Calibration method, calibration device, tracking type scanning system and storage medium

Abstract

The invention provides a calibration method, a calibration device, a tracking type scanning system and a storage medium, and the method comprises the steps: scanning a reference object on the calibration device through a scanner, and obtaining first scanning data corresponding to the reference object in a scanning coordinate system; acquiring the pose of the marker on the scanner and the pose of the calibration device by using a tracker; calibrating equipment parameters of the scanner based on the true value corresponding to the reference object and the first scanning data; based on the pose of the marker and the pose of the calibration device, converting the first scanning data to a tracking coordinate system of a tracker; and based on the true value corresponding to the reference object and the first scanning data under the tracking coordinate system, completing rigid body transformation relation calibration between the local coordinate system corresponding to the marker and the scanning coordinate system. Through the method, calibration errors can be reduced to improve measurement precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of three-dimensional scanning, and in particular to a calibration method, a calibration device, a tracking scanning system and a storage medium. BACKGROUND

[0002] The existing calibration mode of the tracking scanning system is to use a hand-eye calibration device with mark points arranged on the side surface and the top surface to calibrate, and to use such mark point devices to calibrate the self-precision of the scanner and the hand-eye calibration relationship between the ball frame and the mark point sensor. However, in the camera coordinate system, due to the imaging characteristics and signal-to-noise ratio of the laser line and the mark point, the result of calibration using the mark point will introduce a part of uncertain system error when the laser line is reconstructed for subsequent scanning. SUMMARY

[0003] Embodiments of the present application disclose a calibration method, a calibration device, a tracking scanning system and a storage medium, which solve the technical problem of low measurement accuracy caused by system error existing between the calibration mode and the actual working mode.

[0004] The present application provides a calibration method applied to a tracking scanning system, wherein the tracking scanning system comprises a tracker and a scanner, and the method comprises the following steps: scanning a reference object on a calibration device by using the scanner to obtain first scanning data corresponding to the reference object in a scanning coordinate system; obtaining the pose of a mark object on the scanner and the pose of the calibration device by using the tracker; calibrating the device parameters of the scanner based on the real value corresponding to the reference object and the first scanning data; converting the first scanning data to a tracking coordinate system of the tracker based on the pose of the mark object and the pose of the calibration device; and completing the calibration of the rigid body transformation relationship between the local coordinate system corresponding to the mark object and the scanning coordinate system based on the real value corresponding to the reference object and the first scanning data in the tracking coordinate system.

[0005] In some embodiments of the present application, after the device parameters of the scanner are calibrated, the method further comprises: updating the first scan data to second scan data based on the calibrated device parameters of the scanner; accordingly, converting the first scan data to the tracking coordinate system of the tracker based on the pose of the marker and the pose of the calibration device comprises: converting the second scan data to the tracking coordinate system of the tracker based on the pose of the marker and the pose of the calibration device; and completing the rigid transformation relationship calibration between the local coordinate system corresponding to the marker and the scan coordinate system based on the real value corresponding to the reference object and the first scan data in the tracking coordinate system comprises: completing the rigid transformation relationship calibration between the local coordinate system corresponding to the marker and the scan coordinate system based on the real value corresponding to the reference object and the second scan data in the tracking coordinate system.

[0006] In some embodiments of the present application, calibrating the device parameters of the scanner based on the real value corresponding to the reference object and the first scan data comprises: in the case that the reference object is a reference sphere, fitting the first scan data in the scan coordinate system based on the feature corresponding to the reference sphere to obtain first fitting data; wherein the first fitting data is the spherical surface data of the virtual model corresponding to the reference sphere; determining the model diameter of the virtual model in the scan coordinate system based on the first fitting data; calculating the deviation value between the model diameter of the virtual model in the scan coordinate system and the real diameter of the reference sphere; if the deviation value is greater than or equal to a preset error threshold, adjusting the device parameters based on the deviation value; and if the deviation value is less than the preset error threshold, completing the calibration of the device parameters of the scanner.

[0007] In some embodiments of the present application, completing the rigid transformation relationship calibration between the local coordinate system corresponding to the marker and the scan coordinate system based on the real value corresponding to the reference object and the first scan data in the tracking coordinate system comprises: in the case that the reference object is a reference sphere, fitting the first scan data in the tracking coordinate system based on the feature corresponding to the reference sphere to obtain second fitting data; wherein the second fitting data is the spherical surface data of the virtual model corresponding to the reference sphere; determining the model diameter of the virtual model in the tracking coordinate system based on the second fitting data; calculating the deviation value between the model diameter of the virtual model in the tracking coordinate system and the real diameter of the reference sphere; and if the deviation value is less than a preset error threshold, completing the rigid transformation relationship calibration between the local coordinate system and the scan coordinate system.

[0008] In some embodiments of the present application, the calibration of the rigid transformation relationship between the local coordinate system corresponding to the marker and the scanning coordinate system based on the real value corresponding to the fiducial and the first scanning data in the tracking coordinate system comprises: in the case that the fiducial comprises a first fiducial sphere and a second fiducial sphere, the real value obtained comprises a first real diameter corresponding to the first fiducial sphere, a second real diameter corresponding to the second fiducial sphere, and a real sphere center distance between the first fiducial sphere and the second fiducial sphere; fitting the first scanning data in the tracking coordinate system based on the feature corresponding to the fiducial to obtain third fitting data, the third fitting data comprising spherical surface data of a virtual model corresponding to the first fiducial sphere and spherical surface data of a virtual model corresponding to the second fiducial sphere; determining a first virtual diameter of the virtual model corresponding to the first fiducial sphere, a first virtual sphere center of the virtual model corresponding to the first fiducial sphere, a second virtual diameter of the virtual model corresponding to the second fiducial sphere, and a second virtual sphere center of the virtual model corresponding to the second fiducial sphere based on the third fitting data; calculating a first difference value between the first virtual diameter and the first real diameter, a second difference value between the second virtual diameter and the second real diameter, a virtual distance between the first virtual sphere center and the second virtual sphere center, and a sphere center distance difference value between the virtual distance and the real sphere center distance; and completing the calibration of the rigid transformation relationship between the local coordinate system and the scanning coordinate system if the first difference value, the second difference value, and the sphere center distance difference value are all less than a preset error threshold.

[0009] In some embodiments of the present application, the method further comprises: if one or more of the first difference value, the second difference value, and the sphere center distance difference value is greater than or equal to the preset error threshold, optimizing the conversion relationship between the local coordinate system and the scanning coordinate system based on the one or more values greater than or equal to the preset error threshold.

[0010] In some embodiments of the present application, the fiducial comprises a fiducial sphere and a top marker point on the calibration device, and the calibration of the device parameters of the scanner based on the real value corresponding to the fiducial and the first scanning data comprises: calibrating the device parameters of the scanner based on the real value corresponding to the fiducial sphere, the real value corresponding to the top marker point, and the first scanning data in the scanner coordinate system.

[0011] In some embodiments of the present application, the fiducial includes a fiducial ball and a top landmark point on the calibration device, and the calibration of the rigid body transformation relationship between the local coordinate system corresponding to the landmark and the scanning coordinate system based on the real value corresponding to the fiducial and the first scanning data in the tracking coordinate system comprises: based on the real value corresponding to the fiducial ball, the real value corresponding to the top landmark point, and the first scanning data in the tracking coordinate system, the rigid body transformation relationship between the local coordinate system corresponding to the landmark and the scanning coordinate system is calibrated.

[0012] In some embodiments of the present application, the calibration of the rigid body transformation relationship between the local coordinate system corresponding to the landmark and the scanning coordinate system based on the real value corresponding to the fiducial ball, the real value corresponding to the top landmark point, and the first scanning data in the tracking coordinate system comprises: based on the first scanning data in the tracking coordinate system, a model diameter corresponding to a virtual model corresponding to the fiducial ball in the tracking coordinate system is determined, and a virtual point corresponding to the top landmark point is determined; a deviation value between the model diameter corresponding to the virtual model in the tracking coordinate system and the real diameter corresponding to the fiducial ball is calculated; an alignment error value between the virtual point and the real value corresponding to the top landmark point is calculated; if the deviation value is less than a preset error threshold value, and the alignment error value is less than a preset difference value, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is calibrated.

[0013] The present application also provides a calibration device, which comprises: a side surface provided with a side landmark point, the side landmark point being used to determine the pose of the calibration device; and a top portion, which is used to carry a fiducial, or the top portion is provided with a top landmark point and is used to carry the fiducial.

[0014] The present application also provides a tracking scanning system, which comprises a scanner, a tracker, and an electronic device; the scanner is used to scan a fiducial on a calibration device, or to scan a fiducial and a top landmark point on the calibration device; the tracker is used to obtain the pose of the landmark on the scanner and to determine the pose of the calibration device based on the side landmark point corresponding to the side surface of the calibration device; the electronic device comprises a processor and a memory, and the processor is used to execute a computer program stored in the memory to realize the calibration method.

[0015] The present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the calibration method.

[0016] The calibration method provided in the application is applied to a tracking scanning system, which comprises a tracker and a scanner. A reference object on a calibration device is scanned by the scanner to obtain first scanning data corresponding to the reference object in a scanning coordinate system, thereby providing a data basis for subsequent calibration. The pose of a marker on the scanner and the pose of the calibration device are obtained by the tracker to position the scanner and the calibration device in real time. The device parameters of the scanner are calibrated based on the real value corresponding to the reference object and the first scanning data, so as to improve the scanning accuracy of the scanner. The first scanning data in the scanning coordinate system is converted to the tracking coordinate system of the tracker through the pose of the marker and the pose of the calibration device, so that the rigid transformation relationship calibration between the local coordinate system corresponding to the reference object and the scanning coordinate system is completed based on the real value corresponding to the reference object and the first scanning data in the tracking coordinate system of the tracker in the tracking coordinate system of the tracker, thereby improving the calibration accuracy. The calibration mode based on the reference object matches the actual working mode, both of which belong to laser scanning, thereby reducing the system error caused by the error between the calibration mode and the working mode, and improving the subsequent measurement accuracy to a certain extent. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a schematic diagram of an application scenario of the calibration method provided in the embodiments of the application.

[0018] Figure 2 FIG. 2 is a flowchart of the calibration method provided in the embodiments of the application.

[0019] Figure 3 FIG. 3 is a scanning scene diagram of the scanner provided in the embodiments of the application.

[0020] Figure 4 FIG. 4 is a schematic diagram of an application scenario of the calibration method provided in another embodiment of the application.

[0021] Figure 5 FIG. 5 is a flowchart of the calibration method provided in another embodiment of the application.

[0022] Figure 6 FIG. 6 is a schematic diagram of an application scenario of the calibration method provided in another embodiment of the application.

[0023] Figure 7 FIG. 7 is a structural schematic diagram of an electronic device provided in the embodiments of the application. DETAILED DESCRIPTION

[0024] For the convenience of understanding, exemplary descriptions of some concepts related to the embodiments of the application are given for reference.

[0025] It should be noted that "at least one" in the present application means one or more, and "multiple" means two or more than two. The association relationship between the associated objects is described as "and / or", which means that there can be three kinds of relationships, for example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the present application and the drawings are used to distinguish similar objects, and are not used to describe a specific order or sequence.

[0026] The existing calibration mode of the tracking scanning system is to calibrate the hand-eye calibration device using the side and top arrangement of the marker points. The marker point device is used to calibrate the accuracy of the scanner itself, and to calibrate the hand-eye calibration relationship of the ball frame to the marker point sensor. However, in the camera coordinate system, due to the imaging characteristics and signal-to-noise ratio of the laser line and the marker point, the result of using the marker point for calibration will introduce a part of the uncertain system error when the laser line is reconstructed for subsequent scanning.

[0027] Therefore, in order to reduce the system error caused by the error between the calibration mode and the working mode, the present application provides a calibration method, a calibration device, a tracking scanning system and a storage medium. In the calibration process, the calibration is assisted by the reference object, the calibration of the device parameters of the scanner is completed, and the calibration of the conversion relationship between the local coordinate system of the marker and the scanning coordinate system is completed, so as to ensure the accuracy of the calibration. In addition, the calibration by means of the reference object can eliminate the system error caused by the mode switching between the calibration mode and the working mode. First, the application scene of the calibration method of the present application is described.

[0028] Figure 1 The application scene of the calibration method provided by the embodiment of the present application is shown in FIG. 1. Figure 1 As shown in FIG. 1, the tracking scanning system includes an electronic device 10, a tracker 20 and a scanner 30.

[0029] The electronic device 10 is communicatively connected with the respective tracker 20 and the scanner 30. The communicatively connected manner can include one or more of a wired communicatively connected manner and a wireless communicatively connected manner. The wired communicatively connected manner can include one or more of a Universal Serial Bus (USB), a Controller Area Network (CAN) bus, and the like. The wireless communicatively connected manner can include one or more of a Wireless Fidelity (Wi-Fi), a Bluetooth (BT), a mobile communication network, a Frequency Modulation (FM), a Near Field Communication (NFC), an Infrared (IR) technology, and the like.

[0030] The electronic device 10 can include a notebook computer, a tablet computer, a Programmable Logic Controller (PLC), a Human Machine Interface (HMI) with a touch input function, and the like, and can also include a virtual machine or a device simulated by a simulator. The electronic device 10 is configured to receive data transmitted by the respective tracker 20 and the scanner 30, to complete calibration of the scanner 30, and to complete calibration between different coordinate systems.

[0031] The tracker 20 can be an optical tracker.

[0032] The scanner 30 can include, but is not limited to, an oral scanning device, a facial scanning device, a CT (Computed Tomography) scanning device or a CBCT (Cone beam Computer Tomography) scanning device, a professional scanner, an industrial scanner, and the like. The oral scanning device can include an intraoral scanner and an extraoral scanner. The scanner 30 can be a handheld scanning device or a fixed scanning device, and the scanner 30 can be configured to measure a specified object to achieve three-dimensional reconstruction. For example, the specified object can be a tooth, a face, a human body, an industrial product, an industrial device, an artifact, an artwork, a prosthesis, a medical instrument, a building, and the like. The present application does not make specific limitations thereto.

[0033] The scanner 30 can include a marker 310, and the marker 310 can be a ball cage. The ball cage can be provided with a plurality of ball plates, and each ball plate can be provided with a plurality of marker points. The tracker 20 can recognize the marker points on the ball plates through a binocular camera system to track the marker 310.

[0034] In the calibration process, the scanner 30 can scan a reference object (such as Figure 1 Q) and a calibration device (such as Figure 1 M) provided with mark points to complete the calibration. The calibration device M includes a top and a side, the top can be provided with a top mark point, and the side can be provided with a side mark point, and the top can also be used to carry the reference object Q. The number and order of the mark points on the calibration device M are not limited by the present application.

[0035] According to the actual calibration situation, in an example, as shown in Figure 1 the marker M, the side mark point M1 is provided on the marker device M, no top mark point is provided on the top, and the reference object Q is placed on the top. In another example, as shown in Figure 6 the marker M, the side mark point M1, the top mark point M2 and the reference object P can be placed on the marker device.

[0036] The schematic Figure 1 is only an example of an application scenario and does not constitute a limitation on the application scenario, and can include more or fewer components than the schematic, or combine certain components, or different components, for example, the electronic device 10 can also include an input / output device, a network access device, etc.

[0037] Figure 2 is a flowchart of the calibration method provided by the embodiments of the present application, which is applied in a tracking type scanning system (such as the tracking type scanning system of Figure 1 ). According to different requirements, the order of the steps in the flowchart can be changed, and some steps can be omitted.

[0038] In step S201, a reference object on a calibration device is scanned by using a scanner to obtain first scanning data corresponding to the reference object in a scanning coordinate system.

[0039] In some embodiments of the present application, the calibration device can be a reference object with known accurate size and spatial position characteristics, for example, a calibrator provided with mark points. The mark points can be divided into side mark points and top mark points according to the deployed positions.

[0040] In the calibration process, if the top of the calibration device is not provided with a top mark point, a reference object can be placed on the top to complete the calibration, and the reference object can be a reference ball or other object with a simple geometric structure. As shown in Figure 1 , the reference object Q is placed on the top of the calibration device M, and the top of the calibration device M is not provided with a top mark point.

[0041] In some embodiments of the present application, the scanner is used to scan the fiducial on the calibration device to obtain first scanning data of the fiducial in a scanning coordinate system. Taking the fiducial as an example of a reference sphere, the scanner is moved around the reference sphere to collect a spherical point cloud corresponding to the reference sphere, thereby obtaining the first scanning data.

[0042] In step S202, the pose of the marker on the scanner and the pose of the calibration device are obtained by using the tracker.

[0043] In some embodiments of the present application, the relative position between the marker on the scanner and the scanner body is fixed. The marker can be a ball cage, and the ball cage has a plurality of ball plates, each of which is provided with a plurality of marker points. In the tracking scanning system, the tracker can be used to track the marker points corresponding to the marker on the scanner to determine the pose of the marker in real time. In addition, the pose of the calibration device can also be determined in real time by tracking the side marker points on the calibration device.

[0044] If the calibration device is fixed at any position, the side marker points on the calibration device can be used to position the calibration device, and the side marker points on the calibration device do not need to be tracked in real time to reduce the calculation amount of the tracker and improve the tracking performance of the tracker. If the calibration device is in a state of motion, the side marker points on the calibration device can be tracked in real time to position the real-time position of the calibration device.

[0045] In step S203, the device parameters of the scanner are calibrated based on the real value of the fiducial and the first scanning data.

[0046] In some embodiments of the present application, in the case where the fiducial is a reference sphere, the real value corresponding to the fiducial can include a real diameter. The characteristic constraint corresponding to the reference sphere can include one or more of a sphere center-point distance constraint, a radius consistency constraint, a normal vector direction constraint, a symmetry constraint, and a curvature constraint, and the present application does not limit the type of characteristic constraint.

[0047] The first scanning data in the scanner coordinate system is fitted based on one or more of a center-point distance constraint, a radius consistency constraint, a normal vector direction constraint, a symmetry constraint, and a curvature constraint. The fitting method includes one or more of a combination of a Random Sample Consensus (RANSAC) point cloud fitting algorithm, a Least Squares Method (LS), a Geometric Algebra Method, a Robust Least Squares (RLS), a Density-Based Spatial Clustering of Applications with Noise (DBSCAN), K-Means Clustering, and Maximum Likelihood Estimation Sample Consensus (MLESAC), and the application is not limited in this regard.

[0048] The first fitting data obtained by fitting the first scanning data in the scanner coordinate system is obtained, and the first fitting data represents the spherical surface data of the virtual model corresponding to the reference sphere. The model diameter of the virtual model in the scanning coordinate system can be determined according to the first fitting data.

[0049] The model diameter of the virtual model in the scanning coordinate system is compared with the true diameter, and a deviation value between the model diameter of the virtual model in the scanning coordinate system and the true diameter is calculated. If the deviation value is greater than or equal to a preset error threshold, the device parameters of the scanner can be adjusted according to the deviation value to realize calibration of the scanner. The device parameters can include but are not limited to binocular extrinsic parameters.

[0050] If the deviation value is less than the preset error threshold, the scanner with the deviation value less than the preset error threshold can be used as a calibrated scanner.

[0051] In other embodiments of the application, if the reference object includes a plurality of reference spheres, the true value can include the true diameter of each reference sphere and a true center distance, which can be the distance between the centers of any two reference spheres in the plurality of reference spheres, or the distance between the centers of specified two reference spheres in the plurality of reference spheres, and the application is not limited in this regard.

[0052] With the first fiducial ball and the second fiducial ball as examples, the virtual diameter of the virtual model corresponding to the first fiducial ball in the scanning coordinate system, the virtual diameter of the virtual model corresponding to the second fiducial ball in the scanning coordinate system, and the virtual distance between the virtual centers of the virtual models corresponding to the first fiducial ball and the second fiducial ball in the scanning coordinate system are determined by fitting the first scanning data in the scanning coordinate system.

[0053] If any one of the difference between the virtual diameter of the virtual model corresponding to the first fiducial ball in the scanning coordinate system and the corresponding real diameter, the difference between the virtual diameter of the virtual model corresponding to the second fiducial ball in the scanning coordinate system and the corresponding real diameter, and the difference between the virtual distance in the scanning coordinate system and the real distance between the centers of the balls is greater than or equal to the preset error threshold, it indicates that the device parameters of the scanner need to be further optimized, and the device parameters of the scanner can be calibrated according to any one difference greater than or equal to the preset error threshold.

[0054] If the difference between the virtual diameter of the virtual model corresponding to the first fiducial ball in the scanning coordinate system and the corresponding real diameter, the difference between the virtual diameter of the virtual model corresponding to the second fiducial ball in the scanning coordinate system and the corresponding real diameter, and the difference between the virtual distance in the scanning coordinate system and the real distance between the centers of the balls are all less than the preset error threshold, the calibration of the device parameters of the scanner is completed.

[0055] In an example, in combination with Figure 3 As shown, the fiducial ball A and the fiducial ball B are arranged on the top of the calibration device M, and the side mark point M1 is arranged on the side. The scanner 30 is used to scan around the fiducial ball A and the fiducial ball B respectively to obtain the scanning data corresponding to the fiducial ball A and the scanning data corresponding to the fiducial ball B in the scanning coordinate system. The scanning data corresponding to the fiducial ball A and the scanning data corresponding to the fiducial ball B are fitted respectively to obtain the fitting data of the virtual model A corresponding to the fiducial ball A, and the fitting data of the virtual model B corresponding to the fiducial ball B.

[0056] According to the fitting data of the virtual model A corresponding to the fiducial ball A, the virtual diameter A corresponding to the virtual model A and the virtual center A are obtained. According to the fitting data of the virtual model B corresponding to the fiducial ball B, the virtual diameter B corresponding to the virtual model B and the virtual center B are obtained. The difference A between the virtual diameter A and the real diameter corresponding to the fiducial ball A, the difference B between the virtual diameter B and the real diameter corresponding to the fiducial ball B, and the difference C between the virtual distance between the virtual center A and the virtual center B and the real distance between the centers of the fiducial ball A and the fiducial ball B are calculated.

[0057] If any one of the difference A, the difference B and the difference C is greater than or equal to the preset error threshold, the device parameters of the scanner are calibrated according to any one of the difference greater than or equal to the preset error threshold. For example, if the difference A is greater than or equal to the preset error threshold, the device parameters of the scanner are calibrated according to the difference A.

[0058] If the difference A, the difference B and the difference C are all less than the preset error threshold, the calibration of the device parameters of the scanner is completed.

[0059] The above is only an example, and the actual application is not limited thereto. A number greater than 2 of reference balls can be deployed to calibrate the device parameters through multiple sets of parameters, reduce the error of calibration, and improve the scanning accuracy of the scanner.

[0060] In step S204, the first scanning data is converted into the tracking coordinate system of the tracker based on the pose of the marker and the pose of the calibration device.

[0061] In some embodiments of the present application, in the process of calibration, a first conversion relationship between the scanning coordinate system of the scanner and the local coordinate system of the marker is preset. The tracker establishes a second conversion relationship between the tracking coordinate system of the tracker and the local coordinate system of the marker by detecting the marker points on the marker.

[0062] The tracker converts the first scanning data in the scanning coordinate system of the scanner to the local coordinate system by using the first conversion relationship, and converts the first scanning data in the local coordinate system to the tracking coordinate system of the tracker by using the second conversion relationship, by tracking the pose of the marker and the pose of the calibration device.

[0063] In step S205, the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system is calibrated based on the real value corresponding to the reference object and the first scanning data in the tracking coordinate system.

[0064] In some embodiments of the present application, the first conversion relationship is a preset value, and the first conversion relationship can be continuously iteratively optimized by using the real value corresponding to the reference object and the first scanning data in the tracking coordinate system to complete the calibration of the first conversion relationship, and the calibrated first conversion relationship is taken as the rigid body transformation relationship between the local coordinate system and the scanning coordinate system.

[0065] In some embodiments of the present application, in the case where the reference object is a reference ball, the real value corresponding to the reference object can include a real diameter. The first scanning data in the tracking coordinate system is fitted according to the feature constraint corresponding to the reference ball to obtain second fitting data, wherein the definition of the feature constraint and the fitting manner can refer to the above step S203, and will not be repeated here. The second fitting data is the spherical surface data of the virtual model corresponding to the reference ball.

[0066] Based on the second fitted data, the diameter of the virtual model in the tracking coordinate system can be determined. The deviation between the virtual model's diameter in the tracking coordinate system and the true diameter of the reference sphere is calculated. If the deviation is less than a preset error threshold, the rigid body transformation relationship between the local coordinate system and the scan coordinate system is calibrated. If the deviation is greater than or equal to the preset error threshold, the first transformation relationship is optimized based on the deviation.

[0067] In other embodiments of this application, if the reference object includes multiple reference spheres, the true value may include the true diameter and true center-to-center distance of each reference sphere. The true center-to-center distance may be the distance between the centers of any two reference spheres among the multiple reference spheres, or it may be the distance between the centers of two specified reference spheres among the multiple reference spheres. This application does not limit this.

[0068] Taking a reference object comprising a first reference sphere and a second reference sphere as an example, the true values ​​include the first true diameter corresponding to the first reference sphere, the second true diameter corresponding to the second reference sphere, and the true center-to-center distance between the first and second reference spheres. Third fitted data is obtained by fitting the first scan data in the tracking coordinate system based on the feature constraints corresponding to the reference object. The third fitted data includes the spherical surface data of the virtual model corresponding to the first reference sphere and the spherical surface data of the virtual model corresponding to the second reference sphere in the tracking coordinate system.

[0069] Based on the third fitted data, determine the first virtual diameter of the virtual model corresponding to the first reference sphere, the first virtual center of the virtual model corresponding to the first reference sphere, the second virtual diameter of the virtual model corresponding to the second reference sphere, and the second virtual center of the virtual model corresponding to the second reference sphere.

[0070] In the coordinate system of the tracker, calculate the first difference between the first virtual diameter and the first real diameter, the second difference between the second virtual diameter and the second real diameter, the virtual distance between the first virtual sphere center and the second virtual sphere center, and the sphere center difference between the virtual distance and the real sphere center distance.

[0071] If the first difference, the second difference, and the difference between the centers of the spheres are all less than the preset error threshold, the rigid body transformation relationship between the local coordinate system and the scan coordinate system is calibrated. If one or more of the first difference, the second difference, and the difference between the centers of the spheres are greater than or equal to the preset error threshold, the transformation relationship between the local coordinate system and the scan coordinate system is optimized based on one or more values ​​that are greater than or equal to the preset error threshold.

[0072] In one example, combining Figure 4 As shown, taking the reference object as the reference sphere as an example, the calibration device M and the reference sphere (such as...) are... Figure 4 E and F (as shown) are set within the measurement range of the tracker 20, and the scanner 30 is used to measure the reference sphere (such as...Figure 4 The scanner 30 is used to scan the reference sphere E and the reference sphere F, the tracker 20 is used to track the marker 310 on the scanner 30, and the side marker points M1 on the calibration device M.

[0073] The scanner 30 is used to scan the reference sphere E and the reference sphere F, and obtain the scanning data corresponding to the reference sphere E and the scanning data corresponding to the reference sphere F in the scanning coordinate system. Based on the first conversion relationship and the second conversion relationship, the scanning data corresponding to the reference sphere E and the scanning data corresponding to the reference sphere F in the scanning coordinate system are converted to the tracking coordinate system of the tracker, and the scanning data corresponding to the reference sphere E and the scanning data corresponding to the reference sphere F in the tracking coordinate system are obtained. The scanning data corresponding to the reference sphere E and the scanning data corresponding to the reference sphere F in the tracking coordinate system are fitted respectively, so as to obtain the virtual diameter E of the virtual model corresponding to the reference sphere E, the virtual center E of the virtual model corresponding to the reference sphere E, the virtual diameter F of the virtual model corresponding to the reference sphere F, and the virtual center F of the virtual model corresponding to the reference sphere F.

[0074] In the tracking coordinate system, the difference E between the virtual diameter E and the real diameter of the reference sphere E is calculated, the difference F between the virtual diameter F and the real diameter of the reference sphere F is calculated, and the difference G between the virtual distance between the virtual center E and the virtual center F and the real center distance between the reference sphere E and the reference sphere F is calculated.

[0075] If the difference E, the difference F, and the difference G are all less than the preset error threshold, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is calibrated.

[0076] If one or more of the difference E, the difference F, and the difference G is greater than or equal to the preset error threshold, the conversion relationship between the local coordinate system and the scanning coordinate system is optimized based on the one or more values greater than or equal to the preset error threshold. Then, the above steps are continued to be executed by using the optimized conversion relationship, so as to complete the rigid body transformation relationship calibration between the local coordinate system and the scanning coordinate system.

[0077] By the above embodiment, the reference object on the calibration device is scanned by the scanner to obtain first scanning data corresponding to the reference object in the scanning coordinate system, thereby providing a data basis for subsequent calibration. The pose of the marker on the scanner and the pose of the calibration device are obtained by the tracker to position the scanner and the calibration device in real time. Based on the real value corresponding to the reference object and the first scanning data, the device parameters of the scanner are calibrated to improve the scanning accuracy of the scanner. By the pose of the marker and the pose of the calibration device, the first scanning data is converted to the tracking coordinate system of the tracker, so that in the tracking coordinate system, based on the real value corresponding to the reference object and the first scanning data in the tracking coordinate system, the rigid body transformation relationship calibration between the local coordinate system corresponding to the reference object and the scanning coordinate system is completed, thereby improving the accuracy of the calibration. The calibration mode based on the reference object matches the actual working mode, both of which belong to laser scanning, thereby reducing the system error caused by the error between the calibration mode and the working mode, and improving the subsequent measurement accuracy to a certain extent.

[0078] In addition, the general calibration process uses identification points for calibration. If after completing the calibration, the scanner no longer uses the camera / sensor for identifying the identification points in the working process, but switches to the laser emitter working (usually a line laser or a point laser). Therefore, there is a certain system error between the calibration mode corresponding to the identification points used in the calibration process and the laser scanning mode used in the actual working mode. By the above embodiment, the reference object is scanned to avoid such error, thereby improving the accuracy of subsequent scanning.

[0079] In other embodiments of the present application, in order to improve the accuracy of subsequent calibration, after completing the calibration of the device parameters of the scanner, the first scanning data can be updated based on the calibrated device parameters of the scanner, thereby obtaining second scanning data in the scanning coordinate system. In the subsequent calibration process, based on the pose of the marker and the pose of the calibration device, the second scanning data is converted to the tracking coordinate system of the tracker, and based on the real value corresponding to the reference object and the second scanning data in the tracking coordinate system, the rigid body transformation relationship calibration between the local coordinate system corresponding to the marker and the scanning coordinate system is completed, thereby improving the accuracy of the rigid body transformation relationship calibration.

[0080] Figure 5 is a flowchart of a calibration method provided by another embodiment of the present application. The reference object can include a reference ball and a top marker point on the calibration device, and the calibration is completed by using the reference ball and the top marker point, as shown in Figure 5 The calibration method includes the following steps.

[0081] In step S501, the reference object on the calibration device is scanned by the scanner to obtain first scanning data corresponding to the reference object in the scanning coordinate system.

[0082] In some embodiments of the present application, the fiducial includes fiducial balls and top landmark points on the calibration device, and the present application does not limit the arrangement and number of the fiducial balls and the top landmark points. The scanner scans the fiducial to obtain first scanning data, which can include scanning data corresponding to the top landmark points and scanning data corresponding to the fiducial balls.

[0083] In step S502, the pose of the marker on the scanner and the pose of the calibration device are obtained by using the tracker.

[0084] In some embodiments of the present application, the tracker can obtain the pose of the marker by tracking the landmark points on the marker on the scanner. The tracker can also obtain the pose of the calibration device by tracking the side landmark points of the calibration device. In addition, the specific description of step S502 can also refer to the above-mentioned step S202, which will not be repeated here.

[0085] In step S503, the device parameters of the scanner are calibrated based on the real value corresponding to the fiducial balls, the real value corresponding to the top landmark points, and the first scanning data in the scanner coordinate system.

[0086] In some embodiments of the present application, fitting the first scanning data in the scanning coordinate system includes fitting the scanning data corresponding to the top landmark points and the scanning data corresponding to the fiducial balls in the scanning coordinate system to obtain fourth fitting data in the scanning coordinate system, and the fourth fitting data includes spherical surface data of the virtual model of the fiducial balls. Based on the fourth fitting data, the virtual diameter and the virtual center of the virtual model of the fiducial balls are determined.

[0087] The real value corresponding to the fiducial balls includes a real diameter, and the real value corresponding to the top landmark points includes a real point position, which can include positioning information, and the present application does not limit the specific setting of the real point position information, which can be set according to the type of the top landmark points. In the scanning coordinate system, if the deviation value between the real diameter of the fiducial balls and the virtual diameter of the virtual model is less than a preset error threshold, and the real point position corresponding to the top landmark points matches the virtual point position corresponding to the top landmark points in the first scanning data, then the scanner with the deviation value less than the preset error threshold can be regarded as a calibrated scanner. Wherein, the real point position corresponding to the top landmark points matches the virtual point position corresponding to the top landmark points in the first scanning data can be that the real point position and the virtual point position correspond to the aligned positions.

[0088] If the deviation value between the real diameter of the reference sphere and the virtual diameter of the virtual model is greater than or equal to the preset error threshold, or the real point position corresponding to the top marker point does not match the virtual point position corresponding to the top marker point in the first scanning data in the scanning coordinate system, the device parameters of the scanner can be optimized based on the deviation value or the deviation between the real point position and the virtual point position, so that the device parameters of the scanner are calibrated.

[0089] In step S504, the first scanning data is converted into the tracking coordinate system of the tracker based on the pose of the marker and the pose of the calibration device.

[0090] In some embodiments of the present application, a first conversion relationship between the scanning coordinate system of the scanner and the local coordinate system of the marker is preset in the calibration process. The tracker establishes a second conversion relationship between the tracking coordinate system of the tracker and the local coordinate system of the marker by detecting the marker points on the marker.

[0091] The tracker converts the first scanning data in the scanning coordinate system to the local coordinate system by tracking the pose of the marker and the pose of the calibration device, converts the first scanning data in the local coordinate system to the tracking coordinate system of the tracker by using the second conversion relationship, and obtains the scanning data corresponding to the reference sphere and the scanning data corresponding to the top marker point in the tracking coordinate system.

[0092] In step S505, the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system is calibrated based on the real value corresponding to the reference sphere, the real value corresponding to the top marker point, and the first scanning data in the tracking coordinate system.

[0093] In some embodiments of the present application, the model diameter corresponding to the virtual model corresponding to the reference sphere in the tracking coordinate system is determined by fitting the first scanning data in the tracking coordinate system, and the virtual point position corresponding to the top marker point is determined. The deviation value between the model diameter corresponding to the virtual model in the tracking coordinate system and the real diameter corresponding to the reference sphere is calculated, and the alignment error value between the virtual point position and the real value corresponding to the top marker point is calculated. If the deviation value is less than the preset error threshold, and the alignment error value is less than the preset difference value, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is calibrated. If the deviation value is greater than or equal to the preset error threshold, or the alignment error value is greater than or equal to the preset difference value, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is optimized based on the deviation value and / or the alignment error value, until the deviation value is less than the preset error threshold, and the alignment error value is less than the preset difference value, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is calibrated.

[0094] In order to better understand the embodiments as shown in Figure 5 the following will be described in conjunction withFigure 6 Describe it. For example... Figure 6 As shown, the calibration device M and the reference ball (such as...) Figure 6 The reference ball P is set within the measurement range of the tracker 20. The scanner 30 scans the reference ball P and the top marker M2 of the calibration device M. The tracker 20 tracks the marker 310 on the scanner 30 and the side marker M1 on the calibration device M.

[0095] The scanner 30 is used to scan the reference sphere P and the top marker M2, obtaining the scan data corresponding to the reference sphere P and the top marker M2 in the scan coordinate system. Based on the scan data corresponding to the reference sphere P, the scan data corresponding to the top marker M2, the true value of the reference sphere P, and the true value of the top marker M2 in the scanner coordinate system, the scanner 30 is calibrated.

[0096] The calibrated scanner 30 scans the reference sphere P and the top marker M2, obtaining updated scan data for the reference sphere P and the top marker M2 in the scanning coordinate system. Based on the first and second transformation relationships, the updated scan data for the reference sphere P and the top marker M2 in the scanning coordinate system are transformed to the tracking coordinate system, obtaining the scan data for the reference sphere P and the top marker M2 in the tracking coordinate system.

[0097] In the tracking coordinate system, the virtual diameter P and virtual center P of the virtual model corresponding to the reference sphere P are obtained by fitting the scan data corresponding to the reference sphere P in the tracking coordinate system. The deviation value P between the virtual diameter P and the real diameter corresponding to the reference sphere P is calculated. The virtual point M2 is obtained from the scan data corresponding to the top marker point M2, and the alignment error value M2 between the virtual point M2 and the real point corresponding to the top marker point M2 is calculated.

[0098] If the deviation value P is less than the preset error threshold and the alignment error value M2 is less than the preset difference, the rigid body transformation relationship between the local coordinate system and the scan coordinate system is calibrated.

[0099] If the deviation value P is greater than or equal to the preset error threshold, or the alignment error value M2 is greater than or equal to the preset difference, then the rigid body transformation relationship between the local coordinate system and the scan coordinate system is optimized based on the deviation value P and / or the alignment error value M2 until the deviation values ​​are all less than the preset error threshold.

[0100] like Figure 6The embodiment shown describes the case of calibrating the rigid body transformation relationship between the local coordinate system and the scanning coordinate system based on a reference sphere and the top landmark point. In actual applications, multiple reference spheres can also be set to complete the calibration of the rigid body transformation relationship between the local coordinate system and the scanning coordinate system in combination with the real diameter, the real point position, and the real sphere center distance.

[0101] Specifically, in combination with Figure 6 As shown, it is assumed that there are a top landmark point M2 and multiple reference spheres P, for example, including a reference sphere P1 and a reference sphere P2. Based on the calculation method as shown in Figure 5 The deviation value P1 corresponding to the reference sphere P1 and the deviation value P2 corresponding to the reference sphere P2 are determined. The virtual sphere center distance P12 of the reference sphere P1 and the reference sphere P2 in the tracking coordinate system is calculated, and the deviation value P12 between the virtual sphere center distance P12 and the real sphere center distance is calculated.

[0102] If the deviation value P1, the deviation value P2, and the deviation value P12 are all less than the preset error threshold, and the alignment error value M2 is less than the preset difference value, the calibration of the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is completed.

[0103] If any one of the deviation value P1, the deviation value P2, and the deviation value P12 is greater than or equal to the preset error threshold, or the alignment error value M2 is greater than or equal to the preset difference value, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is optimized until all the deviation values are less than the preset error threshold.

[0104] Through the above embodiment, the calibration is performed in combination with the reference sphere and the top landmark point, which can avoid the error caused by a single calibration method, improve the accuracy of the calibration, and improve the accuracy of subsequent measurement.

[0105] Figure 7 FIG. 1 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. As shown in Figure 7 The electronic device 10 can include a display device 100, a communication module 101, a memory 102, a processor 103, an input / output (I / O) interface 104, and a bus 105. The processor 103 is coupled to the display device 100, the communication module 101, the memory 102, and the I / O interface 104 through the bus 105.

[0106] The display device 100 can be a touch screen, which is a kind of inductive touchable liquid crystal display device. Alternatively, the display device 100 can also be a non-touch screen. The display device 100 is used to display scanning data.

[0107] The communication module 101 can include a wired communication module and / or a wireless communication module. The wired communication module can provide one or more of the following wired communication solutions: Universal Serial Bus (USB), Controller Area Network (CAN) bus, etc. The wireless communication module can provide one or more of the following wireless communication solutions: Wireless Fidelity (Wi-Fi), Bluetooth (BT), mobile communication network, Frequency Modulation (FM), Near Field Communication (NFC), Infrared (IR) technology, etc. The memory 102 can include one or more Random Access Memories (RAMs) and one or more Non-Volatile Memories (NVMs). The Random Access Memory can be directly read and written by the processor 103, and can be used to store executable programs (e.g., machine instructions) of operating systems or other programs running, and also can be used to store data of users and applications, etc.

[0108] The Random Access Memory can include Static Random-Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM), etc.

[0109] The Non-Volatile Memory can also store executable programs and store data of users and applications, etc., and can be loaded in advance into the Random Access Memory for direct reading and writing by the processor 103. The Non-Volatile Memory can include a magnetic disk storage device, a Flash Memory.

[0110] The memory 102 is configured to store one or more computer programs. The one or more computer programs are configured to be executed by the processor 103. The one or more computer programs include a plurality of instructions, which when executed by the processor 103, can implement the calibration method executed on the electronic device 10.

[0111] In other embodiments, the electronic device 10 further comprises an external memory interface for connecting an external memory to extend the storage capability of the electronic device 10.

[0112] The processor 103 can include one or more processing units, for example: the processor 103 can include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units can be independent devices or integrated in one or more processors.

[0113] The processor 103 provides computing and control capabilities, for example, the processor 103 is used to execute a computer program stored in the memory 102 to implement the calibration method described above.

[0114] The I / O interface 104 is used to provide a channel for user input or output, for example, the I / O interface 104 can be used to connect various input and output devices, such as a mouse, a keyboard, a touch device, a display screen, etc., so that the user can enter information or make the information visualized.

[0115] The bus 105 is used to provide a communication channel between the communication module 101, the memory 102, the processor 103, and the I / O interface 104 in the electronic device 10.

[0116] It can be understood that the structure illustrated in the embodiments of the present application does not constitute a specific limitation on the electronic device 10. In other embodiments of the present application, the electronic device 10 can include more or fewer components than the illustration, or combine certain components, or split certain components, or different component arrangements. The illustrated components can be implemented in hardware, software, or a combination of software and hardware.

[0117] The embodiments of the present application also provide a computer readable storage medium, the computer readable storage medium stores a computer program, the computer program includes program instructions, and the method implemented by the program instructions when executed can refer to the method in each of the embodiments of the present application.

[0118] The computer readable storage medium can be an internal storage of the electronic device, such as a hard disk or a memory of the electronic device. The computer readable storage medium can also be an external storage of the electronic device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, and the like.

[0119] In some embodiments, the computer readable storage medium can include a program storage area and a data storage area. The program storage area can store an operating system, an application required by at least one function, and the like. The data storage area can store data created according to use of the electronic device, and the like.

[0120] In the above embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in detail in a certain embodiment can be referred to the related description of other embodiments.

[0121] Those skilled in the art can understand that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solutions. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0122] In the embodiments provided in the present application, it should be understood that the disclosed apparatus / terminal device and method can be implemented by other ways. For example, the apparatus / terminal device embodiments described above are only schematic, and the division of the modules or units is only a logical function division, and there can be another division way in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0123] The units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e. can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0124] The above examples are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A calibration method applied to a tracking scanning system, characterized in that, The tracking scanning system includes a tracker and a scanner, and the method includes: The reference object on the calibration device is scanned using the scanner to obtain the first scan data of the reference object in the scanning coordinate system; The position and pose of the marker on the scanner are obtained using the tracker, as well as the position and pose of the calibration device; Based on the true value corresponding to the reference object and the first scan data, the device parameters of the scanner are calibrated. Based on the pose of the marker and the pose of the calibration device, the first scan data is converted to the tracking coordinate system of the tracker; Based on the true value corresponding to the reference object and the first scan data in the tracking coordinate system, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system of the marker is calibrated.

2. The calibration method according to claim 1, characterized in that, After calibrating the device parameters of the scanner, the method further includes: Based on the calibrated scanner's device parameters, the first scan data is updated to the second scan data; Accordingly, the step of converting the first scan data to the tracking coordinate system of the tracker based on the pose of the marker and the pose of the calibration device includes: Based on the pose of the marker and the pose of the calibration device, the second scanning data is converted to the tracking coordinate system of the tracker; The step of calibrating the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system based on the true value corresponding to the reference object and the first scan data in the tracking coordinate system includes: Based on the true value corresponding to the reference object and the second scan data in the tracking coordinate system, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system of the marker is calibrated.

3. The calibration method according to claim 1, characterized in that, The calibration of the scanner's device parameters based on the true value corresponding to the reference object and the first scan data includes: When the reference object is a reference sphere, the first scan data in the scan coordinate system is fitted based on the feature constraints corresponding to the reference sphere to obtain the first fitted data; wherein, the first fitted data is the spherical data of the virtual model corresponding to the reference sphere; Based on the first fitted data, determine the model diameter of the virtual model in the scanning coordinate system; Calculate the deviation between the diameter of the virtual model in the scan coordinate system and the actual diameter of the reference sphere; If the deviation value is greater than or equal to a preset error threshold, the device parameters are adjusted based on the deviation value. If the deviation value is less than a preset error threshold, the calibration of the scanner's device parameters is completed.

4. The calibration method according to claim 1, characterized in that, The step of calibrating the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system based on the true value corresponding to the reference object and the first scan data in the tracking coordinate system includes: When the reference object is a reference sphere, the first scan data in the tracking coordinate system is fitted based on the feature constraints corresponding to the reference sphere to obtain the second fitted data; wherein, the second fitted data is the spherical data of the virtual model corresponding to the reference sphere; Based on the second fitted data, the diameter of the virtual model in the tracking coordinate system is determined; Calculate the deviation between the diameter of the virtual model in the tracking coordinate system and the actual diameter of the reference sphere; If the deviation value is less than the preset error threshold, the rigid body transformation relationship between the local coordinate system and the scan coordinate system is calibrated.

5. The calibration method according to claim 1, characterized in that, The step of calibrating the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system based on the true value corresponding to the reference object and the first scan data in the tracking coordinate system includes: When the reference object includes a first reference sphere and a second reference sphere, the obtained true values ​​include the first true diameter corresponding to the first reference sphere, the second true diameter corresponding to the second reference sphere, and the true center distance between the first reference sphere and the second reference sphere. The first scan data in the tracking coordinate system is fitted based on the feature constraints corresponding to the reference object to obtain the third fitted data. The third fitted data includes the spherical data of the virtual model corresponding to the first reference sphere and the spherical data of the virtual model corresponding to the second reference sphere. Based on the third fitting data, the first virtual diameter of the virtual model corresponding to the first reference sphere, the first virtual center of the virtual model corresponding to the first reference sphere, the second virtual diameter of the virtual model corresponding to the second reference sphere, and the second virtual center of the virtual model corresponding to the second reference sphere are determined. Calculate the first difference between the first virtual diameter and the first real diameter, the second difference between the second virtual diameter and the second real diameter, the virtual distance between the first virtual center and the second virtual center, and the center-to-center difference between the virtual distance and the real center-to-center distance; If the first difference, the second difference, and the difference between the centers of the spheres are all less than a preset error threshold, the rigid body transformation relationship between the local coordinate system and the scanning coordinate system is calibrated.

6. The calibration method according to claim 5, characterized in that, The method further includes: If one or more of the first difference, the second difference, and the difference between the centers of the spheres are greater than or equal to the preset error threshold, the transformation relationship between the local coordinate system and the scan coordinate system is optimized based on one or more values ​​that are greater than or equal to the preset error threshold.

7. The calibration method according to claim 1, characterized in that, The reference object includes a reference sphere and a top marker on the calibration device. The calibration of the scanner's device parameters based on the true value corresponding to the reference object and the first scan data includes: The device parameters of the scanner are calibrated based on the true value corresponding to the reference sphere, the true value corresponding to the top marker point, and the first scan data in the scanner coordinate system.

8. The calibration method according to claim 1, characterized in that, The reference object includes a reference sphere and a top marker point on the calibration device. The calibration of the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system, based on the true value corresponding to the reference object and the first scan data in the tracking coordinate system, includes: Based on the true value corresponding to the reference sphere, the true value corresponding to the top marker point, and the first scan data in the tracking coordinate system, the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system is calibrated.

9. The calibration method according to claim 8, characterized in that, The process of calibrating the rigid body transformation relationship between the local coordinate system of the marker and the scanning coordinate system based on the true value corresponding to the reference sphere, the true value corresponding to the top marker point, and the first scan data in the tracking coordinate system includes: Based on the first scan data in the tracking coordinate system, determine the model diameter of the virtual model corresponding to the reference sphere in the tracking coordinate system, and determine the virtual point position corresponding to the top marker point; Calculate the deviation between the model diameter corresponding to the virtual model in the tracking coordinate system and the actual diameter corresponding to the reference sphere; Calculate the alignment error between the virtual point and the actual value corresponding to the top marker point; If the deviation value is less than a preset error threshold and the alignment error value is less than a preset difference, the rigid body transformation relationship between the local coordinate system and the scan coordinate system is calibrated.

10. A calibration device, characterized in that, The calibration device includes: The side is provided with side markers, which are used to determine the position and orientation of the calibration device; The top is used to support the reference object, or... The top is provided with a top marker point and is used to support the reference object.

11. A tracking scanning system, characterized in that, The tracking scanning system includes: A scanner is used to scan a reference object on a calibration device, or to scan the reference object and vertex markers on the calibration device. A tracker is used to acquire the pose of a marker on the scanner and to determine the pose of the calibration device based on the side marker points corresponding to the side of the calibration device. Electronic devices, including processors and memory; The memory stores a computer program, and the processor, when executing the computer program, implements the calibration method as described in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which, when executed by a processor, implements the calibration method as described in any one of claims 1 to 9.

Images