Target sphere for 3D laser scanner and total station and coordinate conversion method

Abstract

The present application provides a target ball and coordinate conversion method for a three-dimensional laser scanner and a total station, including: a surveying prism, a hemisphere, a bracket, an adjustment mechanism, and a horizontal detection mechanism, wherein the adjustment mechanism is arranged on the bracket; the hemisphere is arranged in the adjustment mechanism, the surveying prism is arranged at the center of the hemisphere, and the adjustment center of the adjustment mechanism coincides with the center of the hemisphere, the prism center of the prism coincides with the center of the sphere, and the rotation axis of the hemisphere and the two rotation axes of the adjustment mechanism are perpendicular to each other, and are used to perform rotation adjustment of the surveying prism in three axes while keeping the center of the prism unchanged; the horizontal detection mechanism is arranged on the bracket, and is used to detect whether the bracket is horizontal. In this way, the center of the target ball and the center of the prism are physically in the same physical position, which simplifies the measurement process, avoids factors such as excessive scanning angle, unstable fixing method, unclear center of the target, etc., thereby reducing the generation of errors and improving the surveying accuracy.

Description

Technical Field

[0001] The present application relates to the field of surveying and mapping instrument auxiliary equipment, and in particular to a target ball for dual-purpose use of a three-dimensional laser scanner and a total station and a coordinate conversion method. Background Art

[0002] Since its invention, 3D laser scanning technology has been widely used in scientific research and production scenarios such as architectural design, engineering construction, surveying and mapping. In practical applications, it is often necessary to calculate the coordinate system of the scanned point cloud data. Since the spatial information data recorded by the 3D scanner is an independent relative coordinate system, a total station is often required to convert the coordinate system in engineering practice.

[0003] For example, the FARO X330 3D laser scanner generally uses a reflective target ball with a diameter of 247mm, and the effective collection distance is 30m. The positioning method is as follows: the system fits the acquired spherical point cloud data, finds a set of circle centers, and calculates the value closest to the actual circle center through the least squares method, and then the point is the target point. Each scene is spliced ​​through at least 3 common target points. According to actual measurement, the positioning point accuracy error is no more than 3mm, and the splicing deviation between each scanning station can be as low as 1mm. The point cloud coordinates obtained at this time are relative coordinate systems. If other coordinate systems need to be converted, it is necessary to import the coordinates of at least three points in the scene through the total station. Since the center of the target ball is not visible, the common method is to use a special flat target paper for coordinate import. However, in actual applications, data accuracy is often affected by problems such as excessive scanning angles, unstable fixing methods, and unclear bull's eye. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a target ball and a coordinate conversion method for use with a three-dimensional laser scanner and a total station, so as to improve the surveying accuracy of the three-dimensional laser scanner and the total station.

[0005] In order to achieve the above purpose, the embodiments of the present application are implemented in the following manner:

[0006] In the first aspect, an embodiment of the present application provides a target ball for use as a three-dimensional laser scanner and a total station, comprising: a surveying prism, a hemisphere, a bracket, an adjustment mechanism, and a horizontal detection mechanism, wherein the adjustment mechanism is arranged on the bracket; the hemisphere is arranged in the adjustment mechanism, the surveying prism is arranged at the center of the hemisphere, and the adjustment center of the adjustment mechanism coincides with the center of the hemisphere, the prism center of the prism coincides with the center of the sphere, and the rotation axis of the hemisphere and the two rotation axes of the adjustment mechanism are perpendicular to each other, and the rotation axis of the hemisphere cooperates with the two rotation axes of the adjustment mechanism to perform three-axis rotation adjustment of the surveying prism while keeping the center of the prism unchanged; the horizontal detection mechanism is arranged on the bracket, and is used to detect whether the bracket is horizontal.

[0007] In the embodiment of the present application, the adjustment mechanism is arranged on the bracket, the hemisphere is arranged in the adjustment mechanism, the mapping prism is arranged at the center of the hemisphere, and the adjustment center of the adjustment mechanism coincides with the center of the hemisphere, the prism center of the prism coincides with the center of the sphere, and the rotation axis of the hemisphere and the two rotation axes of the adjustment mechanism are perpendicular to each other, and the rotation axis of the hemisphere matches the two rotation axes of the adjustment mechanism. In this way, the mapping prism can be rotated and adjusted in three directions while keeping the center of the prism unchanged, and the horizontal detection mechanism is arranged on the bracket, so that it can detect whether the bracket is horizontal. In this way, the center of the target ball (i.e., the center of the hemisphere) and the center of the prism are physically in the same position, so that the same coordinate point data can be obtained by two measurement methods, 3D laser scanner surveying and total station surveying. When converting coordinate data, there is no need to use a dedicated flat target paper to import coordinates for at least three points in the scene through the total station, which simplifies the measurement process and avoids the influence of factors such as excessive scanning angle, unstable fixing method, unclear center of the target on data accuracy, thereby reducing the generation of errors and improving surveying accuracy. In addition, the target ball for 3D laser scanner and total station can be designed to be movable in three axes, and its mobility is greatly enhanced, so that the target point setting can overcome the limitations of terrain and environment and achieve greater visual effects.

[0008] In combination with the first aspect, in a first possible implementation of the first aspect, the adjustment mechanism is two circular rings whose rotation axes are perpendicular to each other and concentric, the centers of the two circular rings are the adjustment center, the hemisphere is arranged within the spherical range covered by the circular rings, and the center of the hemisphere coincides with the adjustment center, and the rotation axis of the hemisphere and the rotation axes of the two circular rings are perpendicular to each other.

[0009] In combination with the first possible implementation of the first aspect, in a second possible implementation of the first aspect, the bracket has a rod body, the adjustment mechanism is arranged at the top end of the rod body, and the central axis corresponding to the rod body passes through the center of the hemisphere, and the rotation axis of the hemisphere coincides with the central axis corresponding to the rod body.

[0010] In this implementation, the rotation axis of the hemisphere and the central axis corresponding to the rod body are designed to coincide with each other, so that the accuracy of adjusting the target ball used for both the three-dimensional laser scanner and the total station can be ensured.

[0011] In combination with the first possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the horizontal detection mechanism is a horizontal bubble, the horizontal bubble is arranged on the rod body of the bracket, and the normal of the plane where the horizontal bubble is located is parallel to the rod body.

[0012] In this implementation, by using the level bubble as a level detection mechanism, the level of the target ball used for both the three-dimensional laser scanner and the total station can be simply and intuitively determined, and it is easy to design and install.

[0013] In combination with the first possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the hemisphere is white, a balance rod is provided on the rod body, the balance rod and the rod body are crossed in a "cross" shape, the three-dimensional laser scanner and total station dual-purpose target ball also includes a dark background plate and a counterweight block, one end of the balance rod is provided with a background plate bearing portion for bearing the dark background plate; the other end of the balance rod is provided with a counterweight bearing portion for bearing the counterweight block, so that the balance rod remains horizontal, so that the position of the dark background plate is directly behind the surveying and mapping prism.

[0014] In this implementation, by designing the hemisphere to be white and equipping it with a dark background, under special conditions (such as long distance, low contrast background, etc.), it provides conditions that can enhance the visual difference between the target ball and the background, which can enhance the recognition rate at long distance and low contrast background, thereby improving the recognition efficiency of the software. The counterweight can balance the tilt problem caused by the gravity of the dark background to ensure the accuracy of surveying and mapping.

[0015] In combination with the first aspect, in a fifth possible implementation manner of the first aspect, a universal connecting piece is provided below the bracket for connecting with an expansion device, and the expansion device includes a tripod.

[0016] In this implementation, by setting a universal connector under the bracket, the dual-purpose target ball of the three-dimensional laser scanner and total station can be applied to different expansion devices. For example, it can be connected to a tripod or other connecting devices, so that it can be compatible with most of the current tripods and other connecting devices, effectively increasing the expandability and facilitating the application in various working environments.

[0017] In a second aspect, an embodiment of the present application provides a coordinate conversion method for a three-dimensional laser scanner and a total station, the method comprising: obtaining relative coordinate data surveyed by a three-dimensional laser scanner, wherein the relative coordinate data is obtained by surveying a three-dimensional laser scanner and a total station dual-purpose target sphere based on the first aspect or any one of the possible implementation methods of the first aspect by the three-dimensional laser scanner; obtaining the center coordinates of the three-dimensional laser scanner and total station dual-purpose target sphere calculated by point cloud fitting; obtaining the coordinates of a prism of the three-dimensional laser scanner and total station dual-purpose target sphere by a total station to obtain the center coordinates of the prism; performing coordinate conversion according to the center coordinates of the sphere, the center coordinates of the prism and the relative coordinate data to obtain the coordinate data after coordinate conversion.

[0018] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of a target sphere for dual-purpose use of a three-dimensional laser scanner and a total station provided in an embodiment of the present application.

[0021] Figure 2 A flowchart of a coordinate conversion method between a three-dimensional laser scanner and a total station provided in an embodiment of the present application.

[0022] Icons: 100-target ball for both 3D laser scanner and total station; 110-surveying prism; 120-hemispherical body; 130-adjustment mechanism; 140-bracket; 150-horizontal detection mechanism; 160-balance bar; 170-counterweight; 180-dark background plate; 190-universal connector. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0024] See also Figure 1 , Figure 1 A schematic diagram of a target sphere 100 for both a three-dimensional laser scanner and a total station provided in an embodiment of the present application.

[0025] In this embodiment, the target ball 100 for a three-dimensional laser scanner and a total station may include a surveying prism 110, a hemisphere 120, a bracket 140, an adjustment mechanism 130, and a horizontal detection mechanism 150. The adjustment mechanism 130 may be arranged on the bracket 140, and the hemisphere 120 is arranged in the adjustment mechanism 130. The surveying prism 110 is arranged at the center of the hemisphere 120, and the adjustment center of the adjustment mechanism 130 coincides with the center of the hemisphere 120, and the prism center of the prism coincides with the center of the sphere, and the rotation axis of the hemisphere 120 and the two rotation axes of the adjustment mechanism 130 are perpendicular to each other, and the rotation axis of the hemisphere 120 cooperates with the two rotation axes of the adjustment mechanism 130 to perform rotation adjustment of the surveying prism 110 in three directions under the condition of keeping the center of the prism unchanged; the horizontal detection mechanism 150 may be arranged on the bracket 140 to detect whether the bracket 140 is horizontal.

[0026] By setting the adjustment mechanism 130 on the bracket 140, setting the hemisphere 120 in the adjustment mechanism 130, and setting the mapping prism 110 at the center of the hemisphere 120, the adjustment center of the adjustment mechanism 130 coincides with the center of the hemisphere 120, the prism center of the prism coincides with the center of the sphere, and the rotation axis of the hemisphere 120 and the two rotation axes of the adjustment mechanism 130 are perpendicular to each other, and the rotation axis of the hemisphere 120 matches the two rotation axes of the adjustment mechanism 130. In this way, the mapping prism 110 can be rotated and adjusted in three directions while keeping the center of the prism unchanged, and the horizontal detection mechanism 150 is set on the bracket 140, so that it can detect whether the bracket 140 is horizontal. In this way, the center of the target ball (i.e., the center of the hemisphere 120) and the center of the prism are physically in the same position, so that the same coordinate point data can be obtained by two measurement methods, namely, the three-dimensional laser scanner surveying and the total station surveying. When converting the coordinate data, there is no need to import the coordinates of at least three points in the scene through the total station using a dedicated flat target paper, which simplifies the measurement process and avoids the factors such as the large scanning angle, the unstable fixing method, and the unclear center of the target affecting the data accuracy, thereby reducing the generation of errors and improving the surveying accuracy. In addition, the target ball 100 for the three-dimensional laser scanner and the total station can be designed to be movable in three axes, and its mobility is greatly enhanced, so that the target point setting can overcome the limitations of terrain and environment and achieve greater visual effects.

[0027] In this embodiment, the adjustment mechanism 130 can be two circular rings with mutually perpendicular and concentric rotation axes, the centers of the two circular rings are the adjustment centers, the hemisphere 120 is arranged within the spherical range covered by the circular rings, and the center of the hemisphere 120 coincides with the adjustment center, and the rotation axis of the hemisphere 120 and the rotation axes of the two circular rings are mutually perpendicular. In addition, the hemisphere 120 can rotate along its rotation axis, and the two circular rings can also rotate independently along their respective rotation axes, so that the posture of the surveying and mapping prism 110 can be adjusted by rotating along these three rotation axes without changing the prism center of the surveying and mapping prism 110.

[0028] Exemplarily, the two rings can be mutually perpendicular metal rings mounted outside the hemisphere 120, and the hemisphere 120 can rotate within the range surrounded by the two rings, and the rotation direction is perpendicular to the rotation direction of the two rings, thereby ensuring the accuracy of the adjustment of the dual-purpose target ball 100 for the three-dimensional laser scanner and total station.

[0029] In this embodiment, the bracket 140 has a rod body, the adjustment mechanism 130 is arranged at the top of the rod body, and the central axis corresponding to the rod body passes through the center of the hemisphere 120, and the rotation axis of the hemisphere 120 coincides with the central axis corresponding to the rod body. By designing the rotation axis of the hemisphere 120 and the central axis corresponding to the rod body to coincide, the accuracy of the target ball 100 for the dual-purpose of the three-dimensional laser scanner and the total station can be guaranteed during adjustment.

[0030] In this embodiment, the level detection mechanism 150 can be a level bubble, which is arranged on the rod body of the bracket 140, and the normal line of the plane where the level bubble is located is parallel to the rod body. By using the level bubble as the level detection mechanism 150, the level of the target ball 100 for both the three-dimensional laser scanner and the total station can be simply and intuitively judged, and it is easy to design and install.

[0031] In this embodiment, the hemisphere 120 is white, and a balance pole 160 is provided on the pole body. The balance pole 160 and the pole body are crossed in a "cross" shape. The target ball 100 for both a three-dimensional laser scanner and a total station also includes a dark background plate 180 and a counterweight 170. A background plate bearing portion is provided at one end of the balance pole 160 for bearing the dark background plate 180; a counterweight bearing portion is provided at the other end of the balance pole 160 for bearing the counterweight 170, so that the balance pole 160 remains horizontal, thereby making the dark background plate 180 directly behind the surveying and mapping prism 110.

[0032] By designing the hemisphere 120 to be white and equipping it with a dark background board 180, under special conditions (such as long distance, low contrast background, etc.), it provides conditions for enhancing the visual difference between the target ball and the background, which can enhance the recognition rate at long distance and low contrast background, thereby improving the recognition efficiency of the software. The counterweight block 170 can balance the tilt problem caused by the gravity of the dark background board 180 to ensure the mapping accuracy.

[0033] Exemplarily, the material of the dark background plate 180 may be matte ABS (Acrylonitrile Butadiene Styrene plastic, ABS plastic) with a size of 400 mm*400 mm.

[0034] Exemplarily, the dark background board 180 can also be foldably connected to the balance pole 160, and can be erected when needed, and the counterweight block 170 can also be fixed on the balance pole 160, so that when the dark background board 180 is not in use, it can also play a balancing role to ensure the surveying and mapping accuracy.

[0035] In this embodiment, a universal connector 190 is provided below the bracket 140 for connecting with an expansion device, and the expansion device includes a tripod. Of course, the expansion device is not limited to a tripod, and may also be other devices. For example, in order to enable the three-dimensional laser scanner and total station dual-purpose target ball 100 to adapt to special terrain, it is necessary to connect with a dedicated stabilizing device designed for such terrain, so that it can be connected with the device through the universal connector 190, which is not limited here.

[0036] By setting a universal connecting piece 190 under the bracket 140, the dual-purpose target ball 100 of the three-dimensional laser scanner and total station can be applied to different expansion devices. For example, it can be connected to a tripod or other connecting devices, so that it can be compatible with most of the current tripods and other connecting devices, effectively increasing the expandability and facilitating the application in various working environments.

[0037] Exemplarily, the universal connector 190 may be a standard British 3 / 8 screw interface, so that it can be compatible with most current tripods and expansion devices.

[0038] In addition, the rod body can be rotated and plugged in and out, which is convenient for assembling and adjusting the posture of the dual-purpose target ball 100 for the three-dimensional laser scanner and total station, which is not limited here.

[0039] It should be noted that the hemisphere 120 introduced in this embodiment can be a strict 1 / 2 sphere or not, as long as the center of the prism is kept consistent with the center of the sphere, and the spherical point cloud of the target sphere can be obtained in three-dimensional laser scanning to accurately fit and calculate the center of the sphere, and the 1 / 2 sphere is sufficient for the center fitting calculation. Therefore, this embodiment only takes the hemisphere 120 of the 1 / 2 sphere as an example, which should not be regarded as a limitation on the present application.

[0040] Based on the same inventive concept, the present application also provides a coordinate conversion method for a three-dimensional laser scanner and a total station. Figure 2 , Figure 2 A flowchart of a coordinate conversion method between a three-dimensional laser scanner and a total station provided in an embodiment of the present application.

[0041] In this embodiment, the coordinate conversion method between the three-dimensional laser scanner and the total station may include step S10, step S20, step S30 and step S40.

[0042] Step S10: Acquire relative coordinate data measured by the three-dimensional laser scanner, wherein the relative coordinate data is obtained by the three-dimensional laser scanner based on a target ball 100 used for both the three-dimensional laser scanner and the total station.

[0043] Step S20: obtaining the center coordinates of the target sphere for both the three-dimensional laser scanner and the total station calculated by point cloud fitting.

[0044] Step S30: acquiring the coordinates of the prism of the target ball used as both a three-dimensional laser scanner and a total station through a total station to obtain the center coordinates of the prism.

[0045] Step S40: performing coordinate transformation according to the spherical center coordinates, the prism center coordinates and the relative coordinate data to obtain coordinate data after coordinate transformation.

[0046] In this embodiment, the 3D laser scanner can scan the target ball based on the 3D laser scanner and the total station to obtain relative coordinate data. After the scanning is completed, the total station is used to obtain the coordinates of the prism at the center of the ball, and the coordinate system conversion of the two surveying and mapping systems can be performed.

[0047] At this point, the total station may execute step S10.

[0048] In this embodiment, the total station can obtain relative coordinate data measured by the three-dimensional laser scanner.

[0049] And, the total station may execute step S20.

[0050] Exemplarily, the total station can obtain the center coordinates of the target sphere 100 for both the three-dimensional laser scanner and the total station calculated by point cloud fitting.

[0051] And, the total station may execute step S30.

[0052] The coordinates of the prism of the target sphere 100 for both the three-dimensional laser scanner and the total station are acquired by a total station to obtain the coordinates of the center of the prism.

[0053] It should be noted that the execution order of step S10, step S20 and step S30 is not strictly limited, and they can be executed in any order or simultaneously, which is not limited here.

[0054] Then, the total station may execute step S40.

[0055] Exemplarily, the total station can perform coordinate transformation according to the spherical center coordinates, the prism center coordinates and the relative coordinate data to obtain coordinate data after coordinate transformation.

[0056] This method eliminates the need to import coordinates of at least three points in the scene through a total station (for example, using dedicated flat target paper for coordinate import), thus avoiding the situation in actual applications where data accuracy is affected by problems such as excessive scanning angles, unstable fixing methods, and unclear bull's eye, thereby improving the accuracy of surveying and mapping data.

[0057] In order to verify the accuracy of a target ball and a coordinate conversion method for a three-dimensional laser scanner and a total station provided in the embodiment of the present application, data comparing the use of the target ball with the traditional method in a certain scanning operation is provided here, as follows:

[0058] Since the point cloud data of 3D laser scanning is an independent coordinate system, when the known control network coordinate conversion is required, at least three common points in the point cloud need to be measured using a total station, and then the measured coordinate values ​​are imported into the point cloud data for conversion. The experimental method is as follows: Group A uses the traditional method to paste the printed black and white chessboard target paper on site. The total station and the scanned point cloud jointly select the center of the target paper as the common point for measurement. Group B uses a 3D laser scanner and a total station dual-purpose target ball 100. The total station directly measures the coordinates of the prism at the center of the sphere, and the scanner uses hemisphere fitting to calculate the coordinates of the center of the sphere as the common point. After the two sets of coordinates are measured and converted, a set of feature points in the point cloud are taken for re-measurement by the total station to check the error between the measured value and the calculated value, and then a comparison is made.

[0059] The retest results of Group A are shown in Table 1:

[0060] Table 1

[0061]

[0062] The retest results of Group B are shown in Table 2:

[0063] Table 2

[0064]

[0065]

[0066] After actual measurement and comparison, the average measurement error was reduced from 5.8mm to 1.8mm after using the dual-purpose target ball of the 3D laser scanner and the total station, and the measurement accuracy was more than 3 times higher than that of the traditional black and white chessboard target paper. This experiment proves that the dual-purpose target ball of the 3D laser scanner and the total station can effectively improve the measurement accuracy in actual engineering measurement applications.

[0067] In summary, the embodiment of the present application provides a target ball 100 for dual-purpose of a three-dimensional laser scanner and a total station and a coordinate conversion method, by setting the adjustment mechanism 130 on the bracket 140, setting the hemisphere 120 in the adjustment mechanism 130, and setting the mapping prism 110 at the center of the hemisphere 120, and the adjustment center of the adjustment mechanism 130 coincides with the center of the hemisphere 120, and the prism center of the prism coincides with the center of the sphere, and the rotation axis of the hemisphere 120 and the two rotation axes of the adjustment mechanism 130 are perpendicular to each other, and the rotation axis of the hemisphere 120 cooperates with the two rotation axes of the adjustment mechanism 130. In this way, the mapping prism 110 can be rotated and adjusted in three directions while keeping the center of the prism unchanged, and the horizontal detection mechanism 150 is set on the bracket 140, so that it can detect whether the bracket 140 is horizontal. In this way, the center of the target ball (i.e., the center of the hemisphere 120) and the center of the prism are physically in the same position, so that the same coordinate point data can be obtained by two measurement methods, namely, the three-dimensional laser scanner surveying and the total station surveying. When converting the coordinate data, there is no need to import the coordinates of at least three points in the scene through the total station using a dedicated flat target paper, which simplifies the measurement process and avoids the factors such as the large scanning angle, the unstable fixing method, and the unclear center of the target affecting the data accuracy, thereby reducing the generation of errors and improving the surveying accuracy. In addition, the target ball 100 for the three-dimensional laser scanner and the total station can be designed to be movable in three axes, and its mobility is greatly enhanced, so that the target point setting can overcome the limitations of terrain and environment and achieve greater visual effects.

[0068] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0069] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A target ball for use as a 3D laser scanner and a total station, characterized in that: include: Surveying prism, hemisphere, bracket, adjustment mechanism, level detection mechanism, The adjustment mechanism is arranged on the bracket; The hemisphere is arranged in the adjustment mechanism, the surveying prism is arranged at the center of the hemisphere, and the adjustment center of the adjustment mechanism coincides with the center of the hemisphere, the prism center of the prism coincides with the center of the sphere, and the rotation axis of the hemisphere and the two rotation axes of the adjustment mechanism are perpendicular to each other, and the rotation axis of the hemisphere cooperates with the two rotation axes of the adjustment mechanism to perform rotation adjustment of the surveying prism in three directions while keeping the center of the prism unchanged; The horizontal detection mechanism is arranged on the bracket, and is used to detect whether the bracket is horizontal; The adjustment mechanism is two circular rings whose rotation axes are perpendicular to each other and concentric, the centers of the two circular rings are the adjustment center, the hemisphere is arranged within the spherical range covered by the circular rings, and the center of the hemisphere coincides with the adjustment center, the rotation axis of the hemisphere and the rotation axes of the two circular rings are perpendicular to each other, and the two circular rings are metal rings.

2. The target ball for a three-dimensional laser scanner and a total station according to claim 1 is characterized in that: The bracket has a rod body, the adjustment mechanism is arranged at the top end of the rod body, and the central axis corresponding to the rod body passes through the center of the hemisphere, and the rotation axis of the hemisphere coincides with the central axis corresponding to the rod body.

3. The target ball for the dual-purpose three-dimensional laser scanner and total station according to claim 1 is characterized in that: The level detection mechanism is a horizontal bubble, The horizontal bubble is arranged on the rod body of the bracket, and the normal line of the plane where the horizontal bubble is located is parallel to the rod body.

4. The target ball for the dual-purpose three-dimensional laser scanner and total station according to claim 2 is characterized in that: The hemisphere is white, a balance bar is arranged on the rod body, and the balance bar and the rod body are in a "cross" shape. The target ball for the three-dimensional laser scanner and the total station also includes a dark background plate and a counterweight. One end of the balance bar is provided with a background board bearing portion for bearing the dark background board; The other end of the balance pole is provided with a counterweight bearing portion for bearing the counterweight block, so that the balance pole remains horizontal, thereby making the dark background plate located directly behind the surveying and mapping prism.

5. The target ball for dual-purpose of a three-dimensional laser scanner and a total station according to claim 1, characterized in that: A universal connector is provided below the bracket for connecting with an expansion device, wherein the expansion device includes a tripod.

6. A coordinate conversion method for a three-dimensional laser scanner and a total station, characterized in that: The method comprises: Acquire relative coordinate data measured by a three-dimensional laser scanner, wherein the relative coordinate data is obtained by the three-dimensional laser scanner based on the three-dimensional laser scanner and total station dual-purpose target ball according to any one of claims 1 to 5; Obtaining the center coordinates of the target sphere for the three-dimensional laser scanner and total station calculated by point cloud fitting; The coordinates of the prism of the target ball used for both the three-dimensional laser scanner and the total station are acquired by a total station to obtain the center coordinates of the prism; Coordinate transformation is performed according to the spherical center coordinates, the prism center coordinates and the relative coordinate data to obtain coordinate data after coordinate transformation.

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