CN215865228U - Target - Google Patents

Abstract

This application belongs to the engineering survey field, and this application embodiment provides a mark target, the target surface of mark target includes: the device comprises an identification area and a background area arranged around the identification area, wherein the brightness difference between the identification area and the background area is larger than a preset threshold value. Obvious brightness contrast is formed by the identification area and the background area, so that the image identification system can accurately fit the identification area and aim at the central position of the target, and the aiming accuracy is improved.

Description

Target

Technical Field

The application belongs to the engineering survey field, especially relates to a mark target.

Background

The current mainstream total station basically has the function of automatically searching the target, so that the target aiming efficiency is greatly improved. However, the target automatic search function of the total station needs to be matched with a special measuring prism, and the total station determines the target according to the received light by emitting light.

When the prism cannot be placed at the target position, prism-free measurement needs to be carried out, the reflector target is used for replacing the prism to carry out automatic target search at present, however, the total station often cannot automatically search the reflector target or the searched sighting error is large due to the influence of factors such as the measurement environment, the angle of the reflector and the like.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the present application provides a target to solve the technical problem that the identification precision of a reflector target is low under the condition that prisms cannot be arranged in the automatic target searching process of a total station.

In order to solve the above technical problem, the technical solution of the embodiment of the present application is implemented as follows:

the utility model provides a target, the target face of target includes: the device comprises an identification area and a background area arranged around the identification area, wherein the brightness difference between the identification area and the background area is larger than a preset threshold value.

Further, the difference between the light reflection rate of the identification area and the light reflection rate of the background area is greater than a preset light reflection threshold value.

Further, the difference between the material reflection rate of the identification area and the material reflection rate of the background area is greater than the preset reflection threshold value.

Furthermore, the identification area material is a light absorption material or a light transmission material, and the background area material is a light reflection material; or the identification area material is a reflective material, and the background area material is a light absorption material or a light transmission material.

Further, the difference between the color reflection rate of the identification area and the color reflection rate of the background area is greater than the preset reflection threshold.

Further, the identification area is white in color, and the background area is black in color; or the color of the identification area is black, and the color of the background area is white.

Further, one of the identification region and the background region may be capable of emitting light.

Further, one of the identification region and the background region is provided with a fluorescent material.

Further, the identification area is a regular closed figure.

Further, the background area is a regular closed figure, and the geometric center of the identification area is coincident with that of the background area.

According to the target provided by the embodiment of the application, the obvious brightness contrast is formed by the identification area and the background area, so that the image identification system can accurately fit the identification area and aim at the central position of the target, and the aiming precision is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic view of a target of a total station acquiring a target measurement point of the present application;

FIG. 2 is a schematic diagram of a target structure according to a first embodiment of the present application;

FIG. 3 is an exploded view of the target of FIG. 2;

FIG. 4 is a schematic diagram of a target structure according to a second embodiment of the present application;

FIG. 5 is an exploded view of the target of FIG. 4;

FIG. 6 is a schematic view of a target surface of a first embodiment of the present application;

FIG. 7 is a schematic view of a target surface of a second embodiment of the present application;

FIG. 8 is a schematic view of a target surface of a third embodiment of the present application;

FIG. 9 is a schematic view of a target surface of a fourth embodiment of the present application;

fig. 10 is a schematic view of a target surface according to a fifth embodiment of the present application.

Description of reference numerals:

1. a total station, 2, a target, S, a target surface, T and a target body;

t1, background part, T2, identification part, S1, background area, S2, identification area, S3, mark point.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The individual features described in the embodiments can be combined in any suitable manner without departing from the scope, for example different embodiments and aspects can be formed by combining different features. In order to avoid unnecessary repetition, various possible combinations of the individual specific features of the present application will not be described further.

The embodiment of the application provides a target for engineering measurement. The measuring device at least comprises a camera device and a terminal device, wherein the camera device is used for acquiring a target image, and the terminal device is used for performing image recognition and controlling the camera device to aim at the target measuring point after acquiring the image through the camera device. The target of the embodiment of the application is used for marking and positioning the target measuring point.

The use of the target of the embodiment of the present application in target sighting is described by taking a leica TS60 total station as an example of the measuring device. The total station is provided with a wide-angle camera, a telescope camera and other camera devices, a secondary development interface of GeoCOM is provided, a terminal application program can be developed to operate the total station to take pictures, orient, measure and the like, and the configuration of the total station meets the requirements of a measuring device. A Total Station, i.e. a Total Station type Electronic distance meter (Electronic Total Station), is a high-tech measuring instrument integrating light collection, mechanical measurement and electrical measurement, and is a surveying instrument system integrating horizontal angle, vertical angle, distance (slant distance, horizontal distance) and height difference measurement functions. The method is widely applied to the field of precision engineering measurement or deformation monitoring of overground large-scale buildings, underground tunnel construction and the like. The procedure of using the total station in cooperation with the target is exemplified below.

As shown in fig. 1, the target 2 is placed at a target measurement point in a pasting manner, and the target measurement point may be a point or a surface. The position of the target 2 is shown as the target measurement point position. The total station 1 is separated from the target 2 by a certain distance, after the target 2 is shot by a telescope camera on the total station 1 to form an image, the coordinate value of the characteristic point of the target 2 on the image is identified by utilizing the image identification technology of the terminal equipment, and then the coordinate value of the center point of the target 2 is determined. The deflection angle of the center of the target 2 relative to the telescope camera can be calculated through the coordinate value of the telescope camera on the image (the parameter can be obtained according to the secondary development interface of the total station) and the angle of view parameter (the parameter can be obtained according to the secondary development interface of the total station) of the shot image size corresponding to the total station telescope camera, and then the telescope camera is controlled to adjust the deflection angle to point to the central point of the target 2, namely, the target measuring point. In this way, the absolute (or relative) angle, distance, height difference, or the like of the target measurement point is measured after the target measurement point is aligned.

Any of the above scenarios of target-to-target measurement point alignment using the embodiments of the present application are included in the application of the target of the present application, and different application scenarios do not have any influence on the structure of the target. The structure of the target is exemplified below.

In some embodiments, as shown in fig. 2, the target surface S of the target 2 includes an identification region S2 and a background region S1 disposed around the identification region. The target surface S of the target 2 is a certain end surface of the target 2, and further, the target surface S of the target 2 is the end surface where the length and the width of the target 2 are located. Furthermore, a surface of the target is identified in the image identification system of the total station terminal equipment, and the identified surface is set as the target surface in the embodiment of the application.

When the total station is used for actual measurement, a target surface S with a recognition area S2 and a background area S1 faces to the opposite surface of the total station with an image pick-up device, and an end surface back to the target surface S is pasted on a target measurement point. The image recognition system finally determines the target 2 center point. Thus, designing the recognition area S2 at the center of the target 2 can reduce the recognition range, and facilitate the terminal device to select a fitting target, for example, by fitting the edge image of the recognition area S2, calculating the coordinate value of the center point of the recognition area S2 in the image, and adjusting the tilt angle of the imaging device to the target measurement point. The background region S1 is generally used for comparison with the recognized region S2 to facilitate the edge image of the recognized region S2, respectively.

The target 2 is generally a three-dimensional structure having a length, a width, and a thickness. The structure of the target 2 can be at least two of the following:

as shown in fig. 3, the target 2 is formed by splicing two solid portions of a background portion T1 and a recognition portion T2, the background portion T1 surrounds and adheres to the recognition portion T2 to form an integral structure as shown in fig. 2, the background portion T1 and the recognition portion T2 are designed to have the same thickness, so that the target 2 combined into a whole has two flat end faces, the end face formed by the adhesion of the two end faces can be regarded as a target surface S, and the target surface S includes a recognition area S2 of the recognition portion T2 and a background area S1 of the background portion T1.

As shown in fig. 5, the target 2 may also be a monolithic three-dimensional structure, which includes a target body T and a target surface S attached to either end of the target body T, wherein the target surface S includes an identification region S2 and a background region S1 surrounding the identification region S2. The target surface S and the target body T are bonded together to obtain the schematic diagram shown in FIG. 4. Target 2 may also result in the schematic shown in fig. 4 for providing a background portion S1 and an identification portion S2 directly on target T.

The mark target of above two kinds of modes simple structure, but batch production also can be according to in-service use, and target length is makeed design to the definite value, width and thickness are in order to satisfy the measurement demand.

In the embodiment of the present application, the specific structure of the target 2 is not limited, and it suffices that the target surface S has the recognition area S2 and the background area S1. It should be noted that, due to differences in manufacturing and processing and requirements for measurement targets, and differences in length, width, and thickness of the target under different usage scenarios, the thickness of the target 2 is suitable for a smaller design, so that operations such as parameter correction are reduced in practical use. For example, a target having a thickness of 0.5mm or less can be used for measurement without correction parameters, for example, a target having a sheet structure. In addition, the smaller the selectable flatness of the target surface S is, the better the flatness is, the flatter the target surface S is, the higher the fitting precision of the identification area S2 is, and the more favorable the determination of the position of the central point is. The following description relates to the features of the identification region S2 and the background region S1:

as shown in fig. 2, the brightness difference between the recognition area S2 and the background area S1 is larger than a preset threshold (the difference in brightness is represented by different gray levels in the drawing, the darker the gray level is, the closer to black, the lower the brightness is, the lighter the gray level is, the closer to white, and the higher the brightness is; the background area S1 in fig. 2 is darker in gray level than the recognition area S2, and the brightness of the background area S1 is lower than the recognition area S2). Lightness is the perception of the eye of the brightness of the light source and the surface of an object, and is a visual experience mainly determined by the intensity of light. Generally, the stronger the light, the brighter it looks; the weaker the light, the darker the look. The same color can produce different brightness changes due to different light irradiation intensities, and the brightness at the position can be equal to the brightness. Lightness also refers to the brightness of the color, with the brightest color being white and the darkest color being black. The shade may be different for colors of the same hue. For example, magenta and pink both contain red, but the former appears dark and the latter appears bright. Adding white into any color can enhance the lightness of the color and lighten the color; the addition of black weakens the lightness of the color and makes the color darker. The brightness here can be equivalent to the brightness of the color.

According to different methods for processing the shot pictures by the total station camera equipment, the lightness measurement indexes are different. For example, in an image recognition system of a total station terminal device, when a target is photographed as a picture and binarized image processing is used, the background region S1 and the recognition region S2 show different gradations, which are brightness. If the logarithmic relationship between white and black is divided into gray levels ranging from 0 to 255, white is 255 and black is 0. When the difference value between the gray value of the background area S1 and the gray value of the identification area S2 is greater than a preset threshold, the preset threshold is a preset gray threshold; for example, without using the binarization image processing, the identification area S2 is directly recognized for the captured image, that is, the obtained colors are lightness-discriminated. Currently, the lightness of colors can be divided into 9 grades, 1-3 low lightness, 4-6 medium lightness, 7-9 high lightness, 1 black, and 9 white. The higher the grade, the lighter the color; the lower the grade, the darker the color. When the difference between the color brightness value of the background region S1 and the color brightness value of the identification region S2 is greater than the preset threshold, the preset threshold is the preset color brightness threshold.

It should be noted that the preset threshold may be flexibly referred to as a corresponding threshold under different situations according to the specific situation of the target surface, and is not limited to a grayscale threshold and a color brightness threshold when performing image processing, but may also be a reflection threshold, a light absorption threshold, a light transmission threshold, or the like of a material or a color of the target in actual manufacturing, that is, the target surface S may be any structure that can make the difference between the brightness of the identification area S2 and the brightness of the background area S1 be greater than the preset threshold. For example, the difference in brightness between the target identification zone S2 and the background zone S1 due to the different material types is greater than the predetermined material threshold; for another example, the difference between the color hues of the identification region S2 and the background region S1 is greater than the preset color lightness threshold.

It should be further noted that, in the embodiment of the present application, for the expression that the difference between the brightness of the identification region S2 and the brightness of the background region S1 is greater than the preset threshold, in order to prevent multiple repetitions, the expression that the brightness of the identification region S2 is significantly or significantly different from the brightness of the background region S1, or the difference is greatly another expression is used here. Thus, the presence of "significant", "significant" or "greatly different" throughout the text means that the difference between the brightness of the recognized region S2 and the brightness of the background region S1 is greater than the preset threshold. Hereinafter, the technical features of which lightness difference is obvious and unobvious are described by referring to the drawings.

As shown in fig. 6, the identification region S2 is white in grayscale, and the background region S1 is black in grayscale, and as described above, the identification region S2 is higher in brightness than the background region S1, and the difference between the identification region S2 and the background region S1 is significant. As shown in fig. 7, the recognition area S2 and the background area S1 have brightness difference, and when the difference is not large, the brightness contrast is not obvious, and the image recognition system of the total station has difficulty in distinguishing the background area S1 from the recognition area S2, which is not favorable for edge recognition and fitting of the recognition area S2. In this way, the brightness difference between the recognition area S2 and the background area S1 is greater than a certain preset threshold value so that the recognition area S2 is clearly contrasted with the background area S1, which is beneficial for the image recognition system to recognize the recognition area S2. The specific threshold value needs to be set correspondingly according to the measurement object of the actual brightness, for example, the gray threshold value is designed to be 200, 250. When the brightness difference is greater than 200 or 250, the gray level of one of the recognition area S2 or the background area S1 of the target surface S is close to 255, i.e., white, and the other is close to 0, i.e., black, as shown in fig. 6. For another example, the color luminance threshold is set to 6, 7, and 8. When the brightness difference is greater than 6 or 7, one of the identification area S2 or the background area S1 of the target surface is close to high brightness 9, i.e., white, and the other is close to low brightness 1, i.e., black, as shown in fig. 6. Thus, the larger the preset threshold is, the more obvious the difference between the background region S1 and the recognition region S2 is, and the clearer the edge of the recognition region S2 is in contrast with the background region S1, so that the terminal device can fit the edge of the recognition region S2 to obtain the coordinate value of the center point of the recognition region S2.

The brightness difference between the background area S1 and the identification area S2 of the target 2 in the embodiment of the application is larger than the preset threshold value, so that the contrast between the background area S1 and the identification area S2 is obvious, an image identification system of the total station terminal equipment can clearly distinguish the identification area S2, a target measuring point of the total station can be quickly and accurately positioned, and the automatic collimation level of the total station in a prism-free mode is improved.

In some embodiments, the difference between the light reflectivity of the identification area S2 and the light reflectivity of the background area S1 is greater than the preset light reflectivity threshold, that is, the brightness difference is caused by the difference between the light reflectivity of the identification area S2 and the light reflectivity of the background area S1, wherein the light reflectivity is the ability of the object to reflect light. The light reflection rate is high, the light reflection capacity of the representative object is high, the light reflection rate is low, and the light reflection capacity of the representative object is low. The identification area S2 has different light reflection rates from the background area S1, and presents different light and shade degrees, so that the identification area S2 has a brightness difference from the background area S1, and when the difference of the light reflection rates is greater than a preset light reflection threshold value, the brightness difference between the identification area S2 and the background area S1 is obvious, so that the identification area S2 and the background area S1 can be clearly distinguished by an image recognition system of the total station terminal device.

The difference in the light reflection rates of the identification region S2 and the background region S1 may be achieved in different ways. For example, the material of the identification region S2 and the background region S1 is different; for another example, the identification region S2 and the background region S1 are different in color.

In some embodiments, the difference between the material reflectance of the identification zone S2 and the material reflectance of the background zone S1 is greater than a preset reflectance threshold. That is, the recognition area S2 and the background area S1 make the brightness difference obvious by the difference in the light-reflecting ability of the material.

In some embodiments, the identification zone S2 and the background zone S1 are of different types of material and have a significant difference in reflectivity.

For example, the identification area S2 is made of a light-reflecting material, the background area S1 is made of a light-absorbing material or a light-transmitting material, and the identification area S2 is brighter than the background area S1, as shown in fig. 6, the gray level of the identification area S2 using the light-reflecting material is much lighter than that of the background area S1 using the light-transmitting material or the light-absorbing material, and the brightness difference is significant, so that the image recognition system of the total station terminal equipment can directly recognize the identification area S2.

For example, the identification region S2 is made of a light absorbing material or a light transmitting material, the background region S1 is made of a light reflecting material, and the identification region S2 is lower in brightness than the background region S1, as shown in fig. 8, the background region S1 is designed to surround the identification region S2, the gray level of the identification region S2 is far deeper than that of the background region S1, the brightness difference is obvious, and the identification region S2 can be quickly identified by an image identification system of the total station terminal equipment under the contrast of the background region S1.

The light absorbing material and the light transmitting material absorb or transmit most of light energy so as to weaken the intensity of reflected light. The retroreflective material can provide retroreflection of light. Under the same illumination, the brightness of the reflecting material is far greater than that of the light absorbing material or the light transmitting material. The reflecting material such as reflecting film, reflecting ink, reflecting leather, reflecting woven tape and the like reflects light through one kind of high-refractive-index glass beads in the reflecting material, so that the brightness is higher than that of a common object. The light absorbing material can be selected from dark color materials, and the light transmitting material can be selected from organic glass, glass fiber reinforced plastics and the like.

When the difference between the material reflectances of the background area S1 and the identification area S2 is greater than the preset reflection threshold value, the lightness difference is obvious, and the rapid identification of the image identification system of the total station terminal equipment can be realized.

In some embodiments, the identification zone S2 and the background zone S1 are of the same material type and have different light reflectivities, depending on the availability, and ease of manufacture of the material.

For example, the identification area S2 and the background area S1 are made of reflective materials, and the identification area S2 and the background area S1 have different reflective rates, and the difference in reflective rates is significant.

For example, the identification region S2 and the background region S1 are both made of light absorbing materials, and the identification region S2 and the background region S1 have different light absorbing abilities, so that the difference in light absorbing abilities is obvious, and the reflected light intensities are different.

For example, the identification region S2 and the background region S1 are made of transparent materials, and the identification region S2 and the background region S1 have different light transmission capabilities, so that the difference in light transmission capabilities is significant, and the reflected light intensities are different.

According to the embodiment of the application, the difference value between the material reflection rate of the identification area S2 and the material reflection rate of the background area S1 is larger than the preset reflection threshold value, so that the brightness difference between the identification area S2 and the background area S1 is obvious, and an image recognition system of the total station terminal equipment can rapidly recognize the identification area S2 conveniently.

In some embodiments, the difference between the color reflectivity of the identification region S2 and the color reflectivity of the background region S1 is greater than the preset reflectivity threshold, i.e., the difference between the brightness of the identification region S2 and the brightness of the background region S1 is made obvious by the different reflectivity of the colors.

In one embodiment, the identification region S2 and the background region S1 have different hues and a distinct reflectivity difference.

For example, as shown in fig. 6, the identification region S2 is white in color, and the background region S1 is black in color; alternatively, as shown in fig. 8, the identification region S2 is black in color and the background region S1 is white in color. The brighter the white is, the darker the black is, the larger the difference in color brightness is, and the more conspicuous the identification region S2 is in contrast with the background region S1. For example, the recognition area S2 or the background area S1 is red, green, blue, or the like.

It should be noted that, the gray scales of the identification area S2 and the background area S1 shown in the drawings in the embodiments of the present application are only colors in the drawings, and different substances, such as a light-reflecting material, a light-transmitting material, a light-absorbing material, white, black, etc., may be actually represented on the target surface.

In one embodiment, the identification region S2 and the background region S1 have the same hue and different purity or saturation, for example, the identification region S2 or the background region S1 is dark red, pink, rose, etc.

The embodiment of the application preferably selects colors with different hues and obvious brightness difference. Such as white or black.

According to the embodiment of the application, the difference value between the color reflection rate of the identification area S2 and the color reflection rate of the background area S1 is larger than the preset reflection threshold value, so that the color brightness difference is obvious, and the rapid identification of the image identification system of the total station terminal equipment is realized.

It should be noted that, because the black material belongs to both the color category and the light absorption material, when the target is actually designed, the selection is flexible according to the difference between the reflection rates of the identification area S2 and the background area S1, and the difference between the reflection rates of the identification area S2 and the background area S1 is larger than the preset reflection threshold, and the difference is obvious.

In some embodiments, one of the identification region S2 and the background region S1 can emit light. That is, the brightness difference is caused by the difference in the light emission intensity between the recognition area S2 and the background area S1, for example, in the dark or the environment where natural light is weak, the light emission intensity between the recognition area S2 and the background area S1 is different. The difference in luminance between the recognition area S2 and the background area S1 is greater than a preset luminance threshold. In this way, the brightness difference between the identification area S2 and the background area S1 is significant, so that the total station can clearly distinguish the identification area S2 from the background area S1.

The difference in the light emission luminance between the recognition area S2 and the background area S1 can be achieved in different ways. For example, the identification region S2 and the background region S1 are made of different materials or provided members, and for example, the identification region S2 and the background region S1 are made of the same material or member, but have different light emitting capabilities.

In some embodiments, one of the identification region S2 and the background region S1 can emit light.

For example, one of the identification region S2 and the background region S1 is provided with a fluorescent material, and the other is a non-luminescent material. The fluorescent material comprises fluorescent powder, fluorescent cloth, fluorescent PVC material and the like.

For example, the identification region S2 may be configured as a light emitting diode that emits light when powered on, and similarly, the background region S1.

In some embodiments, both the identification region S2 and the background region S1 can emit light, but the identification region S2 emits light much more highly than the background region S1; alternatively, the light-emission luminance of the recognition region S2 is much lower than that of the background region S1.

For example, since the fluorescent materials have different brightness according to color difference, the brightness of the fluorescent material in the identification region S2 is much larger than that of the fluorescent material in the background region S1, or the brightness of the fluorescent material in the identification region S2 is much smaller than that of the fluorescent material in the background region S1, both of the identification region S2 and the background region S1 are fluorescent materials.

One of the identification area S2 and the background area S1 of the embodiment of the application can emit light, so that the brightness difference between the identification area S2 and the background area S1 is obvious, and an image recognition system of a total station terminal device can rapidly recognize the identification area S2 conveniently.

In some embodiments, the identification area S2 is a regular closed figure. For example, a circle, a square, a triangle, etc., a regular closed figure is advantageous for the image recognition system of the total station to be able to quickly determine the geometric center.

The target 2 is finally determined to be a target 2 central point in an image recognition system of the total station terminal equipment, a recognition area S2 located at the center is designed on the target surface so as to be convenient for fitting and determining a target measuring point, the recognition area S2 is set to be a regular closed graph, the fitting difficulty can be further reduced, and the central point of the recognition area S2 can be rapidly determined. In the embodiment of the present application, the pattern in the background region 1 is not limited, and may be a regular pattern or may not be a regular pattern.

In some embodiments, the background region S1 is a regular closed figure, and the geometric center of the identification region S2 coincides with the geometric center of the background region S1. As shown in fig. 6-8, the edge of the background region S1 is square, the side length is L, the identification region S2 is circular, the radius is R, and the distance between the edge of the background region S1 and the identification region S2 is L/2-R. In this way, the background region S1 is uniformly disposed around the recognition region S2, and when the background region S1 and the recognition region S2 have a certain distance, the edge of the recognition region S2 is clearer against the background region S1, which is convenient for recognition and fitting.

In an embodiment, the shape of the edge of the background region S1 is the same as the shape of the edge of the recognition region S2, as shown in fig. 9, the recognition region S2 is circular, and the edge of the background region S1 is also circular, so that the material layout of the background region S1 can be saved when the distance between the edge of the background region S1 and the recognition region S2 is the same.

As shown in FIGS. 9-10, a marking point S3, such as a cross-hair, can be designed at the center of the recognition area S2, and the lightness of the marking point S3 is significantly different from the lightness of the recognition area S2, so that the marking point S3 can be directly aligned. The target of this application embodiment not only is applicable to the automatic collimation of total powerstation and measures, can also use in the scene of non-automatic collimation measurement, for example, through set up the cross silk in target center department for can direct center collimation during artifical measurement.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions as claimed herein.

Claims (9)

1. A target, wherein a target surface of the target comprises: the brightness difference between the identification area and the background area is larger than a preset threshold value;

one of the identification region and the background region is capable of emitting light;

wherein, the center of the identification area is provided with a mark point, and the lightness difference between the mark point and the identification area is larger than a preset threshold value.

2. The target of claim 1, wherein the difference between the light reflectance of the identification region and the light reflectance of the background region is greater than a predetermined light reflectance threshold.

3. The target of claim 2, wherein the difference between the material reflectance of the identification region and the material reflectance of the background region is greater than the predetermined reflectance threshold.

4. A target according to claim 3, wherein the identification region material is a light absorbing material or a light transmitting material, and the background region material is a light reflecting material; or the identification area material is a reflective material, and the background area material is a light absorption material or a light transmission material.

5. The target of claim 2, wherein the difference between the color reflectance of the identification region and the color reflectance of the background region is greater than the predetermined reflectance threshold.

6. A target according to claim 5, wherein the identification region is white in color and the background region is black in color; or the color of the identification area is black, and the color of the background area is white.

7. A target according to claim 1, wherein one of the identification region and the background region is provided with a fluorescent material.

8. A target according to claim 1, wherein the identification areas are regular closed figures.

9. A target according to claim 8, wherein the background region is a regular closed figure and the geometric centre of the identification region coincides with the geometric centre of the background region.

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