Positioning method and device in GNSS signal-free area

Abstract

The application relates to a positioning method and device in a GNSS signal-free area. When GNSS signals cannot be received, image information around a vehicle is acquired in real time based on a vehicle-mounted camera, feature points in the image information around the vehicle are identified, and the feature points at least include lanes and signs. Distances between the vehicle and the feature points are measured, absolute coordinates of the feature points in a world coordinate system can be acquired according to a high-precision map, and the absolute coordinates of the feature points in the world coordinate system are used to perform coordinate system conversion on a relative positioning result according to the distances between the vehicle and the feature points, so that absolute coordinates of the vehicle in the world coordinate system are calculated, and vehicle positioning in a GNSS signal-free area is realized.

Description

Technical Field

[0001] This application relates to the field of intelligent transportation technology, and in particular to a positioning method and device in areas without GNSS signals. Background Technology

[0002] Global Navigation Satellite System (GNSS) is a collective term for several major navigation systems, including GPS, GLONASS, Galileo, and BeiDou. It is a space-based radio navigation and positioning system that provides users with all-weather 3D coordinates, velocity, and time information from any location on the Earth's surface or in near-Earth space. Currently, vehicle positioning primarily relies on the Global Positioning System (GPS). Vehicle positioning is a key supporting technology for inter-vehicle information interaction in intelligent transportation systems. Real-time and accurate positioning and communication of moving vehicles are crucial prerequisites for realizing intelligent transportation systems. Although various algorithms based on GNSS positioning signals have been proposed to improve positioning accuracy, such as ZigBee wireless sensor network positioning and dead reckoning positioning, these methods cannot accurately locate vehicles in areas where GNSS signals are weak or completely lost. Summary of the Invention

[0003] To at least partially overcome the problem in related technologies that vehicles cannot be accurately located in areas with weak or completely lost GNSS signals, this application provides a positioning method and device in areas without GNSS signals.

[0004] The proposed solution is as follows:

[0005] According to a first aspect of the embodiments of this application, a positioning method in an area without GNSS signals is provided, comprising:

[0006] When GNSS signals cannot be received, real-time image information of the vehicle's surroundings is acquired based on the vehicle-mounted camera.

[0007] Identify feature points in image information surrounding the vehicle; the feature points include at least: lanes and signs;

[0008] Measure the distance between the vehicle and the feature point;

[0009] Obtain the absolute coordinates of the feature point in the world coordinate system;

[0010] The absolute coordinates of the vehicle in the world coordinate system are calculated based on the distance between the vehicle and the feature point and the absolute coordinates of the feature point in the world coordinate system.

[0011] Preferably, in one possible implementation of this application, measuring the distance between the vehicle and the feature point specifically includes:

[0012] When three signs are identified in the image information around the current vehicle, the distance from the vehicle to each sign is measured.

[0013] Preferably, in one possible implementation of this application, obtaining the absolute coordinates of the feature point in the world coordinate system specifically includes:

[0014] When GNSS signals can be received, high-precision map data of the vehicle's current location can be acquired in real time;

[0015] When the system transitions from being able to receive GNSS signals to being unable to receive GNSS signals, the absolute coordinates of the feature points in the world coordinate system are obtained based on the high-precision map data of the vehicle's current location.

[0016] Preferably, in one feasible implementation of this application, calculating the absolute coordinates of the vehicle in the world coordinate system specifically includes:

[0017] A lane reference coordinate system is established based on the lane, and the reference coordinates of each sign in the lane reference coordinate system are calculated.

[0018] Draw a circle in the lane reference coordinate system with the reference coordinates of each sign as the center and the distance from the vehicle to each sign as the radius;

[0019] Calculate the reference coordinates of the intersection point of the three circles in the lane reference coordinate system, and use the reference coordinates of the intersection point of the three circles as the reference coordinates of the vehicle in the lane reference coordinate system;

[0020] Calculate the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle;

[0021] Based on the absolute coordinates of each sign and the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle, the absolute coordinates of the vehicle in the world coordinate system are obtained.

[0022] Preferably, in one possible implementation of this application, it further includes:

[0023] When GNSS signals can be received, the absolute coordinates of the vehicle in the world coordinate system are obtained based on the BeiDou positioning module.

[0024] According to a second aspect of the embodiments of this application, a positioning device for areas without GNSS signals is provided, comprising:

[0025] Visual perception and recognition module and fusion positioning module;

[0026] The visual perception and recognition module includes: a detection module, a ranging module, and a vision controller; the detection module includes at least: an in-vehicle camera.

[0027] The fusion positioning module includes: a fusion positioning controller;

[0028] The vision controller and the fusion positioning controller are communicatively connected;

[0029] The detection module is used to acquire image information of the vehicle's surroundings in real time when GNSS signals cannot be received; and to identify feature points in the image information of the vehicle's surroundings; the feature points include at least: lanes and signs;

[0030] The ranging module is used to measure the distance between the vehicle and the feature point;

[0031] The vision controller sends the distance between the vehicle and the feature point to the fusion positioning module;

[0032] The fusion positioning module is used to obtain the absolute coordinates of the feature point in the world coordinate system; and to calculate the absolute coordinates of the vehicle in the world coordinate system based on the distance between the vehicle and the feature point and the absolute coordinates of the feature point in the world coordinate system.

[0033] Preferably, in one possible implementation of this application, the vision controller and the fusion positioning controller are connected via serial port or Ethernet protocol communication.

[0034] Preferably, in one possible implementation of this application, it further includes: a BeiDou positioning module;

[0035] The BeiDou positioning module is used to obtain the absolute coordinates of the vehicle in the world coordinate system when GNSS signals can be received.

[0036] The technical solution provided in this application can include the following beneficial effects: The positioning method in areas without GNSS signals in this application, when no GNSS signal can be received, acquires image information of the vehicle's surroundings in real time based on an onboard camera, identifies feature points in the image information of the vehicle's surroundings, and the feature points include at least: lanes and signs. Then, the distance between the vehicle and the feature points is measured, and the absolute coordinates of the feature points in the world coordinate system can be obtained according to a high-precision map. Based on the distance between the vehicle and the feature points and the absolute coordinates of the feature points in the world coordinate system, the relative positioning result is transformed to calculate the absolute coordinates of the vehicle in the world coordinate system, thereby realizing vehicle positioning in the absence of GNSS signals.

[0037] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0039] Figure 1 This is a flowchart illustrating a positioning method in an area without GNSS signals, provided in one embodiment of this application.

[0040] Figure 2 This is a flowchart illustrating the calculation of a vehicle's absolute coordinates in the world coordinate system in a positioning method for areas without GNSS signals, provided in another embodiment of this application.

[0041] Figure 3 This is a schematic diagram of the structure of a positioning device in an area without GNSS signal, provided in one embodiment of this application;

[0042] Figure 4 This is a schematic diagram of the structure of a positioning device in an area without GNSS signals, provided in another embodiment of this application.

[0043] Reference numerals: Visual perception and recognition module-21; Detection module-211; Ranging module-212; Visual controller-213; Fusion positioning module-22; Fusion positioning controller-221; High-precision map module-23; Beidou positioning module-24. Detailed Implementation

[0044] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0045] A positioning method in an area without GNSS signals, comprising:

[0046] S11: When GNSS signals cannot be received, real-time image information of the vehicle's surroundings is acquired based on the vehicle-mounted camera;

[0047] Global Navigation Satellite System (GNSS) is a collective term for several major navigation systems, including GPS, GLONASS, Galileo, and BeiDou. It is a space-based radio navigation and positioning system that can provide users with all-weather 3D coordinates, velocity, and time information at any location on the Earth's surface or in near-Earth space. GNSS signals are global navigation satellite signals.

[0048] In this embodiment, an onboard camera is configured on the vehicle to acquire real-time image information of the vehicle's surroundings when GNSS signals cannot be received.

[0049] Preferably, the vehicle-mounted camera is mounted at the front of the vehicle to acquire 120° image information from the front of the vehicle.

[0050] S12: Identify feature points in image information surrounding the vehicle; feature points include at least: lanes and signs;

[0051] Lanes and signs are relatively obvious map features. Signs include various directional signs on the lanes.

[0052] S13: Measure the distance between the vehicle and the feature point;

[0053] Specifically, this includes: when three signs are identified in the image information around the current vehicle, measuring the distance from the vehicle to each sign.

[0054] S14: Obtain the absolute coordinates of the feature point in the world coordinate system;

[0055] Specifically, this includes: acquiring high-precision map data in real time based on the vehicle's current location when GNSS signals can be received;

[0056] When the system transitions from being able to receive GNSS signals to being unable to receive GNSS signals, the absolute coordinates of the feature points in the world coordinate system are obtained based on the high-precision map data acquired at the current vehicle location.

[0057] Since vehicles can receive GNSS signals for positioning under normal circumstances, when a vehicle can receive GNSS signals, high-precision map data of the vehicle's current positioning is acquired in real time. The high-precision map data includes the precise absolute coordinates of each lane and sign in the world coordinate system.

[0058] S15: Calculate the absolute coordinates of the vehicle in the world coordinate system based on the distance between the vehicle and the feature point and the absolute coordinates of the feature point in the world coordinate system.

[0059] Specifically, it includes:

[0060] S151: Establish a lane reference coordinate system based on the lane, and calculate the reference coordinates of each sign in the lane reference coordinate system;

[0061] S152: Draw a circle in the lane reference coordinate system with the reference coordinates of each sign as the center and the distance from the vehicle to each sign as the radius;

[0062] S153: Calculate the reference coordinates of the intersection point of the three circles in the lane reference coordinate system, and use the reference coordinates of the intersection point of the three circles as the reference coordinates of the vehicle in the lane reference coordinate system;

[0063] S154: Calculate the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle;

[0064] S155: Based on the absolute coordinates of each sign, the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle, the absolute coordinates of the vehicle in the world coordinate system are obtained.

[0065] In step S13, when three signs are identified from the image information surrounding the current vehicle, the distance from the vehicle to each sign is measured. Then, a circle is drawn in the lane reference coordinate system with the reference coordinates of each sign as the center and the distance from the vehicle to each sign as the radius. Since the vehicle-mounted camera is positioned in front of the vehicle, it acquires image information from the front of the vehicle. All three signs identified in the image information are located in front of the vehicle. Therefore, the three circles drawn in the lane reference coordinate system with the reference coordinates of each sign as the center and the distance from the vehicle to each sign as the radius share the vehicle as their common intersection point.

[0066] A lane reference coordinate system can be established based on the lane, and the reference coordinates of each sign in the lane reference coordinate system can be calculated. The reference coordinates of the intersection point of the three circles in the lane reference coordinate system can also be calculated, and these reference coordinates can be used as the reference coordinates of the vehicle in the lane reference coordinate system. The relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle can be calculated, and the relative relationship can be transformed to obtain the absolute coordinates of the vehicle in the world coordinate system.

[0067] Preferably, in this embodiment, when GNSS signals can be received, the absolute coordinates of the vehicle in the world coordinate system can be obtained based on the Beidou positioning module 24 as auxiliary positioning.

[0068] The positioning method in this embodiment for areas without GNSS signals acquires real-time image information of the vehicle's surroundings using an onboard camera when no GNSS signal is received. Feature points are identified within these images, including at least lanes and signs. The distance between the vehicle and these feature points is then measured. The absolute coordinates of the feature points in the world coordinate system are obtained from a high-precision map. Based on the distance between the vehicle and the feature points, and their absolute coordinates in the world coordinate system, the relative positioning result is transformed to calculate the vehicle's absolute coordinates in the world coordinate system, thus achieving vehicle positioning in the absence of GNSS signals.

[0069] A positioning device for areas without GNSS signals, comprising:

[0070] Visual perception and recognition module 21 and fusion positioning module 22;

[0071] The visual perception and recognition module 21 includes: a detection module 211, a ranging module 212, and a vision controller 213; the detection module 211 includes at least: an in-vehicle camera;

[0072] The fusion positioning module 22 includes: a fusion positioning controller 221;

[0073] The vision controller 213 and the fusion positioning controller 221 are connected in communication.

[0074] The detection module 211 is used to acquire image information of the vehicle's surroundings in real time when GNSS signals cannot be received; and to identify feature points in the image information of the vehicle's surroundings; the feature points include at least: lanes and signs;

[0075] The ranging module 212 is used to measure the distance between the vehicle and the feature point;

[0076] The vision controller 213 sends the distance between the vehicle and the feature point to the fusion positioning module 22;

[0077] The fusion positioning module 22 is used to obtain the absolute coordinates of the feature points in the world coordinate system; and to calculate the absolute coordinates of the vehicle in the world coordinate system based on the distance between the vehicle and the feature points and the absolute coordinates of the feature points in the world coordinate system.

[0078] In some embodiments, the positioning device in areas without GNSS signals is also equipped with a high-precision map module 23, which can acquire high-precision map data of the vehicle's current positioning in real time when the vehicle can receive GNSS signals. The high-precision map data includes the precise absolute coordinates of each lane and sign in the world coordinate system.

[0079] In some embodiments, the positioning device in areas without GNSS signals, the vision controller 213 and the fusion positioning controller 221 are connected via serial port or Ethernet protocol.

[0080] The positioning device in some embodiments for areas without GNSS signals also includes: a BeiDou positioning module 24;

[0081] The Beidou positioning module 24 is used to obtain the absolute coordinates of the vehicle in the world coordinate system when GNSS signals can be received.

[0082] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0083] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0084] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0085] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0086] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0087] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0088] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0089] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0090] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A positioning method in an area without GNSS signals, characterized in that, include: When GNSS signals cannot be received, real-time image information of the vehicle's surroundings is acquired based on the vehicle-mounted camera. Identify feature points in the image information surrounding the vehicle; The feature points include at least: lanes and signs; Measure the distance between the vehicle and the feature point; Obtain the absolute coordinates of the feature point in the world coordinate system; Calculate the absolute coordinates of the vehicle in the world coordinate system based on the distance between the vehicle and the feature point and the absolute coordinates of the feature point in the world coordinate system. The measurement of the distance between the vehicle and the feature point specifically includes: When three signs are identified in the image information around the current vehicle, the distance from the vehicle to each sign is measured; Obtaining the absolute coordinates of the feature point in the world coordinate system specifically includes: When GNSS signals can be received, high-precision map data of the vehicle's current location can be acquired in real time; When the system transitions from being able to receive GNSS signals to being unable to receive GNSS signals, the absolute coordinates of the feature points in the world coordinate system are obtained based on the high-precision map data of the vehicle's current location. The calculation of the absolute coordinates of the vehicle in the world coordinate system specifically includes: A lane reference coordinate system is established based on the lane, and the reference coordinates of each sign in the lane reference coordinate system are calculated. Draw a circle in the lane reference coordinate system with the reference coordinates of each sign as the center and the distance from the vehicle to each sign as the radius; Calculate the reference coordinates of the intersection point of the three circles in the lane reference coordinate system, and use the reference coordinates of the intersection point of the three circles as the reference coordinates of the vehicle in the lane reference coordinate system; Calculate the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle; Based on the absolute coordinates of each sign, the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle, the absolute coordinates of the vehicle in the world coordinate system are obtained. When GNSS signals can be received, the absolute coordinates of the vehicle in the world coordinate system are obtained based on the BeiDou positioning module.

2. A positioning device for areas without GNSS signals, characterized in that, include: Visual perception and recognition module and fusion positioning module; The visual perception and recognition module includes: a detection module, a ranging module, and a vision controller; the detection module includes at least: an in-vehicle camera. The fusion positioning module includes: a fusion positioning controller; The vision controller and the fusion positioning controller are communicatively connected; The detection module is used to acquire image information of the vehicle's surroundings in real time when GNSS signals cannot be received; and to identify feature points in the image information of the vehicle's surroundings; the feature points include at least: lanes and signs; The ranging module is used to measure the distance between the vehicle and the feature point; The vision controller sends the distance between the vehicle and the feature point to the fusion positioning module; The fusion positioning module is used to obtain the absolute coordinates of the feature point in the world coordinate system; and to calculate the absolute coordinates of the vehicle in the world coordinate system based on the distance between the vehicle and the feature point and the absolute coordinates of the feature point in the world coordinate system. The measurement of the distance between the vehicle and the feature point specifically includes: When three signs are identified in the image information around the current vehicle, the distance from the vehicle to each sign is measured; Obtaining the absolute coordinates of the feature point in the world coordinate system specifically includes: When GNSS signals can be received, high-precision map data of the vehicle's current location can be acquired in real time; When the system transitions from being able to receive GNSS signals to being unable to receive GNSS signals, the absolute coordinates of the feature points in the world coordinate system are obtained based on the high-precision map data of the vehicle's current location. The calculation of the absolute coordinates of the vehicle in the world coordinate system specifically includes: A lane reference coordinate system is established based on the lane, and the reference coordinates of each sign in the lane reference coordinate system are calculated. Draw a circle in the lane reference coordinate system with the reference coordinates of each sign as the center and the distance from the vehicle to each sign as the radius; Calculate the reference coordinates of the intersection point of the three circles in the lane reference coordinate system, and use the reference coordinates of the intersection point of the three circles as the reference coordinates of the vehicle in the lane reference coordinate system; Calculate the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle; Based on the absolute coordinates of each sign, the relative relationship between the reference coordinates of each sign and the reference coordinates of the vehicle, the absolute coordinates of the vehicle in the world coordinate system are obtained. When GNSS signals can be received, the absolute coordinates of the vehicle in the world coordinate system are obtained based on the BeiDou positioning module.

3. The positioning device according to claim 2, characterized in that, The vision controller and the fusion positioning controller are connected via serial port or Ethernet protocol.

4. The positioning device according to claim 2, characterized in that, Also includes: Beidou positioning module; The BeiDou positioning module is used to obtain the absolute coordinates of the vehicle in the world coordinate system when GNSS signals can be received.

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