WO2021049151A1 - Dispositif de mesure de distance et procédé d'ajustement de déviation de mécanisme de mesure de distance pour celui-ci - Google Patents

Dispositif de mesure de distance et procédé d'ajustement de déviation de mécanisme de mesure de distance pour celui-ci Download PDF

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WO2021049151A1
WO2021049151A1 PCT/JP2020/026909 JP2020026909W WO2021049151A1 WO 2021049151 A1 WO2021049151 A1 WO 2021049151A1 JP 2020026909 W JP2020026909 W JP 2020026909W WO 2021049151 A1 WO2021049151 A1 WO 2021049151A1
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light
light receiving
distance measuring
unit
deviation
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PCT/JP2020/026909
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English (en)
Japanese (ja)
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加治　伸暁
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ソニーセミコンダクタソリューションズ株式会社
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    • 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
    • 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
    • G01S7/497—Means for monitoring or calibrating
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/10—Scanning systems

Definitions

  • the technique according to the present disclosure relates to a distance measuring device and a method of adjusting a deviation of a distance measuring mechanism in the device.
  • a distance measuring device (sometimes called a distance measuring sensor) that measures the distance to an object (object) based on ToF (Time of Flight) is known.
  • the TOF generally includes a direct TOF (dTOF) and an indirect TOF (iTOF).
  • Directly ToF emits pulsed light from a light emitting element, receives reflected light from an object irradiated with pulsed light by a light receiving element called SPAD (Single Photon Avalanche Diode), detects photons, and detects carriers generated by this.
  • SPAD Single Photon Avalanche Diode
  • This is a technology that measures the arrival time of reflected light by converting it into an electrical signal pulse using Avalanche multiplication and inputting it to a TDC (Time to Digital Converter), and calculates the distance to an object.
  • TDC Time to Digital Converter
  • the indirect ToF detects the charge generated by emitting pulsed light from the light emitting element and receiving the reflected light from the object irradiated with the pulsed light by the light receiving element, and the accumulated amount of the light is set at the arrival timing of the light.
  • the flight time of light is measured by using a semiconductor device structure that changes depending on the device.
  • Patent Document 1 describes a light source that irradiates an object with luminance-modulated scanning light, a pixel array that converts reflected light from the object into an electrical signal, and sensitivity-modulates the object in synchronization with the luminance modulation.
  • a distance image input device having a pixel drive circuit that drives the pixel array and reads out a signal in synchronization with scanning in the scanning light.
  • the present disclosure provides a distance measuring device capable of eliminating a deviation in the distance measuring processing timing due to a change over time of the distance measuring mechanism, and a method for adjusting the deviation of the distance measuring mechanism in the device.
  • This technology for solving the above problems is configured to include the following specific items or technical features.
  • an irradiation unit that irradiates light from a light source while scanning the target area at a predetermined irradiation timing, and a plurality of irradiation units that receive the observation light in the target area and output an electric signal.
  • the light receiving unit including the light receiving element of the above and the irradiation unit included in the observation light received by some light receiving element group among the plurality of light receiving elements.
  • a distance measuring processing unit that performs distance measuring processing for calculating the distance to the object based on the value of the electric signal based on the accumulated electric charge, and the light corresponding to the light emitted by the irradiation unit. It is a distance measuring device including a control unit for controlling a light collecting region of reflected light and a charge storage region formed by a group of some light receiving elements among the plurality of light receiving elements. Then, the control unit calculates the amount of deviation between the condensing region and the charge storage region, and positions the condensing region and the charge storage region so that the calculated deviation amount becomes small. It is provided with a shift adjustment unit that adjusts the relationship.
  • the technique according to the present disclosure is a method of adjusting the deviation of the distance measuring mechanism in the distance measuring device.
  • the distance measuring mechanism may be configured to include an irradiation unit and a light receiving unit.
  • the deviation adjusting method is to irradiate the target area with light from a light source while scanning the target area at a predetermined irradiation timing, and to irradiate the observed light in the target area with a plurality of light receiving elements in the light receiving unit. Light received by some of the light receiving element groups and reflected light from an object irradiated with the light by the irradiation unit included in the observed light from some of the light receiving element groups.
  • the electric signal based on the accumulated electric charge is read out according to the above, distance measurement processing for calculating the distance to the object is performed based on the value of the read electric signal, and the irradiation unit is used. It includes controlling a condensing region of the reflected light corresponding to the irradiated light and a charge storage region by some light receiving element group among the plurality of light receiving elements. Then, the control calculates the amount of deviation between the condensing region and the charge storage region, and the relationship between the condensing region and the charge storage region so that the calculated deviation amount becomes small. Including adjusting.
  • the means does not simply mean a physical means, but also includes a case where the function of the means is realized by software. Further, the function of one means may be realized by two or more physical means, or the function of two or more means may be realized by one physical means.
  • system refers to a logical collection of a plurality of devices (or functional modules that realize a specific function), and whether or not each device or functional module is in a single housing. Is not particularly limited.
  • the distance measuring device and the timing adjusting method of the distance measuring mechanism in the device include a region (condensing region) of the light receiving portion in which the reflected light for the pulsed light emitted from the irradiation unit including the light source is collected.
  • the condensing region is included in the charge accumulation. It is characterized in that the condensing region for the charge accumulation can be adjusted (so that the charge accumulation timing matches the irradiation timing).
  • the adjustment of the condensing region is adjusted by controlling the scanning angle of the pulsed light by the irradiation unit.
  • FIG. 1 is a block diagram showing an example of the configuration of a distance measuring device according to an embodiment of the present technology.
  • the distance measuring device 1 emits pulsed light from a light source and receives reflected light from the object OBJ irradiated with the pulsed light by a light receiving element, and based on an electric signal obtained, the distance measuring device 1 reaches the object OBJ (object or subject).
  • an indirect TOF type distance measuring sensor will be described as an example, but the same can be applied to various sensors using a direct TOF type distance measuring sensor, an optical cutting method, or the like.
  • the distance measuring device 1 includes, for example, components such as a control unit 10, a driver unit 20, an irradiation unit 30, a light receiving unit 40, a storage unit 50, and a distance measuring processing unit 60. Consists of. These components can be integrally configured as, for example, a system-on-chip (SoC) such as a CMOS LSI, but for example, some components such as the irradiation unit 30 and the light receiving unit 40 are configured as separate LSIs. May be done.
  • SoC system-on-chip
  • the distance measuring device 1 also has a communication interface unit (communication IF unit) for outputting data related to the distance calculated by the distance measuring processing unit 60 (distance measuring data) to a host IC (not shown) arranged outside.
  • a communication interface unit communication IF unit
  • the distance measuring device 1 may be provided with a temperature sensor 80 for detecting a change in the operating environment, for example, temperature.
  • the control unit 10 executes, for example, the timing adjustment process of the distance measuring mechanism in the distance measuring device 1 described in the present disclosure based on the temperature detected by the temperature sensor 80.
  • the control unit 10 is a component that comprehensively controls the operation of the distance measuring device 1.
  • the control unit 10 includes, for example, a control signal generation unit 12 and a deviation adjusting unit 14.
  • the control unit 10 may include a clock generation unit that generates a clock that controls the operation of the distance measuring device 1.
  • the clock generation unit outputs the generated clock to, for example, the control signal generation unit 12.
  • the control signal generation unit 12 generates and outputs control signals for each of the driver unit 20 and the light receiving unit 40 according to the given clock. Specifically, the control signal generation unit 12 outputs an irradiation control signal for the irradiation unit 30 to irradiate and scan light at a predetermined irradiation timing to the driver unit 20, and at a read timing corresponding to the irradiation timing. A light receiving control signal for reading an electric signal from a specific light receiving element group of the light receiving unit 40 is output to the light receiving unit 40.
  • the deviation adjusting unit 14 is a region of a light receiving unit (condensing region) in which reflected light corresponding to laser pulsed light (hereinafter referred to as “pulse light”) emitted from an irradiation unit including a light source toward an object OBJ is collected. ) And the region of the light receiving portion (charge storage region) where the charge is accumulated in response to the irradiation of the pulsed light, the positional relationship is adjusted.
  • the shift adjusting unit 14 determines a parameter for adjusting the range of the focusing region in order to eliminate the positional or profile deviation between the focusing region and the charge storage region.
  • the positional relationship between the condensing region and the charge storage region is adjusted by adjusting the scanning angle of the irradiated pulsed light, as will be described later. Therefore, the deviation adjusting unit 14 gives the control signal generation unit 12 a parameter for controlling the drive voltage with respect to the scanning mirror.
  • the positional relationship between the condensing region and the charge storage region is adjusted by controlling the operation timing of the light receiving element group that stores the charge with respect to the irradiation timing of the pulsed light.
  • the driver unit 20 drives the irradiation unit 30 based on the irradiation control signal given from the control signal generation unit 12. For example, the driver unit 20 drives the light source so that the pulsed light is emitted based on the irradiation control signal, and the irradiation optical system of the irradiation unit 30 is used to scan the emitted pulsed light in a predetermined direction (FIG. (Not shown) is driven.
  • the irradiation unit 30 is a component that scans the target area while emitting pulsed light for TOF distance measurement.
  • the pulsed light used for such distance measurement is sometimes referred to as active light.
  • the irradiation unit 30 may include, for example, a light source and an irradiation optical system.
  • the light source can be, for example, a vertical cavity surface emitting laser (VCSEL laser).
  • the irradiation unit 30 is driven at high speed at a frequency of, for example, 10 to 200 MHz, and may have a pulse width of several to several tens of ns, but is not limited thereto.
  • the irradiation optical system includes, for example, a scanning mirror, a cylindrical lens, and the like.
  • the MEMS (Micro Electro Mechanical Systems) mirror is an example of a scanning mirror.
  • the irradiation unit 30 uses, for example, a scanning mirror or the like driven by the driver unit 20 to emit line-shaped light along one direction (for example, the horizontal direction) emitted from the light source under the control of the driver unit 20.
  • stepwise scanning in another direction (for example, the vertical direction) orthogonal to the one direction the target area is spatially irradiated with light.
  • the scanning angle of the scanning mirror is, for example, proportional to the magnitude of the drive voltage applied from the driver unit 20.
  • a light source that emits line-shaped light is used, but the present invention is not limited to this, and a point light source may be used.
  • surface irradiation is realized by two-dimensional scanning.
  • the light source is provided outside the LSI chip, but the light source is not limited to this, and may be configured by the on-chip.
  • the light receiving unit 40 is a sensor that reacts to light incident from the target area, accumulates electric charges under the control of the control unit 10, and outputs an electric signal corresponding to the electric charge.
  • a light receiving optical system such as a condenser lens is provided in front of the light receiving surface of the light receiving unit 40 so that light can be efficiently received.
  • the light receiving unit 40 is typically a CMOS image sensor including a plurality of light receiving elements arranged in a two-dimensional array.
  • the present invention is not limited to this, and for example, a CCD image sensor may be used.
  • the specific light receiving element group of the light receiving unit 40 operates under the control of the control unit 10 at a predetermined light receiving timing synchronized with, for example, a predetermined irradiation timing, and accumulates charges according to the received observation light.
  • a specific light receiving element group of the light receiving unit 40 is applied and driven by a voltage modulated to the same frequency (10 to 200 MHz) as the pulse driving frequency (10 to 200 MHz) described above.
  • the irradiation timing of the pulsed light and the accumulation timing of the light receiving element group are matched.
  • the light receiving unit 40 performs four charge storage and output (reading) for each zone (charge storage region) described later, for example, in response to four pulse light emissions.
  • the electric charge (electrical signal) read from the light receiving unit 40 is transferred to the storage unit 50.
  • the storage unit 50 is a memory that temporarily holds the electric signal read from the light receiving unit 40.
  • the storage unit 50 may be a volatile memory or a non-volatile memory.
  • the storage unit 50 is configured to hold an electric signal pulse for one frame read from the light receiving unit 40, but is not limited to this.
  • the storage unit 50 may hold an electrical signal based on the observed light corresponding to the irradiation of several lines of pulsed light by the irradiation unit 30.
  • the distance measurement processing unit 60 is a component that calculates (measures the distance) to the object OBJ based on the pulsed light emitted by the irradiation unit 30 and the observation light received by the light receiving unit 40.
  • the ranging processing unit 60 is typically configured by a signal processing processor.
  • the distance measuring processing unit 60 corresponds to the pulsed light having different phases (multiphase pulsed light) emitted by the irradiation unit 30, and the electric charge received and accumulated for each phase by the light receiving unit 40. Based on, it is configured to calculate the distance.
  • FIG. 2 is a block diagram showing an example of the configuration of the light receiving unit in the distance measuring device according to the embodiment of the present technology.
  • the light receiving unit 40 includes a light receiving element array 42, a vertical scanning circuit 44, and a horizontal scanning circuit 46.
  • the light receiving element array is a CMOS image sensor in which a plurality of light receiving elements are arranged in a two-dimensional array.
  • the light receiving element is, for example, an embedded photodiode having a lock-in pixel structure.
  • One light receiving element corresponds to, for example, one pixel, but is not limited to this.
  • the two-dimensional array may include a configuration in which the light receiving element groups are arranged along the row and column directions, and may include, for example, a configuration in which the light receiving element groups are arranged in a staggered manner.
  • the vertical scanning circuit 44 is a circuit that generates a row selection signal according to a control signal from the control signal generation unit 12, thereby sequentially enabling a group of light receiving elements arranged in the row direction.
  • the vertical scanning circuit 44 includes, for example, a shift register (not shown).
  • the vertical scanning circuit 44 is a light receiving element having a plurality of rows in a condensing region corresponding to scanning of pulsed light emitted by the irradiation unit 30 and a region circumscribing the condensing region (that is, a charge storage region) by a single row selection signal. Activate the swarm.
  • the horizontal scanning circuit 46 is a circuit that reads out an electric signal based on the electric charge generated by the activated light receiving element group according to the control signal from the control signal generation unit 12.
  • the horizontal scanning circuit 46 includes, for example, a shift register (not shown).
  • the horizontal scanning circuit 46 writes the electric signal read in parallel from the light receiving element group into the storage unit 50 while converting it into a serial electric signal.
  • the distance measuring device 1 selects, for example, a group of light receiving elements in the vertical direction by the vertical scanning circuit 44 in accordance with the irradiation timing of the pulsed light by the irradiation unit 30, and adjusts the charge accumulation and readout timings thereof. It may be configured.
  • FIG. 3 shows an example of a timing chart for explaining the operation of the light receiving unit in the distance measuring device according to the embodiment of the present technology. That is, as shown in the figure, the pulsed light having a pulse width T0 emitted by the irradiation unit 30 is irradiated to the object OBJ, and after the delay time Td, it is observed as reflected light in the light receiving unit 40. The observed reflected light is received by a specific light receiving element group (light receiving element group corresponding to scanning of the irradiated pulsed light) of the light receiving unit 40.
  • a specific light receiving element group light receiving element group corresponding to scanning of the irradiated pulsed light
  • Each light receiving element has a pair of gates, and by alternately applying pulse signals to each of the pair of gates, the gates are opened alternately, and the charges Q1 and Q2 generated by the light receiving elements are stored in each charge storage unit (FIG. Transfer to).
  • the charges Q1 and Q2 accumulated in each charge storage unit of each light receiving element are converted into the amount of change in voltage and read out as an electric signal.
  • the light receiving unit 40 configured as described above receives a plurality of lines of light by the cooperative operation of the vertical scanning circuit 44 and the horizontal scanning circuit 46 according to the control signal from the control signal generation unit 12 under the control of the control unit 10.
  • the element group is sequentially activated, and the accumulated charge is read out as an electric signal from the light receiving element group and output.
  • the distance measuring device 1 is positioned between the light collecting region and the charge storage region based on the absolute value of the difference between the charges Q1 and Q2 read from the light receiving element group.
  • the deviation is not limited to this, and may be configured to calculate the deviation based on either the charges Q1 or Q2, or the charges Q1 and Q2. It may be configured to calculate the deviation based on the absolute value of the sum.
  • the distance measuring device 1 performs four charge accumulation and charge reading in response to four pulsed lights. That is, under the control of the control unit 10, the irradiation unit 30 emits pulsed light (multiphase pulsed light) having different phases such as 0 degree, 90 degree, 180 degree, and 270 degree for each zone. Under the control of the control unit 10, the light receiving unit 40 collects the reflected light for the pulsed light emitted out of phase in this way, and accumulates charges according to the amount of light received for each phase.
  • the calculation of the distance D using the polymorphic pulsed light is performed, for example, as follows.
  • the distance D from the light source of the irradiation unit 20 to the object OBJ is calculated by the following formula.
  • D (1/2) ⁇ c ⁇ ⁇ t... Equation 1
  • c is the speed of light.
  • ⁇ t (1 / f) ⁇ ( ⁇ / 2 ⁇ ).
  • the distance D is calculated by substituting the calculated phase difference ⁇ into Equation 3.
  • FIG. 4 is a diagram for explaining the relationship between the condensing region and the charge storage region in the distance measuring device according to the embodiment of the present technology.
  • the condensing region A is an region where the reflected light corresponding to the pulsed light on the light receiving element array 42 is assumed to be condensed when the irradiation unit 30 irradiates and scans the pulsed light at a certain irradiation timing.
  • the charge storage region B shows a region in which charges are actually accumulated by the light receiving element group of the light receiving element array 42 for the irradiation / scanning and read out as an electric signal.
  • FIG. 3A shows the line direction in the charge storage region B with respect to the virtual center line L1 along the line direction in the condensing region A due to a time-dependent change of the distance measuring mechanism in a general distance measuring device. It shows a state in which the virtual center line L2 extended to is deviated by ⁇ . That is, in FIG. 3A, the light receiving element group that operates (accumulates charge) in response to the pulsed light irradiated at a certain irradiation timing does not match the light receiving element group in the original condensing region A. .. In such a case, the correct electric signal is not read out for the irradiation / scanning of the pulsed light, and a more accurate distance image cannot be obtained.
  • FIG. 3B shows the relationship between the condensing region A and the charge storage region B in the distance measuring device 1 according to the present technology. That is, as shown in the figure, the charge storage region B is set to include a region (circumscribing region) outside the condensing region A.
  • the margin m Since there is a margin corresponding to the above, the correct electric signal can be read out, and further, as will be described later, by adjusting the deviation of the charge accumulation region B with respect to the condensing region A, the activated charge in the condensing region A is activated.
  • the electric signal is correctly read out from the light receiving element group in which the electric charge is accumulated.
  • the width of the margin m is set to be the same at the top and bottom, but the width is not limited to this and may be different at the top and bottom.
  • FIG. 5 is a diagram for explaining a light receiving element array in a distance measuring device according to an embodiment of the present technology. This figure is used to explain the terms related to the deviation adjustment of the distance measuring mechanism in the present disclosure.
  • the light receiving element array 42 of this example is composed of a group of M ⁇ N pixels P (light receiving elements).
  • the light receiving element array 42 shown in the figure a group of N light receiving elements arranged along one direction (horizontal direction in the figure) is referred to as a "line”. Therefore, the light receiving element array 42 is composed of M lines. Further, it is assumed that the position of a certain pixel P is indicated by P (i, j).
  • the "zone” is a group of light receiving elements that accumulates electric charges centered on a certain line (corresponding to the electric charge accumulating region B in FIG. 4).
  • Zone i indicates a charge storage region centered on line i.
  • one zone is composed of 3 to 5 lines. Assuming that the total number of lines is M, the zones are as follows. Zone 1: Lines 1-3 Zone 2: Lines 1-4 Zone 3: Lines 1-5 Zone 4: Lines 2-6 Zone 5: Lines 3-7 (Omitted) Zone i: Lines i-2 to i + 2 (Omitted) Zone M: Lines M-2 to M
  • FIG. 6 is a sequence diagram for explaining the relationship between charge accumulation and charge readout in the distance measuring device according to the embodiment of the present technology.
  • the irradiation unit 30 receives the driver 20 at the timing of the falling edge. It emits multi-phase pulsed light that is driven by and is expected to be focused on Zone 1. Further, the control signal generation unit 12 outputs a scanning synchronization signal Ssync so as to synchronize with this.
  • the driver unit 20 controls the scanning mirror of the irradiation unit 30 to have a scanning angle corresponding to the voltage by sequentially lowering the driving voltage for the scanning mirror from V1 to VM according to the scanning synchronization signal Ssync. To do.
  • the scanning angle of the scanning mirror is proportional to the driving voltage, and when the voltage Vi is applied, the virtual center line L1 (see FIG. 4) of the condensing region A corresponding to the pulsed light is in the zone i. It is adjusted to match the center, that is, the line i.
  • the zone charge storage region B is provided with a margin m of several pixels or a few percent of the number of array pixels in the line direction and approximately three pixels in the scanning direction.
  • the deviation adjusting unit 14 determines an operation parameter for controlling the drive voltage for the scanning mirror according to the calculated deviation amount d, and outputs the operation parameter to the control signal generation unit 12.
  • each light receiving element of the light receiving unit 40 accumulates charges Q1 and Q2 in the charge storage unit in response to the vertical synchronization signal VSsync by the control signal generation unit 12, and the accumulated charges Q1 and Q2 are read out as charges Q.
  • the charge Q is an electric signal indicating the difference between the absolute values of the charge Q1 and the charge Q2. That is, as described above, for example, since the zone 1 is composed of the lines 1 to 3, the irradiation unit 30 is the pulsed light in which the virtual center line L1 in the condensing region A corresponding to the pulsed light coincides with the line 1.
  • the light receiving unit 40 accumulates charges Q1 and Q2 by the light receiving element group of lines 1 to 3, and reads them out.
  • charge accumulation and charge reading corresponding to the emission of pulsed light are performed four times during the time Tz for each zone. Then, after the transition time T2 elapses from the time T1 which is the sum of the time of four charge accumulation and the time of three charge reading, the charge accumulation and charge reading of the next zone are started.
  • the irradiation unit 30 emits pulsed light for focusing on the next zone, that is, zone 2, after a predetermined transition time T2 elapses from the time T1 required for four charge accumulations and three charge readouts.
  • the light receiving unit 40 accumulates charges Q1 and Q2 by the light receiving element group of lines 1 to 4, and the accumulated charges Q1 and Q2 are read out as charges Q.
  • charge accumulation and charge reading are repeated up to zone M, and then the process returns to zone 1 and charge accumulation and charge reading are repeated up to zone M.
  • such charge accumulation and charge reading from zones 1 to M are repeated 1000 times, for example, for error leveling.
  • FIG. 7 is a flowchart for explaining the deviation adjustment process of the distance measuring mechanism in the distance measuring device according to the embodiment of the present technology.
  • Such a deviation adjustment process is executed, for example, when the distance measuring device is started. Alternatively, it may be executed when the operating environment of the distance measuring device 1 suddenly changes or in accordance with an external instruction from a user or the like.
  • control unit 10 of the distance measuring device 1 first initially sets the irradiation position of the pulsed light and the charge storage region B (zone) corresponding thereto (S701).
  • the irradiation unit 30 irradiates and scans the target zone with a line-shaped pulsed light at a predetermined irradiation timing (in this example, four pulsed lights).
  • the light receiving unit 40 accumulates the charges Q1 and Q2 in the charge storage unit by receiving the reflected light by the light receiving element, and reads out the accumulated charges Q1 and Q2 as the charge Q (S702).
  • the read charge Q is temporarily stored in the storage unit 50. That is, in the storage unit 50, the charge from the light receiving element group in the charge storage region B formed by the horizontal line corresponding to the pulsed light and each line in the scanning direction (up to 5 lines in this example). Q is retained.
  • charge accumulation and charge reading are performed four times, but the charge Q referred to here may correspond to one charge accumulation and charge reading. It may be the total amount of electric charges for four times.
  • the deviation adjusting unit 14 identifies the number of the line in which the calculated total charge Q sum (i) is equal to or higher than a predetermined threshold value in the target zone, and counts up the number n. (S704).
  • the predetermined threshold value is provided to eliminate the influence of noise or the like because the charge Q does not become 0 due to noise or the like even in the line that does not receive the reflected light from the object.
  • the deviation adjusting unit 14 calculates the center of gravity position G in the zone based on the counted number of lines n (S705).
  • the center of gravity position G is calculated by the following formula.
  • G ( ⁇ Ln) / n ... Equation 7
  • Ln is the number of the line charge amount Q sum is equal to or greater than a predetermined threshold value
  • n is the number of lines total amount of charges Q sum is equal to or greater than a predetermined threshold value.
  • the center of gravity position G is set to.
  • the deviation adjusting unit 14 calculates the difference value (deviation amount) d between the calculated center of gravity position G and the reference position L Ref in the condensing region, and records this (S706).
  • the deviation adjusting unit 14 determines whether or not the above process has been repeated a predetermined number of times (for example, 1000 times) (S707), and if it determines that the process has not been repeated a predetermined number of times (No in S707), the process in S702 go back. On the other hand, when it is determined that the deviation adjusting unit 14 has been repeated a predetermined number of times (Yes in S707), the deviation adjusting unit 14 calculates the average value d Ave based on the recorded difference value d (S708).
  • the deviation adjusting unit 14 subsequently determines whether or not the calculated difference average value dAve is within a predetermined range (S709). That is, if the calculated difference average value dAve is within a predetermined range, it is determined that the deviation between the condensing region A and the charge storage region B is within an allowable range, and the deviation adjustment is not executed.
  • the deviation adjusting unit 14 determines that the calculated average value dAve is not within a predetermined range (No in S709), the deviation adjusting unit 14 adjusts the positional relationship between the condensing region A and the charge storage region B.
  • the operating parameter is changed so that the drive voltage for the scanning mirror is changed by, for example, one step (S710), and the process returns to S702.
  • the control signal generation unit 12 transmits a control signal based on the changed operation parameter to the driver 20, and the driver 20 drives the scanning mirror with a drive voltage based on the control signal.
  • the deviation adjusting unit 14 repeats the above processing for the target zone until the difference average value dAve falls within a predetermined range. As a result, in the target zone, the positional relationship between the condensing region A and the charge storage region B is gradually adjusted, and the deviation is eliminated.
  • the deviation adjusting unit 14 determines the operating parameters for adjusting the driving voltage for the scanning mirror, but the present invention is not limited to this, and for example, the reading timing from the light receiving element is adjusted. Is also good.
  • the deviation adjusting unit 14 adjusts the positional relationship between the condensing region A and the charge storage region B for the target zone, whether or not such a displacement of the positional relationship is adjusted for all the zones. Is determined (S711). When the deviation adjusting unit 14 determines that such a displacement of the positional relationship is not adjusted for all the zones (No in S711), the deviation adjusting unit 14 shifts the target zone by one (S712), and the above-mentioned Repeat the process. In this way, the misalignment adjustment is repeated until the final zone M.
  • the distance measuring device 1 is configured to adjust the scanning angle of the scanning mirror by controlling the driving voltage with respect to the scanning mirror, but the present invention is not limited to this.
  • the distance measuring device 1 should, for example, accumulate an electric charge and read an electric signal by the vertical scanning circuit 44 with respect to the irradiation timing of the pulsed light by the irradiation unit 30.
  • the deviation may be adjusted by controlling the number of light receiving element groups (number of lines) in the scanning direction.
  • a distance measuring device that eliminates the timing deviation of the distance measuring process due to a change over time of the distance measuring mechanism, and a method of adjusting the deviation of the distance measuring operation in the device. Therefore, the correct electric signal can be read out for the irradiation / scanning of the pulsed light, and a more accurate distance image can be obtained.
  • FIG. 8 is a diagram for explaining the relationship between the condensing region and the charge storage region corresponding to the irradiation light in the distance measuring device according to the embodiment of the present technology.
  • the condensing region A indicates an region where the pulsed light on the light receiving element array 42 is originally supposed to be condensed when the irradiation unit 30 irradiates and scans the pulsed light at a certain irradiation timing.
  • the charge storage region B indicates a region in which an electric signal is actually read out on the light receiving element array 42 for the irradiation / scanning.
  • the charge storage region B is set to include a region (circumscribing region) outside the original condensing region A.
  • the axis of the pulsed light in the line direction rotates by an angle ⁇
  • the axis thereof rotates by an angle ⁇ .
  • the distance measuring device 1 when the condensing region A'is displaced by an angle ⁇ with respect to the charge storage region B due to a change over time of the distance measuring mechanism or the like, the charge is charged according to the deviation amount.
  • the storage area B By expanding the storage area B in the scanning direction, the normal positional relationship between the light collection area A and the charge storage area B is calibrated, and an electric signal is read out from a group of light receiving elements suitable for the emission of pulsed light. I am trying to do it.
  • FIG. 9 is a flowchart for explaining the deviation adjustment process of the distance measuring mechanism in the distance measuring device according to the embodiment of the present technology.
  • control unit 10 of the distance measuring device 1 first initially sets the irradiation position of the pulsed light and the charge storage region B (zone) corresponding thereto (S901).
  • the irradiation unit 30 irradiates and scans a line-shaped pulsed light at a predetermined irradiation timing in order to collect light on the target zone, and accordingly, the light receiving unit 30 receives light.
  • the light receiving unit 40 accumulates charges Q1 and Q2 in the charge storage unit, and reads out the accumulated charges Q1 and Q2 as charge Q (S902).
  • the electric charge Q read from each of the light receiving element groups in the zone is temporarily held in the storage unit 50.
  • the shift adjusting unit 14 compares the charge Q with a predetermined threshold value for the purpose of removing noise and the like, and the charge Q is a predetermined threshold value among the light receiving element (pixel) group in the zone.
  • the above-mentioned pixels are specified, and the number n is counted (S903).
  • the deviation adjusting unit 14 calculates the center of gravity position G according to, for example, the following formula (S904).
  • G (xg, yg) ( ⁇ Pi / n, ⁇ Pj / n) ...
  • Equation 8 Pi is the x-coordinate of a pixel whose charge Q is equal to or higher than a predetermined threshold value (the x direction corresponds to the scanning direction), and Pj is a pixel whose charge Q is equal to or higher than a predetermined threshold value. It is the y coordinate (the y direction corresponds to the line direction). Further, n is the number of pixels whose electric charge Q is equal to or higher than a predetermined threshold value.
  • the deviation adjusting unit 14 determines the vector V2 (Pi ⁇ xg) for a pixel whose charge Q is equal to or higher than a predetermined threshold value and whose pixel coordinate Pi is smaller than the x coordinate xg of the center of gravity position G in the x direction.
  • u2, v2) is calculated.
  • V2 (u2, v2) (- ⁇ Pi / n, - ⁇ Pj / n,) ... Equation 5
  • the shift adjusting unit 14 calculates the inclination ⁇ (see FIG. 8) of the condensing region A with respect to the charge storage region B according to the following equation.
  • sin ⁇
  • is the absolute value of the component u of the vector V.
  • the deviation adjusting unit 14 calculates the number of pixels corresponding to the inclination G_tilt according to the following formula based on the calculated inclination ⁇ , and records this (S906).
  • the number of pixels corresponding to the inclination G_tilt indicates how many pixels the end of the condensing region A is deviated in the scanning direction at the end of the charge storage region B.
  • G_tilt (N / 2) * sin ⁇ ... Equation 12
  • N is the number of pixels that exceeds the threshold value.
  • the deviation adjusting unit 14 determines whether or not the above processing has been repeated a predetermined number of times (for example, 1,000 times) (S907), and if it determines that the above processing has not been repeated a predetermined number of times (No in S907), the processing in S902. Return to. On the other hand, when it is determined that the deviation adjusting unit 14 has been repeated a predetermined number of times (Yes in S907), the deviation adjusting unit 14 calculates the average value G_tilt_ave of the number of pixels corresponding to the inclination based on the recorded number of pixels corresponding to the inclination G_tilt (Yes). S908).
  • a predetermined number of times for example, 1,000 times
  • the deviation adjusting unit 14 subsequently determines whether or not the calculated average value G_tilt_ave of the number of pixels corresponding to the inclination is within a predetermined range (S909). For example, the deviation adjusting unit 14 determines whether or not the average value G_tilt_ave of the number of pixels corresponding to the inclination satisfies the following equation with respect to the margin m. G_tilt_ave ⁇ m / 2 ... Equation 13
  • the deviation adjusting unit 14 determines that the equation 13 is satisfied (true) (Yes in S909), the deviation between the condensing region A and the charge storage region B due to the inclination ⁇ of the virtual center line is determined by the distance measuring device. In the operation of 1, it is judged that it is within the allowable range, and the number of lines constituting the zone is not adjusted (increased or decreased).
  • the deviation adjusting unit 14 determines that the calculated average value G_tilt_ave of the number of pixels corresponding to the inclination is not within the predetermined range (No in S909), it determines that the equation 13 is not satisfied (false). In this case, the parameters for the control signal that controls the light receiving unit 40 are adjusted so that the number of lines included in the zone increases (S910). That is, the shift adjusting unit 14 expands the charge storage region B by increasing the group of light receiving elements activated for charge storage in the light receiving element array 42 in line units with respect to the irradiation timing of the pulsed light. The deviation adjusting unit 14 returns to the process of S902 after adjusting the number of lines in the zone.
  • the deviation adjusting unit 14 repeats the above processing for the target zone until the average G_tilt_ave of the number of pixels corresponding to the inclination falls within a predetermined range.
  • the relationship between the condensing region A and the charge storage region B is gradually adjusted, and even if there is a deviation due to the inclination of the condensing region A with respect to the charge storage region B, the collection is performed.
  • the entire region of the optical region A is adjusted to be included in the charge storage region B, and as a result, the distance measurement data in the charge storage region B can be prevented from being lost, and the distance measurement can be performed accurately.
  • the present embodiment is a distance measuring device that executes the above-described deviation adjusting process in response to a command from the outside by the operator, and a timing adjusting method of the distance measuring mechanism in the device.
  • a reflector having a size sufficient to cover the entire angle of view of the light receiving unit 40 is installed in front of the distance measuring device 1, but the present invention is not limited to this.
  • the reflector for example, a reflector that is entirely white can be adopted.
  • the operator instructs the distance measuring device 1 to execute the timing adjustment process, for example, via an external input.
  • the control unit 10 of the distance measuring device 1 receives the adjustment start signal based on the instruction of the operator, it irradiates the pulse light toward the reflector installed in front and receives the reflected light to adjust the deviation.
  • the unit 14 executes the timing adjustment process as shown in the above embodiment.
  • the deviation adjusting unit 14 may receive the reflected light not in the zone unit described above but in the entire light receiving element array 42, and calculate the deviation based on this. Further, the number of repetitions can be reduced to several to several tens of times as compared with the case without the reflector.
  • steps, actions or functions may be performed in parallel or in a different order, as long as the results are not inconsistent.
  • the steps, actions and functions described are provided merely as examples, and some of the steps, actions and functions can be omitted and combined with each other to the extent that they do not deviate from the gist of the invention. It may be one, or other steps, actions or functions may be added.
  • the present technology can also adopt the following configurations.
  • An irradiation unit that irradiates light from a light source while scanning the target area at a predetermined irradiation timing.
  • a light receiving unit including a plurality of light receiving elements that receive observation light in the target area and output an electric signal. The electricity based on the charge accumulated according to the reflected light from the object irradiated with the light by the irradiation unit included in the observation light received by some light receiving element group among the plurality of light receiving elements.
  • a distance measuring processing unit that performs distance measuring processing for calculating the distance to the object based on the value of the signal, and a distance measuring unit.
  • a control unit for controlling a condensing region of the reflected light corresponding to the light emitted by the irradiation unit and a charge storage region by a group of some light receiving elements among the plurality of light receiving elements is provided.
  • the control unit calculates the amount of deviation between the condensing region and the charge storage region, and the positional relationship between the condensing region and the charge storage region so that the calculated deviation amount becomes small. Equipped with a shift adjustment unit to adjust Distance measuring device.
  • the shift adjusting unit has a center of gravity position based on the value of the first electric signal read from the first light receiving element group among the plurality of light receiving elements in the charge storage region, and a reference position in the light collecting region. Based on this, the amount of deviation is calculated.
  • the distance measuring device according to (1) above.
  • (3) The control unit controls so that the irradiation of the light by the irradiation unit is repeated at the predetermined irradiation timing.
  • the deviation adjusting unit calculates an average value of the position of the center of gravity based on the value of the first electric signal based on the electric charge accumulated by the first light receiving element group according to the repetition of the irradiation, and obtains the average value. Calculate the deviation amount based on The distance measuring device according to (2) above.
  • (4) The deviation adjusting unit calculates the position of the center of gravity when the value of the first electric signal is equal to or higher than a predetermined threshold value.
  • the distance measuring device according to (2) or (3) above.
  • the deviation adjusting unit adjusts the positional relationship between the condensing region and the charge storage region when the deviation amount is equal to or greater than a predetermined allowable value.
  • the distance measuring device according to any one of (1) to (4).
  • the irradiation unit irradiates the line-shaped light along one direction according to the predetermined irradiation timing while sequentially scanning the light in a direction orthogonal to the one direction at a predetermined scanning angle.
  • the control unit controls to read out a first electric signal based on the charge accumulated in the first light receiving element group among the plurality of light receiving elements in the charge storage region from the first light receiving element group.
  • the distance measuring device according to any one of (1) to (5).
  • the deviation adjusting unit controls so that the predetermined scanning angle is adjusted according to the deviation amount.
  • the irradiation unit includes a scanning mirror for sequentially scanning the light at a predetermined scanning angle according to a driving voltage.
  • the deviation adjusting unit controls so that the predetermined scanning angle is adjusted by controlling the driving voltage with respect to the scanning mirror.
  • the distance measuring device according to (7) above. (9) The deviation adjusting unit controls the operation of some light receiving element groups among the plurality of light receiving elements so that the charge storage region is expanded according to the deviation amount.
  • the shift adjusting unit calculates the inclination of the light collecting region with respect to the charge storage region, and based on the calculated inclination, some of the plurality of light receiving elements so that the charge storage region is expanded. Controls the operation of the light receiving element group of The distance measuring device according to (9) above. (11) The deviation adjusting unit controls the irradiation timing so as to adjust the operation timing of the light receiving element group that accumulates the electric charge.
  • a memory for holding the value of the electric signal read from a group of some light receiving elements among the plurality of light receiving elements is further provided. The distance measuring device according to claim 1, wherein any one of (1) to (11) is described.
  • the control unit operates the deviation adjustment unit according to an adjustment start instruction signal given from the outside.
  • the distance measuring device according to any one of (1) to (12).
  • the first light receiving element group includes a light receiving element group among the plurality of light receiving elements in the light collecting region and a light receiving element group in a region circumscribing the region.
  • the distance measuring device according to any one of (2) to (13).
  • It is a method of adjusting the deviation of the distance measuring mechanism in a distance measuring device. The light from the light source is irradiated to the target area at a predetermined irradiation timing while being scanned by the irradiation unit.
  • the observation light in the target area is received by some light receiving element groups among the plurality of light receiving elements in the light receiving unit, and Reading an electric signal based on an electric charge accumulated according to the reflected light from an object irradiated with the light by the irradiation unit included in the observation light from a group of some light receiving elements among the plurality of light receiving elements.
  • the control is This includes calculating the amount of deviation between the condensing region and the charge storage region and adjusting the relationship between the condensing region and the charge storage region so that the calculated deviation amount becomes small. How to adjust the deviation of the distance measuring mechanism. (16)
  • the adjustment is The position of the center of gravity is calculated based on the value of the first electric signal read from the first light receiving element group among the plurality of light receiving elements in the charge storage region.
  • the deviation amount is calculated based on the calculated center of gravity position and the reference position in the charge storage region.
  • the method for adjusting the deviation of the distance measuring mechanism according to (15) above.

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

Abstract

La présente invention comprend : une unité d'émission permettant d'émettre de la lumière à partir d'une source de lumière tout en balayant une zone donnée avec la lumière ; une unité de réception de lumière comprenant une pluralité d'éléments de réception de lumière permettant de recevoir de la lumière d'observation à partir de la zone donnée et fournir en sortie des signaux électriques ; une unité de traitement de mesure de distance permettant de calculer la distance jusqu'à un objet en fonction de la valeur d'un signal électrique basé sur la charge accumulée selon la lumière qui a été émise par l'unité d'émission et réfléchie par l'objet et est incluse dans la lumière d'observation reçue par la pluralité d'éléments de réception de lumière ; une zone où est concentrée la lumière réfléchie correspondant à la lumière émise par l'unité d'émission ; et une zone d'accumulation de charge comprenant un groupe d'éléments de réception de lumière parmi la pluralité d'éléments de réception de lumière. Une unité de commande comprend une unité d'ajustement de déviation permettant de calculer la quantité de déviation entre la zone de concentration et la zone d'accumulation de charge et d'ajuster la relation de position entre la zone de concentration et la zone d'accumulation de charge de sorte que la quantité de déviation calculée diminue.
PCT/JP2020/026909 2019-09-13 2020-07-09 Dispositif de mesure de distance et procédé d'ajustement de déviation de mécanisme de mesure de distance pour celui-ci WO2021049151A1 (fr)

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JP2002039716A (ja) * 2000-07-25 2002-02-06 Olympus Optical Co Ltd 距離画像入力装置
JP2003004850A (ja) * 2001-06-20 2003-01-08 Denso Corp 距離測定装置
JP2004157044A (ja) * 2002-11-07 2004-06-03 Nippon Signal Co Ltd:The 走査型レーザレーダ
JP2012058158A (ja) * 2010-09-10 2012-03-22 Toshiba Corp 目標追跡装置及び目標追跡方法
JP2017003391A (ja) * 2015-06-09 2017-01-05 株式会社デンソー レーザレーダシステム
JP2018537680A (ja) * 2015-12-20 2018-12-20 アップル インコーポレイテッドＡｐｐｌｅ Ｉｎｃ． 光検出測距センサ
WO2019021887A1 (fr) * 2017-07-27 2019-01-31 シャープ株式会社 Dispositif radar optique
JP2020118569A (ja) * 2019-01-24 2020-08-06 ソニーセミコンダクタソリューションズ株式会社 受光装置および測距装置

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002039716A (ja) * 2000-07-25 2002-02-06 Olympus Optical Co Ltd 距離画像入力装置
JP2003004850A (ja) * 2001-06-20 2003-01-08 Denso Corp 距離測定装置
JP2004157044A (ja) * 2002-11-07 2004-06-03 Nippon Signal Co Ltd:The 走査型レーザレーダ
JP2012058158A (ja) * 2010-09-10 2012-03-22 Toshiba Corp 目標追跡装置及び目標追跡方法
JP2017003391A (ja) * 2015-06-09 2017-01-05 株式会社デンソー レーザレーダシステム
JP2018537680A (ja) * 2015-12-20 2018-12-20 アップル インコーポレイテッドＡｐｐｌｅ Ｉｎｃ． 光検出測距センサ
WO2019021887A1 (fr) * 2017-07-27 2019-01-31 シャープ株式会社 Dispositif radar optique
JP2020118569A (ja) * 2019-01-24 2020-08-06 ソニーセミコンダクタソリューションズ株式会社 受光装置および測距装置

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