CN115451862A - Three-dimensional scanning method and three-dimensional scanning system - Google Patents

Abstract

The application relates to a three-dimensional scanning method and a three-dimensional scanning system, wherein the three-dimensional scanning method comprises the following steps: when the scanning device is positioned outside the preset optimal tracking range of the tracking device, changing the tracking visual angle of the tracking device so as to enable the scanning device to be positioned in the preset optimal tracking range of the tracking device and obtain the tracking result of the tracking device; and completing the three-dimensional reconstruction of the measured object according to the tracking result of the scanning device by the tracking device of the scanning device under different tracking visual angles of the tracking device, the scanning result of the scanning device and the tracking pose of the tracking device relative to a preset reference coordinate system. According to the tracking device, the tracking visual angle of the tracking device is adjusted, so that the working range of the tracking device when the tracking device tracks the scanning device is expanded, and the problem that the working range of the tracking device is limited by the tracking range of the tracking device in the current three-dimensional scanning is solved.

Description

Three-dimensional scanning method and three-dimensional scanning system

technical field

The present application relates to the field of three-dimensional scanning, in particular to a three-dimensional scanning method and a three-dimensional scanning system.

Background technique

In the process of scanning objects based on a tracking 3D scanner, the pose of the scanning head is often tracked by setting the tracking head on a fixed bracket, and the scanning head is used to move to different areas within the field of view of the tracking head The object is scanned to complete the three-dimensional reconstruction of the object. Since the position of the tracking head is fixed during the scanning process, this scanning method is limited by the tracking range of the tracking head at the fixed position.

Aiming at the problem in the related art that the working range of the tracking device is limited by its own fixed tracking range, no effective solution has been proposed so far.

Contents of the invention

In this embodiment, a three-dimensional scanning method and a three-dimensional scanning system are provided to solve the problem in the related art that the working range of the tracking device is limited by its own fixed tracking range.

In the first aspect, this embodiment provides a three-dimensional scanning method for a three-dimensional scanning system, the three-dimensional scanning system includes a scanning device and a tracking device, wherein the tracking device can keep the original position unchanged In some cases, change the tracking angle of view of the tracking device; the three-dimensional scanning method includes:

In the process of scanning the object under test by the scanning device, judging whether the scanning device is outside the preset optimal tracking range of the tracking device;

When the scanning device is outside the preset optimal tracking range of the tracking device, changing the tracking angle of view of the tracking device so that the scanning device is located within the preset optimal tracking range of the tracking device , and obtain the tracking result of the tracking device;

According to the tracking results of the scanning device by the tracking device under different tracking angles of view of the tracking device, the scanning results of the scanning device, and the tracking of the tracking device relative to a preset reference coordinate system pose to complete the three-dimensional reconstruction of the measured object.

In some of the embodiments, when the scanning device is outside the preset optimal tracking range of the tracking device, the tracking angle of view of the tracking device is changed so that the scanning device is located in the tracking range. within the preset optimal tracking range of the device, and obtain the tracking results of the tracking device, including:

When the scanning device is outside the preset optimal tracking range of the tracking device, adjust the tracking angle of view of the tracking device according to a preset range until the scanning device is located at the preset optimal tracking range of the tracking device. Within the tracking range, stop adjusting the tracking angle of view.

In some of the embodiments, when the scanning device is outside the preset optimal tracking range of the tracking device, the tracking angle of view of the tracking device is changed so that the scanning device is located in the tracking range. within the preset optimal tracking range of the device, and obtain the tracking result of the tracking device, further comprising:

When the scanning device is outside the preset optimal tracking range of the tracking device, calculating the position of the scanning device within the preset optimal tracking range of the tracking device according to the scanning position of the scanning device projection information;

Converting the projection information into viewing angle adjustment parameters of the tracking device based on a preset projection conversion relationship;

The tracking viewing angle of the tracking device is adjusted based on the viewing angle adjustment parameter, so that the scanning device is located within a preset optimal tracking range of the tracking device.

In some of the embodiments, the calculation of the projection information of the scanning device within the preset optimal tracking range of the tracking device according to the scanning position of the scanning device includes:

According to the scanning position of the scanning device, calculate the projection angle of the scanning device on each coordinate axis under the three-dimensional coordinate system mapped by the preset optimal tracking range of the tracking device;

The projection angles of the scanning device on each coordinate axis in the coordinate system mapped by the optimal tracking range are determined as the projection information.

In some of these embodiments, according to the tracking results of the scanning device by the tracking device under different tracking angles of view of the tracking device, the scanning results of the scanning device, and the tracking device Relative to the tracking pose of the preset reference coordinate system, before completing the three-dimensional reconstruction of the measured object, the three-dimensional scanning method further includes:

According to the viewing angle transformation relationship pre-calibrated by the tracking device, calculate the tracking pose of the tracking device relative to the preset reference coordinate system under different tracking viewing angles; wherein the viewing angle transformation relationship is pre-adjusted by the tracking device It is obtained by tracking the preset calibration pieces under different tracking angles of view.

In some of these embodiments, the preset reference coordinate system is the origin coordinate system of the pre-established marker point library; when the scanning device is located at different tracking angles of view of the tracking device for the tracking device The tracking result of the scanning device, the scanning result of the scanning device, and the tracking pose of the tracking device relative to a preset reference coordinate system, before completing the three-dimensional reconstruction of the measured object, the three-dimensional scanning method also include:

Acquiring local marker points identified by the tracking device under the different tracking viewing angles;

Match the local markers with the marker library, and if the local markers are successfully matched with the marker library, obtain the tracking based on the local markers and the marker library The tracking pose of the device relative to the origin coordinate system of the marker point library under different tracking viewing angles.

In some of these embodiments, the preset reference coordinate system is a marker point library origin coordinate system updated in real time based on the marker points acquired by the tracking device. The tracking result of the scanning device by the tracking device, the scanning result of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system are used to complete the three-dimensional reconstruction of the measured object Before, the three-dimensional scanning method also includes:

Acquiring local marker points identified by the tracking device under the different tracking viewing angles;

If there is marker data in the marker library, match the local markers with the marker library, and if the local markers are successfully matched with the marker library, based on the The local marker point and the marker point library, obtain the tracking pose of the tracking device relative to the origin coordinate system of the marker point library under different tracking angles of view, and update the marker point library based on the local marker points;

When the marker data in the marker library is empty, the marker library is established based on the local markers.

In some of the embodiments, the tracking device is fixedly arranged on the rotating platform, and the tracking device is rotated by the rotating platform to change the tracking angle of view of the tracking device.

In the second aspect, this embodiment provides a three-dimensional scanning system, the three-dimensional scanning system includes a scanning device, a tracking device, and a control device, wherein the tracking device can keep the original position unchanged , changing the tracking angle of view of the tracking device;

The scanning device is used to scan the measured object to obtain a scanning result, and send the scanning result to the control device;

The tracking device is used to track the scanning device to obtain a tracking result;

The control device is used to implement the three-dimensional scanning method described in the first aspect above.

In some of the embodiments, the three-dimensional scanning system further includes a rotating platform and a guide rail; wherein: the tracking device is fixedly arranged on the rotating platform; the rotating platform is arranged on the guide rail;

The rotating platform is used to drive the tracking device to rotate and drive the tracking device to move along the guide rail.

Compared with related technologies, the three-dimensional scanning method and three-dimensional scanning system provided in this embodiment judge whether the scanning device is located in the preset optimal tracking range of the tracking device during the process of scanning the measured object by the scanning device; When the scanning device is outside the preset optimal tracking range of the tracking device, change the tracking angle of view of the tracking device so that the scanning device is located in the preset optimal tracking range of the tracking device, and obtain the tracking result of the tracking device; according to the scanning The device is located under different tracking angles of view of the tracking device, the tracking results of the tracking device to the scanning device, the scanning results of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system complete the three-dimensional reconstruction of the measured object. By adjusting the tracking angle of view of the tracking device, the working range of the tracking device when tracking the scanning device is expanded, thereby solving the problem that the working range of the tracking device is limited by its own tracking range in the current three-dimensional scanning.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below, so as to make other features, objects, and advantages of the application more comprehensible.

Description of drawings

The drawings described here are used to provide a further understanding of the application and constitute a part of the application. The schematic embodiments and descriptions of the application are used to explain the application and do not constitute an improper limitation to the application. In the attached picture:

FIG. 1 is an application scene diagram 1 of the three-dimensional scanning method provided in this embodiment;

Fig. 2 is the application scene diagram 2 of the three-dimensional scanning method provided by this embodiment;

Fig. 3 is a flow chart of the three-dimensional scanning method of the present embodiment;

Fig. 4 is a schematic diagram of the combination of the tracking device and the turntable in this embodiment;

FIG. 5 is a schematic diagram of the optimal tracking range of the tracking device provided in this embodiment;

Fig. 6 is a schematic diagram of adjusting the tracking range of the tracking device in this embodiment;

Fig. 7 is a flow chart of the three-dimensional scanning method of the preferred embodiment 1;

Fig. 8 is a flow chart of the three-dimensional scanning method of the preferred embodiment 2;

Fig. 9 is a flow chart of the three-dimensional scanning method of the third preferred embodiment;

Fig. 10 is a schematic structural diagram of the three-dimensional scanning system provided in this embodiment.

detailed description

In order to understand the purpose, technical solution and advantages of the present application more clearly, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

Unless otherwise defined, the technical terms or scientific terms involved in the application shall have the general meanings understood by those skilled in the technical field to which the application belongs. In this application, words like "a", "an", "an", "the", "these" and the like do not denote quantitative limitations, and they may be singular or plural. The terms "comprising", "comprising", "having" and any variants thereof referred to in this application are intended to cover non-exclusive inclusion; for example, processes, methods and The system, product or device is not limited to the steps or modules (units) listed, but may include steps or modules (units) not listed, or may include other steps or modules inherent to the process, method, product or device (unit). The terms "connected", "connected", "coupled" and the like referred to in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Plurality" referred to in this application means two or more. "And/or" describes the association relationship of associated objects, indicating that there may be three types of relationships. For example, "A and/or B" may indicate: A exists alone, A and B exist simultaneously, and B exists independently. Usually, the character "/" indicates that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third" and the like involved in this application are only for distinguishing similar objects, and do not represent a specific ordering of objects.

FIG. 1 is the first application scene diagram of the three-dimensional scanning method provided in this embodiment. As shown in FIG. 1 , the three-dimensional scanning system includes a scanning device 101 and a tracking device 102 . Wherein, the scanning device 101 is used to scan the measured object 103, and the tracking device 102 is used to track the scanning device 101, and the tracking device 102 can change the tracking angle of view of the tracking device 102 while keeping the original position unchanged. Wherein, in the process of scanning the measured object 103 by the scanning device 101 , it is judged whether the scanning device 101 is located in the preset optimal tracking range of the tracking device 102 . When the scanning device 101 is outside the preset optimal tracking range of the tracking device 102, change the tracking angle of view of the tracking device 102 so that the scanning device 101 is located in the preset optimal tracking range of the tracking device 102, and obtain the tracking device 102 tracking results. According to the different tracking angles of view of the scanning device 101 located in the tracking device 102, the tracking results of the tracking device 102 on the scanning device 101, the scanning results of the scanning device 101, and the tracking pose of the tracking device 102 relative to the preset reference coordinate system, the tracking of the tracked device 102 is completed. 3D reconstruction of the measured object 103.

FIG. 2 is the second application scene diagram of the three-dimensional scanning method provided in this embodiment. As shown in FIG. 2 , the three-dimensional scanning system includes a scanning device 201 and a tracking device 202 . Wherein, the scanning device 201 is used to scan the measured object 203, and the tracking device 202 is used to track the scanning device 201, and the tracking device 202 can change the tracking angle of view of the tracking device 202 while keeping the original position unchanged. When the scanning device 201 scans the measured object 203, the tracking device 202 can track the scanning device 201 by adjusting the tracking angle of view so that the scanning device 201 is within its optimal tracking range, so as to complete the measured Three-dimensional reconstruction of object 203 . Wherein, as shown in Figure 2, in this application scenario, the surface of the measured object 203 can also be pasted with several marking points, which are represented by black dots in the figure, and the tracking device 202 can also be completed based on the marking points on the surface of the measured object 203. pose calibration.

In this embodiment, a three-dimensional scanning method is provided, which is used in a three-dimensional scanning system. The three-dimensional scanning system includes a scanning device and a tracking device, wherein the tracking device can change the tracking position of the tracking device while keeping the original position unchanged. perspective. Fig. 3 is a flow chart of the three-dimensional scanning method of the present embodiment, as shown in Fig. 3, the process includes the following steps:

Step S310, during the process of the scanning device scanning the measured object, it is judged whether the scanning device is outside the preset optimal tracking range of the tracking device.

Wherein, the tracking device can be installed on any mechanical rotating device that can be rotated by driving, so as to realize the change of the tracking angle of view of the tracking device. For example, the tracking device can be driven to rotate by a rotating device such as a servo motor, a turntable, or a turntable, so as to change its tracking angle of view. Preferably, the tracking device can be fixed on the turntable, and the tracking angle of view of the tracking device can be adjusted based on the rotation of the turntable. FIG. 4 is a schematic diagram of the combination of the tracking device and the turntable in this embodiment. As shown in FIG. 4 , the turntable 402 includes a base and a flange, and the tracking device 401 is fixedly installed on the flange of the turntable 402 . The base of the turntable 402 is connected to the flange through one or more driving shafts, and the movement of the driving shafts is controlled to drive the flange to rotate relative to the base, thereby driving the tracking device 401 to rotate. It should be noted that the tracking device changes the tracking angle of view while keeping the original position unchanged, which means that the position of the bracket or base on which the tracking device is installed does not change during the process of changing the tracking angle of view of the tracking device.

During the three-dimensional scanning process, the tracking device is used to track the scanning device. Therefore, in order to realize the real-time tracking of the scanning device by the tracking device, it is necessary to ensure that the scanning device is in the tracking device during the process of the scanning device scanning the measured object. within the tracking range. Wherein, whether the scanning device is located within the tracking range of the tracking device can be determined by judging whether the tracking device can observe the locator set on the scanning device within its tracking range. Preferably, in order to improve the tracking accuracy of the scanning device by the tracking device, it can be determined whether the scanning device is within the optimal tracking range preset by the tracking device, and the preset optimal tracking range is based on the tracking range with the highest imaging accuracy of the tracking device. determined, and the preset optimal tracking range is smaller than the overall tracking range of the tracking device. It can be seen that when the scanning device is at the edge of the tracking range of the tracking device, it means that the scanning device is outside the optimal tracking range of the tracking device.

Step S320, when the scanning device is outside the preset optimal tracking range of the tracking device, change the tracking angle of view of the tracking device so that the scanning device is located within the preset optimal tracking range of the tracking device, and obtain the tracking information of the tracking device result.

Wherein, after the tracking angle of view of the tracking device is adjusted, the information observed by the tracking device within its tracking range will change accordingly. When it is determined that the scanning device is located outside the preset optimal tracking range of the tracking device, the tracking angle can be changed by adjusting the rotation range of the tracking device, so that the scanning device can be relocated to the preset optimal tracking range of the tracking device. within the tracking range. For example, when it is determined that the scanning device is located in the edge area of the tracking range of the tracking device, the accuracy of the tracking result of the scanning device is low at this time, so it is necessary to adjust the tracking angle of view of the tracking device so that the scanning device is repositioned at the edge of the tracking device. Best tracking range. The adjustment of the tracking angle of view of the tracking device can be realized by automatic adjustment or manual adjustment.

For example, in combination with the pre-calibrated kinematics solution model of the rotating device mounted on the tracking device, the kinematic parameters of each component of the rotating device can be set to realize the rotation of the rotating device, thereby changing the tracking angle of view of the tracking device. For another example, based on the image information collected by the tracking device within its tracking range, the tracking angle of view of the tracking device may be continuously manually adjusted until the scanning device is within the preset optimal tracking range of the tracking device, and the adjustment of the tracking angle of view is stopped. In addition, it should be noted that when adjusting the tracking angle of view of the tracking device, the calculation of the angle of view adjustment parameter corresponding to the adjustment of the tracking angle of view can be performed before the adjustment, and the automatic tracking of the tracking angle of view of the tracking device can be completed based on the angle of view adjustment parameter. Adjustment, so that the scanning device can be located within the preset optimal tracking range of the tracking device under one tracking viewing angle adjustment of the tracking device. Similarly, the tracking angle of view can also be adjusted successively according to the preset adjustment range until the scanning device is within the preset optimal tracking range of the tracking device and then the adjustment of the tracking angle of view is stopped. To sum up, the way of adjusting the tracking angle of view can be adaptively set according to the requirements of the actual application scenario, which is not specifically limited in this embodiment.

In addition, when the scanning device is located in the preset optimal tracking range of the tracking device, the tracking device tracks the pose of the scanning device to obtain a tracking result. Specifically, the tracking device can track the locator on the scanning device to obtain its position information in the coordinate system of the tracking device, and then calculate the pose of the scanning device in the coordinate system of the tracking device. Wherein, the locator is rigidly connected with the scanning device, and the positional relationship between the two is fixed.

In the related art, the tracking device is arranged on a fixed bracket to track the pose of the scanning head, so the scanning device needs to scan within the fixed tracking range of the tracking device during the scanning process. Therefore, the working range of the current tracking three-dimensional scanner is limited by the fixed tracking range of the tracking device. In this embodiment, by adjusting the tracking angle of view of the tracking device, the scanning device is located within the preset optimal tracking range of the tracking device, thereby releasing the restriction of the tracking device's tracking work by the fixed tracking range of the tracking device, and further expanding the work of the tracking device scope.

Step S330, according to the tracking results of the scanning device by the tracking device located at different tracking angles of view of the tracking device, the scanning results of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system, complete the tracking of the measured object Three-dimensional reconstruction.

Wherein, the preset reference coordinate system may be a coordinate system of a fixed reference object in the scanning scene. For example, the turntable described above that includes a flange and a base. The base of the turntable is fixedly installed at the preset working position. When the viewing angle of the tracking device needs to be adjusted, only the flange is controlled to rotate, while the base is kept fixed. Therefore, the coordinate system of the base can be used as a reference coordinate system. In addition, the preset reference coordinate system may also be the global coordinate system of the three-dimensional scanning system determined in advance based on the global photogrammetry technology. For example, the global photogrammetry equipment pre-photographs all the marker points pasted in the entire scanning scene of the 3D scanning system, so as to establish a global marker point library. The origin coordinate system of the marker point library is the above-mentioned reference coordinate system.

During the three-dimensional scanning process, the scanning device scans the measured object to obtain the point cloud data of the measured object, and the tracking device tracks the scanning device to obtain the pose of the scanning device relative to the tracking device. The cloud data is transformed into the coordinate system of the tracking device. When adjusting the tracking angle of view of the tracking device, the tracking pose of the tracking device relative to the reference coordinate system in the three-dimensional scanning system will also change, that is, the corresponding tracking poses of the tracking device under different tracking angles of view are different. Therefore, it is also necessary to unify the coordinate system of the tracking device under different tracking poses, so as to complete the three-dimensional reconstruction of the measured object.

Exemplarily, it is assumed that the scanning device scans the measured object in a certain pose, and a point in the obtained point cloud data in the coordinate system of the scanning device is p. At this time, the scanning device is located within the tracking range of the tracking device, and the pose of the scanning device relative to the tracking device is T1. The tracking pose of the tracking device relative to the reference coordinate system at this time is T2. Convert the point p in the coordinate system of the scanning device to the reference coordinate system to obtain point p'. Then the conversion process between the point p' and point p is shown as follows:

p'=T2*T1*p (1)

The above step S310 to step S330, in the process of scanning the measured object by the scanning device, judge whether the scanning device is outside the preset optimal tracking range of the tracking device; When it is outside the range, change the tracking angle of view of the tracking device so that the scanning device is within the preset optimal tracking range of the tracking device, and obtain the tracking results of the tracking device; The tracking result of the scanning device, the scanning result of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system complete the three-dimensional reconstruction of the measured object. By adjusting the tracking angle of view of the tracking device, the working range of the tracking device when tracking the scanning device is expanded, thereby solving the problem that the working range of the tracking device is limited by its own tracking range in the current three-dimensional scanning.

Further, in one embodiment, based on the above step S320, when the scanning device is outside the preset optimal tracking range of the tracking device, the tracking angle of view of the tracking device is changed so that the scanning device is located at the preset maximum tracking range of the tracking device. within the optimal tracking range, and obtain the tracking results of the tracking device, which may specifically include the following steps:

Step S321, when the scanning device is outside the preset optimal tracking range of the tracking device, adjust the tracking angle of view of the tracking device according to the preset range until the scanning device is within the preset optimal tracking range of the tracking device, and stop tracking Adjustment of viewing angle.

Specifically, a range can be preset, and when the scanning device is outside the preset optimal tracking range of the tracking device, the rotating device mounted on the tracking device is controlled to gradually change the corresponding kinematic parameters according to the range, so that the tracking device can continuously Rotation occurs, and then the tracking angle of view is continuously changed until the scanning device is within the preset optimal tracking range of the tracking device, and the adjustment of the tracking angle of view of the tracking device is stopped. Alternatively, based on a preset range, the tracking angle of view of the tracking device may be continuously adjusted manually until the scanning device is within the optimal tracking range of the tracking device.

Afterwards, when the scanning device is located in the optimal tracking range of the tracking device by adjusting the tracking angle of view, the tracking result of the scanning device by the tracking device is obtained. In this embodiment, by adjusting the tracking viewing angle of the tracking device based on the preset range, dynamic adjustment of the working range of the tracking device can be realized, thereby expanding the working range of the tracking device.

Additionally, in one embodiment, based on the above step S320, when the scanning device is outside the preset optimal tracking range of the tracking device, the tracking angle of view of the tracking device is changed so that the scanning device is located at the preset maximum tracking range of the tracking device. within the optimal tracking range, and obtain the tracking result of the tracking device, the following steps may also be included:

Step S322, when the scanning device is outside the preset optimal tracking range of the tracking device, calculate projection information of the scanning device within the preset optimal tracking range of the tracking device according to the scanning position of the scanning device.

Specifically, the projection information may be the projection information obtained by projecting the scanning position of the scanning device within the optimal tracking range based on the imaging principle of the tracking device, and mapping. For example, the projection information may be the rotation angle of each coordinate axis projected from the position of the scanning device to the origin coordinate system of the tracking device.

In step S323, the projection information is converted into viewing angle adjustment parameters of the tracking device based on a preset projection transformation relationship.

Wherein, the preset projection transformation relationship may be specifically determined based on the structural form of the rotating device. For example, after the above projection information is obtained, based on the structure of the turntable, the projection information can be converted into angles that each drive shaft of the turntable needs to rotate, and the angle that each drive shaft needs to rotate is the above-mentioned viewing angle adjustment parameter. Further, when the scanning device is located at the center of the tracking range of the tracking device, the tracking accuracy of the tracking device is the best. Therefore, when the position of the scanning device deviates from the center of the tracking range, based on the projection information and the structure of the rotating device, the viewing angle adjustment parameter can be calculated to adjust the tracking viewing angle of the tracking device.

Step S324, adjusting the tracking viewing angle of the tracking device based on the viewing angle adjustment parameter, so that the scanning device is located within a preset optimal tracking range of the tracking device.

From the above steps S322 to S324, when the scanning device is outside the optimal tracking range of the tracking device, the projection information of the scanning device within the optimal tracking range of the tracking device is calculated according to the scanning position of the scanning device; based on the preset projection conversion The relationship converts the projection information into the viewing angle adjustment parameters of the tracking device; adjusts the tracking viewing angle of the tracking device based on the viewing angle adjustment parameters, so that the scanning device is located in the best tracking range of the tracking device. It determines the viewing angle adjustment parameters of the tracking device based on the position of the scanning device, so that the precise adjustment of the tracking viewing angle of the tracking device can be realized, and the adjustment accuracy of the tracking viewing angle of the tracking device can be improved. In addition, by adjusting the tracking viewing angle Adjusting so that the scanning device is located in the best tracking range of the tracking device can also improve the tracking accuracy of the tracking device to the scanning device.

Further, in one embodiment, based on the above step S322, according to the scanning position of the scanning device, calculating the projection information of the scanning device within the preset optimal tracking range of the tracking device may specifically include: according to the scanning position of the scanning device , calculate the projection angle of the scanning device on each coordinate axis under the three-dimensional coordinate system mapped by the preset optimal tracking range of the tracking device; the projection angle of the scanning device on each coordinate axis under the coordinate system mapped by the optimal tracking range, Determined as projection information.

The coordinate system of the above-mentioned tracking range mapping may specifically be the origin coordinate system of the tracking device. FIG. 5 is a schematic diagram of an optimal tracking range of the tracking device provided in this embodiment. As shown in FIG. 5 , the optimal tracking range of the tracking device can be simplified as a trapezoidal platform, where oxyz is the origin coordinate system of the tracking device, and the trapezoidal platform is symmetrical about the xoz plane and the yoz plane. The direction oz is the center direction of the best tracking range of the tracking device. Fig. 6 is a schematic diagram of adjusting the tracking range of the tracking device in this embodiment, wherein the origin coordinate system of the scanning device is located at point c, and the projection information of point c within the optimal tracking range can specifically be the projection of point c in the oxyz coordinate system The angle of rotation α to the x-axis, the angle of rotation β to project on the y-axis. Further, when the scanning device is located at the center of the tracking range of the tracking device, the tracking accuracy of the tracking device is the best. Therefore, referring to FIG. 6 , when the point c is not in the central direction of the tracking range, the rotation angle of each coordinate axis projected from the position of the scanning device to the origin coordinate system of the tracking device can be calculated.

It can be seen from Fig. 6 that when the position of the scanning device deviates from the center of the tracking range, the above-mentioned rotation angle α and rotation angle β can be calculated, and based on the rotation angle α and rotation angle β, the viewing angle adjustment parameters can be obtained, and then the tracking of the tracking device can be realized Adjust the viewing angle so that the scanning device is located in the center of the tracking range to obtain the best tracking accuracy. Exemplarily, for a single-axis turntable, by adjusting the angle of view adjustment parameter, the line oc connecting the point c and the origin o of the coordinate system in FIG. 6 coincides with the xoz plane, so that the scanning device is located in the center direction of the tracking range. For a multi-axis turntable, the viewing angle adjustment parameters can be set so that the line oc connecting the point c and the origin o of the coordinate system coincides with the direction oz.

In addition, in one embodiment, based on the above step S330, according to the tracking results of the scanning device by the tracking device at different tracking angles of view of the scanning device, the scanning results of the scanning device, and the relative preset reference coordinates of the tracking device Before completing the three-dimensional reconstruction of the measured object, the above-mentioned three-dimensional scanning method may also include the following steps:

Step S340, according to the viewing angle transformation relationship pre-calibrated by the tracking device, calculate the tracking pose of the tracking device relative to the preset reference coordinate system under different tracking viewing angles; The set calibration parts are tracked and obtained.

Specifically, the pre-calibrated viewing angle transformation relationship is a pose transformation relationship between the origin coordinate system of the tracking device and the reference coordinate system when the tracking viewing angle of the tracking device is adjusted. For example, the perspective transformation relationship may be determined by a pre-established kinematics model of the rotating device and a pre-calibrated pose transformation relationship between the tracking device and the rotating device. Taking the turntable as an example, the kinematic solution model of the turntable can be established according to the DH (Denavit–Hartenberg) parameters of the turntable. Among them, the DH parameter is a mathematical model of the mechanical arm and a coordinate system determination system that expresses the position angle relationship between two pairs of joint links with four parameters. That is to say, the pose of the coordinate system of the turntable flange relative to the coordinate system of the turntable base can be obtained through the rotation angles of each drive shaft of the turntable. In addition, the pose transformation relationship between the origin coordinate system of the tracking device and the center coordinate system of the flange can be calibrated in advance based on the calibration plate.

Exemplarily, after the turntable is fixed at the working position, the calibration board is fixed within the field of view of the tracking device, and the pose T _MtoT 1 of the origin coordinate system of the calibration board relative to the origin coordinate system of the tracking head is calculated at this time. Next, according to the angles of the drive shafts of the turntable at this time, calculate the pose T _P 1 of the center coordinate system of the flange of the turntable relative to the base coordinate system of the turntable, and set the origin coordinate system of the tracking device and the center of the flange The coordinate system relationship is T _TtoF . , the pose of the calibration plate relative to the base coordinate system of the turntable is T _M , and finally the equation is as follows:

T _P 1*T _TtoF *T _MtoT 1＝T _M (2)

By rotating the angle of each drive shaft of the turntable, the pose of the tracking device is changed, and every time the pose of the tracking device is changed, the calibration plate needs to be located within the field of view of the tracking device. Similarly, the equation is obtained as follows:

T _P 2*T _TtoF *T _MtoT 2＝T _M (3)

Among them, T _P 2 is the pose of the rotated flange center coordinate system relative to the base coordinate system. T _MtoT 2 is the pose of the origin coordinate system of the calibration board relative to the origin coordinate system of the tracking device after rotation. Since both the calibration plate and the turntable are fixed, the pose T _M of the calibration plate relative to the base coordinate system of the turntable remains unchanged, and the pose transformation relationship T _TtoF between the origin coordinate system of the tracking device and the flange center coordinate system remains unchanged.

Finally, the following formula can be obtained:

T _P 1*T _TtoF *T _MtoT 1＝T _P 2*T _TtoF *T _MtoT 2 (4)

Among them, only the pose transformation relationship T _TtoF between the origin coordinate system of the tracking device and the center coordinate system of the flange in the equation is an unknown quantity. Then rotate the tracking device several times to obtain more equations, and obtain T _{TtoF through} simultaneous equations. After obtaining the pose transformation relationship between the origin coordinate system of the tracking device and the center coordinate system of the flange, according to the pose transformation relationship between the origin coordinate system of the tracking device and the center coordinate system of the flange, and the flange The pose of the center coordinate system relative to the base coordinate system can obtain the above viewing angle transformation relationship.

Additionally, in one embodiment, based on the above step S330, the preset reference coordinate system is the origin coordinate system of the pre-established marker point library; The tracking result, the scanning result of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system, before completing the three-dimensional reconstruction of the measured object, may specifically include:

Step S351, acquiring local marker points recognized by the tracking device under different tracking viewing angles.

Wherein, the marker point library can be obtained by pasting marker points on the measured object and its surrounding area in advance, and photographing all marker points through the global photogrammetry equipment. The origin coordinate system of this marker library is the reference coordinate system. After the marker point library is established, in the process of the scanning device scanning the measured object, based on the tracking device tracking the scanning device at different tracking angles of view, the synchronous recognition of the marker points in the marker point library is used to obtain tracking A local marker point in the device's origin coordinate system.

Step S352, matching the local markers with the marker library, and if the local markers are successfully matched with the marker library, based on the local markers and the marker library, the tracking device relative to the marker library under different tracking angles of view is obtained. The tracking pose of the origin coordinate system.

Wherein, by comparing the local marker points under different tracking viewing angles with the marker point library, the tracking pose of the tracking device relative to the origin coordinate system of the marker point library under different tracking angles of view can be calculated. This embodiment is based on the origin coordinate system of the pre-established marker point library as the reference coordinate system. During the scanning process, while the tracking device tracks the scanning device under different tracking angles of view, it recognizes part of the marker points in the marker point library within its tracking range, and then obtains the position of the tracking device relative to the preset reference coordinate system under different tracking angles of view. Track pose. The method for calculating the tracking pose in this embodiment can improve the convenience and efficiency of tracking pose calculation.

In addition, in one embodiment, based on the above step S330, the preset reference coordinate system is the coordinate system of the origin of the marker library updated in real time based on the marker points acquired by the tracking device. The tracking result of the tracking device on the scanning device, the scanning result of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system, before completing the three-dimensional reconstruction of the measured object, the above three-dimensional scanning method may also include the following steps:

Step S361, acquiring local marker points recognized by the tracking device under different tracking viewing angles.

Likewise, the local marker points are part of the marker point library within the tracking range identified by the tracking device while tracking the scanning device under different tracking angles of view during the scanning process. Wherein, the marker library can be obtained by updating some marker points identified by the tracking device. For example, before the tracking device recognizes the marker points within its tracking range, the marker points in the marker library are empty, and the local marker points identified by the tracking device at the first tracking angle of view are obtained, based on the first tracking angle of view Create a marker library for the local markers below. Afterwards, the marker library can also be updated based on the local markers from the follow-up tracking perspective.

Step S362, in the case where the marker data exists in the marker library, match the local markers with the marker library, and if the local markers are successfully matched with the marker library, based on the local markers and the marker library, The tracking poses of the tracking device relative to the origin coordinate system of the marker library under different tracking viewing angles are obtained, and the marker library is updated based on the local marker points.

Wherein, the local marker points recognized by the tracking device in the follow-up tracking perspective are matched with the existing marker point library. If the matching is successful, the pose of the tracking device relative to the origin coordinate system of the marker library is calculated based on the local markers and the marker library. At this time, the markers that are not included in the marker library in the local markers obtained will be identified, Update to the marker library.

Step S363, when the marker data in the marker library is empty, create a marker library based on the local markers.

The above steps S361 to S363, based on the marker points acquired by the tracking device under different tracking viewing angles during the tracking of the scanning device, real-time update of the marker point library is realized, thereby improving the efficiency of calculating the tracking pose of the tracking device. efficiency.

In addition, in one embodiment, the tracking device is fixedly arranged on the rotating platform, and the tracking device is rotated by the rotating platform to change the tracking angle of view of the tracking device. Wherein, understandably, the rotating platform may be the turntable in the above-mentioned embodiments.

The present embodiment is described and illustrated through preferred embodiments below.

Fig. 7 is a flow chart of the three-dimensional scanning method of the preferred embodiment 1. As shown in Figure 7, the three-dimensional scanning method includes the following steps:

Step S701, based on the DH parameters of the turntable, establishing a kinematic solution model of the turntable;

Step S702, obtain the pose transformation relationship between the origin coordinate system of the calibration tracking device and the center coordinate system of the flange through hand-eye calibration;

Step S703, in the process of scanning the object under test by the scanning device, judge whether the scanning device is within the preset optimal tracking range of the tracking device, if so, execute step S705; otherwise, execute step S704;

Step S704, by adjusting the rotation angle of each drive shaft of the turntable, controlling the rotation of the flange of the turntable, and then driving the tracking device fixed on the flange to rotate, changing the tracking angle of view of the tracking device, so that the scanning device is located at the preset position of the tracking device within the optimal tracking range;

Step S705, while the scanning device acquires the point cloud data of the measured object, the tracking device recognizes the locators set on the scanning device, and calculates the pose of the scanning device relative to the tracking device in real time;

Step S706, based on the solution results of steps S701 and S702, and the pose of the scanning device relative to the tracking device, the point cloud data acquired by the scanning device is converted into the base coordinate system of the turntable in real time to complete the three-dimensional reconstruction of the measured object.

Fig. 8 is a flow chart of the three-dimensional scanning method in the second preferred embodiment. As shown in Figure 8, the three-dimensional scanning method includes the following steps:

Step S801, based on the global photogrammetry equipment, photographing all the marked points in the scanning scene, and establishing the origin coordinate system of the marked point library;

Step S802, in the process of scanning the object under test by the scanning device, determine whether the scanning device is within the preset optimal tracking range of the tracking device, if so, perform step S804; otherwise, perform step S803;

Step S803, by adjusting the rotation angle of each drive shaft of the turntable, controlling the rotation of the flange of the turntable, and then driving the tracking device fixed on the flange to rotate, changing the tracking angle of view of the tracking device, so that the scanning device is located at the preset position of the tracking device within the optimal tracking range;

Step S804, while the scanning device acquires the point cloud data of the measured object, the tracking device recognizes the locators set on the scanning device, and calculates the pose of the scanning device relative to the tracking device in real time;

Step S805, while the tracking device recognizes the locator of the scanning device, acquire the local marker points of the marker library identified by the tracking device;

Step S806, matching the local markers with the marker library to obtain the pose of the tracking device relative to the origin coordinate system of the marker library;

In step S807, based on the solution result of step S806 and the pose of the scanning device relative to the tracking device, the point cloud data acquired by the scanning device is converted into the origin coordinate system of the marker point library in real time to complete the three-dimensional reconstruction of the measured object.

Fig. 9 is a flow chart of the three-dimensional scanning method of the third preferred embodiment. As shown in Figure 9, the three-dimensional scanning method includes the following steps:

Step S901, in the process of scanning the object under test by the scanning device, judge whether the scanning device is within the preset optimal tracking range of the tracking device, if so, execute step S903; otherwise, execute step S902;

Step S902, by adjusting the rotation angle of each drive shaft of the turntable, controlling the rotation of the flange of the turntable, and then driving the tracking device fixed on the flange to rotate, changing the tracking angle of view of the tracking device, so that the scanning device is located at the preset position of the tracking device within the optimal tracking range;

Step S903, while the scanning device acquires the point cloud data of the measured object, the tracking device recognizes the locators set on the scanning device, and calculates the pose of the scanning device relative to the tracking device in real time;

Step S904, while the tracking device recognizes the locator of the scanning device, acquire the local marker points pasted in the scanning scene identified by the tracking device within its tracking range;

Step S905, judging whether the marker library is empty, if so, execute step S906, otherwise, execute step S907;

Step S906, establishing a marker library according to the local markers at this time;

Step S907, match the local markers with the marker library, if the matching is successful, calculate the pose of the tracking device relative to the origin coordinate system of the marker library, and compare the local markers that are not included in the marker library Update to the marker library;

Step S908, based on the solution result of step S907 and the pose of the scanning device relative to the tracking device, the point cloud data acquired by the scanning device is converted into the origin coordinate system of the marker point library in real time to complete the three-dimensional reconstruction of the measured object.

In addition, in one embodiment, a three-dimensional scanning system 100 is also provided. FIG. 10 is a schematic structural diagram of a three-dimensional scanning system 100 provided in this embodiment. As shown in Figure 10, a three-dimensional scanning system 100 includes a scanning device 12, a tracking device 14, and a control device 16, wherein the tracking device 14 can change the tracking angle of view of the tracking device 14 while maintaining the original position; The device 12 is used to scan the measured object to obtain the scanning result, and send the scanning result to the control device 16; the tracking device 14 is used to track the scanning device 12 to obtain the tracking result; the control device 16 is used to execute any of the above-mentioned embodiments 3D scanning method provided.

The above three-dimensional scanning system 100 expands the working range of the tracking device when tracking the scanning device by adjusting the tracking angle of view of the tracking device, thereby solving the problem that the working range of the tracking device is limited by its own tracking range in the current three-dimensional scanning.

Further, in one embodiment, the three-dimensional scanning system 100 also includes a rotating platform and a guide rail; wherein: the tracking device is fixedly arranged on the rotating platform; the rotating platform is arranged on the guide rail; the rotating platform is used to drive the tracking device to rotate, and The guide rail drives the tracking device to move. Specifically, the above-mentioned rotating platform may be the turntable in the above-mentioned embodiments. By arranging the rotating platform on the guide rail, it is also possible to control the displacement of the tracking device relative to the measured object while changing the tracking angle of view of the tracking device, thereby further expanding the working range of the tracking device.

It should be understood that the specific embodiments described here are only used to illustrate the application, not to limit it. According to the embodiments provided in the present application, all other embodiments obtained by persons of ordinary skill in the art without creative work shall fall within the scope of protection of the present application.

Apparently, the drawings are only some examples or embodiments of the present application, and those skilled in the art can also apply the present application to other similar situations according to these drawings, but no creative work is required. In addition, it can be understood that although the work done in this development process may be complicated and lengthy, for those of ordinary skill in the art, certain designs, manufactures based on the technical content disclosed in this application Or production and other changes are only conventional technical means, and should not be regarded as insufficient in the content disclosed in this application.

The term "an embodiment" in this application means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply mutual exclusion or independence or alternatives to other embodiments. Those of ordinary skill in the art can clearly or implicitly understand that the embodiments described in this application can be combined with other embodiments without conflict.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is relatively specific and detailed, but should not be construed as limiting the protection scope of the patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be determined by the appended claims.

Claims (10)

1. A three-dimensional scanning method for a three-dimensional scanning system, characterized in that the three-dimensional scanning system includes a scanning device and a tracking device, wherein the tracking device can change the The tracking angle of view of the tracking device; the three-dimensional scanning method includes: In the process of scanning the object under test by the scanning device, judging whether the scanning device is outside the preset optimal tracking range of the tracking device; When the scanning device is outside the preset optimal tracking range of the tracking device, changing the tracking angle of view of the tracking device so that the scanning device is located within the preset optimal tracking range of the tracking device , and obtain the tracking result of the tracking device; According to the tracking results of the scanning device by the tracking device under different tracking angles of view of the tracking device, the scanning results of the scanning device, and the tracking of the tracking device relative to a preset reference coordinate system pose to complete the three-dimensional reconstruction of the measured object. 2. The three-dimensional scanning method according to claim 1, wherein when the scanning device is outside the preset optimal tracking range of the tracking device, the tracking angle of view of the tracking device is changed to The scanning device is located within the preset optimal tracking range of the tracking device, and the tracking result of the tracking device is obtained, including: When the scanning device is outside the preset optimal tracking range of the tracking device, adjust the tracking angle of view of the tracking device according to a preset range until the scanning device is located at the preset optimal tracking range of the tracking device. Within the tracking range, stop adjusting the tracking angle of view. 3. The three-dimensional scanning method according to claim 1, wherein when the scanning device is outside the preset optimal tracking range of the tracking device, changing the tracking angle of view of the tracking device to Positioning the scanning device within the preset optimal tracking range of the tracking device, and obtaining a tracking result of the tracking device, further comprising: When the scanning device is outside the preset optimal tracking range of the tracking device, calculating the position of the scanning device within the preset optimal tracking range of the tracking device according to the scanning position of the scanning device projection information; Converting the projection information into viewing angle adjustment parameters of the tracking device based on a preset projection conversion relationship; The tracking viewing angle of the tracking device is adjusted based on the viewing angle adjustment parameter, so that the scanning device is located within a preset optimal tracking range of the tracking device. 4. The three-dimensional scanning method according to claim 3, characterized in that, according to the scanning position of the scanning device, the projection information of the scanning device within the preset optimal tracking range of the tracking device is calculated ,include: According to the scanning position of the scanning device, calculate the projection angle of the scanning device on each coordinate axis under the three-dimensional coordinate system mapped by the preset optimal tracking range of the tracking device; The projection angles of the scanning device on each coordinate axis in the coordinate system mapped by the optimal tracking range are determined as the projection information. 5. The three-dimensional scanning method according to claim 1, characterized in that, according to the tracking results of the scanning device on the scanning device when the scanning device is located at different tracking angles of view of the tracking device, the scanning device The scanning result, and the tracking pose of the tracking device relative to the preset reference coordinate system, before completing the three-dimensional reconstruction of the measured object, the three-dimensional scanning method also includes: According to the viewing angle transformation relationship pre-calibrated by the tracking device, calculate the tracking pose of the tracking device relative to the preset reference coordinate system under different tracking viewing angles; wherein the viewing angle transformation relationship is pre-adjusted by the tracking device It is obtained by tracking the preset calibration pieces under different tracking angles of view. 6. The three-dimensional scanning method according to claim 1, characterized in that, the preset reference coordinate system is the origin coordinate system of a pre-established marker library; tracking The tracking result of the tracking device on the scanning device under the viewing angle, the scanning result of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system, complete the three-dimensional measurement of the measured object Before reconstruction, the three-dimensional scanning method also includes: Acquiring local marker points identified by the tracking device under the different tracking viewing angles; Match the local markers with the marker library, and if the local markers are successfully matched with the marker library, obtain the tracking based on the local markers and the marker library The tracking pose of the device relative to the origin coordinate system of the marker point library under different tracking viewing angles. 7. The three-dimensional scanning method according to claim 1, wherein the preset reference coordinate system is a marker point library origin coordinate system updated in real time based on the marker points acquired by the tracking device, and according to the scanning The tracking results of the scanning device by the tracking device located at different tracking angles of view of the tracking device, the scanning results of the scanning device, and the tracking pose of the tracking device relative to the preset reference coordinate system are completed. Before the three-dimensional reconstruction of the measured object, the three-dimensional scanning method also includes: Acquiring local marker points identified by the tracking device under the different tracking viewing angles; If there is marker data in the marker library, match the local markers with the marker library, and if the local markers are successfully matched with the marker library, based on the The local marker point and the marker point library, obtain the tracking pose of the tracking device relative to the origin coordinate system of the marker point library under different tracking angles of view, and update the marker point library based on the local marker points; When the marker data in the marker library is empty, the marker library is established based on the local markers. 8. The three-dimensional scanning method according to any one of claims 1 to 7, wherein the tracking device is fixedly arranged on a rotating platform, and the tracking device is driven by the rotating platform to rotate to change the tracking The tracking angle of view of the device. 9. A three-dimensional scanning system, characterized in that the three-dimensional scanning system includes a scanning device, a tracking device, and a control device, wherein the tracking device can change the tracking device while keeping the original position unchanged tracking angle of view; The scanning device is used to scan the measured object to obtain a scanning result, and send the scanning result to the control device; The tracking device is used to track the scanning device to obtain a tracking result; The control device is used to implement any one of the three-dimensional scanning methods in claims 1-8. 10. The three-dimensional scanning system according to claim 9, characterized in that, the three-dimensional scanning system further comprises a rotating platform and guide rails; wherein: the tracking device is fixedly arranged on the rotating platform; the rotating platform is arranged on the on the guide rail; The rotating platform is used to drive the tracking device to rotate and drive the tracking device to move along the guide rail.

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