Parking lot active positioning method and system based on V2X

Abstract

The invention relates to a parking lot active positioning method based on V2X. The method comprises the following steps that a platform end positions a target vehicle through RSUs of a parking lot: each RSU receives a positioning request initiated by the platform end; each RSU broadcasts and sends the positioning request to a target vehicle in the parking lot; a plurality of RSUs of the parking lot receive the vehicle broadcast of the OBU of the target vehicle of the parking lot, analyze the vehicle identification number and the vehicle broadcast signal intensity in the vehicle broadcast, and upload the vehicle identification number and the vehicle broadcast signal intensity to the platform end; and the at least three different RSUs upload the analyzed vehicle identification numbers and the vehicle broadcast signal intensities to the platform end so as to calculate the current positioning point coordinates and / or the moving speed of the target vehicle.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle Internet of Things, and specifically relates to a parking lot active positioning method and system based on V2X. Background Art

[0002] Smart parking refers to the use of advanced scientific and technological means to realize the intelligence and optimization of the parking process through the interconnection between vehicles. As one of the key technologies of the Internet of Vehicles, V2X technology combined with smart parking can bring a lot of convenience to parking management. Through the V2X communication system, vehicles can exchange information with road infrastructure and other vehicles in real time. Traditional positioning methods can only be used by the user, that is, the vehicle or mobile phone itself, but the location is not shared with the parking lot, and the parking lot cannot provide more services. The invention application with patent number CN202010647785 discloses an indoor positioning method based on V2X technology. This method relies on the data exchange of V2X roadside equipment and can be applied to underground and indoor parking lots. It has accurate positioning, low requirements on the vehicle side compared to other methods, and accurate and comprehensive information. However, this method mainly relies on modules such as Bluetooth and WIFI for indoor positioning, and only uses V2X for communication. Summary of the invention

[0003] In view of the above technical problems, the technical solution proposed by the present invention includes a V2X-based parking lot active positioning method, including the following steps of positioning the target vehicle by the platform end through the RSU of the parking lot:

[0004] Each RSU receives a positioning request initiated by the platform;

[0005] Each RSU broadcasts the positioning request to the target vehicle in the parking lot;

[0006] Multiple RSUs in the parking lot receive the vehicle broadcast of the OBU of the target vehicle in the parking lot, parse the vehicle identification number and vehicle broadcast signal strength therein, and upload them to the platform end;

[0007] At least three different RSUs upload their resolved vehicle identification numbers and vehicle broadcast signal strengths to the platform end for calculating the current positioning point coordinates and / or moving speed of the target vehicle.

[0008] On the other hand, the present invention also proposes a parking lot positioning device based on a V2X-based parking lot active positioning method, the device comprising a plurality of RSUs distributed in the parking lot and a platform end communicating with each RSU, and the location information of each of the RSUs is stored in the platform end.

[0009] On the other hand, the present invention also proposes a V2X-based parking lot active positioning system, which includes at least one processor; and a memory storing instructions, which implement the method of the present invention when the instructions are executed by at least one processor.

[0010] The technical effect of the present invention is reflected in: the active positioning initiated by the parking lot solves the problem that the traditional positioning method can only be performed by the user, that is, the vehicle or mobile phone, but the location is not shared with the parking lot, and the parking lot cannot provide more services. Through continuous positioning, the moving direction and speed of the vehicle can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 : Flowcharts of some embodiments;

[0012] Figure 2 : Schematic diagrams of some embodiments;

[0013] Figure 3 : Flowcharts of some embodiments;

[0014] Figure 4 : parking lots of some embodiments;

[0015] Figure 5 : Product schematics of some embodiments. DETAILED DESCRIPTION

[0016] First, the technical solution of the present invention and related terms are explained:

[0017] Vehicle to everything (V2X) is an IoT technology where X includes other connected devices such as other vehicles, pedestrians, and roads.

[0018] Roadside Unit / Roadside Communication Terminal (RSU): It consists of a high-gain directional beam-steering read-write antenna and a radio frequency controller. The high-gain directional beam-steering read-write antenna is a microwave transceiver module responsible for sending / receiving, modulating / demodulating, encoding / decoding, and encrypting / decrypting signals and data; the radio frequency controller is a module that controls the transmission and reception of data and processes the information sent and received to the upper computer.

[0019] Roadside Computing Unit (MEC): Utilizing raw data such as videos and point clouds collected by roadside sensing equipment such as cameras and radars, it can effectively identify three main information on the road: traffic participants, traffic events, and traffic flow. Traffic participants are divided into three categories: motor vehicles, non-motor vehicles, and pedestrians. All targets carry key information such as speed, heading, and location. Traffic events include more than ten types of events such as abnormal parking, wrong-way driving, speeding, and pedestrian intrusion, providing holographic perception capabilities for the vehicle-road collaborative system.

[0020] On-board unit (OBU): A microwave device that uses DSRC technology to communicate with the RSU.

[0021] BSM is an information format specified by national standards.

[0022] V2X received signal strength: RSSI, unit: dB.

[0023] The communication port PC5 between the roadside unit and the vehicle-mounted unit can be used for near field communication. The communication port also has an LTE port for wireless Internet communication.

[0024] The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and substance of the present invention, modifications or substitutions made to the methods, steps or conditions of the present invention all fall within the scope of the present invention.

[0025] Some solutions include Figure 1 The platform uses the RSU in the parking lot to locate the target vehicle in the following steps:

[0026] Each RSU receives a positioning request initiated by the platform;

[0027] Each RSU broadcasts the positioning request to the target vehicle in the parking lot;

[0028] Multiple RSUs in the parking lot receive the vehicle broadcast of the OBU of the target vehicle in the parking lot, parse the vehicle identification number and vehicle broadcast signal strength therein, and upload them to the platform end;

[0029] At least three different RSUs upload their resolved vehicle identification numbers and vehicle broadcast signal strengths to the platform end for calculating the current positioning point coordinates and / or moving speed of the target vehicle.

[0030] Based on the above solutions, some solutions have the following steps performed by the platform:

[0031] S1 obtains the location coordinates of the three RSUs in the parking lot.

[0032] S2 calculates the distances d1, d2, and d3 between the target vehicle and the three RSUs according to formula (1):

[0033]

[0034] In the formula (1), i=1, 2, 3, d1 is the distance between the target vehicle and the first RSU, d2 is the distance between the target vehicle and the second RSU, d3 is the distance between the target vehicle and the third RSU; RSSI is the vehicle broadcast signal strength, RSSI1 is the vehicle broadcast signal strength received by the first RSU, RSSI2 is the vehicle broadcast signal strength received by the second RSU, RSSI3 is the vehicle broadcast signal strength received by the third RSU, N is the environmental attenuation factor of the signal strength; S1 is the signal strength between the OBU and the first RSU at every 1 meter interval, S2 is the signal strength between the OBU and the second RSU at every 1 meter interval, S3 is the signal strength between the OBU and the third RSU at every 1 meter interval. It should be noted that the value of parameter S is fixed for the same device model, and the value may be different for different device models. The principle of the above step S2 refers to Figure 2 .

[0035] S3 calculates the current positioning point coordinates of the target vehicle by using the least squares method.

[0036] S3 specifically calculates the current positioning point coordinates of the target vehicle according to formula (2-4):

[0037] X=(A T A) -1 A T b (2)

[0038]

[0039] In the above formula (2-4), X represents the current positioning point coordinates of the target vehicle, (x j ,y j ) is the location coordinate of the RSU in the parking lot that communicates with the OBU of the target vehicle. There are n RSUs in the parking lot that currently communicate with the OBU of the target vehicle. j is the distance between the target vehicle and the RSU calculated according to formula (1); j = 1, 2, ..., n.

[0040] Since the number of RSUs deployed in the parking lot is usually greater than 3, and the number of RSUs currently communicating with the OBU at different locations is n, in order to solve the impact of ranging error on the positioning of the target vehicle, the least squares method can be used to more accurately determine the current positioning point coordinates of the target vehicle. The matrix A and matrix b in formula (3-4) are the matrices obtained by solving the ranging error constrained by formula (5).

[0041]

[0042] In formula (5), (x, y) represents the current positioning point coordinate X of the target vehicle; (xj, yj) is the location coordinate of the RSU in the parking lot that communicates with the OBU of the target vehicle. The number of RSUs at different locations that currently communicate with the OBU is n; j = 1, 2, ..., n.

[0043] Some solutions based on the above solution, calculating the moving speed of the target vehicle through the platform end specifically include the following steps: calculating the moving distance L of the target vehicle within the time interval t through the positioning point coordinates (x1, y1) and (x2, y2) of the target vehicle at two time points, and taking the quotient of the moving distance L of the target vehicle and the time interval t as the moving speed V of the target vehicle. That is, as shown in the following formula (6-7):

[0044]

[0045] In formula (5), t is the time interval, L is the moving distance of the target vehicle within the time interval t, (x1, y1) is the coordinates of the positioning point of the target vehicle calculated at the first time point, and (x2, y2) is the coordinates of the positioning point of the target vehicle calculated at the second time point.

[0046] Some solutions based on the above solutions also include the following steps: the platform side saves the calculated current positioning point coordinates and moving speed of the target vehicle to the database, and the platform side checks the specific position of the vehicle whose position has been obtained in the parking lot.

[0047] In some more specific solutions based on the above solutions, the platform marks the vehicle to be located as the target vehicle, and sends the positioning request to all RSU devices in the parking lot. The positioning request includes the vehicle identification number of the target vehicle, the current time, the agreed positioning time, and the positioning frequency. The positioning request is encapsulated in BSM format.

[0048] Based on the above scheme, the OBU of the target vehicle parses the positioning request broadcast after receiving it. When it is parsed as a positioning request, the vehicle positioning authority setting is accessed. If positioning is not allowed according to the vehicle positioning authority, the positioning request is rejected and the first feedback is encapsulated in BSM format. Otherwise, the vehicle identification number of the target vehicle is encapsulated in BSM format as the second feedback, and the first or second feedback is broadcast to all RSUs in the parking lot.

[0049] The technical solution of the present invention is explained in more detail below through a specific embodiment. The flow chart of the solution is as follows Figure 3 In this embodiment, when the vehicle establishes V2X communication with the parking lot for the first time, the vehicle identification number, license plate and other information are transmitted.

[0050] When positioning the vehicle on the platform, perform the following steps:

[0051] S0: Figure 4 There are several RSU devices distributed in the parking lot, and their locations have been recorded on the platform in advance.

[0052] S1: The platform sends the vehicle identification number to be located, the current time, and the agreed positioning time to all RSU devices in the parking lot through the wired network.

[0053] S2: After receiving the request, the RSU encapsulates the requested positioning frequency and current time into a BSM message and broadcasts the radio frequency through the PC5 interface.

[0054] S3: The vehicle OBU device receives the BSM message and parses it. If the vehicle identification code matches that of its own vehicle, it considers it as a broadcast to itself, otherwise it does not process the message.

[0055] S4: When parsed as a positioning request, access the vehicle positioning permission setting. If it is set to not allow positioning, encapsulate the code of rejecting the positioning request into a BSM message and broadcast it. Otherwise, continue with S5-1.

[0056] S5-1: Encapsulate the current vehicle identification number into a BSM message and broadcast it through the PC5 interface of the OBU device. If the receiving frequency is multiple times, the positioning broadcast is sent in sequence according to the frequency time. (For example, if the current time is 12:00:00, and the positioning frequency is 12:00:01, 12:00:02, and 12:00:03, then the messages are sent in sequence at this time, and a total of 3 messages are sent.

[0057] S5-2: After receiving the broadcast, the parking lot RSU device parses the BSM message and uploads the received vehicle identification number and RSSI to the parking management platform.

[0058] S6-1, after receiving the data uploaded by RSU, the parking management platform obtains the vehicle identification number and RSSI, and calculates the spatial distance to the positioning target.

[0059] S6-2, when at least three different RSUs upload the vehicle positioning information, triangulate the target. Figure 2 , if 3 RSU devices receive the target broadcast, then the parking lot coordinates of these 3 RSUs are taken, (x1, y1), (x2, y2), and (x3, y3).

[0060] S7: After acquiring the vehicle coordinate information multiple times through continuous broadcasting, the difference between each coordinate can be calculated to obtain the distance between two intervals, and then the moving direction and speed can be obtained.

[0061] S8: Store the calculated coordinate results in the server database.

[0062] S9: The specific location of the vehicles whose positions have been acquired in the parking lot can be viewed through the parking lot management platform, laying the foundation for providing convenient services in the future.

[0063] The calculation of triangulation positioning of the target is as follows: Where d is the calculated distance (unit: meter), RSSI is the received signal strength (unit: dB), Si is the signal strength when the OBU and RSU are separated by 1 meter, N is the environmental attenuation factor of the signal strength, and i = 1, 2, 3.

[0064]

[0065] By using the least squares method, the coordinate X of the positioning point can be obtained:

[0066] X=(A T A) -1 A T b

[0067]

[0068] Some solutions propose a V2X-based parking lot positioning device, which includes: Figure 4 The smart parking lot shown is provided with a plurality of RSUs distributed at different locations in the parking lot and a platform end communicating with each RSU, and the location information of each of the RSUs is stored in the platform end.

[0069] Some solutions also propose a V2X-based parking lot active positioning system, such as Figure 5 , comprising at least one processor; and a memory storing instructions, which, when executed by at least one processor, implement the steps of any of the above-mentioned schemes.

[0070] The embodiments and functional operations of the subject matter described in this specification may be implemented in: digital electronic circuits, tangibly implemented computer software or firmware, computer hardware, including the structures disclosed in this specification and their structural equivalents, or a combination of more than one of the above. The embodiments of the subject matter described in this specification may be implemented as one or more computer programs, that is, one or more modules of computer program instructions encoded on one or more tangible non-transitory program carriers, for execution by a data processing device or to control the operation of the data processing device. Alternatively or in addition, the program instructions may be encoded on an artificially generated propagating signal, such as a machine-generated electrical, optical or electromagnetic signal, which is generated as encoded information for transmission to an appropriate receiver device executed by the data processing device. The computer storage medium may be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or a combination of one or more of the above devices.

[0071] A computer program (which may also be referred to or described as a program, software, software application, module, software module, script or code) may be written in any form of programming language, including compiled or interpreted languages ​​or declarative or procedural languages, and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including, as examples: semiconductor memory devices, such as EPROM, EEPROM and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by or incorporated into a special purpose logic circuit.

[0072] A computer may interact with a user by sending documents to and receiving documents from a device used by the user; for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser.

[0073] Although this specification contains many specific implementation details, these should not be interpreted as limitations on the scope of any invention or the scope of what can be claimed, but rather as an illustration of features that can concretize a particular embodiment of a particular invention. The specific features described in this specification in the context of independent embodiments can also be implemented in combination with a single embodiment. Conversely, the various features described in the context of a single embodiment can also be implemented independently in multiple embodiments, or in any suitable sub-combination. In addition, although the features can be described above as a combination effect and even initially required, one or more features from the required combination can be removed from the combination in some cases, and the required combination can be turned to a sub-combination or a variation of the sub-combination.

[0074] Specific implementations of the subject matter have been described. Other implementations are within the scope of the following claims. For example, the activities recited in the claims can be performed in a different order and still achieve the desired results. As an example, the processes described in the accompanying drawings do not necessarily require the specific order or sequential order shown in order to achieve the desired results. In certain implementations, multitasking and parallel processing may be advantageous.

Claims

1. A parking lot active positioning method based on V2X, characterized in that: The following steps are included to locate the target vehicle through the RSU in the parking lot: Each RSU receives a positioning request initiated by the platform; Each RSU broadcasts the positioning request to the target vehicle in the parking lot; Multiple RSUs in the parking lot receive the vehicle broadcast of the OBU of the target vehicle in the parking lot, parse the vehicle identification number and vehicle broadcast signal strength therein, and upload them to the platform end; At least three different RSUs upload their resolved vehicle identification numbers and vehicle broadcast signal strengths to the platform end for calculating the current positioning point coordinates and / or moving speed of the target vehicle.

2. The method according to claim 1, characterized in that The platform side calculates the current positioning point coordinates of the target vehicle specifically including the following steps: S1 obtains the location coordinates of the three RSUs in the parking lot; S2 calculates the distances d1, d2, and d3 between the target vehicle and the three RSUs according to formula (1): In the formula (1), i=1, 2, 3, d1 is the distance between the target vehicle and the first RSU, d2 is the distance between the target vehicle and the second RSU, and d3 is the distance between the target vehicle and the third RSU; RSSI is the vehicle broadcast signal strength, RSSI1 is the signal strength of the vehicle broadcast received by the first RSU, RSSI2 is the signal strength of the vehicle broadcast received by the second RSU, RSSI3 is the signal strength of the vehicle broadcast received by the third RSU, S1 is the signal strength of the OBU and the first RSU at every 1 meter interval, S2 is the signal strength of the OBU and the second RSU at every 1 meter interval, S3 is the signal strength of the OBU and the third RSU at every 1 meter interval, and N is the environmental attenuation factor of the signal strength; S3 calculates the current positioning point coordinates of the target vehicle by using the least squares method.

3. The method according to claim 2, characterized in that S3 specifically calculates the current positioning point coordinates of the target vehicle according to formula (2-4): X=(A T A) -1 A T b (2) In the above formula (2-4), X represents the current positioning point coordinates of the target vehicle, (xj, yj) is the site coordinates of the RSU in the parking lot that communicates with the OBU of the target vehicle, there are n RSUs in the parking lot that currently communicate with the OBU of the target vehicle, dj is the distance between the target vehicle and the RSU calculated according to formula (1); j = 1, 2, ..., n.

4. The method according to claim 3, characterized in that The platform side calculates the moving speed of the target vehicle specifically including the following steps: calculating the moving distance L of the target vehicle within the time interval t through the positioning point coordinates of the target vehicle at two time points, and taking the quotient of the moving distance L of the target vehicle and the time interval t as the moving speed of the target vehicle.

5. The method according to claim 4, characterized in that The following steps are also included: The platform end saves the calculated current positioning point coordinates and moving speed of the target vehicle to a database, and the platform end checks the specific position of the vehicle whose position has been acquired in the parking lot.

6. The method according to claim 1, characterized in that The following steps are also included: The platform marks the vehicle to be located as a target vehicle and sends the positioning request to all RSU devices in the parking lot. The positioning request includes the vehicle identification number of the target vehicle, the current time, the agreed positioning time, and the positioning frequency.

7. The method according to claim 1, characterized in that The positioning request is encapsulated in BSM format.

8. The method according to claim 7, characterized in that The OBU of the target vehicle parses the positioning request broadcast after receiving it. When it is parsed as a positioning request, the vehicle positioning authority setting is accessed. If positioning is not allowed according to the vehicle positioning authority, the positioning request is rejected and the first feedback is encapsulated in BSM format. Otherwise, the vehicle identification number of the target vehicle is encapsulated in BSM format as the second feedback, and the first or second feedback is broadcast to all RSUs in the parking lot.

9. A parking lot positioning device according to the V2X-based parking lot active positioning method according to claim 1, characterized in that: The device comprises a plurality of RSUs distributed in a parking lot and a platform end communicating with each RSU, wherein the location information of each RSU is stored in the platform end.

10. A parking lot active positioning system based on V2X, characterized in that: The system comprises at least one processor; and a memory storing instructions, which, when executed by the at least one processor, implement the steps of the method according to any one of claims 1 to 8.

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