WO2021168847A1 - 一种基于飞行时间ToF的测距芯片、装置及方法 - Google Patents

一种基于飞行时间ToF的测距芯片、装置及方法 Download PDF

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WO2021168847A1
WO2021168847A1 PCT/CN2020/077308 CN2020077308W WO2021168847A1 WO 2021168847 A1 WO2021168847 A1 WO 2021168847A1 CN 2020077308 W CN2020077308 W CN 2020077308W WO 2021168847 A1 WO2021168847 A1 WO 2021168847A1
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signal
target object
ranging
pulse
pulses
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PCT/CN2020/077308
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English (en)
French (fr)
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唐样洋
罗鹏飞
周鸿彬
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华为技术有限公司
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Priority to PCT/CN2020/077308 priority Critical patent/WO2021168847A1/zh
Priority to CN202080087026.8A priority patent/CN114829878A/zh
Publication of WO2021168847A1 publication Critical patent/WO2021168847A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C25/00—Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass

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  • the present application relates to the field of chip technology, and in particular to a ranging chip, device and method based on time-of-flight ToF.
  • ToF ranging technology is widely used in many fields, such as automatic driving, three-dimensional imaging, face recognition, or intelligent robots.
  • ToF ranging is to illuminate the target object with a light signal sent by the transmitter, and the signal reflected by the target object is received by the receiver.
  • the round-trip time (time of flight) of the light signal sent by the transmitter between the target object and the receiver the distance information between the transmitter and the target object is calculated, and the distance information can be used to generate information such as a three-dimensional image of the target object.
  • ToF ranging technology can adopt a continuous wave (CW) ToF modulation measurement method and a pulse wave (P) ToF modulation based measurement method.
  • the CW TOF measurement method is to calculate the distance of the target object based on the phase difference between the transmitted continuous optical signal and the received continuous optical signal.
  • the exposure time is long, and it is easy to receive a large amount of background light during the exposure process, resulting in low signal-to-noise ratio and large ranging error.
  • the optical signal that needs to be sent is a standard square wave signal, and the distance between the transmitter and the target object is calculated by measuring the phase delay of the received square wave signal.
  • the PTOF measurement method requires high requirements on the shape of the square wave waveform, but in practice the waveform is mostly imperfect, and there are distortions or glitches. Therefore, the PTOF measurement method has a larger ranging error, and the effective test distance is shorter than that of the CWTOF.
  • the embodiments of the present application provide a ranging chip, device and method based on Time-of-Flight ToF, which are used to improve the accuracy of ToF ranging.
  • a ranging chip based on Time of Flight ToF includes: a first signal generator for generating a first signal, the first signal includes a plurality of first pulses, and the width of the first pulse Is the first width T, the first signal is used to control the light emitting device to emit light signals to the target object; the second signal generator is used to generate a second signal according to the first signal, the second signal includes a plurality of first signals in the first signal A pulse, and at least one second pulse with a first width T delayed from each of the plurality of first pulses; a continuous wave processing circuit for reflecting the light signal of the received target object according to the second signal Perform integration processing to obtain multiple exposure values, which are used to calculate the phase delay corresponding to the flight time of the optical signal between the chip and the target object.
  • the received pulsed light signals can be exposed for a short time, avoiding the noise signal caused by receiving a large amount of background light in CW ToF ranging, thereby improving the signal-to-noise ratio and improving the ranging Accuracy.
  • the transmitted signal does not need to be a continuous wave, nor a standard square wave, but a discrete pulse wave, which can solve the limitation of the PToF ranging chip on the standard square wave waveform.
  • the width of each second pulse in the at least one second pulse is the first width T.
  • the second pulse generated according to the first pulse is used to generate a demodulation signal for demodulating the received signal according to the second pulse, so that the received pulse signal can be demodulated according to the continuous wave ranging algorithm, Can improve the signal-to-noise ratio and increase the ranging distance.
  • the second pulse is a plurality of second pulses, and the interval between two adjacent second pulses in the plurality of second pulses is the first width T.
  • the multiple second pulses generated according to the first pulse are used to generate a demodulation signal for demodulating the received signal according to the second pulse, so that the received pulse can be demodulated according to the continuous wave ranging algorithm Signal, can improve the signal-to-noise ratio and increase the ranging distance.
  • the continuous wave processing circuit specifically includes: a first delay device for respectively delaying the second signal to obtain a plurality of third signals with different phases; an image sensor array for Perform multiple exposures on the light signal reflected by the target object received by the lens according to multiple third signals with different phases to obtain multiple fourth signals; an analog-to-digital converter is used to perform analog-digital on multiple fourth signals Through conversion, multiple digital image arrays are obtained, and the multiple digital image arrays include exposure values corresponding to multiple pixels.
  • the interval between two adjacent first pulses in the plurality of first pulses is (N+1)*T, where N is a preset positive integer or a random positive integer.
  • N in the emitted laser signal is a random signal
  • different pixels of the image sensor array are exposed to the reflected signal through different phase delays, so that the modulation signal is in the codeword dimension, time and The dimension of frequency does not interfere with each other, which improves the anti-interference of the ranging result.
  • the delayer is specifically used to: delay processing the second signal m times to obtain m third signals, the m delay processing includes 0 phase delay processing, and the m delay processing mid-phase delay processing The time difference between two adjacent delay processing is 2T/m.
  • different phase delay processing is performed on the second signal to generate different third signals, so that the received pulse signal can be demodulated with the third signal according to the continuous wave ranging algorithm, and the ranging accuracy can be improved.
  • the ranging chip further includes: a second delayer, used to generate a delayed signal of the first signal; a light emitting device, used to emit light to the target object according to the delayed signal of the first signal Signal.
  • the second delayer can enable the ToF ranging device to obtain multiple accurate exposure values within a range of 0 meters from the target object to the blurring distance of the ToF ranging device.
  • a distance measuring device in a second aspect, includes: the distance measuring chip, a light source driver, a light emitting device, and a lens as described in any one of the first aspect;
  • the first signal drives the light-emitting device to emit light signals;
  • the light-emitting device is used to transmit light signals to the target object based on the driving of the first signal;
  • the lens is used to receive the light signal reflected by the target object and transmit the light signal to the ranging chip .
  • the light emitting device is a straight cavity surface emitting laser VCSEL.
  • an electronic device in a third aspect, includes the distance measuring device according to any one of the first aspect, and the electronic device further includes: a calculation module, which is configured to obtain multiple exposure values according to the distance measuring device Calculate the phase delay corresponding to the flight time of the optical signal between the ranging device and the target object.
  • a distance measurement method based on time-of-flight ToF includes: generating a first signal, the first signal includes a plurality of first pulses, the width of the first pulse is a first width T, and the first signal uses To emit a light signal to the target object; generate a second signal according to the first signal, the second signal includes a plurality of first pulses in the first signal, and a first pulse delay from each of the plurality of first pulses by a first width At least one second pulse of T; perform integration processing on the received light signal reflected by the target object according to the second signal to obtain multiple exposure values, which are used to calculate the flight time of the light signal between the ranging chip and the target object The corresponding phase delay.
  • the width of each second pulse in the at least one second pulse is the first width T.
  • the second pulse is a plurality of second pulses, and the interval between two adjacent second pulses in the plurality of second pulses is the first width T.
  • performing integration processing on the received light signal reflected by the target object according to the second signal to obtain multiple exposure values includes: respectively delaying the second signal to obtain multiple signals with different phases.
  • the interval between two adjacent first pulses in the plurality of first pulses is (N+1)*T, where N is a preset positive integer or a random positive integer.
  • performing a delay operation on the second signal to obtain multiple third signals with different phases specifically includes: performing m delay processing on the second signal to obtain m third signals, and m delays.
  • the processing includes 0-phase delay processing, and the time difference between two adjacent delay processing in m delay processing is 2T/m.
  • the ranging method further includes: transmitting an optical signal to the target object according to the first signal.
  • the ranging method further includes: generating a delay signal of the first signal; transmitting an optical signal to the target object according to the first signal specifically includes: according to the delay of the first signal The signal emits a light signal to the target object.
  • the received light signal reflected by the target object is integrated according to the second signal to obtain multiple exposure values
  • the ranging method further includes: calculating the distance measurement device and the The phase delay corresponding to the flight time of the optical signal between the target objects.
  • an electronic device in a fifth aspect, includes a processor coupled with a memory; the memory is used to store computer programs or instructions; the processor is used to execute the computer programs or instructions stored in the memory, so that the electronic device The method as described in any one of the above-mentioned fourth aspects can be performed.
  • a computer-readable storage medium for storing programs or instructions.
  • the instructions in the storage medium are executed by a processor of an electronic device, the electronic device can execute any of the above-mentioned fourth aspects. The method described in the item.
  • a computer program product including a program or instruction, which when the computer program product runs on a computer, causes the computer to execute the method described in any one of the foregoing fourth aspects.
  • Figure 1 is a schematic diagram of the transmitted signal and reflected signal of ToF ranging
  • FIG. 2 is a first structural diagram of a ToF ranging device provided by an embodiment of this application.
  • FIG. 3 is a schematic structural diagram of a ToF ranging chip provided by an embodiment of the application.
  • FIG. 4(a) is a schematic diagram 1 of the waveform of the first signal provided by an embodiment of this application.
  • Fig. 4(b) is a second schematic diagram of the waveform of the first signal provided by the embodiment of this application.
  • FIG. 5(a) is a schematic diagram 1 of the waveform of the second signal provided by an embodiment of this application.
  • Fig. 5(b) is a second schematic diagram of the waveform of the second signal provided by the embodiment of this application.
  • FIG. 6 is a second structural diagram of a ToF ranging device provided by an embodiment of this application.
  • FIG. 7 is a schematic diagram of a modulation waveform of a ToF ranging device provided by an embodiment of the application.
  • FIG. 8 is a schematic diagram of a modulation mode of a ToF ranging device provided by an embodiment of the application.
  • FIG. 9 is a third structural diagram of a ToF ranging device provided by an embodiment of the present invention.
  • FIG. 10 is a schematic diagram of a modulation waveform of another ToF ranging device provided by an embodiment of this application.
  • FIG. 11 is a schematic flowchart of a ToF ranging method provided by an embodiment of this application.
  • FIG. 12 is a schematic structural diagram of an electronic device provided by an embodiment of this application.
  • first and second are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined with “first” and “second” may explicitly or implicitly include one or more of these features.
  • plural means two or more, and “at least one” means one or more.
  • the embodiments of the present application provide a method and device for distance measurement based on time-of-flight ToF.
  • the technical terms and principles involved will be briefly described below.
  • LiDAR Light Detection and Ranging
  • LiDAR is a radar system that emits laser beams to detect the location and speed of target objects. Its working principle is to transmit a laser detection signal to the target object, and then compare the received signal reflected from the target object with the transmitted detection signal, and then perform signal processing according to the comparison result to obtain relevant information of the target object, such as laser Parameters such as the distance, azimuth, height, speed, attitude, and even shape between the radar and the target object.
  • lidar has high measurement accuracy, fine time and space resolution, and can complete functions such as distance measurement (ranging), target detection, imaging, tracking, and image recognition. Among them, ranging is the basic function of lidar.
  • lidar can use the time-of-flight principle of light to measure the distance between the lidar and the target object.
  • n is the refractive index in the medium through which light propagates
  • c is the speed of light, which is about 299792.458km/s. This principle can realize the detection from several meters to several kilometers.
  • the ToF ranging device illuminates the target object by transmitting a signal, and when the modulated signal is reflected back to the surface of the ToF ranging device, a phase difference related to the distance is generated.
  • the ToF ranging device receives the reflected signal of the modulated signal, and demodulates it to obtain the phase difference caused during the flight, and then calculates the ToF ranging device and the target object based on the known quantities such as the light flight rate and the frequency of the modulated signal. the distance between.
  • each pixel in the ToF image sensor array is required to be independent Receive and demodulate the phase difference between the lidar and each corresponding point on the surface of the target object, so as to obtain the distance information of each corresponding point on the surface of the target object.
  • the same number of distance information as the sensor image pixels can be obtained, that is, the depth distance image of the target object can be obtained.
  • the transmitted signal can be a cosine signal or a square wave signal.
  • the reflected signal reflected from the target object will produce a certain offset, and the reflected signal g(t) can be expressed as: Among them, a represents the amplitude value, Indicates the phase difference between the reflected signal and the transmitted signal.
  • the ToF ranging device By modulating the transmitted signal, the ToF ranging device receives and demodulates the reflected signal with phase difference reflected by the target object, and indirectly calculates the distance information between the ToF ranging device and the target object.
  • the calculation formula of the distance information D can be for: Among them, c represents the speed of light, and f represents the frequency of the modulation signal.
  • the process of ToF ranging and demodulation can be realized by the correlation function method.
  • the correlation function describes the degree of correlation between the values of the reference signal at any two different moments. Using the transmitted signal as a reference signal, the correlation function can be used to obtain the degree of correlation between the frequency-modulated transmitted signal and the reflected signal that produces a phase difference after illuminating the target object.
  • the calculation formula of the correlation function is as follows:
  • ⁇ 0 0°
  • ⁇ 1 90°
  • ⁇ 2 180°
  • ⁇ 3 270° to be substituted into c( ⁇ ) for calculation.
  • the reflected signal may include the reflected signal generated by the background light
  • an offset K can be added to its correlation function. After the superposition process, the following values C( ⁇ 0 ), C( ⁇ 1 ), C( ⁇ 2 ) and C( ⁇ 3 ) can be obtained.
  • Phase delay represents the propagation delay of light during flight.
  • the offset K can be used to provide a conventional 2D intensity image and to indicate the amount of charge in the image sensor pixels.
  • the amplitude value A represents the depth resolution of pixels that can be directly measured. in:
  • each pixel of the two-dimensional array image sensor can measure the distance information corresponding to the ToF ranging device and the surface of the target object
  • the CW ToF ranging device actually obtains the relative ToF ranging from the surface of the target object.
  • the depth-distance image of the device The three-dimensional coordinate information of the surface of the target object can be obtained by further processing the depth and distance image data.
  • the transmitted signal and the reflected signal are continuous wave signals, the exposure time is long, and it is easy to receive a large amount of background light during the exposure process, resulting in low signal-to-noise ratio and ranging error Larger.
  • the transmitted signal is not a continuous wave but a pulse wave
  • the optical signal to be sent is a standard square wave signal.
  • the phase delay of the received square wave signal is measured to calculate the transmitter and The distance of the target object.
  • the PToF measurement method requires high requirements on the shape of the square waveform, but in reality, the waveform is mostly imperfect, and there are distortions or glitches. Therefore, the PToF measurement method has a larger ranging error, and the effective test distance is shorter than that of the CWToF.
  • This application proposes a novel ToF ranging device and ranging method by combining the ranging technology of CW ToF and P ToF.
  • the transmitter of the ToF distance measuring device transmits a transmission signal, it transmits a pulsed light signal in a pulse mode, and when receiving, it receives the reflected pulsed light signal at intervals in a manner similar to a continuous wave CW ToF.
  • the ranging algorithm also uses the CW ToF ranging algorithm.
  • the embodiments of the present application provide a range-finding chip based on Time-of-Flight ToF.
  • the range-finding chip can be applied to devices such as three-dimensional (3 Dimension, 3D) cameras, smart vehicles, or computers.
  • 3D three-dimensional
  • this embodiment of the present application takes a distance measuring device of a 3D ToF camera as an example for description.
  • the ToF distance measuring device may include: a distance measuring chip 201, a lens 202, a light source driver 203 and a light emitting device 204.
  • the ranging chip 201 can be used to generate a first signal, and the first signal can be used to control the light source drive 203 so that the light emitting device 204 can emit a specified light signal to the target object, for example, a pulsed light signal to the target object.
  • the optical signal is one of the above-mentioned transmitted signals
  • the target object refers to an object that the transmitted optical signal can reach and form a reflected optical signal.
  • the ranging chip 201 can also be used to receive the optical signal reflected by the target object transmitted by the lens 202, and perform signal processing according to the first signal and the optical signal reflected by the target object transmitted by the lens 202 to obtain the ToF ranging device and the target The phase delay corresponding to the flight time of the optical signal between the objects, so as to obtain the distance between the ToF ranging device and the target object through calculation.
  • the lens 202 is an optical device composed of one or more optical lenses, which can be used to receive the light signal reflected by the target object and transmit the light signal reflected by the target object to the ranging chip 201.
  • the light source driver 203 is used to drive the light emitting device 204 to emit light signals according to the first signal generated by the distance measuring chip 201.
  • the light source driving 203 may be laser driving.
  • the light emitting device 204 is configured to emit a light signal to the target object according to the instruction signal of the light source driving 203.
  • a diode or a laser is a device capable of emitting visible light signals or emitting laser signals.
  • the light-emitting device may be a vertical-cavity surface-emitting laser (VCSEL) or a light-emitting diode (LED) or the like.
  • VCSEL vertical-cavity surface-emitting laser
  • LED light-emitting diode
  • VCSEL is a special kind of laser whose laser is emitted perpendicular to the top surface, and its luminous power is strongly related to the working mode, and it can stably emit high-power pulses under certain conditions.
  • the ranging chip 201 provided by the embodiment of the present application may specifically include: a first signal generator 301, a second signal generator 302 and a continuous wave processing circuit 303.
  • the signal generator is a device that can provide electrical signals of various frequencies, various waveforms and output levels, and is also called a signal source or oscillator.
  • Various wave curves are represented by trigonometric function equations.
  • the signal generator can generate a variety of waveforms, such as triangular waves, sawtooth waves, rectangular waves or sine waves, including sine signal generators, low-frequency signal generators, high-frequency signal generators, pulse signal generators or pseudo-random signal generators, etc. Wait.
  • the signal generator in the embodiment of the present application is used to generate a pulse signal, and therefore can be a pulse signal generator or a pseudo-random signal generator that can generate a pulse signal.
  • the first signal generator 301 may be used to generate a first signal.
  • the first signal includes a plurality of first pulses, and the pulse width of the first pulse may be a first width.
  • the first signal can be used for the light source driving 203 to drive the light emitting device 204 to emit light signals to the target object according to the first signal.
  • the first signal can also be used by the second signal generator 302 to generate a second signal according to the first signal.
  • the pulse width of the first pulse is the first width Tp, and the pulse interval may be N+1 times the first width.
  • the pulse interval of adjacent first pulses may be the same or different. That is, the interval between two adjacent first pulses in the first signal may be (N+1)*Tp, where N may be a preset positive integer or a random positive integer.
  • the signal generator can work in a random state or a non-random state. If N is a random positive integer, different random positive integers can be used to generate pulse signals with different pulse intervals, which can avoid interference between multiple pulse signals at the same time and improve the anti-interference of the ranging result.
  • the waveform diagram of the first signal may be as shown in Fig. 4(a) or Fig. 4(b).
  • N can be a random positive integer.
  • the pseudo-random positive integer range can be set to (N1 to N2), and the first signal generator generates the first pulse signal according to the received Tp and the random positive integer range.
  • the pulse width of the first pulse signal is Tp, and the interval between pulses is (N+1)*Tp, where N is a random positive integer generated by the pseudo-random number generator inside the first signal generator, for example, N can be randomly selected as 1, 2, or 3, etc.
  • the waveform diagram of the first signal may also be as shown in FIG. 4(a), and N may be a preset positive integer.
  • the first signal generator When the ToF ranging device works in a non-random state, the first signal generator generates a first pulse signal, the pulse width of the first pulse signal is Tp, and the interval between adjacent first pulses is (n+1)*Tp , Where n is a preset positive integer, and the pulse interval between adjacent pulses is the same.
  • the second signal generator 302 is configured to generate a second signal according to the first signal, the second signal includes the first pulse in the first signal; the second signal also includes at least one pulse with a first width Tp separated from each first pulse The second pulse.
  • the pulse width of the second pulse may be the first width Tp; if there are at least two second pulses, the pulse interval of the at least two adjacent second pulses may be the same as that of the first pulse.
  • the width Tp is the same.
  • the number of pulses of the second pulse can be multiple, for example, 2 or 3, etc., and the second pulse will not overlap with any of the first pulses.
  • the waveform diagram of the second signal may be as shown in FIG. 5(a), and the second signal includes the first signal with a pulse width of Tp.
  • a pulse also includes a plurality of second pulses with a width of Tp separated from each of the first pulses, wherein the pulse width of the second pulse is also Tp.
  • the waveform of the first signal is as shown in Figure 4(b) and the pulse interval is random
  • the waveform of the second signal can be as shown in Figure 5(b), and the pulse interval of the second signal is also Random.
  • the continuous wave processing circuit 303 may be used to perform integration processing on the received light signal reflected by the target object according to the input second signal to obtain multiple exposure values, and the multiple exposure values are used for the ToF measurement according to the continuous wave CW.
  • the distance algorithm calculates the phase delay corresponding to the flight time of the optical signal between the distance measuring chip 201 and the target object.
  • the first signal is generated by the first signal generator, and the second signal is generated according to the first signal.
  • the second signal includes at least two pulse signals.
  • the reflected signal of the received target object is demodulated through the second signal. Since the farthest testable distance of the ToF ranging chip is positively correlated with the period of the modulation signal, the period of the modulation signal becomes larger, so that the farthest possible The test distance is increased.
  • the received pulsed light signals can be exposed for a short time, avoiding receiving a large amount of noise signals caused by background light, thereby improving the signal-to-noise ratio and solving P ToF ranging chip limits the standard square wave waveform.
  • the above-mentioned continuous wave processing circuit 303 may specifically include a delay 601, an image sensor array 602 and an analog-to-digital converter 603.
  • the delayer 601 is used to perform a time delay operation on the input second signal to obtain a plurality of third signals with different phases, and a plurality of third signals with different phases are input to the image sensor array 602 for comparison
  • the light signal reflected by the target object received by the lens is subjected to multiple exposures.
  • the DLL delay value of different ToF ranging devices may be different.
  • the delayer 601 may specifically be a delay-locked loop (DLL), also called a delay line.
  • the DLL is an element or device that accurately delays a signal for a period of time.
  • the DLL delayer may include N delay modules, and output signals of 0 to N delay modules are controlled by instructions, so that there is a precise time delay between the output signal and the input signal.
  • the delay value can be preset by the delayer or inputted externally through the delayer.
  • the second signal can be delayed by 0 phase to obtain signal 1; the second signal can be delayed by 1/2 phase to obtain signal 2; and the second signal can be delayed by 1/4 phase.
  • the second signal is delayed by 3/4 to obtain signal 3.
  • the image sensor array 602 is used for multiple exposures of the signal reflected by the target object received by the lens according to the inputted multiple third signals with different phases, that is, the reflected signal and multiple third signals with different phases
  • the superposition, that is, the integration operation can obtain multiple fourth signals.
  • each pixel of the image sensor array corresponds to a plurality of fourth signals obtained by multiple exposures.
  • the image sensor array 602 inputs a plurality of fourth signals to the analog-to-digital converter for generating a digital image array.
  • the exposure modulation process can be set to 1, 2, 3, 4 or more times according to the actual pixels, ToF ranging chip accuracy and application requirements.
  • 1 time refers to a set of continuous waveforms, not a periodic waveform).
  • the continuous wave exposure modulation is 4 times; alternatively, it can be set as the continuous wave exposure modulation 2 times.
  • Other exposure modulation times with similar principles are also included in the protection scope of this application.
  • the pixels can be separated spatially, that is, adjacent pixels can be exposed with different delay values, as long as the principle of exposure modulation is the same as that of the present application, it is also included in the scope of protection of the present application.
  • the image sensor array of the ToF distance measuring device can sequentially perform continuous wave A 0 B 180 , A 90 B 270 , A 180 B 0 , and A 270 B 90 exposures for four times. Or perform two exposures of low-frequency continuous wave A 0 B 180 and A 90 B 270. In actual operation, the above-mentioned exposure sequence can be exchanged.
  • the analog-to-digital converter 603 is configured to perform digital processing on the multiple input fourth signals according to the conversion algorithm from the analog signal to the digital signal to obtain multiple digital image arrays.
  • the ToF ranging device may further include: a ranging module 901, configured to calculate the distance between the ToF ranging device and the target object based on the multiple digital image arrays obtained by the ToF ranging chip distance.
  • the ranging module 901 can be implemented by hardware or software, which is not specifically limited in this application.
  • the above-mentioned embodiment of the application combines CW ToF and PToF two ranging technologies, the transmitted signal adopts the PTOF ranging technology, and the pulse signal (first signal) is sent at intervals; the image sensor array performs exposure reception At the time, the received reflected light is exposed according to the second signal, and the exposure is performed in the four-phase delay mode of the CW ToF ranging algorithm (two or four exposures).
  • the transmitted signal adopts the PTOF ranging technology
  • the pulse signal first signal
  • the image sensor array performs exposure reception
  • the received reflected light is exposed according to the second signal, and the exposure is performed in the four-phase delay mode of the CW ToF ranging algorithm (two or four exposures).
  • it can effectively improve the signal-to-noise ratio of ranging, and can perform ToF ranging when the waveform is not a standard square wave.
  • it effectively increases the farthest measurable distance and improves the overall measurement. Distance performance.
  • the emitted laser signal is a random signal
  • different pixels of the image sensor array are exposed to the reflected signal through different phase delays, so that the modulation signal is different in the dimensions of the codeword, time and frequency. Interference, improve the accuracy of ranging.
  • a delayer for example, a second delayer, can be added between the first signal generator 301 and the light source driver 203 to delay processing the first signal, so that the light source
  • the driving 203 may drive the light-emitting device to emit a pulsed light signal according to the signal generated after the delay processing of the first signal is performed.
  • the waveform diagram of the first signal may be as shown in FIG. 10, and the transmitted signal may be pulsed light emitted after the first signal is subjected to a 1/2-phase delay processing.
  • the multiple third signals are still generated according to the first signal through different delay processing, and are used to respectively perform four exposure modulations on the reflected pulse signal of the target object.
  • S01 Set the pulse duration to Tp, and input the first signal generator.
  • the distance measuring device works in a random mode, it is also necessary to set a random number range and generate a random positive integer, which is input to the first signal generator.
  • the first signal generator generates the first signal.
  • the first signal generator may generate the first signal according to the received pulse width Tp, or the pulse width Tp and a random positive integer N.
  • the first signal may include a plurality of first pulse signals, the pulse width of the first pulse signal is Tp, and the pulse interval between the plurality of first pulses may be (N+1)*Tp.
  • S03 Send a pulse signal according to the first signal.
  • the laser drive drives the light-emitting device according to the first signal or the delay signal of the first signal, so that the light-emitting device emits pulsed light signals corresponding to bright and dark information.
  • the specific flow of the ToF ranging device provided in the embodiment of the present application receiving the reflected signal and performing modulation processing may be S04-S08 as shown in FIG. 11.
  • the second signal generator generates a second signal according to the first signal.
  • the second signal includes all the first pulse signals in the first signal, and one or more second pulse signals will be transmitted after the first pulse of the first signal and after an interval of Tp.
  • the second pulse The pulse width of the signal can be Tp.
  • S05 Perform a time delay operation according to the second signal, and output the delayed third signal.
  • the delayer performs a time delay operation on the input second signal to output multiple third signals P1, for example, the first exposure is not delayed, the second exposure is delayed by 1/4 period, and the third exposure is delayed by 1/2. Cycle, the fourth exposure is delayed by 3/4 cycles.
  • the image sensor array exposes the reflection signal P collected through the lens according to the plurality of third signals P1 to obtain a plurality of fourth signal P2 arrays. Among them, each pixel of the image sensor array outputs a different exposure value.
  • S07 Perform analog-to-digital conversion according to multiple fourth signals to obtain multiple digital image arrays.
  • the analog-to-digital converter performs analog-to-digital conversion on the P2 array signal to obtain the P3 array, which is transmitted to the ranging module.
  • S08 Obtain the phase delay for the digital image array according to the ranging algorithm, and calculate the distance of the target object according to the frequency of the modulation signal.
  • the ranging module After receiving the P3 arrays exposed by different delay signals, the ranging module calculates the phase delay according to the above formula of the CW ToF ranging algorithm, and then obtains the distance information or image information of the pixel corresponding to the target object through calculation.
  • the foregoing embodiment of the present application combines two ranging technologies, CW ToF and P ToF, to effectively improve the signal-to-noise ratio of ranging, and to perform ToF ranging when the waveform is not a perfect square wave.
  • the electronic device 1200 may include at least one processor 1201, a communication line 1202, and a memory 1203.
  • the processor 1201 may be a general-purpose central processing unit (central processing unit, CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more programs for controlling the execution of the program of the present disclosure. integrated circuit.
  • CPU central processing unit
  • ASIC application-specific integrated circuit
  • the communication line 1202 may include a path for transferring information between the above-mentioned components, such as a bus.
  • the memory 1203 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM), or other types that can store information and instructions
  • the dynamic storage device can also be electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disk storage, optical disc storage (Including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or can be used to carry or store desired program codes in the form of instructions or data structures and can be used by a computer Any other media accessed, but not limited to this.
  • the memory may exist independently, and is connected to the processor 1201 through a communication line 1202.
  • the memory 1203 may also be integrated with the processor 1201.
  • the memory provided by the embodiments of the present disclosure may generally be non-volatile. Among them, the memory 1203 is used to store and execute the computer-executable instructions involved in the solution of the present disclosure, and the processor 1201 controls the execution.
  • the processor 1201 is configured to execute computer-executable instructions stored in the memory 1203, so as to implement the method provided in the embodiment of the present disclosure.
  • the computer-executed instructions in the embodiments of the present disclosure may also be referred to as application program codes, which are not specifically limited in the embodiments of the present disclosure.
  • the processor 1201 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 12.
  • the electronic device 1200 may include multiple processors, such as the processor 1201 and the processor 1207 in FIG. 12.
  • Each processor can be a single-CPU (single-CPU) processor or a multi-core (multi-CPU) processor.
  • the processor here may refer to one or more devices, circuits, and/or processing cores for processing data (for example, computer program instructions).
  • the electronic device 1200 may further include a communication interface 1204.
  • the communication interface 1204 uses any device such as a transceiver to communicate with other devices or communication networks, such as an Ethernet interface, a radio access network (RAN), and a wireless local area network (wireless local area networks). WLAN) etc.
  • RAN radio access network
  • WLAN wireless local area network
  • the electronic device 1200 may further include an output device 1205 and an input device 1206.
  • the output device 1205 communicates with the processor 1201, and can display information in a variety of ways.
  • the output device 1205 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector (projector) Wait.
  • the input device 1206 communicates with the processor 1201, and can receive user input in a variety of ways.
  • the input device 1206 may be a mouse, a keyboard, a touch screen device, a sensor device, or the like.
  • the electronic device 1200 can be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, or a similar structure in Figure 12 equipment.
  • PDA personal digital assistant
  • the embodiment of the present disclosure does not limit the type of the electronic device 1200.
  • the processor 1201 in FIG. 12 may invoke a computer-executed instruction stored in the memory 1203, so that the apparatus 1200 executes the ToF ranging method in the foregoing method embodiment.
  • a storage medium including instructions, for example, a memory 1203 including instructions, and the foregoing instructions may be executed by the processor 1201 of the electronic device 1200 to complete the foregoing ToF ranging method.
  • the disclosed device and method may be implemented in other ways.
  • the device embodiments described above are merely illustrative.
  • the division of the circuits or units is only a logical function division.
  • there may be other division methods for example, multiple units or components may be It can be combined or integrated into another device, or some features can be omitted or not implemented.
  • the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate parts may or may not be physically separate.
  • the parts displayed as units may be one physical unit or multiple physical units, that is, they may be located in one place, or they may be distributed to multiple different places. . Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.
  • the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.
  • the above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.
  • the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium.
  • the technical solutions of the embodiments of the present application are essentially or the part that contributes to the prior art, or all or part of the technical solutions can be embodied in the form of a software product, and the software product is stored in a storage medium. It includes several instructions to make a device (which may be a single-chip microcomputer, a chip, etc.) or a processor (processor) execute all or part of the steps of the methods described in the various embodiments of the present application.
  • the aforementioned storage media include: U disk, mobile hard disk, read only memory (read only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other media that can store program codes.

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Abstract

一种基于飞行时间ToF的测距芯片（201）、装置及方法，涉及芯片技术领域，提高ToF测距的准确度，且能有效改善ToF的测距距离。测距芯片（201）包括：第一信号发生器（301），用于生成第一信号，第一信号包括多个第一脉冲，第一脉冲的宽度为第一宽度T，第一信号用于控制发光器件向目标物体发射光信号；第二信号发生器（302），用于根据第一信号生成第二信号，第二信号包括第一信号中的多个第一脉冲，以及与多个第一脉冲中每个第一脉冲延时第一宽度T的至少一个第二脉冲；连续波处理电路（303），用于根据第二信号对接收到的目标物体反射的光信号进行积分处理，得到多个曝光值，多个曝光值用于计算测试芯片（201）与目标物体之间的光信号飞行时间对应的相位延迟。

Description

一种基于飞行时间ToF的测距芯片、装置及方法 技术领域
本申请涉及芯片技术领域，尤其涉及一种基于飞行时间ToF的测距芯片、装置及方法。
背景技术
目前飞行时间(Time of Flight，ToF)测距技术被广泛应用于众多领域，如自动驾驶、三维成像、人脸识别或者智能机器人等。ToF测距是通过发射器发送光信号照射目标物体，经过目标物体反射后的信号被接收器接收。通过测量发射器发送的光信号在目标物体与接收器之间的往返时间(飞行时间)，计算发射器与目标物体的距离信息，该距离信息可用于生成目标物体的三维图像等信息。
ToF测距技术可以采用连续波(continuous wave，CW)ToF调制的测量方法，和基于脉冲波(pulse，P)ToF调制的测量方法。其中，CW TOF测量方法是通过计算发射的连续光信号与接收的连续光信号之间的相位差，根据相位差计算目标物体的距离。但是，CW TOF测量方法中，曝光时间较长，易在曝光的过程中接收大量的背景光，导致信噪比较低，测距误差较大。而P TOF测量方法中，需要发送的光信号是标准的方波信号，通过测量接收到的方波信号的相位延迟来计算发射器与目标物体的距离。但是，P TOF测量方法对方波波形形状要求很高，而实际当中波形大都不完美，存在失真或者毛刺等。因此P TOF测量方法测距误差也较大，且有效测试距离相比CW TOF的测试距离较短。
发明内容
本申请实施例提供一种基于飞行时间ToF的测距芯片、装置及方法，用于提高ToF测距的准确度。
第一方面，提供一种基于飞行时间ToF的测距芯片，该测距芯片包括：第一信号产生器，用于生成第一信号，第一信号包括多个第一脉冲，第一脉冲的宽度为第一宽度T，第一信号用于控制发光器件向目标物体发射光信号；第二信号产生器，用于根据第一信号生成第二信号，第二信号包括第一信号中的多个第一脉冲，以及与多个第一脉冲中每个第一脉冲延时第一宽度T的至少一个第二脉冲；连续波处理电路，用于根据第二信号对接收到的目标物体反射的光信号进行积分处理，得到多个曝光值，多个曝光值用于计算芯片与目标物体之间的光信号飞行时间对应的相位延迟。
上述技术方案中，通过发射脉冲光信号，使得接收的脉冲光信号可以短时间曝光，避免了CW ToF测距中由于接收大量的背景光导致的噪声信号，从而可以提高信噪比，提高测距的准确度。同时，发射信号不需要是连续波，也不要求是标准的方波，而是离散的脉冲波，可以解决P ToF测距芯片对标准的方波波形的限制。
在一种可能的实施方式中，至少一个第二脉冲中的每个第二脉冲的宽度为第一宽度T。上述可能的实现方式中，根据第一脉冲生成的第二脉冲，用于根据第二脉冲生 成用于解调接收信号的解调信号，从而可以根据连续波测距算法解调接收的脉冲信号，可以提高信噪比并增大测距距离。
在一种可能的实施方式中，第二脉冲为多个第二脉冲，多个第二脉冲中相邻的两个第二脉冲的间隔为第一宽度T。上述可能的实现方式中，根据第一脉冲生成的多个第二脉冲，用于根据第二脉冲生成用于解调接收信号的解调信号，从而可以根据连续波测距算法解调接收的脉冲信号，可以提高信噪比并增大测距距离。
在一种可能的实施方式中，连续波处理电路具体包括：第一延时器，用于分别对第二信号进行延迟操作，得到多个具有不同相位的第三信号；图像传感器阵列，用于根据多个具有不同相位的第三信号对镜头接收到的目标物体反射的光信号进行多次曝光，得到多个第四信号；模数转换器，用于对多个第四信号进行模拟-数字转换，得到多个数字图像阵列，多个数字图像阵列包括多个像素点对应的曝光值。
在一种可能的实施方式中，多个第一脉冲中相邻两个第一脉冲的间隔为(N+1)*T，其中，N为预设正整数或者随机正整数。上述可能的实现方式中，当发射的激光信号中N是随机信号的情况下，图像传感器阵列的不同像素点经过不同的相位延时对反射信号进行曝光，从而调制信号在码字维度、时间和频率的维度上都互不干扰，提高测距结果的抗干扰性。
在一种可能的实施方式中，延时器具体用于：对第二信号进行m次延迟处理，得到m个第三信号，m次延迟处理包括0相位延迟处理，且m次延迟处理中相邻的两次延迟处理的时间差为2T/m。上述可能的实现方式中，对第二信号进行不同相位的延迟处理生成不同的第三信号，从而可以根据连续波测距算法用第三信号解调接收的脉冲信号，可以提高测距准确度。
在一种可能的实施方式中，测距芯片还包括：第二延时器，用于生成第一信号的延时信号；发光器件，用于根据第一信号的延时信号向目标物体发射光信号。上述可能的实现方式中，第二延时器可使ToF测距装置在目标物体距离ToF测距装置0米到模糊距离内得到准确的多个准确曝光值。
第二方面，提供一种测距装置，该测距装置包括：如第一方面中任一项所述的测距芯片、光源驱动、发光器件和镜头；光源驱动，用于根据测距芯片生成的第一信号驱动发光器件发射光信号；发光器件，用于基于第一信号的驱动向目标物体发射光信号；镜头，用于接收目标物体反射的光信号，并将光信号传输到测距芯片。在一种可能的实施方式中，发光器件为直腔面发射激光器VCSEL。
第三方面，提供一种电子设备，该电子设备包括如第一方面中任一项所述的测距装置，该电子设备还包括：计算模块，用于根据测距装置得到的多个曝光值计算测距装置与目标物体之间的光信号飞行时间对应的相位延迟。
第四方面，提供一种基于飞行时间ToF的测距方法，该方法包括：生成第一信号，第一信号包括多个第一脉冲，第一脉冲的宽度为第一宽度T，第一信号用于向目标物体发射光信号；根据第一信号生成第二信号，第二信号包括第一信号中的多个第一脉冲，以及与多个第一脉冲中每个第一脉冲延时第一宽度T的至少一个第二脉冲；根据第二信号对接收到的目标物体反射的光信号进行积分处理，得到多个曝光值，曝光值用于计算测距芯片与目标物体之间的光信号飞行时间对应的相位延迟。
在一种可能的实施方式中，至少一个第二脉冲中的每个第二脉冲的宽度为第一宽度T。
在一种可能的实施方式中，第二脉冲为多个第二脉冲，多个第二脉冲中相邻的两个第二脉冲的间隔为第一宽度T。
在一种可能的实施方式中，根据第二信号对接收到的目标物体反射的光信号进行积分处理，得到多个曝光值包括：分别对第二信号进行延迟操作，得到多个具有不同相位的第三信号；根据多个具有不同相位的第三信号对接收到的目标物体反射的光信号进行多次曝光，得到多个第四信号；对多个第四信号进行模拟-数字转换，得到多个数字图像阵列，多个数字图像阵列包括多个像素点对应的曝光值。
在一种可能的实施方式中，多个第一脉冲中相邻两个第一脉冲的间隔为(N+1)*T，其中，N为预设正整数或者随机正整数。
在一种可能的实施方式中，对第二信号进行延迟操作，得到多个具有不同相位的第三信号具体包括：对第二信号进行m次延迟处理，得到m个第三信号，m次延迟处理包括0相位延迟处理，且m次延迟处理中相邻的两次延迟处理的时间差为2T/m。
在一种可能的实施方式中，生成第一信号之后，测距方法还包括：根据第一信号向目标物体发射光信号。
在一种可能的实施方式中，生成第一信号之后，测距方法还包括：生成第一信号的延时信号；根据第一信号向目标物体发射光信号具体包括：根据第一信号的延时信号向目标物体发射光信号。
在一种可能的实施方式中，根据第二信号对接收到的目标物体反射的光信号进行积分处理，得到多个曝光值之后，测距方法还包括：根据多个曝光值计算测距装置与目标物体之间的光信号飞行时间对应的相位延迟。
第五方面，提供一种电子设备，该电子设备包括处理器，处理器与存储器耦合；存储器用于存储计算机程序或指令；处理器用于执行所述存储器中存储的计算机程序或指令，使得电子设备能够执行如上述第四方面中任意一项所述的方法。
第六方面，提供一种计算机可读存储介质，用于存储程序或指令，当所述存储介质中的指令由电子设备的处理器执行时，使得电子设备能够执行如上述第四方面中任意一项所述的方法。
第七方面，提供一种计算机程序产品，包括程序或指令，当所述计算机程序产品在计算机上运行时，使得所述计算机执行如上述第四方面中任意一项所述的方法。
本申请提供的上述基于飞行时间ToF的测距芯片、装置、电子设备、计算机可读存储介质和计算机程序产品，解决的技术问题和带来的技术效果可以参照上述第一方面中任一项所述的内容，此处不再一一赘述。
应当理解的是，以上的一般描述和后文的细节描述仅是示例性和解释性的，并不能限制本申请。
附图说明
图1为ToF测距的发射信号与反射信号示意图；
图2为本申请实施例提供的ToF测距装置的结构示意图一；
图3为本申请实施例提供的ToF测距芯片的结构示意图；
图4(a)为本申请实施例提供的第一信号的波形示意图一；
图4(b)为本申请实施例提供的第一信号的波形示意图二；
图5(a)为本申请实施例提供的第二信号的波形示意图一；
图5(b)为本申请实施例提供的第二信号的波形示意图二；
图6为本申请实施例提供的ToF测距装置的结构示意图二；
图7为本申请实施例提供的一种ToF测距装置的调制波形示意图；
图8为本申请实施例提供的ToF测距装置的调制方式示意图；
图9为本发明实施例提供的ToF测距装置的结构示意图三；
图10为本申请实施例提供的另一种ToF测距装置的调制波形示意图；
图11为本申请实施例提供的一种ToF测距方法的流程示意图；
图12为本申请实施例提供的一种电子设备的结构示意图。
具体实施方式
本申请中，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。在本实施例的描述中，除非另有说明，“多个”的含义是两个或两个以上，“至少一个”是指一个或者多个。
需要说明的是，本申请中，“示例性的”或者“例如”等词用于表示作例子、例证或说明。本申请中被描述为“示例性的”或者“例如”的任何实施例或设计方案不应被解释为比其他实施例或设计方案更优选或更具优势。确切而言，使用“示例性的”或者“例如”等词旨在以具体方式呈现相关概念。
本申请实施例提供一种基于飞行时间ToF的测距方法及装置，下面先对涉及的技术术语及其原理做简单说明。
激光雷达(Light Detection and Ranging，LiDAR)是以发射激光束探测目标物体的位置、速度等特征量的雷达系统。其工作原理是向目标物体发射激光探测信号，然后将接收到的从目标物体反射回来的信号与发射的探测信号进行对比，根据对比的结果进行信号处理后，获得目标物体的有关信息，如激光雷达与目标物体之间的距离、方位、高度、速度、姿态、甚至形状等参数。此外，激光雷达具有高测量精度、精细的时间和空间分辨率，能完成距离测量(测距)、目标探测、成像、跟踪和图像识别等功能，其中，测距是激光雷达的基本功能。
目前，激光雷达可以采用光的飞行时间原理测量激光雷达与目标物体之间的距离，例如，通过公式：R＝c×t/(2×n)计算得到激光雷达与目标物体的距离。其中，n为光传播的介质中的折射率，c为光速，约为299792.458km/s。该原理可以实现几米到几千米的探测。
其中，CW ToF测量方法的基本原理如图1所示，ToF测距装置通过发射信号照射目标物体，调制信号反射回到ToF测距装置表面时产生与距离相关的相位差。ToF测距装置接收调制信号的反射信号，并解调得到飞行过程中引起的相位差，再依据光飞行速率和调制信号的频率等已知量来根据相位差计算出ToF测距装置与目标物体之间的距离。
进一步的，为了得到目标物体距离激光雷达的三维坐标信息，并通过二维的ToF 图像传感器阵列来重建目标物体所在的场景中目标物体表面的形状，要求ToF图像传感器阵列中的各个像素点能够独立的接收并解调出激光雷达与目标物体表面各对应点的相位差，从而得到目标物体表面各对应点的距离信息。最终，对ToF成像系统进行每一次曝光时，则可得到与传感器图像像素点相同数量的距离信息，即可以得到目标物体的深度距离图像。
接下来对CW ToF的测距原理进行简单介绍。如图1所示，发射信号可以为余弦信号或方波信号，设该发射信号s(t)可以表示为：s(t)＝cos(ω·t)，其中，t表示时间，ω表示该发射信号的频率。
发射信号到达目标物体后从目标物体反射回来的反射信号会产生一定的偏移量，设该反射信号g(t)可以表示为：
Figure PCTCN2020077308-appb-000001
其中，a表示幅度值，
Figure PCTCN2020077308-appb-000002
表示反射信号相对于发射信号的相位差。
通过调制发射信号，ToF测距装置接收并解调目标物体反射回的带有相位差的反射信号，间接的计算出ToF测距装置与目标物体之间的距离信息，距离信息D的计算公式可以为：
Figure PCTCN2020077308-appb-000003
其中，c表示光速，f表示调制信号的频率。
ToF测距解调的过程可以采用相关函数法实现。相关函数是描述参考信号在任意两个不同时刻的取值之间的相关程度。以发射信号作为参考信号，可以通过相关函数求取经过频率调制后的发射信号与照射目标物体后产生相位差的反射信号两者之间相关程度。相关函数的计算公式如下：
Figure PCTCN2020077308-appb-000004
示例性的，可以选取4个不同的延时τ值：τ 0＝0°、τ 1＝90°、τ 2＝180°和τ 3＝270°分别进行代入c(τ)进行计算。由于反射回来的信号可能会包含有背景光产生的反射信号，可以对其相关函数加入一个偏移量K。通过叠加处理后，可以得到下述值C(τ 0)、C(τ 1)、C(τ 2)和C(τ 3)。
Figure PCTCN2020077308-appb-000005
Figure PCTCN2020077308-appb-000006
Figure PCTCN2020077308-appb-000007
Figure PCTCN2020077308-appb-000008
利用上述公式换算可以分别求出相位
Figure PCTCN2020077308-appb-000009
偏移量K和幅度值A。相位延迟
Figure PCTCN2020077308-appb-000010
代表光在飞行过程中的传播延迟，当调制频率设定为一个固定的值时，其与目标的距离成正比。偏移K可以用来提供一个常规的2D强度图像，以及指示图像传感器像素中电荷量。幅度值A代表可直接测量的像素的深度分辨率。其中：
Figure PCTCN2020077308-appb-000011
Figure PCTCN2020077308-appb-000012
Figure PCTCN2020077308-appb-000013
通过相位延迟
Figure PCTCN2020077308-appb-000014
带入上述公式
Figure PCTCN2020077308-appb-000015
即可计算出ToF测距装置与目标物体之间的距离D。
进一步的，由于二维阵列图像传感器的每个像素都可以测量出ToF测距装置与目标物体表面所对应的距离信息，因此该CW ToF测距装置实际上得到的是目标物体表面相对ToF测距装置的深度距离图像。可以通过进一步对深度距离图像数据进行数据处理，得到目标物体表面的三维坐标信息。本申请对具体的算法不做详细介绍。
由上述方法可知，CW ToF测量方法中，由于发射信号和反射信号都是连续波信号，曝光时间较长，易在曝光的过程中接收大量的背景光，导致信噪比较低，测距误差较大。而采用脉冲波的P ToF测量方法中，发射信号不是连续波而是脉冲波，且需要发送的光信号是标准的方波信号，通过测量接收到的方波信号的相位延迟来计算发射器与目标物体的距离。但是，P ToF测量方法对方波波形形状要求很高，而实际当中波形大都不完美，存在失真或者毛刺现象等。因此P ToF测量方法测距误差也较大，且有效测试距离相比CW ToF的测试距离较短。
本申请通过结合CW ToF和P ToF的测距技术，提出一种新型的ToF测距装置和测距方法。该ToF测距装置发射端发送发射信号的时候，以脉冲模式发射脉冲光信号，接收时则以类似于连续波CW ToF的方式间隔接收反射的脉冲光信号。测距算法使用的也是CW ToF的测距算法。通过结合两种测距技术，避免了CW ToF测距中连续接收反射光信号导致的信噪比低的问题，同时避免了P ToF对标准的方波要求较高的问题，而采用脉冲波信号。从而可以降低CW ToF测距技术的缺陷，可有效的提升测距信噪比，并可在波形并不是标准的方波的情况下进行ToF测距。
本申请实施例提供一种基于飞行时间ToF的测距芯片，该测距芯片可以应用于三维(3 Dimension，3D)相机、智能车辆或计算机等设备。示例性的，如图2所示，本申请实施例以3D ToF相机的测距装置为例进行说明。该ToF测距装置可以包括：测距芯片201，镜头202，光源驱动203和发光器件204。
测距芯片201可以用于生成第一信号，其第一信号可以用于控制光源驱动203，以使发光器件204能够向目标物体发射指定的光信号，例如，向目标物体发射脉冲光信号。其中，光信号为上述提到的发射信号的一种，目标物体是指发射的光信号能够到达并形成反射的光信号的物体。另外，测距芯片201还可以用于接收镜头202传输的目标物体反射的光信号，并根据第一信号和镜头202传输的目标物体反射的光信号进行信号处理，得到该ToF测距装置与目标物体之间的光信号飞行时间对应的相位延迟，从而通过计算得到该ToF测距装置与目标物体之间的距离。
镜头202，是由一个或者多个光学透镜组成的光学器件，其可以用于接收目标物体反射的光信号，并将目标物体反射的光信号传输到测距芯片201。
光源驱动203，用于根据测距芯片201生成的第一信号驱动发光器件204发射光信号。例如，光源驱动203可以是激光器驱动。
发光器件204，用于根据光源驱动203的指示信号向目标物体发射光信号。例如，二极管或者激光器，是能够发射可见光信号或者发射激光信号的装置。具体的，该发光器件可以为直腔面发射激光器(Vertical-Cavity Surface-Emitting Laser，VCSEL)或发光二极管(Light Emitting Diode，LED)等。其中，VCSEL是一种特殊的激光器，其激光垂直于顶面射出，其发光功率与工作模式强相关，在一定条件下能够稳定的发射高功率脉冲。
结合图2，如图3所示，本申请实施例提供的测距芯片201具体可以包括：第一信号发生器301，第二信号发生器302和连续波处理电路303。
其中，信号发生器是一种能提供各种频率、各种波形和输出电平电信号的器件，也称为信号源或振荡器。各种波形曲线以用三角函数方程式来表示。信号发生器能够产生多种波形，如三角波、锯齿波、矩形波或正弦波等，包括正弦信号发生器、低频信号发生器、高频信号发生器、脉冲信号发生器或者伪随机信号发生器等等。本申请实施例中的信号发生器用于生成脉冲信号，因此可以为脉冲信号发生器或者可以生成脉冲信号的伪随机信号发生器。
第一信号发生器301，可以用于生成第一信号，第一信号包括多个第一脉冲，第一脉冲的脉冲宽度可以为第一宽度。第一信号可以用于光源驱动203根据第一信号驱动发光器件204向目标物体发射光信号。另外，第一信号还可以用于第二信号发生器302根据第一信号生成第二信号。
在一种实施方式中，第一脉冲的脉冲宽度为第一宽度Tp，脉冲间隔可以为第一宽度的N+1倍。其中，相邻第一脉冲的脉冲间隔可以是相同的，也可以是不同的。也就是说，第一信号中相邻两个第一脉冲的间隔可以为(N+1)*Tp，其中，N可以为预设的正整数或者随机正整数。
其中，在上述的实施方式中，信号发生器可以工作在随机状态或者非随机状态。如果N是随机正整数，则可以通过不同的随机正整数而产生脉冲间隔不同的脉冲信号，则可以避免多种脉冲信号之间在相同时刻产生的干扰，提高测距结果的抗干扰性。
示例性的，第一信号的波形图可以为如图4(a)或图4(b)。如图4(b)所示的，N可以为随机正整数。当ToF测距装置工作在随机状态，可以设置伪随机正整数范围为(N1～N2)，第一信号发生器根据接收到的Tp和随机正整数范围产生第一脉冲信号。第一脉冲信号的脉冲宽度为Tp，脉冲与脉冲之间的间隔为(N+1)*Tp，其中，N为第一信号发生器内部的伪随机数产生器产生的随机正整数，例如，N可以随机取值为1、2或3等。
示例性的，第一信号的波形图还可以为如图4(a)所示的，N可以为预设正整数。当ToF测距装置工作在非随机状态，第一信号发生器产生第一脉冲信号，第一脉冲信号的脉冲宽度为Tp，相邻的第一脉冲之间的间隔为(n+1)*Tp，其中，n为预设正整数，相邻脉冲的脉冲间隔是相同的。
第二信号发生器302，用于根据第一信号生成第二信号，第二信号包括第一信号中的第一脉冲；第二信号还包括与每个第一脉冲间隔第一宽度Tp的至少一个第二脉冲。
在一种可能的实施方式中，第二脉冲的脉冲宽度可以为第一宽度Tp；若第二脉冲为至少两个，则所述至少两个相邻的第二脉冲的脉冲间隔可以与第一宽度Tp相同。其 中，第二脉冲的脉冲个数可以为多个，例如2个或3个等，第二脉冲不会与任一第一脉冲相重叠。
示例性的，当第一信号的波形图为如图4(a)所示，则第二信号的波形图可以为如图5(a)所示的，第二信号包括脉冲宽度为Tp的第一脉冲，还包括与每个第一脉冲间隔宽度为Tp的多个第二脉冲，其中，第二脉冲的脉冲宽度也为Tp。
当第一信号的波形图为如图4(b)所示，脉冲间隔是随机的，则第二信号的波形图可以为如图5(b)所示的，其第二信号的脉冲间隔也是随机的。
连续波处理电路303，可以用于根据输入的第二信号对接收到的目标物体反射的光信号进行积分处理，得到多个曝光值，所述多个曝光值用于根据连续波CW的ToF测距算法计算测距芯片201与目标物体之间的光信号飞行时间对应的相位延迟。
上述本申请的实施例，通过第一信号发生器生成第一信号，根据第一信号生成第二信号，第二信号包括至少两个脉冲信号，将第二信号与第一信号的反射信号进行互相关运算。从而通过第二信号对接收到的目标物体的反射信号进行解调，由于ToF测距芯片的最远可测试距离与调制信号的周期正相关，因此调制信号的周期变大，从而使得最远可测试距离增加。另外，与现有的CW ToF测距技术相比，通过发射脉冲光信号，使得接收的脉冲光信号可以短时间曝光，避免接收大量的背景光导致的噪声信号，从而提高信噪比，并解决P ToF测距芯片对标准的方波波形的限制。
在一种实施方式中，如图6所示，上述的连续波处理电路303具体可以包括延时器601、图像传感器阵列602和模数转换器603。
其中，延时器601，用于对输入的第二信号进行时间延时操作，得到多个具有不同相位的第三信号，多个具有不同相位的第三信号输入图像传感器阵列602，用于对镜头接收到的目标物体反射的光信号进行多次曝光。不同的ToF测距装置的DLL延迟值可能会不同。
在一种实施方式中，延时器601具体可以为延迟锁相环(Delay—locked Loop，DLL)，也称为延迟线，DLL是一种将信号精确延迟一段时间的元件或器件。示例性的，该DLL延时器可以包括N个延时模块，通过指令控制输出0～N个延时模块的输出信号，从而能够让输出信号与输入信号之间有一个精准的时间延迟。其中，延迟值可以是延时器预设的，也可以是通过延时器外部输入的。
示例性的，如图7所示，可以对第二信号进行0相位的延迟，得到信号1；对第二信号进行1/2相位的延迟，得到信号2；对第二信号进行1/4相位的延迟，得到信号3；对第二信号进行3/4相位的延迟，得到信号4。
图像传感器阵列602，用于根据输入的上述的多个具有不同相位的第三信号分别对镜头接收到的目标物体反射的信号进行多次曝光，也就是反射信号与多个不同相位的第三信号叠加，也就是进行积分运算可以得到多个第四信号。其中，图像传感器阵列的每个像素点都对应进行多次曝光得到的多个第四信号。图像传感器阵列602将多个第四信号输入至模数转换器，用于生成数字图像阵列。
需要说明的是，在实际应用中，曝光调制过程可以根据实际像素、ToF测距芯片精度和应用的需求，将曝光调制设置为1次，2次，3次，4次或以上(此处的1次指一组连续波形，而不是一个周期波形)。
示例性的，上述本申请实施例中的，连续波曝光调制4次；或者，可以设置为连续波曝光调制2次。其它相似原理的曝光调制次数也包括在本申请保护范围内。同时，可以将像素在空间上分开，即相邻像素可以进行不同延时值的曝光，只要曝光调制的原理与本申请相同，也包括在本申请保护范围内。
例如，相邻的像素A和像素B分别进行不同延时值的曝光，像素A进行0相位的曝光，表示为A 0；像素B进行1/2相位的曝光，表示为B 180。则如图8所示，ToF测距装置的图像传感器阵列可以依次进行连续波A 0B 180，A 90B 270，A 180B 0，A 270B 90四次曝光。或者进行低频连续波A 0B 180，A 90B 270的两次曝光，实际操作中，上述的曝光顺序可交换。
模数转换器603，用于根据模拟信号到数字信号的转换算法，对输入的多个第四信号进行数字化处理，得到多个数字图像阵列。
在一种实施方式中，如图9所示，该ToF测距装置还可以包括：测距模块901，用于根据ToF测距芯片得到的多个数字图像阵列计算ToF测距装置与目标物体的距离。该测距模块901可以通过硬件方式实现，也可以通过软件方式实现，本申请对此不作具体限定。
上述本申请的实施例，通过结合CW ToF和P ToF两种测距技术，发射信号采用的是P TOF测距技术的方式，间隔式发送脉冲信号(第一信号)；图像传感器阵列进行曝光接收时，按照第二信号对接收到的反射光进行曝光，并且以CW ToF测距算法的四相位延迟方式进行曝光(两次或四次曝光)。相比较于现有技术，可有效的提升测距信噪比，并且可以在波形并非标准的方波的情况下进行ToF测距，另外，还有效增加了最远可测距离，提升整体的测距性能。同时，当发射的激光信号是随机信号的情况下，图像传感器阵列的不同像素点经过不同的相位延时对反射信号进行曝光，从而调制信号在码字维度、时间和频率的维度上都互不干扰，提高测距的准确度。
在另一种可能的实施方式中，可以在第一信号发生器301和光源驱动203之间增加一个延迟器，例如，第二延时器，用于对第一信号进行延时处理，从而光源驱动203可以根据对第一信号进行延迟处理后生成的信号，驱动发光器件发射脉冲光信号。
示例性的，第一信号的波形图可以为如图10所示的，发射信号可以为根据第一信号经过1/2相位的延时处理后的发射的脉冲光。而多个第三信号仍是根据第一信号经过不同的延时处理生成的，用于对经过目标物体的反射的脉冲信号分别进行四次曝光调制，通过计算发射信号与接收信号的相位差，从而得到ToF测距装置与目标物体之间的距离信息。该实施例可使ToF测距装置在目标物体距离ToF测距装置0米到模糊距离内得到准确的多个准确曝光值。
接来下，对本申请实施例提供的上述ToF测距装置的工作流程进行介绍。接前述图6或图7可知，本申请实施例提供的ToF测距装置发射信号的具体流程可以为如图11所示的S01-S03。
S01：设置脉冲持续宽度为Tp，输入第一信号发生器。
在一种可能的实施方式中，当该测距装置工作在随机模式下的时候，还需要设置随机数范围并产生随机正整数，输入第一信号发生器。
S02：第一信号发生器产生第一信号。
其中，第一信号发生器可以根据接收到的脉冲宽度Tp，或者脉冲宽度Tp和随机正整数N生成第一信号。该第一信号可以包括多个第一脉冲信号，第一脉冲信号的脉冲宽度为Tp，多个第一脉冲之间的脉冲间隔可以为(N+1)*Tp。
S03：根据第一信号发出脉冲信号。
激光驱动根据第一信号或者第一信号的延时信号驱动发光器件，使得发光器件发出相应亮暗信息的脉冲光信号。
结合前述的内容可知，本申请实施例提供的ToF测距装置接收反射信号并进行调制处理的具体流程可以为如图11所示的S04-S08。
S04：第二信号发生器根据第一信号产生第二信号。
其中，第二信号包含第一信号中所有的第一脉冲信号，还会在第一信号的第一脉冲后，间隔一个Tp之后会再发射一个或者多个第二脉冲信号，其中，第二脉冲信号的脉冲宽度可以为Tp。
S05：根据第二信号进行时间延迟操作，输出延迟后的第三信号。
延时器对输入的第二信号进行时间延迟操作输出多个第三信号P1，例如，第一次曝光不延迟，第二次曝光延迟1/4个周期，第三次曝光延迟1/2个周期，第四次曝光延迟3/4个周期。
S06：根据第三信号对经过镜头收集到的反射信号进行曝光，得到多个第四信号。
图像传感器阵列根据多个第三信号P1对经过镜头收集到的反射信号P进行曝光，得到多个第四信号P2阵列。其中，图像传感器阵列的每个像素都输出不同的曝光值。
S07：根据多个第四信号进行模数转换，得到多个数字图像阵列。
模数转换器对P2阵列信号进行模数转换，得到P3阵列，传输给测距模块。
S08：对数字图像阵列根据测距算法获得相位延迟，并根据调制信号的频率计算得到目标物体的距离。
测距模块在分别接收到不同延时信号曝光得到的P3阵列后，根据CW ToF测距算法的上述公式，计算得到相位延迟，再通过计算得到目标物体对应像素点的距离信息或者图像信息。
本申请的上述实施例，通过结合CW ToF和P ToF两种测距技术，可有效的提升测距信噪比，并且可以在波形并非完美的方波的情况下进行ToF测距。
本申请实施例还提供一种电子设备，示例性的，如图12所示，该电子设备1200可以包括至少一个处理器1201，通信线路1202以及存储器1203。
处理器1201可以是一个通用中央处理器(central processing unit，CPU)，微处理器，特定应用集成电路(application-specific integrated circuit，ASIC)，或一个或多个用于控制本公开方案程序执行的集成电路。
通信线路1202可包括一通路，在上述组件之间传送信息，例如总线。
存储器1203可以是只读存储器(read-only memory，ROM)或可存储静态信息和指令的其他类型的静态存储设备，随机存取存储器(random access memory，RAM)或者可存储信息和指令的其他类型的动态存储设备，也可以是电可擦可编程只读存储器(electrically erasable programmable read-only memory，EEPROM)、只读光盘(compact disc read-only memory，CD-ROM)或其他光盘存储、光碟存储(包括压缩光碟、激光 碟、光碟、数字通用光碟、蓝光光碟等)、磁盘存储介质或者其他磁存储设备、或者能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质，但不限于此。存储器可以是独立存在，通过通信线路1202与处理器1201相连接。存储器1203也可以和处理器1201集成在一起。本公开实施例提供的存储器通常可以具有非易失性。其中，存储器1203用于存储执行本公开方案所涉及的计算机执行指令，并由处理器1201来控制执行。处理器1201用于执行存储器1203中存储的计算机执行指令，从而实现本公开实施例提供的方法。
可选的，本公开实施例中的计算机执行指令也可以称之为应用程序代码，本公开实施例对此不作具体限定。
在具体实现中，作为一种实施例，处理器1201可以包括一个或多个CPU，例如图12中的CPU0和CPU1。
在具体实现中，作为一种实施例，电子设备1200可以包括多个处理器，例如图12中的处理器1201和处理器1207。每一个处理器可以是一个单核(single-CPU)处理器，也可以是一个多核(multi-CPU)处理器。这里的处理器可以指一个或多个设备、电路、和/或用于处理数据(例如计算机程序指令)的处理核。
在具体实现中，作为一种实施例，电子设备1200还可以包括通信接口1204。通信接口1204，使用任何收发器一类的装置，用于与其他设备或通信网络通信，如以太网接口，无线接入网接口(radio access network，RAN)，无线局域网接口(wireless local area networks，WLAN)等。
在具体实现中，作为一种实施例，电子设备1200还可以包括输出设备1205和输入设备1206。输出设备1205和处理器1201通信，可以以多种方式来显示信息。例如，输出设备1205可以是液晶显示器(liquid crystal display，LCD)，发光二级管(light emitting diode，LED)显示设备，阴极射线管(cathode ray tube，CRT)显示设备，或投影仪(projector)等。输入设备1206和处理器1201通信，可以以多种方式接收用户的输入。例如，输入设备1206可以是鼠标、键盘、触摸屏设备或传感设备等。
在具体实现中，电子设备1200可以是台式机、便携式电脑、网络服务器、掌上电脑(personal digital assistant，PDA)、移动手机、平板电脑、无线终端设备、嵌入式设备或有图12中类似结构的设备。本公开实施例不限定电子设备1200的类型。
在一些实施例中，图12中的处理器1201可以通过调用存储器1203中存储的计算机执行指令，使得装置1200执行上述方法实施例中的ToF测距方法。
在示例性实施例中，还提供了一种包括指令的存储介质，例如包括指令的存储器1203，上述指令可由电子设备1200的处理器1201执行以完成上述ToF测距方法。
通过以上实施方式的描述，所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，仅以上述各功能模块的划分进行举例说明，实际应用中，可以根据需要而将上述功能分配由不同的功能模块完成，即将装置的内部结构划分成不同的功能模块，以完成以上描述的全部或者部分功能。
在本申请所提供的几个实施例中，应该理解到，所揭露的装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述电路或单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如 多个单元或组件可以结合或者可以集成到另一个装置，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是一个物理单元或多个物理单元，即可以位于一个地方，或者也可以分布到多个不同地方。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
所述集成的单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个可读取存储介质中。基于这样的理解，本申请实施例的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的全部或部分可以以软件产品的形式体现出来，该软件产品存储在一个存储介质中，包括若干指令用以使得一个设备(可以是单片机，芯片等)或处理器(processor)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(read only memory，ROM)、随机存取存储器(random access memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
最后应说明的是：以上内容，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何在本申请揭露的技术范围内的变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (22)

  1. 一种基于飞行时间ToF的测距芯片，其特征在于，所述测距芯片包括：
    第一信号产生器，用于生成第一信号，所述第一信号包括多个第一脉冲，所述第一脉冲的宽度为第一宽度T，所述第一信号用于控制发光器件向目标物体发射光信号；
    第二信号产生器，用于根据所述第一信号生成第二信号，所述第二信号包括所述第一信号中的所述多个第一脉冲，以及与所述多个第一脉冲中每个第一脉冲延时所述第一宽度T的至少一个第二脉冲；
    连续波处理电路，用于根据所述第二信号对接收到的所述目标物体反射的光信号进行积分处理，得到多个曝光值，所述多个曝光值用于计算所述芯片与所述目标物体之间的光信号飞行时间对应的相位延迟。
  2. 根据权利要求1所述的测距芯片，其特征在于，所述至少一个第二脉冲中的每个第二脉冲的宽度为所述第一宽度T。
  3. 根据权利要求2所述的测距芯片，其特征在于，所述第二脉冲为多个第二脉冲，所述多个第二脉冲中相邻的两个第二脉冲的间隔为所述第一宽度T。
  4. 根据权利要求1-3任一项所述的测距芯片，其特征在于，所述连续波处理电路具体包括：
    第一延时器，用于分别对所述第二信号进行延迟操作，得到多个具有不同相位的第三信号；
    图像传感器阵列，用于根据所述多个具有不同相位的第三信号对镜头接收到的所述目标物体反射的光信号进行多次曝光，得到多个第四信号；
    模数转换器，用于对所述多个第四信号进行模拟-数字转换，得到多个数字图像阵列，所述多个数字图像阵列包括多个像素点对应的曝光值。
  5. 根据权利要求1-4任一项所述的测距芯片，其特征在于，所述多个第一脉冲中相邻两个第一脉冲的间隔为(N+1)*T，其中，所述N为预设正整数或者随机正整数。
  6. 根据权利要求4或5所述的测距芯片，其特征在于，第一延时器具体用于：
    对所述第二信号进行m次延迟处理，得到m个第三信号，所述m次延迟处理包括0相位延迟处理，且m次延迟处理中相邻的两次延迟处理的时间差为2T/m。
  7. 根据权利要求1-6任一项所述的测距芯片，其特征在于，所述测距芯片还包括：
    第二延时器，用于生成第一信号的延时信号；
    所述发光器件，用于根据所述第一信号的延时信号向所述目标物体发射光信号。
  8. 一种基于飞行时间ToF的测距装置，其特征在于，所述测距装置包括：如权利要求1-7任一项所述的测距芯片、光源驱动、发光器件和镜头；
    所述光源驱动，用于根据所述测距芯片生成的第一信号驱动所述发光器件发射光信号；
    所述发光器件，用于基于第一信号的驱动向目标物体发射光信号；
    所述镜头，用于接收所述目标物体反射的光信号，并将所述光信号传输到所述测距芯片。
  9. 根据权利要求8所述测距装置，其特征在于，所述发光器件为直腔面发射激光器VCSEL。
  10. 一种电子设备，其特征在于，所述电子设备包括如权利要求8或9所述的测距装置，所述电子设备还包括：
    计算模块，用于根据所述测距装置得到的所述多个曝光值计算所述测距装置与所述目标物体之间的光信号飞行时间对应的相位延迟。
  11. 一种基于飞行时间ToF的测距方法，其特征在于，所述方法包括：
    生成第一信号，所述第一信号包括多个第一脉冲，所述第一脉冲的宽度为第一宽度T，所述第一信号用于向目标物体发射光信号；
    根据所述第一信号生成第二信号，所述第二信号包括所述第一信号中的所述多个第一脉冲，以及与所述多个第一脉冲中每个第一脉冲延时所述第一宽度T的至少一个第二脉冲；
    根据所述第二信号对接收到的所述目标物体反射的光信号进行积分处理，得到多个曝光值，所述曝光值用于计算测距芯片与所述目标物体之间的光信号飞行时间对应的相位延迟。
  12. 根据权利要求11所述的测距方法，其特征在于，所述至少一个第二脉冲中的每个第二脉冲的宽度为所述第一宽度T。
  13. 根据权利要求12所述的测距方法，其特征在于，所述第二脉冲为多个第二脉冲，所述多个第二脉冲中相邻的两个第二脉冲的间隔为所述第一宽度T。
  14. 根据权利要求11-13任一项所述的测距方法，其特征在于，所述根据所述第二信号对接收到的所述目标物体反射的光信号进行积分处理，得到多个曝光值包括：
    分别对所述第二信号进行延迟操作，得到多个具有不同相位的第三信号；
    根据所述多个具有不同相位的第三信号对接收到的所述目标物体反射的光信号进行多次曝光，得到多个第四信号；
    对所述多个第四信号进行模拟-数字转换，得到多个数字图像阵列，所述多个数字图像阵列包括多个像素点对应的曝光值。
  15. 根据权利要求11-14任一项所述的测距方法，其特征在于，所述多个第一脉冲中相邻两个第一脉冲的间隔为(N+1)*T，其中，所述N为预设正整数或者随机正整数。
  16. 根据权利要求11-15任一项所述的测距方法，其特征在于，所述对所述第二信号进行延迟操作，得到多个具有不同相位的第三信号具体包括：
    对所述第二信号进行m次延迟处理，得到m个第三信号，所述m次延迟处理包括0相位延迟处理，且m次延迟处理中相邻的两次延迟处理的时间差为2T/m。
  17. 根据权利要求11-16任一项所述的测距方法，其特征在于，所述生成第一信号之后，所述测距方法还包括：
    根据所述第一信号向所述目标物体发射光信号。
  18. 根据权利要求17所述的测距方法，其特征在于，所述生成第一信号之后，所述测距方法还包括：
    生成第一信号的延时信号；
    所述根据所述第一信号向目标物体发射光信号具体包括：根据所述第一信号的延时信号向目标物体发射光信号。
  19. 根据权利要求11-18任一项所述的测距方法，其特征在于，所述根据所述第二信号对接收到的所述目标物体反射的光信号进行积分处理，得到多个曝光值之后，所述测距方法还包括：
    根据所述多个曝光值计算测距装置与所述目标物体之间的光信号飞行时间对应的相位延迟。
  20. 一种电子设备，其特征在于，包括处理器，所述处理器与存储器耦合；
    存储器，用于存储计算机程序或指令；
    处理器，用于执行所述存储器中存储的计算机程序或指令，以使得电子设备能够执行如权利要求11至19中任意一项所述的方法。
  21. 一种计算机可读存储介质，用于存储程序或指令，当所述存储介质中的指令由电子设备的处理器执行时，使得电子设备能够执行如权利要求11至19中任意一项所述的方法。
  22. 一种计算机程序产品，包括程序或指令，当所述计算机程序产品在计算机上运行时，使得所述计算机执行如权利要求11至19中任意一项所述的方法。
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