CN110940985B

CN110940985B - Multi-UUV tracking and trapping system and method

Info

Publication number: CN110940985B
Application number: CN201911284544.4A
Authority: CN
Inventors: 周佳加; 张强; 王莹莹; 管凤旭; 陈涛; 李本银
Original assignee: Harbin Engineering University
Current assignee: Harbin Engineering University
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2022-12-13
Anticipated expiration: 2039-12-13
Also published as: CN110940985A

Abstract

The invention discloses a multi-UUV tracking and capturing system and a capturing method, comprising four isomorphic UUV; each UUV consists of a perception module, a communication module, a behavior control module, a cooperation planning module and a coordination control module. The sensing module performs contact detection on the self state and the underwater environment; the cooperation planning module receives other UUV states and target states to plan tasks according to the communication module; and the coordination control module is used for forming a regular tetrahedron type formation behavior for accurately monitoring the behavior of the target intrusion according to the expected control input given to each UUV by the output of the cooperation planning module, and tracking and capturing the target according to a distributed consistency algorithm. The method realizes tracking and trapping of the multi-UUV target, can accurately position the tracking target, and autonomously forms an expected tracking formation according to the tracking accuracy; when underwater communication is not smooth and has delay or is lost, the multiple UUV can track and capture the target according to the received incomplete state information.

Description

Multi-UUV tracking and trapping system and method

Technical Field

The invention belongs to the field of MUUV (Multi-unmanned underwater vehicle) target tracking, and relates to a Multi-UUV tracking and enclosing system, in particular to a Multi-UUV tracking and enclosing system and an enclosing method based on a consistency algorithm.

Background

With the increasing development of oceans in the economic field and the military field, an underwater vehicle becomes a device with the highest neutral price ratio for ocean development and exploration, and is one of the key research hotspots in the fields of ocean engineering and robots. Due to the complexity of the underwater environment and tasks, a single UUV cannot meet the requirements of certain tasks, and the multi-aircraft technology is generated by the UUV, improves the working efficiency by utilizing the cooperative cooperation among the aircrafts, increases the adaptability to the underwater environment, and is more suitable for the complex tasks.

Compared with a single aircraft, the formation of the multiple aircrafts when tracking underwater targets enhances the multi-base detection capability, isomorphic transformation of the formation increases the tracking distance and the concealment of the formation, and cooperation among the multiple aircrafts enlarges the underwater monitoring range and improves the detection efficiency of the whole formation.

The distributed consistency algorithm is an important technology for formation of a plurality of UUV, particularly under the conditions of communication delay, packet loss and the like in severe water conditions, distributed consistency control mainly depends on local information, the system structure has higher flexibility, and the increase or decrease of the UUV can not have serious influence on the stability of the whole system. In the underwater enclosure process, the formation among the UUV is required to be reconstructed frequently, and the control of the UUV cannot depend on the global information completely, so that the enclosure task can be finished smoothly.

Disclosure of Invention

Aiming at the prior art, the invention aims to solve the technical problems of providing a multi-UUV tracking and capturing system and a capturing method, wherein the system and the capturing method can independently form a formation, are reliable in underwater communication, are high in target tracking precision in a concealed environment, increase the monitoring range and the flexibility of capturing a target, and can track the target when the underwater communication is not smooth.

In order to solve the problems, the multi-UUV tracking and capturing system comprises four isomorphic UUV; each UUV comprises a perception module, a communication module, a behavior control module, a cooperation planning module and a coordination control module;

the sensing module collects self-state and surrounding environment information through a sensor and performs fusion processing, wherein the fusion processing comprises DVL (dynamic video logging), inertial navigation, active sonar and passive sonar;

the communication module is responsible for information interaction between aircrafts and comprises underwater sound communication, radio communication and wireless network communication;

the cooperative planning module detects a target state through the sensing module and receives other UUV information through the communication module, and plans an expected path of the UUV, namely the optimal position in an expected tetrahedral formation;

the coordination control module gives expected control input to each UUV according to the output of the cooperation planning module;

the behavior control module controls the control output of each UUV execution unit, including the force of the propulsion system and the angle of the operation surface.

The multi-UUV tracking and enclosing system further comprises:

the passive sonar is in a normally open state in the tracking process, and is switched into the active sonar when being used for surrounding.

A capture method of the multi-UUV tracking capture system comprises the following steps:

the method comprises the following steps: the method comprises the following steps that a plurality of UUV keep navigation formation, the self state and the surrounding environment are detected, and the communication between the UUV is kept;

step two: when a UUV detects a task target, the UUV is switched into an active sonar to track the UUV and other UUV approach the UUV, and the relative distance between the UUV and the target is measured according to the following rules:

in the formula, t _i Representing the time of arrival of the sonar measurement signal at the ith UUV, | | · | | | represents the Euclidean norm, ξ _i Indicating the position, ξ, of the i-th UUV relative to the geometric center point of the formation of UUV' s ^r Representing the position of the target relative to the UUV formation geometric center point, wherein C is the underwater sound propagation speed; n is _i The representation is a noise term and is zero mean Gaussian noise with standard deviation sigma;

step three: the target is accurately positioned according to the detection information data fusion of the UUV, and the UUV starts to approach the target until an expected regular tetrahedron type tracking formation is formed, and the following planning is performed through a cooperation planning module:

||t _i -t _ij ||≤ε

above formula, t _ij ＝||t _i -t _j ||,n _ij ＝n _i -n _j Epsilon is more than or equal to 0 and is a constant value;

step four: after the MUUV tetrahedral formation is formed, the target is tracked continuously, and each UUV generates a control instruction according to a consistency formula of the coordination control module and carries out tracking control;

the length of the regular tetrahedron formation edge is expected to be alpha, i.e. the expected distance between each UUV is alpha, the expected distance between each UUV and the target is R,

only the initial UUV starts active sonar, and other UUV forms a formation according to the information measured by the initial UUV;

the four UUV power system models for executing the tracking task are as follows:

xi in the formula _i ∈R ^m Position information of the i UUV; zeta _i ∈R ^m The speed information of the ith UUV; u. of _i ∈R ^m Control input for the i UUV;

the consistency algorithm controls the following law:

where for i =1,2,3,4 and j =1,2,3,4; a is _ij Is the (i, j) th entry of the adjacency matrix at time t, when a _ij >0，a _ij When not equal to 1, the obtained adjacency matrix is a graph with weights, and represents parameters among individual aircrafts; gamma ray ₁ 、γ ₂ Is a normal number;

△ _ij is the position difference between the i UUV and the j UUV, Δ _i The position difference between the ith UUV and the tracking target is obtained; xi shape ^r For tracking position information of objects, ζ ^r To track velocity information of the target.

Step five: after the MUUV expectation tracking formation is formed, switching to a surrounding capture mode, starting to continue tracking the target and reducing the formation range, and then converting other UUV passive sonars into active sonars to finally surround the target;

step six: judging whether the trapping task is finished or not, wherein the method meets the following formula:

t _i ≤δ，i＝1,2,3,4

in the formula, delta >0 is a constant value, and the formula shows that the enclosure task is completed when the UUV formation is to enclose the tracked target to the minimum value; and if not, entering the step five.

The invention has the beneficial effects that: the invention relates to maintenance of a multi-UUV formation and tracking of an intruding target, wherein a consistency algorithm ensures the reliability of underwater communication, four-point positioning ensures the accuracy of tracking the target in a hidden environment, and isomorphic transformation of the formation increases the monitoring range and the flexibility of target capture. In the process of detecting the multi-UUV target, the detection precision of the tracking target is improved by adjusting the formation size, the underwater monitoring range is expanded, and the detection efficiency of the whole formation is improved. The design of the controller of the MUUV formation can be realized in the multi-UUV tracking and enclosing process, particularly under the condition of poor communication. The information quantity required in the target tracking and enclosing process is small, and the calculation is simple. The method realizes tracking and trapping of the multi-UUV target, can accurately position the tracking target, and autonomously forms an expected tracking formation according to the tracking accuracy; when underwater communication is not smooth and has delay or loss, the UUV can track and trap the target according to the received incomplete state information.

Drawings

FIG. 1 is a schematic diagram of a MUUV formation tracking system;

FIG. 2 illustrates MUUV and tracking target spacing;

FIG. 3 is a schematic representation of the MUUV expected fleet type;

fig. 4 is a MUUV tracking enclosure process flow diagram.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings.

With reference to fig. 1 and 2, the MUUV tracking capture system is structured as follows, and includes four isomorphic complete UUVs. Each UUV is provided with a sensing module, a communication module, a cooperation planning module, a coordination control module and a behavior control module, the sensing module of each UUV detects the state of the sensing module, the surrounding environment and the state of a tracking target, the sensing module comprises passive sonar and active sonar, the passive sonar is in a normally open state in the tracking process, the concealment in UUV tasks is kept, and when the UUV is in enclosure, the active sonar is switched to increase the detection precision of the target; the communication module is responsible for information interaction among the UUV; the cooperative planning module is used for reasonably planning a tracking task according to the MUUV formation and the target state information, detecting the target state through the sensing module, receiving other UUV information through the communication module, and planning an expected path of the UUV, namely the optimal position in the expected tetrahedral formation. The coordination control module is responsible for the formation motion control problem of the multi-aircraft system, the state information of the MUUV is controlled by combining the planning information transmitted by the communication module, the expected control input value of each UUV is obtained, the coordination control module adopts a consistency algorithm for the distributed design of the controllers of the UUV, and the control input is output to the behavior control module only under the condition of receiving part of UUV information; and the coordination control module is used for forming a regular tetrahedron type formation behavior for accurately monitoring the behavior of the target intrusion according to the expected control input given to each UUV by the output of the cooperation planning module, and tracking and capturing the target according to a distributed consistency algorithm. And adjusting the tracking formation according to the tracking precision by each edge length of the regular tetrahedron. The behavior control module mainly controls the output of the actuating mechanism, including the force of the propeller system, the angle of the control surface and the like.

In the whole process, all UUV have three kinds of behaviors, (1) target detection is carried out, and surrounding environment information is detected through passive sonar until a target is found. (2) And (4) target tracking, namely, only the initial UUV is converted into the relative coordinate of the target measured by the active sonar through other UUV and target states transmitted by the communication module. Each UUV makes its own rational planning of the tracking tasks until the entire formation forms the desired tracking formation. (3) And (4) tracking and capturing the target, wherein after the MUUV forms an expected formation, the other UUV switches the passive sonar into the active sonar, accurately tracks the target and reduces the formation until a capturing task is completed.

In connection with the description of figure 3,introducing MUUV (multi-user vehicle) enclosure expected formation and tracking enclosure, wherein four UUV1, UUV2, UUV3 and UUV4 are expected positions for executing a tracking task UUV, V is a tracked target position, the four UUV form a regular tetrahedron structure with the edge length of a, the target V is the center of a circumscribed circle, and the distance between the target V and each UUV is

When the ith UUV detects the tracking target, the speed of the ith UUV is zeta _i The target obstacle speed is ζ ^r Require ζ _i >ζ ^r . At the moment, the position xi of the i UUV _i Is an origin, and a target position xi is detected ^r Other UUVs gradually get closer to it, forming a figure-desired enclosure. Considering the underwater noise influence, the target is positioned as follows:

in the formula for t _i The time of the sonar measurement signal reaching the ith UUV is C the underwater sound propagation speed, | | xi _i -ξ _j I | is the distance between the ith UUV and the target, n _i Is the measurement noise of the ith UUV. n is _i Is zero-mean gaussian noise with standard deviation σ.

The constraint that each UUV form the desired formation is:

||t _i -t _ij ||≤ε (3)

and | is Euclidean norm, and the constant value is equal to or more than 0.

In order to ensure the positioning accuracy, four UUVs are required to be not in the same plane and form a tetrahedral formation, and in order to maintain the sensitivity of the tracking system, the geometric center expected by the formation is as much as possible coincident with V. And then the distance between UUV is adjusted according to the target positioning precision.

xi in the formula _i ∈R ^m Position information of the i UUV; zeta _i ∈R ^m The speed information of the ith UUV; u. of _i ∈R ^m The control input for the i UUV.

The consistency algorithm control law is as follows:

where for i =1,2,3,4 and j =1,2,3,4; a is _ij Is the (i, j) th entry of the adjacency matrix at time t, when a _ij >0，a _ij When the adjacency matrix is not equal to 1, the obtained adjacency matrix is a graph with weights and can be used for representing parameters such as the trust degree among individual aircrafts; gamma ray ₁ 、γ ₂ Is a normal number;

△ _ij is the position difference between the i UUV and the j UUV, Δ _i The position difference between the ith UUV and the tracking target is obtained; xi ^r For tracking position information of objects, ζ ^r To track velocity information of the target.

With reference to fig. 4, a multi-UUV trapping method based on a consistency algorithm includes:

the method comprises the following steps: the UUVs maintain navigational formation, detect their own status and surrounding environment, and maintain communication between the UUVs.

Step two: when a UUV detects a task target, the UUV tracks the task target and other UUV gradually get close to the UUV.

Step three: and accurately positioning the target according to the detection information of the UUV and gradually forming an expected formation.

Step four: after the tetrahedral tracking formation is formed, each UUV generates a control instruction according to a consistency formula and carries out tracking control.

Step five: and switching the formation into a tracking and enclosing mode, tracking the target and gradually reducing the formation target for enclosing.

Step six: judging whether the trapping task is completed or not, namely:

t _i ≤δ，i＝1,2,3,4

in the formula, delta>0 is constant for t _i δ is a constant for the time the sonar measurement signal arrives at the i UUV. And if not, entering the step five, otherwise, finishing the defense task.

Claims

1. An enclosure method based on a multi-UUV tracking enclosure system is characterized in that: the enclosure system comprises four isomorphic UUV; each UUV comprises a perception module, a communication module, a behavior control module, a cooperation planning module and a coordination control module;

the cooperative planning module detects a target state through the sensing module and receives other UUV information through the communication module, and plans out an expected path of the UUV, namely the optimal position in an expected tetrahedral formation;

the behavior control module controls the control output of each UUV execution unit, including the force of the propulsion system and the angle of the operation surface;

the enclosure method comprises the following steps:

the method comprises the following steps: the UUV keeps sailing formation, detects the self state and the surrounding environment, and keeps the communication between the UUV;

step two: when a UUV detects a task target, the UUV is switched to be an active sonar to track the UUV, other UUV approaches the UUV, and the relative distance between the UUV and the target is measured according to the following rules:

in the formula, t _i Represents the time of the sonar measurement signal arriving at the ith UUV, | | | - | represents the Euclidean norm, ξ _i Indicating the position, ξ, of the i-th UUV relative to the geometric center point of the formation of UUV' s ^r Representing the position of the target relative to the UUV formation geometric center point, wherein C is the underwater sound propagation speed; n is _i The representation is a noise term and is zero mean Gaussian noise with standard deviation sigma;

||t _i -t _ij ||≤ε

it is desirable that the length of the regular tetrahedron formation is α, i.e. the desired distance of each UUV is α, the desired distance of each UUV from the target is R,

xi in the formula _i ∈R ^m Position information of the i UUV; zeta _i ∈R ^m The speed information of the ith UUV is obtained; u. of _i ∈R ^m Control input for the i UUV;

the consistency algorithm controls the following law:

where for i =1,2,3,4 and j =1,2,3,4; a is a _ij Is the (i, j) th entry of the adjacency matrix at time t, when a _ij ＞0，a _ij Not equal to 1, the adjacency matrix obtained is a graph with weights, representing parameters between individual aircraft; gamma ray ₁ 、γ ₂ Is a normal number;

Δ _ij is the position difference, Δ, between the i UUV and the j UUV _i The position difference between the ith UUV and the tracking target is obtained; xi shape ^r For tracking position information of objects, ζ ^r Velocity information for tracking the target;

step five: after the MUUV expectation tracking formation is formed, switching to a surrounding capture mode, starting to continue tracking the target and reducing the formation range, and at the moment, converting the other UUV passive sonar into the active sonar to carry out final surrounding capture on the target;

t _i ≤δ，i＝1,2,3,4

in the formula, delta is more than 0 and is a constant value, and the formula shows that the enclosure task is completed when the UUV formation enables the tracked target to be enclosed to the minimum value; and if not, entering the step five.

2. The enclosure capturing method according to claim 1, characterized in that: the passive sonar is in a normally open state in the tracking process, and is switched into the active sonar when in enclosure.