A multi-robot encirclement control method and device with physical connection

Abstract

The present invention relates to a multi-robot encirclement control method and device with physical connections. The method comprises: obtaining the position and velocity of each node and the position of a target object; calculating the position and velocity of a virtual center formed by all nodes, the expected distance of each node from the virtual center, the distance between nodes, and the distance from each node to the target object; controlling the movement of each node based on a node encirclement formation control model for each node until the virtual center formed by all nodes coincides with the target object; and controlling each node to capture the target object. The multi-robot encirclement device with physical connections comprises at least two robots capable of three-dimensional spatial motion. Through mutual cooperation, the encirclement range is gradually increased, thereby achieving encirclement of the target object. The multi-robot encirclement device with physical connections can control the encirclement of the target object in a short period of time.

Description

Technical Field

[0001] The present invention belongs to the field of robot control, and in particular relates to a multi-robot encirclement control method with physical connection and a device thereof. Background Art

[0002] In recent years, multi-robot collaborative control has attracted widespread attention due to its superior fault tolerance and mission adaptability compared to single-robot systems. Multi-robot collaborative control has been widely used in applications such as land surveying, search and rescue operations, remote sensing, and disaster monitoring. Research on multi-robot collaborative control encompasses many aspects, and enclosure control is one of these collaborative control issues. Existing technologies generally do not consider how to implement enclosure control in three-dimensional space, how to control the formation of robots in physically connected environments, and how to achieve enclosure control of a target in the shortest possible time. Summary of the Invention

[0003] The present invention provides a multi-robot encirclement control method with a physical connection, aiming to address at least one of the technical problems existing in the prior art. The physically connected multi-robot encirclement device comprises at least two robots capable of three-dimensional spatial motion. By collaborating with each other, the encirclement range gradually increases, thereby encircling a target object. The physically connected multi-robot encirclement device can achieve encirclement control of the target object in a short period of time.

[0004] The technical solution of the present invention relates to a method for controlling a multi-robot enclosure with a physical connection, wherein the multi-robot with a physical connection includes at least two nodes, each of which is a single robot. Each node is physically connected to another node, and the entirety of each node and the physical connection is used to perform enclosure control on a target object. The method comprises the following steps:

[0005] S100, obtaining the position and velocity of each node and the position of the target, calculating the position and velocity of the virtual center formed by all nodes, the expected distance of each node from the virtual center, the distance between nodes, and the distance from each node to the target;

[0006] S200, based on the node encirclement formation control model of each node, controlling the movement of each node until the virtual center formed by all nodes coincides with the target object;

[0007] S300: Control each node to capture the target object.

[0008] Furthermore, the step S200 includes:

[0009] S210, establishing and initializing the node encirclement formation control model of each node;

[0010] S220: Optimize the node encirclement formation control model based on process deduction.

[0011] Furthermore, the node encirclement formation control model is:

[0012]

[0013] Where i is the node number, is the distance component between the current node and other nodes, is the speed difference component between the current node and other nodes, is the distance component from the current node to the virtual center, is the velocity difference component between the current node and the virtual center, is the distance component from the current node to the target position, and It is the gain parameter corresponding to each component of the node formation control model.

[0014] Furthermore, the distance component between the current node and other nodes The speed difference component between the current node and other nodes The distance component from the current node to the virtual center The speed difference component between the current node and the virtual center and the distance component from the current node to the target position They are:

[0015]

[0016]

[0017]

[0018]

[0019]

[0020] Among them, j represents the jth node except the current node, is the position of the current node, is the speed of the current node, is the position of other nodes except the current node, is the speed of other nodes except the current node, d0 is the expected distance from the current node to the virtual center, and are the position and velocity of the virtual center, The position of the target, d react is the reaction distance between the node and the target.

[0021] Furthermore, the step S220 further includes:

[0022] S221. Establish node constraints and constraints between nodes and targets;

[0023] S222, establishing a node closed-loop motion equation;

[0024] S223, initializing the gain parameters corresponding to each component of the node encirclement formation control model;

[0025] S224. Based on the termination condition of the process deduction, embed the node constraint and the constraint between the node and the target object into the node encirclement formation control model, and output the time consumed in encircling the target object;

[0026] S225 , looping through step S224 to iterate the gain parameters corresponding to the various components of the node encirclement formation control model, so as to minimize the time consumed in encircling the target object.

[0027] Furthermore, the node constraints include a minimum distance and a maximum distance between a node and other nodes, a maximum acceleration of a node, and a maximum speed of a node;

[0028] The constraints between the node and the target object include a minimum distance and a maximum distance between the node and the target object.

[0029] Furthermore, the node closed-loop motion equation is:

[0030]

[0031] Where i is the node number, represents the velocity of the i-th node, Represents the input of the encirclement formation control model of the i-th node.

[0032] Furthermore, the step S225 further includes:

[0033] If the node constraints and the constraints between the node and the target object are violated during the iterative process of process deduction, the preset maximum value of the time consumed to surround the target object is output.

[0034] Furthermore, the termination condition is that the distance norm of each node from the target object begins to increase, and the increase in the distance norm of each node from the target object is greater than a preset threshold.

[0035] The present invention further provides a multi-robot encirclement control device with physical connection, which is used to implement the above-mentioned multi-robot encirclement control method with physical connection, wherein the multi-robot with physical connection includes:

[0036] Nodes, used to perform encirclement control on the target object, wherein there are at least two nodes, each of which is connected by an entity, and the whole formed by each of the nodes and the entity is used to perform encirclement control on the target object;

[0037] The overall control system is used to control the movement of each node.

[0038] Compared with the existing technology, the present invention has the following characteristics.

[0039] This invention achieves the control of a target encirclement by a physically connected multi-robot system under time-optimal conditions, overcoming the shortcomings of existing technologies. This optimal encirclement of a target has strong practical significance, particularly in military applications. This physically connected multi-robot system is more realistic and has broad application potential, such as collaborative lifting and handling by robots, netting by multiple drones, coordinated netting by multiple unmanned submersibles, and coordinated operation of multiple spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Flowchart of the multi-robot encirclement control method with physical connections.

[0041] Figure 2 Schematic diagram of the node encirclement formation control model for calculating each node in the multi-robot encirclement control method with physical connections.

[0042] Figure 3 A schematic diagram of optimizing the node encirclement formation control model in a multi-robot encirclement control method with physical connections.

[0043] Figure 4 Schematic diagram of the collaborative encirclement control of multiple robot nodes in a multi-robot encirclement control method with physical connections.

[0044] Figure 5 Schematic diagram of the unfolding process of multiple robot nodes in the multi-robot encirclement control method with physical connections.

[0045] Figure 6 This is a schematic diagram of the collaborative encirclement control method for multiple robot nodes in a multi-robot encirclement control method with physical connections.

[0046] Figure 7 Schematic diagram of the encirclement effect in the multi-robot encirclement control method with physical connections.

[0047] Figure 8 Schematic diagram of the process of iterating the shortest encirclement time in the multi-robot encirclement control method with physical connections. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0049] The following will provide a clear and complete description of the concept, specific structure and technical effects of the present invention in conjunction with the embodiments and drawings to fully understand the purpose, scheme and effects of the present invention.

[0050] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. The singular forms "a", "said" and "the" used herein are also intended to include the plural forms, unless the context clearly indicates otherwise. In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used in this specification are only for describing specific embodiments and are not intended to limit the invention. The term "and / or" used herein includes any combination of one or more related listed items.

[0051] It should be understood that although the terms first, second, third, etc. may be used to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. The use of any and all examples or exemplary language ("for example", "such as", etc.) provided herein is only intended to better illustrate embodiments of the present invention, and unless otherwise required, will not impose limitations on the scope of the present invention. In addition, the industry term "posture" used herein refers to the position and attitude of a certain element relative to a spatial coordinate system.

[0052] Reference Figures 1 to 8 The embodiment of the present invention provides a multi-robot encirclement control method with physical connection, wherein the multi-robot with physical connection includes at least two nodes, each of which is a single robot, and each node is connected by a physical connection, and each node and the entity constitute a whole for encircling and controlling the target object, referring to Figure 1 , the method comprises the following steps:

[0053] S100, obtaining the position and velocity of each node and the position of the target, calculating the position and velocity of the virtual center formed by all nodes, the expected distance of each node from the virtual center, the distance between nodes, and the distance from each node to the target;

[0054] S200, based on the node encirclement formation control model of each node, controlling the movement of each node until the virtual center formed by all nodes coincides with the target object;

[0055] S300: Control each node to capture the target object.

[0056] In a specific embodiment, controlling each node to capture a target object includes controlling multiple robot nodes to accelerate their flight so that an entity connecting all nodes, such as a mesh, can wrap around the target object from behind; then controlling each node to decelerate and retract so that the entity mesh can retract and wrap around the target object, thereby capturing the target object.

[0057] This paper proposes an optimization-based enclosure control algorithm for a physically connected multi-robot system. The algorithm addresses the control of encircling a target object by physically connected multi-robots, achieving encirclement of the target object in the shortest possible time while ensuring encirclement accuracy. The physically connected multi-robot system includes multiple robots connected by ropes, mesh fabric, or the like.

[0058] Reference Figure 4 In a specific embodiment, three robot nodes with three-dimensional spatial motion capabilities are set up. Through mutual cooperation, the covered space is gradually enlarged, and the target object is followed, and finally the target object is surrounded.

[0059] Reference Figure 2 , further, the step S200 includes:

[0060] S210, establishing and initializing the node encirclement formation control model of each node;

[0061] S220: Optimize the node encirclement formation control model based on process deduction.

[0062] Furthermore, the node encirclement formation control model is:

[0063]

[0064] Where i is the node number, is the distance component between the current node and other nodes, is the speed difference component between the current node and other nodes, is the distance component from the current node to the virtual center, is the velocity difference component between the current node and the virtual center, is the distance component from the current node to the target position, and It is the gain parameter corresponding to each component of the node formation control model.

[0065] Reference Figure 5 , showing the process of multiple node deployment. In a specific embodiment, three robot nodes are set up. These nodes will follow a virtual center, and the virtual center itself follows a predetermined trajectory in the environment. Assuming that there is a target object to be surrounded in the environment, the nodes must be deployed collaboratively under the constraints of flexible entity connection, while also maintaining a formation with the virtual center. Eventually, the virtual center will fall in the center of the target object to be surrounded. The nodes are formed around the virtual center. When the target to be surrounded is detected, the entire formation begins to expand until it can surround the target object. The formation will be composed of a formation vector u i Parameterize the formation vector u i It consists of the positions and relative velocities of all nodes and the virtual center. Once the sum of all these values ​​is equal to zero (or within a certain tolerance), the system is considered to be stable. It is assumed that all nodes have access to global information and there are no delays or limitations on sensor speed.

[0066] Furthermore, the distance component between the current node and other nodes The speed difference component between the current node and other nodes The distance component from the current node to the virtual center The speed difference component between the current node and the virtual center and the distance component from the current node to the target position They are:

[0067]

[0068]

[0069]

[0070]

[0071]

[0072] Among them, j represents the jth node except the current node, is the position of the current node, is the speed of the current node, is the position of other nodes except the current node, is the speed of other nodes except the current node, d0 is the expected distance from the current node to the virtual center, and are the position and velocity of the virtual center, The position of the target, d react is the reaction distance between the node and the target.

[0073] Reference Figure 3 Furthermore, the step S220 further includes:

[0074] S221. Establish node constraints and constraints between nodes and targets;

[0075] S222, establishing a node closed-loop motion equation;

[0076] S223, initializing the gain parameters corresponding to each component of the node encirclement formation control model;

[0077] S224. Based on the termination condition of the process deduction, embed the node constraint and the constraint between the node and the target object into the node encirclement formation control model, and output the time consumed in encircling the target object;

[0078] S225 , looping through step S224 to iterate the gain parameters corresponding to the various components of the node encirclement formation control model, so as to minimize the time consumed in encircling the target object.

[0079] Specifically, refer to Figure 6 The multi-robot encirclement control method with physical connections is divided into two parts: process deduction and controller parameter optimization. All constraints are embedded in the process deduction as a penalty function, that is, the node encirclement formation control model is transformed into a penalty function, thereby implicitly constructing the relevant constraints. The process deduction is used as the penalty function of the optimizer, whose input is the relevant control parameters and output is the encirclement time (which is then optimized and gradually minimized by the optimizer). If a constraint violation occurs during the process deduction, the encirclement time is increased (increased to 10,000 seconds, indicating that this set of parameters is unusable), causing the optimizer to significantly adjust the encirclement controller parameters.

[0080] Furthermore, the node constraints include a minimum distance and a maximum distance between a node and other nodes, a maximum acceleration of a node, and a maximum speed of a node;

[0081] The constraints between the node and the target object include a minimum distance and a maximum distance between the node and the target object.

[0082] In order to achieve the shortest encirclement time, an optimization algorithm will be constructed. A time-optimal goal will be defined. This optimization goal will include the controller parameters and the real-time distance between the node and the obstacle.

[0083] There are three main constraints:

[0084] ① Due to the existence of physical connections, a safe distance must be left between nodes. Physical connections have compression and stretching ranges, and the distance cannot be too large or too small.

[0085] ②Each node cannot collide with the target object.

[0086] ③ Each node will have a maximum allowed acceleration (up to actuator saturation), as well as a maximum allowed driving speed for each node.

[0087] Furthermore, the node closed-loop motion equation is:

[0088]

[0089] Where i is the node number, represents the velocity of the i-th node, represents the input of the encirclement formation control model of the ith node. In particular, the process deduction is mainly related to the dynamics of the node.

[0090] Furthermore, the step S225 further includes:

[0091] If the node constraints and the constraints between the node and the target object are violated during the iterative process of process deduction, the preset maximum value of the time consumed to surround the target object is output.

[0092] Furthermore, the termination condition is that the distance norm of each node from the target object begins to increase, and the increase in the distance norm of each node from the target object is greater than a preset threshold ε. Setting the termination condition allows the process deduction to reach the end condition as soon as possible without endless calculation.

[0093] The present invention further provides a multi-robot encirclement control device with physical connection, which is used to implement the above-mentioned multi-robot encirclement control method with physical connection, wherein the multi-robot with physical connection includes:

[0094] Nodes, used to perform encirclement control on the target object, wherein there are at least two nodes, each of which is connected by an entity, and the whole formed by each of the nodes and the entity is used to perform encirclement control on the target object;

[0095] The overall control system is used to control the movement of each node.

[0096] In a specific embodiment, in order to prove the effectiveness of the solution of the present invention, the method proposed by the present invention is simulated and verified by MATLAB simulation. The simulation scenario is: three robots in a plane perform semi-enclosed control on an irregular area. Figure 7 Shown enclosure effect and reference Figure 8 Shown is the iterative process of bracketing time.

[0097] Reference Figure 7 ,The running trajectories of the three nodes during the encirclement process. It can be seen that during the encirclement process, there is no relative collision between the nodes, and there is no collision with the target object, successfully achieving semi-encirclement of the target object.

[0098] Reference Figure 8 Using the method described in this invention, the encirclement process was simulated a total of 112 times. Between the 50th and 100th iterations, two collisions occurred, causing the algorithm to over-set the encirclement time. Ultimately, the encirclement time was optimized from 110 seconds to 40 seconds. This demonstrates the effectiveness and feasibility of the proposed method, effectively minimizing encirclement time.

[0099] The optimized surround controller parameter optimization results are as follows:

[0100]

[0101] In a specific embodiment, it is assumed that the multi-robot system can communicate with each other arbitrarily and has obtained the global map information of the environment in which the multi-robot system is located (for example, each node). There is a target object that needs to be surrounded in the environment.

[0102] The implementation steps of the multi-robot encirclement control method with physical connection are as follows:

[0103] According to the environmental map information, according to the distance between the node and the target object The distance between nodes ) and the movement speed of each node Determine the distance component between the current node and other nodes The speed difference component between the current node and other nodes The distance component from the current node to the virtual center The speed difference component between the current node and the virtual center and the distance component from the current node to the target position

[0104] According to the distance components between the current node and other nodes described by each node The speed difference component between the current node and other nodes The distance component from the current node to the virtual center The speed difference component between the current node and the virtual center and the distance component from the current node to the target position Construct a node encirclement formation control model, and the encirclement control controller related gain is and Its control object is the movement speed of the node;

[0105] Combining the node encirclement formation control model of the node with the node motion speed to form a node closed-loop motion equation, which will be used as a penalty function of the optimizer later;

[0106] The initial values ​​of the wraparound controller related gains are input into the optimizer. Due to the existence of the wraparound control termination condition, different control gains will produce different wraparound times. Therefore, the optimization objective of the optimizer is set to the wraparound time of the node to the target.

[0107] Substitute the control rate generated by each set of controller gains into the node closed-loop motion equation. If a collision occurs between nodes during the evolution process, Or the collision between the node and the target Then, a preset maximum surround time is returned to the optimizer. In a specific embodiment, the preset maximum surround time is 1000 seconds, indicating that the set of controller parameters is not feasible.

[0108] Iterative execution embeds the node constraints and the constraints between the node and the target object into the node surrounding formation control model, and outputs the time consumed in surrounding the target object until the surrounding time is minimized.

[0109] It should be appreciated that the method steps in the embodiments of the present invention can be implemented or executed by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The method can use standard programming techniques. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with the computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. In addition, for this purpose, the program can be run on a programmed application-specific integrated circuit.

[0110] Furthermore, the operations of the processes described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by the context. The processes described herein (or variations and / or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) that is executed collectively on one or more processors, by hardware, or a combination thereof. The computer program includes a plurality of instructions that can be executed by one or more processors.

[0111] Further, the methods can be implemented in any type of computing platform that is operably connected to a suitable computer, including but not limited to a personal computer, a minicomputer, a mainframe, a workstation, a network or distributed computing environment, a separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, etc. Various aspects of the present invention can be implemented as machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, an optical read and / or write storage medium, RAM, ROM, etc., so that it can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the processes described herein. In addition, the machine-readable code, or portions thereof, can be transmitted over a wired or wireless network. When such media includes instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor, the invention described herein includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques of the present invention, the present invention can also include the computer itself.

[0112] The computer program can be applied to input data to perform the functions described herein, thereby converting the input data to generate output data that is stored in a non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the converted data represents a physical and tangible object, including a specific visual depiction of the physical and tangible object produced on the display.

[0113] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the aforementioned embodiments. As long as the technical effects of the present invention are achieved by the same means, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. Within the scope of protection of the present invention, various modifications and variations of the technical solutions and / or implementation methods are possible.

Claims

1. A method for controlling a multi-robot enclosure with physical connections, wherein the multi-robot enclosure with physical connections comprises at least two nodes, each of which is a single robot. Each node is physically connected to another node, and the entirety of each node and the physical connection is used to perform enclosure control on a target object, characterized in that: The method comprises the following steps: S100, obtaining the position and velocity of each node and the position of the target, calculating the position and velocity of the virtual center formed by all nodes, the expected distance of each node from the virtual center, the distance between nodes, and the distance from each node to the target; S200, based on a node encirclement formation control model for each node, controlling the movement of each node until a virtual center formed by all nodes coincides with the target object; the node encirclement formation control model is: Among them, u i is the control speed of each node, is the node number, is the distance component between the current node and other nodes, is the speed difference component between the current node and other nodes, is the distance component from the current node to the virtual center, is the velocity difference component between the current node and the virtual center, is the distance component from the current node to the target position, and The gain parameters corresponding to each component of the node encirclement formation control model; S300: Control each node to capture the target object.

2. The multi-robot encirclement control method with physical connection according to claim 1, characterized in that: The step S200 includes: S210, establishing and initializing the node encirclement formation control model of each node; S220: Optimize the node encirclement formation control model based on process deduction.

3. The multi-robot encirclement control method with physical connection according to claim 1, characterized in that: The distance component between the current node and other nodes The speed difference component between the current node and other nodes The distance component from the current node to the virtual center The speed difference component between the current node and the virtual center and the distance component from the current node to the target position They are: Among them, j represents the jth node except the current node, is the position of the current node, is the speed of the current node, is the position of other nodes except the current node, is the speed of other nodes except the current node, d0 is the expected distance from the current node to the virtual center, and are the position and velocity of the virtual center, The position of the target, d react is the reaction distance between the node and the target.

4. The multi-robot encirclement control method with physical connection according to claim 2, characterized in that: The step S220 further includes: S221. Establish node constraints and constraints between nodes and targets; S222, establishing a node closed-loop motion equation; S223, initializing the gain parameters corresponding to each component of the node encirclement formation control model; S224. Based on the termination condition of the process deduction, embed the node constraint and the constraint between the node and the target object into the node encirclement formation control model, and output the time consumed in encircling the target object; S225 , looping through step S224 to iterate the gain parameters corresponding to the various components of the node encirclement formation control model, so as to minimize the time consumed in encircling the target object.

5. The multi-robot encirclement control method with physical connection according to claim 4, characterized in that: The node constraints include the minimum distance and the maximum distance between the node and other nodes, the maximum acceleration of the node and the maximum speed of the node; The constraints between the node and the target object include a minimum distance and a maximum distance between the node and the target object.

6. The multi-robot encirclement control method with physical connection according to claim 4, characterized in that: The closed-loop motion equation of the node is: in, is the node number, Indicates the The speed of the nodes, Indicates the The surrounding formation of nodes controls the input of the model.

7. The multi-robot encirclement control method with physical connection according to claim 4, characterized in that: The step S225 further includes: If the node constraints and the constraints between the node and the target object are violated during the iterative process of process deduction, the preset maximum value of the time consumed to surround the target object is output.

8. The multi-robot encirclement control method with physical connection according to claim 4, characterized in that: The termination condition is that the distance norm of each node from the target object begins to increase, and the increase in the distance norm of each node from the target object is greater than a preset threshold.

9. A multi-robot encirclement control device with physical connection, used to implement the multi-robot encirclement control method with physical connection according to any one of claims 1 to 8, characterized in that: The physically connected multi-robots include: Nodes, there are at least two nodes, each node is connected by an entity, and the whole formed by each node and the entity is used to surround and control the target object; The overall control system is used to control the movement of each node.

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