CN112904850B - Road positioning mark for service of unmanned vehicle - Google Patents

Abstract

The present application provides a road positioning marker for unmanned vehicles, which uses a color block array with simple geometric shapes to represent unique and accurate road geographic location information, provides accurate positioning information for autonomous driving vehicles, and represents data bits through the color block array, which is easy for camera recognition and image processing; the geographic location information represented by the road positioning marker provided by the present invention is unique geographic information based on global positioning, which is more applicable than the road markings based on relative geographic location in the prior art; different from the standing or hanging road positioning markers in the prior art, the road positioning marker provided by the present application is small in size, can be assembled and laid on the road surface, occupies a small road area, is convenient for image acquisition and road construction, and can reduce production and installation costs.

Description

A road positioning mark for unmanned vehicles

Technical Field

The present invention belongs to the technical field of automatic driving positioning, and in particular relates to a road positioning mark serving an unmanned vehicle.

Background technique

Self-driving cars can sense the external environment and drive safely without human intervention. Their reliability and safety are related to whether they can obtain accurate positioning information. Positioning technology has become a key link in the control of autonomous driving systems.

Traditional GPS positioning technology has a positioning accuracy of up to 16 feet in open areas, but in densely built-up areas, tunnels, and three-dimensional transportation systems such as viaducts, the accuracy of GPS drops to 10-20 meters, and it cannot provide height-direction location information. Such technical deficiencies will affect traffic efficiency and safety, and limit its application in the field of autonomous driving.

In addition to satellite-based positioning, currently mature driving positioning technologies also include RFID-based wireless positioning. However, due to its high cost, this technology has not been widely popularized. It is currently mostly used in transportation systems such as rail transit and logistics parks that mainly use fixed driving routes.

Other positioning technologies such as Cell ID, AFLT (forward link trilateration), AGPS (assisted GPS), RTK (real-time kinematic carrier phase differential technology), etc., can solve the GPS positioning accuracy problem to a certain extent, but they still cannot solve the signal reflection and obstruction in urban environments, have low sensitivity, and have high requirements for the technical environment.

At present, in the field of vehicle-road cooperative systems, especially in the field of autonomous driving, relevant research has designed a vehicle precision positioning method that sets white circular color block marks on the road surface, uses an imaging device installed on the vehicle to collect images, and uses the weighted least squares method to fit the image and analyze the positioning information. This method only uses simple dots and spaces to express binary codes, and the efficiency of expressing information is not high. Instead, it occupies a large amount of road space. Moreover, the location information it carries is not the only accurate three-dimensional geographic location information based on global positioning, but only the relative position data of each mark. When the user end embeds it for development, it needs to load the matching database, which is not conducive to the development of offline user-end devices. In addition, this method also requires accurate calibration points, and its positioning effect is not good when driving at night or in environments with poor lighting conditions.

Summary of the invention

Based on this, the present invention aims to provide a road positioning mark for unmanned vehicles, providing self-driving cars with road positioning marks that are easy for computers to process images and can represent unique and accurate geographic location information, thereby assisting self-driving cars in precise positioning.

The present invention provides a road positioning mark for unmanned vehicles, comprising:

A representation information unit composed of several basic units, each of which expresses a decimal or hexadecimal number through an array of two-color blocks;

A digital string composed of numbers expressed by a plurality of basic units represents the geographical location information of the location of the road positioning mark;

The basic units in the representation information unit are assembled on the same base;

The road positioning mark is laid on the road surface of the marked geographical location.

Preferably, the color block is mainly made of wear-resistant glass, concrete, or polymer.

Preferably, in order to enhance the color difference between the color blocks in a nighttime driving environment, fluorescent powder is also added to the color blocks.

Preferably, the array of color blocks is a 2×2 matrix.

Preferably, the effective length of the color block is 2-5 cm.

Preferably, the base has a length of 15-50 cm, a width of 15-50 cm, and a thickness of 0.5-5 cm.

Preferably, the color blocks of the basic unit use the same geometric shape.

Preferably, the color blocks of the basic unit have different geometric shapes.

Preferably, in order to facilitate reading of geographical location information, the road positioning mark further includes:

A boundary unit, including a plurality of identification blocks, is arranged at the boundary of the representation information unit and is used to identify the start bit and the end bit of the geographical location information reading;

The boundary unit and the representation information unit are assembled on the same base.

Preferably, several identification blocks in a boundary unit use the same geometric shape.

Preferably, the identification block indicating the start position has a different geometric shape from other identification blocks in the boundary unit.

Preferably, in order to reduce heat conduction between the color blocks, the color blocks assembled on the same base are bonded to each other using a heat insulating material.

Preferably, the thickness of the thermal insulation material is 0.2-1 cm.

Preferably, in order to compensate for the color difference and thermal difference between the color blocks, a light emitting device and/or a heating device is provided between the color block and the base and/or between the boundary unit and the base.

It can be seen from the above technical solutions that the present invention has the following beneficial effects:

The present invention provides a road positioning mark for unmanned vehicles. The road positioning mark uses a color block with a simple geometric shape to represent unique and accurate road geographical location information, provides accurate positioning information for the automatic driving vehicle, and represents data bits through a color block array, which is easy for camera recognition and image processing. The geographical location information represented by the road positioning mark provided by the present invention is unique geographical information based on global positioning, which is more applicable than the road marking based on relative geographical location in the prior art. The color blocks use different geometric shapes to further increase the redundancy and fault tolerance of image processing. A light-emitting device and/or a heating device are arranged between the color block and the base to compensate for the contrast change between the color blocks caused by light and temperature changes, so that the road positioning mark of the present invention still has a high degree of recognition in environments such as night driving, poor lighting conditions, and poor visibility, thereby improving the robustness and reliability of the present invention. The color block component used in the present invention is small in size, with an effective length of only 2-5 cm, which is convenient for large-scale production and assembly, thereby reducing production costs and improving production efficiency. Different from the standing or hanging road positioning mark in the prior art, the present invention can be assembled and laid on the road surface, which is convenient for image acquisition and road construction, and saves space.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

FIG. 1 is a schematic diagram of the road positioning mark in use according to the present invention.

Figure 2 Schematic diagram of digital expression of basic unit of road positioning mark of the present invention

Figure 3 Schematic diagram of the basic unit of the road positioning mark of the present invention

FIG. 4 is a schematic diagram of a road positioning mark boundary unit of the present invention.

FIG. 5 is a schematic diagram of another marking boundary unit of the road positioning mark of the present invention.

FIG. 6 is a schematic diagram of the use of the road positioning mark light emitting device and the heating device of the present invention.

Figure 7 Schematic diagram of the position of the light emitting device and the heating device of the road positioning mark of the present invention

FIG8 is a schematic diagram of the assembly of the road positioning mark light emitting device and the heating device of the present invention.

FIG. 9 is a schematic diagram of the image acquisition of the road positioning mark of the present invention.

In the figure: 1. Camera; 2. Basic unit; 3. Color block; 31. Light block; 32. Dark block; 4. Characterization information unit; 5. Boundary unit; 51. Start position identification block; 52. Other identification blocks; 6. Light-emitting device; 7. Heating device; 8. Partition; 9. Base; 91. Groove.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Referring to FIG. 1 , this embodiment provides a road positioning marker for unmanned vehicles, which is used to be laid on the road surface to indicate the geographic information of the location. A camera 1 installed on the vehicle performs image acquisition to provide unique and accurate geographic location information, thereby calculating the exact location of the vehicle.

The camera installed on the vehicle may be a common optical camera, an infrared camera, or an integrated optical and thermal infrared camera, and the present invention does not make any specific limitation thereto.

As shown in FIG2 , the road positioning mark includes a characterization information unit, which is composed of a plurality of basic units 2. Each basic unit expresses a decimal number 0-9 through an array of color blocks. The color block 3 includes two colors. The array of light and dark color blocks can express a data string that is easy for the computer to recognize. After the camera image is collected and processed by the computer, the specific digital string can be parsed to obtain the geographical location marked by the road positioning mark. Compared with the method of using white dots in the prior art to express only binary codes, the color block array provided in this embodiment can express more information.

Black and white are often used to represent the difference in light and dark colors. It is easy to understand that in addition to black and white, other colors with obvious color difference contrast can also play the same role. The color block array given in this embodiment is a 2×2 matrix. Figure 2 shows the digital expression of 0-9 in this embodiment. The color blocks are represented by squares, but this cannot be regarded as a limitation of the present invention. Those skilled in the art can obtain other digitally expressed color block arrangements and combinations according to the technical solution of the present invention, including 3×3 matrices, 4×4 matrices, non-matrix arrays, etc.; in addition to squares, color blocks can also be digitally expressed using other simple geometric shapes such as circles, triangles, rhombuses, parallelograms, etc. The above color block arrays and color block shape solutions are not repeated here.

In this embodiment, the information contained in the road positioning mark is absolute geographic location information, such as longitude and latitude, elevation, etc., which can uniquely and accurately determine the location of the location, while the information contained in the prior art is the relative position between each road positioning mark, such as horizontal position, vertical position, etc. In comparison, the road positioning mark of this embodiment has a wider applicability and better stability than the prior art.

In addition to decimal numbers, in a further embodiment, the basic unit can also express hexadecimal numbers, and the expression of longitude and latitude and elevation in decimal code is used as an example for explanation. Considering the influence of the decimal digit accuracy of longitude and latitude on the actual positioning requirements, when the longitude or latitude is the same and the integer digit length is the same, the accuracy reaches 0.1 meter when the latitude or longitude reaches 6 decimal digits, and this accuracy is enough to meet the actual positioning requirements. The elevation is represented by a 4-digit decimal code. General GPS positioning can provide accurate longitude and latitude integer parts, so the digital string of this embodiment gives 6 decimal digits of longitude and latitude, and is represented by a decimal code of 16 data bits, the 1st-6th data bits are 6 decimal digits of longitude, the 7th-12th data bits are 6 decimal digits of latitude, and the 13th-16th data bits represent the elevation.

It is easy to understand that the positioning accuracy can be improved by increasing the number of basic units, and the geographic information expressed by the data bits can be changed according to actual needs. For example, the 1st to 4th data bits represent elevation, and the 5th to 16th data bits represent latitude and longitude. These are not listed here in detail.

In a further embodiment, the color blocks can also use different geometric shapes for boundary distinction to facilitate the later image processing of the computer. FIG3 shows an example of using different geometric shapes to represent light blocks and dark blocks. The light block 31 is represented by a square, and the dark block 32 is represented by a circle. The basic unit shown in FIG3 includes both color difference and graphic difference, and the data redundancy and fault tolerance are better. It is easy to understand that in addition to using different geometric shapes for light and dark blocks, different geometric shapes can also be used for the color blocks contained in a single basic unit without considering the color. For example, a basic unit composed of a 2×2 color block matrix can include one shape, two shapes, three shapes, and four shapes. The geometric shape of the color block in the present invention mainly plays the role of boundary distinction to facilitate computer image processing. On this basis, compared with the prior art that only uses a single geometric shape to express binary code, the data fault tolerance of the present invention is better.

As shown in FIG. 4 and FIG. 5 , in a further embodiment, in order to facilitate the identification of image areas containing geographic location information in computer post-processing, boundary units 5 are further provided at the four edges of the representation information unit 4. The boundary unit 5 includes a plurality of identification blocks for identifying the start position and the end position of the geographic location information reading. The identification blocks may be represented by the same geometric shape, or different geometric shapes may be used to distinguish the start position from other boundaries. The start position identification block 51 in FIG. 4 and FIG. 5 is represented by a triangle, and the other identification blocks 52 are represented by a square. In addition to squares and triangles, other geometric shapes with obvious boundaries may also play the same role, and the present invention does not specifically limit this.

Taking the digital expression given in FIG. 2 and the road location mark shown in FIG. 4 as an example, image acquisition and information reading are performed on FIG. 4, and the resulting digital string is 133742168, which is used for computer post-processing to parse out the geographic location information contained in the road location mark.

Under natural conditions, changes in the light and temperature environment may cause the contrast of the temperature difference and color difference between the color blocks to decrease, thereby affecting the accuracy of image recognition. In order to make up for the shortcomings of the temperature difference and color difference formed under natural conditions, in a further embodiment, a light-emitting device and a heating device may be added to the road positioning mark. As shown in FIG6, in order to maximize the color difference, the light-emitting device 6 is arranged between the light block 31 and the base 9, and the heating device 7 is arranged between the dark block 32 and the base 9, and the light block 31 uses a light-transmitting material. The light-emitting device 6 and the heating device 7 can also be arranged between the boundary unit 5 and the base 9. The light-emitting device and the heating device can also be installed between the identification block of the boundary unit and the base.

As shown in FIG. 7 , the specific placement may be to provide a groove 91 on the side of the base 9 that contacts the color block, and the light emitting device 6 and the heating device 7 are placed in the groove 91 to protect them from being squeezed by the vehicle load.

In order not to affect the thermal difference between the color blocks, the light emitting device 6 is preferably an LED lamp with low heat generation.

Fig. 8 shows the assembly process of the basic unit 2 and the base 9. The light emitting device 6 and the heating device 7 are first placed in the groove 91, and the color blocks are installed on the base 9, wherein the light-transmitting light block 31 is installed on the light emitting device 6, and the dark block 32 is installed on the heating device 7. In order to reduce heat conduction between the color blocks and strengthen the boundaries between the color blocks, a heat-insulating partition 8 with a color different from that of the color blocks can be used for bonding. The thickness of the partition 8 is 0.2-1 cm. Finally, the assembled road positioning sign is laid on the road surface of the marked geographical location.

The color blocks of the basic units are made of materials such as wear-resistant glass, concrete, and polymers. The effective length is only 2-5 cm, and the road area is small. The small size design allows the color blocks to be mass-produced and assembled, greatly reducing the production cost. The positioning signs can be laid while the road is under construction, and the construction cost is also greatly reduced. In order to facilitate the production and assembly and road construction, the basic units and/or boundary units used in the same road positioning sign are assembled on the same base, which is made of metal or concrete and has a size of 15-50 cm in length, 15-50 cm in width, and 0.5-5 cm in thickness.

In order to increase the color difference between color blocks, especially in night driving environments or tunnels with poor lighting, to improve the recognizability of road positioning signs, fluorescent powder can also be added to the color blocks to enhance the color difference between the color blocks. In addition to fluorescent powder, color powder, reflective glass beads and other materials that can enhance color differences can be added to the color blocks.

Figure 9 shows the result of the camera acquiring the image of the road positioning mark provided in this embodiment. The left side of Figure 9 simulates the road positioning mark, and the right side is the thermal imaging picture acquired by the camera. It can be seen that the boundaries between the light and dark blocks are obvious in the thermal imaging picture. This thermal imaging picture will be used for later image processing on the computer to analyze the geographic location information.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (12)

1. A road location identifier for servicing an unmanned vehicle, comprising:

the system comprises a characterization information unit consisting of a plurality of basic units and a boundary unit comprising a plurality of identification blocks;

each basic unit expresses a decimal or hexadecimal number through an array of the bright and dark blocks, and a number string formed by the numbers expressed by a plurality of basic units represents absolute geographic position information of the position where the road positioning mark is located;

the identification block is arranged at the boundary of the characterization information unit and is used for identifying a start bit and a stop bit of absolute geographic position information reading;

the boundary unit and the characterization information unit are assembled on the same base;

the color blocks are made of wear-resistant glass, concrete and polymers, so that the road positioning mark is paved on the road ground at the marked geographic position along with road construction.

2. The road location marking for use in servicing an unmanned vehicle of claim 1, wherein the color block is further supplemented with a phosphor.

3. The road location marking for servicing an unmanned vehicle of claim 1, wherein the array of color patches is a 2 x 2 matrix.

4. The road location marking for servicing an unmanned vehicle of claim 1, wherein the effective length of the color block is 2-5cm.

5. The pavement marker for use in servicing an unmanned vehicle of claim 1, wherein the base is 15-50cm long, 15-50cm wide, and 0.5-5cm thick.

6. The road location marking for servicing an unmanned vehicle of claim 1, wherein the color patches of the base unit use the same geometry.

7. The road location marking for servicing an unmanned vehicle of claim 1, wherein the color blocks of the base unit have different geometries.

8. The road location marking for servicing an unmanned vehicle of claim 1, wherein several marking blocks in the border element use the same geometry.

9. The road location marking for servicing an unmanned vehicle of claim 1, wherein the marking block in the boundary element representing the start bit has a different geometry than the other marking blocks.

10. The pavement marker for use in servicing an unmanned vehicle of claim 1, wherein the color blocks assembled on the same base are bonded to each other with a thermally insulating material.

11. The pavement marker for servicing an unmanned vehicle of claim 10, wherein the insulating material has a thickness of 0.2-1cm.

12. Road location marking for the service of unmanned vehicles according to claim 1, characterized in that a lighting device and/or a heating device is provided between the color block and the base and/or between the border element and the base.