Automatic charging method and system for unmanned vehicle

Abstract

The invention discloses an automatic charging method for an unmanned vehicle, and relates to the technical field of automatic charging, and the method comprises the following steps: S1, searching a charging station within the maximum mileage of the driving of residual electric quantity; s2, the target vehicle node sends charging request information to the charging station; s3, collecting information of surrounding vehicle nodes which are not added into the charging network; s4, the charging station selectively adds the target vehicle node into a charging station vehicle list; and S5, performing active charging according to the selection information obtained from the charging station. According to the invention, charging demand selection of each vehicle node in the charging network is completed through cooperation among the vehicle nodes on the basis of vehicle node competition, so that the vehicle nodes can select the optimal charging station as much as possible and the common benefits of the vehicle nodes for competition are taken into consideration; and finally, the local overall benefit optimization is achieved, the load balance of the charging station is reduced, and meanwhile, the path overhead between the vehicle nodes can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of automatic charging technology, and in particular to an automatic charging method and system for an unmanned vehicle. Background Art

[0002] In a complex urban traffic network, vehicle nodes for distribution logistics travel on urban roads in order to quickly complete their tasks, or driverless taxis carry passengers to their destinations. As the power of these vehicle nodes on the road is continuously consumed, charging needs will arise, and they need to go to charging stations to replenish power. In the Chinese patent application number 202111108524.9, "an automated guided vehicle (AGV) charging scheduling control method is disclosed, comprising the following steps: detecting the remaining power state of the automated guided vehicle in the current working environment, and determining whether the remaining power of the automated guided vehicle is less than a set threshold. If so, the automated guided vehicle with a remaining power less than the set threshold is set as an automated guided vehicle that needs to be charged, and the charging demand information of the automated guided vehicle is released; receiving the charging demand information of the automated guided vehicle, and detecting the location distribution state of the charging piles in the current working environment and the idle state of the charging piles; detecting the location information of the automated guided vehicle that currently needs to be charged, and allocating the charging piles of the automated guided vehicle that needs to be charged according to the location information of the automated guided vehicle, the location distribution state of the charging piles, and the idle state of the charging piles."

[0003] The above-mentioned file can reasonably allocate the automatic guided vehicle to each charging pile in the working environment according to the real-time remaining power status, real-time location and distribution of the charging piles of the automatic guided vehicle. However, each charging station will have a certain service area, among which the service areas of some charging stations may overlap. The vehicle node will look for a charging station after generating a charging demand. Depending on the different destinations of the vehicle nodes or the different charging waiting times, the vehicle nodes have their own preferences for choosing charging stations. The vehicle nodes are in a distributed scheduling network. The limitations of information lead to competition when the vehicle nodes choose charging stations, which makes the load of the charging stations unbalanced, and the path overhead or waiting time of the vehicle nodes will become larger. Summary of the invention

[0004] The object of the present invention is to provide an automatic charging method and system for an unmanned vehicle to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: an automatic charging method for an unmanned vehicle, comprising the following steps:

[0006] S1. Searching for charging stations within the maximum mileage of the remaining power: The target vehicle node travels along the shortest route generated by the starting point and the end point. When the power of the target vehicle node is reduced to a predetermined threshold, the target vehicle node joins the charging network. The location of the target vehicle node at this time is the new starting point. Then, the information of all charging stations is searched in a circular area with the new starting point as the center and the maximum mileage of the remaining power of the target vehicle node as the radius;

[0007] S2. The target vehicle node sends a charging request message to the charging station: After the target vehicle node sends the charging request message to the searched charging station, the charging station updates the information of the new target vehicle node that needs to be charged at this moment, and adds the target vehicle node information requesting charging to the charging request list stored in the charging station. At the same time, the target vehicle node, the charging station, and the surrounding vehicle nodes of the target vehicle node broadcast information periodically. If the surrounding vehicle nodes have not joined the charging network, the information is broadcast to the target vehicle node. If the surrounding vehicle nodes join the charging network, that is, the surrounding vehicle nodes are transformed into target vehicle nodes, and the information is broadcast to the charging station.

[0008] S3. Collect information about surrounding vehicle nodes that have not joined the charging network: When the remaining power of the target vehicle node reaches the threshold, it joins the charging network. At the same time, the surrounding vehicle nodes that have not joined the charging network continuously broadcast their own information to the target vehicle node. The filter flags of the surrounding vehicle node broadcast information are constantly changing according to the degree of association between the target vehicle node and the surrounding vehicle nodes. When the filter flag is 0, the broadcast information is invalid. Otherwise, the target vehicle node integrates the surrounding vehicle nodes whose filter flags are not 0 into its own list, and arranges them in descending order according to the size of the filter flags in the list as suspicious competitors of the target vehicle node, and sends the list to the charging station;

[0009] S4. The charging station selectively adds the target vehicle node to the vehicle list of the charging station: the target vehicle node finds the initial optimal charging station according to the distance of the charging station and the busy status of the charging station, and then sends a request message to the initial optimal charging station. After the target vehicle node sends the request message to the charging station, the charging station will have one or more surrounding vehicle nodes requesting it within the next T time. The charging station selects the target vehicle node to add to the vehicle list of the charging station according to the vehicle node collaborative charging strategy;

[0010] S5. Actively charge according to the selected information obtained from the charging station: The target vehicle node obtains the usage status of the charging station and the competition status with the surrounding vehicle nodes based on the information exchange, transmission, and update of the surrounding vehicle nodes and the information of the charging station vehicle list, and actively goes to the selected charging station to charge. If the target vehicle node cannot find a charging station within the maximum mileage of the remaining power, it will actively report the information that it cannot charge.

[0011] Preferably, step S2 comprises the following steps:

[0012] S201, the request message sent by the vehicle node to the charging station includes the ID of the vehicle node, the ID of the charging station, the coordinate position of the vehicle node, the path information of the vehicle node, and the remaining power of the vehicle node;

[0013] S202, the list information stored in the vehicle node itself includes the ID of the charging station, the coordinate position of the charging station, and the ID of the vehicle nodes around the vehicle node that need to be charged;

[0014] S203, the information broadcasted by the vehicle node that has not joined the charging network includes the ID of the vehicle node, the path information of the vehicle node, the ID of the accessible charging station, and the coordinate position of the accessible charging station;

[0015] S204, the information broadcasted by the vehicle node after joining the charging network includes the ID of the vehicle node, the path information of the vehicle node, the ID and coordinate position of the accessible charging station, the remaining power, and the screening flag used to selectively collect the information of the surrounding vehicle nodes that need to be charged;

[0016] S205. The information broadcast by the charging station includes the ID of the charging station and the coordinate position of the charging station. The vehicle list of the charging station includes vehicle nodes that are charging at the charging station, vehicle nodes waiting in line, and vehicle nodes requesting charging. The information received by the charging station includes request information from vehicle nodes that have joined the charging network and broadcast information from vehicle nodes.

[0017] Preferably, in step S3, the degree of association between the target vehicle node and the surrounding vehicle nodes includes the probability that the target vehicle node and the surrounding vehicle nodes use the same charging station at the same time and the probability of the charging stations that can be allocated to the target vehicle node and the surrounding vehicle nodes, involving a probability prediction algorithm, specifically:

[0018] p ij (t) = p(X t =j|X0=i), X t ∈{1,2,···,m};

[0019]

[0020] Among them, p ij (t) represents the probability that the charging station changes from usage state i to usage state j at time t, X t represents the predicted usage status of the charging station at time t, X0 represents the current usage status of the charging station, m represents the number of charging stations, and q ij (t) represents the probability of the charging station transitioning from usage state i to usage state j at time t, that is, the probability of obtaining the usage state of the charging station at a future time from the current usage state of the charging station;

[0021] p(X T <M|X T0 =n) = p nm (T-T0);

[0022] Where T0 represents the current time, T represents the time when the target vehicle node finds and arrives at the charging station, n represents the number of occupied charging stations, m represents the number of idle charging stations, M represents the number of charging stations in the search area, and X T represents the usage status of the charging station at time T, X T0 Indicates the current usage status of the charging station, p(X T <M|X T0 =n) represents the probability that the target vehicle node can be assigned to a charging station, p nm (T-T0) represents the probability of using state nm at time T-T0;

[0023] W = [p(X T <M|X T0 =n)&q ij (t)];

[0024] Where W represents the screening flag, [p(X T <M|X T0 =n)&q ij (t)] represents the probability of ensuring that the target vehicle node can be assigned to the charging station based on the transfer of the charging station. If the probability is lower than 0.5, the filter mark is 0, otherwise it is sorted in descending order according to the probability of the filter mark.

[0025] Preferably, in step S4, the vehicle node collaborative charging strategy is: randomly select the initial optimal charging station through the iterative update model, then continuously generate the latest charging station, and calculate the path cost of the target vehicle node and the surrounding vehicle nodes based on the latest charging station. If the latest charging station is better than the initial optimal charging station, update the latest charging station as the optimal charging station, otherwise receive the latest charging station as an alternative charging station, and then update the path cost. When the total cost of the shortest path from the target vehicle node to the charging station is optimal, the charging station finally selected allows the target vehicle node to join.

[0026] Preferably, in step S4, the iterative update model is:

[0027]

[0028] Among them, V i represents the target vehicle node, CS i represents the set of charging stations around the target vehicle, represents the optimal charging station for the target vehicle node, represents the total cost from the location of the target vehicle node to the charging station, represents the shortest path from the location of the target vehicle node to the optimal charging station, represents the shortest path between the surrounding vehicle nodes and the optimal charging station around the target vehicle node, α∈[0,1], and different values ​​of α represent the degree of coordination between vehicle nodes, min(CS i ,N i ) represents the number of surrounding vehicle nodes that select the same charging station as the target vehicle node, NC i represents the set of surrounding vehicle nodes, Indicates the surrounding vehicle nodes that select the same charging station as the target vehicle node, CSC i represents the set of optimal charging stations searched by the target vehicle node and the surrounding vehicle nodes, represents the charging station searched by the target vehicle node, R i Indicates the optimal charging station selected.

[0029] Preferably, in step S4, if the charging station selects the target vehicle node to join, it sends a receiving message, otherwise it sends a rejection message, and the target vehicle node that receives the receiving message goes to the charging station to charge, and at the same time, the target vehicle node that receives the rejection message goes to the next round of charging station selection. After receiving the receiving message from the charging station, the target vehicle node replies to the charging station for confirmation, otherwise the charging station replies to the target vehicle node with a pending confirmation message every two minutes. If the target vehicle node does not reply for more than three times, it is deemed to have abandoned the charging request.

[0030] Preferably, in step S5, after joining the charging network, the target vehicle node continuously receives information broadcast from surrounding vehicle nodes and charging stations, and proposes the location of the charging station from these information. When the target vehicle node finds the first charging station, the angle formed by the line between the first charging station and the vehicle node location and the line between the destination and the vehicle node location is used as the primary search area. If there is no charging station in the primary search area, the search area angle is expanded until a charging station is found. If no charging station is found, the charging network is exited and the information that charging is impossible is actively reported.

[0031] An automatic charging system for an unmanned vehicle, comprising:

[0032] A charging station search unit, wherein when the power of a target vehicle node is reduced to a predetermined threshold, the target vehicle node joins the charging network, and the location of the target vehicle node at this time is a new starting point, and then the information of all charging stations is searched in a circular area with the new starting point as the center and the maximum mileage of the remaining power in the target vehicle node as the radius;

[0033] A charging request unit, after sending charging request information to the searched charging station, the charging station updates the information of the new target vehicle node that needs to be charged at this moment, adds the target vehicle node information requested for charging to the charging request list stored in the charging station, and at the same time, the target vehicle node, the charging station and the surrounding vehicle nodes of the target vehicle node periodically broadcast information respectively;

[0034] A surrounding vehicle collection unit, wherein when the remaining power of the target vehicle node reaches a threshold, the surrounding vehicle collection unit joins the charging network, and at the same time, surrounding vehicle nodes that have not joined the charging network continuously broadcast their own information to the target vehicle node, and the screening flag of the surrounding vehicle node broadcast information continuously changes according to the degree of association between the target vehicle node and the surrounding vehicle nodes;

[0035] The vehicle selection unit first finds the initial optimal charging station, and then sends a request message to the initial optimal charging station. After the target vehicle node sends the request message to the charging station, the charging station will have one or more surrounding vehicle nodes requesting it within the next T time. The charging station selects the target vehicle node to add to the charging station vehicle list according to the vehicle node collaborative charging strategy;

[0036] An active charging unit enables the target vehicle node to actively go to the selected charging station to charge after obtaining the usage status of the charging station and the competition status with the surrounding vehicle nodes. If the target vehicle node cannot find a charging station within the maximum mileage of the remaining power, the information that charging is impossible will be actively reported.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention sends charging request information to the charging station within the maximum mileage of the remaining power through the target vehicle node, adds the target vehicle node information requesting charging to the charging request list stored in the charging station, and at the same time, the target vehicle node, the charging station and the surrounding vehicle nodes of the target vehicle node periodically broadcast information respectively, so that the target vehicle node joining the charging network knows the use status of the charging station. If the surrounding vehicle nodes of the target vehicle node join the charging network at this time, they become the target vehicle nodes, and the target vehicle node and the charging station broadcast information to each other. Otherwise, it is only the surrounding vehicle nodes of the target vehicle node, which broadcast information to the target vehicle node, and the target vehicle node broadcasts information to the charging station. According to the degree of association between the target vehicle node and the surrounding vehicle nodes, the surrounding vehicle nodes that may be highly competitive to the target vehicle node and have not joined the charging network are collected, thereby laying a foundation for selecting the optimal charging station;

[0039] 2. The present invention completes the charging demand selection of each vehicle node in the charging network by adding the cooperation between vehicle nodes on the basis of vehicle node competition, so that the vehicle node can take into account the common interests of its competing vehicle nodes while selecting the optimal charging station as much as possible, and finally achieve the local overall optimal interests. By sending a request message to the initial optimal charging station, the initial optimal charging station selects the target vehicle node to add to the charging station vehicle list according to the vehicle node cooperative charging strategy, sends and receives messages and obtains confirmation, and reaches an agreement with the target vehicle node, so that the target vehicle node actively goes to the selected charging station to charge, which reduces the load balancing of the charging station and reduces the path overhead between each vehicle node;

[0040] 3. The present invention aims at the distribution of vehicle nodes on various roads in urban traffic. With the continuous movement of vehicles and the flow of surrounding vehicle nodes, the vehicle nodes can update their own information so as to find charging stations well. This method does not need to rely on the central control platform to collect information from each vehicle node to make decisions, so that the network deployment overhead is smaller than the centralized scheduling overhead and the structure is more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of the overall method provided by an embodiment of the present invention;

[0042] Figure 2 A schematic diagram of the overall system flow provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 creative work are within the scope of protection of the present invention.

[0044] See also Figure 1 to Figure 2 The present invention provides a technical solution: an automatic charging method for an unmanned vehicle, comprising the following steps:

[0045] S1. Searching for charging stations within the maximum mileage of the remaining power: The target vehicle node travels along the shortest route generated by the starting point and the end point. When the power of the target vehicle node is reduced to a predetermined threshold, the target vehicle node joins the charging network. The location of the target vehicle node at this time is the new starting point. Then, the information of all charging stations is searched in a circular area with the new starting point as the center and the maximum mileage of the remaining power of the target vehicle node as the radius;

[0046] S2. The target vehicle node sends a charging request message to the charging station: After the target vehicle node sends the charging request message to the searched charging station, the charging station updates the information of the new target vehicle node that needs to be charged at this moment, and adds the target vehicle node information requesting charging to the charging request list stored in the charging station. At the same time, the target vehicle node, the charging station, and the surrounding vehicle nodes of the target vehicle node broadcast information periodically. If the surrounding vehicle nodes have not joined the charging network, the information is broadcast to the target vehicle node. If the surrounding vehicle nodes join the charging network, that is, the surrounding vehicle nodes are transformed into target vehicle nodes, and the information is broadcast to the charging station.

[0047] S3. Collect information about surrounding vehicle nodes that have not joined the charging network: When the remaining power of the target vehicle node reaches the threshold, it joins the charging network. At the same time, the surrounding vehicle nodes that have not joined the charging network continuously broadcast their own information to the target vehicle node. The filter flags of the surrounding vehicle node broadcast information are constantly changing according to the degree of association between the target vehicle node and the surrounding vehicle nodes. When the filter flag is 0, the broadcast information is invalid. Otherwise, the target vehicle node integrates the surrounding vehicle nodes whose filter flags are not 0 into its own list, and arranges them in descending order according to the size of the filter flags in the list as suspicious competitors of the target vehicle node, and sends the list to the charging station;

[0048] S4. The charging station selectively adds the target vehicle node to the vehicle list of the charging station: the target vehicle node finds the initial optimal charging station according to the distance of the charging station and the busy status of the charging station, and then sends a request message to the initial optimal charging station. After the target vehicle node sends the request message to the charging station, the charging station will have one or more surrounding vehicle nodes requesting it within the next T time. The charging station selects the target vehicle node to add to the vehicle list of the charging station according to the vehicle node collaborative charging strategy;

[0049] S5. Actively charge according to the selected information obtained from the charging station: The target vehicle node obtains the usage status of the charging station and the competition status with the surrounding vehicle nodes based on the information exchange, transmission, and update of the surrounding vehicle nodes and the information of the charging station vehicle list, and actively goes to the selected charging station to charge. If the target vehicle node cannot find a charging station within the maximum mileage of the remaining power, it will actively report the information that it cannot charge.

[0050] Step S2 includes the following steps:

[0051] S201, the request message sent by the vehicle node to the charging station includes the ID of the vehicle node, the ID of the charging station, the coordinate position of the vehicle node, the path information of the vehicle node, and the remaining power of the vehicle node;

[0052] S202, the list information stored in the vehicle node itself includes the ID of the charging station, the coordinate position of the charging station, and the ID of the vehicle nodes around the vehicle node that need to be charged;

[0053] S203, the information broadcasted by the vehicle node that has not joined the charging network includes the ID of the vehicle node, the path information of the vehicle node, the ID of the accessible charging station, and the coordinate position of the accessible charging station;

[0054] S204, the information broadcasted by the vehicle node after joining the charging network includes the ID of the vehicle node, the path information of the vehicle node, the ID and coordinate position of the accessible charging station, the remaining power, and the screening flag used to selectively collect the information of the surrounding vehicle nodes that need to be charged;

[0055] S205. The information broadcast by the charging station includes the ID of the charging station and the coordinate position of the charging station. The vehicle list of the charging station includes the vehicle nodes that are charging at the charging station, the vehicle nodes waiting in line, and the vehicle nodes requesting charging. The information received by the charging station includes the request information of the vehicle nodes that have joined the charging network and the broadcast information of the vehicle nodes.

[0056] In step S3, the degree of association between the target vehicle node and the surrounding vehicle nodes includes the probability that the target vehicle node and the surrounding vehicle nodes use the same charging station at the same time and the probability that the charging stations can be allocated to the target vehicle node and the surrounding vehicle nodes, which involves a probability prediction algorithm, specifically:

[0057] p ij (t) = p(X t =j|X0=i), X t ∈{1,2,···,m};

[0058]

[0059] Among them, p ij (t) represents the probability that the charging station changes from usage state i to usage state j at time t, X t represents the predicted usage status of the charging station at time t, X0 represents the current usage status of the charging station, m represents the number of charging stations, and q ij (t) represents the probability of the charging station transitioning from usage state i to usage state j at time t, that is, the probability of obtaining the usage state of the charging station at a future time from the current usage state of the charging station;

[0060] p(X T <M|X T0 =n) = p nm (T-T0);

[0061] Where T0 represents the current time, T represents the time when the target vehicle node finds and arrives at the charging station, n represents the number of occupied charging stations, m represents the number of idle charging stations, M represents the number of charging stations in the search area, and X T represents the usage status of the charging station at time T, X T0 Indicates the current usage status of the charging station, p(X T <M|X T0 =n) represents the probability that the target vehicle node can be assigned to a charging station, p nm (T-T0) represents the probability of using state nm at time T-T0;

[0062] W = [p(X T <M|X T0 =n)&q ij (t)];

[0063] Where W represents the screening flag, [p(X T <M|X T0 =n)&q ij (t)] represents the probability of ensuring that the target vehicle node can be assigned to the charging station based on the transfer of the charging station. If the probability is less than 0.5, the filter flag is 0, otherwise it is sorted in descending order according to the probability of the filter flag;

[0064] In step S4, the vehicle node cooperative charging strategy is: randomly select the initial optimal charging station through the iterative update model, then continuously generate the latest charging station, and calculate the path cost of the target vehicle node and the surrounding vehicle nodes based on the latest charging station. If the latest charging station is better than the initial optimal charging station, update the latest charging station as the optimal charging station, otherwise accept the latest charging station as an alternative charging station, and then update the path cost. When the total cost of the shortest path from the target vehicle node to the charging station is optimal, the charging station finally selected allows the target vehicle node to join;

[0065] In step S4, the iterative update model is:

[0066]

[0067] Among them, V i represents the target vehicle node, CS i represents the set of charging stations around the target vehicle, represents the optimal charging station for the target vehicle node, represents the total cost from the location of the target vehicle node to the charging station, represents the shortest path from the location of the target vehicle node to the optimal charging station, represents the shortest path between the surrounding vehicle nodes and the optimal charging station around the target vehicle node, α∈[0,1], and different values ​​of α represent the degree of coordination between vehicle nodes, min(CS i ,N i ) represents the number of surrounding vehicle nodes that select the same charging station as the target vehicle node, NC i represents the set of surrounding vehicle nodes, Indicates the surrounding vehicle nodes that select the same charging station as the target vehicle node, CSC i represents the set of optimal charging stations searched by the target vehicle node and the surrounding vehicle nodes, represents the charging station searched by the target vehicle node, R i Indicates the optimal charging station selected;

[0068] In step S4, if the charging station selects the target vehicle node to join, it sends a receiving message, otherwise it sends a rejection message, and the target vehicle node that receives the receiving message goes to the charging station to charge, while the target vehicle node that receives the rejection message goes to the next round of charging station selection. After receiving the receiving message from the charging station, the target vehicle node replies to the charging station for confirmation, otherwise the charging station replies to the target vehicle node every two minutes with a pending confirmation message, and if the target vehicle node fails to reply for more than three times, it is deemed to have abandoned the charging request;

[0069] In step S5, after joining the charging network, the target vehicle node continuously receives information broadcasted by surrounding vehicle nodes and charging stations, and proposes the location of the charging station from the information. When the target vehicle node finds the first charging station, the angle formed by the line between the first charging station and the vehicle node location and the line between the destination and the vehicle node location is used as the primary search area. If there is no charging station in the primary search area, the search area angle is expanded until a charging station is found. If no charging station is found, the charging network is exited, and the information that charging is impossible is actively reported;

[0070] An automatic charging system for an unmanned vehicle, comprising:

[0071] A charging station search unit, when the power of the target vehicle node is reduced to a predetermined threshold, the target vehicle node joins the charging network, and the location of the target vehicle node at this time is a new starting point, and then the information of all charging stations is searched in a circular area with the new starting point as the center and the maximum mileage of the remaining power in the target vehicle node as the radius;

[0072] The charging request unit sends a charging request message to the searched charging station, and the charging station updates the information of the new target vehicle node that needs to be charged at this moment, and adds the target vehicle node information requested for charging to the charging request list stored in the charging station. At the same time, the target vehicle node, the charging station, and the surrounding vehicle nodes of the target vehicle node periodically broadcast information respectively;

[0073] The surrounding vehicle collection unit, when the remaining power of the target vehicle node reaches the threshold, joins the charging network. At the same time, the surrounding vehicle nodes that have not joined the charging network continuously broadcast their own information to the target vehicle node. The screening flag of the surrounding vehicle node broadcast information is constantly changing according to the degree of association between the target vehicle node and the surrounding vehicle nodes;

[0074] The vehicle selection unit first finds the initial optimal charging station, and then sends a request message to the initial optimal charging station. After the target vehicle node sends a request message to the charging station, the charging station will have one or more surrounding vehicle nodes requesting it within the next T time. The charging station selects the target vehicle node according to the vehicle node collaborative charging strategy to add it to the charging station vehicle list;

[0075] Active charging unit: The active charging unit enables the target vehicle node to actively go to the selected charging station to charge after obtaining the usage status of the charging station and the competition status with the surrounding vehicle nodes. If the target vehicle node cannot find a charging station within the maximum mileage of the remaining power, it will actively report the information that it cannot be charged.

[0076] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0077] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic charging method for an unmanned vehicle, characterized in that: The method comprises the following steps: S1. Searching for charging stations within the maximum mileage of the remaining power: The target vehicle node travels along the shortest route generated by the starting point and the end point. When the power of the target vehicle node is reduced to a predetermined threshold, the target vehicle node joins the charging network. The location of the target vehicle node at this time is the new starting point. Then, the information of all charging stations is searched in a circular area with the new starting point as the center and the maximum mileage of the remaining power of the target vehicle node as the radius; S2. The target vehicle node sends a charging request message to the charging station: After the target vehicle node sends the charging request message to the searched charging station, the charging station updates the information of the new target vehicle node that needs to be charged at this moment, and adds the target vehicle node information requesting charging to the charging request list stored in the charging station. At the same time, the target vehicle node, the charging station, and the surrounding vehicle nodes of the target vehicle node broadcast information periodically. If the surrounding vehicle nodes have not joined the charging network, the information is broadcast to the target vehicle node. If the surrounding vehicle nodes join the charging network, that is, the surrounding vehicle nodes are transformed into target vehicle nodes, and the information is broadcast to the charging station. S3. Collect information about surrounding vehicle nodes that have not joined the charging network: When the remaining power of the target vehicle node reaches the threshold, it joins the charging network. At the same time, the surrounding vehicle nodes that have not joined the charging network continuously broadcast their own information to the target vehicle node. The filter flags of the surrounding vehicle node broadcast information are constantly changing according to the degree of association between the target vehicle node and the surrounding vehicle nodes. When the filter flag is 0, the broadcast information is invalid. Otherwise, the target vehicle node integrates the surrounding vehicle nodes whose filter flags are not 0 into its own list, and arranges them in descending order according to the size of the filter flags in the list as suspicious competitors of the target vehicle node, and sends the list to the charging station; S4. The charging station selectively adds the target vehicle node to the vehicle list of the charging station: the target vehicle node finds the initial optimal charging station according to the distance of the charging station and the busy status of the charging station, and then sends a request message to the initial optimal charging station. After the target vehicle node sends the request message to the charging station, the charging station will have one or more surrounding vehicle nodes requesting it within the next T time. The charging station selects the target vehicle node to add to the vehicle list of the charging station according to the vehicle node collaborative charging strategy; S5. Actively charge according to the selected information obtained from the charging station: The target vehicle node obtains the usage status of the charging station and the competition status with the surrounding vehicle nodes based on the information exchange, transmission, and update of the surrounding vehicle nodes and the information of the charging station vehicle list, and actively goes to the selected charging station to charge. If the target vehicle node cannot find a charging station within the maximum mileage of the remaining power, it will actively report the information that it cannot charge.

2. The automatic charging method for an unmanned vehicle according to claim 1, characterized in that: The step S2 comprises the following steps: S201, the request message sent by the vehicle node to the charging station includes the ID of the vehicle node, the ID of the charging station, the coordinate position of the vehicle node, the path information of the vehicle node, and the remaining power of the vehicle node; S202, the list information stored in the vehicle node itself includes the ID of the charging station, the coordinate position of the charging station, and the ID of the vehicle nodes around the vehicle node that need to be charged; S203, the information broadcasted by the vehicle node that has not joined the charging network includes the ID of the vehicle node, the path information of the vehicle node, the ID of the accessible charging station, and the coordinate position of the accessible charging station; S204, the information broadcasted by the vehicle node after joining the charging network includes the ID of the vehicle node, the path information of the vehicle node, the ID and coordinate position of the accessible charging station, the remaining power, and the screening flag used to selectively collect the information of the surrounding vehicle nodes that need to be charged; S205. The information broadcast by the charging station includes the ID of the charging station and the coordinate position of the charging station. The vehicle list of the charging station includes vehicle nodes that are charging at the charging station, vehicle nodes waiting in line, and vehicle nodes requesting charging. The information received by the charging station includes request information from vehicle nodes that have joined the charging network and broadcast information from vehicle nodes.

3. The automatic charging method for an unmanned vehicle according to claim 1, characterized in that: In step S3, the degree of association between the target vehicle node and the surrounding vehicle nodes includes the probability that the target vehicle node and the surrounding vehicle nodes use the same charging station at the same time and the probability that the charging stations can be allocated to the target vehicle node and the surrounding vehicle nodes, which involves a probability prediction algorithm, specifically: W=[p(X T <M|X T0 =n)&q ij (t)]; Among them, W represents the screening flag, q ij (t) represents the probability of the charging station transitioning from usage state i to usage state j at time t, p(X T <M|X T0 =n) represents the probability that the target vehicle node can be assigned to a charging station, [p(X T <M|X T0 =n)&q ij (t)] represents the probability of ensuring that the target vehicle node can be assigned to the charging station based on the transfer of the charging station. If the probability is lower than 0.5, the filter mark is 0, otherwise it is sorted in descending order according to the probability of the filter mark.

4. The automatic charging method for an unmanned vehicle according to claim 1, characterized in that: In step S4, the vehicle node collaborative charging strategy is: randomly select the initial optimal charging station through the iterative update model, then continuously generate the latest charging station, and calculate the path cost of the target vehicle node and the surrounding vehicle nodes based on the latest charging station. If the latest charging station is better than the initial optimal charging station, update the latest charging station as the optimal charging station, otherwise receive the latest charging station as an alternative charging station, and then update the path cost. When the total cost of the shortest path from the target vehicle node to the charging station is optimal, the charging station finally selected allows the target vehicle node to join.

5. The automatic charging method for an unmanned vehicle according to claim 4, characterized in that: In step S4, the iterative update model is: Among them, V i represents the target vehicle node, CS i represents the set of charging stations around the target vehicle, represents the optimal charging station for the target vehicle node, represents the total cost from the location of the target vehicle node to the charging station, represents the shortest path from the location of the target vehicle node to the optimal charging station, represents the shortest path between the surrounding vehicle nodes and the optimal charging station around the target vehicle node, α∈[0,1], and different values ​​of α represent the degree of coordination between vehicle nodes, min(CS i ,N i ) represents the number of surrounding vehicle nodes that select the same charging station as the target vehicle node, NC i represents the set of surrounding vehicle nodes, Indicates the surrounding vehicle nodes that select the same charging station as the target vehicle node, CSC i represents the set of optimal charging stations searched by the target vehicle node and the surrounding vehicle nodes, represents the charging station searched by the target vehicle node, R i Indicates the optimal charging station selected.

6. The automatic charging method for an unmanned vehicle according to claim 5, characterized in that: In step S4, if the charging station selects the target vehicle node to join, it sends a receiving message, otherwise it sends a rejection message. The target vehicle node that receives the receiving message goes to the charging station to charge. At the same time, the target vehicle node that receives the rejection message goes to the next round of charging station selection. After receiving the receiving message from the charging station, the target vehicle node replies to the charging station for confirmation. Otherwise, the charging station replies to the target vehicle node with a pending confirmation message every two minutes. If the target vehicle node does not reply for more than three times, it is deemed to have abandoned the charging request.

7. The automatic charging method for an unmanned vehicle according to claim 1, characterized in that: In step S5, after joining the charging network, the target vehicle node continuously receives information broadcast from surrounding vehicle nodes and charging stations, and proposes the location of the charging station from this information. When the target vehicle node finds the first charging station, the angle formed by the line between the first charging station and the vehicle node position and the line between the destination and the vehicle node position is used as the primary search area. If there is no charging station in the primary search area, the search area angle is expanded until a charging station is found. If no charging station is found, the charging network is exited and the information that charging is impossible is actively reported.

8. An automatic charging system for an unmanned vehicle, characterized in that: The automatic charging system is applicable to the automatic charging method for an unmanned vehicle according to claims 1 to 7, comprising: A charging station search unit, wherein when the power of a target vehicle node is reduced to a predetermined threshold, the target vehicle node joins the charging network, and the location of the target vehicle node at this time is a new starting point, and then the information of all charging stations is searched in a circular area with the new starting point as the center and the maximum mileage of the remaining power in the target vehicle node as the radius; A charging request unit, after sending charging request information to the searched charging station, the charging station updates the information of the new target vehicle node that needs to be charged at this moment, adds the target vehicle node information requested for charging to the charging request list stored in the charging station, and at the same time, the target vehicle node, the charging station and the surrounding vehicle nodes of the target vehicle node periodically broadcast information respectively; A surrounding vehicle collection unit, wherein when the remaining power of the target vehicle node reaches a threshold, the surrounding vehicle collection unit joins the charging network, and at the same time, surrounding vehicle nodes that have not joined the charging network continuously broadcast their own information to the target vehicle node, and the screening flag of the surrounding vehicle node broadcast information continuously changes according to the degree of association between the target vehicle node and the surrounding vehicle nodes; The vehicle selection unit first finds the initial optimal charging station, and then sends a request message to the initial optimal charging station. After the target vehicle node sends the request message to the charging station, the charging station will have one or more surrounding vehicle nodes requesting it within the next T time. The charging station selects the target vehicle node to add to the charging station vehicle list according to the vehicle node collaborative charging strategy; An active charging unit enables the target vehicle node to actively go to the selected charging station to charge after obtaining the usage status of the charging station and the competition status with the surrounding vehicle nodes. If the target vehicle node cannot find a charging station within the maximum mileage of the remaining power, the information that charging is impossible will be actively reported.

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