Three-dimensional scanning system

Abstract

The present invention relates to a three-dimensional scanning system. According to an embodiment of the present invention, disclosed is a three-dimensional scanning system which includes two or more scanners for projecting structured light onto an object to photograph same to thereby perform multi-scanning, wherein the three-dimensional scanning system is configured to control a projection time point of the structured light to project the structured light according to a projection time point synchronized between the scanners, and to project structured light and photograph by another scanner between a time point when arbitrary structured light is projected for photographing by one scanner and a time point when the structured light is changed to another structured light and projected for photographing, thereby significantly reducing the time taken to acquire stereoscopic information of the object.

Description

3D scanner system

[0001] The present invention relates to a three-dimensional scanner system, which includes two or more scanners that project structured light onto an object and photograph it, performs multi-scanning, and controls the projection time of the structured light so that the structured light is projected according to projection time points synchronized with each other among the scanners, and is configured to project and photograph structured light from another scanner between the time point at which one scanner projects and photographs a random structured light and the time point at which it changes to another structured light and projects and photographs it, thereby significantly reducing the time for acquiring three-dimensional information of the object.

[0002]

[0003] 3D scanners are used to obtain three-dimensional information of various objects.

[0004] As an example of a 3D scanner, a structured light method is widely used, which projects structured light of multiple patterns (frames) onto an object using a projector, photographs the object onto which the structured light of each pattern is projected using a camera, and acquires three-dimensional information by using image information for each pattern.

[0005] Furthermore, a multi-scanning 3D scanner system was proposed to obtain omnidirectional stereoscopic information of an object in a 360-degree direction by arranging multiple 3D scanners in an array form surrounding the object to obtain image information.

[0006] Figure 9 is a schematic diagram for explaining the projection point of structured lights of a 3D scanner system according to an example of the prior art.

[0007] In the case of the 3D scanner system illustrated in Fig. 9, two or more scanners (scanner 1 to scanner n) are provided so that an object can be photographed from different directions to obtain image information for each pattern in each direction, and scanner 1 to scanner n change and project structured light of multiple patterns (pattern 1 to pattern m), and photograph an object onto which the structured light of each pattern is projected to obtain image information for each pattern. Typically, when phaseshift technology is used, scanning is performed while projecting about 18 to 20 structured light patterns.

[0008] The conventional 3D scanner system, as an example, sequentially performs the shooting of scanners 1 to n by changing and projecting structured light of multiple patterns corresponding to pattern 1 to pattern m in scanner 1 and then changing and projecting structured light of multiple patterns corresponding to pattern 1 to pattern m in scanner 2.

[0009] Meanwhile, the digital camera installed in the scanner requires exposure time to generate image information by taking a picture of one pattern (e.g., pattern 1), and also requires downloading time to download the generated image to memory.

[0010] In the example of Fig. 9, it takes time t0 to t1 to generate image information by projecting structured light corresponding to pattern 1 from scanner 1 and taking a picture, and it takes time t1 to t4 to download the image generated based on pattern 1 to memory.

[0011] For example, if the exposure time for taking a picture from the camera's image sensor is 0.1 ms and the time (I / O time) required to download the image to the camera's memory is 10 ms, then when one scanner scans while changing and projecting a total of 20 structured light patterns, it takes a total of 202 ms (= 20×10.1 ms).

[0012] However, in the case of the conventional method in which scanner 1 completes photographing the entire structured light of patterns 1 to m, and scanner 2 to scanner n sequentially proceed with photographing in the same manner, there was a limitation in that the entire scanning time was long because a relatively long I / O time was included between the exposure times of the cameras for each pattern.

[0013] Considering this, there were limitations in that when applying a high-speed camera, it would be expensive and the exposure time of the image sensor would have to be minimized, which could result in a lot of noise.

[0014] Meanwhile, an example of prior art, Korean Patent No. 10-1909552 (October 12, 2018), proposes a 3D scanner including a plurality of 3D scan modules including a structured light module for projecting structured light onto a subject and a camera module for photographing the subject onto which the structured light is projected, and a control unit for obtaining three-dimensional information of the entire subject by using a single video stream in which a plurality of unit image signals output from each of the plurality of camera modules are time-division synthesized.

[0015] However, since the above-mentioned conventional technology is configured such that multiple 3D scan modules sequentially photograph a subject and generate each unit image signal, there was a limitation in that a relatively long I / O time was included between the exposure times of each pattern camera in the process in which each 3D scan module generates a unit image signal.

[0016]

[0017] The present invention has been made in consideration of the above problems, and the purpose of the present invention is to provide a three-dimensional scanner system that performs multi-scanning by including two or more scanners that project structured light onto an object and photograph it, and controls the projection time of the structured light so that the structured light is projected according to projection time points synchronized with each other among the scanners, and is configured to project and photograph structured light from another scanner between the time point at which one scanner projects and photographs a random structured light and the time point at which it changes to another structured light and projects and photographs it, thereby drastically reducing the time for acquiring three-dimensional information of the object.

[0018]

[0019] According to one aspect of the present invention for achieving the above object, a three-dimensional scanner system is disclosed, including a projector that changes and projects structured light of a plurality of patterns onto an object, and a camera that photographs the object onto which the structured light of each pattern is projected to obtain image information for each pattern; a signal processing unit that provides a trigger signal for controlling a projection point of the structured light to the scanner; and an information processing unit that obtains three-dimensional information of the object based on the image information for each pattern obtained by the scanner; wherein the scanner is provided in two or more units so as to be able to photograph the object from different directions and obtain image information for each pattern for each direction, and is configured to have a projection point of time for projecting structured light of an arbitrary pattern from another arbitrary scanner between a projection point of time for projecting structured light of an arbitrary pattern from a random scanner and a projection point of time for projecting structured light changed into another arbitrary pattern from the random scanner.

[0020] Preferably, the scanner is provided with n (n≥2) scanners, and is configured such that the second scanner to the nth scanner each have one projection point at which they project structured light of an arbitrary pattern between a projection point at which the first scanner projects structured light of a first pattern and a projection point at which the first scanner projects structured light changed to a second pattern.

[0021] Preferably, each of the above scanners can store pattern-specific image information acquired by a camera included in the scanner, and the information processing unit receives the pattern-specific image information stored in each of the above scanners and acquires three-dimensional information of the object based on the received pattern-specific image information.

[0022] Preferably, each of the above scanners can store image information for each pattern acquired by a camera included in the scanner, and can acquire scanner-specific stereoscopic information of the object through a scanner information processing unit included in the scanner based on the stored image information for each pattern, and the information processing unit receives each scanner-specific stereoscopic information acquired from each of the above scanners, and acquires stereoscopic information of the object based on the received scanner-specific stereoscopic information.

[0023] Preferably, the signal processing unit provides a trigger signal for controlling the projection point of the structured light to the projector of each scanner, and the projector of each scanner provides a trigger signal for photographing an object to the camera of the corresponding scanner.

[0024] Preferably, the signal processing unit provides a trigger signal for controlling the projection point of the structured light to the projector of each scanner, and also provides a trigger signal for photographing an object to the camera of the scanner.

[0025] Preferably, the signal processing unit is installed in one of two or more scanners and provides a trigger signal for controlling the projection time of structured light to the projector of each scanner, and provides the trigger signal so that a plurality of patterns of structured light can be changed and projected according to the projection time points synchronized between each scanner.

[0026] Preferably, the signal processing unit provides each trigger signal for controlling the initial projection point of the structured light to the projector of each scanner, and the projector of each scanner generates each periodic projection point based on each trigger signal, and periodically changes and projects a plurality of patterns of structured light according to the projection point.

[0027] Preferably, the signal processing unit periodically provides each trigger signal for controlling the projection time of the structured light to the projector of each scanner, and the projector of each scanner periodically changes and projects a plurality of patterns of structured light based on each of the periodic trigger signals.

[0028] Preferably, the signal processing unit provides each trigger signal for controlling the projection point of the structured light to an embedded module included in each scanner, and the embedded module included in each scanner provides the trigger signal to a projector included in the scanner.

[0029] Preferably, the camera is a global shutter type camera.

[0030] Preferably, the projector is a DLP (Digital Light Processing) type projector that stores information about structured light of multiple patterns in firmware.

[0031] Preferably, the time difference between the projection point at which structured light of an arbitrary pattern is projected from an arbitrary scanner and the projection point at which structured light changed to another arbitrary pattern is projected from said arbitrary scanner is determined by the exposure time of the camera set to acquire image information for each pattern and the total number of scanners.

[0032] Preferably, the trigger signal is a signal in the form of a clock pulse.

[0033] Preferably, the scanner is configured to change and project a plurality of patterns of structured light according to projection points synchronized with each other.

[0034] Preferably, the scanner acquires pattern-specific image information by photographing an object onto which structured light of the arbitrary pattern is projected by another arbitrary scanner, while downloading pattern-specific image information acquired by photographing an object onto which structured light of the arbitrary pattern is projected by the arbitrary scanner.

[0035]

[0036] The present invention has the advantage of significantly reducing the time required to acquire three-dimensional information of an object when performing multi-scanning by including two or more scanners that project structured light onto an object and capture the image.

[0037]

[0038] Figure 1 is a schematic diagram of a 3D scanner system according to an embodiment of the present invention;

[0039] Figure 2 is another schematic diagram of a 3D scanner system according to an embodiment of the present invention;

[0040] Figure 3 is an example diagram of patterns of structured light according to an embodiment of the present invention.

[0041] Figure 4 is a schematic diagram for explaining the projection point of the structured light of the scanner and the shooting point of the camera according to an embodiment of the present invention.

[0042] FIG. 5 is a schematic diagram for explaining the synchronized projection point of the structured lights of the scanners constituting the 3D scanner system according to an embodiment of the present invention.

[0043] Figures 6a to 6e are schematic diagrams for explaining the operation process of a 3D scanner system according to an embodiment of the present invention.

[0044] Figure 7 is a schematic diagram of the main computer of the 3D scanner system according to an embodiment of the present invention.

[0045] Figure 8 is a schematic diagram of an embedded module of a 3D scanner system according to an embodiment of the present invention.

[0046] Figure 9 is a schematic diagram for explaining the projection point of structured lights of a 3D scanner system according to an example of the prior art.

[0047]

[0048] The present invention may be embodied in various forms without departing from its technical spirit or essential characteristics. Therefore, the embodiments of the present invention are merely illustrative in all respects and should not be construed as limiting.

[0049] Terms such as "first" and "second" are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0050] When a component is referred to as being "connected" or "connected" to another component, it may be directly connected or connected to that other component, but there may also be other components in between.

[0051] The singular expressions used in this application include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "include," "have," and "have" are intended to indicate the presence of components or combinations thereof described in the specification, but do not preclude the possibility of other components or features being present or added.

[0052]

[0053] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0054] FIG. 1 is a schematic diagram of a 3D scanner system according to an embodiment of the present invention, FIG. 2 is another schematic diagram of a 3D scanner system according to an embodiment of the present invention, FIG. 3 is an example diagram of patterns of structured light according to an embodiment of the present invention, FIG. 4 is a schematic diagram for explaining a projection point of structured light of a scanner and a shooting point of a camera according to an embodiment of the present invention, FIG. 7 is a schematic diagram of a main computer of a 3D scanner system according to an embodiment of the present invention, and FIG. 8 is a schematic diagram of an embedded module of a 3D scanner system according to an embodiment of the present invention.

[0055] The 3D scanner system of this embodiment includes a scanner (10), a signal processing unit (SP), and an information processing unit (IP).

[0056] The above scanner (10) is equipped with two or more (10-1 to 10-n), and each scanner (10) is configured to photograph the object (S) from different directions and acquire image information for each pattern in each direction. Fig. 1 illustrates a case where seven scanners (10) are equipped as an example.

[0057] For example, the object (S) may be, but is not limited to, a person requiring 360-degree omnidirectional body scanning. In the case of body scanning, the position and orientation of the limbs and head may change over time due to the movement of the person's joints, so scanning must be completed within a short period of time. The 3D scanner system of the present embodiment significantly reduces the time required to acquire three-dimensional information of an object, making it particularly useful in situations requiring rapid scanning, such as body scanning.

[0058] Image information for a single pattern can be understood as a single image information acquired by a single scanner (10) by photographing an object (S) onto which structured light of a single pattern (frame) is projected. Fig. 3 illustrates various binary patterns that can be used as structured light. For example, a single scanner (10) requires structured light of approximately 18 to 20 patterns to obtain three-dimensional information from a single direction.

[0059] Each scanner (10) includes a projector (14) that changes and projects a plurality of patterns of structured light onto an object (S), and a camera (16) that photographs the object (S) onto which the structured light of each pattern is projected to obtain image information for each pattern.

[0060] Referring to FIG. 4, preferably, the projection point and projection time of the structured light of each pattern and the camera's corresponding shooting (exposure) point and shooting time are mutually synchronized. Preferably, the projection time of one pattern is set to be equal to or greater than the exposure time required for the camera to acquire pattern-specific image information for the pattern.

[0061] Preferably, the projector (14) may be a DLP (Digital Light Processing) type projector that stores information about structured light of multiple patterns in firmware.

[0062] The DLP method is a method that implements high-precision display of images using a DMD (Digital Micromirror Device) chip, and has the advantage of providing a higher contrast ratio and more uniform and stable colors than the LCD method, which is another method.

[0063] Since the 3D scanner system of the present embodiment must change and project multiple patterns of structured light into a clear state for a short period of time according to projection points (t0, t1, t2, ...) synchronized between two or more (10-1 to 10-n) scanners (10), it is recommended to use a DLP type projector. The DLP type projector can control projection (exposure) with an accuracy of microseconds.

[0064] For example, some commercial DLP projectors developed for 3D scanners (e.g., Texas Instrument LightCrafter4500) provide a binary pattern mode that can project the structured light of the 3D scanner in the form of a binary pattern, in addition to a video mode that provides regular images. The binary pattern is stored in the flash memory of the embedded system built into the projector and can be projected at speeds exceeding 10,000 Hz. Pattern data for the binary pattern can be input together with the projector's firmware when uploading.

[0065] Preferably, the camera (16) may be a global shutter type camera.

[0066] A global shutter is a shutter method in which the pixel rows of the camera's digital image sensor are exposed simultaneously. It has the advantage of faster shooting speed and less distortion than the rolling shutter method in which the pixel rows are exposed sequentially.

[0067] Since the 3D scanner system of the present embodiment must photograph while changing and projecting multiple patterns of structured light for a short period of time according to projection points (t0, t1, t2, ...) synchronized between two or more (10-1 to 10-n) scanners (10), it is recommended to use a camera with a global shutter method. A camera with a global shutter method can control exposure with an accuracy of microseconds. For example, the camera of the present embodiment can maintain a ready state and maintain an exposure state for photographing while an external trigger signal is in an ON state.

[0068] The signal processing unit (SP) provides a trigger signal to the scanner (10) that controls the projection timing of the structured light. For example, the trigger signal may be a signal in the form of a clock pulse, and projection of the structured light may be triggered at a high level of the clock pulse.

[0069] For example, the signal processing unit (SP) may be provided in an embedded module (12) of the scanner (10), and as a variant, may be provided as a separate module not included in the scanner (10) or may be provided in the main computer (20) described below.

[0070] To this end, each scanner (10) may be equipped with an embedded module (12) for executing operational control of the projector (14) and camera (16) and for managing data storage regarding these elements.

[0071] In this embodiment, the signal processing unit (SP) is provided in an embedded module (12) of a first scanner (10-1) that serves as a host among two or more (10-1 to 10-n) scanners (10). Scanners (10-2 to 10-n) other than the first scanner (10-1) that serves as a host may not necessarily require an embedded module (12).

[0072] Referring to FIG. 8, the embedded module (12) includes a memory (12a) for storing one or more commands and a processor (12b) for executing the one or more commands stored in the memory (12a), and is a computing device in which a computer program for controlling the operation of the projector (14) and the camera (16) and managing data storage is executed. The embedded module (12) of the present embodiment may further include a data input / output interface (12c), a communication interface (12d), a data display means (12e), and a data storage means (12f). As a variation, the embedded module (12) may further include a scanner information processing unit (SIP) to acquire scanner-specific stereoscopic information of the object (S) for each scanner (10) based on image information for each pattern stored in each scanner (10), which will be described later.

[0073] For example, the embedded module (12) may be implemented using a commercial single-board PC such as Jetson Nano or Raspberry Pi, or may be manufactured in the form of a separate dedicated module, and a clock pulse signal provided by such a single-board PC may be provided as a trigger signal through a GPIO (general-purpose input / output) header (12a). As another example, some commercial projector products are equipped with a processor and memory, and control logic may be input into such products in the form of firmware to implement the function of the embedded module. When the embedded module (12) is manufactured as a dedicated module for a 3D scanner system, the embedded module (12) may be equipped with a pulse generator for generating a clock pulse signal, and may be equipped with a control element for controlling a pulse cycle and a pulse width.

[0074] The above information processing unit (IP) acquires three-dimensional information of the object (S) based on image information for each pattern acquired from the scanner (10). The image information for each pattern is digital image data obtained by photographing the object (S) on which the projection light of each pattern is projected, and the three-dimensional information of the object (S) can be understood as three-dimensional shape data based on a point cloud in which three-dimensional coordinates (xyz coordinates) are assigned to each point, or geometric data obtained by further processing and converting the same.

[0075] For example, the information processing unit (IP) stores information about the camera coordinate systems of two or more (10-1 to 10-n) scanners (10) constituting the system, and converts the coordinate system (respective camera coordinate system) of the image information for each pattern acquired by each scanner (10) into the system coordinate system of the 3D scanner system and integrates them to acquire three-dimensional information of the object (S). Various known technologies are known in relation to technologies for acquiring three-dimensional information of the object (S) based on the image information for each pattern acquired by the scanner (10), and a description thereof is omitted.

[0076] For example, the information processing unit (IP) may be provided in the main computer (20) that executes the overall system control of the 3D scanner system, and as a variant example, may be provided in the embedded module (12) of any one scanner (10-1) that serves as a host among two or more (10-1 to 10-n) scanners (10). However, in the present embodiment, the information processing unit (IP) is described as being provided in the main computer (20).

[0077] To this end, the three-dimensional scanner system of the present embodiment may be equipped with a main computer (20) to execute operation control of the scanner (10) and to acquire three-dimensional information of the object (S) based on image information for each pattern acquired from the scanner (10).

[0078] Referring to FIG. 7, the main computer (20) includes a memory (21) that stores one or more commands and a processor (22) that executes the one or more commands stored in the memory (21), and is a computing device on which a computer program for controlling the operation of the scanner (10), managing data storage, and acquiring three-dimensional information is executed. The main computer (20) of the present embodiment may further include a data input / output interface (23), a communication interface (24), a data display means (25), and a data storage means (26).

[0079] For example, a 3D scanner application program that acquires 360-degree omnidirectional stereoscopic information of the object (S) based on image information for each pattern provided by each scanner (10-1 to 10-n) may be installed and operated in the main computer (20), and the function providing element of the main computer (20) according to the operation of the 3D scanner application program may be understood as the information processing unit (IP) of the present embodiment.

[0080] Depending on the system configuration, the main computer (20) may not be installed separately, and in this case, the embedded module (12) of one of the scanners (10) acting as a host among two or more (10-1 to 10-n) scanners (10) may provide the functions of the main computer.

[0081] For example, each of the above scanners (10-1 to 10-n) can store image information for each pattern acquired by the camera (16) included in the scanner (10). For example, the image information for each pattern can be stored in the memory (12a) of the embedded module (12) of each scanner (10) or in the built-in memory of the camera (16).

[0082] In this case, the information processing unit (IP) receives image information for each pattern stored in each scanner (10-1 to 10-n), and acquires three-dimensional information of the object (S) based on the received image information for each pattern.

[0083] For example, transmitting the image information for each pattern stored in each of the above scanners (10-1 to 10-n) to the information processing unit (IP) may be performed after the shooting of all scanners (10-1 to 10-n) included in the 3D scanner system is completed, but is not necessarily limited thereto.

[0084] As another example, each of the above scanners (10-1 to 10-n) can store image information for each pattern acquired by a camera (16) included in the scanner (10), and based on the stored image information for each pattern, it is possible to acquire three-dimensional information for each scanner of the object (S) through a scanner information processing unit (SIP) included in the scanner (10).

[0085] To this end, the embedded module (12) of each of the above scanners (10-1 to 10-n) can each install and run a 3D scanner application program that acquires three-dimensional information of an object (S), and the function providing element of the embedded module (12) according to the running of the 3D scanner application program can be understood as the scanner information processing unit (SIP) of the present embodiment.

[0086] In this case, the information processing unit (IP) receives stereoscopic information for each scanner acquired from each scanner (10-1 to 10-n), and acquires stereoscopic information of the object (S) based on the stereoscopic information for each scanner received.

[0087] For example, if each scanner (10-1 to 10-n) projects structured light of 20 patterns and acquires image information for each of 20 patterns, the scanner-specific stereoscopic information of one scanner (10) can be understood as having been acquired using the image information for each of the 20 patterns acquired from the scanner (10).

[0088] For example, if a 3D scanner system is equipped with a total of n scanners (10-1 to 10-n) installed facing different directions, the information processing unit (IP) acquires 360-degree omnidirectional stereoscopic information of the object (S) by using the stereoscopic information of each of the n scanners acquired from different directions.

[0089] The above signal processing unit (SP) can provide a trigger signal as follows.

[0090] As described above, the signal processing unit (SP) can be installed in one (10-1) of two or more scanners (10-1 to 10-n), and provides a trigger signal for controlling the projection point of structured light to the projector (14) of each scanner (10-1 to 10-n).

[0091] At this time, the signal processing unit (SP) provides the trigger signal so that the structured light of multiple patterns can be changed and projected according to the projection time points synchronized between each scanner (10-1 to 10-n). The projection of the structured light of each scanner (10-1 to 10-n) must not overlap each other to avoid mutual interference.

[0092] In this embodiment, the fact that the projection time points of each scanner (10-1 to 10-n) are 'synchronized' means that the projection time points (t0, t1, t2, ..., tn, ...) of the structured light of each scanner (10-1 to 10-n) are not controlled separately, but are controlled as a single system.

[0093] For example, synchronization of projection points can be provided in a manner in which one signal processing unit (SP) controls the projection points (t0, t1, t2, ..., tn, ...) of the structured light of the scanners (10-1 to 10-n) of the entire system, but is not necessarily limited thereto.

[0094] Also, preferably, the scanners (10-1 to 10-n) of the entire system can have projection points (t0, t1, t2, ..., tn, ...) of the structured light according to the same cycle according to the synchronization of projection points, but are not necessarily limited thereto.

[0095] For example, the signal processing unit (SP) provides a trigger signal for controlling the projection point of structured light to the projector (14) of each scanner (10-1 to 10-n).

[0096] The projector (14) of each scanner (10-1 to 10-n) provides a trigger signal for photographing an object (S) to the camera (16) of the corresponding scanner (10).

[0097] For example, some commercially available DLP projectors developed for 3D scanners (e.g., Texas Instrument LightCrafter4500) include a trigger IN (14a) and a trigger OUT terminal (14b) in the projector's I / O interface. The projector (14) of the scanner (10), which receives a trigger signal from the signal processing unit (SP) through the trigger IN terminal (14a), provides the trigger signal to the camera (16) of the scanner (10) through the trigger OUT terminal (14b). The projector (14) that receives the trigger signal from the signal processing unit (SP) projects structured light onto the object (S) according to preset projection conditions (e.g., projection cycle, projection time, pattern sequence).

[0098] Some commercially available global shutter type cameras include a trigger IN terminal (16a) in the I / O interface of the projector, through which a trigger signal provided through the trigger OUT terminal (14b) of the projector (14) is received. The camera (16) that receives the trigger signal from the projector (14) photographs an object (S) onto which structured light is projected according to preset shooting conditions (e.g., exposure time) and acquires image information for each pattern.

[0099] As another example, the signal processing unit (SP) provides a trigger signal for controlling the projection point of the structured light to the projector (14) of each scanner (10-1 to 10-n).

[0100] Additionally, the signal processing unit (SP) provides a trigger signal for photographing an object (S) to the camera (16) of the scanner (10).

[0101] In this example, the signal processing unit (SP) provides a trigger signal to the projector (14) and the camera (16) simultaneously and provides a periodic trigger signal.

[0102]

[0103] FIG. 5 is a schematic diagram for explaining the synchronized projection time points of the structured lights of the scanners constituting the 3D scanner system according to an embodiment of the present invention, and FIGS. 6a to 6e are schematic diagrams for explaining the operation process of the 3D scanner system according to an embodiment of the present invention.

[0104] In the 3D scanner system of the present embodiment, the scanner (10) changes and projects a plurality of patterns of structured light according to projection points (t0, t1, t2,...) synchronized between each scanner (10-1 to 10-n).

[0105] The initial control command for the start of a synchronized projection point (t0, t1, t2,...) can be initiated by a scanning start command of the main computer (20), and this scanning start command is transmitted to the embedded module (12) of the first scanner (10-1) acting as a host (Fig. 6a).

[0106] The signal processing unit (SP) equipped in the embedded module (12) of the first scanner (10-1) that received the scanning start command sequentially transmits a trigger signal to the first to nth scanners (10-1 to 10-n) (Fig. 6b to Fig. 6d).

[0107] In the case of the embodiments of FIGS. 6a to 6e, the signal processing unit (SP) provided in the embedded module (12) of the first scanner (10-1) sequentially transmits a trigger signal for structured light projection to the projector (14) of the first to n-th scanners (10-1 to 10-n), and the projector (14) transmits a trigger signal for shooting to the camera (16). The transmission of the trigger signal can be configured in various modified examples as described above.

[0108] The digital camera installed in the scanner (10) requires exposure time to take a picture of one pattern and generate image information, and also requires downloading time to download the generated image to memory.

[0109] In consideration of this, the 3D scanner system of the present embodiment is configured to have a projection time point (t1 to tn-1) for projecting structured light of an arbitrary pattern from another arbitrary scanner (10-2 to 10-n) between a projection time point (t0) for projecting structured light of an arbitrary pattern from an arbitrary scanner (10-1) and a projection time point (tn) for projecting structured light changed to another arbitrary pattern from the arbitrary scanner (10-1).

[0110] For example, when n (n≥2) scanners (10) are provided in the 3D scanner system of the present embodiment, the second scanner (10-2) to the n-th scanner (10-n) are configured to have one projection time point (t1 to tn-1) at which they each project structured light of an arbitrary pattern between the projection time point (t0) at which the first scanner (10-1) projects structured light of a first pattern and the projection time point (tn) at which the first scanner (10-1) projects structured light changed to a second pattern.

[0111] To explain in more detail, the first scanner (10-1) starts projecting structured light of the first pattern at projection time t0, and captures an object (S) onto which the structured light of the first pattern is projected to obtain image information for each pattern.

[0112] Afterwards, when the time set for acquiring pattern-specific image information for the first pattern from the first scanner (10-1) ends, the second scanner (10-2) starts projecting the structured light of the first pattern at projection time t1 and photographs the object (S) onto which the structured light of the first pattern is projected to acquire pattern-specific image information.

[0113] As a preferred example, the time set for acquiring pattern-specific image information for the first pattern in the first scanner (10-1) may be set to be the same as the exposure time required for the camera (10) to acquire pattern-specific image information. In addition, the projection time point t1 of the second scanner (10-2) may be set to be the same as the time point at which the time set for acquiring pattern-specific image information for the first pattern in the first scanner (10-1) ends.

[0114] Through this operation control, it is possible to continuously acquire image information for each pattern from another scanner without waiting time during the downloading time of one scanner, and also, since this operation process is accurately executed by synchronized point control, it is possible to minimize the time for acquiring stereoscopic information of the object (S).

[0115] In addition, while the second scanner (10-2) starts to project the structured light of the first pattern at the projection time t1 and captures the object (S) onto which the structured light of the first pattern is projected to obtain image information for each pattern, the first scanner (10-1) captures the object (S) onto which the structured light of the first pattern is projected and the image information for each pattern obtained is downloaded to the memory of the first scanner (10-1) (Fig. 6c).

[0116] Afterwards, when the time set for acquiring pattern-specific image information for the first pattern from the second scanner (10-2) ends, the third scanner (10-3) starts projecting the structured light of the first pattern at projection time t2 and captures the object (S) onto which the structured light of the first pattern is projected to acquire pattern-specific image information.

[0117] In addition, while the third scanner (10-3) starts to project the structured light of the first pattern at projection time t2 and captures the object (S) onto which the structured light of the first pattern is projected to obtain image information for each pattern, the second scanner (10-2) captures the object (S) onto which the structured light of the first pattern is projected and the acquired image information for each pattern is downloaded to the memory of the second scanner (10-2).

[0118] After going through this sequential process, when the set time for acquiring pattern-specific image information for the first pattern from the n-th scanner (10-n) ends, each scanner (10-1 to 10-n) stores pattern-specific image information for the first pattern acquired from each direction in its respective memory.

[0119] Thereafter, a projection / shooting cycle based on the second pattern is performed, and the structured light of the second pattern is projected at the projection point tn from the first scanner (10-1) to acquire pattern-specific image information for the second pattern (Fig. 6e).

[0120] Afterwards, when the time set for acquiring pattern-specific image information for the second pattern from the first scanner (10-1) ends, the second scanner (10-2) projects the structured light of the second pattern at projection time tn+1 to acquire pattern-specific image information for the second pattern.

[0121] In addition, while the second scanner (10-2) starts to project the structured light of the second pattern at projection time t1+1 and captures the object (S) onto which the structured light of the second pattern is projected to obtain image information for each pattern, the first scanner (10-1) captures the object (S) onto which the structured light of the second pattern is projected and the image information for each pattern obtained is downloaded to the memory of the first scanner (10-1).

[0122] Afterwards, when each scanner (10-1 to 10-n) acquires all image information for each pattern for a total of m set patterns through this sequential process, the projection of the structured light and the corresponding image capturing are terminated, and the image information for each pattern for a total of m acquired from different directions is stored in the memory of each scanner (10-1 to 10-n).

[0123] The information processing unit (IP) receives a total of m × n pattern-specific image information stored in the memory of each scanner (10-1 to 10-n) and acquires three-dimensional information of the object (S) based on this.

[0124] Meanwhile, between the projection time point (t0) at which the first scanner (10-1) projects the structured light of the first pattern and the projection time point (tn) at which the first scanner (10-1) projects the structured light changed to the second pattern, the second scanner (10-2) to the n-th scanner (10-n) do not necessarily need to project the first pattern and acquire pattern-specific image information for it, and may acquire pattern-specific image information for any one pattern among pattern 1 to pattern m. Each scanner (10-1 to 10-n) only needs to be controlled to acquire all pattern-specific image information for a total of m set patterns according to the synchronized projection time point.

[0125] Meanwhile, the time difference (tn-t0) between the projection time point (t0) at which structured light of an arbitrary pattern is projected from an arbitrary scanner (10-1) and the projection time point (tn) at which structured light changed to another arbitrary pattern is projected from the arbitrary scanner (10-1) can be determined by the exposure time of the camera (16) set to acquire image information for each pattern and the total number (n) of scanners (10-1 to 10-n). From another perspective, the exposure time of the camera (16) set to acquire image information for each pattern and the total number (n) of scanners (10-1 to 10-n) can be viewed as the exposure time of the camera (16) and the total number (n) of scanners (10-1 to 10-n) required to acquire image information for each pattern.

[0126] Referring to FIG. 5, the time difference (tn-t0) between the projection time point (t0) at which the first scanner (10-1) projects the structured light of the first pattern and the projection time point (tn) at which the first scanner (10-1) projects the structured light changed to the second pattern can be determined by the exposure time (t1-t0 or t2-t1) of the camera (16) required to obtain image information for one pattern and the total number (n) of scanners (10-1 to 10-n).

[0127] For example, in the case of a camera with a global shutter method, an exposure time of about 0.1 millisec (1 / 10,000 second) is sufficient to capture an image of an object (S) on which a pattern is projected. In the example of Fig. 5, the times for projection and shooting of the first pattern for each scanner (10-1 to 10-n) can be viewed as t0 to t1, t1 to t2, ..., tn-1 to tn, respectively (each time is the same), so for example, when t0 to t1 is set to 0.1 millisec (1 / 10,000 second), the time difference between the projection time point (t0) and the projection time point (tn) can be obtained as n × 0.1 millisec.

[0128] Periodic provision of trigger signals can be accomplished as follows:

[0129] For example, the signal processing unit (SP) provides each trigger signal for controlling the initial projection time (t0 to tn) of the structured light to the projector (14) of each scanner (10-1 to 10-n).

[0130] In this case, the projector (14) of each scanner (10-1 to 10-n) generates each periodic projection point (t1, t2,...) based on each trigger signal, and periodically changes and projects a plurality of patterns of structured light according to the projection point (t1, t2,...).

[0131] As described above, some of the commercially available DLP projectors developed for 3D scanners provide a binary pattern mode that can project the structured light of the 3D scanner in the form of a binary pattern, and the number of patterns, pattern order, and projection cycle can be set and controlled based on firmware programming.

[0132] As another example, the signal processing unit (SP) periodically provides each trigger signal for controlling the projection point of the structured light to the projector (14) of each scanner (10-1 to 10-n).

[0133] In this case, the projector (14) of each scanner (10-1 to 10-n) periodically changes and projects a plurality of patterns of structured light based on each of the periodic trigger signals.

[0134] As described above, some commercial single-board PCs can provide a clock pulse signal as a trigger signal through a GPIO header, and the cycle of the trigger signal can be set and controlled based on a control program.

[0135] As another example, the signal processing unit (SP) provides each trigger signal for controlling the projection point of the structured light to the embedded module (12) included in each scanner (10-1 to 10-n).

[0136] As described above, among two or more (10-1 to 10-n) scanners (10), the embedded module (12) of one scanner (10-1) acting as a host provides the function of a signal processing unit (SP), and can provide each trigger signal for controlling the projection time of structured light to the embedded modules (12) of the remaining scanners (10-2 to 10-n).

[0137] In this case, the embedded module (12) included in each scanner (10-1 to 10-n) provides a trigger signal to the projector (14) included in the corresponding scanner (10).

[0138]

[0139] While the present invention has been described with reference to the accompanying drawings, focusing on preferred embodiments, it will be apparent to those skilled in the art that numerous obvious modifications are possible without departing from the scope of the invention. Therefore, the scope of the present invention should be construed as encompassing these numerous modifications as defined by the claims.

Claims

1. A scanner including a projector that changes and projects structured light of multiple patterns onto an object, and a camera that photographs the object onto which the structured light of each pattern is projected to obtain image information for each pattern; A signal processing unit that provides a trigger signal for controlling the projection point of the structured light to the scanner; and An information processing unit that obtains three-dimensional information of the object based on image information for each pattern obtained from the scanner; The above scanner, Two or more are provided so that the object can be photographed from different directions to obtain image information for each pattern in each direction. A 3D scanner system characterized in that it is configured to have a projection point for projecting structured light of an arbitrary pattern from another arbitrary scanner between a projection point for projecting structured light of an arbitrary pattern from an arbitrary scanner and a projection point for projecting structured light changed into another arbitrary pattern from the arbitrary scanner.

2. In paragraph 1, The above scanner, n (n≥2) are provided, A 3D scanner system characterized in that the second scanner to the n-th scanner each have one projection point at which they project structured light of an arbitrary pattern between a projection point at which the first scanner projects structured light of a first pattern and a projection point at which the first scanner projects structured light changed to a second pattern.

3. In paragraph 1, Each of the above scanners, It is possible to save image information for each pattern acquired by the camera included in the scanner. The above information processing unit, A 3D scanner system characterized in that it receives image information for each pattern stored in each scanner and acquires three-dimensional information of the object based on the received image information for each pattern.

4. In paragraph 1, Each of the above scanners, It is possible to store image information for each pattern acquired by the camera included in the scanner, and based on the stored image information for each pattern, it is possible to obtain three-dimensional information for each scanner of the object through the scanner information processing unit included in the scanner. The above information processing unit, A 3D scanner system characterized in that it receives stereoscopic information for each scanner acquired from each scanner and acquires stereoscopic information of the object based on the received stereoscopic information for each scanner.

5. In paragraph 1, The above signal processing unit, A trigger signal that controls the projection point of the structured light is provided to the projector of each scanner, Each scanner's projector has: A 3D scanner system characterized in that it provides a trigger signal for photographing an object with the camera of the scanner.

6. In paragraph 1, The above signal processing unit, A trigger signal that controls the projection point of the structured light is provided to the projector of each scanner, A 3D scanner system characterized in that it also provides a trigger signal for capturing an object with the camera of the scanner.

7. In paragraph 1, The above signal processing unit, A trigger signal is provided to the projector of each scanner to control the projection point of the structured light by being installed on one of two or more scanners. A 3D scanner system characterized in that it provides the trigger signal so that it can change and project a plurality of patterns of structured light according to projection points synchronized between each scanner.

8. In paragraph 1, The above signal processing unit, Provide each trigger signal controlling the initial projection point of the structured light to the projector of each scanner, Each scanner's projector has: A 3D scanner system characterized in that it generates each periodic projection point based on each of the above trigger signals, and periodically changes and projects a plurality of patterns of structured light according to the projection point.

9. In paragraph 1, The above signal processing unit, Each trigger signal that controls the projection point of the structured light is periodically provided to the projector of each scanner, Each scanner's projector has: A 3D scanner system characterized in that it projects structured light of multiple patterns by periodically changing them based on each of the above periodic trigger signals.

10. In paragraph 1, The above signal processing unit, Each trigger signal that controls the projection point of the structured light is provided to the embedded module included in each scanner, A 3D scanner system characterized in that an embedded module included in each scanner provides a trigger signal to a projector included in the scanner.

11. In paragraph 1, A 3D scanner system characterized in that the above camera is a global shutter type camera.

12. In paragraph 1, A 3D scanner system characterized in that the above projector is a DLP (Digital Light Processing) type projector that stores information about structured light of multiple patterns in firmware.

13. In paragraph 1, The time difference between the projection point where a structured light of a random pattern is projected from a random scanner and the projection point where the structured light changed to another random pattern is projected from the random scanner is A 3D scanner system characterized in that the exposure time of the camera and the total number of scanners are determined to obtain image information for each pattern.

14. In paragraph 1, A 3D scanner system, characterized in that the above trigger signal is a signal in the form of a clock pulse.

15. In paragraph 1, The above scanner, A 3D scanner system characterized in that it is configured to change and project a plurality of patterns of structured light according to projection points synchronized with each other.

16. In paragraph 1, The above scanner, While photographing an object on which structured light of the arbitrary pattern is projected from another arbitrary scanner, image information for each pattern is acquired, A 3D scanner system characterized in that it downloads image information for each pattern obtained by photographing an object on which structured light of the arbitrary pattern is projected from the arbitrary scanner.

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