Handheld 3D scanning system using tracking cameras

Abstract

A handheld three-dimensional (3D) measuring system is tracked using at least two camera tracking systems. Each camera tracking system has at least one motorized axis of rotation. The camera tracking systems use cameras to accurately measure the pose of the 3D measuring system based the position of visible targets on the 3D measuring system and the rotated angle of each camera tracking system.

Description

HANDHELD 3D SCANNING SYSTEM USING TRACKING CAMERASRELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Application No. 63 / 571,693, filed on March 29, 2024, the entire contents of which are incorporated herein by reference.BACKGROUND

[0002] The present disclosure relates to a three-dimensional (3D) scanning system, including, for example, a scanning device for scanning or measuring objects and environments, and at least one camera having at least one motorized axis for tracking the scanning device as the scanning device moves around an object or through an environment.

[0003] Known scanning systems utilize (i) a scanning device for taking measurements of a desired target, such as an object, an environment or a physical area, as well as (ii) one or more cameras for tracking the pose or position of the scanning device. Such systems use the principle of triangulation to determine 3D coordinates of points on a target relative to each other based on the pose or position of the scanner when the measurements were taken. It is desirable to accurately track the position of the scanning device while the measurements are made thereby in order to create an accurate digital representation of the target. Small errors in triangulation measurements cumulatively compound as the scanning device is moved around the target, thereby causing the measured and actual position of the scanning device to drift and differ over time. This, in turn, causes errors and inaccuracies in the digital representation of the target object or environment (i.e., a point cloud representative thereof) generated from measurement data taken by the scanning system.

[0004] Traditionally, such 3D scanning and camera tracking systems have utilized a rigid camera bar or the like having cameras at known and fixed positions relative to each other in order to accurately track the scanning device. In such prior systems, the camera bar uses two cameras fixed at a predetermined known distance apart to triangulate the position of a target at an intersection of the cameras’ respective fields of view. The accuracy of the triangulation of the scanning device depends onthe resolution of the cameras, the relative position of the cameras, and the cameras’ fields of view (e.g., their focal lengths).

[0005] The volume of area that is tracked by prior camera bar or similar fixed camera system, i.e., the intersection of the tracking cameras’ fields of view, can be increased by adjusting the position of the tracking cameras to be farther apart, or by using a wide angle lens in one or both cameras. Using a wide angle lens, however, will reduce the image resolution and accuracy of the tracking cameras to triangulate the position of the scanning device. Spacing the cameras farther apart, on the other hand, increases the distance to the objects or environments being measured. As such distance increases, the target appears smaller in the images (i.e., with lower resolution), and errors in triangulating the positions of the same will increase as a result.

[0006] Conversely, using a camera with a smaller field of view (i.e., a higher focal length) will improve the resolution of the image and the accuracy of the position triangulation. However, the camera’s field of view also becomes smaller and therefore disadvantageously tracks the desired target over a smaller volume of space.

[0007] While existing tracking systems are suitable for their intended purposes there remains a need for improvement, particularly in providing a 3D object scanning or measuring system having the features provided herein.BRIEF DESCRIPTION

[0008] According to one aspect of the present disclosure, a scanning system for measuring a target is provided. The scanning system includes a measurement device having a plurality of artifacts disposed therein, which artifacts are used to track a pose or position of the measurement device. The scanning system also includes a first camera having at least two degrees of freedom, i.e. about at least its first, substantially horizontal axis and a second substantially vertical axis perpendicular to the first axis, wherein the first camera rotates about the first axis and the second axis to maintain line of sight to the measurement device as the measurement device moves about the target and takes measurements thereof. The scanning system also includes a second camera having at least two degrees of freedom, i.e., about its first axis and thesecond axis, wherein the second camera rotates about its first axis and the second axis to maintain line of sight to the measurement device as the measurement device moves about the target. The scanning system also includes a third camera having at least two rotational degrees of freedom about its first axis and its second axis, such that the third camera rotates about its first axis and its second axis to maintain line of sight to the measurement device as the measurement device moves about the target and takes measurements. Each of the first camera, the second camera, and the third camera are independently positionable about the target object. When the measurement device takes a measurement of the target object, at least two of the first camera, the second camera, and the third camera are used to determine a pose of the measurement device based on the plurality of artifacts, where the pose of the measurement device is used to determine measurements of the target.

[0009] According to another aspect of the present disclosure, a method for tracking a measuring device having a plurality of artifacts is provided. The method includes providing a plurality of cameras about a target to be measured, each of the plurality of cameras having at least two degrees of freedom, i.e. can rotate about a first axis and a second axis perpendicular to the first axis. The method includes moving the measurement device to a first location about the target, capturing a first measurement of the target with the measurement device, and determining a first pose of the measurement device when the measurement device takes the first measurement using at least two of the plurality of cameras, where the first pose is associated with the first measurement. The method further includes moving the measurement device to a second location about the target, capturing a second measurement of the target with the measurement device, and determining a second pose of the measurement device when the measurement device takes the second measurement using at least two of the plurality of cameras, where the second pose is associated with the second measurement. As the measurement device moves about the target, the plurality of cameras rotate to maintain line of sight with the measurement device. The plurality of cameras are independently positionable about the target.

[0010] According to a further aspect of the present disclosure, a method for generating a digital representation of a target is provided, the method includingproviding a plurality of cameras around the target to be measured, each of the plurality of cameras having at least two degrees of freedom, i.e., rotationally about a first axis and a second axis perpendicular to the first axis, and the plurality of cameras are independently positionable about the target object. The method includes triangulating a position of the measurement device in real time and transmitting the position of the measurement device to at least one of the plurality of cameras when line of sight from at least one of the plurality of cameras to the measurement device is obstructed. The method also includes moving the measurement device to a first location about the target, capturing a first measurement of the target with the measurement device, determining a first pose of the measurement device when the measurement device takes the first measurement using at least two of the plurality of cameras, and transforming the first measurement into a global frame of reference based on the first pose of the measurement device. The method further includes, moving the measurement device to a second location about the target, capturing a second measurement of the target with the measurement device, determining a second pose of the measurement device when the measurement device takes the second measurement using at least two of the plurality of cameras, and transforming the second measurement into the global frame of reference based on the second pose of the measurement device. The method further includes generating the digital presentation of the target based on the first measurement transformed by the first pose and the second measurement transformed by the second pose. As the measurement device moves about the target, the plurality of cameras rotate to maintain line of sight of the measurement device. The plurality of cameras rotate to follow the measurement device based on the transmitted position of the measurement device.

[0011] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing and other features, and advantages of the disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

[0013] FIG. l is a perspective view of a camera tracking system with two axes of rotation according to an embodiment of the present disclosure;

[0014] FIG. 2 is a schematic representation of a handheld 3D measuring device with a collection of reflectors or light sources for imaging according to an embodiment of the present disclosure;

[0015] FIG. 3 is a schematic representation of two cameras with two axes of rotation connected to a processor according to an embodiment;

[0016] FIG. 4A and FIG. 4B are schematic representation of the handheld measuring device of FIG. 2 being tracked by a plurality of camera tracking systems of FIG. 1 to measure an object according to an embodiment of the present disclosure.

[0017] FIG. 5 is a flow chart of an exemplary process of tracking a scanner as it moves throughout an environment.

[0018] The detailed description explains embodiments of the disclosure, together with advantages and features, by way of non-limiting example and with reference to the drawings.DETAILED DESCRIPTION

[0019] Improvements described herein include systems and methods that improve the accuracy of large volume measurements with a collection of cameras, and providing ways to accurately take large volume measurements without having to replace or reposition the tracking cameras.

[0020] With traditional 3D object scanning systems that include tracking of a handheld scanner with a camera, the volume of area that is tracked, i.e., the intersection of the tracking camera’s field of view, is increased by adjusting the position of the cameras to be farther apart or by using a wide angle camera lens. Using a wide angle lens, however, will reduce the image resolution and accuracy of the cameras and positioning the cameras farther apart will increase the distance to the object being tracked causing the object to appear smaller in the images, i.e., with lower resolution. This in turn increases errors in triangulating the position of the scanner.

[0021] Conversely, using a camera with a smaller field of view (high focal length), will improve the resolution of the image and the accuracy of the position triangulation. However, one drawback is that the camera’s field of view is smaller and therefore tracks the desired object over a smaller volume of space.

[0022] Thus, there is a need for a 3D scanner tracking system that accurately tracks the handheld measurement device over a wide volume of area, thereby reducing errors and increasing the efficiency of measurements.

[0023] FIG. 1 illustrates, a camera tracking system 10 according to an embodiment of the present disclosure. The camera tracking system 10 includes a camera 11 having a lens 13. In various instances, the lens 13 is either a static lens having a fixed focal length, or a zoom lens having an adjustable focal length that enables magnification of a visible target. In an embodiment, the lens 13 is a fixed focal length lens that is replaceable, and different focal length lenses are swapped or replaced for a given application. In an embodiment, the lens 13 is a 100 mm fixed focal-length lens. In another embodiment, an autofocus lens is used to increase the operating range of the camera 11. The camera 11 is rotatably coupled to a bracket 15, or the like, such that the camera 11 rotates about a horizontal -axis (e.g. x-axis or zenith axis) in a first degree of freedom. In various embodiments, the bracket 15 is also rotatably coupled to a post 19, via a ball bearing 17 or other rotatable means of attachment, such that the camera 11 also rotates about a vertical axis (e.g. y-axis or azimuth axis), being orthogonal to the x-axis, in a second degree of freedom. In certain embodiments, the x-axis is considered as extending vertically through a center of an outer surface of the lens 13 with respect to body of the camera 11. In certain embodiments, the y-axis is considered as extending horizontally through the center of the outer surface of the lens 13 with respect to body of the camera 11.

[0024] In various embodiments, the camera tracking system 10 also includes a first motor 21 and a second motor 23 for rotating the camera 11 about their x-axis and y-axis, respectively. In various embodiments, the motors 21, 23 are servo motors, actuators or other precision spindles, which fluidly rotates the camera 11 to follow an artifact, as described below. The motors 21, 23 are the same as or similar to motorsused with articulated arm coordinate measurement machines (AACMM) known in the art, an example of which is described in United States Patent No. 11,874,101 entitled “Modular Servo Cartridges for Precision Metrology,” the entirety of which is hereby incorporated by reference. In an embodiment, the motors 21, 23 are able to accurately rotate the camera 11 in approximately 200 micro degree increments about the x-axis and the y-axis respectively, but are not limited thereto. In various embodiments, the first motor 21 is attached to the bracket 15 and operatively coupled to the camera 11. The first motor 21 rotates the camera 11 back and forth around the x-axis. In various embodiments, the second motor 23 is attached to the post 19 and operatively coupled to the bracket 15. The second motor 23 rotates the camera 11 back and forth about the y-axis. In an embodiment, the motors 21, 23 are coupled to the camera 11 or bracket 15 via a drive train or are attached directly to the camera 11. In an embodiment, the motors 21, 23 are integral with the camera 11, bracket 15, and / or post 19.

[0025] Each of the x-axis and y-axis includes an optical encoder that measures the rotational position of the camera 11. For example, a first encoder 24 measures the rotation about the y-axis and a second encoder 25 measures rotation about the x-axis. In an embodiment, the measurement of camera angle in the x and y directions made by each encoder 24, 25 is accurate to at least 0.00014 degrees, or 0.5 arc seconds or less.

[0026] While the particular motorized set up is illustrated with reference to a particular embodiment, it is understood and appreciated that in some embodiments, the motors 21, 23 are hidden and / or connected to the camera via a drive train or other means of translating motion. Furthermore, the camera tracking system 10 is described with two motors and two degrees of motions; however, in other contemplated configurations, the camera tracking system 10 includes any combination of one or more motors and one or more axis of rotation. For example, in some embodiments, the camera tracking system 10 includes a single motor which operatively connects and is switched between multiple drive trains that each rotate the camera 11 about a respective axis, or by multiple motors that rotate the camera 11 about a single axis, e.g., in order to adjust the speed or precision of rotation of the same.

[0027] Referring now to FIG. 2, a 3D measuring system 250 is shown, that includes a 3D measurement device such as a handheld scanner 200 having disposed therein a collection of visible artifacts 260. The visible artifacts 260 are, in various embodiments, reflectors, reflective dots, active light emitting diodes (LEDs) or similar artifacts, which are adhered to, disposed on, or otherwise affixed to multiple locations about the handheld scanner 200. Reflectors or retroreflective targets are then illuminated by a light source (not shown) on the camera tracking system 10, while the active LEDs are instead illuminated in one or more particular patterns, in order to readily enable tracking of the pose or position of the handheld scanner 200 as an operator 210 moves the handheld scanner 200 around an environment or an object being measured. In various embodiments, one or more types of artifacts may be used in conjunction as the various visible artifacts 260 disposed on the handheld scanner 200.

[0028] In the case of active LEDs used as one or more of the visible artifacts 260, in various instances, the LEDs are flashed in a recognizable pattern to identify the corresponding artifacts in each image generated by the camera tracking system 10. The LEDs, in various instances, are a group of LEDs arranged in a recognizable configuration, such as a triangle or other geometric arrangement, wherein an LED is disposed at each vertex thereof in order to define the geometric relationship. In various embodiments, the shape of the geometric arrangement formed by the LEDs include a determinable center point of the shape. This center point of the geometric shape is then calculated by the 3D measuring system 250. In various embodiments, the center point of the geometric shape is where the camera 11 of each camera tracking system 10 of the 3D measuring system 250 will endeavor to remain focused as the handheld scanner 200 is moved around the target by the operator 210.

[0029] In an embodiment, the collection of visible artifacts 260 are coupled to a frame 262, which frame 262 is then removably attached to the handheld scanner 200. In other embodiments, the visible targets 260 are directly affixed to the handheld scanner 200 with connector elements 264. The 3D measuring system 250 is then directly connectable to an external computer such as a workstation computer or networked computer, for example. Alternatively, the 3D measuring system 250 isaffixed to a unit that includes a computing unit and power source, which is wearable by the operator 210.

[0030] In an embodiment, the 3D measuring system 250 measures 3D coordinates of surfaces of the target in the manner described in commonly-owned United States Patent Nos. 11,908,162; 11,262,194; 10,499,040; 9,599,455; as well as commonly-owned United States Patent Publ. Nos. 2022 / 0316869, 2022 / 0321659, and 2022 / 0321659, the contents of each of which are incorporated herein by reference.

[0031] In an embodiment, the handheld scanner 200 is replaced with other measuring devices, for example, a hard probe, a laser line scanner, an enclosure housing a laser line probe, or a portable coordinate measurement machine, although the measuring devices are not limited thereto. In the case of using a single laser line probe, or other device that typically cannot determine its own position in an environment, another measuring device such as a portable coordinate measurement machine is additionally used to supplement the measuring of the target by these other measuring device types.

[0032] Referring now to FIG. 3, a cooperative camera tracking system 300 is shown with individual camera tracking systems 300 A, 300B to capture images and track the position of, for example, visible artifacts 260 of the handheld scanner 200, in the manners described with respect to the camera tracking system 10 above. The captured images are then used to track the pose (position and orientation) of the handheld scanner 200 as it is moved about a target by an operator 210 in various cases. In some instances, the camera tracking systems 300A, 300B are the same or substantially the same as camera tracking system 10 shown in FIG. 1, with each camera tracking system having one or more motors, and the respective cameras 310A and 310B are likewise rotatable about at least an x-axis and a y-axis, respectively.

[0033] In an embodiment, electrical signals from a camera tracking system 300A, 300B are sent over a wired or wireless communication channel 340 to a computing system (processor) 330 that calculates the 3D coordinates of the target being measured by the handheld scanner 200 of the 3D measuring system 250. To perform this calculation, the computing system 330 needs to determine the relativepose (position and orientation) of the two cameras 310A, 310B with respect to each other. In an embodiment, the relative poses of the two cameras 310A, 301B are determined by performing a compensation procedure at the location where the cameras 310A, 31 OB are operated. An exemplary compensation procedure involves capturing a pattern on an artifact, such as a dot plate. Such an artifact is moved to a plurality of positions and orientations and the cameras 310A, 31 OB then capture images in each position. Optimization methods such as bundle adjustment are then used to determine the relative pose of the cameras 310A, 310B. Examples of the functions described hereinabove are described in further detail in commonly-owned United States Patent No. 11,408,728 entitled “Registration of Three-dimensional Coordinates Measured on Interior and Exterior Portions of an Object,” the contents of which are incorporated herein by reference.

[0034] Cameras 310A, 310B include optical imaging systems 312A, 312B having lenses, image sensors, and processing electronics in various applications. In an embodiment, the lenses within optical imaging systems 312A, 312B are zoom lenses that enable magnification of the visible targets 260 on the 3D measuring system 250. The cameras 310A, 310B are mounted on respective mounting stands 320 A, 320B. In some embodiments, the stands 320A and 320B are, for example, tripods, instrument stands, or any other structures for readily supporting camera systems. In this way, the camera tracking systems 300 A, 300B are positioned and set up independently from each other. This provides greater flexibility in the range of applications for which the camera tracking system 300 is suitable, since the cameras 310A, 310B are not fixed relative to each other, e.g., as opposed to cameras fixed on a rigid camera bar.

[0035] FIGS. 4A and 4B, show a 3D measurement and tracking system 500 having a 3D measuring system 250 that is tracked by a plurality of camera tracking systems 510A, 510B, 510C to measure an target 505. It should be appreciated that while FIG. 4 A and FIG. 4B illustrate three camera tracking systems 510A, 510B, 510C, this is for exemplary purposes, and the 3D measurement and tracking system 500 includes any number of two or more camera tracking systems as is necessary for a given application. In certain embodiments, each of the camera tracking systems 510A, 510B, 510C are the same as camera tracking system 10 or camera trackingsystem 300A, 300B described previously above. Similar to the camera tracking system 300, the camera tracking systems 510A, 510B, 510C are communicatively coupled to the computing system 330 by a wireless or wired connection 340 in various embodiments.

[0036] The camera tracking systems 510A, 510B, 510C each have a respective field of view 550A, 550B, 550C. The camera tracking systems 510A, 510B, 510C are set up around the object 505 to be measured and are placed around the object to reduce or eliminate blind spots (e.g. locations where the 3D measuring system 250 is not visible by at least two camera tracking systems) and provide the desired coverage and accuracy for a given application. While the present embodiment is described using three camera tracking systems 10, it should be appreciated that any number of two or more camera tracking systems may likewise be used depending on desired coverage and accuracy.

[0037] Once the camera tracking systems 510A, 510B, 510C are setup, the operator 210 or a motorized vehicle moves the 3D measuring system 250 around and / or in front of at least two of the camera tracking systems 510A, 510B, 510C and their respective field of view 550A, 550B, 550C. In various instances, the image from the at least two camera tracking systems 510A, 510B, 510C is processed to find the visible targets 260 and the motors 21, 23 of a respective camera will rotate the camera tracking system 510A, 510B, 510C to keep the visible artifacts 260 centrally located within the respective fields of view 550A, 550B, 550C. A process for keeping the cameras centered on a target is illustrated in commonly-owned United States Patent No. 10,697,754 entitled “Three-dimensional Coordinates of Two-dimensional Edge Lines Obtained with a Tracker Camera,” the contents of which are incorporated herein by reference. As the camera tracking systems 510A, 510B, 510C track the handheld scanner 200 of the 3D measuring system 250, the position of the visible artifacts 260 and the angles of the camera tracking systems 510A, 510B, 510C (i.e., the change in their positions about their x-axis and y-axis), as measured by the encoders 24, 25, are sent to a processor, for example the computing system 330, to determine the pose and 3D position of the 3D measuring system 250 in a global coordinate frame of reference.

[0038] In some embodiments, where the number and relative position of the artifacts 260 is known in advance or a priori, the computing system 330 determines the relative position and pose of the camera tracking systems 510A, 51 OB, 510C with respect to each other. In an embodiment where the artifacts 260 are LEDs, the LEDs are flashed to allow identification of the LEDs in images acquired by the camera tracking systems 510A, 510B, 510C. With the position of the LEDs and position of the tracking systems 510A, 510B, 510C determined, the computing system 330 determines the pose and 3D position of the handheld scanner of the 3D measuring system 250 in a global coordinate frame of reference based on images acquired by at least two of the camera tracking systems 510A, 510B, 510C, such as by using photogrammetry techniques, an example of which is described in commonly-owned United States Patent No. 9,967,545 entitled “System and Method of Acquiring Three- dimensional Coordinates Using Multiple Coordinate Measurement Devices”, the contents of which are incorporated herein by reference.

[0039] In an embodiment, the handheld scanner 200 is moved in front of the camera systems 510A, 510B, 510C to establish the relative positions of the camera tracking systems 510A, 510B, 510C (e.g., via a setup or calibration procedure) prior to initiating measurements of the object 505. In another embodiment, the relative positions of the camera tracking systems 510A, 510B, 510C are determined on a continuous, periodic, or aperiodic basis during the operation of the 3D measurement and tracking system 500.

[0040] Once the relative positions of the camera tracking systems 510A, 510B, 510C are established, the handheld scanner 200 of the 3D measuring system 250 is used to measure the target 505, either optically or through a physical probe. The measurements by the 3D measuring system 250 in such embodiments are measured in a frame of reference maintained by the handheld scanner 200, as opposed to a global frame of reference. Using the pose and position of the handheld scanner 200 of 3D measuring system 250, as determined from the camera tracking systems 510A, 510B, 510C after acquiring the artifacts 260 or the centers of the shapes formed thereby, the 3D coordinates from the scanner frame of reference are readily transformable into the global frame of reference, thereby allowing for rapidregistration of data gathered by the 3D measuring system 250. In some embodiments, a digital representation of the target is generated based on the registered data transformed into the global frame of reference.

[0041] In an embodiment, the measurements of the 3D measuring system 250 and the pose of the camera tracking systems 510A, 510B, 510C (e.g., as measured by the encoders 24, 25) are synchronized to each other. In some embodiments, this synchronization occurs within approximately one microsecond. In an embodiment, the 3D measuring system 250 measures 3D coordinates at a predetermined first frame rate and the cameras (e.g., camera 11) have a predetermined second frame rate. In an embodiment, the first frame rate is the same as the second frame rate, such as but not limited to 10 - 20 frames per second, which allows for more accurate tracking, pose determination and data registration.

[0042] It should be appreciated that any two of the camera tracking systems (e.g. systems 510A, 510B) are able to track the position of the handheld scanner 200 of the 3D measuring system 250 together. In an embodiment, the camera tracking systems (e.g. systems 510A, 510B) use triangulation to determine the position of the handheld scanner 200 of the 3D measuring system 250 when it is in the field of view (e.g., field of view 550A, 550B) of any two or more of the camera tracking systems. In an embodiment, this position information can be transmitted to another camera tracking system (e.g. system 510C) so the additional camera tracking systems will continue to point its optical axis in the direction towards the 3D measuring system 250, even when the line of sight to the camera tracking system is blocked or temporarily occluded. In some embodiments, the position of the handheld scanner 200 of the 3D measuring system 250 is determined and transmitted in real time.

[0043] As illustrated in FIG. 4 A, camera tracking systems 510A, 510B are tracking the 3D measuring system 250 and transmitting the position of the 3D measuring system 250 to camera tracking system 510C so that even though the field of view 550C of the camera tracking system 510C is blocked by the object 505, the field of view 550C is still pointed in the direction of the handheld scanner 200 of the 3D measuring system 250. In this way, when line of sight to the handheld scanner 200is no longer occluded by the target 505 or other obstruction, e.g., the operator 210, the camera tracking system 510C begins tracking the 3D measuring system 250 without having to search for the handheld scanner 200 or having to be calibrated or recalibrated. In an embodiment, as the 3D coordinates of the target 505 are determined in the global frame of reference, the 3D coordinate data is displayed to the operator 210, for example on a display of a cellular phone, a tablet, a computing device, a measuring device, or a scanner, such as the handheld scanner 200. In an embodiment, the 3D coordinate data is determined in the global frame of reference and displayed in real time as the handheld scanner 200 of the 3D measuring system 250 measures the target 505.

[0044] Turning now to FIG. 5, a method 50 of imaging / measuring a target object using a 3D measuring system and a camera tracking system is shown. The method 50 commences at operation 51, wherein two or more camera tracking systems, e.g., camera tracking systems 10, 300A, 300B, 510A, 510B, 510C, are setup around a target object to be imaged. In some embodiments, the target is an environment to be imaged or measured, or is a physical object. The number and position of the camera tracking systems will depend on the size of the measurement area of the target and desired measurement accuracy. In some embodiments, operation 51 includes an initializing sequence of powering up the camera tracking systems and connecting, pairing, and / or synchronizing the camera tracking systems to each other or a network computer, such as, computing system 330. In operation 52, a handheld scanner 200 is moved in front of each camera tracking system, the camera tracking system will detect visible artifacts 260 on the handheld scanner system 200 and begin tracking the position of the handheld scanner 200 as it moves about the target being measured. Once the camera tracking systems are set up and are tracking the position and pose of the handheld scanner 200, target measurements begin in operation 53.

[0045] In operation 54 the handheld scanner 200 is moved, e.g., by an operator 210 or a vehicle, to a position in order to image or otherwise measure the target. Once the handheld scanner 200 has been moved into position to image / measure the target, each of the camera tracking systems rotates about one or more of the x-axis and the y- axis to maintain line of sight to the handheld scanner 200 (operation 55). In someembodiments, if one of the camera tracking systems is unable to maintain line of sight, position data of the handheld scanner 200 is transmitted to the camera tracking system to maintain a general orientation toward the handheld scanner 200. In this way, once line of sight is reestablished, the camera tracking system is already directed towards the handheld scanner and the camera tracking system does not need to search for it or be recalibrated. In some embodiments, the camera tracking systems are continuously rotated as the handheld scanner moves about the target so that a field of view of the camera tracking system remains centered.

[0046] Next, at operation 56, the handheld scanner 200 images / measures the target. The pose of the handheld scanner 200 at each image / measurement is then recorded by the camera tracking systems in operation 57. The image / measurement taken by the handheld scanner is recorded and associated with the pose of the handheld scanner 200 and the pose of each of the camera tracking systems. In operation 58, if imaging or measurement of the target is incomplete, then operations 54, 55, 56, and 57 are repeated until imaging of the target is complete. Once imaging or measuring of the target is complete the process 50 terminates at operation 59. In some embodiments, operation 59 includes a shutdown procedure, whereby the images and associated poses are transmitted to be stored in a database, the camera tracking systems and the handheld scanner 200 are powered down and the various camera tracking systems are removed from their positions.

[0047] In an embodiment, the stored images / measurements of the target are transformed based on the associated pose of each camera tracking system, as measured by respective encoders 24, 25. The pose of the handheld scanner 200, as determined by the camera tracking systems, is based on the artifacts 260. The transformed images / measurements are then used to create a more comprehensive representation of the target. Depending on the measurement device used the resultant representation will vary. For example, in some embodiments, if the measurement device takes 2D images, the resulting representation will be a panoramic picture. In other instances, if the handheld scanner 200 is a Light Detection and Ranging (LiDAR) scanner, the resulting representation will be a 3D point cloud.

[0048] Although the systems and methods discussed herein are disclosed with respect to specific embodiments, the features of the systems and methods are utilized independently from or in combination with other described components and operations without departing from the scope of the present disclosure.

[0049] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and / or groups thereof.

[0050] While the disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the disclosure is not limited to such disclosed embodiments. Rather, it can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments have been described, it is to be understood that aspects of the disclosure include only some of the described embodiments. Accordingly, the disclosure is not limited by the foregoing descriptions.

Claims

What is claimed is:

1. A scanning system for measuring a target object, the scanning system comprising: a measurement device for determining measurements of a target, the measurement device having a plurality of artifacts disposed thereon; a first camera having a first degree of freedom to rotate about a first axis and a second degree of freedom to rotate about a second axis perpendicular to the first axis, the first camera rotating about the first axis and the second axis to maintain a line of sight to the measurement device as the measurement device moves about the target and makes measurements of the target; a second camera having a third degree of freedom to rotate about a third axis and a fourth degree of freedom to rotate about a fourth axis perpendicular to the third axis, the second camera rotating about the first axis and the second axis to maintain line of sight to the measurement device as the measurement device moves about the target and makes measurements of the target; a third camera having a fifth degree of freedom to rotate about a fifth axis and a sixth degree of freedom to rotate about a sixth axis perpendicular to the fifth axis, the third camera rotating about the fifth axis and the sixth axis to maintain line of sight to the measurement device as the measurement device moves about the target and makes measurements of the target; wherein each of the first camera, the second camera, and the third camera are independently positioned about the target; and when the measurement device takes a measurement of the target, at least two of the first camera, the second camera, and the third camera are used to determine a pose of the measurement device based on the plurality of artifacts, and the pose of the measurement device is used to transform the measurement of the target.

2. The scanning system of claim 1, wherein when line of sight between the first camera and the measurement device is obstructed, the second camera and the third camera transmit a current pose of the measurement device to the first camera;when line of sight between the second camera and the measurement device is obstructed, the first camera and the third camera transmit the current pose of the measurement device to the second camera; and when line of sight between the third camera and the measurement device is obstructed, the first camera and the second camera transmit the current pose of the measurement device to the third camera.

3. The scanning system of claim 2, wherein when line of sight between the first camera and the measurement device is obstructed, the first camera rotates to follow the measurement device based on the current pose of the measurement device; when line of sight between the second camera and the measurement device is obstructed, the second camera rotates to follow the measurement device based on the current pose of the measurement device; and when the line of sight between the third camera and the measurement device is obstructed, the third camera rotates to follow the measurement device based on the current pose of the measurement device.

4. The scanning system of claim 1, wherein the first camera, the second camera, and the third camera each further comprise at least one encoder to measure a pose of the first camera, the second camera, and the third camera, respectively.

5. The scanning system of claim 4, wherein determining the pose of the measurement device is further based on a pose of the first camera, a pose of the second camera, and a pose of the third camera measured by their respective encoders.

6. The scanning system of claim 1, wherein the measurement device is at least one of: a hard probe; a laser line scanner; an enclosure housing a laser line probe; a handheld scanner; anda portable coordinate measurement machine.

7. The scanning system of claim 1, wherein the plurality of artifacts are at least one of: reflectors; reflective dots; and active light emitting diodes (LEDs).

8. The scanning system of claim 7, wherein the plurality of artifacts include the active LEDs and the active LEDs are disposed in a geometric arrangement on the measurement device.

9. The scanning system of claim 7, wherein the plurality of artifacts are mounted on a frame that is removably coupled to the measurement device.

10. A method for tracking a measuring device having a plurality of artifacts disposed thereon, the method comprising: providing a plurality of cameras about a target to be measured, each of the plurality of cameras having at least a first rotational degree of freedom about a first axis and a second rotational degree of freedom about a second axis perpendicular to the first axis; moving the measurement device to a first location about the target; capturing a first measurement of the target with the measurement device; determining a first pose of the measurement device when the measurement device takes the first measurement using at least two of the plurality of cameras, the first pose associated with the first measurement; moving the measurement device to a second location about the target capturing a second measurement of the target with the measurement device; determining a second pose of the measurement device when the measurement device takes the second measurement using at least two of the plurality of cameras, the second pose associated with the second measurement;wherein as the measurement device moves about the target, the plurality of cameras rotate to maintain line of sight of the measurement device based on the artifacts; and wherein the plurality of cameras are independently positioned about the target.

11. The method of claim 10, further comprising triangulating a position of the measurement device in real time; and transmitting the position of the measurement device to at least one of the plurality of cameras when line of sight from the at least one of the plurality of cameras to the measurement device is obstructed.

12. The method of claim 11, wherein the at least one of the plurality of cameras rotates to follow the measurement device based on the position of the measurement device.

13. The method of claim 10, further comprising determining a pose of each of the plurality of cameras.

14. The method of claim 13, wherein the determining the first pose and the second pose of the measurement device is based at least in part on the pose of each of the plurality of cameras.

15. The method claim 10, wherein the measurement device is at least one of: a hard probe; a laser line scanner; an enclosure housing a laser line probe; a handheld scanner; and a portable coordinate measurement machine.

16. The method of claim 10, wherein the plurality of artifacts are at least one of: reflectors;reflective dots; and active light emitting diodes (LEDs).

17. The method of claim 10, wherein the plurality of artifacts are mounted on a frame removably coupled to the measurement device.

18. The method of claim 10, wherein each of the plurality of cameras comprise a single camera.

19. A method for generating a digital representation of a target the method comprising: providing a plurality of cameras about the target to be measured, each of the plurality of cameras having at least a first rotational degree of freedom about a first axis and a second rotational degree of freedom about a second axis perpendicular to the first axis, the plurality of cameras each being independently positioned around the target; triangulating a position of the measurement device in real time; transmitting the position of the measurement device to at least one of the plurality of cameras when line of sight from the at least one of the plurality of cameras to the measurement device is obstructed moving the measurement device to a first location around the target; capturing a first measurement of the target with the measurement device; determining a first pose of the measurement device when the measurement device takes the first measurement using at least two of the plurality of cameras; transforming the first measurement into a global frame of reference based on the first pose of the measurement device; moving the measurement device to a second location around the target; capturing a second measurement of the target with the measurement device; determining a second pose of the measurement device when the measurement device takes the second measurement using at least two of the plurality of cameras; transforming the second measurement into the global frame of reference based on the second pose of the measurement device;generating a digital presentation of the target based on the transforming of the first measurement and the transforming of the second measurement; wherein as the measurement device moves about the target, the plurality of cameras rotate to maintain line of sight with the measurement device; and wherein the at least one of the plurality of cameras rotate to follow the measurement device based on the position of the measurement device.

20. The method of claim 19, wherein the digital representation of the target is a point cloud generated in real time.

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