JP7736093B2 - Measurement device, measurement method, and program - Google Patents

Description

This disclosure relates to a measurement device, a measurement method, and a program.

In recent years, the use of LiDAR (Light Ranging and Detection) has been considered as a technology for determining the position and shape of a measurement object in three dimensions. Swept-wavelength LiDAR, a type of LiDAR, utilizes the coherence of light to create high-speed three-dimensional images of the measurement object. For example, swept-wavelength LiDAR, which uses a tunable light source, is used as an important technology in the field of autonomous driving, where real-time spatial position measurement is required.

Patent document 1 discloses the configuration of a system that scans a sample by changing the wavelength over time.

U.S. Patent No. 1,175,388

When measuring an object using LIDAR, it is necessary to measure 3D data at multiple scanning points. This poses the problem that as the number of scanning points increases, the measurement time also increases.

The purpose of this disclosure is to provide a measurement device, measurement method, and program that can minimize increases in measurement time.

A measurement device according to a first aspect of the present disclosure includes a control unit that selects scanning points to be used for measuring three-dimensional data from among multiple scanning points present within a predetermined area, a measurement unit that measures the three-dimensional data of the selected scanning points by sweeping the wavelength of laser light, and the control unit changes the scanning points to be used for measuring the three-dimensional data depending on the measurement timing of the scanning points present within the predetermined area.

A measurement method according to a second aspect of the present disclosure selects scanning points from among a plurality of scanning points present within a predetermined area as targets for measuring three-dimensional data, measures the three-dimensional data of the selected scanning points by sweeping the wavelength of the laser light, and, when selecting the scanning points, changes the scanning points as targets for measuring the three-dimensional data according to the measurement timing of the scanning points present within the predetermined area.

A program according to a third aspect of the present disclosure causes a computer to select scanning points to be used for measuring three-dimensional data from among multiple scanning points present within a predetermined area, measure the three-dimensional data of the selected scanning points by sweeping the wavelength of the laser light, and, when selecting the scanning points, change the scanning points to be used for measuring the three-dimensional data depending on the measurement timing of the scanning points present within the predetermined area.

This disclosure provides a measurement device, measurement method, and program that can minimize increases in measurement time.

FIG. 1 is a configuration diagram of a measurement device according to the present disclosure. FIG. 2 is a diagram showing the flow of a measurement process executed in the measurement device according to the present disclosure. FIG. 1 is a configuration diagram of a measurement device according to the present disclosure. FIG. 1 illustrates scanning of an object according to the present disclosure. FIG. 2 is a configuration diagram of a light source unit according to the present disclosure. FIG. 1 is a diagram illustrating a mode region according to the present disclosure. 10 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. 10A and 10B are diagrams illustrating the measurement time of an object in the measurement device according to the present disclosure. FIG. 2 is a diagram showing the flow of a measurement process executed in the measurement device according to the present disclosure. FIG. 10 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. FIG. 1 is a configuration diagram of a measurement device according to the present disclosure.

(Embodiment 1)
An example configuration of the measuring device 10 will be described below 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 Time of Flight (ToF) method or a Frequency Modulated Continuous Wave (FMCW) method and generates points that represent the shape of the object. A collection of points that represent the shape of the object constitutes point cloud data. The points that represent the shape of the object may be identified using three-dimensional coordinates in a predetermined space. In other words, the points that represent the shape of the object may be represented using three-dimensional coordinates in a predetermined coordinate system. Points identified using three-dimensional coordinates and point cloud data, which is a collection of points, may be referred to as three-dimensional data.

The measuring 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 modules that perform processing when a processor executes a program stored in memory. Alternatively, the control unit 11 and the measurement unit 12 may be hardware such as a circuit or chip.

The control unit 11 controls the control current value that sweeps 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 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. In other words, 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, by changing the value of the wavelength of the laser light, the control unit 11 can output laser light to multiple locations or to an area having a predetermined area.

A mode corresponds to the wavelength value when light resonates and is output as laser light. A mode region may be a range of control current values that can be changed without changing the wavelength value. In other words, a 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 wavelength value" may include fluctuations of a value that are sufficiently small relative to the wavelength value associated with the mode region. The wavelength value associated with the mode region may be rephrased as the wavelength value that indicates the position of the mode. A control current is a current injected into the measurement 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. Furthermore, 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.

By changing the control current within the mode region, the wavelength of the laser light will fluctuate, but the range of wavelength fluctuation in this case is sufficiently small compared to the wavelength value that indicates the mode position. The wavelength fluctuation caused by changing the control current within the mode region is used to sweep the wavelength of the laser light. In other words, the wavelength of the laser light is swept by changing the control current so that mode hopping does not occur. Mode hopping is when the mode of the laser light that is in a resonant state changes due to fluctuations in the control current.

The measurement unit 12 generates point cloud data of an object located in a predetermined direction using wavelength-swept laser light 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 laser light having a different frequency. For example, the measurement unit 12 may determine the distance between the measurement device 10 and the object based on the time between emitting laser light and receiving reflected light having the same frequency as the emitted laser light. The wavelength of the laser light output from the measurement device 10 may be changed so that it monotonically increases, decreases, or is changed randomly.

Next, the flow of the measurement process executed by the measurement device 10 will be explained using Figure 2. First, the control unit 11 controls the control current value that sweeps 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).

As described above, the measurement device 10 controls the control current to prevent mode hopping when sweeping the wavelength of the laser light. This prevents the phase of the laser light from becoming discontinuous when scanning an object located in a specific direction. As a result, the measurement device 10 can maintain the measurement accuracy of distance measurements.

(Embodiment 2)
Next, an example configuration of the measurement device 20 will be described using Fig. 3. Detailed description of the functions and processes of the measurement device 20 that are the same as 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.

The light source unit 23 may be a laser light source that outputs laser light. Furthermore, the light source unit 23 may be a tunable 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 operates, for example, using the FMCW method. In FMCW operation, the light source unit 23 outputs laser light of a certain frequency while frequency modulating it for a certain period of time. Laser light of a certain frequency may be referred to as laser light within a certain mode region. Alternatively, the light source unit 23 may sweep the wavelength for a certain period of time to perform frequency modulation. The certain period may be a period during which a specified area of the object 30 is measured.

Furthermore, the light source unit 23 switches the wavelength of the laser light when changing the area to be measured on the 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 also mean changing the wavelength of the laser light to a wavelength of a different mode. Here, the wavelength sweep range is set to be sufficiently small compared to the wavelength values considered to be in the same mode region. For example, if the mode regions correspond to each 1 nanometer, the wavelength sweep range is set to a value sufficiently smaller than 1 nanometer.

Now, using Figure 4, we will explain scanning of the object 30. The object 30 may be a moving object, an object fixed in a specific position, or a stationary object. Scanning the object 30 may also be described as scanning the object 30. Scanning the object 30 may also mean obtaining information about the surface or line of the object by emitting laser light onto the surface of the object in a manner that traces the surface of the object. The information about the surface or line of the object may be, for example, three-dimensional data.

The rectangular area in Figure 4 represents an area on the surface of the object 30. Furthermore, each point within the rectangular area represents a scanning point. The light source unit 23 performs wavelength sweeping within one mode region to acquire three-dimensional data for one scanning point. Furthermore, the light source unit 23 adjusts the position where the laser light strikes the object 30 by switching the wavelength of the laser light to acquire three-dimensional data for each scanning point along the dotted arrows. The three-dimensional data may also be referred to as point cloud data. When the light source unit 23 has completed acquiring three-dimensional data for a scanning point on a dotted arrow, it changes the output direction of the laser light, for example, using a mirror or the like, to acquire three-dimensional data for a scanning point along a different dotted arrow. Specifically, the light source unit 23 may use a mirror or the like to change the output direction of the laser light to the vertical direction in Figure 4. Using a mirror may involve adjusting the reflection angle of the laser light reflected by the mirror. The dotted arrow may also be referred to as the scanning axis. The time required to change the scanning axis using a mirror or the like can be longer than the time required to change the scanning point to be measured on the scanning axis.

Here, a detailed configuration example of the light source unit 23 will be described using Figure 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 output laser light of different wavelengths from the light source unit 23.

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 can also be said to shift the phase of the light. Furthermore, as the control current I_ph input to the phase shifter 43 changes, the wavelength of the laser light also changes. The amount of change in wavelength caused by control of the phase shifter 43 is assumed to be sufficiently small compared to the amount of change in wavelength caused by control of the rear mirror 41 and the front mirror 44.

A drive current I_g is input to the active region 42. Resonated light is amplified in the active region 42. Furthermore, 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 small compared to the amount of change in wavelength caused by control of the rear mirror 41 and the front mirror 44.

Next, we will explain the mode region using Figure 6. Figure 6 shows that the mode region is determined by the control currents I_rm and I_fm. The vertical axis of Figure 6 represents the value of the control current I_rm, and the horizontal axis represents the value of the control current I_fm.

The areas surrounded by solid lines in Figure 6 are referred to as mode regions. Figure 6 shows mode regions M1 to M4. Each of mode regions M1 to M4 is associated with a specific wavelength. For example, mode regions may be associated with wavelengths 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 switched mainly by changing the control currents I_rm and I_fm.

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 mode region M1. The control unit 21 determines the values of the control currents I_rm and I_fm for outputting laser light of the wavelength associated with 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 light remains or is maintained within mode region M1. In other words, the control unit 21 adjusts the values of the control currents I_rm and I_fm to avoid mode hopping, which occurs when the mode region changes, when scanning one scanning point on one scanning axis.

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 of the mode region M1. The control unit 21 may then 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 remains or is maintained within the mode region M1.

Returning to Figure 3, the laser light output from the light source unit 23 is split into laser light that is reflected by the splitter 24 and directed toward the mirror 25, and laser light that passes through the splitter 24 and directed toward the target 30.

The laser light directed toward mirror 25 is reflected by mirror 25. The laser light reflected by mirror 25 passes through splitter 24 as laser light R1 and is input to detection unit 22. Laser light R1 may also be referred to as reference light, etc.

The laser light directed toward the object 30 passes through the dispersing unit 26, which deflects the light at an angle dependent on the wavelength of the laser light, and is reflected by the object 30. Deflecting light at an angle dependent on the wavelength of the laser light means changing the direction of the light to a direction dependent on the wavelength of the light. The dispersing unit 26 may be a prism. The dispersing unit 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 unit 22. The laser light S1 may also be referred to as measurement light, sample light, etc.

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 object 30, for example, based on the difference in timing at which the laser beams R1 and S1 are received. Alternatively, the detection unit 22 may measure the distance from the measurement device 20 to the object 30 based on the difference in frequency between the laser beams R1 and S1 at the times they are received.

Next, the flow of the laser light wavelength control process in the measurement device 20 will be explained using Figure 7. First, the control unit 21 determines the wavelength of the laser light to scan the scanning point of a certain scanning axis (S21). The certain scanning axis may be any scanning axis among the scanning axes for which scanning is not being performed.

Next, the control unit 21 determines the mode region corresponding to the wavelength determined in step S21 (S22). Determining the mode region can also be said to identify the mode region. The wavelength value and mode region are assumed to be predetermined as shown in Figure 6.

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 that it monotonically increases or decreases. 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 control current output timings and the values of the control currents to a control current output unit configured by a current output circuit or element, etc.

Next, the control unit 21 determines whether there are any unscanned scanning points on the currently scanned scanning axis (S23).

If the control unit 21 determines that there is an unscanned scanning point on the currently scanned scanning axis, it repeats the processing from step S21 onwards. 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 that can scan the unscanned scanning point.

In step S24, if the control unit 21 determines that there are no unscanned scanning points on the currently scanned scanning axis, it determines whether there are any unscanned scanning axes (S25). The absence of unscanned scanning points on the currently scanned scanning axis means that scanning of all scanning points on the currently scanned scanning axis has been completed. If 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 scanning axes for which scanning has been completed and scanning axes for which scanning has not been completed. After executing the processing of step S26, the control unit 21 repeats the processing from step S21 onwards.

Here, it is assumed that the detection unit 22 performs the measurement process after the process of step S23 is performed. In other words, when the control current is changed and wavelength sweeping is performed in step S23, the detection unit 22 generates three-dimensional data at scanning points on the surface of the object 30 using the reference light and sample light.

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. This allows the measuring device 20 to prevent mode hopping from occurring while performing wavelength sweeping. As a result, by preventing discontinuities in the phase of the laser light while performing wavelength sweeping, it is possible to prevent a decrease in measurement accuracy.

(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 indicate the change in the wavelength of the laser light over time.

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

Figure 8 shows three solid lines. That is, Figure 8 shows the time required to measure scanning points on three scanning axes. Here, we will explain the measurement time for the scanning points shown in Figure 4. In Figure 4, there are six scanning points on one scanning axis. Therefore, the time required to measure one scanning axis is time T1 x 6. Furthermore, Figure 4 shows four scanning axes. Therefore, the time required to complete the measurement is determined to be time T1 x 6 x 4.

In the explanation using Figures 8 and 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.

As explained using Figure 8, the measurement time in a specified area is defined as time T1 x number of scanning points x number of scanning axes. Measurement time can also be referred to as scan time. The following explanation will discuss functions or methods for shortening the measurement time in a specified area.

For example, the control unit 21 selects scanning points to be used for measuring three-dimensional data from among multiple scanning points that exist within a predetermined area. The control unit 21 may also change the scanning points to be used for measuring three-dimensional data, depending on the measurement timing of the scanning points that exist within the predetermined area.

Selecting scanning points to be measured for three-dimensional data may involve determining scanning points for which three-dimensional data measurement will be omitted. For example, the control unit 21 may omit measurement of several scanning points at time t1. Furthermore, at time t2, which is the measurement time following time t1, the control unit 21 may resume measurement of the scanning points omitted at 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 positions of the omitted scanning points 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 same number of scanning points to be scanned at each time, or may decrease or increase the number of scanning points to be scanned over time. Times t1 and t2 may each be the times at which scanning along one scanning axis begins.

The control unit 21 may also determine which scanning points to omit so as to avoid omitting measurements of scanning points at the same position consecutively when measuring at different times.

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.

Next, the flow of the measurement process executed by the measurement device 20 will be explained using Figure 9. First, the control unit 21 selects a scanning point from among multiple scanning points present within a predetermined area as the target for measuring 3D data (S31). Next, the detection unit 22 sweeps the wavelength of the laser light to measure the 3D data of the scanning point selected by the control unit 21 (S32).

As explained above, by reducing the positions of the scanning points at which the control unit 21 performs measurements, the measurement time in a given area can be shortened compared to measuring all scanning points. Furthermore, by changing the positions of the scanning points at which measurements are performed for each measurement time, it is possible to prevent certain scanning points from not being measured consecutively. As a result, it is possible to prevent a significant decrease in the measurement accuracy for each scanning point. "For each measurement time" can also be rephrased as "for each measurement timing."

(Fourth embodiment)
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 earliest time. Black circles in Fig. 10 indicate scanning points on one scanning axis. Each of times t1 to t3 may be the time at which scanning of one scanning axis starts.

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 also be referred to as adjusting.

The scanning point at the end of the dotted arrow at time t1 does not represent a moving vehicle, but is located on the road. In this case, the state of the object at the scanning point's position does not change over time, so it is estimated that there will be little change in the 3D data. On the other hand, for scanning points included in moving vehicles, the position of the vehicle indicated by the scanning point changes over time. Therefore, it is estimated that there will be large changes in the 3D data of scanning points included in moving vehicles. A large change in the 3D data can be rephrased as a large amount of change in the 3D data.

For this reason, at time t2, which is the measurement timing following time t1, the control unit 21 may omit measuring the scanning points located 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 compared to the number of scanning points measured at time t1.

At time t2 in Figure 10, the scanning point at the position indicated by the arrow at time t1 has not been measured.

At time t2 in Figure 10, a dotted arrow is shown on a scanning point near the center of the vehicle. It is estimated that a scanning point near the center of the vehicle will also represent the vehicle at the next measurement time, t3. Therefore, at time t3, the next measurement timing after time t2, the control unit 21 may omit measuring the scanning point located at the position of the dotted arrow inside the vehicle. Furthermore, the dotted arrow shown on the road indicates that no measurement of the scanning point was performed at time t2. Therefore, at time t3, the next measurement timing after time t2, the control unit 21 may measure the scanning point located at the position of the dotted arrow shown on the road. In other words, at time t3, compared to time t2, the control unit 21 omits measurement of two scanning points inside the vehicle and increases the measurement of scanning points on the road. As a result, the number of scanning points measured at time t3 will be greater than at time t2 and less than at time t1.

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

Here, the control unit 21 may use, for example, image recognition processing when estimating positions where there is little change in the 3D data. For example, the control unit 21 may identify objects included in the image based on the image at each time. Furthermore, the control unit 21 may determine whether the identified object is moving. The control unit 21 may estimate that there is a large change in the 3D data for scanning points on moving objects and a small change in the 3D data for scanning points on non-moving objects. The image recognition processing and the processing for determining whether the identified object is moving may be performed using AI (Artificial Intelligence). For example, the image recognition processing and the processing for determining whether the identified object is moving may be performed using a learning model that has learned objects that may be included in the image as training data.

For example, the control unit 21 may identify objects by performing semantic segmentation, which assigns a label that identifies the object to each pixel that makes up the image. The control unit 21 may also store in advance information regarding whether the object identified by each label moves.

In this way, the control unit 21 can shorten the measurement time by omitting measurements of scanning points on a stationary object. Furthermore, even for a moving object, the control unit 21 can shorten the measurement time by omitting measurements of scanning points where changes in the 3D data on the object's surface are expected to be small. Furthermore, the control unit 21 can prevent 3D data at specific scanning points from being omitted from measurement by measuring, at the next measurement time, scanning points that were not measured at the previous measurement time. This prevents a deterioration in the measurement accuracy of 3D data at specific scanning points.

Figure 11 is a block diagram showing an example configuration of the measuring devices 10 and 20 (hereinafter referred to as measuring device 10, etc.) described in the above-mentioned embodiments. Referring to Figure 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) that complies with the IEEE 802.3 series. IEEE stands for Institute of Electrical and Electronics Engineers.

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

Memory 1203 is composed of a combination of volatile memory and non-volatile memory. Memory 1203 may also include storage located remotely from processor 1202. In this case, processor 1202 may access memory 1203 via an I/O (Input/Output) interface (not shown).

In the example of FIG. 11, memory 1203 is used to store software modules. The processor 1202 reads and executes these software modules from memory 1203, thereby performing the processing of the measuring device 10 and the like described in the above-described embodiment.

As explained using FIG. 11, each of the processors included in the measuring device 10, etc., in the above-described embodiments executes one or more programs containing instructions for causing a computer to execute the algorithms explained using the drawings.

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 on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, 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® disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

The present disclosure has been described above with reference to the embodiments, but the present disclosure is not limited to the above-described embodiments. Various modifications that would 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 combined with other embodiments as appropriate.

The drawings are merely examples for illustrating one or more embodiments. Each drawing may not relate to only one particular embodiment, but may also relate to one or more other embodiments. As will 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 figures, for example, to create an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to illustrate an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.
(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 measurement unit that generates point cloud data of an object present in the predetermined direction using laser light that has been wavelength-swept within the mode region.
(Appendix 2)
The control unit
2. The measurement device according to claim 1, wherein the control current value for sweeping the wavelength of the laser beam is determined based on control information that associates a plurality of the mode regions with ranges of the control current value that realize wavelength sweeping of the laser beam in each of the mode regions.
(Appendix 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 included in a control current.
(Appendix 4)
The control unit
4. The measurement apparatus of claim 3, wherein values of the front mirror current and the rear mirror current that fix the laser light at a substantially center position of the mode region are determined, and the wavelength of the laser light is swept within the mode region by changing a value of a phase shifter current included in the control current.
(Appendix 5)
The control unit
5. The measurement device according to claim 1, wherein the control current value for performing wavelength sweep is determined so that the wavelength of the laser light monotonically decreases or monotonically increases.
(Appendix 6)
The measurement unit
6. The measurement device according to claim 1, wherein the point cloud data is generated for each mode region using laser light that has been wavelength-swept in each of a plurality of mode regions.
(Appendix 7)
The measurement unit
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 predetermined direction using laser light whose wavelength is swept within the mode region.
(Appendix 9)
When controlling the control current value,
9. The measurement method according to claim 8, wherein the control current value for sweeping the wavelength of the laser beam is determined based on control information that associates a plurality of the mode regions with ranges of the control current value that realize wavelength sweeping of the laser beam in each of the mode regions.
(Appendix 10)
10. The measurement method according to claim 8, wherein the mode region is associated with values of a front mirror current and a rear mirror current included in a control current.
(Appendix 11)
When controlling the control current value,
11. 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 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 12)
When controlling the control current value,
12. The measurement method according to any one of appendices 8 to 11, wherein the control current value for performing wavelength sweep is determined so that the wavelength of the laser light monotonically decreases or monotonically increases.
(Appendix 13)
When generating the point cloud data,
13. The measurement method according to any one of appendixes 8 to 12, wherein the point cloud data is generated for each mode region using laser light that has been 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 appendices 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 predetermined direction using laser light that has been wavelength-swept within the mode region.
(Appendix 16)
When controlling the control current value,
16. The program according to claim 15, wherein the control current value for sweeping the wavelength of the laser beam is determined based on control information that associates a plurality of the mode regions with ranges of the control current value that realize 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 is associated with values of a front mirror current and a rear mirror current included in a control current.
(Appendix 18)
When controlling the control current value,
18. The program according to claim 17, further comprising determining values of the front mirror current and the rear mirror current that fix the laser light at a substantially 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 19)
When controlling the control current value,
19. The program according to any one of appendices 15 to 18, which determines the control current value for performing wavelength sweep so that the wavelength of the laser light monotonically decreases or monotonically increases.
(Appendix 20)
When generating the point cloud data,
20. The program according to any one of appendices 15 to 19, wherein the point cloud data is generated for each mode region using laser light wavelength-swept in each of a plurality of mode regions.
(Appendix 21)
a control unit that selects a scanning point that is to be used for measuring three-dimensional data from among a plurality of scanning points that exist within a predetermined area;
a measurement unit that measures three-dimensional data of the selected scanning point by sweeping the wavelength of a laser beam;
The control unit
A measuring device that changes the scanning points to be selected as measurement targets for the three-dimensional data according to the measurement timing of the scanning points present in the predetermined region.
(Appendix 22)
The control unit
22. The measurement device according to claim 21, wherein scanning points with small amounts of change in three-dimensional data are estimated at different measurement timings, and measurements of the scanning points with small amounts of change in three-dimensional data are omitted.
(Appendix 23)
The control unit
23. The measurement 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
24. The measuring device according to claim 22, wherein the scanning points on a moving object included in the image data of the predetermined region are estimated to be scanning points with a small amount of change in the three-dimensional data.
(Appendix 25)
The measurement unit
25. The measurement device according to any one of appendices 21 to 24, wherein the wavelength of the laser light is swept within the same mode region to measure three-dimensional data of the selected scanning point.
(Appendix 26)
The control unit
26. The measuring device according to claim 25, wherein the value of a control current input to a light source of the laser light is controlled so that the swept wavelength range of the laser light falls within the same mode region.
(Appendix 27)
27. The measurement device 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 a scanning point to be measured for 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 in which the scanning points to be selected as measurement targets for the three-dimensional data are changed depending on the measurement timing of the scanning points present in the predetermined region.
(Appendix 29)
When selecting the scanning points,
29. The measurement method according to claim 28, wherein scanning points with small amounts of change in three-dimensional data are estimated at different measurement timings, and measurements of the scanning points with small amounts of change in three-dimensional data are omitted.
(Appendix 30)
When selecting the scanning points,
30. The measurement method of claim 29, 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 31)
When selecting the scanning points,
31. The measurement method according to claim 29, wherein the scanning points on a moving object included in the image data of the predetermined region are estimated as 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 appendices 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 according to claim 32, wherein the value of a control current input to a light source of the laser light is controlled 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 is associated with values of a front mirror current and a rear mirror current included in a control current.
(Appendix 35)
Select a scanning point to be measured for 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 that causes a computer to execute the following: changing the scanning points to be selected as measurement targets for the three-dimensional data, depending on the measurement timing of the scanning points that exist within the specified area.
(Appendix 36)
When selecting the scanning points,
36. The program according to claim 35, wherein scanning points with small amounts of change in three-dimensional data are estimated at different measurement timings, and measurements of the scanning points with small amounts of change in three-dimensional data are omitted.
(Appendix 37)
When selecting the scanning points,
37. The program according to claim 36, 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 38)
When selecting the scanning points,
38. The program described in Appendix 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,
A program described in any one of appendices 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 Appendix 39, which controls the 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.

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.

REFERENCE SIGNS LIST 10 Measuring device 11 Control unit 12 Measuring unit 20 Measuring device 21 Control unit 22 Detecting unit 23 Light source unit 24 Splitter 25 Mirror 26 Dispersing unit 30 Object 41 Rear mirror 42 Active region 43 Phase shifter 44 Front mirror

Claims (7)

a control unit that selects a scanning point that is to be used for measuring three-dimensional data from among a plurality of scanning points that exist within a predetermined area;
a measurement unit that measures three-dimensional data of the selected scanning point by sweeping the wavelength of a laser beam;
The control unit
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 in the predetermined area;
The control unit
At the different measurement timings, scanning points with small changes in three-dimensional data are estimated, and measurements of the scanning points with small changes in three-dimensional data are omitted to control the number of scanning points to be measured at the different measurement timings;
The control unit
A measuring device that estimates that the scanning points near the center of a moving object, among the objects included in the image data of the specified region, are scanning points with little change in the three-dimensional data. The control unit
The measurement device according to claim 1 , wherein measurement of the scanning points for which measurement was omitted at a first measurement timing is resumed at a second measurement timing that is performed after the first measurement timing. The measurement unit
The measurement device according to claim 1 , wherein the three-dimensional data of the selected scanning points is measured using the wavelength of the laser light swept within the same mode region. The control unit
4. The measuring device according to claim 3, wherein a value of a control current input to a light source of said laser light is controlled so that the range over which the wavelength of said laser light is swept falls within said same mode region. The measurement device of claim 4, wherein the mode region corresponds to the values of the front mirror current and rear mirror current included in the control current. Select a scanning point to be measured for 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,
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 in the predetermined area;
When selecting the scanning points,
a measurement method in which, at the different measurement timings, the scanning points near the center of a moving object among the objects included in the image data of the specified region are estimated to be scanning points with little change in three-dimensional data, and the number of scanning points measured at the different measurement timings is controlled by omitting measurements of the scanning points with little change in three-dimensional data. Select a scanning point to be measured for 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,
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 in the predetermined area;
When selecting the scanning points,
A program that causes a computer to execute the following steps: At different measurement times, among objects included in image data of the specified region, the scanning points near the center of the moving object are estimated to be scanning points with little change in three-dimensional data, and the number of scanning points measured at the different measurement times is controlled by omitting measurements of the scanning points with little change in three-dimensional data.