WO2019124177A1 - Optical scanning device and distance measuring device - Google Patents

Optical scanning device and distance measuring device Download PDF

Info

Publication number
WO2019124177A1
WO2019124177A1 PCT/JP2018/045606 JP2018045606W WO2019124177A1 WO 2019124177 A1 WO2019124177 A1 WO 2019124177A1 JP 2018045606 W JP2018045606 W JP 2018045606W WO 2019124177 A1 WO2019124177 A1 WO 2019124177A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
scanning
unit
region
area
Prior art date
Application number
PCT/JP2018/045606
Other languages
French (fr)
Japanese (ja)
Inventor
琢也 白戸
佐藤　充
Original Assignee
パイオニア株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パイオニア株式会社 filed Critical パイオニア株式会社
Publication of WO2019124177A1 publication Critical patent/WO2019124177A1/en

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C3/00—Measuring distances in line of sight; Optical rangefinders
    • G01C3/02—Details
    • G01C3/06—Use of electric means to obtain final indication
    • 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
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/87—Combinations of systems using electromagnetic waves other than radio waves
    • 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
    • G01S7/483—Details of pulse systems
    • G01S7/484—Transmitters
    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/16—Anti-collision systems

Definitions

  • the present invention relates to an optical scanning device that performs optical scanning and a distance measuring device that performs optical distance measurement.
  • the distance measuring device is configured to measure the distance to the object by irradiating the light to the object in the scanning area and detecting the light reflected by the object.
  • a distance measuring apparatus which has an optical scanning unit which two-dimensionally scans and which obtains two-dimensional distance measurement results in the scanning region.
  • the light scanning type distance measuring apparatus includes, for example, a MEMS (Micro Electro Mechanical Systems) mirror as a light scanning unit, a light source for irradiating light to the mirror, and a light receiving unit for receiving reflected light from the object to be measured.
  • the light scanning unit two-dimensionally scans the scanning region using the light reflected by the mirror.
  • Patent Document 1 discloses a radar apparatus that has a scanning unit that emits a transmission wave in a predetermined range, and detects the distance and direction to a target.
  • the light scanning unit of the distance measuring apparatus sequentially emits, for example, pulsed laser light to the scanning region, and receives reflected light from the object to obtain optical scanning information (hereinafter referred to as optical scanning information). get.
  • optical scanning information hereinafter referred to as optical scanning information.
  • the distance measuring device measures the distance to the object based on the light scanning information, for example, the time taken from irradiation to light reception.
  • the distance measuring apparatus be configured to accurately scan the scanning region and measure the distance of the object in consideration of the case where the device is placed under various environments. For example, in an environment where accurate distance measurement information is difficult to obtain, when the light reflectance of the object is extremely low or high, the object is at a very distant position or near position from the distance measuring device, or irradiation There is a case where the intensity of ambient light other than the one to be used, such as sunlight, is high.
  • the intensity of the reflected light from the object may be reduced and buried in the ambient light, resulting in a decrease in the signal to noise ratio.
  • the intensity of the reflected light may be too high, and the light reception signal may be saturated.
  • the distance measuring apparatus can acquire light scanning information in the scanning area accurately even when placed in such an environment, for example. In addition, similarly, it is preferable that the distance measuring apparatus can accurately perform distance measuring operation in the scanning region and obtain accurate distance measuring information.
  • the present invention has been made in view of the above-described point, and an optical scanning device capable of performing accurate optical scanning in a scanning area and accurate ranging of an object in the scanning area can be performed.
  • One of the problems is to provide a range finder.
  • the invention according to claim 1 is characterized in that the light source section for emitting the emitted light, the scanning section for scanning the predetermined area with the emitted light, and the reflected light reflected by the object whose emitted light is present in the predetermined area And a recognition unit that recognizes a situation in the predetermined area prior to scanning of the predetermined area by the scanning unit, and a situation in the predetermined area based on the situation recognized by the recognition unit. And a control unit that controls the light source unit so as to change the emission mode of the emitted light with respect to the area of the unit.
  • a light source section for emitting emitted light
  • a scanning section for scanning a predetermined area by the emitted light, and reflected light reflected by an object whose emitted light is present in the predetermined area.
  • the light receiving unit Prior to the scanning of the predetermined area by the scanning unit, the light receiving unit generating the light reception signal according to the light reception signal, the distance measuring unit measuring the distance to the object based on the light reception signal, and recognizing the situation in the predetermined region It has a recognition part and a control part which controls a light source part so that a radiation mode of outgoing radiation to a partial field in a predetermined field may be changed based on a situation which a recognition part recognized. .
  • FIG. 2 is a layout view of a distance measuring apparatus according to a first embodiment.
  • FIG. 5 is a block diagram of a control unit in the distance measuring apparatus according to the first embodiment.
  • FIG. 6 is a top view of a scanning unit in the distance measuring apparatus according to the first embodiment.
  • FIG. 5 is a cross-sectional view of a scanning unit in the distance measuring apparatus according to the first embodiment.
  • FIG. 5 is a diagram showing a waveform of a drive signal applied to a scanning unit of the distance measuring apparatus according to the first embodiment and a locus of scanning light reflected by the scanning unit.
  • FIG. 7 is a diagram showing an example of distance measurement points in a signal quality deterioration region in the distance measurement apparatus according to the first embodiment.
  • FIG. 7 is a view showing another example of a distance measurement point of a signal quality deterioration region in the distance measurement apparatus according to the first embodiment.
  • FIG. 1A is a schematic layout diagram of the distance measuring apparatus 10 according to the first embodiment.
  • the distance measuring apparatus 10 performs an optical scan of a predetermined area (hereinafter referred to as a scan area) R0, and based on the scan result, measures the distance to the distance measurement object OB present in the scan area R0. It is a distance device.
  • the entire configuration of the distance measuring apparatus 10 will be described using FIG. 1A. Note that, for the sake of clarity of the drawing, the scanning region R0 and the distance measurement object OB are schematically shown in FIG. 1A.
  • the distance measuring apparatus 10 periodically scans the scanning region R0 with pulsed laser light (hereinafter referred to as pulsed light), and receives reflected light from the distance measuring object OB in the scanning region R0.
  • An optical scanning information acquisition unit SC that acquires optical scanning information in the scanning region R0 is included.
  • the light scanning information acquisition unit SC includes a light source unit 11 that generates and emits the emission light L1 that is pulse light.
  • the light source unit 11 includes a laser device that generates laser light having a peak wavelength in the infrared region as the emitted light L1.
  • the light scanning information acquisition unit SC also has a scanning unit 12 that periodically scans the scanning region R0 using the outgoing light L1.
  • the scanning unit 12 has a movable light reflecting surface 12A that reflects the emitted light L1 toward the scanning region R0.
  • the scanning unit 12 has a movable mirror provided with the light reflecting surface 12A.
  • the scanning unit 12 changes the direction of the light reflection surface 12A to change the direction in which the outgoing light L1 is reflected continuously and periodically.
  • the scanning unit 12 performs light scanning of the scanning region R0 using the emitted light L1 reflected by the light reflecting surface 12A as the scanning light L2.
  • the scanning region R0 has a width and a height corresponding to the movable range of the light reflecting surface 12A, and can receive reflected light of a predetermined intensity when the scanning light L2 reaches and is reflected. It is a virtual three-dimensional space having a depth corresponding to a certain distance.
  • the outer edge of the scanning region R0 is indicated by a broken line.
  • the scanning light L2 is irradiated to the ranging object OB.
  • the scanning light L2 is reflected by the distance measuring object OB.
  • the light scanning information acquisition unit SC receives and detects the light L3 reflected on the object for distance measurement (hereinafter referred to as reflected light) L3 by irradiating the object for distance measurement OB with the scanning light L2
  • the light receiving unit 13 is provided.
  • the light receiving unit 13 includes, for example, a light detector that detects light in a wavelength band including the peak wavelength of the outgoing light L1.
  • the light receiving unit 13 performs photoelectric conversion on the received reflected light L3 to generate an electric signal (hereinafter, referred to as a light receiving signal) SR according to the reflected light L3.
  • a beam splitter BS is provided on the light path of the emitted light L1 between the light source unit 11 and the light reflecting surface 12A of the scanning unit 12.
  • the scanning light L2 is reflected by the distance measurement object OB to be a reflected light L3, and returns toward the light reflecting surface 12A.
  • the reflected light L3 is reflected by the light reflecting surface 12A, separated by the beam splitter BS, and then received by the light receiving unit 13.
  • the emitted light L1 emitted by the light source unit 11 passes through the beam splitter BS and travels toward the scanning unit 12.
  • the distance measuring apparatus 10 has a distance measuring unit 14 that measures the distance to the distance measuring object OB based on the light reception signal SR.
  • the distance measuring unit 14 detects the pulse of the reflected light L3 from the light reception signal SR, and the distance measuring object OB (and part of it) by the time of flight method based on the time difference from the emission of the outgoing light L1.
  • Measure the distance to the surface area of The ranging unit 14 generates data (hereinafter, referred to as ranging data) indicating the measured distance information.
  • the distance measuring apparatus 10 has a distance measuring image generation unit 15 that performs imaging of the scanning region R0 based on the distance measuring data.
  • the distance measurement image generation unit 15 measures distance measurement image data in which the emission direction of the scanning light L2 (that is, the direction (angle) of the light reflection surface 12A in the scanning unit 12) is associated with the distance measurement data generated by the distance measurement unit 14 Generate
  • the distance measurement image generation unit 15 generates one distance measurement image data for each scanning cycle of the scanning unit 12.
  • the scan cycle is again from the time of an arbitrary scan state (for example, the direction of the light reflection surface 12A that emits the scan light L2) It refers to the period until it returns to the state.
  • the operation of the distance measuring apparatus 10 in one scanning cycle and one distance measuring image data obtained thereby are referred to as a frame.
  • the distance measurement image generation unit 15 may have a display unit (not shown) that displays a plurality of distance measurement image data as a moving image in time series.
  • the distance measuring unit 14 sets a predetermined area in the scanning area R0 as an effective scanning area (or a distance measuring area), and corresponds to the scanning light L2 emitted toward the effective scanning area. Based on the light reception signal SR of the reflected light L3, the distance to the distance measurement object OB is measured.
  • a virtual surface separated by a predetermined distance from the scanning unit 12 in the scanning region R0 is referred to as a scanning surface (scanning surface) R1.
  • the effective scanning area is an area (space) excluding the outer edge portion of the scanning area R0, and in FIG. 1A, the effective scanning area is an inner area excluding the outer edge portion of the scanning surface R1. It illustrated as field R2.
  • the distance measuring operation of the distance measuring unit 14 is performed using the scanning light L2 emitted toward the effective scanning surface R2 which is a part of the virtual scanned surface.
  • the distance measuring apparatus 10 includes a recognition unit 16 that recognizes a situation in the scanning region R0 or a partial region thereof (hereinafter referred to as a recognition region) R3.
  • the recognition unit 16 includes, for example, an imaging device that performs imaging with the recognition region R3 as an imaging range.
  • the imaging device is, for example, an infrared camera.
  • the recognition unit 16 includes an object detection device that sets the recognition area R3 as a detection range. In FIG. 1A, the recognition area R3 is schematically shown by a broken line.
  • the scanning unit 12 and the recognition unit 16 are configured such that the scanning region R0 and the recognition region R3 are substantially the same. That is, the position of the distance measuring object OB in the effective scanning surface R2 viewed from the scanning unit 12 and the position of the distance measuring object OB in the effective scanning surface R2 viewed from the recognition unit 16 match as much as possible. Is preferred.
  • the recognition unit 16 outputs, for example, information indicating the captured image or the position and size of the detected object as recognition information. Further, in the present embodiment, the recognition unit 16 periodically performs the recognition operation of the recognition region R3 in the same cycle as the scanning cycle of the scanning unit 12, and generates the above-described recognition information for each cycle. For example, when the recognition unit 16 includes an imaging device, the imaging device captures an image of the recognition area R3 during each scanning cycle of the scanning unit 12, and outputs the captured image before the end of each scanning cycle.
  • the distance measuring apparatus 10 is a control unit that performs operation control of the light scanning information acquisition unit SC (including the light source unit 11, the scanning unit 12, and the light receiving unit 13), the distance measuring unit 14, the distance measuring image generating unit 15, and the recognition unit 16. It has seventeen.
  • the control unit 17 supplies a drive signal (light source drive signal) DL to the light source unit 11, and drives and controls the light source unit 11.
  • the drive signal DL is also supplied to the distance measuring unit 14, and the distance measuring unit 14 is used to know the emission timing of the outgoing light L1.
  • the control unit 17 supplies drive signals (first and second MEMS drive signals) DX and DY to the scanning unit 12 to drive the scanning unit 12 and control the same.
  • FIG. 1B is a block diagram of the control unit 17.
  • the control unit 17 includes a scanning trajectory determination unit 17A that acquires information indicating the scanning condition of the scanning unit 12 from the optical scanning information acquisition unit SC and determines the actual trajectory of the scanning light L2.
  • the scanning track determination unit 17A acquires, for example, an output value of a swing position sensor (not shown) connected to the scanning unit 12 or to the scanning unit 12 and determines which direction the scanning light L2 is directed (effective scanning surface It is determined which position in R2 is irradiated.
  • the scanning trajectory determination unit 17A may determine the trajectory of the scanning light L2 by acquiring the MEMS drive signals DX and DY of the scanning unit 12 instead of the output value of the rocking position sensor.
  • the control unit 17 includes a recognition information acquisition unit 17B that acquires recognition information of the status of the scanning region R0 from the recognition unit 16.
  • the recognition information acquisition unit 17B acquires, for example, an image captured by an imaging device as the recognition unit 16.
  • the control unit 17 determines that the signal-to-noise ratio of the light reception signal SR in the scanning region R0 is It has the signal quality degradation area definition part 17C which defines one or more areas (hereinafter, referred to as signal degradation area) where the light reception signal RS may become low.
  • the object for distance measurement OB is present at a position very far or near from the distance measuring device 10 In the case where the intensity of the ambient light other than the scanning light L2, for example, the intensity of sunlight is large.
  • the signal quality degradation area definition unit 17 B defines a signal quality degradation area by analyzing an image acquired from the recognition unit 16, for example.
  • the imaging device included in the recognition unit 16 has a predetermined sensitivity to the wavelength of the scanning light L2. Therefore, for example, a region where the luminance value of the image obtained by the imaging device is lower or higher than a predetermined value (that is, a region where the intensity of the reflected light L3 deviates from the predetermined range) is defined as the signal quality deterioration region.
  • a predetermined value that is, a region where the intensity of the reflected light L3 deviates from the predetermined range
  • the intensity of the light reception signal SR decreases when the scanning light L2 is irradiated.
  • the intensity of the light reception signal SR is saturated when the scanning light L2 is irradiated.
  • the control unit 17 controls the emission mode of the emitted light L1 of the light source unit 11 in the scanning cycle after acquiring the definition result based on the definition result of the signal quality deterioration area by the signal quality deterioration area definition unit 17B. It has part 17D.
  • the light source control unit 17D outputs the emission light L1 to the area other than the signal quality deterioration area in the scanning area R0 (hereinafter, may be referred to as another area).
  • the light source unit 11 is controlled to change from the aspect. For example, the light source unit 11 is controlled such that the emission density or the intensity of the emission light L1 is increased relative to the signal quality deterioration region more than the other regions in the scanning region R0.
  • FIG. 2A is a schematic top view of the scanning unit 12.
  • FIG. 2B is a cross-sectional view of the scanning unit 12.
  • FIG. 2B is a cross-sectional view taken along the line VV of FIG. 2A.
  • a configuration example of the scanning unit 12 will be described with reference to FIGS. 2A and 2B.
  • the scanning unit 12 is a micro electro mechanical systems (MEMS) mirror including a light reflecting film (movable mirror) 24 having a light reflecting surface 12A, and the light reflecting film 24 swings. Further, in the present embodiment, the scanning unit 12 is configured to oscillate the light reflecting film 24 electromagnetically.
  • MEMS micro electro mechanical systems
  • the scanning unit 12 includes a fixed unit (base unit) 21, a movable unit (rocking unit) 22, a driving force generation unit 23, and a light reflecting film 24. Further, in the present embodiment, the scanning unit 12 is configured such that the light reflecting film 24 swings around two swinging axes (first and second swinging axes) AX and AY orthogonal to each other. ing.
  • the fixed portion 21 includes a fixed substrate B1 and an annular fixed frame B2 formed on the fixed substrate B1.
  • the movable portion 22 includes a pair of torsion bars (first torsion bars) TX, one end of each of which is fixed to the inside of the fixed frame B2.
  • Each of the pair of torsion bars TX is made of a rod-like elastic member having at least circumferential elasticity, and is aligned along the swing axis AX.
  • the movable portion 22 has an annular swinging frame (movable frame) SX whose outer peripheral side surface is connected to the other end of each of the pair of torsion bars TX.
  • the movable portion 22 has a pair of torsion bars (one end connected to the side surface of the inner peripheral portion of the movable frame SX) and aligned in a direction (direction along the swing axis AY) orthogonal to the pair of torsion bars TX.
  • a second torsion bar TY and an oscillating plate (movable plate) SY whose outer peripheral side surface is connected to the other end of each of the pair of torsion bars TY.
  • Each of the pair of torsion bars TY is formed of a rod-like elastic member having at least circumferential elasticity.
  • the swing frame SX swings about the swing axis AX (as a swing center), and the swing plate SY swings around the swing axes AX and AY.
  • a light reflection film 24 is formed on the rocking plate SY. Accordingly, the light reflecting surface 24A of the light reflecting film 24 swings about the swing axes AX and AY orthogonal to each other together with the swing plate SY.
  • the driving force generation unit 23 shakes the permanent magnet MG disposed on the fixed substrate B1, the metal wire (first coil) CX wired along the outer periphery of the swing frame SX on the swing frame SX, and And a metal wire (second coil) CY wired along the outer periphery of the swing plate SY on the moving plate SY.
  • the permanent magnet MG is composed of a plurality of magnet pieces provided in the outer region of the fixed frame B2 on the fixed substrate B1.
  • four magnet pieces are disposed along the swing axes AX and AY, respectively, and at positions outside the pair of torsion bars TX and TY.
  • two magnet pieces facing each other in the direction along the swing axis AX are arranged such that parts showing opposite polarities face each other.
  • the two magnet pieces facing each other in the direction along the swing axis AY are arranged such that portions exhibiting opposite polarities face each other.
  • a pair of torsion bars TX is generated by the interaction with the magnetic field generated by the two magnet pieces of the permanent magnet MG aligned in the direction along the swing axis AY. Twisting in the circumferential direction, the swing frame SX swings around the swing axis AX. Similarly, the pair of torsion bars TY is twisted by the electric field by the current flowing through the metal wire CY and the magnetic field by the two magnetic pieces of the permanent magnet MG aligned in the direction along the swing frame AX, and the swing plate SY swings. Swing around the dynamic axis AY.
  • the metal wires CX and CY are connected to the control unit 17.
  • the control unit 17 supplies the MEMS drive signals DX and DY to the metal wires CX and CY.
  • the driving force generation unit 23 generates an electromagnetic force that causes the movable portion 22 and the light reflecting film 24 to swing by application of the MEMS driving signals DX and DY.
  • the light reflecting film 24 has a disk shape.
  • the light reflection film 24 has a central axis AC orthogonal to the swing axes AX and AY.
  • the movable portion 22 and the light reflecting film 24 are formed so as to be rotationally symmetric by 90 degrees with respect to the central axis AC of the light reflecting film 24.
  • the fixed substrate B1 of the fixed portion 21 has a recess.
  • the fixed frame B2 is fixed to the fixed substrate B1 so as to suspend the movable portion 22 in the recess of the fixed substrate B1.
  • the fixed frame B2 and the movable portion 22 are parts of the semiconductor substrate formed by processing, for example, a semiconductor substrate.
  • the light reflection film 24 is swingably suspended (supported) in the recess of the fixed substrate B1 together with the swing plate SY.
  • the permanent magnet MG is formed outside the recess on the fixed substrate B1.
  • the torsion bars TX and TY are twisted, so that both ends of the movable portion 22 sandwiching the torsion bars TX and TY in the inside of the fixed frame B2 move in the direction and toward the recess of the fixed substrate B1. Swing in the direction.
  • the light reflecting film 24 swings with respect to the fixed frame B2 with one point on the central axis AC as a swing center.
  • the light scanning information acquisition unit SC scans the scanning region R0 using the scanning light L2. That is, the scanning unit 12 periodically scans the scanning region R0 at a predetermined cycle by continuously changing the emission direction of the emission light L1.
  • FIG. 3 shows MEMS drive signals (hereinafter simply referred to as drive signals) DX and DY generated by the control unit 17, changes in the swing state of the light reflecting film 24 based on these, and the scanning trajectory of the scanning light L2. It is a figure which shows typically the relationship of. The scanning aspect of scanning area R0 by the scanning part 12 is demonstrated using FIG.
  • variable theta 1 the drive signal DX is, the torsion bar TX scan units 12 are set so that the oscillating frame SX, sine wave having a frequency corresponding to the resonant frequency of the torsion bar TY and the swinging plate SY .
  • the variable theta 2 the drive signal DY is set to be a sine wave of a frequency corresponding to the resonance frequency of the torsion bar TY and the swinging plate SY scanning unit 12.
  • the light reflection film 24 (the swinging plate SY) resonates around the swing axis AX and resonates around the swing axis AY. Therefore, as shown in FIG. 3, when the scanning surface R1 of the scanning region R0 is viewed, the scanning light L2, which is the outgoing light L1 reflected by the light reflecting film 24, has a locus TR (L2) that draws a Lissajous curve.
  • the scanning unit 12 has the light reflecting surface 12A that reflects the emitted light L1 and swings about the first and second swing axes AX and AY orthogonal to each other. , And has a scanning aspect in which the scanning region R0 is scanned so as to draw a locus TR according to the Lissajous curve.
  • a distance measurement point which is a distance measurement point within the effective scanning surface R2 to which the distance measurement unit 14 measures distance, that is, a swing position (swing angle) of the light reflection surface 12A.
  • the relationship between the and the emission timing of the emission light L1 will be described.
  • 4A and 4B are enlarged views of a region R21 surrounded by a broken line in FIG. 3 in two scanning periods (frames) P1 and P2.
  • the first scan cycle P1 is a scan cycle before the signal quality degradation area is defined by the signal quality degradation area definition unit 17C, and the second scan cycle P2 is after the signal quality degradation area is defined. Scan cycle of In the following, the case where a partial area of the area R21 is defined as the signal quality deterioration area RB will be described.
  • a scanning cycle in the case where the light source unit 11 operates to emit the emitted light L1 at a constant interval (first interval) is set as a first scanning cycle P1.
  • first scanning cycle P1 a scanning cycle in the case where the light source unit 11 operates to emit the emitted light L1 at a constant interval (first interval) is set as a first scanning cycle P1.
  • each of the distance measurement points MP is an interval corresponding to the first interval and the displacement speed of the light reflecting surface 12A in the entire scanning region R0.
  • the scan cycle after the signal quality degradation area RB is defined (defined) by the signal quality degradation area definition unit 17C is set as a second scan cycle P2.
  • the light source control unit 17D changes the emission density or the intensity of the emitted light L1 by the light source unit 11 at the timing of scanning the signal quality deterioration area RB.
  • the light source control unit 17D causes the light source unit to make the emission frequency of the emitted light L1 directed to the signal quality deterioration area RB higher than that in the other areas.
  • Control 11 Therefore, the emitted light L1 is emitted with high frequency at the timing of scanning the signal quality deteriorated region RB, and the emitted light L1 is emitted at the same frequency as the first scanning cycle P1 at the timing of scanning the other regions. Therefore, distance measurement points MP1 having a higher density than the other areas are provided in the signal quality deterioration area RB.
  • the distance measurement image generation unit 15 can process the light reception signals SR at a plurality of distance measurement points MP1 collectively as one light reception signal RS.
  • the distance measurement image generation unit 15 may perform processing of simply adding and averaging the light reception signals SR of the plurality of adjacent distance measurement points MP1. This improves the signal-to-noise ratio of the light reception signal SR in the signal quality degradation region RB.
  • the light source control unit 17D may control the light source unit 11 so that the emission intensity of the emission light L1 directed to the signal quality deterioration area RB is higher than that of the other areas.
  • the emitted light L1 having a higher intensity than that of the other areas is emitted. Therefore, the signal-to-noise ratio is improved at the distance measurement point MP1 in the signal quality degradation region RB as compared with the first scan cycle P1.
  • the light source control unit 17D may be configured to perform control to emit the emission light L1 with high frequency to the signal quality deterioration region RB and to increase the emission intensity of each emission light L1. . That is, the signal quality degraded region RB may be irradiated with the scanning light L2 that is higher in density and intensity than the other regions.
  • the distance measuring apparatus 10 recognizes the scanning area R0 before the specific scanning cycle (for example, the second scanning cycle P2) in which the scanning section 12 scans the scanning area R0.
  • the region where the signal-to-noise ratio of the light reception signal SR is expected to decrease when scanning is performed in the scanning period is defined as a signal quality deterioration region RB.
  • control part 17 emits outgoing radiation light L1 with high density or high intensity to the signal quality degradation field RB concerned than other fields, and performs ranging. As a result, it is possible to obtain highly reliable optical scanning information and ranging information over the entire scanning region R0.
  • the definition period of the signal quality deterioration region RB may be the same as the scanning period of the scanning unit 12.
  • the recognition unit 16 may perform the recognition operation at a cycle equal to or shorter than the scanning cycle of the scanning unit 12.
  • the signal quality degradation area defining unit 17C may define the signal quality degradation area RB based on one or more pieces of recognition information newly acquired during the scanning cycle for each scanning cycle of the scanning section 12.
  • the control period of the emitted light L1 by the light source control unit 17D is also the same as the scanning period of the scanning unit 12.
  • the light source control unit 17D acquires the definition result of the new signal quality deterioration area RB for each scanning cycle. Therefore, the light source control unit 17D controls the light source unit 11 so as to switch the emission mode of the emission light L1 to the scanning region R0 in the next scanning cycle for each scanning cycle.
  • the emission control of the emission light L1 for each scanning cycle by the light source control unit 17D is, for example, based on the emission mode of the emission light L1 when the signal quality deterioration area RB is not defined, and a predetermined change from the reference mode It may be performed to change the frequency or intensity of the emitted light L1 in units.
  • the emission control of the emission light L1 for each scanning cycle by the light source control unit 17D takes the emission mode in the immediately preceding scanning cycle as the immediately preceding mode, and the frequency or intensity of the emitted light L1 in a predetermined change unit from the immediately preceding mode. It may be done to change.
  • the control unit 17 controls the light quantity of the emitted light L1 for each scanning cycle, for example, the light quantity of the emitted light L1 emitted in the scanning cycle (total light quantity in the cycle) and the signal quality degradation region RB in the scanning cycle
  • the light amount (total light amount in the area) of the emitted light L1 emitted toward the light source may be calculated, and emission control of the emitted light L1 of the next scanning cycle may be performed based on this.
  • the signal quality degradation area defining unit 17C defines a relatively wide area as the signal quality degradation area RB
  • the outgoing light L1 is frequently emitted to the wide area in the next scanning cycle. . Therefore, in the scanning period, the scanning light R2 with a large amount of light is irradiated to the scanning region R0.
  • the distance measuring apparatus 10 when mounted on a mobile object such as a vehicle, for example, the distance measuring apparatus 10 performs optical scanning with the peripheral region of the vehicle as the scanning region R0.
  • the pedestrian, the driver of the other vehicle, etc. exist as a distance measurement object OB in addition to the road and the intersection in the scanning region R0, and the laser light which is the scanning light L2 It will be irradiated.
  • the distance measuring apparatus 10 be configured to control the emission amount of the emission light L1 so that even if the scanning light L2 is irradiated to a living thing such as a human body, the living thing is not affected.
  • the control unit 17 may calculate the total light amount of the emitted light L1 emitted in a unit time (for example, one scanning cycle).
  • the control unit 17 (light source control unit 17D) may control the emission frequency and intensity of the emission light L1 to the signal quality deterioration region RB in the scan cycle after the calculation based on the calculated light amount.
  • JIS Japanese Industrial Standards
  • the control unit 17 sets a threshold for calculating the light amount in consideration of the test condition of this safety standard (for example, the time or the area size for measuring the irradiation amount of the laser light).
  • control unit 17 sets a time sufficiently shorter than the test time of the safety standard as the light amount calculation time (unit time).
  • the control unit 17 calculates the light amount of the emitted light L1 for each scanning cycle, for example, using one scanning cycle as the calculation time.
  • control unit 17 sets an upper limit value (threshold value) of the total light amount of the emitted light L1 in the scanning cycle. For example, the control unit 17 sets the threshold value of the light amount of the emitted light L1 per the scanning cycle (unit time) from the upper limit value of the light amount of the laser light of the safety standard and the test time. Then, the light source control unit 17D controls the emission amount of the emission light L1 in the next scanning cycle, for example, the frequency or the intensity of the emission light L1 with respect to the signal quality deterioration region RB, so that the calculated light amount of the emission light L1 does not exceed the threshold. Suppress the amount of rise.
  • the light amount threshold is set to a value sufficiently smaller than the light amount unit time corresponding to the upper limit value so as not to exceed the upper limit value of the safety standard even when the threshold value is exceeded for a predetermined time thereafter.
  • the distance measuring apparatus 10 calculates, for example, the emission amount of the emission light L1 every unit time, and within the range of the light amount satisfying the safety standard, the emission frequency of the emission light L1 to the signal quality reduction region RB and The intensity is controlled to be greater than in the other regions.
  • the light source unit 11 adjusts the emission mode of the emitted light L1 so that the total light amount for each scanning cycle of the emitted light L1 emitted toward the scanning region R0 is less than a predetermined value, for example. Therefore, light scanning and ranging can be performed safely and accurately.
  • control aspect of the emitted light L1 by the control part 17 is not limited above.
  • the case where the outgoing light L1 is emitted with a frequency or intensity higher than that in the other regions with respect to the signal quality deterioration region RB has been described.
  • the outgoing light L1 may be emitted to the signal quality deteriorated region RB at a frequency or intensity lower than that of the other regions.
  • the light receiving unit 13 can not operate for a certain period of time by receiving light exceeding the light receiving intensity (sensitivity range) (for example, a state in which the light receiving signal SR with the maximum signal level is continuously output) And the light reception signal SR is saturated, so that accurate peaks can not be detected.
  • the light receiving intensity sensitivity range
  • the recognition unit 16 recognizes the intensity of the reflected light L3 received by the light receiving unit 13 when the scanning unit 12 scans the scanning region R0, and in the signal quality deterioration region 17C, the intensity of the light reception signal SR is equal to or more than a predetermined threshold And the surrounding area may be defined as a signal degradation area.
  • the emission light L1 is emitted to the signal quality deterioration region RB at a low intensity, or the emission of the emission light L1 is stopped. Is preferred.
  • control unit 17 determines that the signal-to-noise ratio of the light reception signal RS is a predetermined reference value when the scanning unit 12 scans the scanning region R0 based on the situation in the scanning region R0 recognized by the recognition unit 16 It may be configured to change the emission aspect of the outgoing light L1 to the signal quality deterioration area RB lower than that from the emission aspect of the outgoing light L1 to the other areas of the signal quality deterioration area RB in the scanning area R0. .
  • control unit 17 defines the signal quality degradation region RB which is a region with a low signal-to-noise ratio.
  • the control unit 17 may define an arbitrary partial region in the scanning region R0 as a control region of the outgoing light L1 based on the recognition information (the state in the scanning region R0) from the recognition unit 16 .
  • control unit 17 may define a signal quality enhancement region, that is, a region where the signal-to-noise ratio is expected to be high by receiving the preferable reflected light L3.
  • the control unit 17 may emit the outgoing light L1 with a frequency or intensity lower than that of the other areas with respect to the signal quality increase area.
  • control unit 17 Based on the situation in the scanning area R recognized by the recognition unit 16, the control unit 17 outputs an emission aspect different from other areas in the scanning area R0 with respect to a part of the scanning area R0. It should just be comprised so that emitted light L1 may be emitted.
  • the scanning unit 12 includes the MEMS mirror that electromagnetically swings the light reflecting surface 12A, and the scanning trajectory TR has a scanning mode that draws a Lissajous curve.
  • the configuration of the scanning unit 12 and the operation mode thereof are not limited to the above.
  • the driving force of the scanning unit 12 is not limited to electromagnetic force, and may be electrostatic force or piezoelectric power.
  • the driving force generation unit 23 is not the permanent magnet MG and the metal wires CX and CY, but on the fixed frame B2, the rocking frame SX and the rocking plate SY, respectively.
  • the electrode pairs may be spaced apart from each other.
  • the scanning unit 12 is not limited to the case of scanning the scanning region R0 in the trajectory according to the Lissajous curve.
  • it may be a scanning trajectory for performing raster scanning, or the scanning trajectory may be different for each scanning cycle (for example, for each frame of image data).
  • the scanning unit 12 may be configured to scan the scanning region R0 (effective scanning surface R2) with the outgoing light L1 (scanning light L2).
  • the distance measuring apparatus 10 includes the light source unit 11 that emits the outgoing light L1, the scanning unit 12 that scans a predetermined area (scanning area R0) with the outgoing light L1, and the outgoing light L1.
  • a light receiving unit 13 that generates an electric signal (light reception signal SR) according to the reflected light L3 reflected by the distance measurement target object OB present in the predetermined area, and the distance measurement target object OB based on the light reception signal SR
  • a distance measuring unit 14 for measuring the distance to the point.
  • the distance measuring apparatus 10 recognizes the situation in the predetermined area prior to the scanning of the predetermined area by the scanning unit 12 with the recognition unit 16 recognizing the situation in the predetermined area, and the situation in the predetermined area recognized by the recognition unit 16. And a control unit that changes an emission mode of the pulsed light L1 (that is, the scanning light L2) to a partial area in the predetermined area. Therefore, it is possible to provide the distance measuring apparatus 10 capable of performing accurate distance measurement of the distance measuring object OB in the scanning region R0.
  • the light source unit 11, the scanning unit 12, the light receiving unit 13, and the recognition unit 16 can be connected to functional circuits other than the distance measuring unit 14, and the light reception signal SR (optical scanning information) is used for applications other than distance measurement. Can be used. That is, the light source unit 11, the scanning unit 12, the light receiving unit 13, and the recognition unit 16 constitute an optical scanning device together with, for example, the control unit 17. In this case, the ranging object OB is a scanning object. Also in this case, the light source unit 11 switches the emission mode of the emitted light L1 based on the recognition information of the recognition unit 16, for example, to configure an optical scanning device capable of accurately scanning the scanning region R0.

Landscapes

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

Abstract

The present invention addresses the problem of providing: an optical scanning device capable of accurately performing an optical scan in a scanning region; and a distance measuring device capable of accurately performing distance measurement for an object in the scanning region. The present invention has: a light source part (11) for emitting emission light (L1); a scanning part (12) for scanning a predetermined region (a scanning region R0) with scanning light (L2); a light reception part (13) for generating a light reception signal according to reflection light (L3) that is the scanning light reflected from an object (OB) present in the predetermined region; a recognition part (an image capturing device 16) for recognizing the situation in the predetermined region, prior to the scanning of the predetermined region, by means of the scanning part; and a control part (17) which, on the basis of the situation recognized by the recognition part, controls the light source part to change the emission state of the emission light (for example, increases the emission density or intensity of the emission light L1) with respect to a certain region (a signal quality degradation region RB) in the predetermined region.

Description

光走査装置及び測距装置Optical scanning device and distance measuring device
　本発明は、光走査を行う光走査装置、及び光学的な測距を行う測距装置に関する。 The present invention relates to an optical scanning device that performs optical scanning and a distance measuring device that performs optical distance measurement.
　例えば、測距装置は、光を走査領域内の物体に照射し、当該物体によって反射された光を検出することで、当該物体までの距離を測定するように構成されている。また、例えば、２次元的に走査を行う光走査部を有し、当該走査領域内における２次元的な測距結果を得る測距装置が知られている。 For example, the distance measuring device is configured to measure the distance to the object by irradiating the light to the object in the scanning area and detecting the light reflected by the object. Further, for example, there is known a distance measuring apparatus which has an optical scanning unit which two-dimensionally scans and which obtains two-dimensional distance measurement results in the scanning region.
　当該光走査型の測距装置は、例えば、光走査部として、ＭＥＭＳ（Micro Electro Mechanical Systems）ミラーと、当該ミラーに光を照射する光源と、測定対象物からの反射光を受光する受光部とを有する。当該光走査部は、当該ミラーによって反射された光を使用し、当該走査領域を２次元的に走査する。例えば、特許文献１には、送信波を所定範囲に放射する走査手段を有し、物標までの距離及び方向を検出するレーダ装置が開示されている。 The light scanning type distance measuring apparatus includes, for example, a MEMS (Micro Electro Mechanical Systems) mirror as a light scanning unit, a light source for irradiating light to the mirror, and a light receiving unit for receiving reflected light from the object to be measured. Have. The light scanning unit two-dimensionally scans the scanning region using the light reflected by the mirror. For example, Patent Document 1 discloses a radar apparatus that has a scanning unit that emits a transmission wave in a predetermined range, and detects the distance and direction to a target.
特開2003-28960号公報Japanese Patent Application Laid-Open No. 2003-28960
　測距装置の光走査部は、例えば、パルス状のレーザ光を走査領域に順次照射し、対象物からの反射光を受光することで光学的な走査情報（以下、光走査情報と称する）を取得する。また、測距装置は、当該光走査情報、例えば照射から受光にかかった時間に基づいて当該対象物までの距離を測定する。 The light scanning unit of the distance measuring apparatus sequentially emits, for example, pulsed laser light to the scanning region, and receives reflected light from the object to obtain optical scanning information (hereinafter referred to as optical scanning information). get. In addition, the distance measuring device measures the distance to the object based on the light scanning information, for example, the time taken from irradiation to light reception.
　ここで、測距装置は、種々の環境下に置かれた場合を考慮し、走査領域の走査及び対象物の測距を正確に行うように構成されていることが好ましい。例えば、正確な測距情報を得にくい環境としては、対象物の光の反射率が極端に低い若しくは高い場合、対象物が測距装置から非常に遠い位置若しくは近い位置に存在する場合、又は照射する光とは別の環境光、例えば太陽光の強度が大きい場合が挙げられる。 Here, it is preferable that the distance measuring apparatus be configured to accurately scan the scanning region and measure the distance of the object in consideration of the case where the device is placed under various environments. For example, in an environment where accurate distance measurement information is difficult to obtain, when the light reflectance of the object is extremely low or high, the object is at a very distant position or near position from the distance measuring device, or irradiation There is a case where the intensity of ambient light other than the one to be used, such as sunlight, is high.
　このような環境では、対象物からの反射光の強度が低下して当該環境光に埋もれ、信号対雑音比が低下するおそれがある。また、反射光の強度が大きくなりすぎ、受光信号が飽和するおそれがある。 In such an environment, the intensity of the reflected light from the object may be reduced and buried in the ambient light, resulting in a decrease in the signal to noise ratio. In addition, the intensity of the reflected light may be too high, and the light reception signal may be saturated.
　測距装置は、例えばこのような環境に置かれた場合でも正確に走査領域内の光走査情報を取得できることが好ましい。また、同様に、測距装置は、走査領域内において正確に測距動作を行い、正確な測距情報を取得できることが好ましい。 It is preferable that the distance measuring apparatus can acquire light scanning information in the scanning area accurately even when placed in such an environment, for example. In addition, similarly, it is preferable that the distance measuring apparatus can accurately perform distance measuring operation in the scanning region and obtain accurate distance measuring information.
　本発明は上記した点に鑑みてなされたものであり、走査領域内の正確な光走査を行うことが可能な光走査装置及び当該走査領域内の対象物の正確な測距を行うことが可能な測距装置を提供することを課題の１つとしている。 The present invention has been made in view of the above-described point, and an optical scanning device capable of performing accurate optical scanning in a scanning area and accurate ranging of an object in the scanning area can be performed. One of the problems is to provide a range finder.
　請求項１に記載の発明は、出射光を出射する光源部と、出射光によって所定の領域を走査する走査部と、出射光が所定の領域内に存在する対象物によって反射した反射光に応じて受光信号を生成する受光部と、走査部による所定の領域の走査に先立って所定の領域内の状況を認識する認識部と、認識部が認識した状況に基づいて、所定の領域内の一部の領域に対する出射光の出射態様を変化させるように光源部を制御する制御部と、を有することを特徴とする。 The invention according to claim 1 is characterized in that the light source section for emitting the emitted light, the scanning section for scanning the predetermined area with the emitted light, and the reflected light reflected by the object whose emitted light is present in the predetermined area And a recognition unit that recognizes a situation in the predetermined area prior to scanning of the predetermined area by the scanning unit, and a situation in the predetermined area based on the situation recognized by the recognition unit. And a control unit that controls the light source unit so as to change the emission mode of the emitted light with respect to the area of the unit.
　また、請求項５に記載の発明は、出射光を出射する光源部と、出射光によって所定の領域を走査する走査部と、出射光が所定の領域内に存在する対象物によって反射した反射光に応じて受光信号を生成する受光部と、受光信号に基づいて対象物までの距離を測定する測距部と、走査部による所定の領域の走査に先立って所定の領域内の状況を認識する認識部と、認識部が認識した状況に基づいて、所定の領域内の一部の領域に対する出射光の出射態様を変化させるように光源部を制御する制御部と、を有することを特徴とする。 According to the fifth aspect of the present invention, there is provided a light source section for emitting emitted light, a scanning section for scanning a predetermined area by the emitted light, and reflected light reflected by an object whose emitted light is present in the predetermined area. Prior to the scanning of the predetermined area by the scanning unit, the light receiving unit generating the light reception signal according to the light reception signal, the distance measuring unit measuring the distance to the object based on the light reception signal, and recognizing the situation in the predetermined region It has a recognition part and a control part which controls a light source part so that a radiation mode of outgoing radiation to a partial field in a predetermined field may be changed based on a situation which a recognition part recognized. .
実施例１に係る測距装置の配置図である。FIG. 2 is a layout view of a distance measuring apparatus according to a first embodiment. 実施例１に係る測距装置における制御部のブロック図である。FIG. 5 is a block diagram of a control unit in the distance measuring apparatus according to the first embodiment. 実施例１に係る測距装置における走査部の上面図である。FIG. 6 is a top view of a scanning unit in the distance measuring apparatus according to the first embodiment. 実施例１に係る測距装置における走査部の断面図である。FIG. 5 is a cross-sectional view of a scanning unit in the distance measuring apparatus according to the first embodiment. 実施例１に係る測距装置の走査部に印加される駆動信号の波形及び当該走査部によって反射された走査光の軌跡を示す図である。FIG. 5 is a diagram showing a waveform of a drive signal applied to a scanning unit of the distance measuring apparatus according to the first embodiment and a locus of scanning light reflected by the scanning unit. 実施例１に係る測距装置における信号品質低下領域の測距点の例を示す図である。FIG. 7 is a diagram showing an example of distance measurement points in a signal quality deterioration region in the distance measurement apparatus according to the first embodiment. 実施例１に係る測距装置における信号品質低下領域の測距点の他の例を示す図である。FIG. 7 is a view showing another example of a distance measurement point of a signal quality deterioration region in the distance measurement apparatus according to the first embodiment.
　以下に本発明の実施例について詳細に説明する。 Examples of the present invention will be described in detail below.
　図１Ａは、実施例１に係る測距装置１０の模式的な配置図である。測距装置１０は、所定の領域（以下、走査領域と称する）Ｒ０の光走査を行い、その走査結果に基づいて走査領域Ｒ０内に存在する測距対象物ＯＢまでの距離を測定する光測距装置である。図１Ａを用いて、測距装置１０の全体構成について説明する。なお、図の明確さのため、図１Ａには、走査領域Ｒ０及び測距対象物ＯＢを模式的に示している。 FIG. 1A is a schematic layout diagram of the distance measuring apparatus 10 according to the first embodiment. The distance measuring apparatus 10 performs an optical scan of a predetermined area (hereinafter referred to as a scan area) R0, and based on the scan result, measures the distance to the distance measurement object OB present in the scan area R0. It is a distance device. The entire configuration of the distance measuring apparatus 10 will be described using FIG. 1A. Note that, for the sake of clarity of the drawing, the scanning region R0 and the distance measurement object OB are schematically shown in FIG. 1A.
　測距装置１０は、パルス化されたレーザ光（以下、パルス光と称する）によって走査領域Ｒ０を周期的に走査し、走査領域Ｒ０内の測距対象物ＯＢからの反射光を受光することで走査領域Ｒ０内の光走査情報を取得する光走査情報取得部ＳＣを有する。 The distance measuring apparatus 10 periodically scans the scanning region R0 with pulsed laser light (hereinafter referred to as pulsed light), and receives reflected light from the distance measuring object OB in the scanning region R0. An optical scanning information acquisition unit SC that acquires optical scanning information in the scanning region R0 is included.
　光走査情報取得部ＳＣは、パルス光である出射光Ｌ１を生成及び出射する光源部１１を有する。本実施例においては、光源部１１は、出射光Ｌ１として、赤外領域にピーク波長を有するレーザ光を生成するレーザ装置を有する。 The light scanning information acquisition unit SC includes a light source unit 11 that generates and emits the emission light L1 that is pulse light. In the present embodiment, the light source unit 11 includes a laser device that generates laser light having a peak wavelength in the infrared region as the emitted light L1.
　また、光走査情報取得部ＳＣは、出射光Ｌ１を用いて走査領域Ｒ０を周期的に走査する走査部１２を有する。走査部１２は、出射光Ｌ１を走査領域Ｒ０に向けて反射させる可動式の光反射面１２Ａを有する。本実施例においては、走査部１２は、光反射面１２Ａが設けられた可動ミラーを有する。 The light scanning information acquisition unit SC also has a scanning unit 12 that periodically scans the scanning region R0 using the outgoing light L1. The scanning unit 12 has a movable light reflecting surface 12A that reflects the emitted light L1 toward the scanning region R0. In the present embodiment, the scanning unit 12 has a movable mirror provided with the light reflecting surface 12A.
　走査部１２は、光反射面１２Ａの向きを変化させることで、出射光Ｌ１が反射する方向を連続的かつ周期的に変化させる。走査部１２は、この光反射面１２Ａによって反射された出射光Ｌ１を走査光Ｌ２として用い、走査領域Ｒ０の光走査を行う。 The scanning unit 12 changes the direction of the light reflection surface 12A to change the direction in which the outgoing light L1 is reflected continuously and periodically. The scanning unit 12 performs light scanning of the scanning region R0 using the emitted light L1 reflected by the light reflecting surface 12A as the scanning light L2.
　なお、図１Ａに示すように、走査領域Ｒ０は、光反射面１２Ａの可動範囲に対応する幅及び高さを有し、走査光Ｌ２が到達及び反射したときに所定強度の反射光を受光可能な距離に対応する奥行を有する仮想の３次元空間である。図１Ａにおいては、走査領域Ｒ０の外縁を破線で示した。 As shown in FIG. 1A, the scanning region R0 has a width and a height corresponding to the movable range of the light reflecting surface 12A, and can receive reflected light of a predetermined intensity when the scanning light L2 reaches and is reflected. It is a virtual three-dimensional space having a depth corresponding to a certain distance. In FIG. 1A, the outer edge of the scanning region R0 is indicated by a broken line.
　例えば、図１Ａに示すように、走査領域Ｒ０内における走査光Ｌ２の光路上に測距対象物ＯＢが存在する場合、走査光Ｌ２が測距対象物ＯＢに照射される。また、測距対象物ＯＢが出射光Ｌ１を反射する特性を持った物体である場合、走査光Ｌ２は測距対象物ＯＢによって反射される。 For example, as shown in FIG. 1A, when the ranging object OB is present on the optical path of the scanning light L2 in the scanning region R0, the scanning light L2 is irradiated to the ranging object OB. In addition, in the case where the distance measuring object OB is an object having a characteristic of reflecting the emitted light L1, the scanning light L2 is reflected by the distance measuring object OB.
　また、光走査情報取得部ＳＣは、走査光Ｌ２が測距対象物ＯＢに照射されることで測距対象物ＯＢによって反射された光（以下、反射光と称する）Ｌ３を受光して検出する受光部１３を有する。受光部１３は、例えば、出射光Ｌ１のピーク波長を含む波長帯域の光を検出する光検出器を含む。受光部１３は、受光した反射光Ｌ３に対して光電変換を行い、反射光Ｌ３に応じた電気信号（以下、受光信号と称する）ＳＲを生成する。 Further, the light scanning information acquisition unit SC receives and detects the light L3 reflected on the object for distance measurement (hereinafter referred to as reflected light) L3 by irradiating the object for distance measurement OB with the scanning light L2 The light receiving unit 13 is provided. The light receiving unit 13 includes, for example, a light detector that detects light in a wavelength band including the peak wavelength of the outgoing light L1. The light receiving unit 13 performs photoelectric conversion on the received reflected light L3 to generate an electric signal (hereinafter, referred to as a light receiving signal) SR according to the reflected light L3.
　なお、本実施例の光走査情報取得部ＳＣにおいては、光源部１１と走査部１２の光反射面１２Ａとの間の出射光Ｌ１の光路上には、ビームスプリッタＢＳが設けられている。走査光Ｌ２は、測距対象物ＯＢによって反射されて反射光Ｌ３となり、光反射面１２Ａに向かって戻る。そして、反射光Ｌ３は、光反射面１２Ａによって反射され、ビームスプリッタＢＳによって分離された後、受光部１３によって受光される。なお、光源部１１によって出射された出射光Ｌ１は、ビームスプリッタＢＳを透過して走査部１２に向かって進む。 In the light scanning information acquisition unit SC of the present embodiment, a beam splitter BS is provided on the light path of the emitted light L1 between the light source unit 11 and the light reflecting surface 12A of the scanning unit 12. The scanning light L2 is reflected by the distance measurement object OB to be a reflected light L3, and returns toward the light reflecting surface 12A. Then, the reflected light L3 is reflected by the light reflecting surface 12A, separated by the beam splitter BS, and then received by the light receiving unit 13. The emitted light L1 emitted by the light source unit 11 passes through the beam splitter BS and travels toward the scanning unit 12.
　測距装置１０は、受光信号ＳＲに基づいて、測距対象物ＯＢまでの距離を測定する測距部１４を有する。本実施例においては、測距部１４は、受光信号ＳＲから反射光Ｌ３のパルスを検出し、出射光Ｌ１の出射からの時間差に基づくタイムオブフライト法によって測距対象物ＯＢ（及びその一部の表面領域）までの距離を測定する。測距部１４は、測定した距離情報を示すデータ（以下、測距データと称する）を生成する。 The distance measuring apparatus 10 has a distance measuring unit 14 that measures the distance to the distance measuring object OB based on the light reception signal SR. In the present embodiment, the distance measuring unit 14 detects the pulse of the reflected light L3 from the light reception signal SR, and the distance measuring object OB (and part of it) by the time of flight method based on the time difference from the emission of the outgoing light L1. Measure the distance to the surface area of The ranging unit 14 generates data (hereinafter, referred to as ranging data) indicating the measured distance information.
　測距装置１０は、当該測距データに基づいて走査領域Ｒ０の画像化を行う測距画像生成部１５を有する。測距画像生成部１５は、走査光Ｌ２の出射方向（すなわち走査部１２における光反射面１２Ａの向き（角度））と測距部１４が生成した測距データとを対応付けた測距画像データを生成する。 The distance measuring apparatus 10 has a distance measuring image generation unit 15 that performs imaging of the scanning region R0 based on the distance measuring data. The distance measurement image generation unit 15 measures distance measurement image data in which the emission direction of the scanning light L2 (that is, the direction (angle) of the light reflection surface 12A in the scanning unit 12) is associated with the distance measurement data generated by the distance measurement unit 14 Generate
　また、本実施例においては、測距画像生成部１５は、走査部１２の走査周期毎に１つの測距画像データを生成する。なお、走査周期とは、例えば、走査領域Ｒ０に対する走査を周期的に行う場合において、任意の走査状態（例えば走査光Ｌ２を出射する光反射面１２Ａの向き）の時点から、その後に再度当該走査状態に戻る時点までの期間をいう。また、１つの走査周期内における測距装置１０の動作及びこれによって得られる１つ測距画像データをフレームと称する。なお、測距画像生成部１５は、複数の測距画像データを時系列に沿って動画として表示する表示部（図示せず）を有していてもよい。 Further, in the present embodiment, the distance measurement image generation unit 15 generates one distance measurement image data for each scanning cycle of the scanning unit 12. Note that, for example, in the case of periodically performing a scan on the scan region R0, the scan cycle is again from the time of an arbitrary scan state (for example, the direction of the light reflection surface 12A that emits the scan light L2) It refers to the period until it returns to the state. In addition, the operation of the distance measuring apparatus 10 in one scanning cycle and one distance measuring image data obtained thereby are referred to as a frame. The distance measurement image generation unit 15 may have a display unit (not shown) that displays a plurality of distance measurement image data as a moving image in time series.
　また、本実施例においては、測距部１４は、走査領域Ｒ０内の所定の領域を有効走査領域（又は測距領域）とし、この有効走査領域内に向けて出射された走査光Ｌ２に対応する反射光Ｌ３の受光信号ＳＲに基づいて、測距対象物ＯＢまでの距離を測定する。 Further, in the present embodiment, the distance measuring unit 14 sets a predetermined area in the scanning area R0 as an effective scanning area (or a distance measuring area), and corresponds to the scanning light L2 emitted toward the effective scanning area. Based on the light reception signal SR of the reflected light L3, the distance to the distance measurement object OB is measured.
　なお、本明細書においては、説明上、走査領域Ｒ０内における走査部１２から所定の距離だけ離れた仮想の面を走査面（被走査面）Ｒ１と称する。また、本実施例においては、有効走査領域は、走査領域Ｒ０の外縁部分を除いた領域（空間）であり、図１Ａには、走査面Ｒ１の外縁部分を除いた内側の領域である有効走査面Ｒ２として例示した。測距部１４の測距動作は、この仮想の被走査面の一部である有効走査面Ｒ２に向けて出射される走査光Ｌ２を用いて行われる。 In the present specification, for convenience of explanation, a virtual surface separated by a predetermined distance from the scanning unit 12 in the scanning region R0 is referred to as a scanning surface (scanning surface) R1. Further, in the present embodiment, the effective scanning area is an area (space) excluding the outer edge portion of the scanning area R0, and in FIG. 1A, the effective scanning area is an inner area excluding the outer edge portion of the scanning surface R1. It illustrated as field R2. The distance measuring operation of the distance measuring unit 14 is performed using the scanning light L2 emitted toward the effective scanning surface R2 which is a part of the virtual scanned surface.
　測距装置１０は、走査領域Ｒ０又はその一部の領域（以下、認識領域と称する）Ｒ３内の状況を認識する認識部１６を有する。認識部１６は、例えば、認識領域Ｒ３を撮像範囲とした撮像を行う撮像装置を含む。当該撮像装置は、例えば赤外線カメラからなる。また、例えば、認識部１６は、認識領域Ｒ３を検出範囲とする物体検出装置を含む。なお、図１Ａにおいては、認識領域Ｒ３を破線で模式的に示した。 The distance measuring apparatus 10 includes a recognition unit 16 that recognizes a situation in the scanning region R0 or a partial region thereof (hereinafter referred to as a recognition region) R3. The recognition unit 16 includes, for example, an imaging device that performs imaging with the recognition region R3 as an imaging range. The imaging device is, for example, an infrared camera. Also, for example, the recognition unit 16 includes an object detection device that sets the recognition area R3 as a detection range. In FIG. 1A, the recognition area R3 is schematically shown by a broken line.
　なお、走査領域Ｒ０と認識領域Ｒ３がほぼ同一の領域となるように走査部１２及び認識部１６が構成されていることが好ましい。すなわち、走査部１２から見た有効走査面Ｒ２内の測距対象物ＯＢの位置と、認識部１６から見た有効走査面Ｒ２内の測距対象物ＯＢの位置とが極力一致していることが好ましい。 Preferably, the scanning unit 12 and the recognition unit 16 are configured such that the scanning region R0 and the recognition region R3 are substantially the same. That is, the position of the distance measuring object OB in the effective scanning surface R2 viewed from the scanning unit 12 and the position of the distance measuring object OB in the effective scanning surface R2 viewed from the recognition unit 16 match as much as possible. Is preferred.
　認識部１６は、例えば、これらの撮像した画像、又は検出した物体の位置及びサイズなどを示す情報を認識情報として出力する。また、本実施例においては、認識部１６は、走査部１２の走査周期と同一の周期で周期的に認識領域Ｒ３の認識動作を行い、当該周期毎に上記したような認識情報を生成する。例えば、認識部１６が撮像装置を含む場合、当該撮像装置は、走査部１２の各走査周期中に認識領域Ｒ３を撮像し、各走査周期の終了前に当該撮像した画像を出力する。 The recognition unit 16 outputs, for example, information indicating the captured image or the position and size of the detected object as recognition information. Further, in the present embodiment, the recognition unit 16 periodically performs the recognition operation of the recognition region R3 in the same cycle as the scanning cycle of the scanning unit 12, and generates the above-described recognition information for each cycle. For example, when the recognition unit 16 includes an imaging device, the imaging device captures an image of the recognition area R3 during each scanning cycle of the scanning unit 12, and outputs the captured image before the end of each scanning cycle.
　測距装置１０は、光走査情報取得部ＳＣ（光源部１１、走査部１２、受光部１３を含む）、測距部１４、測距画像生成部１５及び認識部１６の動作制御を行う制御部１７を有する。まず、図１Ａに示すように、本実施例においては、制御部１７は、光源部１１に駆動信号（光源駆動信号）ＤＬを供給し、光源部１１の駆動及びその制御を行う。駆動信号ＤＬは、測距部１４にも供給され、測距部１４が出射光Ｌ１の出射タイミングを知ることに利用される。また、制御部１７は、走査部１２に駆動信号（第１及び第２のＭＥＭＳ駆動信号）ＤＸ及びＤＹを供給し、走査部１２の駆動及びその制御を行う。 The distance measuring apparatus 10 is a control unit that performs operation control of the light scanning information acquisition unit SC (including the light source unit 11, the scanning unit 12, and the light receiving unit 13), the distance measuring unit 14, the distance measuring image generating unit 15, and the recognition unit 16. It has seventeen. First, as shown in FIG. 1A, in the present embodiment, the control unit 17 supplies a drive signal (light source drive signal) DL to the light source unit 11, and drives and controls the light source unit 11. The drive signal DL is also supplied to the distance measuring unit 14, and the distance measuring unit 14 is used to know the emission timing of the outgoing light L1. Further, the control unit 17 supplies drive signals (first and second MEMS drive signals) DX and DY to the scanning unit 12 to drive the scanning unit 12 and control the same.
　次に、図１Ｂは、制御部１７のブロック図である。本実施例においては、制御部１７は、光走査情報取得部ＳＣから走査部１２の走査状況を示す情報を取得して、走査光Ｌ２の実際の軌道を判定する走査軌道判定部１７Ａを有する。 Next, FIG. 1B is a block diagram of the control unit 17. In the present embodiment, the control unit 17 includes a scanning trajectory determination unit 17A that acquires information indicating the scanning condition of the scanning unit 12 from the optical scanning information acquisition unit SC and determines the actual trajectory of the scanning light L2.
　走査軌道判定部１７Ａは、例えば走査部１２内又は走査部１２に接続された揺動位置センサ（図示せず）の出力値を取得し、走査光Ｌ２がどの方向を向いているか（有効走査面Ｒ２内のどの位置に照射されているか）を判定する。なお、走査軌道判定部１７Ａは、当該揺動位置センサの出力値に代えて、走査部１２のＭＥＭＳ駆動信号ＤＸ及びＤＹを取得することで、走査光Ｌ２の軌道を判定してもよい。 The scanning track determination unit 17A acquires, for example, an output value of a swing position sensor (not shown) connected to the scanning unit 12 or to the scanning unit 12 and determines which direction the scanning light L2 is directed (effective scanning surface It is determined which position in R2 is irradiated. The scanning trajectory determination unit 17A may determine the trajectory of the scanning light L2 by acquiring the MEMS drive signals DX and DY of the scanning unit 12 instead of the output value of the rocking position sensor.
　制御部１７は、認識部１６から走査領域Ｒ０の状況の認識情報を取得する認識情報取得部１７Ｂを有する。認識情報取得部１７Ｂは、例えば、認識部１６としての撮像装置が撮像した画像を取得する。 The control unit 17 includes a recognition information acquisition unit 17B that acquires recognition information of the status of the scanning region R0 from the recognition unit 16. The recognition information acquisition unit 17B acquires, for example, an image captured by an imaging device as the recognition unit 16.
　制御部１７は、認識情報取得部１７Ｂが取得した走査領域Ｒ０内の認識情報に基づいて、走査部１２が走査領域Ｒ０を走査した場合に走査領域Ｒ０内における受光信号ＳＲの信号対雑音比が低くなる、又は受光信号ＲＳが飽和するおそれがある１又は複数の領域（以下、信号品質低下領域と称する）を画定する信号品質低下領域画定部１７Ｃを有する。 When the scanning unit 12 scans the scanning region R0 based on the recognition information in the scanning region R0 acquired by the recognition information acquiring unit 17B, the control unit 17 determines that the signal-to-noise ratio of the light reception signal SR in the scanning region R0 is It has the signal quality degradation area definition part 17C which defines one or more areas (hereinafter, referred to as signal degradation area) where the light reception signal RS may become low.
　なお、信号品質が低下する要因としては、光の反射特性が極端に低い若しくは高い物体が存在している場合、測距装置１０から非常に遠い若しくは近い位置に測距対象物ＯＢが存在している場合、又は走査光Ｌ２以外の環境光、例えば太陽光の強度が大きい場合などが挙げられる。 In addition, as a factor of deterioration of the signal quality, when there is an object with extremely low or high light reflection characteristics, the object for distance measurement OB is present at a position very far or near from the distance measuring device 10 In the case where the intensity of the ambient light other than the scanning light L2, for example, the intensity of sunlight is large.
　この信号品質低下領域から得られる光走査情報は、信頼性が低い情報であることが想定される。換言すれば、信号品質低下領域は、他の領域よりも測距部１４による測距が困難な領域である。信号品質低下領域画定部１７Ｂは、例えば認識部１６から取得した画像を解析することによって信号品質低下領域を画定する。 It is assumed that the light scanning information obtained from this signal quality degradation area is information with low reliability. In other words, the signal quality deterioration area is an area in which distance measurement by the distance measurement unit 14 is more difficult than the other areas. The signal quality degradation area definition unit 17 B defines a signal quality degradation area by analyzing an image acquired from the recognition unit 16, for example.
　具体的には、例えば認識部１６に含まれる撮像装置は走査光Ｌ２の波長に対して所定の感度を持っている。従って、例えば、当該撮像装置によって得られた画像の輝度値が所定値よりも低い又は高い領域（すなわち反射光Ｌ３の強度が所定の範囲から外れた領域）が信号品質低下領域として画定されることができる。 Specifically, for example, the imaging device included in the recognition unit 16 has a predetermined sensitivity to the wavelength of the scanning light L2. Therefore, for example, a region where the luminance value of the image obtained by the imaging device is lower or higher than a predetermined value (that is, a region where the intensity of the reflected light L3 deviates from the predetermined range) is defined as the signal quality deterioration region. Can.
　例えば、当該撮像装置によって得られた画像の輝度値が低い領域においては、走査光Ｌ２を照射した場合に受光信号ＳＲの強度が低くなることが予測される。一方、当該画像の輝度値が高い領域においては、走査光Ｌ２を照射した場合に受光信号ＳＲの強度が飽和することが予測される。 For example, in a region where the luminance value of the image obtained by the imaging device is low, it is predicted that the intensity of the light reception signal SR decreases when the scanning light L2 is irradiated. On the other hand, in the region where the luminance value of the image is high, it is predicted that the intensity of the light reception signal SR is saturated when the scanning light L2 is irradiated.
　制御部１７は、信号品質低下領域画定部１７Ｂによる信号品質低下領域の画定結果に基づいて、その画定結果を取得した後の走査周期における光源部１１の出射光Ｌ１の出射態様を制御する光源制御部１７Ｄを有する。光源制御部１７Ｄは、信号品質低下領域に対する出射光Ｌ１の出射態様を、走査領域Ｒ０内における当該信号品質低下領域以外の領域（以下、他の領域と称する場合がある）に対する出射光Ｌ１の出射態様から変化させるように、光源部１１を制御する。例えば、信号品質低下領域に対して走査領域Ｒ０内の他の領域よりも出射光Ｌ１の出射密度又は強度を上げるように、光源部１１を制御する。 The control unit 17 controls the emission mode of the emitted light L1 of the light source unit 11 in the scanning cycle after acquiring the definition result based on the definition result of the signal quality deterioration area by the signal quality deterioration area definition unit 17B. It has part 17D. The light source control unit 17D outputs the emission light L1 to the area other than the signal quality deterioration area in the scanning area R0 (hereinafter, may be referred to as another area). The light source unit 11 is controlled to change from the aspect. For example, the light source unit 11 is controlled such that the emission density or the intensity of the emission light L1 is increased relative to the signal quality deterioration region more than the other regions in the scanning region R0.
　図２Ａは、走査部１２の模式的な上面図である。図２Ｂは、走査部１２の断面図である。図２Ｂは、図２ＡのＶ－Ｖ線に沿った断面図である。図２Ａ及び図２Ｂを用いて、走査部１２の構成例について説明する。 FIG. 2A is a schematic top view of the scanning unit 12. FIG. 2B is a cross-sectional view of the scanning unit 12. FIG. 2B is a cross-sectional view taken along the line VV of FIG. 2A. A configuration example of the scanning unit 12 will be described with reference to FIGS. 2A and 2B.
　本実施例においては、走査部１２は、光反射面１２Ａを有する光反射膜（可動ミラー）２４を含み、この光反射膜２４が揺動するＭＥＭＳ（Micro Electro Mechanical Systems）ミラーである。また、本実施例においては、走査部１２は、電磁気的に光反射膜２４を揺動させるように構成されている。 In the present embodiment, the scanning unit 12 is a micro electro mechanical systems (MEMS) mirror including a light reflecting film (movable mirror) 24 having a light reflecting surface 12A, and the light reflecting film 24 swings. Further, in the present embodiment, the scanning unit 12 is configured to oscillate the light reflecting film 24 electromagnetically.
　より具体的には、走査部１２は、固定部（ベース部）２１、可動部（揺動部）２２、駆動力生成部２３及び光反射膜２４を有する。また、本実施例においては、走査部１２は、互いに直交する２つの揺動軸（第１及び第２の揺動軸）ＡＸ及びＡＹを中心に光反射膜２４が揺動するように構成されている。 More specifically, the scanning unit 12 includes a fixed unit (base unit) 21, a movable unit (rocking unit) 22, a driving force generation unit 23, and a light reflecting film 24. Further, in the present embodiment, the scanning unit 12 is configured such that the light reflecting film 24 swings around two swinging axes (first and second swinging axes) AX and AY orthogonal to each other. ing.
　本実施例においては、固定部２１は、固定基板Ｂ１及び固定基板Ｂ１上に形成された環状の固定枠Ｂ２を含む。可動部２２は、各々の一端が固定枠Ｂ２の内側に固定された一対のトーションバー（第１のトーションバー）ＴＸを含む。一対のトーションバーＴＸの各々は、少なくとも周方向の弾性を有する棒状の弾性部材からなり、揺動軸ＡＸに沿って整列している。また、可動部２２は、外周部側面が一対のトーションバーＴＸの各々の他端に接続された環状の揺動枠（可動枠）ＳＸを有する。 In the present embodiment, the fixed portion 21 includes a fixed substrate B1 and an annular fixed frame B2 formed on the fixed substrate B1. The movable portion 22 includes a pair of torsion bars (first torsion bars) TX, one end of each of which is fixed to the inside of the fixed frame B2. Each of the pair of torsion bars TX is made of a rod-like elastic member having at least circumferential elasticity, and is aligned along the swing axis AX. Further, the movable portion 22 has an annular swinging frame (movable frame) SX whose outer peripheral side surface is connected to the other end of each of the pair of torsion bars TX.
　また、可動部２２は、各々の一端が可動枠ＳＸの内周部側面に接続され、一対のトーションバーＴＸに直交する方向（揺動軸ＡＹに沿った方向）に整列した一対のトーションバー（第２のトーションバー）ＴＹと、外周部側面が一対のトーションバーＴＹの各々の他端に接続された揺動板（可動板）ＳＹと、を有する。一対のトーションバーＴＹの各々は、少なくとも周方向の弾性を有する棒状の弾性部材からなる。 The movable portion 22 has a pair of torsion bars (one end connected to the side surface of the inner peripheral portion of the movable frame SX) and aligned in a direction (direction along the swing axis AY) orthogonal to the pair of torsion bars TX. A second torsion bar TY and an oscillating plate (movable plate) SY whose outer peripheral side surface is connected to the other end of each of the pair of torsion bars TY. Each of the pair of torsion bars TY is formed of a rod-like elastic member having at least circumferential elasticity.
　本実施例においては、揺動枠ＳＸは揺動軸ＡＸを中心に（揺動中心として）揺動し、揺動板ＳＹは揺動軸ＡＸ及びＡＹを中心に揺動する。また、揺動板ＳＹ上には光反射膜２４が形成されている。従って、光反射膜２４の光反射面２４Ａは、揺動板ＳＹと共に、互いに直交する揺動軸ＡＸ及びＡＹを中心に揺動する。 In the present embodiment, the swing frame SX swings about the swing axis AX (as a swing center), and the swing plate SY swings around the swing axes AX and AY. In addition, a light reflection film 24 is formed on the rocking plate SY. Accordingly, the light reflecting surface 24A of the light reflecting film 24 swings about the swing axes AX and AY orthogonal to each other together with the swing plate SY.
　駆動力生成部２３は、固定基板Ｂ１上に配置された永久磁石ＭＧと、揺動枠ＳＸ上において揺動枠ＳＸの外周に沿って配線された金属配線（第１のコイル）ＣＸと、揺動板ＳＹ上において揺動板ＳＹの外周に沿って配線された金属配線（第２のコイル）ＣＹと、を含む。 The driving force generation unit 23 shakes the permanent magnet MG disposed on the fixed substrate B1, the metal wire (first coil) CX wired along the outer periphery of the swing frame SX on the swing frame SX, and And a metal wire (second coil) CY wired along the outer periphery of the swing plate SY on the moving plate SY.
　本実施例においては、永久磁石ＭＧは、固定基板Ｂ１上における固定枠Ｂ２の外側領域に設けられた複数の磁石片からなる。本実施例においては、４つの磁石片が、それぞれ、揺動軸ＡＸ及びＡＹの各々に沿ってかつ一対のトーションバーＴＸ及びＴＹの外側の位置に配置されている。 In the present embodiment, the permanent magnet MG is composed of a plurality of magnet pieces provided in the outer region of the fixed frame B2 on the fixed substrate B1. In the present embodiment, four magnet pieces are disposed along the swing axes AX and AY, respectively, and at positions outside the pair of torsion bars TX and TY.
　また、揺動軸ＡＸに沿った方向において互いに対向する２つの磁石片は、互いに反対の極性を示す部分が対向するように配置されている。同様に、揺動軸ＡＹに沿った方向において互いに対向する２つの磁石片は、互いに反対の極性を示す部分が対向するように配置されている。 Further, two magnet pieces facing each other in the direction along the swing axis AX are arranged such that parts showing opposite polarities face each other. Similarly, the two magnet pieces facing each other in the direction along the swing axis AY are arranged such that portions exhibiting opposite polarities face each other.
　本実施例においては、金属配線ＣＸに電流が流れると、揺動軸ＡＹに沿った方向に並んだ永久磁石ＭＧの２つの磁石片によって生じた磁界との相互作用により、一対のトーションバーＴＸが周方向にねじれ、揺動枠ＳＸが揺動軸ＡＸを中心に揺動する。同様に、金属配線ＣＹに流れた電流による電界と揺動枠ＡＸに沿った方向に並んだ永久磁石ＭＧの２つの磁石片による磁界とによって一対のトーションバーＴＹがねじれ、揺動板ＳＹが揺動軸ＡＹを中心に揺動する。 In the present embodiment, when current flows in the metal wire CX, a pair of torsion bars TX is generated by the interaction with the magnetic field generated by the two magnet pieces of the permanent magnet MG aligned in the direction along the swing axis AY. Twisting in the circumferential direction, the swing frame SX swings around the swing axis AX. Similarly, the pair of torsion bars TY is twisted by the electric field by the current flowing through the metal wire CY and the magnetic field by the two magnetic pieces of the permanent magnet MG aligned in the direction along the swing frame AX, and the swing plate SY swings. Swing around the dynamic axis AY.
　また、図２Ａに示すように、金属配線ＣＸ及びＣＹは、制御部１７に接続されている。制御部１７は、金属配線ＣＸ及びＣＹにＭＥＭＳ駆動信号ＤＸ及びＤＹを供給する。駆動力生成部２３は、当該ＭＥＭＳ駆動信号ＤＸ及びＤＹの印加によって、可動部２２及び光反射膜２４を揺動させる電磁気力を生成する。 Further, as shown in FIG. 2A, the metal wires CX and CY are connected to the control unit 17. The control unit 17 supplies the MEMS drive signals DX and DY to the metal wires CX and CY. The driving force generation unit 23 generates an electromagnetic force that causes the movable portion 22 and the light reflecting film 24 to swing by application of the MEMS driving signals DX and DY.
　なお、本実施例においては、光反射膜２４は、円板形状を有する。また、光反射膜２４は、揺動軸ＡＸ及びＡＹに直交する中心軸ＡＣを有する。可動部２２及び光反射膜２４は、光反射膜２４の中心軸ＡＣに関して９０度回転対称に形成されている。 In the present embodiment, the light reflecting film 24 has a disk shape. The light reflection film 24 has a central axis AC orthogonal to the swing axes AX and AY. The movable portion 22 and the light reflecting film 24 are formed so as to be rotationally symmetric by 90 degrees with respect to the central axis AC of the light reflecting film 24.
　また、図２Ｂを参照すると、本実施例においては、固定部２１の固定基板Ｂ１は、凹部を有する。また、固定枠Ｂ２は、固定基板Ｂ１の当該凹部に可動部２２を懸架するように固定基板Ｂ１に固定されている。また、固定枠Ｂ２及び可動部２２（揺動枠ＳＸ、揺動板ＳＹ並びにトーションバーＴＸ及びＴＹ）は、例えば半導体基板を加工することで形成された当該半導体基板の部分である。 Further, referring to FIG. 2B, in the present embodiment, the fixed substrate B1 of the fixed portion 21 has a recess. The fixed frame B2 is fixed to the fixed substrate B1 so as to suspend the movable portion 22 in the recess of the fixed substrate B1. The fixed frame B2 and the movable portion 22 (the swing frame SX, the swing plate SY, and the torsion bars TX and TY) are parts of the semiconductor substrate formed by processing, for example, a semiconductor substrate.
　光反射膜２４は、揺動板ＳＹと共に、固定基板Ｂ１の凹部に揺動可能に懸架（支持）されている。また、永久磁石ＭＧは、固定基板Ｂ１上における凹部の外側に形成されている。また、本実施例においては、トーションバーＴＸ及びＴＹがねじれることで、固定枠Ｂ２の内側において、トーションバーＴＸ及びＴＹを挟んだ可動部２２の両端部が固定基板Ｂ１の凹部に向かう方向及び離れる方向に揺動する。また、光反射膜２４は、中心軸ＡＣ上の１点を揺動中心とし、固定枠Ｂ２に対して傾斜するように揺動する。 The light reflection film 24 is swingably suspended (supported) in the recess of the fixed substrate B1 together with the swing plate SY. The permanent magnet MG is formed outside the recess on the fixed substrate B1. Further, in the present embodiment, the torsion bars TX and TY are twisted, so that both ends of the movable portion 22 sandwiching the torsion bars TX and TY in the inside of the fixed frame B2 move in the direction and toward the recess of the fixed substrate B1. Swing in the direction. In addition, the light reflecting film 24 swings with respect to the fixed frame B2 with one point on the central axis AC as a swing center.
　光反射膜２４（光反射面２４Ａ）が揺動することで、出射光Ｌ１の反射方向、すなわち走査光Ｌ２の出射方向が変化する。このようにして、光走査情報取得部ＳＣは、走査光Ｌ２を用いて走査領域Ｒ０の走査を行う。すなわち、走査部１２は、出射光Ｌ１の出射方向を連続的に変化させることで、走査領域Ｒ０を所定の周期で周期的に走査する。 As the light reflecting film 24 (light reflecting surface 24A) swings, the reflection direction of the outgoing light L1, that is, the outgoing direction of the scanning light L2 changes. Thus, the light scanning information acquisition unit SC scans the scanning region R0 using the scanning light L2. That is, the scanning unit 12 periodically scans the scanning region R0 at a predetermined cycle by continuously changing the emission direction of the emission light L1.
　図３は、制御部１７が生成するＭＥＭＳ駆動信号（以下、単に駆動信号と称する）ＤＸ及びＤＹと、これに基づいた光反射膜２４の揺動状態の変化及び走査光Ｌ２の走査軌道と、の関係を模式的に示す図である。図３を用いて、走査部１２による走査領域Ｒ０の走査態様について説明する。 FIG. 3 shows MEMS drive signals (hereinafter simply referred to as drive signals) DX and DY generated by the control unit 17, changes in the swing state of the light reflecting film 24 based on these, and the scanning trajectory of the scanning light L2. It is a figure which shows typically the relationship of. The scanning aspect of scanning area R0 by the scanning part 12 is demonstrated using FIG.
　まず、制御部１７が生成する駆動信号ＤＸは、Ａ1及びＢ1を定数とし、θ1を変数としたとき、ＤＸ（θ1）＝Ａ1ｓｉｎ（θ1＋Ｂ1）の式で示される正弦波の信号である。また、駆動信号ＤＹは、Ａ2及びＢ2を定数とし、θ2を変数としたとき、ＤＹ（θ2）＝Ａ2ｓｉｎ（θ2＋Ｂ2）の式で示される正弦波の信号である。 First, the drive signal DX generated by the control unit 17 is expressed by the equation DX (θ 1 ) = A 1 sin (θ 1 + B 1 ), where A 1 and B 1 are constants and θ 1 is a variable. It is a sine wave signal. The drive signal DY is a sine wave signal represented by the equation DY (θ 2 ) = A 2 sin (θ 2 + B 2 ), where A 2 and B 2 are constants and θ 2 is a variable. .
　また、変数θ1は、駆動信号ＤＸが、走査部１２のトーションバーＴＸ、揺動枠ＳＸ、トーションバーＴＹ及び揺動板ＳＹの共振周波数に対応する周波数の正弦波となるように設定される。また、変数θ2は、駆動信号ＤＹが、走査部１２のトーションバーＴＹ及び揺動板ＳＹの共振周波数に対応する周波数の正弦波となるように設定される。 Further, the variable theta 1, the drive signal DX is, the torsion bar TX scan units 12 are set so that the oscillating frame SX, sine wave having a frequency corresponding to the resonant frequency of the torsion bar TY and the swinging plate SY . Further, the variable theta 2, the drive signal DY is set to be a sine wave of a frequency corresponding to the resonance frequency of the torsion bar TY and the swinging plate SY scanning unit 12.
　従って、光反射膜２４（揺動板ＳＹ）は、揺動軸ＡＸを中心に共振し、かつ揺動軸ＡＹを中心に共振する。従って、図３に示すように、走査領域Ｒ０の走査面Ｒ１を見たとき、光反射膜２４に反射された出射光Ｌ１である走査光Ｌ２は、リサージュ曲線を描くような軌跡ＴＲ（Ｌ２）を示す。 Accordingly, the light reflection film 24 (the swinging plate SY) resonates around the swing axis AX and resonates around the swing axis AY. Therefore, as shown in FIG. 3, when the scanning surface R1 of the scanning region R0 is viewed, the scanning light L2, which is the outgoing light L1 reflected by the light reflecting film 24, has a locus TR (L2) that draws a Lissajous curve. Indicates
　換言すれば、本実施例においては、走査部１２は、出射光Ｌ１を反射させかつ互いに直交する第１及び第２の揺動軸ＡＸ及びＡＹを中心に揺動する光反射面１２Ａを有し、リサージュ曲線に従った軌跡ＴＲを描くように走査領域Ｒ０を走査する走査態様を有する。 In other words, in the present embodiment, the scanning unit 12 has the light reflecting surface 12A that reflects the emitted light L1 and swings about the first and second swing axes AX and AY orthogonal to each other. , And has a scanning aspect in which the scanning region R0 is scanned so as to draw a locus TR according to the Lissajous curve.
　次に、図４Ａ及び図４Ｂを用いて、測距部１４が測距する有効走査面Ｒ２内の測距ポイントである測距点、すなわち、光反射面１２Ａの揺動位置（揺動角度）と出射光Ｌ１の出射タイミングとの関係について説明する。図４Ａ及び図４Ｂは、２つの走査周期（フレーム）Ｐ１及びＰ２内における図３の破線で囲まれた領域Ｒ２１を拡大して示す図である。 Next, with reference to FIGS. 4A and 4B, a distance measurement point which is a distance measurement point within the effective scanning surface R2 to which the distance measurement unit 14 measures distance, that is, a swing position (swing angle) of the light reflection surface 12A. The relationship between the and the emission timing of the emission light L1 will be described. 4A and 4B are enlarged views of a region R21 surrounded by a broken line in FIG. 3 in two scanning periods (frames) P1 and P2.
　なお、第１の走査周期Ｐ１は、信号品質低下領域画定部１７Ｃによって信号品質低下領域が画定される前の走査周期であり、第２の走査周期Ｐ２は、信号品質低下領域が画定された後の走査周期である。以下においては、領域Ｒ２１の一部領域が信号品質低下領域ＲＢとして画定される場合について説明する。 The first scan cycle P1 is a scan cycle before the signal quality degradation area is defined by the signal quality degradation area definition unit 17C, and the second scan cycle P2 is after the signal quality degradation area is defined. Scan cycle of In the following, the case where a partial area of the area R21 is defined as the signal quality deterioration area RB will be described.
　まず、図４Ａに示すように、走査部１２によって走査光Ｌ２が照射される走査面Ｒ１内の被照射スポット、すなわち、測距部１４が測距を行うポイントである測距点ＭＰは、走査光Ｌ２の軌跡ＴＲ上に存在する。従って、測距点ＭＰの集合を測距点群ＭＧとした場合、測距点群ＭＧは、この軌跡ＴＲ上において、出射光Ｌ１の出射間隔と光反射面１２Ａの変位速度とに応じた間隔で点在する測距点ＭＰからなる。 First, as shown in FIG. 4A, a spot to be irradiated in the scanning surface R1 to which the scanning light L2 is irradiated by the scanning unit 12, that is, a distance measurement point MP which is a point at which the distance measurement unit 14 performs distance measurement It exists on the trajectory TR of the light L2. Therefore, assuming that the set of distance measurement points MP is the distance measurement point group MG, the distance measurement point group MG is an interval according to the emission interval of the outgoing light L1 and the displacement speed of the light reflection surface 12A on this locus TR. It consists of ranging points MP scattered.
　例えば、初期設定として光源部１１が一定の間隔（第１の間隔）で出射光Ｌ１を出射するように動作を行う場合の走査周期を第１の走査周期Ｐ１とする。この場合、図４Ａに示すように、第１の走査周期Ｐ１では、測距点ＭＰの各々は、走査領域Ｒ０の全体において、当該第１の間隔及び光反射面１２Ａの変位速度に応じた間隔で設けられる。 For example, as an initial setting, a scanning cycle in the case where the light source unit 11 operates to emit the emitted light L1 at a constant interval (first interval) is set as a first scanning cycle P1. In this case, as shown in FIG. 4A, in the first scanning cycle P1, each of the distance measurement points MP is an interval corresponding to the first interval and the displacement speed of the light reflecting surface 12A in the entire scanning region R0. Provided.
　一方、信号品質低下領域画定部１７Ｃによって信号品質低下領域ＲＢが画定（定義）された後の走査周期を第２の走査周期Ｐ２とする。この第２の走査周期Ｐ２では、光源制御部１７Ｄによって、信号品質低下領域ＲＢを走査するタイミングでの光源部１１による出射光Ｌ１の出射密度又は強度が変化する。 On the other hand, the scan cycle after the signal quality degradation area RB is defined (defined) by the signal quality degradation area definition unit 17C is set as a second scan cycle P2. In the second scanning cycle P2, the light source control unit 17D changes the emission density or the intensity of the emitted light L1 by the light source unit 11 at the timing of scanning the signal quality deterioration area RB.
　例えば、図４Ａに示すように、第２の走査周期Ｐ２では、光源制御部１７Ｄは、信号品質低下領域ＲＢに向けた出射光Ｌ１の出射頻度を他の領域よりも高くするように、光源部１１を制御する。従って、信号品質低下領域ＲＢを走査するタイミングでは高頻度で出射光Ｌ１が出射され、他の領域を走査するタイミングでは第１の走査周期Ｐ１と同様の頻度で出射光Ｌ１が出射される。従って、信号品質低下領域ＲＢ内には他の領域よりも高い密度の測距点ＭＰ１が設けられる。 For example, as shown in FIG. 4A, in the second scanning cycle P2, the light source control unit 17D causes the light source unit to make the emission frequency of the emitted light L1 directed to the signal quality deterioration area RB higher than that in the other areas. Control 11 Therefore, the emitted light L1 is emitted with high frequency at the timing of scanning the signal quality deteriorated region RB, and the emitted light L1 is emitted at the same frequency as the first scanning cycle P1 at the timing of scanning the other regions. Therefore, distance measurement points MP1 having a higher density than the other areas are provided in the signal quality deterioration area RB.
　信号品質低下領域ＲＢに他の領域よりも高い密度の測距点ＭＰ１が設けられることで、例えば、信号品質低下領域ＲＢの全体として受光信号ＳＲの品質の低下が抑制される。例えば、測距画像生成部１５は、複数の測距点ＭＰ１における受光信号ＳＲをまとめて１つの受光信号ＲＳとして処理することができる。例えば、測距画像生成部１５は、隣接する複数の測距点ＭＰ１の受光信号ＳＲを単純に加算・平均する処理を行ってもいい。これによって、信号品質低下領域ＲＢ内の受光信号ＳＲの信号対雑音比が改善される。 By providing the distance measurement point MP1 having a density higher than that of the other areas in the signal quality deterioration area RB, for example, deterioration in the quality of the light reception signal SR as the entire signal quality deterioration area RB is suppressed. For example, the distance measurement image generation unit 15 can process the light reception signals SR at a plurality of distance measurement points MP1 collectively as one light reception signal RS. For example, the distance measurement image generation unit 15 may perform processing of simply adding and averaging the light reception signals SR of the plurality of adjacent distance measurement points MP1. This improves the signal-to-noise ratio of the light reception signal SR in the signal quality degradation region RB.
　また、図４Ｂに示すように、光源制御部１７Ｄは、信号品質低下領域ＲＢに向けた出射光Ｌ１の出射強度を他の領域よりも高くするように、光源部１１を制御してもよい。この場合、信号品質低下領域ＲＢを走査するタイミングでは他の領域よりも高い強度の出射光Ｌ１が出射される。従って、信号品質低下領域ＲＢ内の測距点ＭＰ１では、第１の走査周期Ｐ１に比べて信号対雑音比が改善される。 Further, as shown in FIG. 4B, the light source control unit 17D may control the light source unit 11 so that the emission intensity of the emission light L1 directed to the signal quality deterioration area RB is higher than that of the other areas. In this case, at the timing of scanning the signal quality deterioration area RB, the emitted light L1 having a higher intensity than that of the other areas is emitted. Therefore, the signal-to-noise ratio is improved at the distance measurement point MP1 in the signal quality degradation region RB as compared with the first scan cycle P1.
　なお、光源制御部１７Ｄは、信号品質低下領域ＲＢに対し、高頻度で出射光Ｌ１を出射し、かつそれぞれの出射光Ｌ１の出射強度を上げるような制御をなすように構成されていてもよい。すなわち、信号品質低下領域ＲＢには、他の領域よりも高密度かつ高強度な走査光Ｌ２が照射されてもよい。 The light source control unit 17D may be configured to perform control to emit the emission light L1 with high frequency to the signal quality deterioration region RB and to increase the emission intensity of each emission light L1. . That is, the signal quality degraded region RB may be irradiated with the scanning light L2 that is higher in density and intensity than the other regions.
　このように、本実施例においては、測距装置１０は、走査部１２が走査領域Ｒ０を走査する特定の走査周期（例えば第２の走査周期Ｐ２）の前に、走査領域Ｒ０を認識部１６によって認識させ、当該走査周期に走査が行われた時に受光信号ＳＲの信号対雑音比が低下すると予測される領域を信号品質低下領域ＲＢとして画定する。そして、制御部１７は、当該信号品質低下領域ＲＢに対しては他の領域よりも高密度又は高強度の出射光Ｌ１を出射して測距を行う。これによって、走査領域Ｒ０の全体で信頼性の高い光走査情報及び測距情報を得ることができる。 Thus, in the present embodiment, the distance measuring apparatus 10 recognizes the scanning area R0 before the specific scanning cycle (for example, the second scanning cycle P2) in which the scanning section 12 scans the scanning area R0. The region where the signal-to-noise ratio of the light reception signal SR is expected to decrease when scanning is performed in the scanning period is defined as a signal quality deterioration region RB. And control part 17 emits outgoing radiation light L1 with high density or high intensity to the signal quality degradation field RB concerned than other fields, and performs ranging. As a result, it is possible to obtain highly reliable optical scanning information and ranging information over the entire scanning region R0.
　なお、信号品質低下領域ＲＢの画定周期は、走査部１２の走査周期と同一の周期であってもよい。具体的には、例えば、認識部１６は、走査部１２の走査周期と同一の周期又はこれより短い周期で認識動作を行ってもよい。そして、信号品質低下領域画定部１７Ｃは、走査部１２の走査周期毎に、その走査周期中に新たに取得した１つ以上の認識情報に基づいて信号品質低下領域ＲＢを画定してもよい。 Note that the definition period of the signal quality deterioration region RB may be the same as the scanning period of the scanning unit 12. Specifically, for example, the recognition unit 16 may perform the recognition operation at a cycle equal to or shorter than the scanning cycle of the scanning unit 12. Then, the signal quality degradation area defining unit 17C may define the signal quality degradation area RB based on one or more pieces of recognition information newly acquired during the scanning cycle for each scanning cycle of the scanning section 12.
　この場合、光源制御部１７Ｄによる出射光Ｌ１の制御周期も、走査部１２の走査周期と同一の周期となる。例えば、光源制御部１７Ｄは、走査周期毎に新たな信号品質低下領域ＲＢの画定結果を取得する。従って、光源制御部１７Ｄは、走査周期毎のその次の走査周期における走査領域Ｒ０への出射光Ｌ１の出射態様を切替えるように、光源部１１を制御することとなる。 In this case, the control period of the emitted light L1 by the light source control unit 17D is also the same as the scanning period of the scanning unit 12. For example, the light source control unit 17D acquires the definition result of the new signal quality deterioration area RB for each scanning cycle. Therefore, the light source control unit 17D controls the light source unit 11 so as to switch the emission mode of the emission light L1 to the scanning region R0 in the next scanning cycle for each scanning cycle.
　また、光源制御部１７Ｄによる走査周期毎の出射光Ｌ１の出射制御は、例えば信号品質低下領域ＲＢが画定されていない場合の出射光Ｌ１の出射態様を基準態様とし、当該基準態様から所定の変更単位で出射光Ｌ１の頻度又は強度を変更するように行われてもよい。また、光源制御部１７Ｄによる走査周期毎の出射光Ｌ１の出射制御は、直前の走査周期内での出射態様を直前態様とし、当該直前態様から所定の変更単位で出射光Ｌ１の頻度又は強度を変更するように行われてもよい。 The emission control of the emission light L1 for each scanning cycle by the light source control unit 17D is, for example, based on the emission mode of the emission light L1 when the signal quality deterioration area RB is not defined, and a predetermined change from the reference mode It may be performed to change the frequency or intensity of the emitted light L1 in units. The emission control of the emission light L1 for each scanning cycle by the light source control unit 17D takes the emission mode in the immediately preceding scanning cycle as the immediately preceding mode, and the frequency or intensity of the emitted light L1 in a predetermined change unit from the immediately preceding mode. It may be done to change.
　これによって、例えば、信号品質低下領域ＲＢにおける測距点数が増加すること、又はその測距点での受光信号ＳＲの信号対雑音比が改善されることが予想される。従って、走査領域Ｒ０（又は有効走査領域）の全体で正確な走査結果（測距結果）を得ることができる。これによって、この走査結果及び測距結果の種々の用途への有用度が大幅に向上する。例えば、測距対象物ＯＢとしての障害物の検出精度が向上する。 This is expected to increase, for example, the number of distance measurement points in the signal quality degradation region RB or improve the signal-to-noise ratio of the light reception signal SR at the distance measurement point. Therefore, accurate scanning results (ranging results) can be obtained in the entire scanning region R0 (or effective scanning region). This greatly improves the usefulness of the scanning results and the ranging results for various applications. For example, the detection accuracy of the obstacle as the distance measurement target object OB is improved.
　なお、制御部１７は、走査周期毎の出射光Ｌ１の光量、例えば、当該走査周期内で出射された出射光Ｌ１の光量（周期内の総光量）及び当該走査周期内で信号品質低下領域ＲＢに向けて出射された出射光Ｌ１の光量（領域内の総光量）を算出し、これに基づいて次の走査周期の出射光Ｌ１の出射制御を行ってもよい。 The control unit 17 controls the light quantity of the emitted light L1 for each scanning cycle, for example, the light quantity of the emitted light L1 emitted in the scanning cycle (total light quantity in the cycle) and the signal quality degradation region RB in the scanning cycle The light amount (total light amount in the area) of the emitted light L1 emitted toward the light source may be calculated, and emission control of the emitted light L1 of the next scanning cycle may be performed based on this.
　例えば、信号品質低下領域画定部１７Ｃが比較的広い領域を信号品質低下領域ＲＢとして画定した場合、その次の走査周期では当該広い領域に対して高頻度で出射光Ｌ１が出射されることとなる。従って、当該走査周期中においては、走査領域Ｒ０には大光量の走査光Ｌ２が照射されることとなる。 For example, when the signal quality degradation area defining unit 17C defines a relatively wide area as the signal quality degradation area RB, the outgoing light L1 is frequently emitted to the wide area in the next scanning cycle. . Therefore, in the scanning period, the scanning light R2 with a large amount of light is irradiated to the scanning region R0.
　ここで、測距装置１０は、例えば車両などの移動体に搭載される場合、当該車両の周辺領域を走査領域Ｒ０とした光走査を行う。換言すれば、走査領域Ｒ０内には、道路や交差点の他、歩行者及び他車両の運転者などが測距対象物ＯＢとして存在することが想定され、これらに走査光Ｌ２であるレーザ光が照射されることとなる。 Here, when mounted on a mobile object such as a vehicle, for example, the distance measuring apparatus 10 performs optical scanning with the peripheral region of the vehicle as the scanning region R0. In other words, it is assumed that the pedestrian, the driver of the other vehicle, etc. exist as a distance measurement object OB in addition to the road and the intersection in the scanning region R0, and the laser light which is the scanning light L2 It will be irradiated.
　従って、測距装置１０は、走査光Ｌ２が人体などの生物に照射された場合でも当該生物に影響が及ばないように、出射光Ｌ１の出射量の制御するように構成されていることが好ましい。例えば、制御部１７は、単位時間（例えば１の走査周期）内に出射された出射光Ｌ１の総光量を算出してもよい。また、制御部１７（光源制御部１７Ｄ）は、算出された光量に基づいて、当該算出後の走査周期における信号品質低下領域ＲＢへの出射光Ｌ１の出射頻度及び強度を制御してもよい。 Therefore, it is preferable that the distance measuring apparatus 10 be configured to control the emission amount of the emission light L1 so that even if the scanning light L2 is irradiated to a living thing such as a human body, the living thing is not affected. . For example, the control unit 17 may calculate the total light amount of the emitted light L1 emitted in a unit time (for example, one scanning cycle). In addition, the control unit 17 (light source control unit 17D) may control the emission frequency and intensity of the emission light L1 to the signal quality deterioration region RB in the scan cycle after the calculation based on the calculated light amount.
　例えば、日本工業規格（ＪＩＳ）には、レーザの安全基準が定められている。例えば、制御部１７は、この安全基準の試験条件（例えばレーザ光の照射量を測定する時間や領域サイズ）などを考慮して光量算出の際の閾値を設定する。 For example, Japanese Industrial Standards (JIS) define safety standards for lasers. For example, the control unit 17 sets a threshold for calculating the light amount in consideration of the test condition of this safety standard (for example, the time or the area size for measuring the irradiation amount of the laser light).
　例えば、制御部１７は、当該安全基準の試験時間よりも十分に短い時間を光量の算出時間（単位時間）として設定する。制御部１７は、例えば１つの走査周期を当該算出時間として、走査周期毎の出射光Ｌ１の光量を算出する。 For example, the control unit 17 sets a time sufficiently shorter than the test time of the safety standard as the light amount calculation time (unit time). The control unit 17 calculates the light amount of the emitted light L1 for each scanning cycle, for example, using one scanning cycle as the calculation time.
　また、制御部１７は、走査周期内の出射光Ｌ１の総光量の上限値（閾値）を設定する。例えば、制御部１７は、安全基準のレーザ光の光量の上限値及びその試験時間から、当該走査周期（単位時間）当たりの出射光Ｌ１の光量の閾値を設定する。そして、光源制御部１７Ｄは、算出した出射光Ｌ１の光量が閾値を超えないように、次の走査周期における出射光Ｌ１の出射量、例えば信号品質低下領域ＲＢに対する出射光Ｌ１の頻度又は強度の上昇量を抑制する。 Further, the control unit 17 sets an upper limit value (threshold value) of the total light amount of the emitted light L1 in the scanning cycle. For example, the control unit 17 sets the threshold value of the light amount of the emitted light L1 per the scanning cycle (unit time) from the upper limit value of the light amount of the laser light of the safety standard and the test time. Then, the light source control unit 17D controls the emission amount of the emission light L1 in the next scanning cycle, for example, the frequency or the intensity of the emission light L1 with respect to the signal quality deterioration region RB, so that the calculated light amount of the emission light L1 does not exceed the threshold. Suppress the amount of rise.
　なお、この光量の閾値は、当該閾値をその後一定時間超えた場合でも安全基準の上限値を超えないように、当該上限値となる光量の単位時間分の値よりも十分に小さい値に設定されることができる。 The light amount threshold is set to a value sufficiently smaller than the light amount unit time corresponding to the upper limit value so as not to exceed the upper limit value of the safety standard even when the threshold value is exceeded for a predetermined time thereafter. Can be
　本実施例においては、測距装置１０は、例えば単位時間毎に出射光Ｌ１の出射量を算出し、安全基準を満たす光量の範囲内で、信号品質低下領域ＲＢに対する出射光Ｌ１の出射頻度及び強度を他の領域よりも大きくするように制御される。換言すれば、光源部１１は、例えば、走査領域Ｒ０に向けて出射される出射光Ｌ１の走査周期毎の総光量が所定値未満となるように、出射光Ｌ１の出射態様を調節する。従って、安全にかつ正確な光走査及び測距を行うことができる。 In the present embodiment, the distance measuring apparatus 10 calculates, for example, the emission amount of the emission light L1 every unit time, and within the range of the light amount satisfying the safety standard, the emission frequency of the emission light L1 to the signal quality reduction region RB and The intensity is controlled to be greater than in the other regions. In other words, the light source unit 11 adjusts the emission mode of the emitted light L1 so that the total light amount for each scanning cycle of the emitted light L1 emitted toward the scanning region R0 is less than a predetermined value, for example. Therefore, light scanning and ranging can be performed safely and accurately.
　なお、制御部１７による出射光Ｌ１の制御態様は上記に限定されない。例えば、本実施例においては、信号品質低下領域ＲＢに対して、他の領域よりも高い頻度又は強度で出射光Ｌ１が出射される場合について説明した。しかし、信号品質低下領域ＲＢに対しては、他の領域よりも低い頻度又は強度で出射光Ｌ１が出射されてもよい。 In addition, the control aspect of the emitted light L1 by the control part 17 is not limited above. For example, in the present embodiment, the case where the outgoing light L1 is emitted with a frequency or intensity higher than that in the other regions with respect to the signal quality deterioration region RB has been described. However, the outgoing light L1 may be emitted to the signal quality deteriorated region RB at a frequency or intensity lower than that of the other regions.
　例えば、光反射率が高い測距対象物ＯＢが測距装置１０に近接した位置に存在する場合、設計上の強度を大きく超えた強度の反射光Ｌ３が測距装置１０に戻って来る。この場合、受光部１３は、受光可能な強度（感度範囲）を超えた光を受光することで、その後、一定時間動作不能な状態（例えば信号レベルが最大値の受光信号ＳＲを出力し続ける状態）となったり、受光信号ＳＲが飽和して正確なピークを検出できなくなる。そこで、認識部１６は走査部１２が走査領域Ｒ０を走査した場合に受光部１３が受光する反射光Ｌ３の強度を認識し、信号品質低下領域１７Ｃは、受光信号ＳＲの強度が所定の閾値以上となった領域及びその周辺領域を信号品質低下領域として画定してもよい。 For example, when the distance measuring object OB having a high light reflectance is present at a position close to the distance measuring apparatus 10, the reflected light L3 having an intensity which greatly exceeds the design intensity returns to the distance measuring apparatus 10. In this case, the light receiving unit 13 can not operate for a certain period of time by receiving light exceeding the light receiving intensity (sensitivity range) (for example, a state in which the light receiving signal SR with the maximum signal level is continuously output) And the light reception signal SR is saturated, so that accurate peaks can not be detected. Therefore, the recognition unit 16 recognizes the intensity of the reflected light L3 received by the light receiving unit 13 when the scanning unit 12 scans the scanning region R0, and in the signal quality deterioration region 17C, the intensity of the light reception signal SR is equal to or more than a predetermined threshold And the surrounding area may be defined as a signal degradation area.
　この場合は、その後の走査周期での測距精度及び動作の安定性を考慮すると、信号品質低下領域ＲＢには低い強度で出射光Ｌ１を出射すること、又は出射光Ｌ１の出射を停止することが好ましい。 In this case, in consideration of distance measurement accuracy in the subsequent scanning cycle and stability of operation, the emission light L1 is emitted to the signal quality deterioration region RB at a low intensity, or the emission of the emission light L1 is stopped. Is preferred.
　このように、制御部１７は、認識部１６が認識した走査領域Ｒ０内の状況に基づいて、走査部１２が走査領域Ｒ０を走査した場合に受光信号ＲＳの信号対雑音比が所定の基準値よりも低くなる信号品質低下領域ＲＢに対する出射光Ｌ１の出射態様を、走査領域Ｒ０内における信号品質低下領域ＲＢの他の領域に対する出射光Ｌ１の出射態様から変化させるように構成されていればよい。 As described above, the control unit 17 determines that the signal-to-noise ratio of the light reception signal RS is a predetermined reference value when the scanning unit 12 scans the scanning region R0 based on the situation in the scanning region R0 recognized by the recognition unit 16 It may be configured to change the emission aspect of the outgoing light L1 to the signal quality deterioration area RB lower than that from the emission aspect of the outgoing light L1 to the other areas of the signal quality deterioration area RB in the scanning area R0. .
　また、本実施例においては、制御部１７が信号対雑音比の低い領域である信号品質低下領域ＲＢを画定する場合について説明した。しかし、制御部１７は、認識部１６からの認識情報（走査領域Ｒ０内の状況）に基づいて、走査領域Ｒ０内の任意の一部の領域を、出射光Ｌ１の制御領域として画定すればよい。 Further, in the present embodiment, the case where the control unit 17 defines the signal quality degradation region RB which is a region with a low signal-to-noise ratio has been described. However, the control unit 17 may define an arbitrary partial region in the scanning region R0 as a control region of the outgoing light L1 based on the recognition information (the state in the scanning region R0) from the recognition unit 16 .
　例えば、制御部１７は、信号品質上昇領域、すなわち好ましい反射光Ｌ３を受光することで信号対雑音比が高くなることが予想される領域を画定してもよい。この場合、制御部１７は、この信号品質上昇領域に対して他の領域よりも低い頻度又は強度で出射光Ｌ１を出射してもよい。 For example, the control unit 17 may define a signal quality enhancement region, that is, a region where the signal-to-noise ratio is expected to be high by receiving the preferable reflected light L3. In this case, the control unit 17 may emit the outgoing light L1 with a frequency or intensity lower than that of the other areas with respect to the signal quality increase area.
　換言すれば、制御部１７は、認識部１６が認識した走査領域Ｒ内の状況に基づいて、走査領域Ｒ０内の一部の領域に対し、走査領域Ｒ０内の他の領域とは異なる出射態様で出射光Ｌ１を出射するように構成されていればよい。 In other words, based on the situation in the scanning area R recognized by the recognition unit 16, the control unit 17 outputs an emission aspect different from other areas in the scanning area R0 with respect to a part of the scanning area R0. It should just be comprised so that emitted light L1 may be emitted.
　また、本実施例においては、走査部１２が電磁気的に光反射面１２Ａを揺動させるＭＥＭＳミラーを有し、走査軌跡ＴＲがリサージュ曲線を描くような走査態様を有する場合について説明した。しかし、走査部１２の構成及びその動作態様は、上記に限定されない。 Further, in the present embodiment, the case has been described in which the scanning unit 12 includes the MEMS mirror that electromagnetically swings the light reflecting surface 12A, and the scanning trajectory TR has a scanning mode that draws a Lissajous curve. However, the configuration of the scanning unit 12 and the operation mode thereof are not limited to the above.
　例えば、走査部１２の駆動力は電磁気力に限定されず、静電気力であってもよいし、圧電力であってもよい。例えば静電気力によって光反射面１２Ａを揺動させる場合、駆動力生成部２３は、永久磁石ＭＧ及び金属配線ＣＸ及びＣＹではなく、それぞれ固定枠Ｂ２上、揺動枠ＳＸ上及び揺動板ＳＹ上において互いに離間して配置された電極対であればよい。 For example, the driving force of the scanning unit 12 is not limited to electromagnetic force, and may be electrostatic force or piezoelectric power. For example, when the light reflecting surface 12A is rocked by electrostatic force, the driving force generation unit 23 is not the permanent magnet MG and the metal wires CX and CY, but on the fixed frame B2, the rocking frame SX and the rocking plate SY, respectively. The electrode pairs may be spaced apart from each other.
　また、走査部１２は、リサージュ曲線に従った軌道で走査領域Ｒ０を走査する場合に限定されない。例えば、ラスタースキャンを行う走査軌道であってもよいし、走査周期毎（例えば画像データのフレーム毎）に走査軌道が異なっていてもよい。走査部１２は、出射光Ｌ１（走査光Ｌ２）によって走査領域Ｒ０（有効走査面Ｒ２）を走査するように構成されていればよい。 In addition, the scanning unit 12 is not limited to the case of scanning the scanning region R0 in the trajectory according to the Lissajous curve. For example, it may be a scanning trajectory for performing raster scanning, or the scanning trajectory may be different for each scanning cycle (for example, for each frame of image data). The scanning unit 12 may be configured to scan the scanning region R0 (effective scanning surface R2) with the outgoing light L1 (scanning light L2).
　このように、本実施例においては、測距装置１０は、出射光Ｌ１を出射する光源部１１と、出射光Ｌ１によって所定の領域（走査領域Ｒ０）を走査する走査部１２と、出射光Ｌ１が当該所定の領域内に存在する測距対象物ＯＢによって反射した反射光Ｌ３に応じて電気信号（受光信号ＳＲ）を生成する受光部１３と、当該受光信号ＳＲに基づいて測距対象物ＯＢまでの距離を測定する測距部１４と、を有する。 As described above, in this embodiment, the distance measuring apparatus 10 includes the light source unit 11 that emits the outgoing light L1, the scanning unit 12 that scans a predetermined area (scanning area R0) with the outgoing light L1, and the outgoing light L1. A light receiving unit 13 that generates an electric signal (light reception signal SR) according to the reflected light L3 reflected by the distance measurement target object OB present in the predetermined area, and the distance measurement target object OB based on the light reception signal SR And a distance measuring unit 14 for measuring the distance to the point.
　また、測距装置１０は、走査部１２による当該所定の領域の走査に先立って当該所定の領域内の状況を認識する認識部１６と、認識部１６が認識した当該所定の領域内の状況に基づいて、当該所定の領域内の一部の領域に対するパルス光Ｌ１（すなわち走査光Ｌ２）の出射態様を変化させる制御部１７と、を有する。従って、走査領域Ｒ０内の測距対象物ＯＢの正確な測距を行うことが可能な測距装置１０を提供することができる。 In addition, the distance measuring apparatus 10 recognizes the situation in the predetermined area prior to the scanning of the predetermined area by the scanning unit 12 with the recognition unit 16 recognizing the situation in the predetermined area, and the situation in the predetermined area recognized by the recognition unit 16. And a control unit that changes an emission mode of the pulsed light L1 (that is, the scanning light L2) to a partial area in the predetermined area. Therefore, it is possible to provide the distance measuring apparatus 10 capable of performing accurate distance measurement of the distance measuring object OB in the scanning region R0.
　なお、光源部１１、走査部１２、受光部１３及び認識部１６は、測距部１４以外の機能回路に接続されることができ、受光信号ＳＲ（光走査情報）は、測距以外の用途に用いられることができる。すなわち、光源部１１、走査部１２、受光部１３及び認識部１６は、例えば制御部１７と共に、光走査装置を構成する。この場合、測距対象物ＯＢは走査対象物となる。この場合においても、例えば認識部１６の認識情報に基づいて光源部１１が出射光Ｌ１の出射態様を切替えることで、走査領域Ｒ０を正確に走査することが可能な光走査装置を構成する。 The light source unit 11, the scanning unit 12, the light receiving unit 13, and the recognition unit 16 can be connected to functional circuits other than the distance measuring unit 14, and the light reception signal SR (optical scanning information) is used for applications other than distance measurement. Can be used. That is, the light source unit 11, the scanning unit 12, the light receiving unit 13, and the recognition unit 16 constitute an optical scanning device together with, for example, the control unit 17. In this case, the ranging object OB is a scanning object. Also in this case, the light source unit 11 switches the emission mode of the emitted light L1 based on the recognition information of the recognition unit 16, for example, to configure an optical scanning device capable of accurately scanning the scanning region R0.
１０　測距装置
１１　光源部
１２　走査部
１３　受光部
１４　測距部
１６　認識部
１７　制御部 DESCRIPTION OF REFERENCE NUMERALS 10 distance measuring device 11 light source unit 12 scanning unit 13 light receiving unit 14 distance measuring unit 16 recognition unit 17 control unit

Claims (5)

  1. 　出射光を出射する光源部と、
    　前記出射光によって所定の領域を走査する走査部と、
    　前記出射光が前記所定の領域内に存在する対象物によって反射した反射光に応じて受光信号を生成する受光部と、
    　前記走査部による前記所定の領域の走査に先立って前記所定の領域内の状況を認識する認識部と、
    　前記認識部が認識した前記状況に基づいて、前記所定の領域内の一部の領域に対する前記出射光の出射態様を変化させるように前記光源部を制御する制御部と、を有することを特徴とする光走査装置。     A light source unit that emits outgoing light;
    A scanning unit configured to scan a predetermined area by the emitted light;
    A light receiving unit that generates a light reception signal according to reflected light that is emitted from the target and is present in the predetermined area;
    A recognition unit that recognizes a situation in the predetermined area prior to the scanning of the predetermined area by the scanning unit;
    A control unit configured to control the light source unit so as to change an emission mode of the emitted light with respect to a partial area in the predetermined area based on the situation recognized by the recognition unit. Optical scanning device.
  2. 　前記認識部は、前記出射光の波長域に対して感度を有することを特徴とする請求項１に記載の光走査装置。 The optical scanning device according to claim 1, wherein the recognition unit has sensitivity to a wavelength range of the outgoing light.
  3. 　前記制御部は、前記認識部が認識した前記状況に基づいて、前記光走査部が前記所定の領域を走査した場合に前記受光信号の信号対雑音比が所定の基準値よりも低くなる１又は複数の信号品質低下領域に対する前記出射光の出射態様を、前記所定の領域内における前記信号品質低下領域の他の領域に対する前記出射光の出射態様から変化させることを特徴とする請求項１又は２に記載の光走査装置。 The controller controls the signal-to-noise ratio of the light reception signal to be lower than a predetermined reference value when the light scanning unit scans the predetermined area based on the situation recognized by the recognition unit. The emission mode of the emitted light with respect to a plurality of signal quality reduced areas is changed from the emission mode of the emitted light with respect to another area of the signal quality deteriorated area in the predetermined area. The optical scanning device described in.
  4. 　前記制御部は、前記１又は複数の前記信号品質低下領域に対して前記他の領域よりも高い頻度又は強度で前記出射光を出射するように前記光源部を制御することを特徴とする請求項２又は３に記載の光走査装置。 The control unit controls the light source unit to emit the outgoing light with a frequency or intensity higher than that of the other area with respect to the one or more signal quality deterioration areas. The optical scanning device according to 2 or 3.
  5. 　出射光を出射する光源部と、
    　前記出射光によって所定の領域を走査する走査部と、
    　前記出射光が前記所定の領域内に存在する対象物によって反射した反射光に応じて受光信号を生成する受光部と、
    　前記受光信号に基づいて前記対象物までの距離を測定する測距部と、
    　前記走査部による前記所定の領域の走査に先立って前記所定の領域内の状況を認識する認識部と、
    　前記認識部が認識した前記状況に基づいて、前記所定の領域内の一部の領域に対する前記出射光の出射態様を変化させるように前記光源部を制御する制御部と、を有することを特徴とする測距装置。     A light source unit that emits outgoing light;
    A scanning unit configured to scan a predetermined area by the emitted light;
    A light receiving unit that generates a light reception signal according to reflected light that is emitted from the target and is present in the predetermined area;
    A distance measuring unit that measures the distance to the object based on the light reception signal;
    A recognition unit that recognizes a situation in the predetermined area prior to the scanning of the predetermined area by the scanning unit;
    A control unit configured to control the light source unit so as to change an emission mode of the emitted light with respect to a partial area in the predetermined area based on the situation recognized by the recognition unit. Range finder.
PCT/JP2018/045606 2017-12-19 2018-12-12 Optical scanning device and distance measuring device WO2019124177A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017-242463 2017-12-19
JP2017242463 2017-12-19

Publications (1)

Publication Number Publication Date
WO2019124177A1 true WO2019124177A1 (en) 2019-06-27

Family

ID=66994116

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/045606 WO2019124177A1 (en) 2017-12-19 2018-12-12 Optical scanning device and distance measuring device

Country Status (1)

Country Link
WO (1) WO2019124177A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3674749A4 (en) * 2017-09-28 2021-04-28 Pioneer Corporation Distance measurement device and optical scanning device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050068517A1 (en) * 2003-06-25 2005-03-31 Evans Bruno J. Multi-spectral ladar
JP2006023150A (en) * 2004-07-07 2006-01-26 Nissan Motor Co Ltd Infrared light projector, infrared imaging device, and vehicle
JP2013124968A (en) * 2011-12-15 2013-06-24 Ihi Aerospace Co Ltd Automatic range finding apparatus
JP2017173298A (en) * 2016-03-16 2017-09-28 株式会社リコー Object detection device and mobile entity device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050068517A1 (en) * 2003-06-25 2005-03-31 Evans Bruno J. Multi-spectral ladar
JP2006023150A (en) * 2004-07-07 2006-01-26 Nissan Motor Co Ltd Infrared light projector, infrared imaging device, and vehicle
JP2013124968A (en) * 2011-12-15 2013-06-24 Ihi Aerospace Co Ltd Automatic range finding apparatus
JP2017173298A (en) * 2016-03-16 2017-09-28 株式会社リコー Object detection device and mobile entity device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3674749A4 (en) * 2017-09-28 2021-04-28 Pioneer Corporation Distance measurement device and optical scanning device

Similar Documents

Publication Publication Date Title
KR101964971B1 (en) A lidar device
US20130188043A1 (en) Active illumination scanning imager
US9829579B2 (en) Electronic apparatus and method for measuring direction of output laser light
CN109581360B (en) Apparatus and method for light detection and ranging
US11592530B2 (en) Detector designs for improved resolution in lidar systems
CN113924510A (en) Scanner control for lidar systems
JP2011089874A (en) Distance image data acquisition device
JP2022159464A (en) Ranging device
JP2023015199A (en) Scanner and distance measuring device
CN110300900B (en) Lidar sensor for sensing objects
US20210011281A1 (en) Light scanning apparatus, object detecting apparatus, light scanning method, object detecting method and storage medium
WO2019124177A1 (en) Optical scanning device and distance measuring device
JP6714665B2 (en) Device and method for light detection and ranging
JP2021170033A (en) Scanner
JP2024038361A (en) Distance measuring device and optical scanning device
JP2019109143A (en) Optical scanning device and ranging device
JP2018013370A (en) Laser radar device
JP2020020703A (en) Scanner, method for controlling scanner, program, recording medium, and distance measuring device
JP2019109142A (en) Optical scanning device and ranging device
JP2019074329A (en) Ranging device and optical scanner
JP6804619B1 (en) Laser distance measuring device
JP2019086423A (en) Distance measuring device
JP2019095354A (en) Ranging device
US20230079909A1 (en) Dynamic laser emission control in light detection and ranging (lidar) systems
JP2020027043A (en) Scanner, method for controlling scanner, program, recording medium, and distance measuring device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18892751

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18892751

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP