WO2019222255A1 - Computer aided inspection system and methods - Google Patents
Computer aided inspection system and methods Download PDFInfo
- Publication number
- WO2019222255A1 WO2019222255A1 PCT/US2019/032276 US2019032276W WO2019222255A1 WO 2019222255 A1 WO2019222255 A1 WO 2019222255A1 US 2019032276 W US2019032276 W US 2019032276W WO 2019222255 A1 WO2019222255 A1 WO 2019222255A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- sensor package
- model
- computer
- computer aided
- information
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING OR CALCULATING; COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
- G06T7/0004—Industrial image inspection
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/017—Head mounted
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/022—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness by means of tv-camera scanning
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/026—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness by measuring distance between sensor and object
-
- G—PHYSICS
- G06—COMPUTING OR CALCULATING; COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
- G06T7/0004—Industrial image inspection
- G06T7/001—Industrial image inspection using an image reference approach
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
- G02B2027/0138—Head-up displays characterised by optical features comprising image capture systems, e.g. camera
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0101—Head-up displays characterised by optical features
- G02B2027/014—Head-up displays characterised by optical features comprising information/image processing systems
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/0179—Display position adjusting means not related to the information to be displayed
- G02B2027/0187—Display position adjusting means not related to the information to be displayed slaved to motion of at least a part of the body of the user, e.g. head, eye
-
- G—PHYSICS
- G06—COMPUTING OR CALCULATING; COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/10—Image acquisition modality
- G06T2207/10028—Range image; Depth image; 3D point clouds
-
- G—PHYSICS
- G06—COMPUTING OR CALCULATING; COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/30—Subject of image; Context of image processing
- G06T2207/30181—Earth observation
- G06T2207/30184—Infrastructure
Definitions
- Embodiments of the present invention generally relate to computer aided inspection systems (CAIS) and methods and, more particularly, to methods and systems for using augmented reality and localization techniques to assist in performing fine level inspections and comparisons to 3D model of structures for applications such as surveying, inspection, maintenance and repair.
- CAIS computer aided inspection systems
- a computer aided inspection method for inspection, error analysis and comparison of structures may include determining real-world global localization information of a user in relation to a structure being inspected using information obtained from a first sensor package; using the determined global localization information to index into a corresponding location in a 3D computer model of the structure being inspected and extract the relevant parts of the model; aligning observations and/or information obtained from the first sensor package to the 3D computer model of the structure; and obtaining fine level measurements using a second sensor package to compare information obtained about the structure from the second sensor package to the 3D computer model of the structure.
- FIG. 1 depicts a high-level block diagram of a computer aided inspection system (CAIS) in accordance with embodiments of the present principles.
- CAIS computer aided inspection system
- FIG. 3 depicts at least one embodiment of a first global localization sensor package worn by a user in accordance with an embodiment of the present principles.
- FIG. 4 depicts at least one embodiment of a second fine level measurement handheld sensor and display package in accordance with an embodiment of the present principles.
- FIG. 5 depicts a functional block diagram of a handshaking process between a first sensor package and a second sensor package in accordance with an embodiment of the present principles.
- FIG. 6 depicts a flow diagram of a computer aided inspection method for inspection, error analysis and comparison of structures in accordance with a general embodiment of the present principles.
- FIG. 7 depicts a flow diagram of at least one other embodiment of a computer aided inspection method for inspection, error analysis and comparison of structures in accordance with a general embodiment of the present principles.
- Embodiments of the present principles generally relate to computer aided inspection systems (CAIS) and methods and, more particularly, to methods and systems for using augmented reality and localization techniques to assist in performing fine level inspections and comparisons to 3D model of structures for applications such as inspection, surveying, error detection and analysis, maintenance and repair.
- CAIS computer aided inspection systems
- augmented reality and localization techniques to assist in performing fine level inspections and comparisons to 3D model of structures for applications such as inspection, surveying, error detection and analysis, maintenance and repair.
- embodiments consistent with the present disclosure generally performs computer aided inspection by localizing user to within a local area (e.g. within 10 cm), using the localization to index to a corresponding position in a 3D computer model and extract the relevant parts of the model (for instance a CAD 3D representation such as a BIM model), match observations from sensors to model, and finally make fine level measurements (at mm scale) and comparisons to the 3D model.
- a local area e.g. within 10 cm
- a 3D computer model e.g. within 10 cm
- the relevant parts of the model for instance a CAD 3D representation such as a BIM model
- match observations from sensors to model e.g., a BIM model
- fine level measurements at mm scale
- FIG. 1 depicts a high-level block diagram of a computer aided inspection system (CAIS) 100 in accordance with embodiments of the present principles.
- the CAIS 100 includes a global localization system 102 and a local measurement system 114.
- Global localization performed by the GLS 102 works by acquiring and tracking image features using a first sensor package 104 and matching visual landmarks, tags, or location coordinates to a pre-built map of the area. Using information acquired by the first sensor package 104, the GLS 102 is able to track a user’s location across a worksite (e.g., a construction site, a ship or ship building yard, railroad tracks, etc.) to within 5-15 cm, or about 10 cm, in a global coordinate systems at 106 in Figure 1. The GLS 102 is then able to use the tracking information localize the user to within that same level of precision in a model coordinate system associated with the 3D computer model of the structure/site being inspected at 108 (i.e. , index into the model at a corresponding location).
- a worksite e.g., a construction site, a ship or ship building yard, railroad tracks, etc.
- visual tags e.g., QR type codes, or other easily identifiable objects placed in real-world locations over a worksite/construction area are used for precise model to map alignment and improved map-based tracking, navigation, and localization.
- Tags may be used to enhance SLAM framework to automatically generate a model-aligned map with minimal overhead and little to no user intervention.
- a few surveyed points available in the real world are used with attached model coordinates (i.e. , real world tags).
- model coordinates i.e. , real world tags.
- at least three non-linear points are used, and in one embodiment, those points are relatively spaced apart from each - the further the better. This is usually accomplished via a total station, an electro-optical instrument for precise distance measurements.
- all surveyed points are identified as tags and stored as 3D-2D tie-points.
- the SLAM framework can take advantage of un-surveyed tags in the environment all of which act as special landmarks that can be matched across wide baseline and across different scales.
- surveyed tags are used for global alignment of the two coordinate frames (i.e., the global and 3D model coordinate systems) and refinement of the map, as a byproduct of which, we also obtain the 3D corner coordinates of the un-surveyed tags.
- excluding a subset of surveyed tags and treating them as un-surveyed allows the SLAM system to obtain quantitative error numbers by comparing the estimated coordinates of these tags to the hidden but known ground truth tag corners (i.e., the surveyed tags with known locations).
- the GLS 102 is also able to mark and store a location identified by the user at 110, and associate a virtual note with the marked location (e.g., similar to an electronic version of a POST-IT note) at 112.
- a virtual note e.g., similar to an electronic version of a POST-IT note
- This allows users to create, retrieve, edit and delete notes (i.e. , text, images, audio messages, video message, etc.) at a specific 3D location in association with the 3D computer model of the structure, and overlay the note on the 3D computer model.
- Each marked location and associated note(s) is stored in a table. When a certain location in the model is encountered, the information is extracted from the table and displayed on the display (e.g., the helmet mounted display).
- a handshaking process is performed between elements of the GLS 102 and the LMS 114 to align information between the two systems as described below with respect to in Figure 5 in more detail.
- the first sensor package 104 including helmet mounted cameras, sensors, and AR display may handshake with the second sensor package 116 including a tablet to align a pose captured by the second sensor package with the pose captured by the first sensor package.
- the pose captured by the first or second sensor packages may be a six (6) degrees of freedom (6DOF) pose. This is achieved by sending a number of salient features (image feature descriptors and the corresponding 3D points) from the first sensor package 104 to the second sensor package 116 (left diagram in Figure 5).
- the tablet sub-system 116 performs a 3D-2D matching (right diagram in Figure 5) based on the features received (506 and 510) and the matched image features in the tablet image (508) to compute the 6DOF pose transformation (rotation and translation) between the tablet camera and the helmet camera. This transformation is then used to align the pose of the second sensor package with the pose of the first sensor package.
- This handshake procedure is initiated by the user (e.g., by pressing a button on the tablet or associated with the first sensor package) before recording a sequence for local inspection, to ensure that the second sensor poses are aligned to the global reference frame.
- the second sensor package 116 is configured to obtain fine level measurements (mm level measurements) and information about the structure
- the model recognition system 256 compare is configured to compare the fine level measurements and information obtained about the structure from the second sensor package to the 3D computer model of the structure.
- the model recognition system 256 is further configured to generate a compliance report including discrepancies determined between the measurements and information obtained about the structure from the second sensor package and the 3D computer model of the structure.
- the networks/cloud 220 comprise one or more communication systems that connect computers by wire, cable, fiber optic and/or wireless link facilitated by various types of well-known network elements, such as hubs, switches, routers, and the like.
- the networks 220 may include an Internet Protocol (IP) network or other packet-based communication networks, and may employ various well-known protocols to communicate information amongst the network resources.
- IP Internet Protocol
- User A devices i.e. , first sensor package 104A, and second sensor package 116A
- User B devices i.e., first sensor package 104B, and second sensor package 116B
- server 250 through WIFI, BLUETOOTFI, or any other wireless or wired communication protocols.
- Each second sensor package 116 may comprise a Central Processing Unit (CPU) 202, support circuits 204, display 206, memory 208, measurement module 216, model comparison module 218, and model information 214.
- CPU Central Processing Unit
- the server 250 may comprise a Central Processing Unit (CPU) 202, support circuits 204, display 206, memory 208, SLAM system 252, 3D alignment system 254, model recognition system 256, and model information 214.
- CPU Central Processing Unit
- the CPU 202 may comprise one or more commercially available microprocessors, microcontrollers, FPGA, etc. that facilitate data processing and storage.
- the various support circuits 204 facilitate the operation of the CPU 202 and include one or more clock circuits, power supplies, cache, input/output devices and circuits, and the like.
- the input/output devices of support circuits 204 may include audio input and output (e.g., commands or instructions for repairs where discrepancies are found).
- the display 206 may be an AR display as part of a helmet mounted display as shown and described with respect to Figure 3 for the GLS 102.
- the display 206 may be a hand held device display (e.g., a tablet) as part of the second sensor package 116 as shown and described with respect to Figure 4 for the LMS 114.
- the memory 208 comprises at least one of Read Only Memory (ROM), Random Access Memory (RAM), disk drive storage, optical storage, removable storage and/or the like.
- user A may be using a first sensor package 104A as part of GLS 102A to track and geolocate their position across a worksite (e.g., a construction site, a ship or ship building yard, railroad tracks, etc.) to within 5-15 cm, or about 10 cm, in a global coordinate system using a first sensor package 104 (e.g., body worn equipment as shown in Figure 3).
- the information obtained from the first sensor package 104 is used by the geolocation tracking module 210 and SLAM system 252 to globally localize the user.
- the geolocation tracking module 210 may itself include a SLAM system 252 as described above to globally localize the user.
- the geolocation tracking module 210 may communicate with SLAM system 252 on server 250 which will perform the localization calculations/determination and provide that information back to first sensor package 104.
- the user may mark and store a location (i.e. , coordinates) identified by the user, and associate a virtual note with the marked location (e.g., similar to an electronic version of a POST-IT note) using virtual marking module 212.
- a location i.e. , coordinates
- virtual marking module 212 This allows users to create, retrieve, edit and delete notes (i.e., text, images, audio messages, video message, etc.) at a specific 3D location in association with the 3D computer model of the structure, and overlay the note on the 3D computer model.
- Each marked location and associated note(s) is stored in a table.
- the information is extracted from the table and displayed on the display (e.g., the helmet mounted display). Locations marked by User A and associated virtual notes may be seen by User B via User’s B’s display 206. In some embodiments, User A and User B may be able to see what each other sees and/or communicate with each other audibly or visually, while walking around the site/structure.
- the user may initiate local inspection and measurement of a local area of the structure.
- the user may select an object or press a button on the first sensor package 104 or second sensor package 116 to initiate the handshaking process described above with respect to Figure 5 to align a pose captured by the second sensor package with a pose captured by the first sensor package.
- This alignment may be performed by the 3D model alignment module 254 of server 250 or local on the second sensor package 116.
- local measurements may be performed by measurement module 216 and/or model recognition system 256. The measured information is then compared to the model information and discrepancies are determined.
- At least some of the advantages provided by the embodiments disclosed herein and shown in Figures 1 , 2A and 2B include: obtaining relative measurements of structures, and portions thereof, without 3D computer models of the structure (e.g., without a BIM), and measure distances in a 3m x 3m area with mm precision (118, 120); performing visual inspections by displaying 3D computer models of the structure (e.g., a BIM) overlaid on the video/display image (122, 124); performing local inspections to determine structural information such as, but not limited to, number of structural support elements, diameter/thickness of the support elements, pitch between each support element, and tensile markings within a 0.1 meter - 10 meter section with or without a 3D computer models of the structure to check against (126, 128); performing worksite localization to localize the user within 5 - 15 cm across the building construction site or within a large structure such as a ship, for example, relative to markers laid out throughout the site
- Figure 6 depicts a flow diagram of a computer aided inspection method 600 for inspection, error analysis and comparison of structures in accordance with a general embodiment of the present principles.
- the method 600 starts at 602 and proceeds to 604 where real-world global localization information is determined for a user in relation to a structure being inspected using information obtained from a first sensor package.
- the determined global localization information is used to index into a corresponding location in a 3D computer model of the structure being inspected and extract the relevant parts of the model.
- the method proceeds to 608 where observations and/or information obtained from the first sensor package are aligned to the 3D computer model of the structure.
- fine level measurements are obtained using a second sensor package to compare information obtained about the structure from the second sensor package to the 3D computer model of the structure.
- the method proceeds to 612 where discrepancies between the measurements and information obtained about the structure from the second sensor package and the 3D computer model of the structure are determined and compiled, and a compliance report is generated including those discrepancies or information/summary about the discrepancies.
- the discrepancies determined between the measurements and information obtained about the structure and the 3D computer model of the structure may include differences in the number of structural support elements measured versus the number of structural support elements in the model, differences in the diameter/thickness of the support elements, pitch between each support element, tensile markings on various support elements, angles of railroad tracks and/or support elements, etc.
- the compliance report may include, for example, what was measured and where the discrepancies are.
- the measured data is compared to the model data, and values that exceed a predetermined threshold (e.g., 0.1 - 25% of expected value) may be flagged as a discrepancy and included in the compliance report.
- the element in error would be repaired/corrected and re-inspected. For example, if a crack is found in a structural element, all work associated with that element will stop until it is corrected. In other examples, the as long as the pitch or gage is within a certain tolerance (i.e. , predefined threshold), it may be considered acceptable and work may proceed.
- the discrepancies may be visually detected by displaying 3D computer models of the structure (e.g., a BIM) overlaid on the video/display image (122, 124). The user can mark those areas of discrepancies with virtual notes as described above (110,112). The method ends at 614.
- FIG. 7 depicts a flow diagram of a computer aided inspection method 700 for inspection, error analysis and comparison of structures in accordance with a general embodiment of the present principles.
- the method 700 starts at 702 and proceeds to 704 where a 3D computer model of a structure is received from a first sensor package.
- a 3D point cloud representation of the structure is generated using fine level measurements and information about the structure obtained from high-resolution sensors configured to obtain mm level measurements.
- the method proceeds to 708 where objects of interest and detected in the 3d point cloud representation of the structure, and at 710, measurements and information of said objects of interest are obtained using the high-resolution sensors.
- the 3d point cloud representation of the structure is aligned to the 3D computer model received.
- detecting the discrepancies further includes generating a compliance report including the discrepancies determined.
- the method ends at 716.
- the systems described herein integrate two key capabilities, a GLS 102 to perform global localization and alignment, and an LMS 114 to perform fine measurements and error detection.
- the first capability enables the users to walk around a large worksite and locate themselves within the site at an accuracy of about 10 centimeters and overlay AR icons on the wearable display. Doing localization to 10 cm precision, will also enable the system to automatically match the model to the high-precision tablet video without user intervention.
- the second capability enables the users to make high-precision and high-accuracy measurements (millimeter level).
- accuracy refers to the closeness of a measured value to a standard or known value while precision refers to the closeness of two or more measurements to each other.
- precision means that if you measure something 10 times, the measurement is always consistent (i.e. , it is always the same even if it is wrong). Meanwhile, accuracy refers to the right measurement. Therefore, high-precision and high-accuracy measurements refers to both consistent and accurate measurements to the millimeter level.
- a tablet with an attached stereo sensor head for making the 1 mm precision measurements with a high- resolution video display screen is used for local measurements (as part of LMS 114 - i.e., the second sensor package), and an independent head-mounted optical-see- through display for localizing the user to 5 cm to about 15 cm accuracy, or about 10 cm accuracy and providing augmented reality overlays to the user anywhere on the worksite (as part of GLS 102 - i.e., the first sensor package).
- discrepancies determined between the measurements and information obtained about the structure obtained from the second sensor package, and the 3D computer model of the structure may include differences in the number of structural support elements measured versus the number of structural support elements in the model, differences in the diameter/thickness of the support elements, pitch between each support element, tensile markings on various support elements, angles of railroad tracks and/or support elements, etc.
- the CAIS is used for inspection of rail tracks.
- Rail tracks need to be inspected monthly to assess for deviations as small as 1/16 of an inch from the prescribed values.
- the current inspection procedure is completely manual, labor intensive and exclusively relies on human observation and measurements.
- Figures 8A-8E a system for automating the track inspection is achieved as shown in Figures 8A-8E Specifically, as shown in Figure 8A, a video-based 3D recovery and measurement system for automated rail inspection is depicted.
- an operator records video along the track with the data capture system using a fine level sensor package (e.g., such as the second sensor package 116 described above), following the guidance displayed on the screen.
- a 3D model of the track is generated from the collected video and used for generating the measurements required and determining if any regions are non-compliant with specifications (e.g., requirements/specifications defined in the Track and Rail and Infrastructure Integrity Compliance Manual).
- non-compliant items may include center-cracked or broken joint bars, number of center-cracked or broken joint bars, multiple defective conditions occurring at the same location (e.g., joint tie defect with a center-cracked bar, a geometry defect with defective ties, etc.), “breakout in rail heads”, missing nails, track defects caused by improper repairs (installation of a joint bar that is not of a structurally sound design and dimension for the rail on which it is applied, or failure to drill holes in rail ends not complying with TSS), defective turnout ties or poor support causing a spring rail frog to have excessive clearance between the hold-down housing and the horn(s), gouging or contact by the outside of the wheels against the gage side of the wing rail, excessively chipped or worn switch points that are so chipped or worn as to present a significant derailment hazard.
- joint tie defect with a center-cracked bar e.g., a geometry defect with defective ties, etc.
- breakout in rail heads missing nails
- FIG. 8B A system diagram for the proposed approach is presented in Figure 8B.
- data collection (802) by the fine level sensor package 116 for this use case may consist of a sensor head and 12-inch tablet PC that runs the data collection application and provides the user interface through its touch screen display.
- the sensors will be powered from a battery that can be carried in a backpack or on a belt.
- the sensor head has a stereo pair of high-definition cameras (e.g., 1920 x 1200 pixels) with a 25-cm baseline and 50 degrees horizontal Field of View lenses as well as a GPS/IMU unit.
- the 3D recovery module 804 generates a dense 3D point cloud from a sequence of images with multiple views of the same area on the ground obtained by the sensor package 116.
- the 3D recovery module 804 first runs Visual Navigation on the input video sequence to obtain initial pose estimates for each image. Based on these poses a subset of images (key-frames) is selected for 3D recovery.
- feature tracks are generated across multiple frames and then Bundle Adjustment is run to refine the camera poses, and 3D point locations corresponding to each feature track.
- the Bundle Adjustment step uses the fact that the relative motion between the left and right camera is constant over time and it is known from calibration to fix the scale of the 3D reconstruction.
- the 3D point clouds from each stereo pair are aggregated to generate a dense point cloud for the inspected area.
- the 3D model 214 is provided as input to the Visualization and Measurement tool 806.
- the first step is the automatic detection of the rails based on their known 3D profile.
- several measurements are performed to determine regions that are not compliant and included in a compliance report 810.
- gage distance between tracks
- the following steps are performed: align the local point cloud so that the main track direction is aligned with the Y axis; divide the rail points in chunks along the track (e.g. one foot long) and fit a plane through the classified rail points; use the point distribution along the X axis to fit the local tangent to each rail and measure distance between the center point of each segment; and repeat for every section along the track to generate a list of measurements.
- the system would globally localize the user in the ship using the GLS 102 by acquiring and tracking image features using a first sensor package 104 and matching visual landmarks, tags, or location coordinates to a pre-built map of the ship. Using information acquired by the first sensor package 104, the GLS 102 is able to track a user’s location across a ship to within 5-15 cm, or about 10 cm, in a global coordinate systems at 106 in Figure 1.
- the system would then index in the appropriate portion of a model of the ship based on the user’s location, and assist the user in repair, maintenance by overlaying instructions and providing audio cues on what to do next.
- any component from the CAD model can be presented as an Augmented Reality overlay in the display (tablet or optically see through HMD).
- This functionality enables quick visual inspection of constructed elements, e.g. verifying that the location of air ducts, pipes, beams, etc. matches the model/plan, as well as visualizing the location of elements not yet constructed.
- CAIS system 100 can also be used for training and guidance for emergency situations, e.g., switching off a furnace in a factory, which must be done in a certain sequence of steps executed over a large area.
- the inventive system would guide the user through safety and emergency response procedures with visual (AR) and vocal instructions.
- the user can ask questions and interactively diagnose problems.
- the system would display overlaid animations with directions on an HMD worn or tablet/ smartphone carried by user.
- the system may further automatically observe user actions and provide warnings and feedback
- Figure 9 depicts a computer system 900 that can be utilized in various embodiments of the present invention to implement the computer and/or the display, according to one or more embodiments.
- FIG. 9 Various embodiments of method and apparatus using augmented reality and localization techniques to assist in performing fine level inspections and comparisons to 3D model of structures for applications such as surveying, inspection, maintenance and repair, as described herein, may be executed on one or more computer systems, which may interact with various other devices.
- One such computer system is computer system 900 illustrated by Figure 9, which may in various embodiments implement any of the elements or functionality illustrated in Figures 1-8B.
- computer system 900 may be configured to implement methods described above.
- the computer system 900 may be used to implement any other system, device, element, functionality or method of the above- described embodiments.
- computer system 900 may be configured to implement the methods 600 and 700 as processor-executable executable program instructions 922 (e.g., program instructions executable by processor(s) 910) in various embodiments.
- computer system 900 includes one or more processors 910a-910n coupled to a system memory 920 via an input/output (I/O) interface 930.
- Computer system 900 further includes a network interface 940 coupled to I/O interface 930, and one or more input/output devices 950, such as cursor control device 960, keyboard 970, and display(s) 980.
- I/O input/output
- any of the components may be utilized by the system to receive user input described above.
- a user interface may be generated and displayed on display 980.
- embodiments may be implemented using a single instance of computer system 900, while in other embodiments multiple such systems, or multiple nodes making up computer system 900, may be configured to host different portions or instances of various embodiments.
- some elements may be implemented via one or more nodes of computer system 900 that are distinct from those nodes implementing other elements.
- multiple nodes may implement computer system 900 in a distributed manner.
- computer system 900 may be any of various types of devices, including, but not limited to, a personal computer system, desktop computer, laptop, notebook, tablet or netbook computer, mainframe computer system, handheld computer, workstation, network computer, a camera, a set top box, a mobile device, a consumer device, video game console, handheld video game device, application server, storage device, a peripheral device such as a switch, modem, router, or in general any type of computing or electronic device.
- computer system 900 may be a uniprocessor system including one processor 910, or a multiprocessor system including several processors 910 (e.g., two, four, eight, or another suitable number).
- Processors 910 may be any suitable processor capable of executing instructions.
- processors 910 may be general-purpose or embedded processors implementing any of a variety of instruction set architectures (ISAs). In multiprocessor systems, each of processors 910 may commonly, but not necessarily, implement the same ISA.
- System memory 920 may be configured to store program instructions 922 and/or data 932 accessible by processor 910.
- system memory 920 may be implemented using any suitable memory technology, such as static random-access memory (SRAM), synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory, or any other type of memory.
- SRAM static random-access memory
- SDRAM synchronous dynamic RAM
- program instructions and data implementing any of the elements of the embodiments described above may be stored within system memory 920.
- program instructions and/or data may be received, sent or stored upon different types of computer-accessible media or on similar media separate from system memory 920 or computer system 900.
- I/O interface 930 may be configured to coordinate I/O traffic between processor 910, system memory 920, and any peripheral devices in the device, including network interface 940 or other peripheral interfaces, such as input/output devices 950.
- I/O interface 930 may perform any necessary protocol, timing or other data transformations to convert data signals from one component (e.g., system memory 920) into a format suitable for use by another component (e.g., processor 910).
- I/O interface 930 may include support for devices attached through various types of peripheral buses, such as a variant of the Peripheral Component Interconnect (PCI) bus standard or the Universal Serial Bus (USB) standard, for example.
- PCI Peripheral Component Interconnect
- USB Universal Serial Bus
- I/O interface 930 may be split into two or more separate components, such as a north bridge and a south bridge, for example. Also, in some embodiments some or all of the functionality of I/O interface 930, such as an interface to system memory 920, may be incorporated directly into processor 910.
- Network interface 940 may be configured to allow data to be exchanged between computer system 900 and other devices attached to a network (e.g., network 990), such as one or more external systems or between nodes of computer system 900.
- network 990 may include one or more networks including but not limited to Local Area Networks (LANs) (e.g., an Ethernet or corporate network), Wide Area Networks (WANs) (e.g., the Internet), wireless data networks, some other electronic data network, or some combination thereof.
- LANs Local Area Networks
- WANs Wide Area Networks
- wireless data networks some other electronic data network, or some combination thereof.
- network interface 940 may support communication via wired or wireless general data networks, such as any suitable type of Ethernet network, for example; via digital fiber communications networks; via storage area networks such as Fiber Channel SANs, or via any other suitable type of network and/or protocol.
- general data networks such as any suitable type of Ethernet network, for example; via digital fiber communications networks; via storage area networks such as Fiber Channel SANs, or via any other suitable type of network and/or protocol.
- Input/output devices 950 may, in some embodiments, include one or more display terminals, keyboards, keypads, touchpads, scanning devices, voice or optical recognition devices, or any other devices suitable for entering or accessing data by one or more computer systems 900. Multiple input/output devices 950 may be present in computer system 900 or may be distributed on various nodes of computer system 900. In some embodiments, similar input/output devices may be separate from computer system 900 and may interact with one or more nodes of computer system 900 through a wired or wireless connection, such as over network interface 940.
- the illustrated computer system may implement any of the operations and methods described above, such as the methods illustrated by the flowcharts of Figures 6 and 7. In other embodiments, different elements and data may be included.
- computer system 900 is merely illustrative and is not intended to limit the scope of embodiments.
- the computer system and devices may include any combination of hardware or software that can perform the indicated functions of various embodiments, including computers, network devices, Internet appliances, PDAs, wireless phones, pagers, and the like.
- Computer system 900 may also be connected to other devices that are not illustrated, or instead may operate as a stand-alone system.
- the functionality provided by the illustrated components may in some embodiments be combined in fewer components or distributed in additional components.
- the functionality of some of the illustrated components may not be provided and/or other additional functionality may be available.
- instructions stored on a computer-accessible medium separate from computer system 900 may be transmitted to computer system 900 via transmission media or signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as a network and/or a wireless link.
- Various embodiments may further include receiving, sending or storing instructions and/or data implemented in accordance with the foregoing description upon a computer-accessible medium or via a communication medium.
- a computer-accessible medium may include a storage medium or memory medium such as magnetic or optical media, e.g., disk or DVD/CD-ROM, volatile or non-volatile media such as RAM (e.g., SDRAM, DDR, RDRAM, SRAM, and the like), ROM, and the like.
- references in the specification to“an embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is believed to be within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly indicated.
- Embodiments in accordance with the disclosure may be implemented in hardware, firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored using one or more machine-readable media, which may be read and executed by one or more processors.
- a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device or a“virtual machine” running on one or more computing devices).
- a machine-readable medium may include any suitable form of volatile or non-volatile memory.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Optics & Photonics (AREA)
- Quality & Reliability (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Theoretical Computer Science (AREA)
- Processing Or Creating Images (AREA)
- Length Measuring Devices With Unspecified Measuring Means (AREA)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020520008A JP7327872B2 (ja) | 2018-05-14 | 2019-05-14 | コンピュータによる検査システム及び方法 |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201862670985P | 2018-05-14 | 2018-05-14 | |
| US62/670,985 | 2018-05-14 | ||
| US16/412,067 | 2019-05-14 | ||
| US16/412,067 US11270426B2 (en) | 2018-05-14 | 2019-05-14 | Computer aided inspection system and methods |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2019222255A1 true WO2019222255A1 (en) | 2019-11-21 |
Family
ID=68464932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/US2019/032276 Ceased WO2019222255A1 (en) | 2018-05-14 | 2019-05-14 | Computer aided inspection system and methods |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US11270426B2 (https=) |
| JP (1) | JP7327872B2 (https=) |
| WO (1) | WO2019222255A1 (https=) |
Families Citing this family (28)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2553148A (en) * | 2016-08-26 | 2018-02-28 | Nctech Ltd | Modelling system and method |
| JP6911914B2 (ja) * | 2017-02-28 | 2021-07-28 | 日本電気株式会社 | 点検支援装置、点検支援方法およびプログラム |
| US20210201273A1 (en) * | 2018-08-14 | 2021-07-01 | Carrier Corporation | Ductwork and fire suppression system visualization |
| US11349843B2 (en) * | 2018-10-05 | 2022-05-31 | Edutechnologic, Llc | Systems, methods and apparatuses for integrating a service application within an existing application |
| US20220292173A1 (en) * | 2018-10-05 | 2022-09-15 | Edutechnologic, Llc | Systems, Methods and Apparatuses For Integrating A Service Application Within An Existing Application |
| DE102019201490A1 (de) * | 2019-02-06 | 2020-08-06 | Robert Bosch Gmbh | Kalibriereinrichtung für eine Überwachungsvorrichtung, Überwachungsvorrichtung zur Man-Overboard-Überwachung sowie Verfahren zur Kalibrierung |
| JP6748793B1 (ja) * | 2019-03-22 | 2020-09-02 | Sppテクノロジーズ株式会社 | 保守支援システム、保守支援方法、プログラム及び加工画像の生成方法 |
| CN110956032B (zh) * | 2019-12-04 | 2023-06-27 | 广联达科技股份有限公司 | 模型与模型的对量方法、装置、存储介质、电子设备 |
| US11481857B2 (en) | 2019-12-23 | 2022-10-25 | Shopify Inc. | Methods and systems for generating a product packaging model |
| US11042953B1 (en) * | 2019-12-23 | 2021-06-22 | Shopify Inc. | Methods and systems for detecting errors in kit assembly |
| US11557046B2 (en) | 2020-09-30 | 2023-01-17 | Argyle Inc. | Single-moment alignment of imprecise overlapping digital spatial datasets, maximizing local precision |
| EP4229395A4 (en) * | 2020-10-14 | 2025-02-19 | AMEC Foster Wheeler USA Corporation | METHOD AND SYSTEM FOR MEASURING THE DEFORMATION OF A COKE DRUM |
| US12163786B2 (en) | 2020-12-01 | 2024-12-10 | Clearedge3D, Inc. | Construction verification system, method and computer program product |
| WO2022167097A1 (en) * | 2021-02-08 | 2022-08-11 | Abb Schweiz Ag | Human-robot collaborative navigation |
| US12288249B2 (en) | 2021-05-31 | 2025-04-29 | Shopify Inc. | Systems and methods for generating three-dimensional models corresponding to product bundles |
| KR102603276B1 (ko) * | 2021-06-21 | 2023-11-17 | 정재헌 | Xr 기반의 감리 보조 장치, 방법 및 프로그램 |
| KR20220169825A (ko) * | 2021-06-21 | 2022-12-28 | 정재헌 | Bim 설계 데이터 내 설비 라인을 자동으로 설계하는 장치, 방법 및 프로그램 |
| US12308892B2 (en) * | 2021-08-23 | 2025-05-20 | Verizon Patent And Licensing Inc. | Methods and systems for location-based audio messaging |
| GB2613155B (en) | 2021-11-24 | 2026-03-04 | Xyz Reality Ltd | Matching a building information model |
| JP7200422B1 (ja) | 2022-04-28 | 2023-01-06 | 株式会社 商船三井 | プログラム、システム及び情報処理装置 |
| US11900490B1 (en) * | 2022-09-09 | 2024-02-13 | Morgan Stanley Services Group Inc. | Mobile app, with augmented reality, for checking ordinance compliance for new and existing building structures |
| KR102701335B1 (ko) * | 2023-01-18 | 2024-08-30 | 정재헌 | Xr 기반으로 시공 정밀도를 향상시키는 확장현실 장치, 방법 및 프로그램 |
| CN116679449B (zh) * | 2023-05-25 | 2025-11-25 | 歌尔股份有限公司 | 一种眼罩及头戴显示设备 |
| US12413436B2 (en) * | 2023-07-28 | 2025-09-09 | Cisco Technology, Inc. | Collaboration and cognitive analysis for hybrid work visual aid sessions |
| US20250348540A1 (en) * | 2024-05-10 | 2025-11-13 | Insightful Mechanisms LLC | Montaging System |
| US20250349323A1 (en) * | 2024-05-10 | 2025-11-13 | Insightful Mechanisms LLC | Data Capture System |
| CN120495536B (zh) * | 2025-07-16 | 2025-09-16 | 中国建筑第五工程局有限公司 | 一种多模态紧耦合slam的砖混建筑结构快速体检方法 |
| CN120970630A (zh) * | 2025-08-13 | 2025-11-18 | 兰笺(苏州)科技有限公司 | 基于slam的施工过程巡检轨迹生成方法及装置 |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101583723B1 (ko) * | 2015-01-16 | 2016-01-08 | 단국대학교 산학협력단 | Bim 디지털 모델과 건설 현장의 양방향 동기화 시스템 |
| JP2017020972A (ja) * | 2015-07-14 | 2017-01-26 | 東急建設株式会社 | 三次元形状計測装置、三次元形状計測方法、及びプログラム |
| JP2017204222A (ja) * | 2016-05-13 | 2017-11-16 | 株式会社トプコン | 管理装置、管理方法および管理用プログラム |
Family Cites Families (32)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2980195B2 (ja) | 1996-01-10 | 1999-11-22 | 鹿島建設株式会社 | 鉄筋径の計測方法及び装置 |
| US6922599B2 (en) * | 2001-08-13 | 2005-07-26 | The Boeing Company | System and method for producing an assembly by directly implementing three-dimensional computer-aided design component definitions |
| US7965886B2 (en) | 2006-06-13 | 2011-06-21 | Sri International | System and method for detection of multi-view/multi-pose objects |
| CA2787646C (en) * | 2010-02-05 | 2016-12-13 | Trimble Navigation Limited | Systems and methods for processing mapping and modeling data |
| US9031809B1 (en) | 2010-07-14 | 2015-05-12 | Sri International | Method and apparatus for generating three-dimensional pose using multi-modal sensor fusion |
| JP5784818B2 (ja) * | 2011-03-29 | 2015-09-24 | クアルコム,インコーポレイテッド | 拡張現実システムにおける実世界表面への仮想画像のアンカリング |
| US8761439B1 (en) | 2011-08-24 | 2014-06-24 | Sri International | Method and apparatus for generating three-dimensional pose using monocular visual sensor and inertial measurement unit |
| US9222771B2 (en) * | 2011-10-17 | 2015-12-29 | Kla-Tencor Corp. | Acquisition of information for a construction site |
| WO2013141922A2 (en) * | 2011-12-20 | 2013-09-26 | Sadar 3D, Inc. | Systems, apparatus, and methods for data acquisiton and imaging |
| JP6236199B2 (ja) * | 2012-06-18 | 2017-11-22 | 株式会社大林組 | 配筋検査システム |
| US9488492B2 (en) | 2014-03-18 | 2016-11-08 | Sri International | Real-time system for multi-modal 3D geospatial mapping, object recognition, scene annotation and analytics |
| US9285296B2 (en) * | 2013-01-02 | 2016-03-15 | The Boeing Company | Systems and methods for stand-off inspection of aircraft structures |
| CN105144238B (zh) * | 2013-02-25 | 2018-11-02 | 联邦科学和工业研究组织 | 3d成像方法和系统 |
| JP6083091B2 (ja) | 2013-06-18 | 2017-02-22 | 株式会社竹中工務店 | 鉄筋検査支援装置およびプログラム |
| EP2916189B1 (en) * | 2014-03-06 | 2019-05-08 | Hexagon Technology Center GmbH | Quality assured manufacturing |
| CN107111641B (zh) * | 2014-10-27 | 2021-08-13 | 华为技术有限公司 | 用于更新定位数据的数据库的定位估计 |
| US10043319B2 (en) * | 2014-11-16 | 2018-08-07 | Eonite Perception Inc. | Optimizing head mounted displays for augmented reality |
| US10504218B2 (en) * | 2015-04-21 | 2019-12-10 | United Technologies Corporation | Method and system for automated inspection utilizing a multi-modal database |
| US9761015B2 (en) * | 2015-04-28 | 2017-09-12 | Mitsubishi Electric Research Laboratories, Inc. | Method for determining dimensions in an indoor scene from a single depth image |
| EP3182065A1 (de) * | 2015-12-14 | 2017-06-21 | Leica Geosystems AG | Handhaltbares entfernungsmessgerät und verfahren zum erfassen relativer positionen |
| WO2017127711A1 (en) * | 2016-01-20 | 2017-07-27 | Ez3D, Llc | System and method for structural inspection and construction estimation using an unmanned aerial vehicle |
| JP2017151026A (ja) | 2016-02-26 | 2017-08-31 | 東急建設株式会社 | 三次元情報取得装置、三次元情報取得方法、及びプログラム |
| US10989542B2 (en) * | 2016-03-11 | 2021-04-27 | Kaarta, Inc. | Aligning measured signal data with slam localization data and uses thereof |
| US10191486B2 (en) * | 2016-03-28 | 2019-01-29 | Aveopt, Inc. | Unmanned surveyor |
| JP2018010599A (ja) * | 2016-07-15 | 2018-01-18 | 富士通株式会社 | 情報処理装置、パノラマ画像表示方法、パノラマ画像表示プログラム |
| EP4398566A3 (en) * | 2016-08-11 | 2024-10-09 | Magic Leap, Inc. | Automatic placement of a virtual object in a three-dimensional space |
| US20180082414A1 (en) | 2016-09-21 | 2018-03-22 | Astralink Ltd. | Methods Circuits Assemblies Devices Systems Platforms and Functionally Associated Machine Executable Code for Computer Vision Assisted Construction Site Inspection |
| JP6911914B2 (ja) * | 2017-02-28 | 2021-07-28 | 日本電気株式会社 | 点検支援装置、点検支援方法およびプログラム |
| US10948285B2 (en) * | 2017-07-28 | 2021-03-16 | Faro Technologies, Inc. | Three-dimensional measurement device mobile geometry verification |
| US11042146B2 (en) * | 2017-11-17 | 2021-06-22 | Kodak Alaris Inc. | Automated 360-degree dense point object inspection |
| US10713840B2 (en) * | 2017-12-22 | 2020-07-14 | Sony Interactive Entertainment Inc. | Space capture, modeling, and texture reconstruction through dynamic camera positioning and lighting using a mobile robot |
| US11288412B2 (en) * | 2018-04-18 | 2022-03-29 | The Board Of Trustees Of The University Of Illinois | Computation of point clouds and joint display of point clouds and building information models with project schedules for monitoring construction progress, productivity, and risk for delays |
-
2019
- 2019-05-14 US US16/412,067 patent/US11270426B2/en active Active
- 2019-05-14 WO PCT/US2019/032276 patent/WO2019222255A1/en not_active Ceased
- 2019-05-14 JP JP2020520008A patent/JP7327872B2/ja active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101583723B1 (ko) * | 2015-01-16 | 2016-01-08 | 단국대학교 산학협력단 | Bim 디지털 모델과 건설 현장의 양방향 동기화 시스템 |
| JP2017020972A (ja) * | 2015-07-14 | 2017-01-26 | 東急建設株式会社 | 三次元形状計測装置、三次元形状計測方法、及びプログラム |
| JP2017204222A (ja) * | 2016-05-13 | 2017-11-16 | 株式会社トプコン | 管理装置、管理方法および管理用プログラム |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2021524014A (ja) | 2021-09-09 |
| US20190347783A1 (en) | 2019-11-14 |
| US11270426B2 (en) | 2022-03-08 |
| JP7327872B2 (ja) | 2023-08-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11270426B2 (en) | Computer aided inspection system and methods | |
| JP6940047B2 (ja) | コンピュータによる鉄筋測定検査システム及び鉄筋測定検査方法 | |
| Ahn et al. | 2D drawing visualization framework for applying projection-based augmented reality in a panelized construction manufacturing facility: Proof of concept | |
| Fusco et al. | Indoor localization for visually impaired travelers using computer vision on a smartphone | |
| JP7337654B2 (ja) | 保全活動サポートシステムおよび保全活動サポート方法 | |
| Ellenberg et al. | Use of unmanned aerial vehicle for quantitative infrastructure evaluation | |
| CN109146938B (zh) | 动态障碍物的位置校准方法、装置、设备及存储介质 | |
| JP6168833B2 (ja) | 3DGeoArcを用いた多モードデータの画像登録 | |
| US20140022281A1 (en) | Projecting airplane location specific maintenance history using optical reference points | |
| US9546002B1 (en) | Virtual instrument verification tool | |
| US20190377330A1 (en) | Augmented Reality Systems, Methods And Devices | |
| KR20140108428A (ko) | 착용형 디스플레이 기반 원격 협업 장치 및 방법 | |
| US11395102B2 (en) | Field cooperation system and management device | |
| CN114419590A (zh) | 高精地图的验证方法、装置、设备以及存储介质 | |
| CN114565908A (zh) | 车道线的检测方法、装置、电子设备及存储介质 | |
| CN113776546A (zh) | 一种机器人路径的确定方法、装置、电子设备及介质 | |
| Matiki et al. | A graphics-based digital twin (GBDT) framework for accurate UAV localization in GPS-denied environments | |
| Kuo et al. | Integration of BIM and ar with VSLAM to assist in construction site inspection | |
| CN117294008A (zh) | 一种基于综合ar的换流站新型智能交互运维装置 | |
| Jeelani et al. | Real-time hazard proximity detection—Localization of workers using visual data | |
| CN110081861A (zh) | 一种基于图像识别的激光快速测绘系统及测绘方法 | |
| Zhang et al. | Developing novel monocular-vision-based standard operational procedures for nondestructive inspection on constructed concrete cracks | |
| Karji et al. | Integration of lidar and augmented reality for construction quality control, a conceptual framework | |
| US12211223B2 (en) | System and method for setting a viewpoint for displaying geospatial data on a mediated reality device using geotags | |
| Matiki et al. | Digital Twin Approach for Drift-Free UAV Localization in GPS-Denied Environments |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 19804467 Country of ref document: EP Kind code of ref document: A1 |
|
| ENP | Entry into the national phase |
Ref document number: 2020520008 Country of ref document: JP Kind code of ref document: A |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 19804467 Country of ref document: EP Kind code of ref document: A1 |