Three-dimensional measurement apparatus, three-dimensional measurement method, and program

Abstract

A three-dimensional measurement apparatus 10 comprises a plurality (three) of three-dimensional measuring instruments (LiDAR) 11A, 11B, 11C, and sets measurement timings at which each measuring instrument 11A, 11B, 11C emits laser light to carry out a measurement, with the measurement timings being shifted by a fixed time from the measurement timing of the measuring instrument 11A that serves as a reference. The three-dimensional measurement apparatus 10 also sets the directions in which the measuring instruments 11A, 11B, 11C each emit laser light to measure an object, with the directions being shifted by a fixed interval from the direction of the measuring instrument 11A that serves as the reference. Moreover, on the basis of external parameters measured (calculated) through calibration of the measuring instruments 11A, 11B, 11C, the measurement data of a point cloud measured by the measuring instruments 11A, 11B, 11C is converted into integrated three-dimensional point cloud data and saved (stored) as a measurement result.

Description

Three-dimensional measurement device, three-dimensional measurement method, and program

[0001] An embodiment of the present invention relates to a three-dimensional measurement device, a three-dimensional measurement method, and a program.

[0002] In a three-dimensional measurement device that uses laser light, the measuring device is rotated while irradiating surrounding objects with laser light, and the distance to the surrounding objects is measured by the reflection of the irradiated laser light, and the three-dimensional data is measured as a point cloud.

[0003] If the distance to the object to be measured (target object) is long, the number of points that the laser light irradiates on the object decreases, and the point cloud representing the target object becomes sparse.

[0004] Therefore, as described in Non-Patent Document 1, a method has been devised for interpolating point clouds by combining multiple types of sensors, such as using camera images.

[0005] When combining camera images, the color information obtained from the camera images is used to supplement the point cloud with the same color information as the point cloud at the same distance. However, actual target objects can have unevenness even if they are the same color, and the measurement results often differ from the actual situation.

[0006] "Interpolation Method for Long-Range Sparse Point Clouds Using Sensor Fusion with LiDAR and Camera," Saito, Shen, and Ito, Transactions of the Society of Automotive Engineers of Japan, Vol. 53, No. 3, May 2022.

[0007] On the other hand, in the case of 3D measurement devices that rotate a measuring instrument and output the point cloud measurement data obtained with each rotation, one method is to increase the point cloud obtained by irradiating it with laser light by slowing down the rotation of the measuring instrument, but if the target object is moving, the movement cannot be tracked and accurate measurements cannot be made.

[0008] In other words, if the object being measured is moving, it is difficult to increase the density of the point cloud, i.e., the resolution, while maintaining a measurement frequency that can track the movement, and it is not possible to perform 3D measurements with a certain level of quality.

[0009] The present invention has been made in consideration of these problems, and aims to provide a 3D measurement device, a 3D measurement method, and a program that make it possible to perform 3D measurements with a certain level of quality even when the object being measured is moving.

[0010] A three-dimensional measuring apparatus according to an embodiment of the present invention includes a plurality of three-dimensional measuring devices that use laser light, and a control unit that executes the following: setting the measurement timing of each of the three-dimensional measuring devices to be shifted by a fixed time, and setting the measurement direction of each of the three-dimensional measuring devices to be shifted by a fixed interval; calculating external parameters of each of the three-dimensional measuring devices; and converting measurement data of each of the three-dimensional measuring devices into three-dimensional point cloud data integrated based on the external parameters.

[0011] According to the three-dimensional measuring apparatus of the embodiment of the present invention, it is possible to perform three-dimensional measurement with a certain level of quality even when the object to be measured is moving.

[0012] FIG. 1 is a diagram showing, as an example, the overall configuration of a three-dimensional measurement apparatus 10 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the background for considering the three-dimensional measurement apparatus 10 according to the embodiment. FIG. 3 is a diagram illustrating, as an example, an outline (part 1) of the concept of the three-dimensional measurement apparatus 10 according to the embodiment. FIG. 4 is a diagram illustrating, as an example, an outline (part 2) of the concept of the three-dimensional measurement apparatus 10 according to the embodiment. FIG. 5 is a functional block diagram showing the configuration of functions possessed by the three-dimensional measurement apparatus 10 according to the embodiment. FIG. 6 is a block diagram showing the hardware configuration of the three-dimensional measurement apparatus 10 according to the embodiment. FIG. 7 is a flowchart showing three-dimensional measurement processing executed by the three-dimensional measurement apparatus 10 according to the embodiment.

[0013] Hereinafter, embodiments of a three-dimensional measurement apparatus, a three-dimensional measurement method, and a program according to the present invention will be described with reference to the drawings.

[0014] (Configuration of the embodiment) FIG. 1 is a diagram showing an example of the overall configuration of a three-dimensional measuring device 10 according to an embodiment of the three-dimensional measuring device, three-dimensional measuring method, and program of the present invention.

[0015] The three-dimensional measuring device 10 includes multiple (e.g., three) three-dimensional measuring devices (LiDAR: Light Detection and Ranging) 11A, 11B, and 11C. The measuring devices 11A, 11B, and 11C irradiate pulsed laser light and measure the time it takes for the light to reflect off an object and return, thereby measuring the distance and direction to the object and detecting the position, shape, etc. of the target object.

[0016] Measuring instruments 11A, 11B, and 11C are installed on pan heads 12A, 12B, and 12C, respectively, which are capable of numerically controlling the pan (horizontal), tilt (vertical), and roll (rotation) angles. Pan heads 12A, 12B, and 12C are fixed to a base 13, for example, which is placed in a space where a target object of device 10 exists.

[0017] The measuring instruments 11A, 11B, 11C (including the pan heads 12A, 12B, 12C) may be arranged, for example, horizontally on a long, plate-like base 13 as shown in Figure 1, or one on each of three bases attached vertically to an upright support, or one on each of a row of mass shelves (shelves covered with boards on the top, bottom, left, and right sides and open on the front and back).

[0018] The pan heads 12A, 12B, and 12C operate in accordance with control signals from the pan head control device 14, and change the measurement direction (i.e., the direction of laser light irradiation) by numerically controlling the pan (horizontal), tilt (vertical), and roll (rotation) angles of each of the measuring instruments 11A, 11B, and 11C.

[0019] By initial setting, the point cloud processing device 15 shifts the direction in which each of the measuring instruments 11A, 11B, and 11C irradiates laser light to measure an object by a fixed interval, for example, within the irradiation interval per unit of laser light by any one of the measuring instruments (e.g., 11A) that is used as a reference, via the pan head control device 14 and the pan heads 12A, 12B, and 12C, and also shifts the timing (measurement timing) in which each of the measuring instruments 11A, 11B, and 11C irradiates laser light to measure an object by a fixed time, for example, within the irradiation timing per unit of laser light by any one of the measuring instruments (e.g., 11A) that is used as a reference.

[0020] The measurement data of the point cloud measured by the measuring instruments 11A, 11B, and 11C is transmitted to the point cloud processing device 15.

[0021] The point cloud processing device 15 calculates external parameters of each of the measuring instruments 11A, 11B, and 11C based on the measurement data transmitted from each of the measuring instruments 11A, 11B, and 11C, and calibrates each of the measuring instruments 11A, 11B, and 11C.

[0022] The external parameters are parameters for converting and integrating the measurement data of the point clouds measured by each measuring instrument 11A, 11B, and 11C and expressed in a different coordinate system for each measuring instrument into a reference coordinate system (world coordinate system), and represent the position and orientation of the measuring instrument in the world coordinate system, and are composed of a rotation matrix R and a translation vector t.

[0023] The world coordinate system may be specified separately, or one of the measuring instruments, for example, measuring instrument 11A, may be used as the world coordinate system.

[0024] The point cloud processing device 15 converts the point cloud measurement data from each of the measuring instruments 11A, 11B, and 11C into integrated three-dimensional point cloud data based on external parameters, and stores the integrated three-dimensional point cloud data as measurement results.

[0025] The point cloud processing device 15 monitors the deviation in the measurement timing of each of the measuring instruments 11A, 11B, and 11C based on the three-dimensional point cloud data saved as the measurement result, corrects it so as to maintain the deviation at an initially set fixed time, counts the number of point clouds for the detected target object, and changes and adjusts the measurement direction of the measuring instruments 11A, 11B, and 11C via the pan / tilt head control device 14 and pan / tilt heads 12A, 12B, and 12C so that the number of point clouds is equal to or greater than the preset threshold value.

[0026] FIG. 2 is a diagram for explaining the background for considering the three-dimensional measurement apparatus 10 of the embodiment.

[0027] As shown in Figure 2 (A), a conventional three-dimensional measuring device rotates a measuring instrument 11, such as a LiDAR, irradiates laser light L onto a surrounding target object T, and measures the distance to the target object T based on the time it takes for the laser light L reflected from the target object T to be received.

[0028] For example, as shown by arrow B1 in Figure 2 (B), if the number of measurements per second (frame rate) by the measuring instrument 11 is increased (here, from 1 frame to 2 frames), the amount of laser light L irradiated onto the target object T per measurement will decrease, and as shown by arrow B2, the resolution (density of the point cloud) will decrease, making it difficult to achieve both high resolution and high frequency measurement.

[0029] Furthermore, as shown in Figure 2 (C), as the distance from the measuring instrument 11 to the object to be measured (here, a person) increases, the number of points that the laser light irradiates onto the object decreases, and the point cloud representing the target object T becomes sparse.

[0030] FIG. 3 is a diagram illustrating an outline (part 1) of the concept of the three-dimensional measurement apparatus 10 according to the embodiment.

[0031] FIG. 4 is a diagram illustrating an outline (part 2) of the concept of the three-dimensional measurement apparatus 10 according to the embodiment as an example.

[0032] As shown in FIGS. 3 and 4, the three-dimensional measuring apparatus 10 of the embodiment performs measurements using a plurality of measuring instruments (LiDAR) 11A, 11B, and 11C.

[0033] In the three-dimensional measuring device 10 of the embodiment, as shown in FIG. 3A, the measurement timings (laser light irradiation timings) t11, t21, and t31 of the measuring instruments 11A, 11B, and 11C are shifted by a fixed time dt within the measurement timing per unit t11 ​​to t12 by an arbitrary measuring instrument 11A that is used as a reference, for example.

[0034] Then, by integrating the measurement data obtained at measurement timings t11, t12, ... / t21, t22, ... / t31, t32, ... of each measuring instrument 11A, 11B, 11C as shown in Figure 3 (B) (t11, t21, t31, ..., t13, t23, t33), high-frequency three-dimensional measurement is achieved.

[0035] Furthermore, in the three-dimensional measuring device 10 of the embodiment, as shown in FIG. 4A, the direction in which each measuring instrument 11A, 11B, 11C irradiates laser light L1, L2, L3 to measure the object T is shifted by a constant interval dp within the measurement interval per unit (laser light irradiation interval: interval at which a point cloud is obtained) L11 to L12 by an arbitrary measuring instrument 11A that is used as a reference, for example.

[0036] Then, by integrating the measurement data obtained at the measurement points (laser light irradiation points) L11, L12, ... / L21, L22, ... / L31, L32, ... of each measuring instrument 11A, 11B, 11C as shown in Figure 4 (B) (L11, L21, L31, ..., L14, L24, L34, ...), high-density (high-resolution) three-dimensional measurement is realized.

[0037] Furthermore, in the 3D measuring device 10 of the embodiment, based on the 3D point cloud data of the measurement results, the deviation in measurement timing of each of the measuring instruments 11A, 11B, and 11C shown in Figure 3 is monitored and corrected so as to maintain the deviation for a certain time dt, and the number of point clouds (measurement points) (irradiation points) for the target object T shown in Figure 4 is counted, and the measurement direction of the measuring instruments 11A, 11B, and 11C is changed and adjusted (for example, by tracking the movement of the target object T and changing it) so that the number of point clouds (density) is equal to or greater than a preset threshold value, thereby ensuring the quality of high-frequency, high-resolution (high-density) 3D measurements.

[0038] The deviation in measurement timing among the measuring instruments 11A, 11B, and 11C may be caused by, for example, a drop in the voltage supplied to the measuring instruments, heating of the housing due to long-term operation, and the like.

[0039] FIG. 5 is a functional block diagram showing the functional configuration of the three-dimensional measurement apparatus 10 according to the embodiment.

[0040] The three-dimensional measuring device 10 of the embodiment includes multiple (three in this case) measuring devices (LiDAR) 11A, 11B, 11C, pan heads 12A, 12B, 12C on which each measuring device 11A, 11B, 11C is installed and which are capable of numerically controlling the pan (horizontal), tilt (vertical), and roll (rotation) angles (movement) of each measuring device 11A, 11B, 11C, a pan head control device 14 that controls the movement of each pan head 12A, 12B, 12C, and a point cloud processing device 15 that controls each measuring device 11A, 11B, 11C and each pan head 12A, 12B, 12C to acquire measurement data (three-dimensional point cloud data) as a three-dimensional point cloud.

[0041] The point cloud processing device 15 includes a LiDAR measurement data receiving unit 151, an external parameter calculation unit 152, a measurement data storage unit 153, a three-dimensional point cloud storage unit 154, a measurement control determination unit 155, and a LiDAR measurement control unit 156.

[0042] The LiDAR measurement data receiving unit 151 receives the measurement data measured and transmitted by each measuring instrument (LiDAR) 11A, 11B, and 11C.

[0043] The external parameter calculation unit 152 calculates the external parameters of each measuring instrument 11A, 11B, 11C based on the measurement data from each measuring instrument 11A, 11B, 11C received by the LiDAR measurement data receiving unit 151.

[0044] The measurement data storage unit 153 converts the point cloud measurement data of each measuring instrument 11A, 11B, and 11C received by the LiDAR measurement data receiving unit 151 into integrated three-dimensional point cloud data based on the external parameters of each measuring instrument 11A, 11B, and 11C calculated by the external parameter calculation unit 152, and saves (memorizes) the integrated three-dimensional point cloud data in the three-dimensional point cloud memory unit 154 as the measurement result.

[0045] Based on the three-dimensional point cloud data stored (memorized) in the three-dimensional point cloud memory unit 154, the measurement control decision unit 155 confirms the measurement frequency, which is the interval between the measurement timings of each measuring instrument 11A, 11B, and 11C, and the measurement density (resolution), which is, for example, the number of point clouds (measurement points) present within a specific area.

[0046] If the confirmed measurement frequency differs from the specified value (for example, the difference in measurement timing of each of the measuring instruments 11A, 11B, and 11C that was initially set in advance: a certain time dt), the measurement control decision unit 155 instructs the LiDAR measurement control unit 156 to correct the measurement timing.

[0047] In addition, if the confirmed measurement density (resolution) differs from the specified value (for example, if it is less than a predetermined threshold value for the number (density) of point clouds), the measurement control decision unit 155 instructs the camera head control device 14 to change the direction in which each measuring instrument 11A, 11B, and 11C measures.

[0048] The LiDAR measurement control unit 156 controls the measurement timing of each measuring instrument 11A, 11B, 11C in accordance with the deviation (fixed time dt) of the measurement timing of each measuring instrument 11A, 11B, 11C that has been previously initialized by the measurement control decision unit 155 or an instruction to correct the measurement timing from the measurement control decision unit 155.

[0049] FIG. 6 is a block diagram showing the hardware configuration of the three-dimensional measurement apparatus 10 according to the embodiment.

[0050] As shown in FIG. 6, the point cloud processing device 15 of the three-dimensional measuring device 10 includes a control circuit (processor) 21 which is a control unit.

[0051] The point cloud processing device 15 may be a personal computer (PC) or a personal data assistant (PDA) such as a tablet terminal.

[0052] The control circuit 21 is connected via a system and data bus to a memory 22 such as RAM, a storage device 23 including a storage medium 23a such as a magnetic disk or SSD (Solid State Drive), a user interface 24 including keys, switches, a touch panel, an external input terminal for the user to operate from the outside, and a display, speaker, printer, and external output terminal for outputting data, a wired communication module 25 and / or a wireless communication module 26 for communicating with the outside, and the like.

[0053] The measuring instruments 11A, 11B, 11C and the platform control device 14 may be connected to the point cloud processing device 15 via, for example, a wired communication module 25 and / or a wireless communication module 26 .

[0054] The control circuit 21 controls the operation of each part of the point cloud processing device 15 based on the control program that controls the processing of the point cloud processing device 15 and that is stored in the control program area 22a of the memory 22, and on the management information that is stored in or read from the management information area 22b of the memory 22. The control circuit (processor) 21 is not limited to one processor, and may include multiple processors.

[0055] The control program stored in the control program area 22a of the point cloud processing device 15 includes functions corresponding to each process performed by the LiDAR measurement data receiving unit 151, external parameter calculation unit 152, measurement data storage unit 153, three-dimensional point cloud memory unit 154, measurement control determination unit 155, and LiDAR measurement control unit 156 described with reference to Figure 5.

[0056] In addition, the management information area 22b of the point cloud processing device 15 stores or reads data that is input, acquired, generated, updated, output, etc. in accordance with each process performed by the LiDAR measurement data receiving unit 151, external parameter calculation unit 152, measurement data storage unit 153, measurement control determination unit 155, and LiDAR measurement control unit 156 described with reference to Figure 5.

[0057] The storage medium 23a of the point cloud processing device 15 stores or reads data stored (saved) by the three-dimensional point cloud storage unit 154 described with reference to FIG.

[0058] The functions corresponding to the processing performed by the camera head control device 14 may be included in the functions executed by the control circuit (processor) 21 of the point cloud processing device 15 .

[0059] In the 3D measuring device 10 configured in this manner, the control circuit (control unit) of the point cloud processing device 15 controls the operation of each unit in accordance with the commands written in the control program, and the software and hardware work together to realize various functions as described in the operation explanation below.

[0060] (Operation of the embodiment) Next, the operation of the three-dimensional measurement apparatus 10 of the embodiment will be described.

[0061] FIG. 7 is a flowchart showing the three-dimensional measurement process executed by the three-dimensional measurement apparatus 10 of the embodiment.

[0062] Measurement using the three-dimensional measuring device 10 is performed through a process of installing measuring instruments 11A, 11B, and 11C (step S1), a process of calibrating measuring instruments 11A, 11B, and 11C (step S2), and a process of performing measurement (step S3).

[0063] A plurality of measuring instruments (LiDAR) 11A, 11B, and 11C are installed on pan heads 12A, 12B, and 12C fixed to a base 13 in a space where a target object T exists (step S1).

[0064] In this case, as shown in Figure 4, for example, each measuring instrument 11A, 11B, 11C is installed via the pan head control device 14 and the pan heads 12A, 12B, 12c so that the direction in which laser light L1, L2, L3 is irradiated in each measuring instrument 11A, 11B, 11C (the direction in which object T is measured) is shifted by a certain distance dp from the reference measuring instrument 11A.

[0065] The point cloud processing device 15 instructs the measuring instruments 11A, 11B, and 11C and the camera head control device 14 to perform calibration (step S2). Any existing calibration technique may be used for the calibration of each measuring instrument 11A, 11B, and 11C. The point cloud processing device 15 calculates (measures) and saves (stores) the external parameters of each measuring instrument 11A, 11B, and 11C using the external parameter calculation unit 152 based on the measurement data received by the LiDAR measurement data receiving unit 151 from each measuring instrument 11A, 11B, and 11C (steps S21 and S22).

[0066] The point cloud processing device 15 instructs the measuring instruments 11A, 11B, and 11C and the platform control device 14 to start measurement (step S3).

[0067] At this time, as shown in Figure 3, for example, the measurement timing of each measuring instrument 11A, 11B, 11C is controlled according to measurement timing parameters preset by the LiDAR measurement control unit 156 so that the measurement timing (laser light irradiation timing) t11, t21, t31 of each measuring instrument 11A, 11B, 11C is shifted by a certain time dt from the reference measuring instrument 11A, and measurement is started (step S31).

[0068] For example, when measuring instruments 11A, 11B, and 11C measure one frame per second (1 fps), the timing (measurement timing) at which each measuring instrument 11A, 11B, and 11C starts measuring is shifted by a certain time dt (= 0.333 seconds) at a timing of less than one second, so that the first measuring instrument 11A, which serves as the reference, starts at "0.0" seconds, the second measuring instrument 11B at "0.333" seconds, and the third measuring instrument 11C at "0.666" seconds.

[0069] In this case, the measuring instruments 11A, 11B, and 11C perform measurements every fixed time dt (=0.333 seconds), resulting in measurements of 3 frames per second (3 fps), enabling highly frequent measurements to be achieved.

[0070] The three-dimensional point cloud measurement data received sequentially by the LiDAR measurement data receiving unit 151 from each measuring instrument 11A, 11B, 11C is converted into integrated three-dimensional point cloud data by the measurement data storage unit 153 based on the external parameters calculated (measured) and saved (stored) by the external parameter calculation unit 152, and the data is saved (stored) in the three-dimensional point cloud memory unit 154 (steps S31, S32).

[0071] During the process in which the measurement data storage unit 153 converts the measurement data from each measuring instrument 11A, 11B, 11C into integrated three-dimensional point cloud data and stores (stores) it in the three-dimensional point cloud memory unit 154 (steps S31 to S36 → S31), the measurement control decision unit 155 checks the measurement status based on the three-dimensional point cloud data stored in the three-dimensional point cloud memory unit 154 (step S33).

[0072] Specifically, the measurement frequency, which is the interval between the measurement timings of each measuring instrument 11A, 11B, and 11C, and the measurement density (resolution), which is, for example, the number of point clouds (measurement points) present within a specific area, are checked (monitored).

[0073] The specific region in the three-dimensional point cloud data is a specific region where the target object T may exist, and the measurement density (resolution) is confirmed by counting the number of point clouds (measurement points) in a region previously identified as a region where the target object T may exist. Alternatively, any existing object recognition technology may be used to identify a region labeled as the target object T from the three-dimensional point cloud data, and the measurement density (resolution) may be confirmed by counting the number of point clouds (measurement points) in the specific region.

[0074] The number of point clouds (measurement points) within a specific area can be checked (monitored) according to the speed of movement of the target object T; for example, if the movement is faster than a certain level, it can be checked every second, and if the movement is slower than a certain level, it can be checked every minute.

[0075] If the confirmed measurement frequency differs from the specified value (for example, the difference in measurement timing of each of the measuring instruments 11A, 11B, and 11C that was initially set in advance: a certain time dt) ("NG" in step S35), the measurement control decision unit 155 corrects the measurement timing parameters set in the LiDAR measurement control unit 156 and corrects the measurement timing (steps S37, S38).

[0076] For example, depending on the increase (+) or decrease (-) in the measurement timing deviation from the preset initial value (fixed time dt) of each measuring instrument 11A, 11B, 11C, the measurement timing parameters are corrected in the direction of decreasing or increasing the deviation, and measurement by each measuring instrument 11A, 11B, 11C is continued (steps S31, S32).

[0077] Furthermore, if the confirmed measurement density (resolution) differs from the specification (for example, is less than a predetermined threshold value for the number (density) of point clouds) ("NG" in step S34), the measurement control decision unit 155 instructs the pan / tilt head control device 14 to change the measurement direction of each measuring instrument 11A, 11B, 11C so as to track an area where the target object T may exist (for example, a specific area where the object has been recognized), and numerically controls the pan / tilt heads 12A, 12B, 12C to adjust the measurement direction of each measuring instrument 11A, 11B, 11C (step S23).

[0078] In order to track the area where the target object T may be present, object detection technology utilizing AI, for example, may be used, or the pan heads 12A, 12B, and 12C may be remotely controlled, for example, using an electric pan head, to numerically control the pan heads 12A, 12B, and 12C so as to track the target object T.

[0079] Here, if the target object T is a stationary object, the number of point clouds (measurement points) within a specific area does not change, so the adjustment of the measurement direction of each measuring instrument 11A, 11B, and 11C is performed only once in the process of installing each measuring instrument 11A, 11B, and 11C (step S1). On the other hand, if the target object T is a moving object, the number of point clouds (measurement points) within the measured specific area changes, so the measurement direction of each measuring instrument 11A, 11B, and 11C is changed to track an area where the target object T may be present, and is adjusted so that the number of point clouds (density) for the target object T is maintained at or above a threshold.

[0080] In the three-dimensional measuring device 10, as the distance to the target object T increases, the number (density) of point clouds for the target object T becomes sparse. However, as shown in FIG. 4, laser beams L1, L2, and L3 are emitted from multiple (three) measuring instruments 11A, 11B, and 11C so as to be shifted by a fixed interval dp, and therefore, for example, within a certain distance range, the number (density) of point clouds for the target object T is maintained above a threshold value.

[0081] In step S23, if the measurement control determination unit 155 numerically controls the pan / tilt heads 12A, 12B, and 12C via the pan / tilt head control unit 14 and adjusts (changes) the measurement direction of each measuring instrument 11A, 11B, and 11C, the point cloud processing device 15 performs calibration again, and the external parameter calculation unit 152 calculates (measures) and saves (memorizes) new external parameters for each measuring instrument 11A, 11B, and 11C (steps S21, S22).

[0082] In addition, the calculation of new external parameters when the direction in which each measuring instrument 11A, 11B, 11C measures is adjusted (changed) is not limited to calculation (measurement) by performing calibration again, but for example, new external parameters may be calculated based on the numerical value of the external parameters calculated and saved before the change, resulting from the adjustment (change) of the direction.

[0083] After this, in response to a user operation or when the required amount of three-dimensional point cloud data integrating the measurement data from each measuring instrument 11A, 11B, 11C is saved (stored) in the three-dimensional point cloud memory unit 154, an instruction to end measurement is given in the point cloud processing device 15 ("NO" in step S36), and the measurement control decision unit 155 stops the measurement operation of each measuring instrument 11A, 11B, 11C via the LiDAR measurement control unit 156, thereby ending the series of three-dimensional measurement processes.

[0084] (Summary of the embodiment) According to the three-dimensional measuring device 10 of the embodiment, multiple (three) three-dimensional measuring devices (LiDAR) 11A, 11B, 11C are provided, and the measurement timings t11, t12, t13, ... / t21, t22, t23, ... / t31, t32, t33, ... at which the measuring devices 11A, 11B, 11C each irradiate laser light to measure are set to be shifted by a certain time dt from the measurement timings t11, t12, t13, ... of the reference measuring device 11A (see FIG. 3 ), and the directions in which the measuring devices 11A, 11B, 11C each irradiate laser light L1, L2, L3 to measure the target object T are set to be shifted by a certain interval dp from the reference measuring device 11A (see FIG. 4 ).

[0085] The point cloud measurement data measured by each measuring instrument 11A, 11B, and 11C is converted into integrated 3D point cloud data based on external parameters measured (calculated) by calibration of each measuring instrument 11A, 11B, and 11C, and saved (stored) as measurement results. This allows for high-density (high-resolution) and consequently high-frequency 3D measurement.

[0086] Furthermore, according to the embodiment of the three-dimensional measuring device 10, the measurement timing (measurement frequency) of each measuring instrument 11A, 11B, and 11C and the number of point clouds (measurement density) present within a specific area where the target object T may exist are confirmed (monitored) based on the three-dimensional point cloud data of the measurement results.

[0087] If the measurement timing deviation of each of the confirmed measuring instruments 11A, 11B, and 11C differs from the preset measurement timing deviation (dt), the measurement timing is corrected to maintain the preset deviation (dt), and if the number of point clouds existing within the confirmed specific area is less than a preset threshold, the direction in which each measuring instrument 11A, 11B, and 11C measures is changed by controlling the pan heads 12A, 12B, and 12C to track the specific area, and adjustments are made so that the number of point clouds existing within the specific area is maintained above the threshold.

[0088] Therefore, according to the three-dimensional measuring apparatus 10 of the embodiment, it is possible to perform three-dimensional measurement with a certain level of quality even when the object to be measured is moving.

[0089] The methods described in the embodiments may be stored as a program (software means) that can be executed by a computer on a recording medium such as a magnetic disk (e.g., a floppy disk, a hard disk, etc.), an optical disk (e.g., a CD-ROM, a DVD, an MO, etc.), or a semiconductor memory (e.g., a ROM, a RAM, a flash memory, etc.), or may be transmitted and distributed via a communication medium. The program stored on the medium also includes a configuration program that configures the software means (including not only executable programs but also tables and data structures) that the computer executes. The computer that implements this system reads the program stored on the recording medium and, in some cases, configures the software means using the configuration program, and executes the above-described processing by controlling the operation of this software means. The recording medium may be a storage medium, such as a magnetic disk or semiconductor memory, installed inside the computer or in a device connected via a network, and may be distributed for distribution.

[0090] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0091] DESCRIPTION OF SYMBOLS 10 ... 3D measuring device 11A, 11B, 11C... 3D measuring device (LiDAR) 12A, 12B, 12C... Pan head 13... Base 14... Pan head control device 15... Point cloud processing device 151... LiDAR measurement data receiving unit 152... External parameter calculation unit 153... Measurement data storage unit 154... 3D point cloud storage unit 155... Measurement control determination unit 156... LiDAR measurement control unit 21... Control circuit (control unit) 22a... Control program area 22b... Management information area 23a... Storage medium T... Target object t1n, t2n, t3n... Measurement timing L1, L2, L3... Laser light L1n, L2n, L3n... Measurement point

Claims

1. A three-dimensional measuring device comprising a plurality of three-dimensional measuring devices using laser light, setting the measurement timing of each of the three-dimensional measuring devices to be shifted by a fixed time, and setting the measurement direction of each of the three-dimensional measuring devices to be shifted by a fixed interval, and comprising a control unit that executes the following processes: a process of calculating the external parameters of each of the three-dimensional measuring devices; and a process of converting the measurement data of each of the three-dimensional measuring devices into three-dimensional point cloud data integrated based on the external parameters.

2. The three-dimensional measuring device according to claim 1, wherein the control unit checks the measurement timing of each of the three-dimensional measuring devices based on the three-dimensional point cloud data, and if the deviation in each of the measurement timings differs from the certain time, executes a process to correct the deviation in each of the measurement timings so as to maintain it at the certain time.

3. The three-dimensional measuring device according to claim 1 or claim 2, wherein the control unit checks the number of point clouds present in a specific region of the three-dimensional point cloud data, and if the number of point clouds is less than a preset threshold, executes a process of changing the measurement direction of each of the three-dimensional measuring devices so that the number of point clouds is maintained at or above the threshold.

4. The three-dimensional measuring device according to claim 3, wherein the specific area is an area where a target object of the three-dimensional measuring device may exist, and the control unit performs object recognition of the target object based on the three-dimensional point cloud data, and executes processing to change the measurement direction of each of the three-dimensional measuring devices so as to track the specific area in which the recognized target object exists.

5. A three-dimensional measuring device according to claim 3, comprising a plurality of pan heads on which the three-dimensional measuring devices are respectively mounted, and the control unit changes the measuring direction of each of the three-dimensional measuring devices by numerically controlling each of the pan heads.

6. The three-dimensional measuring device according to claim 3, wherein the control unit executes a process of recalculating the external parameters when the measurement direction of each of the three-dimensional measuring devices is changed.

7. A three-dimensional measurement method for a three-dimensional measurement device equipped with a plurality of three-dimensional measuring devices using laser light and a control unit, which sets the measurement timing of each of the three-dimensional measuring devices to be shifted by a fixed time, and sets the measurement direction of each of the three-dimensional measuring devices to be shifted by a fixed interval, and causes the control unit to execute the following processes: calculating external parameters of each of the three-dimensional measuring devices; and converting the measurement data of each of the three-dimensional measuring devices into three-dimensional point cloud data integrated based on the external parameters.

8. A program that causes the control unit of a three-dimensional measuring device equipped with multiple three-dimensional measuring devices using laser light, each with its measurement timing set to be shifted by a fixed time and its measurement direction set to be shifted by a fixed interval, to perform the following processes: calculating the external parameters of each of the three-dimensional measuring devices; and converting the measurement data of each of the three-dimensional measuring devices into three-dimensional point cloud data integrated based on the external parameters.

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