Three-dimensional measuring device

Abstract

To provide a configuration capable of suppressing generation of noise in three-dimensional measurement utilizing event data.SOLUTION: A control section 11 controls a projection section 20 so as to switch on / off of reflection between first measurement timing t1 and second measurement timing t2 as measurement objects during unit time T and multiple other pieces of timing (light retransmission timing t3 and re-extinction timing t4). A measurement section 40 obtains stripe pattern information Is as a time difference of output timing between event data outputted according to the first measurement timing t1 during the unit time T from an image pickup device and event data outputted according to the second measurement timing t2 when measuring a three-dimensional shape of a measurement object R by a phase-shift method by utilizing the stripe pattern information Is obtained from a captured image of a capturing section 30.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a three-dimensional measuring apparatus that measures the three-dimensional shape of a measurement object. [Background technology]

[0002] Conventionally, as a three-dimensional measuring device for measuring the three-dimensional shape of a measurement object, for example, a device using a phase shift method is known. The phase shift method is a technique for projecting a plurality of stripe pattern images with shifted phases, and performing three-dimensional measurement of the measurement object onto which the stripe pattern images are projected.

[0003] In relation to the technology of performing three-dimensional measurement using the phase shift method, a three-dimensional measuring device disclosed in the following Patent Document 1 is known for generating an image of a measurement object at a higher speed. In this three-dimensional measuring device, a sine wave pattern is adopted as a predetermined stripe pattern for the phase shift method, and an event camera is adopted that outputs event data including two-dimensional point data that identifies the position of a pixel corresponding to a pixel that has changed in luminance when receiving light, and is configured to generate a captured image of the measurement object on which a stripe pattern is projected from the event data. The event camera has a feature that it does not output pixel information with no change in luminance, that is, redundant data (event data) like conventional cameras, and therefore, by realizing a reduction in the amount of data communication and a reduction in the amount of image processing, it is possible to obtain information on the shape of the measurement object at a higher speed. On the other hand, since the event data does not contain the luminance information used in the phase shift method, luminance information (stripe pattern information) is obtained based on the time difference between the occurrence time of event data of a positive luminance change (positive polarity event data) that is output on a pixel-by-pixel basis when light is projected and the occurrence time of event data of a negative luminance change (negative polarity event data) that is output when the light is turned off, making it possible to measure the three-dimensional shape of the object to be measured using event data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-067644 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a sine wave stripe pattern as described above is projected, some pixels are turned off late and some are turned off early in the captured image, and the more pixels in the off state, the darker the image. Due to the characteristics of the event camera, even a slight change in brightness in a dark state causes a potential difference and makes it easier for event data to be output, so the darker it becomes, the more likely event data that should not be output is to be generated as noise. Therefore, if a large amount of noise is generated and exceeds the event amount allowed by the event camera and becomes saturated, a problem occurs in which it is not possible to correctly detect brightness changes.

[0006] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a configuration that can suppress the occurrence of noise in three-dimensional measurement using event data. [Means for solving the problem]

[0007] In order to achieve the above object, the invention described in claim 1 of the claims is as follows: a projection unit (20) that projects a predetermined stripe pattern onto a measurement object (R); an imaging unit (30) that images the measurement object onto which the predetermined stripe pattern is projected; a measurement unit (40) that measures a three-dimensional shape of the measurement object by a phase shift method using stripe pattern information (Is) obtained from an image captured by the imaging unit; A control unit (11) that controls the projection unit; A three-dimensional measuring device (10) comprising: The projection unit projects the predetermined stripe pattern by controlling ON / OFF of reflection of incident light by a DMD having a plurality of mirrors arranged in an array by the control unit for each of the mirrors; the control unit controls the projection unit to switch ON / OFF of the reflection at a first measurement timing (t1) and a second measurement timing (t2) that are to be measured during a unit time (T) and at a plurality of other timings (t3, t4); the imaging unit includes an imaging element that outputs event data including two-dimensional point data that identifies a position of a pixel corresponding to a pixel that has undergone a luminance change upon receiving light, and generates the captured image from the event data output from the imaging element; the imaging device is configured to output positive event data when the luminance changes to brighter, and to output negative event data when the luminance changes to darker; The measurement unit is characterized in that it obtains the stripe pattern information as a time difference between the output timing of event data output from the imaging element in accordance with the first measurement timing and the output timing of event data output in accordance with the second measurement timing during the unit time. The symbols in parentheses above indicate the corresponding relationship with the specific means described in the embodiments described later. Effect of the Invention

[0008] In the invention of claim 1, the projection unit projects a predetermined stripe pattern onto the measurement object by controlling the ON / OFF of reflection of incident light by a DMD having multiple mirrors arranged in an array by the control unit for each mirror. The control unit controls the projection unit to switch the ON / OFF of the reflection at a first measurement timing, a second measurement timing, and multiple other timings that are to be measured during a unit time. When measuring the three-dimensional shape of the measurement object by a phase shift method using stripe pattern information obtained from an image captured by the imaging unit, the measurement unit obtains the stripe pattern information as a time difference between the output timing of event data output from the imaging element in response to the first measurement timing and the output timing of event data output in response to the second measurement timing during the unit time.

[0009] As a result, by obtaining stripe pattern information as the time difference between the output timing of event data output according to the first measurement timing and the output timing of event data output according to the second measurement timing in a unit time (for example, the time difference between the output timing of positive polarity event data output first and negative polarity event data output next in a unit time), it is possible to measure the three-dimensional shape of the measurement object using the event data. In particular, since the reflection is switched ON / OFF again at a timing different from the first measurement timing and the second measurement timing in a unit time, compared to a case where the reflection is switched ON / OFF only at the first measurement timing and the second measurement timing, an image is captured in a brighter state, and the generation of noise is suppressed. Therefore, it is possible to realize a three-dimensional measuring device that can suppress the generation of noise in three-dimensional measurement using event data.

[0010] In the invention of claim 2, the control unit outputs a projection start signal to the measurement unit in accordance with the projection start timing of a predetermined stripe pattern, the first measurement timing is the projection start timing, and the measurement unit obtains stripe pattern information using the input timing of the projection start signal from the control unit as the first measurement timing.

[0011] This makes it possible to shorten processing time and further speed up image generation of the object to be measured, since it is only necessary to obtain the output timing of the event data output according to the second measurement timing, without obtaining the output timing of both the event data output according to the first measurement timing and the event data output according to the second measurement timing for all pixels. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a schematic configuration of a three-dimensional measuring apparatus according to a first embodiment. [Diagram 2]FIG. 1 is an explanatory diagram illustrating a state in which a stripe pattern for a general phase shift method is projected onto a measurement object. [Diagram 3] 1A and 1B are diagrams illustrating three-dimensional measurement by a phase shift method. [Figure 4] 5 is an explanatory diagram illustrating a relationship between a first measurement timing, a second measurement timing, a light re-emission timing, and a light-off timing in a unit time in the first embodiment. FIG. [Diagram 5] 10 is an explanatory diagram illustrating the relationship between a luminance value and a detected voltage value in the event camera. [Figure 6] FIG. 6(A) is an explanatory diagram illustrating a verification pattern in which the range that becomes gradually darker expands, and FIG. 6(B) is an explanatory diagram illustrating the event amount output when a surface onto which the verification pattern of FIG. 6(A) is projected is imaged with an event camera. [Figure 7] FIG. 7(A) is an explanatory diagram illustrating a verification pattern in which reflection is switched ON / OFF again in comparison with FIG. 6(A), and FIG. 7(B) is an explanatory diagram illustrating the event amount output when a surface onto which the verification pattern of FIG. 7(A) is projected is imaged with an event camera. [Figure 8] 13 is an explanatory diagram illustrating the relationship between the projection start timing, the projection end timing, the input timing of the projection start signal, the input timing of the projection end signal, the imaging start timing, and the imaging end timing in the second embodiment. FIG. [Figure 9] FIG. 13 is an explanatory diagram illustrating an example in which stripe pattern information is obtained as a time difference between two positive polarity event data. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [First embodiment] Hereinafter, a first embodiment of a three-dimensional measuring device according to the present invention will be described with reference to the drawings. The three-dimensional measuring device 10 according to the present embodiment is a device for measuring the three-dimensional shape of a measurement object R, and is configured to include a control unit 11 for overall control, a projection unit 20 for projecting a predetermined stripe pattern for the phase shift method onto the measurement object R, an imaging unit 30 for capturing an image of the measurement object R onto which the predetermined stripe pattern is projected, and a measurement unit 40 for measuring the three-dimensional shape of the measurement object R from the captured image, as shown in Figs. 1 and 2. The three-dimensional measuring device 10 configured in this manner measures the three-dimensional shape of the measurement object R, such as a workpiece, which is attached to the hand of a robot, for example, and moves relatively to the hand at high speed. Here, the relative movement refers to the relative movement between the movement of the three-dimensional measuring device 10 attached to the hand of the robot and the high-speed movement of the measurement object R. When the position of the three-dimensional measuring device 10 is fixed, the relative movement is the movement of the measurement object R.

[0014] For convenience, a typical stripe pattern having up to 13 stripes is shown in a simplified form in Fig. 2. More specifically, a typical stripe pattern is represented as a sine wave pattern, so the light and dark parts of the stripe pattern have the same width, but for convenience, the dark parts are shown as lines with smaller widths in Fig. 2. Also, the number of stripes is 13 or more in the embodiment, but is abbreviated to 13.

[0015] The control unit 11 is mainly composed of a microcomputer and has a CPU, a system bus, an input / output interface, etc., and constitutes an information processing device together with a storage unit consisting of a ROM, a RAM, a non-volatile memory, etc. In addition to programs related to robot control, the storage unit stores in advance programs related to control of the projection unit 20 and programs for executing control processing using the three-dimensional measurement results by the measurement unit 40, etc., which are executable by the control unit 11.

[0016] The projection unit 20 is a so-called DLP projector, and is controlled by the control unit 11 to project a predetermined stripe pattern, which will be described later, by reflecting light from a light source with a DMD element. The DMD element is an array of fine mirrors corresponding to each pixel of an image projected on a screen, and is configured to turn on / off the light emitted to the screen by changing the angle of each mirror in microseconds. Therefore, the state is switched to a light-projecting state by changing from reflection OFF to reflection ON, and the state is switched to an extinguishing state by changing from reflection ON to reflection OFF, on a mirror-by-mirror basis. That is, the projection unit 20 functions to project a predetermined stripe pattern by controlling, for each mirror, the ON / OFF of the reflection of incident light by the DMD, which is an array of multiple mirrors, by the control unit 11. Therefore, the gradation (brightness) of the reflected light is changed depending on the ratio of the time each mirror is turned on and off, thereby making it possible to display gradations based on the image data of the image to be projected.

[0017] In such a configuration, the longer the light emission time (the time from reflection ON to reflection OFF) of the single pulse light emitted once within the unit time secured for each light emission state, the brighter the light emission state becomes, so that the light emission state can be specified according to the light emission time. In the case where the upper left pixel in FIG. 2 is (1, 1) and the lower right pixel is (k, l), the projection unit 20 is provided with mirrors corresponding to k×l pixels (for example, 1140×912). In addition, for example, when R (red), G (green), and B (blue) colors are prepared as light incident on the DMD element, an R light emission state in which R light is emitted by reflecting on the mirror, a G light emission state in which G light is emitted by reflecting on the mirror, and a B light emission state in which B light is emitted by reflecting on the mirror are repeated in a short predetermined cycle, and the light emission time of each is individually adjusted, so that a color image can be projected. For this reason, the control unit 11 functions to set the reflection ON / OFF timing within the unit time for each mirror according to a predetermined stripe pattern described later.

[0018] The imaging unit 30 is a so-called event camera, and is equipped with an imaging element that outputs event data (specifically, two-dimensional point data, time, and polarity of brightness change) including two-dimensional point data that identifies the position of a pixel corresponding to a pixel that has undergone a brightness change when light is received, and is configured to be able to generate an image from the event data output from the imaging element. For this reason, the imaging unit 30 outputs event data of positive polarity (positive brightness change) when a brightness change occurs that makes the pixel brighter by receiving light, and outputs event data of negative polarity (negative brightness change) when a brightness change occurs that makes the pixel darker by extinguishing the light. Image data of the measurement object R can be generated by plotting the two-dimensional point data of a plurality of event data output within a certain period of time as points on a predetermined plane, and the imaging unit 30 is configured to output the image data or event data (two-dimensional point data, time, and polarity of brightness change) generated in this way to the measurement unit 40.

[0019] The measurement unit 40 is controlled by the control unit 11 and measures the three-dimensional shape of the measurement object R using a phase shift method based on an image captured by the imaging unit 30 of the measurement object R in a state where a predetermined stripe pattern is projected from the projection unit 20.

[0020] Generally, in the phase shift method, a sine wave pattern specified by the luminance value I(x,y,n) in the following formula (1) is adopted in order to obtain a phase value θ corresponding to a distorted value according to the surface shape of the measurement object R based on a lattice image (stripe image) captured by projecting a predetermined stripe pattern (a pattern in which the luminance changes periodically in a first direction and does not change in a second direction perpendicular to the first direction) onto the measurement object R. That is, when the number of phase shifts is N, the luminance values ​​I(x,y,n) of N phase-shifted lattice images (stripe images) are expressed by formula (1). I(x,y,n)=a(x,y)cos{θ(x,y)+2πn / N}+b(x,y) (1) Here, point (x, y) is a point in the lattice image, a(x, y) indicates the luminance amplitude, b(x, y) indicates the background luminance, and θ(x, y) indicates the phase value of the lattice where n=0. The distance z to point (x, y) is measured according to the phase value θ(x, y) calculated from the luminance values ​​I(x, y, n) of the N lattice images.

[0021] Specifically, for example, when three grating images are obtained in one period of the above-mentioned R, G, and B light emission states, the luminance value I(x, y, 0) in the R light emission state, the luminance value I(x, y, 1) in the G light emission state, and the luminance value I(x, y, 2) in the B light emission state are obtained from the captured image with N = 3. In this case, the predetermined stripe pattern for the phase shift method is configured such that the phases of a sine wave pattern consisting of only R, a sine wave pattern consisting of only G, and a sine wave pattern consisting of only B are shifted by 2π / 3.

[0022] When the luminance values ​​I(x,y,0), I(x,y,1), and I(x,y,2) at the point (x,y) in the captured image are obtained, the measurement unit 40 obtains the phase value θ(x,y) using the above formula (1) and measures the distance z to the point (x,y) according to the phase value θ(x,y) thus obtained. By measuring the distance z to each point (x,y) of the captured measurement object R in this manner, the three-dimensional shape of the measurement object R can be measured.

[0023] For example, when determining the distance z of point P1 in FIG. 3, the phase value θ of point P1 and information on which stripe the point P1 is located (stripe number) are obtained from N captured images of the imaging unit 30 in a state where a predetermined stripe pattern is shifted and projected by the projection unit 20 N times. When the angle θp1 at the projection unit 20 and the angle θc1 at the imaging unit 30 are obtained from the phase value θ and stripe number obtained in this way, the distance z of point P1 can be obtained by triangulation since the distance (parallax L) between the projection unit 20 and the imaging unit 30 is known. Similarly, the distance z of point P2 in FIG. 3 can be obtained by triangulation based on the angle θp2 at the projection unit 20 and the angle θc2 at the imaging unit 30 obtained from the phase value θ of point P2 obtained from the N captured images and the stripe number. By performing this calculation over the entire measurement area, three-dimensional measurement can be performed.

[0024] Here, the three-dimensional measurement process performed by the measurement unit 40 when measuring the three-dimensional shape of the measurement object R using the phase shift method will be described in detail with reference to the drawings. In this embodiment, an event camera is used as an imaging unit for accurately imaging the measurement target R that moves relatively at high speed. In such a configuration, event data corresponding to pixels where a luminance change occurs is output, but the event data does not include a luminance value, so that it is not possible to directly obtain the luminance values ​​(e.g., I(x,y,0), I(x,y,1), and I(x,y,2)) required for the phase shift method.

[0025] For this reason, in this embodiment, stripe pattern information Is(x,y,n) corresponding to the luminance value I(x,y,n) is obtained as the time difference between the output timing of the positive polarity event data (see the upward arrow in FIG. 4) that is output first in a unit time T and the negative polarity event data (see the downward arrow in FIG. 4) that is output next, as shown in FIG. 4. That is, in this embodiment, in the captured image of the measurement target R in a state where a predetermined stripe pattern is projected from the projection unit 20, the actual luminance value is not obtained for each pixel, but the time difference between the output timing of two event data generated by reflection ON (light projection state) at the first measurement timing t1 and reflection OFF (light off state) at the second measurement timing t2 that are the measurement target assuming that a stripe pattern of a sine wave pattern is projected is obtained as stripe pattern information Is(x,y,n) for each pixel.

[0026] The stripe pattern information Is(x,y,n) obtained in this manner is affected by the three-dimensional shape of the measurement object R, so that the phase value θ(x,y) can be obtained using the following equation (2). Is(x,y,n)=a(x,y)cos{θ(x,y)+2πn / N} +b(x,y) (2)

[0027] In this embodiment, as shown in Fig. 4, the first measurement timing t1 is the timing to start projection of a predetermined stripe pattern and is set as the timing to switch reflection ON (light projection state). Also, the second measurement timing t2 is set as the timing to switch the reflection ON switched at the first measurement timing t1 to reflection OFF (light off state).

[0028] Particularly, in this embodiment, the control unit 11 controls the projection unit 20 to switch reflection ON / OFF again after switching reflection ON / OFF at the above-described first measurement timing t1 and second measurement timing t2 during the unit time T. More specifically, the control unit 11 controls the projection unit 20 to switch reflection ON (light-projecting state) at a light-reprojection timing t3 immediately after switching to reflection OFF (light-off state) at the second measurement timing t2, and to switch reflection OFF (light-off state) at a light-reprojection timing t4 immediately before the end of the unit time T, as shown in FIG.

[0029] Here, the reason for controlling the projection unit 20 so as to switch reflection ON / OFF again during the unit time T will be described with reference to FIGS. Figure 5 shows the relationship between the brightness value and the detection voltage value in an event camera, and as can be seen from this figure, due to the characteristics of the event camera, in bright conditions, the potential difference caused by a change in brightness is small (see symbols ΔI1 and ΔV1 in Figure 5), so event data is not output unless there is a large change in brightness. On the other hand, in dark conditions, even a small change in brightness causes a potential difference (see symbols ΔI2 and ΔV2 in Figure 5), so the sensitivity value decreases and event data is more likely to be output. As a result, the darker it becomes, the more likely event data that should not be output is generated as noise.

[0030] For example, as shown in FIG. 6(A), when a surface onto which a verification pattern with a gradually darkening range is projected is imaged, a large amount of noise occurs after reflection OFF (light-off state) in the event data outputted when imaging the surface (see range D1 in FIG. 6(B)). In addition, in the x pixel with a long light projection time (late timing of reflection OFF), noise occurs even before reflection OFF (light-off state) (see range D2 in FIG. 6(B)). Note that the above verification pattern is a projection pattern in which the vertical direction (y coordinate) has the same brightness, and the horizontal direction (x coordinate) becomes brighter (the timing of reflection OFF becomes later) by gradually lengthening the light projection time toward the right (as x becomes larger). In FIG. 6(A) and FIG. 7(A) described later, the range of the light projection state is hatched. In addition, in FIG. 6(B), the horizontal axis is x pixels (pixels based on the x coordinate) and the vertical axis is the event occurrence time at which the event data occurred, and since y pixels are used in the depth direction, multiple event occurrence times with different y pixels are plotted for the same x pixel.

[0031] If a large amount of noise like this occurs and exceeds the event amount allowable in the event camera, causing saturation, problems will occur such as the inability to correctly detect changes in luminance.

[0032] 4, in this embodiment, reflection is switched to ON (light-projecting state) at light-reprojection timing t3 immediately after switching to reflection OFF (light-out state) at second measurement timing t2, and is switched to reflection OFF (light-out state) at light-reprojection timing t4 immediately before the end of unit time T, thereby switching reflection ON / OFF again during unit time T. That is, in order to prevent a decrease in the sensitivity value of the event camera, a predetermined stripe pattern is projected so as to reproject light during unit time T.

[0033] Fig. 7(B) shows the event data output when imaging a surface onto which a verification pattern (see Fig. 7(A)) is projected in which reflection is switched ON / OFF again as described above, in addition to the verification pattern in Fig. 6(A). Fig. 7(B) shows that noise generation is suppressed after reflection is turned OFF (light-out state). It also shows that noise generation is suppressed before reflection is turned OFF, even for x pixels with a long light projection time.

[0034] In this way, it is possible to suppress the occurrence of noise by switching reflection ON / OFF again during the unit time T. On the other hand, the event data corresponding to the re-projection timing t3 and the event data corresponding to the re-off timing t4 caused by the re-switching as described above can be ignored and not used in the calculation of the stripe pattern information Is.

[0035] As described above, in the three-dimensional measuring device 10 according to this embodiment, the control unit 11 controls the projection unit 20 to switch ON / OFF of the reflection at the first measurement timing t1 and the second measurement timing t2 and other timings (re-light-projection timing t3 and re-light-off timing t4) that are to be measured during the unit time T. When measuring the three-dimensional shape of the measurement object R by the phase shift method using the stripe pattern information Is obtained from the image captured by the imaging unit 30, the measurement unit 40 obtains the stripe pattern information Is as the time difference between the output timing of event data output from the imaging element in response to the first measurement timing t1 and the output timing of event data output in response to the second measurement timing t2 during the unit time T.

[0036] As a result, by obtaining stripe pattern information Is as the time difference between the output timing of event data output in response to the first measurement timing t1 and the output timing of event data output in response to the second measurement timing t2 during unit time T, it is possible to measure the three-dimensional shape of the measurement object R using the event data. In particular, during unit time T, the reflection is switched ON / OFF again at timings (re-projection timing t3 and re-off timing t4) different from the first measurement timing t1 and the second measurement timing t2, so that imaging is performed in a brighter state than when the reflection is switched ON / OFF only at the first measurement timing t1 and the second measurement timing t2, and therefore the generation of noise is suppressed. Therefore, it is possible to realize a three-dimensional measuring device that can suppress the generation of noise in three-dimensional measurement using event data.

[0037] During the unit time T, not only is reflection ON / OFF switching performed at the re-projection timing t3 and the re-extinguishing timing t4 after reflection ON / OFF switching at the first measurement timing t1 and the second measurement timing t2, but also one or more reflection ON / OFF switchings can be performed to capture an image in a brighter state, thereby achieving the above-mentioned effect.

[0038] [Second embodiment] Next, a three-dimensional measuring apparatus according to a second embodiment of the present invention will be described with reference to the drawings. The second embodiment is different from the first embodiment in that the input timing of the projection start signal from the control unit is used as the first measurement timing. Therefore, the same reference numerals are used for the components that are substantially the same as those in the first embodiment, and the description thereof will be omitted.

[0039] In this embodiment, the control unit 11 outputs a start light emission instruction signal to the projection unit 20 to start the projection of a predetermined stripe pattern, and the projection unit 20, to which this start light emission instruction signal is input, starts projecting the predetermined stripe pattern. At this time, the control unit 11 outputs a projection start signal S1 to the measurement unit 40 and the imaging unit 30 as a synchronization signal synchronized with the start light emission instruction signal, as shown in FIG. 8. The control unit 11 also outputs a stop light emission instruction signal to the projection unit 20 to end the projection of the predetermined stripe pattern, and the projection unit 20, to which this stop light emission instruction signal is input, ends the projection of the predetermined stripe pattern. At this time, the control unit 11 outputs a projection end signal S2 to the measurement unit 40 and the imaging unit 30 as a synchronization signal synchronized with the stop light emission instruction signal.

[0040] The imaging unit 30 starts imaging at the timing when the projection start signal S1 is input from the control unit 11, and ends imaging when the projection end signal S2 is input thereafter. Therefore, in the imaging unit 30, positive polarity event data is generated and output in all pixels at the timing when the projection start signal S1 is input. Thereafter, in the imaging unit 30, negative polarity event data is generated and output later for brighter pixels until the projection end signal S2 is input. Note that the imaging unit 30 may end imaging after a specified time has elapsed since the input time of the projection start signal S1, without using the projection end signal S2.

[0041] Therefore, in the measurement unit 40, at the timing when the projection start signal S1 is input from the control unit 11, positive polarity event data is input from the imaging unit 30 for all pixels, and then, negative polarity event data is input from the imaging unit 30 at different timings for each pixel.

[0042] That is, the occurrence time of the positive polarity event data coincides with the input time of the projection start signal S1, and the negative polarity event data is output after the input time of the projection start signal S1. Therefore, the stripe pattern information Is can be obtained for each pixel based on the time difference between the input time of the projection start signal S1 when the above-mentioned predetermined stripe pattern is projected and the occurrence time of the event data output after that input time.

[0043] As described above, in the three-dimensional measuring device 10 according to this embodiment, the control unit 11 outputs a projection start signal S1 to the measurement unit 40 in accordance with the projection start timing of a predetermined stripe pattern, the first measurement timing is the projection start timing, and the measurement unit determines stripe pattern information Is using the input timing of the projection start signal S1 from the control unit 11 as the first measurement timing t1.

[0044] As a result, it is not necessary to obtain the output timing of both the event data output in accordance with the first measurement timing t1 and the event data output in accordance with the second measurement timing t2 for all pixels, but rather it is necessary to obtain the output timing of only the event data output in accordance with the second measurement timing t2, thereby shortening the processing time and further speeding up the generation of an image of the measurement object R.

[0045] The present invention is not limited to the above-described embodiment, and may be embodied as follows, for example. (1) The stripe pattern information Is is not limited to being obtained as the time difference between the output timing of positive polarity event data outputted first and negative polarity event data outputted next in unit time T, but may be obtained as the time difference between the output timing of positive polarity event data outputted at the first light projection and the output timing of positive polarity event data outputted at the next light projection in unit time T, as illustrated in Fig. 9. In this case, the first measurement timing t1 and the second measurement timing t2 to be measured are the timing of the first reflection ON and the timing of the next reflection ON in unit time T, as illustrated in Fig. 9. In other words, on the premise that the timings of the first measurement timing and the second measurement timing are determined in advance, the stripe pattern information Is can be obtained as the time difference between the output timing of event data outputted from the imaging element according to the first measurement timing and the output timing of event data outputted according to the second measurement timing in unit time T.

[0046] (2) The three-dimensional measuring device 10 may be configured such that the projection unit 20, the imaging unit 30 and the measurement unit 40 are separate entities, and the measurement unit 40 is configured as an information processing terminal capable of wireless or wired communication with the projection unit 20 and the imaging unit 30. [Explanation of symbols]

[0047] 10...3D measuring device 11...Control section 20…Projection section 30…Imaging unit 40…Measuring section R: Measurement target T…unit time t1…First measurement timing t2: Second measurement timing S1…Projection start signal

Claims

1. A projection unit that projects a predetermined stripe pattern onto an object to be measured, An imaging unit that images the object to be measured onto which the predetermined stripe pattern has been projected, A measurement unit that measures the three-dimensional shape of the object to be measured using stripe pattern information obtained from an image captured by the imaging unit, A control unit that controls the projection unit, A three-dimensional measurement device comprising: The projection unit projects the predetermined stripe pattern by controlling, for each mirror, the ON / OFF of the reflection of incident light by a DMD in which a plurality of mirrors are arranged in an array, The control unit controls the projection unit to switch the ON / OFF of the reflection at a first measurement timing and a second measurement timing to be measured and a plurality of other timings within a unit time, The imaging unit includes an image sensor that outputs event data including two-dimensional point data in which the position of a pixel is specified corresponding to a pixel having a luminance change when receiving light, and generates the captured image from the event data output from the image sensor, The image sensor is configured to output positive-polarity event data in the case of a luminance change to bright and negative-polarity event data in the case of a luminance change to dark, The measurement unit obtains the stripe pattern information as a time difference in output timing between event data output from the image sensor in accordance with the first measurement timing and event data output in accordance with the second measurement timing within the unit time. A three-dimensional measurement device characterized by this.

2. The control unit outputs a projection start signal to the measurement unit in accordance with the projection start timing of the predetermined stripe pattern, The first measurement timing is the projection start timing, The three-dimensional measurement device according to claim 1, wherein the measurement unit obtains the stripe pattern information using the input timing of the projection start signal from the control unit as the first measurement timing.

Images