Metering system

Abstract

The present invention relates to a metrology system. The present invention generally relates to a metrology system and a coordinate measuring device for use within the framework of a smart factory environment having a defined arrangement of different metrology devices configured such that coordinate measurement data generated by the different metrology devices can be referenced to a common coordinate system.

Description

Technical Field

[0001] The present invention generally relates to a metrology system and a coordinate measuring device for use within the framework of a smart factory environment. Background Art

[0002] In metrology, determining geometrical properties such as coordinates, distance and orientation of one or more target objects relative to a survey device is a general goal, wherein in most cases these properties must be determined relative to a known reference system, e.g. defined by one or more known reference points.

[0003] Methods and systems for measuring target coordinates are used in many applications, for example: very precise measurements in geodetic applications, measurement problems in the field of building installations, or for controlling industrial processes, where many structural features of the measurement equipment used (such as total stations and industrial laser trackers) are nowadays increasingly merging. Summary of the invention

[0004] It is an object of the present invention to provide an improved workflow and an improved system for determining geometrical properties of objects in a smart factory environment.

[0005] One aspect of the invention relates to a metrology system having at least a first coordinate measuring device and a second coordinate measuring device, which are configured in each case to automatically track a movable accessory device and generate coordinate measurement data for determining the position and, in particular, the orientation of the movable accessory device. The first coordinate measuring device and the second coordinate measuring device are arranged in a fixed positional relationship so that the coordinate measurement data generated by the first coordinate measuring device and the second coordinate measuring device can be referenced to a common coordinate system, wherein the first coordinate measuring device and the second coordinate measuring device are configured to communicate with each other, in particular by device-to-device communication and / or by communication of a central computer. In addition, the system includes the movable accessory device, which is configured to scan or detect an object, in particular at least one of tactile scanning, laser-based scanning and camera-based scanning, and / or for performing interventions on an object, in particular for manufacturing and / or marking an object.

[0006] According to this aspect, the first coordinate measuring device is configured to track the movable accessory device and generate coordinate measurement data when the movable accessory device is within the first measuring area, and the second coordinate measuring device is configured to track the movable accessory device and generate coordinate measurement data when the movable accessory device is within the second measuring area, wherein the system is configured to emit a position signal when the movable accessory device is within the first measuring area, the position signal providing position information about the position of the movable accessory device, and the second coordinate measuring device is configured to initiate tracking of the movable accessory device based on the position signal.

[0007] In one embodiment, the first measurement area includes a transition area intersecting with the second measurement area, wherein the system (particularly the first coordinate measurement device) is configured to issue a trigger signal when the movable accessory device is located within the transition area, and the second coordinate measurement device is configured to start tracking based on the trigger signal.

[0008] In another embodiment, the system is configured to derive an estimated motion path of the movable accessory device and to send a trigger signal based on the derived estimated motion path. For example, the system is configured to derive a current speed and / or acceleration parameter of the movable accessory device and / or to derive a current position parameter providing a current position of the movable accessory device within the transition area, e.g., indicating a distance to a boundary of the transition area, wherein the trigger signal is sent based on the derived current speed and / or acceleration parameter and / or based on the current position parameter.

[0009] In another embodiment, the system comprises a communication network for exchanging position signals and / or trigger signals, wherein the communication network is based on at least one of a wired connection, WLAN technology, Bluetooth beacon technology and radio frequency technology.

[0010] For example, the movable accessory device is at least one of: a probing or scanning device configured to approach an object and perform at least one of tactile coordinate measurement, laser-based coordinate measurement, and camera-based coordinate measurement, a marking device configured to mark an object, a tool and / or manufacturing instrument, and another coordinate measurement device (e.g., embodied as a laser tracker). In particular, the movable accessory device may have a mounting interface that is specifically foreseen for mounting the movable accessory device to an automated guided vehicle or an articulated arm robot.

[0011] In another embodiment, the system is configured to determine a quality parameter of at least one of coordinate measurement accuracy and tracking accuracy provided by the coordinate measurement data of the first coordinate measuring device, and the system is configured to send the position signal and / or the trigger signal based on the quality parameter, in particular based on a predefined nominal coordinate measurement accuracy to be ensured.

[0012] In another embodiment, the system is configured to determine a potential upcoming measurement blind spot of the first coordinate measuring device, the potential upcoming measurement blind spot being defined by at least one of: a coordinate measurement accuracy of the first coordinate measuring device depending on the relative position of the movable accessory device relative to the first coordinate measuring device, for example, wherein the generation of the first coordinate measurement data is disturbed by an interfering object, in particular interrupted by the interfering object; and a reduced tracking accuracy of the first coordinate measuring device depending on the relative position of the movable accessory device relative to the first coordinate measuring device, in particular wherein a tracking signal for tracking the movable accessory device is disturbed by an interfering object, in particular interrupted by the interfering object. Therefore, the system is configured to send the position signal and / or the trigger signal based on the potential upcoming measurement blind spot.

[0013] In another embodiment, the system comprises a camera device configured to generate image data, the image data being referenced to a common coordinate system, for example, wherein the camera device comprises a camera arranged in a fixed positional relationship relative to the first coordinate measuring device. Furthermore, the system comprises an identifier configured to identify interfering objects within an image of the image data, in particular to identify interfering objects within an image of the image data based on a computer vision algorithm. For example, the camera device comprises an external camera separate from the first coordinate measuring device and / or a camera integrated in the first coordinate measuring device.

[0014] In another embodiment, the camera device is embodied as a panoramic camera device, which is configured to provide image data covering a field of view of at least 120° in at least one spatial direction, in particular image data of a field of view of at least 180°, more particularly image data of a field of view of 360°. As an example, the camera device comprises a wide-angle camera configured to provide a single image with a field of view of at least 120°, in particular a wide-angle camera providing a single image with a field of view of at least 180°, more particularly a wide-angle camera providing a single image with a field of view of 360°, and / or the camera device comprises a plurality of cameras and is configured to generate a panoramic image from the image data of the plurality of cameras, i.e. wherein the individual images of the plurality of cameras are stitched together to form an image with a wider field of view than the individual images.

[0015] Another aspect of the invention, either alone or in combination with other aspects of the invention, relates to a coordinate measuring device configured to automatically track a movable accessory device and to generate coordinate measurement data for determining the position and, in particular, the orientation of the movable accessory device. The coordinate measuring device is configured to be automatically movable and comprises a measuring aid configured in such a way and arranged in a fixed relationship to the coordinate measuring device that the movement and orientation of the measuring aid indicates the movement and orientation of the coordinate measuring device. The measuring aid has a marking arrangement which is arranged in a defined spatial relationship and forms a reflective and / or self-luminous pattern; and a retroreflector, in particular wherein the retroreflector is arranged in a fixed spatial relationship relative to the marking arrangement, more particularly, in a central area of ​​the pattern formed by the marking arrangement.

[0016] In one embodiment, the coordinate measuring device has a mounting interface, which is particularly foreseen for mounting the coordinate measuring device to an automated guided vehicle or an articulated arm robot.

[0017] In another embodiment, the coordinate measuring device comprises a plurality of measuring aids, each of which has a marking arrangement, which is arranged in a defined spatial relationship and forms a reflective and / or self-luminous pattern, and has a retroreflector, in particular wherein the retroreflector is arranged in a fixed spatial relationship relative to the marking arrangement, more particularly, in a central area of ​​the pattern formed by the marking arrangement. For example, the coordinate measuring device comprises exactly two such measuring aids arranged at two different faces of the coordinate measuring device. In particular, the coordinate measuring device comprises exactly four such measuring aids arranged at four different faces of the coordinate measuring device.

[0018] In another embodiment, a coordinate measuring device (e.g., a measuring aid) includes an inertial measurement unit and / or a visual inertial system and a transmitter, wherein the inertial measurement unit and / or the visual inertial system are configured to generate attitude data indicating a change in position and / or orientation of the coordinate measuring device, and the transmitter is used to provide the attitude data to an external reference device to determine the position and orientation of the measuring aid.

[0019] In another embodiment, the coordinate measuring device is configured to automatically move to a repositioning position to avoid a measurement blind spot defined by at least one of: a reduced coordinate measurement accuracy of the coordinate measuring device depending on the relative position of the movable accessory device relative to the coordinate measuring device, for example wherein the generation of coordinate measurement data is disturbed by, for example interrupted by, an interfering object; and a reduced tracking accuracy of the coordinate measuring device depending on the relative position of the movable accessory device relative to the coordinate measuring device, for example wherein a tracking signal for tracking the movable accessory device is disturbed by, for example interrupted by, an interfering object. As an example, the coordinate measuring device is configured to determine a potential upcoming measurement blind spot and determine an associated repositioning position, or the coordinate measuring device is configured to receive a movement command including the repositioning position.

[0020] In another embodiment, the coordinate measuring device includes a camera device configured to generate image data, and an identifier configured to identify interfering objects within an image of the image data. As an example, the coordinate measuring device is configured to access a database including identification marks (indicia), the identification marks indicating the appearance of multiple measurement and / or manufacturing devices to be used in a given measurement and / or manufacturing environment, wherein the identification marks provide identification of the devices through image processing of the generated image data. In addition, the coordinate measuring device is configured to perform an object search function, for example, automatically performing the object search function at fixed intervals or manually triggered by a user to perform the object search function, wherein the object search function includes automatically generating image data and identifying devices within the automatically generated image data, and determining and storing position data, such as azimuth position parameters, of the device identified by the identification relative to the position of the coordinate measuring device. Therefore, the coordinate measuring device can be configured to take into account the position data to determine the potential upcoming measurement blind spot.

[0021] In another embodiment, the camera device is embodied as a panoramic camera device, which is configured to provide image data covering a field of view of at least 120° in at least one spatial direction, in particular image data of a field of view of at least 180°, more particularly image data of a field of view of 360°. For example, the camera device comprises a wide-angle camera configured to provide a single image with a field of view of at least 120°, in particular a wide-angle camera providing a single image with a field of view of at least 180°, more particularly a wide-angle camera providing a single image with a field of view of 360°, and / or the camera device comprises a plurality of cameras and is configured to generate a panoramic image from the image data of the plurality of cameras, i.e. wherein the individual images of the plurality of cameras are stitched together to form an image with a wider field of view than the individual images.

[0022] In another embodiment, the coordinate measuring device has a communication interface configured to communicate with an external reference device for determining the position and orientation of a measuring aid, in particular a laser tracker. Furthermore, the coordinate measuring device is configured to emit a movement signal indicating a repositioning movement of the coordinate measuring device and comprising information about the current position and / or the repositioning position of the coordinate measuring device.

[0023] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a metrology system having a coordinate measuring device as described above, the coordinate measuring device being configured to automatically track a movable accessory device and generate coordinate measurement data for determining the position and in particular the orientation of the movable accessory device. The system further comprises a movable accessory device, a camera device configured to generate image data that can be referenced to a local coordinate system of the coordinate measuring device, and an identifier configured to identify an interfering object within an image of the image data, the interfering object interfering with (e.g., interrupting) the coordinate measuring device generating the coordinate measurement data of the movable accessory device and / or interfering with (e.g., interrupting) the generation of a tracking signal of the coordinate measuring device for tracking the movable accessory device. The system is configured to determine a potential upcoming measurement blind spot of the coordinate measuring device and automatically move the coordinate measuring device to a repositioned position to avoid the measurement blind spot defined by at least one of: a reduced coordinate measurement accuracy of the coordinate measuring device depending on the relative position of the movable accessory device and / or the coordinate measuring device relative to the interfering object, and a reduced tracking accuracy of the coordinate measuring device depending on the relative position of the movable accessory device and / or the coordinate measuring device relative to the interfering object.

[0024] For example, the identifier is configured to access a database including identification marks indicating the appearance of multiple measurement and / or manufacturing devices to be used within the system, the identification marks providing identification of the devices through image processing of the generated image data. In addition, the system is configured to perform an object search function, for example, automatically at fixed intervals or manually triggered by a user to perform the object search function, the object search function comprising: automatically generating image data and identifying devices within the automatically generated image data, and determining and storing position data, such as azimuth position parameters, of the position of the device identified by the identification relative to the coordinate measuring device. Therefore, the system can then be configured to take into account the position data for determining potential upcoming measurement blind spots.

[0025] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a metrology system having a coordinate measuring device having a measuring aid, such as the measuring aid described above. In the following, the coordinate measuring device is referred to as a movable tracker. In addition, the system comprises a reference device, in particular a total station or a laser tracker, more in particular a coordinate measuring device as described above, the coordinate reference device being configured to generate reference data indicating the position and orientation of the measuring aid of the movable tracker. The system has a communication network configured to provide communication between the movable tracker and the reference device, wherein the system is configured to send a movement signal indicating a repositioning movement of the movable tracker via the communication network. For example, the movement signal comprises information about the current position of the movable tracker and / or about the target position of the movable tracker. Here, the reference device is configured to generate reference data based on the movement signal, in particular wherein the system comprises a data processing network, the data processing network being configured to: receive coordinate measurement data of the movable tracker and reference data of the reference device, and merge the coordinate measurement data and the reference data into a common coordinate system.

[0026] In one embodiment, the movable tracker comprises an inertial measurement unit and / or a visual inertial system, wherein the inertial measurement unit and / or the visual inertial system are configured to generate pose data indicating a change in position and / or a change in orientation of the movable tracker, wherein the reference device is configured to generate the reference data based on the pose data. For example, the movable tracker is configured to provide feature recognition data for identifying features used by the visual inertial system to the reference device, in particular together with image data of the visual inertial system, wherein the reference device is configured to determine the position and / or orientation of the movable tracker based on the feature recognition data.

[0027] In another embodiment, the system comprises another coordinate measuring device, such as a coordinate measuring device according to one of the above embodiments, wherein the coordinate measuring device is embodied as a laser tracker and is referred to as a relay laser tracker in the following. The relay laser tracker is configured to generate first intermediate data indicating the position and orientation of the measurement aid of the movable tracker relative to the relay laser tracker. Furthermore, the reference device is configured to generate second intermediate data indicating the position and orientation of the measurement aid of the relay laser tracker relative to the reference device, wherein the relay laser tracker and the reference device are configured to provide the first intermediate data and the second intermediate data to the data processing network.

[0028] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a metrology system having a laser tracker having an optoelectronic rangefinder configured to emit a distance measuring beam in the direction of a sighting axis to a cooperating target of a movable accessory device and to determine distance measuring data based on at least a portion of the distance measuring beam returned from the cooperating target. The laser tracker further has an angle determination unit configured to provide angle determination data for determining the pointing direction of the sighting axis; and a tracking unit configured to: receive a tracking signal indicating a change in the angular position of the cooperating target via a tracking channel, determine the change in the angular position of the cooperating target based on the tracking signal, and generate control data for adjusting the alignment of the sighting axis based on the determined change in the angular position. The system further comprises a movable accessory device configured for scanning or probing an object, in particular for at least one of tactile scanning, laser-based scanning and camera-based scanning, and / or for performing an intervention on an object, in particular for manufacturing and / or marking an object. In addition, the system comprises an auxiliary position determination unit separate from the laser tracker, wherein the auxiliary position determination unit is configured to communicate with the laser tracker, in particular in a wired or wireless manner, and to generate auxiliary measurement data for determining the position and in particular the orientation of the movable accessory device. Here, the laser tracker and the auxiliary position determination unit are configured such that the auxiliary measurement data can be referenced to a local coordinate system of the laser tracker, for example, the laser tracker and the auxiliary position determination unit are arranged in a fixed positional relationship relative to each other. Furthermore, the laser tracker is configured to determine a quality parameter, which provides at least one of: a coordinate measurement accuracy provided by the distance measurement data and the angle determination data; and a tracking accuracy provided by the tracking signal, wherein the laser tracker and the auxiliary position determination unit are configured to generate auxiliary control data for adjusting the alignment of the aiming axis of the laser tracker based on the quality parameter and the auxiliary measurement data.

[0029] In one embodiment, the laser tracker is configured to send a trigger signal to the auxiliary position determination unit based on the quality parameter, for example, when the quality parameter indicates that a predefined nominal coordinate measurement accuracy is below a quality threshold, and the auxiliary position determination unit is configured to start generating the auxiliary control data based on the trigger signal.

[0030] As an example, the system includes a plurality of auxiliary measurement devices, each of which is configured to generate auxiliary measurement data that can be referenced to the local coordinate system of the laser tracker, and the laser tracker is configured to send the trigger signal as a broadcast signal.

[0031] In another embodiment, a laser tracker and the auxiliary position determination unit are configured to determine the position of the movable accessory device based on the distance measurement data, the angle determination data and the auxiliary measurement data.

[0032] Another aspect of the invention, either alone or in combination with other aspects of the invention, relates to a metrology system having a plurality of movable accessory devices, each of which is configured for scanning or probing an object, for example, at least one of tactile scanning, laser-based scanning and camera-based scanning, and / or for performing interventions on an object, for example, for manufacturing and / or marking an object. The system also has a plurality of coordinate measuring devices, each of which is configured to automatically track one of the movable accessory devices and generate coordinate measurement data for determining the position and, in particular, the orientation of the movable accessory device. The accessory device database includes identification data providing identification of each of the accessory devices, wherein the system includes an inspection device configured for generating inspection data of the accessory device, and an evaluator configured to provide a classification of one of the movable accessory devices based on the identification data and the inspection data. Here, the system is configured to perform (in particular automatically perform) a presetting of the plurality of coordinate measuring devices based on the classification.

[0033] For example, the presetting comprises selecting a subset of devices from the plurality of movable accessory devices and / or the plurality of coordinate measuring devices, for example, the selection taking into account current availability of the devices and / or predefined combination parameters providing allowed combinations for combining the devices.

[0034] In one embodiment, the presetting includes executing a calibration procedure for calibrating the devices within the device subset relative to each other, wherein the calibration procedure includes setting relative addition constants of identified accessory devices (e.g., identified prisms), and / or providing measurement data for referencing at least a portion of the device subset within a reference common coordinate system.

[0035] In another embodiment, the inspection apparatus includes a camera configured to generate camera data, and the classification is based on image processing and feature extraction algorithms. For example, for each removable accessory device, template image data is stored in an image database, and the classification is based on image processing and feature extraction algorithms programmed to find matching features in both the camera data and the template image data.

[0036] In another embodiment, at least one of the removable accessory devices has an electronic device tag, such as an RFID tag, which is configured to provide a device identification about the at least one removable accessory device, wherein the inspection device includes a device tag detector, such as a radio frequency receiver, which is configured to communicate with the electronic device tag to query the device identification, and wherein the system is configured to perform classification based on the device identification.

[0037] In another embodiment, the system is configured such that the preset is based on a categorization of a user operating the system, for example, wherein the selection depends on the categorization. For example, the system comprises a set of electronic user tags (e.g., RFID tags), which are specifically foreseen to be carried by a set of users, wherein the set of electronic user tags is configured to provide a user identification to distinguish at least two different user categories. In addition, the system comprises a user tag detector, for example, a radio frequency receiver, which is configured to communicate with the electronic user tags to query the user identification, wherein the system is configured to perform the categorization based on the user identification.

[0038] In another embodiment, the system includes an instruction database having operating instructions for at least a portion of a plurality of movable accessory devices and / or at least a portion of a plurality of coordinate measuring devices, wherein the system also includes a user assistance device configured to provide visual and / or acoustic operating instructions to a user based on the classification and, for example, according to the categorization.

[0039] As an example, the user assistance device is embodied as one of a personal computer or laptop computer, a tablet computer, a smart phone, video glasses, a speaker, a laser projector, and one or more contact lens projectors. In particular, the user assistance device can be configured to work with augmented reality technology.

[0040] The plurality of coordinate measuring devices may include one of a laser tracker, a camera system, an articulated arm robot, a tachymeter, a theodolite, a total station, a projection scanner (e.g. a fringe projection scanner), a triangulation scanner, a laser scanner, a time of flight measurement unit, and a lidar unit.

[0041] In another embodiment, the plurality of movable accessory devices include: at least one of a detection or scanning device, a marking device, a tool and / or manufacturing instrument, a ranging imaging camera, a stereo imaging camera, an articulated arm robot, a white light sensor, a laser scanner, and a time-of-flight measurement unit, wherein the detection or scanning device is configured to approach an object and perform at least one of tactile coordinate measurement, laser-based coordinate measurement, and camera-based coordinate measurement, and the marking device is configured to mark an object.

[0042] Another aspect of the invention, either alone or in combination with other aspects of the invention, relates to a metrology system having a plurality of system devices, the plurality of system devices comprising at least a coordinate measuring device, the coordinate measuring device being configured to automatically track a movable accessory device and to generate coordinate measurement data for determining the position and in particular the orientation of the movable accessory device. The system further comprises a movable accessory device, the movable accessory device being configured for scanning or probing an object, for example, at least one of tactile scanning, laser-based scanning and camera-based scanning, and / or for performing interventions on the object, for example, for manufacturing and / or marking the object. According to this aspect, the system further comprises: a region database comprising identification data for identifying different regions on the object; an inspection device configured for generating inspection data of the object; and an evaluator configured to provide identification of at least one measurement region in the measurement region based on the identification data and the inspection data. In addition, the system has a user-assisted device configured to provide measurement instructions to a user, wherein the system is configured to determine the measurement instructions based on the identification of the at least one measurement area and provide the measurement instructions through the user-assisted device, and the measurement instructions include at least instructions to use a specific system device from the multiple system devices.

[0043] For example, the specific system devices are selected by taking into account current availability of the system devices and / or predefined combination parameters that provide allowed combinations for combining different system devices.

[0044] In one embodiment, the system is configured to automatically perform a calibration procedure to calibrate the specific system device relative to each other within a subset of the system devices, wherein the calibration procedure provides measurement data for referencing the specific system device within a common coordinate system of the subset of the system devices.

[0045] In another embodiment, the inspection device includes a camera configured to generate camera data, in particular a ranging imaging camera or a stereo imaging device configured to generate 3D image data, and the recognition is based on image processing and feature extraction algorithms, for example, wherein the recognition parameters are based on a CAD model of the object.

[0046] For example, template image data for different measurement areas of an object are stored in an image database and the recognition is based on image processing and feature extraction algorithms programmed to find matching features in both the camera data and the template image data.

[0047] In another embodiment, the system is configured to provide the measurement instructions based on the classification of the user operating the system. For example, the system includes a set of electronic user tags (e.g., RFID tags) specifically foreseen to be carried by a group of users, wherein the set of electronic user tags is configured to provide a user identification to distinguish at least two different users and / or two different user categories, wherein the system also includes a user tag detector, e.g., a radio frequency receiver, the user tag detector is configured to communicate with the electronic user tags to query the user identification. Thus, the system can be configured to perform classification based on the user identification.

[0048] As an example, the measurement instructions include instructions for setting up one of the movable accessory devices, instructions for setting up one of the coordinate measuring devices, instructions for using a specific movable accessory device in conjunction with at least one of the coordinate measuring devices, and at least one of warning messages (e.g., warning messages regarding user safety and measurement accuracy).

[0049] In another embodiment, the system is configured to provide measurement instructions based on settable nominal measurement parameters (eg, at least one of a nominal point density of coordinate measurement data, a nominal accuracy level of coordinate measurement data, and a nominal measurement time window).

[0050] For example, the user assistance device is embodied as one of a personal computer or laptop computer, a tablet computer, a smart phone, video glasses, a speaker, a laser projector, and one or more contact lens projectors, for example, wherein the user assistance device is configured to work with augmented reality technology.

[0051] The plurality of system devices may include a plurality of coordinate measuring devices, wherein the plurality of coordinate measuring devices include one of a laser tracker, a camera system, an articulated arm robot, a tachymeter, a theodolite, a total station, a projection scanner (e.g., a fringe projection scanner), a triangulation scanner, a stereo imaging camera, an articulated arm robot, a white light sensor, a laser scanner, a time of flight measurement unit, and a lidar unit.

[0052] In another embodiment, the plurality of system devices may include a plurality of movable accessory devices, wherein the plurality of movable accessory devices include one of a detection or scanning device, a marking device, a tool and / or manufacturing instrument, a range imaging camera, a stereo imaging camera, an articulated arm robot, a white light sensor, a laser scanner, and a time-of-flight measurement unit, the detection or scanning device being configured to approach an object and perform at least one of tactile coordinate measurement, laser-based coordinate measurement, and camera-based coordinate measurement, and the marking device being configured to mark the object.

[0053] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a computer program product, the computer program product comprising a program code stored on a machine-readable medium or embodied by an electromagnetic wave comprising program code segments, and the program code having computer executable instructions for performing at least the following steps, for example when run on a computing device of a coordinate measuring device or system as described above:

[0054] reading input data defining a measurement task to be performed by at least a part of a plurality of system devices, the plurality of system devices being part of a fixed measurement environment having a plurality of distributed measurement areas, the plurality of system devices comprising at least: a coordinate measurement device configured to automatically track a movable accessory device and to generate coordinate measurement data for determining a position and in particular an orientation of the movable accessory device, and the movable accessory device being configured for scanning or probing an object, for example at least one of tactile scanning, laser-based scanning and camera-based scanning, and / or for performing an intervention on the object, for example for manufacturing and / or marking the object;

[0055] Reading status data of the plurality of system devices;

[0056] determining a subset of the system devices that perform the measurement task based on the status data; and

[0057] An output is provided indicative of at least a portion of a subset of the system devices that perform the measurement task.

[0058] In one embodiment, the status data includes at least one of location data of a current location of the system device, a power status of the system device, a power consumption rate of the system device, a measurement range of the system device, an indication of a measurement accuracy of the system device, and an indication of an occupancy time of the system device.

[0059] For example, the computer program product is configured to initiate a broadcast or multicast signal configured to solicit a response signal comprising the status data.

[0060] In another embodiment, the computer program product is configured to determine a free movement area for interacting with a subset of system devices based on the status data in order to perform the measurement task, wherein the free movement area is configured such that the subset of system devices or any other object within the free movement area is movable arbitrarily without interfering with the measurement task performed by any of the remaining devices of the system devices, and is configured to provide position data indicating the range and position of the free movement area as part of the output.

[0061] For example, the computer program product is configured to determine a restricted area based on the status data, and to provide position data indicating the extent and location of the restricted area as part of the output.

[0062] Another aspect of the invention, either alone or in combination with other aspects of the invention, relates to a metrology system having a plurality of system devices, the plurality of system devices being part of a fixed measurement environment having a plurality of distributed measurement areas. The plurality of system devices comprises at least a coordinate measurement device, which is configured to automatically track a movable accessory device and to generate coordinate measurement data for determining the position and, in particular, the orientation of the movable accessory device. In addition, the plurality of system devices comprises a movable accessory device, which is configured for scanning or probing an object, for example, at least one of tactile scanning, laser-based scanning, and camera-based scanning, and / or for performing interventions on an object, for example, for manufacturing and / or marking an object. Here, the system is further configured to read input data defining a measurement task to be performed by at least a portion of the system devices; read status data indicating a current status of the system devices; determine a subgroup of the system devices that performs the measurement task based on the status data; and provide an indication that at least a portion of the subgroup of the system devices performs the measurement task.

[0063] For example, the status data includes at least one of location data of a current location of the system device, a power state of the system device, a power consumption rate of the system device, a measurement range of the system device, an indication of measurement accuracy of the system device, and an indication of an occupancy time of the system device.

[0064] In another embodiment, a first one of the system devices has a visual and / or acoustic notification unit configured to indicate that the first system device is part of a subgroup of the system devices.

[0065] In another embodiment, the system is configured to provide position data to a second system device in the system devices, the position data providing the position of the system devices in the subset of the system devices relative to the second system device, and the second system device is configured to emit a visual pointing beam to the position provided by the position data.

[0066] For example, the system includes at least one of: a camera and an identifier, which are configured to generate image data and to determine the position data by identifying features indicating system devices in a subset of the system devices; a visual positioning system, which is configured to determine the position data by decoding position coordinates from visual markers arranged within the fixed measurement environment; and an indoor positioning system, which is configured to determine the position data by utilizing wireless technology (e.g., based on radio signals, WiFi signals and / or Bluetooth signals).

[0067] In another embodiment, the system is configured to determine a free movement area for interacting with the subgroup of the system devices to perform the measurement task based on the status data, wherein the free movement area is configured so that the subgroup of the system devices or any other object within the free movement area is movable without interfering with the measurement task performed by any of the remaining system devices in the system devices. Alternatively or in addition, the system is configured to determine a restricted area based on the status data. Here, the system is also configured to provide a visual indication of at least one of the range and position of the free movement area and the range and position of the restricted area.

[0068] Another aspect of the invention, either alone or in combination with other aspects of the invention, relates to a computer program product comprising a program code stored on a machine-readable medium or embodied by an electromagnetic wave comprising program code segments and having computer executable instructions for performing at least the following steps when run, for example, on a computing device of a coordinate measuring device or system as described above:

[0069] reading external reference data providing a fixed measurement environment expressed in an external coordinate system, wherein the measurement environment comprises at least a pointing device having a position referenceable relative to the external coordinate system and configured to generate a visual laser pointing beam;

[0070] reading intrinsic reference data from a mobile user assistance device, the intrinsic reference data indicating a position and orientation of the mobile user assistance device relative to the fixed measurement environment;

[0071] determining a position and an orientation of the mobile user assistance device relative to the external coordinate system based on the intrinsic reference data and the extrinsic reference data;

[0072] reading input data indicating coordinates of a guide point in the external coordinate system;

[0073] Determining positional relationship data between the pointing device and the guidance point;

[0074] The position data is provided to the pointing device and instructs the pointing device to generate a visual laser pointing beam towards the guidance point, for example, wherein the pointing device is a coordinate measuring device.

[0075] In one embodiment, the computer program product is configured to process as internal reference data imaging data (e.g., data from a camera, a smartphone, or video glasses), distance measurement data and / or angle measurement data (e.g., in the form of 3D point cloud data), data from an inertial measurement unit, and at least one of GNSS or DGNSS data.

[0076] In another embodiment, the computer program product is configured to process at least one of imaging data, computer-aided design (CAD) data, 3D point cloud data, and GNSS or DGNSS data as extrinsic reference data.

[0077] In another embodiment, in addition to the pointing device, the measurement environment also includes a coordinate measuring device as another device, the coordinate measuring device having a position that can be referenced relative to the external coordinate system. The computer program product is configured to instruct the other device to generate device data, in particular imaging data from a camera of the other device or point cloud data generated by a laser scanning unit of the other device, and the computer program product is configured to generate the external reference data based on the device data. For example, the computer program product is configured to provide a realistic 3D model based on the device data.

[0078] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a coordinate measuring device, such as a laser tracker, which is configured to automatically align an aiming axis of the coordinate measuring device with a movable accessory device to track the movable accessory device and generate coordinate measurement data for determining the position and in particular the orientation of the movable accessory device. Here, the coordinate measuring device includes an acoustic positioning unit, such as an acoustic positioning unit with at least two microphones, wherein the acoustic positioning unit is configured for detecting and identifying an acoustic identification signal and for determining the direction of origin of the acoustic identification signal, wherein the coordinate measuring device is configured to automatically perform the alignment of the aiming axis with the direction of origin of the acoustic identification signal.

[0079] In one embodiment, the coordinate measuring device is configured to detect and identify a specific acoustic identification signal that is specific to the coordinate measuring device and / or specific to a group of coordinate measuring devices including the coordinate measuring device, wherein the specific acoustic identification signal is a necessary prerequisite for performing alignment of the sighting axis. In another embodiment, the coordinate measuring device includes a visual target positioning unit, which has a position detection sensor and is configured to locate a collaborative target within a field of view of the position detection sensor, and to derive positioning data for aligning the sighting axis to the collaborative target. Here, the coordinate measuring device is configured to automatically align the sighting axis to the collaborative target based on the visual target positioning unit after the sighting axis is aligned to the source direction of the acoustic identification signal.

[0080] For example, the visual object localization unit has a viewing angle greater than 3°, in particular a viewing angle greater than 10°.

[0081] In particular, the coordinate measuring device comprises a light source, in particular an LED, which is configured to generate a cone of visible light indicative of a field of view of the visual targeting unit.

[0082] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a metrology system having a laser tracker having: an optoelectronic rangefinder configured to emit a distance measuring beam to a cooperative target of a movable accessory device in the direction of an aiming axis and to provide distance measurement data based on at least a portion of the distance measuring beam returned from the cooperative target; an angle determination unit configured to provide angle determination data for determining the pointing direction of the aiming axis; and a tracking unit. The tracking unit is configured to receive a tracking signal indicating a change in the angular position of the cooperative target through a tracking channel, determine the change in the angular position of the cooperative target based on the tracking signal, and generate control data for adjusting the alignment of the aiming axis based on the determined change in the angular position. In addition, the system includes: a movable accessory device configured to scan or detect an object, for example, at least one of tactile scanning, laser-based scanning, and camera-based scanning; and a computing unit configured to generate coordinate measurement data of the object based on the distance measurement data, the angle determination data, and scanning and / or detection by means of the movable accessory device. Here, the system further comprises a reference unit, the reference unit being configured to generate reference data about a reference point associated with the object, the reference data providing a determination of a relative position change between the reference unit and the reference point independently of the optoelectronic rangefinder, for example, wherein the reference data are distance measurement data or 3D point cloud data, wherein the reference unit and the reference point are arranged relative to the object such that a position change between the reference unit and the reference point indicates a movement of the object. The computing unit is configured to take into account the reference data to generate the coordinate measurement data, for example, wherein the reference unit is provided by a laser tracker or by a separate device, wherein the separate device and the laser tracker are configured such that the reference data can refer to the coordinate measurement data.

[0083] For example, the reference point is embodied by a cooperative target mounted on the object or defined by a reference surface of the object, for example, wherein the reference unit is embodied as a camera unit, for example, the camera unit comprises two cameras arranged spaced apart from each other, the camera unit being configured to generate 3D data of the object based on imaging data. In particular, the camera unit comprises: a projector configured to project a pattern of structured radiation (e.g., a fringe or moiré projection pattern) onto the object; and a processor configured to determine a 3D model of the object based on a photogrammetric method (e.g., a stereophotogrammetric method) and by utilizing the pattern of structured radiation.

[0084] In another embodiment, the reference unit is configured to detect movement of the object in at least one degree of freedom, such as vibration of the object, for example wherein the reference unit is configured to detect at least one of a roll change, a pitch change and a yaw angle change of the object.

[0085] In another embodiment, the computing unit is configured to generate the coordinate measurement data by at least one of: compensating for the movement of the object determined based on the reference data; ignoring the distance measurement data of the photoelectric rangefinder and / or the angle determination data of the angle determination unit if the relative position change between the object and the reference unit exceeds an allowed threshold; and marking the coordinate measurement data if the relative position change between the object and the reference unit exceeds a threshold defined to ensure the desired measurement accuracy of the coordinate measurement data.

[0086] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a coordinate measuring device, the coordinate measuring device being configured to generate coordinate measurement data, the coordinate measuring device having an optoelectronic distance meter, the optoelectronic distance meter being configured to emit distance measurement radiation in the direction of a sighting axis and to provide distance measurement data based on at least a portion of the distance measurement radiation. The coordinate measuring device also has an angle determination unit configured to provide angle determination data for determining the pointing direction of the sighting axis and a tracking unit, wherein the tracking unit is configured to receive a tracking signal indicating a change in the angular position of a cooperating target via a tracking channel, to determine the change in the angular position of the cooperating target based on the tracking signal, and to generate control data for adjusting the alignment of the sighting axis based on the determined change in the angular position. A computing unit is configured to generate the coordinate measurement data of the object based on the distance measurement data and the angle determination data and, for example, based on scanning and / or detection by means of a movable accessory device including the cooperating target.

[0087] Here, the coordinate measuring device also includes a reference unit, which is configured to generate reference data about a reference point, and the reference data provides a determination of a relative position change between the reference unit and the reference point independently of the photoelectric rangefinder, for example, wherein the reference data is distance measurement data or 3D point cloud data, wherein the reference unit is configured and arranged so that the reference data can refer to the coordinate measurement data, and wherein the computing unit is configured to take into account the reference data to generate the coordinate measurement data.

[0088] For example, the reference unit is embodied as a camera unit, for example, the camera unit includes two cameras arranged spaced apart from each other, and the camera unit is configured to generate 3D data of the object based on imaging data.

[0089] Another aspect of the invention, either alone or in combination with other aspects of the invention, relates to a metrology system having a plurality of coordinate measuring devices. Each coordinate measuring device has a target positioning unit, which is configured to position a target within the perimeter of the coordinate measuring device, for example, wherein the target is a collaborative target, and to derive positioning data for aligning the aiming axis of the coordinate measuring device onto the target. Furthermore, each coordinate measuring device has a data acquisition unit, which is configured to generate coordinate measurement data of an object to be measured, wherein each coordinate measuring device also includes a reference target. The system has a reference function, which is configured to reference the coordinate measurement data of at least a part of the coordinate measuring devices to a common coordinate system, wherein the reference function comprises:

[0090] a first coordinate measuring device among the coordinate measuring devices automatically positioning a reference target of a second coordinate measuring device among the coordinate measuring devices and deriving first positioning data for aligning its sighting axis relative to the reference target of the second coordinate measuring device;

[0091] a third one of the coordinate measuring devices automatically positions a reference target of a fourth one of the coordinate measuring devices and derives second positioning data for aligning its aiming axis relative to the reference target of the fourth coordinate measuring device; and

[0092] Coordinate measurement data of at least a portion of the coordinate measurement device is referenced to the common coordinate system based on the first positioning data and the second positioning data.

[0093] In one embodiment, the referencing is performed relative to a reference position provided by the position of one of the coordinate measuring devices, i.e. wherein the one of the coordinate measuring devices represents a fixed point in the common coordinate system. For example, the referencing is based on triangulation or multilateration.

[0094] In another embodiment, the reference function is performed upon system initialization and / or based on a predefined reference schedule, for example wherein the reference function is performed periodically.

[0095] In another embodiment, at least a portion of the coordinate measuring devices form a group of coordinate measuring devices, and the system comprises a monitoring function configured to monitor an arrangement parameter about the group of coordinate measuring devices. For example, the arrangement parameter indicates at least one of a group size, a positional relationship between group members, and an activity state of each group member. Thus, the reference function may be performed based on the arrangement parameter, for example, wherein a change in the arrangement parameter triggers the reference function.

[0096] In another embodiment, the plurality of coordinate measuring devices comprises a coordinate measuring device, hereinafter referred to as an overview device, and having a full dome search unit, the full dome search unit being configured to generate search data providing an azimuth-altitude capture field of view of at least 360° by 90° around the overview device. For example, the full dome search unit comprises a panoramic camera or camera device configured to provide 360 ​​degree panoramic image data, or the full dome search unit comprises a rotatable laser scanning unit configured to provide 3D point cloud data. The target positioning unit of the overview device is configured to locate a target within the perimeter of the overview device based on the search data, for example, a reference target of another coordinate measuring device of the plurality of coordinate measuring devices.

[0097] In another embodiment, a plurality of coordinate measuring devices include a coordinate measuring device, hereinafter referred to as a power locking device, and having a power locking unit. The power locking unit includes: a position detection sensor, the position detection sensor being configured to generate position data for determining an incident position of an incident light beam on the position detection sensor; and a light source, such as an LED, configured to radiate a search beam in the direction of the aiming axis, wherein a reflection of at least a portion of the search beam at a cooperative target is visible as an incident light beam on the position detection sensor. The target positioning unit of the power locking device is configured to locate a cooperative target within the perimeter of the power locking device based on the position data of the power locking unit.

[0098] In another embodiment, a plurality of coordinate measuring devices comprises a coordinate measuring device, hereinafter referred to as a marking device, having a marking arrangement arranged in a defined spatial relationship and forming a reflective and / or self-luminous pattern on the body of the marking device. In addition, a plurality of coordinate measuring devices comprises a coordinate measuring device, hereinafter referred to as a pose determination device, having a pose determination unit, for example, comprising a camera, the pose determination unit being configured to determine the pose of the marking device by determining the distance of the reference target of the marking device and determining the orientation of the marking arrangement. Thus, the reference of the coordinate measurement data of at least a part of the plurality of coordinate measuring devices to the common coordinate system can be based on the pose of the marking device.

[0099] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a laser tracker having an optoelectronic rangefinder configured to emit a distance measuring beam in the direction of an aiming axis to a cooperative target and to generate distance measurement data based on at least a portion of the distance measuring beam returned from the cooperative target. In addition, the laser tracker comprises an angle determination unit configured to generate angle determination data for determining the pointing direction of the aiming axis. The laser tracker has a first tracking unit configured to receive a tracking signal indicating a change in the angular position of the cooperative target via a tracking channel, determine the change in the angular position of the cooperative target based on the tracking signal, and generate control data for adjusting the alignment of the aiming axis based on the determined change in the angular position. The laser tracker also has a visual target positioning unit having a position detection sensor and configured to position the cooperative target within the field of view of the position detection sensor and to derive positioning data for aligning the aiming axis onto the cooperative target.

[0100] According to this aspect, the laser tracker comprises a second tracking unit having a camera for generating image data, wherein the second tracking unit is configured for video tracking of a target carrier carrying the cooperative target by generating image data by the camera, for determining a position of the target carrier within an image of the image data by using an identifier configured to identify the target carrier within the image data, and for generating adjustment data for adjusting the aiming axis based on the determined position of the target carrier. Furthermore, the laser tracker is configured to derive motion parameters indicating that the target carrier is moving based on the image data, and to activate the visual target positioning unit based on the motion parameters to provide alignment of the aiming axis on the cooperative target.

[0101] As an example, the identifier is configured to identify the target carrier based on predefined identification parameters that provide at least one of: an identification mark for the type of the target carrier; an identification mark for a specific target carrier; an identification code of the target carrier; information indicating the spatial arrangement of the collaborative target relative to the target carrier, and position information of the target carrier, such as the absolute position of the target carrier.

[0102] In one embodiment, the laser tracker is configured to train the identifier for the target carrier, wherein an identification mark indicative of the appearance of the target carrier imaged by the image data is determined by image processing. For example, the training is based on image data generated in a locked state, wherein the tracking channel is undisturbed, i.e., such that the tracking signal can be received without unplanned interruptions, and the sighting axis is continuously adjusted based on the control data so that the sighting axis continuously follows the cooperative target.

[0103] In another embodiment, the motion parameter indicates a relative speed of the target carrier with respect to the laser tracker, and the laser tracker is configured to activate the visual targeting unit when the relative speed drops below a threshold speed (e.g. when the relative speed is substantially zero).

[0104] In another embodiment, the video tracking is activated when the tracking channel is disturbed such that continuous adjustment of the sighting axis for continuous following of the cooperating target is compromised.

[0105] In another embodiment, the visual target localization unit is configured to locate the collaborative target within the field of view of the position detection sensor based on arrangement parameters indicating the spatial arrangement of the collaborative target relative to the target carrier and the determined position of the target carrier within the image of the image data.

[0106] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a metrology system configured to generate coordinate measurement data of an object. The metrology system comprises a coordinate measuring device configured to emit a laser measuring beam along a laser axis to move the laser axis to different spatial directions and to generate distance measurement data and orientation data about the alignment of the laser axis based on the laser measuring beam. The system further comprises a deflection unit, which is separate from the coordinate measuring device and is configured to deflect an outgoing laser measuring beam from the coordinate measuring device along an incident axis to a redirection axis and to deflect a return portion of the laser measuring beam from the object along the redirection axis to the incident axis. The deflection unit is configured to set different deflection angles between the incident axis and the redirection axis relative to at least one rotation axis, wherein the system is configured for determining or being provided with alignment data providing mutual alignment between the coordinate measuring device and the deflection unit; for determining control data providing different deflection angles; and for generating the coordinate measurement data by taking into account the orientation data, the distance measurement data, the alignment data and the control data.

[0107] In one embodiment, the deflection unit comprises a movable reflection surface, for example, wherein the reflection surface is movable relative to two orthogonal rotation axes, in particular relative to three orthogonal rotation axes.

[0108] In another embodiment, the reflecting surface is a planar surface and comprises fixed points with respect to rotation about two, in particular three, axes of rotation, and the coordinate measuring device and the deflection unit are configured to perform an autocollimation process for determining the orientation of the reflecting surface.

[0109] In another embodiment, the reflective surface is a flat surface and comprises a fixed point relative to the rotation about two, in particular three, axes of rotation. Furthermore, the reflective surface has a set of reference marks arranged in a fixed relationship relative to the fixed point, and the coordinate measuring device is configured to acquire an image of the reflective surface, the image comprising at least a portion of the reference marks, and based thereon, determine the fixed point by image analysis of the image.

[0110] In another embodiment, the system has a first data acquisition mode, in which the laser measuring beam is guided through the deflection unit and first coordinate measurement data are generated based on the orientation data and the distance measurement data (i.e., the data are generated without interaction between the laser measuring beam and the deflection unit). In addition, the system has a second data acquisition mode, in which the laser measuring beam is guided onto the deflection unit and the incidence axis remains fixed, and second coordinate measurement data are generated by setting the deflection angle (in particular by setting a plurality of different deflection angles) and by taking into account the orientation data, the distance measurement data, the alignment data and the control data.

[0111] In another embodiment, the system has an alignment mode, wherein the fixed point is determined and, to perform the second data acquisition mode, the laser axis is automatically set and kept fixed to a fixed position defined by the fixed point, e.g., wherein, in the fixed position, the laser axis penetrates the fixed point.

[0112] In another embodiment, the system is configured to determine a potential upcoming measurement blind spot of the first data acquisition mode, i.e., a potential upcoming measurement blind spot of the coordinate measuring device. The measurement blind spot is defined by at least one of a reduced coordinate measurement accuracy of the coordinate measuring device depending on the relative position of the coordinate measuring device and the object and an interfering object interfering (e.g., interrupting) the generation of distance measurement data by the coordinate measuring device. In addition, the system is configured to automatically switch from the first data acquisition mode to the second data acquisition mode to avoid the measurement blind spot.

[0113] As an example, the coordinate measuring device has a nominal field of view for setting the laser axis to generate the distance measurement data, and the system includes a plurality of deflection units, such as a plurality of movable mirrors. For example, the deflection units are arranged in a fixed positional relationship relative to the coordinate measuring device. In addition, each of the deflection units is associated with an extended field of view, which provides for the generation of coordinate measurement data in a field of view outside the nominal field of view of the coordinate measuring device, and the system is configured to automatically select one of the plurality of deflection units to avoid the measurement blind spot.

[0114] In another embodiment, the deflection unit comprises a movable reflective surface, for example wherein the reflective surface is movable relative to two orthogonal rotation axes, in particular relative to three orthogonal rotation axes. The deflection unit comprises an orientation marker arrangement, for example a set of at least three LEDs, configured to move together with the movable reflective surface and to indicate the orientation of the reflective surface when analyzing a spatial relationship between imaged orientation markers in an image including at least a portion of the orientation markers.

[0115] Thus, for example, the coordinate measuring device may be configured to acquire a first image of the reflective surface, the first image comprising at least a portion of the orientation marking arrangement. Alternatively or in addition, the system may comprise a movable target, the movable target being configured to reflect at least a portion of the laser measurement beam, for example, by means of a retroreflective element to reflect at least a portion of the laser measurement beam, and the movable target further comprising a camera and being configured to acquire a second image of the reflective surface, the second image comprising at least a portion of the orientation marking arrangement. Thus, the system is configured to determine, based on the first image or the second image, respectively: first orientation data, the first orientation data providing the orientation of the reflective surface relative to the coordinate measuring device, and / or second orientation data, the second orientation data providing the orientation of the reflective surface relative to the movable target. The coordinate measurement data may then be generated taking into account the first orientation data and / or the second orientation data, for example, wherein the system is configured to generate the coordinate measurement data such that the coordinate measurement data provides a 6DoF orientation (6 degrees of freedom) of the object.

[0116] As an example, the coordinate measuring device is configured to determine first orientation data, and / or the movable target is configured to determine second orientation data, e.g., wherein acquisition of the first image and / or the second image is coordinated with acquisition of orientation data, distance measurement data and control data.

[0117] In another embodiment, the coordinate measuring device and the deflection unit are configured for communicating with each other in real time, for example via an EtherCat connection, to exchange at least one of the control data and command data to change the deflection angle.

[0118] In a further embodiment, the coordinate measuring device and the deflection unit are arranged in a fixed positional relationship relative to each other, for example, wherein the coordinate measuring device and the deflection unit are associated with a fixed measuring region.

[0119] In another embodiment, at least one of the coordinate measuring device and the deflection unit is configured to be movable, wherein the system is configured to adjust the orientation data by determining (in particular tracking) the position and in particular the orientation of the movable coordinate measuring device or the movable deflection unit, respectively.

[0120] Another aspect of the invention, either alone or in combination with other aspects of the invention, relates to a metrology system having: a scanning device configured to scan a region of interest on an object, for example, by at least one of laser-based scanning and camera-based scanning, and based thereon, deriving three-dimensional coordinate measurement data of the region of interest. The system also has an imaging device configured to capture two-dimensional imaging data of the object, and a segmentation algorithm configured to analyze the two-dimensional imaging data and detect features of interest within the two-dimensional imaging data. Here, the system is configured such that: the field of view of the imaging device can be referenced to a targeting axis of the scanning device, wherein the system is further configured to: automatically detect features of interest to be scanned by the scanning device within the two-dimensional imaging data captured by the imaging device, and automatically provide setup parameters of the scanning device so that the scanning device scans the region of interest including the detected features of interest.

[0121] In one embodiment, the segmentation algorithm is configured to detect features of interest, the features of interest comprising at least one of an edge, a surface, a curvature, a texture, a hole, a stud, a thread, and a color of the object. For example, the segmentation algorithm is based on an artificial intelligence algorithm, more particularly wherein the segmentation algorithm is configured to perform semantic segmentation.

[0122] In another embodiment, the system is configured to automatically set up the scanning device based on the provided setup parameters. Specifically, the system is configured to determine a current offset (distance) between the scanning device and the region of interest including the detected feature of interest, wherein the system is configured to provide the setup parameters based on the determined current offset.

[0123] In another embodiment, the provided setup parameters define at least one of: a peripheral boundary of an area of ​​interest including the detected features; a point density provided by the three-dimensional coordinate measurement data of the scanning device; a scanning frequency of the scanning device; an intensity of a laser measurement beam of the scanning device; an exposure time of a camera of the scanning device; and a gain setting of a detector of the scanning device.

[0124] In another embodiment, the system is configured to automatically set the orientation of the target axis of the scanning device to the region of interest including the detected feature of interest based on the provided setup parameters.

[0125] In another embodiment, the system includes a set of predefined texture and / or color parameters for identifying the features of interest to be scanned by the scanning device, and the system is configured to select among the detected features within the two-dimensional imaging data based on the predefined texture and / or color parameters to identify the features of interest to be scanned by the scanning device.

[0126] In another embodiment, the system is configured to perform, by the scanning device, an overview scan of the object including at least a portion of the object, and based thereon, derive three-dimensional coordinate measurement data. Furthermore, the system is configured to analyze the three-dimensional coordinate measurement data derived from the overview scan, detect features of interest in the three-dimensional coordinate measurement data from the overview scan, and provide setting parameters of the scanning device based on the features of interest detected in the three-dimensional coordinate measurement data.

[0127] Another aspect of the invention, alone or in combination with other aspects of the invention, relates to a metrology system comprising a coordinate measuring device having a light source for generating measurement radiation (e.g., a laser measurement beam). The coordinate measuring device is configured to generate coordinate measurement data for determining the position of a measurement point based on the measurement radiation. The system also includes nominal operating data providing nominal operating conditions of the light source including at least one of a maximum number of initialization cycles of the light source, a nominal temperature range of the light source during operation, and a nominal temperature range of the environment during operation of the light source. Here, the system is configured to generate usage data of the light source and to generate a prediction model providing a degradation estimate of the light source based on a comparison of the usage data with the nominal operating data, wherein the usage data includes at least one of a number of operating hours of the light source, a number of initialization cycles of the light source, a time record of temperature data of the light source, and a time record of temperature data of the environment.

[0128] In one embodiment, the system is configured to generate the predictive model based on a selection among the usage data, wherein the selection is based on a determined deviation of a current operating condition indicated by the usage data from the nominal operating condition indicated by the nominal operating data.

[0129] In another embodiment, the system is configured to generate quality monitoring data providing a time record of data quality of the coordinate measurement data, and to generate the predictive model based on the quality monitoring data.

[0130] In another embodiment, the system is configured to generate the predictive model based on an artificial intelligence algorithm, particularly a selection among the usage data. BRIEF DESCRIPTION OF THE DRAWINGS

[0131] Aspects of the invention are described or explained in more detail below, by way of example only, with reference to the working examples schematically shown in the accompanying drawings. Identical elements are indicated by the same reference numerals in the drawings. The described embodiments are generally not shown true to scale, and they should not be interpreted as limiting the invention. Specifically,

[0132] Figure 1 The arrangement of different metrology devices in a defined measurement environment providing different workflows is exemplarily illustrated;

[0133] Figure 2a to Figure 2c The present invention exemplarily illustrates the use of multiple laser trackers for seamless measurement in a smart factory;

[0134] Figure 3 An embodiment of seamless measurement using multiple laser trackers in a smart factory based on transition and switching regions between two laser trackers is shown;

[0135] Figure 4 The present invention exemplarily illustrates seamless measurement using multiple laser trackers in a smart factory based on context switching between laser trackers;

[0136] Figure 5 depicts an exemplary embodiment of a movable laser tracker configured to be tracked by a reference laser tracker;

[0137] Figure 6b and Figure 6b Depicts an exemplary use case of a movable laser tracker for use in order to avoid measuring blind spots;

[0138] Figure 7 Another use case of a movable laser tracker as part of a measurement chain formed by multiple laser trackers is depicted;

[0139] Figure 8 An exemplary embodiment of a metrology system configured to assist a user in properly setting up and operating a plurality of coordinate measuring devices is shown;

[0140] Fig. 9 Another exemplary embodiment of a metrology system is shown, the metrology system being configured to automatically provide measurement instructions for an identified measurement area belonging to an object to be measured;

[0141] Fig.10Another exemplary embodiment of a metrology system is shown, the metrology system being configured to select a group of measurement devices to perform a measurement task based on status information from a plurality of measurement devices;

[0142] Fig.11a and Fig.11b A system for remote support utilizing an environment having a plurality of different metrology devices that can reference a common coordinate system is shown;

[0143] Fig.12a and Figure 12b An embodiment of a laser tracker configured to automatically adjust the alignment of a sighting axis toward an acoustically identified source direction is shown;

[0144] Fig.13 Another exemplary embodiment of a metrology system is shown, the metrology system comprising a laser tracker for determining the position of a movable accessory device and a reference device for monitoring the remaining movement of an object to be measured;

[0145] Fig.14 Shown is a two laser tracker implementation that can measure each other and thus provide self-calibration of the two laser trackers;

[0146] Fig.15 A system having a plurality of laser trackers configured for self-calibration is shown, wherein a set of laser trackers references a common coordinate system based on relative distance measurements between at least a portion of the plurality of laser trackers;

[0147] Fig.16a and Fig.16b An embodiment of a laser tracker configured to provide video tracking of a person carrying a collaboration target is shown;

[0148] Fig.17 An embodiment of a metrology system is shown, in which a deflection unit is used to avoid blind spots of a laser-based coordinate measuring device;

[0149] Fig.18 An embodiment of a metrology system is shown in which image-based segmentation is used to identify features of interest to be scanned by a scanning device and automatically provide setup parameters of the scanning device for scanning the features of interest. DETAILED DESCRIPTION

[0150] Figure 1A so-called “smart factory” or “metrology environment” is illustrated by way of example, i.e. an environment with a defined arrangement of different metrology devices, which is configured such that coordinate measurement data generated by the different metrology devices can be referenced to a common coordinate system, in particular by means of at least one coordinate measurement device (such as a laser tracker or a scanner) arranged at a fixed position within the smart factory.

[0151] The figure shows an exemplary use case, such as the measurement and quality control of workpieces 2 in industrial automobile or aircraft production.

[0152] A typical metrological measurement system for determining the 3D coordinates of an object 2 comprises a coordinate measurement device with tracking functionality, also referred to below as a tracker, which is configured to automatically track a movable accessory device and generate coordinate measurement data indicating the position and typically also the orientation of the movable accessory device. For example, the tracking capability of the tracker may be provided by at least one of a video tracking unit, a radio frequency tracking unit, and by optical tracking based on emitting a tracking beam towards a cooperating target.

[0153] The movable accessory device is configured for scanning the object 2, for example by means of tactile scanning, laser-based scanning and / or camera-based scanning, and / or the movable accessory device is configured for performing an intervention on the object 2, for example for manufacturing and / or marking the object 2. For example, the movable accessory device can be embodied as a scanning device, which is configured to approach the object and perform coordinate measurements itself, for example, wherein the mobile accessory device is a handheld scanner 4, a tactile detection or scanning device 29, 30A, 30B (see Figure 8 ), an articulated arm robot 5, an x-ray inspection device or a stereo imaging device. The mobile accessory device may also be a marking device for marking objects or tools and / or manufacturing instruments. In addition, the accessory device may also be another laser tracker, such as a laser tracker configured with a scanning function. The metrology system is typically configured such that the coordinate measurement data of the accessory device may typically reference the coordinate system of one of the coordinate measuring devices (e.g., one of the fixed laser trackers) or reference an external coordinate system of a set of coordinate measuring devices.

[0154] As an example, the movable accessory device is specifically implemented as a handheld scanner 4, which is configured to emit a local scanning beam 7 to scan the surface of an object in a local coordinate system, wherein the position of the handheld scanner 4 is tracked and measured by the laser tracker 1, and the measurement points of the handheld scanner 4 (typically coordinate measurement data in the local coordinate system) can be referenced to the coordinate system of the laser tracker 1.

[0155] Both the movable accessory device and the tracker may also be mounted to a robot, such as a UGV 6 (“Unmanned Ground Vehicle”) carrying the tracker 1 or a UAV 206 (“Unmanned Aerial Vehicle”) carrying the photogrammetric camera 207 .

[0156] As an example, the tracker is embodied as an industrial laser tracker 1 which provides high-precision coordinate measurement and tracking of a cooperating target 3, e.g. a passive reflecting unit with defined reflection characteristics, such as a steel ball of known dimensions, or a retroreflecting unit, such as a cubic prism, wherein at least a plurality of parts of a laser beam emitted by the laser tracker 1 are reflected back to the laser tracker (e.g. in parallel). Alternatively, the cooperating target may be an active unit emitting radiation with defined emission characteristics and / or emitting radiation according to a defined radiation pattern (e.g. provided by one or more laser diodes or LEDs), which is recognized by the tracking unit of the coordinate measuring device. In other words: in the context of the present application, the term "cooperating target" relates to a target which is specifically foreseen to be used in combination with a tracking unit to be able to generate a tracking signal. Thus, the cooperating target "cooperates" with the tracking unit in that it has at least one of different reflection characteristics, different emission characteristics, a known shape and a known size.

[0157] The basic structure of a typical laser tracker 1 comprises an optoelectronic rangefinder for determining the distance to an object based on a laser measuring beam 8 , wherein the aiming direction of the laser measuring beam 8 can be changed in a motorized movement, for example relative to one or more independent spatial directions.

[0158] Optoelectronic laser distance meters have now become a standard solution in many areas, with various principles and methods being known in the field of electronic or electro-optical distance measurement.

[0159] One method is to emit pulsed electromagnetic radiation, such as a laser, to the target to be measured and subsequently receive echoes from the target as backscattered objects, wherein the distance to the target to be measured can be determined by the time of flight (ToF), shape and / or phase of the pulse. Another method is to use interferometric distance measurement principles, in particular absolute (i.e. frequency scanning) interferometric measurement methods, frequency modulated continuous wave methods (FMCW, in particular C-FMCW), the Fizeau principle and / or the frequency comb principle.

[0160] Furthermore, the laser tracker 1 comprises a tracking unit for providing automatic adjustment of the aiming direction of the laser measuring beam 8 , the emission direction of which is determined by a sensor for angle measurement, such as an angle encoder, so that the measuring beam 8 continuously tracks a target point.

[0161] For example, for the purpose of continuous target tracking, the deviation of the returning tracking beam 9 (e.g., a portion of the distance measurement beam 8 or a separately emitted tracking beam) can be used to determine the deviation from the zero position on the tracking sensor. With this measurable deviation, the aiming direction of the tracking beam 9 can be corrected or continuously adjusted in a way that reduces the deviation on the tracking sensor.

[0162] As a tracking sensor, a position-sensitive detector (PSD) can be used, for example an area sensor which functions in an analog manner with respect to position and with which the center of mass of the light distribution on the sensor surface can be determined.

[0163] In order to achieve a high level of accuracy, the field of view of such a PSD is usually chosen to be relatively small, for example corresponding to the beam diameter of the tracking beam 9. Therefore, before using such PSD-based tracking, the tracking beam 9 must be coupled to the cooperating target 3. Therefore, problems may arise when the cooperating target 3 moves suddenly and quickly so that it disappears from the visual range of the PSD detector. Furthermore, the coupling may be lost when the line of sight is interrupted, even in cases where the interruption occurs only during a brief moment.

[0164] Furthermore, many different workers and / or movable attachment devices such as articulated arm robots 5 may work on the same object. If two collaborative targets 3 cross each other, the tracking beam associated with the target in the background may be blocked by the target carrier of the target in front. In this case, the laser tracker 1 can perform a so-called power lock procedure, such as automatic positioning of the collaborative target 3, to automatically re-lock the tracking beam 9 to the collaborative target 3.

[0165] For example, the power lock unit includes: a position detection sensor, which is configured to generate position data indicating an incident position of an incident light beam on the position detection sensor; and a light source, such as an LED, which is configured to radiate a search beam in the direction of an aiming axis, wherein a reflection of at least a portion of the search beam at a cooperative target is visible on the position detection sensor as an incident light beam.

[0166] However, since typical power lock procedures scan only in a very narrow search field of view, it may happen that instead of relocking the tracking beam to a cooperative target in the background, the tracking beam is mistakenly locked to a cooperative target in front. In extreme cases, the laser tracker may not even notice this erroneous relock and therefore continue to track the wrong target.

[0167] Various principles and methods are known in order to keep the tracking beam 9 in the “coupled” state even during rapid and sudden movements of the target object or during interruptions of the tracking beam 9 .

[0168] For example, the laser tracker 1 has a camera configured to have a relatively wide field of view, i.e. configured to capture the collaborative target 3 as well as the target carriers 4, 5, 6 and a large part of the background. Thus, based on image processing, e.g. by computer vision algorithms detecting and tracking workers in the video stream generated by the camera, the trajectory of the target object or the movement of objects moving together with the target object can be determined and used to more easily locate the collaborative target 3 and to couple (re-lock) the laser beam again in the event that the collaborative target 3 has been lost from the "coupled" state.

[0169] Alternatively or additionally, tracking (tracking of a target by a tracker or generally tracking of a device within a metrology system) may be based on other known position determination devices and / or laser trackers and / or target carriers installed within the smart factory, for example based on a local radio frequency positioning system 208 such as WLAN positioning or 5G positioning 208. Thus, the tracking signal may be embodied as an optical tracking beam 9, but also as any other type of wireless transmission signal to exchange position information between the laser tracker 1 and the target carrier 4, 5, 6.

[0170] The movable accessory device 4, 5 may have some markers (not shown) for pose determination, and the tracker may have an oriented camera (not shown), wherein the tracker is configured to determine the 6DoF pose (6 degrees of freedom, i.e. position and orientation) of the movable accessory device by means of image processing. Typically, the movable accessory device 4, 5 also has additional pose determination means, such as an inertial measurement unit and / or a visual inertial system, and is configured for wireless communication with the tracker.

[0171] At least a portion of the coordinate measuring devices and movable accessory devices of the smart factory / metrology environment are configured to communicate with each other, for example, through device-to-device communication and / or communication through a central computer. In addition, the smart factory / metrology environment may include additional auxiliary measurement and detection devices configured to communicate with the coordinate measuring devices and / or movable accessory devices. For example, at least a portion of the devices of the smart factory can be configured for peer-to-peer communication within a company's internal (e.g., secure) 5G network.

[0172] For example, the smart factory may include an additional surveying device 10, such as a fisheye camera mounted at the ceiling or a camera mounted in a corner of the smart factory, which is configured to monitor at least a sub-area of ​​the smart factory and identify objects, such as laser trackers, movable accessory devices and / or people. In addition, the measuring device can be mobile, such as mounted on an AGV or UAV. Therefore, in the event that the laser tracker 1 is unable to find a lost (e.g., temporarily decoupled) collaborative target 3, the surveying camera 10 provides a wider search area than the field of view of the power-locked camera of the laser tracker 1 to provide the laser tracker 1 with at least a rough position estimate of the lost collaborative target.

[0173] Alternatively or additionally, since the coordinate measurement data generated by different metrology devices within the smart factory can be referenced to each other, instead of having a dedicated surveying device 10, a group of trackers and / or movable accessory devices can also be configured to share some of their sensor information between each other as mutually assisted search and survey information. For example, a laser tracker that has lost its cooperative target can query the information of the camera of another laser tracker in order to find and locate the lost target.

[0174] The defined measurement environment provided by the smart factory / metrology environment provides new and / or improved workflows and measurement systems, some exemplary aspects of which are explained in more detail below.

[0175] It goes without saying that the skilled person will appreciate that various aspects of the metrology system and coordinate measuring apparatus described below may be combined with one another.

[0176] In particular, although not always explicitly mentioned, it is assumed that the term "coordinate measuring device" relates to a device configured to generate coordinate measurement data for determining the position of a measurement point, such as a device based on a laser measurement beam or based on imaging to generate coordinate measurement data for determining the position of a measurement point. For example, the term coordinate measuring device may relate to a tracker and / or a scanner, such as an industrial laser tracker for tracking and precise coordinate determination of a target object or a 3D scanner for scanning an environment.

[0177] For example, the basic structure of a laser-based coordinate measuring device comprises an optoelectronic rangefinder configured to emit a distance measuring beam in the direction of an aiming axis when a laser tracker is directed toward a cooperative target, wherein the optoelectronic rangefinder is configured to determine distance measurement data based on at least a portion of the return radiation of the distance measuring beam; and an angle determination unit configured to provide angle determination data for determining the pointing direction of the aiming axis.

[0178] The laser tracker further includes a tracking unit configured to receive a tracking signal indicating a change in an angular position of the cooperative target through a tracking channel, to determine the change in the angular position of the cooperative target based on the tracking signal, and to generate control data for adjusting the alignment of the aiming axis based on the determined change in the angular position.

[0179] Thus, typically, the laser tracker works in conjunction with a removable accessory device, which is a device configured for scanning an object (particularly for tactile scanning, laser-based scanning and camera-based scanning) and / or for performing interventions on an object (particularly for manufacturing and / or marking an object). In particular, the accessory device may also be another coordinate measuring device, such as another laser tracker or scanner as outlined in the following embodiments.

[0180] The term "cooperative target" relates to a target that is specifically foreseen to be used in conjunction with the tracking unit to be able to generate a tracking signal. In other words, the cooperative target "cooperates" with the tracking unit of the laser tracker because it has at least one of different reflection properties, different emission properties, a known shape and a known size.

[0181] The skilled person will appreciate that the metrology system may be configured to recognize different types of collaborative targets, and whenever a collaborative target is used to represent a particular target point to be measured, the system is configured to resolve any offset or ambiguity between the position of the collaborative target and the actual measurement point represented by the target, for example, wherein the system may recognize different reflector types, such as prisms and cateye prisms, and automatically obtain or learn relative additive constants regarding their type and mounting location.

[0182] For example, a cooperative target mounted to a laser tracker may be arranged and configured in such a way that measurements of the cooperative target may be referenced to defined points of the laser tracker, eg, the point of origin of a tracking beam generated by the laser tracker is marked with the cooperative target.

[0183] As an example, one benefit of having a set of trackers in a smart factory that can reference each other is that it can provide seamless measurements made with multiple trackers, such as Figure 2a to Figure 2c Schematically depicted.

[0184] According to this embodiment, the metrology system comprises at least a first tracker 10A and a second tracker 10B, such as laser trackers. Each of the two trackers 10A, 10B is configured to automatically track a movable accessory device, such as a handheld scanner 4 .

[0185] As an example, the tracking may be based on a tracking beam of a tracking unit as described above, or the tracker 10A, 10B may be configured for video tracking of an object captured by a camera of the tracker 10A, 10B.

[0186] Furthermore, the two laser trackers 10A, 10B are arranged in a fixed positional relationship so that the coordinate measurement data they generate may be referenced to a common tracker coordinate system, such as the so-called global smart factory coordinate system or a local coordinate system of one of the two laser trackers 10A, 10B.

[0187] As an example, the two laser trackers 10A, 10B are configured to provide their raw or processed data to a central computing unit for further processing and for merging coordinate data of different coordinate systems. Alternatively, the central processing can also be performed by one of the laser trackers 10A, 10B, for example, one of the laser trackers 10A, 10B is configured as a dedicated reference laser tracker.

[0188] Furthermore, the two laser trackers 10A, 10B are configured to communicate with each other, for example by device-to-device communication and / or by communication through a central communication node, and each of the two laser trackers 10A, 10B is assigned to a different measurement area 11A, 11B.

[0189] For example, the measurement area 11A, 11B may be defined relative to the respective laser tracker 10A, 10B, for example, wherein the nominal measurement range of the laser tracker defines the nominal measurement area around the laser tracker. The measurement area 11A, 11B may also be specifically defined as any area within the reach of the laser tracker 10A, 10B, i.e., a specific area of ​​the smart factory to be covered by the respective laser tracker. It goes without saying that the measurement area 11A, 11B may be adjustable, for example depending on different measurement tasks or system conditions.

[0190] The first laser tracker 10A is configured to track the handheld scanner 4 when the handheld scanner 4 is located within the first measurement area 11A, and the second laser tracker 10B is configured to track the handheld scanner 4 when the handheld scanner 4 is located within the second measurement area 11B. Figure 2a , the handheld scanner 4 is well located within the first measurement area 11A and is therefore tracked by the first laser tracker 10A, while the second laser tracker 10B is on standby or tracking a different target object (not shown).

[0191] exist Figure 2bIn the embodiment, the handheld scanner 4 is located in a transition area 12 where the first measurement area 11A and the second measurement area 11B meet. Once the handheld scanner 4 enters the transition area 12, the first laser tracker 10A sends a position signal, for example, as a trigger signal 13. For example, the trigger signal is sent in the form of a broadcast signal or a signal specifically addressed to the second laser tracker 10B, at least notifying the second laser tracker 10B that the handheld scanner 4 is located in the transition area 12.

[0192] As an example, the first laser tracker 10A may also be configured to estimate the motion path 14 of the handheld scanner 4, for example to specifically address a suitable laser tracker to potentially "take over" the movable accessory device or to have the central computing unit estimate the motion path 14, select and address a suitable laser tracker to take over. In particular, the laser tracker 10A or the central computing unit may be configured to estimate the time period until the movable accessory device leaves the first measurement area.

[0193] The position signal (here the trigger signal 13) includes at least the position information of the handheld scanner 4, so that Figure 2c As shown, the second laser tracker 10B can at least begin coarse tracking of the handheld scanner 4, for example, even when the handheld scanner 4 is still not visible to the second laser tracker 10B. Thus, as soon as the handheld scanner 4 reaches the transition boundary 15, it is "handed over" from the first laser tracker 10A to the second laser tracker 10B without substantially causing an interruption in the measurement.

[0194] For example, the second laser tracker 10B may be configured to once the scanner 4 is located at a position such as Figure 3 The handheld scanner 4 is locked to the handheld scanner 4 within the switching region 16 shown, for example by executing a power lock procedure. Thus, within the switching region 16, both laser trackers 10A, 10B are coupled to the handheld scanner 4, thereby providing a seamless switch at the transition boundary 15.

[0195] The switching premise may be essentially "static" in the sense that fixed measurement areas 11A, 11B are assigned to different laser trackers 10A, 10B. However, the measurement areas 11A, 11B and / or the transition area 12 may also be adjusted dynamically, for example depending on the current measurement situation and / or the current arrangement of the objects in the smart factory.

[0196] Figure 4An exemplary example of such a “dynamic” switch is shown, wherein the first laser tracker 10A is configured to request a context switch, for example, in the event of a reduction in coordinate measurement accuracy and / or tracking accuracy, and / or in the event that an interfering object 17 is detected within the field of view 18A of the first laser tracker 10A, i.e., an object that would potentially interfere with the tracking beam of the first laser tracker 10A.

[0197] As an example, the measurement area of ​​the first laser tracker 10A is generally given as a circular measurement range around the laser tracker, and the first laser tracker 10A includes a panoramic camera device configured to provide 360-degree panoramic image data. Interference objects 17 are then identified within the panoramic image data based on image processing and feature recognition algorithms. In addition, the laser tracker is configured to determine at least a rough position of the interfering object 17 within its field of view 18A, and to determine a blind spot area 19 where its tracking beam may be blocked by the interfering object 17.

[0198] The first laser tracker 10A then requests a context switch, which includes comparing the measurement area and / or field of view 18B of the surrounding laser tracker 10B with its own measurement area and the determined blind spot area 19, and determining a transition area 12 based on the comparison, i.e. for the handover process with another laser tracker 10B as described above.

[0199] Alternatively or additionally, the tracker may be configured to be automatically movable to enable the tracker to be automatically moved by repositioning to another tracker position (e.g., see Figure 6a , Figure 6b ) to avoid blind spots. However, in order to reference the determined coordinates relative to a common coordinate system (e.g., a smart factory coordinate system), the movement of the movable tracker needs to be tracked by a reference tracker that has a well-defined position relative to the common coordinate system.

[0200] Figure 5 An exemplary embodiment of a movable coordinate measuring device (e.g., movable laser tracker 20) configured to be tracked by a reference laser tracker is depicted. The movable laser tracker 20 may have structural features known from prior art geodetic or industrial laser trackers. In addition, the laser tracker 20 has a mounting interface that is specifically foreseen for mounting the laser tracker to an automated guided vehicle 21 (AGV), such as a UGV ("Unmanned Ground Vehicle"). Thus, the laser tracker 20 is configured to be automatically movable within a smart factory.

[0201] For example, the movable laser tracker 20 is configured to move according to a fixed guidance system installed in the smart factory, i.e., basically moves along a fixed track, or the movable laser tracker 20 is configured to move freely, for example, wherein the laser tracker 20 and / or AGV 21 are configured to move based on a positioning or guidance system (such as 5G positioning, radio positioning (e.g., based on ultra-wideband radio signals) or WLAN positioning), or wherein the laser tracker 2 and / or AGV 21 are configured for simultaneous localization and mapping (SLAM).

[0202] Furthermore, the movable laser tracker 20 includes a measurement aid 22, which is configured in such a way and arranged in a fixed relationship with the laser tracker 20, that the movement and orientation of the measurement aid 22 indicate the movement and orientation of the movable laser tracker 20. For example, the measurement aid 22 is mounted on the laser tracker 20 (or AGV 21), or is embodied as an integral part of the movable laser tracker 20. In particular, the movable laser tracker 20 may include one or more such measurement aids 22, for example, one or more such measurement aids 22 arranged at different faces of the laser tracker.

[0203] The measurement aid 22 includes a retroreflector 23 configured to be tracked by a reference laser tracker 26 ( Figure 6a ) is tracked by a marker arrangement 24 forming a reflective and / or self-luminous pattern, enabling a reference laser tracker to determine with high accuracy the orientation of the movable laser tracker 20. Thus, the measurement aid 22 enables another laser tracker, for example comprising a camera for capturing the measurement aid 22, to determine the pose (i.e., position and orientation) of the movable laser tracker 20, in particular the 6DoF pose.

[0204] Therefore, if Figure 6a (before moving) and Figure 6b As shown (after movement), the movable laser tracker 20 can be configured to detect interfering objects 17 within its field of view 18, i.e., objects that will potentially interfere with the tracking beam of the movable laser tracker 20. For example, the movable laser tracker 20 can include a camera and be configured to detect the object 17 based on image processing and feature recognition algorithms.

[0205] Furthermore, the laser tracker is configured to determine at least a rough position of interfering objects 17 within its field of view 18 and to determine blind spot areas 19 where its tracking beam may be blocked by interfering objects 17. Based on this information, suitable repositioning positions 25 for avoiding measurement blind spots 19 can be determined.

[0206] The movable laser tracker 20 may then be sent to a repositioned position 25, wherein at least the end position of the movement is determined by the reference laser tracker 26. For example, before starting the movement, the movable laser tracker 20 issues a trigger command 13 to request tracking by the external reference device 26, e.g., wherein the trigger command includes information about the current position of the movable laser tracker 20 and / or the repositioned position 25.

[0207] like Figure 7 As shown, the above-mentioned movable laser tracker 20 can also be part of a measurement chain formed by a plurality of such movable laser trackers 20 .

[0208] As an example, a fixedly mounted reference laser tracker 26 is used, and the coordinate measurement data of the plurality of laser trackers and other movable accessory devices are referenced relative to the reference laser tracker 26. However, it is also possible to configure one of the movable laser trackers 20 to be used as a reference laser tracker. In particular, a dedicated external computing unit 27 connected to at least the reference laser tracker 26 can be foreseen for data processing and data merging.

[0209] Thus, the reference laser tracker 26 and the plurality of movable laser trackers 20 form a variable laser tracker arrangement, wherein individual variations of the arrangement are automatically tracked, i.e. the reference laser tracker 26 and each movable laser tracker 20 except for the last movable laser tracker in the measurement chain are configured to automatically track the respective assigned movable laser tracker 20, e.g. wherein each movable laser tracker 20 is configured to issue a trigger command 13 to request its upstream laser tracker to track. In other words, each movable laser tracker 20 is configured to act as a relay device 28 between the reference laser tracker 26 and a movable attachment device, here in the form of an articulated arm robot 5.

[0210] In industrial metrology, a wide range of different sensors and measuring devices can be used, wherein each sensor and device, often with multiple operating modes, requires a dedicated setup procedure. Often the correct setup and combination of different devices for a specific measuring procedure requires a certain degree of expertise.

[0211] Figure 8 An exemplary embodiment of the metrology system of the present invention is shown, which helps a user to properly set up and operate a plurality of coordinate measuring devices based on selecting a movable accessory device from a plurality of movable accessory devices.

[0212] As an example, the plurality of coordinate measuring devices include two fixed laser trackers 26 and a movable laser tracker 20. The plurality of movable scanning and / or probing devices include a handheld scanner 4, a tactile 6DoF probe 29 and a set of different retro-reflective prisms 30A, 30B.

[0213] One of the fixed laser trackers comprises an inspection device 31, such as an inspection camera, configured to generate inspection data. The inspection device may be configured to automatically identify objects placed within the inspection field of view 32. Alternatively, the inspection device may be configured such that generation of inspection data is triggered by user input.

[0214] The inspection device 31 is coupled to a computing unit 27 including an evaluator configured to provide a classification of a movable accessory device 30B captured by the inspection data and comprising a database having preset information of a plurality of coordinate measuring devices 20, 26 associated with different scanning and / or detection devices 4, 29, 30A, 30B to be used in conjunction with the coordinate measuring devices 20, 26.

[0215] According to one embodiment, the system is configured to automatically perform identification of movable accessory devices 4, 29, 30A, 30B placed in the inspection field of view 32 of the laser tracker and automatically classify the identified movable accessory devices. The image data of the inspection device 31 is then provided to the computing unit 27, which classifies the identified prism 30B into the corresponding probe category, for example based on a comparison of the image data of the inspection camera with template images of a plurality of accessory devices 4, 29, 30A, 30B stored in an image database.

[0216] Based on the classification, the computing unit 27 automatically provides dedicated preset instructions to the plurality of coordinate measuring devices 20 , 26 .

[0217] In particular, the preset may include at least one of: turning on at least one subset of coordinate measuring devices, and executing a calibration procedure to calibrate the subset of coordinate measuring devices, for example, loading the relative addition constant of the identified prism 30B, and referencing each device in the subset relative to a common coordinate system.

[0218] In addition, the system may also include a database with operating instructions for at least a portion of the coordinate measuring device and / or at least a portion of the accessory device. For example, the system includes a user assistance device, such as video glasses 33, which is configured to provide step-by-step operating instructions to the user based on the classification, in particular, wherein the user assistance device is configured to work with augmented reality technology, such as being specifically implemented as augmented reality glasses or an augmented reality helmet.

[0219] For example, the operating instructions include at least one of instructions for setting up a movable accessory device, instructions for setting up a coordinate measuring device, instructions for using a movable accessory device in conjunction with a coordinate measuring device, and warning information (particularly warning information regarding user safety and measurement accuracy).

[0220] For example, the provision of presets and / or operating instructions for the device may also be based on the skill level of the user operating the system, for example where the system is configured to read information from an RFID tag carried by the user, the RFID tag comprising information about a user category assigned to the user. For example, the system may access a database comprising user details (e.g., a list of system users and / or a list of user categories associated with information about user training and / or user authorization levels).

[0221] Fig. 9 An embodiment of the metrology system of the invention is shown, which assists the user by automatically providing measurement instructions for an identified measurement area 34 belonging to the object 2 to be measured.

[0222] As an example, the system includes an inspection camera 35, such as a RIM camera mounted to the user assistance device 33, which is configured to generate inspection data, such as 3D range-finding imaging data.

[0223] In addition, the system includes an evaluator, such as an evaluator based on image processing and feature extraction algorithms, for classifying the inspection data to identify measurement areas 34 on the object 2 to be measured, i.e., where the measurement areas 34 need to be measured by a dedicated measurement program, for example, where some measurement areas 34 need to be measured by a tactile probe 29 at some reference positions with punctual coordinates, while other measurement areas 34 need to be scanned locally at a specific point resolution, for example, by a stereo camera device. The inspection camera 35 can be configured to automatically generate inspection data, for example, automatically generate inspection data based on sequential or continuous data acquisition, and automatically identify different measurement areas 34. Alternatively, the inspection camera can be configured to trigger the generation of inspection data by user input.

[0224] In order to provide the necessary computing power for the classification of the inspection data, the identification of the measurement region 34 can be performed on a dedicated computing unit 27 connected to the inspection camera 35 .

[0225] Based on the identified measurement area 34, instructions 36 for using a specific removable accessory device (e.g., a tactile 6DoF probe 29) are provided to the user, in particular together with instructions on how to use the specific removable accessory device, for example, instructions for setting up the specific removable accessory device and an associated laser tracker and how to use the accessory device in conjunction with the associated laser tracker.

[0226] For example, measurement instructions 36 are provided for the identified measurement area 34 as visual and / or acoustic instructions, for example, wherein written instructions are provided to the user via video glasses 33 , in particular working together with augmented reality technology to directly indicate at least an approximate measurement location within the measurement area 34 .

[0227] In particular, the provision of measurement instructions 36 may take into account the training level of the user, for example where the user carries an RFID identification tag 37 providing a user category with associated user skills indicating available measurement equipment.

[0228] For example, based on the classification 38 of the measurement area 34, the system determines a preselection 39 of suitable mobile accessory devices for performing necessary measurement tasks for measuring the measurement area, wherein the preselection 39 is further reduced based on the user ID to provide a final selection 36 of accessory devices and corresponding instructions.

[0229] As another example, the system is configured such that provision of measurement instructions is based on settable nominal measurement parameters for the measurement area, for example where a user defines a nominal point density or accuracy to be achieved, i.e., requiring use of specific accessory equipment, and / or the system can be configured to perform a trade-off analysis to optimize the overall measurement time.

[0230] Fig.10 A further exemplary embodiment of the inventive metrology system is shown, wherein an indication of available measuring devices for performing a specific measuring task is provided to a user and wherein an improved coordination of parallel measurements is achieved.

[0231] As an example, there are multiple different measuring devices in the metrology area, such as coordinate measuring devices (such as a static laser tracker 1 and a movable laser tracker 20), and various movable accessory devices (such as a tactile 6DoF probe 29, retroreflective prisms 30A, 30B, a handheld scanning device 4 and a stereo scanner (such as a stereo camera mounted on an articulated arm robot 5)).

[0232] Often, different sets of measurement devices may be used to perform a specific measurement task, wherein selecting an appropriate set of devices often requires an overview of the available measurement devices and some level of expertise.

[0233] Especially in extensive metrology environments, such as a large building hall with many workers, an overview of the availability of measuring devices can be cumbersome, since many measurement tasks run in parallel and many workers use devices from the same set of equipment at the same time. Furthermore, some devices may be subject to degradation, or even damaged or under repair.

[0234] Furthermore, it must be ensured that workers or devices performing different measuring tasks do not interfere with each other, for example by blocking each other's laser measuring beams.

[0235] According to this embodiment of the invention, the metrology system is configured to capture status information indicating current status of the plurality of measuring devices, and use the status information to determine a suitable set of measuring devices from the plurality of measuring devices to perform a given measurement task.

[0236] For example, the system may comprise a central computing unit 27 which is configured to have access to a predefined list of measurement tasks to be performed, wherein for each measurement task at least one set of device types is defined which can be used to perform the task. The user can then select a measurement task 40 from the list of measurement tasks to be performed next. Alternatively, instead of selecting a predefined measurement task, the system can also be configured such that the user sets different measurement parameters and thus defines a new measurement task 40 and which types of measurement devices may be suitable.

[0237] In addition, the system comprises a communication network 41 configured to provide communication between the measuring devices 1, 4, 5, 20, 29, 30A, 30B and the computing unit 27. Some measuring devices 4, 29, 30A, 30B may not be able to communicate directly with the computing unit 27. However, when not in use, they can be stored in a storage unit 42, which has a dedicated shelf for placing each device type 4, 29, 30A, 30B and is configured to identify whether the device is stored and ready for use. The storage unit 42 is further configured to communicate via the communication network 41, and thus at least provides information about the availability of these devices 4, 29, 30A, 30B. In addition, the storage unit 42 can be further configured to provide further status information about the stored measuring devices 4, 29, 30A, 30B, for example, wherein the status information is automatically derived or manually stored by the user.

[0238] When selecting / defining a measurement task 40 to be performed next or, for example, in a continuous manner, the system is configured to capture the actual status of a plurality of measurement devices, for example wherein a broadcast or multicast signal is sent via a communication network 41 requesting a response from the measurement devices 1, 5, 20 and a storage unit 42. For example, the response may include at least location information indicating the current location or availability of the respective measurement devices 1, 4, 5, 20, 29, 30A, 30B.

[0239] Based on the selection / definition of the measuring task 40 and the actual status of the measuring devices 1 , 4 , 20 , 29 , 30A, 30B, the system determines a set of measuring devices, in particular a set of measuring devices having suitable measuring instructions for the measuring task 40 .

[0240] The set of measuring devices is then made identifiable to the user by means of a visual notification 43 and / or an acoustic notification 44, where, for example, the measuring devices are configured to provide a red color code (occupied) and a green color code (available) or simply an on / off code (e.g., LED on = available, LED off = occupied) and / or an acoustic pattern.

[0241] Alternatively or additionally, the system may comprise a pointer unit (not shown) configured to emit a directional visual pointing beam towards the measuring device to be used, i.e. to mark the measuring device by pointing at it. For example, the laser tracker 1 may be configured to point at a movable scanner and / or probe 4, 29, 30A, 30B that has to be used in conjunction with the tracker 1. The computing unit 27 may also be connected to a display (not shown) configured to provide information about the set of measuring devices, such as the device positions.

[0242] The system can further be configured to (in particular continuously) collect the status (e.g. at least position and activity indication) of the plurality of measuring devices in order to determine a free movement area 45 for interaction with the group of measuring devices and / or a restricted area 46 that should not be entered. Within the free movement area 45, the group of measuring devices or any other object (e.g., a person carrying a handheld scanner 4 for performing a local scan of an object to be measured) used to perform the measurement task 40 can move freely without the risk of interfering with the measurement task performed by the remaining measuring devices of the plurality of measuring devices. In turn, the area associated with the measurement task performed by the remaining measuring devices of the plurality of measuring devices can be determined as a restricted area 46.

[0243] The extent and location of the free movement area 45 and / or restricted area 46 are visible to workers in the metrology environment, for example through dedicated LED markers 47, 48 on the floor or through a video projection system configured to project dedicated markers onto surfaces in the smart factory.

[0244] Additionally, the system may be configured to monitor restricted areas 46 and generate an alarm signal if a person and / or object enters this area, for example based on a monitoring system using RFID tags, thereby indicating access rights to different areas 45, 46 of the metering environment.

[0245] Fig.11a and Fig.11b A system for remote support utilizing a well-defined smart factory environment, ie an environment with a plurality of different metrology devices that can be referenced to a common coordinate system, is exemplarily illustrated.

[0246] The system is a measurement environment comprising coordinate measurement devices (eg, fixed laser tracker 1 and movable laser tracker 20) having a referenceable position relative to an external coordinate system.

[0247] As an example, in a conventional remote support system, a field worker wears smart glasses equipped with a camera that is configured to enable a remote expert to access the current view of the field operator wearing the smart glasses. Thus, the remote expert can guide the field worker to complete tasks to solve the problem.

[0248] However, even with a real-time field view, guiding a field worker 49 through a complex measurement task may be cumbersome, for example involving properly setting up different measurement equipment at different locations within the measurement environment and approaching various measurement points.

[0249] According to this embodiment of the invention, guiding the field worker 49 is particularly accelerated and facilitated, since it is possible for the remote expert 50 to remotely use the field devices 1, 20 to point to different measuring devices and locations where the field worker 49 needs to take some action (e.g. measure or investigate something).

[0250] In order to provide such pointing functionality, the system is configured to process internal reference data from a mobile user auxiliary device 51 (e.g., smart glasses having a camera 52), which indicates the position and orientation of the mobile user auxiliary device 51 relative to a fixed measurement environment. For example, the internal reference data may be imaging data, distance measurement data, and / or data from an inertial measurement unit of the user auxiliary device 51.

[0251] Therefore, based on the intrinsic reference data and the extrinsic reference data indicating the measurement environment represented in the external coordinate system, the remote support system can determine the position and orientation of the mobile user assistance device 51 relative to the external coordinate system.

[0252] Furthermore, the system is configured to read input data provided by the remote expert 50, which defines a guide point within the measurement environment, such as the position of a measuring device 53 or the position of a point to be measured 54. For example, the remote expert 50 can explicitly provide the coordinates of the guide points 53, 54 in an external coordinate system and / or the remote expert can provide a point ID (e.g., a specific measuring device), wherein the point ID is automatically linked to the associated point ID coordinates by the system. Then, based on this input data, the coordinate measuring device (e.g., a laser tracker 1, 20 configured to generate a visual laser pointing beam 55) is instructed to point to one of the guide points 53, 54.

[0253] As an example, Fig.11aAs shown, the measurement environment comprises two fixed laser trackers 1A, 1B and a movable laser tracker 20 linked to a central computing unit 27 and referenced to a common coordinate system. Fig.11b As shown, the remote expert 50 guides the field worker 49 to measure a specific measurement point 54 on the object 2 to be measured by using the tactile probe 29 and one of the two fixed laser trackers 1A. The fixed laser tracker 1A to be used and the approximate location to perform the measurement are indicated by generating two pointing beams 55, that is, using the movable laser tracker 20 and the other fixed laser tracker 1B.

[0254] In particular, the external coordinate system can also be generated based on data from one of the measuring devices 1A, 1B, 20, such as image data from a camera or point cloud data generated by a laser scanning unit. For example, the external reference data can be based on a so-called full dome scan of one of the measuring devices 1A, 1B, 20, i.e. imaging or point cloud data providing a substantially 90° (vertical) by 360° (azimuth) field of view. In particular, a realistic 3D model can be derived from these data of one of the measuring devices, so that the remote expert 50 can access a geometrical 3D twin of the measurement environment.

[0255] Fig.12a and Figure 12b An embodiment of the coordinate measuring device of the present invention is shown, where the laser tracker 100 is configured to automatically adjust the alignment of the sighting axis towards the direction of origin of the acoustic identification signal.

[0256] As an example, a typical laser tracker usually has a visual target location function for automatically or at least semi-automatically locking the tracking beam 9 to the cooperating target 3. Sometimes this function is called a "power lock procedure", for example, where the laser tracker 100 automatically scans the surroundings to find the cooperating target 3.

[0257] However, a typical power lock procedure has a very narrow search field of view 56 for locating the cooperative target 3. Therefore, at least a rough pre-alignment of the cooperative target 3 and the target locating unit must be performed, either by moving the cooperative target 3 or by adjusting the orientation of the visual target locating unit associated with the power lock function, to bring the target 3 into the search field of view 56 of the visual target locating unit.

[0258] As an example, the visual target localization unit may comprise a light source, in particular an LED, configured to radiate a search beam in the direction of the aiming axis, wherein a reflection of at least a portion of the search beam at the cooperating target is visible to the position detection sensor as a target point. Alternatively or in addition, target localization may also be performed by radio signal based positioning, for example by using radio frequency telegraph transceiver (RFTT) modules referenced to the coordinate measuring device and the cooperating target, respectively (e.g. wherein the positions of the first RFTT anchor module and the second RFTT anchor module are referenced to a laser tracker, and the RFTT tag module is referenced to the cooperating target), such that a rough position of the cooperating target is determined based on radio frequency telegraph transmissions between the RFTT anchor module and the tag module.

[0259] According to this embodiment of the invention, laser tracker 100 includes an acoustic localization unit, such as an acoustic localization unit having at least two microphones for stereo localization, which is configured to detect and recognize an acoustic identification signal 57. For example, identification signal 57 may be a pass phrase or pass word specific to a particular laser tracker 100 or a particular group of laser trackers, such as "Hey, laser tracker!" for generally addressing laser trackers, or "Find me, laser tracker five!" for specifically addressing the fifth laser tracker in a group of laser trackers. Upon detecting and recognizing pass phrase 57, laser tracker 100 automatically determines the direction of origin of pass phrase 57 and automatically adjusts the alignment of the sighting axis to align the sighting axis to the determined direction of origin, i.e., provides a rough alignment to bring target 3 into the search field of view 56 of the visual target localization unit.

[0260] Additionally, the laser tracker may be configured to generate a visible light cone 58 indicative of the visual targeting unit's field of view 56. Thus, in addition to adjusting the orientation of the visual targeting unit, the worker holding the collaborative target 3 may also manually adjust the position of the collaborative target 3 to bring the collaborative target 3 within the visible light cone 58, for example, if the acoustic drive alignment is slightly off the collaborative target 3.

[0261] Fig.13 An embodiment of the metrology system of the invention is shown, in which a movement of the object to be measured is taken into account in the position measurement by the coordinate measuring device and the movable attachment device.

[0262] As an example, the system comprises a laser tracker 1 to determine the position of a handheld scanner 4 configured to perform laser-based measurements on an object to be measured 2. Based on the coordinate measurement data of the laser tracker 1 and the measurements of the movable accessory device (here the handheld scanner 4), the calculation unit 27 determines position data of the object to be measured 2, for example for comparison with specified manufacturing tolerances of the object 2, for example with CAD data of the object.

[0263] In addition, the system includes a reference device 59 configured to generate reference data about a reference point, wherein the reference data indicates a change in distance between the reference device 59 and the reference point. For example, the reference point may be a point on the object to be measured 2, such as a cooperative target mounted on the object to be measured. Alternatively, the reference point may be arranged away from the object to be measured 2, while the reference device 59 is arranged at the object to be measured, i.e. in a manner such that a change in distance between the reference device 59 and the reference point indicates movement of the object to be measured 2.

[0264] In other words, the reference device 59 , the reference point and the object to be measured 2 are arranged relative to each other, the reference device 59 being able to pick up movements of the object to be measured 2 , for example vibrations 61 of the object to be measured 2 , in at least one degree of freedom.

[0265] For example, the reference device 59 is embodied as a stereo scanner having two cameras 63 arranged spaced apart from each other, and a projector 64 configured to project a pattern 65 of structured radiation (e.g., a fringe or moiré projection pattern) onto the object 2. The stereo scanner is configured to determine a 3D model of the object 2 based on a stereophotogrammetry method and by utilizing the pattern 65 of structured radiation.

[0266] Thus, the measurement data of the stereo scanner can be provided to the computing unit 27 to compensate for any movement of the object 2 when determining the position data. For example, without reference data, natural vibrations of the object 2 or another unwanted movement of the object (e.g., unwanted movement caused by vibrations when a worker accidentally bumps into the object 2) will be ignored in the measurement of the movable attachment device.

[0267] As an alternative to a separate computing unit 27, it can also be part of a tracker or part of a reference device 59 which determines the position of the movable accessory device.

[0268] Fig.14 and Fig.15 A system is provided having a plurality of coordinate measuring devices (here in the form of laser trackers) which are configured for self-calibration, wherein each coordinate measuring device is configured to receive a measuring beam 8 of another coordinate measuring device so that coordinate measurement data in a set of coordinate measuring devices are measured based on relative distances between at least some of the plurality of coordinate measuring devices with reference to a common coordinate system.

[0269] like Fig.14As shown schematically, the first laser tracker 101A includes a cooperative target 3, such as a reflective unit with defined reflective properties (such as a steel ball of known size) or a retroreflective unit such as a cubic prism, so that it can be measured by the second laser tracker 101B. In addition, the second laser tracker 101B also includes a cooperative target 3, such as a cooperative target 3 measured by the first laser tracker 101A or another laser tracker in the plurality of laser trackers.

[0270] Each laser tracker of the system further has a target positioning unit, which is configured to locate a cooperative target 3, such as a cooperative target of another laser tracker, within the perimeter of the respective laser tracker, and to derive positioning data, which are configured to orient the tracker aiming axis towards the located cooperative target 3.

[0271] Thus, as an example, each laser tracker may be configured to automatically search its periphery to locate one or more cooperating targets 3 , and automatically generate local coordinate measurement data regarding the one or more located cooperating targets 3 .

[0272] The local coordinate measurement data of the different laser trackers 101A, 101B may then be exchanged between the laser trackers and / or provided to a central computing unit, such that the system is able to reference the local coordinate measurement data of at least a portion of the plurality of laser trackers to a common coordinate system.

[0273] As an example, in the case where a complex object is to be measured, more than one position of a laser tracker and / or multiple different laser trackers are needed. In order to combine data acquisition of multiple positions of a single tracker or from multiple trackers, the same point of interest (POI), typically more than three POIs, needs to be measured from all positions / by all trackers in order to calculate the transformation between different local coordinate systems.

[0274] As another example, automatic referencing to a common coordinate system may be performed upon system initialization, eg, where all laser trackers of the system are referenced to each other.

[0275] In another example, a group of laser trackers may be defined to perform a specific measurement task, wherein only the group of laser trackers is referenced to a common coordinate system. In particular, the system may be configured to monitor the group of laser trackers to automatically detect changes or problems within the group and automatically perform a new reference to the group.

[0276] For example, in the event that a laser tracker has to be serviced and therefore replaced by another laser tracker, the added replacement tracker automatically references the group coordinate system, e.g., where the replacement tracker measures a set of reference points and / or where a set of laser trackers in the plurality of trackers determines the relative distances between the set of laser trackers and the replacement tracker. Thus, the coordinate measurement data of the replacement laser tracker can be "integrated" into the common group coordinate system based on the triangulation or multilateration principle.

[0277] Fig.15 An embodiment is shown in which the referencing is done relative to a reference position provided by the position of one specific laser tracker 102 (hereinafter referred to as reference tracker) representing a fixed point in a common coordinate system. Three laser trackers 103A, 103B, 103C form a set of laser trackers foreseen for measuring an object 2 to be measured, for example in conjunction with a mobile articulated arm robot 5.

[0278] In this example, the reference tracker 102 and one of the laser trackers 103A in the set of laser trackers are embodied as fixed stations, i.e. having a fixed position within the metrology environment, wherein two of the laser trackers 103B, 103C in the set of laser trackers are embodied as movable laser trackers, such as movable laser trackers according to any embodiment of the movable laser tracker of the present invention. Furthermore, the reference tracker 102 is connected to the computing unit 27 and is configured to communicate with the individual laser trackers 103A, 103B, 103C in the set of laser trackers to forward the coordinate measurement data of the individual laser trackers in the set of laser trackers to the computing unit 27.

[0279] As an example, reference tracker 102 itself determines the position of one of movable group laser trackers 103B, which in turn determines position data relative to another movable group laser tracker 103C, which in turn determines position data relative to fixed group laser tracker 103A. In addition, fixed group laser tracker 103A provides position data relative to reference tracker 102.

[0280] Thus, computing unit 27 is then able to reference group laser trackers 103A, 103B, 103C relative to each other based on the knowledge that reference tracker 102 is a fixed point in a common coordinate system.

[0281] It goes without saying that the system may utilize additional position determination means, such as an inertial measurement unit or a GPS-based positioning system on the movable laser trackers 103B, 103C, to resolve ambiguities in an undetermined system or for simplifying and / or accelerating references. For example, instead of determining only the relative position, at least some of the plurality of laser trackers may be configured to additionally determine the pose, i.e., position and orientation, of another laser tracker.

[0282] Fig.16a and Fig.16b Embodiments of a laser tracker configured to provide video tracking of a person carrying a cooperative target 3 are contemplated, for example wherein in the tracking beam 9 ( Figure 1 ) is blocked or when a worker is stowing movable accessory equipment for repositioning.

[0283] As an example, in particular in the case of large objects to be measured, such as suspended aircraft parts in a production hall, a worker 49 carrying a movable attachment device with a cooperative target 3 may need to adopt different measurement positions, such as walking around the object to be measured. This may result in some interruptions of the tracking beam 9, such as when the tracking beam is blocked by the worker himself when he turns around.

[0284] Furthermore, many different workers may be working on the same object to be measured. If two workers cross each other, the tracking beam associated with the worker in the background is blocked by the person in front. In this case, the laser tracker can perform a power lock procedure to find a collaborative target and automatically relock the tracking beam to the collaborative target. However, since typical power lock procedures usually have a very narrow search field of view, it may happen that instead of relocking the tracking beam to the removable accessory device of the worker in the background, the tracking beam is mistakenly locked to the removable accessory device of the worker in front. In extreme cases, the laser tracker may not even notice this erroneous relock and therefore continue to track the wrong worker.

[0285] In many cases, the worker may also need to put away the accessory device to reposition, for example, to safely climb a ladder to reach the next scanning location. In this case, a camera can be used to track the worker's position as a rough position of the movable accessory device, such as by using a computer vision algorithm to detect and track the worker in the video stream generated by the camera, so that the tracking beam can be quickly re-locked onto the cooperative target of the movable accessory device once the worker reaches the next scanning location.

[0286] According to this embodiment of the laser tracker 104, the laser tracker 104 comprises a typical tracking unit, which is configured to (for example, based on the tracking beam 9 ( Figure 1))receive a tracking signal through a tracking channel, the tracking signal indicating a change in the angular position of the cooperative target 3, wherein the change in the angular position of the cooperative target 3 is determined based on the tracking signal, and control data for adjusting the alignment of an aiming axis (for example, defined by the tracking beam 9) is generated based on the determined change in the angular position.

[0287] In addition, the laser tracker 104 has a second tracking unit, which includes a camera configured to generate image data, wherein the second tracking unit is configured for video tracking of a target carrier, such as a shell or a supporting structure of the collaborative target 3, or a machine or person 49 carrying the collaborative target 3.

[0288] The second tracking mode uses a recognizer (e.g., based on a computer vision algorithm to detect and track objects in a video stream) for determining the position of a target carrier (e.g., a worker 49) within an image of the image data generated by the camera. In particular, identification marks indicating the appearance of the worker 49 imaged by the camera are determined by image processing, for example, wherein the recognizer is configured to identify the target carrier 49 based on predefined identification information.

[0289] For example, the predefined information may be stored on a local computing unit of the laser tracker 104, and / or the laser tracker 104 may be configured for bidirectional communication with a remote computing unit that has stored the predefined information. As an example, such predefined information includes at least one of: an identification mark for a type of target carrier, such as a specific shape of a machine type or a color of a worker's uniform; an identification mark for a specific target carrier, such as a mark that enables two machines of the same type or a worker in uniform to be distinguished; an identification code that specifies a specific type of target carrier; information indicating a spatial arrangement of the cooperating target relative to the target carrier; and position information of the target carrier, such as an absolute position of the target carrier provided by a GPS or radio frequency positioning system.

[0290] As another example, the laser tracker 104 is configured to train the identifier for a specific target carrier 49, wherein an identification mark indicative of the appearance of the target carrier 49 imaged by the image data is determined by image processing. For example, the training may be based on image data generated in a locked state, wherein the tracking channel is not disturbed, i.e., such that the tracking signal can be received without unplanned interruptions, and the aiming axis is continuously adjusted based on the control data so that it continuously follows the cooperating target.

[0291] Thus, continuous locking on to the cooperating target causes the target carrier to remain approximately at the same position in the image of the first image data, while the background and other untracked objects are moving. Thus, this knowledge about the rough position of the target carrier in the camera image and about the behavior of the target carrier when moving can be used to understand the visual appearance of the imaged target carrier, for example, from all sides of the carrier if the carrier is moving and turning.

[0292] In addition, the laser tracker 104 has a conventional visual target positioning unit, which utilizes a position detection sensor to locate the collaborative target 3 within the field of view of the position detection sensor, and is used to derive positioning data, which is configured to provide alignment of the tracking beam 9 (i.e., the aiming axis) of the conventional tracking unit relative to the collaborative target 3.

[0293] In addition, the laser tracker 104 is configured to support the conventional visual target positioning unit by video tracking, because the laser tracker 104 is configured to derive motion parameters indicating that the target carrier 49 is in motion based on the image data of the second tracking unit. Therefore, the visual target positioning unit can be activated based on the motion parameters to provide alignment of the aiming axis relative to the cooperative target 3.

[0294] For example, the laser tracker 104 may automatically notice that the worker has reached the next scanning position because the worker is now substantially stationary, at which point the laser tracker 104 automatically initiates a power lock procedure to re-lock the tracking beam 9 onto the collaborative target 3. In particular, the laser tracker 104 may also be configured to take into account the position of the target carrier determined by video tracking in conjunction with the known arrangement of the collaborative target 9 relative to the target carrier 49, so as to accelerate the power lock procedure by the visual target positioning unit. As an example, the laser tracker 104 is configured for video tracking of a human worker, and once the worker is stationary, the collaborative target 9 is expected to be approximately at chest height.

[0295] Therefore, if Fig.16a As shown, a worker 49 who may need to reposition (e.g., need to stow collaborative target 3 to safely reach the next location) addresses the laser tracker 104 to follow the worker via video tracking 105, wherein during video tracking, the worker 49 no longer has to pay attention to the collaborative target 3 being captured by the tracking beam 9.

[0296] As soon as he reaches the next measurement position, the laser tracker 104 recognizes that the worker 49 is stationary based on the knowledge of the worker's position determined by video tracking and based on the knowledge of the expected position of the collaborative target 9 (here at chest height of the worker 49) and automatically initiates the power lock procedure. Thus, despite the narrow search field of view 56 of the visual target location unit, the laser tracker 104 is able to quickly find the collaborative target 9 in order to relock the tracking beam 9 onto the collaborative target 9.

[0297] Fig.17 Schematically depicted is an embodiment which is configured to use a deflection unit to avoid blind spots for measuring an object, for example due to separate interfering objects or due to the object itself interfering with the laser measurement beam 8 of a laser-based coordinate measuring device, here exemplarily embodied as a laser tracker 210 with scanning functionality.

[0298] Here, the smart factory includes one or more deflection units 211, for example including a movable mirror, separate from the coordinate measuring device 210. In the example shown, the coordinate measuring device 210 and the deflection unit 211 are arranged in a fixed positional relationship relative to each other, wherein the system knows the relative position of the coordinate measuring device 210 and the deflection unit 211 relative to each other, the movement direction of the laser beam 8 relative to the coordinate measuring device 210, and the orientation of the movable mirror of the deflection unit 211. Therefore, the system is configured to generate scanning data providing the coordinates of the measurement point based on the known relative position and orientation, the coordinate measurement data provided by the coordinate measuring device, and the control data indicating the orientation of the deflection unit 210.

[0299] For example, when using a deflection unit 211, the laser measurement beam 8 is directed onto the deflection unit 211 and then kept fixed, for example at a so-called "geometric mirror center", so that the orientation parameters defining the overall aiming of the laser measurement beam 8 depend only on the deflection setting of the deflection unit 211.

[0300] For example, the reflector 211 is mounted at a two-axis electric rotation device (not shown) so that it can be quickly and accurately moved based on control commands from the coordinate measurement device 210. The precise reflector orientation can be detected by a high-resolution angle encoder, for example, where the encoder has a defined zero position. The deflection unit 211 can have an included CPU that can send and receive commands, for example, where the deflection unit 211 and the coordinate measurement device 210 are connected via an EtherCat real-time interface 212.

[0301] In the embodiment depicted by the figures, the coordinate measurement is based on so-called "stable beam pointing", in which the laser measuring beam 8 remains fixed at a fixed point relative to two rotation axes (the so-called "geometric mirror center"). In this mode, all beam movements are done only by the deflection unit 211, here by setting different orientations of the movable mirror.

[0302] For example, the deflection unit 211 and the coordinate measuring device 210 are configured and communicate with each other so that the reflector 211 provides the commonly known functions of the coordinate measuring device 210, such as an automatic target recognition function, for example, in which a find reflector command is established via a reflector sensor movement; a power lock function, in which a reflector is locked via a reflector movement; or a tracking function for tracking a reflector only by a reflector movement, for example, in which a movement command based on a position sensitive detector of the coordinate measuring device is sent to the deflection unit via a real-time interface. In addition, by providing a sufficient mirror diameter, the reflector 211 and the coordinate measuring device 210 can interact with each other to provide a typical 6DoF function of a coordinate measuring device, for example, in which a laser tracker has a 6DoF camera for detecting and analyzing marks on a 6DoF measuring probe via an image of the 6DoF measuring probe seen through the reflector.

[0303] For example, the reflector 211 may further include an arrangement of orientation marks (not shown), such as a set of at least three LEDs, the arrangement of orientation marks being mounted and arranged such that the orientation marks move together with the reflector. Thus, the coordinate measuring device 210 is configured to determine the reflector orientation by acquiring and analyzing an image of at least a portion of the arrangement including the orientation marks. The determined reflector orientation may then be used to provide control data indicating the orientation of the deflection unit 210 in order to derive the 6DoF orientation of the measuring probe, i.e. by further analyzing the image of the 6DoF measuring probe seen via the reflector.

[0304] As another example, the reflector 211 can be rotated to become a self-collimating reflector for detecting the coordinates of the reflector position. In particular, the reflector 211 has a set of reference marks 213, in particular at least three reference marks, arranged in a fixed relationship, so that the geometric center of the reflector can be detected, for example, by image analysis of an image of the reflector captured by the coordinate measuring device 210.

[0305] In particular, the smart factory may include multiple deflection units, wherein the system is configured such that different coordinate measuring devices can interact with the same deflection unit (not simultaneously), one coordinate measuring device can interact with multiple deflection units, or a coordinate measuring device can interact only with a dedicated deflection unit assigned to the coordinate measuring device.

[0306] Fig.18An embodiment of a metrology system is schematically depicted, in which image-based segmentation is used to identify a feature of interest 214 to be scanned by a scanning device 215 and automatically provide setting parameters of the scanning device 215 for scanning the feature of interest 214. The left part of the figure shows a test measurement in vehicle production as an exemplary application of the embodiment, wherein the right part shows an enlarged view of a captured image of a test component captured by a camera.

[0307] For example, the scanning device is a handheld scanning device as described above, wherein the image of the object 2 to be measured is provided by a conventional camera (not shown). Therefore, the system can utilize fast feature detection by segmentation algorithms known in the prior art, for example to detect edges, flat surfaces, textures and / or different colors of the object 2.

[0308] As an example, the provided setup parameters may indicate a perimeter boundary 216 for scanning a feature, which may be visualized substantially immediately in an image of the object. More specifically, the system may include a projector configured to project the boundary 216 directly onto the object. Furthermore, based on the identified feature of interest 214, optimal scanning settings of the scanning device 215 (e.g., defining optimal resolution conditions for scanning the feature) may be automatically preset, such that an operator of the scanning device 215 may begin scanning the feature substantially immediately.

[0309] As another example, the scanning device 215 can be part of an automated system configured to automatically measure a test object, for example, where the scanning device is mounted on a robotic arm. The system can then be configured to automatically preset the scanning device using the provided setup parameters and take the setup parameters into account, such as providing a perimeter boundary to which a local coordinate system of the robotic arm can be referenced for controlling the robotic arm to automatically scan the test object.

[0310] Although the present invention has been described above in part with reference to some preferred embodiments, it must be understood that many modifications and combinations of different features of the embodiments are possible. All these modifications are within the scope of the appended claims.

Claims

1. A metering system, comprising: A laser tracker, the laser tracker having: o an electro-optical rangefinder configured to emit a distance measuring beam in the direction of the sighting axis towards a cooperating target of the mobile accessory device and to provide distance measurement data based on at least a portion of the distance measuring beam returned from the cooperating target; an angle determination unit configured to provide angle determination data for determining a pointing direction of the sighting axis; as well as ○ A tracking unit, the tracking unit being configured to: □ receiving a tracking signal indicating a change in the angular position of the cooperating target via a tracking channel, □ determining a change in the angular position of the cooperating target based on the tracking signal, and □ generating control data for adjusting the alignment of the sighting axis based on the determined change in angular position; the removable accessory device being configured to scan or detect an object, and a calculation unit configured to generate coordinate measurement data of the object based on the distance measurement data, the angle determination data and the scanning and / or detection by means of the movable accessory device, It is characterized in that The system comprises a reference unit configured to generate reference data about a reference point associated with the object, the reference data providing a determination of a relative position change between the reference unit and the reference point independently of the optoelectronic rangefinder, wherein The reference unit and the reference point are intended to be arranged relative to the object so that the reference unit and The change in position between the reference points indicates movement of the object, and the calculation unit is configured to take into account the reference data to generate the coordinate measurement data, wherein the calculation unit is configured to generate the coordinate measurement data by at least one of the following: ignoring the distance measurement data of the photoelectric rangefinder and / or the angle determination data of the angle determination unit if the relative position change between the object and the reference unit exceeds an allowable threshold; and • Flagging the coordinate measurement data if the relative position between the object and the reference unit changes by more than a threshold value defined to ensure a desired measurement accuracy of the coordinate measurement data.

2. The system according to claim 1, It is characterized in that The reference point is embodied by a cooperating target mounted on the object or defined by a reference surface of the object.

3. The system according to claim 2, It is characterized in that The reference unit is embodied as a camera unit, which is configured to generate 3D data of the object based on imaging data.

4. The system according to claim 3, It is characterized in that The camera unit comprises: a projector configured to project a pattern of structured radiation onto the object, and A processor configured to determine a 3D model of the object based on a photogrammetric method and by utilizing the pattern of structured radiation.

5. The system according to any one of claims 1 to 4, It is characterized in that The reference unit is configured to detect movement of the object in at least one degree of freedom.

6. The system according to claim 5, It is characterized in that The reference unit is configured to detect vibration of the object.

7. The system according to claim 5, It is characterized in that The reference unit is configured to detect at least one of a roll change, a pitch change, and a yaw angle change of the object.

8. The system according to any one of claims 1 to 4, It is characterized in that The computing unit is configured to generate the coordinate measurement data further by compensating for a movement of the object determined based on the reference data.

9. The system according to any one of claims 1 to 4, It is characterized in that The removable accessory device is at least one of: a probing or scanning device configured to approach the object and perform at least one of tactile coordinate measurement, laser-based coordinate measurement, and camera-based coordinate measurement, a marking device, the marking device being configured to mark the object, Tools and / or manufacturing equipment, and Another coordinate measuring device.

10. The system according to claim 9, It is characterized in that The detection or scanning device is specifically implemented as a ranging imaging camera, a stereo imaging camera, an articulated arm robot or a white light sensor, and The other coordinate measuring device is embodied as a laser tracker.

11. A coordinate measuring device, the coordinate measuring device being configured to generate coordinate measurement data, the coordinate measuring device having: an electro-optical rangefinder configured to emit distance measuring radiation in the direction of the sighting axis, and providing distance measurement data based on at least a portion of said distance measuring radiation, an angle determination unit configured to provide angle determination data for determining a pointing direction of the sighting axis, and A tracking unit, the tracking unit being configured to: o receiving, via the tracking channel, a tracking signal indicative of a change in the angular position of the cooperating target, o determining a change in the angular position of the cooperating target based on the tracking signal, and o generating control data for adjusting the alignment of the sighting axis based on the determined change in angular position; a calculation unit configured to generate said coordinate measurement data of an object based on said distance measurement data and said angle determination data, It is characterized in that The coordinate measuring device comprises a reference unit configured to generate reference data about a reference point, the reference data providing for a determination of a relative position change between the reference unit and the reference point independently of the optoelectronic distance meter, wherein the reference unit is configured and arranged so that the reference data can reference the coordinate measurement data, and the computing unit is configured to take into account the reference data to generate the coordinate measurement data, wherein the computing unit is configured to generate the coordinate measurement data by at least one of the following: ignoring a change in the relative position between the object and the reference unit if it exceeds an allowed threshold; Ignore the distance measurement data of the photoelectric distance meter and / or the angle determination data of the angle determination unit; and The relative position between the object and the reference unit changes by more than the amount required to ensure that the coordinate measurement data The coordinate measurement data are marked according to a threshold value defined according to a desired measurement accuracy.

12. The coordinate measuring device according to claim 11, It is characterized in that The reference unit is embodied as a camera unit, which is configured to generate 3D data of the object based on imaging data.

13. The coordinate measuring device according to claim 12, It is characterized in that The camera unit comprises: a projector configured to project a pattern of structured radiation onto the object, and A processor configured to: The 3D model of the object is determined by the pattern of projections.

14. A coordinate measuring device according to any one of claims 11 to 13, It is characterized in that The reference unit is configured to detect movement of the object in at least one degree of freedom.

15. The coordinate measuring device according to claim 14, It is characterized in that The reference unit is configured to detect vibration of the object.

16. The coordinate measuring device according to claim 14, It is characterized in that The reference unit is configured to detect at least one of a roll change, a pitch change, and a yaw angle change of the object.

17. A coordinate measuring device according to any one of claims 11 to 13, It is characterized in that The tracking unit comprises a tracking sensor and is configured to generate a tracking beam by determining a deviation from a zero position on the tracking sensor and to receive the tracking signal based on the tracking beam returned from the cooperating target.

18. The coordinate measuring device according to claim 17, It is characterized in that The tracking sensor is embodied as a position sensitive detector PSD, wherein the PSD has a field of view corresponding to a beam diameter of the tracking beam.

Images