Continuous laser single-photon ranging method, device and equipment

Abstract

The invention provides a continuous laser single-photon ranging method, device and equipment, which can be applied to the technical field of laser radars. The method comprises the following steps: periodically modulating a received continuous light wave to generate a target light signal; transmitting the target optical signal to a target object, and receiving an initial echo optical signal reflected from the target object; converting the initial echo optical signal into an electric pulse signal; the output moment of the electric pulse signal and the period starting moment of the target optical signal are measured, and the period starting moment of the target optical signal is represented as the emission moment of the target optical signal; performing signal processing on the output moment of the output electric pulse signal to generate a target echo optical signal; generating an initial delay moment of the target echo optical signal according to the waveform of the target echo optical signal; and determining a target distance according to the initial delay time of the target echo optical signal and the period starting time of the target optical signal.

Description

Technical Field

[0001] The present disclosure relates to the field of laser radar technology, and specifically to a continuous laser single-photon ranging method, device and equipment. Background Art

[0002] Existing single-photon laser ranging technology generally uses narrow pulse lasers as light sources. Although narrow pulses improve ranging accuracy, the pulses are short and the system cannot support high-power pulses in a short period of time, and the pulse energy does not meet the ranging requirements. In order to achieve a larger ranging range and higher measurement accuracy, it is necessary to increase the single pulse energy and reduce the laser pulse width at the same time. Existing single-photon ranging technology is limited by laser performance and is difficult to improve further.

[0003] In addition, narrower pulse widths and higher single pulse energies can be achieved, and some innovative solutions are being continuously explored, such as detection methods based on nonlinear optical effects. However, these methods will make the system more complex and less efficient, and their technical maturity is far from meeting practical requirements. Summary of the invention

[0004] In view of the above problems, the present disclosure provides a continuous laser single photon ranging method, device and equipment.

[0005] According to a first aspect of the present disclosure, a continuous laser single photon ranging method is provided, comprising:

[0006] Performing periodic modulation on the received continuous optical wave to generate a target optical signal, wherein the target optical signal represents an optical signal reaching a target bandwidth;

[0007] transmitting a target optical signal to a target object and receiving an initial echo optical signal reflected from the target object;

[0008] Converting the initial echo optical signal into an electrical pulse signal;

[0009] Measuring the output time of the electric pulse signal and the cycle start time of the target light signal, wherein the cycle start time of the target light signal is characterized as the emission time of the target light signal;

[0010] Performing signal processing on the output time of the output electrical pulse signal to generate a target echo optical signal;

[0011] Generate an initial delay time of the target echo light signal according to the waveform of the target echo light signal;

[0012] The target distance is determined according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal.

[0013] According to an embodiment of the present disclosure, converting the initial echo optical signal into an electrical pulse signal comprises:

[0014] Generate a photon loss probability value according to an initial echo light signal and a background light signal, wherein the initial echo light signal is composed of a plurality of echo photons, and the background light signal is composed of a plurality of noise photons;

[0015] When the photon loss probability value meets a preset threshold, the initial echo light signal is converted into an electrical pulse signal.

[0016] According to an embodiment of the present disclosure, signal processing is performed on the output time of the output electrical pulse signal to generate a target echo optical signal, including:

[0017] For a cycle, data preprocessing is performed on the output time according to the cycle start time to generate first time data;

[0018] For multiple periods, merging the first time data in each period to generate second time data;

[0019] Performing preliminary signal processing according to the second time data to generate an intermediate echo optical signal;

[0020] The final signal processing is performed on the intermediate echo optical signal to generate the target echo optical signal.

[0021] According to an embodiment of the present disclosure, performing final signal processing according to the intermediate echo optical signal to generate a target echo optical signal includes:

[0022] Determining a second filtering rule according to the periodically modulated signal waveform;

[0023] The intermediate echo optical signal is compressed using the second filtering rule to generate a target echo optical signal.

[0024] According to an embodiment of the present disclosure, generating an initial delay time of the target echo optical signal according to the waveform of the target echo optical signal includes:

[0025] Generate an echo photon time distribution probability function according to the waveform of the target echo light signal and the initial overall probability coefficient;

[0026] Generate i probability values ​​according to the echo photon time distribution probability function and the time corresponding to the top i peak points in the target echo light signal, where i≥1, i represents the preset value;

[0027] The peak point time corresponding to the maximum probability value is selected to generate the initial delay time of the target echo optical signal.

[0028] According to an embodiment of the present disclosure, determining the target distance according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal includes:

[0029] Generate an estimated likelihood function according to the initial overall probability coefficient, the initial delay time and the probability function of the echo photon time distribution;

[0030] Generate a target delay time of the target echo optical signal according to the estimated likelihood function;

[0031] The target distance is determined based on the time difference between the target delay moment and the cycle start moment.

[0032] A second aspect of the present disclosure provides a continuous laser single photon ranging device, comprising:

[0033] A modulation module, used for periodically modulating the received continuous optical wave to generate a target optical signal, wherein the target optical signal represents an optical signal reaching a target bandwidth;

[0034] A light receiving and transmitting module, used for transmitting a target light signal to a target object and receiving an initial echo light signal reflected from the target object;

[0035] A single photon detector module, used to convert the initial echo light signal into an electrical pulse signal;

[0036] A time measurement module, used to measure the output time of the electric pulse signal and the cycle start time of the target light signal, wherein the cycle start time of the target light signal is characterized as the emission time of the target light signal;

[0037] A signal processing module, used for performing signal processing at the output time of the output electrical pulse signal to generate a target echo optical signal;

[0038] A generating module, used for generating an initial delay time of the target echo light signal according to the waveform of the target echo light signal;

[0039] The determination module is used to determine the target distance according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal.

[0040] A third aspect of the present disclosure provides a continuous laser single photon ranging device, comprising:

[0041] A continuous laser emission component, a component configured to generate a continuous light wave;

[0042] A continuous laser single photon ranging device is a device configured to receive continuous light waves generated by a continuous laser emitting component.

[0043] According to the continuous laser single photon ranging method, device and equipment provided by the present disclosure, the received continuous light wave is periodically modulated to generate a target light signal reaching the target bandwidth, and then the target light signal is emitted to the target object, and the initial echo light signal reflected from the target object is received and converted into an electrical pulse signal; signal processing is performed on the output time of the output electrical pulse signal to generate a narrow pulse target echo light signal; finally, the target distance is determined according to the initial delay time of the target echo light signal and the cycle start time of the target light signal. Since the continuous light wave has a long pulse width, the signal bandwidth and power are increased by periodically modulating the emitted continuous light wave, the target light signal energy is increased, and the ranging range is increased; in addition, the target light signal with the target bandwidth improves the measurement accuracy, and the echo light signal is processed at the same time to obtain the target echo light signal, thereby obtaining a more accurate delay time, and the target distance is calculated with accurate time resolution, which further improves the measurement accuracy, and solves the problem that the ranging range and accuracy cannot be improved at the same time when single photon ranging is used. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0045] Figure 1 The flowchart of the continuous laser single photon ranging method according to the embodiment of the present disclosure is schematically shown;

[0046] Figure 2 The application scenario diagram of the continuous laser single photon ranging method according to the embodiment of the present disclosure is schematically shown;

[0047] Figure 3 Schematically shows a flow chart of generating a target echo optical signal according to an embodiment of the present disclosure;

[0048] Figure 4 A schematic diagram of generating first time data according to an embodiment of the present disclosure is schematically shown;

[0049] Figure 5 A schematic diagram schematically shows generating second time data according to an embodiment of the present disclosure;

[0050] Figure 6 A schematic diagram of generating an intermediate echo optical signal according to an embodiment of the present disclosure is schematically shown;

[0051] Figure 7 A schematic diagram of generating a target echo optical signal according to an embodiment of the present disclosure is schematically shown;

[0052] Figure 8 The structure block diagram of the continuous laser single photon ranging device according to the embodiment of the present disclosure is schematically shown;

[0053] Fig. 9 A block diagram schematically shows a device suitable for implementing a continuous laser single photon ranging method according to an embodiment of the present disclosure; and

[0054] Fig.10 A block diagram of an electronic device suitable for implementing a continuous laser single photon ranging method according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0055] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0056] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0057] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0058] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0059] In the process of implementing the present disclosure, it is found that since the existing single-photon laser ranging technology generally uses a narrow pulse laser as a light source, although the narrow pulse improves the ranging accuracy, the pulse is short, the system cannot support the provision of high peak power pulses in a short time, and the pulse energy does not meet the ranging requirements, that is, it is impossible to simultaneously reduce the laser pulse width and increase the single pulse energy, and thus it is impossible to achieve a larger ranging range and higher measurement accuracy. Therefore, there is an urgent need for a continuous laser single-photon ranging method that can solve the contradiction between single pulse energy and laser pulse width.

[0060] In view of this, the embodiments of the present disclosure provide a continuous laser single-photon ranging method, a continuous laser single-photon ranging device and equipment. The method includes: periodically modulating the received continuous light wave to generate a target light signal; transmitting the target light signal to the target object, receiving the initial echo light signal reflected from the target object; converting the initial echo light signal into an electrical pulse signal; measuring the output time of the electrical pulse signal and the cycle start time of the target light signal, wherein the cycle start time of the target light signal is characterized as the emission time of the target light signal; performing signal processing on the output time of the output electrical pulse signal to generate a target echo light signal; generating the initial delay time of the target echo light signal according to the waveform of the target echo light signal; determining the target distance according to the initial delay time of the target echo light signal and the cycle start time of the target light signal.

[0061] In the technical solution of the present invention, the user information (including but not limited to user personal information, user image information, user device information, such as location information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved are all information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of relevant data comply with the relevant laws, regulations and standards of relevant countries and regions, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0062] Figure 1 The flowchart of the continuous laser single photon ranging method according to an embodiment of the present disclosure is schematically shown.

[0063] like Figure 1 As shown, the method 100 includes operations S110 to S170.

[0064] In operation S110 , periodic modulation is performed on the received continuous optical wave to generate a target optical signal, wherein the target optical signal represents an optical signal reaching a target bandwidth.

[0065] According to the embodiments of the present disclosure, signal periodic modulation refers to controlling the on and off of inverter circuit switching devices according to the signal variation rule and signal waveform, and changing the signal bandwidth by changing the frequency and amplitude of the modulation signal wave.

[0066] According to an embodiment of the present disclosure, the modulation method includes an equal area method, a hardware modulation method, a software generation method, and the like.

[0067] According to the embodiments of the present disclosure, the hardware implementation of periodic modulation includes: directly modulating the laser pump current; using a DC single-frequency seed laser, an intensity modulator and a power amplifier cascade; and an intensity modulator (such as an electro-optic intensity modulator, an acousto-optic intensity modulator, an electro-absorption modulator and an optical switch) modulating the amplitude of the seed laser according to a radio frequency drive signal. The hardware implementation is not limited to this.

[0068] According to the embodiment of the present disclosure, the periodically modulated signal waveform includes: a frequency modulated continuous wave, a pseudo-random code sequence, a single-frequency sine wave, and a composite waveform of a multi-frequency sine wave. The signal waveform is not limited thereto.

[0069] According to an embodiment of the present disclosure, pulse energy may include the product of power and pulse width.

[0070] According to the embodiments of the present disclosure, the continuous light wave has a longer pulse time, and the modulated light signal power is amplified by a power amplifier to obtain a light signal of target energy to meet the requirements of the detection distance range.

[0071] According to the embodiments of the present disclosure, the pulse width represents the action time or duration of each pulse signal emitted. For example, the pulse width is 1us and the pulse duration is 1000 seconds. It can be seen that the pulse width has only a time attribute.

[0072] According to an embodiment of the present disclosure, a received continuous light wave is periodically modulated to generate an optical signal reaching a target bandwidth.

[0073] According to an embodiment of the present disclosure, the target optical signal characterization has two properties: target bandwidth and target energy.

[0074] According to an embodiment of the present disclosure, optionally, polarization modulation may be performed on the received continuous light wave to generate a target optical signal.

[0075] In operation S120 , a target optical signal is transmitted to a target object, and an initial echo optical signal reflected from the target object is received.

[0076] In operation S130, the initial echo optical signal is converted into an electrical pulse signal.

[0077] According to an embodiment of the present disclosure, a single-photon detector is used to detect the initial echo light signal, and the initial echo light signal is converted into an electrical pulse signal.

[0078] According to the embodiments of the present disclosure, various existing single-photon detectors may be optionally used, such as single-photon avalanche diodes, superconducting nanowire single-photon detectors, and photomultiplier tubes.

[0079] In operation S140 , the output time of the electrical pulse signal and the cycle start time of the target light signal are measured, wherein the cycle start time of the target light signal is characterized as the emission time of the target light signal.

[0080] According to an embodiment of the present disclosure, the implementation method for measuring and recording the output time of the electrical pulse signal output by the single-photon detector includes a dedicated time-to-digital conversion chip (TDC), a field programmable gate array (FPGA)-based implementation, etc., but is not limited to these.

[0081] According to an embodiment of the present disclosure, the cycle start time is obtained by synchronizing the modulation module with the time measurement module, that is, the target light signal is emitted to the target object, and a synchronization signal of the emission time is transmitted and recorded as the cycle start time of the target light signal.

[0082] In operation S150 , signal processing is performed on the output timing of the output electrical pulse signal to generate a target echo optical signal.

[0083] According to an embodiment of the present disclosure, signal processing is performed on the output time of the output electrical pulse signal, such as pulse width, signal waveform, signal bandwidth, etc., so as to obtain a target echo optical signal.

[0084] In operation S160, an initial delay time of the target echo light signal is generated according to the waveform of the target echo light signal.

[0085] According to an embodiment of the present disclosure, the initial delay moment represents the delay caused by the target object from the emitted target light signal to the received initial echo light signal.

[0086] In operation S170, the target distance is determined according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal.

[0087] According to the embodiments of the present disclosure, by further optimizing the initially obtained initial delay moment, a more accurate delay moment is obtained, and then the target distance from the emission point to the target object is calculated by using the time difference between the delay moment and the start moment of the cycle of the target light signal.

[0088] According to the embodiment of the present disclosure, the received continuous light wave is periodically modulated to generate a target light signal with a target bandwidth and a target energy; the target light signal is transmitted to the target object, the initial echo light signal reflected from the target object is received, and the initial echo light signal is converted into an electrical pulse signal; according to the output time of the measured electrical pulse signal, the signal processing is performed to obtain the target echo light signal; then according to the waveform of the target echo light signal, the initial delay time of the target echo light signal is obtained; finally, according to the time difference between the initial delay time and the cycle start time of the target light signal, the target distance is calculated. Since the continuous light wave has a long pulse width, the signal bandwidth and power are increased by periodically modulating the emitted continuous light wave, the target light signal energy is increased, and the ranging range is increased; in addition, the target light signal with the target bandwidth improves the measurement accuracy, and the echo light signal is processed to obtain the target echo light signal, thereby obtaining a more accurate delay time, and the target distance is calculated with accurate time resolution, which further improves the measurement accuracy, and solves the problem that the ranging range and accuracy cannot be improved at the same time when single photon ranging is used.

[0089] Figure 2 The application scenario diagram of the continuous laser single photon ranging method according to an embodiment of the present disclosure is schematically shown.

[0090] like Figure 2 As shown, in one embodiment, the method for measuring the start time of a cycle also includes obtaining the start time of the cycle by adding a reference optical path. The modulation module 210 performs periodic modulation on the received continuous light wave to generate a target optical signal, and a part of the output target optical signal is split into a beam and enters the single-photon detector A module 230, and the other part of the light beam is emitted to the target object by the light receiving and light receiving module 220; the light receiving and light receiving module 220 receives the initial echo optical signal reflected from the target object, and the single-photon detector B module 240 converts the initial echo optical signal into an electrical pulse signal; the time measurement module 250 simultaneously measures and records the time of the single-photon detector A module 220 and the target single-photon detector B module 240; in the signal processing module 260, the time data of the two signals are processed in the same way, and the time obtained by processing the single-photon detector A channel data is the start time of the cycle.

[0091] According to an embodiment of the present disclosure, converting an initial echo optical signal into an electrical pulse signal includes:

[0092] Generate a photon loss probability value according to an initial echo light signal and a background light signal, wherein the initial echo light signal is composed of a plurality of echo photons, and the background light signal is composed of a plurality of noise photons;

[0093] When the photon loss probability value meets a preset threshold, the initial echo light signal is converted into an electrical pulse signal.

[0094] According to an embodiment of the present disclosure, in the process of a single-photon detector receiving an echo light signal (ie, receiving a plurality of echo photons), the echo photons may be lost due to a certain dead time during which the echo light signal cannot be received.

[0095] According to an embodiment of the present disclosure, dead time refers to a period of time during which a single-photon detector no longer responds to a new echo light signal after receiving an echo photon count.

[0096] According to an embodiment of the present disclosure, the photon loss probability value P loss Characterizes the probability of losing the echo photon during the dead time. The calculation formula is shown in (1):

[0097]

[0098] Among them, n e and n b They represent the number of echo photons and noise photons received by the single-photon detector per unit time, η represents the efficiency value of the existing single-photon detector, T d represents the dead time, and k represents the number of echo photons received during the dead time.

[0099] According to the embodiment of the present disclosure, the single-photon detector can filter out the weak initial echo light signal and the background light signal through a narrow-band filter, so n e and n b Smaller, that is, take k=2.

[0100] According to the embodiment of the present disclosure, the preset threshold is 0.2, that is, when the photon loss probability value satisfies P loss ≤0.2, convert the received initial echo light signal into an electrical pulse signal.

[0101] According to an embodiment of the present disclosure, when the photon loss probability value meets a preset threshold, the initial echo light signal is converted into an electrical pulse signal, which controls the number of echo photons lost during the dead time to be lower, thereby improving the accuracy of the initial echo light signal.

[0102] Figure 3 The flowchart schematically shows a process of performing signal processing on the output timing of an output electrical pulse signal to generate a target echo optical signal according to an embodiment of the present disclosure.

[0103] like Figure 3 As shown, signal processing is performed at the output time of the output electrical pulse signal to generate a target echo optical signal, including operations S310 to S370.

[0104] In step S310, for a cycle, data preprocessing is performed on the output time according to the start time of the cycle to generate first time data.

[0105] Figure 4 The diagram schematically shows a schematic diagram of generating first time data according to an embodiment of the present disclosure.

[0106] like Figure 4 As shown, according to an embodiment of the present disclosure, within a cycle, according to the start time of the cycle, the output time data of the single photon detection output electrical pulse signal is intercepted and arranged to generate the first time data, wherein, wherein the horizontal axis X represents the output time, and the vertical axis Y represents the amplitude value. If there is no output time data within a cycle, the cycle is eliminated.

[0107] In step S320, for multiple periods, the first time data in each period are merged to generate second time data.

[0108] Figure 5 The diagram schematically shows a schematic diagram of generating second time data according to an embodiment of the present disclosure.

[0109] like Figure 5 As shown, according to an embodiment of the present disclosure, the same or similar first time data corresponding to each period are merged, that is, multi-period first time data are merged to generate second time data, wherein the horizontal axis X represents the output moment and the vertical axis Y represents the amplitude value.

[0110] According to an embodiment of the present disclosure, by intercepting and arranging the output time data of the single-photon detection output electrical pulse signal in each cycle and then merging multiple cycle data, the amount of available data at the output time of the output electrical pulse signal is increased, thereby improving the ranging accuracy.

[0111] In step S330, a first filtering rule is determined according to a target bandwidth of periodic modulation.

[0112] According to an embodiment of the present disclosure, based on the target bandwidth of periodic modulation, for example, the target bandwidth ranges from 20M to 25M, the first filtering rule is to satisfy the signal bandwidth range of 20M to 25M.

[0113] In step S340, a discrete sampling time domain signal is generated according to the second time data.

[0114] In step S350, the discrete sampling time domain signal is filtered and converted using the first filtering rule to generate an intermediate echo optical signal.

[0115] Figure 6 The diagram schematically shows a schematic diagram of generating an intermediate echo optical signal according to an embodiment of the present disclosure.

[0116] like Figure 6As shown, according to an embodiment of the present disclosure, a discrete sampling time domain signal is established according to the second time data, and under the first filtering rule condition, the discrete sampling time domain signal is filtered by a filter to remove signals that do not meet the bandwidth range, and then the discrete sampling time domain signal after filtering is waveform converted to generate an intermediate echo optical signal, wherein the horizontal axis X represents the output moment and the vertical axis Y represents the amplitude value.

[0117] In step S360, a second filtering rule is determined according to the periodically modulated signal waveform.

[0118] According to an embodiment of the present disclosure, based on a periodically modulated signal waveform, for example, the signal waveform is a sine wave, the second filtering rule is a sine wave signal waveform.

[0119] In step S370, the intermediate echo optical signal is compressed using the second filtering rule to generate a target echo optical signal.

[0120] Figure 7 The diagram schematically shows a schematic diagram of generating a target echo optical signal according to an embodiment of the present disclosure.

[0121] like Figure 7 As shown, in one embodiment, under the second filtering rule condition, a filter is used to perform signal compression processing on the intermediate echo light signal, that is, only the intermediate echo light signal with a sinusoidal waveform is compressed to generate a target echo light signal, wherein the horizontal axis X represents the output time and the vertical axis Y represents the amplitude value.

[0122] According to an embodiment of the present disclosure, signal compression refers to compressing a wide pulse signal into a narrow pulse signal.

[0123] According to an embodiment of the present disclosure, by performing final signal processing on the intermediate echo light signal, the intermediate echo light signal with a wide pulse is compressed into a narrow pulse signal to obtain a target echo light signal, so as to obtain sufficiently high distance resolution and time resolution.

[0124] According to an embodiment of the present disclosure, generating an initial delay time of a target echo optical signal according to a waveform of the target echo optical signal includes:

[0125] Generate an echo photon time distribution probability function according to the waveform of the target echo light signal and the initial overall probability coefficient;

[0126] Generate i probability values ​​according to the echo photon time distribution probability function and the time corresponding to the top i peak points in the target echo light signal, where i≥1, i represents the preset value;

[0127] The peak point time corresponding to the maximum probability value is selected to generate the initial delay time of the target echo optical signal.

[0128] According to an embodiment of the present disclosure, there are multiple peak points in the waveform of the target echo optical signal, and the moments corresponding to the peak points with the top i peak rankings are selected, that is, i peak point moments are generated.

[0129] In one embodiment, the default value of i is 4.

[0130] According to an embodiment of the present disclosure, the echo photon time distribution probability function (2) is as follows:

[0131] P(t)=A·s(t-τ) (2)

[0132] Where t represents time, A is the initial overall probability coefficient, s(·) is the modulated signal waveform, and τ is the peak point moment.

[0133] According to the embodiments of the present disclosure, based on each peak point moment and the echo photon time distribution probability function, the probability value corresponding to each peak point moment, ie, i probability values, is obtained.

[0134] According to the embodiment of the present disclosure, the peak point moment corresponding to the maximum probability value is selected to generate the initial delay moment of the target echo light signal. In the moment corresponding to the higher probability value, the number of echo photons received by the single photon detector is larger, which means that the time resolution is also higher and the ranging accuracy is high.

[0135] According to an embodiment of the present disclosure, determining the target distance according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal includes:

[0136] Generate an estimated likelihood function according to the initial overall probability coefficient, the initial delay time and the probability function of the echo photon time distribution;

[0137] Generate a target delay time of the target echo optical signal according to the estimated likelihood function;

[0138] The target distance is determined based on the time difference between the target delay moment and the cycle start moment.

[0139] According to an embodiment of the present disclosure, an estimated likelihood function is generated based on the initial overall probability coefficient, the initial delay moment and the echo photon time distribution probability function, and the two parameters of the initial overall probability coefficient and the initial delay moment are continuously iterated and updated to finally generate the target delay moment.

[0140] According to an embodiment of the present disclosure, the target distance is determined according to the time difference between the target delay time and the cycle start time, and the calculation formula (3) is as follows:

[0141]

[0142] Where c represents the speed of the optical signal, Δ tRepresents the time difference between the target delay time and the cycle start time.

[0143] According to the embodiments of the present disclosure, by iteratively updating the two parameters of the initial overall probability coefficient and the initial delay time through the estimated likelihood function, a more accurate target delay time is obtained, thereby more precisely calculating the time difference and improving the accuracy of measuring the distance from the launch point to the target object.

[0144] Based on the above continuous laser single photon ranging method, the present disclosure also provides a continuous laser single photon ranging device. Figure 8 The device is described in detail.

[0145] Figure 8 The structural block diagram of the continuous laser single photon ranging device according to an embodiment of the present disclosure is schematically shown.

[0146] like Figure 8 As shown, the continuous laser single-photon ranging device 800 of this embodiment includes a modulation module 810, a light-emitting and receiving module 820, a single-photon detector module 830, a time measurement module 840, a signal processing module 850, a generation module 860 and a determination module 870.

[0147] The modulation module 810 is used to periodically modulate the received continuous optical wave to generate a target optical signal, wherein the target optical signal represents an optical signal reaching a target bandwidth. In one embodiment, the modulation module 810 can be used to perform the operation S110 described above, which will not be described in detail here.

[0148] The light emitting and receiving module 820 is used to transmit the target light signal to the target object and receive the initial echo light signal reflected from the target object. In one embodiment, the light emitting and receiving module 820 can be used to perform the operation S120 described above, which will not be described in detail here.

[0149] The single photon detector module 830 is used to convert the initial echo light signal into an electrical pulse signal. In one embodiment, the single photon detector module 830 can be used to perform the operation S130 described above, which will not be described in detail here.

[0150] The time measurement module 840 is used to measure the output time of the electrical pulse signal and the cycle start time of the target light signal, wherein the cycle start time of the target light signal is characterized as the emission time of the target light signal. In one embodiment, the time measurement module 840 can be used to perform the operation S140 described above, which will not be repeated here.

[0151] The signal processing module 850 is used to perform signal processing on the output time of the output electrical pulse signal to generate a target echo optical signal. In one embodiment, the signal processing module 850 can be used to perform the operation S150 described above, which will not be described in detail here.

[0152] The generating module 860 is used to generate the initial delay time of the target echo light signal according to the waveform of the target echo light signal. In one embodiment, the generating module 860 can be used to perform the operation S160 described above, which will not be described in detail here.

[0153] The determination module 870 is used to determine the target distance according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal. In one embodiment, the determination module 870 can be used to perform the operation S170 described above, which will not be described in detail here.

[0154] According to an embodiment of the present disclosure, the single-photon detector module 830 includes a first generating unit and a first converting unit.

[0155] The first generating unit is used to generate a photon loss probability value according to an initial echo light signal and a background light signal, wherein the initial echo light signal is composed of a plurality of echo photons, and the background light signal is composed of a plurality of noise photons.

[0156] The first conversion unit is used to convert the initial echo light signal into an electrical pulse signal when the photon loss probability value meets a preset threshold.

[0157] According to an embodiment of the present disclosure, the signal processing module 850 includes a first generating submodule, a second generating submodule, a third generating submodule, and a fourth generating submodule.

[0158] The first generating submodule is used to perform data preprocessing on the output time according to the start time of the cycle for a cycle, so as to generate first time data.

[0159] The second generating submodule is used to merge the first time data in each period for multiple periods to generate second time data.

[0160] A third generating submodule is used to perform preliminary signal processing according to the second time data to generate an intermediate echo optical signal;

[0161] The fourth generating submodule is used to perform final signal processing according to the intermediate echo optical signal to generate a target echo optical signal.

[0162] According to an embodiment of the present disclosure, the third generation submodule includes a second generation unit, a third generation unit and a fourth generation unit.

[0163] The second generating unit is used to determine a first filtering rule according to a target bandwidth of periodic modulation.

[0164] The third generating unit is used to generate a discrete sampling time domain signal according to the second time data.

[0165] The fourth generating unit is used to filter and convert the discrete sampling time domain signal by using the first filtering rule to generate an intermediate echo optical signal.

[0166] According to an embodiment of the present disclosure, the fourth generation submodule includes a fifth generation unit and a sixth generation unit.

[0167] The fifth generating unit is used to determine a second filtering rule according to the periodically modulated signal waveform.

[0168] The sixth generating unit is used to compress the intermediate echo light signal by using the second filtering rule to generate the target echo light signal.

[0169] According to an embodiment of the present disclosure, the generation module 860 includes a fifth generation submodule, a sixth generation submodule and a seventh generation submodule.

[0170] The fifth generating submodule is used to generate an echo photon time distribution probability function according to the waveform of the target echo optical signal and the initial overall probability coefficient.

[0171] The sixth generation submodule is used to generate i probability values ​​according to the echo photon time distribution probability function and the time corresponding to the top i peak points in the target echo optical signal, where i≥1 and i represents a preset value.

[0172] The seventh generation submodule is used to select the peak point time corresponding to the maximum probability value to generate the initial delay time of the target echo optical signal.

[0173] According to an embodiment of the present disclosure, the determination module 870 includes a seventh generation submodule, an eighth generation submodule and a target distance determination submodule.

[0174] The seventh generation submodule is used to generate an estimated likelihood function according to the initial overall probability coefficient, the initial delay time and the echo photon time distribution probability function.

[0175] The eighth generating submodule is used to generate a target delay time of the target echo optical signal according to the estimated likelihood function.

[0176] The target distance determination submodule is used to determine the target distance according to the time difference between the target delay time and the cycle start time.

[0177] According to an embodiment of the present disclosure, any multiple modules of the modulation module 810, the light receiving and emitting module 820, the single photon detector module 830, the time measurement module 840, the signal processing module 850, the generation module 860 and the determination module 870 can be combined in one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present disclosure, at least one of the modulation module 810, the light receiving and emitting module 820, the single photon detector module 830, the time measurement module 840, the signal processing module 850, the generation module 860 and the determination module 870 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation modes of software, hardware and firmware or in a suitable combination of any of them. Alternatively, at least one of the modulation module 810, the light transmitting and receiving module 820, the single photon detector module 830, the time measurement module 840, the signal processing module 850, the generation module 860 and the determination module 870 can be at least partially implemented as a computer program module, and when the computer program module is executed, the corresponding function can be performed.

[0178] Fig. 9 A block diagram of a device suitable for implementing a continuous laser single photon ranging method according to an embodiment of the present disclosure is schematically shown.

[0179] like Fig. 9 As shown, the device 900 according to an embodiment of the present disclosure includes a continuous laser emission component 910 and a continuous laser single photon ranging device 800.

[0180] According to an embodiment of the present disclosure, the continuous laser emitting component 910 is configured as a component for generating continuous light waves, and the continuous laser single photon ranging device 800 receives the continuous light waves generated by the continuous laser emitting component.

[0181] The modulation module 810 is used to perform periodic modulation on the received continuous light wave to generate a target optical signal, wherein the target optical signal represents an optical signal reaching a target bandwidth.

[0182] The light transmitting and receiving module 820 is used to transmit a target light signal to the target object 920 and receive an initial echo light signal reflected from the target object 920 .

[0183] The single photon detector module 830 is used to convert the initial echo light signal into an electrical pulse signal.

[0184] The time measurement module 840 is used to measure the output time of the electric pulse signal and the cycle start time of the target light signal, wherein the cycle start time of the target light signal is characterized as the emission time of the target light signal.

[0185] The signal processing module 850 is used to perform signal processing on the output time of the output electrical pulse signal to generate a target echo optical signal.

[0186] The generating module 860 is used to generate an initial delay time of the target echo light signal according to the waveform of the target echo light signal.

[0187] The determination module 870 is used to determine the target distance according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal.

[0188] Fig.10 A block diagram of an electronic device suitable for implementing a continuous laser single photon ranging method according to an embodiment of the present disclosure is schematically shown.

[0189] like Fig.10 As shown, the electronic device 1000 according to an embodiment of the present disclosure includes a processor 1001, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage part 1008 into a random access memory (RAM) 1003. The processor 1001 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1001 may also include an onboard memory for caching purposes. The processor 1001 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0190] In RAM 1003, various programs and data required for the operation of electronic device 1000 are stored. Processor 1001, ROM 1002 and RAM 1003 are connected to each other via bus 1004. Processor 1001 performs various operations of the method flow according to the embodiment of the present disclosure by executing the program in ROM 1002 and / or RAM 1003. It should be noted that the program can also be stored in one or more memories other than ROM 1002 and RAM 1003. Processor 1001 can also perform various operations of the method flow according to the embodiment of the present disclosure by executing the program stored in one or more memories.

[0191] According to an embodiment of the present disclosure, the electronic device 1000 may further include an input / output (I / O) interface 1005, which is also connected to the bus 1004. The electronic device 1000 may further include one or more of the following components connected to the I / O interface 1005: an input portion 1006 including a keyboard, a mouse, etc.; an output portion 1007 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 1008 including a hard disk, etc.; and a communication portion 1009 including a network interface card such as a LAN card, a modem, etc. The communication portion 1009 performs communication processing via a network such as the Internet. A drive 1010 is also connected to the I / O interface 1005 as needed. A removable medium 1011, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 1010 as needed, so that a computer program read therefrom is installed into the storage portion 1008 as needed.

[0192] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present disclosure is implemented.

[0193] According to an embodiment of the present disclosure, a computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device. For example, according to an embodiment of the present disclosure, a computer-readable storage medium may include the ROM 1002 and / or RAM 1003 described above and / or one or more memories other than ROM 1002 and RAM 1003.

[0194] The embodiment of the present disclosure also includes a computer program product, which includes a computer program, and the computer program contains program code for executing the method shown in the flowchart. When the computer program product is run in a computer system, the program code is used to enable the computer system to implement the continuous laser single photon ranging method provided by the embodiment of the present disclosure.

[0195] The above functions defined in the system / device of the embodiment of the present disclosure are performed when the computer program is executed by the processor 1001. According to the embodiment of the present disclosure, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0196] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 1009, and / or installed from the removable medium 1010. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0197] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 1009, and / or installed from the removable medium 1011. When the computer program is executed by the processor 1001, the above functions defined in the system of the embodiment of the present disclosure are performed. According to the embodiment of the present disclosure, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0198] According to an embodiment of the present disclosure, the program code for executing the computer program provided by the embodiment of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0199] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0200] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0201] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A continuous laser single photon ranging method, comprising: Performing periodic modulation on the received continuous light wave to generate a target optical signal, wherein the target optical signal represents an optical signal reaching a target bandwidth; Transmitting the target optical signal to a target object and receiving an initial echo optical signal reflected from the target object; Converting the initial echo optical signal into an electrical pulse signal; measuring the output time of the electrical pulse signal and the cycle start time of the target light signal, wherein the cycle start time of the target light signal is characterized as the emission time of the target light signal; Performing signal processing at the output time of the electrical pulse signal to generate a target echo optical signal; Generating an initial delay time of the target echo light signal according to the waveform of the target echo light signal; The target distance is determined according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal.

2. The method according to claim 1, wherein: Converting the initial echo optical signal into an electrical pulse signal comprises: generating a photon loss probability value according to the initial echo light signal and the background light signal, wherein the initial echo light signal is composed of a plurality of echo photons, and the background light signal is composed of a plurality of noise photons; When the photon loss probability value meets a preset threshold, the initial echo light signal is converted into an electrical pulse signal.

3. The method according to claim 1, wherein: Performing signal processing at the output time of the electrical pulse signal to generate a target echo optical signal includes: For a cycle, according to the start time of the cycle, data preprocessing is performed on the output time to generate first time data; For multiple periods, merging the first time data in each period to generate second time data; Performing preliminary signal processing according to the second time data to generate an intermediate echo optical signal; Final signal processing is performed according to the intermediate echo optical signal to generate the target echo optical signal.

4. The method according to claim 3, wherein: Performing preliminary signal processing according to the second time data to generate an intermediate echo optical signal includes: Determining a first filtering rule according to a target bandwidth of the periodic modulation; generating a discrete sampling time domain signal according to the second time data; The discrete sampling time domain signal is filtered and converted using the first filtering rule to generate the intermediate echo optical signal.

5. The method according to claim 3, wherein: Performing final signal processing according to the intermediate echo optical signal to generate the target echo optical signal includes: Determining a second filtering rule according to the periodically modulated signal waveform; The intermediate echo optical signal is compressed using the second filtering rule to generate the target echo optical signal.

6. The method according to claim 1, wherein: Generating an initial delay time of the target echo light signal according to the waveform of the target echo light signal, comprising: Generate an echo photon time distribution probability function according to the waveform of the target echo light signal and the initial overall probability coefficient; Generate i probability values ​​according to the echo photon time distribution probability function and the time corresponding to the top i peak points in the target echo light signal, where i≥1 and i represents a preset value; The peak point time corresponding to the maximum probability value is selected to generate the initial delay time of the target echo optical signal.

7. The method according to claim 6, wherein: Determining a target distance according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal includes: Generate an estimated likelihood function according to the initial overall probability coefficient, the initial time delay and the echo photon time distribution probability function; Generating a target delay time of the target echo optical signal according to the estimated likelihood function; The target distance is determined according to the time difference between the target delay time and the cycle start time.

8. A continuous laser single photon ranging device, comprising: A modulation module, used for periodically modulating the received continuous light wave to generate a target optical signal, wherein the target optical signal represents an optical signal reaching a target bandwidth; A light receiving and transmitting module, used for transmitting the target light signal to the target object and receiving the initial echo light signal reflected from the target object; A single photon detector module, used for converting the initial echo light signal into an electrical pulse signal; A time measurement module, used for measuring the output time of the electrical pulse signal and the cycle start time of the target optical signal, wherein the cycle start time of the target optical signal is characterized as the emission time of the target optical signal; A signal processing module, used for performing signal processing at the output time of the electrical pulse signal to generate a target echo optical signal; A generating module, used for generating an initial delay time of the target echo light signal according to the waveform of the target echo light signal; A determination module is used to determine the target distance according to the initial delay time of the target echo optical signal and the cycle start time of the target optical signal.

9. A continuous laser single photon ranging device, comprising: A continuous laser emission component, a component configured to generate a continuous light wave; The continuous laser single photon ranging device according to claim 8 is configured as a device for receiving continuous light waves generated by a continuous laser emitting component.

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