阅读说明：本技术 一种基于介数中心性的卫星网络备份路由计算方法及系统 (Method and system for calculating backup route of satellite network based on betweenness centrality ) 是由 张琦 周蓉 陶滢 张伟 陈东 刘晔祺 李怡嫱 李姗姗 曹桂兴 沈宇飞 刘情嫄 于 2020-12-21 设计创作，主要内容包括：本发明涉及一种基于介数中心性的卫星网络备份路由计算方法及系统,方法包括：构建无权图；所述无权图的节点为卫星网络中的卫星节点,所述无权图的边为所述卫星节点之间的通信链路；利用介数中心性计算各所述卫星节点的重要程度,获得重要节点；利用蚁群算法计算所述卫星节点中的源卫星节点和目的卫星节点之间的最短延时路径；判断所述最短延时路径中是否包含所述重要节点；若所述最短延时路径中包含所述重要节点,则为所述最短延时路径对应的源卫星节点和目的卫星节点计算备份路由。本发明根据介数中心性计算卫星节点的重要程度,只针对含有重要节点的最短延时路径计算备份路由,在有效提高卫星网络抗毁性能的同时,降低了路由计算的时间开销。(The invention relates to a satellite network backup route calculation method and a system based on betweenness centrality, wherein the method comprises the following steps: constructing an unweighted graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes; calculating the importance degree of each satellite node by using betweenness centrality to obtain an important node; calculating the shortest delay path between a source satellite node and a destination satellite node in the satellite nodes by using an ant colony algorithm; judging whether the shortest delay path contains the important node or not; and if the shortest delay path comprises the important node, calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path. According to the invention, the importance degree of the satellite nodes is calculated according to the betweenness centrality, and the backup route is calculated only aiming at the shortest delay path containing the important nodes, so that the satellite network survivability is effectively improved, and the time cost of route calculation is reduced.)

1. A satellite network backup route calculation method based on betweenness centrality is characterized by comprising the following steps:

constructing an unweighted graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes;

calculating the importance degree of each satellite node by using betweenness centrality to obtain an important node;

calculating the shortest delay path between a source satellite node and a destination satellite node in the satellite nodes by using an ant colony algorithm;

judging whether the shortest delay path contains the important node or not;

and if the shortest delay path comprises the important node, calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path.

2. The method for computing backup routes for a satellite network based on betweenness centrality of claim 1, further comprising:

and if the shortest delay path does not contain the important node, calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path.

3. The method for calculating the backup route of the satellite network based on the betweenness centrality according to claim 1, wherein the calculating the importance degree of the satellite nodes by using the betweenness centrality to obtain the important nodes specifically comprises:

calculating the node betweenness of each satellite node according to the number of shortest paths passing through each satellite node in the weightless graph and the number of shortest paths of the weightless graph;

calculating edge betweenness of each edge according to the number of shortest paths passing through each edge in the weightless graph and the number of shortest paths of the weightless graph;

calculating the importance degree of the satellite node according to the node betweenness and the edge betweenness;

and obtaining important nodes according to the importance degree of the satellite nodes.

4. The method for calculating the backup route of the satellite network based on the betweenness centrality according to claim 1, wherein the calculating the shortest path between the satellite nodes by using the ant colony algorithm specifically comprises:

initializing pheromones for each satellite node;

calculating a heuristic function of the satellite nodes;

constructing paths for ants in the ant colony algorithm according to the heuristic function;

locally updating pheromones on the paths according to the initialized pheromones;

globally updating the pheromone on the path after the local updating;

and obtaining the globally updated shortest path, and recording as the shortest delay path.

5. The method according to claim 4, wherein the backup route calculation process comprises:

and acquiring the globally updated secondary short path as a backup route.

6. A satellite network backup routing computing system based on betweenness centrality, comprising:

the construction module is used for constructing the weightless graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes;

the acquisition module is used for calculating the importance degree of each satellite node by using betweenness centrality to obtain important nodes;

the first calculation module is used for calculating the shortest delay path between a source satellite node and a destination satellite node in the satellite nodes by using an ant colony algorithm;

the judging module is used for judging whether the shortest delay path contains the important node;

and the second calculation module is used for calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path when the shortest delay path contains the important node.

7. The system according to claim 1, wherein the obtaining module specifically comprises:

the first calculation unit is used for calculating the node betweenness of each satellite node according to the shortest path number passing through each satellite node in the weightless graph and the shortest path number of the weightless graph;

the second calculation unit is used for calculating the edge betweenness of each edge according to the shortest path number passing through each edge in the weightless graph and the shortest path number of the weightless graph;

a third calculating unit, configured to calculate an importance degree of the satellite node according to the node betweenness and the edge betweenness;

and the first acquisition unit is used for acquiring the important nodes according to the importance degrees of the satellite nodes.

8. The system according to claim 1, wherein the first computing module comprises:

the initialization unit is used for initializing pheromones for each satellite node;

a fourth calculation unit, configured to calculate a heuristic function of the satellite node;

the path construction unit is used for constructing paths for ants in the ant colony algorithm according to the heuristic function;

the local updating unit is used for locally updating the pheromone on the path according to the initialized pheromone;

the global updating unit is used for globally updating the pheromone on the path after the local updating;

and the second acquisition unit is used for acquiring the globally updated shortest path and recording the shortest path as the shortest delay path.

9. The betweenness centrality-based satellite network backup routing computing system of claim 8, wherein the second computing module comprises:

and the third acquisition unit is used for acquiring the globally updated secondary short path as a backup route.

Technical Field

The invention relates to the technical field of satellite communication, in particular to a satellite network backup routing method and system based on betweenness centrality.

Background

Satellite communication refers to communication between two or more earth stations by using an artificial earth satellite as a relay station to relay radio waves. The method has the advantages of long communication distance, no geographic environment limitation and the like, and can provide reliable network data service for the increasing information demand of human beings. And the satellite node is positioned in the outer space, once the satellite node fails, the satellite node is not easy to repair immediately, and particularly in future space attack and defense, the probability of passive failure of the satellite node is greatly increased.

The elasticity capability of the network is: the ability of a network to provide and maintain acceptable levels of service in the face of various failures and normal operational challenges. At present, a series of traditional schemes are used to solve the problem of elastic survivability of the network, such as a multi-path backup strategy and a dynamic rerouting strategy based on a redundancy idea, so that the elastic survivability of the satellite network can be effectively improved. However, multipath backup and rerouting cause additional time overhead, and satellite communication causes communication delay to be large due to long communication distance, so that the communication delay is likely to be too large to be accepted by users by simply using the above strategy.

In view of the disadvantages of the above methods, a satellite network backup routing method or system needs to be designed, which effectively improves the survivability of the satellite network and reduces the time overhead of routing calculation as much as possible.

Disclosure of Invention

The invention aims to provide a satellite network backup routing method and a satellite network backup routing system based on betweenness centrality, so that the satellite network survivability is effectively improved, and meanwhile, the time overhead of routing calculation is reduced.

In order to achieve the purpose, the invention provides the following scheme:

a satellite network backup route calculation method based on betweenness centrality comprises the following steps:

constructing an unweighted graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes;

calculating the importance degree of each satellite node by using betweenness centrality to obtain an important node;

calculating the shortest delay path between a source satellite node and a destination satellite node in the satellite nodes by using an ant colony algorithm;

judging whether the shortest delay path contains the important node or not;

and if the shortest delay path comprises the important node, calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path.

Optionally, if the shortest delay path does not include the important node, the backup route is not calculated for the source satellite node and the destination satellite node corresponding to the shortest delay path.

Optionally, the calculating the importance degree of the satellite node by using the betweenness centrality to obtain an important node specifically includes:

calculating the node betweenness of each satellite node according to the number of shortest paths passing through each satellite node in the weightless graph and the number of shortest paths of the weightless graph;

calculating edge betweenness of each edge according to the number of shortest paths passing through each edge in the weightless graph and the number of shortest paths of the weightless graph;

calculating the importance degree of the satellite node according to the node betweenness and the edge betweenness;

and obtaining important nodes according to the importance degree of the satellite nodes.

Optionally, the calculating the shortest path between the satellite nodes by using the ant colony algorithm specifically includes:

initializing pheromones for each satellite node;

calculating a heuristic function of the satellite nodes;

constructing paths for ants in the ant colony algorithm according to the heuristic function;

locally updating pheromones on the paths according to the initialized pheromones;

globally updating the pheromone on the path after the local updating;

and obtaining the globally updated shortest path, and recording as the shortest delay path.

Optionally, the backup route calculation process is as follows:

and acquiring the globally updated secondary short path as a backup route.

A satellite network backup routing computing system based on betweenness centrality, comprising:

the construction module is used for constructing the weightless graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes;

the acquisition module is used for calculating the importance degree of each satellite node by using betweenness centrality to obtain important nodes;

the first calculation module is used for calculating the shortest delay path between a source satellite node and a destination satellite node in the satellite nodes by using an ant colony algorithm;

the judging module is used for judging whether the shortest delay path contains the important node;

and the second calculation module is used for calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path when the shortest delay path contains the important node.

Optionally, the obtaining module specifically includes:

the first calculation unit is used for calculating the node betweenness of each satellite node according to the shortest path number passing through each satellite node in the weightless graph and the shortest path number of the weightless graph;

the second calculation unit is used for calculating the edge betweenness of each edge according to the shortest path number passing through each edge in the weightless graph and the shortest path number of the weightless graph;

a third calculating unit, configured to calculate an importance degree of the satellite node according to the node betweenness and the edge betweenness;

and the first acquisition unit is used for acquiring the important nodes according to the importance degrees of the satellite nodes.

Optionally, the first computing module specifically includes:

the initialization unit is used for initializing pheromones for each satellite node;

a fourth calculation unit, configured to calculate a heuristic function of the satellite node;

the path construction unit is used for constructing paths for ants in the ant colony algorithm according to the heuristic function;

the local updating unit is used for locally updating the pheromone on the path according to the initialized pheromone;

the global updating unit is used for globally updating the pheromone on the path after the local updating;

and the second acquisition unit is used for acquiring the globally updated shortest path and recording the shortest path as the shortest delay path.

Optionally, the second computing module comprises:

and the third acquisition unit is used for acquiring the globally updated secondary short path as a backup route.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the invention discloses a satellite network backup route calculation method and a system based on betweenness centrality, wherein the method comprises the following steps: constructing an unweighted graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes; calculating the importance degree of each satellite node by using betweenness centrality to obtain an important node; calculating the shortest delay path between a source satellite node and a destination satellite node in the satellite nodes by using an ant colony algorithm; judging whether the shortest delay path contains the important node or not; and if the shortest delay path comprises the important node, calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path. According to the invention, the importance degree of the satellite nodes is calculated according to the betweenness centrality, and the backup route is calculated only aiming at the shortest delay path containing the important nodes, so that the satellite network survivability is effectively improved, and the time cost of route calculation is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a flowchart of a method for calculating a backup route of a satellite network based on betweenness centrality according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a method for calculating a backup route of a satellite network based on betweenness centrality according to an embodiment of the present invention;

fig. 3 is a process diagram of a method for calculating a backup route of a satellite network based on betweenness centrality according to an embodiment of the present invention;

fig. 4 is a flowchart of acquiring an important node according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a backup path mechanism according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a satellite network backup routing method and a satellite network backup routing system based on betweenness centrality, so that the satellite network survivability is effectively improved, and meanwhile, the time overhead of routing calculation is reduced.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1, the method for calculating the backup route of the satellite network based on betweenness centrality includes:

step 101: constructing an unweighted graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes.

Step 102: and calculating the importance degree of each satellite node by using the betweenness centrality to obtain an important node. Wherein, step 102 specifically comprises:

step 1021: and calculating the node betweenness of each satellite node according to the shortest path number passing through each satellite node in the weightless graph and the shortest path number of the weightless graph.

Step 1022: and calculating the edge betweenness of each edge according to the shortest path number passing through each edge in the weightless graph and the shortest path number of the weightless graph.

Step 1023: and calculating the importance degree of the satellite node according to the node betweenness and the edge betweenness.

Step 1024: and obtaining important nodes according to the importance degree of the satellite nodes.

Step 103: and calculating the shortest delay path between the source satellite node and the destination satellite node in the satellite nodes by using an ant colony algorithm. Wherein, step 103 specifically comprises:

step 1031: and initializing pheromones for each satellite node.

Step 1032: and calculating the heuristic function of the satellite node.

Step 1033: constructing paths for ants in the ant colony algorithm according to the heuristic function.

Step 1034: and locally updating the pheromone on the path according to the initialized pheromone.

Step 1035: and globally updating the pheromone on the path after the local updating.

Step 1036: and obtaining the globally updated shortest path, and recording as the shortest delay path.

Step 104: and judging whether the shortest delay path contains the important node or not.

Step 105: and if the shortest delay path comprises the important node, calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path.

In this embodiment, the backup route calculation process is as follows:

and acquiring the globally updated secondary short path as a backup route. The secondary short path is a path with the length only longer than the shortest path in all paths after global updating.

In this embodiment, the method further includes:

and if the shortest delay path does not contain the important node, calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path.

The embodiment also provides a satellite network backup routing computing system based on betweenness centrality, and the system comprises:

the construction module is used for constructing the weightless graph; the nodes of the weightless graph are satellite nodes in a satellite network, and the edges of the weightless graph are communication links among the satellite nodes.

And the acquisition module is used for calculating the importance degree of each satellite node by using the betweenness centrality to obtain the important nodes.

And the first calculation module is used for calculating the shortest delay path between a source satellite node and a destination satellite node in the satellite nodes by using an ant colony algorithm.

And the judging module is used for judging whether the shortest delay path contains the important node.

And the second calculation module is used for calculating backup routes for the source satellite node and the destination satellite node corresponding to the shortest delay path when the shortest delay path contains the important node.

In this embodiment, the acquiring module specifically includes:

and the first calculation unit is used for calculating the node betweenness of each satellite node according to the shortest path number passing through each satellite node in the weightless graph and the shortest path number of the weightless graph.

And the second calculation unit is used for calculating the edge betweenness of each edge according to the shortest path number passing through each edge in the weightless graph and the shortest path number of the weightless graph.

And the third calculating unit is used for calculating the importance degree of the satellite node according to the node betweenness and the edge betweenness.

And the first acquisition unit is used for acquiring the important nodes according to the importance degrees of the satellite nodes.

In this embodiment, the first calculating module specifically includes:

the initialization unit is used for initializing pheromones for each satellite node;

a fourth calculation unit, configured to calculate a heuristic function of the satellite node;

the path construction unit is used for constructing paths for ants in the ant colony algorithm according to the heuristic function;

the local updating unit is used for locally updating the pheromone on the path according to the initialized pheromone;

the global updating unit is used for globally updating the pheromone on the path after the local updating;

and the second acquisition unit is used for acquiring the globally updated shortest path and recording the shortest path as the shortest delay path.

In this embodiment, the second calculating module includes:

and the third acquisition unit is used for acquiring the globally updated secondary short path as a backup route.

The following is a detailed description of the principles of the present invention:

(1) and calculating the nodes and edges in the satellite network according to the indexes of the edge betweenness and the point betweenness in the graph theory, sequencing according to the calculation result, and screening out the 'important nodes' in the network. And calculating the backup route only for the important node, thereby achieving the purpose of reducing the time overhead.

(2) When the ant colony algorithm is iterated, based on the thought, when reverse ants record paths, whether important nodes are contained in the paths or not is detected, and if and only if the important nodes are contained in the paths, backup routes are calculated for the routes, so that the influence on normal communication of a satellite network caused by the independent intelligent attack or natural damage of the important nodes is avoided. If the path does not contain important nodes, backup routing calculation is not needed.

(3) When the satellite node is naturally damaged or is attacked by autonomous intelligence, whether the current path has an optional backup path or not is detected, and if the backup path exists, the path is selected for communication forwarding, so that the communication success rate is improved.

According to the idea of graph theory, a topological network can be described by the graph G ═ (V, E), where V ═ V_iI 1, 2.. N is a non-empty set of nodes, N being the total number of nodes. E is a node V_i，V_jSet of edges in between, E ═ { l_i,j|V_i,V_jE.g., V), where a node represents a satellite node and an edge represents a communication link between satellite nodes.

According to a formula of centrality of the intermediaries in the graph theory, the node betweenness and the edge betweenness of the iridium satellite model are calculated, statistical analysis is carried out according to the calculation results, the nodes with the highest betweenness values are sequentially screened, the global important nodes of the satellite network are finally selected, and backup paths are calculated only for the important nodes, so that the time cost is reduced.

The IMB-ACR algorithm (the satellite network backup route calculation method based on betweenness centrality) can be briefly divided into three parts, as shown in FIG. 2.

S1: and (3) calculating the importance degree of the nodes in the global satellite network according to the betweenness centrality, and carrying out sorting screening according to the importance degree, wherein the nodes in the top 20% of the sorting are listed as 'important nodes'.

S2: and (4) according to the source node and the destination node, iteratively calculating the shortest path through an ant colony routing algorithm, then detecting nodes contained in the path, if the nodes contain important nodes, executing the step S3, otherwise, ending the routing calculation, and calculating a shortest route for the source node and the destination node.

S3: the important node is deleted from the candidate set of nodes and a backup route is computed for it. At the moment, two routes are calculated for the source node and the destination node, and one route is used as a preferred route and is started when the nodes have no abnormal condition. One as a backup route, is enabled only when a node fails.

As shown in FIG. 3, the steps S1-S3 are specifically as follows:

s11: let C_N(i) Indicates the node betweenness, g, of the node i_jk(i) Number, g, representing shortest path through node i_jkRepresenting the number of shortest paths in the graph. Calculation formula according to node betweennessAnd calculating the node betweenness of each node in the iridium satellite model.

S12: let C_N(l) Denotes the edge number of edge l, g_jk(l) Representing the shortest path through edge lThe number of (2) is calculated according to the edge betweennessAnd calculating the edge betweenness of each edge in the iridium satellite model.

S13: and (3) performing statistical analysis on the obtained node betweenness and the edge betweenness, sequentially screening from high to low according to betweenness values (if the betweenness values of two nodes are higher, the edge betweenness value between the two nodes is also higher, and finally screening by taking the node betweenness as a standard), and finally selecting a certain number of nodes as 'global important nodes' in the network according to the size of the satellite network scale. Fig. 4 is a flowchart of acquiring an important node according to an embodiment of the present invention.

The specific process of step S2 is as follows:

s21: for each satellite s, a pheromone is initialized. For each destination satellite d, a candidate set of neighbor nodes from satellite s to satellite d is established at time tExpressing, and computing heuristic functions η of nodes_ijThe formula is as follows:

wherein, | d_i,j(t) | represents the shortest path from the intermediate node i to the next hop j, i, j ∈ p (s, d).

S22: when all ants sent from a source node to a destination node in the network select a next-hop node, the probability that a node j is selected as the next-hop node needs to be calculated. The calculation rule is as follows:

wherein p is_ik(t) represents the probability of selecting a node k as the next hop at time t; tau is_ik(t) is the pheromone concentration of link (i, k) at time t; eta_ikAs a heuristic function(ii) a Alpha is the proportion of the pheromone in the probability and represents the attention degree of the following ants to the information left by the former ants in the route selection process; beta is an enlightening factor and represents the possibility weight of exploring a new path, so that the situation that a local optimal solution is trapped is avoided, and the path search result has more variability; n is a radical of_kFor the neighbor node candidate set, τ_is(t) is the pheromone concentration of the link (i, s) at time t.

S23: when finding out that the current node transmits data by using the optimal path from the ant currently, if the current node meets the time delay constraint, local pheromone updating is required, and the pheromone updating rule is as follows:

wherein, Δ l is the difference between the actual path length traveled by the ant and the shortest path length, ω is the attenuation constant, a₁As incremental constants of information, a₁∈(0,1)，Δτ_ijThe pheromone released by the ants at the current node.

S24: when the forward ants searching for the path are blocked or reach the destination satellite, backward ants need to be generated, return to the source satellite along the path searched by the forward ants, and perform the overall update of the pheromone, wherein the update rule is as follows:

τ_ij(t+1)＝(1-ρ)τ_ij(t)+ρ·flag·Δτ_ij

wherein rho is an pheromone attenuation parameter, rho belongs to (0,1), flag is equal to 1 or minus 1, and flag is 1, which represents that the target satellite is successfully reached and accords with the time delay constraint, and the concentration of the pheromone is increased at the moment; and the flag is-1, which represents that the communication blockage or the forwarding time delay does not accord with the constraint condition, and the pheromone is weakened.

S25: and when the reverse ants reach the source node, recording the searched path, and if the path does not pass through the important node, selecting a minimum delay path from the candidate paths as a message transmission path between the node pairs. If the path contains the important node, the important node is selected from the node candidate set N when the next iteration is carried out_kDeletion of the ant to allow the ant to searchAnd avoiding important nodes during the road till all ants finish the searching work.

S26: after the iteration is finished, the first two paths with the minimum time delay are selected from all the candidate paths, and the path with the minimum time delay is used as a preferred transmission path, and the path with a larger time delay is used as a backup path.

The specific process of step S3 is as follows:

s31: and if the path is detected to contain the important node, recalculating a backup path avoiding the important node aiming at the source node and the destination node. When the important node has not failed, the backup path is not enabled.

S32: when the important node in the path fails (active failure or passive failure), the backup path is started to improve the success rate of message forwarding.

As shown in fig. 5, when a node in the satellite network has a random fault or is attacked by autonomous intelligence, if a backup path exists in the failed node, the backup path is enabled to forward a message, so that the communication success rate of the satellite network is improved.

The invention takes the traditional multipath routing algorithm of the satellite network as the research background, optimizes and improves the multipath selection and calculation of the satellite nodes, and has the characteristics that the method is different from the traditional multipath routing algorithm: a backup (multipath) route is computed for the original path if and only if it contains significant nodes. In addition, the invention evaluates and screens the importance degree of the nodes in the satellite network based on the parameter of the centrality of the number of graph theory intermediaries, screens out specific number of 'important nodes' according to the scale of the satellite network, and calculates backup routes for the important nodes only aiming at the condition that the important nodes are contained. Therefore, the invention can improve the elastic survivability of the satellite network and simultaneously reduce the time overhead of the routing calculation as much as possible.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.