Measurement device, measurement method, and program

Abstract

To provide a measuring device capable of preventing a decrease in measurement accuracy due to discontinuity in the phase of a laser beam. [Solution] The measurement device disclosed herein includes a control unit that controls a control current value that sweeps the wavelength of laser light within a mode region that is determined based on the wavelength value of 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 wavelength-swept laser light within the mode region.

Description

[Technical field]

[0001] The present disclosure relates to a measurement device, a measurement method, and a program. [Background technology]

[0002] In recent years, the use of LiDAR (Light Ranging and Detection) has been considered as a technology for identifying the position and shape of a measurement target in 3D. Wavelength-swept LiDAR, a type of LiDAR, can quickly generate 3D images of a measurement target by utilizing the coherence of light. For example, wavelength-swept LiDAR using a tunable light source is used as an important technology in the field of autonomous driving, which requires real-time spatial position measurement.

[0003] Patent Document 1 discloses a system configuration in which a sample is scanned by changing the wavelength over time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 1,175,388 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, mode hopping is not taken into consideration when changing the wavelength, which results in a problem that mode hopping occurs while scanning a measurement target that exists in a specific direction, causing discontinuity in the phase of the laser light and reducing measurement accuracy.

[0006] An object of the present disclosure is to provide a measurement device, a measurement method, and a program that can prevent the phase of laser light from becoming discontinuous and causing a decrease in measurement accuracy. [Means for solving the problem]

[0007] A measurement device according to a first aspect of the present disclosure includes a control unit that controls a control current value that sweeps the wavelength of a laser light within a mode region that is 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 present in the predetermined direction using the laser light that has been wavelength-swept within the mode region.

[0008] A measurement method according to a second aspect of the present disclosure controls a control current value that sweeps the wavelength of a laser light within a mode region that is 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 present in the predetermined direction using the laser light that has been wavelength-swept within the mode region.

[0009] A program according to a third aspect of the present disclosure causes a computer to control a control current value that sweeps the wavelength of a laser light within a mode region that is 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 present in the predetermined direction using the laser light that has been wavelength-swept within the mode region. Effect of the Invention

[0010] The present disclosure makes it possible to provide a measurement device, a measurement method, and a program that can prevent the phase of laser light from becoming discontinuous and causing a decrease in measurement accuracy. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a configuration diagram of a measurement device according to the present disclosure. [Diagram 2] 1 is a diagram showing a flow of a measurement process executed in a measurement device according to the present disclosure. [Diagram 3] FIG. 1 is a configuration diagram of a measurement device according to the present disclosure. [Figure 4] FIG. 2 is a diagram illustrating scanning of an object according to the present disclosure. [Diagram 5] FIG. 2 is a configuration diagram of a light source unit according to the present disclosure. [Figure 6] FIG. 2 is a diagram illustrating a mode region according to the present disclosure. [Figure 7] 5 is a diagram showing a flow of a process for controlling the wavelength of laser light in a measurement device according to the present disclosure. FIG. [Figure 8] FIG. 13 is a diagram illustrating the measurement time of an object in the measurement device according to the present disclosure. [Figure 9] 1 is a diagram showing a flow of a measurement process executed in a measurement device according to the present disclosure. [Figure 10] FIG. 13 is a diagram showing a process flow for reducing the number of scanning points to be measured in a control unit according to the present disclosure. [Figure 11] FIG. 1 is a configuration diagram of a measurement device according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 operated by a processor executing a program stored in a memory. The measuring device 10 may also 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 a ToF (Time of Flight) method or an FMCW (Frequency Modulated Continuous Wave) method, and generates points that indicate the shape of the object. A collection of points that indicate the shape of the object becomes point cloud data. The points that indicate the shape of the object may be specified using three-dimensional coordinates in a predetermined space. In other words, the points that indicate the shape of the object may be indicated using three-dimensional coordinates in a predetermined coordinate system. The points specified using three-dimensional coordinates and the point cloud data that is a collection of points may be referred to as three-dimensional data.

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

[0014] The control unit 11 controls a control current value that sweeps the wavelength of the laser light within a mode region that is 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 a means for controlling the control current value. The output direction of the laser light output from the measurement device 10 is 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 multiple locations or to an area having a predetermined area by changing the value of the wavelength of the laser light.

[0015] The mode corresponds to the wavelength value when the light resonates and is output as a laser beam. The mode region may be a range of control current values ​​that can be changed without changing the wavelength value. In other words, the mode region may be associated with a range of control current values ​​that can maintain the position of the mode in which the light resonates. "Without changing the wavelength value" may include a sufficiently small value variation with respect to the wavelength value associated with the mode region. The wavelength value associated with the mode region may be rephrased as the wavelength value indicating the position of the mode. The control current is a current injected into the measurement device 10 to control the wavelength of the laser beam. Controlling the wavelength of the laser beam may be changing the wavelength of the laser beam. Controlling the control current value may be 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 fluctuate, but the wavelength fluctuation range in this case is sufficiently small compared to the wavelength value indicating the mode position. The wavelength fluctuation caused by changing the control current within the mode region is utilized to sweep the wavelength of the laser light. 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 a change in the mode of the laser light that is in a resonant state due to fluctuations in the control current.

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

[0018] Next, the flow of the measurement process executed in the measurement device 10 will be described with reference to Fig. 2. First, 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 (S11). Next, the measurement unit 12 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 (S12).

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

[0020] (Embodiment 2) Next, a configuration example of the measurement device 20 will be described with reference to Fig. 3. In the measurement device 20, detailed description of functions and processes similar to those of the measurement device 10 will be omitted. The measurement device 20 has 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 measurement device 10. The detection unit 22 corresponds to the measurement unit 12 in the measurement device 10.

[0021] The light source unit 23 may be a laser light source that outputs laser light. Furthermore, the light source unit 23 may be a variable wavelength light source that switches and sweeps the wavelength of the laser light. The light source unit 23 may be used as a means for outputting laser light. The light source unit 23 performs, for example, an FMCW operation. In the FMCW operation, the light source unit 23 outputs laser light of a certain frequency while frequency modulating the laser light for a certain period of time. The laser light of a certain frequency may be rephrased as laser light within a certain mode region. In addition, the light source unit 23 may be rephrased as sweeping the wavelength for a certain period of time to perform frequency modulation. The certain period may be a period for measuring a predetermined area of ​​the object 30.

[0022] Furthermore, the light source unit 23 switches the wavelength of the laser light when changing the area to be measured in the target object 30. Switching the wavelength of the laser light may be rephrased as changing the wavelength of the laser light. Switching the wavelength of the laser light may be changing the wavelength of the laser light to a wavelength of a different mode. Here, the wavelength sweep range is sufficiently smaller than the value of the wavelength regarded as the same mode area. For example, when the mode areas correspond to each 1 nanometer, the wavelength sweep range is set to a value sufficiently smaller than 1 nanometer.

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

[0024] The area surrounded by a square in FIG. 4 indicates an area on the surface of the object 30. Furthermore, each point in the area surrounded by a square indicates a scanning point. The light source unit 23 performs wavelength sweeping in one mode area to acquire three-dimensional data of one scanning point. Furthermore, the light source unit 23 adjusts the position where the laser light hits the object 30 by switching the wavelength of the laser light to acquire three-dimensional data of each scanning point along the dotted arrow. The three-dimensional data may be rephrased as point cloud data. When the acquisition of the three-dimensional data of the scanning point on the dotted arrow is completed, the light source unit 23 changes the output direction of the laser light, for example, using a mirror or the like, to acquire three-dimensional data of the scanning point along a different dotted arrow. Specifically, the light source unit 23 may use a mirror or the like when changing the output direction of the laser light to the vertical direction in FIG. 4. The use of a mirror may be to adjust 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 scan axis using a mirror or the like may be longer than the time required to change the scan point to be measured on the scan 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 has 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 to output laser light. The specific wavelength is determined based on the values ​​of the control currents I_rm and I_fm. In other words, the control unit 21 controls the values ​​of the control currents I_rm and I_fm input to the light source unit 23 to cause the light source unit 23 to output laser light of different wavelengths.

[0026] A control current I_ph is input to the phase shifter 43. The phase shifter 43 changes the phase of the resonated light based on the control current I_ph. Changing the phase of the light may be rephrased as shifting the phase of the light. In addition, the wavelength of the laser light also changes as the control current I_ph input to the phase shifter 43 changes. The amount of change in wavelength caused by the control of the phase shifter 43 is assumed to be sufficiently smaller than the amount of change in wavelength caused 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, the resonated light is amplified. In addition, the wavelength of the laser light changes as the control current I_g input to the active region 42 changes. The amount of change in wavelength caused by control of the active region 42 is assumed to be sufficiently smaller than the amount of change in wavelength caused by control of the rear mirror 41 and the front mirror 44.

[0028] Next, 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 regions surrounded by solid lines in Fig. 6 are mode regions. 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, the mode regions and wavelengths may be associated such that M1 is a wavelength of 1554 nanometers, M2 is a wavelength of 1555 nanometers, M3 is a wavelength of 1556 nanometers, and M4 is a wavelength of 1557 nanometers. 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 the wavelength sweep for scanning one scanning point on one scanning axis is performed in one mode region. For example, the control unit 21 causes the light source unit 23 to output a laser beam having a wavelength associated with the mode region M1 when scanning one scanning point on one scanning axis. The control unit 21 determines the values ​​of the control currents I_rm and I_fm for outputting a laser beam having a wavelength associated with the mode region M1 shown in FIG. 6. Furthermore, the control unit 21 may change the values ​​of the control currents I_rm and I_fm so that the wavelength of the laser beam remains or is maintained in the mode region M1. In other words, 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 when scanning one scanning point on one scanning axis.

[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 a laser beam having a wavelength associated with an arbitrary position in the mode region M1. The arbitrary position may be, for example, the center of the mode region M1. Then, the control unit 21 may change the value of the control current I_ph input to the phase shifter. In this manner, 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 beam remains or is maintained in the mode region M1.

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

[0033] The laser light directed 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 a reference light, etc.

[0034] The laser light directed toward the object 30 passes through the dispersing section 26, which deflects the light at an angle depending on the wavelength of the laser light, and is reflected by the object 30. Deflecting the light at an angle depending on the wavelength of the laser light means changing the direction of the light to a direction that depends on the wavelength of the light. The dispersing section 26 may be a prism. The dispersing section 26 may also be a diffraction grating. The laser light reflected by the object 30 is reflected by the splitter 24 as laser light S1 and input to the detection section 22. The laser light S1 may be called measurement light, sample light, etc.

[0035] The detection unit 22 receives the laser beams R1 and S1. The detection unit 22 may measure the distance from the measurement device 20 to the target 30 based on the difference in timing at which the laser beams R1 and S1 are received, for example. Alternatively, the detection unit 22 may measure the distance from the measurement device 20 to the target 30 based on the difference in frequency of the laser beams R1 and S1 at the times at which the laser beams are received.

[0036] Next, a flow of the control process of the wavelength of the laser light in the measurement device 20 will be described with reference to Fig. 7. First, the control unit 21 determines the wavelength of the laser light for scanning a scanning point of a certain scanning axis (S21). The certain scanning axis may be any scanning axis among the scanning axes on which 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. The wavelength value and the mode region are assumed to be predetermined as shown in FIG.

[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 currents I_rm, I_fm, and I_ph. For example, the control unit 21 may change the value of the control current so as to monotonically increase or decrease. 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 timings of the control current and the values ​​of the control currents to be output at each timing to a control current output unit constituted by a circuit or element that outputs a current.

[0039] Next, the control unit 21 determines whether or not there is an unscanned scanning point on the currently scanned scanning axis (S23).

[0040] When the control unit 21 determines that there is an unscanned scanning point on the currently scanned scanning axis, the control unit 21 repeats the processes from step S21 onward. That is, the control unit 21 switches the wavelength of the laser light to scan the unscanned scanning point. In other words, the control unit 21 determines the wavelength of the laser light capable of scanning the unscanned scanning point.

[0041] In step S24, when the control unit 21 determines that there is no unscanned scanning point on the currently scanned scanning axis, it determines whether or not there is an unscanned scanning axis (S25). The absence of an unscanned scanning point on the currently scanned scanning axis means that scanning of all scanning points on the currently scanned scanning axis has been completed. When the control unit 21 determines that there is an unscanned scanning axis, it 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 scanning axis on which scanning has been completed and the scanning axis on which scanning has not been completed. After executing the process of step S26, the control unit 21 repeats the processes from step S21 onwards.

[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 sweep is performed in step S23, the detection unit 22 generates three-dimensional data at a scanning point present 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 measurement device 20 changes the control current so that the wavelength of the laser light remains within the mode region. This allows the measurement device 20 to prevent mode hopping from occurring while performing wavelength sweeping. As a result, by preventing discontinuity in the phase of the laser light while performing wavelength sweeping, it is possible to prevent a decrease in measurement accuracy.

[0044] (Embodiment 3) Next, the measurement time of the object 30 in the measurement device 20 will be described with reference to Fig. 8. In Fig. 8, the vertical axis represents the wavelength value of the laser light, and the horizontal axis represents the passage of time. The dotted lines parallel to the vertical axis are arranged at equal intervals. The diagonal solid lines represent the change in the wavelength of the laser light over time.

[0045] The interval between the dotted lines is time T1. The unit of time may be seconds, microseconds, nanoseconds, etc. Time T1 indicates the time required to measure three-dimensional data for one scanning point. Time T2 indicates the time required to measure six scanning points on one scanning axis. In other words, time T2 is defined as time T1 × number of scanning points. Furthermore, the time required to complete the measurement of scanning points present in a specified area is defined as time T2 × number of scanning axes. Furthermore, the time required to complete the measurement of scanning points present in a specified area may be calculated by adding the time required to change the scanning axis to be measured to time T2 × number of scanning axes.

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

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

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

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

[0050] Selecting scanning points to be measured for three-dimensional data may be determining scanning points for which measurement of three-dimensional data is to be omitted. For example, the control unit 21 may omit measurement of several scanning points at time t1. Furthermore, the control unit 21 may resume measurement of the scanning points omitted at time t1 at time t2, which is the measurement time next to time t1, and omit measurement of other scanning points. In this way, the control unit 21 may omit measurement of scanning points at any position, and change the position of the omitted scanning point 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 keep the number of scanning points to be scanned at each time the same, may decrease the number of scanning points to be scanned over time, or may increase the number of scanning points to be scanned over time. Time t1 and time t2 may each be a time to start scanning one scanning axis.

[0051] Furthermore, the control unit 21 may determine scanning points to be omitted so as to avoid omitting measurements of scanning points at the same positions consecutively in measurements at different timings.

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

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

[0054] As described above, by reducing the positions of the scanning points where the control unit 21 performs measurements, the measurement time in a predetermined area can be shortened compared to the case where all scanning points are measured. In addition, by changing the positions of the scanning points where measurements are performed for each measurement time, it is possible to avoid a situation where a specific scanning point is not continuously measured. As a result, it is possible to prevent a significant decrease in the measurement accuracy for each scanning point. "For each measurement time" may be rephrased as "for each measurement timing."

[0055] (Embodiment 4) Next, the process of reducing the scanning points to be measured in the control unit 21 will be described with reference to Fig. 10. Fig. 10 shows a vehicle moving on a road at times t1 to t3. Of times t1 to t3, t3 is the most advanced time and t1 is the most ancient time. Black circles in Fig. 10 indicate scanning points existing on one scanning axis. Each of times t1 to t3 may be a time at which scanning of one scanning axis starts.

[0056] At time t1, the control unit 21 performs wavelength sweeping to scan one scanning point, and then switches the wavelength to scan all scanning points. Here, the control unit 21 may control the control current so that the wavelength value changed by the wavelength sweep falls within the same mode region. Controlling may be rephrased as adjusting.

[0057] The scanning point at the tip of the dotted arrow at time t1 does not indicate a moving vehicle, but is on the road. In this case, the state of the object at the position of the scanning point does not change over time, so it is estimated that there is little change in the three-dimensional data. On the other hand, for scanning points included in a moving vehicle, the position of the vehicle indicated by the scanning point changes over time. Therefore, it is estimated that there will be a large change in the three-dimensional data of the scanning points included in the moving vehicle. A large change in the three-dimensional data can be rephrased as a large amount of change in the three-dimensional data.

[0058] Therefore, at time t2, which is the measurement timing next to time t1, the control unit 21 may omit the measurement of the scanning points at the positions of the dotted arrows. In other words, the control unit 21 may reduce the number of scanning points measured at time t2 from the number of scanning points measured at time t1.

[0059] At time t2 in FIG. 10, the scanning point at the position indicated by the arrow at time t1 is not measured.

[0060] At time t2 in FIG. 10, a dotted arrow is shown on a scanning point near the center of the vehicle. It is estimated that the scanning point near the center of the vehicle is also a scanning point indicating the vehicle at the next time t3. Therefore, the control unit 21 may omit the measurement of the scanning point at the position of the dotted arrow in the vehicle at time t3, which is the measurement timing next to time t2. Also, the dotted arrow shown on the road indicates that the measurement of the scanning point is not performed at time t2. Therefore, the control unit 21 may perform the measurement of the scanning point at the position of the dotted arrow shown on the road at time t3, which is the measurement timing next to time t2. That is, the control unit 21 omits the measurement of two scanning points in the vehicle at time t3 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 greater than at time t2 and less than at time t1.

[0061] In this manner, 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 an image based on an image at each time. Furthermore, the control unit 21 may determine whether or not the identified object moves. The control unit 21 may estimate that the change in the three-dimensional data is large for a scanning point on a moving object, and that the change in the three-dimensional data is small for a scanning point on a non-moving object. The image recognition processing and the determination processing of whether or not the identified object moves may be performed using AI (Artificial Intelligence). For example, the image recognition processing and the determination processing of whether or not the identified object moves may be performed using a learning model that has learned objects that may be included in the image as training data.

[0063] For example, the control unit 21 may identify an object by performing semantic segmentation that assigns a label for identifying the object to each pixel constituting the image. The control unit 21 may also hold in advance information regarding whether or not 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 scanning points on a stationary object. Also, even for a moving object, the control unit 21 can shorten the measurement time by omitting the measurement of scanning points where the change in the three-dimensional data of the surface of the object is expected to be small. Furthermore, the control unit 21 can prevent the three-dimensional data of a specific scanning point from not being measured by measuring a scanning point that was not measured at the previous measurement time at the next measurement time. This can 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 measuring devices 10 and 20 (hereinafter, referred to as the measuring device 10, etc.) described in the above-mentioned embodiment. Referring to Fig. 11, the measuring 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) conforming to the IEEE 802.3 series. IEEE stands for Institute of Electrical and Electronics Engineers.

[0066] The processor 1202 reads out and executes software (computer programs) from the memory 1203 to perform the processing of the measuring device 10 and the like described using the flowcharts in the above-mentioned embodiments. The processor 1202 may be, for example, a microprocessor, an MPU, or a CPU. The processor 1202 may include multiple processors.

[0067] The memory 1203 is configured by a combination of volatile memory and non-volatile memory. The memory 1203 may include storage located away 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] 11, the memory 1203 is used to store software modules. The processor 1202 reads out and executes these software modules from the memory 1203 to perform the processing of the measuring device 10 and the like described in the above-mentioned embodiment.

[0069] As explained using FIG. 11, each of the processors of the measuring device 10 in the above-described embodiment executes one or more programs including a set of instructions for causing a computer to execute the algorithm explained using the drawings.

[0070] In the above examples, the program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. 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 technology, CD-ROM, digital versatile disc (DVD), Blu-ray® disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or 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 above with reference to the embodiments, the present disclosure is not limited to the above-mentioned embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be appropriately combined with other embodiments.

[0072] Each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but to 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 may be combined with features or steps shown in one or more other drawings to create an embodiment not explicitly shown or described, for example. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0073] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes. (Appendix 1) a control unit that controls a control current value for sweeping the wavelength of a laser beam within a mode region that is determined based on a value of the wavelength of the laser beam output in a predetermined direction; a measurement unit that generates point cloud data of an object present in the specified direction using laser light that has been wavelength swept within the mode region. (Appendix 2) The control unit is 2. The measurement device according to claim 1, further comprising: a control information associating a plurality of the mode regions with a range of the control current value that realizes wavelength sweeping of the laser beam in each of the mode regions, and determining the control current value for sweeping the wavelength of the laser beam. (Appendix 3) 3. The measurement device according to claim 1, wherein the mode region corresponds to values ​​of a front mirror current and a rear mirror current included in a control current. (Appendix 4) The control unit is The measurement apparatus of claim 3, further comprising: determining values ​​of the front mirror current and the rear mirror current that fix the laser light substantially at a center position of the mode region; and changing a value of a phase shifter current included in the control current, thereby sweeping the wavelength of the laser light within the mode region. (Appendix 5) The control unit is 5. The measurement device according to claim 1, further comprising: determining the control current value for performing wavelength sweep so that the wavelength of the laser light monotonically decreases or increases. (Appendix 6) The measurement unit includes: 6. The measurement device according to claim 1, wherein the point cloud data is generated for each of a plurality of mode regions using laser light that is wavelength swept in each of the mode regions. (Appendix 7) The measurement unit includes: 7. The measuring device according to claim 1, wherein the point cloud data is generated by applying a Frequency Modulated Continuous Wave (FMCW) method to the laser light. (Appendix 8) controlling 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 measurement method for generating point cloud data of an object present in the specified direction using laser light that is wavelength swept within the mode region. (Appendix 9) When controlling the control current value, 9. The measurement method according to claim 8, further comprising determining the control current value for sweeping the wavelength of the laser beam based on control information associating a plurality of the mode regions with ranges of the control current values ​​for realizing the wavelength sweep of the laser beam in each of the mode regions. (Appendix 10) 10. The measurement method according to claim 8, wherein the mode region corresponds to values ​​of a front mirror current and a rear mirror current included in a control current. (Appendix 11) When controlling the control current value, The measurement method of claim 10, further comprising determining values ​​of the front mirror current and the rear mirror current that fix the laser light at a substantially central position of the mode region, and changing a value of a phase shifter current included in the control current, thereby sweeping the wavelength of the laser light within the mode region. (Appendix 12) When controlling the control current value, The measurement method according to any one of appendixes 8 to 11, further comprising determining the control current value for performing wavelength sweep so that the wavelength of the laser light monotonically decreases or increases. (Appendix 13) When generating the point cloud data, 13. The measurement method according to any one of claims 8 to 12, wherein the point cloud data is generated for each mode region by using laser light that is wavelength swept in each of a plurality of mode regions. (Appendix 14) When generating the point cloud data, The measurement method according to any one of appendixes 8 to 13, wherein the point cloud data is generated by applying an FMCW method to the laser light. (Appendix 15) controlling 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 program that causes a computer to generate point cloud data of an object present in the specified direction using laser light that has been wavelength swept within the mode region. (Appendix 16) When controlling the control current value, The program according to claim 15, further comprising determining the control current value for sweeping the wavelength of the laser beam based on control information associating a plurality of the mode regions with ranges of the control current values ​​for realizing wavelength sweeping of the laser beam in each of the mode regions. (Appendix 17) 17. The program according to claim 15, wherein the mode region corresponds to values ​​of a front mirror current and a rear mirror current included in a control current. (Appendix 18) When controlling the control current value, The program described in Appendix 17, further comprising determining values ​​of the front mirror current and the rear mirror current that fix the laser light at a substantially central position of the mode region, and changing a value of a phase shifter current included in the control current, thereby sweeping a wavelength of the laser light within the mode region. (Appendix 19) When controlling the control current value, 19. The program according to any one of appendixes 15 to 18, which determines the control current value for performing wavelength sweep so that the wavelength of the laser light monotonically decreases or increases. (Appendix 20) When generating the point cloud data, 20. The program according to any one of appendix 15 to 19, wherein the point cloud data is generated for each mode region by using laser light that has been wavelength swept in each of a plurality of mode regions. (Appendix 21) A control unit that selects a scanning point that is to be a measurement target of three-dimensional data from among a plurality of scanning points present within a predetermined area; A measurement unit that measures three-dimensional data of the selected scanning point by sweeping the wavelength of a laser light; The control unit is A measuring device that changes the scanning points to be measured of the three-dimensional data to be selected depending on the measurement timing of the scanning points present in the specified region. (Appendix 22) The control unit is 22. The measurement device according to claim 21, wherein scanning points at which the amount of change in the three-dimensional data is small are estimated at different measurement timings, and measurement of the scanning points at which the amount of change in the three-dimensional data is small is omitted. (Appendix 23) The control unit is 23. The measuring device of claim 22, wherein measurement of the scanning points for which measurement was omitted at a first measurement timing is resumed at a second measurement timing performed after the first measurement timing. (Appendix 24) The control unit is 24. The measuring device according to claim 22 or 23, wherein the scanning points on a moving object among objects included in the image data of the specified region are estimated to be scanning points with a small amount of change in the three-dimensional data. (Appendix 25) The measurement unit includes: 25. The measuring device according to any one of claims 21 to 24, wherein the three-dimensional data of the selected scanning point is measured using the wavelength of the laser light swept within the same mode region. (Appendix 26) The control unit is 26. The measurement apparatus of claim 25, further comprising: a control circuit for controlling a value of a control current input to a light source of the laser light so that the swept range of the wavelength of the laser light falls within the same mode region. (Appendix 27) 27. The measurement apparatus of claim 26, wherein the mode region corresponds to values ​​of a front mirror current and a rear mirror current included in a control current. (Appendix 28) Select scanning points to be used for measuring 3D data from among multiple scanning points present within a specified area, measuring three-dimensional data of the selected scanning points by sweeping the wavelength of the laser light; When selecting the scanning points, A measurement method comprising changing a scanning point to be a measurement target of the selected three-dimensional data depending on a measurement timing of the scanning point present in the specified region. (Appendix 29) When selecting the scanning points, 29. The measurement method according to claim 28, further comprising estimating scanning points at which the amount of change in the three-dimensional data is small at the different measurement timings, and omitting measurement of the scanning points at which the amount of change in the three-dimensional data is small. (Appendix 30) When selecting the scanning points, 30. The measurement method of claim 29, wherein for the scanning points for which measurement was omitted at a first measurement timing, measurement is resumed at a second measurement timing performed after the first measurement timing. (Appendix 31) When selecting the scanning points, 31. The measurement method according to claim 29 or 30, wherein the scanning points on a moving object among objects included in the image data of the specified region are estimated to be scanning points with a small amount of change in the three-dimensional data. (Appendix 32) When measuring the three-dimensional data, 32. The measurement method according to any one of claims 28 to 31, wherein three-dimensional data of the selected scanning points is measured using the wavelength of the laser light swept within the same mode region. (Appendix 33) When selecting the scanning points, 33. The measurement method of claim 32, further comprising controlling a value of a control current input to a light source of the laser light so that the swept range of the wavelength of the laser light falls within the same mode region. (Appendix 34) 34. The measurement method according to claim 33, wherein the mode region corresponds to values ​​of a front mirror current and a rear mirror current included in a control current. (Appendix 35) Select scanning points to be used for measuring 3D data from among multiple scanning points present within a specified area, measuring three-dimensional data of the selected scanning points by sweeping the wavelength of the laser light; When selecting the scanning points, A program for causing a computer to execute the following: changing the scanning points to be selected as measurement targets of the three-dimensional data according to the measurement timing of the scanning points present within the specified area. (Appendix 36) When selecting the scanning points, 36. The program according to claim 35, further comprising estimating scanning points with small amounts of change in the three-dimensional data at different measurement timings, and omitting measurements of the scanning points with small amounts of change in the three-dimensional data. (Appendix 37) When selecting the scanning points, The program described in Appendix 36, wherein measurement of the scanning points for which measurement was omitted at the first measurement timing is resumed at a second measurement timing performed after the first measurement timing. (Appendix 38) When selecting the scanning points, 38. The program according to claim 36 or 37, wherein the scanning points on a moving object among objects included in the image data of the specified region are estimated to be scanning points with a small amount of change in the three-dimensional data. (Appendix 39) When measuring the three-dimensional data, 39. A program described in any one of appendix 35 to 38, which measures three-dimensional data of the selected scanning point using the wavelength of the laser light swept within the same mode region. (Appendix 40) When selecting the scanning points, 40. The program described in claim 39, which controls a value of a control current input to a light source of the laser light so that the swept range of the wavelength of the laser light falls within the same mode region.

[0074] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 7 that are dependent on Supplementary Note 1 may also be dependent on Supplementary Notes 8 and 15 in the same dependent relationship as Supplementary Notes 2 to 7. Some or all of the elements described in any Supplementary Note may be applied to various hardware, software, recording means for recording software, systems, and methods. [Explanation of symbols]

[0075] 10. Measuring Equipment 11 Control section 12 Measuring part 20 Measuring Equipment 21 Control section 22 Detection unit 23 Light source section 24 Splitter 25. Mirror 26 Dispersion section 30 Objects 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 a laser beam within a mode region that is determined based on a value of the wavelength of the laser beam output in a predetermined direction; a measurement unit that generates point cloud data of an object present in the predetermined direction by using the laser light that is wavelength swept within the mode region, the control unit determines the control current value for sweeping the wavelength of the laser light based on control information that associates a plurality of the mode regions with a range of the control current value for realizing the wavelength sweep of the laser light in each of the mode regions; the measurement unit generates the point cloud data for each mode region by using laser light that has been wavelength swept in each of the plurality of mode regions; A measuring device, wherein the control unit controls the control current value so as to change the wavelength of the laser light to a wavelength of a different mode when changing a scanning point on one scanning axis on the object.

2. The measurement unit includes: The measurement device according to claim 1 , wherein the point cloud data is generated by applying a Frequency Modulated Continuous Wave (FMCW) method to the laser light.

3. 3. The measurement device according to claim 1, wherein the mode region is associated with values ​​of a front mirror current and a rear mirror current contained in a control current.

4. The control unit is 4. The measurement apparatus according to claim 3, further comprising: determining values ​​of the front mirror current and the rear mirror current that fix the laser light substantially at a center position of the mode region; and changing a value of a phase shifter current included in the control current, thereby sweeping the wavelength of the laser light within the mode region.

5. A control current value for sweeping the wavelength of a laser beam is determined based on control information associating a plurality of mode regions determined based on the value of the wavelength of a laser beam output in a predetermined direction with a range of control current values ​​for realizing wavelength sweeping of the laser beam within each of the mode regions; generating point cloud data of an object present in the predetermined direction for each of the plurality of mode regions using a laser beam swept in wavelength in each of the plurality of mode regions; A measurement method, comprising controlling the control current value so as to change the wavelength of the laser light to a wavelength of a different mode when changing a scanning point on one scanning axis on the object.

6. A control current value for sweeping the wavelength of a laser beam is determined based on control information associating a plurality of mode regions determined based on the value of the wavelength of a laser beam output in a predetermined direction with a range of control current values ​​for realizing wavelength sweeping of the laser beam within each of the mode regions; generating point cloud data of an object present in the predetermined direction for each of the plurality of mode regions using a laser beam swept in wavelength in each of the plurality of mode regions; A program for causing a computer to execute the following: controlling the control current value so as to change the wavelength of the laser light to a wavelength of a different mode when changing a scanning point on one scanning axis on the object.

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