An unmanned ship formation turning formation keeping method, device and computer equipment

Abstract

The present application relates to unmanned ship control technical field, disclose a kind of unmanned ship formation turning formation keeping method, device and computer equipment, method includes: based on the relative position of initial leader unmanned ship of unmanned ship formation, determine follower unmanned ship;Based on the relative position determination first candidate unmanned ship and second candidate unmanned ship;Based on the navigation path of initial leader unmanned ship, first candidate unmanned ship and second candidate unmanned ship determine turning direction;When turning direction is left turn or right turn, determine target leader unmanned ship from candidate unmanned ship;Switch leader to target leader unmanned ship, turn according to turning direction, keep formation formation in turning process using formation turning formation control algorithm;Switch back to initial leader unmanned ship in the case where turning direction is straight ahead.The present application keeps formation stable in turning process by dynamic leader switching and formation turning formation control algorithm, avoids path convolution, improves formation stability.

Description

Technical Field

[0001] This invention relates to the field of unmanned surface vessel (USV) control technology, specifically to a method, apparatus, and computer equipment for maintaining the formation of USVs during turns. Background Technology

[0002] Unmanned surface vessels (USVs) swarms can rapidly and accurately explore and perceive environmental information in their area through division of labor and cooperation, finding wide application in various fields and scenarios such as security patrols and marine surveillance. In actual missions, multiple USVs typically navigate autonomously in a designated formation, following a specific route or towards a specific target. This requires the formation to establish and maintain a specific geometric shape, i.e., a formation configuration, while adapting to environmental constraints (such as obstacles) and mission changes (such as turns), adjusting its navigation strategy in real time to maintain formation stability.

[0003] When most unmanned surface vessel (USV) formations make coordinated turns, the USV on the inside of the turn experiences path swinging due to its own kinematic constraints, making it impossible to maintain formation. Current technologies typically address this issue by individually controlling the motion of the USV on the inside of the turn during the turn itself. However, this approach easily leads to formation instability, resulting in distance control issues and internal collisions within the formation. Summary of the Invention

[0004] In view of this, the present invention provides a method, apparatus and computer equipment for maintaining the formation of unmanned surface vessels (USVs) when turning, so as to solve the problem of unstable formation of USVs when turning.

[0005] In a first aspect, the present invention provides a method for maintaining the formation of an unmanned surface vessel (USV) convoy while turning, the method comprising:

[0006] Based on the initial leader UAV in the UAV formation, determine the relative positions of all follower UAVs in the UAV formation relative to the initial leader UAV. The relative position of any follower UAV includes the longitudinal and lateral displacements of the follower UAV relative to the initial leader UAV in the northeast coordinate system.

[0007] Based on the relative positions of all follower UAVs, a first candidate UAV and a second candidate UAV are determined from all follower UAVs. The first candidate UAV and the second candidate UAV are located to the left and right of the initial navigator UAV, respectively.

[0008] Based on the navigation paths of the initial navigator UAV, the first candidate UAV, and the second candidate UAV, the turning direction of the UAV formation is determined. The turning direction includes left turn, straight ahead, and right turn.

[0009] When the turning direction is left or right, the target navigator UAV is determined from the first candidate UAV and the second candidate UAV. The navigator of the UAV formation is switched from the initial navigator UAV to the target navigator UAV. The UAV turns according to the turning direction. The formation turning control algorithm is used to maintain the formation of the UAV formation during the turning process.

[0010] Continuously determine the turning direction of the unmanned surface vessel (USV) formation. When the turning direction is straight, switch the navigator of the USV formation from the target navigator USV to the initial navigator USV.

[0011] The unmanned surface vessel (USV) formation turning and formation maintenance method provided in this invention obtains precise relative positions by determining the longitudinal and lateral displacements of each follower in the USV formation relative to the initial leader. It then selects a first candidate USV to the left of the initial leader and a second candidate USV to the right, while simultaneously determining the turning direction of the USV formation. Based on the turning direction, it selects a target leader USV from the two candidate USVs to achieve leader switching, which facilitates a smooth transition during turns. Through an advanced formation turning and formation control algorithm, it ensures that each USV maintains a stable formation during turns. By accurately determining relative positions, intelligently selecting turning directions, dynamically switching leaders, and using the formation turning and formation control algorithm, the USV formation maintains its formation and achieves smooth turns, avoiding path looping of inner USVs during turns, reducing the risk of internal collisions, improving the stability of the USV formation, and adapting to different turning requirements, thus enhancing robustness and reliability.

[0012] In one optional implementation, determining a first candidate UAV and a second candidate UAV from all follower UAVs based on their relative positions includes:

[0013] Based on the relative positions of all follower UAVs, the follower UAV with the smallest longitudinal displacement is determined from all follower UAVs with the smallest lateral displacement and is selected as the first candidate UAV.

[0014] The follower UAV with the smallest longitudinal displacement is determined from all follower UAVs with the largest lateral displacement and selected as the second candidate UAV.

[0015] The unmanned surface vessel (USV) formation turning formation maintenance method provided in this invention determines candidate USVs to the left and right of the initial navigator USV, respectively. This allows the selection of USVs located on the innermost side of the curve when turning left and right, which helps to switch navigators later and thus ensures the formation stability of the USV formation during the turning process.

[0016] In one optional implementation, the turning direction of the unmanned surface vessel (USV) formation is determined based on the navigation paths corresponding to the initial navigator USV, the first candidate USV, and the second candidate USV, including:

[0017] Based on the relative positions of the initial navigator UAV, the first candidate UAV, and the second candidate UAV, a preset number of first position points are selected on the navigation path of the initial navigator UAV, a preset number of second position points are selected on the navigation path of the first candidate UAV, and a preset number of third position points are selected on the navigation path of the second candidate UAV.

[0018] Based on a vector composed of a preset number of first position points, a vector composed of a preset number of second position points, and a vector composed of a preset number of third position points, the first path turning value, the second path turning value, and the third path turning value are determined respectively.

[0019] If any one of the three path turning values ​​(first path turning value, second path turning value, and third path turning value) is positive, the turning direction of the unmanned surface vessel formation is determined to be a left turn; or,

[0020] If the first path turning value, the second path turning value, and the third path turning value are all zero, the turning direction of the unmanned surface vessel formation is determined to be straight ahead; or,

[0021] If any of the three path turning values ​​(first path turning value, second path turning value, and third path turning value) is negative, the turning direction of the unmanned surface vessel formation is determined to be a right turn.

[0022] The unmanned surface vessel (USV) formation turning and formation maintenance method provided in this invention selects position points on the navigation paths of the three USVs respectively. By analyzing multiple position points, the movement trend of the USVs can be better perceived. The vector formed by the position points is converted into a path turning value. By comprehensively considering the path turning values ​​of the initial navigator, the first candidate, and the second candidate USVs, the movement trend of the entire formation can be comprehensively evaluated, thus improving the accuracy of determining the turning direction.

[0023] In one optional implementation, the turning is performed according to the turning direction, and a formation turning control algorithm is used to maintain the formation of the unmanned surface vessel (USV) during the turning process, including:

[0024] Based on the target leader UAV, determine the relative positions of all follower UAVs in the UAV formation relative to the target leader UAV, and generate the target formation parameters;

[0025] For any follower UAV in the UAV formation, obtain the navigation parameters and environmental factors of the follower UAV at the current moment, and construct the kinematic and dynamic models of the follower UAV at the current moment. The navigation parameters include thrust and yaw moment.

[0026] Based on the target formation parameters, the kinematic model and dynamic model at the current moment, determine the expected position, expected speed and expected heading of the follower unmanned surface vessel at the next moment;

[0027] Based on the expected position, expected velocity, and expected heading at the next moment, determine the target thrust and target bow torque of the follower unmanned surface vessel;

[0028] Adjust the thrust and turning moment of the follower UAV at the current moment to achieve the target thrust and turning moment, return to the steps of obtaining the navigation parameters and environmental factors of the follower UAV at the current moment, and constructing the kinematic model and dynamic model of the follower UAV at the current moment, until the UAV formation completes the turn.

[0029] The unmanned surface vessel (USV) formation turning formation maintenance method provided in this invention determines the relative position of each follower USV with respect to the target leader USV, forming target formation parameters to ensure that the formation maintains a consistent formation during the turn. For each follower USV, a kinematic and dynamic model is constructed for the current moment, enabling real-time monitoring and adjustment of the formation state. Based on the above data, the desired position, desired velocity, and desired heading angle of each follower USV in the next moment are determined, thereby determining the corresponding target thrust and target turning torque. By adjusting the thrust and turning torque, each follower USV achieves the target thrust and target turning torque, ensuring coordinated movements of the formation during the turn and avoiding collisions or loss of control. By continuously acquiring and adjusting the current position to achieve the desired position in the next moment, the formation completes the turn, ensuring a stable formation is maintained during the turn.

[0030] In one optional implementation, for any follower UAV in the UAV platoon, the navigation parameters and environmental factors of the follower UAV at the current moment are obtained, and a kinematic model and a dynamic model of the follower UAV at the current moment are constructed, including:

[0031] Based on the navigation parameters of the follower UAV at the current moment, the actual position and heading of the follower UAV are determined, and the kinematic model at the current moment is generated. The actual position includes the longitude and latitude of the follower UAV in the northeast coordinate system.

[0032] Based on the navigation parameters and environmental factors of the follower UAV at the current moment, the longitudinal velocity, lateral velocity, and bow roll rate of the follower UAV are determined, and the dynamic model at the current moment is generated.

[0033] The unmanned surface vessel (USV) formation turning formation maintenance method provided in this invention, through detailed kinematic and dynamic modeling, can more accurately represent the current state of the USV formation and provide support for maintaining formation during turning.

[0034] In one optional implementation, based on the target formation parameters, the kinematic model and dynamic model at the current moment, the desired position, desired velocity, and desired heading of the follower unmanned surface vessel at the next moment are determined, including:

[0035] Based on the desired position of the follower UAV, the parameters of the target leader UAV in the target formation parameters, and the tangential angle of the desired navigation path of the follower UAV, a formation maintenance error expression is constructed. The formation maintenance error expression is used to represent the position error between the follower UAV and the target leader UAV in order to maintain the formation of the UAV formation. The position error includes longitudinal error and lateral error.

[0036] The expression for formation maintenance error is differentiated, and the longitudinal and lateral errors are determined based on the drift angle of the follower unmanned surface vessel, while the longitudinal and lateral errors converge.

[0037] Based on the expressions for the position error and formation maintenance error of the leader UAV, the expected position of the follower UAV at the next moment is obtained;

[0038] Based on the heading corresponding to the actual position, the desired position, the drift angle, the preset desired motion speed, the position error, and the lateral velocity at the current moment in the dynamic model, the desired velocity and desired heading are determined.

[0039] The unmanned surface vessel (USV) formation turning method provided in this invention, through detailed modeling and error analysis, can more accurately control the behavior of each USV, ensuring that they always remain in the ideal relative position, thereby maintaining the formation.

[0040] In one optional implementation, the target thrust and target bow turning moment of the follower unmanned surface vessel are determined based on the expected position, expected velocity, and expected heading at the next moment, including:

[0041] Based on the longitudinal velocity and desired velocity at the current moment in the dynamic model of the follower unmanned surface vessel, the velocity error is determined; based on the heading and desired heading at the current moment in the kinematic model of the follower unmanned surface vessel, the heading error is determined.

[0042] After differentiating the velocity error, a first sliding surface is set, and the first thrust is obtained by differentiating the first sliding surface.

[0043] Determine the second thrust during the switching process of the first sliding surface, and take the sum of the first thrust and the second thrust as the target thrust;

[0044] After differentiating the heading error, a second sliding surface is set, and the first bow torque is obtained by differentiating the second sliding surface.

[0045] Determine the second bow torque during the second sliding surface switching process, and take the sum of the first bow torque and the second bow torque as the target bow torque.

[0046] The unmanned surface vessel formation turning formation maintenance method provided in this embodiment of the invention, through sliding mode control, can quickly converge to the desired speed and heading in a short time, significantly improving control efficiency.

[0047] Secondly, the present invention provides an unmanned surface vessel (USV) formation turning and maintaining formation device, the device comprising:

[0048] The first determining module is used to determine the relative positions of all follower unmanned surface vessels (USVs) in the USV formation relative to the initial leader USV, based on the initial leader USV in the USV formation. The relative position of any follower USV includes the longitudinal and lateral displacements of the follower USV relative to the initial leader USV in the northeast-northeast coordinate system.

[0049] The second determining module is used to determine the first candidate unmanned surface vessel and the second candidate unmanned surface vessel from all the follower unmanned surface vessels based on the relative positions of all the follower unmanned surface vessels. The first candidate unmanned surface vessel and the second candidate unmanned surface vessel are located to the left and right of the initial navigator unmanned surface vessel, respectively.

[0050] The third determining module is used to determine the turning direction of the unmanned surface vessel formation based on the navigation paths corresponding to the initial navigator unmanned surface vessel, the first candidate unmanned surface vessel, and the second candidate unmanned surface vessel. The turning direction includes left turn, straight ahead, and right turn.

[0051] The turning control module is used to determine the target navigator UAV from the first candidate UAV and the second candidate UAV when the turning direction is left or right. It switches the navigator of the UAV formation from the initial navigator UAV to the target navigator UAV, turns according to the turning direction, and uses a formation turning formation control algorithm to maintain the formation of the UAV formation during the turning process.

[0052] The turning switching module is used to continuously determine the turning direction of the unmanned surface vessel (USV) formation. When the turning direction is straight, the navigator of the USV formation is switched from the target navigator USV to the initial navigator USV.

[0053] Thirdly, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the unmanned surface vessel formation turning formation maintenance method described in the first aspect or any corresponding embodiment thereof.

[0054] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the unmanned surface vessel formation turning and formation maintenance method described in the first aspect or any corresponding embodiment thereof. Attached Figure Description

[0055] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0056] Figure 1 This is a schematic diagram of the path rotation of an unmanned surface vessel formation when turning, according to an embodiment of the present invention;

[0057] Figure 2 This is a flowchart of a method for maintaining unmanned surface vessel formation during turning according to an embodiment of the present invention;

[0058] Figure 3 This is a schematic diagram of the location points according to an embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram illustrating the formation maintenance of unmanned surface vessels during turns according to an embodiment of the present invention;

[0060] Figure 5 This is a structural block diagram of an unmanned surface vessel formation turning and maintaining formation according to an embodiment of the present invention;

[0061] Figure 6 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] Figure 1 This is a schematic diagram of the path maneuvering of an unmanned surface vessel (USV) formation during a turn, according to an embodiment of the present invention. Figure 1 As shown, the yellow circles represent the leader UAVs, and the white circles represent the follower UAVs, which maintain a certain relative displacement with the leader UAV. The leader UAV moves along the path from yellow circle 1 to yellow circle 9, while the follower UAVs located inside the curve move from the corresponding white circle 1 to white circle 9. When the leader UAV is in yellow circle 1, the follower UAV is in white circle 1, and so on. Due to its own dynamic constraints, i.e., the turning radius constraints of the UAVs at different speeds, the follower UAVs appear on the following path loop when maintaining the path from white circle 1 to circle 9, making it impossible to maintain formation during the turn. To solve the above problem, the existing technology separately controls the motion of the UAVs inside the curve during the turn, which makes the formation unstable, resulting in distance control problems and internal collisions within the formation. The unmanned surface vessel (USV) formation turning formation maintenance method provided in this invention enables smooth turning of the USV formation by accurately determining the relative position, intelligently selecting the turning direction, dynamically switching the navigator, and using a formation turning formation control algorithm. This avoids path swirl of the inner USVs during turns, reduces the risk of internal collisions, and improves the stability of the USV formation.

[0064] According to an embodiment of the present invention, an embodiment of a method for maintaining the turning formation of unmanned surface vessels is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0065] This embodiment provides a method for maintaining unmanned surface vessel (USV) formation while turning, which can be used on a terminal such as a computer. Figure 2 This is a flowchart of a method for maintaining formation while turning in unmanned surface vessels according to an embodiment of the present invention, as shown below. Figure 2 As shown, the process includes the following steps:

[0066] Step S201: Based on the initial leader UAV in the UAV formation, determine the relative positions of all follower UAVs in the formation relative to the initial leader UAV. The relative position of any follower UAV includes its longitudinal and lateral displacements relative to the initial leader UAV in the northeast-northeast coordinate system. Specifically, an UAV formation typically includes one leader UAV and multiple follower UAVs. Each follower UAV maintains a certain distance and orientation from the leader UAV to maintain formation stability. Using the initial leader UAV as a reference point, the lateral and longitudinal displacements of each follower UAV relative to it can be obtained.

[0067] Optionally, the relative positions of all unmanned surface vessels in the unmanned surface vessel formation can be used as the formation parameters, as shown in equation (1) below.

[0068]

[0069] Where l represents the index of the initial navigator unmanned surface vessel; F(l) represents the formation parameters; and N represents the number of unmanned surface vessels in the formation. This represents the longitudinal displacement of the Nth unmanned surface vessel relative to the initial navigator unmanned surface vessel; This represents the lateral displacement of the Nth unmanned surface vessel relative to the initial navigator unmanned surface vessel.

[0070] Step S202: Based on the relative positions of all follower UAVs, a first candidate UAV and a second candidate UAV are determined from all follower UAVs. The first candidate UAV and the second candidate UAV are located to the left and right of the initial navigator UAV, respectively. Specifically, in order to solve the path turning problem of the inner UAV during turns, this embodiment of the invention considers switching the navigator, that is, switching the navigator to the innermost candidate UAV of the curve during turns.

[0071] Step S203: Based on the navigation paths of the initial navigator UAV, the first candidate UAV, and the second candidate UAV, determine the turning direction of the UAV formation. The turning direction includes left turn, straight ahead, and right turn. Specifically, since the turning directions include left turn, straight ahead, and right turn, and the navigator switching strategy is different for different turning directions, the turning direction of the UAV formation is accurately determined by using the navigation paths of the initial navigator UAV, the first candidate UAV, and the second candidate UAV.

[0072] Step S204: When the turning direction is left or right, a target leader UAV is determined from the first and second candidate UAVs. The leader of the UAV formation is switched from the initial leader UAV to the target leader UAV. The UAV then turns according to the turning direction, and a formation turning control algorithm is used to maintain the formation of the UAV formation during the turn. Specifically, since path loops occur on the inside of the curve, and there are no curves when the turning direction is straight, there is no need to switch the leader when the turning direction is straight. When the turning direction is left or right, the corresponding UAV is determined from the two candidate UAVs as the target leader UAV. The leader of the UAV formation is switched. When the new target leader UAV leads the UAV formation to turn, the formation turning control algorithm is used to adjust the navigation parameters of each follower UAV to ensure that the UAV formation maintains a smooth turn during the turn and does not experience path loops, thereby avoiding collisions between UAVs.

[0073] Step S205: Continuously determine the turning direction of the unmanned surface vessel (USV) formation. If the turning direction is straight, switch the navigator of the USV formation from the target navigator USV to the initial navigator USV. Specifically, continuously determine the turning direction of the USV formation. If the turning direction is left or right, maintain the formation during the turn by switching the navigator and the formation turning formation control algorithm. If the formation's turning direction is straight, switch the navigator back to the initial navigator USV, thereby restoring the original formation, maintaining formation consistency and stability, and avoiding formation deviations and error accumulation caused by long-term use of different navigators.

[0074] The unmanned surface vessel (USV) formation turning and formation maintenance method provided in this invention obtains precise relative positions by determining the longitudinal and lateral displacements of each follower in the USV formation relative to the initial leader. It then selects a first candidate USV to the left of the initial leader and a second candidate USV to the right, while simultaneously determining the turning direction of the USV formation. Based on the turning direction, it selects a target leader USV from the two candidate USVs to achieve leader switching, which facilitates a smooth transition during turns. Through an advanced formation turning and formation control algorithm, it ensures that each USV maintains a stable formation during turns. By accurately determining relative positions, intelligently selecting turning directions, dynamically switching leaders, and using the formation turning and formation control algorithm, the USV formation maintains its formation and achieves smooth turns, avoiding path looping of inner USVs during turns, reducing the risk of internal collisions, improving the stability of the USV formation, and adapting to different turning requirements, thus enhancing robustness and reliability.

[0075] This embodiment provides a method for maintaining the formation when turning in unmanned surface vessels, which can be used in the aforementioned terminal, such as a computer. The method specifically includes the following steps:

[0076] Step S301: Based on the initial leader UAV in the UAV formation, determine the relative positions of all follower UAVs in the formation relative to the initial leader UAV. The relative position of any follower UAV includes its longitudinal and lateral displacements relative to the initial leader UAV in the northeast-northeast coordinate system. For details, please refer to [link to relevant documentation]. Figure 2 Step S201 of the illustrated embodiment will not be described again here.

[0077] Step S302: Based on the relative positions of all follower unmanned surface vessels (USVs), determine the first candidate USV and the second candidate USV from all follower USVs. The first candidate USV and the second candidate USV are located to the left and right of the initial navigator USV, respectively.

[0078] Specifically, step S302 includes:

[0079] Step S3021: Based on the relative positions of all follower UAVs, determine the follower UAV with the smallest longitudinal displacement from all follower UAVs with the smallest lateral displacement, and designate it as the first candidate UAV. Specifically, since the UAV formation can turn left or right, a candidate UAV needs to be determined for each turn. Select the follower UAV located at the lower left corner of the UAV formation as the first candidate UAV. More specifically, select all follower UAVs with the smallest lateral displacement, i.e., those located on the far left of the initial leader UAV. Among these leftmost follower UAVs, further select the UAV with the smallest longitudinal displacement as the first candidate UAV.

[0080] Step S3022: From all follower UAVs with the largest lateral displacement, determine the follower UAV with the smallest longitudinal displacement as the second candidate UAV. Specifically, select a follower UAV located at the lower right corner of the UAV formation as the second candidate UAV. More specifically, filter out all follower UAVs with the largest lateral displacement, i.e., those located on the far right of the initial leader UAV. Among these rightmost follower UAVs, further filter out the UAV with the smallest longitudinal displacement as the second candidate UAV.

[0081] Step S303: Based on the navigation paths of the initial navigator UAV, the first candidate UAV, and the second candidate UAV, determine the turning direction of the UAV formation. The turning direction includes left turn, straight ahead, and right turn.

[0082] Specifically, step S303 includes:

[0083] Step S3031: Based on the relative positions of the initial navigator UAV, the first candidate UAV, and the second candidate UAV, a preset number of first position points are selected on the navigation path of the initial navigator UAV, a preset number of second position points are selected on the navigation path of the first candidate UAV, and a preset number of third position points are selected on the navigation path of the second candidate UAV. Specifically, in the navigator-follower mode, generally only the path is planned for the navigator UAV, and the other follower UAVs follow the movement of the navigator UAV. After two candidate UAVs are determined through step S302, the navigation paths of the two candidate UAVs can be determined according to their relative positions and the navigation path of the initial navigator UAV, as represented by the following formulas (2) and (3), respectively.

[0084]

[0085] Where, Path L (x,y) represents the navigation path of the first candidate unmanned surface vessel; Indicates the relative position of the first candidate unmanned surface vessel; This represents the position point along the initial navigator unmanned surface vessel's path, measured longitudinally. Translation, performed horizontally. Translation; Path R (x,y) represents the navigation path of the second candidate unmanned surface vessel; Indicates the relative position of the second candidate unmanned surface vessel; This represents the position point along the initial navigator unmanned surface vessel's path, measured longitudinally. Translation, performed horizontally. Translation.

[0086] In some alternative implementations, based on the current positions of the three unmanned surface vessels, a preset number of positions are taken along the forward direction on each of the three paths at preset step sizes. Figure 3 This is a schematic diagram of the location points according to an embodiment of the present invention, such as... Figure 3 As shown, taking the selection of three locations on the initial navigator unmanned surface vessel's (USV) navigation path as an example, P 0,l P represents the current position. 1,l P represents a position point that is one step away from the current position. 2,l This represents a position two steps away from the current position. And P 0,l With P 1,l The distance between and P 1,l With P 2,l The distances between them are consistent, each being one step. The position points of the first and second candidate unmanned surface vessels are selected with reference to the initial navigator unmanned surface vessel, and will not be repeated here.

[0087] Step S3032: Based on the vector formed by a preset number of first position points, the vector formed by a preset number of second position points, and the vector formed by a preset number of third position points, determine the first path turning value, the second path turning value, and the third path turning value, respectively. Specifically, the first path turning value, the second path turning value, and the third path turning value are determined by the following formulas (4)-(6) to represent the turning trend of the initial navigator unmanned surface vessel.

[0088]

[0089] Among them, Direc l Indicates the first path turning value; P 0,l P represents the current position of the initial navigator unmanned surface vessel; 1,l P represents a position point that is one step away from the current position. 2,l This indicates a position that is two steps away from the current position.

[0090]

[0091] Among them, Direc L Indicates the second path turning value; P 0,L P represents the current position of the first candidate unmanned surface vessel; 1,L P represents a position point that is one step away from the current position. 2,L This indicates a position that is two steps away from the current position.

[0092]

[0093] Among them, Direc R Indicates the third path turning value; P 0,R P represents the current position of the second candidate unmanned surface vessel; 1,R P represents a position point that is one step away from the current position. 2,R This indicates a position that is two steps away from the current position.

[0094] Step S3033: If any one of the three path turning values ​​(first, second, and third) is positive, the turning direction of the unmanned surface vessel (USV) formation is determined to be a left turn. Specifically, the three path turning values ​​obtained through the cross product of vectors reflect the rotation direction between vectors, thus indicating the turning trend of the USVs. When any one of the three path turning values ​​is positive, according to the right-hand rule, the turning direction of the USV formation is left.

[0095] Alternatively, in step S3034, if the first path turning value, the second path turning value, and the third path turning value are all zero, the turning direction of the unmanned surface vessel formation is determined to be straight. Specifically, when all three path turning values ​​are 0, it indicates that the vector has not formed an angle, and in this case, it is straight.

[0096] Alternatively, in step S3035, if any one of the three path turning values ​​(first, second, and third) is negative, the turning direction of the unmanned surface vessel (USV) formation is determined to be a right turn. Specifically, when any one of the three path turning values ​​is negative, according to the right-hand rule, the turning direction of the USV formation is determined to be a right turn.

[0097] Step S304: When the turning direction is left or right, a target leader UAV is determined from the first and second candidate UAVs. The leader of the UAV formation is switched from the initial leader UAV to the target leader UAV. The UAV then turns according to the turning direction, and a formation control algorithm is used to maintain the formation of the UAV formation during the turn. Specifically, when the turning direction is left, the first candidate UAV is located at the lower left corner of the formation, i.e., closest to the inside of the curve, and is thus determined as the target leader UAV. When the turning direction is right, the second candidate UAV is located at the lower right corner of the formation, i.e., closest to the inside of the curve, and is thus determined as the target leader UAV. By determining the target leader UAV, switching the formation's leader to the target leader UAV ensures a smooth turn and avoids path looping.

[0098] Specifically, step S304 above involves turning in the direction of turn, employing a formation turning control algorithm to maintain the unmanned surface vessel's formation during the turn, including:

[0099] Step S3041: Based on the target leader UAV, determine the relative positions of all follower UAVs in the UAV formation relative to the target leader UAV, forming the target formation parameters. Specifically, switch the formation leader from the initial leader UAV to the target leader UAV, and redetermine the relative positions of each follower UAV relative to the target leader UAV, forming the target formation parameters as shown in equation (7). Optionally, simply subtract the relative displacement between the initial leader and the target leader from the above equation (1), that is, from the formation parameters corresponding to the initial leader UAV.

[0100]

[0101] Where m represents the index of the target navigator unmanned surface vessel; F(m) represents the formation parameters of the target formation; and N represents the number of unmanned surface vessels in the formation. This represents the longitudinal displacement of the Nth unmanned surface vessel relative to the initial navigator unmanned surface vessel; This represents the lateral displacement of the Nth unmanned surface vessel relative to the initial navigator unmanned surface vessel; This represents the longitudinal displacement of the target navigator UAV relative to the initial navigator UAV; This represents the lateral displacement of the target navigator UAV relative to the initial navigator UAV.

[0102] Step S3042: For any follower UAV in the UAV formation, obtain the navigation parameters and environmental factors of the follower UAV at the current moment, and construct the kinematic model and dynamic model of the follower UAV at the current moment. The navigation parameters include thrust and yaw moment.

[0103] In some optional implementations, step S3042 above includes:

[0104] Step a1: Based on the navigation parameters of the follower UAV at the current moment, determine the actual position and heading of the follower UAV, and generate the kinematic model for the current moment. The actual position includes the longitude and latitude of the follower UAV in the northeast coordinate system. Specifically, by considering the navigation parameters of the follower UAV and environmental factors, the kinematic model shown in Equation (8) is constructed.

[0105]

[0106] Where x, y, ψ represent the longitude, latitude, and heading of the follower UAV in the northeast coordinate system; u, v, r represent the longitudinal velocity, lateral velocity, and bow roll rate of the follower UAV in the ship's coordinate system, where the origin of the ship's coordinate system is the ship's center of gravity, the x-axis is the ship's centerline pointing from the stern to the bow, the y-axis points from the port side to the starboard side, and the z-axis is the direction of gravity.

[0107] Step a2: Based on the navigation parameters and environmental factors of the follower UAV at the current moment, determine the longitudinal velocity, lateral velocity, and bow angular velocity of the follower UAV, and generate the dynamic model for the current moment. Specifically, since UAVs are generally underactuated, only three degrees of freedom are considered when applying the formation turning control algorithm: sway, roll, and bow. By considering the navigation parameters and environmental factors of the follower UAV, the kinematic model shown in equation (9) is constructed.

[0108]

[0109] Where u, v, r represent the longitudinal velocity, lateral velocity, and bow roll rate of the follower unmanned surface vessel in the ship's coordinate system; (m 11 ,m 22 ,m 33 (d) represents the inertial mass parameter of the follower unmanned surface vessel (USV) in the pitch, sway, and yaw directions, including the USV's mass and its added mass; 11 ,d 22 ,d 33 (τ) represents the damping coefficient of the follower unmanned surface vessel in the pitch, sway, and yaw directions; u ,τ r (τ) represents thrust and turning torque; eu ,τ ev ,τ er ) represents the disturbance vector generated by wind and wave surges in the sway, sway, and pitch directions.

[0110] Step S3043: Based on the target formation parameters, the kinematic model and dynamic model at the current moment, determine the expected position, expected speed and expected heading of the follower unmanned surface vessel at the next moment.

[0111] In some optional implementations, step S3043 above includes:

[0112] Step b1: Based on the desired position of the follower UAV, the parameters of the target leader UAV in the target formation formation parameters, and the tangential angle of the desired navigation path of the follower UAV, a formation maintenance error expression is constructed. This expression represents the positional error between the follower UAV and the target leader UAV in order to maintain the formation of the UAV formation. The positional error includes longitudinal and lateral errors. Specifically, the desired navigation path of any follower UAV can be obtained through the Path() function. During the UAV formation navigation, each follower UAV maintains a certain distance from the leader UAV, i.e., a positional error. This positional error must be maintained during turns to maintain formation stability. Optionally, this positional error can be represented by the following equation (10).

[0113]

[0114] Among them, [x i ,y i ] T Indicates the longitude and latitude of the follower unmanned surface vessel's actual location; ψ pi The tangential angle representing the expected navigation path of the follower unmanned surface vessel can be derived from... Calculated; [x ei ,y ei ] T Indicates position error, x ei Represents the longitudinal error, y ei Indicates lateral error; [x di ,y di ] T Indicates the desired position of the follower unmanned surface vessel; [x l ,y l ] T This indicates the longitude and latitude of the target navigator unmanned surface vessel.

[0115] Step b2: Differentiate the expression for formation maintenance error. Based on the drift angle of the follower UAV, determine the longitudinal and lateral errors while converging the longitudinal and lateral errors. Specifically, differentiating the above equation (10) yields the following equation (11).

[0116]

[0117] Among them, [x ei ,y ei] T Indicates position error, x ei Represents the longitudinal error, y ei Indicates lateral error; u represents the resultant velocity of the unmanned surface vessel. i and v i For the longitudinal and lateral velocities in the dynamic model; x represents the preset expected velocity of the follower unmanned surface vessel (USV) to indicate its desired flight path. di and y di ψ is the desired position. i ψ represents the heading in the kinematic model. pi The tangential angle represents the expected navigation path of the follower unmanned surface vessel; This indicates the drift angle of the unmanned surface vessel following the user.

[0118] The drift angle formed by external disturbances such as wind, waves, and currents, as well as the lateral velocity caused by turning, is very small, thus making cosβ... i ≈1, sinβ i ≈β i Define the reduced-order extended state observer as shown in equation (12) to estimate the drift angle, and obtain the drift angle estimate shown in equation (13). Substitute the drift angle estimate into equation (11) above.

[0119]

[0120] Where p represents the observer state; k1 represents the observer reward; ψ pi ψ represents the tangential angle of the expected navigation path of the follower unmanned surface vessel. di Indicates the desired heading corresponding to the desired location; This represents the estimated value of g, where g represents a nonlinear function, enabling the estimation of uncertainties or disturbances in the drift angle estimation system. And p(t0)=k1y ei (t0); x ei U represents the longitudinal error, yei represents the lateral error; i This indicates the combined speed of the unmanned surface vessel.

[0121]

[0122] in, Indicates the estimated drift angle; U i ψ represents the resultant velocity of the unmanned surface vessel following the unmanned surface vessel. pi ψ represents the tangential angle of the expected navigation path of the follower unmanned surface vessel. di This indicates the desired heading corresponding to the desired location.

[0123] Step b3: Based on the position error and formation maintenance error expressions of the leader UAV, the expected position of the follower UAV at the next moment is obtained. Specifically, by substituting the lateral error and longitudinal error calculated after differentiation into the above equation (10), the expected position at the next moment can be obtained, which is the position that the follower UAV needs to move to at the next moment.

[0124] Step b4: Based on the heading corresponding to the actual position, the desired position, the drift angle, the preset desired motion speed, the position error, and the lateral velocity at the current moment in the dynamic model, determine the desired speed and desired heading. Specifically, the following formula (14) is the expression for determining the desired speed and desired heading. Through the above various data, the desired speed and desired heading that the follower unmanned surface vessel should have to move to the desired position are obtained.

[0125]

[0126] Where, ψ di Indicates the desired heading; ψ p i Δ1 represents the tangential angle of the expected navigation path of the follower unmanned surface vessel; k2 and k3 represent variable coefficients, which have no physical meaning and satisfy k2 > 1 and 0 < k3 < 1; Δ1 > 0 represents the forward sight distance. This indicates a finite-time term; k4 > 0 indicates a relative velocity adjustment term. U represents the desired speed; di The preset expected velocity represents the desired flight path of the follower unmanned surface vessel; x ei Represents the longitudinal error, y ei Indicates lateral error; β i The drift angle of the follower unmanned surface vessel is estimated using the drift angle calculated by formula (13) above; v i This indicates lateral velocity.

[0127] Step S3044: Based on the expected position, expected velocity and expected heading at the next moment, determine the target thrust and target bow torque of the follower unmanned surface vessel.

[0128] In some optional implementations, step S3044 above includes:

[0129] Step c1: Based on the longitudinal velocity and desired velocity at the current moment in the dynamic model of the follower unmanned surface vessel (USV), determine the velocity error; based on the bow direction and desired bow direction at the current moment in the kinematic model of the USV, determine the bow direction error. Specifically, the difference between the current longitudinal velocity and the desired velocity is determined as the velocity error, and the difference between the current bow direction and the desired bow direction is determined as the bow direction error.

[0130] Step c2: After differentiating the velocity error, set the first sliding surface, and differentiate the first sliding surface to obtain the first thrust. Specifically, differentiating the velocity error yields the following equation (15).

[0131]

[0132] Among them, u ei Indicates speed error; r i This indicates the bow roll rate of the follower unmanned surface vessel; u i and v i For the longitudinal and lateral velocities in the dynamic model; (m 11 ,m 22 ) represents the inertial mass parameter of the follower unmanned surface vessel (USV) in the pitch and sway directions, including the USV's mass and its added mass; d 11 τ represents the damping coefficient of the follower unmanned surface vessel in the pitch direction; u τ represents thrust; eu This represents the disturbance vector generated by the swell in the direction of the wave flow; Indicates the desired speed.

[0133] Define an integral first-order exponentially stable sliding surface:

[0134]

[0135] Among them, u ei λ represents the speed error; λ1 represents the preset coefficient.

[0136] Differentiating the first sliding surface of equation (16) above, we obtain equation (17):

[0137]

[0138] Where S1 represents the first sliding surface; u ei Indicates speed error; (m) 11 ,m 22 ) represents the inertial mass parameter of the follower unmanned surface vessel (USV) in the pitch and sway directions, including the USV's mass and its added mass; d 11 The damping coefficient of the follower unmanned surface vessel in the pitch direction; r i This indicates the bow roll rate of the follower unmanned surface vessel; u i and v i For the longitudinal and lateral velocities in the dynamic model; τ represents the desired velocity. uq λ represents the first thrust; λ1 represents the preset coefficient.

[0139] make Substituting into equation (17) above, we can obtain the first thrust shown in equation (18) below.

[0140]

[0141] Where, τ uq Indicates the first thrust; This represents an estimate of the inertial mass parameter of the follower unmanned surface vessel in the pitch and sway directions, including the mass of the unmanned surface vessel and its added mass. This represents an estimate of the damping coefficient of the follower unmanned surface vessel in the pitch direction; r i This indicates the bow roll rate of the follower unmanned surface vessel; u i and v i For the longitudinal and lateral velocities in the dynamic model; Indicates the desired speed; u ei λ represents the speed error; λ1 represents the preset coefficient.

[0142] Step c3: Determine the second thrust during the switching process of the first sliding surface, and use the sum of the first and second thrusts as the target thrust. Specifically, in practical engineering applications, it is necessary to control the problem of severe vibration on the sliding surface. Within the Δ2 domain above and below the switching point of the sliding surface, a smooth sliding surface is used to replace the severe switching, thereby reducing the vibration phenomenon during the switching process, and the second thrust during the switching process is shown in the following formula (19).

[0143] τ uqs =-k5sat(S1)-k6S1

[0144]

[0145] Where, τ uqs S1 represents the second thrust; k5 > 0 represents the variable coefficient; k6 represents the parameter of sat(S1); Δ2 represents the set boundary layer.

[0146] As shown in Equation (20), the sum of the first thrust and the second thrust is determined as the target thrust of the follower unmanned surface vessel.

[0147]

[0148] Where, τ u Indicates the target thrust; τ uq Indicates the first thrust; τ uqs This indicates the second thrust.

[0149] Step c4: After differentiating the heading error, a second sliding surface is set, and the second sliding surface is differentiated to obtain the first bow torque. Specifically, the second derivative of the heading error is obtained as follows (21).

[0150]

[0151] Where, ψ ei Indicates heading error; ψ i ψ represents the heading in the kinematic model. di Indicates the desired heading.

[0152] Design the second sliding surface as shown in equation (22):

[0153]

[0154] Where S2 represents the second sliding surface; ψ ei λ represents the heading error; λ2 represents the preset coefficient.

[0155] Differentiating the first sliding surface of equation (22) above, we obtain equation (23):

[0156]

[0157] Where S2 represents the second sliding surface; ψ i ψ represents the heading in the kinematic model. di Indicates the desired heading; (m) 11 ,m 22 ,m 33 ) represents the inertial mass parameter of the follower unmanned surface vessel in the pitch, sway, and yaw directions, including the mass of the unmanned surface vessel and its added mass; This represents an estimate of the inertial mass parameter of the follower unmanned surface vessel (USV) in the yaw direction, including the USV's mass and its added mass; d 33 The damping coefficient r represents the drag coefficient of the follower unmanned surface vessel in the yaw direction. i This indicates the bow roll rate of the follower unmanned surface vessel; u i and v i For the longitudinal and lateral velocities in the dynamic model; τ rq λ1 represents the first turning torque; λ2 represents the preset coefficient.

[0158] make Substituting into equation (23) above, we can obtain the first yaw torque shown in equation (24) below.

[0159]

[0160] Where, τ rq Indicates the first turning torque; The estimated values ​​of the inertial mass parameters of the follower unmanned surface vessel in the pitch, sway, and yaw directions, including the mass of the unmanned surface vessel and its added mass. This represents an estimated value of the damping coefficient of the follower unmanned surface vessel in the yaw direction; r i This indicates the bow roll rate of the follower unmanned surface vessel; ui and v i For the longitudinal and lateral velocities in the dynamic model; ψ di λ represents the desired heading; λ2 represents the preset coefficient.

[0161] Step c5: Determine the second bow torque during the second sliding surface switching process, and use the sum of the first bow torque and the second bow torque as the target bow torque. Specifically, referring to the sliding surface switching process in step c3, the second bow torque during the second sliding surface switching process is determined by the following formula (25).

[0162] τ rqs =-k7sat(S2)-k8S2

[0163]

[0164] Where, τ rqs S1 represents the second turning torque; S2 represents the second sliding surface; k7 > 0 represents the variable coefficient, which has no physical meaning; k8 represents the parameter of sat(S2); Δ3 represents the set boundary layer.

[0165] As shown in Equation (26), the sum of the first and second bow torques is determined as the target bow torque of the follower unmanned surface vessel.

[0166]

[0167] Where, τ r Indicates the target turning torque; τ rq τ represents the first turning torque. rqs This indicates the second turning torque.

[0168] Step S3045: Adjust the thrust and turning moment of the follower UAVs at the current moment to achieve the target thrust and target turning moment. Return to the step of obtaining the navigation parameters and environmental factors of the follower UAVs at the current moment, and constructing the kinematic and dynamic models of the follower UAVs at the current moment, until the UAV formation completes the turn. Specifically, adjust the thrust and turning moment in the navigation parameters of each follower UAV to achieve its corresponding target thrust and target turning moment, so that each follower UAV can move to the desired position, thereby ensuring that the UAV formation maintains formation stability during the turn. After adjusting the navigation parameters of all follower UAVs at the current moment, return to step S3042 to continue determining the desired position, target thrust, and target turning moment that each follower UAV should reach at the next moment, until the UAV formation completes the turn.

[0169] Step S305: Continuously determine the turning direction of the unmanned surface vessel (USV) formation. If the turning direction is straight ahead, switch the navigator of the USV formation from the target navigator USV to the initial navigator USV. For details, please refer to [link to details]. Figure 2 Step S205 of the illustrated embodiment will not be described again here.

[0170] In some alternative implementations, Figure 4 This is a schematic diagram of unmanned surface vessels maintaining formation while turning, according to an embodiment of the present invention. Figure 4 As shown, the dashed line represents the initial navigator UAV's navigation path. While the initial navigator UAV follows this path, it continuously determines its turning direction. When it reaches the position of yellow circle 2, the turning direction is left. At this point, the navigator switches to yellow circle 3, and the formation turning control algorithm is applied to maintain the formation and complete the turn. When it reaches the position of yellow circle 6, the determined turning direction is straight ahead. The navigator needs to be switched back to the initial navigator UAV, and the UAV continues to follow the initial navigation path, i.e., from yellow circle 7 to yellow circle 9.

[0171] The unmanned surface vessel (USV) formation turning and formation maintenance method provided in this invention obtains precise relative positions by determining the longitudinal and lateral displacements of each follower in the USV formation relative to the initial leader. It then selects a first candidate USV to the left of the initial leader and a second candidate USV to the right, while simultaneously determining the turning direction of the USV formation. Based on the turning direction, it selects a target leader USV from the two candidate USVs to achieve leader switching, which facilitates a smooth transition during turns. Through an advanced formation turning and formation control algorithm, it ensures that each USV maintains a stable formation during turns. By accurately determining relative positions, intelligently selecting turning directions, dynamically switching leaders, and using the formation turning and formation control algorithm, the USV formation maintains its formation and achieves smooth turns, avoiding path looping of inner USVs during turns, reducing the risk of internal collisions, improving the stability of the USV formation, and adapting to different turning requirements, thus enhancing robustness and reliability.

[0172] This embodiment also provides an unmanned surface vessel (USV) formation turning and formation maintenance device, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as already described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0173] This embodiment provides a device for maintaining the formation when an unmanned surface vessel (USV) turns, such as... Figure 5 As shown, it includes:

[0174] The first determining module 501 is used to determine the relative positions of all follower unmanned surface vessels (USVs) in the USV formation relative to the initial leader USV, based on the initial leader USV in the USV formation. The relative position of any follower USV includes the longitudinal and lateral displacements of the follower USV relative to the initial leader USV in the northeast coordinate system.

[0175] The second determining module 502 is used to determine a first candidate unmanned surface vessel and a second candidate unmanned surface vessel from all the follower unmanned surface vessels based on the relative positions of all the follower unmanned surface vessels. The first candidate unmanned surface vessel and the second candidate unmanned surface vessel are located to the left and right of the initial navigator unmanned surface vessel, respectively.

[0176] The third determining module 503 is used to determine the turning direction of the unmanned surface vessel formation based on the navigation paths corresponding to the initial navigator unmanned surface vessel, the first candidate unmanned surface vessel, and the second candidate unmanned surface vessel. The turning direction includes left turn, straight ahead, and right turn.

[0177] The turning control module 504 is used to determine the target navigator UAV from the first candidate UAV and the second candidate UAV when the turning direction is left or right, switch the navigator of the UAV formation from the initial navigator UAV to the target navigator UAV, turn according to the turning direction, and use a formation turning formation control algorithm to maintain the formation of the UAV formation during the turning process.

[0178] The turning switching module 505 is used to continuously determine the turning direction of the unmanned surface vessel (USV) formation. When the turning direction is straight, the navigator of the USV formation is switched from the target navigator USV to the initial navigator USV.

[0179] In some alternative implementations, the second determining module 502 includes:

[0180] The first determining unit is used to determine the follower unmanned surface vessel with the smallest longitudinal displacement from all follower unmanned surface vessels with the smallest lateral displacement based on the relative positions of all follower unmanned surface vessels, and to select the follower unmanned surface vessel as the first candidate unmanned surface vessel.

[0181] The second determining unit is used to determine the follower unmanned surface vessel with the smallest longitudinal displacement from all follower unmanned surface vessels with the largest lateral displacement, and to select it as the second candidate unmanned surface vessel.

[0182] In some alternative implementations, the third determining module 503 includes:

[0183] The selection unit is used to select a preset number of first position points on the navigation path of the initial navigator unmanned surface vessel, a preset number of second position points on the navigation path of the first candidate unmanned surface vessel, and a preset number of third position points on the navigation path of the second candidate unmanned surface vessel, based on the relative positions of the initial navigator unmanned surface vessel, the first candidate unmanned surface vessel, and the second candidate unmanned surface vessel.

[0184] The third determining unit is used to determine the first path turning value, the second path turning value, and the third path turning value based on the vector formed by the preset number of first position points, the vector formed by the preset number of second position points, and the vector formed by the preset number of third position points, respectively.

[0185] The first direction determination unit is used to determine the turning direction of the unmanned surface vessel formation as left turn when any one of the first path turning value, the second path turning value, and the third path turning value is positive.

[0186] Alternatively, the second direction determination unit is used to determine that the turning direction of the unmanned surface vessel formation is straight when the first path turning value, the second path turning value, and the third path turning value are all zero.

[0187] Alternatively, a third direction determination unit is used to determine that the turning direction of the unmanned surface vessel formation is a right turn when any of the path turning values ​​among the first path turning value, the second path turning value, and the third path turning value is negative.

[0188] In some alternative implementations, the turning control module 504 includes:

[0189] The generation unit is used to determine the relative positions of all follower UAVs in the UAV formation relative to the target leader UAV, based on the target leader UAV, and generate the target formation parameters.

[0190] The construction unit is used to obtain the navigation parameters and environmental factors of any follower UAV in the UAV formation at the current moment, and to construct the kinematic and dynamic models of the follower UAV at the current moment. The navigation parameters include thrust and yaw moment.

[0191] The fourth determining unit is used to determine the expected position, expected speed, and expected heading of the follower unmanned surface vessel at the next moment, based on the target formation parameters, the kinematic model and dynamic model at the current moment.

[0192] The fifth determining unit is used to determine the target thrust and target bow torque of the follower unmanned surface vessel based on the expected position, expected velocity and expected heading at the next moment.

[0193] The control unit is used to adjust the thrust and turning torque of the follower UAV at the current moment to achieve the target thrust and target turning torque, return to the steps of obtaining the navigation parameters and environmental factors of the follower UAV at the current moment, and constructing the kinematic model and dynamic model of the follower UAV at the current moment, until the UAV formation completes the turn.

[0194] In some alternative implementations, the building unit includes:

[0195] The first generation sub-unit is used to determine the actual position and heading of the follower UAV based on the navigation parameters corresponding to the current moment, and generate the kinematic model of the current moment. The actual position includes the longitude and latitude of the follower UAV in the northeast coordinate system.

[0196] The second generation sub-unit is used to determine the longitudinal velocity, lateral velocity, and bow roll rate of the follower UAV based on the navigation parameters and environmental factors corresponding to the current moment, and generate the dynamic model of the current moment.

[0197] In some optional implementations, the fourth determining unit includes:

[0198] A sub-unit is constructed to build a formation-keeping error expression based on the desired position of the follower UAV, the parameters of the target leader UAV in the target formation parameters, and the tangential angle of the desired navigation path of the follower UAV. The formation-keeping error expression is used to represent the positional error between the follower UAV and the target leader UAV in order to maintain the formation of the UAV formation. The positional error includes longitudinal error and lateral error.

[0199] The derivative sub-unit is used to differentiate the expression for formation maintenance error. Based on the drift angle of the follower UAV, the longitudinal and lateral errors are determined while converging.

[0200] The first determining sub-unit is used to obtain the expected position of the follower unmanned surface vessel at the next moment based on the position error and formation maintenance error expressions of the leader unmanned surface vessel.

[0201] The second determining sub-unit is used to determine the desired velocity and desired heading based on the heading corresponding to the actual position, the desired position, the drift angle, the preset desired motion velocity, the position error, and the lateral velocity at the current moment in the dynamic model.

[0202] In some optional implementations, the fifth determining unit includes:

[0203] The third determining sub-unit is used to determine the velocity error based on the longitudinal velocity and desired velocity at the current moment in the dynamic model of the follower unmanned surface vessel, and to determine the heading error based on the heading and desired heading at the current moment in the kinematic model of the follower unmanned surface vessel.

[0204] The fourth sub-unit is used to determine the first sliding surface after differentiating the velocity error, and to obtain the first thrust by differentiating the first sliding surface.

[0205] The fifth determining subunit is used to determine the second thrust during the switching process of the first sliding surface, and the sum of the first thrust and the second thrust is used as the target thrust.

[0206] The sixth sub-unit is used to determine the second sliding surface after differentiating the heading error, and to obtain the first bow torque by differentiating the second sliding surface.

[0207] The seventh determining subunit is used to determine the second bow torque during the second sliding surface switching process, and the sum of the first bow torque and the second bow torque is used as the target bow torque.

[0208] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0209] In this embodiment, the unmanned surface vessel formation turning and formation maintenance device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0210] This invention also provides a computer device having the above-described features. Figure 5 The unmanned surface vessel formation turning formation maintenance device shown.

[0211] Please see Figure 6 , Figure 6 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 6As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 6 Take a processor 10 as an example.

[0212] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GPA), or any combination thereof.

[0213] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0214] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0215] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0216] The computer device also includes an input device 30 and an output device 40. The processor 10, memory 20, input device 30, and output device 40 can be connected via a bus or other means. Figure 6 Taking the example of a connection between China and Israel via a bus.

[0217] Input device 30 can receive input numerical or character information, and generate key signal inputs related to user settings and function control of the computer device, such as a touchscreen, keypad, mouse, trackpad, touchpad, joystick, one or more mouse buttons, trackball, joystick, etc. Output device 40 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touchscreen.

[0218] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0219] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0220] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An unmanned surface vehicle formation turning formation keeping method, characterized in that, The method comprises: determining relative positions of all follower unmanned surface vehicles (USVs) in the USV formation relative to an initial leader USV in the USV formation, wherein the relative position of any follower USV comprises a longitudinal displacement and a lateral displacement of the follower USV relative to the initial leader USV in a North-East-Down (NED) coordinate system; determining a first candidate USV and a second candidate USV from all follower USVs based on the relative positions of all follower USVs, wherein the first candidate USV and the second candidate USV are located on left and right sides of the initial leader USV respectively; determining a turning direction of the USV formation based on navigation paths corresponding to the initial leader USV, the first candidate USV and the second candidate USV respectively, wherein the turning direction comprises left turn, straight and right turn; in a case where the turning direction is left turn or right turn, determining a target leader USV located at an innermost side of a curve from the first candidate USV and the second candidate USV, switching a leader of the USV formation from the initial leader USV to the target leader USV, turning according to the turning direction, and maintaining a formation of the USV formation in a turning process by using a formation turning formation control algorithm; continuously determining the turning direction of the USV formation, and in a case where the turning direction is straight, switching the leader of the USV formation from the target leader USV to the initial leader USV.

2. The method of claim 1, wherein, The determining the first candidate USV and the second candidate USV from all follower USVs based on the relative positions of all follower USVs comprises: determining a follower USV with minimum longitudinal displacement as the first candidate USV from all follower USVs with minimum lateral displacement based on the relative positions of all follower USVs; determining a follower USV with minimum longitudinal displacement as the second candidate USV from all follower USVs with maximum lateral displacement.

3. The method of claim 1, wherein, The determining the turning direction of the USV formation based on the navigation paths corresponding to the initial leader USV, the first candidate USV and the second candidate USV respectively comprises: selecting a preset number of first position points on the navigation path of the initial leader USV, a preset number of second position points on the navigation path of the first candidate USV, and a preset number of third position points on the navigation path of the second candidate USV based on the relative positions of the initial leader USV, the first candidate USV and the second candidate USV; determining a first path turning value, a second path turning value and a third path turning value based on a vector formed by the preset number of first position points, a vector formed by the preset number of second position points, and a vector formed by the preset number of third position points respectively; in a case where any path turning value among the first path turning value, the second path turning value and the third path turning value is positive, determining that the turning direction of the USV formation is left turn; or, determining that the unmanned surface vehicle formation turns straight in the case that the first path turning value, the second path turning value and the third path turning value are all zero values; or determining that the unmanned surface vehicle formation turns right in the case that any one of the first path turning value, the second path turning value and the third path turning value is a negative value.

4. The method of claim 1, wherein, the turning according to the turning direction, the formation turning formation control algorithm is adopted to maintain the formation of the unmanned surface vehicle formation during the turning, comprising: determining the relative positions of all follower unmanned surface vehicles in the unmanned surface vehicle formation relative to the target leader unmanned surface vehicle based on the target leader unmanned surface vehicle, and generating target formation formation parameters; for any follower unmanned surface vehicle in the unmanned surface vehicle formation, obtaining the navigation parameters and environmental factors of the follower unmanned surface vehicle at the current time, and constructing the kinematic model and the dynamic model of the follower unmanned surface vehicle at the current time, the navigation parameters including thrust and turning moment; determining the expected position, expected speed and expected heading of the follower unmanned surface vehicle at the next time based on the target formation formation parameters, the kinematic model and the dynamic model at the current time; determining the target thrust and target turning moment of the follower unmanned surface vehicle based on the expected position, expected speed and expected heading at the next time; adjusting the thrust and turning moment of the follower unmanned surface vehicle at the current time to the target thrust and target turning moment, returning to the step of obtaining the navigation parameters and environmental factors of the follower unmanned surface vehicle at the current time, and constructing the kinematic model and the dynamic model of the follower unmanned surface vehicle at the current time, until the unmanned surface vehicle formation completes the turning.

5. The method of claim 4, wherein, the step of obtaining the navigation parameters and environmental factors of the follower unmanned surface vehicle at the current time, and constructing the kinematic model and the dynamic model of the follower unmanned surface vehicle at the current time, comprising: determining the actual position and heading of the follower unmanned surface vehicle based on the navigation parameters corresponding to the follower unmanned surface vehicle at the current time, generating the kinematic model at the current time, the actual position including the longitude and latitude of the follower unmanned surface vehicle in the north-east earth coordinate system; determining the longitudinal speed, lateral speed and yaw angular speed of the follower unmanned surface vehicle based on the navigation parameters and environmental factors corresponding to the follower unmanned surface vehicle at the current time, generating the dynamic model at the current time.

6. The method of claim 5, wherein, the step of determining the expected position, expected speed and expected heading of the follower unmanned surface vehicle at the next time based on the target formation formation parameters, the kinematic model and the dynamic model at the current time, comprising: constructing a formation keeping error expression based on the expected position of the follower unmanned surface vehicle, the parameters of the target leader unmanned surface vehicle in the target formation formation parameters and the tangent angle of the expected navigation path of the follower unmanned surface vehicle, the formation keeping error expression being used to represent the position error between the follower unmanned surface vehicle and the target leader unmanned surface vehicle for maintaining the formation of the unmanned surface vehicle formation, the position error including longitudinal error and lateral error; deriving the formation keeping error expression, determining the longitudinal error and the lateral error based on a drift angle of the follower unmanned surface vehicle (USV) in case of converging the longitudinal error and the lateral error; obtaining an expected position of the follower USV at a next time based on a position error of the leader USV and the formation keeping error expression; determining the expected velocity and the expected heading based on a current time's lateral velocity in the dynamics model, the actual position corresponding heading, the expected position, the drift angle, a preset expected motion velocity, the position error and the dynamics model.

7. The method of claim 6, wherein, the target thrust and the target turning moment of the follower USV are determined based on the expected position, the expected velocity and the expected heading corresponding to the next time, including: determining a velocity error based on a current time's longitudinal velocity in the dynamics model of the follower USV and the expected velocity, and determining a heading error based on a current time's heading in the kinematics model of the follower USV and the expected heading; deriving the velocity error to set a first sliding surface, deriving the first sliding surface to obtain a first thrust; determining a second thrust in a switching process of the first sliding surface, and taking a sum of the first thrust and the second thrust as the target thrust; deriving the heading error to set a second sliding surface, deriving the second sliding surface to obtain a first turning moment; determining a second turning moment in a switching process of the second sliding surface, and taking a sum of the first turning moment and the second turning moment as the target turning moment.

8. An unmanned surface vehicle formation turning formation keeping device, characterized in that, The device includes: a first determining module configured to determine relative positions of all follower USVs in a USV formation relative to an initial leader USV in the USV formation based on the initial leader USV, wherein the relative position of any follower USV includes a longitudinal displacement and a lateral displacement of the follower USV relative to the initial leader USV in a North-East-Down coordinate system; a second determining module configured to determine a first candidate USV and a second candidate USV from all the follower USVs based on the relative positions of all the follower USVs, wherein the first candidate USV and the second candidate USV are located on left and right sides of the initial leader USV respectively; a third determining module configured to determine a turning direction of the USV formation based on navigation paths corresponding to the initial leader USV, the first candidate USV and the second candidate USV respectively, wherein the turning direction includes left turn, straight and right turn; a turning control module configured to determine a target leader USV located at an innermost side of a turning road from the first candidate USV and the second candidate USV in case that the turning direction is left turn or right turn, switch a leader of the USV formation from the initial leader USV to the target leader USV during turning, turn according to the turning direction, and maintain a formation of the USV formation during turning by using a formation turning formation control algorithm. A turning switching module is configured to continuously determine a turning direction of the unmanned vehicle formation, and switch a leader of the unmanned vehicle formation from the target leader unmanned vehicle to the initial leader unmanned vehicle in a case where the turning direction is straight.

9. A computer device, comprising: The application further provides a computer readable storage medium having stored computer instructions for causing a computer to execute the unmanned vehicle formation turning formation keeping method according to any one of claims 1 to 7. The computer readable storage medium has stored computer instructions for causing a computer to execute the unmanned vehicle formation turning formation keeping method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, ​

Images