Measuring apparatus, measuring method and program

Abstract

To provide a measuring apparatus capable of preventing discontinuity of a phase of a laser beam and deterioration in measurement accuracy.SOLUTION: A measuring apparatus includes: a control part configured to control a control current value for sweeping a wavelength of a laser beam within a mode region determined on the basis of a value of the wavelength of the laser beam emitted in a prescribed direction; and a measurement part configured to generate point group data of an object present in the prescribed direction by using the wavelength-swept laser beam within the mode region.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a measuring device, a measuring method, and a program.

Background Art

[0002] In recent years, as a technique for specifying the position and shape of a measurement target in three dimensions, the use of LiDAR (Light Ranging and Detection) has been considered. Wavelength-scanning LiDAR, which is a type of LiDAR, can perform high-speed three-dimensional imaging of a measurement target by utilizing the coherence of light. For example, wavelength-scanning LiDAR using a wavelength-variable light source is used as an important technique in the field of autonomous driving that requires real-time in-space position measurement.

[0003] Patent Document 1 discloses a configuration of a system that scans a sample by changing the wavelength over time.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, mode hopping is not considered when changing the wavelength. Therefore, as a result of mode hopping occurring during scanning of a measurement target existing in a specific direction, the phase of the laser light becomes discontinuous, and there is a problem that the measurement accuracy decreases.

[0006] An object of the present disclosure is to provide a measuring device, a measuring method, and a program capable of preventing the phase of laser light from becoming discontinuous and reducing the measurement accuracy.

Means for Solving the Problems

[0007] The measuring device according to the first aspect of the present disclosure includes a control unit that controls a control current value for sweeping the wavelength of the laser light within a mode region determined based on the value of the wavelength of the laser light output in a predetermined direction, and a measurement unit that generates point cloud data of an object existing in the predetermined direction using the laser light whose wavelength has been swept within the mode region.

[0008] The measuring method according to the second aspect of the present disclosure controls a control current value for sweeping the wavelength of the laser light within a mode region determined based on the value of the wavelength of the laser light output in a predetermined direction, and generates point cloud data of an object existing in the predetermined direction using the laser light whose wavelength has been swept within the mode region.

[0009] The program according to the third aspect of the present disclosure causes a computer to control a control current value for sweeping the wavelength of the laser light within a mode region determined based on the value of the wavelength of the laser light output in a predetermined direction, and generate point cloud data of an object existing in the predetermined direction using the laser light whose wavelength has been swept within the mode region.

Advantages of the Invention

[0010] According to the present disclosure, it is possible to provide a measuring device, a measuring method, and a program that can prevent the phase of the laser light from becoming discontinuous and reduce the measurement accuracy.

Brief Description of the Drawings

[0011]

Figure 1

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Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0012] (Embodiment 1) Hereinafter, a configuration example of the measuring device 10 will be described with reference to FIG. 1. The measuring device 10 may be a computer device that operates by a processor executing a program stored in a memory. Further, the measuring device 10 may be, for example, a device that measures the distance from the measuring device to an object to be measured. Specifically, the measuring device 10 may be a LiDAR (Light Detection And Ranging) device. The LiDAR device measures the distance to an object using the ToF (Time of Flight) method or the FMCW (Frequency Modulated Continuous Wave) method, and generates points indicating the shape of the object. A set of points indicating the shape of the object becomes point cloud data. The points indicating the shape of the object may be specified using three-dimensional coordinates in a predetermined space. In other words, the points indicating the shape of the object may be shown using three-dimensional coordinates in a predetermined coordinate system. The points specified using three-dimensional coordinates and the point cloud data that is a set of points may be referred to as three-dimensional data.

[0013] The measuring device 10 has a control unit 11 and a measuring unit 12. The control unit 11 and the measuring unit 12 may be software or modules in which processing is executed by a processor executing a program stored in a memory. Alternatively, the control unit 11 and the measuring unit 12 may be hardware such as a circuit or a chip.

[0014] The control unit 11 controls a control current value for sweeping the wavelength of the laser light within a mode region determined based on the value of the wavelength of the laser light output in a predetermined direction. The control unit 11 may be used as means for controlling the control current value. The laser light output from the measuring device 10 has an output direction determined based on the value of the wavelength of the laser light. That is, the control unit 11 changes the output direction of the laser light by changing the value of the wavelength of the laser light. In other words, the control unit 11 can output the laser light to a region having a plurality of locations or a predetermined area by changing the value of the wavelength of the laser light.

[0015] The mode corresponds to the value of the wavelength when light resonates and is output as laser light. The mode region may be a range of control current values that can be changed without changing the value of the wavelength. That is, the mode region may be associated with a range of control current values that can maintain the position of the mode in which light resonates. "Without changing the value of the wavelength" may include fluctuations of a sufficiently small value with respect to the value of the wavelength associated with the mode region. The value of the wavelength associated with the mode region may also be referred to as the value of the wavelength indicating the position of the mode. The control current is the current injected into the measuring device 10 to control the wavelength of the laser light. Controlling the wavelength of the laser light may mean changing the wavelength of the laser light. Also, controlling the control current value may mean changing the control current value within the mode region, for example, increasing or decreasing the control current value.

[0016] By changing the control current within the mode region, the wavelength of the laser light will vary. However, in this case, the fluctuation range of the wavelength is a value that is sufficiently small compared to the wavelength value indicating the position of the mode. Utilizing the wavelength fluctuation that occurs by changing the control current within the mode region, the wavelength sweep of the laser light is performed. In other words, the wavelength sweep of the laser light is performed by changing the control current so that mode hopping does not occur. Mode hopping is the change of the mode of the laser light in a resonant state due to the fluctuation of the control current.

[0017] The measurement unit 12 generates point cloud data of an object existing in a predetermined direction using the laser light whose wavelength is swept within the mode region. The measurement unit 12 may be used as means for generating the point cloud data. The laser light whose wavelength is swept is reflected by the object as laser light having different frequencies. For example, the measurement unit 12 may specify the distance between the measuring device 10 and the object based on the time from when the laser light is output until the reflected light having the same frequency as the output laser light is received. The wavelength of the laser light output from the measuring device 10 may be changed to increase monotonically, may be changed to decrease monotonically, or may be changed randomly.

[0018] Subsequently, the flow of the measurement process executed in the measuring device 10 will be described with reference to FIG. 2. First, the control unit 11 controls the control current value for sweeping the wavelength of the laser light within the mode region determined based on the wavelength value of the laser light output in a predetermined direction (S11). Next, the measurement unit 12 generates point cloud data of an object existing in a predetermined direction using the laser light whose wavelength is swept within the mode region (S12).

[0019] As described above, when the measuring device 10 performs wavelength sweeping of the laser light, it controls the control current so that mode hopping does not occur. Therefore, when scanning an object existing in a predetermined direction, an event in which the phase of the laser light becomes discontinuous can be avoided. As a result, the measuring device 10 can maintain the measurement accuracy regarding distance measurement.

[0020] (Embodiment 2) Subsequently, a configuration example of the measuring device 20 will be described with reference to FIG. 3. In the measuring device 20, detailed descriptions of functions and processes similar to those of the measuring device 10 will be omitted. The measuring device 20 includes a control unit 21, a detection unit 22, a light source unit 23, a splitter 24, a mirror 25, and a dispersion unit 26. The control unit 21 corresponds to the control unit 11 in the measuring device 10. The detection unit 22 corresponds to the measurement unit 12 in the measuring device 10.

[0021] The light source unit 23 may be a laser light source that outputs laser light. Further, the light source unit 23 may be a wavelength tunable light source that switches the wavelength of the laser light and performs wavelength sweeping. The light source unit 23 may be used as a means for outputting laser light. The light source unit 23 performs, for example, an operation in the FMCW method. In the operation of the FMCW method, the light source unit 23 outputs laser light of a certain frequency while frequency-modulating it for a certain period. The laser light of a certain frequency may be regarded as laser light within a certain mode region. Also, the light source unit 23 may be regarded as performing wavelength sweeping for a certain period in order to perform frequency modulation. The certain period may be a period for measuring a predetermined region of the object 30.

[0022] Furthermore, when changing the area to be measured on the object 30, the light source unit 23 switches the wavelength of the laser light. Switching the wavelength of the laser light may also be referred to as changing the wavelength of the laser light. Switching the wavelength of the laser light may also be changing the wavelength of the laser light to the wavelengths of different modes. Here, it is assumed that the wavelength sweep range is sufficiently small compared to the values of the wavelengths regarded as the same mode region. For example, when the mode region is associated with each 1 nanometer, the wavelength sweep range is set to a value sufficiently smaller than 1 nanometer.

[0023] Here, with reference to FIG. 4, the scanning of the object 30 will be described. The object 30 may be a moving object, an object fixed at a specific position, or a stationary object. Scanning the object 30 may also be referred to as scanning the object 30. Scanning the object 30 may also be obtaining information regarding the surface or line of the object by outputting laser light to the surface of the object so as to trace the surface of the object. The information regarding the surface or line of the object may be, for example, three-dimensional data.

[0024] The area surrounded by the square in FIG. 4 indicates the area of the surface of the object 30. Further, each point within the area surrounded by the square indicates a scanning point. The light source unit 23 performs wavelength sweeping within one mode area in order to acquire three-dimensional data of one scanning point. Further, the light source unit 23 adjusts the position where the laser light hits the object 30 by switching the wavelength of the laser light in order to acquire three-dimensional data of each scanning point along the dotted arrow. The three-dimensional data may be referred to as point cloud data. When the acquisition of the three-dimensional data of the scanning points on the dotted arrow is completed, the light source unit 23 changes the output direction of the laser light using, for example, a mirror or the like in order to acquire the three-dimensional data of the scanning points along a different dotted arrow. Specifically, when the light source unit 23 changes the output direction of the laser light in the vertical direction of FIG. 4, a mirror or the like may be used. Using a mirror may also mean adjusting the reflection angle of the laser light reflected by the mirror. The dotted arrow may be referred to as a scanning axis. The time required to change the scanning axis using a mirror or the like may be longer than the time required to change the scanning points to be measured on the scanning axis.

[0025] Here, a detailed configuration example of the light source unit 23 will be described with reference to FIG. 5. The light source unit 23 includes a rear mirror 41, a phase shifter 43, and a front mirror 44. A control current I_rm is input to the rear mirror 41, and a control current I_fm is input to the front mirror 44. The rear mirror 41 and the front mirror 44 operate as a resonator that resonates light having a specific wavelength and outputs laser light. The specific wavelength is determined based on the values of the control currents I_rm and I_fm. That is, the control unit 21 controls the values of the control currents I_rm and I_fm input to the light source unit 23 to output laser light of different wavelengths from the light source unit 23.

[0026] A control current \(I_{ph}\) is input to the phase shifter 43. The phase shifter 43 changes the phase of the resonant light based on the control current \(I_{ph}\). Changing the phase of the light may also be referred to as shifting the phase of the light. Also, as the control current \(I_{ph}\) input to the phase shifter 43 changes, the wavelength of the laser light also changes. It is assumed that the amount of change in the wavelength changed by the control of the phase shifter 43 is sufficiently small compared to the amount of change in the wavelength changed by the control of the rear mirror 41 and the front mirror 44.

[0027] A drive current \(I_{g}\) is input to the active region 42. In the active region 42, amplification of the resonant light is performed. Also, as the control current \(I_{g}\) input to the active region 42 changes, the wavelength of the laser light also changes. It is assumed that the amount of change in the wavelength changed by the control of the active region 42 is sufficiently small compared to the amount of change in the wavelength changed by the control of the rear mirror 41 and the front mirror 44.

[0028] Subsequently, the mode region will be described with reference to FIG. 6. FIG. 6 shows that the mode region is determined by the control currents \(I_{rm}\) and \(I_{fm}\). The vertical axis of FIG. 6 indicates the value of the control current \(I_{rm}\), and the horizontal axis indicates the value of the control current \(I_{fm}\).

[0029] The region surrounded by the solid line shown in FIG. 6 is defined as the mode region. FIG. 6 shows mode regions M1 to M4. It is assumed that a specific wavelength is associated with each of the mode regions M1 to M4. For example, M1 may be associated with a wavelength of 1554 nanometers, M2 with a wavelength of 1555 nanometers, M3 with a wavelength of 1556 nanometers, and M4 with a wavelength of 1557 nanometers, so that the mode region and the wavelength are associated. The wavelength of the laser light output from the light source unit 23 is mainly switched by changing the control currents \(I_{rm}\) and \(I_{fm}\).

[0030] Returning to FIG. 3, the control unit 21 controls the current injected into the light source unit 23 so that wavelength sweeping for scanning one scanning point on one scanning axis is performed within one mode region. For example, when scanning one scanning point on one scanning axis, the control unit 21 causes the light source unit 23 to output laser light having a wavelength associated with the mode region M1. The control unit 21 determines the values of the control currents I_rm and I_fm for outputting laser light having a wavelength associated with the mode region M1 shown in FIG. 6. Further, the control unit 21 may change the values of the control currents I_rm and I_fm so that the wavelength of the laser light stays or is maintained within the mode region M1. That is, when scanning one scanning point on one scanning axis, the control unit 21 adjusts the values of the control currents I_rm and I_fm so as to avoid the occurrence of mode hopping caused by the occurrence of a change in the mode region.

[0031] Alternatively, the control unit 21 may determine or fix the values of the control currents I_rm and I_fm so as to output laser light having a wavelength associated with an arbitrary position within the mode region M1. The arbitrary position may be, for example, the center within the mode region M1. Thereafter, the control unit 21 may change the value of the control current I_ph input to the phase shifter. In this way, the control unit 21 may adjust the values of the control currents I_rm, I_fm, and I_ph so that the wavelength of the laser light stays or is maintained within the mode region M1.

[0032] Returning to FIG. 3, the laser light output from the light source unit 23 is separated into laser light that is reflected by the splitter 24 and travels toward the mirror 25 and laser light that passes through the splitter 24 and travels toward the object 30.

[0033] The laser light traveling toward the mirror 25 is reflected by the mirror 25. The laser light reflected by the mirror 25 passes through the splitter 24 as laser light R1 and is input to the detection unit 22. The laser light R1 may be referred to as reference light or the like.

[0034] The laser light directed towards the object 30 passes through the dispersion unit 26 that deflects the light at an angle according to the wavelength of the laser light, and is reflected by the object 30. Deflecting the light at an angle according to the wavelength of the laser light means changing the direction of the light in a direction that depends on the wavelength of the light. The dispersion unit 26 may be a prism. Also, the dispersion unit 26 may be a diffraction grating. The laser light reflected by the object 30 is reflected at the splitter 24 as the laser light S1 and input to the detection unit 22. The laser light S1 may be referred to as measurement light, sample light, etc.

[0035] The detection unit 22 receives the laser lights R1 and S1. The detection unit 22 may measure the distance from the measuring device 20 to the object 30, for example, based on the difference in the timing of receiving the laser light R1 and the laser light S1. Alternatively, the detection unit 22 may measure the distance from the measuring device 20 to the object 30 based on the frequency difference between the respective laser lights at the timing of receiving the laser light R1 and the laser light S1.

[0036] Subsequently, the flow of the control process of the wavelength of the laser light in the measuring device 20 will be described with reference to FIG. 7. First, the control unit 21 determines the wavelength of the laser light that scans the scanning point on a certain scanning axis (S21). A certain scanning axis may be any scanning axis among the scanning axes where scanning is not being performed.

[0037] Next, the control unit 21 determines the mode region corresponding to the wavelength determined in step S21 (S22). Determining the mode region may be rephrased as specifying the mode region. It is assumed that the wavelength value and the mode region are predetermined as shown in FIG. 6.

[0038] Next, the control unit 21 changes the control current so as to perform wavelength sweeping within the mode region determined in step S22 (S23). The control unit 21 may change at least one of the control current I_rm, the control current I_fm, and the control current I_ph. For example, the control unit 21 may change the value of the control current so as to increase or decrease monotonically. The control unit 21 may input the changed control current to the light source unit 23 at a predetermined timing. Alternatively, the control unit 21 may output information indicating the output timing of the control current and the value of the control current to be output at each timing to the output unit of the control current constituted by a circuit or an element that outputs a current.

[0039] Next, the control unit 21 determines whether there is a scanning point that has not been scanned on the scanning axis currently being scanned (S23).

[0040] When the control unit 21 determines that there is a scanning point that has not been scanned on the currently scanned scanning axis, the control unit 21 repeats the processing after step S21. That is, the control unit 21 switches the wavelength of the laser light to scan the scanning point that has not been scanned. In other words, the control unit 21 determines the wavelength of the laser light that can scan the scanning point that has not been scanned.

[0041] In step S24, when the control unit 21 determines that there is no scanning point that has not been scanned on the currently scanned scanning axis, the control unit 21 determines whether there is a scanning axis that has not been scanned (S25). The fact that there is no scanning point that has not been scanned on the currently scanned scanning axis means that the scanning of all the scanning points on the currently scanned scanning axis has been completed. When the control unit 21 determines that there is a scanning axis that has not been scanned, the control unit 21 changes the output direction of the laser light using a mirror or the like (S26). The control unit 21 may have information for managing the scanned scanning axis and the unscanned scanning axis. After executing the process of step S26, the control unit 21 repeats the processing after step S21.

[0042] Here, it is assumed that the detection unit 22 executes the measurement process after the process of step S23 is executed. That is, when the control current is changed and wavelength sweeping is performed in step S23, the detection unit 22 generates three-dimensional data at the scanning point existing on the surface of the object 30 by using the reference light and the sample light.

[0043] As described above, when performing wavelength sweeping to scan one scanning point on the scanning axis, the control unit 21 of the measuring device 20 changes the control current so that the wavelength of the laser light remains within the mode region. Thereby, the measuring device 20 can prevent mode hopping from occurring during the execution of wavelength sweeping. As a result, by preventing the phase of the laser light from becoming discontinuous during the execution of wavelength sweeping, a decrease in measurement accuracy can be prevented.

[0044] (Embodiment 3) Subsequently, with reference to FIG. 8, the measurement time of the object 30 in the measuring device 20 will be described. In FIG. 8, the vertical axis represents the value of the wavelength of the laser light, and the horizontal axis represents the passage of time. The dotted lines shown parallel to the vertical axis are arranged at equal intervals. The oblique solid line indicates the change in the wavelength of the laser light with the passage of time.

[0045] Let the interval between the dotted lines be time T1. The unit of time may be seconds, microseconds, nanoseconds, etc. It is assumed that the time T1 indicates the time required to measure the three-dimensional data regarding one scanning point. It is assumed that the time T2 indicates the time required to measure six scanning points on one scanning axis. That is, it is defined as time T2 = time T1 × number of scanning points. Further, the time required to complete the measurement of the scanning points existing in a predetermined region is defined as time T2 × number of scanning axes. Further, the time required to complete the measurement of the scanning points existing in a predetermined region may be calculated by adding the time required when changing the scanning axis to be measured to time T2 × number of scanning axes.

[0046] Figure 8 shows three solid lines. That is, Figure 8 shows the time required to measure the scanning points on three scanning axes. Here, the measurement time of the scanning points shown in Figure 4 will be described. Figure 4 shows six scanning points on one scanning axis. Therefore, the time required for the measurement of one scanning axis is time T1×6. Furthermore, Figure 4 shows four scanning axes. Therefore, the time required for the completion of the measurement is determined to be time T1×6×4.

[0047] In the description using Figures 8 and 4, it is premised that the scanning of one scanning point existing on one scanning axis can be completed by wavelength sweeping in the same mode region.

[0048] As described with reference to Figure 8, the measurement time in a predetermined region is determined as time T1×the number of scanning points×the number of scanning axes. The measurement time may be referred to as the scanning time. In the following description, a function or method for shortening the measurement time in a predetermined region will be described.

[0049] For example, the control unit 21 selects the scanning points to be the measurement targets of the three-dimensional data from among the plurality of scanning points existing within a predetermined region. Also, the control unit 21 may change the scanning points to be the measurement targets of the three-dimensional data to be selected according to the measurement timing of the scanning points existing within the predetermined region.

[0050] Selecting the scanning points to be measured for the three-dimensional data may also be to determine the scanning points that omit the measurement of the three-dimensional data. For example, the control unit 21 may omit the measurement of several scanning points at time t1. Further, the control unit 21 may resume the measurement of the scanning points omitted at time t1 at time t2, which is the next measurement time after time t1, and may omit the measurement of other scanning points. In this way, the control unit 21 may omit the measurement of the scanning points at any position and change the position of the scanning points to be omitted at the next measurement timing. For example, the control unit 21 may predetermine the number of scanning points to be scanned at each time. The control unit 21 may make the number of scanning points to be scanned at each time the same, may decrease the number of scanning points to be scanned as time elapses, or may increase the number of scanning points to be scanned as time elapses. Time t1 and time t2 may each be the time when the scanning of one scanning axis starts.

[0051] Further, the control unit 21 may determine the scanning points to be omitted so as to avoid the omission of the measurement of the scanning points at the same position continuously in the measurements at different timings.

[0052] The detection unit 22 measures the three-dimensional data of the scanning points selected by the control unit 21 by sweeping the wavelength of the laser light.

[0053] Subsequently, the flow of the measurement process executed in the measuring device 20 will be described with reference to FIG. 9. First, the control unit 21 selects the scanning points to be measured for the three-dimensional data from among a plurality of scanning points existing within a predetermined region (S31). Next, the detection unit 22 measures the three-dimensional data of the scanning points selected by the control unit 21 by sweeping the wavelength of the laser light (S32).

[0054] As described above, by reducing the position of the scanning point at which the control unit 21 performs measurement, the measurement time in a predetermined region can be shortened as compared with the case of measuring all the scanning points. Also, by changing the position of the scanning point to be measured for each measurement time, it is possible to avoid a specific scanning point from being continuously measured. As a result, it is possible to prevent the measurement accuracy regarding each scanning point from being significantly reduced. "For each measurement time" may be paraphrased as "for each measurement timing".

[0055] (Embodiment 4) Subsequently, with reference to FIG. 10, the process in the control unit 21 for reducing the scanning points to be measured will be described. FIG. 10 shows the state of a vehicle moving on a road at times t1 to t3. Among times t1 to t3, t3 is the most advanced time and t1 is the most past time. The black circles in FIG. 10 indicate the scanning points existing on one scanning axis. Each of times t1 to t3 may be the time to start scanning one scanning axis.

[0056] At time t1, the control unit 21 performs wavelength sweeping to scan one scanning point, and further switches the wavelength to scan all the scanning points. Here, the control unit 21 may control the control current so that the value of the wavelength changed by the wavelength sweeping falls within the same mode region. "To control" may be paraphrased as "to adjust".

[0057] The scanning point existing at the tip of the dotted arrow at time t1 does not indicate the moving vehicle but exists on the road. In this case, since the state of the object at the position of the scanning point does not change with time, it is presumed that the change in the three-dimensional data is small. On the other hand, for the scanning points included in the moving vehicle, the position of the vehicle indicated by the scanning points changes with the passage of time. Therefore, it is presumed that the change in the three-dimensional data of the scanning points included in the moving vehicle becomes large. "The change in the three-dimensional data is large" may be paraphrased as "the amount of change in the three-dimensional data is large".

[0058] Therefore, at time t2, which is the next measurement timing after time t1, the control unit 21 may omit the measurement of the scanning points at the positions of the dotted arrows. That is, the control unit 21 may reduce the number of scanning points to be measured at time t2 compared to the number of scanning points measured at time t1.

[0059] At time t2 in FIG. 10, it shows that the scanning points at the positions indicated by the arrows at time t1 have not been measured.

[0060] At time t2 in FIG. 10, a dotted arrow is shown on the scanning point near the center of the vehicle. The scanning points existing near the center of the vehicle are presumed to be the scanning points indicating the vehicle also at the next time t3. Therefore, at time t3, which is the next measurement timing after time t2, the control unit 21 may omit the measurement of the scanning points at the positions of the dotted arrows inside the vehicle. Also, the dotted arrow shown on the road indicates that the measurement of the scanning points has not been performed at time t2. Therefore, at time t3, which is the next measurement timing after time t2, the control unit 21 may perform the measurement of the scanning points at the positions of the dotted arrows shown on the road. That is, at time t3, the control unit 21 omits the measurement of two scanning points inside the vehicle compared to time t2 and increases the measurement of the scanning points on the road. As a result, the number of scanning points measured at time t3 is more than that at time t2 and less than that at time t1.

[0061] In this way, the control unit 21 may control the number of scanning points to be measured for each measurement time.

[0062] Here, when estimating a position where the change in the three-dimensional data is small, the control unit 21 may use, for example, image recognition processing. For example, the control unit 21 may identify an object included in the image based on the images at respective times. Further, the control unit 21 may determine whether the identified object moves. The control unit 21 may estimate that the change in the three-dimensional data is large for the scanning points on the moving object and the change in the three-dimensional data is small for the scanning points on the non-moving object. The image recognition processing and the determination processing as to whether the identified object moves may be performed using AI (Artificial Intelligence). For example, the image recognition processing and the determination processing as to whether the identified object moves may be performed using a learning model learned with objects that may be included in the image as training data.

[0063] For example, the control unit 21 may identify an object by executing semantic segmentation for assigning a label for identifying the object to each pixel constituting the image. Further, the control unit 21 may previously hold information regarding whether the object identified by each label moves.

[0064] In this way, the control unit 21 can shorten the measurement time by omitting the measurement of the scanning points on the non-moving object. Further, even for a moving object, the control unit 21 can shorten the measurement time by omitting the measurement of the scanning points where the change in the three-dimensional data on the surface of the object is assumed to be small. Furthermore, the control unit 21 can prevent the three-dimensional data at a specific scanning point from not being measured by measuring the scanning points not measured at the previous measurement time at the next measurement time. Thereby, it is possible to prevent the measurement accuracy of the three-dimensional data at a specific scanning point from deteriorating.

[0065] FIG. 11 is a block diagram showing a configuration example of the measurement devices 10 and 20 (hereinafter referred to as the measurement device 10 etc.) described in the above-described embodiment. Referring to FIG. 11, the measurement device 10 etc. includes a network interface 1201, a processor 1202, and a memory 1203. The network interface 1201 may be used to communicate with a network node. The network interface 1201 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series. IEEE represents the Institute of Electrical and Electronics Engineers.

[0066] The processor 1202 reads and executes software (computer program) from the memory 1203 to perform the processing of the measurement device 10 etc. described using the flowchart in the above-described embodiment. The processor 1202 may be, for example, a microprocessor, an MPU, or a CPU. The processor 1202 may include a plurality of processors.

[0067] The memory 1203 is composed of a combination of a volatile memory and a non-volatile memory. The memory 1203 may include storage arranged separately from the processor 1202. In this case, the processor 1202 may access the memory 1203 via an I / O (Input / Output) interface (not shown).

[0068] In the example of FIG. 11, the memory 1203 is used to store a group of software modules. The processor 1202 can perform the processing of the measurement device 10 etc. described in the above-described embodiment by reading and executing these software module groups from the memory 1203.

[0069] As described with reference to FIG. 11, each of the processors included in the measuring device 10 and the like in the above-described embodiments executes one or more programs including a set of instructions for causing a computer to execute the algorithms described with reference to the drawings.

[0070] In the above example, the program includes a set of instructions (or software code) for causing a computer to perform one or more functions described in the embodiment when the program is loaded into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD), or other memory technologies, CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disc, or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0071] Although the present disclosure has been described with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. And each embodiment can be combined with other embodiments as appropriate.

[0072] The respective drawings are merely illustrative for explaining one or more embodiments. Each drawing may be associated with not only one specific embodiment but also one or more other embodiments. As can be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with the features or steps shown in one or more other drawings, for example, to create embodiments that are not explicitly illustrated or described. Not all of the features or steps shown in any one drawing for explaining exemplary embodiments are necessarily essential, and some features or steps may be omitted. The order of the steps described in any drawing may be changed as appropriate.

[0073] Some or all of the above embodiments may be described as follows, but are not limited thereto. (Appendix 1) A control unit that controls a control current value for sweeping the wavelength of the laser light within a mode region determined based on the value of the wavelength of the laser light output in a predetermined direction; A measuring device comprising a measuring unit that generates point cloud data of an object existing in the predetermined direction using the laser light whose wavelength has been swept within the mode region. (Appendix 2) The control unit determines the control current value for sweeping the wavelength of the laser light based on control information associating a plurality of the mode regions with the range of the control current values for realizing wavelength sweeping of the laser light within each of the mode regions, the measuring device according to Appendix 1. (Appendix 3) The mode region is associated with the values of the front mirror current and the rear mirror current included in the control current, the measuring device according to Appendix 1 or 2. (Appendix 4) The control unit The measuring device according to appendix 3, which determines values of the front mirror current and the rear mirror current for fixing the laser light at a position substantially at the center of the mode region, and sweeps the wavelength of the laser light within the mode region by changing the value of the phase shifter current included in the control current. (Appendix 5) The control unit The measuring device according to any one of appendices 1 to 4, which determines a control current value for performing wavelength sweeping so that the wavelength of the laser light decreases monotonically or increases monotonically. (Appendix 6) The measuring unit The measuring device according to any one of appendices 1 to 5, which generates the point cloud data for each mode region by using laser light wavelength-swept in each of a plurality of mode regions. (Appendix 7) The measuring unit The measuring device according to any one of appendices 1 to 6, which generates the point cloud data by applying the FMCW (Frequency Modulated Continuous Wave) method to the laser light. (Appendix 8) Controls a control current value for sweeping the wavelength of the laser light within a mode region determined based on a value of the wavelength of the laser light output in a predetermined direction, A measuring method for generating point cloud data of an object existing in the predetermined direction by using laser light wavelength-swept within the mode region. (Appendix 9) When controlling the control current value, The measuring method according to appendix 8, which determines the control current value for sweeping the wavelength of the laser light based on control information associating a plurality of the mode regions with a range of the control current values for realizing wavelength sweeping of the laser light within each of the mode regions. (Appendix 10) The mode region is associated with values of a front mirror current and a rear mirror current included in a control current. The measuring method according to appendix 8 or 9. (Appendix 11) When controlling the control current value, The method of measurement according to Supplementary Note 10, wherein when controlling the control current value, the values of the front mirror current and the rear mirror current for fixing the laser light at a position substantially at the center of the mode region are determined, and the wavelength of the laser light is swept within the mode region by changing the value of the phase shifter current included in the control current. (Supplementary Note 12) When controlling the control current value, The method of measurement according to any one of Supplementary Notes 8 to 11, wherein when controlling the control current value, the control current value for performing wavelength sweeping is determined so that the wavelength of the laser light decreases monotonically or increases monotonically. (Supplementary Note 13) When generating the point cloud data, The method of measurement according to any one of Supplementary Notes 8 to 12, wherein when generating the point cloud data, the point cloud data is generated for each mode region using laser light wavelength-swept in each of a plurality of mode regions. (Supplementary Note 14) When generating the point cloud data, The method of measurement according to any one of Supplementary Notes 8 to 13, wherein when generating the point cloud data, the FMCW method is applied to the laser light to generate the point cloud data. (Supplementary Note 15) Control the control current value for sweeping the wavelength of the laser light within the mode region determined based on the value of the wavelength of the laser light output in a predetermined direction, A program for causing a computer to generate point cloud data of an object existing in the predetermined direction using laser light wavelength-swept within the mode region. (Supplementary Note 16) When controlling the control current value, The program according to Supplementary Note 15, wherein when controlling the control current value, the control current value for sweeping the wavelength of the laser light is determined based on control information associating a plurality of the mode regions with a range of the control current values for realizing wavelength sweeping of the laser light within each of the mode regions. (Supplementary Note 17) The mode region is the program described in Appendix 15 or 16, which is associated with the values of the front mirror current and the rear mirror current included in the control current. (Appendix 18) When controlling the control current value, Determine the values of the front mirror current and the rear mirror current that fix the laser beam at a position substantially at the center of the mode region, and change the value of the phase shifter current included in the control current to sweep the wavelength of the laser beam within the mode region, which is the program described in Appendix 17. (Appendix 19) When controlling the control current value, Determine the control current value for performing wavelength sweeping so that the wavelength of the laser beam decreases monotonically or increases monotonically, which is the program described in any one of Items 15 to 18 of the appendix. (Appendix 20) When generating the point cloud data, Using the laser beam whose wavelength is swept in each of a plurality of mode regions, generate the point cloud data for each mode region, which is the program described in any one of Items 15 to 19 of the appendix. (Appendix 21) A control unit that selects a scanning point to be a measurement target of three-dimensional data from among a plurality of scanning points existing in a predetermined region, A measurement unit that measures the three-dimensional data of the selected scanning point by sweeping the wavelength of the laser beam, The control unit, A measuring device that changes the scanning point to be the measurement target of the three-dimensional data to be selected according to the measurement timing of the scanning points existing in the predetermined region. (Appendix 22) The control unit, Estimate a scanning point with a small change amount of three-dimensional data at different measurement timings, and omit the measurement of the scanning point with a small change amount of the three-dimensional data, which is the measuring device described in Appendix 21. (Appendix 23) The control unit, The measuring apparatus according to appended note 22, wherein for the scanning points where measurement is omitted at the first measurement timing, measurement is resumed at a second measurement timing performed after the first measurement timing. (Appended note 24) The control unit The measuring apparatus according to appended note 22 or 23, wherein among the objects included in the image data of the predetermined region, the scanning points on the moving object are estimated as scanning points with a small change amount in the three-dimensional data. (Appended note 25) The measuring unit The measuring apparatus according to any one of appended notes 21 to 24, wherein the three-dimensional data of the selected scanning points is measured using the wavelength of the laser light scanned within the same mode region. (Appended note 26) The control unit The measuring apparatus according to appended note 25, wherein the value of the control current input to the light source of the laser light is controlled so that the range in which the wavelength of the laser light is scanned falls within the same mode region. (Appended note 27) The measuring apparatus according to appended note 26, wherein the mode region is associated with the values of the front mirror current and the rear mirror current included in the control current. (Appended note 28) Select a scanning point to be a measurement target for three-dimensional data from among a plurality of scanning points existing within a predetermined region, Measure the three-dimensional data of the selected scanning point by sweeping the wavelength of the laser light, When selecting the scanning point, A measuring method, wherein the scanning point to be a measurement target for the three-dimensional data to be selected is changed according to the measurement timing of the scanning points existing within the predetermined region. (Appended note 29) When selecting the scanning point, At different measurement timings, estimate scanning points with a small change amount in the three-dimensional data, and omit the measurement of the scanning points with a small change amount in the three-dimensional data. The measuring method according to appended note 28. (Appended note 30) When selecting the scanning point, For the scanning points where measurement was omitted at the first measurement timing, resume measurement at the second measurement timing that is performed after the first measurement timing, the measurement method according to Supplementary Note 29. (Supplementary Note 31) When selecting the scanning point, Of the objects included in the image data of the predetermined region, estimate the scanning point on the moving object as a scanning point with a small amount of change in the three-dimensional data, the measurement method according to Supplementary Note 29 or 30. (Supplementary Note 32) When measuring the three-dimensional data, Using the wavelength of the laser beam scanned within the same mode region, measure the three-dimensional data of the selected scanning point, the measurement method according to any one of Supplementary Notes 28 to 31. (Supplementary Note 33) When selecting the scanning point, Control the value of the control current input to the light source of the laser beam so that the range over which the wavelength of the laser beam is scanned falls within the same mode region, the measurement method according to Supplementary Note 32. (Supplementary Note 34) The mode region is associated with the values of the front mirror current and the rear mirror current included in the control current, the measurement method according to Supplementary Note 33. (Supplementary Note 35) Select a scanning point to be the measurement target of the three-dimensional data from among a plurality of scanning points existing within a predetermined region, Measure the three-dimensional data of the selected scanning point by sweeping the wavelength of the laser beam, When selecting the scanning point, A program that causes a computer to change the scanning point to be the measurement target of the selected three-dimensional data according to the measurement timing of the scanning points existing within the predetermined region. (Supplementary Note 36) When selecting the scanning point, Estimate a scanning point with a small amount of change in the three-dimensional data at different measurement timings, and omit the measurement of the scanning point with a small amount of change in the three-dimensional data, the program according to Supplementary Note 35. (Appendix 37) When selecting the scanning point, For the scanning point where measurement is omitted at the first measurement timing, resume measurement at the second measurement timing performed after the first measurement timing, the program according to Appendix 36. (Appendix 38) When selecting the scanning point, Among the objects included in the image data of the predetermined region, estimate the scanning point on the moving object as a scanning point with a small change amount of the three-dimensional data, the program according to Appendix 36 or 37. (Appendix 39) When measuring the three-dimensional data, Using the wavelength of the laser beam scanned within the same mode region, measure the three-dimensional data of the selected scanning point, the program according to any one of Appendices 35 to 38. (Appendix 40) When selecting the scanning point, Control the value of the control current input to the light source of the laser beam so that the range of the wavelength of the laser beam being scanned is within the same mode region, the program according to Appendix 39.

[0074] Some or all of the elements (for example, configuration and function) described in Appendices 2 to 7 subordinate to Appendix 1 may be subordinate to Appendices 8 and 15 in the same subordinate relationship as Appendices 2 to 7. Some or all of the elements described in any appendix may be applied to various hardware, software, recording means for recording software, systems, and methods.

Explanation of Reference Signs

[0075] 10 Measuring device 11 Control unit 12 Measuring unit 20 Measuring device 21 Control unit 22 Detection unit 23 Light source unit 24 Splitter 25 Mirror 26 Dispersion part 30 Object 41 Rear mirror 42 Active region 43 Phase shifter 44 Front mirror

Claims

1. A control unit that controls a control current value for sweeping the wavelength of the laser light within a mode region determined based on the value of the wavelength of the laser light output in a predetermined direction; A measuring device comprising: a measuring unit that generates point cloud data of an object existing in the predetermined direction using the laser light whose wavelength has been swept within the mode region.

2. The control unit determines the control current value for sweeping the wavelength of the laser light based on control information associating a plurality of the mode regions with ranges of the control current values that realize wavelength sweeping of the laser light within each of the mode regions. The measuring device according to claim 1.

3. The mode region is associated with values of a front mirror current and a rear mirror current included in the control current. The measuring device according to claim 1 or 2.

4. The control unit determines values of the front mirror current and the rear mirror current that fix the laser light at a position substantially at the center of the mode region, and changes the value of a phase shifter current included in the control current, thereby sweeping the wavelength of the laser light within the mode region. The measuring device according to claim 3.

5. The control unit determines the control current value for performing wavelength sweeping so that the wavelength of the laser light decreases monotonically or increases monotonically. The measuring device according to claim 1 or 2.

6. The measuring unit generates the point cloud data for each mode region using the laser light whose wavelength has been swept in each of a plurality of mode regions. The measuring device according to claim 1 or 2.

7. The measuring unit applies an FMCW (Frequency Modulated Continuous Wave) method to the laser light to generate the point cloud data. The measuring device according to claim 1 or 2.

8. controls a control current value for sweeping the wavelength of the laser light within a mode region determined based on the value of the wavelength of the laser light output in a predetermined direction, and generates point cloud data of an object existing in the predetermined direction using the laser light whose wavelength has been swept within the mode region. A measuring method.

9. When controlling the control current value, The measuring method according to claim 8, wherein a control current value for sweeping the wavelength of the laser light is determined based on control information associating the plurality of mode regions with ranges of the control current values that realize wavelength sweeping of the laser light within each of the mode regions.

10. controlling a control current value for sweeping the wavelength of the laser light within a mode region determined based on a value of the wavelength of the laser light output in a predetermined direction, causing a computer to execute: generating point cloud data of an object existing in the predetermined direction using the laser light whose wavelength has been swept within the mode region.

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