JP2016136090A - Laser ranging device, laser ranging method and laser ranging program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent useless light emission which cannot be used for ranging.SOLUTION: A light projection section of a laser ranging device comprises a laser source emitting a laser beam, a mirror reflecting the laser beam while rotating and scanning a scan range by the reflected laser beam, and a lens enlarging the scan range of the laser beam and projects the laser beam, the scan range of which is enlarged, to an object. A light reception section receives reflected light from the object to which the laser beam is projected by the light projection section. A storage device stores information on a rotation angle of the mirror in the case where an optical path of the laser beam reflected by the mirror passes through a lens. A processing device makes the mirror rotate so that the laser beam reflected by the mirror scans the region including the lens. The processing device stops emission of the laser beam from the laser light source if it is determined that the optical path of the laser beam is out of the lens due to rotation of the mirror on the basis of the information on the rotation angle of the mirror.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser distance measuring device, a laser distance measuring method, and a laser distance measuring program.

  In recent years, for example, surveying, person and object detection, and gesture input systems using a scanning laser distance measuring device have appeared. There is an example having a storage unit, a measurement unit, and a control unit as a scanning laser distance measuring device. The storage unit shows the relationship between the mirror angle of the reciprocating vibration type mirror that deflects the laser beam and the emission angle from the scanning angle enlarging lens that enlarges the scanning angle of the laser beam deflected by the mirror, and the mirror angle as the reference position of the mirror. Stored as the elapsed time from The detection unit detects a reference position based on an output signal of a sensor that detects a mirror angle. The measurement unit measures time based on the reference position detected by the detection unit. The control unit drives the laser light source so that the laser beam is emitted when the measurement time of the measurement unit matches the elapsed time stored in the storage unit, and corrects the timing of driving from the mirror angle amplitude. A laser distance measuring device having a semiconductor laser, a lens actuator, a scanning magnification lens, a beam splitter, and a photodiode is also known (see, for example, Patent Documents 1 and 2).

  As an example of a scanning method, for example, a video projection device including a laser light source unit, a laser scanning unit, and a control unit is known. The control unit of the video projection apparatus is configured to control the video signal so that the scanning angle when stopping laser emission in the forward path and the scanning angle when starting laser emission in the backward path are different with respect to the scanning direction in which reciprocal scanning is performed. The operations of the laser light source unit and the laser scanning unit are controlled accordingly. An example in which an optical scanning device of a laser radar includes a scanning control unit, a semiconductor laser driving circuit, a semiconductor laser, a horizontal collimator, a vertical collimator, a scanner, and a convex mirror is also known (see, for example, Patent Documents 3 and 4).

JP 2014-20963 A JP 2009-58341 A International Publication WO2011-086849 JP 2004-101828 A

  In such a scanning laser distance measuring device, it is expected that the detection angle is further increased. However, in the case of the conventional laser distance measuring apparatus as described above, if the beam projection direction is changed with a mirror, a sufficient scanning angle may not be obtained. In order to further enlarge the scanning angle, when attempting to enlarge the scanning range of the laser using the scanning angle enlarging lens, light that is not incident on the scanning angle enlarging lens may be generated. In addition, an unused portion may be formed at the outer edge of the scanning angle magnifying lens, and the magnification effect may not be fully utilized.

  However, in order to obtain a magnifying effect, if the scanning range when the laser light is incident on the scanning angle magnifying lens is set to be larger than the range including the scanning angle magnifying lens, for example, a portion where the beam deviates from the scanning angle magnifying lens occurs . At this time, the portion of the light deviating from the scanning angle magnifying lens is not projected onto the object to be measured, and therefore distance measurement cannot be performed, which is wasted.

  According to one aspect, an object of the present invention is to prevent unnecessary light emission that cannot be used for distance measurement in a laser distance measuring device.

  A laser distance measuring device as one aspect includes a light projecting unit, a light receiving unit, a storage device, and a processing device. The light projecting unit has a laser light source that emits laser light, a mirror that scans the scanning range with the laser light reflected and reflected while rotating, and a lens that expands the scanning range of the laser light. The laser beam whose scanning range is expanded is projected onto the object. The light receiving unit receives the reflected light from the object on which the laser light is projected by the light projecting unit. The storage device stores information on the rotation angle of the mirror when the optical path of the laser light reflected by the mirror passes through the lens. The processing device rotates the mirror so that the laser beam reflected by the mirror scans the region including the lens. Further, when the processing apparatus determines that the optical path of the laser beam is out of the lens due to the rotation of the mirror based on the information on the rotation angle of the mirror, the processing device stops the emission of the laser beam by the laser light source.

  According to one embodiment, in the laser distance measuring device, it is possible to prevent useless light emission that cannot be used for distance measurement.

It is a figure which shows an example of a structure of the laser range finder by 1st Embodiment. It is a figure explaining an example of the distance measuring method by the laser ranging apparatus by 1st Embodiment. It is a figure which shows an example of the rotation angle change of the MEMS mirror by 1st Embodiment. It is a figure explaining an example of the scanning area | region by a comparative example. It is a figure explaining an example of the rectangular range by 1st Embodiment. It is a figure which shows an example of a structure of the calibration apparatus by 1st Embodiment. It is a figure which shows the example of a production | generation of the edge detection output in the calibration by 1st Embodiment. It is a figure which shows an example of the light emission table produced | generated by the calibration apparatus by 1st Embodiment. It is a flowchart which shows an example of the calibration process by 1st Embodiment. It is a flowchart which shows an example of the ranging process in the laser ranging apparatus by 1st Embodiment. It is a figure which shows an example of the light emission table by the modification 1 by 1st Embodiment. It is a figure which shows an example of the light emission table by the modification 2 by 1st Embodiment. It is a flowchart which shows an example of the ranging process in the laser ranging apparatus by the modification 2 of 1st Embodiment. It is a figure which shows an example of the light emission table by the modification 3 by 1st Embodiment. It is a figure which shows an example of a structure of the calibration apparatus by the modification 4 of 1st Embodiment. It is a figure which shows the example of a production | generation of the edge detection output in the calibration by the modification 4 of 1st Embodiment. It is a figure which shows an example of the hardware constitutions of the laser range finder by 2nd Embodiment. It is a flowchart which shows an example of the ranging process by 2nd Embodiment. It is a block diagram which shows an example of the hardware constitutions of a standard computer.

(First embodiment)
Hereinafter, the laser distance measuring device 10 according to the first embodiment will be described with reference to the drawings. The laser distance measuring device 10 is a device that calculates a distance of an object by emitting a pulse of laser light, measuring a round-trip time until returning from the object, and multiplying by the speed of light.

  FIG. 1 is a diagram illustrating an example of a configuration of a laser distance measuring device 10 according to the first embodiment. FIG. 2 is a diagram for explaining an example of a distance measuring method by the laser distance measuring apparatus 10 according to the first embodiment. As shown in FIG. 1, the laser distance measuring device 10 includes an optical unit 20, a drive unit 50, and a control device 70. The optical unit 20 includes an optical component that emits laser light and receives reflected light. The drive unit 50 is a device that drives the optical unit 20, receives a signal output from the optical unit 20, and outputs the signal to the control device 70. The control device 70 controls the operation of the optical unit 20 via the drive unit 50, acquires a measurement result, and performs a process of calculating a distance.

  As shown in FIG. 2, when laser light is emitted corresponding to the signal S1 and received like the signal S2, the laser distance measuring device 10 calculates a time ΔT from the signal S1 to the signal S2. At this time, the distance to the object is represented by distance = (c × ΔT) / 2 (where c is the speed of light). For example, as will be described later, a two-dimensional scan as represented by beams L1, L2,... Is performed by changing the laser projection direction. The laser distance measuring device 10 may calculate the time ΔT for each of the beams L1, L2,... In FIG. At this time, the direction in which the two-dimensional scan is performed is a vertical direction 78 and a horizontal direction 79. The vertical direction 78 may be referred to as a first direction. The horizontal direction 79 is sometimes referred to as a second direction. For example, in the two-dimensional scan, the light projecting direction in the second direction may be changed with respect to one light projecting direction in the first direction. However, FIG. 2 is a diagram illustrating distance measurement using laser light, and does not indicate that all of the laser light beams that scan the rectangular range are used in distance measurement according to the present embodiment.

  Returning to FIG. 1, the optical unit 20 includes a light projecting unit 30 and a light receiving unit 35. The light projecting unit 30 includes a laser 22, a lens 24, a Micro Electro Mechanical Systems (MEMS) mirror 26, and an angle magnifying lens 28. The laser 22 is a laser light source that emits laser light. The lens 24 is a lens for collimating the laser beam from the laser 22.

  The MEMS mirror 26 is a mirror in which a sensor, a drive mechanism, and a circuit are integrated. The MEMS mirror 26 reflects the laser light from the laser 22 while rotating, and scans the scanning range with the reflected laser light. The MEMS mirror 26 may be, for example, a mirror having horizontal resonance and vertical non-resonance. The angle enlarging lens 28 is a lens for enlarging the scanning range by the MEMS mirror 26. The light projecting unit 30 changes the rotation angle of the MEMS mirror 26 to project the laser beam having an expanded scanning range onto the object as shown in FIG.

  The light receiving unit 35 includes a lens 37 and a photo diode (PD) 39. The lens 37 is a condensing lens that condenses laser light on the PD 39. The PD 39 is a light receiving element that receives reflected light. Other light receiving elements may be used as long as they can convert light into electrical signals such as Avalanche Photo Diode (APD) and Complementary Metal Oxide Semiconductor (CMOS). Based on the timing of the laser beam received by the PD 39, the control device 70 measures the distance of the object as described above.

  The drive unit 50 includes a mirror driver 52, a mirror angle detector 54, a horizontal reciprocation counter 56, a light emission timing controller 58, and a light emission clock output device 60. The drive unit 50 is controlled by the control device 70 to generate various signals for driving the optical unit 20 and output the generated signals to the optical unit 20. Further, the drive unit 50 detects a signal output from the optical unit 20 and outputs the signal to the control device 70.

  The mirror driver 52 outputs drive signals for controlling the vertical rotation 33 and the horizontal rotation 31 to the MEMS mirror 26, respectively. In addition, it is preferable that the rotation 31 and the rotation 33 repeat the angle change which reflects light in the area | region containing the angle expansion lens 28. FIG. The region including the angle magnifying lens 28 is a region including the angle magnifying lens 28 in which the optical path of the laser light changed by the rotation 31 and the rotation 33 is changed. This region may be, for example, a rectangular range described later. At this time, it is preferable that the MEMS mirror 26 is oscillating rotation that repeats an angular change in a range corresponding to the rectangular range. In the following description, a case where the region including the angle magnifying lens 28 is a rectangular range will be described as an example.

  The drive signal is a signal for changing the rotation angle of the MEMS mirror 26 so that the projection direction of the laser light reflected by the MEMS mirror 26 is two-dimensionally scanned in the region including the angle magnifying lens 28 as described above. . The drive signal is generated based on an instruction from the control device 70. The drive signal is a rotation angle of the MEMS mirror 26 in which the laser light whose projection direction is changed by the MEMS mirror 26 scans a rectangular range in which the lens diameter of the angle expansion lens 28 is equal to or smaller than the diameter of the inscribed circle of the rectangular range. May be a signal.

  The mirror angle detector 54 receives a vertical angle signal related to the rotation 33 from the MEMS mirror 26 and detects a rotation angle related to the rotation 33 (sometimes referred to as a vertical angle). The mirror angle detector 54 receives a horizontal angle signal related to the rotation 31 from the MEMS mirror 26 and detects a rotation angle related to the rotation 31 (sometimes referred to as a horizontal angle). The mirror angle detector 54 outputs, for example, a signal indicating that the horizontal angle change has made one round trip to the horizontal round trip counter 56. That the angle change in the horizontal direction is reciprocated means that the angle change corresponding to one reciprocation in which the laser beam irradiation destination makes a round from one end to the other end in the horizontal direction and returns to the other end is performed. The irradiation destination refers to the position on the optical path of the laser light. The timing for outputting a signal indicating that the angle change has made one round trip is an angle corresponding to one round trip in which the laser beam irradiation destination makes a round trip from one end to the other end in the horizontal direction of the above-mentioned region, for example, a rectangular range. Any timing can be used as long as it can be detected that the change has been made. The timing at which this signal is output may be, for example, a timing at which the amplitude value of the horizontal angle signal falls below a predetermined value.

  The horizontal reciprocation counter 56 counts the number of horizontal reciprocations of the rotation 31 of the MEMS mirror 26. The number of horizontal reciprocations is the number of times the horizontal angle change of the MEMS mirror 26 is repeated, and is counted as one when the horizontal angle change is completed. The horizontal reciprocation counter 56 counts the number of repetitions of the horizontal angle change of the MEMS mirror 26 based on the signal indicating that the horizontal angle change output from the mirror angle detector 54 has made one reciprocation, and controls the light emission timing. The data may be output to the device 58. The count of the number of horizontal reciprocations is preferably initialized when two-dimensional scanning is completed for the rectangular range described above.

  Here, a change in the rotation angle of the MEMS mirror 26 will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of a change in the rotation angle of the MEMS mirror 26 according to the first embodiment. In FIG. 3, the horizontal axis is time, and the vertical axis is the rotation angle. The horizontal angle 87 is a rotation angle at the rotation 31 of the MEMS mirror 26. For example, the rotation angle may be based on the direction of the optical path of the laser light incident on the MEMS mirror 26. The vertical angle 89 is a rotation angle in the rotation 33 of the MEMS mirror 26. Here, time T1 indicates the period of change of the vertical angle 89. The reciprocating rotation in the rotation 31 of the MEMS mirror 26 corresponding to the rectangular range described above is repeatedly performed in one cycle time of the vertical angle 89 like the horizontal angle 87.

  Returning to FIG. 1, the light emission timing controller 58 outputs a laser light emission signal for causing the laser 22 to emit light at a predetermined timing. In the present embodiment, the laser emission signal is a signal that causes the laser 22 to emit pulses at predetermined intervals, for example, when the optical path of the laser beam from the laser 22 passes through a lens described later. Therefore, there is an irradiation destination that does not emit light among the irradiation destinations corresponding to the rectangular range described above. In the present embodiment, the laser emission signal includes the rotation angle (the above-described vertical angle) of the rotation of the MEMS mirror 26 detected by the mirror angle detector 54, the clock generated by the light emission clock output device 60, and It is generated according to a light emission table 180 described later. At this time, the control device 70 receives the detection result output from the drive unit 50 and refers to the light emission table 180, for example, so as to output information for causing the light emission timing controller 58 to generate a laser light emission signal. May be. An example of the light emission condition information indicating the conditions for generating the laser light emission signal will be described later.

  The control device 70 includes a processing device 72 and a storage device 74. The processing device 72 controls each device of the drive unit 50 and measures the distance to the object. The processing device 72 may be a processing device such as a processor, a field-programmable gate array (FPGA), or a microcomputer. The processing device 72 calculates the distance to the object based on the laser light received by the PD 39 as described with reference to FIG. At this time, the processing device 72 refers to information stored in the storage device 74 that stores the rotation angle of the MEMS mirror 26 where the irradiation destination of the laser light is within the lens of the angle expansion lens 28. The term “inside the lens” refers to a region within the lens opening. The information storing the rotation angle of the MEMS mirror 26 where the irradiation destination of the laser light is in the lens of the angle expansion lens 28 is, for example, a light emitting table 180 described later.

  The processing device 72 stops the emission of the laser 22 when it is determined that the irradiation destination of the laser light due to the change in the rotation angle of the MEMS mirror 26 is outside the lens of the angle magnifying lens 28. For example, the processing device 72 reads the light emission table 180 from the storage device 74, and acquires the start horizontal angle and the number of times of light emission that are the laser light emission start timing corresponding to the vertical angle of the MEMS mirror 26 received from the drive unit 50. The output may be output to the drive unit 50. In this case, the light emission condition information indicating the conditions for generating the laser light emission signal is the start horizontal angle corresponding to the current vertical angle acquired by the mirror angle detector 54 and the number of times of light emission.

  The storage device 74 is a device that stores information, and holds a data table that stores conditions for the laser light irradiation destination to be within the lens of the angle magnifying lens 28, which is generated by a calibration process described later. The storage device 74 may store a control program for performing the ranging process by being read and executed by the processing device 72. The conditions are information indicating the vertical angle of the MEMS mirror 26, information indicating the horizontal angle at which laser light emission is started in horizontal scanning, and laser light to be emitted from when laser light emission is started to when it is stopped. Is the number of times of light emission. As an example of the conditions, details of the light emission table 180 will be described later.

  FIG. 4 is a diagram illustrating an example of a scanning region according to a comparative example. FIG. 5 is a diagram illustrating an example of a rectangular area according to the first embodiment. As shown in FIG. 4, the sampling point group 81 indicates the irradiation destinations of the laser light angle magnifying lens 28 according to the comparative example with circles. The irradiation destination of the laser light in the angle magnifying lens 28 may be, for example, the laser irradiation position on the lens surface of the angle magnifying lens 28 on the laser 22 side. Hereinafter, the laser beam irradiation destination may be referred to as a sampling point. In the example of FIG. 4, the opening of the lens of the angle magnifying lens 28 circumscribes the region of the sampling point group 81. At this time, the region 82 has no sampling point and is a non-use region although the laser beam can be projected.

  In FIG. 5, the sampling point group 83 circumscribes the lens opening of the angle magnifying lens 28. The sampling point group 83 is an example of a region including the angle magnifying lens 28. In the sampling point group 83, there is no unused area in the angle magnifying lens 28, but a kicked portion 85 is generated. The kicked portion 85 is a useless area because the irradiation destination of the laser beam is located outside the lens of the angle magnifying lens 28, and the object is not irradiated and the distance cannot be measured.

  Therefore, in the first embodiment, the light emission timing controller 58 determines that the laser light irradiation destination is kicked and becomes an irradiation destination corresponding to the portion 85 by the control of the processing device 72. A laser emission signal is output to stop the light emission. Thereby, the irradiation destination of the laser light is in the lens of the angle magnifying lens 28.

  Next, a process for generating a data table that is referred to for outputting the above laser emission signal will be described. The process of generating a data table that is referred to for outputting a laser emission signal may be referred to as calibration. FIG. 6 is a diagram illustrating an example of the configuration of the calibration apparatus 160 according to the first embodiment.

  As illustrated in FIG. 6, the calibration device 160 includes a light projecting unit 130, a PD 135, a driving unit 150, a table generation processing device 162, and a storage device 164. Since the calibration device 160 has the same configuration as that of the laser distance measuring device 10, the same reference numeral is given to the same configuration, and redundant description is omitted.

  As illustrated in FIG. 6, the light projecting unit 130 includes a laser 22, a lens 24, a MEMS mirror 26, and an angle magnifying lens 28, as with the light projecting unit 30. In the light projecting unit 130, the angle expanding lens 28 is provided in the lens holder 128. The lens holder 128 is a member that supports the angle magnifying lens 28 and scatters laser light outside the lens of the angle magnifying lens 28. The PD 135 receives the laser light scattered by the lens holder 128 and outputs it to the edge detector 152 described later. At this time, the laser light corresponding to the kicked portion 85 described in FIG. 5 is scattered and received by the PD 135.

  Similar to the drive unit 50, the drive unit 150 includes a mirror driver 52, a mirror angle detector 54, a horizontal reciprocation counter 56, a light emission timing controller 58, and a light emission clock output device 60, and further includes an edge detector 152. doing. The edge detector 152 detects the laser beam corresponding to the kicked portion 85 received by the PD 135. The edge detector 152 preferably has a circuit for determining the position based on an output from the PD 135 with the boundary between the portion where the kick occurs and the portion where the kick does not occur as an edge.

  The table generation processing device 162 generates a light emission table 180 to be described later based on the timing at which the laser beam is detected by the PD 135. That is, the table generation processing device 162 generates, for example, the light emission table 180 based on the output of the PD 135 with the conditions for emitting the laser light as the rotation angle of the MEMS mirror 26, the timing for emitting the laser, and the like. In addition, the table generation processing device 162 stores the generated light emission table 180 in, for example, the storage device 164.

  FIG. 7 is a diagram illustrating an example of generation of the edge detection output in the calibration according to the first embodiment. FIG. 7 shows an example of signals output when the calibration device 160 generates the light emission table 180, for example. In FIG. 7, the horizontal axis represents time, and the vertical axis represents the horizontal angle, laser emission signal, PD output, and edge detection output.

  As shown in FIG. 7, the horizontal angle signal 171 is a signal indicating a time change of one round trip of the horizontal angle which is the rotation angle of the rotation 31 of the MEMS mirror 26. The horizontal angle signal 171 is detected by the mirror angle detector 54 and output to the table generation processing device 162. For example, the horizontal angle signal 171 indicates a change until the angle at the rotation 31 of the MEMS mirror 26 returns from the horizontal reference position to the horizontal reference position again. The horizontal reference position may be a position where the rotation angle of the MEMS mirror 26 in the horizontal direction is maximized. At this time, the angle in the horizontal direction may be set to zero when no driving force is applied in the vertical direction with respect to the mirror surface of the MEMS mirror 26, for example, and may be the angle inclined by driving.

  The laser emission signal 173 is a signal for causing the laser 22 to emit a pulse every predetermined time during the horizontal reciprocation time indicated by the horizontal angle signal 171. In other words, the laser emission signal 173 is a signal for causing the laser 22 to emit light in a horizontal reciprocation time so that the irradiation destination of the laser beam is in a rectangular range. The laser emission signal 173 is output from the emission timing controller 58 to the laser 22 based on the control of the table generation processing device 162.

  The PD output 175 is an output signal from the PD 135 during one horizontal round trip. The PD output 175 is a signal indicating the light reception status of the scattered light from the lens holder 128 at the PD 135. In the example of FIG. 7, the PD output 175 outputs a pulse indicating that the laser beam has been received within a range where the absolute value of the horizontal angle signal 171 increases. The range of time during which pulses are output at the PD output 175 is, for example, the range of time corresponding to the kicked portion 85 in FIG.

  The edge detection output 177 is a signal indicating the time during which a pulse is output at the PD output 175. The time in the edge detection output 177 is, for example, the time from the horizontal reference position. For example, the edge detection output 177 may be a signal that goes high when the PD output 175 from the PD 135 reaches a predetermined amplitude level. During calibration, the laser 22 emits light from the horizontal reference position to all irradiation positions (rectangular regions) at every vertical angle of scanning by the MEMS mirror 26. The edge detector 152 outputs an edge detection output 177 indicating a range where there is a kick at each horizontal scanning position.

  In the example of FIG. 7, the time during which the edge detection output 177 is high is the time during which the laser beam irradiation destination is outside the lens of the angle magnifying lens 28 such as the kicked portion 85 described above. In this horizontal reciprocation, the PD output 175 is output at times t1 to t2 and times t3 to t4, and it can be seen that these times are kicked and correspond to the portion 85. For example, it is not always necessary to cause the laser 22 to emit light in one round trip in the horizontal direction, so that the time t1 to t2 may be a time range in which the laser 22 emits light. At this time, the time t1 is a time when the laser 22 starts to emit light in one horizontal reciprocation indicated by the horizontal angle signal 171. The horizontal angle θ1 at time t1 is a start horizontal angle at which the laser 22 starts to emit light. The table generation processing device 162 obtains the horizontal angle range of the MEMS mirror 26 that is not kicked for each vertical angle, determines the start horizontal angle and the number of times of light emission (sampling number), and stores them as the light emission table 180.

  FIG. 8 is a diagram illustrating an example of the light emission table 180 generated by the calibration device 160 according to the first embodiment. As shown in FIG. 8, the light emission table 180 is a data table indicating conditions for emitting laser light. The light emission table 180 has a vertical angle, a start horizontal angle, and the number of samples corresponding to each other. The vertical angle is an angle of the MEMS mirror 26 in the rotation 33, and in this example, the incident direction of the laser beam with respect to the MEMS mirror 26 is shown as zero, the vertical upward direction is positive, and the vertical downward direction is negative. The start horizontal angle is a horizontal angle at which light emission of the laser 22 is started for each vertical angle, for example, the horizontal angle θ1 described with reference to FIG. The number of samples is the number of times the laser 22 emits light from the start horizontal angle in one horizontal round trip for each vertical angle. The light emission table 180 may be generated by the calibration device 160 and stored in the storage device 164. In addition, the light emission table 180 is preferably read from the storage device 164 and stored in the storage device 74 in advance, for example, at the time of measurement by the laser distance measuring device 10.

  Hereinafter, the calibration process by the calibration device 160 will be further described with reference to the flowchart. FIG. 9 is a flowchart illustrating an example of calibration processing according to the first embodiment. In performing the calibration process, for example, the table generation processing device 162 preferably sets in advance in what order the vertical angle and the horizontal angle are changed. For example, the table generation processing device 162 causes the mirror driver 52 to output a drive signal that changes the vertical angle from, for example, the vertical upward to the downward sequentially and changes the horizontal angle by one reciprocation for each vertical angle.

  As shown in FIG. 9, the calibration device 160 detects the vertical angle of the MEMS mirror 26 by the mirror angle detector 54 (S201). When the detected vertical angle is not a desired angle (S202: NO), the table generation processing device 162 returns to S201 and repeats the processing. The desired angle is a predetermined set angle that is set by, for example, setting the initial value to plus 10 degrees and decreasing it by 1 degree for each horizontal round trip when performing calibration from the vertical upward direction. .

  When the vertical angle is a desired angle (S202: YES), the table generation processing device 162 detects the horizontal angle by the mirror angle detector 54 (S203). When the detected angle is not the reference angle corresponding to the horizontal reference position (S204: NO), the table generation processing device 162 returns to S203 and repeats the process.

  When the horizontal angle is the reference angle (S204: YES), the table generation processing device 162 starts the light emission of the laser 22 via the light emission timing controller 58 (S205). At this time, the table generation processing device 162 causes the light emission timing controller 58 to start outputting a signal such as the laser light emission signal 173 shown in FIG. For example, the light emission timing controller 58 outputs a laser light emission signal 173 to the laser 22 so that the laser 22 emits pulses at regular intervals.

  The table generation processing device 162 performs edge detection based on the edge detection output detected by the edge detector 152 (S207). The edge detection is performed based on the edge detection output 177 output from the edge detector 152 based on, for example, the PD output 175 from the PD 135 as shown in FIG. For example, the table generation processing device 162 receives the edge detection output 177 from the edge detector 152 and detects edges such as times t1 and t2.

  If the table generation processing device 162 has not detected both edges in one horizontal reciprocation (S207: NO), the table generation processing device 162 returns to S206 and repeats the processing. Both edges are, for example, an edge indicating that the PD output 175 is not detected (for example, the time t1 of the edge detection output 177) and an edge indicating that the PD output 175 starts to be detected again (for example, the edge detection output 177). At time t2).

  When the table generation processing device 162 detects both edges (S207: YES), the table generation processing device 162 ends the light emission of the laser 22 via the light emission timing controller 58 (S208). The table generation processing device 162 stores the vertical angle detected in S201 and the edge position (horizontal angle θ1 at the edge) detected in S206 in the storage device 164 or the like (S209).

  The table generation processing device 162 detects the current vertical angle via the mirror angle detector 54 (S210), and if it is not the end angle (S211: NO), it returns to S201 and repeats the processing. When the detected vertical angle is a preset calibration end angle (S211: YES), the table generation processing device 162 obtains data such as the edge position at each vertical angle stored in the storage device 164 or the like. Reading, for example, writing to the storage device 164 as the light emission table 180 (S212). At this time, the table generation processing device 162 preferably counts the pulses of the laser emission signal 173 between the edges and writes the number of samples in the emission table 180. As described above, the light emission table 180 is generated and stored in the storage device 164, for example.

  Next, distance measurement processing by the laser distance measuring device 10 will be described with reference to a flowchart. FIG. 10 is a flowchart illustrating an example of a distance measurement process in the laser distance measuring device 10 according to the first embodiment. It is assumed that the laser distance measuring device 10 stores the light emission table 180 generated by, for example, the calibration device 160 in the storage device 74 in advance. Further, similarly to the calibration device 160, the laser distance measuring device 10 is set in advance with a method for changing the angle of the MEMS mirror 26. For example, it is assumed that the mirror driver 52 outputs a drive signal to the MEMS mirror 26, and the MEMS mirror 26 is reciprocally rotated at the rotation 31 and the rotation 33.

  As shown in FIG. 10, in the laser distance measuring device 10, the control device 70 detects the vertical angle of the MEMS mirror 26 via the mirror angle detector 54 (S231). The control device 70 reads the light emission table 180 from the storage device 74 and sets it so that it can be referred to (S232). The control device 70 detects the horizontal angle via the mirror angle detector 54 (S233). The control device 70 refers to the detected vertical angle and horizontal angle on the light emission table 180, and when it is not the light emission start angle (S234: NO), returns to S233 and repeats the process. The light emission start angle is a read vertical angle and a start horizontal angle stored in the light emission table 180 corresponding to the vertical angle.

  When the detected vertical angle and horizontal angle are the light emission start angles (S234: YES), the control device 70 causes the laser 22 to emit light via the light emission timing controller 58 (S235). At this time, the information output from the control device 70 to the drive unit 50 is, for example, information indicating that the detected vertical angle and horizontal angle are the light emission start angles, and this is for generating the above-described laser emission signal. It is an example of the light emission condition information.

  The controller 70 repeats light emission until the number of pulse emission of the laser 22 reaches the number of samples in the light emission table 180 (S236: NO). When the number of samples is reached (S236: YES), the control device 70 determines whether there is an end instruction. (S236). The end instruction may be input by the user via an input device (not shown), for example. If there is no end instruction (S237: NO), the control device 70 returns to S231 and repeats the process. At this time, the vertical angle is changed by a preset method. If there is an end instruction (S237: YES), control device 70 ends the process.

  As described above, the laser distance measuring device 10 according to the first embodiment includes the light projecting unit 30, the light receiving unit 35, the driving unit 50, and the control device 70. The light projecting unit 30 includes a laser 22 that emits laser light, and a MEMS mirror 26 that changes the reflection angle of the laser light and scans the laser light. The light projecting unit 30 includes an angle magnifying lens 28 that expands the scanning range of the laser light by the MEMS mirror 26. The light projecting unit 30 projects laser light that is two-dimensionally scanned onto an object.

  The light receiving unit 35 receives reflected light from the object on which the laser light is projected from the light projecting unit 30. The processing device 72 of the control device 70 changes the rotation angle of the MEMS mirror 26 so that the laser beam scans a region including the angle magnifying lens 28. The processing device 72 refers to the information on the rotation angle of the MEMS mirror 26 in which the optical path of the laser light passes through the lens in the storage device 74. When the processing device 72 determines that the optical path of the laser light is outside the lens due to the change in the rotation angle of the MEMS mirror 26, the processing device 72 stops the emission of the laser light from the laser light source. The processing device 72 calculates the distance of the object based on the light projected and received as described above.

  As described above, according to the laser distance measuring device 10, the scanning range can be further expanded by projecting the laser light reflected by the MEMS mirror 26 through the angle magnifying lens 28 when performing distance measurement. . At this time, in the laser distance measuring device 10, it is possible to prevent generation of a region that is not used as a laser beam irradiation destination in the angle magnifying lens 28 and laser light that is not incident on the angle magnifying lens 28. In this way, useless light emission can be prevented by preventing kicking that is not incident on the angle expansion lens 28. Thereby, power consumption is reduced. For example, assuming that the rectangular region is a square having a lens diameter as one side, power consumption is expected to be reduced by about 20% by stopping the light emission to the kicked portion. Further, since it is possible to prevent a region that does not become the laser beam irradiation destination in the opening of the angle magnifying lens 28, the opening of the lens of the angle magnifying lens 28 can be fully utilized, and scanning of the laser light can be performed. The range can be large.

  The control device 70 according to the first embodiment refers to the light emission table 180 and controls the timing of starting the emission of the laser light in the horizontal scanning at a certain angle in the vertical direction of the MEMS mirror 26. At this time, the light emission table 180 is generated in advance. The generation of the light emission table 180 is performed by the calibration device 160, for example. The calibration device 160 is provided with a PD 135 for monitoring kicking (scattered light from the lens holder 128) by the MEMS mirror 26, and the scattered light of the laser light caused by the kicking is detected. The edge detector 152 preferably has a circuit for determining the position based on, for example, a boundary between a portion where kicking occurs and a portion where no kick occurs based on, for example, a PD output 175 from the PD 135.

  As described above, the control device 70 refers to the detected angle of the MEMS mirror 26 with the light emission table 180 and controls the timing at which laser light emission is started. With such a configuration, it is possible to use the MEMS mirror 26 capable of high-speed scanning and to prevent waste of power. At this time, since the control device 70 is a driving method using mechanical resonance, the irradiation destination of the laser light from the MEMS mirror 26 that is difficult to drive so as to change the rotation angle along the angle magnifying lens 28. Can be controlled along the angle magnifying lens 28. As described above, even when the light projecting unit 30 is arranged in combination with the MEMS mirror 26 and the angle magnifying lens 28, since the laser beam is not kicked, it is possible to efficiently perform sampling for distance measurement. It is.

(Modification 1 of the first embodiment)
Hereinafter, Modification 1 of the first embodiment will be described. In this modification, the same number is attached | subjected about the structure and operation | movement similar to 1st Embodiment, and duplication description is abbreviate | omitted. In this modification, a light emitting table 250 is used instead of the light emitting table 180.

  FIG. 11 is a diagram illustrating an example of the light emission table 250 according to the first modification according to the first embodiment. The light emission table 250 is a data table indicating conditions for emitting laser light. Similar to the light emission table 180, the light emission table 250 has vertical angles and sample numbers corresponding to each other. The light emitting table 250 has a delay amount instead of the start horizontal angle of the light emitting table 180. The delay amount is the time required for the rotation of the MEMS mirror 26 from the horizontal reference angle to the start horizontal angle, and is expressed in nanosecond units, for example.

  In this modification, the calibration device 160 measures the time from the reference horizontal angle to the start horizontal angle and stores it in the light emission table 250 instead of storing the start horizontal angle in the light emission table 180. The control device 70 refers to the light emission table 250 at the time of measurement, and controls the light emission timing controller 58 so as to perform laser emission of the corresponding number of samples from the time corresponding to the delay amount corresponding to the detected vertical angle. .

  For example, the processing device 72 reads the light emission table 250 from the storage device 74 and acquires the delay amount and the number of times of light emission corresponding to the vertical angle of the MEMS mirror 26 received from the drive unit 50 and serving as the laser light emission start timing. The output may be output to the drive unit 50. In this case, the light emission condition information indicating the conditions for generating the laser light emission signal is the delay amount corresponding to the vertical angle acquired by the mirror angle detector 54 and the number of times of light emission. The configuration of the laser distance measuring device used for distance measurement and the distance measuring method other than those described above are the same as those described in the first embodiment.

  When the light emission table 250 according to the present modification is used for distance measurement, for example, the light emission condition information for laser light emission output from the control device 70 of the laser distance measuring device 10 to the drive unit 50 is detected from the MEMS mirror 26. The information of the time memorize | stored corresponding to the rotation angle of a direction is included. This time information is information indicating the time to start emitting the laser beam from the horizontal reference angle in the horizontal scanning. The light emission condition information includes information indicating the number of times the laser light is emitted from the start of the laser light emission until the stop.

  As described above, according to the present modification, it is possible to achieve the same effect as the effect of the first embodiment. Further, by using the delay amount instead of the start horizontal angle, for example, even when the change timing of the rotation angle of the MEMS mirror 26 becomes faster, the light emission timing of the laser 22 is determined based on the detected angle. There is no need to do. At this time, since it is sufficient to measure the time until the scattered light from the PD 135 is not detected, it is possible to cope with a faster angle change timing of the MEMS mirror 26.

(Modification 2 according to the first embodiment)
Hereinafter, Modification 2 of the first embodiment will be described. In this modification, the same number is attached | subjected about the structure and operation | movement similar to 1st Embodiment or its modification 1, and duplication description is abbreviate | omitted. In this modification, a light emitting table 260 is used instead of the light emitting table 180.

  FIG. 12 is a diagram illustrating an example of the light emission table 260 according to the second modification according to the first embodiment. The light emission table 260 is a data table indicating conditions for emitting laser light. Like the light emission table 180, the light emission table 260 has a start horizontal angle and a sample number corresponding to each other. The light emitting table 260 has a horizontal reciprocating count instead of the vertical angle of the light emitting table 180. The horizontal reciprocation count is, for example, the number of repetitions of changing the rotation angle from the horizontal reference angle to the next horizontal reference angle.

  In this modification, instead of storing the vertical angle in the light emission table 180, the calibration device 160 counts the horizontal reciprocation count from a reference vertical angle such as the vertical angle at which scanning is started, and performs the light emission table. 260 is stored. The controller 70 refers to the light emission table 260 when measuring the distance, and reads the start horizontal angle stored corresponding to the horizontal reciprocation count that matches the detected horizontal reciprocation count. The control device 70 controls the light emission timing controller 58 to start laser emission of the corresponding number of samples when the read horizontal angle matches the detected horizontal angle.

  For example, the processing device 72 reads the light emission table 260 from the storage device 74 and acquires the start horizontal angle and the number of times of light emission corresponding to the vertical angle of the MEMS mirror 26 received from the drive unit 50 and serving as the light emission start timing of the laser light. The output may be output to the drive unit 50. In this case, the light emission condition information indicating the conditions for generating the laser light emission signal is the start horizontal angle corresponding to the vertical angle acquired by the mirror angle detector 54 and the number of times of light emission. The configuration of the laser distance measuring device used for distance measurement is the same as that described in the first embodiment.

  Hereinafter, the distance measurement processing according to this modification will be described with reference to a flowchart with reference to FIG. FIG. 13 is a flowchart illustrating an example of a distance measurement process in the laser distance measuring device 10 according to the second modification of the first embodiment. It is assumed that the laser distance measuring device 10 stores the light emission table 260 generated as described above by the calibration device 160 in the storage device 74 in advance, for example. Similarly to the calibration device 160, the laser distance measuring device 10 is set in advance by changing the angle of the MEMS mirror 26, and the mirror driver 52 outputs a drive signal to set the MEMS mirror 26. Suppose that it is rotating.

  As shown in FIG. 13, in the laser distance measuring device 10, the control device 70 detects the vertical angle of the MEMS mirror 26 via the mirror angle detector 54 (S271). When the detected angle is not the reference vertical angle (S272: NO), the control device 70 repeats the processing from S271. When it is a reference | standard vertical angle (S272: YES), the control apparatus 70 resets the horizontal reciprocation counter 56 (S273). The control device 70 starts the horizontal reciprocating counter 56 (S274).

  The control device 70 reads the light emission table 260 from the storage device 74 and sets it so that it can be referred to (S275). The control device 70 detects the horizontal angle via the mirror angle detector 54 (S276). The control device 70 refers to the detected counter value and horizontal angle of the horizontal reciprocating counter 56 with the light emission table 260, and when it is not the light emission start angle (S277: NO), returns to S275 and repeats the process. The light emission start angle is a vertical angle and a horizontal angle of the MEMS mirror 26 corresponding to the read horizontal reciprocation count and the corresponding start horizontal angle stored in the light emission table 260.

  When the detected horizontal reciprocation count and horizontal angle correspond to the light emission start angle (S277: YES), the control device 70 causes the laser 22 to emit light via the light emission timing controller 58 (S278). At this time, the information output from the control device 70 to the drive unit 50 is, for example, information indicating that the detected horizontal reciprocation count and the horizontal angle is the light emission start angle, and this generates the above-described laser emission signal. It is an example of the light emission condition information for making it do.

  The controller 70 repeats light emission until the number of pulse emission of the laser 22 reaches the number of samples in the light emission table 260 (S279: NO). If the number of samples reaches (S279: YES), is the predetermined horizontal count or more? Is determined (S280). If it is not greater than or equal to the predetermined count (less than the predetermined count) (S280: NO), the control device 70 detects the vertical angle via the mirror angle detector 54 (S281), and repeats the processing from S275.

  In S280, when it is equal to or greater than the predetermined count (S280: YES), the control device 70 determines whether or not there is an end instruction (S282). If there is no termination instruction (S282: NO), the control device 70 returns to S271 and repeats the process. At this time, the vertical angle is preferably changed by a preset method. If there is an end instruction (S282: YES), control device 70 ends the process.

  As described above, according to the present modification, it is possible to achieve the same effect as the effect of the first embodiment. Further, since the horizontal reciprocation count is used instead of the vertical angle, it is not necessary to detect the vertical angle other than at the start of measurement.

(Modification 3 of the first embodiment)
Hereinafter, Modification 3 of the first embodiment will be described. In this modification, the same number is attached | subjected about the structure and operation | movement similar to 1st Embodiment or the modifications 1-2, and duplication description is abbreviate | omitted. In this modification, a light emitting table 290 is used in place of the light emitting table 260 of the second modification according to the first embodiment.

  FIG. 14 is a diagram illustrating an example of the light emission table 290 according to the third modification according to the first embodiment. The light emission table 290 is a data table indicating conditions for emitting laser light. Similar to the light emission table 260, the light emission table 290 has a horizontal reciprocation count and the number of samples. The light emitting table 290 has a delay amount instead of the start horizontal angle of the light emitting table 260. The delay amount is the time from the horizontal reference angle to the start horizontal angle.

  In this modification, the calibration device 160 measures the time from the reference horizontal angle to the start horizontal angle and stores it in the light emission table 290 instead of storing the start horizontal angle in the light emission table 260. The control device 70 refers to the light emission table 290 at the time of measurement, and controls the light emission timing controller 58 so as to perform laser emission of the number of samples from the time corresponding to the delay amount corresponding to the detected vertical angle.

  For example, the processing device 72 reads the light emission table 290 from the storage device 74, and acquires the delay amount and the number of times of light emission corresponding to the vertical angle of the MEMS mirror 26 received from the drive unit 50 and serving as the laser light emission start timing. The output may be output to the drive unit 50. In this case, the information indicating the conditions for generating the laser emission signal is the delay amount stored corresponding to the vertical angle acquired by the mirror angle detector 54 and the number of times of emission. The configuration of the laser distance measuring device used for distance measurement and the processing method other than those described above are the same as those described in the first embodiment.

  As described above, according to the present modification, it is possible to achieve the same effect as that of the modification 2 of the first embodiment. Further, by using the delay amount instead of the start horizontal angle, for example, even when the change timing of the rotation angle of the MEMS mirror 26 becomes faster, the light emission timing of the laser 22 is determined based on the detected angle. There is no need to do. At this time, since it is only necessary to measure the time until the scattered light from the PD 135 is not detected, it is possible to cope with a faster change timing.

(Modification 4 of the first embodiment)
Hereinafter, Modification 4 of the first embodiment will be described. In this modification, the same number is attached | subjected about the structure and operation | movement similar to 1st Embodiment or its modifications 1-3, and duplication description is abbreviate | omitted. In this modification, each light emitting table 180, 250, 260, 290 is generated by the calibration device 300 instead of the calibration device 160. In the calibration apparatus 300, the calibration is performed by detecting the transmitted light of the angle magnifying lens 28 instead of the scattered light from the lens holder 128 detected by the calibration apparatus 160.

  FIG. 15 is a diagram illustrating an example of the configuration of the calibration apparatus 300 according to the fourth modification of the first embodiment. As illustrated in FIG. 15, the calibration device 300 includes a light projecting unit 130 and a storage device 164, as with the calibration device 160. The calibration apparatus 300 has a PD 137 instead of the PD 135 of the calibration apparatus 160. The calibration device 300 includes a control device 350 instead of the drive unit 150 of the calibration device 160 and a table generation processing device 362 instead of the table generation processing device 162.

  As shown in FIG. 15, the PD 137 receives the laser light transmitted through the angle expansion lens 28 and outputs it to an edge detector 352 described later. At this time, the laser beam corresponding to the kicked portion 85 described in FIG. 5 is scattered by the lens holder 128 and is not received by the PD 137. The light transmitted through the angle expansion lens 28 is received by the PD 137.

  Similar to the drive unit 50 and the drive unit 150, the drive unit 350 includes a mirror driver 52, a mirror angle detector 54, a light emission timing controller 58, and a light emission clock output device 60. The drive unit 350 includes an edge detector 352 instead of the edge detector 152 of the drive unit 150. The edge detector 352 detects the laser light transmitted through the angle expansion lens 28 received by the PD 137. The edge detector 352 preferably has a circuit that determines the position based on the output from the PD 137 with the boundary between the portion through which the laser light passes through the angle magnifying lens 28 and the portion that does not pass through the edge. For example, this circuit may be a circuit that latches the detection value until the next sampling when the PD 137 detects the laser beam.

  The table generation processing device 362 generates the above-described light emission table 180 and the like based on the timing at which the laser light is detected by the PD 137. That is, the table generation processing device 362 generates the light emission table 180, for example, using the conditions for detecting or not detecting the output of the PD 137 as the rotation angle of the MEMS mirror 26, the timing for emitting the laser, and the like. Further, the table generation processing device 362 stores the generated light emission table 180 and the like in the storage device 164, for example.

  FIG. 16 is a diagram illustrating an example of generation of an edge detection output in the calibration according to the fourth modification of the first embodiment. FIG. 16 shows an example of a signal output when the calibration apparatus 300 generates the light emission table 180, for example. In FIG. 16, the horizontal axis represents time, and the vertical axis represents the horizontal angle, laser emission signal, PD output, and edge detection output.

  As shown in FIG. 16, the horizontal angle signal 302 is a signal indicating a one-time reciprocal change in the horizontal angle, which is the rotation angle of the rotation 31 of the MEMS mirror 26. The horizontal angle signal 302 is detected by the mirror angle detector 54 and output to the table generation processing device 362. For example, the horizontal angle signal 302 indicates a change until the angle at the rotation 31 of the MEMS mirror 26 returns from the horizontal reference position to the horizontal reference position again. The horizontal reference position may be the scanning start point in the horizontal direction with the vertical angle fixed. At this time, the angle in the horizontal direction may be expressed using, for example, the direction of the optical path of the laser light incident on the MEMS mirror 26 as a reference (zero degree).

  The laser emission signal 304 is a signal for causing the laser 22 to emit a pulse every predetermined time during the horizontal reciprocation time indicated by the horizontal angle signal 302. In other words, the laser emission signal 304 is a signal for causing the laser 22 to emit a pulse during one horizontal reciprocation time so that the irradiation destination of the laser beam is in a rectangular range. The laser emission signal 304 is output from the emission timing controller 58 to the laser 22 based on the control of the table generation processing device 362.

  The PD output 306 is an output signal from the PD 135 during one horizontal round trip. A PD output 306 is a signal indicating a light receiving state of the laser light transmitted through the angle expansion lens 28 in the PD 137. In the example of FIG. 16, the PD output 306 outputs a pulse indicating that the laser beam has been received within a range where the absolute value of the horizontal angle signal 302 is smaller than a predetermined value. The range of time for which a pulse is output at the PD output 306 is, for example, a range of time corresponding to the irradiation destination of the laser 22 within the lens of the angle magnifying lens 28.

  The edge detection output 308 is a signal indicating the time during which a pulse is output from the PD output 306. The time in the edge detection output 308 is, for example, the time from the horizontal reference position. For example, the edge detection output 308 may be a signal that goes high when the PD output 306 from the PD 137 reaches a predetermined amplitude level. During calibration, the laser 22 emits light from the horizontal reference position to all irradiation positions (rectangular regions) at every vertical angle of scanning by the MEMS mirror 26. The edge detector 152 outputs an edge detection output 308 indicating a range where there is no kick in each horizontal scanning line.

  In the example of FIG. 16, the time during which the edge detection output 308 is high is the time during which the laser beam irradiation destination is within the lens of the angle magnifying lens 28. In this horizontal reciprocation, the PD output 306 is output from time t1 to t2 and from time t3 to t4, so that it corresponds to the kicked portion 85. For example, it is not always necessary to cause the laser 22 to emit light in one round trip in the horizontal direction, so that the time t1 to t2 may be a time range in which the laser 22 emits light. At this time, the time t1 is a time when the laser 22 starts to emit light in one horizontal reciprocation indicated by the horizontal angle signal 302. The horizontal angle θ1 at time t1 is a start horizontal angle at which the laser 22 starts to emit light. The table generation processing device 362 determines the horizontal angle range of the MEMS mirror 26 that is not kicked for each vertical angle, determines the start horizontal angle and the number of times of light emission (sampling number), and stores them as the light emission table 180.

  As described above, according to the present modification, it is possible to achieve the same effect as the effect of the first embodiment. Further, since the PD 137 receives the light transmitted through the angle expansion lens 28, it is possible to directly and reliably detect kicking by the lens.

(Second Embodiment)
Hereinafter, the laser distance measuring device 340 according to the second embodiment will be described. In the second embodiment, the laser distance measuring device 340 performs calibration and distance measurement processing. The same reference numerals are given to the same configurations and operations as those in the first embodiment or the first to fourth modifications thereof, and the duplicate description is omitted.

  FIG. 17 is a diagram illustrating an example of a hardware configuration of the laser distance measuring device 340 according to the second embodiment. As shown in FIG. 17, the laser distance measuring device 340 includes a light projecting unit 345, a light receiving unit 35, a driving unit 150, and a control device 350. The light projecting unit 345 includes the laser 22, the lens 24, the MEMS mirror 26, and the angle magnifying lens 28, similarly to the light projecting unit 30 of the laser distance measuring device 10. Further, the light projecting unit 345 includes a lens holder 128 and a PD 135, similar to the light projecting unit 130 of the calibration device 160. Similar to the laser distance measuring device 10, the light receiving unit 35 includes a lens 37 and a PD 39.

  Similar to the calibration device 160, the driving unit 150 includes a mirror driver 52, a mirror angle detector 54, a light emission timing controller 58, and an edge detector 152.

  The control device 350 includes a processing device 352 and a storage device 354. First, the processing device 352 performs calibration, for example, similarly to the table generation processing device 162 of the calibration device 160, and causes the storage device 354 to store, for example, the light emission table 180. The processing device 352 measures the distance in the same manner as the processing device 72 of the laser distance measuring device 10 while referring to the light emission table 180. In the present embodiment, the processing device 352 performs processing that combines processing by the processing device 72 and processing by the table generation processing device 162.

  FIG. 18 is a flowchart illustrating an example of a distance measurement process according to the second embodiment. As shown in FIG. 18, the processing device 352 activates the laser distance measuring device 340 (S371). The processing device 352 performs calibration (S372). The process of S372 may be the same as the process described with reference to FIG. At this time, for example, a light emission table 180 is generated based on the laser light detected by the PD 135 and stored in the storage device 354.

  The processing device 352 starts measuring the distance (S373). The distance measurement (S374) may be the same as the process described with reference to FIG. At this time, the laser light incident on the angle magnifying lens 28 enters the lens of the angle magnifying lens 28. If the laser beam kicking is detected by the PD 135 during this measurement (S375: YES), the processing device 352 returns to S372 and performs calibration. If no kick has occurred (S375: NO), the processing device 352 determines whether an instruction to end measurement has been input (S376). If the measurement end instruction is not detected (S376: NO), the processing device 352 returns to S379 and repeats the processing. When the measurement end instruction is detected (S376: YES), the processing device 352 ends the processing.

  As described above, in the laser distance measuring device 340 according to the second embodiment, calibration and distance measurement are performed by one laser distance measuring device 340. Furthermore, when laser beam kicking is observed during distance measurement, calibration may be performed again.

  As described above, according to the laser distance measuring device 340 according to the second embodiment, in addition to the same effects as those of the first embodiment or any of the first to fourth modifications, one laser distance measuring device 340 is provided. This makes it possible to confirm calibration and kicking of the laser beam. Therefore, it is possible to more easily prevent unnecessary light emission during distance measurement. Further, since kicking can be monitored during measurement, useless light emission can be prevented more reliably.

  The present invention is not limited to the embodiments described above, and various configurations or embodiments can be adopted without departing from the gist of the present invention. The configuration of the laser distance measuring device and the calibration device described above, the processing order in the flowchart showing the distance measuring processing, and the like are not limited to the above example. Modifications are possible as long as they have the same operational effects or processing order. Further, the light emission tables 250, 260, and 290 according to the first, second, and third modifications according to the first embodiment may be used in place of the light emission table 180 in the second embodiment.

  For example, in the laser distance measuring device 10 shown in FIG. 1, for example, the horizontal reciprocation counter 56 is not necessarily provided in the case of control performed with reference to the light emission table 180. In the laser distance measuring device 340, for example, when using the light emission table 250 and the light emission table 290, it is preferable to provide the horizontal reciprocating counter 56. The configurations of the light projecting unit and the light receiving unit can be modified, for example, by configuring the lens 24, the lens 37, etc. with a plurality of lenses. Moreover, although the light projecting unit and the light receiving unit have been described as being independent from each other, at least a part of the configuration may be shared. For example, PD 135 and PD 137 are examples, and APD, CMOS, or the like may be used.

  The calibration device 160, the calibration device 300, and the laser distance measuring device 340 determine the sampling frequency so as to sample the number of light emission times of the laser 22, that is, the sampling number, as desired. At the time of actual measurement, the processing device 72 and the processing device 352 obtain a ratio between the number of effective samples at the time of calibration and a desired number of samples, and integrate the ratio to the frequency at the time of calibration, thereby obtaining a sample at the time of measurement. The frequency may be determined. The light emission tables 180, 250, 260, and 290 have been described with respect to the example in which the conditions for causing the laser to emit light have been stored.

  Here, an example of a computer that is commonly applied to cause a computer to perform the operations of the laser ranging method according to the first and second embodiments and the first to fourth modifications of the first embodiment. explain. FIG. 19 is a block diagram illustrating an example of a hardware configuration of a standard computer. As shown in FIG. 19, a computer 400 includes a central processing unit (CPU) 402, a memory 404, an input device 406, an output device 408, an external storage device 412, a medium driving device 414, a network connection device 418, and the like via a bus 410. Connected.

  The CPU 402 is an arithmetic processing unit that controls the operation of the entire computer 400. The memory 404 is a storage unit for storing a program for controlling the operation of the computer 400 in advance, or using it as a work area as needed when executing the program. The memory 404 is, for example, a random access memory (RAM), a read only memory (ROM), or the like. The input device 406 is a device that, when operated by a computer user, acquires various information inputs from the user associated with the operation content, and sends the acquired input information to the CPU 402. Keyboard device, mouse device, etc. The output device 408 is a device that outputs a processing result by the computer 400, and includes a display device and the like. For example, the display device displays text and images according to display data sent by the CPU 402.

  The external storage device 412 is, for example, a storage device such as a hard disk, and stores various control programs executed by the CPU 402, acquired data, and the like. The medium driving device 414 is a device for writing to and reading from the portable recording medium 416. The CPU 402 can perform various control processes by reading and executing a predetermined control program recorded on the portable recording medium 416 via the medium driving device 414. The portable recording medium 416 is, for example, a Compact Disc (CD) -ROM, a Digital Versatile Disc (DVD), a Universal Serial Bus (USB) memory, or the like. The network connection device 418 is an interface device that manages transmission / reception of various data performed between the outside by wired or wireless. A bus 410 is a communication path for connecting the above devices and the like to exchange data.

  A program for causing a computer to execute the laser ranging method according to the first to fourth embodiments is stored in, for example, the external storage device 412. The CPU 402 reads out a program from the external storage device 412 and executes the program using the memory 404 to perform laser ranging operation. At this time, first, a control program for causing the CPU 402 to perform laser ranging processing is created and stored in the external storage device 412. Then, a predetermined instruction is given from the input device 406 to the CPU 402 so that the control program is read from the external storage device 412 and executed. Further, this program may be stored in the portable recording medium 416.

The following additional notes are further disclosed with respect to the first and second embodiments and the first to fourth modifications of the first embodiment.
(Appendix 1)
A laser light source that emits laser light, a mirror that scans a scanning range with the laser light reflected and reflected while rotating, and a lens that expands the scanning range of the laser light, A light projecting unit that projects the laser beam having an enlarged scanning range onto an object;
A light receiving unit that receives reflected light from the object projected by the laser beam by the light projecting unit;
A storage device for storing information on the rotation angle of the mirror when the optical path of the laser beam reflected by the mirror passes through the lens;
The mirror is rotated so that the laser beam reflected by the mirror scans a region including the lens, and the optical path of the laser beam is changed by the rotation of the mirror based on information on the rotation angle of the mirror. A processing device for stopping emission of the laser beam by the laser light source when it is determined that
A laser distance measuring device comprising:
(Appendix 2)
2. The laser range finder according to appendix 1, wherein the mirror is a microelectromechanical system mirror, and the mirror uses resonance for at least one axis for driving.
(Appendix 3)
In the scanning in the second direction orthogonal to the first direction at the first rotation angle in the first direction of the mirror when the optical path of the laser light passes through the lens, the information is A starting rotation angle in the second direction of the mirror, which is a starting point where the optical path of the laser light enters the lens, and the number of times the laser light is emitted from the starting point at the first rotation angle. ,
The processing device refers to the rotation angle in the first direction and the rotation angle in the second direction of the mirror to be detected in the storage device and detects the rotation in the first direction. When it is determined that the angle and the rotation angle in the second direction are the first rotation angle and the start rotation angle of the start point, the laser beam is generated according to the number of times of light emission from the start point. The laser distance measuring device according to appendix 1 or appendix 2, wherein
(Appendix 4)
The information is the start of the scanning in a second direction orthogonal to the first direction at a first rotation angle in the first direction of the mirror when the optical path of the laser light passes through the lens. From the time until the optical path of the laser light becomes a start point entering the lens, and the number of times of emission of the laser light from the start point,
The processing device refers to the rotation angle in the first direction of the mirror to be detected in the storage device, and the time corresponding to the rotation angle in the first direction to be detected and the number of times of light emission. Is stored, the laser beam is emitted in accordance with the time and the number of times of light emission.
(Appendix 5)
The information includes the number of repetitions of repeatedly changing the rotation angle of the mirror when the optical path of the laser light passes through the lens, and the start of the optical path of the laser light corresponding to the number of repetitions entering the lens. Including the starting rotation angle of the mirror at a point, and the number of times of emission of laser light before the next repetition from the starting point,
The processing device refers to the number of repetitions and the rotation angle of the mirror to be detected in the storage device, and the number of repetitions to be detected and the rotation angle correspond to the start rotation angle. The laser range finder according to appendix 1 or appendix 2, wherein the laser beam is emitted according to the number of times of light emission.
(Appendix 6)
The information includes the number of repetitions of repeatedly changing the rotation angle of the mirror when the optical path of the laser light passes through the lens, and the optical path of the laser light from the beginning of the repetition corresponding to the number of repetitions. Including a time until a start point entering the lens and a number of times of light emission for emitting the laser light from the start point,
The processing device refers to the number of repetitions of the detected mirror in the storage device, and when the time corresponding to the number of repetitions detected and the number of times of light emission are stored, the time and The laser range finder according to appendix 1 or appendix 2, wherein the laser beam is emitted according to the number of times of emission.
(Appendix 7)
The light projecting unit detects a scattered light from the lens,
Further comprising
7. The laser distance measuring device according to any one of appendix 1 to appendix 6, wherein the processing device stores a condition in which the scattered light is not detected by the detection unit in the storage device.
(Appendix 8)
Computer
The rotation angle of the mirror is changed so that the light reflected by the mirror that scans the scanning range with the laser beam reflected and reflected while rotating rotates the region including the lens that expands the scanning range. Let
And stopping the emission of the laser light by the laser light source when it is determined that the optical path of the laser light is outside the lens based on the rotation angle information of the mirror. Laser ranging method.
(Appendix 9)
The laser ranging method according to appendix 8, wherein the mirror is a microelectromechanical system mirror, and the mirror uses resonance for at least one axis for driving.
(Appendix 10)
In the scanning in the second direction orthogonal to the first direction at the first rotation angle in the first direction of the mirror when the optical path of the laser light passes through the lens, the information is A starting rotation angle in the second direction of the mirror, which is a starting point where the optical path of the laser light enters the lens, and the number of times the laser light is emitted from the starting point at the first rotation angle. ,
Further, the rotation angle in the first direction and the rotation angle in the second direction detected by referring to the rotation angle in the first direction and the rotation angle in the second direction of the mirror detected in the storage device. If the rotation angle in the direction is determined to be the first rotation angle and the start rotation angle of the start point, the laser light is emitted according to the number of times of light emission from the start point. 10. The laser distance measuring method according to appendix 8 or appendix 9, which is a feature.
(Appendix 11)
The information is the start of the scanning in a second direction orthogonal to the first direction at a first rotation angle in the first direction of the mirror when the optical path of the laser light passes through the lens. From the time until the optical path of the laser light becomes a start point entering the lens, and the number of times of emission of the laser light from the start point,
Further, the rotation angle of the first direction of the mirror to be detected is referred to in the storage device,
(Note 8) When the time corresponding to the detected rotation angle in the first direction and the number of times of light emission are stored, the laser light is emitted according to the time and the number of times of light emission. Alternatively, the laser ranging method according to appendix 9.
(Appendix 12)
The information includes the number of repetitions of repeatedly changing the rotation angle of the mirror when the optical path of the laser light passes through the lens, and the start of the optical path of the laser light corresponding to the number of repetitions entering the lens. Including the starting rotation angle of the mirror at a point, and the number of times of emission of laser light before the next repetition from the starting point,
Further, the number of repetitions and the rotation angle of the mirror to be detected are referred to in the storage device, and it is determined that the number of repetitions to be detected and the rotation angle correspond to the start rotation angle. Then, the laser ranging method according to appendix 8 or appendix 9, wherein the laser beam is emitted according to the number of times of emission.
(Appendix 13)
The information includes the number of repetitions of repeatedly changing the rotation angle of the mirror when the optical path of the laser light passes through the lens, and the optical path of the laser light from the beginning of the repetition corresponding to the number of repetitions. Including a time until a start point entering the lens and a number of times of light emission for emitting the laser light from the start point,
Further, the number of repetitions of the detected mirror is referred to in the storage device, and when the time corresponding to the number of repetitions detected and the number of times of light emission are stored, the time and the number of times of light emission are stored. 10. The laser ranging method according to appendix 8 or appendix 9, wherein the laser beam is emitted in response.
(Appendix 14)
Furthermore, the light projecting unit causes the storage device to store a condition in which the scattered light is not detected by a detection unit that detects the scattered light from the lens. Laser ranging method.
(Appendix 15)
The rotation angle of the mirror is changed so that the light reflected by the mirror that scans the scanning range with the laser beam reflected and reflected while rotating rotates the region including the lens that expands the scanning range. Let
Based on information on the rotation angle of the mirror, when it is determined that the optical path of the laser beam is outside the lens due to the rotation of the mirror, the computer is caused to execute a process of stopping the emission of the laser beam by the laser light source Laser ranging program.

DESCRIPTION OF SYMBOLS 10 Laser ranging device 20 Optical part 22 Laser 24 Lens 26 MEMS mirror 28 Angle expansion lens 30 Light projection part 31 Rotation 33 Rotation 35 Light reception part 37 Lens 39 PD
50 Drive Unit 52 Mirror Driver 54 Mirror Angle Detector 56 Horizontal Reciprocating Counter 58 Light Emitting Timing Controller 60 Light Emitting Clock Output 70 Controller 72 Processing Device 74 Storage Device 77 Scanning Example 78 Vertical Direction 79 Horizontal Direction 81 Sampling Point Group 83 Sampling point group 85 Kicked portion 87 Horizontal angle 89 Vertical angle 128 Lens holder 1
130 Light Emitter 135 PD
137 PD
150 Drive unit 152 Edge detector 160 Calibration device 162 Table generation processing device 164 Storage device 171 Horizontal angle signal 173 Laser emission signal 175 PD output 177 Edge detection output 180 Light emission table

Claims (8)

A laser light source that emits laser light, a mirror that scans a scanning range with the laser light reflected and reflected while rotating, and a lens that expands the scanning range of the laser light, A light projecting unit that projects the laser beam having an enlarged scanning range onto an object;
A light receiving unit that receives reflected light from the object projected by the laser beam by the light projecting unit;
A storage device for storing information on the rotation angle of the mirror when the optical path of the laser beam reflected by the mirror passes through the lens;
The mirror is rotated so that the laser beam reflected by the mirror scans a region including the lens, and the optical path of the laser beam is changed by the rotation of the mirror based on information on the rotation angle of the mirror. A processing device for stopping emission of the laser beam by the laser light source when it is determined that
A laser distance measuring device comprising: In the scanning in the second direction orthogonal to the first direction at the first rotation angle in the first direction of the mirror when the optical path of the laser light passes through the lens, the information is A starting rotation angle in the second direction of the mirror, which is a starting point where the optical path of the laser light enters the lens, and the number of times the laser light is emitted from the starting point at the first rotation angle. ,
The processing device refers to the rotation angle in the first direction and the rotation angle in the second direction of the mirror to be detected in the storage device and detects the rotation in the first direction. When it is determined that the angle and the rotation angle in the second direction are the first rotation angle and the start rotation angle of the start point, the laser beam is generated according to the number of times of light emission from the start point. The laser distance measuring device according to claim 1, wherein: The information is the start of the scanning in a second direction orthogonal to the first direction at a first rotation angle in the first direction of the mirror when the optical path of the laser light passes through the lens. From the time until the optical path of the laser light becomes a start point entering the lens, and the number of times of emission of the laser light from the start point,
The processing device refers to the rotation angle in the first direction of the mirror to be detected in the storage device, and the time corresponding to the rotation angle in the first direction to be detected and the number of times of light emission. 2. The laser range finder according to claim 1, wherein the laser light is emitted according to the time and the number of times of light emission. The information includes the number of repetitions of repeatedly changing the rotation angle of the mirror when the optical path of the laser light passes through the lens, and the start of the optical path of the laser light corresponding to the number of repetitions entering the lens. Including the starting rotation angle of the mirror at a point, and the number of times of emission of laser light before the next repetition from the starting point,
The processing device refers to the number of repetitions and the rotation angle of the mirror to be detected in the storage device, and the number of repetitions to be detected and the rotation angle correspond to the start rotation angle. 2. The laser distance measuring device according to claim 1, wherein if it is determined that the laser light is emitted, the laser light is emitted according to the number of times of light emission. The information includes the number of repetitions of repeatedly changing the rotation angle of the mirror when the optical path of the laser light passes through the lens, and the optical path of the laser light from the beginning of the repetition corresponding to the number of repetitions. Including a time until a start point entering the lens and a number of times of light emission for emitting the laser light from the start point,
The processing device refers to the number of repetitions of the detected mirror in the storage device, and when the time corresponding to the number of repetitions detected and the number of times of light emission are stored, the time and The laser distance measuring device according to claim 1, wherein the laser light is emitted according to the number of times of light emission. The light projecting unit detects a scattered light from the lens,
Further comprising
6. The laser distance measuring device according to claim 1, wherein the processing device stores a condition in which the scattered light is not detected by the detection unit in the storage device. 7. Computer
The rotation angle of the mirror is changed so that the light reflected by the mirror that scans the scanning range with the laser beam reflected and reflected while rotating rotates the region including the lens that expands the scanning range. Let
And stopping the emission of the laser light by the laser light source when it is determined that the optical path of the laser light is outside the lens based on the rotation angle information of the mirror. Laser ranging method. The rotation angle of the mirror is changed so that the light reflected by the mirror that scans the scanning range with the laser beam reflected and reflected while rotating rotates the region including the lens that expands the scanning range. Let
Based on information on the rotation angle of the mirror, when it is determined that the optical path of the laser beam is outside the lens due to the rotation of the mirror, the computer is caused to execute a process of stopping the emission of the laser beam by the laser light source Laser ranging program.

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