A collaborative obstacle avoidance decision-making method for multi-node landers under inconsistent constraints

Abstract

The present invention relates to a method for collaborative obstacle avoidance for multi-node landers under non-uniform constraints, comprising: controlling the multi-node lander to descend to a preset altitude and acquiring an environmental map of a star catalog; calculating the trajectory of the multi-node lander's virtual center and the position of each node; determining the real-time distance of each node relative to the virtual center and calculating each node's own trajectory based on flexible transformation constraints such as the multi-node lander's configuration potential field, obstacle avoidance potential field, and collision avoidance potential field; and controlling each node to track its own trajectory to achieve collaborative obstacle avoidance. This method enables future asteroid probes to robustly and accurately adhere to landing sites of high scientific value during landing and sample return missions, and to cope with various hazardous terrains, such as steep slopes and narrow valleys.

Description

Technical Field

[0001] The present invention belongs to the field of deep space exploration, and in particular relates to a multi-node lander collaborative obstacle avoidance (decision-making) method under non-uniform constraints. Background Art

[0002] Most of the existing patents are for landing obstacle avoidance planning for single-node landers. For multi-node landers, in addition to considering overall obstacle avoidance and collision avoidance, it is also necessary to consider how to avoid collisions and obstacles between nodes. Summary of the Invention

[0003] This invention provides a collaborative obstacle avoidance method for multi-node landers under non-uniform constraints, aiming to address at least one of the technical issues existing in the prior art. This invention addresses a rigid-flexibly coupled multi-node lander and proposes how multiple nodes within the lander can collaborate to plan an obstacle avoidance path, enabling the lander to autonomously avoid hazards and maintain fixed-point attachment.

[0004] The technical solution of the present invention relates to a collaborative obstacle avoidance method for a multi-node lander under non-uniform constraints, wherein the multi-node lander comprises a flexible body, three rigid nodes arranged inside the flexible body, the centers of the three rigid nodes are virtual centers, and a virtual center coordinate system is established with the virtual center as the origin. The method comprises the following steps:

[0005] S100, controlling the multi-node lander to descend to a preset altitude and obtaining an environmental map of the star catalog;

[0006] S200, calculating the trajectory δ of the virtual center of the multi-node lander v (t) and the position p of each node i (t);

[0007] S300, based on the flexible transformation constraints such as the configuration potential field, obstacle avoidance potential field and collision avoidance potential field of the multi-node lander, determine the real-time distance r of each node relative to the virtual center i (t), calculate the trajectory δ of each node itself i (t);

[0008] S400, controlling each node to track its own trajectory δ i (t) Achieve collaborative obstacle avoidance.

[0009] Furthermore, the node is in the virtual center coordinate system The relative position of the coordinate system is expressed as:

[0010] {r1(t), r2(t), r3(t)},

[0011] Where t is time;

[0012] Node i in the world coordinate system The position in is represented as:

[0013] p i (t) = p v (t)+R v (t)r i (t),

[0014] Among them, p v (t)∈R 3 and R v (t)∈SO 3 Indicates the virtual center coordinate system The origin is under the world star position and posture.

[0015] Further, step S200 includes:

[0016] S210, based on the virtual center obstacle avoidance potential field, using key waypoints and interpolation method to calculate the virtual center real-time waypoints {K1...K N} position p v (t) and yaw angle ψ v Flat output of (t);

[0017] S220, calculate the position p of the node i (t) and its fourth-order derivative,

[0018]

[0019] Among them, r i Indicated in the virtual center coordinate system The real-time distance of each node relative to the virtual center, p i Indicates that node i is in the stellar coordinate system The position under the yaw angle ψ i (t) and its fourth-order derivative are consistent with the yaw angle of the virtual center.

[0020] Furthermore, step S300 includes: the configuration potential field of the multi-node lander is:

[0021]

[0022] Among them, A is the node configuration parameter, is the expected position of the node, r is the actual position of the node, and i represents the i-th node.

[0023] Further, step S300 includes that the obstacle avoidance potential field of the multi-node lander includes a virtual center obstacle avoidance potential field and a node obstacle avoidance potential field.

[0024] Furthermore, the overall repulsion vector of the vector field generated by the obstacle in the virtual central obstacle avoidance potential field is:

[0025]

[0026] in, is the repulsion vector pointing from the obstacle position to the virtual center, and its size is a Gaussian function related to the position and radius of the obstacle and the direction of the virtual center. k is the number of obstacles in the environment. is the obstacle k in the global coordinate system The horizontal position in r k represents the obstacle radius, Indicates the direction of the virtual center,

[0027] in,

[0028]

[0029] Among them, B k is a radius r from the obstacle k k The relevant parameters, ∑ is a 2x2 positive definite matrix,

[0030]

[0031] in, is a unit vector In the vertical direction, σ1 and σ2 are covariances.

[0032] Furthermore, the node obstacle avoidance potential field is:

[0033]

[0034] Among them, C k is a radius r from the obstacle k k Related parameters.

[0035] Furthermore, step S300 also includes, in the virtual center coordinate system Under this condition, the collision avoidance potential field of the node is:

[0036]

[0037] in, represents the neighboring points of node i.

[0038] The present invention also proposes a multi-node lander for an asteroid, which is used to implement the above-mentioned multi-node lander collaborative obstacle avoidance method under non-uniform constraints. The multi-node lander includes:

[0039] Flexible body;

[0040] Nodes, each of which is disposed inside the flexible body, is a rigid node, and there are three nodes. The nodes are not distributed on the same straight line, and each node includes a node thruster. The node thrusters include an upward thruster for compensating for the weak gravity of the asteroid and a downward thruster for translation and attitude adjustment of the node, as well as driving the flexible body to perform flexible transformation. The node also includes sensing equipment and payloads such as wide and narrow field of view cameras, lidar, and IMU;

[0041] An overall control system is used to control the movement of the nodes and the flexible body.

[0042] The present invention further provides a computer-readable storage medium having program instructions stored thereon, wherein the program instructions implement the above method when executed by a processor.

[0043] Compared with the existing technology, the present invention has the following characteristics.

[0044] The present invention is aimed at a rigid-flexibly coupled multi-node lander, and proposes how multiple nodes in the lander can cooperate with each other to plan obstacle avoidance paths, so that the lander has the ability to autonomously avoid risks and attach to fixed points; this method enables future asteroid probes to be able to robustly and accurately attach to landing points with high scientific value when performing landing and sample return missions, and to cope with various dangerous bottom lines, such as steep slopes and narrow valleys. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The flowchart of the multi-node lander collaborative obstacle avoidance method under non-uniform constraints;

[0046] Figure 2 Schematic diagram of the multi-node lander collaborative obstacle avoidance method under non-uniform constraints;

[0047] Figure 3 Schematic diagram of the virtual center obstacle avoidance potential field in the multi-node lander collaborative obstacle avoidance method under non-uniform constraints;

[0048] Figure 4 Schematic diagram of the node obstacle avoidance potential field in the multi-node lander collaborative obstacle avoidance method under non-uniform constraints;

[0049] Figure 5 Schematic diagram of the landing scenario of the lander in the multi-node lander collaborative obstacle avoidance method under non-uniform constraints;

[0050] Figure 6 This is the flexible transformation process in the multi-node lander collaborative obstacle avoidance method under non-uniform constraints. DETAILED DESCRIPTION

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Reference Figures 1 to 5 The embodiment of the present invention provides a method for collaborative obstacle avoidance (decision-making) of a multi-node lander under non-uniform constraints. The multi-node lander includes a flexible body and three rigid nodes arranged inside the flexible body. The centers of the three rigid nodes are virtual centers. A virtual center coordinate system is established with the virtual center as the origin. The method comprises the following steps:

[0056] S100, controlling the multi-node lander to descend to a preset altitude and obtaining an environmental map of the star catalog;

[0057] S200, calculating the trajectory δ of the virtual center of the multi-node lander v (t) and the position p of each node i (t);

[0058] S300, based on the flexible transformation constraints such as the configuration potential field, obstacle avoidance potential field and collision avoidance potential field of the multi-node lander, determine the real-time distance r of each node relative to the virtual center i (t), calculate the trajectory δ of each node itself i (t);

[0059] S400, controlling each node to track its own trajectory δ i (t) Achieve collaborative obstacle avoidance.

[0060] The present invention is aimed at a rigid-flexibly coupled multi-node lander, and proposes how multiple nodes in the lander can cooperate with each other to plan obstacle avoidance paths, so that the lander has the ability to autonomously avoid risks and attach to fixed points; this method enables future asteroid probes to be able to robustly and accurately attach to landing points with high scientific value when performing landing and sample return missions, and to cope with various dangerous bottom lines, such as steep slopes and narrow valleys.

[0061] To illustrate the trajectory planning problem of the new detector multi-node when avoiding obstacles, please refer to Figure 5 Future asteroid landing and sample return missions will seek landing sites of high scientific value, such as hazardous terrain. This requires the spacecraft to be able to autonomously avoid hazards, hence the definition of collision avoidance zones. The study scenario shown here is designed based on the concept of collision avoidance zones. At a distance of only 20 meters from the surface, the probe must avoid two collision avoidance zones (physical obstacles or no-fly zones with no lighting) on ​​the surface of the planet to reach the target landing site. To demonstrate the flexible transformation process of the new probe, a gap is intentionally left between the two collision avoidance zones for the probe to pass through.

[0062] The non-uniform constraint refers to a multi-node lander, which includes a flexible body and three rigid nodes arranged inside the flexible body. Each node inside the flexible body must not only avoid the rocks on the celestial body, but also prevent excessive extrusion and stretching of the flexible material caused by the node spacing being too close or too far. The inconsistency between the environmental constraints and the lander's own flexible constraints is called a non-uniform constraint.

[0063] Reference Figure 2First, a virtual center of three nodes is constructed. The virtual center is used to abstract the multi-node lander into a whole, providing a simple and natural way to represent the multiple nodes within it. During the movement of the three nodes, the speed and position of the virtual center are "controlled" by the three nodes. Assuming that the probe obtains a detailed environmental map of the star when it is very close to the star, the trajectory of the virtual center δ is first generated in the environmental map. v (t), and then communicate the trajectory to all nodes, and use the node's configuration potential field, obstacle avoidance potential field, collision avoidance potential field, etc. as flexible transformation constraints to enable each node to solve its own trajectory δ i (t), and finally control each node to track its own trajectory δ i (t) Achieve collaborative obstacle avoidance.

[0064] Furthermore, the node is in the virtual center coordinate system The relative position of the coordinate system is expressed as:

[0065] {r1(t), r2(t), r3(t)},

[0066] Where t is time;

[0067] Node i in the world coordinate system The positions of and are expressed as:

[0068] p i (t) = p v (t)+R v (t)r i (t),

[0069] Among them, p v (t)∈R 3 and R v (t)∈SO 3 Indicates the virtual center coordinate system The origin is under the world star position and posture.

[0070] Further, step S200 includes:

[0071] S210, based on the virtual center obstacle avoidance potential field, using key waypoints and interpolation method to calculate the virtual center real-time waypoints {K1...K N} position p v (t) and yaw angle ψ v Flat output of (t);

[0072] In the obstacle avoidance strategy, the most important link is the multi-node trajectory collaborative planning. Since the virtual center is a virtual object without relevant dynamic constraints, the key waypoints and interpolation method are used to generate the virtual center obstacle avoidance trajectory. The trajectory only needs to determine the virtual center real-time waypoints {K1...K N} position p v (t) and yaw angle ψ v (t) flat output, virtual center real-time waypoint {K1...K N} position p v (t) and yaw angle ψ v The flat output of (t) can be obtained by solving the virtual center obstacle avoidance potential field.

[0073] S220, calculate the position p of the node i (t) and its fourth-order derivative,

[0074]

[0075] Among them, r i Indicated in the virtual center coordinate system The real-time distance of each node relative to the virtual center, p i Indicates that node i is in the stellar coordinate system The position under the yaw angle ψ i (t) and its fourth-order derivative are consistent with the yaw angle of the virtual center.

[0076] The node is a specific physical entity with relevant dynamic constraints. The node trajectory must determine each state quantity, such as position, velocity, acceleration, Euler angle and Euler angular rate. The real-time position and yaw angle of the node are determined by the virtual center trajectory δ v (t)(virtual center position p v (t) and yaw angle ψ v (t)) and node collision avoidance, obstacle avoidance, and configuration potential fields are jointly solved and determined. The various potential fields designed mainly determine the real-time distance r of each node relative to the virtual center. i (t), that is, the flexible transformation of the detector. After determining the position of the node p i (t) and yaw angle ψ i (t) and its fourth-order derivative, the remaining state quantities can be obtained using the differential flatness theory, and finally the trajectory of each node can be obtained by interpolating between the waypoints. i (t).

[0077] Please refer to Figure 6 Flexible transformation means that the relative positions of the three nodes from the virtual center are time-varying {r1(t), r2(t), r3(t)}. This is used to achieve the expansion and deformation of the flexible body.

[0078] Furthermore, step S300 includes: the configuration potential field of the multi-node lander is:

[0079]

[0080] Among them, A is the node configuration parameter, is the expected position of the node, r is the actual position of the node, and i represents the i-th node.

[0081] The nodes can only move relatively in a small range inside the flexible body. In order to stabilize the configuration of the flexible body, each node is in the virtual center coordinate system. A vector field is generated under the virtual center coordinate system, so that when the node deviates from its expected position, a forced potential field will act on the node to push it back to the expected position. In this way, you don't need to consider the node in the global coordinate system For maneuvers, only their virtual positions in the virtual center coordinate system are considered.

[0082] Further, step S300 includes that the obstacle avoidance potential field of the multi-node lander includes a virtual center obstacle avoidance potential field and a node obstacle avoidance potential field.

[0083] In order to achieve better obstacle avoidance effect, when an obstacle is detected, the speed of the entire lander should be reduced first, and then the coordination of obstacle avoidance speeds between nodes should be ensured. Therefore, the obstacle avoidance potential field mainly consists of two parts: the first is the virtual center obstacle avoidance potential field, please refer to Figure 3 , generates a potential field for each obstacle in the environment. When the virtual center moves toward the obstacle, the potential field will force the virtual center to slow down, so that each node can slow down and buffer when encountering an obstacle. The second is the node obstacle avoidance potential field, please refer to Figure 4 , another potential field is generated for each obstacle in the environment. Since the distances between each node and the obstacle are inconsistent during the movement process, the speeds of each node should be coordinated with each other when avoiding obstacles. The nodes that have avoided the obstacles "wait" for the nodes that have not avoided the obstacles, so as to ensure that the node spacing is appropriate and does not violate the flexible connection constraint.

[0084] Furthermore, the overall repulsion vector of the vector field generated by the obstacle in the virtual central obstacle avoidance potential field is:

[0085]

[0086] in, is the repulsion vector pointing from the obstacle position to the virtual center, and its size is a Gaussian function related to the position and radius of the obstacle and the direction of the virtual center. k is the number of obstacles in the environment. is the obstacle k in the global coordinate system The horizontal position in r krepresents the obstacle radius, Indicates the direction of the virtual center,

[0087] in,

[0088]

[0089] Among them, B k is a radius r from the obstacle k k The relevant parameters, ∑, are a 2x2 positive definite matrix, and the value of Bk is selected to slow down the speed of the virtual center. Since the virtual center does not really exist, the main and secondary axes of the dynamic Gaussian function are determined.

[0090]

[0091] in, is a unit vector In the vertical direction, σ1 and σ2 are covariances.

[0092] Define a repulsion vector p pointing from the obstacle position to the virtual center, whose size is a Gaussian function related to the position and radius of the obstacle and the direction of the virtual center. Assume that there are k obstacles in the environment, and use Indicates that obstacle k is in the global coordinate system The horizontal position in the horizontal coordinate The overall repulsion vector of the vector field generated by k obstacles at is

[0093] Therefore, if the virtual center is directed towards an obstacle, it will experience a large repulsive force that prevents the virtual center from directly hitting the obstacle.

[0094] Furthermore, the node obstacle avoidance potential field is:

[0095]

[0096] Among them, C k is a radius r from the obstacle k k Related parameters. C k The value of must be chosen large enough to ensure that collisions are avoided.

[0097] The node obstacle avoidance potential field is similar to the virtual center obstacle avoidance potential field, but the node needs a stronger "repulsion force" so that when the node is too close to an obstacle, the force of the repulsion vector is enough to "push the node away".

[0098] Furthermore, step S300 also includes, in the virtual center coordinate system Under this condition, the collision avoidance potential field of the node is:

[0099]

[0100] in, represents the neighboring points of node i.

[0101] In addition to obstacle avoidance, collision avoidance between nodes also needs to be considered. By analogy with the above obstacle avoidance potential field, node j can be regarded as an obstacle to node i, thereby achieving mutual collision avoidance between nodes.

[0102] The present invention also proposes a multi-node lander for an asteroid, which is used to implement the above-mentioned multi-node lander collaborative obstacle avoidance (decision-making) method under non-uniform constraints. The multi-node lander includes:

[0103] Flexible body;

[0104] Nodes, each of which is disposed inside the flexible body, is a rigid node, and there are three nodes. The nodes are not distributed on the same straight line, and each node includes a node thruster. The node thrusters include an upward thruster for compensating for the weak gravity of the asteroid and a downward thruster for translation and attitude adjustment of the node, as well as driving the flexible body to perform flexible transformation. The node also includes sensing equipment and payloads such as wide and narrow field of view cameras, lidar, and IMU;

[0105] An overall control system is used to control the movement of the nodes and the flexible body.

[0106] The present invention further provides a computer-readable storage medium having program instructions stored thereon, wherein the program instructions implement the above method when executed by a processor.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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 multi-node lander collaborative obstacle avoidance method under non-uniform constraints, characterized by: The multi-node lander includes a flexible body and three rigid nodes arranged inside the flexible body. The center of the three rigid nodes is a virtual center. A virtual center coordinate system is established with the virtual center as the origin. The method comprises the following steps: S100, controlling the multi-node lander to descend to a preset altitude and obtaining an environmental map of the star catalog; S200, calculating the trajectory δ of the virtual center of the multi-node lander v (t) and the position p of each node i (t); S300, based on the flexible transformation constraints of the configuration potential field, obstacle avoidance potential field and collision avoidance potential field of the multi-node lander, determine the real-time distance r of each node relative to the virtual center i (t), calculate the trajectory δ of each node itself i (t); S400, controlling each node to track its own trajectory δ i (t) Achieve collaborative obstacle avoidance.

2. The multi-node lander collaborative obstacle avoidance method under non-uniform constraints according to claim 1 is characterized in that: The node is in the virtual center coordinate system The relative position of the coordinate system is expressed as: {r1(t), r2(t), r3(t)}, Where t is time; Node i in the world coordinate system The position in is represented as: p i (t)=p v (t)+R v (t)r i (t), Wherein, i represents the i-th node, p v (t)∈R 3 and R v (t)∈SO 3 Indicates the virtual center coordinate system The origin of the world coordinate system The position and posture below.

3. The multi-node lander collaborative obstacle avoidance method under non-uniform constraints according to claim 1, characterized in that: Step S200 includes: S210, based on the virtual center obstacle avoidance potential field, using key waypoints and interpolation method to calculate the virtual center real-time waypoints {K1...K N } position p v (t) and yaw angle ψ v Flat output of (T); S220, calculate the position p of the node i (t) and its fourth-order derivative, Wherein, i represents the i-th node, r i Indicated in the virtual center coordinate system The real-time distance of each node relative to the virtual center, p i Indicates that node i is in the world coordinate system The position under the yaw angle ψ i (t) and its fourth-order derivative are consistent with the yaw angle of the virtual center.

4. The multi-node lander collaborative obstacle avoidance method under non-uniform constraints according to claim 1, characterized in that: Step S300 includes: the configuration potential field of the multi-node lander is: Among them, A is the node configuration parameter, is the expected position of the node, r is the actual position of the node, and i represents the i-th node.

5. The multi-node lander collaborative obstacle avoidance method under non-uniform constraints according to claim 1, characterized in that: Step S300 includes: the obstacle avoidance potential field of the multi-node lander includes a virtual center obstacle avoidance potential field and a node obstacle avoidance potential field.

6. The multi-node lander collaborative obstacle avoidance method under non-uniform constraints according to claim 5, characterized in that: The overall repulsion vector of the vector field generated by obstacles in the virtual central obstacle avoidance potential field is: in, is the repulsion vector pointing from the obstacle position to the virtual center, and its size is a Gaussian function related to the position and radius of the obstacle and the direction of the virtual center. k is the number of obstacles in the environment. is the obstacle k in the world coordinate system The horizontal position in r k represents the obstacle radius, Indicates the direction of the virtual center, v v is the motion velocity vector of the virtual center; in, Among them, B k is a radius r from the obstacle k k The relevant parameters, ∑ is a 2x2 positive definite matrix, in, is a unit vector is the vertical direction, σ1 and σ2 are the covariances of the virtual center obstacle avoidance potential field.

7. The multi-node lander collaborative obstacle avoidance method under non-uniform constraints according to claim 5, characterized in that: The node obstacle avoidance potential field is: Among them, C k is a radius r from the obstacle k k Related parameters, is the repulsion vector pointing from the obstacle position to node i, and its size is a Gaussian function related to the position and radius of the obstacle and the orientation of the node. k is the number of obstacles in the environment. is the obstacle k in the world coordinate system is the horizontal position in , and σ3 is the covariance of the node obstacle avoidance potential field.

8. The multi-node lander collaborative obstacle avoidance method under non-uniform constraints according to claim 1, characterized in that: Step S300 also includes: in the virtual center coordinate system Under this condition, the collision avoidance potential field of the node is: in, represents the adjacent points of node i, r i With r j Node i and node j are in the virtual center coordinate system , D is the node collision avoidance potential field parameter, and σ4 is the node collision avoidance potential field covariance.

9. A multi-node lander for an asteroid, used to implement the multi-node lander collaborative obstacle avoidance method under non-uniform constraints as described in any one of claims 1 to 8, characterized in that: The multi-node lander includes: Flexible body; Nodes, each of which is disposed inside the flexible body, is a rigid node, and there are three nodes. The nodes are not distributed on the same straight line, and each node includes a node thruster. The node thrusters include an upward thruster for compensating for the weak gravity of the asteroid and a downward thruster for translation and attitude adjustment of the node, and for driving the flexible body to perform flexible transformation. The node also includes wide and narrow field of view cameras, a lidar, an IMU sensing device, and a payload. An overall control system is used to control the movement of the nodes and the flexible body. 10 . A computer-readable storage medium having program instructions stored thereon, wherein the program instructions are executed by a processor to implement the method according to claim 1 .

Images