[go: up one dir, main page]

WO2017138032A1 - Dispositif de mesure de distance par temps de vol et procédé de détection d'erreur multivoie - Google Patents

Dispositif de mesure de distance par temps de vol et procédé de détection d'erreur multivoie Download PDF

Info

Publication number
WO2017138032A1
WO2017138032A1 PCT/JP2016/000638 JP2016000638W WO2017138032A1 WO 2017138032 A1 WO2017138032 A1 WO 2017138032A1 JP 2016000638 W JP2016000638 W JP 2016000638W WO 2017138032 A1 WO2017138032 A1 WO 2017138032A1
Authority
WO
WIPO (PCT)
Prior art keywords
signals
switch
photodetectors
different types
subset
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/JP2016/000638
Other languages
English (en)
Inventor
Toshiaki Nagai
Martin Popp
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Espros Photonics AG
Denso Corp
Original Assignee
Espros Photonics AG
Denso Corp
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 Espros Photonics AG, Denso Corp filed Critical Espros Photonics AG
Priority to PCT/JP2016/000638 priority Critical patent/WO2017138032A1/fr
Publication of WO2017138032A1 publication Critical patent/WO2017138032A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G01S17/32—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S17/36—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated with phase comparison between the received signal and the contemporaneously transmitted signal
    • 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
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
    • G01S17/894—3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
    • 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
    • G01S7/491—Details of non-pulse systems
    • G01S7/4911—Transmitters
    • 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
    • G01S7/491—Details of non-pulse systems
    • G01S7/4912—Receivers
    • G01S7/4915—Time delay measurement, e.g. operational details for pixel components; Phase measurement

Definitions

  • the present disclosure relates to a time-of-flight distance measuring device and a method for detecting a multipath error.
  • a time-of-flight (TOF) technology As a method for measuring the distance to an object in a scene, a time-of-flight (TOF) technology has been developed.
  • TOF technology may be used in a variety of fields, such as automotive industries, human-interfaces and gaming, robotics or the like.
  • the TOF technology works by illuminating a scene with modulated light emitted from a light source and by observing reflected light reflected by an object in the scene. By measuring the phase difference between the emitted light and the reflected light, the distance to the object is calculated (see, e.g., Patent Literatures 1 to 4).
  • multipath interference may affect the accuracy of the measured distance.
  • the multipath interference arises when the emitted light travels along multiple paths that have a different path length from each other and then is sensed by a single photo receiver as integrated light. Although the phases of light along the different path lengths are different each other, the conventional distance measuring device computes a distance based on mixed phases of the integrated light. Therefore, the computed distance may include an error value arising from the multipath interference.
  • the objective of the present disclosure is to provide a time-of-flight distance measuring device and a method for detecting a multipath error that may estimate an error value associated with a multipath error without a time lag or with a reduced time lag.
  • a time-of-flight distance measuring device includes (i) a light source that emits light, as emitted light, toward an object, (ii) a light receiver that includes a plurality of photodetectors, the light receiver detecting, as reflected light, the emitted light reflected by the object, (iii) a first controller that controls the light source to emit the emitted light as an amplitude-modulated waveform such that the emitted light includes a fundamental component at a fundamental frequency and at least one harmonic component of the fundamental frequency, (iv) a second controller that generates a plurality of control signals and outputs each of the plurality of control signals to a respective one of the plurality of photodetectors, (v) a calculator that calculates amplitudes and phase angles of the fundamental component and the at least one harmonic component based on a detection value of the light receiver, and (vi) an error estimator that estimates an error value associated with a multipath error based on the amplitude
  • the second controller generates the plurality of controls signals to simultaneously sense the fundamental component and the at least one harmonic component.
  • the time-of-flight distance measuring device may estimate an error value due to a multipath error with high accuracy.
  • a method for detecting a multipath error using a time-of-flight distance measuring technology includes (i) emitting light, as emitted light, from a light source toward an object, (ii) detecting, as detected light, the emitted light reflected by the object by a light receiver, the light receiver including a plurality of photodetectors, (iii) controlling the light source to emit the emitted light as an amplitude-modulated waveform such that the emitted light includes a fundamental component at a fundamental frequency and at least one harmonic component of the fundamental frequency, (iv) generating a plurality of control signals and outputting each of the plurality of control signals to a respective one of the plurality of photodetectors, (v) calculating amplitudes and phase angles of the fundamental component and the at least one harmonic component based on a detection value of the light receiver, and (vi) estimating an error value associated with a multipath error based on the amplitudes and the phase angles calculated by
  • the plurality of controls signals is generated to simultaneously sense the fundamental component and the at least one harmonic component.
  • the method for detecting a multipath error may estimate an error value due to a multipath error with high accuracy.
  • Figure 1 is an explanatory model where multipath interference occurs (Fig. 1(a)) and the multipath interference is resolved (Fig. 1(b)).
  • Figure 2 is a schematic view of a time-of-flight distance measuring device according to a first embodiment.
  • Figure 3 is a plan view of pixel sensors according to the first embodiment.
  • Figure 4 is a schematic view of the pixel sensor according to the first embodiment.
  • Figure 5 is one example of a signal sequence for one pixel sensor.
  • Figure 6 is one example of a differential signal sequence for one pixel sensor.
  • Figure 7 is emitted light at a 25% duty cycle according to the first embodiment.
  • Figure 8 is a graph showing a relation between amplitude and a duty cycle for a fundamental component, a second harmonic component and a third harmonic component.
  • Figure 9 is one example of a control signal according to the first embodiment.
  • Figure 10 is a schematic view of one pixel sensor when the pixel sensor is in a third state.
  • Figure 11 is the differential sequence of the control signals according to the first embodiment.
  • Figure 12 is a comparative view of a sampling sequence according to the first embodiment and a comparative example.
  • Figure 13 is a schematic view of a processing unit according to the first embodiment.
  • Figure 14 is a schematic view illustrating a mechanism of generating mixed light.
  • Figure 15 is a graph showing a relation between a multipath error and a path length difference (Fig.
  • Figure 16 is a graph showing the relation between the phase difference and the path length difference at a reflection rate of 0.3, 0.5 and 0.7 (Fig. 16(a)) and the relation between the amplitude ratio and the path length difference at the reflection rate of 0.3, 0.5 and 0.7 (Fig. 16(b)).
  • Figure 17 is a graph showing a relation between the phase difference and an error value at the reflection rate of 0.3, 0.5 and 0.7 (Fig.
  • Figure 18 is a flowchart showing a process to estimate the error value according to the first embodiment.
  • Figure 19 is a schematic view of one pixel sensor when the pixel sensor is in the third state according to a second embodiment.
  • Figure 20 is a schematic view of the pixel sensors according to a third embodiment.
  • Figure 21 is a comparative view of the sampling sequence according to a fourth embodiment and a comparative example.
  • Figure 22 is a schematic view of the processing unit according to the fourth embodiment.
  • Figure 23 is a schematic view of the pixel sensors according to a fifth embodiment.
  • Figure 24 is a comparative view of the sampling sequence according to the fifth embodiment and a comparative example.
  • Figure 25 is a schematic view of the pixel sensors according to a sixth embodiment.
  • Figure 26 is a schematic view of the pixel sensors according to a seventh embodiment.
  • Figure 27 is a graph showing the relation between the phase difference and the path length difference at a reflection rate of 0.3, 0.5 and 0.7 (Fig. 27(a)) and the relation between the amplitude ratio and the path length difference at the reflection rate of 0.3, 0.5 and 0.7 (Fig. 27(b)).
  • Figure 28 is a graph showing the relation between the phase difference and the error value at the reflection rate of 0.3, 0.5 and 0.7 (Fig.
  • Figure 29 is a flowchart showing a process to estimate the error value according to the eighth embodiment.
  • Figure 30 is a schematic view of the processing unit according to a ninth embodiment.
  • Figure 31 is a flowchart showing a process to determine a foggy condition according to the ninth embodiment.
  • Fig. 1(a) shows an explanatory model where multipath interference arises.
  • a distance measuring device 10 as a comparative example to the present disclosure, is used to calculate a distance to an object (e.g., a pedestrian) 12 in a scene.
  • the distance measuring device (hereinafter "comparative device") 10 emits light from a light source 14 and receives the light reflected by the object with a light receiver 16.
  • a first path indicated by the solid line shows a direct path where the light emitted from the light source 14 directly reaches, and is reflected by, the object 12 and returns to the light receiver 16.
  • a second path indicated broken line shows a multi-reflected path where the light emitted from the light source 14 is reflected first by an intermediate object, such as a vehicle, 18 and then the light is reflected by the object 12.
  • the path length along the multi-reflected path can be represented as d+ ⁇ d.
  • the comparative device 10 calculates a distance value L+ ⁇ L, where L is a distance value arising from d and an error value ⁇ L arising from ⁇ d. If the multipath error does not occur, the distance value L is nearly equal to the actual path length d.
  • the comparative device 10 sequentially emits the light with different frequencies.
  • the light source 14 emits the light with a first frequency f1 (e.g., 10MHz) for a predetermined period (e.g., 10msec) at a first timing, and then the light source 14 emits the light with a second frequency f2 (e.g., 20MHz) for the same period at a second timing. Therefore, it takes, in total, at least two predetermined periods (i.e., 20msec) for the comparative device 10 to detect the multipath error. In other words, a time lag due to the sequential emission of light is inevitably generated in the comparative example 10.
  • the distance value calculated by the comparative device 10 may still include an error in a situation described below.
  • a multipath arises during the measurement with the first frequency f1
  • the multipath error is resolved when the intermediate object 18 moves away from the scene during the measurement with the second frequency f2 as shown in Fig. 1(b).
  • the comparative device 10 obtains information affected by the multipath interference for the light with the first frequency f1, and then obtains information without the multipath interference for the light with the second frequency f2. Therefore, the comparative device calculates the error value using both the information affected by the multipath interference and the information not affected by the multipath interference. As a result, the error value of the multipath error calculated by the comparative device 10 may still be inaccurate.
  • the inventors of the present disclosure here present a plurality of embodiments of the time-of-flight distance measuring device that may detect a multipath error without a time lag or with a reduced time lag.
  • the time-of-flight distance measuring device (hereinafter, collectively "TOF device") is used in a vehicle to calculate a distance to an object from the vehicle (i.e., the TOF device), but the usage of the TOF device is not limited to a vehicle.
  • the TOF device may be used for human-interface devices, gaming consoles, robots or the like.
  • the "object" for the TOF device may include a pedestrian, other vehicles, obstacles on a road, buildings or the like.
  • FIG. 2 is a block diagram illustrating a general configuration of the TOF device 20 according to the first embodiment.
  • the TOF device 20 includes a clock generator 22, a light source 24, a light receiver 26, an emitter controller (first controller) 28, a receiver controller (second controller) 30, a common-mode choke 32, a differential amplifier 34, an A/D converter 36 and a processing unit 38.
  • the clock generator 22 generates and outputs a clock signal to both the emitter controller 28 and the receiver controller 30 to establish synchronization between the light source 24 and the light receiver 26.
  • the emitter controller 28 and the receiver controller 30 On receiving the clock signal from the clock generator 22, the emitter controller 28 and the receiver controller 30 generate and output a variety of signals to the light source 24 and the light receiver 26, respectively, to work in synchronism with each other.
  • the emitter controller 28 When the emitter controller 28 receives the clock signal from the clock generator 22, the emitter controller 28 outputs a square wave as an emission control signal to the light source 24.
  • the light source 24 emits light, as emitted light, with a square waveform (i.e., an amplitude-modulated waveform) corresponding to the emission control signal.
  • the emitted light has a same waveform as the emission control signal.
  • the light source 24 may emit light having a sine waveform, a triangle waveform, or a waveform with a pseudo random pattern.
  • the light source 24 is a light emitting diode (LED) that emits infrared light toward the object 12.
  • a laser diode (LD) that emits infrared light may be used as the light source 24.
  • the emitter controller 28 controls the light source 24 such that the emitted light includes a fundamental component at a fundamental frequency and at least one harmonic component of the fundamental frequency.
  • the emitted light includes the fundamental component (i.e., first-order component) at the fundamental frequency (e.g., 10MHz) and a second harmonic component (i.e., second-order component) at two times the fundamental frequency (e.g., 20MHz).
  • the emitted light with the fundamental component and the second harmonic component is emitted from the single light source 24.
  • the emitted light may include the fundamental component and two other harmonic components, such as the second and third harmonic components.
  • the emitted light may include the fundamental component and another harmonic component other than the second harmonic component, such as the third harmonic, the fourth harmonic, or the like.
  • the receiver controller 30 generates and outputs a plurality of control signals (e.g., see D 1 to D 6 in Fig. 11) to the light receiver 26 to control a light receiving pattern of the light receiver 26.
  • the receiver controller 30 generates the control signals D N such that the light receiver 26 simultaneously senses the fundamental component and the second harmonic component of the emitted light reflected by the object 12, as will be described later.
  • the light receiver 26 detects, as reflected light, the emitted light reflected by the object 12 in the scene.
  • the light receiver 26 includes a plurality of pixel sensors (photodetectors) 80 that are arranged in a regular array form.
  • the plurality of pixel sensors 80 are grouped into a plurality of sensing units 40 and each sensing unit 40 is formed of six pixel sensors (subset of M photodetectors) 80.
  • the pixel sensors 80 forming one sensing unit 40 may be also referred to as the pixel sensors A to F in place of the reference numeral "80".
  • the receiver controller 30 controls each sensing unit 40 as a single unit.
  • the receiver controller 30 outputs each of the plurality of control signals D N to a respective one of the plurality of pixel sensors A to F through wiring CTL1 to CTL6.
  • each control signal D N is a differential signal including a pair of normally complimentary gate signals TG1, TG2.
  • the pixel sensor 80 is an image sensor using CMOS (Complementary Metal Oxide Semiconductor) technology, CCD (Charge Coupled Device) technology, or combination of both the technologies.
  • CMOS Complementary Metal Oxide Semiconductor
  • CCD Charge Coupled Device
  • each pixel sensor 80 includes a PD (photo diode, photo element) 42, a first capacitor 44, a second capacitor 46, a first switch 48 and a second switch 50.
  • the first switch 48 and the second switch 50 are a MOS-type device, such as a MOS transistor or a transfer gate, or a charge-coupled device (CCD).
  • the first capacitor 44 and the second capacitor 46 are a capacitive element, such as MOS, CCD or MIM (Metal Insulator Metal).
  • the first capacitor 44 is electrically connected to the first switch 48, and the first switch 48 is electrically connected to the PD 42, and therefore the first capacitor 44 is electrically connected to the PD 42 through the first switch 48.
  • the second capacitor 46 is electrically connected to the second switch 50 and the second switch 50 is electrically connected to the PD 42, and therefore the second capacitor 46 is electrically connected to the PD 42 through the second switch 50.
  • the PD 42 generates electricity while being exposed to the reflected light.
  • the control signal D N received from the receiver controller 30 operates the pixel sensor 80 by controlling an on/off state of the first switch 48 and the second switch 50.
  • the control signal D N includes a pair of gate signals TG1, TG2 that are normally complimentary
  • the first capacitor 44 stores electric charge generated from the PD 42.
  • the second capacitor 46 stores electric charge generated from the PD 42.
  • first switch 48 and the first capacitor 44, and the second switch 50 and the second capacitor 46 are used in the present embodiment, three or more pairs of a switch and a capacitor may be used.
  • the electric charge stored in the first capacitor 44 and the electric charge stored in the second capacitor 46 are separately output to the common-mode choke 32 as analog data.
  • the common-mode choke 32 is used to avoid light saturation by removing common mode (CM) components from the data output from the pixel sensor 80.
  • CM common mode
  • the CM components are generated when light saturation occurs, i.e., when sufficiently high background light exists in the scene.
  • the differential amplifier 34 After removing the CM component, the data corresponding to the first capacitor 44 and the data corresponding to the second capacitor 46 are input into the differential amplifier 34.
  • the differential amplifier 34 outputs the difference value between each pair of the electric charge data to the A/D converter 36. That is, the difference value between the data corresponding to the electric charge stored in the first capacitor 44 and the data corresponding to the electric charge stored in the second capacitor 46 are output from the differential amplifier 34.
  • the A/D converter 36 converts the analog data from the differential amplifier 34 to digital data and outputs the digital data to the processing unit 38.
  • the processing unit 38 includes a CPU, a ROM, a RAM or the like, and performs programs stored in the ROM to execute a variety of processing. Especially, the processing unit 38 calculates the distance (a distance value L) to the object 12 based on the digital data output from the A/D converter 36. Further, the processing unit 38 estimates an error value ⁇ L due to a multipath error and corrects the distance based on the estimated error value ⁇ L.
  • Fig. 5 shows one example of a signal sequence (modulation cycle: Tm, exposure period: Tw) where the emitted light has a 50% duty cycle and the pixel sensor 80 is controlled through the gate signalsTG1, TG2 having a different phase from each other.
  • the pixel sensor 80 is first controlled through a first pair of gate signals TG1-1, TG2-1, and then is controlled through a second pair of gate signals TG1-2, TG2-2.
  • the waveform (emitted light waveform 52) of the emitted light from the light source 24 is a square form in synchronism with the gate signals TG1, TG2.
  • the waveform (reflected light waveform 54) of the reflected light has a time difference relative to the emitted light waveform 52, and thus the reflected light waveform 54 is sensed as a waveform having a phase delay with a phase difference ⁇ relative to the emitted light waveform 52.
  • the first pair of gate signals TG1-1, TG2-1 has a phase difference of 180° from each other
  • the second pair of gate signals TG1-2, TG2-2 has a phase difference of 180° from each other.
  • the first pair of gate signals TG1-1, TG2-1 and the second pair of gate signals TG1-2, TG2-2 have a phase difference of 90° from each other.
  • each gate signal TG1-1, TG2-1, TG1-2, TG2-2 is output for several to hundreds of thousands of cycles.
  • the electric charges generated by the first pair of gate signals TG1-1, TG2-1 are obtained as data Q1, Q2, while the electric charges generated by the second pair gate signals TG1-2, TG2-2 are obtained as data Q3, Q4.
  • the data is a voltage value that is a converted value of the electric charge through electric charge voltage conversion.
  • the estimation value ⁇ of the phase difference ⁇ can be calculated by equation (1) using the discrete Fourier transform (DFT) with the data Q1 to Q4 obtained through the four samplings.
  • DFT discrete Fourier transform
  • equation (1) represents an equation when four samplings are executed
  • the equation (1) can be generalized as to N phases (i.e., N samplings) as represented in equation (2).
  • ⁇ tan -1 (( ⁇ Qk*sin(2 ⁇ /N*k)/( ⁇ Qk*cos(2 ⁇ /N*k))) (2)
  • a distance to the object 12 can be calculated based on a relationship between ⁇ and the speed of light. It should be noted although these equations can be generally used to a distance to the object 12, the distance to the object 12 is calculated by using the phase angle of the fundamental component and the second harmonic component at the processing unit 38 in the first embodiment, as will be described below.
  • the first pair of gate signals TG1-1, TG2-1 and the second pair of gate signals TG1-2, TG2-2 can be represented by respective differential signals D 1 , D 2 , as shown in Fig. 6.
  • the differential signal D 1 , D 2 is an imaginary signal that indicates the state of the pair of gate signals TG1, TG2.
  • the gate signals TG1, TG2 are normally complimentary.
  • the differential signal D 1 , D 2 has a value of "1" when a first gate signal TG1 is "H” and a second gate signal TG2 is "L".
  • the differential signal D 1 , D 2 has the value "1"
  • the on/off state of the first switch 48 and the second switch 50 is a first state where the first switch 48 is on and the second switch 50 is off.
  • the differential signal D 1 , D 2 has the value of "-1" when the first gate signal is “L” and the second gate signal is "H".
  • the on/off state of the first switch 48 and the second switch 50 is a second state where the first switch 48 is off and the second switch 50 is on. Therefore, the state of the pair of gate signals TG1, TG2 (i.e., the on/off state of the first and second switches 48, 50) can be represented by a differential signal (control signal D N ) that is normally either "1" or "-1".
  • the emitted light is emitted with a fundamental component and its second order harmonic component, which are reflected and then simultaneously sensed by the light receiver 26.
  • the emitted light is emitted with a fundamental component and its second order harmonic at a duty cycle of less than 50% and (ii) the control signal is generated to be sensitive to the second harmonic component as well as the fundamental component.
  • the emitter controller 28 in the present embodiment controls the light source 24 to emit the emitted light having a duty cycle of less than 50%.
  • the emitted light may be emitted with a duty cycle of 25%.
  • the second harmonic component can be effectively sensed as described below.
  • Fig. 7 shows the emitted light 56 having a 25% duty cycle in the present embodiment indicated by the solid line and a comparative emitted light 58 having a 50% duty cycle indicated by the broken line.
  • Fig. 8 shows a relation between amplitude and a duty cycle [%] for the fundamental component, the second harmonic component and the third harmonic component.
  • the amplitude of the second harmonic component and the third harmonic component gradually increase as the duty cycle decreases from 50%.
  • the amplitude of the second harmonic component has a maximum value at a duty cycle of 25%. Therefore, by setting the emitted light to have a 25% duty cycle in the present embodiment, the amplitude of the second harmonic component can be sensitively detected.
  • the duty cycle is not limited to 25%.
  • the amplitude of the second component and the third component are positive at duty cycles other than 25%. For example, if the emitted light includes the third harmonic component, the duty cycle may be set to, e.g., about 18% at which the third harmonic component has a maximum value.
  • the receiver controller 30 generates each of the plurality of control signals D N to respective ones of the plurality of pixel sensors 80.
  • the control signals D N are described as differential signals of the gate signals TG1, TG2 for the first switch 48 and the second switch 50 in the subsequent description, the differential signal is a representative signal that is physically implemented as a pair of normally complementary gate signals TG1, TG2 as explained previously..
  • the control signal D N as shown in Fig. 9 in the present embodiment switches the on/off state of the first and the second switches 48, 50 between the first state indicated by "1" and the second state indicated by "-1".
  • the receiver controller 30 Furthermore, to simultaneously sense the fundamental component and the second harmonic component of the reflected light, the receiver controller 30 generates the control signal D N to have a value of “0”, which represents a null period, as shown in Fig. 9. As described below, the data of the electric charge during the null period is cancelled. As a result, the electricity generated from the PD 42 during the null period is not used for calculating the distance value L or the error value ⁇ L at the subsequent process.
  • the control signal D N has a value of “0” (i.e., the null period) when the first and second gate signals TG1, TG2, which are normally complimentary, are both set to be “H”.
  • the control signal D N has the value "0”
  • the on/off state of the first switch 48 and the second switch 50 is a third state where the first switch 48 is on and the second switch 50 is on
  • the control signal D N is generated such that the third state occurs between the first state and the second state.
  • the electricity generated from the PD 42 is evenly distributed to the first capacitor 44 and the second capacitor 46, and thus the first capacitor 44 stores the electric charge Qa and the second capacitor 46 stores the electric charge Qb that is equal to Qa during the third state (i.e., the null period). Therefore, the electric charges Qa and Qb stored during the third state are cancelled through the common-mode choke 32 and the differential amplifier 34, whereby the electric charges Qa and Qb are not used for calculating the distance value L and the error value ⁇ L at the processing unit 38.
  • the data output from the differential amplifier 34 can include information associated with the second component as well as the fundamental component. In other words, the data associated with the fundamental component and the second component can be simultaneously obtained.
  • the third state (the discharging state) is inserted from 1/2 ⁇ to 3/2 ⁇ phase (i.e., 90° to 270°) in one cycle of the control signal D N as shown in Fig. 9.
  • one cycle of the control signal D N is formed of the first state ("1") from 0 to 1/2 ⁇ phase, the third state ("0") from 1/2 ⁇ to 3/2 ⁇ phase, and the second state ("-1") from 3/2 ⁇ to 2 ⁇ phase.
  • Fig. 11 shows a differential signal sequence for one sensing unit 40 with 6 pixel sensors A to F in the present embodiment.
  • the control signals are formed of 6 different types of signals D 1 to D 6 having a different phase from each other. More specifically, the signals D 1 to D 6 have a phase difference of, for example, 60° from each other.
  • the receiver controller 30 outputs, at substantially the same time (specified timing), the 6 different types of signals D 1 to D 6 to the 6 pixel sensors A to F.
  • the signals D 1 to D 6 are output for several hundreds to thousands of cycles.
  • Each pixel sensor A to F receives a respective one of the 6 different signals D 1 to D 6 .
  • each pixel sensor A to F in one sensing unit 40 is controlled by a different phase, and thus outputs electric charge data having a different value.
  • the receiver controller 30 outputs the same subset of the 6 different types of signals D 1 to D 6 to each sensing unit 40.
  • each sensing unit 40 is controlled to sense the reflected light with the same light sensing pattern as another sensing unit 40.
  • the emitted light includes the fundamental component and the second harmonic component and has a 25% duty cycle. Further, the control signals are generated such that the light receiver 26 simultaneously senses the fundamental component and the second harmonic component.
  • the data associated with the fundamental component and the second harmonic component can be obtained at substantially the same time. In other words, a sampling time period necessary for obtaining the data associated with the fundamental component and the second harmonic component can be shortened.
  • Fig. 12 shows the sampling time period for obtaining the data of the fundamental component and the second harmonic component according to the present embodiment and a comparative example.
  • the light source is controlled to emit the emitted light with the fundamental component indicated by "f1" in Fig. 12 (and light receiver is controlled to receive the reflected light) at a first timing, and then emit the emitted light with the second harmonic component indicated by "f2" in Fig. 12 (and receive the reflected light) at a second timing.
  • the 6 different signals D 1 to D 6 are sequentially (i.e., not simultaneously) output to one pixel sensor A for the first timing to sense the fundamental component.
  • the data corresponding to the 6 different signals D 1 to D 6 is temporally stored in a frame memory (not shown).
  • the 6 different signals D 1 to D 6 are sequentially output again to the one pixel sensor A at the second timing to sense the second harmonic component. Thereafter, the data obtained at the second timing and the data stored in the frame memory are used to calculate a distance and an error value due to a multipath error.
  • the fundamental component and the second harmonic component are sensed at substantially the same time in the present embodiment as shown in Fig. 12.
  • the signals D 1 to D 6 are output in turn and twelve signals D 1 to D 6 are sequentially output in total. Therefore, the sampling time period in the present embodiment is shorter than the comparative example. More specifically, the sampling time period for the present embodiment is about 1/12 of the comparative example.
  • the data of the fundamental component and the second harmonic component can be simultaneously detected, it is possible to avoid generating a time lag when obtaining the data. Furthermore, since the data of both the fundamental component and the second harmonic component can be detected at the same time, a memory such as the frame memory of the comparative example can be omitted.
  • the processing unit 38 includes a discrete Fourier transform circuit (DFT) 60, a phase calculator (calculator) 62, an amplitude calculator (calculator) 64, a distance calculator 66, an error estimator 68 and a corrector 70.
  • the DFT 60 calculates, based on the data output from the A/D converter 36, real parts Re1, Re2 of the fundamental component and the second harmonic component and imaginary parts Im1, Im2 of the fundamental component and the second harmonic component.
  • the DFT 60 outputs the real parts Re1, Re2 and the imaginary parts Im1, Im2 to the phase calculator 62 and the amplitude calculator 64.
  • the phase calculator 62 calculates an estimation value (first phase angle ⁇ 1) of a phase difference of the fundamental component and an estimation value (second phase angle ⁇ 2) of a phase difference of the second harmonic component based on the real parts Re1, Re2 and the imaginary parts Im1, Im2 calculated by the DFT 60 with reference to the equation (2) as described above. Then, the phase calculator 62 outputs the first phase angle ⁇ 1 and the second phase angle ⁇ 2 to the distance calculator 66 and the error estimator 68.
  • the amplitude calculator 64 calculates absolute values of amplitude A1, A2 of the fundamental component and the second harmonic component based on the real parts Re1, Re2 and the imaginary parts Im1, Im2 calculated by the DFT 60. Then, the amplitude calculator 64 outputs the amplitude A1, A2 to the error estimator 68.
  • the amplitude for the fundamental component is referred to as "first amplitude A1” and the amplitude for the second harmonic component is referred to as "second amplitude A2".
  • the distance calculator 66 obtains L' by, for example, linearly combining L1' and L2', i.e., a linear combination. It can be understood that, if the multipath occurs, the distance L' calculated by the distance calculator 66 includes an error value ⁇ L due to the multipath error. That is, the distance L' calculated by the distance calculator 66 may include the real distance value L and the error value ⁇ L.
  • the error estimator 68 includes a lookup table (LUT) 72 therein and estimates, using the LUT 72, the error value ⁇ L based on the first phase angle ⁇ 1, the second phase angle ⁇ 2, the first amplitude A1 and the second amplitude A2. More specifically, the error estimator 68 estimates the error value ⁇ L based on (i) a phase difference between the first phase angle ⁇ 1 and a half value of the second phase angle ⁇ 2, i.e., ⁇ 1- ⁇ 2/2, and (ii) an amplitude ratio of the second amplitude A2 to the first amplitude A1, i.e., A1/A2, as will be described below.
  • LUT lookup table
  • Fig. 14 shows a mixed waveform of the reflected lightLL 1 through the direct path and the reflected light L 2 through the multi-reflected path (see Fig. 1(a)).
  • the reflected light L 2 has phase delay of ⁇ due to the path length difference ⁇ d.
  • the amplitude of the reflected light L 1 is A
  • the amplitude of the reflected light L 2 can be represented as ⁇ A, where ⁇ is a reflection rate of the reflected light B through the multipath. Therefore, when multipath interference occurs, the mixed light L 1 +L 2 is generated by synthesizing the reflected light L 1 and the reflected light L 2 .
  • Fig. 15 shows a relation between the error value ⁇ L due to the multipath error and the path length difference ⁇ d (Fig. 15(a)), a relation between the phase difference ⁇ 1- ⁇ 2/2 and the path length difference ⁇ d (Fig. 15(b)), and a relation between the amplitude ratio A2/A1 and the path length difference ⁇ d (Fig. 15(c)).
  • the phase difference ⁇ 1- ⁇ 2/2 has a dependency on the path length difference ⁇ d.
  • the amplitude ratio A2/A1 also has a dependency on the path length difference ⁇ d, as shown in Fig. 15 (c).
  • the phase difference ⁇ 1- ⁇ 2/2 and the amplitude ratio A2/A1 can be used as reference information for the LUT 72 to calculate the error value ⁇ L that is also dependent on the path length difference ⁇ d.
  • Fig. 16 shows the relation between the phase difference ⁇ 1- ⁇ 2/2 and the path length difference ⁇ d when the reflection rate ⁇ is 0.3, 0.5 or 0.7 (Fig. 16 (a)) and the relation between the amplitude ratio A2/A1 and the path length difference ⁇ d when the refection rate ⁇ is 0.3, 0.5 or 0.7 (Fig. 16 (b)).
  • the relation between the phase difference ⁇ 1- ⁇ 2/2 and the path length difference ⁇ d varies according to the value of the reflection rate ⁇ .
  • the relation between the amplitude ratio A2/A1 and the path length difference ⁇ d varies according to the value of the refection rate ⁇ .
  • both the path length difference ⁇ d and the reflection rate ⁇ are calculated with two parameters ( ⁇ 1- ⁇ 2/2 and A2/A1) for the entire range of the path length difference ⁇ d to estimate the error value ⁇ L, its calculation would be complicated, resulting in increasing calculation load on the error estimator 68.
  • the error estimator 68 uses approximation for a certain range to simplify the calculation for estimating the error value ⁇ L.
  • Fig. 17 shows relations of the phase difference ⁇ 1- ⁇ 2/2 (Fig. 17 (a)) and the amplitude ratio A2/A1 (Fig. 17 (b)) relative to the error value ⁇ L in place of the path length difference ⁇ d.
  • the phase difference ⁇ 1- ⁇ 2/2 is represented with the error value ⁇ L
  • the phase difference ⁇ 1- ⁇ 2/2 can be approximated with a linear function C regardless of the value of the reflection rate ⁇ , as shown in Fig. 17 (a).
  • the phase difference ⁇ 1- ⁇ 2/2 can be approximately represented with the error value ⁇ L using the linear function C.
  • the amplitude ratio A2/A1 can be approximated for a certain range with a secondary function A regardless of the value of the reflection rate ⁇ , as shown in Fig. 17 (b).
  • the amplitude ratio A2/A1 can be approximately represented using the error value ⁇ L with the secondary function A.
  • a threshold ratio value THA1 (e.g., 0.7) of the amplitude ratio A2/A1 is set based on a crossing point P1 at which three graphs of the amplitude ratio A2/A1 for ⁇ of 0.3, 0.5 and 0.7 intersect, as shown in Fig. 16 (b).
  • a threshold difference value THP1 (e.g., 8°) of the phase difference ⁇ 1- ⁇ 2/2 is set based on a crossing point P2 at which three graphs of the phase difference ⁇ 1- ⁇ 2/2 for ⁇ of 0.3, 0.5 and 0.7 intersect.
  • the error value ⁇ L can be approximately calculated using the linear function C.
  • the amplitude ratio A2/A1 is equal to or less than the THA1 and the phase difference ⁇ 1- ⁇ 2/2 is less than the THP1, the error value ⁇ L can be approximately calculated using the secondary function A.
  • the LUT stores therein the linear function C and the secondary function A
  • the error estimator 68 calculates the error value ⁇ L using only the amplitude ratio A2/A1 or the phase difference ⁇ 1- ⁇ 2/2 when the amplitude ratio A2/A1 and/or the phase difference ⁇ 1- ⁇ 2/2 are within the above described range.
  • Fig. 18 is a flowchart for a process performed by the processing unit 38 to estimate the error value ⁇ L.
  • the processing unit 38 receives the electric charge data corresponding to the control signals D 1 to D 6 from the A/D converter 36, and the DFT 60 calculates, at Step 12, the real parts Re1, Re2 of the fundamental component and the second harmonic component and the imaginary parts Im1, Im2 of the fundamental component and the second harmonic component.
  • the phase calculator 62 calculates the first phase angle ⁇ 1 and the second phase angle ⁇ 2, and the amplitude calculator 64 calculates the first amplitude A1 and the second amplitude A2.
  • the error estimator 68 determines whether the amplitude ratio A2/A1 is greater than the threshold ratio value THA1. If the amplitude ratio A2/A1 is greater than the threshold ratio value THA1 (S16: YES), the error estimator 68 refers to the LUT 72 and estimates the error value ⁇ L using the linear function C stored in the LUT 72, at Step 18. Specifically, the error estimator 68 estimates the error value ⁇ L from the linear function C based on only the phase difference ⁇ 1- ⁇ 2/2 without considering the reflection rate ⁇ .
  • the error estimator 68 determines whether the phase difference ⁇ 1- ⁇ 2/2 is less than the threshold difference value THP1 at Step 20. If the phase difference ⁇ 1- ⁇ 2/2 is less than the threshold difference value THP1 (S20: YES), the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the secondary function A stored in the LUT 72, at Step 22. More specifically, the error estimator 68 estimates the error value ⁇ L from the secondary function A based on only the amplitude ratio A2/A1 without considering the reflection rate ⁇ .
  • the calculation can be simplified as compared to when the error value ⁇ L is calculated using two parameters ( ⁇ 1- ⁇ 2/2, A2/A1) in all cases, whereby processing load to the error estimator 68 can be reduced in the present embodiment.
  • the calculation period can be reduced.
  • the error estimator 68 When the error estimator 68 obtains the error value ⁇ L through the process showed in Fig. 18, the error estimator 68 outputs the error value ⁇ L to the corrector 70.
  • the corrector 70 corrects L' obtained by the distance calculator 66 by subtracting the error value ⁇ L from the distance value L', whereby the corrector 70 obtains the corrected distance value L (i.e., a corrected distance to the object 12). Then, the corrector 70 (the processing unit 38) outputs the corrected distance value L.
  • the receiver controller 30 generates the plurality of controls signals D N to simultaneously sense the fundamental component and the second harmonic component.
  • the TOF device 20 and the method for detecting a multipath error according to the first embodiment may estimate the error value ⁇ L due to a multipath error with high accuracy.
  • the third state (i.e., the null period) of the control signal D N is defined as a state where the first switch 48 and the second switch 50 are both on.
  • the third state of the control signal D N is defined as a state where the first switch 48 and the second switch 50 are both off, as shown in Fig. 19.
  • each pixel sensor 80 further includes a sub switch 74 that is electrically connected between the PD 42 and a discharge target (not shown).
  • the sub switch 74 is controlled by a sub gate signal TG3 output from the receiver controller 30 such that the sub switch 74 is off during the first state (i.e., "1") and the second state (i.e., "-1") and is on during the third state (i.e., "0").
  • electricity (Qc) generated during the third state is discharged through the sub switch 74 without being stored in the first capacitor 44 and the second capacitor 46.
  • the electricity during the third state is not output from the pixel sensor 80, and thus data associated with the electricity generated during the third state is not used for calculating the error value ⁇ L.
  • the data used to calculate the error value ⁇ L includes information of the second harmonic component as well as the fundamental component. In other words, the fundamental component and the second harmonic component can be simultaneously sensed, as with the first embodiment.
  • the 6 different types of signals D 1 to D 6 are output to each sensing unit 40 to obtain data of 6 mutually phase-shifted electric charge output signals corresponding to the signals D 1 to D 6 .
  • the emitted light includes the fundamental component and the second harmonic component, it is possible to sense the fundamental component and the second harmonic component with at least 5 different types of signals.
  • the sensing unit 40 is formed of 5 pixel sensors A to E, and the receiver controller 30 generates 5 different types of signals D 1 to D 5 each having a different phase from each other. Then, the receiver controller 30 outputs, at the substantially same timing, the 5 different types of signals D 1 to D 5 to the 5 pixel sensors A to E. Thus, each pixel sensor A to E receives a respective one of the 5 different types of signals D 1 to D 5 .
  • one pixel sensor 80 in one sensing unit 40 receives one type of signal.
  • the pixel sensor A receives the signal D1 as shown in Fig. 12 in the first embodiment.
  • the pixel sensor A may sequentially receive different types of signals D N .
  • Fig. 21 shows a sampling time period necessary for obtaining data of 6 mutually phase-shifted electric charge output signals according to the fourth embodiment.
  • the comparative example is the same as the comparative example shown in Fig. 12.
  • the plurality of control signals D N includes 6 types of signals D 1 to D 6 each having a different phase from each other.
  • the receiver controller 30 sequentially outputs the 6 different types of signals D 1 to D 6 to one pixel sensor A such that the pixel sensor A receives, in order, all of the 6 different types of signals D 1 to D 6 .
  • the TOF device 20 further includes a frame memory 76 between the A/D converter 36 and the processing unit 38 as shown in Fig. 22.
  • the frame memory 76 is a temporary storage to store the data sequentially generated from the signals D 1 to D 5 , and when the final data corresponding to the signal D 6 is obtained, the processing unit 38 calculates the distance value L' and the error value ⁇ L using the final data corresponding to the signal D 6 and the data of 5 electric charge output signals stored in the frame memory 76.
  • the receiver controller 30 generates and outputs the signal D 1 to the pixel sensor A at a first specified timing, and then the data corresponding to the signal D 1 is outputted from the pixel sensor A. Then, the frame memory 76 temporally stores the data corresponding to the signal D 1 . In this case, the fundamental component and the second component are reflected in the data corresponding to the signal D 1 as indicated by f1/f2 in Fig. 21. Next, the receiver controller 30 generates and outputs the signal D 2 to the pixel sensor A at a second specified timing, and then the data corresponding to the signal D 2 is stored in the frame memory 76. Similarly, the fundamental component and the second component of the reflected light are reflected in the data corresponding to the signal D 2 .
  • the receiver controller 30 repeatedly generates and outputs the signals D 1 to D 6 in the fourth embodiment, and all data reflecting the fundamental component and the second harmonic component corresponding to the signals D 1 to D 6 are obtained over six specified timings.
  • the pixel sensor A according to the comparative example sequentially receives the signals D 1 to D 6 with the fundamental component first, and then receives the signals D 1 to D 6 with the second harmonic component. Therefore, the comparative example needs for two times the sampling time period of the fourth embodiment to obtain the data corresponding to the signals D 1 to D 6 with the fundament component and the second harmonic component.
  • sampling time period for the fourth embodiment is longer than the first embodiment (refer to Fig. 12)
  • one pixel sensor A detects the data corresponding to the signals D 1 to D 6 . Therefore, resolution of the light receiver 26 can be increased as compared to the first embodiment where the 6 data corresponding to the signals D 1 to D 6 are obtained by 6 pixel sensors A to F.
  • Fig. 23 shows one sensing unit 40 of the light receiver 26 according to the fifth embodiment.
  • each sensing unit 40 is formed of a subset of 3 pixel sensors (pixel sensor A to C).
  • the plurality of control signals D N includes 6 different types of signals D 1 to D 6 and the 6 different types of signals D 1 to D 6 are further grouped into 2 subsets of 3 different types of signals. More specifically, one subset of 3 different types of signals is formed of signals D 1 to D 3 , and the other subset of 3 different types of signals is formed of signals D 4 to D 6 .
  • the receiver controller 30 outputs, at each of 2 specified timings, a respective one of the 2 subsets of 6 different types of signals to the subset of 3 pixel sensors A to C such that each pixel sensor 80 of the subset of 3 pixel sensors A to C receives a different respective one of the outputted subset of 3 different types of signals. Accordingly, the subset of 3 pixel sensors A to C receives, over the 2 specified timings, all of the 6 types of signals D 1 to D 6 .
  • the receiver controller 30 outputs, at a first specified timing, a respective one of the 2 subset of the signals D 1 to D 3 to the pixel sensors A to C.
  • the pixel sensor A receives the signal D 1
  • the pixel sensor B receives the signal D 2
  • the pixel sensor C receives the signal D 3 .
  • the data corresponding to the signal D 1 is obtained from the pixel sensor A
  • the data corresponding to the signal D 2 is obtained from the pixel sensor B
  • the data corresponding to the signal D 3 is obtained from the pixel sensor C
  • each data reflects the fundamental component and the second harmonic component is temporally stored in a frame memory (not shown) that is the same as the frame memory 76 shown in Fig. 22.
  • the receiver controller 30 outputs, at a second specified timing, a respective one of the other of the 2 subsets of signals D 4 to D 6 to the pixel sensors A to C.
  • the pixel sensor A receives the signal D 4
  • the pixel sensor B receives the signal D 5
  • the pixel sensor C receives the signal D 6 .
  • the data corresponding to the signal D 4 is obtained the pixel sensor A
  • the data corresponding to the signal D 5 is obtained from the pixel sensor B
  • the data corresponding to the signal D 6 is obtained from the pixel sensor C.
  • 6 data corresponding to the signals D 1 to D 6 reflecting the fundamental component and the second harmonic component are obtained through the 2 specified timings, and then the processing unit 38 calculates the distance value L' and the error value ⁇ L using the 6 data.
  • the sampling time period according to the fifth embodiment is shorter than the comparative example that is the same as the comparative example shown in Fig. 12.
  • the TOF device 20 according to the fifth embodiment can detect the multipath error with a reduced time lag.
  • the sampling time period (i.e., two specified timings) in the fifth embodiment is longer than the sampling period in the first embodiment (i.e., one specified timing) as shown in Fig. 12, since the data of 6 output signals corresponding to the signals D 1 to D 6 are obtained from the 3 pixel sensors A to C, resolution of the light receiver 26 can be increased compared to the first embodiment where the data of 6 output signals corresponding to the signals D 1 to D 6 are obtained by 6 pixel sensors A to F.
  • the frame memory is necessary to store the data obtained during the first specified timing, the amount of data to be stored (i.e., data of 3 output siganls corresponding to the signals D 1 to D 3 ) is less than the fourth embodiment where data of 5 output signals corresponding to the signals D 1 to D 5 are stored in the frame memory. Therefore, the memory capacity of the frame memory in the fifth embodiment can be reduced as compared to the fourth embodiment.
  • the sensing unit 40 is formed of the subset of 3 pixel sensors A to C and the receiver controller 30 outputs the signals D 1 to D 3 first, and then the signals D 4 to D 6 , to the 3 pixel sensors A to C.
  • the number of the pixel sensors 80 forming the subset i.e., one sensing unit 40
  • the control signals includes N different types of signals D 1 to D N , where N is greater than M
  • the N different types of signals D 1 to D N may be grouped into K subsets of M different types of signals, where K is N/M.
  • the receiver controller 30 may output, at each of K specified timings, a respective one of the K subsets of M different types of signals to the subset of M pixel sensors 80.
  • the sensing unit 40 is formed of 2 pixel sensors A and B, and the control signals includes 6 different types of signals D 1 to D 6
  • the 6 different types of signals D 1 to D 6 are grouped into 3 (i.e., 6/2) subsets of 2 different types of signals (e.g., D 1 -D 2 , D 3 -D 4 , and D 5 -D 6 ).
  • the receiver controller 30 outputs, at a first specified timing, the signals D 1 and D 2 to the pixel sensors A and B, respectively, and then, at a second specified timing, the signals D 3 and D 4 to the pixel sensors A and B, respectively, and lastly, at a third specified timing, the signals D 5 and D 6 to the pixel sensors A and B, respectively.
  • Fig. 25 shows the light receiver 26 according to the sixth embodiment.
  • the sensing unit 40 is formed of a subset of 6 pixel sensors A to F and the control signals D N include 6 different types of signals D 1 to D 6 .
  • the receiver controller 30 outputs, at each of 6 specified timings, the 6 different types of signals D 1 to D 6 to the subset of 6 pixel sensors A to F such that each pixel sensor 80 of the subset of 6 pixel sensors A to F receives a different respective one of the 6 different types of signals D 1 to D 6 .
  • each pixel sensor 80 of the subset of 6 pixel sensors A to F receives, over the 6 specified timings, all of the 6 different types of signals D 1 to D 6 .
  • the receiver controller 30 outputs the 6 signals D 1 to D 6 to the pixel sensors A to F, and therefore, the pixel sensor A receives the signal D 1 , the pixel sensor B receives the signal D 2 , the pixel sensor C receives the signal D 3 , the pixel sensor D receive the signal D 4 , the pixel sensor E receives the signal D 5 and the pixel sensor F receives the signal D 6 .
  • the pixel sensor A receives the signal D 1
  • the pixel sensor B receives the signal D 2
  • the pixel sensor C receives the signal D 3
  • the pixel sensor D receive the signal D 4
  • the pixel sensor E receives the signal D 5
  • the pixel sensor F receives the signal D 6 .
  • the receiver controller 30 outputs the 6 signals D 1 to D 6 again to the pixel sensors A to F so that the pixel sensor A receives the signal D 2 , the pixel sensor B receives the signal D 4 , the pixel sensor C receives the signal D 1 , the pixel sensor D receives the signal D 6 , the pixel sensor E receives the signal D 3 , and the pixel sensor F receives the signal D 5 .
  • the pixel sensor A receives the signals D 1 ⁇ D 2 ⁇ D 4 ⁇ D 6 ⁇ D 5 ⁇ D 3
  • the pixel sensor B receives the signals D 2 ⁇ D 4 ⁇ D 6 ⁇ D 5 ⁇ D 3 ⁇ D 1
  • the pixel sensor C receives the signals D 3 ⁇ D 1 ⁇ D 2 ⁇ D 4 ⁇ D 6 ⁇ D 5
  • the pixel sensor D receives the signals D 4 ⁇ D 6 ⁇ D 5 ⁇ D 3 ⁇ D 1 ⁇ D 2
  • the pixel sensor E receives the signals D 5 ⁇ D 3 ⁇ D 1 ⁇ D 2 ⁇ D 4 ⁇ D 6
  • the pixel sensor F receives the signals D 6 ⁇ D 5 ⁇ D 3 ⁇ D 1 ⁇ D 2 ⁇ D 4 , in this order, through the 6 specified timings.
  • data of 6 output signals corresponding to the signals D 1 to D 6 are obtained from the different pixel sensors A to F.
  • each pixel sensor A to F receives all 6 different types of signals D 1 to D 6 through the 6 specified timings.
  • the data of 6 output signals corresponding to the signals D 1 to D 6 can be obtained from each pixel sensors A to F. Accordingly, even if there is abnormality in one of pixel sensors A to F occurs (i.e., mismatch error occurs), since other pixel sensors A to F detect all types of data corresponding to the signals D 1 to D 6 , the mismatch error can be compensated (reduced).
  • the control signals includes 6 different types of signals D 1 to D 6 and the sensing unit 40 is formed of the 6 pixel sensors A to F.
  • the number of the types of the signals and the pixel sensors 80 forming the sensing unit 40 may be changed. That is, if the control signals includes N different types of signals D 1 to D N , and the sensing unit 40 is formed of a subset of N pixel sensors 80, the receiver controller 30 may output, at each of N specified timings, the N different types of signals D 1 to D 6 to the subset of N pixel sensors 80 such that each pixel sensor 80 of the subset of N pixel sensors 80 receives a different respective one of the N different types of signals D 1 to D 6 . As a result, each pixel sensor 80 of the subset of N pixel sensors 80 receives, over the N specified timings, all of the N different types of signals D 1 to D 6 .
  • the receiver controller 30 outputs, at each of 5 specified timings, the 5 different types of signals D 1 to D 5 to the 5 pixel sensors A to E.
  • each pixel sensor A to E receives, over the 5 specified timings, all of the 5 signals D 1 to D 5 .
  • Fig. 26 shows the light receiver 26 according to the seventh embodiment.
  • the sensing unit 40 is formed of a subset of 4 pixel sensors A to D and the control signals D N include 5 different types of signals D 1 to D 5 each having a different phase from each other.
  • the receiver controller 30, at each of 5 specified timings, selects a subset of 4 types of signals from the 5 different types of signals D 1 to D 5 and outputs the selected subset of 4 types of signals to the subset of 4 pixel sensors A to D such that each of the subset of 4 pixel sensors A to D receives a different respective one of the selected subset of 4 signals.
  • the subset of 4 different types of signals selected at each of the 5 specified timings includes at least one different types of signals as compared to the subset of 4 different types of signals selected at all other ones of the 5 specified timings.
  • each pixel sensor 80 of the subset of 4 pixel sensors A to D receives, over the 5 specified timings, all of the 5 different types of signals D 1 to D 5 .
  • the receiver controller 30 selects, at a first specified timing, the signals D 1 to D 4 as a first subset from the 5 different types of signals D 1 to D 5 , and then outputs the selected signals D 1 to D 4 to the pixel sensors A to D. Accordingly, during the first specified timing, the pixel sensor A receives the signal D 1 , the pixel sensor B receives the signal D 2 , the pixel sensor C receives the signal D 3 , and the pixel sensor D receives he signal D 4 .
  • the receiver controller 30 selects, at a second specified timing, the signals D 5 , D 1 , D 2 and D 3 as a second subset from the 5 different types of signals D 1 to D 5 .
  • the second subset of the D 5 , D 1 , D 2 and D 3 selected at the second specified timing includes the signal D 5 that is a different type of signal as compared to the first subset of the signals D 1 to D 4 selected at the first specified timing.
  • the receiver controller 30 outputs the signals D 5 , D 1 , D 2 and D 3 to the pixel sensors A to D. Accordingly, during the second specified timing, the pixel sensor A receives the signal D 5 , the pixel sensor B receives the signal D 1 , the pixel sensor C receives the signal D 2 and the pixel sensor D receives the signal D 3 .
  • the receiver controller 30 selects, at a third specified timing, the signals D 4 , D 5 , D 1 and D 2 as a third subset from the 5 different types of signals D 1 to D 5 .
  • the third subset of the D 4 , D 5 , D 1 and D 2 selected at the third specified timing includes the signal D 4 that is a different type of signal as compared to the second subset of the signals D 5 , D 1 , D 2 and D 3 selected at the second specified timing.
  • the third subset of the D 4 , D 5 , D 1 and D 2 selected at the third specified timing includes the signal D 5 that is a different type of signal as compared to the first subset of the signals D 1 to D 4 selected at the first specified timing.
  • the receiver controller 30 outputs the signals D 4 , D 5 , D 1 and D 2 to the pixel sensors A to D.
  • the pixel sensor A receives the signal D 4
  • the pixel sensor B receives the signal D 5
  • the pixel sensor C receives the signal D 1
  • the pixel sensor D receives the signal D 2 .
  • the pixel sensor A receives the signals D 1 ⁇ D 5 ⁇ D 4 ⁇ D 3 ⁇ D 2
  • the pixel sensor B receives the signals D 2 ⁇ D 1 ⁇ D 5 ⁇ D 4 ⁇ D 3
  • the pixel sensor C receives the signals D 3 ⁇ D 2 ⁇ D 1 ⁇ D 5 ⁇ D 4
  • the pixel sensor E receives the signals D 4 ⁇ D 3 ⁇ D 2 ⁇ D 1 ⁇ D 5 , in this order, through the 5 specified timings.
  • each of the pixel sensors A to D receives, over the 5 specified timings, all of the different types of 5 signals D 1 to D 5 .
  • mismatch error occurs
  • the seventh embodiment by switching the signals to be output to the pixel sensors A to D, 5 derived from to the 5 different signals D 1 to D 5 can be obtained by the 4 pixel sensors A to D.
  • 5 derived from to the 5 different signals D 1 to D 5 can be obtained by the 4 pixel sensors A to D.
  • the 5 different types of signals D 1 to D 5 are output to the 4 pixel sensors A to D.
  • the number of the types of the signals and the pixel sensors 80 forming one sensing unit 40 may be changed. That is, if one sensing unit 40 is formed of a subset of M pixel sensors 80, the control signals include N different types of signals D 1 to D N , where N is greater than M.
  • the receiver controller 30 selects a subset of M different types of signals form the N different types of signals D 1 to D N and outputs the selected subset of M different types of signals to the subset of M pixel sensors 80 such that each of the subset of M pixel sensors 80 receives a different respective one of the selected subset of M pixel sensors 80.
  • the subset of M different types of signals selected at each of the N specified timings includes at least one different types of signals as compared to the subset of M different types of signals selected at all other ones of the N specified timings.
  • each pixel sensor 80 of the subset M pixel sensors 80 receives, over the N specified timings, all of the N different types of signals D 1 to D N .
  • the receiver controller 30 selects a subset of 4 different types of signals from the 6 different types of signals D 1 to D 6 and outputs the selected subset of 4 different types signals to the subset of 4 pixel sensors A to D.
  • the receiver controller 30, at each of 6 specified timings selects a subset of 5 different types of signals from the 6 different types of signals D 1 to D 6 and outputs the selected subset of 5 different types of signals to the subset of 5 pixel sensors A to E.
  • the error estimator 68 estimates the error value ⁇ L using the linear function C or the secondary function A (refer to Figs. 17 and 18).
  • the error estimator 68 estimates the error value ⁇ L using other linear functions in addition to the linear function C and the secondary function A. More specifically, the LUT 72 stores two additional linear functions (a first sub linear function B1 and a second sub linear function B2) as defined in Figs. 27 and 28, which are the same types of graphs as those of Figs. 16 and 17 described in the first embodiment.
  • phase difference ⁇ 1- ⁇ 2/2 when the phase difference ⁇ 1- ⁇ 2/2 is represented with the error value ⁇ L, the phase difference ⁇ 1- ⁇ 2/2 for the reflection rate ⁇ is 0.3 can be approximated with the sub linear function B1 in a certain range (between THP1 and THP2 as shown in Fig. 28). Furthermore, the phase difference ⁇ 1- ⁇ 2/2 for the reflection rate ⁇ is 0.5 can be approximated with the sub linear function B2 in a certain range (between THP2 and THP3 as shown in Fig. 28).
  • the first threshold ratio value THA1 e.g., 0.7
  • the threshold ratio value THA1 described in the first embodiment is the same as the threshold ratio value THA1 described in the first embodiment.
  • the first threshold difference value THP1 e.g., 8°
  • the threshold difference value THP1 described in the first embodiment is the same as the threshold difference value THP1 described in the first embodiment.
  • the LTU stores therein the liner function C, the first sub linear function B1, the second sub linear function B2 and the secondary function A, and the error estimator 68 calculates the error value ⁇ L using only the amplitude ratio A2/A1 or the phase difference ⁇ 1- ⁇ 2/2 within a certain range defined by the first to third threshold ratio values THA1, THA2, THA3 and the first to third threshold difference values THP1, THP2, THP3.
  • the error estimator 68 presumes, on condition that the amplitude ratio A2/A1 is below the THA2, the reflection rate ⁇ to be 0.3 and approximates the ⁇ L using the first sub linear function B1. Furthermore, when the phase difference ⁇ 1- ⁇ 2/2 is between the THP2 and the THP3, the error estimator 68 presumes, on condition that the amplitude ratio A2/A1 is below the THA3, the reflection rate ⁇ to be 0.5 and approximates the ⁇ L using the second sub linear function B2.
  • Fig. 29 is a flowchart according to the eighth embodiment for a process performed by the processing unit 38 to estimate the error value ⁇ L. Since the processing at Steps 10 to 14 is similar to the processing shown in Fig. 18, the description of the processing at Steps 10 to 14 is omitted.
  • the error estimator 68 determines whether the amplitude ratio A2/A1 is greater than the first threshold ratio value THA1. If the amplitude ratio A2/A1 is greater than the first threshold ratio value THA1 (S16: YES), the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the linear function C stored in the LUT 72 at Step 18. Specifically, the error estimator 68 estimates the error value ⁇ L from the linear function C with only the phase difference ⁇ 1- ⁇ 2/2 without considering the reflection rate ⁇ .
  • the error estimator 68 determines whether the phase difference ⁇ 1- ⁇ 2/2 is less than the first threshold difference value THP1 at Step 20. If the phase difference ⁇ 1- ⁇ 2/2 is less than the first threshold difference value THP1 (S20: YES), the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the secondary function A stored in the LUT 72 at Step 22. More detail, the error estimator 68 estimates the error value ⁇ L from the secondary function A with only the amplitude ratio A2/A1 without considering the reflection rate ⁇ .
  • the error estimator 68 determines whether the phase difference ⁇ 1- ⁇ 2/2 is less than the second threshold difference value THP2 at Step 30.
  • the process proceeds to Step 32 where the error estimator 68 determines whether the amplitude ratio A2/A1 is greater than the second threshold ratio value THA2.
  • Step 34 the error estimator 68 determines whether the phase difference ⁇ 1- ⁇ 2/2 is less than the third threshold difference value THP3.
  • the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the secondary function A stored in the LUT 72 at Step 22.
  • the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the first sub linear function B1 stored in the LUT 72 at Step 36. More specifically, the error estimator 68 estimates the error value ⁇ L from the first sub linear function B1 with only the phase difference ⁇ 1- ⁇ 2/2 by presuming the reflection rate ⁇ is 0.3.
  • Step 34 when the phase difference ⁇ 1- ⁇ 2/2 is less than the third threshold difference value THP3 (S34: YES), the process proceeds to Step 38 where the error estimator 68 determines whether the amplitude ratio A2/A1 is greater than the third threshold ratio value THA3. On the other hand, when the phase difference ⁇ 1- ⁇ 2/2 is equal to or greater than the third threshold difference value THP3 (S34: NO), the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the linear function C stored in the LUT 72 at Step 18.
  • the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the secondary function A stored in the LUT 72 at Step 22.
  • the error estimator 68 refers to the LUT 72 and approximates the error value ⁇ L using the second sub linear function B2 stored in the LUT 72 at Step 40. More specifically, the error estimator 68 estimates the error value ⁇ L from the second sub linear function B2 with only the phase difference ⁇ 1- ⁇ 2/2 by presuming the reflection rate ⁇ is 0.5.
  • the error estimator 68 estimates the error value ⁇ L using a single parameter in the above-described range defined by the first to third threshold difference values THA1, THA2, THA3 and the first to third threshold ratio values THP1, THP2, THP3.
  • the calculation can be simplified compared to when the error value ⁇ L is calculated using two parameters ( ⁇ 1- ⁇ 2/2, A2/A1) considering the reflection rate ⁇ , whereby processing load to the error estimator 68 can be reduced.
  • the TOF device 20 Refers to the ninth embodiment. If a foggy condition exists in the scene, the amplitude ratio A2/A1 tends to have a small value (e.g., 0.2). However, the amplitude ratio A2/A1 is also low when multipath interference exists. Therefore, when a small value of the amplitude ratio A2/A1 is calculated, the error estimator 68 may not be able to differentiate whether the small value of the amplitude ratio A2/A1 is due to the multipath interference or a foggy condition. Therefore, if a foggy condition exists, the error estimator 68 may falsely determine that the multipath interference occurs.
  • a foggy condition exists in the scene, the amplitude ratio A2/A1 tends to have a small value (e.g., 0.2). However, the amplitude ratio A2/A1 is also low when multipath interference exists. Therefore, when a small value of the amplitude ratio A2/A1 is calculated, the error estimator 68 may not be able to differentiate whether the small value of
  • the error estimator 68 further includes a foggy condition determiner 78 as shown in Fig. 30.
  • a foggy condition exists, almost all of the pixel sensors 80 detect data affected by the foggy condition, and therefore almost all of the amplitude ratios A2/A2 obtained from the pixel sensors 80 tend to have a small value.
  • the multipath occurs, only some pixel sensors 80 detect data affected by the multipath interference, whereby only some of the amplitude ratios A2/A1 have a small value.
  • the foggy condition determiner 78 determines that the foggy condition exists when a predetermined ratio (e.g., 90%) of the pixel sensors 80 shows the amplitude ratio A2/A1 having a value less than a foggy condition threshold value (e.g., 0.2).
  • a predetermined ratio e.g. 90%
  • a foggy condition threshold value e.g., 0.2
  • Fig. 31 illustrates a flowchart of a process to determine the existence of a foggy condition.
  • the foggy condition determiner 78 determines whether 90% of the pixel sensors 80 show the amplitude ratio A2/A1 having a value less than 0.2 (the foggy condition threshold value) at Step 102.
  • the foggy condition determiner 78 determines that a foggy condition exists in the scene at Step 104.
  • the foggy condition determiner 78 determines that a multipath error occurs at Step 106. In this way, the foggy condition determiner 78 can determine the existence of the foggy condition or the occurrence of the multipath error. Therefore, the TOF device 20 according to the ninth embodiment can obtain the distance value L with high accuracy.
  • the emitted light is controlled to have a 25% duty ratio (i.e., less than 50%).
  • the emitted light may be controlled to have a duty cycle more than 50%.
  • the second-order harmonic component can be sensed by the light receiver 26 by introducing the third state in the control signals. Accordingly, even if there is a situation where it is difficult to set a duty cycle to be less than 50%, the second-order harmonic component can be detected.

Landscapes

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

Abstract

La présente invention concerne un dispositif de mesure de distance par temps de vol. Le dispositif comprend une source de lumière (24) qui émet une lumière émise vers un objet (12), et un récepteur de lumière (26) qui comprend des photodétecteurs (80). Le récepteur de lumière (26) détecte une lumière réfléchie par l'objet. Un premier contrôleur (28) commande la source de lumière pour émettre la lumière émise de telle sorte que la lumière émise comprend une composante fondamentale et au moins une composante harmonique. Un second contrôleur (30) génère des signaux de commande (DN) et émet chacun des signaux de commande vers un photodétecteur respectif. Un calculateur (62, 64) calcule des amplitudes (A1, A2) et des angles de phase (θ1, θ2). Un estimateur d'erreur (68) estime une valeur d'erreur (ΔL) d'une erreur multivoie. Le second contrôleur génère la pluralité de signaux de commande pour détecter simultanément la composante fondamentale et ladite composante harmonique.
PCT/JP2016/000638 2016-02-08 2016-02-08 Dispositif de mesure de distance par temps de vol et procédé de détection d'erreur multivoie Ceased WO2017138032A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2016/000638 WO2017138032A1 (fr) 2016-02-08 2016-02-08 Dispositif de mesure de distance par temps de vol et procédé de détection d'erreur multivoie

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2016/000638 WO2017138032A1 (fr) 2016-02-08 2016-02-08 Dispositif de mesure de distance par temps de vol et procédé de détection d'erreur multivoie

Publications (1)

Publication Number Publication Date
WO2017138032A1 true WO2017138032A1 (fr) 2017-08-17

Family

ID=55398350

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/000638 Ceased WO2017138032A1 (fr) 2016-02-08 2016-02-08 Dispositif de mesure de distance par temps de vol et procédé de détection d'erreur multivoie

Country Status (1)

Country Link
WO (1) WO2017138032A1 (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108445500A (zh) * 2018-02-07 2018-08-24 余晓智 一种tof传感器的距离计算方法及系统
CN108445499A (zh) * 2018-02-07 2018-08-24 余晓智 一种tof传感器的环境光抑制系统及方法
CN108445502A (zh) * 2018-02-11 2018-08-24 余晓智 一种基于arm和linux的tof模组及其实现方法
CN108594254A (zh) * 2018-03-08 2018-09-28 北京理工大学 一种提高tof激光成像雷达测距精度的方法
US10215856B1 (en) 2017-11-27 2019-02-26 Microsoft Technology Licensing, Llc Time of flight camera
JP2020071143A (ja) * 2018-10-31 2020-05-07 ファナック株式会社 測距装置を有する物体監視システム
US10901087B2 (en) 2018-01-15 2021-01-26 Microsoft Technology Licensing, Llc Time of flight camera
US10928489B2 (en) 2017-04-06 2021-02-23 Microsoft Technology Licensing, Llc Time of flight camera
US20210149053A1 (en) * 2019-11-19 2021-05-20 Samsung Electronics Co., Ltd. Lidar device and operating method of the same
WO2021157439A1 (fr) * 2020-02-03 2021-08-12 株式会社ソニー・インタラクティブエンタテインメント Dispositif de calcul de déphasage, procédé de calcul de déphasage, et programme
EP3961258A1 (fr) * 2020-08-26 2022-03-02 Melexis Technologies NV Appareil de détermination de distorsion et procédé de détermination d'une distorsion
US20220163641A1 (en) * 2020-11-23 2022-05-26 Nuvoton Technology Corporation Japan Multipath detection device and multipath detection method
EP4283254A4 (fr) * 2021-01-25 2024-07-24 Toppan Inc. Dispositif de capture d'image de distance et procédé de capture d'image de distance

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080000709A1 (en) 2006-05-31 2008-01-03 Nissan Motor Co., Ltd. Brake pedal apparatus for automobile
JP2010025906A (ja) 2008-07-24 2010-02-04 Panasonic Electric Works Co Ltd 距離画像センサ
JP2010096730A (ja) 2008-10-20 2010-04-30 Honda Motor Co Ltd 測距システム及び測距方法
WO2012014077A2 (fr) 2010-07-29 2012-02-02 Waikatolink Limited Appareil et procédé de mesure des caractéristiques de distance et/ou d'intensité d'objets
US20120033045A1 (en) 2010-07-23 2012-02-09 Mesa Imaging Ag Multi-Path Compensation Using Multiple Modulation Frequencies in Time of Flight Sensor
JP5579893B2 (ja) 2012-03-01 2014-08-27 オムニヴィジョン テクノロジーズ インコーポレイテッド 飛行時間センサのための回路構成及び方法
JP5585903B2 (ja) 2008-07-30 2014-09-10 国立大学法人静岡大学 距離画像センサ、及び撮像信号を飛行時間法により生成する方法
US20140340569A1 (en) 2013-05-17 2014-11-20 Massachusetts Institute Of Technology Methods and apparatus for multi-frequency camera
US20150013938A1 (en) 2013-07-12 2015-01-15 Tokyo Electron Limited Supporting member and substrate processing apparatus
US20150362586A1 (en) * 2014-06-12 2015-12-17 Delphi International Operations Luxembourg S.A.R.L. Distance-measuring-device

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080000709A1 (en) 2006-05-31 2008-01-03 Nissan Motor Co., Ltd. Brake pedal apparatus for automobile
JP2010025906A (ja) 2008-07-24 2010-02-04 Panasonic Electric Works Co Ltd 距離画像センサ
JP5585903B2 (ja) 2008-07-30 2014-09-10 国立大学法人静岡大学 距離画像センサ、及び撮像信号を飛行時間法により生成する方法
JP2010096730A (ja) 2008-10-20 2010-04-30 Honda Motor Co Ltd 測距システム及び測距方法
US20120033045A1 (en) 2010-07-23 2012-02-09 Mesa Imaging Ag Multi-Path Compensation Using Multiple Modulation Frequencies in Time of Flight Sensor
WO2012014077A2 (fr) 2010-07-29 2012-02-02 Waikatolink Limited Appareil et procédé de mesure des caractéristiques de distance et/ou d'intensité d'objets
JP5579893B2 (ja) 2012-03-01 2014-08-27 オムニヴィジョン テクノロジーズ インコーポレイテッド 飛行時間センサのための回路構成及び方法
US20140340569A1 (en) 2013-05-17 2014-11-20 Massachusetts Institute Of Technology Methods and apparatus for multi-frequency camera
US20150013938A1 (en) 2013-07-12 2015-01-15 Tokyo Electron Limited Supporting member and substrate processing apparatus
US20150362586A1 (en) * 2014-06-12 2015-12-17 Delphi International Operations Luxembourg S.A.R.L. Distance-measuring-device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LARRY LI: "Time-of-Flight Camera - An Introduction", 31 May 2014 (2014-05-31), XP055300210, Retrieved from the Internet <URL:http://www.ti.com/lit/wp/sloa190b/sloa190b.pdf> [retrieved on 20160906] *

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10928489B2 (en) 2017-04-06 2021-02-23 Microsoft Technology Licensing, Llc Time of flight camera
US10215856B1 (en) 2017-11-27 2019-02-26 Microsoft Technology Licensing, Llc Time of flight camera
US10901087B2 (en) 2018-01-15 2021-01-26 Microsoft Technology Licensing, Llc Time of flight camera
CN108445499A (zh) * 2018-02-07 2018-08-24 余晓智 一种tof传感器的环境光抑制系统及方法
CN108445500A (zh) * 2018-02-07 2018-08-24 余晓智 一种tof传感器的距离计算方法及系统
CN108445502A (zh) * 2018-02-11 2018-08-24 余晓智 一种基于arm和linux的tof模组及其实现方法
CN108594254A (zh) * 2018-03-08 2018-09-28 北京理工大学 一种提高tof激光成像雷达测距精度的方法
US11454721B2 (en) 2018-10-31 2022-09-27 Fanuc Corporation Object monitoring system including distance measuring device
JP2020071143A (ja) * 2018-10-31 2020-05-07 ファナック株式会社 測距装置を有する物体監視システム
JP7025317B2 (ja) 2018-10-31 2022-02-24 ファナック株式会社 測距装置を有する物体監視システム
EP3825721A1 (fr) * 2019-11-19 2021-05-26 Samsung Electronics Co., Ltd. Dispositif lidar temps de vol et son procédé d'opération
KR20210061200A (ko) * 2019-11-19 2021-05-27 삼성전자주식회사 라이다 장치 및 그 동작 방법
CN112904305A (zh) * 2019-11-19 2021-06-04 三星电子株式会社 LiDAR设备及其操作方法
US20210149053A1 (en) * 2019-11-19 2021-05-20 Samsung Electronics Co., Ltd. Lidar device and operating method of the same
KR102874458B1 (ko) * 2019-11-19 2025-10-20 삼성전자주식회사 라이다 장치 및 그 동작 방법
CN112904305B (zh) * 2019-11-19 2025-10-03 三星电子株式会社 LiDAR设备及其操作方法
US12405381B2 (en) 2019-11-19 2025-09-02 Samsung Electronics Co., Ltd. LiDAR device and operating method of the same
US11815603B2 (en) 2019-11-19 2023-11-14 Samsung Electronics Co., Ltd. LiDAR device and operating method of the same
WO2021157439A1 (fr) * 2020-02-03 2021-08-12 株式会社ソニー・インタラクティブエンタテインメント Dispositif de calcul de déphasage, procédé de calcul de déphasage, et programme
JP7241710B2 (ja) 2020-02-03 2023-03-17 株式会社ソニー・インタラクティブエンタテインメント 位相差算出装置、位相差算出方法およびプログラム
JP2021124307A (ja) * 2020-02-03 2021-08-30 株式会社ソニー・インタラクティブエンタテインメント 位相差算出装置、位相差算出方法およびプログラム
CN114200466A (zh) * 2020-08-26 2022-03-18 迈来芯科技有限公司 畸变确定装置和确定畸变的方法
EP3961258A1 (fr) * 2020-08-26 2022-03-02 Melexis Technologies NV Appareil de détermination de distorsion et procédé de détermination d'une distorsion
US20220163641A1 (en) * 2020-11-23 2022-05-26 Nuvoton Technology Corporation Japan Multipath detection device and multipath detection method
EP4283254A4 (fr) * 2021-01-25 2024-07-24 Toppan Inc. Dispositif de capture d'image de distance et procédé de capture d'image de distance

Similar Documents

Publication Publication Date Title
WO2017138032A1 (fr) Dispositif de mesure de distance par temps de vol et procédé de détection d&#39;erreur multivoie
US11307296B2 (en) Time-of-flight distance measuring device and method for detecting multipath error
US11536804B2 (en) Glare mitigation in LIDAR applications
CN111045029B (zh) 一种融合的深度测量装置及测量方法
US10903254B2 (en) Distance-measuring imaging device, distance measuring method of distance-measuring imaging device, and solid-state imaging device
Dorrington et al. Separating true range measurements from multi-path and scattering interference in commercial range cameras
EP2729826B1 (fr) Améliorations apportées ou se rapportant au traitement des signaux de temps de vol
US20190178995A1 (en) Ranging device and method thereof
US10948596B2 (en) Time-of-flight image sensor with distance determination
US20210263137A1 (en) Phase noise and methods of correction in multi-frequency mode lidar
IL224134A (en) Methods and systems for eliminating hierarchical curve scaling in tof systems
EP3835819B1 (fr) Appareil de calcul de plage optique et procédé de calcul de plage
TWI835760B (zh) 距離飛行時間模組
Hussmann et al. Real-time motion artifact suppression in tof camera systems
US20220066004A1 (en) Distortion determination apparatus and method of determining a distortion
TWI873160B (zh) 飛行時間感測系統和其中使用的圖像感測器
US12140677B2 (en) Pseudo random number pulse control for distance measurement
CN112099036B (zh) 距离测量方法以及电子设备
CN112748441A (zh) 一种探测器阵列异常像素的识别方法
Schönlieb et al. Hybrid sensing approach for coded modulation time-of-flight cameras
US12429594B2 (en) Time-of-flight sensing using continuous wave and coded modulation measurements
US20220075063A1 (en) Method and Apparatus for Time-of-Flight Sensing
JP7264474B2 (ja) 物体検出装置及び物体検出方法
CN112946678B (zh) 一种探测装置
US20240241254A1 (en) Distance measurement device and distance measurement method

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: 16705308

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: 16705308

Country of ref document: EP

Kind code of ref document: A1