CN108663062B - Path planning method and system - Google Patents

Abstract

The invention discloses a path planning method and a path planning system, wherein the path planning method comprises the following steps: receiving a path planning request, wherein the path planning request comprises starting place information and destination information; identifying a first alternative path from a map database according to the starting place information and the destination information; identifying a second alternative path from a map database according to the starting place information and the destination information; solving the proportion of the road section, which is overlapped by the second alternative path and the first alternative path, in the first alternative path, and setting the proportion as a first similarity; and outputting the first alternative path and the second alternative path in response to the judgment that the first similarity is smaller than a certain preset threshold value.

Description

Path planning method and system

Technical Field

The present invention relates to the field of navigation, and more particularly, to a method and system for planning a route.

Background

With the rapid development of new concept cars such as "smart cars" and "internet cars", the service providers and equipment manufacturers associated with the cars continuously provide more valuable and convenient services to consumers through network services, wherein the navigation service is one of popular services. Through the navigation engine path planning service provided by the supplier, the consumer can effectively obtain a plurality of path plans from the starting point to the destination, so that the consumer can freely select according to the preference of the consumer.

There are many implementations of the algorithm for path planning, and common ones include a-star and Dijkstra algorithms. The Dijkstra algorithm is a typical algorithm used to solve the shortest path. The algorithm a is a standard algorithm in navigation path calculation, and compared with Dijkstra, the algorithm has an additional estimation function, and by using this characteristic, a large number of path planning lines can be obtained by using the algorithm a. However, there may be only minor differences between many of these planned paths, almost duplicate paths. That is, there are many invalid paths between the recommended planned paths generated by the a-x algorithm, which interfere with the selection and judgment of the consumer.

Therefore, a multi-path screening strategy is usually provided in the existing path planning algorithm. A common way to screen multiple paths is: as shown in fig. 1, a first planned path S1 (e.g., the shortest planned route of the roadbed route) is determined, and in order to ensure the difference between the next planned path S2 and the first planned path S1, the original path S1 is avoided. However, the processing strategy inevitably completely avoids the newly generated planned path S2 from the first planned path S1, and cannot ensure that the difference between the two paths satisfies the predetermined requirement. That is, the strategy for avoiding the original path is too harsh, so that many planned paths that may meet the use requirements of consumers are filtered during the path planning process, and the expected paths cannot be obtained. Meanwhile, the strategy also increases the search range and reduces the path calculation efficiency of the whole path planning.

Disclosure of Invention

The invention mainly aims to provide a path planning method and a system thereof, wherein the path planning system can effectively provide multi-path planning selection for users, and the difference and similarity between different planned paths meet preset requirements.

Another objective of the present invention is to provide a path planning method and a system thereof, wherein the path planning system calculates similarities between different planned paths through modeling, so as to ensure that the similarities between the different planned paths can meet preset requirements.

Another objective of the present invention is to provide a path planning method and a system thereof, wherein the path planning system can limit the search range of the path planning system based on the difference between different paths, so as to improve the path calculation efficiency of the path planning system.

Another object of the present invention is to provide a path planning system and a system thereof, wherein the path planning system can be configured based on a cloud computing environment, so as to facilitate the configuration and implementation of the path planning system.

Other advantages and features of the invention will become apparent from the following description and may be realized by means of the instrumentalities and combinations particularly pointed out in the appended claims.

In accordance with the present invention, the foregoing and other objects and advantages are realized by a path planning method comprising the steps of:

receiving a path planning request, wherein the path planning request comprises starting place information and destination information;

identifying a first alternative path from a map database according to the starting place information and the destination information;

identifying a second alternative path from a map database according to the starting place information and the destination information;

solving the proportion of the second alternative path and the first alternative path in the coincident road section in the first alternative path, and setting the proportion as a first similarity; and

and outputting the first alternative path and the second alternative path in response to the judgment that the first similarity is smaller than a certain preset threshold value.

In an embodiment of the present invention, the step of solving the first similarity includes the steps of:

marking the link segments of the first alternative path as A0-An in sequence, wherein A0-An are arranged in sequence from the starting information to the destination information, wherein a set formed by all link segments A0-An of the first alternative path is set as alpha, and any link segment A0-An has a known distance;

marking the link segments of the second alternative path as B0-Bk in sequence, wherein B0-Bk are arranged in sequence from the starting information to the destination information, and any link segment of B0-Bk has a known distance;

respectively judging whether the link segments B0-Bk of the second alternative path belong to the set alpha or not, and adding the link segments belonging to the set alpha in the second alternative path to solve the distance sum of the second alternative path and the superposed road segment of the first alternative path; and

and solving the first similarity according to the sum of the distances between the second alternative path and the superposed road segments of the first alternative path and the total length of the first alternative path, wherein the total length of the first alternative path is the sum of the distances of the link segments from A0 to An in the set alpha.

In an embodiment of the present invention, the step of solving the first similarity includes the steps of:

marking the link segments of the first alternative path as A0-An in sequence, wherein A0-An are arranged in sequence from the starting information to the destination information, and any link segment of A0-An has a known distance;

identifying segments of the second alternative path different from the first alternative path, and sequentially marking link segments of the second alternative path different from the first alternative path as B0-Bk, wherein B0 is adjacent to the start point information, Bk is adjacent to the destination information, and B0-Bk are arranged in order from the start point information to the destination information, wherein any link segment from B0-Bk has a known distance;

identifying a pair of junction points of any two link sections in the section of the second alternative path different from the section of the first alternative path;

respectively searching in the direction towards the information of the starting point and the direction towards the information of the destination by taking the pair of contact points as the starting point, stopping searching until the searching result is any link segment from A0 to An, and acquiring all link segments marked as A in the second alternative path in such a way;

adding all the road sections marked as A in the second alternative path to solve the distance sum of the second alternative path and the first alternative path coincident road section; and

and solving the first similarity according to the sum of the distances between the second alternative path and the superposed road segments of the first alternative path and the total length of the first alternative path, wherein the total length of the first alternative path is the sum of the distances of the link segments from A0 to An.

In an embodiment of the present invention, the first alternative path is a shortest distance path between the origin information and the destination information.

In an embodiment of the present invention, the first alternative path is a shortest distance path between the origin information and the destination information.

In an embodiment of the invention, the first alternative path is the most economical path between the origin information and the destination information.

In an embodiment of the present invention, the path planning method further includes:

solving the proportion of the different road sections of the second alternative path and the first alternative path in the first alternative path, and setting the proportion as a first difference degree; and

and outputting the information of the first alternative path and the second alternative path in response to the judgment that the first difference degree is smaller than a certain preset threshold value and the similarity degree is smaller than a certain preset threshold value.

In an embodiment of the present invention, the step of solving the first difference includes the steps of:

marking the link segments of the first alternative path as A0-An in sequence, wherein A0-An are arranged in sequence from the starting information to the destination information, wherein a set formed by all link segments A0-An of the first alternative path is set as alpha, and any link segment A0-An has a known distance;

marking the link segments of the second alternative path as A0-An in sequence, wherein B0-Bk are arranged in sequence from the starting information to the destination information, and any link segment of B0-Bk has a known distance;

respectively judging whether the link segments B0-Bk of the second alternative path belong to the set alpha or not, and adding the link segments which do not belong to the set alpha in the second alternative path to solve the distance sum of the different road segments of the second alternative path and the first alternative path; and

and solving the first difference degree according to the sum of the distances between the second alternative path and the different road sections of the first alternative path and the total length of the first alternative path, wherein the total length of the first alternative path is the sum of the distances of the link sections A0-An in the set alpha. In an embodiment of the invention, the step of solving the first difference includes the steps of:

marking the link segments of the first alternative path as A0-An in sequence, wherein A0-An are arranged in the direction from the starting information to the destination information, and any link segment of A0-An has a known distance;

identifying segments of the second alternative path different from the first alternative path, and sequentially marking the link segments of the different segments of the second alternative path and the first alternative path as B0-Bk, wherein B0 is adjacent to the starting point information, Bk is adjacent to the destination information, and B0-Bk are arranged in sequence in a direction from the starting point information to the destination information, wherein any link segment of B0-Bk has a known distance;

adding the link segments B0-Bk included in the second alternative path and the segment different from the first alternative path to solve the distance sum of the second alternative path and the segment different from the first alternative path; and

and solving the first difference degree according to the sum of the distances between the different road sections of the second alternative path and the first alternative path and the total length of the first alternative path, wherein the total length of the first alternative path is the sum of the distances of the link sections A0-An.

In an embodiment of the present invention, the path planning method further includes the steps of: identifying a third alternative path from a map database according to the starting place information and the destination information;

solving the proportion of the road segment of the third alternative path, which is overlapped with the first alternative path, in the first alternative path, setting the proportion as a second similarity, solving the proportion of the road segment of the third alternative path, which is different from the first alternative path, in the first alternative path, and setting the proportion as a second difference;

solving the proportion of the road section of the third alternative path, which is coincident with the second alternative path, in the second alternative path, setting the proportion as a third similarity, solving the proportion of the road section of the third alternative path, which is dissimilar with the second alternative path, in the second alternative path, and setting the proportion as a third difference;

and outputting the first alternative path, the second alternative path and the third alternative path in response to the judgment that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the judgment that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold.

In an embodiment of the present invention, in the step of outputting the first alternative path, the second alternative path, and the third alternative path in response to the determination that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the determination that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold, the first preset threshold is greater than the second preset threshold, and the third threshold is greater than the fourth preset threshold.

According to another aspect of the present invention, there is also provided a path planning system comprising:

a communication module communicatively coupled to a mobile computing device of a vehicle for receiving a path planning request provided from the vehicle, wherein the path planning request includes a start location information and a destination information;

a path identification module, wherein the path identification module is communicably connected to the communication module for identifying a first alternative path, a second alternative path and a third alternative path from a map database according to the starting location information and the destination information; and

and the path screening module is connected with the path identification module in a communication way, and is used for solving the proportion of the second alternative path and the first alternative path in the first alternative path, setting the proportion as a first similarity, and judging whether the first similarity is smaller than a preset threshold value or not so as to screen the second alternative path.

In an embodiment of the present invention, the path screening module further requests to solve a ratio of the second alternative path to the first alternative path in the different road segments of the first alternative path, and sets the ratio as a first difference, and screens the second alternative path in response to a determination that the first difference is smaller than a preset threshold and the similarity is smaller than a preset threshold.

In an embodiment of the invention, the path filtering module is further configured to:

solving the proportion of the section of the third alternative path which is coincident with the first alternative path and accounts for the first alternative path, setting the proportion as a second similarity, solving the proportion of the section of the third alternative path which is different from the first alternative path and accounts for the first alternative path, and setting the proportion as a second difference;

solving the proportion of the section of the third alternative path which is coincident with the second alternative path to the second alternative path, setting the proportion as a third similarity, solving the proportion of the section of the third alternative path which is dissimilar with the second alternative path to the second alternative path, and setting the proportion as a third difference; and

and outputting the first alternative path, the second alternative path and the third alternative path in response to the judgment that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the judgment that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold.

Further objects and advantages of the invention will be fully apparent from the ensuing description and drawings.

These and other objects, features and advantages of the present invention will become more fully apparent from the following detailed description, the accompanying drawings and the claims.

Drawings

Fig. 1 is a diagram illustrating a multi-path filtering strategy of a path planning algorithm in the prior art.

FIG. 2 is a block diagram of a path planning system according to a preferred embodiment of the present invention.

Fig. 3 is a flowchart of a path planning method provided by the path planning system according to the above preferred embodiment.

Fig. 4 is a second flowchart of a path planning method provided by the path planning system according to the above preferred embodiment.

Fig. 5 is a third flowchart of a path planning method provided by the path planning system according to the above preferred embodiment.

Fig. 6 is a schematic distribution diagram of link segments included in the first alternative path and the second alternative path.

Fig. 7 is another distribution diagram of the link segments included in the first alternative path and the second alternative path.

FIG. 8 is a schematic diagram illustrating the distribution of the second alternative path S2 and the second alternative path S2' with the first alternative path S1.

Fig. 9 is a fourth flowchart of a path planning method provided by the path planning system according to the above preferred embodiment.

Fig. 10 is a fifth flowchart of a path planning method provided by the path planning system according to the above preferred embodiment.

Fig. 11 is a sixth flowchart of a path planning method provided by the path planning system according to the above preferred embodiment.

Fig. 12 is a schematic distribution diagram of link segments included in the first candidate route, the second candidate route, and the third candidate route.

Fig. 13 is another distribution diagram of link segments included in the first candidate route, the second candidate route, and the third candidate route.

FIG. 14 is a schematic diagram of a cloud computing environment.

FIG. 15 is a schematic diagram of a set of abstraction functional layers provided by a cloud computing environment.

Detailed Description

The following description is provided to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments described below are by way of example only, and other obvious variations will occur to those skilled in the art. The underlying principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced devices or components must be constructed and operated in a particular orientation and thus are not to be considered limiting.

It will be understood that the terms "a" and "an" should be interpreted as meaning "at least one" or "one or more" in that, in one embodiment, a number of elements may be one, and in that, in another embodiment, the number of elements may be more than one, and the terms "a" and "an" should not be taken as limiting the number.

The present disclosure relates to systems, methods, and/or computer program products. When implemented as a computer program product, the computer program product comprises a computer readable storage medium having computer readable program instructions embodied therein for invocation by a processor to implement the method or system disclosed herein. It is worth mentioning that the computer readable storage medium includes, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination of the foregoing. More specifically, the computer-readable storage device may be embodied as a portable computer diskette, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a Static Random Access Memory (SRAM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanically encoded device (e.g., a punch card with index, etc.), or any suitable combination of the foregoing.

The computer-readable program instructions may be downloaded to associated computing/processing devices from a computer-readable storage medium, or downloaded to external computers or external storage devices via a network, such as the internet, local area networks, wide area networks, and/or wireless networks. The network may include copper cable transmissions, fiber optic transmissions, wireless transmissions, routers, firewalls, switches, edge servers, and/or the like. The network adapter card or network interface of the computing/processing device receives the computer-readable program instructions from the network and stores the computer-readable program instructions in the computer-readable storage medium of the computing/processing device.

Those skilled in the art will appreciate that the computer-readable program instructions for carrying out operations associated with the present invention may be assembler instructions, instruction set architecture instructions, machine-related instructions, microcode, firmware instructions, state setting data, configuration data for an integrated circuit, or source or object code language written in one or more programming languages, such as the Smalltalk, C + + or other suitable programming language. The computer-readable program instructions may execute entirely on the user's computer, partly on the user's computer and partly on the remote side, as a stand-alone software package, or entirely on the remote or server side. In the latter scenario, the remote computer may be connected to the user's computer through any type of network connection, including, but not limited to, a local area network, a wide area network, or the remote computer may communicate with the user's computer through an external computer (e.g., through the Internet, etc.). In some embodiments of the present invention, an electronic circuit, such as a programmable logic circuit, a thread programmable gate array, or a programmable logic array, can be designed by utilizing state information provided by computer readable program instructions to execute the computer readable program instructions to perform a homemade design of the electronic circuit, thereby implementing the search algorithm disclosed herein.

It is noted that the present disclosure has been described in terms of flowchart illustrations or block diagrams of systems and computer program products. That is, each block or combination of blocks in the flowchart and block diagrams contemplated by the present invention may be implemented by computer readable program instructions. It should be further noted that the flowchart and block diagrams of the present invention illustrate the architecture, functionality, and operation of the disclosed systems, methods and computer program products according to embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module or portion of instructions which comprises one or more executable instructions for implementing the specified logical function(s). It should be noted that, in other embodiments of the invention, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order.

As shown in fig. 2, a path planning system according to a preferred embodiment of the present invention is illustrated, wherein the path planning system is capable of providing a user with path planning and recommendation functions. In the preferred embodiment of the present invention, the path planning system is configured in a server mode to specifically describe the technical features of the path planning system. Of course, those skilled in the art should readily understand that in other embodiments of the present invention, the path planning system may be integrated into an onboard computer or a cloud-based computing environment, and the present invention is not limited thereto.

As described above, with the explosive development of new concept cars such as "smart cars" and "internet cars", service providers and equipment manufacturers who are associated therewith continue to provide consumers with more valuable and convenient services through web services, of which navigation services are one of popular services. However, in the process of planning multi-route paths, the conventional navigation service has too harsh selection and judgment strategy for multiple routes, so that many planned paths which may meet the use requirements of consumers are filtered in the process of planning the routes, and the expected paths cannot be obtained.

Accordingly, one of the objectives of the path planning system provided by the present invention is to provide users with multi-path planning selection, wherein the difference and similarity between different planned paths meet the preset requirements. More specifically, as shown in fig. 2, in the present invention, the path planning system includes a communication module 10, a path identifying module 20 and a path filtering module 30, wherein the communication module 10 is used for implementing interaction between the path planning system and external devices. In particular, in the preferred embodiment of the present invention, the path planning system is connected to a mobile computing device through a network (not shown) by the communication module 10 (local area network, wide area network, wireless network, etc.), and provides information interaction with the mobile computing device. The mobile computing devices may be implemented as an onboard computer 82A, a smart phone 82B, a personal digital assistant 82C, a tablet 82D, etc., and those skilled in the art will readily appreciate that the type of mobile computing device is not a limitation of the present invention.

During operation of the path planning system, the mobile computing device sends a path planning request to the communication module 10, where the path planning request includes a start location information and a destination information. Accordingly, the path planning request is further transmitted to the path identification module 20 by the communication module 10, wherein the path identification module 20 extracts the start information and the destination information of the path planning request and identifies a series of alternative paths from a map database. The series of alternative paths are transmitted to the path screening module 30, wherein the path identification module 20 screens the alternative paths generated by the path identification module 20 according to a preset algorithm, so that the finally obtained difference values and similarities between different paths both meet preset requirements.

For convenience of explaining the algorithm mechanism of the path identifying module 20 and the path screening module 30, the series of alternative paths includes a first alternative path S1, a second alternative path S2, and a third alternative path S3. It will be appreciated that in the present invention, first, second, and third are relative concepts, wherein the second is relative to the first and the third is relative to the first and second. Based on this logic, those skilled in the art should easily understand that the series of alternative paths further includes a fourth alternative path, a fifth alternative path, and so on, and the filtering algorithm of the fourth alternative path and the fifth alternative path may fall back according to the filtering algorithm of the first, second, and third alternative paths, which will not be described in detail in the following description.

Accordingly, the path identification module 20 identifies a first alternative path S1, a second alternative path S2, and a third alternative path S3 from a map database according to pre-loaded algorithms, such as a x and Dijkstra algorithms, after receiving the path planning request. It should be appreciated that the start and end points of the first alternative path S1, the second alternative path S2, and the third alternative path S3 are the start and destination information provided by the path planning request, respectively. Those skilled in the art should understand that, at this time, the similarity and the difference between the first, second and third alternative paths identified by the path identification module 20 cannot be guaranteed, that is, there may be a large number of overlapping paths between the first, second and third alternative paths or the first alternative path S1, the second alternative path S2 and the third alternative path S3S3 have too large difference, and there is no practical significance.

It should be readily understood that, for example, when there are a large number of overlapping paths between the second alternative path S2 and the first alternative path S1, the second alternative path S2 is actually an invalid path and should not be pushed to the user as a recommended path; or, the second alternative path S2 has too great a difference from the first alternative path S1, and the route of the second alternative path S2 is too long and has no actual navigation meaning, and should also be regarded as an invalid path, and should not be pushed to the user as a recommended path. That is, the planned routes identified by the route identification module 20 need to be further filtered, which is the original design of the route filtering module 30 and is one of the cores of the present invention.

Starting from the bottom logic of the computer, in order to perform multi-path screening, calculable parameters between different planned paths must be found/created, and a physical quantity capable of measuring the difference between the different paths is integrated based on the calculation of the calculable parameters, so as to measure the difference between the different planned paths based on the physical quantity. More specifically, those skilled in the art will appreciate that in the field of navigation, a path is essentially composed of a series of linked segments, each having a known distance. Based on the characteristic, the path screening module 30 may solve the ratio of the overlapped road segments of different planned paths to the reference path, measure the similarity between different paths based on the ratio, and perform path screening. That is, in the present invention, the calculable parameter is a link of different planned paths, and the physical quantity measuring the difference between different planned paths is the ratio, which is set as a first similarity for understanding.

More specifically, in the preferred embodiment of the present invention, the first alternative path S1 is set as the reference path. Accordingly, when the second candidate path S2 is filtered by the path filtering module 30, the algorithm core is: step1, solving the proportion of a road segment, which is overlapped by the second alternative path S2 and the first alternative path S1, in the first alternative path S1, wherein the proportion is the similarity; step 2, judging whether the similarity is smaller than a preset threshold, wherein when the similarity is smaller than the preset threshold, it indicates that the difference between the second alternative path S2 and the first alternative path S1 is large, and the candidate path may be recommended to the user as an alternative path; when the similarity is greater than the preset threshold, it indicates that the similarity between the second candidate path S2 and the second candidate path S2 is greater, and there are more overlapped road segments between the second candidate path S2 and the second candidate path S2, and the second candidate path S2 is an invalid path and is not suitable for being recommended to the client as a candidate path.

Fig. 6 is a schematic diagram illustrating a route calculation principle of Step1 executed by the route screening module 30 when screening the second candidate route S2. As shown in FIG. 6, the first alternative path S1 is the reference path, which has a series of link segments A0-An, wherein A0-An are arranged in the direction from the start information to the destination information. The second alternative path S2 is a path to be filtered, and has a series of linked segments B0-Bk, wherein B0-Bk are arranged in the direction from the start information to the destination information. As mentioned above, whether the first alternative path S1 or the second alternative path S2 has a known distance between each link segment, based on this characteristic, at least the following reasoning can be inferred:

one is as follows: solving the sum of the distances of the link segments of each planned path can obtain the total length of the planned path, for example: solving the sum between A0-An, the total length of the first alternative path S1 can be obtained.

The second step is as follows: the coincident segments between different planned paths may be represented as the sum of the elements of a comparative set between the sets of linked segments that the different planned paths have. For example, the overlapped link between the first alternative path S1 and the second alternative path S2 may be represented as a sum of link segments of intersecting sets between the sets a0 to An (set α) and the sets B0 to Bk (set β).

As can be seen from inference 2, when solving the similarity between the second candidate path S2 and the first candidate path S1, the path screening module 30 may respectively determine whether each of the link segments B0 to Bk of the second candidate path S2 belongs to the set α, and add the link segments belonging to the set α in the second candidate path S2 to solve the sum of the distances between the overlapped segments of the second candidate path S2 and the first candidate path S1.

Further, the similarity may be solved according to a sum of distances between the overlapped segments of the second candidate path S2 and the first candidate path S1 and a total length of the first candidate path S1, where the total length of the first candidate path S1 is a sum of distances between link segments a0 to An in the set α. Further, it is determined whether the similarity is smaller than a preset threshold, for example, 30%, where when the similarity is smaller than the preset threshold, it indicates that the difference between the second alternative path S2 and the first alternative path S1 is large, and the candidate path may be recommended to the user as the alternative path; when the similarity is greater than the preset threshold, it indicates that the similarity between the second candidate path S2 and the second candidate path S2 is great, and there are many overlapped road segments between the two, and the second candidate path S2 is an invalid path, and the second candidate path S2 is deleted.

It should be noted that, in the preferred embodiment of the present invention, the first alternative path S1 can be obtained based on Dijkstra' S algorithm, that is, the first alternative path S1 is a path plan with the shortest distance between the start location and the destination, and this path satisfies the path plan recommendation criterion, so that it has sufficient reference meaning as a reference path. Of course, in another embodiment of the present invention, the first alternative path S1 can be solved based on a shortest time algorithm, i.e. the first alternative path S1 is a shortest time path between the start and the destination, or in another embodiment of the present invention, the first alternative path S1 can be solved based on an economic route algorithm, i.e. the first alternative path S1 is a most economic path between the start and the destination. It should be appreciated that, in the present invention, the algorithm specifically obtained by the first alternative path S1 is not limited by the present invention.

It should also be noted that when the similarity between different planned paths is actually solved, other algorithms, such as a backtracking algorithm, may also be used to identify the overlapped road segments between different planned paths. As shown in fig. 7, when identifying the overlapped segment between the first alternative path S1 and the second alternative path S2, a certain butt-joint link from the second alternative path S2 may be selected, and fast backtracking may be performed in both forward and backward directions until a link segment labeled as a is encountered, in this way, the overlapped segment between the first alternative path S1 and the second alternative path S2 may also be identified, and the sum of the overlapped segments between the second alternative path S2 and the second alternative path S2 may be obtained due to the distance of the starting and ending points of each link.

Further, in the process of the path screening module 30 performing multi-path screening, it is difficult to truly reflect the reliability of the actually planned path only according to the similarity between different paths. More specifically, in some specific application scenarios, as shown in fig. 8, the second alternative path S2 and the second alternative path S2 'S2' are consistent with the segment that is coincident with the first alternative path S1, that is, the first similarity between the second alternative path S2 and the second alternative path S2 'and the first alternative path S1 is consistent, and if only the similarity is used for path filtering, both the second alternative path S2 and the second alternative path S2' are pushed to the user as the recommended path. However, as can be seen from the figure, the overall route of the second alternative path S2 'is too long, and in an actual application scenario, the second alternative path S2' has an extremely low degree of availability, and thus is also an invalid path in nature. In this regard, in the preferred embodiment of the present invention, the path filtering module 30 should also consider a first difference between different planned paths to combine the difference and the similarity to filter the multiple paths.

Similarly, when solving the first difference degree between the second candidate path S2 and the first candidate path S1, the path filtering module 30 may determine whether each of the link segments B0 to Bk of the second candidate path S2 belongs to the set α, and add the link segments that do not belong to the set α in the second candidate path S2 to solve the sum of the distances between the segments that are different from the first candidate path S1 and the second candidate path S2.

Further, the difference degree may be solved according to a sum of distances between different segments of the second candidate path S2 and the first candidate path S1 and a total length of the first candidate path S1, where the total length of the first candidate path S1 is a sum of distances of link segments a0 to An in the set α. Further, it is determined whether the difference degree is smaller than a preset threshold, for example, 150%, where when the difference degree is smaller than the preset threshold, it indicates that the overall path of the second alternative path S2 is within an acceptable range compared with the first alternative path S1, and the overall path may be recommended to the user as an alternative path; when the similarity is greater than the preset threshold, it indicates that the second alternative path S2 is far beyond the total length of the first alternative path S1, the second alternative path S2 is an invalid path, and the second alternative path S2 is deleted.

Further, when the difference and the similarity between the second alternative path S2 and the first alternative path S1 satisfy the preset requirements at the same time, the second alternative path S2 and the first alternative path S1 are pushed to the user at the same time as a recommended path.

Correspondingly, in another embodiment of the present invention, as shown in fig. 7, the first degree of difference may be solved based on other algorithms. For example, the link segments of the second alternative path S2 different from the first alternative path S1 may be directly identified by a correlation algorithm, and the link segments of the second alternative path S2 different from the first alternative path S1 are labeled as B0 to Bk in sequence, where B0 is adjacent to the start point information, Bk is adjacent to the destination information, and B0 to Bk are arranged in sequence in a direction from the start point information to the destination information, where any link segment of B0 to Bk has a known distance. Therefore, the sum of the distances between the second candidate path S2 and the different road segments of the first candidate path S1 can be solved only by adding the link segments B0 to Bk included in the different road segments of the second candidate path S2 and the first candidate path S1. Further, the first difference degree can be solved according to the sum of the distances between the different road segments of the second candidate path S2 and the first candidate path S1 and the total length of the first candidate path S1, wherein the total length of the first candidate path S1 is the sum of the distances of the link segments a0 to An.

Of course, those skilled in the art should readily understand that the algorithm for specifically solving the first difference may be adjusted accordingly based on the specific application scenario, which is not limited by the present invention.

As shown in fig. 12 and fig. 13, the route calculation principle of the path filtering module 30 in filtering the third candidate path S3 should be noted that, when filtering the third candidate path S3, not only the similarity and the difference between the third candidate path S3 and the first candidate path S1 (the reference path) but also the similarity and the difference between the third candidate path S3 and the second candidate path S2 should be considered.

Similarly, the similarity and contrast between the third alternative path S3 and the first alternative path S1, and between the third alternative path S3 and the second alternative path S2 can be calculated based on the above-described calculation mechanism. Therefore, the detailed description of the present invention is omitted.

As shown in fig. 3, according to another aspect of the present invention, the present invention further provides a path planning method, wherein the path planning method includes the steps of:

receiving a path planning request, wherein the path planning request comprises starting place information and destination information;

identifying a first alternative path from a map database according to the starting location information and the destination information S1;

identifying a second alternative path from a map database according to the start location information and the destination information S2;

solving the proportion of the road segment, which is overlapped by the second alternative path S2 and the first alternative path S1, in the first alternative path S1, and setting the proportion as a first similarity; and

in response to a determination that the first similarity is less than a predetermined threshold, the first alternative path S1 and the second alternative path S2 are output.

Accordingly, in an embodiment of the present invention, as shown in fig. 4, the step of solving the first similarity includes the steps of:

marking all link segments of the first alternative path S1 as A0-An in sequence, wherein A0-An are arranged in sequence in the direction from the starting information to the destination information, wherein a set formed by all link segments A0-An of the first alternative path S1 is set as alpha, wherein any link segment of A0-An has a known distance;

marking the link segments of the second alternative path S2 as B0 Bk, wherein B0 Bk are arranged in the direction from the starting information to the destination information, and any link segment of B0 Bk has a known distance;

respectively judging whether the link segments B0-Bk of the second candidate path S2 belong to the set alpha or not, and adding the link segments belonging to the set alpha in the second candidate path S2 to solve the distance sum of the overlapped segments of the second candidate path S2 and the first candidate path S1; and

and solving the first similarity according to the sum of the distances between the superposed road segments of the second alternative path S2 and the first alternative path S1 and the total length of the first alternative path S1, wherein the total length of the first alternative path S1 is the sum of the distances of the link segments a0 to An in the set α.

Accordingly, in another embodiment of the present invention, as shown in fig. 5, the step of solving the first similarity includes the steps of:

marking the link segments of the first alternative path S1 as A0-An in sequence, wherein A0-An are arranged in the direction from the starting information to the destination information, and any one of A0-An has a known distance;

identifying segments of the second alternative path S2 different from the first alternative path S1, and sequentially labeling links of the second alternative path S2 different from the segments of the first alternative path S1 as B0-Bk, wherein B0 is adjacent to the start point information, Bk is adjacent to the destination information, and B0-Bk are arranged sequentially in a direction from the start point information to the destination information, wherein any link of B0-Bk has a known distance;

identifying a pair of junctions of any two link segments in the segment of the second alternative path S2 distinct from the first alternative path S1;

searching in the direction towards the information of the starting point and in the direction towards the information of the destination by taking the pair of contact points as the starting point respectively until the searching result is any link segment from A0 to An, and acquiring all link segments marked as A in the second alternative path S2 in such a way;

adding all the road segments marked as A in the second alternative path S2 to solve the distance sum of the road segments overlapped by the second alternative path S2 and the first alternative path S1; and

and solving the first similarity according to the sum of the distances of the overlapped road segments of the second alternative path S2 and the first alternative path S1 and the total length of the first alternative path S1, wherein the total length of the first alternative path S1 is the sum of the distances of the link segments A0 to An.

In an embodiment of the present invention, the first alternative path S1 is a shortest distance path between the origin information and the destination information.

In an embodiment of the present invention, the first alternative path S1 is a shortest distance path between the start information and the destination information.

In an embodiment of the present invention, the first alternative path S1 is the most economical path between the origin information and the destination information.

In an embodiment of the present invention, as shown in fig. 3, the path planning method further includes the steps of:

solving the proportion of the road sections of the second alternative path S2, which are different from the road sections of the first alternative path S1, in the first alternative path S1, and setting the proportion as a first difference degree; and

and outputting the information of the first alternative path S1 and the second alternative path S2 in response to the judgment that the first difference degree is less than a certain preset threshold value and the similarity degree is less than a certain preset threshold value.

In an embodiment of the invention, as shown in fig. 9, the step of solving the first difference includes the steps of:

marking all link segments of the first alternative path S1 as A0-An in sequence, wherein A0-An are arranged in sequence in the direction from the starting information to the destination information, wherein a set formed by all link segments A0-An of the first alternative path S1 is set as alpha, wherein any link segment of A0-An has a known distance;

marking the link segments of the second alternative path S2 as A0-An in sequence, wherein the B0-Bk are arranged in the direction from the starting information to the destination information, and any link segment of the B0-Bk has a known distance;

respectively judging whether the link segments B0-Bk of the second candidate path S2 belong to the set alpha or not, and adding the link segments which do not belong to the set alpha in the second candidate path S2 to solve the distance sum of the segments different from the first candidate path S1 in the second candidate path S2; and

and solving the first difference degree according to the sum of the distances between the different road segments of the second alternative path S2 and the first alternative path S1 and the total length of the first alternative path S1, wherein the total length of the first alternative path S1 is the sum of the distances of the link segments A0 to An in the set alpha.

In an embodiment of the invention, as shown in fig. 10, the step of solving the first difference includes the steps of:

marking the link segments of the first alternative path S1 as A0-An in sequence, wherein A0-An are arranged in the direction from the starting information to the destination information, and any link segment of A0-An has a known distance;

identifying segments of the second alternative path S2 that are different from the first alternative path S1, and sequentially labeling links of the segments of the second alternative path S2 that are different from the first alternative path S1 as B0-Bk, wherein B0 is adjacent to the start point information, Bk is adjacent to the destination information, and B0-Bk are arranged in order from the start point information to the destination information, wherein any link of B0-Bk has a known distance;

adding the link sections B0-Bk included in the second alternative path S2 and the road section different from the first alternative path S1 to solve the sum of the distances between the second alternative path S2 and the road section different from the first alternative path S1; and

and solving the first difference degree according to the sum of the distances between the different road segments of the second alternative path S2 and the first alternative path S1 and the total length of the first alternative path S1, wherein the total length of the first alternative path S1 is the sum of the distances of the link segments A0 to An.

In an embodiment of the present invention, as shown in fig. 11, the path planning method further includes the steps of: identifying a third alternative path from a map database according to the starting place information and the destination information;

solving the proportion of the road segment of the third alternative path S3, which is overlapped with the first alternative path S1, in the first alternative path S1, setting the proportion as a second similarity, solving the proportion of the road segment of the third alternative path S3, which is different from the first alternative path S1, in the first alternative path S1, and setting the proportion as a second similarity;

solving the proportion of the segment where the third alternative path S3 and the second alternative path S2 coincide in the second alternative path S2, and setting the proportion as a third similarity, and solving the proportion of the segment where the third alternative path S3 and the second alternative path S2 differ in the second alternative path S2, and setting the proportion as a third difference;

and outputting the first alternative path S1, the second alternative path S2 and the third alternative path S3 in response to the determination that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the determination that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold.

In an embodiment of the invention, in the step of outputting the first alternative path S1, the second alternative path S2 and the third alternative path S3 in response to the determination that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the determination that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold, the first preset threshold is greater than the second preset threshold, and the third threshold is greater than the fourth preset threshold.

It should be appreciated that the path planning system provided by the invention can be based on a cloud computing environment for system architecture. Those skilled in the art will appreciate that cloud computing is a service provisioning model that enables on-demand network access to a shared pool of resources composed of configurable computing resources (e.g., networks, network bandwidth, servers, processors, memory, storage media, applications, virtual machines, and services). The shared resource pool can be configured and published quickly with only minor administrative effort or interaction with the service provider.

Cloud computing models typically have five features, three service modes and four deployment modes.

The cloud computing is characterized in that:

self-service on demand: cloud users can unilaterally configure computing functions such as server time and network disk storage on their own as needed without interacting with service providers.

Broad access: the cloud computing functions are accessible via a network and are obtained via standard mechanisms to facilitate the use of various client platforms (e.g., cell phones, laptops, PDAs, etc.).

Resource pooling: the computing resources provided by the provider are centralized (pooled) and serve multiple users through a shared schema. The physical resources and virtual resources in the resource pool can be dynamically configured and reallocated according to requirements. Since users typically have no desire for concept and control over the exact location of the provided resources, there are related psychological appeal to locations with higher levels of abstraction (e.g., country, state, or data center). Therefore, the user feels that the resource pool of the cloud computing has a sense of location existence.

Fast and flexible architecture: in some cases, related functions of cloud computing may be quickly and flexibly configured to quickly expand or quickly release resources. The functionality provided by available cloud computing often appears unlimited to a user, and may be purchased in any number at any time.

Ease of measurement evaluation a cloud computing system may control and optimize resource configuration and usage with some abstract metering functionality that is appropriate for a particular type of service (e.g., storage, processing, bandwidth, and active user accounts). The usage of the resource can be supervised, controlled and reported to provide transparency of resource usage for the provider and the user.

The service mode is as follows:

software-level service (SaaS, Software as a service)

The service mode refers to that the cloud user uses an application program which can run on the cloud infrastructure and is provided by a service provider. These applications may be accessed through a variety of thin client interfaces, such as a web browser or email, for example. Cloud users do not need to manage or control the underlying cloud infrastructure (e.g., network, server, operating system, storage or even individual application functionality), but have limited permissions to set the configuration of that application.

Platform level service (PaaS, Platform as a service)

The service model refers to a service model that allows applications created or acquired by cloud users to be deployed on a cloud infrastructure, the applications being created by programming languages and tools supported by a service provider. Cloud users do not manage or control the underlying cloud infrastructure (e.g., network, servers, operating system or storage, etc.), but may control the configuration of deployed applications and application hosting environments (hosts).

Infrastructure level Service (IaaS, Infrastructure as a Service)

The service model refers to providing the underlying computing resources (processing, storage, networking, etc.) that a consumer can deploy and run arbitrary software, including operating systems and applications. Cloud users do not manage or control the underlying cloud infrastructure, but can have control over operating systems, stored and deployed applications while having limited control over network components (e.g., host firewalls, etc.).

The deployment pattern is as follows:

private cloud: such a cloud infrastructure is only targeted at an organization, whether managed by itself or hosted by a third party, deployed internally or externally, and has no relevance. As long as the using mode has no problem, the method can bring remarkable help to enterprises. However, this model is required to deal with security problems such as correction and inspection, which are not only responsible for the enterprise itself but also responsible for the problem itself, and the whole system is also required to be purchased, constructed and managed for its own money. The cloud computing mode can generate positive benefits very widely, and as seen from the name of the mode, the cloud computing mode can provide services with sufficient advantages and functions for owners.

Community cloud: this model is built between multiple similarly targeted companies in a particular team, sharing a set of infrastructure, as well as the business as a corporate progression. The resulting costs are shared by them and, therefore, the cost savings that can be achieved are not significant. Members of the community cloud can log into the cloud to obtain information and use the application program. The community cloud may be self-administered or hosted by a third party, deployed internally or externally, etc.

Public cloud: in this model, applications, resources, storage, and other services are offered to a wide range of users by cloud service providers, most of which are free and some of which are paid for usage on demand. Such a deployment model can generally provide scalable cloud services and can be efficiently deployed.

Mixing cloud: the hybrid cloud is a mixture of two or more cloud computing modes, such as a public cloud and a private cloud. The cloud computing models are independent of each other, but are combined with each other in the cloud, so that the advantages of the mixed multiple cloud computing models can be exerted

Cloud computing is service oriented, focusing on stateless, low-coupling, modular, and semantic interoperability. At the heart of cloud computing is a cloud computing infrastructure, which comprises a network of nodes made up of a myriad of interconnected nodes.

As shown in fig. 14, an exemplary cloud computing environment 80 is illustrated that includes a series of cloud computing nodes 81. Through the cloud computing nodes 81, local computing devices, such as a vehicle-mounted computer 82A, a smart phone 82B, a personal digital assistant 82C, a tablet computer 82D and the like, can realize internet communication. The cloud computing nodes 81 may be in communication with each other and may be grouped, either virtually or physically, to form a series of networks of nodes, such as private clouds, public clouds, community clouds, hybrid clouds, etc. as described above, in such a way as to provide cloud users with cloud services that do not require resource maintenance on the local computing devices, such as the infrastructure, software programs or platforms, etc. as described above. It should be appreciated that the computing device illustrated in FIG. 14 is merely an example, and that a cloud computing environment may be interconnected with any other computing device via a network, directly or indirectly, and is not intended to limit the present invention.

As shown in fig. 15, a set of abstraction functional layers provided by cloud computing environment 80 is illustrated. Before proceeding with the detailed description, those skilled in the art will appreciate that the components, layers, and functions illustrated in fig. 15 are merely examples to illustrate features of a cloud computing environment and are not intended to limit the present invention.

Hardware and software layers

This layer includes a range of hardware and software, where the hardware includes, but is not limited to, a host, a server of a RISC (Reduced Instruction Set Computer) architecture, a server, a blade server, a storage device, a network and network components, and the like. In some embodiments of the invention, the software includes web application server and database software, among others.

Virtual layer

The layer comprises a series of virtual entities including, but not limited to, virtual servers, virtual storage spaces, virtual networks, virtual private networks, virtual applications and operating systems, and virtual clients, among others.

Management layer

In one embodiment of the invention, the management layer may implement the functions described below. One is as follows: a resource provisioning function capable of providing dynamic procurement of computing and other resources required for performing tasks within the cloud computing environment; secondly, a metering and pricing function, which can track the use cost of the resources in the cloud computing environment, and perform charging or pricing on the resource consumption, and the like, in an embodiment of the present invention, the resources include software licenses and the like; and thirdly, the safety protection function can carry out identity verification on cloud users and tasks and protect data and other resources. Fourthly, a user portal function which can provide access channels for cloud users and system administrators to the cloud computing environment; fifthly, the service management function can allocate and manage the cloud computing resources to meet the requirements of the required service; and sixthly, a Service Level Agreement planning and implementation function, which can pre-arrange and purchase the required cloud computing resources according to SLA (Service Level Agreement).

Working layer

This layer provides functional examples that can be implemented by a cloud computing environment, such as mapping and navigation, software development and period management, virtual classroom education, data analysis processing, transaction processing, and internet search methods, etc.

It should be appreciated that although the present disclosure includes detailed descriptions with respect to cloud computing, the disclosed embodiments are not limited to only a cloud computing environment. Rather, embodiments of the invention can be implemented in connection with any other type of computing environment, whether now known or later developed.

It can thus be seen that the objects of the invention are sufficiently well-attained. The described embodiments have been fully illustrated and described for the purpose of explaining the functional and structural principles of the present invention, and the present invention is not limited by changes based on the principles of these embodiments. Accordingly, this invention includes all modifications encompassed within the scope and spirit of the following claims.

Claims (7)

1. A method of path planning, comprising the steps of:

receiving a path planning request, wherein the path planning request comprises starting place information and destination information;

identifying a first alternative path from a map database according to the starting place information and the destination information;

identifying a second alternative path from a map database according to the starting place information and the destination information; solving the proportion of the road section, which is overlapped by the second alternative path and the first alternative path, in the first alternative path, and setting the proportion as a first similarity;

solving the proportion of the different road sections of the second alternative path and the first alternative path in the first alternative path, and setting the proportion as a first difference degree;

responding to the judgment that the first similarity is smaller than a certain preset threshold and the first difference is smaller than a certain preset threshold, and outputting the first alternative path and the second alternative path;

identifying a third alternative path from a map database according to the starting place information and the destination information;

solving the proportion of the section of the third alternative path which is coincident with the first alternative path and accounts for the first alternative path, setting the proportion as a second similarity, solving the proportion of the section of the third alternative path which is different from the first alternative path and accounts for the first alternative path, and setting the proportion as a second difference;

solving the proportion of the road section of the third alternative path, which is coincident with the second alternative path, in the second alternative path, setting the proportion as a third similarity, solving the proportion of the road section of the third alternative path, which is dissimilar with the second alternative path, in the second alternative path, and setting the proportion as a third difference; and

and outputting the first alternative path, the second alternative path and the third alternative path in response to the judgment that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the judgment that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold.

2. The path planning method according to claim 1, wherein the step of solving the first similarity includes the steps of:

marking the link segments of the first alternative path as A0-An in sequence, wherein A0-An are arranged in sequence from the starting information to the destination information, wherein a set formed by all link segments A0-An of the first alternative path is set as alpha, and any link segment A0-An has a known distance;

marking the link segments of the second alternative path as B0-Bk in sequence, wherein B0-Bk are arranged in sequence from the starting information to the destination information, and any link segment of B0-Bk has a known distance;

respectively judging whether the link segments B0-Bk of the second alternative path belong to the set alpha or not, and adding the link segments belonging to the set alpha in the second alternative path to solve the distance sum of the second alternative path and the first alternative path superposed road segment; and

and solving the first similarity according to the sum of the distances between the second alternative path and the superposed road segments of the first alternative path and the total length of the first alternative path, wherein the total length of the first alternative path is the sum of the distances of the link segments from A0 to An in the set alpha.

3. The path planning method according to claim 1, wherein the step of solving the first similarity includes the steps of:

marking the link segments of the first alternative path as A0-An in sequence, wherein A0-An are arranged in sequence from the starting information to the destination information, and any link segment of A0-An has a known distance;

identifying segments of the second alternative path that are different from the first alternative path, and sequentially labeling links of the segments of the second alternative path that are different from the first alternative path as C0-Cm, wherein C0 is adjacent to the starting information, Cm is adjacent to the destination information, and C0-Cm are arranged in order from the starting information to the destination information, wherein any link of C0-Cm has a known distance;

identifying a pair of junction points of any two link sections in the section of the second alternative path different from the section of the first alternative path;

searching in the direction of information approaching the starting point and in the direction of information approaching the destination point respectively by taking the pair of contact points as the starting point, stopping searching until the searching result is any link segment from A0-An, and acquiring all link segments marked as A in the second alternative path in such a way;

adding all the road segments marked as A in the second alternative path to solve the distance sum of the second alternative path and the superposed road segments of the first alternative path; and

and solving the first similarity according to the sum of the distances of the second alternative path and the overlapped road section of the first alternative path and the total length of the first alternative path, wherein the total length of the first alternative path is the sum of the distances of the link sections A0-An.

4. A path planning method according to any one of claims 1 to 3 in which the first alternative path is the shortest distance path between the origin information and the destination information.

5. A path planning method according to any one of claims 1 to 3 in which the first alternative path is the most economical path between the origin information and the destination information.

6. The path planning method according to claim 1, wherein in the step of outputting the first candidate path, the second candidate path, and the third candidate path in response to the determination that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the determination that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold, the first preset threshold is larger than the second preset threshold, and the third preset threshold is larger than the fourth preset threshold.

7. A path planning system, comprising:

a communication module communicatively coupled to a mobile computing device of a vehicle for receiving a path planning request provided from the vehicle, wherein the path planning request includes a start location information and a destination information;

a path identification module, wherein the path identification module is communicably connected to the communication module for identifying a first alternative path, a second alternative path and a third alternative path from a map database according to the starting location information and the destination information; and

a path screening module, communicatively connected to the path identification module, for solving a ratio of the second candidate path and the first candidate path overlapping road segment to the first candidate path and setting the ratio as a first similarity, and for solving a ratio of the second candidate path and the first candidate path different road segment to the first candidate path and setting the ratio as a first difference, and determining whether the first similarity is smaller than a preset threshold and whether the first difference is smaller than a preset threshold to screen the second candidate path;

wherein the path screening module is further configured to:

solving the proportion of the section of the third alternative path which is coincident with the first alternative path and accounts for the first alternative path, setting the proportion as a second similarity, solving the proportion of the section of the third alternative path which is different from the first alternative path and accounts for the first alternative path, and setting the proportion as a second difference;

solving the proportion of the road section of the third alternative path, which is coincident with the second alternative path, in the second alternative path, setting the proportion as a third similarity, solving the proportion of the road section of the third alternative path, which is dissimilar with the second alternative path, in the second alternative path, and setting the proportion as a third difference; and

and outputting the first alternative path, the second alternative path and the third alternative path in response to the judgment that the second similarity is smaller than a first preset threshold and the third similarity is smaller than a second preset threshold and the judgment that the second difference is smaller than a third preset threshold and the third difference is smaller than a fourth preset threshold.

Images