TWI563281B - - Google Patents

Abstract

This invention discloses a positioning method and apparatus. The method includes: identifying a positioning marker in a real-time acquired image; determining the relative position of a mobile terminal and the positioning marker; acquiring the geographical location of the positioning marker; and determining the current geographical location of the mobile terminal based on the geographical location of the positioning marker and the relative position of the mobile terminal and the positioning marker. When the GPS positioning system is unavailable, the method provided by this invention can be used to locate the mobile terminal. Because the positioning marker is pre-set, its precise location can be obtained, and the error of the calculated relative position between the mobile terminal and the positioning marker is much smaller than the navigation deviation of the GPS positioning system. Therefore, the accuracy of the geographical location of the mobile terminal determined by the method provided in this embodiment of the invention is far higher than the positioning accuracy obtained by the GPS positioning system.

Description

A positioning method and device

This invention belongs to the field of positioning technology, and in particular relates to a positioning method and device.

Currently, the Global Positioning System (GPS) is the primary positioning system used for navigation. However, GPS positioning accuracy is relatively low, typically around 10 meters (m) for horizontal positioning, and therefore cannot distinguish between lanes. In traffic navigation, the inability to differentiate between lanes can lead to misdirection. For example, the correct navigation route might merge from the secondary road onto the main road, but misidentification of the main road and secondary road can result in misdirection. In applications disseminating vehicle safety information, the inability to distinguish between lanes can lead to missed or false collision warnings and other safety-related information.

Furthermore, GPS positioning systems cannot be used to achieve location tracking in areas with weak GPS signals, such as tunnels and underground parking lots.

The purpose of this invention is to provide a positioning method and apparatus to solve the positioning problem when the GPS positioning system is unavailable and the problem of low positioning accuracy of the GPS positioning system.

The objective of this invention is achieved through the following technical solution: A positioning method, comprising: identifying a positioning marker in a real-time acquired image; determining the relative position of a mobile terminal and the positioning marker; acquiring the geographic location of the positioning marker; and determining the current geographic location of the mobile terminal based on the geographic location of the positioning marker and the relative position of the mobile terminal and the positioning marker.

When the GPS positioning system is unavailable (e.g., due to weak or no GPS signal), the method provided in this embodiment of the invention can achieve positioning of the mobile terminal. Furthermore, the method provided in this embodiment acquires images in real-time during movement and detects positioning markers using image recognition technology. By utilizing the geographic location of the positioning marker and the relative position of the mobile terminal to the positioning marker, the current geographic location of the mobile terminal can be determined. Since the positioning marker is pre-set, its precise location can be obtained, and the error in the calculated relative position between the mobile terminal and the positioning marker is far smaller than the navigation deviation of the GPS positioning system. Therefore, the accuracy of the geographical location of the mobile terminal determined by the method provided in this embodiment of the invention is far higher than the positioning accuracy obtained by the GPS positioning system.

Preferably, location markers can be identified in images acquired in real time by the image acquisition device on the mobile terminal.

Preferably, the relative position of the mobile terminal and the positioning marker can be determined based on the size information of the positioning marker in the image and the actual size information of the positioning marker.

Preferably, the actual size information of the positioning marker is obtained from the network side, or it may be pre-installed in the mobile terminal, or it may be pre-installed in the device using the positioning method provided in this embodiment of the invention, etc.

Preferably, the geographical location of the aforementioned positioning marker can be obtained as follows: Based on the relative position of the mobile terminal and the positioning marker, and the current approximate geographical location of the mobile terminal, determine the estimated position of the positioning marker; obtain the geographical location of the positioning marker closest to the estimated position as the geographical location of the positioning marker. Preferably, the current approximate geographical location of the mobile terminal is determined using dead reckoning or satellite positioning.

Preferably, obtaining the geographical location of the nearest location marker to the estimated location as the geographical location of the location marker can be implemented, but is not limited to: searching for the geographical location of the nearest location marker to the estimated location in an electronic map installed on the mobile terminal; or, reporting the estimated location of the location marker to the network side so that the network side can find the geographical location of the nearest location marker to the estimated location; receiving the geographical location of the location marker found by the network side, and using the received geographical location as the geographical location of the location marker.

Furthermore, a coarse current geographical location of the mobile terminal can be determined based on its initial position using dead reckoning algorithms. Alternatively, a satellite positioning method can also be used to determine the coarse current geographical location of the mobile terminal based on its initial position.

Specifically, the initial position of the mobile terminal can be determined using satellite positioning; alternatively, reference coordinates can be read from an electronic map installed on the mobile terminal as its initial position; or reference coordinates can be obtained from a broadcast message; or the geographical location of another identified location marker can be obtained, the relative position of the mobile terminal to that location marker can be determined, and the initial position of the mobile terminal can be determined based on the geographical location of the other location marker and its relative position.

Based on any of the above method embodiments, preferably, the positioning mark is a cross shape; or, the positioning mark is an arrow shape; or, the positioning mark is a bullseye shape.

Based on any of the above method embodiments, preferably, in the actually deployed positioning markers, the distance between two positioning markers in the direction of movement is greater than twice the initial positioning error.

Based on the same inventive concept as the method, this embodiment of the invention also provides a positioning device, comprising: a positioning marker identification module for identifying a positioning marker in a real-time acquired image; a relative position determination module for determining the relative position of a mobile terminal and the positioning marker; a positioning marker position determination module for acquiring the geographic location of the positioning marker; and a mobile terminal position determination module for determining the current geographic location of the mobile terminal based on the geographic location of the positioning marker and the relative position of the mobile terminal and the positioning marker.

When the GPS positioning system is unavailable (e.g., due to weak or no GPS signal), the device provided in this embodiment can achieve positioning of the mobile terminal. Furthermore, the device provided in this embodiment acquires images in real-time during movement and detects positioning markers using image recognition technology. By utilizing the geographic location of the positioning marker and the relative position of the mobile terminal to the positioning marker, the current geographic location of the mobile terminal can be determined. Since the positioning marker is pre-set, its precise location can be obtained, and the error in the calculated relative position between the mobile terminal and the positioning marker is far smaller than the navigation deviation of the GPS positioning system. Therefore, the accuracy of the geographical location of the mobile terminal determined by the device provided in this embodiment of the invention is far higher than the positioning accuracy obtained by a GPS positioning system.

Preferably, the location marker identification module is specifically used to identify location markers in images acquired in real time by the image acquisition device of the mobile terminal.

Preferably, the relative position determination module is specifically used to: determine the relative position of the mobile terminal and the positioning mark based on the size information of the positioning mark in the image and the actual size information of the positioning mark.

Preferably, the actual size information of the location marker is obtained from the network side, or the actual size information of the location marker is preset in the mobile terminal or the device.

Preferably, the positioning beacon location determination module is specifically used to: determine the estimated location of the positioning beacon based on the relative position between the mobile terminal and the positioning beacon, and the current approximate geographical location of the mobile terminal; and obtain the geographical location of the positioning beacon closest to the estimated location as the geographical location of the positioning beacon. Preferably, the current approximate geographical location of the mobile terminal is determined using dead reckoning or satellite positioning.

Preferably, when obtaining the geographical location of the nearest location marker to the estimated location as the geographical location of the location marker, the location marker location determination module is specifically used to: search for the geographical location of the nearest location marker to the estimated location in the electronic map installed on the mobile terminal as the geographical location of the location marker; or, report the estimated location of the location marker to the network side so that the network side can find the geographical location of the nearest location marker to the estimated location; receive the geographical location of the location marker found by the network side, and use the received geographical location as the geographical location of the location marker.

Preferably, the mobile terminal location determination module is also used to: determine the current approximate geographical location of the mobile terminal based on its initial location using a dead reckoning algorithm; or, determine the current approximate geographical location of the mobile terminal based on its initial location using a satellite positioning method.

Preferably, the system further includes an initial location determination module for: determining the initial location of the mobile terminal using satellite positioning; or, reading reference coordinates from an electronic map installed on the mobile terminal as the initial location of the mobile terminal; or, obtaining reference coordinates from a broadcast message as the initial location of the mobile terminal; or, obtaining the geographical location of another identified location marker, determining the relative position of the mobile terminal to the other location marker, and determining the initial location of the mobile terminal based on the geographical location of the other location marker and the relative position to the other location marker.

Based on any of the above device embodiments, preferably, the positioning mark is a cross shape; or, the positioning mark is an arrow shape; or, the positioning mark is a bullseye shape.

Based on any of the above device embodiments, preferably, in the actually deployed positioning markers, the distance between two positioning markers in the direction of movement is greater than twice the initial positioning error.

Based on the same inventive concept as the method, this embodiment of the invention also provides a positioning device, including a data transmission interface and a processor. The data transmission interface is configured to receive images acquired in real time by an image acquisition device mounted on a mobile terminal. The processor is configured to: identify a positioning marker in the acquired images; determine the relative position of the mobile terminal to the positioning marker; acquire the geographic location of the positioning marker; and determine the current geographic location of the mobile terminal based on the geographic location of the positioning marker and the relative position of the mobile terminal to the positioning marker.

When the GPS positioning system is unavailable (e.g., due to weak or no GPS signal), the device provided in this embodiment can achieve mobile terminal positioning. Furthermore, the device provided in this embodiment acquires images in real-time during movement and detects positioning markers using image recognition technology. By utilizing the geographic location of the positioning marker and the relative position of the mobile terminal to the positioning marker, the current geographic location of the mobile terminal can be determined. Since the positioning marker is pre-set, its precise location can be obtained, and the calculated error in the relative position between the mobile terminal and the positioning marker is far smaller than the navigation deviation of the GPS positioning system. Therefore, the accuracy of the geographical location of the mobile terminal determined by the device provided in this embodiment of the invention is far higher than the positioning accuracy obtained by a GPS positioning system.

Based on the same inventive concept as the method, this embodiment of the invention also provides a positioning device, comprising: a data transmission interface for receiving images acquired in real time by an image acquisition device mounted on a mobile terminal; and a processor for identifying a positioning marker in the images acquired in real time by the data transmission interface, determining the relative position of the mobile terminal and the positioning marker, acquiring the geographical location of the positioning marker, and determining the current geographical location of the mobile terminal based on the geographical location of the positioning marker and the relative position of the mobile terminal and the positioning marker.

Preferably, the processor is specifically used to: determine the relative position of the mobile terminal and the positioning marker based on the size information of the positioning marker in the image and the actual size information of the positioning marker.

Preferably, the processor is specifically configured to: determine the estimated location of the positioning marker based on the relative position of the mobile terminal and the positioning marker, and the current approximate geographical location of the mobile terminal, wherein the current approximate geographical location of the mobile terminal is determined by dead reckoning or satellite positioning; and obtain the geographical location of the positioning marker closest to the estimated location as the geographical location of the positioning marker.

100~130... Steps

601...Location Identification Module

602...Relative Position Determination Module

603...Location Identification and Determination Module

604... Mobile Terminal Location Determination Module

700... Data Transfer Interface

701 Processor

Figure 1 is a flowchart of a method provided by an embodiment of the present invention; Figures 2A-2C are schematic diagrams of positioning markers provided by an embodiment of the present invention; Figure 3 is a schematic diagram of the imaging principle of the image acquisition device in an embodiment of the present invention; Figure 4 is a schematic diagram of the relative position calculation principle in an embodiment of the present invention; Figure 5 is a schematic diagram of the distribution of positioning markers provided by an embodiment of the present invention; Figure 6 is a schematic diagram of an apparatus provided by an embodiment of the present invention; Figure 7 is a schematic diagram of another apparatus provided by an embodiment of the present invention.

The technical solution provided by the embodiments of this invention will be described in detail below with reference to the accompanying drawings.

The positioning method provided by this embodiment of the invention is shown in Figure 1, and specifically includes the following operations:

Step 100: Identify location markers in the instantly acquired images.

In this embodiment of the invention, the mobile terminal may be, but is not limited to, in-vehicle modules on vehicles or other means of transportation, navigation devices, smartphones, handheld computers, etc.

Preferably, the image captured in real-time can be either a photograph or a frame from a video.

Preferably, the images are acquired by the image acquisition device on the mobile terminal. The location marker is placed within the mobile terminal's movement range so that it can be acquired by the mobile terminal's image acquisition device. Taking a land-based mobile terminal as an example, the location marker can be drawn on the road surface, on roadside signs, on land bridges, etc. The location marker is required to be easily identifiable. The shape of the location marker can be a regular shape, such as an equilateral triangle, rectangle, etc., or it can be an irregular shape. For example, the location marker can be a cross shape as shown in Figure 2A, an arrow shape as shown in Figure 2B, a bullseye shape as shown in Figure 2C, etc. Of course, as long as the requirement of easy identification is met, existing traffic signs, road signs, buildings, and other objects can be used as location markers. For example, the cross shape shown in Figure 2A can have one segment placed in the north-south direction and the other in the east-west direction, distinguished by dashed lines, solid lines, different colors, etc., thus serving as both a location marker and a direction indicator. The arrow shape shown in Figure 2B can also be used to indicate driving direction while serving as a location marker. The bullseye shape shown in Figure 2C can also be used to indicate the current location as a reference point while serving as a location marker.

Step 110: Determine the relative position of the mobile terminal and the positioning marker.

Step 120: Obtain the geographic location of the location marker.

Step 130: Determine the current geographical location of the mobile terminal based on the geographical location of the location marker and the relative position of the mobile terminal to the location marker.

When the GPS positioning system is unavailable (e.g., due to weak or no GPS signal), the method provided in this embodiment of the invention can be used to locate the mobile terminal. Furthermore, the method provided in this embodiment acquires images in real-time during movement and detects positioning markers using image recognition technology. By utilizing the geographic location of the positioning marker and the relative position of the mobile terminal to the positioning marker, the current geographic location of the mobile terminal can be determined. Since the positioning marker is pre-set, its precise location can be obtained, and the error in the calculated relative position between the mobile terminal and the positioning marker is far smaller than the navigation deviation of the GPS positioning system. Therefore, the accuracy of the geographical location of the mobile terminal determined by the method provided in this embodiment of the invention is far higher than the positioning accuracy obtained by the GPS positioning system.

The following sections provide a detailed explanation of the possible implementation methods for each of the above steps.

In step 100, location markers can be identified in images acquired in real-time by the image acquisition device on the mobile terminal. This image acquisition device can be a camera module built into the mobile terminal, a camera connected to the mobile terminal, a camera built into the mobile terminal, or a camera connected to the mobile terminal, etc. Image analysis technology is used to identify location markers in the acquired images. For example, based on the location markers, sample training is performed to obtain a model of the location markers. This model is then used to match images to identify whether any images contain the location markers.

In step 110, the relative position of the mobile terminal and the positioning marker is determined based on the size information of the positioning marker in the image and the actual size information of the positioning marker.

The actual size information of the positioning marker and other parameters used to determine the relative position can be preset in the mobile terminal or the device used for positioning using the method provided in this embodiment of the invention. Specifically, they can be preset in the database of an electronic map installed in the mobile terminal. The actual size information of the positioning marker and other parameters used to determine the relative position can also be obtained from the network side. The actual size information of the positioning marker and other parameters used to determine the relative position can also be marked on the positioning marker (e.g., text information, barcode information, QR code information, etc.), and the actual size information of the positioning marker and other parameters used to determine the relative position can be extracted through image analysis. For example, barcodes or QR codes can be marked on the location markers. These barcodes or QR codes can be obtained by scanning an image. Based on the barcode or QR code information, a specific server can be accessed to retrieve the actual dimensions of the location marker, and other parameters used to determine its relative position. The actual dimensions of the location marker and other parameters used to determine its relative position can be implemented in any way that a person skilled in the art could conceive of without creative effort; this invention does not limit the scope of the embodiments.

Since multiple location markers are typically deployed within a certain range, and these markers may differ in size, determining the relative distance between the identified location marker and the mobile terminal requires first identifying which location marker was identified before its actual size and other information can be obtained. This can be achieved, but is not limited to, using existing positioning methods such as dead reckoning or satellite positioning to determine the mobile terminal's current approximate geographical location. Based on this approximate geographical location and the image acquisition equipment's shooting direction, the location marker closest to this approximate geographical location along the shooting direction can be identified as the identified location marker, and its actual size and other information can then be obtained. Of course, the methods for determining the identified location markers are not limited to this; any method that can be conceived by those skilled in the art without creative effort can be applied to embodiments of this invention.

Specifically, it's based on the imaging principle of the image acquisition equipment, specifically the pinhole imaging principle, to determine the relative position of the moving terminal and the positioning mark. The imaging principle of the image acquisition equipment is shown in Figure 3. When the perpendicular line from the pinhole to the photosensitive plate passes through the center point of line segment L and is perpendicular to line segment L (position 1), the distances from the two endpoints of the image formed by line segment L on the photosensitive plate to the center point are equal. However, when the perpendicular line from the pinhole to the photosensitive plate forms an angle with the straight line passing through the center point of line segment L and perpendicular to line segment L (position 2), the distances from the two endpoints of the image formed by straight line L on the photosensitive plate to the center are unequal.

Based on the imaging principle shown in Figure 3, once information such as the actual size of the positioning marker, the size of the image formed by the positioning marker on the photosensitive plate, and the distance from the camera aperture to the photosensitive plate is known, the relative position between the image acquisition device and the positioning marker can be calculated. This relative position is the relative position between the mobile terminal and the positioning marker.

Taking the imaging principle shown in Figure 3 as an example, assuming the perpendicular line from the pinhole to the photosensitive plate and line segment L are on the same plane, the calculation principle of their relative positions is shown in Figure 4. Where _L1,2 , _L2,3 , and _L4,5 are known quantities, and _L5,6 , _L6,7 , and _L7,8 can be measured after identifying the image of the positioning mark. α6 , α7 , and α8 can be calculated using the following formula: α8 = π - arctg( _L4,5 / _L5,6 )

α 7= π -arctg(L _4,5 /L _5,7 )

α 6= π -arctg(L _4,5 /L _5,8 )

Based on the following formula, _L2,4 and α4 can be obtained, determining the relative position of the image acquisition device to the center point of line segment L in the plane. When the line segment becomes a two-dimensional planar figure, the spatial position of the image acquisition device can be determined.

L _2,4 =L _2,3 /[(ctg α 3+ctg α 4)‧sin α 4]

L _2,4 =L _1,2 /[(ctg α 5-ctg α 4)‧sin α 4]

Since L _2,3 =L _1,2 , ctgα5-ctgα4=ctgα3+ctgα4

α3 + α4 = α6 + α7

α3 + α5 = α6 + α8

It should be noted that the above description of the calculation principle for relative position assumes that the perpendicular line from the pinhole to the photosensitive plate and line segment L are on the same plane. When the perpendicular line from the pinhole to the photosensitive plate and line segment L are not on the same plane, the relative position can still be calculated based on the above formula. This embodiment of the invention does not elaborate on the specific calculation method.

In step 120, there are several ways to obtain the geographical location of the location marker. For example, the location marker can be marked with its geographical location information (e.g., text information, barcode information, QR code information, etc.), and the geographical location information can be extracted through image analysis to obtain the location of the location marker. Another example is to mark the location marker with barcode or QR code information, obtain the barcode or QR code information through image scanning, and then retrieve the geographical location of the location marker from a specific server based on the barcode or QR code information. And so on. This invention provides a preferred implementation method: Based on the relative position of the mobile terminal and the positioning marker, and the current approximate geographical location of the mobile terminal, the estimated position of the positioning marker is determined; the geographical location of the positioning marker closest to the estimated position is obtained as the actual geographical location of the current positioning marker. The current approximate geographical location of the mobile terminal is determined using existing positioning methods such as dead reckoning or satellite positioning.

Specifically, the estimated location of the location marker can be reported to the network side, which then finds the geographical location of the nearest location marker and receives the found location. Alternatively, the geographical location of the nearest location marker in the electronic map installed on the mobile terminal can be used as the actual location marker.

Preferably, the coarse geographical location of the mobile terminal can be continuously updated based on its initial position using a dead reckoning algorithm. Alternatively, a satellite positioning method can also be used to continuously update the coarse geographical location of the mobile terminal based on its initial position. The dead reckoning algorithm is implemented by estimating the direction of motion of the mobile terminal using a gyroscope and estimating the distance traveled using an odometer, thereby determining the trajectory of the mobile terminal. Other existing positioning methods can also be used to update the geographical location of the mobile terminal based on its initial position. Any method for updating the coarse geographical location of a mobile terminal that can be conceived by those skilled in the art without creative effort can be applied to embodiments of this invention. Because existing positioning methods yield relatively low accuracy in determining the geographical location of mobile terminals, the geographical location of mobile terminals determined by existing methods such as dead reckoning and satellite positioning is called a coarse geographical location, to distinguish it from the geographical location of mobile terminals determined by positioning markers.

By continuously updating the mobile terminal's coarse geographical location using any of the methods described above, the mobile terminal's current coarse geographical location can be determined.

Existing positioning methods (such as dead reckoning) have the advantage of low computational complexity, but the disadvantage of low positioning accuracy. The method provided in this invention combines a positioning marker-based method with existing positioning methods. Specifically, after identifying a positioning marker, the mobile terminal is accurately positioned based on the marker. Then, the existing positioning method is used to update the mobile terminal's positioning until the next positioning marker is identified. This process is repeated in a loop.

There are several ways to determine the initial location of a mobile terminal. Some examples are as follows: The initial location can be determined using satellite positioning; or, the reference coordinates can be read from an electronic map installed on the mobile terminal as its initial location; or, the reference coordinates can be obtained from a broadcast message as its initial location; or, the geographical location of another identified location marker can be obtained, the relative position of the mobile terminal to that location marker can be determined, and the initial location of the mobile terminal can be determined based on the geographical location of the other location marker and its relative position.

In this embodiment of the invention, the distance between the two actually deployed positioning markers in the direction of travel is preferably greater than twice the initial positioning error, in order to distinguish the two positioning markers. The initial positioning error can be the maximum value of the initial position error range when entering a predetermined area, the maximum value of the error range during inertial navigation, or the level positioning accuracy of the GPS positioning system, etc. As shown in Figure 5, the circle surrounding the mobile terminal A on the vehicle represents the level positioning accuracy of the GPS positioning system. Therefore, when positioning via the GPS positioning system, the determined geographical location of the mobile terminal A on the vehicle is any point within the circle. In the direction of travel, if the distance between the two positioning markers is greater than the horizontal positioning accuracy of the GPS positioning system, then when the mobile terminal A on the vehicle is at the position shown in Figure 5, only one positioning marker deployed on lane 2 will appear within the image acquisition range of the image acquisition equipment, facilitating the precise determination of the positioning marker's location.

Taking vehicle positioning in an underground parking lot or tunnel scenario as an example, positioning markers should be deployed at least at the entrance and within the underground parking lot. The distance between two positioning markers can be around 50 meters, adjusted according to actual needs. A wireless signal broadcasting device should be installed in front of the entrance of the underground parking lot or tunnel to inform the vehicle of the coordinates of the reference location, the coordinates of every positioning marker in the vicinity, the attribute information of each positioning marker (attribute information is the information needed to calculate the relative position between the positioning marker and the vehicle. Attribute information can be, but is not limited to, the shape, size, etc. of the positioning marker; any information needed to calculate the relative position between the positioning marker and the vehicle can be used as the attribute information of that positioning marker), entrance coordinates, etc. Of course, this information can also be communicated to the vehicle through existing communication systems (such as cellular communication systems, device-to-device (D2D) communication systems, etc.). Additionally, this information can be stored in an electronic map database. It should be noted that a combination of these three methods can also be used to provide the vehicle with this information. In this embodiment of the invention, "vehicle" specifically refers to a device installed on the vehicle for vehicle location tracking.

The positioning process based on the above application scenario is as follows: When a vehicle arrives at an underground parking lot or tunnel entrance, it acquires the coordinates and attribute information of each location marker in the vicinity. Additionally, it needs to acquire the coordinates of a reference location and/or the entrance coordinates. This information can be obtained from a wireless signal broadcasting device installed in front of the entrance, through a communication network, or from an electronic map database. The electronic map database can be pre-installed in the vehicle or obtained from the wireless signal broadcasting device or communication network.

The vehicle obtains its current initial position. This can be achieved, but is not limited to, through the following methods:

Method 1: Determine the initial position using satellite positioning before entering the underground parking lot or tunnel.

Method 2: Use the coordinates of the obtained reference position as the current initial position.

Method 3: Use the obtained entrance coordinates as the current initial position.

Method 4: Identify the location marker at the entrance, obtain its geographical location, determine the vehicle's relative position to the marker, and determine the vehicle's initial position based on the marker's location and the relative position.

After a vehicle enters an underground parking lot or tunnel, its approximate geographic location is updated based on its initial position using a dead reckoning algorithm. When a location marker is identified, the vehicle's relative position to that marker is measured. Based on the updated approximate geographic location and the measured relative position, the estimated location *r* of the location marker can be calculated. The geographic location of the location marker closest to *r* is then obtained. Specifically, this can be achieved by searching an electronic map. Furthermore, the geographic location of the location marker closest to *r* can be obtained by searching the coordinates of each acquired location marker. The estimated location *r* can also be sent to the network side, which will then find the geographical location of the nearest location marker to *r* and send it to the vehicle.

Once the location of the location marker is obtained, the vehicle's precise location can be deduced.

To simplify the explanation, we will still use Figure 4 as an example to illustrate the principle of deducing the precise geographical location of a vehicle.

Assuming the position of endpoint 2 (reference point, the center point of the special marker) is (x2, y2), then the relative position of the vehicle (endpoint 4) to endpoint 2 is (L2 _{, 4} and α4 ), and the position of the vehicle is (x4, y4).

x⁴ = x² + sin(α⁴) * L _2,4

y4 = y2 + cos(α4) * L _2,4

Based on the same inventive concept as the method, this embodiment of the invention also provides a positioning device, as shown in FIG6, specifically including: a positioning marker identification module 601, used to identify a positioning marker in an image acquired in real time; a relative position determination module 602, used to determine the relative position of a mobile terminal and the positioning marker; a positioning marker position determination module 603, used to obtain the geographical location of the positioning marker; and a mobile terminal position determination module 604, used to determine the current geographical location of the mobile terminal based on the geographical location of the positioning marker and the relative position of the mobile terminal and the positioning marker.

The device provided in this embodiment of the invention can be a mobile terminal, a hardware entity or logical entity built into a mobile terminal, or a separate device connected to a mobile terminal.

When the GPS positioning system is unavailable (e.g., due to weak or no GPS signal), the device provided in this embodiment can achieve mobile terminal positioning. Furthermore, the device provided in this embodiment acquires images in real-time during movement and detects positioning markers using image recognition technology. By utilizing the geographic location of the positioning marker and the relative position of the mobile terminal to the positioning marker, the current geographic location of the mobile terminal can be determined. Since the positioning marker is pre-set, its precise location can be obtained, and the calculated error in the relative position between the mobile terminal and the positioning marker is far smaller than the navigation deviation of the GPS positioning system. Therefore, the accuracy of the geographical location of the mobile terminal determined by the device provided in this embodiment of the invention is far higher than the positioning accuracy obtained by a GPS positioning system.

Preferably, the location marker identification module is specifically used to identify location markers in images acquired in real time by the image acquisition device of the mobile terminal.

Preferably, the relative position determination module is specifically used to: determine the relative position of the mobile terminal and the positioning mark based on the size information of the positioning mark in the image and the actual size information of the positioning mark.

Preferably, the actual size information of the location marker is obtained from the network side, or the actual size information of the location marker is preset in the mobile terminal or the device.

Preferably, the positioning beacon location determination module is specifically used to: determine the estimated location of the positioning beacon based on the relative position between the mobile terminal and the positioning beacon, and the current approximate geographical location of the mobile terminal; and obtain the geographical location of the positioning beacon closest to the estimated location as the geographical location of the positioning beacon. The current approximate geographical location of the mobile terminal is determined using dead reckoning or satellite positioning.

Preferably, when obtaining the geographical location of the nearest location marker to the estimated location as the geographical location of the location marker, the location marker location determination module is specifically used to: search for the geographical location of the nearest location marker to the estimated location in the electronic map installed on the mobile terminal as the geographical location of the location marker; or, report the estimated location of the location marker to the network side so that the network side can find the geographical location of the nearest location marker to the estimated location; receive the geographical location of the location marker found by the network side, and use the received geographical location as the geographical location of the location marker.

Preferably, the mobile terminal location determination module is also used to: determine the current approximate geographical location of the mobile terminal based on its initial location using a dead reckoning algorithm; or, determine the current approximate geographical location of the mobile terminal based on its initial location using a satellite positioning method.

Preferably, the system further includes an initial location determination module for: determining the initial location of the mobile terminal using satellite positioning; or, reading reference coordinates from an electronic map installed on the mobile terminal as the initial location of the mobile terminal; or, obtaining reference coordinates from a broadcast message as the initial location of the mobile terminal; or, obtaining the geographical location of another identified location marker, determining the relative position of the mobile terminal to the other location marker, and determining the initial location of the mobile terminal based on the geographical location of the other location marker and the relative position to the other location marker.

Based on any of the above device embodiments, preferably, the positioning mark is a cross shape; or, the positioning mark is an arrow shape; or, the positioning mark is a bullseye shape.

Based on any of the above device embodiments, preferably, the distance between the two actually deployed positioning markers in the direction of movement is greater than twice the initial positioning error.

Based on the same inventive concept as the method, this embodiment of the invention also provides a positioning device, as shown in FIG. 7, including a data transmission interface 700 and a processor 701. The data transmission interface 700 is configured to receive images acquired in real time by an image acquisition device mounted on a mobile terminal. The processor 701 is configured to: identify a positioning marker in the acquired images; determine the relative position of the mobile terminal and the positioning marker; acquire the geographic location of the positioning marker; and determine the current geographic location of the mobile terminal based on the geographic location of the positioning marker and the relative position of the mobile terminal and the positioning marker.

When the GPS positioning system is unavailable (e.g., due to weak or no GPS signal), the device provided in this embodiment can achieve positioning of the mobile terminal. Furthermore, the device provided in this embodiment acquires images in real-time during movement and detects positioning markers using image recognition technology. By utilizing the geographic location of the positioning marker and the relative position of the mobile terminal to the positioning marker, the current geographic location of the mobile terminal can be determined. Since the positioning marker is pre-set, its precise location can be obtained, and the error in the calculated relative position between the mobile terminal and the positioning marker is far smaller than the navigation deviation of the GPS positioning system. Therefore, the accuracy of the geographical location of the mobile terminal determined by the device provided in this embodiment of the invention is far higher than the positioning accuracy obtained by a GPS positioning system.

Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including, but not limited to, magnetic disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

This invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine such that instructions executable by the processor of the computer or other programmable data processing apparatus produce means for implementing the functions specified in one or more blocks of the flowchart illustrations and/or one or more blocks of the block diagrams.

These computer program instructions may also be stored in computer-readable memory that directs a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device that implements the functions specified in one or more flowcharts and/or one or more block diagrams.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be executed on the computer or other programmable device to produce computer-implemented processing. Thus, the instructions executing on the computer or other programmable device provide steps for implementing the functions specified in one or more flowcharts and/or one or more block diagrams.

The above detailed description is a specific explanation of one feasible embodiment of the present invention. However, this embodiment is not intended to limit the scope of the patent. All equivalent embodiments or modifications that do not depart from the spirit of the present invention should be included within the scope of the patent.

In conclusion, the technical features disclosed in this case fully meet the statutory requirements for novelty and progress of an invention patent. Therefore, this application is filed in accordance with the law, and we respectfully request your authority to approve this invention patent application in order to encourage invention. We are deeply grateful for your assistance.

100~130... Steps

Claims (18)

A positioning method, characterized by comprising: identifying a positioning marker in a real-time acquired image; determining the relative position of a mobile terminal and the positioning marker; acquiring the geographical location of the positioning marker; and determining the current geographical location of the mobile terminal based on the geographical location of the positioning marker and the relative position of the mobile terminal and the positioning marker; wherein acquiring the geographical location of the positioning marker includes: determining an estimated position of the positioning marker based on the relative position of the mobile terminal and the positioning marker and the current approximate geographical location of the mobile terminal, wherein the current approximate geographical location of the mobile terminal is determined by dead reckoning or satellite positioning; and acquiring the geographical location of the positioning marker closest to the estimated position as the geographical location of the positioning marker. The positioning method as described in claim 1, wherein identifying a positioning marker in real-time acquired images includes: identifying the positioning marker in real-time acquired images by the image acquisition device of the mobile terminal. The positioning method as described in claim 1, wherein determining the relative position of the mobile terminal and the positioning marker includes: determining the relative position of the mobile terminal and the positioning marker based on the size information of the positioning marker in the image and the actual size information of the positioning marker. The positioning method as described in claim 3, wherein the actual size information of the positioning marker is obtained from the network side, or the actual size information of the positioning marker is preset in the mobile terminal. The positioning method as described in claim 1, wherein obtaining the geographical location of the location marker closest to the estimated location as the geographical location of the location marker includes: searching for the geographical location of the location marker closest to the estimated location in an electronic map installed on the mobile terminal as the geographical location of the location marker; or, reporting the estimated location of the location marker to the network side so that the network side can search for the geographical location of the location marker closest to the estimated location; receiving the geographical location of the location marker found by the network side, and using the received geographical location as the geographical location of the location marker. The positioning method as described in claim 1 or 5, further comprising: determining the current coarse geographical location of the mobile terminal based on its initial location using a dead reckoning algorithm; or determining the current coarse geographical location of the mobile terminal based on its initial location using a satellite positioning method. The positioning method as described in claim 6, further comprising: determining the initial position of the mobile terminal using satellite positioning; or, reading reference coordinates from an electronic map installed on the mobile terminal as the initial position of the mobile terminal; or, obtaining reference coordinates from a broadcast message as the initial position of the mobile terminal; or, obtaining the geographical location of another identified positioning marker, determining the relative position of the mobile terminal to the other positioning marker, and determining the initial position of the mobile terminal based on the geographical location of the other positioning marker and the relative position to the other positioning marker. The positioning method described in any of claims 1-5, wherein the positioning mark is a cross shape; or, the positioning mark is an arrow shape; or, the positioning mark is a bullseye shape. A positioning device, characterized in that it comprises: a positioning marker identification module for identifying a positioning marker in an image acquired in real time; a relative position determination module for determining the relative position of a mobile terminal and the positioning marker; a positioning marker position determination module for acquiring the geographical location of the positioning marker; and a mobile terminal position determination module for determining the location of the mobile terminal based on the geographical location of the positioning marker and the relative position of the mobile terminal and the positioning marker. The current geographical location of the mobile terminal; specifically, the positioning marker location determination module is used to: determine the estimated location of the positioning marker based on the relative position between the mobile terminal and the positioning marker, and the current approximate geographical location of the mobile terminal, which is determined by dead reckoning or satellite positioning; and obtain the geographical location of the positioning marker closest to the estimated location as the geographical location of the positioning marker. The positioning device as described in claim 9, wherein the positioning marker identification module is specifically used to: identify positioning markers in images acquired in real time by the image acquisition device of the mobile terminal. The positioning device as described in claim 9, wherein the relative position determining module is specifically used to: determine the relative position of the mobile terminal and the positioning mark based on the size information of the positioning mark in the image and the actual size information of the positioning mark. The positioning device as described in claim 11, wherein the actual size information of the positioning marker is obtained from the network side, or the actual size information of the positioning marker is preset in the mobile terminal or the device. As described in claim 9, in the positioning device, when obtaining the geographical location of the nearest positioning marker to the estimated location as the geographical location of the positioning marker, the positioning marker location determination module is specifically used to: search for the geographical location of the nearest positioning marker to the estimated location in the electronic map installed on the mobile terminal as the geographical location of the positioning marker; or, report the estimated location of the positioning marker to the network side so that the network side can find the geographical location of the nearest positioning marker to the estimated location; receive the geographical location of the positioning marker found by the network side, and use the received geographical location as the geographical location of the positioning marker. The positioning device as described in claim 9 or 13, wherein the mobile terminal location determination module is further configured to: determine the current approximate geographical location of the mobile terminal based on its initial location using a dead reckoning algorithm; or, determine the current approximate geographical location of the mobile terminal based on its initial location using a satellite positioning method. The positioning device as described in claim 14 further includes an initial position determination module for: determining the initial position of the mobile terminal using satellite positioning; or, reading reference coordinates from an electronic map installed on the mobile terminal as the initial position of the mobile terminal; or, obtaining reference coordinates from a broadcast message as the initial position of the mobile terminal; or, obtaining the geographical location of another identified positioning marker, determining the relative position of the mobile terminal to the other positioning marker, and determining the initial position of the mobile terminal based on the geographical location of the other positioning marker and the relative position to the other positioning marker. The positioning device as described in any of claims 9-13, wherein the positioning mark is a cross symbol; or, the positioning mark is an arrow symbol; or, the positioning mark is a bullseye symbol. A positioning device, characterized in that it includes: a data transmission interface for receiving images acquired in real time by an image acquisition device mounted on a mobile terminal; and a processor for identifying a positioning marker in the images acquired in real time by the data transmission interface, determining the relative position of the mobile terminal and the positioning marker, acquiring the geographical location of the positioning marker, and determining the positioning location based on the geographical location of the positioning marker and the relative position of the mobile terminal and the positioning marker. The processor determines the current geographical location of the mobile terminal; specifically, it is used to: determine the estimated location of the positioning marker based on the relative position of the mobile terminal and the positioning marker, and the current approximate geographical location of the mobile terminal, which is determined by dead reckoning or satellite positioning; and obtain the geographical location of the positioning marker closest to the estimated location as the geographical location of the positioning marker. The positioning device as described in claim 17, wherein the processor is specifically configured to: determine the relative position of the mobile terminal and the positioning marker based on the size information of the positioning marker in the image and the actual size information of the positioning marker.