Unmanned ship formation turning formation keeping method and device and computer equipment

Abstract

The invention relates to the technical field of unmanned surface vehicle control, and discloses an unmanned surface vehicle formation turning formation keeping method and device and computer equipment, and the method comprises the steps: determining the relative position of a follower unmanned surface vehicle based on an initial pilot unmanned surface vehicle of an unmanned surface vehicle formation; determining a first candidate unmanned ship and a second candidate unmanned ship based on the relative position; determining a turning direction based on the navigation paths of the initial navigator unmanned ship, the first candidate unmanned ship and the second candidate unmanned ship; when the turning direction is left turning or right turning, determining a target navigator unmanned ship from the candidate unmanned ships; switching the navigator to a target navigator unmanned ship, turning according to the turning direction, and keeping the formation in the turning process by adopting a formation turning formation control algorithm; and under the condition that the turning direction is straight, switching back to the initial pilot unmanned ship. According to the invention, through a dynamic navigator switching and formation turning formation control algorithm, the formation is kept stable in the turning process, the path convolution is avoided, and the formation stability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned boat control, and in particular to a method, a device and a computer device for maintaining a turning formation of an unmanned boat formation. Background Art

[0002] The unmanned boat formation can quickly and accurately explore and perceive the environmental information of the area where the formation is located through division of labor and cooperation, and has a wide range of applications in many fields and scenarios such as public security patrols and marine inspections. When performing actual tasks, multiple unmanned boats usually autonomously navigate in a specified formation, along a specific route or to a specific target, requiring the formation to establish and maintain a specific geometric form, that is, the formation, and at the same time be able to adapt to environmental constraints (such as obstacles) and mission changes (such as turning), adjust the formation navigation strategy in real time, and maintain the stability of the formation.

[0003] When most unmanned boat formations make coordinated turns, the unmanned boats on the inside of the turn are constrained by their own kinematics and experience path swirls, making it impossible to maintain the formation. The existing technology usually solves the above problem by controlling the motion of the unmanned boats on the inside of the turn separately during the turn, but this approach can easily lead to unstable formations, resulting in problems with distance control and internal collisions within the formation. Summary of the invention

[0004] In view of this, the present invention provides a method, device and computer equipment for maintaining the turning formation of an unmanned boat formation to solve the problem of unstable formation of the unmanned boat formation when turning.

[0005] In a first aspect, the present invention provides a method for maintaining a turning formation of an unmanned boat formation, the method comprising:

[0006] Based on the initial leader unmanned boat in the unmanned boat formation, determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the initial leader unmanned boat, the relative position of any follower unmanned boat including the longitudinal displacement and lateral displacement of the follower unmanned boat relative to the initial leader unmanned boat in the north-east coordinate system;

[0007] Based on the relative positions of all follower unmanned boats, determine a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats, the first candidate unmanned boat and the second candidate unmanned boat being located on the left and right of the initial leader unmanned boat, respectively;

[0008] Determine the turning direction of the unmanned boat formation based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat, and the second candidate unmanned boat, respectively. The turning directions include left turn, straight ahead, and right turn.

[0009] When the turning direction is left or right, a target leader unmanned boat is determined from the first candidate unmanned boat and the second candidate unmanned boat, the leader of the unmanned boat formation is switched from the initial leader unmanned boat to the target leader unmanned boat, and the unmanned boat formation is turned according to the turning direction, and the formation turning formation control algorithm is used to maintain the formation of the unmanned boat formation during the turning process;

[0010] The turning direction of the unmanned boat formation is continuously determined, and when the turning direction is straight ahead, the navigator of the unmanned boat formation is switched from the target leader unmanned boat to the initial leader unmanned boat.

[0011] The method for maintaining a turning formation of an unmanned boat formation provided by an embodiment of the present invention determines the longitudinal and lateral displacements of each follower in the unmanned boat formation relative to the initial leader to obtain an accurate relative position, selects a first candidate unmanned boat on the left side of the initial leader and a second candidate unmanned boat on the right side, and simultaneously determines the turning direction of the unmanned boat formation, and selects a target leader unmanned boat from the two candidate unmanned boats according to the turning direction to achieve the switching of the leader, which is beneficial to achieving a smooth transition during the turning process, and through an advanced formation turning formation control algorithm, ensures that each unmanned boat maintains a stable formation during the turning process, and through accurate relative position determination, intelligent turning direction selection, dynamic leader switching and formation turning formation control algorithm, the unmanned boat formation maintains the formation to achieve a smooth turn, avoids the path swirl phenomenon of the inner unmanned boat when turning, reduces the risk of internal collision, improves the stability of the unmanned boat formation, and can adapt to different turning requirements, and enhances robustness and reliability.

[0012] In an optional implementation, based on the relative positions of all follower unmanned boats, determining a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats includes:

[0013] Based on the relative positions of all follower unmanned boats, determine the follower unmanned boat with the smallest longitudinal displacement from all follower unmanned boats with the smallest lateral displacement as the first candidate unmanned boat;

[0014] The follower unmanned boat with the smallest longitudinal displacement is determined from all follower unmanned boats with the largest lateral displacement as the second candidate unmanned boat.

[0015] The method for maintaining the turning formation of an unmanned boat formation provided by an embodiment of the present invention determines candidate unmanned boats on the left and right sides of the initial leader unmanned boat respectively, so that the unmanned boat located at the innermost side of the curve when turning left and right can be selected, which helps to achieve the subsequent switching of the leader, and further ensures the formation stability of the unmanned boat formation during the turning process.

[0016] In an optional implementation, determining the turning direction of the unmanned boat formation based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat, and the second candidate unmanned boat, respectively, includes:

[0017] Based on the relative positions of the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat, a preset number of first position points are selected on the navigation path of the initial leader unmanned boat, a preset number of second position points are selected on the navigation path of the first candidate unmanned boat, and a preset number of third position points are selected on the navigation path of the second candidate unmanned boat;

[0018] Based on a vector formed by a preset number of first position points, a vector formed by a preset number of second position points, and a vector formed by a preset number of third position points, respectively determine a first path turning value, a second path turning value, and a third path turning value;

[0019] When any one of the first path turning value, the second path turning value and the third path turning value is a positive value, the turning direction of the unmanned boat formation is determined to be a left turn; or,

[0020] When the first path turning value, the second path turning value and the third path turning value are all zero, it is determined that the turning direction of the unmanned boat formation is straight ahead; or,

[0021] When any one of the first path turning value, the second path turning value and the third path turning value is a negative value, it is determined that the turning direction of the unmanned boat formation is a right turn.

[0022] The method for maintaining a turning formation for an unmanned boat formation provided by an embodiment of the present invention selects position points on the navigation paths of the three unmanned boats respectively, and through analysis of multiple position points, can better perceive the movement trends of the unmanned boats, and convert the vectors formed by the position points into path steering values. Therefore, by comprehensively considering the path steering values ​​of the initial leader, the first candidate, and the second candidate unmanned boats, the movement trend of the entire formation can be comprehensively evaluated, thereby improving the accuracy of determining the turning direction.

[0023] In an optional implementation, turning is performed in a turning direction, and a formation turning formation control algorithm is used to maintain the formation of the unmanned boat formation during the turning process, including:

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

[0025] For any follower unmanned boat in the unmanned boat formation, obtain the navigation parameters and environmental factors of the follower unmanned boat at the current moment, and construct the kinematic model and dynamic model of the follower unmanned boat at the current moment. The navigation parameters include thrust and bow torque.

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

[0027] Based on the expected position, expected speed and expected heading corresponding to the next moment, the target thrust and target turning moment of the follower unmanned boat are determined;

[0028] Adjust the thrust and bow turning moment of the follower unmanned boat at the current moment to reach the target thrust and target bow turning moment, return to the step of obtaining the navigation parameters and environmental factors of the follower unmanned boat at the current moment, and construct the kinematic model and dynamic model of the follower unmanned boat at the current moment, until the unmanned boat formation completes the turn.

[0029] The method for maintaining the turning formation of an unmanned boat formation provided by an embodiment of the present invention determines the relative position of each follower unmanned boat with respect to the target leader unmanned boat to form target formation formation parameters, thereby ensuring that the formation always maintains a consistent formation during the turning process, and constructs a kinematic model and a dynamic model at the current moment for each follower unmanned boat to achieve real-time monitoring and adjustment of the formation state, so that the expected position, expected speed and expected heading angle of each follower unmanned boat at the next moment are determined based on the above data, thereby determining the corresponding target thrust and target bow turning moment, and adjusting the thrust and bow turning moment so that each follower unmanned boat reaches the target thrust and target bow turning moment, thereby ensuring that the formation's movements are coordinated and consistent during the turning process to avoid collision or loss of control, and continuously obtaining the current position and adjusting it to reach the expected position at the next moment until the formation completes the turn, thereby ensuring that a stable formation is maintained to achieve the turn.

[0030] In an optional implementation, for any follower unmanned boat in the unmanned boat formation, the navigation parameters and environmental factors of the follower unmanned boat at the current moment are obtained, and the kinematic model and dynamic model of the follower unmanned boat at the current moment are constructed, including:

[0031] Based on the navigation parameters corresponding to the follower unmanned boat at the current moment, determine the actual position and heading of the follower unmanned boat, and generate a kinematic model at the current moment. The actual position includes the longitude and latitude of the follower unmanned boat in the north-east coordinate system;

[0032] Based on the navigation parameters and environmental factors corresponding to the follower unmanned boat at the current moment, the longitudinal speed, lateral speed and bow angular velocity of the follower unmanned boat are determined, and the dynamic model at the current moment is generated.

[0033] The method for maintaining the turning formation of an unmanned boat formation provided in an embodiment of the present invention can more accurately represent the current state of the unmanned boat formation through detailed kinematic and dynamic modeling, and provide support for maintaining the formation during the turning process.

[0034] In an optional implementation, based on the target formation parameters, the kinematic model and the dynamic model at the current moment, determining the expected position, expected speed and expected heading of the follower unmanned boat at the next moment includes:

[0035] Based on the expected position of the follower unmanned boat, the parameters of the target leader unmanned boat in the target formation parameters, and the tangent angle of the expected navigation path of the follower unmanned boat, a formation keeping error expression is constructed. The formation keeping error expression is used to express the position error between the follower unmanned boat and the target leader unmanned boat in order to maintain the formation of the unmanned boat formation. The position error includes a longitudinal error and a lateral error.

[0036] The formation keeping error expression is derived, and based on the drift angle of the follower unmanned boat, the longitudinal error and the lateral error are determined when the longitudinal error and the lateral error converge.

[0037] Based on the position error and formation keeping error expressions of the leader unmanned boat, the expected position of the follower unmanned boat at the next moment is obtained;

[0038] The expected speed and the expected heading are determined based on the heading corresponding to the actual position, the expected position, the drift angle, the preset expected movement speed, the position error and the lateral speed at the current moment in the dynamic model.

[0039] The unmanned boat formation turning formation maintaining method provided by the embodiment of the present invention can more accurately control the behavior of each unmanned boat through detailed modeling and error analysis, ensuring that they always remain in an ideal relative position, thereby maintaining the formation.

[0040] In an optional implementation, based on the expected position, expected speed and expected heading corresponding to the next moment, the target thrust and target turning moment of the follower unmanned boat are determined, including:

[0041] Based on the longitudinal speed and the expected speed at the current moment in the dynamic model of the follower unmanned boat, the speed error is determined, and based on the heading and the expected heading at the current moment in the kinematic model of the follower unmanned boat, the heading error is determined;

[0042] After derivation of the velocity error, a first sliding surface is set, and the first sliding surface is derivation to obtain a first thrust;

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

[0044] After derivation of the heading error, a second sliding surface is set, and the second sliding surface is derivation to obtain a first bow moment;

[0045] The second bow moment during the switching process of the second sliding surface is determined, and the sum of the first bow moment and the second bow moment is taken as the target bow moment.

[0046] The unmanned boat formation turning formation maintaining method provided by the embodiment of the present invention can quickly converge to the desired speed and heading in a short time through the sliding mode control method, thereby significantly improving the control efficiency.

[0047] In a second aspect, the present invention provides a device for maintaining a turning formation of an unmanned boat formation, the device comprising:

[0048] The first determination module is used to determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the initial leader unmanned boat based on the initial leader unmanned boat in the unmanned boat formation, wherein the relative position of any follower unmanned boat includes the longitudinal displacement and lateral displacement of the follower unmanned boat relative to the initial leader unmanned boat in the north-east coordinate system;

[0049] A second determination module is used to determine a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats based on the relative positions of all follower unmanned boats, the first candidate unmanned boat and the second candidate unmanned boat being located on the left and right of the initial leader unmanned boat, respectively;

[0050] The third determination module is used to determine the turning direction of the unmanned boat formation based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat, respectively. The turning directions include left turn, straight ahead and right turn;

[0051] A turning control module is used to determine a target leader unmanned boat from the first candidate unmanned boat and the second candidate unmanned boat when the turning direction is left or right, switch the leader of the unmanned boat formation from the initial leader unmanned boat to the target leader unmanned boat, turn according to the turning direction, and use the formation turning formation control algorithm to maintain the formation of the unmanned boat formation during the turning process;

[0052] The turning switching module is used to continuously determine the turning direction of the unmanned boat formation. When the turning direction is straight ahead, the navigator of the unmanned boat formation is switched from the target leader unmanned boat to the initial leader unmanned boat.

[0053] In a third aspect, 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 unmanned boat formation turning formation maintaining method of the above-mentioned first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0054] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for maintaining a turning formation of an unmanned boat formation according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 is a schematic diagram of a path turn when an unmanned boat formation turns according to an embodiment of the present invention;

[0057] Figure 2 is a flow chart of a method for maintaining a turning formation of an unmanned boat formation according to an embodiment of the present invention;

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

[0059] Figure 4 is a schematic diagram of maintaining a turning formation of an unmanned boat formation according to an embodiment of the present invention;

[0060] Figure 5 is a structural block diagram of a device for maintaining a turning formation of an unmanned boat formation according to an embodiment of the present invention;

[0061] Figure 6 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0063] Figure 1 is a schematic diagram of the path turning when the unmanned boat formation turns according to an embodiment of the present invention, such as Figure 1 As shown, the yellow circle represents the leader unmanned boat, and the white circle represents the follower unmanned boat. The follower unmanned boat maintains a certain relative displacement with the leader unmanned boat. The leader unmanned boat moves from the yellow circle 1 to the yellow circle 9 along the path, and the follower unmanned boat located on the inside of the curve moves from the corresponding white circle 1 to the white circle 9. When the leader unmanned boat is in the yellow circle 1, the follower is in the white circle 1, and so on. Affected by its own dynamic constraints, that is, the turning radius constraints of the unmanned boat at different speeds, the follower unmanned boat appears under the following path turning line when maintaining the path of white circle 1-circle 9, making it impossible to maintain the formation during the turn. In order to solve the above problems, the prior art controls the motion of the unmanned boat on the inside of the curve separately during the turn, which makes the formation unstable, resulting in problems with distance control and internal collisions within the formation. The method for maintaining a turning formation of an unmanned boat formation provided in an embodiment of the present invention enables the unmanned boat formation to maintain its formation and achieve smooth turning through precise relative position determination, intelligent turning direction selection, dynamic leader switching and formation turning formation control algorithm, thereby avoiding path swirls of the inner unmanned boat when turning, reducing the risk of internal collision and improving the stability of the unmanned boat formation.

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

[0065] In this embodiment, a method for maintaining a turning formation of an unmanned boat formation is provided, which can be used in a terminal, such as a computer. Figure 2 FIG. 1 is a flow chart of a method for maintaining a turning formation of an unmanned boat formation according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0066] Step S201, based on the initial leader unmanned boat in the unmanned boat formation, determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the initial leader unmanned boat, and the relative position of any follower unmanned boat includes the longitudinal displacement and lateral displacement of the follower unmanned boat relative to the initial leader unmanned boat in the north-east coordinate system. Specifically, the unmanned boat formation usually includes a leader unmanned boat and multiple follower unmanned boats. Each follower unmanned boat maintains a certain distance and direction from the leader unmanned boat to maintain the stability of the formation. Taking the initial leader unmanned boat as a reference point, the lateral displacement and longitudinal displacement of each follower unmanned boat relative to it can be obtained.

[0067] Optionally, the relative positions of all unmanned boats in the unmanned boat formation can be used as formation parameters, as shown in the following formula (1).

[0068]

[0069] Where l represents the index of the initial leader unmanned boat; F(l) represents the formation parameter; N represents the number of unmanned boats in the unmanned boat formation; represents the longitudinal displacement of the Nth unmanned boat relative to the initial leader unmanned boat; Represents the lateral displacement of the Nth unmanned boat relative to the initial leader unmanned boat.

[0070] Step S202, based on the relative positions of all follower unmanned boats, determine the first candidate unmanned boat and the second candidate unmanned boat from all follower unmanned boats, the first candidate unmanned boat and the second candidate unmanned boat are located on the left and right of the initial leader unmanned boat, respectively. Specifically, in order to solve the path turning problem of the inner unmanned boat when turning, the embodiment of the present invention considers switching the leader, that is, switching the leader to the candidate unmanned boat on the innermost side of the curve when turning.

[0071] Step S203, based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat, respectively, the turning direction of the unmanned boat formation is determined, and the turning directions include left turn, straight ahead and right turn. Specifically, since the turning directions include left turn, straight ahead and right turn, and the leader switching strategies corresponding to different turning directions are different, the turning direction of the unmanned boat formation is accurately determined through the navigation paths of the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat.

[0072] Step S204, when the turning direction is left turn or right turn, determine the target leader unmanned boat from the first candidate unmanned boat and the second candidate unmanned boat, switch the leader of the unmanned boat formation from the initial leader unmanned boat to the target leader unmanned boat, turn according to the turning direction, and use the formation turning formation control algorithm to maintain the formation of the unmanned boat formation during the turning process. Specifically, since the path turn occurs on the inside of the curve, and there is no curve when the turning direction is straight, that is, there is no need to switch the leader when the turning direction is straight. When the turning direction is left turn or right turn, determine the corresponding unmanned boat from the above two candidate unmanned boats as the target leader unmanned boat, switch the leader of the unmanned boat formation, and when the new target leader unmanned boat leads the unmanned boat formation to turn, use the formation turning formation control algorithm to adjust the navigation parameters of each follower unmanned boat to ensure that the unmanned boat formation maintains a smooth turn during the turning process, and there will be no path turn phenomenon, thereby avoiding internal collision of the unmanned boats.

[0073] Step S205, continuously determine the turning direction of the unmanned boat formation, and when the turning direction is straight ahead, switch the leader of the unmanned boat formation from the target leader unmanned boat to the initial leader unmanned boat. Specifically, continuously determine the turning direction of the unmanned boat formation, and if the turning direction is left or right, switch the leader and the formation turning formation control algorithm to maintain the formation during the turning process. If the formation's turning direction is straight ahead, switch the leader of the formation back to the initial leader unmanned boat, thereby restoring the original formation, maintaining the consistency and stability of the formation, and avoiding formation deviation and error accumulation caused by long-term use of different leaders.

[0074] The method for maintaining a turning formation of an unmanned boat formation provided by an embodiment of the present invention determines the longitudinal and lateral displacements of each follower in the unmanned boat formation relative to the initial leader to obtain an accurate relative position, selects a first candidate unmanned boat on the left side of the initial leader and a second candidate unmanned boat on the right side, and simultaneously determines the turning direction of the unmanned boat formation, and selects a target leader unmanned boat from the two candidate unmanned boats according to the turning direction to achieve the switching of the leader, which is beneficial to achieving a smooth transition during the turning process, and through an advanced formation turning formation control algorithm, ensures that each unmanned boat maintains a stable formation during the turning process, and through accurate relative position determination, intelligent turning direction selection, dynamic leader switching and formation turning formation control algorithm, the unmanned boat formation maintains the formation to achieve a smooth turn, avoids the path swirl phenomenon of the inner unmanned boat when turning, reduces the risk of internal collision, improves the stability of the unmanned boat formation, and can adapt to different turning requirements, and enhances robustness and reliability.

[0075] In this embodiment, a method for maintaining a formation of an unmanned boat formation during a turn is provided, which can be used in the above-mentioned terminal, such as a computer, etc. The method specifically includes the following steps:

[0076] Step S301, based on the initial leader unmanned boat in the unmanned boat formation, determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the initial leader unmanned boat, and the relative position of any follower unmanned boat includes the longitudinal displacement and lateral displacement of the follower unmanned boat relative to the initial leader unmanned boat in the north-east coordinate system. For details, please refer to Figure 2 Step S201 of the illustrated embodiment will not be described in detail here.

[0077] Step S302: Based on the relative positions of all follower unmanned boats, determine a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats, where the first candidate unmanned boat and the second candidate unmanned boat are located on the left and right of the initial leader unmanned boat, respectively.

[0078] Specifically, the above step S302 includes:

[0079] Step S3021, based on the relative positions of all follower unmanned boats, determine the follower unmanned boat with the smallest longitudinal displacement from all follower unmanned boats with the smallest lateral displacement as the first candidate unmanned boat. Specifically, since the unmanned boat formation can turn left or right, it is necessary to determine a candidate unmanned boat respectively. Select a follower unmanned boat located at the lower left corner of the unmanned boat formation as the first candidate unmanned boat. More specifically, select all follower unmanned boats with the smallest lateral displacement value, that is, located on the leftmost side of the initial leader unmanned boat. Among these leftmost follower unmanned boats, further select the unmanned boat with the smallest longitudinal displacement as the first candidate unmanned boat.

[0080] Step S3022, determine the follower unmanned boat with the smallest longitudinal displacement from all follower unmanned boats with the largest lateral displacement as the second candidate unmanned boat. Specifically, select a follower unmanned boat located at the lower right corner of the unmanned boat formation as the second candidate unmanned boat. More specifically, select all follower unmanned boats with the largest lateral displacement value, that is, located on the far right of the initial leader unmanned boat, and further select the unmanned boat with the smallest longitudinal displacement from these rightmost follower unmanned boats as the second candidate unmanned boat.

[0081] Step S303, based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat, respectively, the turning direction of the unmanned boat formation is determined, and the turning directions include left turn, straight ahead and right turn.

[0082] Specifically, the above step S303 includes:

[0083] Step S3031, based on the relative positions of the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat, a preset number of first position points are selected on the navigation path of the initial leader unmanned boat, a preset number of second position points are selected on the navigation path of the first candidate unmanned boat, and a preset number of third position points are selected on the navigation path of the second candidate unmanned boat. Specifically, in the leader-follower mode, generally only the path is planned for the leader unmanned boat, and other follower unmanned boats follow the movement of the leader unmanned boat. After the two candidate unmanned boats are determined by step S302, the navigation paths of the two candidate unmanned boats can be determined according to their relative positions and the navigation path of the initial leader unmanned boat, which are respectively represented by the following equations (2) and (3).

[0084]

[0085] Among them, Path L (x, y) represents the navigation path of the first candidate unmanned boat; Indicates the relative position of the first candidate unmanned boat; Indicates that at each position point on the navigation path of the initial pilot unmanned boat, the vertical Translation, in the horizontal direction Translation of Path R (x, y) represents the navigation path of the second candidate unmanned boat; Indicates the relative position of the second candidate unmanned boat; Indicates that at each position point on the navigation path of the initial pilot unmanned boat, the vertical Translation, in the horizontal direction of translation.

[0086] In some optional implementations, based on the current position points of the three unmanned boats, a preset number of position points are taken along the forward direction on each of the three paths according to a preset step length. Figure 3 is a schematic diagram of a location point according to an embodiment of the present invention, such as Figure 3 As shown in the figure, taking three position points selected on the navigation path of the initial pilot unmanned boat as an example, P 0,l Indicates the current position point, P 1,l Indicates the position point that is one step away from the current position point, P 2,l represents the position point that is two steps away from the current position point. And P 0,l With P 1,l The distance between 1,l With P 2,l The distances between them are consistent, and are all one step length. The position points of the first candidate unmanned boat and the second candidate unmanned boat are selected with reference to the initial pilot unmanned boat, which will not be repeated here.

[0087] Step S3032: Based on the vectors formed by the preset number of first position points, the vectors formed by the preset number of second position points, and the vectors formed by the preset number of third position points, the first path steering value, the second path steering value, and the third path steering value are determined respectively. Specifically, the first path steering value, the second path steering value, and the third path steering value are determined respectively by the following formulas (4)-(6) to represent the steering trend of the initial pilot unmanned boat.

[0088]

[0089] Among them, Direc l Represents the first path turning value; P 0,l Indicates the current position of the initial pilot unmanned boat; P 1,l Indicates the position point that is one step away from the current position point; P 2,l Indicates the position point that is two steps away from the current position point.

[0090]

[0091] Among them, Direc L Represents the second path steering value; P 0,L represents the current position of the first candidate unmanned boat; P 1,L Indicates the position point that is one step away from the current position point; P 2,L Indicates the position point that is two steps away from the current position point.

[0092]

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

[0094] Step S3033, when any of the first path steering value, the second path steering value, and the third path steering value is a positive value, it is determined that the turning direction of the unmanned boat formation is a left turn. Specifically, the three path steering values ​​obtained by the vector cross product can reflect the rotation direction between the vectors, thereby indicating the turning trend of the unmanned boat. When any of the three path steering values ​​is a positive value, according to the right-hand rule, it can be known that the turning direction of the unmanned boat formation is a left turn.

[0095] Alternatively, in step S3034, when the first path turning value, the second path turning value, and the third path turning value are all zero, it is determined that the turning direction of the unmanned boat formation is straight ahead. Specifically, when the three path turning values ​​are all 0, it means that the vectors do not form an angle, and it is straight ahead at this time.

[0096] Alternatively, in step S3035, when any of the first path turning value, the second path turning value, and the third path turning value is a negative value, it is determined that the turning direction of the unmanned boat formation is a right turn. Specifically, when any of the three path turning values ​​is a negative value, according to the right-hand rule, it can be known that the turning direction of the unmanned boat formation is a right turn.

[0097] Step S304, when the turning direction is left turn or right turn, determine the target leader unmanned boat from the first candidate unmanned boat and the second candidate unmanned boat, switch the leader of the unmanned boat formation from the initial leader unmanned boat to the target leader unmanned boat, turn according to the turning direction, and use the formation turning formation control algorithm to maintain the formation of the unmanned boat formation during the turning process. Specifically, when the turning direction is left turn, the first candidate unmanned boat is located at the lower left corner of the formation, that is, closest to the inside of the curve, and the first candidate unmanned boat is determined as the target leader unmanned boat. When the turning direction is right turn, the second candidate unmanned boat is located at the lower right corner of the formation, that is, closest to the inside of the curve, and the second candidate unmanned boat is determined as the target leader unmanned boat. By determining the target leader unmanned boat, after the leader of the formation is switched to the target leader unmanned boat, the formation can be guided to make a smooth turn and avoid the path swirl phenomenon.

[0098] Specifically, the above step S304 performs a turn according to the turning direction, and uses a formation turning formation control algorithm to maintain the formation of the unmanned boat formation during the turning process, including:

[0099] Step S3041, based on the target leader unmanned boat, determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the target leader unmanned boat, and form the target formation formation parameters. Specifically, the leader of the formation is switched from the initial leader unmanned boat to the target leader unmanned boat, and the relative position of each follower unmanned boat relative to the target leader unmanned boat is re-determined to form the target formation formation parameters as shown in the following formula (7). Optionally, it is only necessary to subtract the relative displacement between the initial leader and the target leader from the above formula (1), that is, from the formation parameters corresponding to the initial leader unmanned boat.

[0100]

[0101] Where m represents the index of the target leader unmanned boat; F(m) represents the target formation parameter; N represents the number of unmanned boats in the unmanned boat formation; represents the longitudinal displacement of the Nth unmanned boat relative to the initial leader unmanned boat; represents the lateral displacement of the Nth unmanned boat relative to the initial leader unmanned boat; represents the longitudinal displacement of the target pilot unmanned boat relative to the initial pilot unmanned boat; Represents the lateral displacement of the target leader unmanned boat relative to the initial leader unmanned boat.

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

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

[0104] Step a1, based on the navigation parameters corresponding to the follower unmanned boat at the current moment, determine the actual position and heading of the follower unmanned boat, and generate a kinematic model at the current moment, where the actual position includes the longitude and latitude of the follower unmanned boat in the north-east coordinate system. Specifically, by considering the navigation parameters and environmental factors of the follower unmanned boat, a kinematic model shown in the following formula (8) is constructed.

[0105]

[0106] Among them, x, y, ψ represent the longitude, latitude and heading of the follower unmanned boat in the northeast coordinate system; u, v, r represent the longitudinal speed, lateral speed and bow angular velocity of the follower unmanned boat in the hull coordinate system. The origin of the hull coordinate system is the center of gravity of the ship, the x-axis is the centerline of the ship, pointing from the stern to the bow, the y-axis is 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 corresponding to the follower unmanned boat at the current moment, determine the longitudinal speed, lateral speed and bow angular velocity of the follower unmanned boat, and generate the dynamic model at the current moment. Specifically, since the unmanned boat is generally an underactuated unmanned boat, only three degrees of freedom are considered when applying the formation turning formation control algorithm: longitudinal sway, lateral sway and bow sway. By considering the navigation parameters and environmental factors of the follower unmanned boat, the kinematic model shown in the following formula (9) is constructed.

[0108]

[0109] Among them, u, v, r represent the longitudinal velocity, lateral velocity and bow angular velocity of the follower unmanned boat in the hull coordinate system; (m 11 ,m 22 ,m 33 ) represents the inertial mass parameter of the follower unmanned boat in the longitudinal, transverse and yaw directions, including the mass of the unmanned boat and the additional mass; (d 11 ,d 22 ,d 33 ) represents the damping coefficient of the follower unmanned boat in the longitudinal, transverse and bow rolling directions; (τ u ,τ r ) represents the thrust and bow moment; (τ eu ,τ ev ,τ er ) represents the disturbance force vector generated by wind, waves and surges in the directions of surge, sway and pitch.

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

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

[0112] Step b1, based on the expected position of the follower unmanned boat, the parameters of the target leader unmanned boat in the target formation formation parameters, and the tangent angle of the expected navigation path of the follower unmanned boat, construct a formation maintenance error expression, the formation maintenance error expression is used to express the position error between the follower unmanned boat and the target leader unmanned boat to maintain the formation of the unmanned boat formation, the position error includes longitudinal error and lateral error. Specifically, the expected navigation path of any follower unmanned boat can be obtained by the Path() function. During the navigation of the unmanned boat formation, each follower unmanned boat maintains a certain distance from the leader unmanned boat, that is, the position error, and the position error needs to be maintained when turning to maintain the stability of the formation. Optionally, the position error can be expressed by the following formula (10).

[0113]

[0114] Among them, [x i ,y i ] T Indicates the longitude and latitude of the actual position of the follower unmanned boat; ψ pi The tangent angle of the expected navigation path of the follower unmanned boat is expressed by Calculated; [x ei ,y ei ] T represents the position error, x ei represents the longitudinal error, y ei represents the lateral error; [x di ,y di ] T represents the expected position of the follower unmanned boat; [x l ,y l ] T Indicates the longitude and latitude of the target pilot unmanned boat.

[0115] Step b2, deriving the formation keeping error expression, based on the drift angle of the follower unmanned boat, determining the longitudinal error and the lateral error when the longitudinal error and the lateral error converge. Specifically, by deriving the above formula (10), the following formula (11) can be obtained.

[0116]

[0117] Among them, [x ei ,y ei] T represents the position error, x ei represents the longitudinal error, y ei Indicates lateral error; Indicates the combined speed of the following unmanned boat, u i and v i are the longitudinal velocity and lateral velocity in the dynamic model; represents the preset expected movement speed of the expected navigation path of the follower unmanned boat, x di and di is the expected position; ψ i represents the heading in the kinematic model; ψ pi represents the tangent angle of the desired navigation path of the follower unmanned boat; Indicates the drift angle of the follower unmanned boat.

[0118] Due to the external interference of wind, waves, currents, lateral speed caused by turning and other factors, the drift angle is very small, so let cosβ i ≈1, sinβ i ≈β i Define the reduced-order extended state observer in equation (12) to estimate the drift angle, and obtain the drift angle estimation value shown in equation (13), which is substituted into equation (11).

[0119]

[0120] Where p represents the observer state; k1 represents the observer benefit; ψ pi represents the tangent angle of the desired navigation path of the follower unmanned boat; ψ di Indicates the desired heading corresponding to the desired position; Represents the estimated value of g, g represents a nonlinear function, which realizes the estimation of uncertainties or interferences in the drift angle estimation system. And p(t0)=k1y ei (t0); x ei represents the longitudinal error, yei represents the lateral error; U i Indicates the combined speed of the following unmanned boat.

[0121]

[0122] in, represents the estimated drift angle; U i represents the combined speed of the following unmanned boat; ψ pi represents the tangent angle of the desired navigation path of the follower unmanned boat; ψ di Indicates the desired heading corresponding to the desired position.

[0123] Step b3, based on the position error and formation keeping error expressions of the leader unmanned boat, the expected position of the follower unmanned boat at the next moment is obtained. Specifically, the lateral error and longitudinal error calculated after derivation are substituted into the above formula (10), and the expected position at the next moment can be obtained, that is, the position that the follower unmanned boat 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 speed at the current moment in the dynamic model, the desired speed and the desired heading are determined. Specifically, the following formula (14) is an expression for determining the desired speed and the desired heading. Through the above-mentioned multiple data, the desired speed and the desired heading that the follower unmanned boat should have in order to move to the desired position are obtained.

[0125]

[0126] Among them, ψ di represents the desired heading; ψ p i represents the tangent angle of the expected navigation path of the follower unmanned boat; k2 and k3 represent variable coefficients, which have no physical meaning and satisfy k2>1, 0<k3<1; Δ1>0 represents the forward distance; represents a finite time term; k4>0 represents a relative speed adjustment term; Indicates the expected speed; U di represents the preset expected movement speed of the expected navigation path of the follower unmanned boat; x ei represents the longitudinal error, y ei represents the lateral error; β i represents the drift angle of the follower unmanned boat, which is the estimated value of the drift angle calculated by the above formula (13); v i Indicates the lateral velocity.

[0127] Step S3044, based on the expected position, expected speed and expected heading corresponding to the next moment, determine the target thrust and target bow torque of the follower unmanned boat.

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

[0129] Step c1, based on the longitudinal speed and the expected speed at the current moment in the dynamic model of the follower unmanned boat, the speed error is determined, and based on the heading and the expected heading at the current moment in the kinematic model of the follower unmanned boat, the heading error is determined. Specifically, the difference between the longitudinal speed at the current moment and the expected speed is determined as the speed error, and the difference between the heading at the current moment and the expected heading is determined as the heading error.

[0130] Step c2, after taking the derivative of the velocity error, a first sliding surface is set, and the first sliding surface is taken the derivative to obtain a first thrust. Specifically, by taking the derivative of the velocity error, the following formula (15) can be obtained.

[0131]

[0132] Among them, u ei represents the speed error; r i represents the bow angular velocity of the follower unmanned boat; u i and v i are the longitudinal velocity and lateral velocity in the dynamic model; (m 11 ,m 22 ) represents the inertial mass parameter of the follower unmanned boat in the longitudinal and transverse directions, including the mass of the unmanned boat and the additional mass; d 11 represents the damping coefficient of the follower unmanned boat in the longitudinal direction; τ u represents thrust; τ eu It represents the disturbance force vector generated by wind, waves and surges in the longitudinal direction; Indicates the expected speed.

[0133] Define the integral first-order exponential stable sliding surface:

[0134]

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

[0136] By taking the derivative of the first sliding surface of equation (16), we can get the following 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 boat in the longitudinal and transverse directions, including the mass of the unmanned boat and the additional mass; d 11 represents the damping coefficient of the follower unmanned boat in the longitudinal direction; r i represents the bow angular velocity of the follower unmanned boat; u i and v i are the longitudinal velocity and lateral velocity in the dynamic model; represents the expected speed; τ uq represents the first thrust; λ1 represents the preset coefficient.

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

[0140]

[0141] Among them, τ uq Indicates the first thrust; represents the estimated value of the inertial mass parameters of the follower unmanned boat in the longitudinal and transverse directions, including the mass of the unmanned boat and the additional mass; represents the estimated value of the damping coefficient of the follower unmanned boat in the longitudinal direction; r i represents the bow angular velocity of the follower unmanned boat; u i and v i are the longitudinal velocity and lateral velocity in the dynamic model; represents the expected speed; u ei 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 thrust and the second thrust as the target thrust. Specifically, in actual engineering applications, severe jitter problems may occur on the control sliding surface. In the upper and lower Δ2 domains of the switching point of the sliding surface, a smooth sliding surface is used to replace the severe switching to reduce the jitter phenomenon during the switching process, and the second thrust during the switching process shown in the following formula (19) is obtained.

[0143] τ uqs =-k5sat(S1)-k6S1

[0144]

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

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

[0147]

[0148] Among them, τ u represents the target thrust; τ uq represents the first thrust; τ uqs Indicates the second thrust.

[0149] Step c4, after taking the derivative of the heading error, a second sliding surface is set, and the second sliding surface is derived to obtain the first turning bow moment. Specifically, the heading error is derived twice to obtain the following formula (21).

[0150]

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

[0152] Design the second sliding surface shown in the following formula (22):

[0153]

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

[0155] By taking the derivative of the first sliding surface of equation (22), we can get the following equation (23):

[0156]

[0157] Where S2 represents the second sliding surface; ψ i represents the heading in the kinematic model; ψ di Indicates the desired heading; (m 11 ,m 22 ,m 33 ) represents the inertial mass parameter of the follower unmanned boat in the surge, sway and pitch directions, including the mass of the unmanned boat and the additional mass; represents the estimated value of the inertial mass parameter of the follower unmanned boat in the bow rolling direction, including the mass of the unmanned boat and the additional mass; d 33 represents the damping coefficient of the follower unmanned boat in the bow rolling direction; r i represents the bow angular velocity of the follower unmanned boat; u i and v i are the longitudinal velocity and lateral velocity in the dynamic model; τ rq represents the first bow moment; λ2 represents the preset coefficient.

[0158] make Substituting into the above formula (23), we can obtain the first bow moment shown in the following formula (24).

[0159]

[0160] Among them, τ rq represents the first bow moment; represents the estimated value of the inertial mass parameters of the follower unmanned boat in the surge, sway and pitch directions, including the mass of the unmanned boat and the additional mass; represents the estimated value of the damping coefficient of the follower unmanned boat in the bow rolling direction; r i represents the bow angular velocity of the follower unmanned boat; ui and v i are the longitudinal velocity and lateral velocity in the dynamic model; ψ di represents the desired heading; λ2 represents the preset coefficient.

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

[0162] τ rqs =-k7sat(S2)-k8S2

[0163]

[0164] Among them, τ rqs represents the second bow moment; 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 the following formula (26), the sum of the first bow turning moment and the second bow turning moment is determined as the target bow turning moment of the follower unmanned boat.

[0166]

[0167] Among them, τ r represents the target bow turning moment; τ rq represents the first bow moment; τ rqs Indicates the second bow moment.

[0168] Step S3045, adjust the thrust and bow turning moment of the follower unmanned boat at the current moment to reach the target thrust and target bow turning moment, return to the step of obtaining the navigation parameters and environmental factors of the follower unmanned boat at the current moment, and construct the kinematic model and dynamic model of the follower unmanned boat at the current moment, until the unmanned boat formation completes the turn. Specifically, adjust the thrust and bow turning moment in the navigation parameters of each follower unmanned boat to achieve its corresponding target thrust and target bow turning moment, so that each follower unmanned boat can move to the desired position, thereby ensuring that the unmanned boat formation maintains a stable formation during the turn. After adjusting the navigation parameters of all follower unmanned boats at the current moment, return to step S3042, and continue to determine the desired position, target thrust and target bow turning moment that each follower unmanned boat should reach at the next moment, until the unmanned boat formation completes the turn.

[0169] Step S305: Continue to determine the turning direction of the unmanned boat formation. If the turning direction is straight ahead, switch the leader of the unmanned boat formation from the target leader unmanned boat to the initial leader unmanned boat. Figure 2 Step S205 of the illustrated embodiment will not be described in detail here.

[0170] In some optional embodiments, Figure 4 Schematic diagram of the unmanned boat formation maintaining turning formation according to an embodiment of the present invention. Figure 4 As shown, the dotted line is the navigation path of the initial pilot unmanned boat. When the initial pilot unmanned boat navigates along the navigation path, it continues to determine the turning direction. When it reaches the location of yellow circle 2, the turning direction is to turn left. At this time, the pilot is switched to yellow circle 3, and the formation turning formation control algorithm is applied to maintain the formation to complete the turn. When it navigates to the location of yellow circle 6, the turning direction determined at this time is to go straight, and it is necessary to switch the pilot again, switch to the initial pilot unmanned boat, and continue to navigate along the initial navigation path, that is, sail from yellow circle 7 to yellow circle 9.

[0171] The method for maintaining a turning formation of an unmanned boat formation provided by an embodiment of the present invention determines the longitudinal and lateral displacements of each follower in the unmanned boat formation relative to the initial leader to obtain an accurate relative position, selects a first candidate unmanned boat on the left side of the initial leader and a second candidate unmanned boat on the right side, and simultaneously determines the turning direction of the unmanned boat formation, and selects a target leader unmanned boat from the two candidate unmanned boats according to the turning direction to achieve the switching of the leader, which is beneficial to achieving a smooth transition during the turning process, and through an advanced formation turning formation control algorithm, ensures that each unmanned boat maintains a stable formation during the turning process, and through accurate relative position determination, intelligent turning direction selection, dynamic leader switching and formation turning formation control algorithm, the unmanned boat formation maintains the formation to achieve a smooth turn, avoids the path swirl phenomenon of the inner unmanned boat when turning, reduces the risk of internal collision, improves the stability of the unmanned boat formation, and can adapt to different turning requirements, and enhances robustness and reliability.

[0172] In this embodiment, a device for maintaining the formation of an unmanned boat formation turning is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and will not be repeated hereafter. 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, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0173] This embodiment provides a device for maintaining a turning formation of an unmanned boat formation, such as Figure 5 As shown, including:

[0174] The first determination module 501 is used to determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the initial leader unmanned boat based on the initial leader unmanned boat in the unmanned boat formation, and the relative position of any follower unmanned boat includes the longitudinal displacement and lateral displacement of the follower unmanned boat relative to the initial leader unmanned boat in the north-east coordinate system.

[0175] The second determination module 502 is used to determine a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats based on the relative positions of all follower unmanned boats, and the first candidate unmanned boat and the second candidate unmanned boat are respectively located on the left and right of the initial leader unmanned boat.

[0176] The third determination module 503 is used to determine the turning direction of the unmanned boat formation based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat respectively. The turning directions include left turn, straight ahead and right turn.

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

[0178] The turning switching module 505 is used to continuously determine the turning direction of the unmanned boat formation, and when the turning direction is straight ahead, the leader of the unmanned boat formation is switched from the target leader unmanned boat to the initial leader unmanned boat.

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

[0180] The first determination unit is used to determine, based on the relative positions of all follower unmanned boats, a follower unmanned boat with the smallest longitudinal displacement from all follower unmanned boats with the smallest lateral displacement as a first candidate unmanned boat.

[0181] The second determination unit is used to determine the follower unmanned boat with the smallest longitudinal displacement from all follower unmanned boats with the largest lateral displacement as the second candidate unmanned boat.

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

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

[0184] The third determination unit is used to determine the first path steering value, the second path steering value and the third path steering value respectively 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.

[0185] The first direction determining unit is used to determine that the turning direction of the unmanned boat formation is a left turn when any one of the first path turning value, the second path turning value and the third path turning value is a positive value.

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

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

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

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

[0190] The construction unit is used to obtain the navigation parameters and environmental factors of any follower unmanned boat in the unmanned boat formation at the current moment, and to construct the kinematic model and dynamic model of the follower unmanned boat at the current moment. The navigation parameters include thrust and bow torque.

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

[0192] The fifth determination unit is used to determine the target thrust and target bow torque of the follower unmanned boat based on the expected position, expected speed and expected heading corresponding to the next moment.

[0193] The control unit is used to adjust the thrust and bow turning moment of the follower unmanned boat at the current moment to reach the target thrust and target bow turning moment, return to the step of obtaining the navigation parameters and environmental factors of the follower unmanned boat at the current moment, and construct the kinematic model and dynamic model of the follower unmanned boat at the current moment until the unmanned boat formation completes the turn.

[0194] In some optional embodiments, the building block includes:

[0195] The first generating subunit is used to determine the actual position and heading of the follower unmanned boat based on the navigation parameters corresponding to the follower unmanned boat at the current moment, and generate a kinematic model at the current moment. The actual position includes the longitude and latitude of the follower unmanned boat in the north-east coordinate system.

[0196] The second generating subunit is used to determine the longitudinal speed, lateral speed and bow angular velocity of the follower unmanned boat based on the navigation parameters and environmental factors corresponding to the follower unmanned boat at the current moment, and generate the dynamic model at the current moment.

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

[0198] A sub-unit is constructed to construct a formation keeping error expression based on the expected position of the follower unmanned boat, the parameters of the target leader unmanned boat in the target formation formation parameters, and the tangent angle of the expected navigation path of the follower unmanned boat. The formation keeping error expression is used to express the position error between the follower unmanned boat and the target leader unmanned boat in order to maintain the formation of the unmanned boat formation. The position error includes longitudinal error and lateral error.

[0199] The derivation subunit is used to derive the formation keeping error expression, and determine the longitudinal error and the lateral error based on the drift angle of the follower unmanned boat when the longitudinal error and the lateral error converge.

[0200] The first determination subunit is used to obtain the expected position of the follower unmanned boat at the next moment based on the position error and formation keeping error expression of the leader unmanned boat.

[0201] The second determination subunit is used to determine the expected speed and expected heading based on the heading corresponding to the actual position, the expected position, the drift angle, the preset expected movement speed, the position error and the lateral speed at the current moment in the dynamic model.

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

[0203] The third determination subunit is used to determine the speed error based on the longitudinal speed and the expected speed in the dynamic model of the follower unmanned boat at the current moment, and to determine the heading error based on the heading and the expected heading in the kinematic model of the follower unmanned boat at the current moment.

[0204] The fourth determination subunit is used to set a first sliding surface after derivation of the velocity error, and to obtain a first thrust by derivation of the first sliding surface.

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

[0206] The sixth determination subunit is used to set a second sliding surface after derivation of the heading error, and to obtain a first bow torque by derivation of the second sliding surface.

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

[0208] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

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

[0210] The embodiment of the present invention also provides a computer device having the above Figure 5 The unmanned boat formation turning formation maintaining device shown.

[0211] See also Figure 6 , Figure 6 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 6As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 6 A processor 10 is taken as an example.

[0212] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0213] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0214] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0215] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a 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, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 6 The example of connecting through bus is taken in the following.

[0217] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0218] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0219] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

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

Claims

1. A method for maintaining a turning formation of an unmanned boat formation, characterized in that: The method comprises: Based on an initial leader unmanned boat in the unmanned boat formation, determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the initial leader unmanned boat, wherein the relative position of any follower unmanned boat includes the longitudinal displacement and lateral displacement of the follower unmanned boat relative to the initial leader unmanned boat in a north-east coordinate system; Based on the relative positions of all follower unmanned boats, determine a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats, wherein the first candidate unmanned boat and the second candidate unmanned boat are respectively located on the left and right of the initial leader unmanned boat; Determining a turning direction of the unmanned boat formation based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat, and the second candidate unmanned boat, respectively, wherein the turning direction includes turning left, going straight, and turning right; In the case where the turning direction is a left turn or a right turn, a target leader unmanned boat is determined from the first candidate unmanned boat and the second candidate unmanned boat, the leader of the unmanned boat formation is switched from the initial leader unmanned boat to the target leader unmanned boat, the unmanned boat formation is turned according to the turning direction, and the formation turning formation control algorithm is used to maintain the formation of the unmanned boat formation during the turning process; The turning direction of the unmanned boat formation is continuously determined, and when the turning direction is straight ahead, the leader of the unmanned boat formation is switched from the target leader unmanned boat to the initial leader unmanned boat.

2. The method according to claim 1, characterized in that The step of determining a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats based on the relative positions of all follower unmanned boats includes: Based on the relative positions of all follower unmanned boats, determine the follower unmanned boat with the smallest longitudinal displacement from all follower unmanned boats with the smallest lateral displacement as the first candidate unmanned boat; A follower unmanned boat with the smallest longitudinal displacement is determined from all follower unmanned boats with the largest lateral displacement as the second candidate unmanned boat.

3. The method according to claim 1, characterized in that: The determining the turning direction of the unmanned boat formation based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat, and the second candidate unmanned boat, respectively, includes: Based on the relative positions of the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat, a preset number of first position points are selected on the navigation path of the initial leader unmanned boat, a preset number of second position points are selected on the navigation path of the first candidate unmanned boat, and a preset number of third position points are selected on the navigation path of the second candidate unmanned boat; Based on a vector formed by a preset number of first position points, a vector formed by a preset number of second position points, and a vector formed by a preset number of third position points, respectively determine a first path turning value, a second path turning value, and a third path turning value; When any one of the first path turning value, the second path turning value and the third path turning value is a positive value, determining that the turning direction of the unmanned boat formation is a left turn; or When the first path turning value, the second path turning value and the third path turning value are all zero, determining that the turning direction of the unmanned boat formation is straight ahead; or, When any one of the first path turning value, the second path turning value and the third path turning value is a negative value, it is determined that the turning direction of the unmanned boat formation is a right turn.

4. The method according to claim 1, characterized in that: The step of turning in the turning direction and maintaining the formation of the unmanned boat formation during the turning process by using a formation turning formation control algorithm includes: Based on the target leader unmanned boat, determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the target leader unmanned boat, and generate the target formation formation parameters; For any follower unmanned boat in the unmanned boat formation, obtain the navigation parameters and environmental factors of the follower unmanned boat at the current moment, and construct a kinematic model and a dynamic model of the follower unmanned boat at the current moment, wherein the navigation parameters include thrust and bow torque; Based on the target formation parameters, the kinematic model and the dynamic model at the current moment, determining the expected position, expected speed and expected heading of the follower unmanned boat at the next moment; Determine the target thrust and target turning moment of the follower unmanned boat based on the expected position, expected speed and expected heading corresponding to the next moment; Adjust the thrust and bow turning moment of the follower unmanned boat at the current moment to reach the target thrust and the target bow turning moment, return to the step of obtaining the navigation parameters and environmental factors of the follower unmanned boat at the current moment, and construct the kinematic model and dynamic model of the follower unmanned boat at the current moment, until the unmanned boat formation completes the turn.

5. The method according to claim 4, characterized in that For any follower unmanned boat in the unmanned boat formation, obtaining the navigation parameters and environmental factors of the follower unmanned boat at the current moment, and constructing the kinematic model and dynamic model of the follower unmanned boat at the current moment, including: Based on the navigation parameters corresponding to the follower unmanned boat at the current moment, determine the actual position and heading of the follower unmanned boat, and generate a kinematic model at the current moment, wherein the actual position includes the longitude and latitude of the follower unmanned boat in the north-east coordinate system; Based on the navigation parameters and environmental factors corresponding to the follower unmanned boat at the current moment, the longitudinal speed, lateral speed and bow angular velocity of the follower unmanned boat are determined, and a dynamic model at the current moment is generated.

6. The method according to claim 5, characterized in that The step of determining the expected position, expected speed and expected heading of the follower unmanned boat at the next moment based on the target formation parameters, the kinematic model and the dynamic model at the current moment includes: Based on the expected position of the follower unmanned boat, the parameters of the target leader unmanned boat in the target formation parameters, and the tangent angle of the expected navigation path of the follower unmanned boat, a formation keeping error expression is constructed, wherein the formation keeping error expression is used to express the position error between the follower unmanned boat and the target leader unmanned boat in order to maintain the formation of the unmanned boat formation, and the position error includes a longitudinal error and a lateral error; Deriving the formation keeping error expression, and determining the longitudinal error and the lateral error based on the drift angle of the follower unmanned boat when the longitudinal error and the lateral error converge; Based on the position error of the leader unmanned boat and the formation keeping error expression, obtaining the expected position of the follower unmanned boat at the next moment; The expected speed and the expected heading are determined based on the heading corresponding to the actual position, the expected position, the drift angle, a preset expected movement speed, the position error, and the lateral speed at the current moment in the dynamic model.

7. The method according to claim 6, characterized in that The step of determining the target thrust and target turning moment of the follower unmanned boat based on the expected position, expected speed and expected heading corresponding to the next moment includes: Determine a speed error based on the longitudinal speed at the current moment and the expected speed in the dynamic model of the follower unmanned boat, and determine a heading error based on the heading at the current moment and the expected heading in the kinematic model of the follower unmanned boat; After derivation of the velocity error, a first sliding surface is set, and the first sliding surface is derivation to obtain a first thrust; determining a second thrust during the switching process of the first sliding surface, and taking the sum of the first thrust and the second thrust as the target thrust; After derivation of the heading error, a second sliding surface is set, and the second sliding surface is derivation to obtain a first bow torque; A second bow moment during the switching of the second sliding mode surface is determined, and a sum of the first bow moment and the second bow moment is used as the target bow moment.

8. A device for maintaining the turning formation of an unmanned boat formation, characterized in that: The device comprises: A first determination module is used to determine the relative positions of all follower unmanned boats in the unmanned boat formation relative to the initial leader unmanned boat based on the initial leader unmanned boat in the unmanned boat formation, wherein the relative position of any follower unmanned boat includes the longitudinal displacement and lateral displacement of the follower unmanned boat relative to the initial leader unmanned boat in the north-east coordinate system; A second determination module is used to determine a first candidate unmanned boat and a second candidate unmanned boat from all follower unmanned boats based on the relative positions of all follower unmanned boats, wherein the first candidate unmanned boat and the second candidate unmanned boat are respectively located on the left and right of the initial leader unmanned boat; A third determination module is used to determine the turning direction of the unmanned boat formation based on the navigation paths corresponding to the initial leader unmanned boat, the first candidate unmanned boat and the second candidate unmanned boat, respectively, where the turning direction includes left turn, straight ahead and right turn; a turning control module, configured to, when the turning direction is a left turn or a right turn, determine a target leader unmanned boat from the first candidate unmanned boat and the second candidate unmanned boat, switch the leader of the unmanned boat formation from the initial leader unmanned boat to the target leader unmanned boat, turn according to the turning direction, and use a formation turning formation control algorithm to maintain the formation of the unmanned boat formation during the turning process; The turning switching module is used to continuously determine the turning direction of the unmanned boat formation, and when the turning direction is straight ahead, the leader of the unmanned boat formation is switched from the target leader unmanned boat to the initial leader unmanned boat.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the unmanned boat formation turning formation maintaining method according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method for maintaining a turning formation of an unmanned boat formation according to any one of claims 1 to 7.

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