Equipment calibration method and system, electronic equipment and storage medium

Abstract

The invention provides an equipment calibration method and system, electronic equipment and a storage medium. The equipment calibration method comprises the following steps: acquiring a scanning coordinate obtained by measuring a preset calibration plate by an optical tracking system, wherein the optical tracking system comprises a target point; obtaining a first coordinate set determined by photographing the calibration plate by photogrammetry devices at different positions, and a second coordinate set determined by photographing the target point; determining a target conversion relationship between a first coordinate system of the optical tracking system and a second coordinate system of the photogrammetry device according to the scanning coordinates and the first coordinate set; according to the target conversion relation and the second coordinate set, determining a first conversion relation between target points measured by photogrammetry devices at different positions and the first coordinate system; and completing calibration of the optical tracking system based on the first conversion relation. According to the method, the equipment calibration efficiency and precision can be improved.

Description

Technical Field

[0001] The present application relates to the field of scanning, and in particular to a device calibration method, system, electronic device and storage medium. Background Art

[0002] When scanning an object using a 3D scanning system, a tracker is required to position the scanner in real time to obtain scan data of the object. Due to the limited measurement range of the tracker, conversion between different coordinate systems must be completed by affixing marker points on the object or in a common area. When the object to be scanned is large, the tracker needs to be moved multiple times, and the coordinates of the marker points need to be measured one by one using a laser tracker to complete the station calibration. This method not only leads to cumulative station errors that affect the scanning accuracy, but also affects the efficiency of the station calibration. Summary of the Invention

[0003] The embodiments of the present application disclose a device calibration method, system, electronic device and storage medium, which solve the technical problems of large cumulative errors during station transfer and low efficiency of station transfer calibration.

[0004] The present application provides a device calibration method, the method comprising: obtaining scanning coordinates obtained by measuring a preset calibration plate with an optical tracking system, the optical tracking system including a target point; obtaining a first coordinate set determined by photographing the calibration plate with a photogrammetric device at different positions, and a second coordinate set determined by photographing the target point; determining a target transformation relationship between a first coordinate system of the optical tracking system and a second coordinate system of the photogrammetric device based on the scanning coordinates and the first coordinate set; determining a first transformation relationship between the target point measured by the photogrammetric device at different positions and the first coordinate system based on the target transformation relationship and the second coordinate set; and completing calibration of the optical tracking system based on the first transformation relationship.

[0005] In some embodiments of the present application, obtaining a first coordinate set determined by photographing the calibration plate by a photogrammetric device at different positions, and a second coordinate set determined by photographing the target point, includes: obtaining a first image set obtained by photographing the calibration plate by the photogrammetric device at different positions, and a second image set obtained by photographing the target point; determining a first image coordinate set corresponding to the first image set in an image coordinate system, and determining a second image coordinate set corresponding to the second image set in the image coordinate system; converting the first image coordinate set to the second coordinate system of the photogrammetric device based on camera parameters of the photogrammetric device to obtain the first coordinate set, and converting the second image coordinate set to the second coordinate system of the photogrammetric device to determine the second coordinate set.

[0006] In some embodiments of the present application, determining the target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device based on the scanning coordinates and the first coordinate set includes: obtaining a position coordinate set obtained by scanning the calibration plate by the photogrammetric device at any position from the first coordinate set; and determining the target transformation relationship between the second coordinate system of the photogrammetric device at any position and the first coordinate system based on the scanning coordinates and the position coordinate set.

[0007] In some embodiments of the present application, acquiring scanning coordinates obtained by measuring a preset calibration plate by the optical tracking system includes: acquiring a sub-coordinate set obtained by each optical tracking system of a plurality of optical tracking systems measuring the calibration plate, wherein the calibration plate is located within a common field of view of the plurality of optical tracking systems; determining a second transformation relationship between first coordinate systems corresponding to the plurality of optical tracking systems based on the sub-coordinate set corresponding to each optical tracking system; and converting the sub-coordinate set corresponding to each optical tracking system into a first reference coordinate system based on the second transformation relationship to determine the scanning coordinates; wherein the first reference coordinate system is determined from the first coordinate system corresponding to each optical tracking system; accordingly, determining a target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetry device based on the scanning coordinates and the first coordinate set includes: determining a target transformation relationship between the first reference coordinate system and the second coordinate system based on the first coordinate set and the second coordinate set.

[0008] In some embodiments of the present application, after completing the calibration of the optical tracking system, the method further includes: determining a first position and a second position of the optical tracking system that continuously moves when tracking a scanner; obtaining a third coordinate set obtained by measuring a target point of the optical tracking system located at the first position with a laser tracker, and a fourth coordinate set obtained by measuring the target point of the optical tracking system located at the second position; and determining a position conversion relationship between a first coordinate system of the optical tracking system located at the first position and a first coordinate system of the optical tracking system located at the second position based on the third coordinate set, the fourth coordinate set and the first conversion relationship.

[0009] In some embodiments of the present application, the method further includes: when the optical tracking system is in the first position, obtaining first data obtained by the scanner when scanning the scanned object; when the optical tracking system is in the second position, obtaining second data obtained by the scanner when scanning the scanned object; based on the position conversion relationship, converting the first data and the second data to a second reference coordinate system; wherein, the second reference coordinate system is determined from the corresponding first coordinate systems of the optical tracking systems at different positions, and the optical tracking system at each position has a corresponding first coordinate system.

[0010] In some embodiments of the present application, after completing the calibration of the optical tracking system, the method further includes: determining multiple positions to which the optical tracking system moves continuously when tracking a scanner; obtaining a fifth coordinate set obtained by measuring the target point of the optical tracking system at each position by each laser tracker among a plurality of laser trackers; determining a sixth coordinate set in a third reference coordinate system based on a conversion relationship between the fifth coordinate set and the coordinate systems of the plurality of laser trackers, the third reference coordinate system being determined from the coordinate systems of the laser trackers at different positions; and determining a conversion relationship between the first coordinate systems of the optical tracking systems at different positions based on the sixth coordinate set and the first conversion relationship.

[0011] The present application also provides a device calibration system, which includes: an optical tracking system for measuring a preset calibration plate to obtain scanning coordinates; a photogrammetric device for photographing the calibration plate at different positions to obtain a first coordinate set, and photographing a target point on the optical tracking system to obtain a second coordinate set; an electronic device for determining a target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device based on the scanning coordinates and the first coordinate set; the electronic device is further used to determine a first transformation relationship between the target point measured by the photogrammetric device at different positions and the first coordinate system based on the target transformation relationship and the second coordinate set; and the calibration of the optical tracking system is completed based on the first transformation relationship.

[0012] The present application also provides an electronic device, which includes a processor and a memory, and the processor is used to implement the device calibration method when executing a computer program stored in the memory.

[0013] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the device calibration method is implemented.

[0014] In the device calibration method provided in the present application, the scanning coordinates obtained by measuring a preset calibration plate by an optical tracking system are obtained, a first coordinate set determined by photographing the calibration plate by a photogrammetric device at different positions, and a second coordinate set determined by photographing the target point are obtained. By obtaining the above-mentioned scanning coordinates, the first coordinate set and the second coordinate set, basic data for subsequent device calibration is provided. Based on the scanning coordinates and the first coordinate set, the target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device is determined, so that the target transformation relationship and the second coordinate set can be used to determine the first transformation relationship between the target point measured by the photogrammetric device at different positions and the first coordinate system, providing a basis for the subsequent accurate station transfer process. Through the above-mentioned embodiment, the coordinate system in the subsequent station transfer process can be realized, and the large cumulative error that occurs during the station transfer can be avoided, thereby improving the scanning accuracy to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the architecture of the device calibration system provided in an embodiment of the present application.

[0016] Figure 2 This is a flow chart of the device calibration method provided in an embodiment of the present application.

[0017] Figure 3 This is the positional relationship between the photogrammetry device provided in the embodiment of the present application and the calibration plate and target point.

[0018] Figure 4 This is a flow chart for determining scanning coordinates provided in an embodiment of the present application.

[0019] Figure 5 This is a measurement diagram of multiple optical tracking systems measuring calibration plates provided in an embodiment of the present application.

[0020] Figure 6 This is an application flow chart of the first conversion relationship provided in an embodiment of the present application.

[0021] Figure 7 This is a flow chart for determining the conversion relationship between the first coordinate systems of the optical tracking systems located at different positions provided in an embodiment of the present application.

[0022] Figure 8 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] To facilitate understanding, some illustrations of concepts related to the embodiments of the present application are given for reference.

[0024] It should be noted that, in this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A alone, A and B together, and B alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," and so on (if any) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or precedence.

[0025] In the automotive, marine, and aerospace industries, 3D scanning systems are commonly used to acquire 3D data. A 3D scanning system consists of a tracker and a scanner (such as a handheld scanner). The tracker can include a laser tracker and an optical tracking system. The optical tracking system can position the handheld scanner in real time to scan objects without markers (such as large workpieces), thereby acquiring 3D data corresponding to the scanned object. The optical tracking system has a limited measurement range, typically between 3m and 10m. If the object being scanned is large and exceeds the optical tracking system's measurement range, the optical tracking system must be relocated to complete 3D data acquisition.

[0026] Before the actual scanning work, it is necessary to complete the conversion between different coordinate systems to complete the transfer station calibration. In the related art, it is necessary to paste marker points on the object or in the public area, and complete the conversion between different coordinate systems by moving the position of the optical tracking system. However, this type of method cannot ensure the scanning accuracy of large scenes. When multiple transfer stations are required, it will lead to the accumulation of multiple transfer station errors, affecting the subsequent transfer station scanning accuracy of the optical tracking system. In addition, in the relevant calibration process, the laser tracker and the optical tracking system will be combined to complete the equipment calibration, but the laser tracker has high requirements for the application scenario. For example, when the laser tracker has slight vibrations, it will affect the accuracy of the equipment calibration.

[0027] In order to solve the technical problems of large cumulative errors during station transfer and low efficiency of station transfer calibration, the embodiments of the present application provide a device calibration method, system, electronic device and storage medium. By combining a photogrammetric device and an optical tracking system for calibration, the flexibility, efficiency and calibration accuracy of the device calibration are improved. In addition, the use of a photogrammetric device instead of a laser tracker during the equipment calibration stage can reduce the use time of the laser tracker, extend the service life of the laser tracker and reduce maintenance costs. To a certain extent, the station transfer accuracy of the optical tracking system in the subsequent scanning process is improved. The architecture of the device calibration system of the present application is first described below.

[0028] Figure 1This is a schematic diagram of the architecture of the device calibration system provided in the embodiment of the present application. Figure 1 As shown, the device calibration system includes an electronic device 10, a photogrammetric device 20, and an optical tracking system 30. The embodiment of the present application does not limit the number of photogrammetric devices 20 and optical tracking systems 30.

[0029] The electronic device 10 may include a device with communication capabilities, such as a laptop computer, tablet computer, programmable logic controller (PLC), or human-machine interface (HMI) with touch input capabilities. It may also include a device simulated by a virtual machine or simulator. The electronic device 10 is used to receive data sent by the photogrammetry device 20 and the optical tracking system 30 and perform calculations on the data to complete the device's transfer calibration.

[0030] The photogrammetry device 20 may be a device with a camera function, such as a monocular camera, a binocular camera, a depth camera, or a high-precision large-scale camera.

[0031] The optical tracking system 30 includes an optical tracker ( Figure 1 not shown) and scanner ( Figure 1 The coordinates of the marker points on the calibration plate can be measured using an optical tracker or a scanner (not shown). The optical tracking system 30 can transmit the coordinates of the marker points on the calibration plate to the electronic device 10. Furthermore, the optical tracking system 30 can be provided with a target point, and the photogrammetry device 20 can also photograph the target point to obtain the corresponding coordinates, and transmit the obtained target point coordinates to the electronic device 10.

[0032] Among them, the optical tracker and scanner in the optical tracking system 30 can be two independently operating devices that can achieve communication connection, or they can be two sub-devices belonging to the same system (for example, a tracking scanner). They can be assembled to operate collaboratively, or they can be disassembled to operate independently. This application does not limit the device form, operation mode, etc. of the optical tracker and scanner in the optical tracking system 30.

[0033] In the application scenario of the device calibration system, the calibration plate and the optical tracking system 30 can be fixed at a certain position, and the calibration plate is located within the measurement range of the optical tracking system 30. The optical tracking system 30 can measure the coordinates corresponding to the calibration plate and send them to the electronic device 10. The photogrammetry device 20 can dynamically move to different positions and capture the target points of the calibration plate and the optical tracking system 30 at different positions, thereby transmitting the captured data to the electronic device 10. In addition, multiple photogrammetry devices 20 at different positions can be used to capture the calibration plate, thereby obtaining the coordinates of the calibration plate at different positions. The electronic device 10 completes the transfer calibration of the optical tracking system based on the received data.

[0034] The schematic Figure 1 It is merely an example of a device calibration system and does not constitute a limitation of the device calibration system. The system may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the device calibration system may also include a depth sensor, etc.

[0035] Figure 2 This is a flow chart of a device calibration method provided in an embodiment of the present application, which is applied to electronic devices (such as Figure 1 According to different requirements, the order of the steps in the flowchart can be changed, and some steps can be omitted.

[0036] Step S201: obtaining scanning coordinates obtained by measuring a preset calibration plate with an optical tracking system.

[0037] In some embodiments of the present application, a preset calibration plate can be placed at a preset position. The calibration plate can be provided with a target base, on which a marker point can be placed. The marker point can be a high-precision reflective marker point, such as a hubbs marker point. The optical tracking system can be pre-fixed in a position, that is, the position of the optical tracking system relative to the ground does not change during the device calibration process. The calibration plate is scanned using the optical tracking system to obtain the scanned coordinates of the marker point corresponding to the calibration plate in the coordinate system (first coordinate system) of the optical tracking system. The electronic device receives the scanned coordinates sent by the optical tracking system, providing a data basis for subsequent device calibration.

[0038] Step S202 : obtaining a first coordinate set determined by photographing the calibration plate with photogrammetry devices at different positions, and a second coordinate set determined by photographing the target point.

[0039] In some embodiments of the present application, the photogrammetric device can move to multiple positions during the calibration process. The photogrammetric device photographs a calibration plate to determine a first image set corresponding to the calibration plate. The coordinates of the first image set in an image coordinate system are referred to as a first image coordinate set. Based on the camera parameters used when photographing the calibration plate, the first image coordinate set is converted to a second coordinate system of the photogrammetric device to obtain a first coordinate set.

[0040] The optical tracking system includes a target point, which can be a marker point. The photogrammetric device also captures the target point on the optical tracking system to obtain a second image set, and the coordinates of the second image set in the image coordinate system are marked as the second image coordinate set. According to the camera parameters when the photogrammetric device captures the target point, the second image coordinate set is converted to the second coordinate system of the photogrammetric device to obtain the second coordinate set. The electronic device receives the first coordinate set and the second coordinate set to provide a data basis for subsequent device calibration. Figure 3 The schematic diagram shown describes the positional relationship between the photogrammetry device, the calibration plate, and the target points.

[0041] like Figure 3 The diagram shown can be a schematic diagram of a single photogrammetric device 20 moving to multiple positions, or a schematic diagram corresponding to multiple photogrammetric devices 20 at fixed positions; this application is not limited thereto. Below, we use the example of a single photogrammetric device 20 moving to multiple positions. Each time the photogrammetric device 20 moves to a different position, a calibration plate and target points will appear within its corresponding field of view. The photogrammetric device 20 will capture both the calibration points on the calibration plate and the target points on the optical tracking system 30.

[0042] Step S203 : determining a target transformation relationship between a first coordinate system of the optical tracking system and a second coordinate system of the photogrammetry device according to the scanning coordinates and the first coordinate set.

[0043] In some embodiments of the present application, after determining the scanning coordinates and the first coordinate set, a target transformation matrix can be calculated between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device, thereby determining a target transformation relationship based on the target transformation matrix. Because the first coordinate set includes coordinates corresponding to measurements at multiple positions, the position coordinate set obtained by scanning the calibration plate with the photogrammetric device at any position can be obtained from the first coordinate set. In one example, the first coordinate set includes coordinate set A corresponding to the photogrammetric device at position A and coordinate set B corresponding to the photogrammetric device at position B. Either coordinate set A or coordinate set B can be used as the position coordinate set. Based on the position coordinate sets and the scanning coordinates, a target transformation relationship can be calculated between the second coordinate system and the first coordinate system of the photogrammetric device at any position. Continuing with the above example, based on coordinate set A and the scanning coordinates, the target transformation relationship between the second coordinate system and the first coordinate system of the photogrammetric device at position A can be calculated. Alternatively, based on coordinate set B and the scanning coordinates, the target transformation relationship between the second coordinate system and the first coordinate system of the photogrammetric device at position B can be calculated.

[0044] Based on the position coordinate set and the scanning coordinates, the target transformation relationship between the second coordinate system and the first coordinate system of the photogrammetric device at any position can be calculated. Specifically, since the scanning coordinates and the position coordinate set correspond to the coordinates of marker points on the same calibration plate, the optimal rigid body transformation from the first coordinate system of the optical tracking system to the second coordinate system of the photogrammetric device can be ensured by minimizing the squared error between the corresponding points. A calibration plate can include multiple marker points, and the scanning coordinates are aligned with the coordinates of each marker point corresponding to the position coordinate set. Based on the coordinates of the aligned marker points, the first center of mass corresponding to the scanning coordinates and the second center of mass corresponding to the position coordinate set are calculated. Each marker point is decentered to obtain the first intermediate coordinate and the second intermediate coordinate. The covariance matrix is calculated based on the first center coordinate and the second center coordinate. The covariance matrix is subjected to SVD decomposition to calculate the rotation matrix and the translation vector. Based on the rotation matrix and the translation vector, the target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device can be calculated.

[0045] Step S204 : determining a first transformation relationship between the target point measured by the photogrammetric device at different positions and the first coordinate system according to the target transformation relationship and the second coordinate set.

[0046] In some embodiments of the present application, the target transformation relationship represents the transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device, and the second coordinate set includes coordinates in the second coordinate system of the photogrammetric device at different locations. Therefore, the second coordinate sets corresponding to the second coordinate systems at different locations can be transformed into the first coordinate system based on the target transformation relationship. The first coordinate system then includes the second coordinate sets corresponding to the multiple converted target points.

[0047] In one example, the second coordinate set includes coordinates A and coordinates B, which are obtained by photographing the target point at position A and position B, respectively, by the photogrammetric device. Coordinates A and B are converted into a first coordinate system of the optical tracking system according to the target transformation relationship, and coordinates B are converted into the first coordinate system of the optical tracking system, so that a first transformation matrix between the target points measured at positions A and B and the first coordinate system can be determined, and a first transformation relationship is determined according to the first transformation matrix.

[0048] Step S205: completing calibration of the optical tracking system based on the first conversion relationship.

[0049] In some embodiments of the present application, a first transformation relationship represents a transformation relationship between a target point measured by a photogrammetric device at different locations and a first coordinate system. Device calibration of the optical tracking system is performed using this first transformation relationship. After device calibration is completed, transfer station calibration of the optical tracking system can be performed based on the first transformation relationship.

[0050] Through the above-mentioned embodiments, the scanning coordinates obtained by measuring the preset calibration plate by the optical tracking system are obtained, the first coordinate set determined by photographing the calibration plate by the photogrammetric device at different positions, and the second coordinate set determined by photographing the target point are obtained. By obtaining the above-mentioned scanning coordinates, the first coordinate set and the second coordinate set, basic data for subsequent equipment calibration is provided. Based on the scanning coordinates and the first coordinate set, the target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device is determined, so that the target transformation relationship and the second coordinate set can be used to determine the first transformation relationship between the target point measured by the photogrammetric device at different positions and the first coordinate system, providing a basis for the subsequent accurate station transfer process. Through the above-mentioned embodiments, the coordinate system can be unified in the subsequent station transfer process, and the large cumulative error that occurs during the station transfer can be avoided, thereby improving the scanning accuracy to a certain extent.

[0051] Figure 4 This is a flow chart for determining the scanning coordinates provided by the embodiment of the present application. During the device calibration process, the scanning coordinates can be determined by multiple optical tracking systems. Figure 4 As shown, the following steps are included.

[0052] Step S401: obtaining a sub-coordinate set obtained by each of a plurality of optical tracking systems measuring a calibration plate.

[0053] In some embodiments of the present application, the calibration plate is placed in a fixed position and ensured to be within the common field of view of multiple optical tracking systems. Each optical tracking system will measure the calibration plate, thereby obtaining the sub-coordinates of the marker points corresponding to the calibration plate measured by each optical tracking system. Figure 5 Provide a description.

[0054] like Figure 5 As shown, the first, second, and third optical tracking systems share a common field of view, within which a calibration plate is placed. The first optical tracking system measures the calibration plate to obtain the coordinates corresponding to the plate's markers, which are recorded as sub-coordinate set A. The second optical tracking system measures the calibration plate to obtain the coordinates corresponding to the plate's markers, which are recorded as sub-coordinate set B. The third optical tracking system measures the calibration plate to obtain the coordinates corresponding to the plate's markers, which are recorded as sub-coordinate set C.

[0055] Step S402: determining a second transformation relationship between first coordinate systems corresponding to a plurality of optical tracking systems based on a sub-coordinate set corresponding to each optical tracking system.

[0056] In some embodiments of the present application, any two optical tracking systems having an adjacent relationship among a plurality of optical tracking systems are determined, and thus, based on the corresponding sub-coordinate sets of the any two optical tracking systems having an adjacent relationship, a conversion relationship between the first coordinate systems corresponding to the any two optical tracking systems having an adjacent relationship is determined.

[0057] Combine Figure 5 Continuing with the above example, it is determined that the first optical tracking system is adjacent to the second optical tracking system, and the second optical tracking system is adjacent to the third optical tracking system. The transformation relationship between the first coordinate system of the first optical tracking system and the first coordinate system of the second optical tracking system is determined based on sub-coordinate set A and sub-coordinate set B. The transformation relationship between the first coordinate system of the second optical tracking system and the first coordinate system of the third optical tracking system is determined based on sub-coordinate set B and sub-coordinate set C.

[0058] The conversion relationships corresponding to all pairs of adjacent optical tracking systems are recorded as second conversion relationships.

[0059] Step S403: Based on the second conversion relationship, the corresponding sub-coordinate set of each optical tracking system is converted to the first reference coordinate system to determine the scanning coordinates.

[0060] In some embodiments of the present application, the first reference coordinate system is determined from the first coordinate system corresponding to each optical tracking system, which can be any first coordinate system. The second transformation relationship includes the transformation relationship corresponding to every two adjacent optical tracking systems among the multiple optical tracking systems. Based on the second transformation relationship, the sub-coordinate sets corresponding to all optical tracking systems can be unified into the same first coordinate system, which is recorded as the first reference coordinate system, and the sub-coordinate sets converted to the first reference coordinate system are recorded as scanning coordinates.

[0061] In other embodiments of the present application, since each optical tracking system measures the same calibration plate, the coordinates converted according to the conversion relationship corresponding to any two adjacent optical tracking systems are applied in the same way. The converted coordinates can be compared to verify whether there is a measurement error in the mark points corresponding to the measured calibration plate to eliminate outliers.

[0062] In other embodiments of the present application, since the scanning coordinates are coordinates on the first reference coordinate system, determining the target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device based on the scanning coordinates and the first coordinate set can be replaced by determining the target transformation relationship between the first reference coordinate system and the second coordinate system based on the first coordinate set and the second coordinate set.

[0063] Through the above-described embodiment, the scanning coordinates of the marker points corresponding to the calibration plate in the first reference coordinate system are determined by utilizing the transformations between multiple optical tracking systems. This avoids the local data loss caused by the viewing angle limitations of a single optical tracking system, provides richer spatial information, and accelerates the optimization process of calibration parameters. Furthermore, the transformation relationships between the coordinate systems of multiple optical tracking systems can serve as a calibration quality verification tool, ensuring the accuracy of the transformation relationships and the correctness of the calibration parameters.

[0064] Figure 6 This is an application flow chart of the first conversion relationship provided by the embodiment of the present application. After completing the equipment calibration, the laser tracker is used to determine the conversion relationship between the first coordinate systems of the optical tracking system at different positions, such as Figure 6 The method comprises the following steps.

[0065] Step S601 : determining a first position and a second position of an optical tracking system that continuously moves while tracking a scanner.

[0066] In some embodiments of the present application, the scanner needs to perform an omnidirectional scan of the scanned object, requiring multiple movement. If the optical tracking system exceeds the scanning range of the optical tracking system while tracking the scanner, the optical tracking system needs to be moved. The optical tracking system is moved from a first position to a second position. The second position can be a pre-set position or a randomly determined position, and this application does not limit this.

[0067] Step S602 : acquiring a third coordinate set obtained by measuring the target point of the optical tracking system at the first position using a laser tracker, and a fourth coordinate set obtained by measuring the target point of the optical tracking system at the second position using a laser tracker.

[0068] In some embodiments of the present application, the optical tracking system includes a target point, which may be a marker point. When the optical tracking system is in a first position, the laser tracker measures the target point to obtain a third set of coordinates for the target point. When the optical tracking system is in a second position, the laser tracker measures the target point to obtain a fourth set of coordinates for the target point. The electronic device receives the third and fourth sets of coordinates transmitted by the laser tracker.

[0069] Step S603 : determining a position conversion relationship between the first coordinate system of the optical tracking system at the first position and the first coordinate system of the optical tracking system at the second position based on the third coordinate set, the fourth coordinate set and the first conversion relationship.

[0070] In some embodiments of the present application, the position conversion relationship represents the coordinate conversion relationship between the first coordinate system of the optical tracking system at the first position and the first coordinate system of the optical tracking system at the second position. The first position can be understood as the position before the transfer station, and the second position can be understood as the position after the transfer station. According to the third coordinate set and the fourth coordinate set, the intermediate conversion relationship is calculated. The intermediate conversion relationship represents the conversion relationship when the position before the transfer station is moved to the position after the transfer station in the second coordinate system of the laser tracker. The matrix corresponding to the first conversion relationship is inversely transformed to obtain an inverse matrix. The position conversion relationship is determined according to the intermediate conversion relationship, the matrix corresponding to the first conversion relationship and the inverse matrix. It is expressed as T2=X^(-1)*T1*X, where T2 represents the position conversion relationship, X^(-1) represents the inverse matrix, T1 represents the intermediate conversion relationship, and X represents the matrix corresponding to the first conversion relationship.

[0071] Step S604: when the optical tracking system is at the first position, first data obtained by the scanner from scanning the scanned object is acquired.

[0072] In some embodiments of the present application, the scanned object can be any device, a part within a device, a human figure, a vehicle, etc. This application does not limit the type of scanned object. The scanner can scan the scanned object in real time. When the optical tracking system is in a first position, the electronic device obtains first data of the scanner scanning the scanned object. The first data can be an image frame of the scanned object.

[0073] Step S605 : when the optical tracking system is at the second position, obtaining second data obtained by the scanner from scanning the scanned object.

[0074] In some embodiments of the present application, the second position may be a position adjacent to the first position. When the optical tracking system is at the second position, the electronic device obtains second data of the scanner scanning the scanned object, and the second data may be an image frame of the scanned object.

[0075] Step S606 : transforming the first data and the second data into a second reference coordinate system based on the position transformation relationship.

[0076] In some embodiments of the present application, the position transformation relationship can unify the position tracked by the scanner before and after the optical tracking system is transferred to the same optical tracking system coordinate system. The first data and the second data can then be spliced based on the position of the scanner in the same optical tracking system coordinate system, thereby unifying the first data and the second data to the same coordinate system. For example, the second reference coordinate system can be determined in the first coordinate system of the optical tracking system at different positions, and the optical tracking system at each position has a corresponding first coordinate system.

[0077] Through the above embodiment, a large-scale expansion of a wide range of scanning space can be achieved. In addition, the cumulative transfer error can be avoided, thereby improving the scanning accuracy.

[0078] Figure 7 This is a flow chart for determining the conversion relationship between the first coordinate systems of the optical tracking systems at different positions provided by the embodiment of the present application. Multiple laser trackers are used to determine the conversion relationship between the first coordinate systems corresponding to the optical tracking systems that move multiple times. Figure 7 As shown, the following steps are included.

[0079] Step S701 : determining a plurality of positions that the optical tracking system moves continuously while tracking a scanner.

[0080] In some embodiments of the present application, the scanner needs to perform an omnidirectional scan of the scanned object, necessitating multiple movement positions. If the optical tracking system exceeds its scanning range while tracking the scanner, the optical tracking system needs to be moved. For example, the optical tracking system may be moved from a first position to a second position. The second position may be a pre-set position or a randomly determined position, and this application does not limit this.

[0081] Step S702 : obtaining a fifth coordinate set obtained by measuring the target point of the optical tracking system at each position by each laser tracker among the multiple laser trackers.

[0082] In some embodiments of the present application, multiple laser trackers are arranged at different positions, and each laser tracker can measure the target point of the laser tracker at each position to obtain a fifth coordinate set.

[0083] Step S703 : determining a sixth coordinate set in the third reference coordinate system based on a conversion relationship between the fifth coordinate set and the coordinate systems of the plurality of laser trackers.

[0084] In some embodiments of the present application, every two laser trackers in a plurality of locations are adjacent to each other, and these adjacent laser trackers share a common measurement range. The coordinates of the target point of the optical tracking system within the common measurement range are obtained, and the transformation relationship between the coordinate systems of the adjacent laser trackers is determined, thereby obtaining the transformation relationship between the coordinate systems of the plurality of laser trackers. A third reference coordinate system is determined from the coordinate systems of the laser trackers at different locations, i.e., the third reference coordinate system is a second coordinate system among the coordinate systems of the laser trackers at different locations.

[0085] Based on the conversion relationship between the coordinate systems of multiple laser trackers, the fifth coordinate set is unified into the same second coordinate system, that is, unified into the third reference coordinate system, to obtain the sixth coordinate set in the third reference coordinate system.

[0086] Step S704 : determining the transformation relationship between the first coordinate systems of the optical tracking systems at different positions based on the sixth coordinate set and the first transformation relationship.

[0087] In some embodiments of the present application, the first transformation relationship represents the transformation relationship between target points measured at different locations and the first coordinate system, and the sixth coordinate set includes the coordinates of the target points measured at different locations in the third reference coordinate system. Therefore, the transformation relationship between the first coordinate systems of optical tracking systems at different locations can be determined. Based on the sixth coordinate set and the first transformation relationship, the target coordinates of the optical tracking systems at different locations in the third reference coordinate system are determined.

[0088] In one example, determining the target coordinates includes first target coordinates and second target coordinates. Then, based on the first target coordinates and the second target coordinates, a transformation relationship between the first coordinate system of the optical tracking system at the first position and the first coordinate system of the optical tracking system at the second position is determined. Using the chain rule, this is expressed as: T = L1^(-1)*L2, where T represents the transformation relationship between the first coordinate system of the optical tracking system at the first position and the first coordinate system of the optical tracking system at the second position, L1 represents the first target coordinates (matrix) of the optical tracking system at the first position in the third reference coordinate system, and L2 represents the second target coordinates (matrix) of the optical tracking system at the second position in the third reference coordinate system.

[0089] The above embodiment can realize coordinate system 1, avoid large cumulative errors that occur during station transfer, and improve scanning accuracy to a certain extent.

[0090] Figure 8 The device calibration method provided in the embodiment of the present application is applied to an electronic device 10, which can be a computer device with a camera function, such as a mobile phone, tablet computer, laptop computer, or facial scanner.

[0091] The electronic device 10 includes 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 communication interface 101, the memory 102, and the I / O interface 104 via the bus 105.

[0092] The communication module 101 may include a wired communication module and / or a wireless communication module. The wired communication module may provide one or more wired communication solutions such as Universal Serial Bus (USB) and Controller Area Network (CAN). The wireless communication module may provide one or more wireless communication solutions such as Wireless Fidelity (Wi-Fi), Bluetooth (BT), mobile communication networks, Frequency Modulation (FM), Near Field Communication (NFC), and Infrared (IR).

[0093] Memory 102 may include one or more random access memories (RAMs) and one or more non-volatile memories (NVMs). RAM can be directly read and written by processor 103 and can be used to store executable programs (e.g., machine instructions) for the operating system or other running programs, as well as user and application data. RAM may 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.

[0094] The non-volatile memory can also store executable programs and user and application data, etc., and can be pre-loaded into the random access memory for direct reading and writing by the processor 110. The non-volatile memory can include disk storage devices and flash memory.

[0095] 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 multiple instructions. When the multiple instructions are executed by the processor 103, the device calibration method executed on the electronic device 10 can be implemented.

[0096] In other embodiments, the electronic device 10 further includes an external memory interface for connecting to an external memory to expand the storage capacity of the electronic device 10 .

[0097] The processor 103 may include one or more processing units. For example, the processor 103 may 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). The different processing units may be independent devices or integrated into one or more processors.

[0098] 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 above-mentioned device calibration method.

[0099] 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, keyboard, touch device, display screen, etc., so that the user can enter information or visualize information.

[0100] The bus 105 is at least used to provide a channel for mutual communication among the communication module 101 , the memory 102 , the processor 103 , and the I / O interface 104 in the electronic device 10 .

[0101] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. The computer program includes program instructions. The method implemented when the program instructions are executed can refer to the methods in the above-mentioned embodiments of the present application.

[0102] The computer-readable storage medium may be an internal memory of the electronic device described in the above embodiment, such as a hard disk or memory of the electronic device. The computer-readable storage medium may also be an external storage device of the electronic device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital (SD) card, a flash memory card, etc. equipped on the electronic device.

[0103] In some embodiments, the computer-readable storage medium may include a program storage area and a data storage area, wherein the program storage area may store an operating system, applications required for at least one function, etc.; the data storage area may store data created according to the use of the electronic device, etc.

[0104] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0105] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0106] In the embodiments provided in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0107] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0108] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A device calibration method, characterized in that: The method comprises: Acquiring scanning coordinates obtained by measuring a preset calibration plate using an optical tracking system, wherein the optical tracking system includes a target point; Acquiring a first coordinate set determined by photographing the calibration plate using photogrammetric devices at different positions, and a second coordinate set determined by photographing the target point; determining a target transformation relationship between a first coordinate system of the optical tracking system and a second coordinate system of the photogrammetric device based on the scan coordinates and the first coordinate set; determining, based on the target transformation relationship and the second coordinate set, a first transformation relationship between target points measured by photogrammetric devices at different positions and the first coordinate system; Based on the first conversion relationship, the calibration of the optical tracking system is completed.

2. The device calibration method according to claim 1, characterized in that: The obtaining of a first coordinate set determined by photographing the calibration plate using a photogrammetric device at different positions, and a second coordinate set determined by photographing the target point, comprises: Acquire a first image set obtained by photographing the calibration plate at different positions by the photogrammetric device, and a second image set obtained by photographing the target point; Determining a first image coordinate set corresponding to the first image set in an image coordinate system, and determining a second image coordinate set corresponding to the second image set in the image coordinate system; Based on camera parameters of the photogrammetric device, the first image coordinate set is converted to a second coordinate system of the photogrammetric device to obtain the first coordinate set, and the second image coordinate set is converted to the second coordinate system of the photogrammetric device to determine the second coordinate set.

3. The device calibration method according to claim 2, characterized in that: Determining a target transformation relationship between a first coordinate system of the optical tracking system and a second coordinate system of the photogrammetry device according to the scanning coordinates and the first coordinate set includes: Acquire, from the first coordinate set, a position coordinate set obtained by scanning the calibration plate by the photogrammetric device at any position; A target transformation relationship between a second coordinate system of the photogrammetric device at any position and the first coordinate system is determined according to the scanning coordinates and the position coordinate set.

4. The device calibration method according to claim 1, characterized in that: The step of obtaining the scanning coordinates obtained by measuring a preset calibration plate with the optical tracking system includes: Acquire a sub-coordinate set obtained by each of a plurality of optical tracking systems measuring the calibration plate, where the calibration plate is located within a common field of view of the plurality of optical tracking systems; determining a second transformation relationship between first coordinate systems corresponding to the plurality of optical tracking systems based on the sub-coordinate set corresponding to each optical tracking system; Based on the second transformation relationship, the sub-coordinate set corresponding to each optical tracking system is transformed into a first reference coordinate system to determine the scanning coordinates; wherein the first reference coordinate system is determined from the first coordinate system corresponding to each optical tracking system; Accordingly, determining the target transformation relationship between the first coordinate system of the optical tracking system and the second coordinate system of the photogrammetric device according to the scanning coordinates and the first coordinate set includes: A target transformation relationship between the first reference coordinate system and the second coordinate system is determined based on the first coordinate set and the second coordinate set.

5. The device calibration method according to claim 1, characterized in that: After completing the calibration of the optical tracking system, the method further includes: determining a first position and a second position of the optical tracking system as it moves continuously while tracking the scanner; Acquire a third coordinate set obtained by measuring the target point of the optical tracking system located at the first position using a laser tracker, and a fourth coordinate set obtained by measuring the target point of the optical tracking system located at the second position; A position conversion relationship between a first coordinate system of the optical tracking system at the first position and a first coordinate system of the optical tracking system at the second position is determined based on the third coordinate set, the fourth coordinate set and the first conversion relationship.

6. The device calibration method according to claim 5, characterized in that: The method further comprises: When the optical tracking system is at the first position, acquiring first data obtained by the scanner scanning the scanned object; When the optical tracking system is at the second position, acquiring second data obtained by the scanner scanning the scanned object; Based on the position conversion relationship, the first data and the second data are converted to a second reference coordinate system; wherein the second reference coordinate system is determined from the corresponding first coordinate systems of the optical tracking systems at different positions, and the optical tracking system at each position has a corresponding first coordinate system.

7. The device calibration method according to claim 1, characterized in that: After completing the calibration of the optical tracking system, the method further includes: determining a plurality of positions that the optical tracking system moves continuously while tracking a scanner; obtaining a fifth coordinate set obtained by measuring a target point of the optical tracking system at each position by each of the plurality of laser trackers; determining a sixth coordinate set in a third reference coordinate system based on a conversion relationship between the fifth coordinate set and the coordinate systems of the plurality of laser trackers, the third reference coordinate system being determined from the coordinate systems of the laser trackers at different positions; Based on the sixth coordinate set and the first transformation relationship, a transformation relationship between the first coordinate systems of the optical tracking systems located at different positions is determined.

8. A device calibration system, characterized in that: The equipment calibration system includes: Optical tracking system, used to measure the preset calibration plate to obtain scanning coordinates; a photogrammetric device, configured to photograph the calibration plate at different positions to obtain a first coordinate set, and to photograph the target point on the optical tracking system to obtain a second coordinate set; an electronic device for determining a target transformation relationship between a first coordinate system of the optical tracking system and a second coordinate system of the photogrammetric device based on the scan coordinates and the first coordinate set; The electronic device is further used to determine a first transformation relationship between a target point measured by a photogrammetric device at a different position and the first coordinate system based on the target transformation relationship and the second coordinate set; and complete calibration of the optical tracking system based on the first transformation relationship.

9. An electronic device, characterized in that: The electronic device includes a processor and a memory, the memory stores a computer program, and the processor implements the device calibration method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores at least one instruction, and when the at least one instruction is executed by a processor, the device calibration method according to any one of claims 1 to 7 is implemented.

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