WO2020014902A1 - 飞时测距系统及校正方法 - Google Patents

飞时测距系统及校正方法 Download PDF

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Publication number
WO2020014902A1
WO2020014902A1 PCT/CN2018/096170 CN2018096170W WO2020014902A1 WO 2020014902 A1 WO2020014902 A1 WO 2020014902A1 CN 2018096170 W CN2018096170 W CN 2018096170W WO 2020014902 A1 WO2020014902 A1 WO 2020014902A1
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Prior art keywords
delay
delayed
time
optimal
signals
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PCT/CN2018/096170
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English (en)
French (fr)
Inventor
阙圣峻
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深圳市汇顶科技股份有限公司
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Application filed by 深圳市汇顶科技股份有限公司 filed Critical 深圳市汇顶科技股份有限公司
Priority to EP18914939.6A priority Critical patent/EP3633406B1/en
Priority to CN201880004641.0A priority patent/CN110168398B/zh
Priority to PCT/CN2018/096170 priority patent/WO2020014902A1/zh
Priority to US16/657,928 priority patent/US11454712B2/en
Publication of WO2020014902A1 publication Critical patent/WO2020014902A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/4861—Circuits for detection, sampling, integration or read-out
    • G01S7/4863—Detector arrays, e.g. charge-transfer gates
    • 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
    • G01C3/08—Use of electric radiation detectors
    • 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
    • G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • 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
    • 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
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/4865—Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak
    • 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

Definitions

  • the present application relates to a flying time ranging system and a correction method, and more particularly, to a flying time ranging system and a correction method that can avoid offset.
  • the structured light three-dimensional measurement method as a non-contact three-dimensional information acquisition technology, has been widely used because of its simple implementation, fast speed, and high accuracy.
  • Time-of-Flight (ToF) ranging method is a commonly used three-dimensional depth measurement method.
  • the existing flying-time ranging system has many non-idealities.
  • the two on-times of two transmission gates in a photosensitive pixel circuit applied to flying-time ranging must be separated by a time interval or transmitted.
  • the pulse to the light-emitting unit may be a non-ideal continuous square wave, resulting in an offset between the measured distance and the actual distance calculated by the flying time ranging method.
  • the purpose of some embodiments of the present application is to provide a flying time ranging system and a correction method that can avoid offset, so as to improve the shortcomings of the prior art.
  • an embodiment of the present application provides a flying time ranging system including a delay unit that receives a plurality of delay signals and is configured to generate a plurality of delay pulses according to the plurality of delay signals.
  • the delay signals correspond to a plurality of delay times;
  • the light emitting unit is coupled to the delay unit and is used to generate a plurality of delay pulse light according to the plurality of delay pulses;
  • Multiple delayed reflected lights of the delayed pulsed light to generate a plurality of pixel signals corresponding to the plurality of delay times;
  • a storage unit for storing correspondences between the plurality of delay times and the plurality of pixel signals Relationship; and a control unit, coupled to the delay unit, for generating the plurality of delayed signals; wherein the time-of-flight ranging system is based on the relationship between the plurality of delay times and the plurality of pixel signals Correspondence, perform flying time ranging.
  • control unit generates an optimal delay signal to the delay unit according to the correspondence between the multiple delay times and the multiple pixel signals, and the flying time ranging system according to the optimal delay
  • the signals perform on-the-fly ranging, where the best delayed signal corresponds to the best delay time.
  • the delay unit generates an optimal delay pulse according to the optimal delay signal
  • the light emitting unit generates an optimal delay pulse light according to the optimal delay pulse
  • the photosensitive pixel circuit receives the light corresponding to the optimal delay pulse.
  • the best delayed reflected light to generate an optimal delayed pixel signal, and the flying time ranging system calculates a flying time distance corresponding to the target object according to the optimal delayed pixel signal.
  • the plurality of delayed reflected lights are reflected from a self-reflecting plate, and the reflecting plate and the flying time ranging system have a fixed distance.
  • the photosensitive pixel circuit includes a photosensitive element; the first reading circuit includes a first transmission gate, the first transmission gate is coupled to the photosensitive element, and the first transmission gate receives a first transmission signal and The first on-time is turned on; and the second reading circuit includes a second transmission gate, the second transmission gate is coupled to the photosensitive element, and the second transmission gate receives the second transmission signal and transmits the signal to the second transmission gate.
  • the on-time is turned on, wherein the second reading circuit outputs the plurality of pixel signals; wherein the first on-time is separated from the second on-time by a time interval.
  • an embodiment of the present application further provides a pixel sensing unit and a correction method applied to a flying time ranging system.
  • the correction method includes generating multiple delay signals, wherein the multiple delay signals The signal corresponds to a plurality of delay times; a plurality of delay pulses are generated according to the plurality of delay signals; a plurality of delay pulse lights corresponding to the plurality of delay pulses are transmitted; a plurality of delay pulse lights corresponding to the plurality of delay pulse lights are received; Delayed reflection light to generate a plurality of pixel signals corresponding to the plurality of delay times; storing a correspondence relationship between the plurality of delay times and the plurality of pixel signals; and according to the plurality of delay times and Correspondence between the plurality of pixel signals is performed on-the-fly ranging.
  • an embodiment of the present application further provides a flying time ranging method, which is applied to a flying time ranging system.
  • the flying time ranging method includes acquiring multiple delay times and the multiple pixel signals. Correspondence between the plurality of delay times and the plurality of pixel signals, and performing flying time ranging according to the correspondence relationship between the plurality of delay times and the plurality of pixel signals, wherein the correspondence relationship between the plurality of delay times and the plurality of pixel signals is determined by flying
  • the time-of-flight correction method obtains and stores the time-of-flight ranging system.
  • the time-of-flight correction method includes generating a plurality of delay signals, wherein the plurality of delay signals correspond to a plurality of delay times.
  • the plurality of delay signals Generating a plurality of delayed pulses; transmitting a plurality of delayed pulse lights corresponding to the plurality of delayed pulses; receiving a plurality of delayed reflected lights corresponding to the plurality of delayed pulse lights to generate a plurality of delayed pulses A plurality of pixel signals; and outputting a correspondence relationship between the plurality of delay times and the plurality of pixel signals.
  • This application uses a plurality of delayed pulsed lights corresponding to different delay times to simulate different simulated distances between the flying time ranging system and the reflector, and then obtains the correspondence between the simulated distance and the measured distance, and according to this correspondence, Perform on-the-fly ranging.
  • the correspondence relationship between the simulated distance and the measured distance can be obtained without manual operation in the calibration phase in the present application, and has the advantages of simple operation and accurate flying time distance.
  • FIG. 1 is a schematic diagram of a time-of-flight ranging system according to Embodiment 1 of the present application; FIG.
  • FIG. 2 is a timing diagram of multiple signals according to an embodiment of the present application.
  • FIG. 3 is a schematic diagram of a photosensitive pixel circuit according to a first embodiment of the present application.
  • FIG. 5 is a waveform diagram of multiple signals according to an embodiment of the present application.
  • FIG. 6 is a schematic diagram of a process according to an embodiment of the present application.
  • FIG. 7 is a schematic diagram of a process according to an example of the present application.
  • FIG. 1 is a schematic diagram of a flying time ranging system 10 according to an embodiment of the present application.
  • the flying time ranging system 10 includes a delay unit 12, a light emitting unit 13, a photosensitive pixel array 14, a storage unit 16, and a control unit 18. .
  • the reflector 11 is set at a place where the fixed distance GD is known from the flying time ranging system 10.
  • the light emitting unit 13 emits light toward the reflecting plate 11 and the photosensitive pixel array 14 receives the reflected light from the reflection plate 11.
  • the control unit 18 in the correction phase, the control unit 18 generates a plurality of delay signals ds 1 to ds n to the delay unit 12, and the plurality of delay signals ds 1 to ds n respectively correspond to a plurality of delay times t d, 1 to t d, n , or the delayed signals ds 1 to ds n are signals used to indicate the delay time t d, 1 to t d, n , or the delayed signals ds 1 to ds n include the delay time t d, 1 to t d, n corresponding information.
  • the light-emitting unit 13 may be a light-emitting diode (LED), such as an infrared (Infrared Ray) light-emitting diode.
  • the light emitting unit 13 is coupled to the delay unit 12 to receive the delayed pulse dp 1 ⁇ dp n, according to the delay pulse dp 1 ⁇ dp n, at time interval T 1 ⁇ T n respectively generate 1 ⁇ dp n corresponding to the delay of the pulse dp
  • the plurality of delayed pulse lights LD 1 to LD n can form a delayed pulse signal DP (that is, the delayed pulse signal DP is composed of multiple delayed pulses dp 1 to dp n , which will be described later), and the light emitting unit 13 can be used to receive the delayed pulse signal DP.
  • the delayed pulse light LD 1 to LD n are generated.
  • the delayed pulse light LD 1 to LD n is emitted toward the reflection plate 11, and the reflection plate 11 reflects a plurality of delayed reflection lights R 1 to R n to the photosensitive pixel array 14.
  • the reflection plate 11 and the flying time ranging system 10 have Known fixed distance GD.
  • the photosensitive pixel array 14 includes a plurality of photosensitive pixel circuits 140 and the plurality of photosensitive pixel circuits 140 are arranged in an array. Without losing the generality, a photosensitive pixel circuit 140 in the photosensitive pixel array 14 will be described as an example below.
  • Photosensitive pixel circuit 140 at time interval T 1 ⁇ T n corresponding to a plurality of receiving the delay pulse light LD 1 ⁇ LD n of the plurality of delay of the reflected light R 1 ⁇ R n, and generates a reflected light corresponding to the retardation R 1 ⁇ R n
  • Multiple pixel signals p 1 to p n at multiple delay times t d, 1 to t d, n , and multiple pixel signals p 1 to p n can form one output signal.
  • the storage unit 16 is configured to store a correspondence relationship between a plurality of delay times t d, 1 to t d, n and a plurality of pixel signals p 1 to p n .
  • the light emitting unit 13 no longer emits light to the reflecting plate 11 and emits light toward the object to be measured or the target object.
  • the flying time ranging system 10 can use the storage unit 16 to store more A correspondence relationship between the delay times t d, 1 to t d, n and a plurality of pixel signals p 1 to p n- is used to perform on-the-fly ranging on the target object.
  • FIG. 2 illustrates a timing diagram of the first pulse signal PP and the delayed pulse signal DP in the embodiment of the present application.
  • the first pulse signal PP can be used as a reference comparison object of the delayed pulse signal DP.
  • the delayed pulse signal DP has delayed pulses dp 1 to dp n , and the first pulse signal PP may have reference pulses p ref in the time intervals T 1 to T n respectively, that is, a plurality of reference pulses p ref may form the first pulse signal PP,
  • the time intervals T 1 to T n may have the same time length.
  • the delay pulses dp 1 to dp n may respectively have a delay time t d, 1 to t d, n relative to the reference pulse p ref .
  • the rising edges of the delay pulses dp1 to dpn are relative to the reference pulse p
  • the rising edges of ref each have a delay time t d, 1 to t d, n
  • the falling edges (Falling Edge) of the delay pulses dp 1 to dp n have a delay time t d, 1 relative to the falling edge of the reference pulse p ref .
  • ⁇ T d, n The delay pulses dp 1 to dp n and the reference pulse pref may have the same pulse width and pulse amplitude.
  • the light emitting unit 13 receives the delayed pulse signal DP and emits the delayed pulse light LD 1 to LD n in the time intervals T 1 to T n according to the delayed pulse signal DP, and the photosensitive pixel circuit 140 may respectively interval T 1 ⁇ T n retardation receiving the reflected light R 1 ⁇ R n.
  • FIG. 3 is a schematic diagram of a photosensitive pixel circuit 140 according to an embodiment of the present application.
  • the photosensitive pixel circuit 140 includes a photosensitive element PD and photoelectric reading circuits 31 and 32.
  • the photosensitive element PD may be a photodiode.
  • the photoelectric reading circuit 31 includes a transmission gate TG1, an output transistor DV1, and a reading transistor RD1, and the photoelectric reading circuit 32 includes a transmission gate TG2, an output transistor DV2, and a reading transistor RD2.
  • the transmission gates TG1 and TG2 are coupled to the photosensitive element PD.
  • the output transistors DV1 and DV2 are respectively coupled to the transmission gates TG1 and TG2.
  • the read transistors RD1 and RD2 are respectively coupled to the output transistors DV1 and DV2 and output the first output signals. Pout1, the second output signal Pout2.
  • the transmission gates TG1 and TG2 respectively receive the transmission signals TX1 and TX2, and the read transistors RD1 and RD2 receive the row selection signal ROW.
  • the photosensitive pixel circuit 140 outputs output signals Pout1 and Pout2 .
  • the photoelectric reading circuits 31 and 32 respectively include reset transistors RT1 and RT2.
  • the reset transistors RT1 and RT2 receive a reset signal Rst.
  • the reset signal Rst controls the reset transistors RT1 and RT2 to be turned on, the floating diffusion ( Floating Diffusion) The charge in the node FD is emptied.
  • the photosensitive pixel circuit 140 further includes an anti-blooming transistor AB.
  • the anti-blooming transistor AB is controlled by the anti-blooming signal TX5, and the anti-blooming signal TX5 controls the anti-blooming transistor AB when the anti-blooming transistor AB is turned on.
  • the photoelectrons generated by the component PD due to receiving the background light are extracted to avoid affecting the normal operation of the circuit.
  • the signals TX1, TX2, Rst, ROW, and TX5 can be generated by the control unit (bits shown in FIG. 1) of the flying time ranging system 10.
  • FIG. 2 also shows a timing diagram of the transmission signals TX1 and TX2 in the embodiment of the present application.
  • the transmission gate TG1 is controlled by the transmission signal TX1 and is turned on at the on time TT1
  • the transmission gate TG2 is controlled by the transmission signal TX2 and is turned on at the on time TT2, where the on time TT1 and the on Time TT2 is separated by a time interval ⁇ T.
  • ⁇ T can be a fixed time interval or a variable time interval.
  • the transmission signal TX1 may have reference pulses p ref (periodically) in the time intervals T 1 to T n respectively, that is, the transmission signal TX1 may have the same timing or waveform as the first pulse signal PP.
  • the delay times t d, 1 to t d, n may be the delay times of the delay pulses dp 1 to dp n relative to the reference pulse p ref in the transmission signal TX1.
  • the pixel signals p 1 to p n output by the photosensitive pixel circuit 140 may be related to the first output signal Pout1 or the second output signal Pout2.
  • the flying time ranging system 10 mainly calculates the distance based on the relative proportional relationship between the first output signal Pout1 or the second output signal Pout2 and the second output signal Pout2 is proportional to the distance calculated using the flying time ranging, that is, The second output signal Pout2 is proportional to the light flight time, so in the following embodiments, the pixel signals p 1 to p n are related to the second output signal Pout2 as an example for description.
  • the pixel signals p 1 to p n may be multiple signal values of the second output signal Pout2 in the time interval T 1 to T n , that is, the photosensitive element PD receives multiple signals in the time interval T 1 to T n .
  • the second output signal Pout2 output by the photoelectric reading circuit 32 in the time intervals T 1 to T n includes a plurality of pixel signals p 1 to p n , and the plurality of pixel signals p 1 to p n respectively correspond to a plurality of delays. Time t d, 1 to t d, n .
  • the storage unit 16 can directly store the correspondence between the delay times t d, 1 to t d, n and the pixel signals p 1 to p n .
  • the flying time ranging system 10 can calculate the simulation distance d 1 to d n based on the known fixed distance GD and the delay time t d, 1 to t d, n , and calculate the amount based on the pixel signals p 1 to p n
  • the measurement distance d 1 ′ ⁇ d n ′, and the storage unit 16 can store the correspondence between the simulation distance d 1 ⁇ d n and the measurement distance d 1 ′ ⁇ d n ′, which can be regarded as the indirect storage delay time t d Correspondence between , 1 to t d, n and pixel signals p 1 to p n .
  • the simulation distances d 1 to d n may be a distance that is a fixed distance GD plus the distance that the light travels at the speed of light in the time t d, 1 to t d, n .
  • the measurement distance d 1 ′ to d n ′ may be a flying time distance calculated by using the flying time ranging method based on a plurality of second output signals Pout2 corresponding to the time interval T 1 to T n , which may not necessarily be equal to the actual distance.
  • the simulation distance d 1 to d n has a linear relationship with time t d, 1 to t d, n (roughly), the pixel signals p 1 to p n and the measurement distance d 1 ′ to d n ′ (roughly) It has a linear relationship. Therefore, the correspondence between the delay time t d, 1 to t d, n and the pixel signals p 1 to p n is equivalent to the simulation distance d 1 to d n and the measurement distance d 1 'to d n '. Correspondence between.
  • FIG. 4 shows a plurality of curves of the relationship between the actual / emulation distance and the measured distance, which may also represent the correspondence between the delay time and the pixel signal.
  • Sub-FIG. 5a in FIG. 5 illustrates that when there is no time gap between the on-time TT1 ′ of the transmission gate TG1 and the on-time TT2 ′ of the transmission gate TG2 in the photosensitive pixel circuit 140, the transmission received by the transmission gate TG1 is transmitted.
  • sub-picture 5c shows the waveform of the output non-continuous square wave output delay pulses dp 1 to dp n
  • sub-picture 5d shows the output to The delayed pulses dp 1 to dp n are waveform diagrams of non-ideal continuous square waves.
  • curve cv3 is the on-time of the transmission gate TG1 When there is no time gap between TT1 'and the conduction time TT2' of transmission gate TG2 (corresponding to subfigure 5a), and the delay pulses dp 1 to dp n are non-ideal continuous square waves shown in subfigure 5d, the actual / simulated distance Correspondence curve with measurement distance; curve cv4 is between the conduction time TT1 of the transmission gate TG1 and the conduction time TT2 of the transmission gate TG2 When a non-zero time interval [Delta] T (corresponding sub FIG.
  • the actual distance is the distance between the time-of-flight ranging system 10 and the object to be measured (which may be a target object or a reflecting plate).
  • the curves cv1 to cv4 may also represent the correspondence curve between the delay time and the pixel signal.
  • the correspondence between the delay times t d, 1 to t d, n stored in the storage unit 16 and the pixel signals p 1 to p n or the simulation distances d 1 to d n and the measurement distances d 1 ′ to d n ′ can be represented by multiple discrete points on the curve cv4 in FIG. 4.
  • the corresponding relationship between d 1 ⁇ d n and d 1 ′ ⁇ d n ′ can be expressed as the abscissa of the discrete points and Ratio between ordinates.
  • curve cv4 has an offset (Offset) compared to curve cv1, that is, the measurement distance calculated by the flying time ranging system is not equal to the actual distance between the flying time ranging system and the object to be measured.
  • the calibration personnel changed the distance between the time-of-flight ranging system and the reflector by continuously moving the reflector to obtain multiple discrete points of the curve cv4 in FIG. 4.
  • the existing calibration method involves manual operation (the distance between the time-of-flight ranging system and the reflecting plate needs to be changed manually), which causes inconvenience to the technicians.
  • the present application simulates the time-of-flight ranging through different delay times t d, 1 to t d, n
  • the system 10 and the reflecting plate 11 have different simulation distances d 1 to d n to obtain a plurality of discrete points of the curve cv4 in FIG. 4.
  • the flying time ranging system 10 may obtain the curve cv4 according to a plurality of discrete points of the curve cv4 and use an interpolation method.
  • the flying time ranging system 10 can according to the second output signal (output from the photoelectric reading circuit 32 in the photosensitive pixel circuit 140) obtained during the ranging phase.
  • Pout2 which can be compared with the vertical axis in FIG. 4
  • the curve cv4 to obtain the actual distance between the flying time ranging system 10 and the target object (which can be compared with the horizontal axis in FIG. 4, at this time according to the distance measurement stage)
  • the distance obtained by comparing the second output signal Pout2 with the curve cv4 on the horizontal axis in FIG. 4 is the actual distance).
  • FIG. 6 is a schematic diagram of a process 60 according to an embodiment of the present application.
  • the process 60 includes the following steps:
  • Step 600 The control unit 18 generates a plurality of delay signals ds 1 to ds n to the delay unit 12.
  • Step 602 The delay unit 12 delays the plurality of 1 ⁇ ds n signals ds, generating a plurality of delayed pulse dp 1 ⁇ dp n.
  • Step 604 the light emitting unit 13 at time interval T 1 ⁇ T n transmit a plurality of delay pulse light LD 1 ⁇ LD n.
  • Step 606 a photosensitive pixel circuit 140 at time interval T 1 ⁇ T n delay in receiving a plurality of reflected light R 1 ⁇ R n, and generates a plurality of delay corresponding to the delay time t d of the reflected light R 1 ⁇ R n, 1 ⁇ A plurality of pixel signals p 1 to p n of t d, n .
  • Step 608 The storage unit 16 is configured to store a correspondence between a plurality of delay times t d, 1 to t d, n and a plurality of pixel signals p 1 to p n- .
  • Step 610 The flying-time ranging system 10 performs flying-time ranging according to the correspondence between the multiple delay times t d, 1 to t d, n and the multiple pixel signals p 1 to p n- .
  • steps 600 to 608 may belong to the calibration phase before the device leaves the factory, and step 610 may belong to the actual ranging phase after the device leaves the factory.
  • the flying time ranging system 10 can calculate the optimal delay time t d, opt (or its corresponding simulation distance) according to the curve cv4, which is located in a relatively linear region in the middle of the curve cv4 (referred to as linear Zone), so that the measurement distance calculated by the flying time ranging system 10 according to the flying time ranging method is closer to the real distance between the flying time ranging system 10 and the target object.
  • FIG. 7 is a flowchart of a process 70 of an embodiment of the present application. schematic diagram. The process 70 includes the following steps:
  • Step 700 The control unit 18 calculates the optimal delay time t d, opt according to the correspondence relationship between the multiple delay times t d, 1 to t d, n and the multiple pixel signals p 1 to p n- and generates a correspondence.
  • the optimal delay signal ds opt at the optimal delay time t d, opt reaches the delay unit 12.
  • Step 702 The optimum delay unit 12 delays the pulse signal ds opt, the optimum delay pulse generation dp opt.
  • Step 704 the light emitting unit 13 according to the optimum delay pulse dp opt, the optimal delay generating pulse light LD opt.
  • Step 706 The photosensitive pixel circuit 140 receives the optimal delayed reflected light R opt corresponding to the optimal delayed pulse light LD opt , and generates an optimal delay corresponding to the optimal delayed time t d, opt according to the optimal delayed reflected light R opt.
  • the pixel signal p opt The photosensitive pixel circuit 140 receives the optimal delayed reflected light R opt corresponding to the optimal delayed pulse light LD opt , and generates an optimal delay corresponding to the optimal delayed time t d, opt according to the optimal delayed reflected light R opt.
  • the pixel signal p opt The photosensitive pixel circuit 140 receives the optimal delayed reflected light R opt corresponding to the optimal delayed pulse light LD opt , and generates an optimal delay corresponding to the optimal delayed time t d, opt according to the optimal delayed reflected light R opt.
  • Step 708 The flying time ranging system 10 calculates the flying time distance corresponding to the target object according to the optimal delayed pixel signal p opt .
  • the optimal delay time t d, opt may be a delay time of the optimal delay pulse dp opt relative to the reference pulse p ref in the transmission signal TX1.
  • the optimal delayed pixel signal p opt is a second output signal Pout2 that the photosensitive pixel circuit 140 receives the optimal delayed reflected light R opt and the corresponding output of the photoelectric reading circuit 32 in the photosensitive pixel circuit 140.
  • the details of calculating the flying time distance corresponding to the target object according to the second output signal Pout2 are known to those having ordinary knowledge in the art, and will not be repeated here. The rest of the details about the process 70 are similar to the process 60, so they are not described in detail.
  • the present application uses a plurality of delayed pulsed lights corresponding to different delay times to simulate different simulated distances between the flying time ranging system and the reflector, and then obtains the correspondence between the simulated distance and the measured distance. According to this correspondence relationship, flying time ranging is performed. Compared with the prior art, the correspondence relationship between the simulated distance and the measured distance can be obtained without manual operation in the calibration phase in the present application, and has the advantages of simple operation and accurate flying time distance.

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Abstract

一种飞时测距系统（10），包括延迟单元（12），用来根据多个延迟信号，产生多个延迟脉冲，其中多个延迟信号对应于多个延迟时间；发光单元（13），用来根据多个延迟脉冲，产生多个延迟脉冲光；感光像素电路（14），用来接收多个延迟反射光，以产生多个像素信号；储存单元（16），用来储存多个延迟时间与多个像素信号之间的对应关系；以及控制单元（18），用来产生多个延迟信号；其中，飞时测距系统（10）根据多个延迟时间与多个像素信号之间的对应关系，进行飞时测距。还涉及一种应用于飞时测距系统的校正方法和飞时测距方法。

Description

飞时测距系统及校正方法 技术领域
本申请涉及一种飞时测距系统及校正方法，尤其涉及一种可避免偏置的飞时测距系统及校正方法。
背景技术
随着科学与技术的飞速发展，物体三维信息的获取在很多应用领域都有着广泛的应用前景，如生产自动化、人机交互、医学诊断、逆向工程、数字化建模等。其中，结构光三维测量法作为一种非接触式的三维信息获取技术，因其实现简单、速度快和精度高等优点得到了广泛应用。
飞时(Time of Flight，ToF)测距法为常用的三维深度测量方法。然而，现有飞时测距系统具有许多非理想性，如应用于飞时测距的感光像素电路中二个传输闸(Transmission Gate)的二个导通时间必须间隔一时间间隔，或是传送至发光单元的脉冲可能为非理想连续方波，而导致利用飞时测距法计算出的量测距离与实际距离之间具有偏置(Offset)。
因此，现有技术实有改进的必要。
发明内容
因此，本申请部分实施例的目的即在于提供一种可避免偏置的飞时测距系统及校正方法，以改善现有技术的缺点。
为了解决上述技术问题，本申请实施例提供了一种飞时测距系统，包括延迟单元，接收多个延迟信号，用来根据所述多个延迟信号，产生多个延迟脉冲，其中所述多个延迟信号对应于多个延迟时间；发光单元，耦接于所述延迟单元，用来根据所述多个延迟脉冲，产生多个延迟脉冲光；感光像素电路，用来接收对应于所述多个延迟脉冲光的多个延迟反射光，以产生对应于所述多个延迟时间的多个像素信号；储存单元，用来储存所述多个延迟时间与所述多个像素信号之间的对应关系；以及控制单元，耦接于所述延迟单元，用来产生所述多个延迟信号；其中，所述飞时测距系统根据所述多个延迟时间与所述多个像素信号之间的对应关系，进行飞时测距。
例如，所述控制单元根据所述多个延迟时间与所述多个像素信号之间的对应关系，产生最佳延迟信号至所述延迟单元，所述飞时测距系统根据所述最佳延迟信号进行飞时测距，其中所述最佳延迟信号对应于最佳延迟时间。
例如，所述延迟单元根据所述最佳延迟信号产生最佳延迟脉冲，发光单元根据所述最佳延迟脉冲产生最佳延迟脉冲光，所述感光像素电路接收对应于所述最佳延迟脉冲光的最佳延迟反射光以产生最佳延迟像素信号，所述飞时测距系统根据所述最佳延迟像素信号计算对应于目标物件的飞时距离。
例如，所述多个延迟反射光反射自反射板，所述反射板与所述飞时测距系统之间具有固定距离。
例如，所述感光像素电路包括感光元件；第一读取电路，包括第一传输闸，所述第一传输闸耦接于所述感光元件，所述第一传输闸接收第一传输信号而于第一导通时间导通；以及第二读取电路，包括第二传输闸，所述第二传输闸耦接于所述感光元件，所述第二传输闸接收第二传输信号而于第二导通时间导通，其中所述第二读取电路输出所述多个像素信号；其中，所述第一导通时间与所述第二导通时间相隔一时间间隔。
为了解决上述技术问题，本申请实施例另提供了一种像素传感单元，一种校正方法，应用于飞时测距系统，所述校正方法包括产生多个延迟信号，其中所述多个延迟信号对应于多个延迟时间；根据所述多个延迟信号，产生多个延迟脉冲；发射对应于所述多个延迟脉冲的多个延迟脉冲光；接收对应于所述多个延迟脉冲光的多个延迟反射光，以产生对应于所述多个延迟时间的多个像素信号；储存所述多个延迟时间与所述多个像素信号之间的对应关系；以及根据所述多个延迟时间与所述多个像素信号之间的对应关系，进行飞时测距。
为了解决上述技术问题，本申请实施例另提供了一种飞时测距方法，应用于飞时测距系统，所述飞时测距方法包括获取多个延迟时间与所述多个像素信号之间的对应关系；以及根据所述多个延迟时间与所述多个像素信号之间的对 应关系，进行飞时测距，其中，多个延迟时间与多个像素信号之间的对应关系通过飞时校正方法获得并存储于所述飞时测距系统，所述飞时校正方法包括产生多个延迟信号，其中所述多个延迟信号对应于多个延迟时间；根据所述多个延迟信号，产生多个延迟脉冲；发射对应于所述多个延迟脉冲的多个延迟脉冲光；接收对应于所述多个延迟脉冲光的多个延迟反射光，以产生对应于所述多个延迟时间的多个像素信号；以及输出所述多个延迟时间与所述多个像素信号之间的对应关系。
本申请利用发射对应不同延迟时间的多个延迟脉冲光，仿真出飞时测距系统与反射板之间不同的仿真距离，进而取得仿真距离与量测距离的对应关系，并根据此对应关系，进行飞时测距。相较于现有技术，本申请于校正阶段中不需透过人为操作即可得到仿真距离与量测距离的对应关系，具有操作简便及可取得精准飞时距离的优点。
附图说明
图1为本申请实施例一飞时测距系统的示意图；
图2为本申请实施例多个信号的时序图；
图3为本申请实施例一感光像素电路的示意图；
图4为本申请实施例多条对应曲线的的示意图；
图5为本申请实施例多个信号的波形图；
图6为本申请实施例一流程的示意图；
图7为本申请实施例一流程的示意图。
具体实施方式
为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本申请，并不用于限定本申请。
请一并参考图1，图1为本申请实施例飞时测距系统10的示意图，飞时测距系统10包括延迟单元12、发光单元13、感光像素阵列14、储存单元16以及控制单元18。于飞时测距系统10的校正(Calibration)阶段中，反射板(Reflector)11设置于距离飞时测距系统10已知固定距离GD的地方，发光单元13朝反射板11发光而感光像素阵列14接收来自反射板11的反射光。
详细来说，于校正阶段中，控制单元18产生多个延迟信号ds 1～ds n至延迟单元12，多个延迟信号ds 1～ds n分别对应多个延迟时间t d,1～t d,n，或者说延迟信号ds 1～ds n是用于表示延迟时间t d,1～t d,n的信号，或者说延迟信号ds 1～ds n包含与延迟时间t d,1～t d,n对应的信息。延迟单元12接收多个延迟信号ds 1～ds n，并根据多个延迟信号ds 1～ds n产生多个延迟脉冲dp 1～dp n，而延迟脉冲dp 1～dp n对应于延迟时间t d,1～t d,n。发光单元13可为发光二极管(Light-Emitting Diode，LED)，如红外线(Infrared Ray，IR)发光二极管。发光单元13耦接于延迟单元12以接收延迟脉冲dp 1～dp n，用来根据延迟脉冲dp 1～dp n，于时间区间T 1～T n分别产生对应于延迟脉冲dp 1～dp n的多个延迟脉冲光LD 1～LD n。其中，延迟脉冲dp 1～dp n可形成一延迟脉冲信号DP(即延迟脉冲信号DP由多个延迟脉 冲dp 1～dp n组成，其于后叙述)，发光单元13可用于接收延迟脉冲信号DP而产生延迟脉冲光LD 1～LD n。延迟脉冲光LD 1～LD n朝反射板11发射，而反射板11反射多个延迟反射光R 1～R n至感光像素阵列14，其中反射板11与飞时测距系统10之间具有已知的固定距离GD。感光像素阵列14包括多个感光像素电路140而多个感光像素电路140排列成一阵列。在不失去一般性的原则下，以下将以感光像素阵列14中一个感光像素电路140为例进行说明。感光像素电路140于时间区间T 1～T n中接收对应于多个延迟脉冲光LD 1～LD n的多个延迟反射光R 1～R n，并根据延迟反射光R 1～R n产生对应于多个延迟时间t d,1～t d,n的多个像素信号p 1～p n，多个像素信号p 1～p n可组成一路输出信号。储存单元16用来储存多个延迟时间t d,1～t d,n与多个像素信号p 1～p n之间的对应关系。
于飞时测距系统10的测距阶段中，发光单元13不再对反射板11发光，而朝向待测对象或目标物件发光，此时飞时测距系统10可利用储存单元16所储存多个延迟时间t d,1～t d,n与多个像素信号p 1～p n-之间的对应关系，对目标物件进行飞时测距。
请参考图2，图2绘示本申请实施例第一脉冲信号PP以及延迟脉冲信号DP的时序图，其中第一脉冲信号PP可作为延迟脉冲信号DP的参考比照对象。延迟脉冲信号DP具有延迟脉冲dp 1～dp n，第一脉冲信号PP可于时间区间T 1～T n中分别具有参考脉冲p ref，即多个参考脉冲p ref可形成第一脉冲信号PP，其中时间区间T 1～T n可具有相同的时间长度。延迟脉冲dp 1～dp n可相对于参考脉冲p ref而分别具有延迟时间t d,1～t d,n，举例来说，延迟脉冲dp1～dpn的上升沿(Rising  Edge)相对于参考脉冲p ref的上升沿分别具有延迟时间t d,1～t d,n，或延迟脉冲dp 1～dp n的下降沿(Falling Edge)相对于参考脉冲p ref的下降沿分别具有延迟时间t d,1～t d,n。其中，延迟脉冲dp 1～dp n与参考脉冲p ref可具有相同的脉冲宽度及脉冲振幅。
另外，于校正阶段中，发光单元13接收延迟脉冲信号DP并根据延迟脉冲信号DP分别于时间区间T 1～T n中发射延迟脉冲光LD 1～LD n，而感光像素电路140可分别于时间区间T 1～T n中接收延迟反射光R 1～R n。
应用于飞时测距的感光像素电路140的运作为本领域具通常知识者所知，而简述如下。请参考图3，图3为本申请实施例感光像素电路140的示意图。感光像素电路140包括感光元件PD以及光电读取电路31、32，感光元件PD可为感光二极管(Photo Diode)。光电读取电路31包括传输闸TG1、输出晶体管DV1以及读取晶体管RD1，光电读取电路32包括传输闸TG2、输出晶体管DV2以及读取晶体管RD2。传输闸TG1、TG2耦接于感光元件PD，输出晶体管DV1、DV2分别耦接于传输闸TG1、TG2，读取晶体管RD1、RD2分别耦接于输出晶体管DV1、DV2，并分别输出第一输出信号Pout1、第二输出信号Pout2。传输闸TG1、TG2分别接收传输信号TX1、TX2，读取晶体管RD1、RD2接收行选信号ROW，当行选信号ROW控制读取晶体管RD1、RD2导通时，感光像素电路140输出输出信号Pout1、Pout2。光电读取电路31、32另分别包括重置晶体管RT1、RT2，重置晶体管RT1、RT2接收重置信号Rst，当重置信号Rst控制重置晶体管RT1、RT2导通时，可将浮动扩散(Floating Diffusion) 节点FD中的电荷清空。感光像素电路140另包括一防晕染(Anti-Blooming)晶体管AB，防晕染晶体管AB受控于防晕染信号TX5，防晕染信号TX5控制防晕染晶体管AB导通时，可将感光元件PD因接收背景光而产生的光电子汲取出来，以免影响电路的正常运作。其中，在一些实施例中，信号TX1、TX2、Rst、ROW、TX5可由飞时测距系统10的控制单元(位绘示于图1)所产生。
请再次参考图2，图2亦绘示本申请实施例传输信号TX1、TX2的时序图。如图2所示，传输闸TG1受控于传输信号TX1而于导通时间TT1导通，传输闸TG2受控于传输信号TX2而于导通时间TT2导通，其中导通时间TT1与导通时间TT2相隔一时间间隔ΔT。ΔT可以为固定的时间间隔，也可以是变化的时间间隔。传输信号TX1可于时间区间T 1～T n中(周期性地)分别具有参考脉冲p ref，即传输信号TX1可与第一脉冲信号PP具有相同的时序(Timing)或波形。从另一个角度来说，延迟时间t d,1～t d,n可为延迟脉冲dp 1～dp n相对于传输信号TX1中参考脉冲p ref的延迟时间。
另外，感光像素电路140输出的像素信号p 1～p n可相关于第一输出信号Pout1或第二输出信号Pout2。由于飞时测距系统10主要根据第一输出信号Pout1或第二输出信号Pout2之间的相对比例关系计算距离，且第二输出信号Pout2与利用飞时测距所计算出的距离成正比，即第二输出信号Pout2与光飞行时间成正比，故于以下实施例中，以像素信号p 1～p n相关于第二输出信号Pout2为例进行说明。更进一步地，像素信号p 1～p n可为第二输出信号Pout2于时间区间T 1～T n的多个信号值，也就是说，感光元件PD于时间区间T 1～T n分别接 收多个延迟反射光R 1～R n，由于延迟脉冲dp 1～dp n相对于传输闸TG2的导通时间TT2具有不同的时间差(其分别相关于延迟时间t d,1～t d,n)，因此光电读取电路32于时间区间T 1～T n输出的第二输出信号Pout2包含多个像素信号p 1～p n，且所述多个像素信号p 1～p n分别对应于多个延迟时间t d,1～t d,n。
储存单元16可直接储存延迟时间t d,1～t d,n与像素信号p 1～p n之间的对应关系。除此之外，飞时测距系统10可根据已知固定距离GD以及延迟时间t d,1～t d,n推算仿真距离d 1～d n，并根据像素信号p 1～p n推算量测距离d 1’～d n’，而储存单元16可储存仿真距离d 1～d n与量测距离d 1’～d n’之间的对应关系，其可视为间接储存延迟时间t d,1～t d,n与像素信号p 1～p n之间的对应关系。其中，仿真距离d 1～d n可为固定距离GD加上光线于时间t d,1～t d,n中以光速行进的距离。量测距离d 1’～d n’可为根据对应于时间区间T 1～T n的多个第二输出信号Pout2，利用飞时测距法所计算出的飞时距离，其不一定等于实际距离。
另外，由于仿真距离d 1～d n与时间t d,1～t d,n(大致)呈线性关系，而像素信号p 1～p n与量测距离d 1’～d n’(大致)呈线性关系，因此，延迟时间t d,1～t d,n与像素信号p 1～p n之间的对应关系相当于仿真距离d 1～d n与量测距离d 1’～d n’之间的对应关系。
请一并参考图4及图5，图4绘示实际/仿真距离与量测距离之间关系的多条曲线，其也可以代表延迟时间与像素信号之间的对应关系。图5中的子图5a绘示当感光像素电路140中传输闸TG1的导通时间TT1’与传输闸TG2的导通 时间TT2’之间无时间缝隙(Seamless)时，传输闸TG1所接收传输信号TX1’及传输闸TG1所接收传输信号TX2’的波形图；子图5b绘示当传输闸TG1的导通时间TT1与传输闸TG2的导通时间TT2之间具有时间间隔ΔT时，传输闸TG1所接收传输信号TX1及传输闸TG1所接收传输信号TX2的波形图；子图5c绘示输出至延迟脉冲dp 1～dp n为理想非连续方波的波形图；子图5d绘示输出至延迟脉冲dp 1～dp n为非理想连续方波的波形图。
另外，图4中曲线cv1为当传输闸TG1的导通时间TT1’与传输闸TG2的导通时间TT2’之间无时间缝隙,ΔT＝0(即图3中传输闸TG1、TG2接收子图5a所绘示的传输信号TX1’、TX2’)且延迟脉冲dp 1～dp n为子图5c所绘示的理想非连续方波时，实际/仿真距离与量测距离的对应关系曲线；曲线cv2为当传输闸TG1的导通时间TT1与传输闸TG2的导通时间TT2之间具有非零的时间间隔ΔT(即传输闸TG1、TG2接收子图5b/图2所绘示的传输信号TX1、TX2)且延迟脉冲dp 1～dp n为子图5c所绘示的理想非连续方波时，实际/仿真距离与量测距离的对应关系曲线；曲线cv3为当传输闸TG1的导通时间TT1’与传输闸TG2的导通时间TT2’之间无时间缝隙(对应子图5a)且延迟脉冲dp 1～dp n为子图5d所绘示的非理想连续方波时，实际/仿真距离与量测距离的对应关系曲线；曲线cv4为当传输闸TG1的导通时间TT1与传输闸TG2的导通时间TT2之间具有非零的时间间隔ΔT(对应子图5b)且延迟脉冲dp 1～dp n为子图5d所绘示的非理想连续方波时，实际/仿真距离与量测距离的对应关系曲线。其中，实际距离为飞时测距系统10与待测物(其可为目标物件或反射板)之间的距离，另外，曲线cv1～cv4亦可代表延迟时间与像素信号的对应关系曲线。
另外，储存单元16所储存的延迟时间t d,1～t d,n与像素信号p 1～p n之间对应关系或仿真距离d 1～d n与量测距离d 1’～d n’之间对应关系即可由图4中曲线cv4上多个离散点(Discrete Points)表示，例如，d 1～d n与d 1’～d n’之间对应关系可表示为离散点的横坐标与纵坐标之间的比。
由图4可知，当最理想的情境(对应曲线cv1的情境)下，飞时测距系统所计算出的量测距离会等于飞时测距系统与待测物之间的实际距离。实际上，为了因应线路而在电路设计时，传输闸TG1的导通时间TT1与传输闸TG2的导通时间TT2之间必须具有一定的时间间隔ΔT(也就是ΔT为非零)，另一方面，当延迟脉冲dp 1～dp n的转态时间相较于脉冲宽度为不可忽略或可比较(Comparable)时，延迟脉冲dp 1～dp n呈现子图5d所绘示的波形。综合以上现实因素，曲线cv4相较于曲线cv1具有偏置(Offset)，即飞时测距系统所计算出的量测距离不等于飞时测距系统与待测物之间的实际距离。
为了避免偏置，现有技术于校正阶段中，校正人员通过不断地移动反射板而改变飞时测距系统与反射板之间的距离，而取得图4中曲线cv4的多个离散点。现有校正方法涉及人为操作(需人为改变飞时测距系统与反射板之间的距离)，造成技术人员的不便。相较之下，本申请在飞时测距系统10与反射板11之间的距离GD为固定的前提下，通过不同的延迟时间t d,1～t d,n，仿真出飞时测距系统10与反射板11不同的仿真距离d 1～d n，而取得图4中曲线cv4的多个离散点。于一实施例中，飞时测距系统10可根据曲线cv4的多个离散点并 利用内插(Interpolation)的方式，取得曲线cv4。
如此一来，于测距阶段中(取得曲线cv4之后)，飞时测距系统10可根据于测距阶段中所得到(感光像素电路140中光电读取电路32所输出)的第二输出信号Pout2(其可对照图4中的纵轴)，对照曲线cv4而得到飞时测距系统10与目标物件的实际距离(其可对照图4中的横轴，此时根据测距阶段中所得到第二输出信号Pout2对照曲线cv4而于图4横轴所取得的距离即为实际距离)。
飞时测距系统10的操作可归纳成为一流程，请参考图6，图6为本申请实施例一流程60的示意图。流程60包括以下步骤：
步骤600：控制单元18产生多个延迟信号ds 1～ds n至延迟单元12。
步骤602：延迟单元12根据多个延迟信号ds 1～ds n，产生多个延迟脉冲dp 1～dp n。
步骤604：发光单元13于时间区间T 1～T n发射多个延迟脉冲光LD 1～LD n。
步骤606：感光像素电路140于时间区间T 1～T n中接收多个延迟反射光R 1～R n，并根据延迟反射光R 1～R n产生对应于多个延迟时间t d,1～t d,n的多个像素信号p 1～p n。
步骤608：储存单元16用来储存多个延迟时间t d,1～t d,n与多个像素信号p 1～p n-之间的对应关系。
步骤610：飞时测距系统10根据多个延迟时间t d,1～t d,n与多个像素信号p 1～p n-之间的对应关系，进行飞时测距。
关于流程60的细节，请参考前述相关段落，于此不再赘述。其中，步骤600～608可属于装置出厂前的校正阶段，步骤610可属于装置出厂后的实际测距阶段。
前述实施例用以说明本申请的发明概念，本领域具通常知识者当可据以做不同的修饰，而不限于此。举例来说，于步骤610中，飞时测距系统10可根据曲线cv4，计算出最佳延迟时间t d,opt(或其所对应的仿真距离)位于曲线cv4中间较为线性的区域(简称线性区)，使得飞时测距系统10根据飞时测距法所计算出的量测距离更贴近飞时测距系统10与目标物件的真实距离。
关于飞时测距系统10计算最佳延迟时间t d,opt并根据最佳延迟时间t d,opt进行飞时测距的细节，请参考图7，图7为本申请实施例一流程70的示意图。流程70包括以下步骤：
步骤700：控制单元18根据多个延迟时间t d,1～t d,n与多个像素信号p 1～p n-之间的对应关系，计算最佳延迟时间t d,opt，并产生对应于最佳延迟时间t d,opt的最佳延迟信号ds opt至延迟单元12。
步骤702：延迟单元12根据最佳延迟脉冲信号ds opt，产生最佳延迟脉冲dp opt。
步骤704：发光单元13根据最佳延迟脉冲dp opt，产生最佳延迟脉冲光LD opt。
步骤706：感光像素电路140接收对应于最佳延迟脉冲光LD opt的最佳延 迟反射光R opt，并根据最佳延迟反射光R opt产生对应于最佳延迟时间t d,opt的最佳延迟像素信号p opt。
步骤708：飞时测距系统10根据最佳延迟像素信号p opt，计算对应于目标物件的飞时距离。
于步骤702中，最佳延迟时间t d,opt可为最佳延迟脉冲dp opt相对于传输信号TX1中参考脉冲p ref的延迟时间。于步骤708中，最佳延迟像素信号p opt为感光像素电路140接收最佳延迟反射光R opt且感光像素电路140中光电读取电路32相应输出的第二输出信号Pout2。根据第二输出信号Pout2计算对应于目标物件的飞时距离的细节为本领域具通常知识者所知，于此不再赘述。其余关于流程70的细节，与流程60类似，故不赘述。
综上所述，本申请利用发射对应不同延迟时间的多个延迟脉冲光，仿真出飞时测距系统与反射板之间不同的仿真距离，进而取得仿真距离与量测距离的对应关系，并根据此对应关系，进行飞时测距。相较于现有技术，本申请于校正阶段中不需透过人为操作即可得到仿真距离与量测距离的对应关系，具有操作简便及可取得精准飞时距离的优点。
以上所述仅为本申请的部分实施例而已，并不用以限制本申请，凡在本申请的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本申请的保护范围之内。

Claims (10)

  1. 一种飞时测距系统，其特征在于，包括：
    延迟单元，接收多个延迟信号，用来根据所述多个延迟信号，产生多个延迟脉冲，其中所述多个延迟信号对应于多个延迟时间；
    发光单元，耦接于所述延迟单元，用来根据所述多个延迟脉冲，产生多个延迟脉冲光；
    感光像素电路，用来接收对应于所述多个延迟脉冲光的多个延迟反射光，以产生对应于所述多个延迟时间的多个像素信号；
    储存单元，用来储存所述多个延迟时间与所述多个像素信号之间的对应关系；以及
    控制单元，耦接于所述延迟单元，用来产生所述多个延迟信号；
    其中，所述飞时测距系统根据所述多个延迟时间与所述多个像素信号之间的对应关系，进行飞时测距。
  2. 如权利要求1所述的飞时测距系统，其特征在于，所述控制单元根据所述多个延迟时间与所述多个像素信号之间的对应关系，产生最佳延迟信号至所述延迟单元，所述飞时测距系统根据所述最佳延迟信号进行飞时测距，其中所述最佳延迟信号对应于最佳延迟时间。
  3. 如权利要求2所述的飞时测距系统，其特征在于，所述延迟单元根据所述最佳延迟信号产生最佳延迟脉冲，发光单元根据所述最佳延迟脉冲产生最佳延迟脉冲光，所述感光像素电路接收对应于所述最佳延迟脉冲光的最佳延迟反 射光以产生最佳延迟像素信号，所述飞时测距系统根据所述最佳延迟像素信号计算对应于目标物件的飞时距离。
  4. 如权利要求1所述的飞时测距系统，其特征在于，所述多个延迟反射光反射自反射板，所述反射板与所述飞时测距系统之间具有固定距离。
  5. 如权利要求1所述的飞时测距系统，其特征在于，所述感光像素电路包括：
    感光元件；
    第一读取电路，包括第一传输闸，所述第一传输闸耦接于所述感光元件，所述第一传输闸接收第一传输信号而于第一导通时间导通；以及
    第二读取电路，包括第二传输闸，所述第二传输闸耦接于所述感光元件，所述第二传输闸接收第二传输信号而于第二导通时间导通，其中所述第二读取电路输出所述多个像素信号；
    其中，所述第一导通时间与所述第二导通时间相隔一时间间隔。
  6. 一种校正方法，应用于飞时测距系统，其特征在于，所述校正方法包括：
    产生多个延迟信号，其中所述多个延迟信号对应于多个延迟时间；
    根据所述多个延迟信号，产生多个延迟脉冲；
    发射对应于所述多个延迟脉冲的多个延迟脉冲光；
    接收对应于所述多个延迟脉冲光的多个延迟反射光，以产生对应于所述多个延迟时间的多个像素信号；
    储存所述多个延迟时间与所述多个像素信号之间的对应关系；以及
    根据所述多个延迟时间与所述多个像素信号之间的对应关系，进行飞时测距。
  7. 如权利要求6所述的校正方法，其特征在于，根据所述多个延迟时间与所述多个像素信号之间的对应关系进行飞时测距的步骤包括：
    根据所述多个延迟时间与所述多个像素信号之间的对应关系，产生最佳延迟信号至所述延迟单元，其中所述最佳延迟信号对应于最佳延迟时间；以及
    根据所述最佳延迟信号，进行飞时测距。
  8. 如权利要求7所述的校正方法，其特征在于，根据所述最佳延迟信号，进行飞时测距的步骤包括：
    根据所述最佳延迟信号，产生最佳延迟脉冲；
    根据所述最佳延迟脉冲，产生最佳延迟脉冲光；
    接收对应于所述最佳延迟脉冲光的最佳延迟反射光，以产生最佳延迟像素信号；以及
    根据所述最佳延迟像素信号，计算对应于目标物件的飞时距离。
  9. 如权利要求6所述的校正方法，其特征在于，所述多个延迟反射光反射自反射板，所述反射板与所述飞时测距系统之间具有固定距离。
  10. 一种飞时测距方法，应用于飞时测距系统，其特征在于：
    获取多个延迟时间与所述多个像素信号之间的对应关系；以及
    根据所述多个延迟时间与所述多个像素信号之间的对应关系，进行飞时测距，其中，多个延迟时间与多个像素信号之间的对应关系通过飞时校正方法获得并存储于所述飞时测距系统，所述飞时校正方法包括：
    产生多个延迟信号，其中所述多个延迟信号对应于多个延迟时间；
    根据所述多个延迟信号，产生多个延迟脉冲；
    发射对应于所述多个延迟脉冲的多个延迟脉冲光；
    接收对应于所述多个延迟脉冲光的多个延迟反射光，以产生对应于所述多个延迟时间的多个像素信号；以及
    输出所述多个延迟时间与所述多个像素信号之间的对应关系。
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113447954A (zh) * 2020-03-25 2021-09-28 深圳市光鉴科技有限公司 场景深度测量方法、系统、设备及存储介质
CN113447954B (zh) * 2020-03-25 2024-06-04 深圳市光鉴科技有限公司 场景深度测量方法、系统、设备及存储介质

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021068156A1 (zh) * 2019-10-10 2021-04-15 深圳市汇顶科技股份有限公司 光传感器、基于飞行时间的测距系统和电子装置
TWI725695B (zh) * 2020-01-06 2021-04-21 緯創資通股份有限公司 檢體檢驗機台與其操作方法
TW202133424A (zh) * 2020-01-29 2021-09-01 日商索尼半導體解決方案公司 攝像元件、攝像裝置及測距裝置
CN111352120B (zh) * 2020-03-25 2022-09-09 炬佑智能科技(苏州)有限公司 飞行时间测距系统及其测距方法
CN111398979B (zh) * 2020-06-08 2020-10-16 深圳市汇顶科技股份有限公司 基于飞行时间的测距方法和相关测距系统
WO2021248273A1 (zh) * 2020-06-08 2021-12-16 深圳市汇顶科技股份有限公司 基于飞行时间的测距方法和相关测距系统

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101449181A (zh) * 2006-05-23 2009-06-03 莱卡地球系统公开股份有限公司 测距方法和用于确定目标的空间维度的测距仪
CN102549380A (zh) * 2009-09-11 2012-07-04 罗伯特·博世有限公司 光学距离测量仪
CN103472457A (zh) * 2013-09-13 2013-12-25 中国科学院空间科学与应用研究中心 稀疏孔径压缩计算关联飞行时间的三维成像系统及方法
CN103616696A (zh) * 2013-11-27 2014-03-05 中国电子科技集团公司第三十八研究所 一种激光成像雷达装置及其测距的方法
CN104884972A (zh) * 2012-11-27 2015-09-02 E2V半导体公司 利用深度信息和图像传感器来产生图像的方法
CN105204032A (zh) * 2015-09-29 2015-12-30 中国人民解放军装备学院 一种用于运动目标三维成像的激光探测系统及成像方法
CN105572681A (zh) * 2014-10-31 2016-05-11 洛克威尔自动控制安全公司 飞行时间传感器的绝对距离测量
CN105607072A (zh) * 2015-12-18 2016-05-25 航天恒星科技有限公司 一种非扫描激光成像系统
WO2017141957A1 (ja) * 2016-02-17 2017-08-24 パナソニックＩｐマネジメント株式会社 距離測定装置
CN107452760A (zh) * 2016-05-13 2017-12-08 英飞凌科技股份有限公司 光学传感器设备和用于操作飞行时间传感器的方法
CN107820572A (zh) * 2015-06-15 2018-03-20 微软技术许可有限责任公司 飞行时间（tof）系统校准

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1094515A (zh) * 1993-02-24 1994-11-02 新典自动化股份有限公司 一种激光测距方法及装置
CN100478704C (zh) * 2006-04-21 2009-04-15 太原理工大学 Ld抽运固体激光器混沌激光测距的装置及方法
US8368876B1 (en) * 2008-10-17 2013-02-05 Odyssey Space Research, L.L.C. Calibration system and method for imaging flash LIDAR systems
US8471895B2 (en) * 2008-11-25 2013-06-25 Paul S. Banks Systems and methods of high resolution three-dimensional imaging
US8619239B2 (en) * 2011-01-28 2013-12-31 Analog Modules Inc. Accuracy of a laser rangefinder receiver
DE102012110538B4 (de) * 2012-11-05 2019-11-21 Odos Imaging Ltd. Vorrichtung und Verfahren zum Messen von Abstandswerten und Abstandsbildern
EP2955539B1 (en) * 2014-06-12 2018-08-08 Delphi International Operations Luxembourg S.à r.l. Distance measuring device
US9720076B2 (en) * 2014-08-29 2017-08-01 Omnivision Technologies, Inc. Calibration circuitry and method for a time of flight imaging system
CN106443692B (zh) * 2016-09-19 2019-08-23 华中师范大学 一种精确测量跳变沿到达时刻的方法和装置

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101449181A (zh) * 2006-05-23 2009-06-03 莱卡地球系统公开股份有限公司 测距方法和用于确定目标的空间维度的测距仪
CN102549380A (zh) * 2009-09-11 2012-07-04 罗伯特·博世有限公司 光学距离测量仪
CN104884972A (zh) * 2012-11-27 2015-09-02 E2V半导体公司 利用深度信息和图像传感器来产生图像的方法
CN103472457A (zh) * 2013-09-13 2013-12-25 中国科学院空间科学与应用研究中心 稀疏孔径压缩计算关联飞行时间的三维成像系统及方法
CN103616696A (zh) * 2013-11-27 2014-03-05 中国电子科技集团公司第三十八研究所 一种激光成像雷达装置及其测距的方法
CN105572681A (zh) * 2014-10-31 2016-05-11 洛克威尔自动控制安全公司 飞行时间传感器的绝对距离测量
CN107820572A (zh) * 2015-06-15 2018-03-20 微软技术许可有限责任公司 飞行时间（tof）系统校准
CN105204032A (zh) * 2015-09-29 2015-12-30 中国人民解放军装备学院 一种用于运动目标三维成像的激光探测系统及成像方法
CN105607072A (zh) * 2015-12-18 2016-05-25 航天恒星科技有限公司 一种非扫描激光成像系统
WO2017141957A1 (ja) * 2016-02-17 2017-08-24 パナソニックＩｐマネジメント株式会社 距離測定装置
CN107452760A (zh) * 2016-05-13 2017-12-08 英飞凌科技股份有限公司 光学传感器设备和用于操作飞行时间传感器的方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3633406A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113447954A (zh) * 2020-03-25 2021-09-28 深圳市光鉴科技有限公司 场景深度测量方法、系统、设备及存储介质
CN113447954B (zh) * 2020-03-25 2024-06-04 深圳市光鉴科技有限公司 场景深度测量方法、系统、设备及存储介质

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