WO2019151092A1 - Dispositif de balayage et dispositif de mesure de distance - Google Patents

Dispositif de balayage et dispositif de mesure de distance Download PDF

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Publication number
WO2019151092A1
WO2019151092A1 PCT/JP2019/002155 JP2019002155W WO2019151092A1 WO 2019151092 A1 WO2019151092 A1 WO 2019151092A1 JP 2019002155 W JP2019002155 W JP 2019002155W WO 2019151092 A1 WO2019151092 A1 WO 2019151092A1
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WO
WIPO (PCT)
Prior art keywords
scanning
light
region
reflecting surface
reflecting
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PCT/JP2019/002155
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English (en)
Japanese (ja)
Inventor
加園　修
佐藤　充
柳澤　琢麿
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パイオニア株式会社
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Publication of WO2019151092A1 publication Critical patent/WO2019151092A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/10—Scanning systems

Definitions

  • the present invention relates to a scanning device and a distance measuring device that perform optical distance measuring.
  • a distance measuring device that scans light within a target area and measures the distance to an object.
  • a distance measuring device has, for example, a light source that emits a laser pulse, a scanning mechanism that reflects and scans the laser pulse, and a light receiving unit that receives the laser pulse reflected by an object. .
  • the distance measuring device measures the distance to the object based on the emission time of the laser pulse emitted by the light source and the light reception time of the laser pulse received by the light receiving unit.
  • an optical scanning unit that has a light reflecting surface and can perform Lissajous scanning of light incident on the light reflecting surface within a target region, and pulsed light emitted from the light source unit is reflected by an object.
  • a light receiving section that receives the reflected light, and a distance measuring section that measures the distance of the object based on the emission timing of the pulsed light from the light source section and the reception timing of the reflected light from the light receiving section.
  • a distance device is disclosed.
  • distance measurement is performed by so-called Lissajous scanning in which pulsed light is irradiated along a Lissajous locus.
  • the Lissajous locus has a low scanning locus density in the central region of the scanning region and a high scanning locus density in the edge region.
  • the present invention has been made in view of the above points, and one object of the present invention is to provide a distance measuring device capable of distance measurement by a scanning mode having a locus of a desired density distribution within an area for distance measurement. It is said.
  • the light is emitted toward the first region and the second region adjacent to each other by periodically changing the light emitting direction and the irradiation direction of the light.
  • An optical scanning unit to be irradiated, and a second scanning that is directed toward the first scanning region from the optical scanning unit to the first scanning region and is irradiated toward the second region
  • An optical path control unit that guides light to a second scanning region, and the optical path control unit changes the optical path of the first scanning light and the second scanning light to change the first scanning region and
  • the scanning device is configured to be able to change the positional relationship of the second scanning region.
  • the light is emitted toward the first region and the second region adjacent to each other by periodically changing the light emitting direction and the irradiation direction of the light.
  • An optical scanning unit to be irradiated, and a second scanning that is directed toward the first scanning region from the optical scanning unit to the first scanning region and is irradiated toward the second region
  • An optical path controller that guides light to the second scanning region, and reflected light reflected by the first scanning light or the second scanning light reflected by an object existing in the first scanning region or the second scanning region
  • a distance measuring unit that measures the distance to the object based on the reflected light received by the light receiving unit, and the optical path control unit includes the first scanning light and the second scanning light.
  • FIG. 1 is a block diagram illustrating the configuration of the distance measuring apparatus according to the embodiment.
  • FIG. 2A is a top view of the scanning unit according to the embodiment.
  • FIG. 2B is a cross-sectional view of the scanning unit according to the embodiment.
  • FIG. 3 is an explanatory diagram illustrating a scanning mode of the scanning unit of the distance measuring apparatus according to the embodiment.
  • FIG. 4 is an explanatory diagram illustrating an example of a waveform of a drive signal applied to the scanning unit according to the embodiment and a scanning trajectory of pulsed light by the scanning unit.
  • FIG. 5 is an explanatory diagram showing an aspect in which the scanning light is reflected by the reflecting mirror section.
  • FIG. 6 is an explanatory diagram showing an aspect of emitted light reflected by the reflecting mirror section.
  • FIG. 1 is a block diagram illustrating the configuration of the distance measuring apparatus according to the embodiment.
  • FIG. 2A is a top view of the scanning unit according to the embodiment.
  • FIG. 2B is a cross-
  • FIG. 7 is a diagram showing the locus of the emitted light irradiated on the scanning plane in FIG.
  • FIG. 8 is a view showing a region of the locus of the emitted light irradiated on the scanning plane of FIG.
  • FIG. 9 is a diagram showing a locus region of the emitted light irradiated on the scanning surface in FIG.
  • FIG. 10 is an explanatory diagram illustrating an aspect in which the scanning light is reflected by the reflecting mirror portion of the scanning device according to the second embodiment.
  • FIG. 11 is an explanatory diagram illustrating an aspect of emitted light reflected by the reflecting mirror portion of the scanning device according to the second embodiment.
  • FIG. 12 is a diagram showing the locus of the emitted light irradiated on the scanning surface in FIG.
  • FIG. 13 is a perspective view illustrating a configuration example of the reflecting mirror portion of the scanning device according to the third embodiment.
  • the distance measuring device 10 is a distance measuring device that optically measures the distance to the object OB. Specifically, the distance measuring device 10 irradiates light toward a predetermined spatial region, that is, the scanning target region R. In addition, the distance measuring device 10 receives the light reflected by the object OB, and measures the distance from the object OB, that is, measures the distance.
  • the light source 20 is a light emitting element such as a laser diode capable of emitting the pulsed light L1, and functions as an emitting unit.
  • the optical system OS is provided on the optical path of the pulsed light L1.
  • the optical system OS includes an optical member such as a collimator lens, and converts the pulsed light L1 emitted from the light source 20 into parallel light.
  • a beam splitter BS is provided on the optical path of the pulsed light L1. Specifically, the pulsed light L1 emitted from the light source 20 is converted into parallel light by the optical system OS and passes through the beam splitter BS.
  • the beam splitter BS is arranged to transmit or reflect incident light incident on the beam splitter BS in a predetermined direction. In this embodiment, the beam splitter BS transmits the pulsed light L1 emitted from the light source 20.
  • the MEMS (Micro Electro Mechanical Systems) mirror device 30 is provided on the optical path of the pulsed light L1. Specifically, the pulsed light L1 is applied to the MEMS mirror device 30 after passing through the optical system OS and the beam splitter BS.
  • the MEMS mirror device 30 has a reflective surface 30S that reflects the pulsed light L1.
  • the reflective surface 30S is made of, for example, a light reflecting film that reflects the pulsed light L1.
  • the MEMS mirror device 30 generates the scanning light L2 by reflecting the pulsed light L1 with a reflecting member. In addition, the MEMS mirror device 30 continuously changes the emission direction of the scanning light L2 by swinging the reflecting member.
  • the light source control unit 13 is a drive circuit that drives the light source 20.
  • the light source controller 13 has a timing table (not shown) for emitting the pulsed light L1 from the light source 20.
  • the light source control unit 13 provides a drive signal to the light source 20 with reference to the timing table.
  • the scanning control unit 14 generates a drive signal for swinging the reflecting member of the MEMS mirror device 30 and supplies the generated drive signal to the MEMS mirror device 30.
  • the reflecting member swings based on the drive signal generated by the scanning control unit 14. Therefore, the direction in which the pulsed light L1 is reflected by the MEMS mirror device 30, that is, the irradiation direction, changes sequentially.
  • the MEMS mirror device 30 reflects the pulsed light L1 to generate the scanning light L2. Specifically, the MEMS mirror device 30 generates, as first scanning light, scanning light L2 that is emitted toward a first region in a virtual surface SS1 described later. Further, the MEMS mirror device 30 generates, as the second scanning light, the scanning light L2 that is emitted toward the second region of the virtual surface SS1 described later. That is, the light source 20 and the MEMS mirror device 30 function as an optical scanning unit that scans the scanning light L2 in a predetermined irradiation direction.
  • the reflecting mirror unit 40 is a mirror member disposed in the irradiation range of the scanning light L2 generated by the MEMS mirror device 30.
  • the reflecting mirror unit 40 has a reflecting surface 41 on the surface facing the MEMS mirror device 30.
  • the scanning light L ⁇ b> 2 is reflected by the reflecting surface 41 of the reflecting mirror unit 40 and is emitted toward the scanning target region R. Accordingly, the reflecting mirror unit 40 functions as an optical path control unit (reflecting unit) that controls the optical path of the scanning light L2.
  • the scanning light L2 emitted from the MEMS mirror device 30 is directly applied to the reflecting mirror unit 40.
  • the scanning light L2 emitted from the MEMS mirror device 30 may be indirectly irradiated onto the reflecting mirror unit 40.
  • the scanning light L2 emitted from the MEMS mirror device 30 may be applied to the reflecting mirror unit 40 via an optical member such as a mirror. That is, when the scanning light L ⁇ b> 2 is indirectly applied to the reflecting mirror unit 40, the reflecting mirror unit 40 may not have the reflecting surface 41 on the surface facing the MEMS mirror device 30.
  • a virtual surface that is separated from the MEMS mirror device 30 in the scanning target region R by a predetermined distance is shown as a scanning target surface S1. Note that the scan target surface S1 does not actually exist, but is illustrated for the purpose of explaining the present embodiment.
  • the emission direction of the scanning light L2 emitted from the MEMS mirror device 30 continuously changes over time due to the oscillation of the reflective surface 30S of the MEMS mirror device 30. Accordingly, the locus of the emitted light L3 is drawn on the scanning target surface S.
  • the irradiation range with respect to the reflective mirror part 40 of the scanning light L2 is determined according to the angular range in which the reflective member of the MEMS mirror apparatus 30 can swing.
  • the emitted light L3 is reflected by the object OB.
  • the reflected light L4 obtained by reflecting the emitted light L3 by the object OB is reflected again by the reflecting surface 41 of the reflecting mirror section 40 and enters the MEMS mirror device 30.
  • the reflected light L4 reflected by the reflective surface 30S of the MEMS mirror device 30 is reflected again by the beam splitter BS and enters the light receiving unit 50.
  • the light receiving unit 50 is disposed on the optical path of the reflected light L4 reflected by the beam splitter BS.
  • the light receiving unit 50 is a photodetector that generates a light reception signal based on the intensity of light incident on the light receiving unit 50.
  • a photodetector a light receiving element such as an avalanche photodiode can be used.
  • the reflected light L4 reflected by the beam splitter BS is converted into a received light signal by the light receiving unit 50.
  • the changed received light signal is supplied to the distance measuring unit 60.
  • the distance measuring unit 60 measures the distance between the light receiving unit 50 and the object OB based on the pulsed light L1 emitted from the light source 20 and the reflected light L4 received by the light receiving unit 50.
  • the distance measuring unit 60 includes a signal processing circuit, and calculates distance data of the object OB by calculation.
  • a time-of-flight method can be used.
  • the light source control unit 13 supplies an emission signal including the time (timing) when the light source 20 emits the pulsed light L1 to the distance measuring unit 60.
  • the light reception signal generated by the light receiving unit 50 includes the timing at which the reflected light L4 is received.
  • the distance measuring unit 60 measures the distance from the distance measuring device 10 to the object OB based on the difference between the timing at which the light source 20 emits the pulsed light L1 and the timing at which the light receiving unit 50 receives the reflected light L4. To do.
  • FIG. 2A is a schematic top view of the MEMS mirror device 30.
  • 2B is a cross-sectional view taken along line VV in FIG. 2A.
  • the fixing portion 31 includes a fixed substrate B1 and a fixed frame B2 that is an annular frame formed on the fixed substrate B1.
  • the fixed substrate B1 has a protrusion B1P having a frame-like planar shape on the upper surface B1S of the fixed substrate B1 in a region facing the fixed frame B2, and is fixed on the protrusion B1P.
  • the frame B2 is placed.
  • the movable portion 32 is disposed inside the fixed frame B2, and includes a swing plate SY and a swing frame SX surrounding the swing plate SY.
  • a circular light reflecting film 33 is provided on the rocking plate SY as the reflecting member.
  • the upper surface of the light reflecting film 33 that is, the center of the reflecting surface 30S is described as AC.
  • the swing frame SX is connected to the fixed frame B2 by the first torsion bar TX.
  • the first torsion bar TX is a pair of long plate-like structural portions that extend along a first swing axis AX that passes through the center AC of the reflective surface 30S and extends in the in-plane direction of the reflective surface 30S.
  • the first torsion bar TX is twisted, and the swing frame SX is centered on the first swing axis AX, that is, the first swing axis AX is moved. It swings as the swing center axis.
  • the swing frame SX has a line-symmetric shape about the first swing axis AX.
  • the swing plate SY is connected to the swing frame SX by the second torsion bar TY.
  • the second torsion bar TY passes through the center AC of the light reflecting film, extends in the in-plane direction of the reflecting surface 30S, and extends along the second swing axis AY that is orthogonal to the first swing axis AX. It is a pair of elongated plate-like structural parts.
  • the second torsion bar TY is twisted, and the swing plate SY is centered on the second swing axis AY, that is, the second swing shaft AY is moved. It swings as the swing center axis.
  • the swing plate SY has a line-symmetric shape about the swing axis AY.
  • the swing plate SY swings about swing axes AX and AY orthogonal to each other.
  • the direction in which the reflecting surface 30S faces is changed by the swing of the swing plate SY.
  • the movable portion 32 is connected to the fixed frame B2, and the fixed portion B2 is placed on the protruding portion B1P of the fixed substrate B1. Therefore, the movable part 32 is separated from the upper surface B1S of the fixed substrate B1.
  • the swing frame SX swings about the swing axis AX and the swing plate SY swings about the swing axis AY
  • the movable portion 32 swings so as to tilt with respect to the fixed frame B2.
  • the protruding portion B1P is formed with a sufficient height such that the movable portion 32 does not contact the upper surface B1S due to the swinging.
  • the fixed frame B2 and the movable portion 32 may have an integrated structure formed by processing from one semiconductor substrate.
  • the driving force generator 34 includes a permanent magnet MG1 and a permanent magnet MG2 disposed outside the protrusion B1P on the fixed substrate B1, and a metal drawn around the outer periphery of the swing frame SX on the swing frame SX.
  • a wiring (first coil) CX and a metal wiring (second coil) CY routed along the outer periphery of the swing plate SY on the swing plate SY are included.
  • Permanent magnet MG1 is a pair of magnet pieces arranged on swinging axis AX and provided to face each other with movable part 32 interposed therebetween.
  • the permanent magnet MG2 is a pair of magnet pieces that are arranged on the swing axis AY and are opposed to each other with the movable portion 32 interposed therebetween. Therefore, in this embodiment, four magnet pieces are arranged so as to surround the movable portion 32.
  • the two magnet pieces constituting the permanent magnet MG1 are arranged so that the portions having opposite polarities are opposed to each other.
  • the two magnet pieces constituting the permanent magnet M2 are arranged such that portions having opposite polarities are opposed to each other.
  • the scanning control unit 14 is connected to the metal wirings CX and CY.
  • the scanning control unit 14 supplies current (drive signal) to the metal wirings CX and CY.
  • the driving force generator 34 generates an electromagnetic force that swings the swing frame SX and the swing plate SY of the movable unit 32 by applying the drive signal.
  • FIG. 3 shows a mode in which the scanning light L2 is emitted from the MEMS mirror device 30.
  • the pulsed light L1 when the pulsed light L1 is incident on the MEMS mirror device 30, it is reflected by the reflective surface 30S to generate the scanning light L2.
  • the reflecting mirror unit 40 is arranged in a spatial region in the irradiation direction as viewed from the MEMS mirror device 30.
  • the position of the swing plate SY when no voltage is applied to the MEMS mirror device 30 is defined as a reference position.
  • the optical axis AZ is the axis of the scanning light L2 at which the pulsed light L1 is reflected by the reflecting surface 30S at the reference position of the swing plate SY.
  • FIG. 3 it is assumed that the scanning light L ⁇ b> 2 is transmitted through the reflecting mirror portion 40 in the emission direction of the scanning light L ⁇ b> 2 emitted from the MEMS mirror device 30 and behind the reflecting surface 41 of the reflecting mirror portion 41.
  • a virtual plane SS1 which is a scanning plane in this case is shown.
  • transmitted light L2 ' that is the scanning light L2 when the scanning light L2 is assumed to pass through the reflecting mirror section 40 is depicted. Note that the virtual surface SS1 and the transmitted light L2 'do not actually exist, but are illustrated for explanation of the present embodiment.
  • the virtual surface SS1 has a first region and a second region that are adjacent to each other.
  • the first region is a region to which transmitted light L2 'transmitted through a first reflecting surface 41L described later is irradiated.
  • the second region is a region irradiated with transmitted light L2 'that has passed through a second reflecting surface 41R described later.
  • FIG. 4 shows the relationship between the drive signals DX and DY generated by the scanning control unit 14 when the MEMS mirror device 30 performs the Lissajous scanning, and the scanning locus of the scanning light L2 scanned by the MEMS mirror device 30 based on this. Is schematically shown.
  • the drive signal DX will be described as a drive signal generated by the scanning control unit 14 and supplied to the metal wiring CX.
  • the swing frame SX swings around the swing axis AX.
  • the drive signal DY will be described as a drive signal generated by the scanning control unit 14 and supplied to the metal wiring CY.
  • the swing plate SY swings around the swing axis AY.
  • FIG. 4A shows a scanning locus TR of the transmitted light L2 'drawn on the virtual surface SS1 shown in FIG. AX1 and AY1 in the figure correspond to the swing axis AX and the swing axis AY of the MEMS mirror device 30, respectively. That is, the swing of the MEMS mirror device 30 about the swing axis AX corresponds to the change in the scanning position in the direction along AY1 in the virtual plane SS1. Further, the swing of the MEMS mirror device 30 about the swing axis AY corresponds to a change in the scanning position in the AX1 direction on the virtual surface SS1.
  • FIG. 4B schematically shows the waveform of the drive signal DX at the time of the Lissajous scanning shown in FIG.
  • the variable ⁇ 1 corresponds to the drive signal DX corresponding to the natural frequency of the swing frame SX and the swing plate SY supported by the fixed frame B 2 by the first torsion bar TX of the MEMS mirror device 30. It is set to be a sine wave of the frequency to be used.
  • FIG. 4C schematically shows the waveform of the drive signal DY during the Lissajous scanning shown in FIG.
  • the drive signal DY is, corresponds to the natural frequency of the oscillating plate SY of the MEMS mirror device 30, it is set this to a sine wave of a frequency to resonate.
  • the swing frame SX and the swing plate SY are swung while resonating around the swing axis AX by the drive signal DX. That is, it is driven in the resonance mode operation mode around the swing axis AX. Further, the swing plate SY is swung while resonating around the swing axis AY by the drive signal DY. Therefore, the swing plate SY swings about the swing axis AX and swings about the swing axis AY.
  • the direction in which the light reflecting film 33 faces changes according to the swing of the swing plate SY.
  • the pulsed light L1 emitted from the light source 20 is reflected by the light reflecting film 33, and is emitted toward the reflecting mirror unit 40 as the scanning light L2 while changing the emission direction according to the oscillation of the oscillation plate SY. .
  • the swing plate SY swings while resonating around the swing axis AX and the swing axis AY. Accordingly, the trajectory TR of the irradiation point (spot position) of the transmitted light L2 'on the virtual surface SS1 is drawn along the Lissajous curve.
  • a dense region having a high locus density is formed in the end region in the direction along the axis AX1 of the virtual surface SS1.
  • a sparse region having a low trajectory density is formed in the central region arranged near the center in the direction along the axis AX1 of the virtual surface SS1. That is, as the distance from the end region approaches the central region, the distance between the tracks becomes wider than that of the end region. Further, when the pulsed light L1 is emitted at equal intervals, the scanning speed is slower in the end region than in the central region, so that the spatial spacing of the pulsed light is high in the end region, and the density in the central region. Lower.
  • the reflecting mirror section 40 has a first member 40a formed in a rectangular plate shape and a second member 40b formed in a rectangular plate shape.
  • the first member 40a and the second member 40b are connected to each other via a hinge H.
  • the reflective surface 41 is provided on the surface of the first member 40a and the second member 40b facing the MEMS mirror device 30.
  • the reflecting surface 41 is made of a light reflecting film.
  • the reflection surface 41 is disposed so as to face the reflection surface 30 ⁇ / b> S of the MEMS mirror device 30.
  • the reflecting surface 41 of the reflecting mirror section 40 has a first reflecting surface 41L and a second reflecting surface 41R.
  • the first reflecting surface 41L is provided on the surface of the first member 40a facing the MEMS mirror device 30.
  • the second reflecting surface 41R is provided on the surface of the second member 40b facing the MEMS mirror device 30.
  • the second reflecting surface 41R is configured by the first member 40a.
  • the first reflecting surface 41L is configured by the second member 40b.
  • the hinge H includes a shaft SH formed along the axial direction of the rotation axis AR1, a first connecting portion (not shown) that is rotatable around the axis of the shaft SH, and an axis around the shaft SH.
  • a second connection portion (not shown) that is rotatable and provided at a predetermined angle with the first connection portion.
  • the 1st member 40a of the reflective mirror part 40 is connected to the 1st connection part, and the 2nd member 40b of the reflective mirror part 40 is connected to the 2nd connection part. That is, the second reflecting surface 41R and the first reflecting surface 41L are connected so as to be rotatable with respect to each other.
  • the first connecting portion and the second connecting portion include a stopper (not shown) that can be fixed at a desired angular position formed by the first member 40a and the second member 40b.
  • the first member 40a and the second member 40b are connected to each other via the hinge H. Accordingly, the second reflecting surface 41R and the first reflecting surface 41L are variable in angle with respect to each other, and the second reflecting surface 41R and the first reflecting surface are controlled by an actuator (not shown) controlled by the reflecting mirror control unit 15. The angle with the surface 41L can be controlled.
  • FIG. 5 shows an aspect of the scanning light L2 reflected by the reflecting mirror unit 40 as viewed from the direction along the axis AR1 of the reflecting mirror unit 40.
  • the thickness of the arrow in the figure depends on the density of the trajectory. That is, a thick arrow indicates that the locus density is high, and a thin arrow indicates that the locus density is low.
  • first scanning light L2F the scanning light L2 traveling toward the first reflecting surface 41L
  • second scanning light L2S the scanning light L2 traveling toward the second reflecting surface 41R.
  • the scanning light L2S emitted at one maximum oscillation angle.
  • the ray is L2R
  • the ray of the scanning light L2F emitted at the other maximum swing angle is L2L.
  • the angle formed by the two rays L2R and L2L that is, the irradiation angle that is the irradiation range of the scanning light L2 around the oscillation axis AY is defined as an angle ⁇ .
  • the angle facing the emitting direction of the emitted light L3 is defined as an angle D1.
  • the angle D1 is an angle formed by the first reflecting surface 41L and the second reflecting surface 41R with respect to the incident direction of the first scanning light L2F or the second scanning light L2S to the reflecting mirror section 40. is there.
  • An angle obtained by subtracting the angle D1 from 180 degrees is defined as an angle Y.
  • the two first reflecting surfaces 41L and the second reflecting surface 41R are arranged so as to be line symmetric with respect to the optical axis AZ.
  • An example of setting the angle formed by the first reflecting surface 41L and the second reflecting surface 41R is that the angle D1 is smaller than a flat angle (180 degrees).
  • the scanning light L2R is reflected by the second reflecting surface 41R, it is emitted in the same direction as the axis AZ on the projection surface of FIG. 5 viewed from the direction along the axis AR1.
  • the scanning light L2L is reflected by the first reflecting surface 41L, the scanning light L2L is emitted in the same direction as the axis AZ on the projection surface of FIG. 5 viewed from the direction along the axis AR1.
  • the outgoing light L3 reflected by the reflecting mirror section 40 is emitted toward the scanning target region R.
  • the light beam L3 is emitted toward the scanning target region R so that the density of the locus of the outgoing light L3 is high in the central region of the scanning target surface S1. That is, of the scanning trajectory TR drawn by the transmitted light L2 ′ on the virtual surface SS1, the scanning light L2 depicting a dense region having a high trajectory density is directed toward the central region of the scanning target region R, and the sparseness having a low trajectory density is obtained.
  • the angles of the second reflecting surfaces 41R and 41L are set so that the scanning light L2 that draws the region (the central portion in the scanning locus TR) is directed toward the end of the scanning target region R.
  • the optical path of the emitted light L3 reflected by the first reflecting surface 41L is set so as to go directly to the scanning target region R.
  • the optical path of the emitted light L3 reflected by the first reflecting surface 41L may not be an optical path directly toward the scanning target region R.
  • an optical member such as a mirror is provided between the reflecting mirror section 40 and the scanning target region R, and the light path is indirectly set so that the emitted light L3 reflected by the first reflecting surface 41L is directed to the scanning target region R. It may be set.
  • the optical path of the outgoing light L3 reflected by the second reflecting surface 41R may not be an optical path directly toward the scanning target region R.
  • an optical member such as a mirror may be provided between the reflecting mirror section 40 and the scanning target region R, and the optical path may be set indirectly so that the emitted light L3 is directed to the scanning target region R.
  • FIG. 6 shows an emission mode of the scanning light L2 reflected by the reflecting mirror section 40 as viewed from the direction along the axis AR1.
  • the thickness of the arrow in the figure depends on the density of the trajectory. That is, a thick arrow indicates that the locus density is high, and a thin arrow indicates that the locus density is low.
  • the distance between the MEMS mirror device 30 and the reflecting mirror unit 40 is very short compared to the distance between the scanning target surface S1 and the reflecting mirror unit 40. Therefore, it can be said that the scanning light L2 is emitted from the reflecting mirror portion 40, that is, the light emission point, when viewed macroscopically.
  • the scanning light L2 reflected by the reflecting mirror section 40 is irradiated toward the scanning target surface S1. Specifically, the scanning light L2 is irradiated so that the locus density is highest in the central region of the scanning target surface S1. Further, the scanning light L2 is irradiated so that the density gradually decreases toward the end region along the axis AX1 of the scanning target surface S1.
  • FIG. 7 shows the locus of the scanning light L2 irradiated on the scanning plane S1 in FIG.
  • the scanning target surface S ⁇ b> 1 is reflected by the scanning locus region S ⁇ b> 1 ⁇ / b> L drawn by the scanning light L ⁇ b> 2 reflected by the second reflecting surface 41 ⁇ / b> R of the reflecting surface 41 and the first reflecting surface 41 ⁇ / b> L of the reflecting surface 41.
  • a scanning locus region S1R drawn by the scanned light L2 is shown.
  • the locus of the scanning light L2 reflected by the second reflecting surface 41R of the reflecting surface 41 is drawn in the scanning region S1L with the positional relationship reversed.
  • the locus of the scanning light L2 reflected by the first reflecting surface 41L is drawn in the scanning region S1R with the positional relationship reversed. That is, in the locus of the scanning light L2 irradiated to the scanning surface S1, the positional relationship between the sparse region and the dense region of the locus changes from the positional relationship in the reflecting mirror unit 40.
  • the reflecting mirror unit 40 can change the positional relationship between the first scanning region Ra and the second scanning region Rb.
  • a sparse region having a low trajectory density of the scanning light L2 is disposed in the central region, and a dense region having a high trajectory density of the scanning light L2 is disposed in the end region.
  • scanning light L2 that describes a dense region having a high trajectory density in the virtual surface SS1 is disposed in the central region of the scanning surface target S1, and the end region of the scanning target surface S1 is in the virtual surface SS1.
  • Scanning light L2 depicting a sparse region with a low locus density is disposed.
  • FIG. 8 shows a scanning locus region S1L and a scanning locus region S1R of the scanning target surface S1 in FIG. That is, of the scanning trajectory regions S1L and S1R, the regions with dense scanning trajectories partially overlap.
  • FIG. 8 shows a scanning locus region in which a range in which the scanning locus region S1L and the scanning locus region S1R overlap each other (hereinafter referred to as an overlapping range) is set small. In the overlap range, the distance measuring device 10 can obtain data of both the scanning locus area S1L and the scanning locus area S1R.
  • the distance measuring device 10 measures data in the other area even if some data may not be obtained in any one of the areas S1L and S1R of the scanning trajectory in the overlap range. It can be used for distance. For this reason, it is possible to reliably obtain distance measurement data in the overlap range.
  • FIG. 9 shows a scanning locus region S1L and a scanning locus region S1R of the scanning plane S1 in FIG.
  • a scanning locus region in which the overlap range is set large is shown.
  • the distance measuring device 10 can obtain data of both the scanning locus area S1L and the scanning locus area S1R.
  • the overlap range becomes larger, the number of scanning lights L2 irradiated on the range also increases. Therefore, it is possible to improve the detection rate of the object OB in the overlap range.
  • the light source control unit 13 may perform control so that the scanning light L2 is not irradiated onto the hinge H.
  • the angle formed between the second reflecting surface 41R irradiated with the two scanning lights L2 emitted at the maximum swing angle around the axis AX and the first reflecting surface 41L changes.
  • the reflecting mirror part 40 was configured.
  • the reflecting mirror portion is changed so that the angle formed between the second reflecting surface 41R irradiated with the two scanning lights L2 emitted at the maximum swing angle around the axis AY and the first reflecting surface 41L changes.
  • 40 may be configured.
  • the reflecting mirror unit 40 When the reflecting mirror unit 40 is configured in this way, it is possible to scan by changing the positional relationship between the dense and sparse regions of the locus formed in the axis AY1 direction (or the axis AX1 direction).
  • the hinges H of the reflecting mirror part 40 may be provided at a plurality of locations.
  • the reflecting mirror unit 40 may be configured by combining two reflecting surfaces 41 having different directions in which the angles formed by the second reflecting surface 41R and the first reflecting surface 41L described above are different from each other.
  • two scanning lights emitted at the maximum swing angle of the swing plate SY of the MEMS mirror device 30 or the maximum swing angle of the swing plate SX are L2R and L2L. There is no denying that light is not emitted in the vicinity of the maximum oscillation angle and is emitted within a maximum emission angle smaller than the maximum oscillation angle. In this case, the two scanning lights emitted at the maximum emission angle may be read as L2R and L2L.
  • the reflecting mirror unit 40 When the reflecting mirror unit 40 is configured in this way, scanning can be performed while changing the positional relationship between the dense and sparse regions of the locus formed in the directions of the axes AX1 and AY1.
  • the setting condition of the first member 40a and the second member 40b of the reflector part 40 (that is, the first member 40a and the first member 40b of the reflector part 40) is set.
  • the angle formed by the second member 40b) can be freely changed.
  • the scanning light L2 is reflected by the reflecting mirror unit 40, thereby making it possible to scan by changing the positional relationship between the dense region and the sparse region.
  • the scanning light L2 is reflected by the reflecting mirror unit 40, so that the positional relationship between the dense region and the sparse region can be changed and scanned.
  • the dense region of the region and the region S1R, the dense region of the region S1L, and the sparse region of the region S1R are bulky and overlap with each other, and in the multiple of ⁇ / 4 ⁇ Y ⁇ / 2, A part of the dense region overlaps.
  • the distance measuring apparatus of the present embodiment it is possible to perform distance measurement by a scanning mode having a desired density distribution locus in the scanning target region R which is a region for distance measurement. For this reason, it is possible to obtain a good distance measurement state, and it is possible to perform the distance measurement of the object OB in the scanning target region R with higher accuracy.
  • the angle D1 changes within 180 degrees with respect to the angle facing the emission direction of the emitted light L3 among the angles formed by the second reflection surface 41R and the first reflection surface 41L.
  • the angle D1 may be further changed to 180 degrees or more.
  • FIG. 10 shows an aspect of the scanning light L2 reflected by the reflecting mirror section 40 as viewed from the direction along the axis AR1 of the reflecting mirror section 40.
  • the thickness of the arrow in the figure depends on the density of the trajectory. That is, a thick arrow indicates that the locus density is high, and a thin arrow indicates that the locus density is low.
  • first scanning light L2F the scanning light L2 traveling toward the first reflecting surface 41L
  • second scanning light L2S the scanning light L2 traveling toward the second reflecting surface 41R.
  • the reflecting surface 41 of the reflecting mirror section 40 is configured so that the emitted light L3 reflected by the second reflecting surface 41R and the emitted light L3 reflected by the first reflecting surface 41L are emitted in directions away from each other. Is formed.
  • the two first reflection surfaces 41L and the second reflection surface 41R of the reflection surface 41 have an angle D1 that faces the MEMS mirror device 30 out of angles relative to each other larger than a flat angle (180 degrees). It has become.
  • An angle obtained by subtracting the angle D1 from 180 degrees is defined as an angle Y.
  • the angle Y is a negative value Y ⁇ 0.
  • the outgoing light L3 reflected by the reflecting mirror section 40 is emitted toward the scanning target region R.
  • the scanning target region R includes a first scanning region Ra and a second scanning region Rb that are spaced apart from each other.
  • the first scanning region Ra and the second scanning region Rb are separated from each other in the direction along the swing axis AX or the axis AY of the reflecting member of the MEMS mirror device 30.
  • the optical path of the emitted light L3 reflected by the first reflecting surface 41L is directed to the first scanning region Ra in the scanning target region R. Further, the optical path of the emitted light L3 reflected by the second reflecting surface 41R is directed to the second scanning region Rb.
  • the size of the angle D1 defines the interval between the first scanning region Ra and the second scanning region Rb, and the larger the angle D1, the wider the interval between the regions Ra and Rb.
  • the magnitude of the irradiation angle ⁇ with respect to the reflecting mirror section 40 of the MEMS mirror device 30 is the first scanning region Ra and the second scanning region. This is reflected in the size of Rb.
  • FIG. 11 shows an emission mode of the scanning light L2 reflected by the reflecting mirror section 40 as viewed from the direction along the axis AR1.
  • the thickness of the arrow in the figure depends on the density of the trajectory. That is, a thick arrow indicates that the locus density is high, and a thin arrow indicates that the locus density is low.
  • the distance between the MEMS mirror device 30 and the reflecting mirror unit 40 is very short compared to the distance between the scanning target surface S and the reflecting mirror unit 40. Therefore, it can be said that the scanning light L2 is emitted from the reflecting mirror portion 40, that is, the light emission point, when viewed macroscopically.
  • the scanning light L2 reflected by the reflecting mirror unit 40 is emitted toward the scanning target surface S as outgoing light L3.
  • the scanning target surface S includes a first scanning surface Sa disposed on the first scanning region Ra side and a second scanning surface Sb disposed on the second scanning region Rb side.
  • the outgoing light L3 obtained by reflecting the scanning light L2 on the first reflecting surface 41L is irradiated toward the first scanning region Ra.
  • the emitted light L3 reflected by the scanning light L2 by the second reflecting surface 41R is irradiated toward the second scanning region Rb.
  • FIG. 12 shows the locus of the emitted light L3 irradiated on the scanning target surface S in FIG.
  • the scanning target surface S is reflected by the region S1L where the scanning locus is drawn by the emitted light L3 reflected by the second reflecting surface 41R of the reflecting surface 41 and the first reflecting surface 41L of the reflecting surface 41.
  • a region S1R in which a scanning locus is drawn by the emitted light L3 is shown.
  • the reflecting surface 41 is bent so that the angle D1 between the first reflecting surface 41L and the second reflecting surface 41R facing the MEMS mirror device 30 is 180 degrees or more, that is, Y ⁇ 0.
  • the first scanning region Ra and the second scanning region Rb in different directions are scanned.
  • the MEMS mirror device 30 scans when the scanning target region R is scanned by emitting the scanning light L2 at the maximum swing angle around the axis AX or AY of the light reflecting surface 30S. It is possible to scan the first scanning region Ra and the second scanning region Rb, which are regions that cannot be separated from each other.
  • the distance measuring device 10 of the present invention scans the scanning target region R by reflecting the scanning light L2 emitted from the MEMS mirror device 30 with the reflecting mirror unit 40.
  • the optical path of the outgoing light L3 reflected by the second reflecting surface 41R is set so as to be directed to the first scanning region Ra in the scanning target region R. Further, the optical path of the emitted light L3 reflected by the first reflecting surface 41L is set so as to go to the second scanning region Rb.
  • the MEMS mirror device 30 scans the scanning target region R by emitting the scanning light L2 at the maximum swing angle around the first swing axis AX or the second swing axis AY of the light reflecting surface 30S.
  • the MEMS mirror device 30 scans the first scanning region Ra and the second scanning region Rb that are separated from each other, which are regions that cannot be scanned.
  • the first scanning region Ra and the second scanning region Rb that are separated from each other can be scanned by one MEMS mirror device 30.
  • the first scanning region Ra and the second scanning region Rb are set under the condition that the angle D1 between the first reflecting surface 41L and the second reflecting surface 41R is 180 degrees or more, that is, Y ⁇ 0. Said about the separation. Even if Y> ⁇ / 2 in the configuration of the first embodiment, the first scanning region Ra and the second scanning region Rb can be separated from each other, and this is not denied. In this case, when viewed macroscopically, the first scanning region Ra and the second scanning region Rb are reversed.
  • Example 1 the first member 40a and the second member 40b of the reflecting mirror part 40 are connected via a hinge H.
  • the configuration of the reflecting mirror section 40 is not limited to the configuration as long as the second reflecting surface 41R and the first reflecting surface 41L have relatively variable angles with respect to each other.
  • FIG. 13 shows a configuration example of the reflecting mirror unit 40 according to the present embodiment.
  • the reflecting mirror part 40 shown in FIG. 13 is different from the reflecting mirror part 40 shown in FIG. Since other configurations are the same, the same reference numerals are given and description thereof is omitted.
  • the first member 40a has a rod-shaped first shaft SH1 formed along the axial direction of the first rotation axis AR1.
  • One end of the first shaft SH1 is connected to an actuator (not shown), and is rotatable around the first rotation axis AR1. That is, the first member 40a is configured to be rotatable around the axis of the first shaft SH1.
  • the second reflecting surface 41R is provided so as to be rotatable about the first rotation axis AR1.
  • the second member 40b has a second shaft SH2 formed along the axial direction of the second rotation axis AR2 parallel to the first rotation axis.
  • One end of the second shaft SH2 is connected to an actuator (not shown) and is rotatable around the second rotation axis AR2.
  • the second member 40b is configured to be rotatable around the axis of the second shaft SH2.
  • the first reflecting surface 41L is provided to be rotatable about the second rotation axis AR2.
  • a gap may be provided between the first member 40a and the second member 40b so as not to prevent the rotation of each member.
  • the light source control unit 13 may control so that the gap between the first member 40a and the second member 40b is not irradiated with the scanning light L2.
  • the first rotation axis AR1 is provided on the proximal side when viewed from the second member 40b of the first member 40a.
  • the second rotation axis AR2 may be provided on the proximal side when viewed from the first member 40 of the second member 40b.
  • the gap between the first member 40a and the second member 40b is: It is preferable to provide at least the spot diameter of the scanning light L2.
  • the first member 40a and the second member 40b are rotated using an actuator.
  • the mechanism for rotating the first member 40a and the second member 40b is not limited to the actuator, and may be, for example, an electromagnetic mechanism.
  • the setting conditions for the first member 40a and the second member 40b of the reflecting mirror section 40 can be freely changed. In other words, it is possible to perform scanning and ranging according to the situation.
  • the scanning light L2 is reflected by the reflecting mirror unit 40, thereby changing the positional relationship between the dense region and the sparse region. It becomes possible to do.
  • scanning can be performed so that the scanning locus region S1L and the scanning locus region S1R overlap each other.
  • the first scanning region Ra and the second scanning region Rb that are separated from each other can be scanned by one MEMS mirror device 30. .
  • the angle of the second reflecting surface 41R and the first reflecting surface 41L of the reflecting mirror section 40 relative to each other is variable, and the angle is obtained by being driven by an actuator (not shown). Can be changed dynamically. Accordingly, by changing the angles of the second reflecting surface 41R and the first reflecting surface 41L, the density distribution of the scanning trajectory in the scanning target region R is changed (when the angle D1 is smaller than the flat angle), or scanning. Can be changed (when the angle D1 is larger than the flat angle).
  • the distance measuring device 10 changes the overlap of the scanning trajectory by adjusting the angles of the second reflecting surface 41R and the first reflecting surface 41L according to the surrounding environment and the purpose of use, for example. Also good. Specifically, when the distance measuring device 10 is mounted on a moving body, it is necessary to perform a detailed distance measuring operation on the central portion (front portion) as viewed from the distance measuring device 10 in the scanning target region R. In a case (for example, when the moving body travels on a highway or moves at a high speed), the scanning locus region S1L and the scanning locus region S1R are scanned so as to overlap each other.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Mechanical Optical Scanning Systems (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

L'invention concerne un dispositif de balayage permettant de mesurer la distance à l'intérieur d'une région de mesure de distance au moyen d'un mode de balayage présentant un lieu de distribution de densité souhaitée. Ledit dispositif de balayage comprend : une unité d'émission qui émet de la lumière; une unité de balayage optique qui transmet la lumière vers une première région et une seconde région adjacentes l'une à l'autre, par le changement cyclique de la direction de transmission de la lumière; et une unité de commande de trajet optique qui guide une première lumière de balayage vers une première région de balayage, ladite première lumière de balayage ayant été transmise depuis la partie de balayage optique vers la première région, et qui guide une seconde lumière de balayage vers une seconde région de balayage, ladite seconde lumière de balayage ayant été transmise vers la seconde région. L'unité de commande de trajet optique est conçue de façon à pouvoir modifier la relation de position de la première région de balayage et de la seconde région de balayage par le changement du trajet optique de la première lumière de balayage et de la seconde lumière de balayage.
PCT/JP2019/002155 2018-01-30 2019-01-24 Dispositif de balayage et dispositif de mesure de distance WO2019151092A1 (fr)

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JP2018-014015 2018-01-30

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5757501A (en) * 1995-08-17 1998-05-26 Hipp; Johann Apparatus for optically sensing obstacles in front of vehicles
JP2004528583A (ja) * 2001-06-05 2004-09-16 イーベーエーオー アウトモビール センサー ゲーエムベーハー 検出法および検出装置
JP2010151809A (ja) * 2008-11-26 2010-07-08 Denso Wave Inc レーザレーダ装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5757501A (en) * 1995-08-17 1998-05-26 Hipp; Johann Apparatus for optically sensing obstacles in front of vehicles
JP2004528583A (ja) * 2001-06-05 2004-09-16 イーベーエーオー アウトモビール センサー ゲーエムベーハー 検出法および検出装置
JP2010151809A (ja) * 2008-11-26 2010-07-08 Denso Wave Inc レーザレーダ装置

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