A uuv packet cluster coordination control method considering double-layer dynamic intermittent communication

Abstract

The application provides a UUV grouping cluster coordination control method considering double-layer dynamic intermittent communication, position attitude information and speed information of each UUV are collected; each sub-platoon of the UUV cluster structure adopts a navigation-following type, desired trajectory information is transmitted to each sub-platoon leader UUV, each sub-platoon leader sends state information to its follower, a dynamic interactive position communication topology and a speed communication topology in a normal communication time period are established; a system state error equation is established; data calculation and compensation are carried out on sea current disturbance, system stability is analyzed through construction of a Lyapunov function; state information of each sub-platoon follower UUV is calculated by using a platoon tracking controller, received state information of each UUV is input into a control algorithm, thrust of each degree of freedom of the UUV is calculated, and is distributed to each execution mechanism of the UUV. The application can effectively realize UUV grouping cluster coordination control considering double-layer dynamic intermittent communication, and grouping tracks a plurality of preset maneuvering paths.

Description

TECHNICAL FIELD

[0001] The application relates to a kind of underwater unmanned vehicle grouping formation coordination control method considering double-layer dynamic intermittent communication, and is a kind of grouping cluster coordination control method suitable for multiple underwater unmanned vehicles in the process of ocean surveying under the condition of intermittent underwater acoustic communication, belongs to underwater unmanned vehicle cluster coordination control technical field. BACKGROUND

[0002] As a kind of small volume, low cost, controllable flexibility, endurance, large range of deep sea mobile carrier, UUV (underwater unmanned vehicle) becomes one of the important tools for exploring and developing the ocean, and is widely used in ocean resource exploration, deep sea target autonomous reconnaissance and rescue, etc. With the increasing diversification of the tasks undertaken by UUV, single UUV often has low information acquisition rate and small effective task range in the process of executing large-area surveying tasks. The grouping cluster mobility of multiple UUVs is an important technical prerequisite for realizing large-area surveying tasks. The multi-UUV formation system uses modern communication network technology and integrated navigation technology to enable communication between individuals, and then uses a mobile controller to realize the set maneuvering task. The signals emitted by the sonar will be intermittently interrupted in the complex marine environment, so it is necessary to ensure that multiple UUVs can still stably maintain the grouping formation survey formation and complete the maneuvering task under the condition of intermittent communication.

[0003] For the UUV cluster coordination control method, many formation control methods do not consider the intermittent communication condition. For example, Zou Boyu in the article "UUV Formation Adaptive Cooperative Tracking Control Research" (published in 2021, Digital Ocean and Underwater Attack and Defense, Issue 6) proposes a method for solving the cooperative formation problem of multiple UUVs based on the leader-follower under normal continuous communication through the sliding mode method. Yang Fang in the article "UUV Formation Obstacle Avoidance Research Based on Fuzzy Control" (published in 2022, Ship Science and Technology, Issue 7) proposes a UUV formation obstacle avoidance control method based on fuzzy control for communication delay. However, in actual marine maneuvering operations, due to communication bandwidth, communication cost and technical limitations, the communication between adjacent UUVs often exists in the form of intermittent communication. SUMMARY

[0004] The purpose of the present application is to provide a multi-UUV cluster coordination control method that can still stably maintain the grouping formation survey formation and complete the maneuvering task under the condition of double-layer dynamic intermittent underwater acoustic communication.

[0005] The purpose of the present application is achieved as follows:

[0006] Step 1: Use the precise feedback linearization method to establish the kinematics and dynamics equations of UUV and equivalently convert them into a second-order integral model under sea current disturbance;

[0007] Step 2: Collect the position information and speed information of each UUV through the navigation equipment and sensors such as speedometer and gyroscope carried by the UUV;

[0008] Step 3: Each sub-platoon of the UUV cluster structure adopts the leader-following type, transmits the expected trajectory information to each sub-platoon leader UUV, and each sub-platoon leader sends state information to its followers, judges the normal communication period and the communication interruption period according to the motion state, and establishes a dynamic interactive position communication topology and a speed communication topology in the normal communication period respectively;

[0009] Step 4: Design a grouping platoon tracking controller considering double-layer dynamic intermittent communication, and establish a system state error equation;

[0010] Step 5: Data calculation and compensation are performed on the sea current disturbance, and system stability analysis is performed through the construction of Lyapunov function;

[0011] Step 6: The state information of each sub-platoon follower UUV is calculated by using the controller designed in step 4, and intermittent transmission of information is performed to the designated members in the platoon according to the double-layer dynamic interactive communication topology in step 3;

[0012] Step 7: The state information of each UUV received in step 6 is input into the control algorithm in step 4, the thrust of each degree of freedom of the UUV is calculated, and is distributed to each actuator of the UUV;

[0013] Step 8: Under the double-layer dynamic intermittent communication mode, after a short time of state adjustment, the motion state of each sub-platoon follower UUV converges to the state of its leader, that is, the multi-UUV formation is kept and the path of each sub-platoon leader is tracked, and the task is completed.

[0014] The application also includes the following structural features:

[0015] 1. The second-order integral model of step one is:

[0016]

[0017] Wherein, η = [x, y, z, θ, ψ] T Indicates the position and attitude vector of the UUV in the inertial coordinate system, v = [u, v, ω, q, r] T Indicates the velocity and angular velocity vector of the UUV in the body coordinate system, J(η) is the coordinate system rotation matrix of the body coordinate system converted to the inertial coordinate system, Is the control input, M is the inertia matrix, τ ω Indicates the ocean environmental disturbance force caused by wind, wave and flow in the body coordinate system, is the velocity vector after the differential homeomorphism coordinate transformation, is the control input under the differential homeomorphism coordinate transformation.

[0018] 2. The expected path of the leader of the two sub-platoons set in step 3 is respectively:

[0019]

[0020] And the position and velocity topology is established:

[0021] 3. The group formation tracking controller considering intermittent communication in step 4 is:

[0022]

[0023] Wherein, i∈E, k∈F, E={1, 2, …N} represents the follower UUV set, F={N+1, N+2, …, M} represents the leader UUV set, Respectively, the position vector and the velocity vector after the differential homeomorphism coordinate transformation of the i-th follower UUV, is the preset distance between each vehicle, K1, K2∈R 5×5 is the feedback control gain matrix to be designed, any follower UUV can only follow one leader UUV, [lT, lT+δ) is the normal communication time period, [lT+δ, (l+1)T) is the communication interruption time;

[0024] The system state error equation is established as:

[0025]

[0026] Wherein, B2=[I5 05], is the external ocean environment disturbance function.

[0027] Compared with the prior art, the beneficial effects of the present application are: the method can effectively solve the group formation control problem of UUV under the double-layer dynamic intermittent communication mode. It can ensure that the trajectories of each UUV in the group converge to the expected trajectory of the leader of each sub-platoon under the conditions of dynamic interactive communication and external ocean current disturbance, and realize the formation keeping of multiple UUVs. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a UUV group formation coordination control flow diagram;

[0029] Figure 2 is a UUV group formation communication relationship diagram;

[0030] Figure 3is a position and velocity network communication topology diagram;

[0031] Figure 4 is a Markov state diagram for a two-layer handoff topology;

[0032] Figure 5 is an eastward position convergence diagram for a UUV group swarm;

[0033] Figure 6 is a northward position convergence diagram for a UUV group swarm;

[0034] Figure 7 is a depth position convergence diagram for a UUV group swarm;

[0035] Figure 8 is a pitch angle convergence diagram for a UUV group swarm;

[0036] Figure 9 is a heading angle convergence diagram for a UUV group swarm;

[0037] Figure 10 is a surge velocity convergence diagram for a UUV group swarm;

[0038] Figure 11 is a sway velocity convergence diagram for a UUV group swarm;

[0039] Figure 12 is a heave velocity convergence diagram for a UUV group swarm;

[0040] Figure 13 is a pitch angle velocity convergence diagram for a UUV group swarm;

[0041] Figure 14 is a heading angle velocity convergence diagram for a UUV group swarm;

[0042] Figure 15 is a three-dimensional trajectory diagram for a UUV group swarm;

[0043] Figure 16 is a formation diagram for a UUV group swarm. DETAILED DESCRIPTION

[0044] The application will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0045] The application provides a UUV grouping cluster coordination control method under a double-layer dynamic intermittent communication condition, and a communication system is a key for whether an aircraft can form an expected formation of a group. The application implements multi-path communication, and adopts a position and speed state double-layer dynamic intermittent communication transmission mode to simulate a communication problem caused by a limited underwater transmission data rate and action distance. State information is randomly transmitted between each sub-formation member in the UUV cluster in a dynamic communication topology graph form, and a joint topology structure of each layer information channel ensures that all members of the whole formation can receive information of a motion state, so that stable grouping formation control is realized.

[0046] Figure 1 is a UUV grouping cluster coordination control flow diagram under a double-layer dynamic intermittent communication condition, Figure 2 is a UUV grouping cluster communication relationship diagram, and the application provides a UUV grouping cluster coordination control method under a double-layer dynamic intermittent communication condition. The method comprises the following steps.

[0047] Step 1, a precise feedback linearization method is used to establish UUV kinematics and dynamics equations and equivalently convert into a second-order integral model under sea current disturbance:

[0048]

[0049] wherein η = [x, y, z, θ, ψ] T represents a UUV position and attitude vector in an inertial coordinate system, v = [u, v, ω, q, r] T represents a UUV speed and angular velocity vector in a body coordinate system, J(η) is a coordinate system rotation matrix of the body coordinate system converted to the inertial coordinate system, is a control input, M is an inertia matrix, τ ω represents a sea environment disturbance force caused by wind, wave and flow in the body coordinate system, represents a velocity vector after a differential homeomorphism coordinate transformation, is a control input after the differential homeomorphism coordinate transformation.

[0050] Step 2, position and attitude information η i = [x i ,y i ,z i ,θ i ,ψ i ] T and speed information v i = [u i ,v i ,ω i ,q i ,r i ] of each UUV are collected by a navigator and a gyroscope and other navigation equipment and sensors carried by the UUV.T ;

[0051] Step 3, the expected path of the leader of the two sub-platoon is set as:

[0052]

[0053] And the position and velocity topology is established: Take n = 3, as shown in Figure 3 .

[0054] Step 4, design a group formation tracking controller considering intermittent communication:

[0055]

[0056] Where, i ∈ E, k ∈ F, E = {1, 2, … N} represents the follower UUV set, F = {N + 1, N + 2, …, M} represents the leader UUV set, respectively represent the position vector and the velocity vector after the differential homeomorphism coordinate transformation of the i-th follower UUV, is the preset distance between each vehicle, K1, K2 ∈ R 5×5 is the feedback control gain matrix to be designed, any follower UUV can only follow one leader UUV, [lT, lT+δ) is the normal communication time period, [lT+δ, (l+1)T) is the communication interruption time.

[0057] Establish the system state error equation:

[0058]

[0059] Where, B2 = [I5 05], is the external ocean environment disturbance function.

[0060] Step 5, data extrapolation and compensation for ocean current disturbance, set the ocean current disturbance function Through the construction of Lyapunov function System stability analysis is carried out;

[0061] Step 6, use the controller designed in step 4 to calculate the state information of each follower UUV in the sub-platoon And according to the double-layer dynamic interactive communication topology in step 3, the information is intermittently transmitted to the designated members in the platoon;

[0062] Step 7, input the received state information of each UUV in step 6 into the control algorithm in step 4, calculate the thrust of each degree of freedom of UUV, and distribute it to each actuator of UUV.

[0063] Step 8, under the double-layer dynamic intermittent communication mode, the effectiveness of the application is proved by simulation test. In three-dimensional space, the initial positions of each member UUV in the formation are randomly distributed. The initial values of the pitch angle and the heading angle are set in the interval [-0.4, 0.4] and [0, 2π] respectively, and the expected trajectory of the two leaders in step 3 is used as the initial trajectory of the follower UUVs:

[0064]

[0065] The test simulation is carried out.

[0066] Considering that the communication mode is periodic random intermittent communication, in every 10s time period, the communication duration is 8s, and the communication interruption duration is 2s. In the normal communication time period, the switching communication topology includes two independent Markov random communication topology structures of position and speed state, and each topology structure includes three communication topologies, respectively and As shown in Figure 3 , the Markov state is as shown in Figure 4 , the preset distance vector between the vehicles is taken as

[0067] The sea current disturbance functions of UUV1 and UUV2 are respectively: and The sea current disturbance of other UUVs in the system is zero, and the position and speed control gain matrices are respectively:

[0068]

[0069] The simulation results are as follows:

[0070] Based on the above simulation condition setting, the simulation test results are as shown in Figures 5 to 16 , and the simulation diagram Figures 5 to 14 illustrates that under the influence of the double-layer dynamic intermittent communication proposed in the application, the follower UUV1, 2 and 3 can track the position and speed state of the leader L1 and asymptotically converge to the expected path of the leader L1, and the follower UUV4, 5 and 6 can track the position and speed state of the leader L2 and asymptotically converge to the expected path of the leader L2. And Figures 5 to 14 the curve oscillation in the convergence process is large, and the reasons include the high frequency of motion state information change caused by the communication topology switching process, the external nonlinear disturbance of the ocean environment, and the influence of intermittent communication interruption. Figure 15 The simulation results in Figure 16The simulation result shows that the follower UUVs in the same sub-platoon can form a stable triangular platoon.

[0071] In conclusion, the application discloses a UUV grouping cluster coordination control method under a double-layer dynamic intermittent communication condition, utilizes an accurate feedback linearization method to establish UUV kinematics and dynamics equations and equivalently converts into a second-order integral model under sea current disturbance; position attitude information and speed information of each UUV are collected through navigation equipment and sensors such as a speedometer and a gyroscope carried by the UUV; each sub-platoon of the UUV cluster structure adopts a leader-follower type, transmits expected trajectory information to each sub-platoon leader UUV, each sub-platoon leader sends state information to its follower, judges normal communication time periods and communication interruption time periods according to the motion state, respectively establishes dynamic interactive position communication topology and speed communication topology in the normal communication time periods; a grouping platoon tracking controller considering intermittent communication is designed, a system state error equation is established; data calculation and compensation of the sea current disturbance are carried out, system stability analysis is carried out through construction of a Lyapunov function; state information of each sub-platoon follower UUV is calculated through the platoon tracking controller, intermittent information transmission to designated members in the platoon is carried out according to the double-layer dynamic interactive communication topology; received state information of each UUV is input into a control algorithm, thrusts of each degree of freedom of the UUV are calculated, and the thrusts are distributed to each actuator of the UUV. Under the double-layer dynamic intermittent communication mode, after a short time of state adjustment, the motion state of each sub-platoon follower UUV converges to the state of its leader, that is, multi-UUV formation keeping and tracking of each sub-platoon leader path are realized. The application can effectively realize UUV grouping cluster coordination control considering double-layer dynamic intermittent communication, and the grouping tracks a plurality of preset maneuvering paths.

Claims

1. A UUV packet swarm coordinated control method considering double-layer dynamic intermittent communication, characterized in that, The steps are as follows: Step 1: Establish the UUV kinematics and dynamics equations using the exact feedback linearization method and equivalently transform them into a second-order integral model under ocean current disturbance; Step 2: Collect the pose information and velocity information of each UUV through the navigation equipment and sensors such as speedometers and gyroscopes carried by the UUV; Step 3: The sub-formations of the UUV cluster structure use the leader-follower type, transmit the desired trajectory information to the leader UUV of each sub-formation, and the leader UUV sends state information to its followers, judges the normal communication period and communication interruption period according to the motion state, and establishes dynamic interactive position communication topology and velocity communication topology in the normal communication period respectively; Step 4: Design a grouping formation tracking controller considering double-layer dynamic intermittent communication, and establish the system state error equation; where i∈E, k∈F, E = {1, 2, …N} represents the follower UUV set, F = {N+1, N+2, …, M} represents the leader UUV set, respectively represent the position vector and the velocity vector after the differential homeomorphism coordinate transformation of the i-th follower UUV, is the preset distance between each vehicle, K1, K2∈R 5×5 is the feedback control gain matrix to be designed, any follower UUV can only follow one leader UUV, [lT, lT+δ) is the normal communication time period, [lT+δ, (l+1)T) is the communication interruption time. The system state error equation is established as: wherein B2 = [I5 05], is an external marine environment disturbance function; Step 5: Data calculation and compensation of ocean current disturbance, system stability analysis by constructing Lyapunov function; Step 6: Calculate the state information of each sub-formation follower UUV using the controller designed in step 4, and transmit the information intermittently to the designated members in the formation according to the double-layer dynamic interactive communication topology in step 3; Step 7: Input the received state information of each UUV in step 6 into the control algorithm in step 4, calculate the thrust of each degree of freedom of the UUV, and distribute it to each actuator of the UUV; Step 8: Under the double-layer dynamic intermittent communication mode, after a short time of state adjustment, the motion state of each sub-formation follower UUV converges to that of its leader, i.e. the multi-UUV formation keeps and tracks the path of each sub-formation leader, and the task is completed.

2. The UUV packet swarm coordinated control method considering double-layer dynamic intermittent communication according to claim 1, characterized in that: The second-order integral model of step one is: where η = [x, y, z, θ, ψ] T denotes the UUV position and attitude vector in the inertial frame, v = [u, v, ω, q, r] T denotes the UUV velocity and angular velocity vector in the body frame, J(η) is the coordinate frame rotation matrix from the body frame to the inertial frame, is the control input, M is the inertia matrix, τ ω denotes the ocean environmental disturbance forces induced by wind, wave and current in the body frame, denotes the velocity vector after the diffeomorphism coordinate transformation, is the control input after the diffeomorphism coordinate transformation.

3. The UUV packet swarm coordinated control method considering double-layer dynamic intermittent communication according to claim 1, characterized in that: The desired paths of the leaders of the two sub-formations in step 3 are respectively: and a position and velocity topological map is established:

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