speed for the i-th AUV; Adjusting the control gain k based on the adaptive law p The current position of the AUV is made to approach the virtual target point, and the distance to the target point is ensured to be the spherical radius.

6. The underwater autonomous vehicle control method according to claim 5, characterized in that: The kinematic controller is as follows: Among them, k v >0,k ω >0,k μ >0 is the controller parameter, a i Indicates relative position and The previous weight, 0 i <1; [v i ,ω i ,μ i ] T is the kinematic controller input, v i ,ω i ,μ i represent the forward speed, yaw rate, and pitch rate of the i-th AUV design respectively;​ in, is the rotation matrix, [x0, y0, z0] is the coordinate of the target in the inertial coordinate system, [x' n ,y' n ,z' n ] is to use the three-dimensional coordinates of the neighbor AUV to map to the orbit where the i-th AUV is located to form the virtual target point coordinates; Flag=[f1,f2,f3…f N ] Among them, f N The state of whether the Nth AUV can observe the target. The elements in Flag are not all 0.

7. The underwater autonomous vehicle control method according to claim 6, characterized in that: Gain k p As follows: Where η is the learning rate; er=||[x0-x i (y0-y i ;z0-z i ]||-R Here, ||·|| represents the Euclidean distance, and R represents the radius of the sphere.

8. An underwater autonomous vehicle control device, characterized in that: include: Building module for constructing AUV kinematic model; An allocation module is used to allocate a virtual target point to each AUV. The virtual target point is the center of the tangent circle formed by the AUV's track. The AUV forms a surrounding capture posture with the virtual target point as the center and the distance from the virtual target point as the radius of the tangent circle where the AUV is located; A generation module is used to generate a virtual target point based on the projection mapping of the neighboring AUV position information when the AUV loses the target information; The driving module is used to drive the coordinated movement of multiple AUVs based on the AUV kinematic model and the virtual target point based on a kinematic controller.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the method for controlling an underwater autonomous vehicle according to any one of claims 1 to 7 is executed in a processor of a device where the program is controlled.

10. An electronic device, characterized in that: include: one or more processors; a storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors execute the underwater autonomous vehicle control method according to any one of claims 1 to 7.

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