Measurement device

Abstract

To extend a measurable distance while securing safety to human body.SOLUTION: A measurement device (10) is a device for measuring an object scanning the object with pulsed light. The measurement device (10) comprises: a light emission element (12); a light reception unit (14); a movable mirror (16); and a control unit (18). The light emission element (12) emits pulsed light. The light reception unit (14) receives reflected pulsed light. The movable mirror (16) changes an emission direction of the pulsed light. The control unit (18) controls a light emission strength of the light emission element (12). In the measurement device (10), a reflection surface of the movable mirror (16) is oscillated in a sinusoidal manner, so that the emission direction of the pulsed light moves in a first direction (101). The control unit (18) emits pulsed light of higher strength in an end region (112) including an end of the scanning range in the first direction (101), than in a center region (114) including a center of the first direction (101) of the scanning range.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a measuring device, a location determining system, a measuring system, and a monitoring system. [Background technology]

[0002] In order to improve the accuracy of automatic driving of vehicles, it is important to improve the performance of measuring devices that measure the surrounding conditions. One such measuring device is one that measures by scanning the surroundings with pulsed light.

[0003] Patent Document 1 describes increasing the sensitivity of a part of the detection area based on vehicle running state information and external environment information. Methods for increasing the sensitivity include adding up at least some of the light receiving values ​​of the light receiving element group over multiple detection periods, and shortening the interval at which the light projecting unit projects the measurement light to increase the number of times the measurement light is projected within a detection period.

[0004] Patent Document 2 describes a LIDAR device in which a pulsed irradiation source and a photosensitive detector rotate relative to a base frame, and performs measurements using a pattern of multiple pulses with different irradiation intensities. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-135273 A [Patent Document 2] Special Publication No. 2019-512705 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, the pulsed light used in the measuring device has a high power density, so it is necessary to ensure human safety so that the pulse irradiation does not cause injury to the user or people around the user.

[0007] One example of a problem to be solved by the present invention is to increase the measurable distance while ensuring safety for the human body. [Means for solving the problem]

[0008] The first invention is A measuring device that scans and measures an object with pulsed light, A light emitting element that emits the pulsed light; a light receiving unit that receives the reflected pulsed light; a movable mirror that changes the emission direction of the pulsed light; A control unit for controlling the light emission intensity of the light emitting element, a reflecting surface of the movable mirror is oscillated in a sinusoidal manner, so that an emission direction of the pulsed light goes back and forth in a first direction; The control unit causes the pulsed light to be emitted at an end region including an end of the scanning range in the first direction, the pulsed light having a higher intensity than a central region including a center of the scanning range in the first direction. It is a measuring device.

[0009] The second invention is A measuring device according to the first aspect of the present invention provided on a moving object; An acquisition unit for acquiring map information; a position specifying unit that specifies a position of the moving object based on the acquired map information and the measurement results of the measuring device. It is a location identification system.

[0010] The third invention is A plurality of measuring devices according to the first aspect of the present invention are provided; The scanning range of one of the measuring devices and the scanning range of the other of the measuring devices are adjacent to each other in the first direction. It is a measurement system.

[0011] The fourth invention is The present invention relates to a measuring device comprising: The one measuring device and the other measuring device are a monitoring system that are provided so as to face each other in a plan view. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a measurement device according to a first embodiment. [Diagram 2] 2 is a diagram illustrating a hardware configuration of a control unit according to the first embodiment. FIG. [Diagram 3] 3 is a diagram illustrating an example of the emission direction (emission angle) of pulsed light according to the first embodiment. FIG. [Figure 4] 4 is a diagram illustrating an example of the relationship between time and an emission angle in one line scan in a first direction according to the first embodiment. FIG. [Diagram 5] FIG. 4 is a diagram illustrating an example of a change in pulse intensity (emission power) according to the first embodiment. [Figure 6] 3 is a diagram illustrating a measurable area of ​​the measurement device according to the first embodiment. FIG. [Figure 7] FIG. 4 is a diagram showing a first modified example of a change in pulse intensity according to the first embodiment. [Figure 8] FIG. 11 is a diagram showing a second modified example of a change in pulse intensity according to the first embodiment. [Figure 9] FIG. 11 is a diagram showing a third modified example of a change in pulse intensity according to the first embodiment. [Figure 10] 10A and 10B are diagrams illustrating the relationship between a light emitting element and a movable mirror according to the second embodiment. [Figure 11] 11 is a diagram illustrating a measurable area of ​​a measurement device according to a second embodiment. FIG. [Figure 12] FIG. 11 is a block diagram illustrating the functional configuration of a measurement device according to a second embodiment. [Figure 13] FIG. 11 is a block diagram illustrating a configuration of a position specifying system according to a third embodiment. [Figure 14] FIG. 13 is a diagram illustrating an example of an environment in which a position specifying system according to a third embodiment is used. [Figure 15]FIG. 13 is a block diagram illustrating the configuration of a measurement system according to a fourth embodiment. [Figure 16] FIG. 13 is a block diagram illustrating an environment in which a measurement system according to a fourth embodiment is used. [Figure 17] FIG. 13 is a diagram illustrating an example of the configuration and usage environment of a monitoring system according to a fifth embodiment. [Figure 18] FIG. 1 is a diagram illustrating a comparative example of a monitoring system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are given the same reference numerals and the description will be omitted as appropriate.

[0014] (First embodiment) FIG. 1 is a diagram illustrating a configuration of a measuring device 10 according to a first embodiment. The measuring device 10 is a device that scans an object with pulsed light to measure it. The measuring device 10 includes a light-emitting element 12, a light-receiving unit 14, a movable mirror 16, and a control unit 18. The light-emitting element 12 emits pulsed light. The light-receiving unit 14 receives the reflected pulsed light. The movable mirror 16 changes the emission direction of the pulsed light. The control unit 18 controls the emission intensity of the light-emitting element 12. In the measuring device 10, the reflection surface of the movable mirror 16 is oscillated in a sinusoidal manner, so that the emission direction of the pulsed light moves back and forth in the first direction 101. The control unit 18 causes an end region 112 including an end of the first direction 101 of the scanning range to emit a pulsed light having a higher intensity than a central region 114 including the center of the first direction 101 of the scanning range. This will be described in detail below.

[0015] The measuring device 10 is a device that measures the distance from the measuring device 10 to an object within a scanning range based on, for example, the difference between the emission timing of pulsed light and the reception timing of reflected light (reflected pulsed light). The pulsed light is, for example, infrared light or other light. The pulsed light is, for example, a laser pulse. The pulsed light output from the light-emitting element 12 and emitted to the outside of the measuring device 10 is reflected by the object and at least a part of it returns toward the measuring device 10. Then, the reflected light enters the measuring device 10. The reflected light that enters the measuring device 10 is received by the light-receiving unit 14, and the intensity is detected. Here, in the measuring device 10, the time from when the pulsed light is emitted from the light-emitting element 12 to when the reflected light is detected by the light-receiving unit 14 is measured. Then, the control unit 18 calculates the distance between the measuring device 10 and the object using the measured time and the propagation speed of the pulsed light. The measuring device 10 is, for example, a LIDAR (Laser Imaging Detection and Ranging, Laser Illuminated Detection and Ranging, or LiDAR (Light Detection and Ranging) device or a radar device.

[0016] The light receiving unit 14 receives the pulsed light incident on the measurement device 10. As shown in Fig. 2 described later, the light receiving unit 14 includes a light receiving element 142 and a detection circuit 141. The light receiving element 142 is, for example, a photodiode such as an avalanche photodiode (APD). The light receiving element 142 includes an IV converter and an amplifier, and outputs a signal indicating the intensity of light detected by the light receiving element 142.

[0017] The movable mirror 16 is, for example, a MEMS mirror movable along one or two axes. The emission direction of the pulsed light emitted from the measurement device 10 can be changed by changing the orientation of the reflecting surface of the movable mirror 16. The movable mirror 16 oscillates sinusoidally around at least one axis as an oscillation axis. This sinusoidal oscillation can be an oscillation at the resonant frequency of the movable mirror 16. Due to the sinusoidal oscillation of the movable mirror 16, the emission direction of the pulsed light changes to a first direction 101.

[0018] When the movable mirror 16 is a biaxially movable MEMS mirror, the movable mirror 16 may oscillate in a sinusoidal manner about at least one axis. For example, the movable mirror 16 may oscillate in a triangular or sawtooth manner about the other axis. By driving the movable mirror 16 on two axes, it is possible to raster scan a predetermined range with pulsed light. Scanning with pulsed light will be described in detail later.

[0019] In the example shown in the figure, measuring device 10 further includes a holed mirror 15 and a condenser lens 17. The pulsed light output from light-emitting element 12 passes through a hole in holed mirror 15, is reflected by movable mirror 16, and then is emitted from measuring device 10. In addition, the reflected light incident on measuring device 10 is reflected by movable mirror 16 and holed mirror 15, and then is incident on light-receiving unit 14 via condenser lens 17. Note that measuring device 10 may further include a collimating lens, a mirror, etc.

[0020] The control unit 18 controls the light emitting element 12, the light receiving unit 14, and the movable mirror 16. In addition, the control unit 18 calculates the distance from the measurement device 10 to an object within the scanning range, as described above.

[0021] 2 is a diagram illustrating a hardware configuration of the control unit 18 according to this embodiment. In this diagram, the control unit 18 is implemented using an integrated circuit 80 and an electronic circuit. The integrated circuit 80 is, for example, a SoC (System On Chip). The electronic circuit is, for example, a drive circuit 120 for the light-emitting element 12 and a drive circuit 160 for the movable mirror 16.

[0022] The integrated circuit 80 has a bus 802, a processor 804, a memory 806, a storage device 808, an input / output interface 810, and a network interface 812. The bus 802 is a data transmission path for the processor 804, the memory 806, the storage device 808, the input / output interface 810, and the network interface 812 to transmit and receive data to and from each other. However, the method of connecting the processor 804 and the like to each other is not limited to bus connection. The processor 804 is an arithmetic processing device realized by using a microprocessor or the like. The memory 806 is a memory realized by using a RAM (Random Access Memory) or the like. The storage device 808 is a storage device realized by using a ROM (Read Only Memory), a flash memory, or the like.

[0023] The input / output interface 810 is an interface for connecting the integrated circuit 80 to peripheral devices. In this figure, the input / output interface 810 is connected to the drive circuit 120 of the light-emitting element 12, the detection circuit 141 of the light-receiving element 142, and the drive circuit 160 of the movable mirror 16.

[0024] The network interface 812 is an interface for connecting the integrated circuit 80 to a communication network. This communication network is, for example, a CAN (Controller Area Network) communication network. The method for connecting the network interface 812 to the communication network may be a wireless connection or a wired connection.

[0025] The storage device 808 stores program modules for implementing the functions of the control unit 18. The processor 804 implements the functions of the control unit 18 by reading the program modules into the memory 806 and executing them.

[0026] The hardware configuration of the integrated circuit 80 is not limited to the configuration shown in the figure. For example, the program module may be stored in the memory 806. In this case, the integrated circuit 80 does not need to include the storage device 808.

[0027] FIG. 3 is a diagram illustrating the emission direction (emission angle) of the pulsed light according to this embodiment. This diagram shows an example in which the movable mirror 16 is movable on two axes and raster scanning is performed with the pulsed light. The two oscillation axes of the movable mirror 16 are perpendicular to each other. In the example of this diagram, the horizontal direction corresponds to the first direction 101. In this embodiment, the emission angle of the pulsed light changes at equal intervals in the first direction 101 from one end to the other end of the scanning range 110. In addition, in the example of this diagram, the emission direction of the pulsed light also changes in a second direction perpendicular to the first direction 101 while reciprocating in the first direction 101. In this way, by changing the emission direction of the pulsed light by the movable mirror 16, the scanning range 110 can be scanned with the pulsed light. Then, the reflected light from an object present in the scanning range 110 can be detected, and the distance from the measuring device 10 to the object can be measured. Although this figure shows an example in which pulsed light is emitted on both the forward and backward paths of scanning in the first direction 101, pulsed light may be emitted only on either the forward or backward path.

[0028] The scanning range 110 includes an end region 112 and a central region 114. The end region 112 includes the end of the scanning range 110 in the first direction 101. The end region 112 exists at both ends in one scanning range 110. The central region 114 includes the center of the scanning range 110 in the first direction 101. The width of the end region 112 and the central region 114 is, for example, a scanning width per unit time. Here, the unit time is a unit time based on the eye-safe regulations, for example, 5 μsec. Furthermore, the end region 112 may be a region that includes the first and second pulsed light from the end at each end, but does not include the third pulsed light. The angular width of the end region 112 and the central region 114 may be 10% or 20% of the scanning angle width of the scanning range 110 in the first direction 101.

[0029] The ends of the edge regions 112 coincide with the ends of the scan range 110. Within the edge regions 112, the pulse intensity may or may not vary. Also, within the central region 114, the pulse intensity may or may not vary.

[0030] FIG. 4 is a diagram illustrating the relationship between time and the emission angle in one line scan in the first direction 101 according to this embodiment. When the emitted pulsed light is plotted on a graph with the horizontal axis being time and the vertical axis being the emission angle in the first direction 101 as in this figure, the plot draws a sine wave. When the movable mirror 16 oscillates sinusoidally, the angular velocity of the angle change of the reflecting surface is faster near the center of the oscillation than near the end. Therefore, when the pulsed light is emitted at equal angular intervals as shown in FIG. 3, Δc<Δe holds. Here, Δc is the time interval of the pulsed light at the center of the first direction 101, and Δe is the time interval of the pulsed light at the end of the first direction 101. In other words, the pulse number density in the end region 112 is smaller than the pulse number density in the central region 114.

[0031] Regarding pulsed light emission, conditions have been established to ensure safety for the human body. Specifically, the following first to third conditions must be satisfied. (First condition) The energy of each pulse of light is equal to or less than a predetermined value. (Second condition) The energy determined by the number of pulses and the pulse train must be below a specified value. However, a pulsed light of 5 μs or less is considered to be one pulsed light. (Third condition) The average energy of the pulsed light per 10 seconds is below a specified value.

[0032] Here, in order to satisfy the second condition, the total energy of the pulsed light within 5 μsec needs to be equal to or less than a predetermined value. As described above, in the measurement device 10 according to this embodiment, Δc and Δe are different, and the number of pulses per 5 seconds in the edge region 112 is less than the number of pulses per 5 seconds in the central region 114. For example, the number of pulses per 5 seconds in the edge region 112 is 1 or less, and the number of pulses per 5 seconds in the central region 114 is more than 1. As a result, the upper limit value of one pulse energy may differ between the edge region 112 and the central region 114.

[0033] In this embodiment, the emission interval of the pulsed light is less than 5 μsec in the central region 114, and the emission interval of the pulsed light is 5 μsec or more in the edge regions 112. When the width of the edge regions 112 is a scanning width per 5 μsec, each edge region 112 contains only the first pulsed light from the edge. Δc is less than 5 μsec, and Δe is 5 μsec or more.

[0034] FIG. 5 is a diagram illustrating a change in pulse intensity (emission power) according to this embodiment. Region 201 is a region where the pulse interval is 5 μsec or more. That is, the number of pulses emitted in any 5 μsec period in region 201 is 1 or less. End region 112 is included in region 201. Region 202 is a region where the pulse interval is shorter than 5 μsec. Specifically, in region 202, the pulse interval is 2.5 μsec or more and less than 5 μsec, and two pulses are emitted in 5 μsec. Center region 114 is included in region 202.

[0035] In this embodiment, the pulse intensity in region 202 is set to satisfy the above-mentioned second condition. In region 202, two pulses are emitted in 5 μsec, whereas the pulse interval in region 201 is longer than 5 μsec. Therefore, the upper limit of the pulse intensity determined by the second condition in region 201 is twice the upper limit of the pulse intensity in region 202. The pulse intensity in edge region 112 can be made higher than the upper limit of the pulse intensity determined by the second condition in central region 114.

[0036] In the example of this figure, the pulse intensity in the region 201 is constant, and the pulse intensity in the region 202 is constant. However, the pulse intensity in the region 201 may not be constant, and the pulse intensity in the region 202 may not be constant. The intensity of each pulse in the region 201 is greater than the intensity of each pulse in the region 202. The average intensity of the pulse light in the region 201 is greater than the average intensity of the pulse light in the region 202. When a plurality of pulse lights are emitted into the edge region 112, the intensity of the pulse light in the edge region 112 may be constant or may be different from each other. When a plurality of pulse lights are emitted into the central region 114, the intensity of the pulse light in the central region 114 may be constant or may be different from each other. The average intensity of the pulse light in the edge region 112 is greater than the average intensity of the pulse light in the central region 114. However, the pulse intensity pattern is not limited to the example of this figure.

[0037] The pulse intensity in each region need only be smaller than the upper limit determined by the second condition, and does not need to be the same. For example, the intensity of each pulse in edge region 112 is 1.9 to 2.1 times the intensity of each pulse in central region 114. Also, for example, the total pulse intensity for 5 μs in edge region 112 may be 90% to 110%, or 95% to 105%, of the total pulse intensity for 5 μs in central region 114.

[0038] The control unit 18 controls the pulse intensity, for example, as shown in the figure, to emit a pulsed light having a higher intensity in the edge region 112 than in the central region 114. Note that the control unit 18 may be capable of switching between a mode in which the pulse intensity is changed in the scanning line in the first direction 101 and a mode in which the pulse intensity is not changed, or may always emit a pulsed light having a higher intensity in the edge region 112 than in the central region 114.

[0039] FIG. 6 is a diagram illustrating the measurable region 20 of the measuring device 10 according to this embodiment. This diagram shows a state seen from a direction perpendicular to a plane including a scanning line in the first direction 101. In this embodiment, the pulse intensity of the edge region 112 is higher than that of the central region 114, so that the measurable distance by the pulsed light in the edge region 112 is longer than that by the pulsed light in the central region 114. Therefore, the measurable distance can be made longer at the end of the scanning range 110 in the first direction 101 direction. In addition, the S / N ratio is higher at the end of the scanning range 110, so that the measurement accuracy can be improved. By making the pulse intensity of the edge region 112 higher than that of the central region 114 while taking into account the upper limit value of each region in this way, the measurement performance of the measuring device 10 as a whole can be improved, rather than by setting all the pulse intensities to a constant value according to the upper limit in the central region 114.

[0040] The control unit 18 may control the light receiving unit 14 so that the signal multiplication factor of the light receiving unit 14 in the edge region 112 is lower than the signal multiplication factor of the light receiving unit 14 in the central region 114. Alternatively, the light receiving unit 14 may be controlled so that the signal multiplication factor of the light receiving unit 14 is lower in a region where the pulse intensity is higher. For example, when the light receiving element 142 is an avalanche photodiode, the signal multiplication factor of the light receiving unit 14 can be changed by changing the voltage applied to the avalanche photodiode. By lowering the signal multiplication factor of the light receiving unit 14 in a region where the pulse intensity is high, signal saturation of the light receiving element 142 can be avoided, and highly accurate measurements can be performed.

[0041] FIG. 7 is a diagram showing a first modified example of the change in pulse intensity according to the present embodiment. In this modified example, the control unit 18 changes the intensity of the pulsed light in three or more stages in the first direction 101. The region 201 is a region where the pulse interval is 5 μsec or more. The region 202 is a region where the pulse interval is shorter than 5 μsec. In this modified example, the pulse intensity is further changed within each region 201. By doing so, the amount of change in pulse intensity between adjacent pulses can be reduced, and the operation of the measurement device 10 can be stabilized. In this modified example as well, the pulse intensity in the edge region 112 is higher than the pulse intensity in the central region 114. Moreover, the pulse intensity increases step by step toward the end of the scanning range 110.

[0042] FIG. 8 is a diagram showing a second modified example of the change in pulse intensity according to the present embodiment. In this modified example, the control unit 18 continuously changes the intensity of the pulsed light in the first direction 101. The region 201 is a region where the pulse interval is 5 μs or more. The region 202 is a region where the pulse interval is shorter than 5 μs. In this modified example, the intensity of the pulsed light is changed linearly in the region 201. By doing so, as in the first modified example, the amount of change in pulse intensity between adjacent pulses can be reduced, and the operation of the measuring device 10 can be stabilized. In this modified example, the pulse intensity in the edge region 112 is higher than the pulse intensity in the central region 114. Moreover, the pulse intensity increases for each pulse toward the end of the scanning range 110.

[0043] FIG. 9 is a diagram showing a third modified example of the change in pulse intensity according to the present embodiment. In this modified example, the control unit 18 changes the intensity of the pulsed light in the first direction 101 in three or more stages. The region 201 is a region where the pulse interval is 5 μsec or more. The region 202 is a region where two pulses are emitted in 5 μsec. The region 203 is a region where three pulses are emitted in 5 μsec. The pulse interval in the region 203 is 1.7 μsec or more and less than 2.5 μsec. In the region 201, the upper limit of the pulse intensity determined by the second condition is three times the upper limit of the pulse intensity in the region 203. The region 203 includes the central region 114. The region 201 includes the edge region 112. For example, the intensity of each pulse in the edge region 112 is 2.9 times or more and 3.1 times or less than the intensity of each pulse in the central region 114. In the example shown in this figure, the sum of the pulse intensities over 5 μsec in the edge regions 112 is between 90% and 110% of the sum of the pulse intensities over 5 μsec in the central region 114 .

[0044] In this modification, the pulse intensity in region 201 is constant, the pulse intensity in region 202 is constant, and the pulse intensity in region 203 is constant. However, the pulse intensity in region 201 may not be constant, the pulse intensity in region 202 may not be constant, and the pulse intensity in region 203 may not be constant. The intensity of each pulse in region 201 is greater than the intensity of each pulse in region 202, and the intensity of each pulse in region 202 is greater than the intensity of each pulse in region 203. The average intensity of the pulsed light in region 201 is greater than the average intensity of the pulsed light in region 202, and the average intensity of the pulsed light in region 202 is greater than the average intensity of the pulsed light in region 203. However, the pulse intensity pattern is not limited to the example shown in this figure.

[0045] Although a plurality of pulse intensity change patterns have been exemplified above, the pulse intensity change pattern according to this embodiment is not limited to these examples. As long as the edge region 112 emits pulsed light with a higher intensity than the central region 114, the intensities of the other pulses can be set in various ways within a range that satisfies the first to third conditions.

[0046] In addition, in the present embodiment, an example has been shown in which the pulse intensities of the end regions 112 on both ends are the same, but the pulse intensities of the end regions 112 on both ends may be different from each other. Of the end regions 112 on both ends, the pulse intensity of only one of the end regions 112 may be higher than the pulse intensity of the central region 114, or the pulse intensity of both end regions 112 may be higher than the pulse intensity of the central region 114. In addition, for example, when performing raster scanning, the pulse intensity patterns may be different from each other or the same in multiple scanning lines in the first direction 101.

[0047] As described above, according to this embodiment, the control unit 18 emits pulsed light having a higher intensity in the end region 112 including the end of the scanning range in the first direction 101 than in the central region 114 including the center of the scanning range in the first direction 101. Therefore, it is possible to increase the measurable distance and improve the measurement accuracy in the end region of the scanning range.

[0048] Second Embodiment Fig. 10 is a diagram illustrating the relationship between the light emitting element 12 and the movable mirror 16 according to the second embodiment. Fig. 11 is a diagram illustrating the measurable area of ​​the measurement device 10 according to the present embodiment. The measurement device 10 according to the present embodiment is the same as the measurement device 10 according to the first embodiment except for the points described below.

[0049] The measuring device 10 according to this embodiment includes two light-emitting elements 12. The scanning range of the pulsed light from one light-emitting element 12 (first light-emitting element 12a) and the scanning range of the pulsed light from the other light-emitting element 12 (second light-emitting element 12b) are adjacent to each other in the first direction 101. This will be described in detail below.

[0050] In the measuring device 10 according to this embodiment, measurements are performed using the pulsed light from the first light-emitting element 12a and the pulsed light from the second light-emitting element 12b. In addition, in the measuring device 10, the light from the two light-emitting elements 12 is reflected by the same movable mirror 16. By doing so, the emission direction of the pulsed light from the first light-emitting element 12a and the emission direction of the pulsed light from the second light-emitting element 12b are changed in synchronization. As a result, the emission direction of the pulsed light from the first light-emitting element 12a and the emission direction of the pulsed light from the second light-emitting element 12b do not intersect. Since the emission direction of the pulsed light from the first light-emitting element 12a and the emission direction of the pulsed light from the second light-emitting element 12b can be always shifted from each other, it is safer for people around.

[0051] In this embodiment as well, the control unit 18 makes the pulse intensity in the edge region 112 higher than the pulse intensity in the central region 114 in each of the scanning range by the pulsed light from the first light-emitting element 12a and the scanning range by the pulsed light from the second light-emitting element 12b. Therefore, the measurable distance can be increased at the end of each scanning range in the first direction 101. Furthermore, the S / N ratio is increased at the end of each scanning range, and the measurement accuracy can be improved.

[0052] As shown in FIG. 11, the measurable area of ​​the measuring device 10 according to this embodiment is the sum of the measurable area 20a by the first light-emitting element 12a and the measurable area 20b by the second light-emitting element 12b. Since the measurable distance at the end of the scanning range in each of the measurable area 20a and the measurable area 20b is long, the measurable distance can be increased not only near the end of the scanning range but also near the center of the scanning range of the measuring device 10 as a whole. In addition, the measurement accuracy can be improved not only near the end of the scanning range but also near the center of the scanning range of the measuring device 10 as a whole. The scanning range of the first light-emitting element 12a and the scanning range of the second light-emitting element 12b may or may not overlap at the end. However, it is preferable that the scanning range of the first light-emitting element 12a and the scanning range of the second light-emitting element 12b are continuous in the first direction 101, and it is preferable that there is no gap between them.

[0053] FIG. 12 is a block diagram illustrating a functional configuration of the measurement device 10 according to this embodiment. The measurement device 10 according to this embodiment further includes a first light receiving unit 14a, a second light receiving unit 14b, and a coupling unit 19. The pulsed light output from the first light emitting element 12a is reflected by the movable mirror 16 and emitted to the outside of the measurement device 10. The pulsed light reflected by the external object returns to the measurement device 10 and is received by the first light receiving unit 14a. The pulsed light output from the second light emitting element 12b is reflected by the movable mirror 16 and emitted to the outside of the measurement device 10. The pulsed light reflected by the external object returns to the measurement device 10 and is received by the second light receiving unit 14b.

[0054] The control unit 18 according to this embodiment controls the first light-emitting element 12a, the second light-emitting element 12b, the first light-receiving unit 14a, the second light-receiving unit 14b, and the movable mirror 16. The control unit 18 also receives signals from the first light-receiving unit 14a and the second light-receiving unit 14b, and calculates the distance from the measurement device 10 to the object, as in the first embodiment. Specifically, the control unit 18 calculates the measurement result of the scanning range by the first light-emitting element 12a based on the output timing of the first light-emitting element 12a and the light-receiving timing of the first light-receiving unit 14a. The control unit 18 also calculates the measurement result of the scanning range by the second light-emitting element 12b based on the output timing of the second light-emitting element 12b and the light-receiving timing of the second light-receiving unit 14b. The combining unit 19 acquires the measurement result of the scanning range by the first light-emitting element 12a and the measurement result of the scanning range by the second light-emitting element 12b from the control unit 18 and combines them. The combining unit 19 then outputs the combined results as a single continuous measurement result for the region. The combining unit 19 can combine the measurement results from the first light-emitting element 12a and the second light-emitting element 12b based on the predetermined positional relationship between the scanning range of the first light-emitting element 12a and the scanning range of the second light-emitting element 12b. When the measurement results from the first light-emitting element 12a and the measurement results from the second light-emitting element 12b are each an image, the combining unit 19 combines them to generate a single image.

[0055] The coupling unit 19 is realized, for example, by using the integrated circuit 80 shown in Fig. 2. The storage device 808 further stores a program module for realizing the function of the coupling unit 19. The processor 804 further realizes the function of the coupling unit 19 by reading the program module into the memory 806 and executing it.

[0056] As described above, according to this embodiment, it is possible to obtain the same actions and effects as the measuring device 10 according to the first embodiment. Moreover, the scanning range of the pulsed light from the first light-emitting element 12a and the scanning range of the pulsed light from the second light-emitting element 12b are adjacent to each other in the first direction 101. Therefore, in the scanning range of the entire measuring device 10, it is possible to lengthen the measurable distance near the center and improve the measurement accuracy.

[0057] (Third embodiment) Fig. 13 is a block diagram illustrating a configuration of a position specifying system 40 according to the third embodiment. Fig. 14 is a diagram illustrating an environment in which the position specifying system 40 according to the present embodiment is used.

[0058] The position identification system 40 according to this embodiment includes a measuring device 10, an acquisition unit 42, and a position identification unit 44. The measuring device 10 is provided in a moving object 30. The acquisition unit 42 acquires map information. The position identification unit 44 identifies the position of the moving object 30 based on the acquired map information and the measurement result of the measuring device 10. The measuring device 10 is the same as the measuring device 10 according to at least one of the first and second embodiments. It will be described in detail below.

[0059] The moving body 30 is, for example, a vehicle, and the measuring device 10 is attached to the center of the front of the moving body 30. However, the measuring device 10 may be attached to the center of the rear of the moving body 30. The positioning system 40 is a system that determines the position of the moving body 30.

[0060] The acquiring unit 42 and the position identifying unit 44 are realized, for example, by using the integrated circuit 80 shown in Fig. 2. The storage device 808 stores program modules for realizing the functions of the acquiring unit 42 and the position identifying unit 44. The processor 804 further realizes the functions of the acquiring unit 42 and the position identifying unit 44 by reading the program modules into the memory 806 and executing them.

[0061] The map information is stored in advance in a server 46 of, for example, a map information service. The map information includes three-dimensional information of structures such as buildings and signs, and their location information (e.g., latitude and longitude). The position identification system 40 communicates with an external server 46, and the acquisition unit 42 acquires the map information from the server 46. If the mobile object 30 is equipped with a GPS or the like, the acquisition unit 42 needs to acquire only map information of the vicinity of the mobile object 30 based on the location information of the mobile object 30.

[0062] The measuring device 10 performs measurements to detect objects around the mobile unit 30. As shown in Figures 6 and 11, the measuring device 10 has a long measurable distance near the edge of the scanning range, and can perform measurements with high accuracy. As a result, when the mobile unit 30 to which the measuring device 10 is attached travels on a road, it is possible to detect structures around the road with high accuracy.

[0063] The position identification unit 44 generates accurate position information of the moving body 30 by matching the structures shown in the map information acquired by the acquisition unit 42 with the structures detected by the measurement device 10. Specifically, the position identification unit 44 calculates the position of the moving body 30 based on the position information of the matched structures in the map information and the distance between the structures acquired by the measurement device 10 and the measurement device 10. The measurement device 10 according to this embodiment is capable of detecting structures around the road with particularly high accuracy, and therefore can also improve the accuracy of the position information of the moving body 30 generated by the position identification unit 44. In turn, the position information generated by the position identification unit 44 can be used to improve the accuracy of, for example, automatic driving and navigation.

[0064] As described above, according to this embodiment, the same actions and effects as those of the measuring device 10 according to the first embodiment can be obtained. Furthermore, in the position identifying system 40 according to this embodiment, the position identifying unit 44 identifies the position of the moving object 30 based on the acquired map information and the measurement result of the measuring device 10. Therefore, the accuracy of the position information of the moving object 30 can be improved.

[0065] (Fourth embodiment) FIG. 15 is a block diagram illustrating a configuration of a measurement system 50 according to a fourth embodiment. FIG. 16 is a block diagram illustrating an environment in which the measurement system 50 according to this embodiment is used. The measurement system 50 according to this embodiment includes a plurality of measurement devices 10. The scanning range of one measurement device 10 (first measurement device 10c) and the scanning range of another measurement device 10 (second measurement device 10d) are adjacent to each other in the first direction 101. The measurement devices 10 are the same as the measurement device 10 according to at least one of the first and second embodiments. This will be described in detail below.

[0066] In the measurement system 50 according to this embodiment, measurements are performed by the first measurement device 10c and the second measurement device 10d. In this embodiment as well, the control unit 18 of each measurement device 10 makes the pulse intensity of the edge region 112 in the scanning range higher than the pulse intensity of the central region 114. Therefore, the measurable distance can be increased at the end of each scanning range in the first direction 101. Furthermore, the S / N ratio is increased at the end of each scanning range, and measurement accuracy can be improved.

[0067] For example, the first measuring device 10c and the second measuring device 10d are attached side by side near the center of the front of a moving object 30 such as a vehicle. However, the first measuring device 10c and the second measuring device 10d may be attached to the center of the rear of the moving object 30.

[0068] As shown in FIG. 16, the measurable area of ​​the measurement system 50 according to this embodiment is the sum of the measurable area 20c by the first measurement device 10c and the measurable area 20d by the second measurement device 10d. Since the measurable distance at the end of the scanning range in each of the measurable area 20c and the measurable area 20d is long, the measurable distance can be increased not only near the end of the scanning range but also near the center of the scanning range of the entire measurement system 50. In addition, the measurement accuracy can be improved not only near the end of the scanning range but also near the center of the scanning range of the entire measurement system 50. The scanning range of the first measurement device 10c and the scanning range of the second measurement device 10d may or may not overlap at the end. However, it is preferable that the scanning range of the first measurement device 10c and the scanning range of the second measurement device 10d are continuous in the first direction 101, and it is preferable that there is no gap between them.

[0069] The processing of the measurement system 50 will be described in more detail with reference to FIG. 15. The measurement system 50 according to this embodiment further includes a combining unit 52. The combining unit 52 acquires and combines the measurement results from the first measurement device 10c and the second measurement device 10d. The combining unit 52 then outputs the combined result as a measurement result of one continuous region. The combining unit 52 can combine the measurement results of the first measurement device 10c and the second measurement device 10d based on the predetermined positional relationship between the scanning range of the first measurement device 10c and the scanning range of the second measurement device 10d. When the measurement results of the first measurement device 10c and the measurement results of the second measurement device 10d are each an image, the combining unit 52 generates a single image by combining them.

[0070] The coupling unit 19 is realized, for example, by using the integrated circuit 80 shown in Fig. 2. The storage device 808 further stores a program module for realizing the function of the coupling unit 19. The processor 804 further realizes the function of the coupling unit 19 by reading the program module into the memory 806 and executing it.

[0071] In this embodiment, it is preferable that the pulsed light emission ports of the multiple measuring devices 10 are spaced apart by 1 cm or more. This ensures safety by preventing the pulsed light from being irradiated simultaneously from the same direction onto surrounding human bodies.

[0072] In this embodiment, it is preferable that the emission directions of the multiple measuring devices 10 are synchronized. The synchronized state is, for example, a state in which the angle between the emission directions is constant. By doing so, the emission direction of the pulsed light from the first measuring device 10c and the emission direction of the pulsed light from the second measuring device 10d do not intersect. Since the emission direction of the pulsed light from the first measuring device 10c and the emission direction of the pulsed light from the second measuring device 10d can be always shifted from each other, it is safer for people in the vicinity.

[0073] As described above, according to this embodiment, the same actions and effects as those of the measuring device 10 according to the first embodiment can be obtained. In addition, the scanning range of the first measuring device 10c and the scanning range of the second measuring device 10d are adjacent to each other in the first direction 101. Therefore, in the scanning range of the entire measuring system 50, the measurable distance near the center can be extended and the measurement accuracy can be improved.

[0074] Fifth embodiment FIG. 17 is a diagram illustrating the configuration and usage environment of a monitoring system 60 according to the fifth embodiment. The monitoring system 60 according to this embodiment includes two or more measuring devices 10. One measuring device 10 (third measuring device 10e) and another measuring device 10 (fth measuring device 10f) are provided to face each other in a plan view. The measuring device 10 according to this embodiment is the same as the measuring device 10 according to at least one of the first and second embodiments. This will be described in detail below.

[0075] This figure shows a monitoring system 60 that monitors a rectangular monitored area 70 using a third measuring device 10e and a fourth measuring device 10f. The monitored area 70 is, for example, the inside of a room. However, the monitored area 70 may be a corridor or a specific area indoors, or it may be outdoors. The third measuring device 10e is installed, for example, near the ceiling at one corner of the monitored area 70. The fourth measuring device 10f is installed near the ceiling at a corner diagonally opposite the corner at which the third measuring device 10e is installed. However, the height at which the third measuring device 10e and the fourth measuring device 10f are installed is not particularly limited.

[0076] As described above, the third measurement device 10e and the fourth measurement device 10f are provided to face each other in a plan view. The facing state is, for example, a state in which the center lines of the scanning ranges (angles of view) of the measurement devices 10 intersect at an angle of 45° or less.

[0077] FIG. 18 is a diagram showing a comparative example of a monitoring system. In this comparative example, a monitored area 70 is monitored by two measuring devices 90. Also shown in this figure is a measurable area 92 for each measuring device 90. In this comparative example, the intensity of the pulsed light of the measuring device 90 is constant, and the measurable distance is constant. As a result, there is an area surrounded by a dashed line in this figure, that is, an area near the corner of the monitored area 70 where no measuring device 90 is provided, where no measurement is possible with either measuring device 90.

[0078] On the other hand, according to the monitoring system 60 according to this embodiment shown in Fig. 17, since the measurable distance is long near the edge of the scanning range of each measuring device 10, it is possible to monitor the vicinity of the corners of the monitored area 70 where no measuring device 10 is installed. In this figure, the measurable area 20e by the third measuring device 10e and the measurable area 20f by the fourth measuring device 10f cover the vicinity of the corners of the monitored area 70. In this way, it is possible to monitor areas that are prone to blind spots, such as corners and edges of the monitored area 70.

[0079] The monitoring system 60 further includes a monitoring terminal 62. The monitoring terminal 62 is, for example, a general-purpose computer or a mobile terminal. The measurement results by the third measuring device 10e and the fourth measuring device 10f are displayed on the screen of the same monitoring terminal 62. This allows the monitor to simultaneously check the measurement results by the third measuring device 10e and the measurement results by the fourth measuring device 10f, thereby enabling efficient monitoring of the monitored area 70.

[0080] As described above, according to this embodiment, the same actions and effects as those of the measuring device 10 according to the first embodiment can be obtained. In addition, the third measuring device 10e and the fourth measuring device 10f are provided so as to face each other in a plan view. This makes it possible to monitor areas that are prone to becoming blind spots, such as corners and edges of the monitored area 70.

[0081] Although the embodiments have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted. Below, examples of reference forms are given. 1. A measuring device that scans an object with pulsed light and measures it, A light emitting element that emits the pulsed light; a light receiving unit that receives the reflected pulsed light; a movable mirror that changes the emission direction of the pulsed light; A control unit for controlling the light emission intensity of the light emitting element, a reflecting surface of the movable mirror is oscillated in a sinusoidal manner, so that an emission direction of the pulsed light goes back and forth in a first direction; The control unit causes the pulsed light to be emitted at an end region including an end of the scanning range in the first direction, the pulsed light having a higher intensity than a central region including a center of the scanning range in the first direction. Measuring equipment. 2. In the measuring device according to 1., The emission angle of the pulsed light changes at equal intervals. Measuring equipment. 3. In the measuring device according to 1. or 2., In the central region, the emission interval of the pulsed light is less than 5 μsec, and in the edge region, the emission interval of the pulsed light is 5 μsec or more. Measuring equipment. 4. In the measuring device according to any one of 1. to 3., The sum of the pulse intensities for 5 μsec in the end regions is 90% or more and 110% or less of the sum of the pulse intensities for 5 μsec in the central region. Measuring equipment. 5. In the measuring device according to any one of 1. to 4., The control unit changes the intensity of the pulsed light in the first direction in three or more stages. Measuring equipment. 6. In the measuring device according to any one of 1. to 5., The control unit continuously changes the intensity of the pulsed light in the first direction. Measuring equipment. 7. In the measuring device according to any one of 1. to 6., The control unit controls the light receiving unit so that a signal multiplication factor of the light receiving unit in the edge region is lower than a signal multiplication factor of the light receiving unit in the central region. Measuring equipment. 8. In the measuring device according to any one of 1. to 7., Two of the light emitting elements are provided, The scanning range by the pulsed light from one of the light-emitting elements and the scanning range by the pulsed light from the other light-emitting element are adjacent to each other in the first direction. Measuring equipment. 9. A measuring device according to any one of 1. to 8. provided on a moving body; An acquisition unit for acquiring map information; a position specifying unit that specifies a position of the moving object based on the acquired map information and the measurement results of the measuring device. Location system. 10. A measuring apparatus comprising a plurality of measuring devices according to any one of 1. to 8. The scanning range of one of the measuring devices and the scanning range of the other of the measuring devices are adjacent to each other in the first direction. Measurement system. 11. The measurement system according to claim 10, The pulsed light emission ports of the plurality of measuring devices are spaced apart by 1 cm or more. Measurement system. 12. 10. or 11. The measurement system according to claim 10, The emission directions of the plurality of measuring devices are synchronized. Measurement system. 13. A measuring apparatus comprising two or more measuring devices according to any one of 1. to 8. A monitoring system in which one of the measuring devices and the other of the measuring devices are provided so as to face each other in a plan view.

[0082] This application claims priority based on Japanese Patent Application No. 2021-038082, filed on March 10, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0083] 10. Measuring Equipment 12 Light emitting element 14 Light receiving part 15 Perforated mirror 16 Movable mirror 17 Condenser lens 18 Control Unit 19 Joint 20 Measurable area 30 Mobile 40 Location System 42 Acquisition Department 44 Location identification part 46 Servers 50 Measurement Systems 52 Joint 60 Surveillance System 62 Monitoring terminal 70 Monitored Areas 80 Integrated Circuits 101 First Direction 110 Scanning range 112 End area 114 Central area

Claims

[Claim 1] A measuring device that scans and measures an object with pulsed light, A light emitting element that emits the pulsed light; a light receiving unit that receives the reflected pulsed light; a movable mirror that changes the emission direction of the pulsed light; A control unit for controlling the light emission intensity of the light emitting element, a reflecting surface of the movable mirror is oscillated in a sinusoidal manner, so that an emission direction of the pulsed light goes back and forth in a first direction; The control unit causes the pulsed light to be emitted at an end region including an end of the scanning range in the first direction, the pulsed light having a higher intensity than a central region including a center of the scanning range in the first direction. Measuring equipment.

Images