Unmanned ship cluster cooperative control method based on virtual-real combination

Abstract

The invention discloses an unmanned ship cluster cooperative control method based on virtuality and reality combination, and the method comprises the steps: building an unmanned ship cluster formation in a virtual marine environment, and obtaining the unmanned ship cluster formation through the mapping position, the mapping speed and the mapping course angle of a mapping ship of a real ship in the virtual marine environment; the actual speed and the actual course angle of the physical ship and the digital simulation unmanned ship at the next moment can be obtained based on a cluster cooperative control algorithm according to the virtual position, the virtual speed and the virtual course angle of the digital simulation virtual unmanned ship in the virtual marine environment. According to the method, the actual unmanned ship is combined with the virtual digital simulation unmanned ship, high-credibility physical feedback and immersive interaction experience can be provided in a complex and changeable scene, the error between the simulation result and the actual operation condition is small, the accuracy and efficiency of algorithm verification are greatly improved, and the method is suitable for popularization and application. And therefore, important support can be provided for the development of an unmanned ship cluster cooperation technology, and diversified application requirements of the unmanned ship cluster cooperation technology in a complex environment can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned boat cluster cooperation, and particularly to a method for cooperative control of unmanned boat clusters based on the combination of virtual and real. Background Art

[0002] In the field of unmanned boat technology research, the verification of unmanned autonomous algorithms is a key link to promote the development of its technology. The current verification methods mainly include two forms: sea trial of real boats and verification in simulation scenarios. However, both of these methods face significant challenges in practical applications. Although the sea trial of unmanned boat clusters can provide real environmental feedback, its implementation cost is high, consuming a large amount of time, manpower and material resources. At the same time, limited by the scenario conditions, it is difficult to construct diverse and complex test environments, and the development and verification of autonomous algorithms are greatly restricted. Although the simulation scenario verification has attracted much attention due to its low cost and high flexibility, the existing simulation tools are difficult to meet the requirements of effectiveness evaluation in complex environments, and the problems of insufficient fidelity and credibility are particularly prominent. At the same time, traditional simulation environments often cannot provide real physical feedback and lack an intuitive user interaction experience, resulting in a large error between the simulation results and the actual operation conditions. Summary of the Invention

[0003] The present invention discloses a method for cooperative control of unmanned boat clusters based on the combination of virtual and real to overcome the above technical problems.

[0004] To achieve the above object, the technical solution of the present invention is as follows:

[0005] A method for cooperative control of unmanned boat clusters based on the combination of virtual and real, comprising the following steps:

[0006] S1: Establish a three-dimensional visual simulation virtual space model and obtain an initialized virtual ocean environment;

[0007] S2: In the initialized virtual ocean environment, establish an unmanned boat cluster formation, and the unmanned boats in the unmanned boat cluster formation include the mapped boats of real boats or digital simulation unmanned boats;

[0008] S3: Establish a motion model of a numerical simulation unmanned boat; at the same time, according to the actual position, actual speed and actual heading angle of a physical ship sailing at sea at the current moment, obtain the mapped position, mapped speed and mapped heading angle of the mapped boat of the real boat in the virtual ocean environment at the current moment;

[0009] S4: Based on the mapped position, mapped speed, and mapped course angle of the mapped boat of the real boat at the current moment in the virtual ocean environment, as well as the virtual position, virtual speed, and virtual course angle of the digital simulation virtual unmanned boat at the current moment in the virtual ocean environment, obtain the expected mapped speed, expected mapped course angle of the mapped boat of the real boat at the next moment in the virtual ocean environment, and the expected virtual speed, expected virtual course angle of the digital simulation unmanned boat at the next moment based on the cluster cooperative control algorithm;

[0010] S5: Obtain the actual speed and actual course angle of the physical ship at the next moment according to the expected mapped speed and expected mapped course angle of the mapped boat of the real boat at the next moment in the virtual ocean environment;

[0011] Obtain the actual virtual speed and actual virtual course angle of the digital simulation unmanned boat at the next moment according to the expected virtual speed and expected virtual course angle of the digital simulation unmanned boat at the next moment;

[0012] S6: Obtain the mapped speed, mapped course angle, and mapped position of the mapped boat of the real boat at the next moment in the virtual ocean environment according to the actual speed, actual course angle, and actual position of the physical ship at the next moment; and repeat S4 - S5 according to the actual virtual speed, actual virtual course angle, and actual virtual position of the digital simulation unmanned boat at the next moment; to realize the cooperative control of the unmanned boat cluster based on the combination of virtual and real, and further realize the control of the physical ship sailing at sea.

[0013] Further, the steps of the cluster cooperative control algorithm are as follows:

[0014] S41: Based on the position of the set reference virtual center point in the virtual ocean environment, obtain the position of the target virtual point of the unmanned boat in the unmanned boat cluster formation;

[0015] S42: According to the position of the target virtual point of the unmanned boat, obtain the expected speed and expected course angle of the unmanned boat in the unmanned boat cluster formation at the next moment in the virtual ocean environment;

[0016] S43: According to the expected speed and expected course angle of the unmanned boat in the unmanned boat cluster formation at the next moment in the virtual ocean environment, obtain the expected mapped speed, expected mapped course angle of the mapped boat of the real boat at the next moment in the virtual ocean environment, and the expected speed and expected course angle of the digital simulation unmanned boat model at the next moment.

[0017] Further, the formula for obtaining the position of the target virtual point of the unmanned boat in the unmanned boat cluster formation is as follows:

[0018]

[0019] In the formula: represents the position of the target virtual point of the \(i\)-th unmanned boat; \(P\) l represents the position of the reference virtual center point, \(R(\psi\) l ) represents the transformation matrix from the local coordinate system to the earth coordinate system; \(\psi\) l represents the heading angle of the reference virtual center point; \(d\) i represents the relative distance between the \(i\)-th virtual center point and the reference virtual point; \(\theta\) i represents the relative angle between the virtual center point and the reference virtual point; \(x\) i l , \(y\) i l respectively represent the X-axis coordinate and Y-axis coordinate of the target virtual point of the \(i\)-th unmanned boat in the earth coordinate system.

[0020] Furthermore, the formulas for obtaining the expected speed and expected heading angle of the unmanned boats in the unmanned boat cluster formation at the next moment in the virtual ocean environment are as follows:

[0021]

[0022] In the formula: is the expected speed of the \(i\)-th unmanned boat at the next moment in the virtual ocean environment; \(k\) p represents the position difference compensation parameter; represents the distance between the unmanned boat and the target virtual point; is the speed of the target virtual point of the \(i\)-th unmanned boat; \(k\) d represents the speed balance parameter; \(u\) i represents the actual speed of the \(i\)-th unmanned boat; \(\Delta\psi\) represents the angle deviation; represents the azimuth angle between the unmanned boat and the target virtual point; \(x\) i l , \(y\) i l respectively represent the abscissa and ordinate of the position of the target virtual point of the \(i\)-th unmanned boat in the virtual ocean environment; \(x\) i , \(y\) i respectively represent the abscissa and ordinate of the position of the \(i\)-th unmanned boat in the virtual ocean environment; \(\psi\) i represents the actual heading angle of the \(i\)-th unmanned boat at the current moment; represents the expected heading angle of the \(i\)-th unmanned boat at the next moment in the virtual ocean environment; \(sign(·)\) represents the sign function; \(r\) max represents the maximum turning angle of the unmanned boat; \(|\cdot|\) represents the absolute value operation.

[0023] Furthermore, the motion model of the digital simulation unmanned boat model is represented as follows:

[0024]

[0025] In the formula: η represents the position and attitude vector of the digital simulation unmanned boat, where η = [α, β, γ, φ, θ, ψ] T , α represents the longitudinal position of the digital simulation unmanned boat, β represents the lateral position of the digital simulation unmanned boat, γ represents the vertical position of the digital simulation unmanned boat, φ represents the roll angle of the digital simulation unmanned boat, θ represents the pitch angle of the digital simulation unmanned boat, and ψ represents the heading angle of the digital simulation unmanned boat. represents the first-order differential; R(η) represents the rotation matrix; ξ represents the velocity vector of the digital simulation unmanned boat, where ξ = [u, v, w, p, q, r] T , u represents the longitudinal velocity of the digital simulation unmanned boat, v represents the lateral velocity of the digital simulation unmanned boat, w represents the vertical velocity of the digital simulation unmanned boat, p represents the longitudinal angular velocity of the digital simulation unmanned boat, q represents the lateral angular velocity of the digital simulation unmanned boat, and r represents the vertical angular velocity of the digital simulation unmanned boat; M represents the inertia matrix; C(ξ) represents the Coriolis centripetal force matrix; D(ξ) represents the fluid damping matrix; g(η) represents the restoring force matrix of the digital simulation unmanned boat model itself; τ represents the control input matrix of the digital simulation unmanned boat, where τ = [τ u , τ v , τ w , τ p , τ q , τ q T , τ u represents the force acting on the longitudinal direction of the digital simulation unmanned boat; τ v represents the force acting on the lateral direction of the digital simulation unmanned boat; τ w represents the force acting on the vertical direction of the digital simulation unmanned boat; τ p represents the moment acting on the roll of the digital simulation unmanned boat; τ q represents the moment acting on the pitch of the digital simulation unmanned boat; τ q represents the moment acting on the yaw of the digital simulation unmanned boat;

[0026] After simplifying the motion model of the digital simulation unmanned boat model, it is expressed as follows:

[0027]

[0028] In the formula: m 11 represents the longitudinal inertia coefficient of the digital simulation unmanned boat; m 22 represents the lateral inertia coefficient of the digital simulation unmanned boat; m 33 represents the vertical inertia coefficient of the digital simulation unmanned boat; d 11 represents the linear damping coefficient of the longitudinal motion of the digital simulation unmanned boat; d 22 ​Represents the linear damping coefficient of the lateral motion of the digital simulation unmanned boat; d 33 Represents the rotational damping coefficient of the vertical rotation of the digital simulation unmanned boat.

[0029] Furthermore, the unmanned boat cluster formation adopts a triangular cluster formation.

[0030] Furthermore, the method for obtaining the outer contour of the unmanned boat in the unmanned boat cluster formation is as follows:

[0031] According to the outer contour of the physical ship, using 3D Max software, the outer dimensions of the physical ship are reduced in proportion and then three-dimensional modeling is carried out.

[0032] Beneficial effects: A method for collaborative control of unmanned boat clusters based on the combination of virtual and real in the present invention. By establishing an unmanned boat cluster formation including the mapped boat of the real boat and the digital simulation unmanned boat in the virtual ocean environment, according to the actual position, actual speed and actual heading angle of the physical ship sailing at sea at the current moment, the mapped position, mapped speed and mapped heading angle of the mapped boat of the real boat in the virtual ocean environment at the current moment are obtained; furthermore, according to the virtual position, virtual speed and virtual heading angle of the digital simulation virtual unmanned boat in the virtual ocean environment at the current moment, based on the cluster collaborative control algorithm, the expected mapped speed, expected mapped heading angle of the mapped boat of the real boat at the next moment and the expected virtual speed, expected virtual heading angle of the digital simulation unmanned boat at the next moment are obtained; furthermore, the actual speed and actual heading angle of the physical ship and the digital simulation unmanned boat at the next moment can be obtained; based on the cluster collaborative control algorithm, through continuous control of the unmanned boat cluster, the control of the physical ship is realized. By combining the actual unmanned boat with the virtual digital simulation unmanned boat in the present invention, high-fidelity physical feedback and immersive interactive experience can be provided in complex and changeable scenarios, and the error between the simulation result and the actual operation situation is small. It not only verifies the calculation effect of the cluster collaborative control algorithm of the present invention, but also can provide important support for the development of the unmanned boat cluster collaborative technology and meet its diverse application requirements in complex environments. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is the flowchart of the method for collaborative control of unmanned boat clusters based on the combination of virtual and real of the present invention;

[0035] Figure 2 Schematic diagram of the experimental results of the combination of virtual and real scenarios at sea in the embodiment of the present invention. The left side is the virtual environment display interface, and the right side is the UAV aerial photography interface.

[0036] Figure 3 Schematic diagram of the structure of the physically autonomous unmanned boat built in the embodiment of the present invention;

[0037] Figure 4a Left view of the digital simulation unmanned boat in the Unity3D visual simulation environment in the embodiment of the present invention;

[0038] Figure 4b Top view of the digital simulation unmanned boat in the Unity3D visual simulation environment in the embodiment of the present invention;

[0039] Figure 5 Schematic diagram of the calculation process of the motion model of the digital simulation unmanned boat in the embodiment of the present invention;

[0040] Figure 6 Schematic diagram of the simulated water body in the Unity3D visual simulation environment in the embodiment of the present invention;

[0041] Figure 7 Schematic diagram of the trajectory of the experimental results of the combination of virtual and real scenarios at sea in the embodiment of the present invention;

[0042] Figure 8a Schematic diagram of the speeds of three physical unmanned boats in the experimental results of the combination of virtual and real scenarios at sea in the embodiment of the present invention;

[0043] Figure 8b Schematic diagram of the speeds of three digital simulation unmanned boats in the experimental results of the combination of virtual and real scenarios at sea in the embodiment of the present invention;

[0044] Figure 9a Schematic diagram of the heading angles of three physical unmanned boats in the experimental results of the combination of virtual and real scenarios at sea in the embodiment of the present invention;

[0045] Figure 9b Schematic diagram of the heading angles of three digital simulation unmanned boats in the experimental results of the combination of virtual and real scenarios at sea in the embodiment of the present invention;

[0046] Figure 10 Schematic diagram of the process of the method for collaborative control of an unmanned boat cluster based on the combination of virtual and real scenarios in the embodiment of the present invention. Specific implementation manners

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] This embodiment introduces a method for collaborative control of an unmanned boat cluster based on the combination of virtual and real, including the following steps, as Figure 1 and Figure 10 shown:

[0049] S1: Establish a three-dimensional visual simulation virtual space model and obtain an initialized virtual ocean environment;

[0050] S2: In the initialized virtual ocean environment, establish an unmanned boat cluster formation, where the unmanned boats in the unmanned boat cluster formation are mapping boats of real boats or digital simulation unmanned boats;

[0051] Specifically, the unmanned boat cluster formation in this embodiment includes several mapping boat models of real boats and several digital simulation unmanned boat models to establish an unmanned boat cluster formation in the virtual ocean environment;

[0052] Preferably, the unmanned boat cluster formation adopts a triangular cluster formation.

[0053] Preferably, the method for obtaining the outer contour of the unmanned boats in the unmanned boat cluster formation is:

[0054] According to the outer contour of the physical ship, use 3D Max software to perform three-dimensional modeling after reducing the outer dimensions of the physical ship in equal proportion.

[0055] Specifically, let the geometric parameters of the physical ship sailing on the sea be length L r , width W r , height H r , the length of the unmanned boat in the unmanned boat cluster formation is L v , the width is W v , the height is H v , and the scale factor is λ ∈ (0, 1). Then the three-dimensional vertex coordinate transformation can be expressed as:

[0056]

[0057] S3: Establish the motion model of the numerical simulation unmanned boat; meanwhile, according to the actual position, actual speed and actual heading angle of the physical ship sailing at sea at the current moment, obtain the mapped position, mapped speed and mapped heading angle of the mapped boat of the actual boat at the current moment in the virtual ocean environment;

[0058] Preferably, the motion model of the digital simulation unmanned boat model is expressed as follows:

[0059]

[0060] In the formula: η represents the position and attitude vector of the digital simulation unmanned boat, where η = [α, β, γ, φ, θ, ψ] T , α represents the longitudinal position of the digital simulation unmanned boat, β represents the lateral position of the digital simulation unmanned boat, γ represents the vertical position of the digital simulation unmanned boat, φ represents the roll angle of the digital simulation unmanned boat, θ represents the pitch angle of the digital simulation unmanned boat, ψ represents the heading angle of the digital simulation unmanned boat, represents the first-order differential; R(η) represents the rotation matrix; ξ represents the speed vector of the digital simulation unmanned boat, where ξ = [u, v, w, p, q, r] T , u represents the longitudinal speed of the digital simulation unmanned boat, v represents the lateral speed of the digital simulation unmanned boat, w represents the vertical speed of the digital simulation unmanned boat, p represents the longitudinal angular velocity of the digital simulation unmanned boat, q represents the lateral angular velocity of the digital simulation unmanned boat, r represents the vertical angular velocity of the digital simulation unmanned boat; M represents the inertia matrix; C(ξ) represents the Coriolis centripetal force matrix; D(ξ) represents the fluid damping matrix; g(η) represents the restoring force matrix of the digital simulation unmanned boat model itself; τ represents the control input matrix of the digital simulation unmanned boat, where τ = [τ u , τ v , τ w , τ p , τ q , τ q T , τ u represents the force acting on the longitudinal direction of the digital simulation unmanned boat; τ v represents the force acting on the lateral direction of the digital simulation unmanned boat; τ w represents the force acting on the vertical direction of the digital simulation unmanned boat; τ p represents the moment acting on the roll of the digital simulation unmanned boat; τ q represents the moment acting on the pitch of the digital simulation unmanned boat; τ q represents the moment acting on the yaw of the digital simulation unmanned boat;

[0061] ​Specifically, since the experimental platform structure in this embodiment is symmetric and only the motion of the digital simulation unmanned boat on the horizontal plane is considered. Therefore, by ignoring the non-diagonal elements in the inertia matrix and damping matrix and neglecting the influence of viscous fluid on the motion of the digital simulation unmanned boat, the equation after simplifying the motion model of the digital simulation unmanned boat model is expressed as follows:

[0062]

[0063] In the formula: m 11 represents the longitudinal inertia coefficient of the digital simulation unmanned boat; m 22 represents the lateral inertia coefficient of the digital simulation unmanned boat; m 33 represents the vertical inertia coefficient of the digital simulation unmanned boat; d 11 represents the linear damping coefficient of the longitudinal motion of the digital simulation unmanned boat; d 22 represents the linear damping coefficient of the lateral motion of the digital simulation unmanned boat; d 33 represents the rotational damping coefficient of the vertical rotation of the digital simulation unmanned boat;

[0064] Specifically, the physical ship (physical unmanned boat) in this embodiment, that is, the actual ship sailing at sea, establishes a serial communication network with the unmanned boat ground station, and sends the status data of the physical unmanned boat back to the unmanned boat ground station in real time. According to the status data of the physical unmanned boat, a corresponding twin unmanned boat, that is, the mapping boat model of the real boat, is generated in the three-dimensional visual scene simulation virtual space model.

[0065] Among them, the twin unmanned boats, that is, the mapping boat model of the real boat has the same appearance, spatial position and pose information (speed and heading angle) as the physical unmanned boat; among them, the appearance model of the twin unmanned boat is obtained by modeling the physical unmanned boat in equal proportion; among them, the spatial position of the twin unmanned boat is obtained by establishing a spatial coordinate system in the virtual space of the three-dimensional visual scene simulation, selecting a reference point in the virtual space, and setting the longitude and latitude of the reference point to be the same as those of the corresponding point in the actual sea scene. The state data of the physical unmanned boat is transmitted back to the unmanned boat ground station through the serial communication network. By calculating the relative position between the physical unmanned boat and the reference point in the actual sea scene, it is converted into the relative position with the point in the virtual space, so as to determine the position of the twin unmanned boat in the virtual space; the pose information transmitted back by the physical unmanned boat is assigned to the twin unmanned boat. Thus, the movement of the twin unmanned boat in the virtual space maps the movement of the physical unmanned boat in the actual sea scene. Specifically, in this embodiment, the design of the digital simulation unmanned boat model includes the design of the outer contour of the digital simulation unmanned boat model and the design of the motion model of the digital simulation unmanned boat. Among them, the outer contour of the digital simulation unmanned boat model is obtained by three-dimensional modeling of the actual physical unmanned boat reduced in equal proportion by 3D Max software. The virtual position of the digital simulation unmanned boat model in the virtual ocean environment is its actual position in the virtual ocean environment. In this embodiment, the initial virtual speed and initial virtual heading angle of the digital simulation unmanned boat model in the virtual ocean environment are set to 0.

[0066] The digital simulation unmanned boat motion model takes the desired speed and desired heading angle as inputs, and takes the actual position and actual attitude information (including speed and heading angle) of the digital simulation unmanned boat model as outputs. The controller generates the underlying control signals, and controls the rotation speed of the propeller and the rudder angle of the rudder machine of the digital simulation unmanned boat model through the obtained navigation speed and heading angle. The propeller generates thrust and the rudder machine generates torque. The speed and heading angle are calculated according to the three-degree-of-freedom dynamics model of the unmanned boat, and the position information is calculated according to the three-degree-of-freedom kinematics model of the unmanned boat.

[0067] S4: Based on the mapping position, mapping speed and mapping heading angle of the mapping boat of the real boat at the current moment in the virtual ocean environment, and the virtual position, virtual speed and virtual heading angle of the digital simulation virtual unmanned boat at the current moment in the virtual ocean environment, based on the cluster cooperative control algorithm, obtain the expected mapping speed, expected mapping heading angle of the mapping boat of the real boat at the next moment in the virtual ocean environment, and the expected virtual speed and expected virtual heading angle of the digital simulation unmanned boat at the next moment.

[0068] Preferably, the steps of the cluster cooperative control algorithm are as follows:

[0069] S41: Based on the position of the set reference virtual center point in the virtual ocean environment, obtain the positions of other virtual points in the virtual ocean environment, so as to obtain the position of the target virtual point of the unmanned boat in the unmanned boat cluster formation; including the position of the target virtual point of the mapped boat of the real boat and the position of the target virtual point of the digital simulation virtual unmanned boat.

[0070] Preferably, the formula for obtaining the position of the target virtual point of the unmanned boat in the unmanned boat cluster formation is as follows:

[0071]

[0072] In the formula: represents the position of the target virtual point of the i-th unmanned boat; P l represents the position of the reference virtual center point, R(ψ l ) represents the transformation matrix from the local coordinate system to the geodetic coordinate system; ψ l represents the course angle of the reference virtual center point; d i represents the relative distance between the i-th virtual center point and the reference virtual point; θ i represents the relative angle between the virtual center point and the reference virtual point; x i l , y i l respectively represent the X-axis coordinate and Y-axis coordinate of the target virtual point of the i-th unmanned boat in the geodetic coordinate system.

[0073] S42: According to the position of the target virtual point of the unmanned boat, obtain the expected speed and expected course angle of the unmanned boat in the unmanned boat cluster formation at the next moment in the virtual ocean environment;

[0074]

[0075] In the formula: is the expected speed of the i-th unmanned boat at the next moment in the virtual ocean environment; k p represents the position difference compensation parameter; represents the distance between the unmanned boat and the target virtual point; is the speed of the target virtual point of the i-th unmanned boat; k d represents the rate balance parameter; u i represents the actual speed of the i-th unmanned boat; Δψ represents the angle deviation; represents the azimuth angle between the unmanned boat and the target virtual point; x i l , y i l respectively represent the abscissa and ordinate of the position of the target virtual point of the i-th unmanned boat in the virtual ocean environment; x i , yi respectively represent the abscissa and ordinate of the position of the i-th unmanned boat in the virtual ocean environment; ψ i represents the actual heading angle of the i-th unmanned boat at the current moment; represents the desired heading angle of the i-th unmanned boat at the next moment in the virtual ocean environment; sign(·) represents the sign function; r max represents the maximum turning angle of the unmanned boat; |·| represents the absolute value operation;

[0076] S43. According to the desired speed and desired heading angle of the unmanned boats in the unmanned boat cluster formation at the next moment in the virtual ocean environment, obtain the desired mapped speed, desired mapped heading angle of the mapped boats of the real boats at the next moment in the virtual ocean environment, and the desired speed and desired heading angle of the digital simulation unmanned boat model at the next moment; so as to obtain the actual desired speed and actual desired heading angle of the physical ship sailing at sea.

[0077] Specifically, in the cluster cooperative control algorithm, by setting a reference virtual point as the virtual center point, the positions of the remaining virtual points are determined based on the virtual center point to form a virtual formation. Among them, the mapped boats of the real boats and the digital simulation unmanned boats have the same form of input and output. Therefore, in the cluster cooperative control algorithm, the physical unmanned boats and the digital simulation unmanned boats are regarded as the same object for calculation. After obtaining the desired speed and desired heading angle of the unmanned boats in the unmanned boat cluster formation at the next moment, the desired speed and desired heading angle of the mapped boats of the real boats and the digital simulation unmanned boats in the unmanned boat cluster formation can be known.

[0078] S5: According to the desired mapped speed and desired mapped heading angle of the mapped boats of the real boats at the next moment in the virtual ocean environment, obtain the actual position, actual speed and actual heading angle of the physical ship at the next moment;

[0079] According to the desired virtual speed and desired virtual heading angle of the digital simulation unmanned boat at the next moment, obtain the actual virtual position, actual virtual speed, actual virtual heading angle of the digital simulation unmanned boat at the next moment;

[0080] Specifically, according to the desired virtual speed and desired virtual heading angle of the digital simulation unmanned boat at the next moment; through the motion model of the digital simulation unmanned boat, the actual virtual position, actual virtual speed, actual desired heading angle of the digital simulation unmanned boat at the next moment can be obtained;

[0081] Specifically, in this embodiment, the expected mapping speed and expected mapping course angle of the mapping boat of the real boat at the next moment in the virtual ocean environment are the expected speed and expected course angle of the physical ship sailing at sea. The physical ship sails according to the expected speed and expected course angle. Due to the existence of various interference information, when the physical ship sails according to the expected speed and expected course angle, there will be a certain deviation in the speed and course angle actually reached at the next moment. Therefore, in this embodiment, the autopilot in the actual ship calculates and generates the underlying control signal according to the expected speed and expected course angle of the physical ship at the next moment, and sends it to the electronic speed controller and the steering gear to execute the control instruction; at the same time, the positioning module and each sensor module obtain the actual position, actual speed and actual course angle of the physical ship sailing at sea.

[0082] S6: According to the actual speed, actual course angle and actual position of the physical ship at the next moment, obtain the mapping speed, mapping course angle and mapping position of the mapping boat of the real boat in the virtual ocean environment at the next moment; repeat S4 - S5 according to the actual virtual speed, actual virtual course angle and actual virtual position of the digital simulation unmanned boat at the next moment; to realize the cooperative control of the unmanned boat cluster based on the combination of virtual and real, and further realize the control of the physical ship sailing at sea. Specifically, the cluster cooperative control algorithm adopted in this embodiment selects the virtual center point, determines the formation shape based on the virtual center point, and assigns the formation positions to the unmanned boats; through the unmanned boat motion controller, obtain the expected speed and expected angle of each unmanned boat, and send them to the physical ship and the digital simulation unmanned boat model to control their movement towards the formation positions, so as to realize the formation control of the real boat and the digital simulation unmanned boat model and the cooperative control of the unmanned boat formation. A specific implementation manner of this embodiment is as follows:

[0083] Based on the three - dimensional visual simulation virtual space model, establish a cooperative motion scenario of a 6 - boat unmanned boat cluster including the mapping boat of the real boat and the digital simulation unmanned boat model.

[0084] Determine that the total number of virtual and real unmanned boat nodes in this embodiment is 6, among which, 3 nodes are digital simulation unmanned boats, and 3 nodes are the mapping boats of the real boats sailing at sea. As Figure 2 shown, through the Unity3D simulation platform, display the formation shape from multiple directions and perspectives, display the unmanned boat identification and movement trajectory to distinguish the mapping boat of the real boat (red) from the digital simulation unmanned boat (yellow). And use a drone to conduct aerial photography following of the actual ship sailing at sea for virtual - real scene comparison. Finally, record the operation data of each moment of the system operation, and form trajectory diagrams, speed change diagrams, angle change diagrams, etc. through post - processing to obtain the virtual - real combined simulation comparison data.

[0085] The virtual-reality combined unmanned autonomous algorithm verification system of this embodiment includes a physical unmanned boat, a digital simulation unmanned boat module, and a three-dimensional visual scene module.

[0086] The physical unmanned boat is an underactuated unmanned boat experimental platform built independently, which executes the cluster cooperative control algorithm of this embodiment in the actual sea scenario and transmits the state data of the physical unmanned boat to the unmanned boat ground station in real time;

[0087] The digital simulation unmanned boat module includes the appearance outline of the unmanned boat and the digital simulation unmanned boat motion model. The cluster cooperative control algorithm is executed by digital simulation to obtain control instructions (desired speed, desired heading angle), and state data (actual speed, actual heading angle) is fed back;

[0088] The three-dimensional visual scene module is used to create a virtual sea scenario, generate a twin unmanned boat according to the physical unmanned boat data, and jointly display the cluster motion state through the twin unmanned boat and the digital simulation unmanned boat model.

[0089] See Figure 3 , which shows the overall construction plan of the physical unmanned boat. An independently built underactuated unmanned boat is selected as the experimental platform. Its shell is made of fiberglass, with the characteristics of light weight, high strength, good insulation, and corrosion resistance. The hull size is 121cm x 39cm, weighing 10.15kg, the propeller diameter is 5.075cm, the rudder length is 10.4cm, the rudder width is 5.4cm, and it adopts a single propeller and single rudder propulsion method. The auxiliary computer in the physical unmanned boat receives the control instructions (desired speed, desired heading angle) sent by the unmanned boat ground station, sends them to the autopilot to calculate and generate the underlying control signal, and sends them to the electronic speed controller and the steering gear to execute the control instructions; at the same time, the positioning module and each sensor module send various state information of the unmanned boat to the on-board auxiliary computer for data processing, and the auxiliary computer sends the unmanned boat state information back to the unmanned boat ground station through the wireless communication module.

[0090] See Figures 4 and Figure 5 respectively show the flow schematic diagrams of the digital simulation unmanned boat model and the digital simulation unmanned boat motion module in Unity3D. The physical unmanned boat is three-dimensionally modeled using 3D Max software in proportion to obtain the appearance outline of the digital simulation unmanned boat, and finally the processed model is imported into Unity3D; the digital simulation unmanned boat motion module takes the control instructions (desired speed and desired angle) as the input and the actual position and actual pose information (speed and heading angle) of the digital simulation unmanned boat as the output, supports parsing the control instructions through the controller to generate the underlying control signal, controlling the rotation speed of the propeller and the rudder angle of the steering gear. After the propeller generates thrust and the steering gear generates torque, the actual speed and actual heading angle are calculated according to the digital simulation unmanned boat dynamics model, and the position information is calculated according to the digital simulation unmanned boat kinematics model.

[0091] Figure 6 and Figure 2 both show virtual maritime scenarios and virtual-real collaborative motion scenarios. The Crest Ocean System plug-in is used to establish the ocean environment. In the scenario, new ocean objects are created, the Ocean Renderer component is mounted, an initial ocean environment is generated, and the sea level height is adjusted to an appropriate position. Details such as the water body material and color are set according to the characteristics of real water bodies. Through the Shape FTT component, the details of the wave effect are set. The pose and other data of the physical unmanned boat are received, and by constructing the virtual space coordinate system of the unmanned boat, the conversion between the longitude and latitude position of the unmanned boat and the virtual space position is realized, and the navigation state of the unmanned boat is displayed in three dimensions, meeting the three-dimensional display and scenario requirements of large-scale unmanned boat cluster simulation.

[0092] See Figure 7 , which shows the trajectory diagram of the experimental results of the virtual-real combination at sea in the embodiment. Among them, the red one is the mapped boat of the physical unmanned boat, and the blue one is the digital simulation unmanned boat. The mapped boat and the digital simulation unmanned boat jointly achieve the desired formation shape and maintain the formation heading, indicating that this embodiment has good effectiveness and stability. There are small fluctuations in the displacement curve of the physical unmanned boat, which is caused by the interference of sea winds and waves; while the displacement trajectory of the digital simulation unmanned boat is closer to the ideal path, indicating that the digital simulation model can better simulate the ideal navigation state of the unmanned boat.

[0093] See Figure 8a , which shows the speed diagrams of three physical unmanned boats in the experimental results of the virtual-real combination at sea in this embodiment; the speeds of the three physical unmanned boats are stable throughout the experiment and can maintain the established speed for navigation, reflecting the reliability of the speed control of the physical unmanned boat in this embodiment.

[0094] Figure 8b are the speed diagrams of three digital simulation unmanned boats in the experimental results of the virtual-real combination at sea described in the embodiment; the speeds of the three digital simulation unmanned boats are relatively stable and can maintain a constant speed, verifying the accuracy and consistency of the speed control of the digital simulation unmanned boat in this embodiment.

[0095] Figure 9a are the heading angle diagrams of three physical unmanned boats in the experimental results of the virtual-real combination at sea described in the embodiment; the heading angles of the physical unmanned boats show a fluctuating phenomenon, and this fluctuation is synchronous with the speed fluctuation period, indicating that the wind and wave interference affects both the speed and heading control of the physical unmanned boat, but the unmanned boat can still maintain the predetermined heading to a certain extent, reflecting the robustness of this embodiment.

[0096] Figure 9bHeading angle diagram of three digital simulation unmanned boats for the experimental results of the virtual-real combination at sea described in the embodiment; since the wind and wave resistance are not considered, its heading angle curve is smooth, which reflects the precise control ability of the digital simulation unmanned boat in an ideal environment and also provides a reference basis for the optimization of control strategies in practical applications.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for cooperative control of unmanned boat swarm based on virtual and real combination, characterized in that: The steps include: S1: Establish a three-dimensional visual simulation virtual space model to obtain an initialized virtual ocean environment; S2: in the initialized virtual ocean environment, establishing an unmanned boat cluster formation, wherein the unmanned boats in the unmanned boat cluster formation include mapping boats of real boats or digital simulation unmanned boats; S3: Establishing a motion model of a numerical simulation unmanned boat; and obtaining the mapping position, mapping speed and mapping heading angle of the mapping boat of the real boat in the virtual ocean environment at the current moment according to the actual position, actual speed and actual heading angle of the physical ship sailing on the sea at the current moment; S4: according to the mapping position, mapping speed and mapping heading angle of the mapping boat of the real boat in the virtual ocean environment at the current moment, and the virtual position, virtual speed and virtual heading angle of the digital simulation virtual unmanned boat in the virtual ocean environment at the current moment, based on the cluster collaborative control algorithm, the expected mapping speed and expected mapping heading angle of the mapping boat of the real boat at the next moment and the expected virtual speed and expected virtual heading angle of the digital simulation unmanned boat at the next moment are obtained; S5: acquiring the actual speed and the actual heading angle of the physical ship at the next moment according to the expected mapping speed and the expected mapping heading angle of the mapping boat of the real ship in the virtual ocean environment at the next moment; According to the expected virtual speed and expected virtual heading angle of the digital simulation unmanned boat at the next moment, the actual virtual speed and actual virtual heading angle of the digital simulation unmanned boat at the next moment are obtained; S6: according to the actual speed, actual heading angle and actual position of the physical ship at the next moment, obtaining the mapped speed, mapped heading angle and mapped position of the mapped ship of the real ship at the next moment in the virtual ocean environment; S4-S5 are repeatedly executed according to the actual virtual speed, actual virtual heading angle and actual virtual position of the digital simulated unmanned boat at the next moment; so as to realize the coordinated control of the unmanned boat cluster based on the combination of virtual and real, and then realize the control of the physical ship sailing at sea.

2. The method for cooperative control of unmanned boat swarm based on virtual-real combination according to claim 1 is characterized in that: The steps of the cluster collaborative control algorithm are as follows: S41: based on the position of the set reference virtual center point in the virtual ocean environment, obtaining the position of the target virtual point of the unmanned boat in the unmanned boat cluster formation; S42: acquiring the expected speed and expected heading angle of the unmanned boats in the unmanned boat cluster formation at the next moment in the virtual ocean environment according to the positions of the target virtual points of the unmanned boats; S43. According to the expected speed and expected heading angle of the unmanned boats in the unmanned boat cluster formation in the virtual ocean environment at the next moment, the expected mapping speed and expected mapping heading angle of the mapping boat of the real boat in the virtual ocean environment at the next moment and the expected speed and expected heading angle of the digital simulation unmanned boat model at the next moment are obtained.

3. The method for cooperative control of unmanned boat swarm based on virtual-real combination according to claim 2 is characterized in that: The formula used to obtain the position of the target virtual point of the unmanned boat in the unmanned boat cluster formation is as follows: Where: represents the position of the target virtual point of the i-th unmanned boat; P l Indicates the position of the reference virtual center point, R(ψ l ) represents the transformation matrix from the local coordinate system to the earth coordinate system; ψ l represents the heading angle of the reference virtual center point; di represents the relative distance between the i-th virtual center point and the reference virtual point; θ i Indicates the relative angle between the virtual center point and the reference virtual point; x i l ,y i l They respectively represent the X-axis coordinate and Y-axis coordinate of the target virtual point of the i-th unmanned boat in the geodetic coordinate system.

4. The method for cooperative control of unmanned boat swarm based on virtual-real combination according to claim 2 is characterized in that: The formula used to obtain the expected speed and expected heading angle of the unmanned boats in the unmanned boat cluster formation in the virtual ocean environment at the next moment is as follows: Where: is the expected speed of the i-th unmanned boat in the virtual ocean environment at the next moment; k p Indicates the position difference compensation parameter; Indicates the distance between the unmanned boat and the target virtual point; is the speed of the target virtual point of the i-th unmanned boat; k d represents the rate balance parameter; u i represents the actual speed of the i-th unmanned boat; Δψ represents the angular deviation; represents the azimuth between the unmanned boat and the target virtual point; x i l ,y i l They represent the horizontal and vertical coordinates of the target virtual point of the i-th unmanned boat in the virtual ocean environment; i ,y i They represent the horizontal and vertical coordinates of the position of the i-th unmanned boat in the virtual ocean environment; ψ i Indicates the actual heading angle of the i-th unmanned boat at the current moment; represents the expected heading angle of the i-th unmanned boat in the virtual ocean environment at the next moment; sign(·) represents the sign function; r max represents the maximum turning angle of the unmanned boat; |·| represents absolute value operation.

5. The method for cooperative control of unmanned boat swarm based on virtual-real combination according to claim 1 is characterized in that: The motion model of the digital simulation unmanned boat model is expressed as follows: Where: η represents the position and attitude vector of the digital simulation unmanned boat, where η = [α, β, γ, φ, θ, ψ] T , α represents the longitudinal position of the digital simulation unmanned boat, β represents the lateral position of the digital simulation unmanned boat, γ represents the vertical position of the digital simulation unmanned boat, φ represents the roll angle of the digital simulation unmanned boat, θ represents the longitudinal inclination angle of the digital simulation unmanned boat, ψ represents the bow phase angle of the digital simulation unmanned boat, represents the first-order differential; R(η) represents the rotation matrix; ξ represents the velocity vector of the digital simulation unmanned boat, where ξ=[u,v,w,p,q,r] T , u represents the longitudinal velocity of the digital simulation unmanned boat, v represents the lateral velocity of the digital simulation unmanned boat, w represents the vertical velocity of the digital simulation unmanned boat, p represents the longitudinal angular velocity of the digital simulation unmanned boat, q represents the lateral angular velocity of the digital simulation unmanned boat, and r represents the vertical angular velocity of the digital simulation unmanned boat; M represents the inertia matrix; C(ξ) represents the Coriolis centripetal force matrix; D(ξ) represents the fluid damping matrix; g(η) represents the restoring force matrix of the digital simulation unmanned boat model itself; τ represents the control input matrix of the digital simulation unmanned boat, where τ=[τ u , τ v , τ w , τ p , τ q , τ q ] T , τ u represents the longitudinal force acting on the digital simulation unmanned boat; τ v represents the lateral force acting on the digital simulation unmanned boat; τ w Represents the vertical force acting on the digital simulation unmanned boat; τ p represents the moment acting on the rolling of the digital simulation unmanned boat; τ q represents the moment acting on the pitch of the digital simulation unmanned boat; τ q Indicates the moment acting on the bow of the digital simulation unmanned boat; The motion model of the digital simulation unmanned boat model is simplified and expressed as follows: Where: m 11 Indicates the longitudinal inertia coefficient of the digital simulation unmanned boat; m 22 Represents the lateral inertia coefficient of the digital simulation unmanned boat; m 33 Indicates the vertical inertia coefficient of the digital simulation unmanned boat; d 11 Represents the linear damping coefficient of the longitudinal motion of the digital simulation unmanned boat; d 22 Represents the linear damping coefficient of the lateral motion of the digital simulation unmanned boat; d 33 Represents the rotational damping coefficient of the vertical rotation of the digital simulation unmanned boat.

6. The method for cooperative control of unmanned boat swarm based on virtual-real combination according to claim 1 is characterized in that: The unmanned boat cluster formation adopts a triangular cluster formation.

7. The method for cooperative control of unmanned boat swarm based on virtual-real combination according to claim 1 is characterized in that: The method for obtaining the outline of the unmanned boats in the unmanned boat cluster formation is: According to the outline of the physical ship, 3D Max software is used to proportionally reduce the size of the physical ship and then perform three-dimensional modeling.

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