JP2015215292A - Measurement device and measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the fluctuation of measurement results due to reflected light at a lens boundary, etc., or the crosstalk of an electrical signal.SOLUTION: A light source 44 emits a laser beam. A photodetector 57 detects light and converts it to an electrical signal. A scanning unit 58 throws back the laser beam outputted from the light source 44 and emits it so as to scan an object 21 to be measured, and accepts the reflected light of the laser beam having scanned the object 21 to be measured and throws back the reflected light so that it is received by the photodetector 57. A non-incident member throws back the reflected light of the laser beam of the light source 44 that is emitted from the scanning unit 58 so that it does not enter the scanning unit 58 for a prescribed period, and prevents the reflected light from being received by the photodetector 57.

Description

  The present invention relates to a measuring device and a measuring method.

  Patent Document 1 discloses a dimension measuring apparatus configured to emit a first beam of light to a target at another location, and the target causes a part of the first beam to travel backward as a second beam. . The apparatus receives a first light source, a fiber coupler assembly, and a first electrical signal having a first state or a second state, when the signal is in the first state, a switch side measurement port, and when the signal is in the second state, a switch side reference port The optical fiber switch which radiates | emits a 2nd part from is provided. The apparatus further generates an optical system, a reference retroreflector, a first electrical signal having a first state or a second state, while converting a third portion to a first reference value, wherein the first electrical signal is The first electric circuit that converts the fifth portion into the first measurement value in the first state, the seventh portion into the second reference value in the second state, and at least the first measurement value, the first reference value, and the second reference value. A processor is provided for deriving a first distance from the dimension measuring device to the target while partially relying on.

Special table 2013-538331 gazette

  However, Patent Document 1 has a problem that the variation in the measurement result due to the thermal drift can be corrected, but the variation in the measurement result due to the reflected light at the lens interface or the crosstalk of the electric signal cannot be corrected. .

  Therefore, an object of the present invention is to provide a technique that can correct fluctuations in measurement results due to reflected light at a lens interface or the like and crosstalk of electrical signals.

  The present application includes a plurality of means for solving at least a part of the above-described problems. Examples of the means are as follows. In order to solve the above-described problems, a measurement apparatus according to the present invention includes a light source that emits laser light, a photodetector that detects light and converts it into an electrical signal, and an output from the light source so as to scan an object to be measured. The laser beam reflected and emitted, the reflected light of the laser beam that has scanned the object to be measured is incident and reflected so as to be received by the photodetector, and from the scanning unit A non-incident member that reflects the reflected light of the laser light emitted from the light source so as not to be incident on the scanning unit for a predetermined period and prevents the light from being received by the photodetector.

  According to the present invention, it is possible to correct variations in measurement results due to crosstalk of reflected light or electrical signals at the lens interface or the like.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a figure explaining the example of application of the measuring device concerning a 1st embodiment of the present invention. It is a figure explaining the shape measurement of a tunnel. It is a figure explaining acquisition of profile data. It is the figure which showed the block structural example of the measuring device. It is the figure which showed the detailed example of the scanning part. It is the flowchart which showed the operation example of the measuring device. It is the figure which showed the example of the scanning part which concerns on the 2nd Embodiment of this invention. It is the figure which showed the block structural example of the measuring device which concerns on the 3rd Embodiment of this invention. It is the figure which showed the detailed example of the chopper. It is a figure explaining the example of application of the measuring device concerning a 4th embodiment of the present invention.

  Hereinafter, a measuring apparatus according to the present invention will be described with reference to the drawings.

[First Embodiment]
Over 50 years have passed since the construction of social infrastructure such as highways, tunnels, and bridges, and the importance of repair and maintenance of facilities has increased. On highways and railways, there are concerns about accidents caused by tunnel collapse and falling objects, and there is a great need for automatic monitoring technology. Laser shape measuring devices are widely used, and demand is expected to increase in the future. Typical techniques used in laser measurement equipment include time-of-flight, frequency insertion, and phase shift methods. To measure displacement while traveling through a tunnel, data must be collected at high density. The phase shift method is suitable. In the phase shift method, the distance from the measuring device to the object to be measured is calculated based on the phase of the reflected light (scattered light) from the object irradiated with the laser.

  FIG. 1 is a diagram for explaining an application example of the measurement apparatus according to the first embodiment of the present invention. In FIG. 1, a measuring device 10, a measurement target object 21, a vehicle 22, and a road surface 23 are shown. The measuring device 10 is mounted on the vehicle 22. As shown in FIG. 1, the measurement device 10 includes a control unit 11, a laser scanning unit 12, a GPS (Global Positioning System) 13, an inertial measurement unit 14, and a travel distance sensor 15.

  A measurement target object 21 illustrated in FIG. 1 is an object measured by the measurement apparatus 10. The measurement target object 21 is, for example, a tunnel, and the measurement apparatus 10 measures, for example, the shape (for example, cracks or cracks) of the tunnel wall surface using laser light.

  The vehicle 22 is, for example, an automobile. It is assumed that the vehicle 22 is traveling on the road surface 23 in the + Z-axis direction in FIG. The measuring device 10 mounted on the vehicle 22 irradiates the measurement target object 21 with the laser light L1 from the laser scanning unit 12, receives the reflected light with the laser scanning unit 12, and Measure distance. The measuring device 10 measures the shape of the wall surface of the measurement target object 21 by measuring the distance to the measurement target object 21.

  As will be described below, the laser scanning unit 12 is equipped with a rotating roller (scanning unit), and is configured to rotationally scan the laser light L1 within the XY plane. The measuring apparatus 10 can measure the shape of the wall surface of the measurement target object 21 when the vehicle 22 travels in the Z-axis direction and the laser scanning unit 12 rotationally scans the laser light L1 in the XY plane.

  The control unit 11 obtains profile data of the measurement target object 21 having the distance to the wall surface of the measurement target object 21 and the coordinate data of the vehicle 22 (laser scanning unit 12) obtained from the GPS 13 and the travel distance sensor 15. Generate. The control unit 11 adds the displacement of the vehicle 22 calculated from the acceleration measured by the inertial measurement unit 14 to the coordinate data calculated when the GPS 13 radio wave arrives, such as in a tunnel, where the GPS 13 radio wave does not reach. The coordinate data where the GPS 13 radio wave does not reach is calculated. For example, the control unit 11 can calculate the displacement of the vehicle 22 by integrating the acceleration in the triaxial direction measured by the inertial measurement unit 14 twice.

  The GPS 13 can receive radio waves again after leaving the tunnel. The control unit 11 compares the coordinate data based on the inertial measurement unit 14 immediately before exiting the tunnel with the coordinate data based on the GPS 13 and the mileage sensor 15 immediately after exiting the tunnel, and the coordinates of the profile data calculated inside the tunnel Data may be corrected. Note that the travel distance sensor 15 measures, for example, the rotational speed of the wheel of the vehicle 22, and the control unit 11 calculates the travel distance of the vehicle based on the rotational speed of the wheel.

  FIG. 2 is a diagram for explaining tunnel shape measurement. In FIG. 2, the same components as those in FIG. In FIG. 2, it is assumed that the measurement target 21 is a tunnel. FIG. 2 shows a state seen from the rear of the vehicle 22.

  The laser scanning unit 12 rotationally scans the laser light in the XY plane. In the case of the example in FIG. 2, the laser beam scans counterclockwise.

The laser beam L11 in FIG. 2 indicates the laser beam when the irradiation angle is “θ = θ ₀ (for example, the vertical downward direction is 0 degree)”. The laser beam L12 indicates the laser beam when the irradiation angle is “θ = θ ₁ ”. The laser beam L13 indicates a laser beam when the irradiation angle is “θ = θ ₂ ”. The laser beam L14 indicates the laser beam when the irradiation angle is “θ = θ ₃ ”.

  For example, as shown at points 21a to 21d in FIG. 2, the measuring device 10 irradiates the tunnel wall surface with laser beams L11 to L14, detects reflected light from each irradiated point, and detects the distance ( The distance between the laser scanning unit 12 and the tunnel wall surface is calculated.

  FIG. 3 is a diagram for explaining the acquisition of profile data. In FIG. 3, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  As described with reference to FIGS. 1 and 2, the vehicle 22 travels in the + Z-axis direction, and the measurement device 10 rotates and scans the laser beam in the XY plane. Therefore, the profile data obtained by the measuring apparatus 10 is spiral as shown in profile data 31 to 33 in FIG. The measuring apparatus 10 stores the profile data 31 to 33 of the measurement target object 21 obtained in a spiral shape, for example, in a database (not shown) and compares it with past profile data. And the measuring device 10 determines whether there is abnormality in the inner wall shape of a tunnel, for example. When the measuring device 10 determines that there is an abnormality in the shape of the inner wall of the tunnel, the user performs, for example, a direct inspection by a person.

  FIG. 4 is a diagram illustrating a block configuration example of the measurement apparatus. FIG. 4 shows the measuring device 10 and the measurement target object 21 shown in FIG. As shown in FIG. 1, the measurement device 10 includes a control unit 11, a laser scanning unit 12, a GPS 13, an inertia measurement unit 14, and a travel distance sensor 15.

  The control unit 11 includes an oscillator 41, a low-frequency modulator 42, a high-frequency modulator 43, a light source 44, an optical amplifier 45, a phase comparator 46, a rotation control unit 47, and a data processing unit 48. doing.

  The oscillator 41 outputs the reference signal to the low frequency modulator 42 and the high frequency modulator 43. The reference signal output from the oscillator 41 is, for example, a 10 MHz sine wave. For example, the oscillator 41 can output a highly accurate reference signal based on a signal received by the GPS 13.

  The low frequency modulator 42 modulates the reference signal output from the oscillator 41 and outputs a signal having a frequency lower than that of the reference signal. For example, the low frequency modulator 42 outputs a 7.5 MHz sine wave signal.

  The high frequency modulator 43 modulates the reference signal output from the oscillator 41 and outputs a signal having a higher frequency than the reference signal. For example, the high frequency modulator 43 outputs a 125 MHz sine wave signal.

  Signals output from the low frequency modulator 42 and the high frequency modulator 43 are superimposed and input to the light source 44.

  The light source 44 is, for example, an LD (Laser Diode) that emits laser light. The light source 44 modulates the intensity of the laser beam to be output based on the superimposed signal of the low frequency modulator 42 and the high frequency modulator 43. The wavelength of the laser beam output from the light source 44 is 1550 nm, for example. Moreover, the average output of the laser beam output from the light source 44 is 50 mW, for example. The laser beam output from the light source 44 is output to the optical amplifier 45 via the optical fiber.

  The optical amplifier 45 amplifies the laser light output from the light source 44 and outputs the amplified laser light to the laser scanning unit 12 via an optical fiber. The gain of the optical amplifier 45 is, for example, a maximum of 100 times and can be arbitrarily adjusted.

  Here, the laser scanning unit 12 will be described. As shown in FIG. 4, the laser scanning unit 12 includes quarter-wave plates 51 and 54, a half-wave plate 52, a PBS (Polarizing Beam Splitter) 53, a condenser lens 55, and a photodetector 56. , 57 and a scanning unit 58.

  Laser light amplified by the optical amplifier 45 is input to the quarter wavelength plate 51. When the laser light output from the optical amplifier 45 propagates through the optical fiber, the polarization state becomes an ellipse, and the major axis of the laser light also rotates. Therefore, the ¼ wavelength plate 51 makes the laser beam output from the optical amplifier 45 substantially linearly polarized light and outputs it to the ½ wavelength plate 52.

  The half-wave plate 52 adjusts the laser light output from the quarter-wave plate 51 to linearly polarized light having a desired polarization direction.

  The PBS 53 outputs the laser light output from the half-wave plate 52 to the quarter-wave plate 54 and outputs a part of the laser light output from the half-wave plate 52 to the photodetector 56. . Further, as will be described below, the reflected light of the laser light irradiated on the measurement target object 21 is input to the PBS 53 via the scanning unit 58, the condensing lens 55, and the ¼ wavelength plate 54. . The PBS 53 outputs the reflected light output from the quarter wavelength plate 54 to the photodetector 57.

  The quarter-wave plate 54 converts the laser beam output from the PBS 53 from linearly polarized light to circularly polarized light and outputs it to the condenser lens 55. As a result, the measurement target object 21 is irradiated with circularly polarized laser light.

  The condensing lens 55 condenses the laser light output from the quarter wavelength plate 54 and outputs it to the scanning unit 58.

  The scanning unit 58 includes a mirror 58a and a spindle motor 58b. The mirror 58a of the scanning unit 58 is connected to the rotation shaft of the spindle motor 58b and rotates. The laser beam output from the condenser lens 55 is emitted to the measurement target object 21 by the reflection of the mirror 58a. The laser light output from the condenser lens 55 is emitted to the measurement target object 21 so as to scan the measurement target object 21 by the rotation of the mirror 58a. In the case of the example in FIG. 4, the mirror 58 a reflects the laser light traveling in the + Z-axis direction so as to rotate on the XY plane, and emits it to the measurement target object 21. The scanning unit 58 has a shielding plate as will be described below.

  The rotation speed of the spindle motor 58b is controlled by the rotation control unit 47. The rotation speed of the spindle motor 58b is, for example, 10,000 rpm.

  The laser light emitted from the mirror 58a to the measurement target object 21 is reflected (scattered) by the measurement target object 21, and the reflected light (scattered light) is emitted from the mirror 58a to the measurement target object 21. Follow the same light path as the light. That is, the reflected light of the laser light emitted to the measurement target object 21 is incident on the mirror 58a, and the mirror 58a reflects the incident reflected light so as to be emitted to the condenser lens 55.

  The condensing lens 55 outputs the reflected light reflected by the mirror 58 a to the quarter-wave plate 54. The quarter wavelength plate 54 outputs the reflected light output from the condenser lens 55 to the PBS 53. The reflected light of the laser beam is converted from circularly polarized light to linearly polarized light again by passing through the quarter wavelength plate 54 again. Further, since the polarization direction of the reflected light of the laser beam is inclined by 90 degrees with respect to the laser beam directed from the light source 44 toward the mirror 58a, most of the reflected light is reflected by the PBS 53 and output to the photodetector 57.

  Part of the laser light emitted from the light source 44 is received by the photodetector 56 via the optical amplifier 45, the quarter wavelength plate 51, the half wavelength plate 52, and the PBS 53. The photodetector 56 converts the received laser light into an electrical signal and outputs it to the phase comparator 46. The photodetector 56 is, for example, a PD (Photo Diode).

  The reflected light reflected by the measurement target 21 is received by the photodetector 57 via the mirror 58 a, the condenser lens 55, the quarter wavelength plate 54, and the PBS 53. The photodetector 57 converts the received reflected light into an electrical signal and outputs it to the phase comparator 46. The photodetector 57 is, for example, a PD.

  That is, the above-described mirror 58 a reflects and emits the laser light output from the light source 44 so as to scan the measurement target 21. Then, the mirror 58 a re-enters the reflected light of the laser beam that has scanned the measurement target object 21, and reflects it to the condenser lens 55 so as to be received by the photodetector 57.

  The light receiving surface elements of the photodetectors 56 and 57 are, for example, InGaAs (Indium Gallium Arsenide), and the frequency band is, for example, 150 MHz at the maximum. The same detectors 56 and 57 can be used. Hereinafter, the electrical signal output from the photodetector 56 may be referred to as a reference signal, and the electrical signal output from the photodetector 57 may be referred to as a detection signal.

  The reference signal output from the optical detector 56 and the detection signal output from the optical detector 57 include a low frequency component by the low frequency modulator 42 and a high frequency component by the high frequency modulator 43. Yes. For example, the reference signal output from the light detector 56 and the detection signal output from the light detector 57 include frequency components of 7.5 MHz and 125 MHz. The reference signal and the detection signal having low frequency and high frequency components are output to the phase comparator 46 of the control unit 11.

  Returning to the description of the control unit 11. The reference signal output from the photodetector 56 and the detection signal output from the photodetector 57 are input to the phase comparator 46. The phase comparator 46 separates the input signal into a low frequency component and a high frequency component (for example, 7.5 MHz component and 125 MHz component) by a filtering process, and detects a reference signal and a reference for each frequency component. The phase difference from the signal is calculated. The phase comparator 46 outputs the calculated phase difference (phase information) to the data processing unit 48. The reason why the phase difference between the two frequency components of the low frequency and the high frequency is calculated is to allow the phase difference when the phase is shifted by 2nπ to be calculated. For example, if the phase shifts by 2nπ, the sine wave overlaps with the waveform before the phase shift, and it becomes impossible to identify whether the phase is shifted.

  The rotation control unit 47 controls the spindle motor 58 b of the scanning unit 58 based on the rotation control data output from the data processing unit 48.

  A reference signal of the oscillator 41 is input to the data processing unit 48. The data processing unit 48 performs the following data processing in synchronization with the reference signal.

  The data processing unit 48 is connected to the GPS 13, the inertial measurement unit 14, and the travel distance sensor 15. The data processing unit 48 calculates coordinate data of the vehicle 22 (coordinate data of the laser scanning unit 12 that emits a laser, for example, coordinate data of the mirror 58a) by the GPS 13 and the travel distance sensor 15 where the radio waves of the GPS 13 reach. . In addition, the data processing unit 48, such as in a tunnel, where the GPS 13 radio wave does not reach, the coordinate data calculated when the GPS 13 radio wave arrives is added to the coordinates of the vehicle 22 calculated from the acceleration measured by the inertial measurement unit 14. Displacement is added, and coordinate data where GPS 13 radio waves do not reach is calculated.

  In addition, the data processor 48 receives the phase difference between the detection signal output from the phase comparator 46 and the reference signal. The data processing unit 48 calculates the distance between the laser scanning unit 12 and each point of the measurement target object 21 based on the phase difference between the detection signal and the reference signal. That is, the data processing unit 48 determines whether the laser scanning unit 12 and the measurement target are based on the phase shift of the laser beam reflected by the measurement target object 21 with respect to the phase of the laser light before being reflected by the measurement target object 21. The distance from each point of the object 21 is calculated. The data processing unit 48 uses the encoder information output from the spindle motor 58b, which will be described below, to detect each point of the measurement target object 21 irradiated with the laser light (for example, the points 21a to 21d shown in FIG. 2). ) Can be detected.

  Further, the data processing unit 48 generates profile data of the measurement target object 21 having the calculated distance (shape) to the wall surface of the measurement target object 21 and the coordinate data of the vehicle 22. The data processing unit 48 stores the generated profile data in a database not shown in FIG. 4 and compares it with past profile data. Then, the data processing unit 48 determines whether or not the wall surface shape of the measurement target object 21 is abnormal. For example, when the shape of the measurement target object 21 based on the generated profile data is significantly different from the shape of the measurement target object 21 based on past profile data, the data processing unit 48 determines the wall surface of the measurement target object 21. It is determined that the shape is abnormal. More specifically, the data processing unit 48 determines that when the distance to the measurement target object 21 at the same point of the same coordinate data and the measurement target object 21 is different by a predetermined threshold or more, the measurement target object 21. It is determined that there is an abnormality in the wall shape.

  Note that the laser scanning unit 12 may include a variable focus mechanism. Since the distance from the wall surface of the measurement target object 21 changes according to the irradiation angle of the laser beam, the intensity of reflected light to be detected can be increased by adjusting the focal position according to the irradiation angle. Measurement accuracy can be improved. As the variable focus mechanism, for example, a mechanism for adjusting the lens position with a stage or a piezoelectric element, a liquid lens, or an ultrasonic lens can be used.

  Further, the phase comparator 46 may perform phase comparison after beat-down for the frequency component of 125 MHz. For example, the phase comparator 46 can beat down to a frequency of 5 MHz by mixing with a 120 MHz signal. Since the circuit generally increases in cost as the cutoff frequency becomes higher, the circuit cost can be suppressed by processing by beating down to a lower frequency.

  Moreover, although the example which performed intensity modulation with the frequency of 7.5 MHz and 125 MHz was demonstrated above, it is not limited to this. Further, the modulation frequency may be changed according to the distance from the measurement target object 21. This makes it possible to optimize the measurement accuracy.

  The data processing unit 48 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory) used for temporary storage of various data, and a ROM (Read Only Memory) storing a program executed by the CPU. , Etc. may be provided. For example, the data processing unit 48 can realize the above functions by the CPU operating according to a program stored in the ROM.

  FIG. 5 is a diagram illustrating a detailed example of the scanning unit. As shown in FIG. 5, the scanning unit 58 includes a shielding plate 61, an incident member 62, and a non-incident member 63. The mirror 58a rotates clockwise in FIG.

  For example, the laser beam irradiated to the measurement target object 21 scans in the + Z-axis direction by the movement of the vehicle 22 in the + Z-axis direction, and scans in the XY plane by the rotation of the mirror 58a. For example, since the measuring device 10 does not need to measure the distance to the road surface 23 illustrated in FIG. 1, the scanning unit 58 includes a shielding plate 61 in an angle range in which the road surface 23 is irradiated with laser light. Yes.

  The shielding plate 61 is disposed on the lower side (the road surface 23 side) of the mirror 58a and has a concave shape so as to partially cover the lower side of the mirror 58a. For example, the shielding plate 61 has a bowl shape.

The laser light emitted from the light source 44 is reflected by the mirror 58a and emitted at a predetermined irradiation angle depending on the rotation angle of the mirror 58a. A laser beam L21 illustrated in FIG. 5 indicates a laser beam when the irradiation angle is “θ = θ ₀ ”. The laser beam L22 indicates the laser beam when the irradiation angle is “θ = θ ₁ ”. The laser beam L23 indicates the laser beam when the irradiation angle is “θ = θ ₂ ”. The laser beam L24 indicates a laser beam when the irradiation angle is “θ = θ ₃ ”. The laser beam L25 indicates the laser beam when the irradiation angle is “θ = θ ₄ ”. The laser beam L26 indicates a laser beam when the irradiation angle is “θ = θ ₅ ”.

Laser light L21 to L24 having an irradiation angle “θ = θ _{0 to} θ ₃ ” is applied to the measurement target object 21. On the other hand, the laser beams L25 and L26 having the irradiation angles “θ = θ ₄ , θ ₅ ” for irradiating the road surface 23 are blocked from being emitted to the outside by the shielding plate 61. That is, when the mirror 58a is in a predetermined rotation angle range (when the laser beam is in a rotation angle range where the laser beam is emitted to the shielding plate 61), the laser beam emitted from the light source 44 is So that it is not injected.

  The shielding plate 61 has an incident member 62 inside the concave shape. The incident member 62 is a member that reflects incident laser light, and is, for example, a mirror.

The incident member 62 arranges the laser beam reflected by the mirror 58a at an angle at which the laser beam is regularly reflected in the direction in which the laser beam has traveled. That is, the incident member 62 is arranged so that the laser light emitted from the mirror 58a is incident on the mirror 58a again. In the case of the example of FIG. 5, the incident member 62 is disposed at the angle of the regular reflection at the irradiation angle “θ = θ ₄ ” of the shielding plate 61. Thereby, for example, the laser beam L25 emitted from the mirror 58a is incident on the mirror 58a again. The laser beam reflected by the incident member 62 is detected as a detection signal by the photodetector 57. That is, the incident member 62 reflects the reflected light of the laser light emitted from the mirror 58a so as to be incident on the mirror 58a for a predetermined period (while the laser light is irradiated on the incident member 62). The device 57 receives the light.

The distance between the mirror 58a and the incident member 62 is constant and known. Accordingly, the data processing unit 48 uses the phase information output from the phase comparator 46 when the laser beam is irradiated to the incident member 62 as a reference distance (a known distance, that is, between the mirror 58a and the incident member 62). Distance). For example, the data processing unit 48 can set the phase information output from the phase comparator 46 when the laser beam L25 with the irradiation angle “θ = θ ₄ ” is output as the reference distance.

  Thereby, for example, even if the phase information output from the phase comparator 46 drifts due to the influence of heat, the data processing unit 48 can correct the phase information that has fluctuated due to the thermal drift according to the reference distance ( Hereinafter, this function is sometimes referred to as origin correction). For example, the data processing unit 48 can correct phase information that has fluctuated due to thermal drift by detecting a deviation in the reference distance.

  The shielding plate 61 has a non-incident member 63 inside the concave shape. The non-incident member 63 is a member that attenuates incident laser light, and is, for example, an ND (Neutral Density) filter.

The non-incident member 63 arranges the laser beam reflected by the mirror 58a at an angle that reflects the direction other than the direction in which the laser beam has traveled. That is, the non-incident member 63 is disposed on the shielding plate 61 so that the laser light emitted from the mirror 58a is reflected so as not to enter the mirror 58a. In the case of the example of FIG. 5, the non-incident member 63 is arranged at an irradiation angle “θ = θ ₅ ” of the shielding plate 61 at an angle that reflects in a direction other than the direction in which the laser light travels. Thereby, for example, the laser beam L26 emitted from the mirror 58a is not incident on the mirror 58a. The reflected light of the laser beam L26 is not received by the photodetector 57. That is, the non-incident member 63 reflects the reflected light of the laser light emitted from the mirror 58a so as not to be incident on the mirror 58a for a predetermined period (while the laser light is irradiated on the non-incident member 63). The detector 57 is prevented from receiving light.

While the non-incident member 63 is irradiated with the laser light, the reflected light does not return to the mirror 58a. For example, when the laser beam irradiation angle is “θ = θ ₅ ”, no reflected light returns to the mirror 58a. Accordingly, at this time, the light detector 57 originally does not detect light (reflected light).

  However, the light may be detected by the photodetector 57 due to the back surface reflected light at the lens interface of the quarter wavelength plate 54 or the condenser lens 55. The phase comparator 46 may output phase information due to electrical signal crosstalk in the circuit.

Therefore, the data processing unit 48 corrects variation in distance due to back surface reflected light and crosstalk using the phase information output from the phase comparator 46 when the non-incident member 63 is irradiated with laser light. (Hereinafter, this function may be referred to as cyclic error correction). For example, the data processing unit 48 uses the phase information when the laser beam irradiation angle is “θ = θ ₅ ” as a noise component, and calculates noise from the phase information when the measurement target 21 is irradiated with the laser beam. Remove ingredients.

  The spindle motor 58b outputs encoder information indicating angle information of the rotation shaft to the rotation control unit 47. Then, the rotation control unit 47 outputs the encoder information output from the spindle motor 58b to the data processing unit 48. Thereby, the data processing part 48 can detect the rotation angle of the mirror 58a. That is, the data processing unit 48 can detect when the laser light is emitted to the incident member 62 and when it is emitted to the non-incident member 63 based on the encoder information. That is, the data processing unit 48 can acquire the phase information when the laser beam is emitted to the incident member 62 and the phase information when the laser beam is emitted to the non-incident member 63. In addition, the data processing unit 48 can acquire a point where the laser beam of the measurement target object 21 is irradiated.

  In the above description, the example in which the incident member 62 is irradiated with laser light to obtain the origin correction data has been described. However, the position where the laser light emitted from the mirror 58a is reflected again to the mirror 58a is described. If fixed, it is not necessary to be limited to this. For example, the incident member 62 may be made of a metal with a rough surface. In general, the reflected light from the object to be measured 21 is greatly attenuated, so that it is necessary to increase the power of the irradiated laser light. In such a state, when the incident member 62 installed at a short distance is irradiated with a laser, the laser is reflected with almost no attenuation, and the photodetector 57 for detecting this is saturated. In order to avoid this, laser light may be irradiated to an object having a low reflectance. Further, even if the incident member 62 is not installed, the data for correcting the origin can be acquired if the surface of the shielding plate 61 is made of a mirror or a metal having a rough surface.

  In the above description, the ND filter is exemplified as the non-incident member 63. However, for example, an optical element such as a diffuser that scatters or attenuates laser light and does not generate reflected light may be used.

  FIG. 6 is a flowchart illustrating an operation example of the measurement apparatus. The flowchart in FIG. 6 is executed, for example, when the measurement apparatus 10 is turned on.

First, the data processing unit 48 acquires the initial value of the origin correction data before measuring the shape of the measurement target object 21 (step S1). For example, the data processing unit 48 rotates the mirror 58a so that the laser beam L25 is emitted to the incident member 62 as indicated by the irradiation angle “θ = θ ₄ ” in FIG. Get initial value of data.

Next, the data processing unit 48 acquires cyclic error correction data (step S2). For example, the data processing unit 48 rotates the mirror 58a so that the laser light L26 is emitted to the non-incident member 63 as indicated by the irradiation angle “θ = θ ₅ ” in FIG. Get the initial value of click error correction data.

  Next, the data processing unit 48 starts irradiation of the measurement target object 21 with laser light and starts measuring the shape of the measurement target object 21 (step S3). For example, the data processing unit 48 emits laser light from the light source 44 and outputs rotation control data to the rotation control unit 47 so that the mirror 58a rotates at a rotation speed of “10000 rpm”.

  Next, the data processing unit 48 acquires phase information of each point of the measurement target object 21 from the phase comparator 46 (step S4). The data processing unit 48 acquires the phase information acquired from the phase comparator 46 in association with the time acquired from the phase comparator 46. Note that the data processing unit 48 can detect the spot where the laser beam of the measurement target 21 is irradiated based on the encoder information output from the spindle motor 58b.

Next, the data processing unit 48 determines whether or not the irradiation angle of the laser light emitted from the mirror 58a is “θ = θ ₄ ” (step S5). That is, the data processing unit 48 determines whether or not the laser light emitted from the mirror 58a is emitted to the incident member 62. If the data processing unit 48 determines that the irradiation angle of the laser light emitted from the mirror 58a is “θ = θ ₄ ” (in the case of “yes” in step S5), the data processing unit 48 proceeds to the processing of step S6. If the data processing unit 48 determines that the irradiation angle of the laser light emitted from the mirror 58a is not “θ = θ ₄ ” (“No” in step S5), the data processing unit 48 proceeds to the processing in step S7.

In step S5, when the data processing unit 48 determines that the irradiation angle of the laser light emitted from the mirror 58a is “θ = θ ₄ ” (in the case of “yes” in step S5), the phase comparator The phase information output from 46 is rewritten as new origin correction data (step S6). When the data processing unit 48 rewrites the origin correction data, the data processing unit 48 proceeds to the process of step S4.

In step S5, when the data processing unit 48 determines that the irradiation angle of the laser beam emitted from the mirror 58a is not “θ = θ ₄ ” (in the case of “No” in step S5), the data processing unit 48 emits from the mirror 58a. It is determined whether or not the irradiation angle of the laser beam is “θ = θ ₅ ” (step S7). That is, the data processing unit 48 determines whether or not the laser beam emitted from the mirror 58a is emitted to the non-incident member 63. When the data processing unit 48 determines that the irradiation angle of the laser light emitted from the mirror 58a is “θ = θ ₅ ” (in the case of “yes” in step S7), the data processing unit 48 proceeds to the process of step S8. If the data processing unit 48 determines that the irradiation angle of the laser light emitted from the mirror 58a is not “θ = θ ₅ ” (in the case of “No” in step S7), the data processing unit 48 proceeds to the processing of step S9.

When the data processing unit 48 determines in step S7 that the irradiation angle of the laser light emitted from the mirror 58a is “θ = θ ₅ ” (in the case of “yes” in step S7), the phase comparator The phase information output from 46 is rewritten as new cyclic error correction data (step S8). After rewriting the cyclic error correction data, the data processing unit 48 proceeds to the process of step S4.

In step S7, when the data processing unit 48 determines that the irradiation angle of the laser beam emitted from the mirror 58a is not “θ = θ ₅ ”, the origin correction and the cyclic error correction of the phase information acquired in step S4 are performed. Is performed (step S9). For example, the data processing unit 48 performs origin correction and cyclic error correction of the phase information based on the origin correction data and the cyclic error correction data acquired in steps S1 and S2. Further, the data processing unit 48 performs origin correction and cyclic error correction of the phase information based on the origin correction data and the cyclic error correction data updated in steps S6 and S8.

  Next, the data processing unit 48 determines whether or not the measurement of the measurement target object 21 is completed (step S10). For example, the data processing unit 48 determines whether or not the measurement of the measurement target object 21 is completed depending on whether or not there is an instruction to end the measurement of the measurement target object 21 by the user. If the data processing unit 48 determines that the measurement of the measurement target 21 has not been completed (“No” in step S10), the data processing unit 48 proceeds to the process of step S4. If the data processing unit 48 determines that the measurement of the measurement target object 21 has been completed (“Yes” in step S10), the data processing unit 48 proceeds to the process of step S11.

  In step S10, when the data processing unit 48 determines that the measurement of the measurement target object 21 is completed (“Yes” in step S10), the data processing unit 48 performs integration processing (step S11). For example, although not shown in the flowchart of FIG. 6, the data processing unit 48 calculates coordinate data of the vehicle 22 at each time by the GPS 13, the inertial measurement unit 14, and the travel distance sensor 15. Further, the data processing unit 48 calculates the distance at each point of the measurement target object 21 based on the phase information at each time corrected in step S9. The data processing unit 48 integrates the coordinate data of the vehicle 22 at each time and the distance at each point of the measurement target object 21 at each time, and profile data of the measurement target object 21 (for example, the measurement target object 21). 3D data of the wall surface).

  Next, the data processing unit 48 stores the profile data generated in step S10 in a database and compares it with past profile data (step S12).

  Next, the data processing unit 48 outputs the comparison result of step S12 to, for example, a terminal device such as a personal computer connected by a cable (step S13).

  As described above, the scanning unit 58 of the measuring device 10 reflects and emits the laser light output from the light source 44 so as to scan the measurement target object 21, and scans the measurement target object 21. The reflected light is incident and reflected by the condenser lens 55 so as to be received by the photodetector 57. Further, the non-incident member 63 of the measuring device 10 scans the reflected light of the laser light emitted from the light source 44 from the scanning unit 58 for a predetermined period (for example, while the laser light is emitted to the non-incident member 63). The light is reflected so as not to be incident on the part 58 and is not received by the photodetector 57. Thereby, the phase comparator 46 outputs phase information (cyclic error correction data) due to crosstalk of reflected light and electrical signals at the lens interface and the like, and the data processing unit 48 is based on the phase information. Then, it becomes possible to correct the variation in the measurement result due to the reflected light at the lens interface and the crosstalk of the electric signal.

  In addition, the incident member 62 of the measuring apparatus 10 is disposed at a known distance, and the reflected light of the laser light from the light source 44 emitted from the scanning unit 58 is reflected for a predetermined period (for example, the laser light is emitted to the incident member 62). In the meantime, the light is reflected so as to be incident on the scanning unit 58 and received by the photodetector 57. Thereby, even if the phase information output from the phase comparator 46 fluctuates due to thermal drift, the measurement apparatus 10 can correct the deviation by a deviation from a known distance (reference distance).

  In the flowchart of FIG. 6, the origin correction and the cyclic error correction are described as being rewritten every time the laser beam irradiation angle reaches a specified angle, but the present invention is not limited to this. The data processing unit 48 may be rewritten every 10 rotations, for example. Thereby, the data processing time can be shortened and the power consumption can be reduced.

[Second Embodiment]
Next, a second embodiment will be described. In the second embodiment, a case where the mirror of the scanning unit is a polygon mirror will be described. Below, only a different part from 1st Embodiment is demonstrated, and the part same as 1st Embodiment is demonstrated using the code | symbol of 1st Embodiment.

  FIG. 7 is a diagram showing an example of a scanning unit according to the second embodiment of the present invention. As shown in FIG. 7, the scanning unit 70 includes a shielding plate 71, a polygon mirror 72, an incident member 73, and a non-incident member 74.

  Similarly to the scanning unit 58 described with reference to FIG. 5, the scanning unit 70 does not need to emit laser light to the road surface 23. Therefore, the scanning unit 70 has a shielding plate 71 in an angle range in which the road surface 23 is irradiated with laser light.

  The number of faces of the polygon mirror 72 is, for example, six. When the number of faces of the polygon mirror 72 is 6, the scanning range of the laser light in the XY plane is about 60 degrees. Therefore, the shielding plate 71 is provided with an opening having an angle range of about 60 degrees, for example.

  The shielding plate 71 is installed on the lower side (road surface 23 side) of the polygon mirror 72 and has a concave shape so as to partially cover the lower side of the mirror 58a. For example, the shielding plate 71 has a bowl shape.

  The polygon mirror 72 is connected to the rotation shaft of the spindle motor 58b. The rotational speed of the polygon mirror 72 is, for example, 10,000 rpm. The polygon mirror 72 rotates counterclockwise in FIG.

  A laser beam L31 illustrated in FIG. 7 indicates the laser beam of the light source 44 that is incident on the polygon mirror 72. The laser beam L31 emitted from the light source 44 is reflected by the polygon mirror 72 and emitted at a predetermined irradiation angle depending on the rotation angle of the polygon mirror 72.

A laser beam L32 illustrated in FIG. 7 indicates the laser beam when the irradiation angle is “θ = θ ₀ ”. The laser beam L33 indicates the laser beam when the irradiation angle is “θ = θ ₁ ”. The laser beam L34 indicates the laser beam when the irradiation angle is “θ = θ ₂ ”. The laser beam L35 indicates the laser beam when the irradiation angle is “θ = θ ₃ ”.

Laser light L32 and L33 with irradiation angles “θ = θ ₀ , θ ₁ ” are applied to the measurement target object 21. On the other hand, the laser beams L34 and L35 having the irradiation angles “θ = θ ₂ , θ ₃ ” for irradiating the road surface 23 are blocked by the shielding plate 71. That is, the shielding plate 71 is configured such that when the polygon mirror 72 is in a predetermined rotation angle range (when the laser beam is in a rotation angle range where the laser beam is emitted to the shielding plate 71), the laser beam emitted from the light source 44 is Do not inject outside.

  The shielding plate 71 has an incident member 73 inside the concave shape. The incident member 73 is a member that reflects incident laser light, and is, for example, a mirror.

The incident member 73 arranges the laser beam reflected by the polygon mirror 72 at an angle at which the laser beam is regularly reflected in the direction in which the laser beam has traveled. That is, the incident member 73 is arranged so that the laser light emitted from the polygon mirror 72 is incident on the polygon mirror 72 again. In the case of the example of FIG. 7, the incident member 73 is disposed at the position of the irradiation angle “θ = θ ₂ ” of the shielding plate 71 at a regular reflection angle. Thereby, the laser beam L34 emitted from the polygon mirror 72 is incident on the polygon mirror 72 again. The laser light reflected by the incident member 73 is detected as a detection signal by the photodetector 57. That is, the incident member 73 reflects the reflected light of the laser light emitted from the polygon mirror 72 so as to be incident on the polygon mirror 72 for a predetermined period (while the laser light is irradiated on the incident member 73). The light is received by the photodetector 57.

  The shielding plate 71 has a non-incident member 74 inside the concave shape. The non-incident member 74 is a member that attenuates incident laser light, and is, for example, an ND filter.

The non-incident member 74 is disposed at an angle that reflects the laser beam reflected by the polygon mirror 72 in a direction other than the direction in which the laser beam has traveled. That is, the non-incident member 74 is disposed on the shielding plate 71 so that the laser light emitted from the polygon mirror 72 is reflected so as not to enter the polygon mirror 72. In the case of the example of FIG. 7, the non-incident member 74 is disposed at an irradiation angle “θ = θ ₃ ” of the shielding plate 71 at an angle that reflects in a direction other than the direction in which the laser light travels. Thereby, for example, the laser light L <b> 35 emitted from the polygon mirror 72 is not incident on the polygon mirror 72. The reflected light of the laser beam L35 is not received by the photodetector 57. That is, the non-incident member 74 reflects the reflected light of the laser light emitted from the polygon mirror 72 so that it is not incident on the polygon mirror 72 for a predetermined period (while the non-incident member 74 is irradiated with the laser light). The light detector 57 is configured not to receive light.

  When the polygon mirror 72 is used, for example, the laser light L31 of the light source 44 emitted to a certain surface is emitted to the right adjacent surface when the polygon mirror 72 further rotates counterclockwise. Become. That is, by using the polygon mirror 72, the scanning range of the laser light is limited, but the scanning density of the laser can be increased.

  As described above, the data processing unit 48 can perform origin correction and cyclic error correction also by using the polygon mirror 72 in the scanning unit 70.

  In the above, the number of surfaces and the rotation speed of the polygon mirror 72 are not limited to the above example. The number of surfaces and the rotation speed can be freely set according to the angle range to be measured of the measurement target object 21 and the point group acquisition density.

[Third Embodiment]
Next, a third embodiment will be described. In the first embodiment and the second embodiment, the laser beam is scanned by the rotating mirror and the polygon mirror. However, in the third embodiment, a laser is obtained by using a chopper and a two-dimensional scanning mirror. Scan the light. Below, only a different part from 1st Embodiment is demonstrated, and the part same as 1st Embodiment is demonstrated using the code | symbol of 1st Embodiment.

  FIG. 8 is a diagram showing a block configuration example of a measuring apparatus according to the third embodiment of the present invention. As shown in FIG. 8, the laser scanning unit 12 includes a chopper 81 and a two-dimensional scanning unit 82. The chopper 81 is provided between the quarter wavelength plate 54 and the condenser lens 55.

  FIG. 9 is a diagram showing a detailed example of the chopper. As shown in FIG. 8, the chopper 81 has a circular shape. The diameter of the chopper 81 is, for example, 50 mm.

  The chopper 81 has an incident member 81a and a non-incident member 81b. The incident member 81a is, for example, a mirror, and the non-incident member 81b is, for example, an ND filter.

  The incident member 81a and the non-incident member 81b rotate about the center of the chopper in the φ direction (counterclockwise in FIG. 9). The rotation speed of the incident member 81a and the non-incident member 81b is, for example, 100 rpm.

  The incident member 81a and the non-incident member 81b have, for example, a fan shape with a central angle of 10 degrees. The normal line of the incident member 81 a is parallel to the traveling direction of the laser light emitted from the quarter-wave plate 54. The incident member 81 a reflects the laser light emitted from the quarter wavelength plate 54 and emits the light again to the quarter wavelength plate 54.

  The normal line of the non-incident member 81b is inclined, for example, about 10 degrees with respect to the traveling direction of the laser light emitted from the quarter-wave plate 54. The non-incident member 81 b reflects the laser light emitted from the quarter wavelength plate 54 so that it is not incident on the quarter wavelength plate 54 again.

  A laser beam L41 shown in FIG. 9 indicates a laser beam emitted from the quarter-wave plate 54 to the condenser lens 55. The laser beam L41 passes through the circle of the chopper 81 and passes, for example, a portion of “φ = 45 degrees”.

  When the incident member 81a is positioned at a portion through which the laser beam L41 passes due to the rotation, the laser beam L41 is reflected to the quarter-wave plate 54. For example, when the incident member 81 a is at the position “φ = 45 degrees”, the laser beam L 41 is reflected to the quarter-wave plate 54. In other words, the incident member 81 a reflects the laser light output from the light source 44 so that it is received by the photodetector 57 via the quarter-wave plate 54 and the PBS 53.

  When the non-incident member 81b is rotated and positioned at a portion through which the laser light L41 passes, the laser light L41 is reflected in a direction other than the quarter-wave plate 54 (a direction other than the optical path through which the laser light should originally pass). . For example, when the non-incident member 81 b is at the position “φ = 45 degrees”, the laser light L 41 is reflected to other than the quarter-wave plate 54. That is, the non-incident member 81 b prevents the laser light output from the light source 44 from being received by the photodetector 57 via the quarter-wave plate 54 and the PBS 53.

  For example, when the position of the incident member 81a reaches “φ = 45 degrees”, the data processing unit 48 irradiates the incident member 81a with the laser beam L41, and acquires the origin correction data at this timing. For example, when the position of the non-incident member 81b is “φ = 45 degrees” (the incident member 81a is “φ = 255 degrees”), the data processing unit 48 irradiates the non-incident member 81b with the laser light L41. Therefore, cyclic error correction data is acquired at this timing. The data processing unit 48 can obtain angle information of the incident member 81a and the non-incident member 81b by receiving the encoder information from the chopper 81.

  Returning to the description of FIG. The two-dimensional scanning unit 82 has a two-dimensional scanning mirror 82a. The two-dimensional scanning mirror 82a emits laser light so as to scan the measurement target 21 two-dimensionally. For example, the two-dimensional scanning mirror 82a emits laser light so as to scan in the XY plane and the YZ plane. The two-dimensional scanning mirror 82a is a galvanometer mirror, for example, and the scanning speed is 5 kHz.

  The measuring apparatus 10 can measure a desired region of the measurement target object 21 in a desired sequence by the two-dimensional scanning mirror 82a. In the first embodiment and the second embodiment, the measuring apparatus 10 measures the shape of the measurement target object 21 while moving by the vehicle 22, but when the two-dimensional scanning mirror 82a is used, the measuring apparatus 10 does not move. A predetermined region can be measured with high density.

  In this way, the incident member 81a that causes the light detector 44 to receive the laser light output from the light source 44 and the laser light that is output from the light source 44 are prevented from being received by the light detector 57. By providing the chopper 81 having the non-incident member 81b between the light source 44 and the two-dimensional scanning unit 82, it is possible to correct fluctuations in measurement results due to reflected light at the lens interface and crosstalk of electrical signals. it can.

  In the above description, the angular relationship between the incident member 81a and the non-incident member 81b is shifted by 180 degrees, but the present invention is not limited to this. Further, the number of incident members 81a and non-incident members 81b is not limited.

  Further, instead of the two-dimensional scanning unit 82, the scanning unit 58 described with reference to FIG. In this case, the incident member 62 and the non-incident member 63 of the scanning unit 58 are not necessary. Further, instead of the two-dimensional scanning unit 82, the scanning unit 70 described with reference to FIG. In this case, the incident member 73 and the non-incident member 74 of the scanning unit 70 are unnecessary.

[Fourth Embodiment]
In the fourth embodiment, an example in which a measuring device is mounted on a railway vehicle will be described. About the same part as 1st Embodiment, it demonstrates using the code | symbol of 1st Embodiment.

  FIG. 10 is a diagram for explaining an application example of the measuring apparatus according to the fourth embodiment of the present invention. As shown in FIG. 10, the laser scanning unit 12 is mounted at the tip of the railway vehicle 91. The laser scanning unit 12 irradiates the wall surface of the tunnel 92 with laser light and makes the reflected light incident. In FIG. 10, the control unit 11, the GPS 13, the inertial measurement unit 14, and the travel distance sensor 15 of the measurement device 10 are not shown.

  The control unit 11 (not shown) measures the distance between the laser scanning unit 12 and the wall surface of the tunnel 92. Since the laser beam is scanned while traveling, the obtained profile data is spiral like profile data 93a to 93c.

  In this way, the measuring device 10 can be mounted on the railway vehicle 91 and the shape of the wall surface of the railway tunnel 92 can be measured.

  As described above, the present invention has been described using the embodiment. However, the configuration of the measurement device 10 is classified according to the main processing contents in order to facilitate understanding of the configuration of the measurement device 10. The present invention is not limited by the way of classification and names of the constituent elements. The configuration of the measuring device 10 can be classified into more components depending on the processing content. Moreover, it can also classify | categorize so that one component may perform more processes. Further, the processing of each component may be executed by one hardware or may be executed by a plurality of hardware.

  In addition, each processing unit in the flowchart described above is divided according to main processing contents in order to facilitate understanding of the processing of the measuring apparatus 10. The present invention is not limited by the way of dividing the processing unit or the name. The processing of the measuring device 10 can be divided into more processing units according to the processing content. Moreover, it can also divide | segment so that one process unit may contain many processes.

  Further, the technical scope of the present invention is not limited to the scope described in the above embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiment.

  For example, in the above description, the measurement method using the phase shift method has been described as an example, but the measurement method is not limited thereto. For example, a distance measurement method using a beat signal between modes of the optical comb laser may be used. When this is used, it becomes possible to measure the distance with higher accuracy than the phase shift method.

  In the above description, distance measurement is performed using intensity modulation of two different frequencies (for example, 7.5 MHz and 125 MHz), but the type of frequency is not limited to this. Further, when the low frequency modulation is used together, it is possible to measure the distance to the object at a longer distance. In addition, when a higher frequency modulation is used together, it becomes possible to perform distance measurement with higher accuracy.

  In the above description, an example in which two oscillators that generate low-frequency and high-frequency intensity modulation signals are synchronized has been described. However, the present invention is not limited to this. For example, the intensity modulation signal may be generated without synchronizing the two oscillators. This makes it possible to simplify the apparatus configuration.

  In the above description, the example in which the reflected light from the wall surface of the measurement target is directly received by the photodetector has been described. However, the present invention is not limited to this. For example, the reflected light may be once guided to an optical fiber, and after light amplification, the light may be received by a photodetector. As a result, even weaker light can be detected, and displacement measurement accuracy can be improved and a measurable distance can be increased.

  In the above description, the measurement device is mounted on an automobile or a railway vehicle. However, the present invention is not limited to this. For example, it may be mounted on an aircraft to perform shape measurement.

  Further, it is apparent from the scope of the claims that embodiments to which the above changes or improvements are added can also be included in the technical scope of the present invention. The present invention can also be provided as a measuring method by the measuring device 10.

10: Measuring device 11: Control unit 12: Laser scanning unit 13: GPS
14: Inertial measurement unit 15: Travel distance sensor 21: Object to be measured 21a to 21d: Point 22: Vehicle 23: Road surface L11 to L14, L21 to L24, L31 to L34, L41: Laser light 31 to 33, 93a to 93c : Profile data 41: Oscillator 42: Low frequency modulator 43: High frequency modulator 44: Light source 45: Optical amplifier 46: Phase comparator 47: Rotation control unit 48: Data processing unit 51, 54: 1/4 wavelength plate 52: 1/2 wavelength plate 53: PBS
55: condenser lens 56, 57: photodetector 58: scanning unit 58a: mirror 58b: spindle motor 61, 71: shielding plate 62, 73, 81a: incident member 63, 74, 81b: non-incident member 72: polygon mirror 81: Chopper 82: Two-dimensional scanning part 91: Railway vehicle 92: Tunnel

Claims (12)

A light source that emits laser light;
A photodetector that detects light and converts it into an electrical signal;
The laser light output from the light source is reflected and emitted so as to scan the measurement object, and the reflected light of the laser light scanned on the measurement object is incident and received by the photodetector. A scanning unit that reflects so that
A non-incident member that reflects the reflected light of the laser light emitted from the light source from the scanning unit so as not to be incident on the scanning unit for a predetermined period and is not received by the photodetector;
A measuring apparatus comprising: The measuring device according to claim 1,
An incident member configured to reflect the reflected light of the laser light emitted from the light source emitted from the scanning unit so as to be incident on the scanning unit for a predetermined period and to be received by the photodetector; A characteristic measuring device. The measuring device according to claim 1,
The scanning unit
The laser beam output from the light source is reflected and emitted so as to scan the object to be measured by rotation, and the reflected light of the laser beam that has scanned the object to be measured is incident to detect the light. A mirror that reflects so as to be received by the instrument,
A shielding plate for preventing the laser light output from the light source from being emitted to the outside when the mirror is within a predetermined rotation angle range;
A measuring apparatus comprising: It is a measuring device of Claim 3, Comprising:
The non-incident member is arranged on the shielding plate so as to reflect the laser light of the light source emitted from the mirror so as not to be incident on the mirror. It is a measuring device of Claim 4, Comprising:
The shielding plate has a concave shape so as to cover a part of the mirror,
The non-incident member is disposed inside the shielding plate having a concave shape. It is a measuring device of Claim 3, Comprising:
An incident member disposed on the shielding plate further reflects the laser light emitted from the light source emitted from the mirror so as to be incident on the mirror and received by the photodetector. A measuring device characterized by that. It is a measuring device of Claim 6, Comprising:
The shielding plate has a concave shape so as to cover a part of the mirror,
The measuring apparatus according to claim 1, wherein the incident member is disposed inside the shielding plate having a concave shape. It is a measuring device of Claim 3, Comprising:
The measuring device, wherein the mirror is a polygon mirror. The measuring device according to claim 1,
A chopper provided between the light source and the scanning unit;
The non-incident member is provided in the chopper, and prevents the laser light output from the light source from being received by the photodetector. It is a measuring device of Claim 9, Comprising:
The measuring apparatus further comprising an incident member provided on the chopper that reflects the laser light output from the light source so as to be received by the photodetector. It is a measuring device of Claim 9, Comprising:
The scanning device includes a galvanometer mirror that two-dimensionally scans the laser beam. A measuring method of a measuring device,
The scanning unit reflects and emits the laser beam output from the light source so as to scan the object to be measured, and the reflected light of the laser beam that has scanned the object to be measured is incident and received by the photodetector. A scanning step that reflects as
A non-incident step for reflecting the reflected light of the laser light emitted from the light source emitted from the scanning unit by a non-incident member so as not to be incident on the scanning unit for a predetermined period and not to be received by the photodetector. When,
A measurement method characterized by comprising:

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