Continuous laser single photon ranging method, device and equipment

Abstract

This disclosure provides a continuous laser single-photon ranging method, apparatus, and device, which can be applied in the field of lidar technology. The method includes: periodically modulating a received continuous light wave to generate a target light signal; transmitting the target light signal to a target object and receiving an 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 periodic start time of the target light signal, wherein the periodic start time of the target light signal represents the transmission 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 an initial delay time of the target echo light signal based on the waveform of the target echo light signal; and determining the target distance based on the initial delay time of the target echo light signal and the periodic start time of the target light signal.

Description

Technical Field

[0001] This disclosure relates to the field of lidar technology, and specifically to a continuous laser single-photon ranging method, apparatus, and equipment. Background Technology

[0002] Existing single-photon laser ranging technologies generally use narrow-pulse lasers as the light source. While narrow pulses improve ranging accuracy, the short pulse length means the system cannot support providing high-power pulses for a short period, and the pulse energy is insufficient for ranging requirements. To achieve a wider ranging range and higher measurement accuracy, it is necessary to simultaneously increase the single-pulse energy and reduce the laser pulse width. However, existing single-photon ranging technologies are limited by laser performance and cannot be further improved.

[0003] Furthermore, while narrower pulse widths and higher single-pulse energies can be achieved, innovative solutions such as detection methods based on nonlinear optical effects are constantly being researched and explored. However, these methods lead to more complex systems, lower efficiency, and their technological maturity is far from meeting practical requirements. Summary of the Invention

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

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

[0006] The received continuous light wave is periodically modulated to generate a target light signal, wherein the target light signal represents the light signal that reaches the target bandwidth;

[0007] The target light signal is emitted to the target object, and the initial echo light signal reflected from the target object is received;

[0008] The initial echo optical signal is converted into an electrical pulse signal;

[0009] The output time of the electrical pulse signal and the start time of the period of the target optical signal are measured, wherein the start time of the period of the target optical signal is characterized as the emission time of the target optical signal;

[0010] Signal processing is performed on the output time of the output electrical pulse signal to generate the target echo light signal;

[0011] The initial delay time of the target echo optical signal is generated based on the waveform of the target echo optical signal;

[0012] The target distance is determined based on the initial delay time of the target echo optical signal and the start time of the period of the target optical signal.

[0013] According to embodiments of this disclosure, converting the initial echo optical signal into an electrical pulse signal includes:

[0014] Based on the initial echo light signal and the background light signal, a photon loss probability value is generated, wherein the initial echo light signal is composed of multiple echo photons and the background light signal is composed of multiple noise photons;

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

[0016] According to embodiments of this disclosure, signal processing is performed at the output time of the output electrical pulse signal to generate a target echo light signal, including:

[0017] For a given period, based on the start time of the period, the output time is preprocessed to generate the first-time data;

[0018] For multiple periods, the first time data within each period is merged to generate the second time data;

[0019] Preliminary signal processing is performed based on the second time data to generate intermediate echo optical signals;

[0020] The target echo signal is generated by performing final signal processing based on the intermediate echo signal.

[0021] According to embodiments of this disclosure, the final signal processing based on the intermediate echo optical signal to generate the target echo optical signal includes:

[0022] The second filtering rule is determined based on the periodically modulated signal waveform;

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

[0024] According to embodiments of this disclosure, generating the initial delay time of the target echo optical signal based on the waveform of the target echo optical signal includes:

[0025] Based on the waveform of the target echo optical signal and the initial overall probability coefficient, generate the echo photon time distribution probability function;

[0026] Based on the probability function of the echo photon time distribution and the time corresponding to the i-th peak point in the target echo light signal, generate i probability values, where i≥1, and i represents a preset value;

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

[0028] According to embodiments of this disclosure, determining the target distance based on the initial delay time of the target echo optical signal and the start time of the period of the target optical signal includes:

[0029] Based on the initial overall probability coefficients, the initial delay time, and the echo photon time distribution probability function, an estimated likelihood function is generated;

[0030] Based on the estimated likelihood function, the target delay time of the target echo optical signal is generated;

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

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

[0033] The modulation module is used to periodically modulate the received continuous light wave to generate a target optical signal, wherein the target optical signal represents an optical signal that reaches the target bandwidth.

[0034] The light-emitting and receiving module is used to transmit the target light signal to the target object and receive the initial echo light signal reflected from the target object.

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

[0036] The time measurement module is used to measure the output time of the electrical pulse signal and the start time of the period of the target optical signal, wherein the start time of the period of the target optical signal is characterized as the emission time of the target optical signal;

[0037] The signal processing module is used to process the output electrical pulse signal at the output time to generate the target echo light signal;

[0038] The generation module is used to generate the initial delay time of the target echo optical signal based on the waveform of the target echo optical signal;

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

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

[0041] A continuous laser emitting component, configured to generate continuous light waves;

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

[0043] According to the continuous laser single-photon ranging method, apparatus, and equipment provided in this disclosure, the received continuous light wave is periodically modulated to generate a target light signal with the target bandwidth. This target light signal is then 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 based on the initial delay time of the target echo light signal and the start time of the target light signal's period. Since continuous light waves have a relatively long pulse width, periodic modulation of the emitted continuous light wave increases the signal bandwidth and power, thereby increasing the target light signal energy and thus improving the ranging range. Furthermore, the target light signal with the target bandwidth improves measurement accuracy. Simultaneously, signal processing of the echo light signal yields the target echo light signal, resulting in a more accurate delay time. Calculating the target distance with precise time resolution further improves measurement accuracy, solving the problem that single-photon ranging cannot simultaneously improve ranging range and accuracy. Attached Figure Description

[0044] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0045] Figure 1 A flowchart illustrating a continuous laser single-photon ranging method according to an embodiment of the present disclosure is shown schematically.

[0046] Figure 2 This diagram schematically illustrates an application scenario of the continuous laser single-photon ranging method according to embodiments of the present disclosure.

[0047] Figure 3 A flowchart illustrating the generation of a target echo optical signal according to an embodiment of the present disclosure is shown schematically;

[0048] Figure 4 A schematic diagram illustrating the generation of first-time data according to an embodiment of the present disclosure is shown.

[0049] Figure 5 A schematic diagram illustrating the generation of second time data according to an embodiment of the present disclosure is shown.

[0050] Figure 6 A schematic diagram illustrating the generation of an intermediate echo optical signal according to an embodiment of the present disclosure is shown.

[0051] Figure 7 A schematic diagram illustrating the generation of a target echo optical signal according to an embodiment of the present disclosure is shown.

[0052] Figure 8 A schematic block diagram of a continuous laser single-photon ranging device according to an embodiment of the present disclosure is shown.

[0053] Figure 9 A block diagram schematically illustrates an apparatus suitable for implementing a continuous laser single-photon ranging method according to embodiments of the present disclosure; and

[0054] Figure 10 A block diagram schematically illustrates an electronic device suitable for implementing a continuous laser single-photon ranging method according to an embodiment of the present disclosure. Detailed Implementation

[0055] The embodiments of the present disclosure will now 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 disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0056] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

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

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

[0059] In the process of realizing this disclosure, it was discovered that existing single-photon laser ranging technology generally uses narrow-pulse lasers as light sources. Although narrow pulses improve ranging accuracy, the pulses are too short, and the system cannot support providing high peak power pulses in a short time. 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, embodiments of the present disclosure provide a continuous laser single-photon ranging method, a continuous laser single-photon ranging device, and an apparatus. The method includes: periodically modulating a received continuous light wave to generate a target light signal; transmitting the target light signal to a target object and receiving an 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 periodic start time of the target light signal, wherein the periodic start time of the target light signal represents the transmission 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 an initial delay time of the target echo light signal based on the waveform of the target echo light signal; and determining the target distance based on the initial delay time of the target echo light signal and the periodic start time of the target light signal.

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

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

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

[0064] In operation S110, the received continuous light wave is periodically modulated to generate a target light signal, wherein the target light signal represents the light signal that reaches the target bandwidth.

[0065] According to embodiments of this disclosure, signal periodic modulation refers to controlling the switching devices of the inverter circuit to turn on and off according to the signal change pattern and signal waveform, thereby changing the signal bandwidth by changing the frequency and amplitude of the modulated signal wave.

[0066] According to embodiments of this disclosure, the modulation method includes the equal area method, hardware modulation method, software generation method, etc.

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

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

[0069] According to embodiments of this disclosure, pulse energy may include the product of power and pulse width.

[0070] According to embodiments of this disclosure, the continuous light wave has a relatively long pulse time, and the modulated light signal power is amplified by a power amplifier to obtain the light signal of the target energy, thereby meeting the requirements of the detection range.

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

[0072] According to embodiments of this disclosure, a received continuous light wave is periodically modulated to generate an optical signal that reaches the target bandwidth.

[0073] According to embodiments of this disclosure, the target optical signal characterization has two attributes: target bandwidth and target energy.

[0074] According to embodiments of this disclosure, optionally, polarization modulation can be performed on the received continuous light wave to generate a target light signal.

[0075] In operation S120, the target optical signal is emitted to the target object, and the 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 embodiments of this disclosure, a single-photon detector is used to detect the initial echo light signal and convert the initial echo light signal into an electrical pulse signal.

[0078] According to embodiments of this disclosure, alternatively, various existing single-photon detectors may be 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 start time of the period of the target optical signal are measured, wherein the start time of the period of the target optical signal is characterized as the emission time of the target optical signal.

[0080] According to embodiments of this disclosure, methods for measuring and recording the output time of the electrical pulse signal output by a single-photon detector include methods such as dedicated time-to-digital converter (TDC) and implementation based on a field-programmable gate array (FPGA), but are not limited thereto.

[0081] According to embodiments of this disclosure, the start time of the cycle is obtained by synchronizing the modulation module and the time measurement module, that is, the target optical signal is transmitted to the target object, and the synchronization signal of the transmission time is transmitted and recorded as the start time of the cycle of the target optical signal.

[0082] During operation S150, signal processing is performed at the output time of the output electrical pulse signal to generate the target echo light signal.

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

[0084] In operation S160, the initial delay time of the target echo optical signal is generated based on the waveform of the target echo optical signal.

[0085] According to embodiments of this disclosure, the initial delay time characterizes the time from the emitted target optical signal to the reception of the initial echo optical signal, thus initially obtaining the delay caused by the target object.

[0086] In operation S170, the target distance is determined based on the initial delay time of the target echo optical signal and the start time of the period of the target optical signal.

[0087] According to embodiments of this disclosure, by further optimizing the initially obtained initial delay time, a more accurate delay time 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 time and the periodic start time of the target optical signal.

[0088] According to embodiments of this disclosure, a received continuous light wave is periodically modulated to generate a target optical signal with target bandwidth and target energy. The target optical signal is then transmitted to the target object, and the initial echo light signal reflected from the target object is received. This initial echo light signal is then converted into an electrical pulse signal. Based on the measured output time of the electrical pulse signal, signal processing is performed to obtain the target echo light signal. The initial delay time of the target echo light signal is then obtained based on its waveform. Finally, the target distance is calculated based on the time difference between the initial delay time and the start time of the period of the target optical signal. Since continuous light waves have a relatively long pulse width, periodic modulation of the emitted continuous light wave increases the signal bandwidth and power, thereby increasing the target optical signal energy and thus improving the ranging range. Furthermore, the target optical signal with the target bandwidth improves measurement accuracy. Simultaneously, signal processing of the echo light signal yields the target echo light signal, resulting in a more accurate delay time. Calculating the target distance with precise time resolution further improves measurement accuracy, solving the problem that single-photon ranging cannot simultaneously improve ranging range and accuracy.

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

[0090] like Figure 2 As shown, in one embodiment, the method for measuring the start time of the period further includes obtaining the start time of the period by adding a reference optical path. The modulation module 210 periodically modulates the received continuous light wave to generate a target light signal. A portion of the output target light signal is split and enters the single-photon detector A module 230, while the other portion of the beam is emitted to the target object by the receiving and emitting module 220. The receiving and emitting module 220 receives the initial echo light signal reflected from the target object, and the single-photon detector B module 240 converts the initial echo light signal into an electrical pulse signal. The time measurement module 250 simultaneously measures and records the times 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 data of the single-photon detector A channel is the start time of the period.

[0091] According to embodiments of this disclosure, converting an initial echo optical signal into an electrical pulse signal includes:

[0092] Based on the initial echo light signal and the background light signal, a photon loss probability value is generated, wherein the initial echo light signal is composed of multiple echo photons and the background light signal is composed of multiple noise photons;

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

[0094] According to embodiments of this disclosure, during the process of a single-photon detector receiving echo light signals (i.e., receiving multiple echo photons), echo photons will be lost due to a certain dead time during which the echo light signals cannot be received.

[0095] According to embodiments of this disclosure, dead time refers to the time during which a single-photon detector no longer responds to new echo signals after receiving one echo photon count.

[0096] According to embodiments of this disclosure, the photon loss probability value P loss The probability of losing echo photons within the dead time is represented by the formula shown in (1):

[0097]

[0098] Where, n e and n b T represents the number of echo photons and noise photons received by the single-photon detector per unit time, respectively; η represents the existing efficiency value of the single-photon detector; and T represents the noise photon. d The dead time is represented by k, which represents the number of echo photons received within the dead time.

[0099] According to embodiments of this disclosure, a single-photon detector can filter out the weak initial echo signal and background light signal using a narrowband filter, therefore n e and n b The value is relatively small, i.e., k = 2.

[0100] According to embodiments of this disclosure, the preset threshold is 0.2, that is, when the photon loss probability value satisfies P... loss ≤0.2, converting the received initial echo optical signal into an electrical pulse signal.

[0101] According to embodiments of this disclosure, when the photon loss probability value meets a preset threshold, the initial echo signal is converted into an electrical pulse signal, thereby controlling the number of lost echo photons within the dead time to be low, and thus improving the accuracy of the initial echo signal.

[0102] Figure 3 The flowchart illustrates a process for generating a target echo light signal by performing signal processing at the output time of an output electrical pulse signal according to an embodiment of the present disclosure.

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

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

[0105] Figure 4 A schematic diagram illustrating the generation of first-time data according to an embodiment of the present disclosure is shown.

[0106] like Figure 4 As shown, according to an embodiment of this disclosure, within one cycle, the output time data of the single-photon detector output electrical pulse signal are truncated and arranged according to the start time of the cycle to generate first time data, where 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 one cycle, that cycle is discarded.

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

[0108] Figure 5 A schematic diagram illustrating the generation of second time data according to an embodiment of the present disclosure is shown.

[0109] like Figure 5 As shown, according to the embodiments of this disclosure, the first time data corresponding to each cycle that are the same or similar are merged, that is, the first time data of multiple cycles are merged to generate the second time data, wherein the horizontal axis X represents the output time and the vertical axis Y represents the amplitude value.

[0110] According to embodiments of this disclosure, by extracting and arranging the output time data of the single-photon detection output electrical pulse signal in each cycle, and then merging the data of multiple cycles, the amount of usable data of the output time of the output electrical pulse signal is increased, thereby improving the ranging accuracy.

[0111] In step S330, the first filtering rule is determined based on the target bandwidth of the periodic modulation.

[0112] According to embodiments of this disclosure, based on the target bandwidth of the periodic modulation, for example, the target bandwidth range is 20M-25M, the first filtering rule is to satisfy the signal bandwidth range of 20M-25M.

[0113] In step S340, a discrete sampled time-domain signal is generated based on the second time data.

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

[0115] Figure 6 A schematic diagram illustrating the generation of an intermediate echo optical signal according to an embodiment of the present disclosure is shown.

[0116] like Figure 6As shown, according to an embodiment of this disclosure, a discrete sampling time-domain signal is established based on second time data. Under the first filtering rule, the discrete sampling time-domain signal is filtered using a filter to remove signals that do not meet the bandwidth range. Then, the filtered discrete sampling time-domain signal is subjected to waveform conversion processing to generate an intermediate echo optical signal. Here, the horizontal axis X represents the output time, and the vertical axis Y represents the amplitude value.

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

[0118] According to embodiments of this disclosure, based on the periodically modulated signal waveform, for example, if the signal waveform is a sine wave, then 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 the target echo optical signal.

[0120] Figure 7 A schematic diagram illustrating the generation of a target echo optical signal according to an embodiment of the present disclosure is shown.

[0121] like Figure 7 As shown, in one embodiment, under the second filtering rule, the intermediate echo optical signal is compressed using a filter, that is, only the intermediate echo optical signal with a sine wave waveform is compressed to generate the target echo optical signal, wherein the horizontal axis X represents the output time and the vertical axis Y represents the amplitude value.

[0122] According to embodiments of this disclosure, signal compression refers to compressing a wide pulse signal into a narrow pulse signal.

[0123] According to embodiments of this disclosure, by performing final signal processing on the intermediate echo optical signal, the intermediate echo optical signal with a wide pulse is compressed into a narrow pulse signal to obtain the target echo optical signal, thereby obtaining sufficiently high range resolution and time resolution.

[0124] According to embodiments of this disclosure, generating the initial delay time of the target echo optical signal based on the waveform of the target echo optical signal includes:

[0125] Based on the waveform of the target echo optical signal and the initial overall probability coefficient, generate the echo photon time distribution probability function;

[0126] Based on the probability function of the echo photon time distribution and the time corresponding to the i-th peak point in the target echo light signal, generate i probability values, where i≥1, and i represents a preset value;

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

[0128] According to an embodiment of this disclosure, the waveform of the target echo optical signal has multiple peak points. The time corresponding to the peak point ranked i is selected, that is, the time of generating i peak points is generated.

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

[0130] According to an embodiment of this 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 time.

[0133] According to embodiments of this disclosure, the probability value corresponding to each peak point time, i.e., i probability values, is obtained based on the probability function of the time distribution of echo photons at each peak point time.

[0134] According to embodiments of this disclosure, the peak time corresponding to the highest probability value is selected to generate the initial delay time of the target echo optical signal. Within the time corresponding to a higher probability value, the single-photon detector receives a larger number of echo photons, indicating higher time resolution and higher ranging accuracy.

[0135] According to embodiments of this disclosure, determining the target distance based on the initial delay time of the target echo optical signal and the start time of the period of the target optical signal includes:

[0136] Based on the initial overall probability coefficients, the initial delay time, and the echo photon time distribution probability function, an estimated likelihood function is generated;

[0137] Based on the estimated likelihood function, the target delay time of the target echo optical signal is generated;

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

[0139] According to embodiments of this disclosure, an estimated likelihood function is generated based on the initial overall probability coefficient, the initial delay time, and the echo photon time distribution probability function. The two parameters, the initial overall probability coefficient and the initial delay time, are iteratively updated continuously, and finally the target delay time is generated.

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

[0141]

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

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

[0144] Based on the above-described continuous laser single-photon ranging method, this disclosure also provides a continuous laser single-photon ranging device. The following will be combined with... Figure 8 The device is described in detail.

[0145] Figure 8 A schematic block diagram of a continuous laser single-photon ranging device according to an embodiment of the present disclosure is 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 light wave to generate a target optical signal, wherein the target optical signal represents an optical signal that reaches a target bandwidth. In one embodiment, the modulation module 810 can be used to perform the operation S110 described above, which will not be repeated 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 repeated 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 repeated here.

[0150] The time measurement module 840 is used to measure the output time of the electrical pulse signal and the start time of the period of the target optical signal, wherein the start time of the period of the target optical signal is characterized as the emission time of the target optical 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 process the output electrical pulse signal at the output time to generate the 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 repeated here.

[0152] The generation module 860 is used to generate the initial delay time of the target echo optical signal based on the waveform of the target echo optical signal. In one embodiment, the generation module 860 can be used to perform the operation S160 described above, which will not be repeated here.

[0153] The determination module 870 is used to determine the target distance based on the initial delay time of the target echo optical signal and the start time of the period 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 repeated here.

[0154] According to embodiments of this disclosure, the single-photon detector module 830 includes a first generation unit and a first conversion unit.

[0155] The first generation unit is used to generate a photon loss probability value based on the initial echo light signal and the background light signal, wherein the initial echo light signal is composed of multiple echo photons and the background light signal is composed of multiple noise photons.

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

[0157] According to embodiments of this disclosure, the signal processing module 850 includes a first generation submodule, a second generation submodule, a third generation submodule, and a fourth generation submodule.

[0158] The first generation submodule is used to preprocess the output time based on the start time of the cycle to generate the first time data for a given period.

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

[0160] The third generation submodule is used to perform preliminary signal processing based on the second time data to generate intermediate echo optical signals.

[0161] The fourth generation submodule is used to perform final signal processing based on the intermediate echo optical signal to generate the target echo optical signal.

[0162] According to embodiments of this disclosure, the third generation submodule includes a second generation unit, a third generation unit, and a fourth generation unit.

[0163] The second generation unit is used to determine the first filtering rule based on the target bandwidth of the periodic modulation.

[0164] The third generation unit is used to generate discrete sampled time-domain signals based on the second time data.

[0165] The fourth generation unit is used to filter and transform the discrete sampled time-domain signal using the first filtering rule to generate the intermediate echo optical signal.

[0166] According to embodiments of this disclosure, the fourth generation submodule includes a fifth generation unit and a sixth generation unit.

[0167] The fifth generation unit is used to determine the second filtering rule based on the periodically modulated signal waveform.

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

[0169] According to embodiments of this disclosure, generation module 860 includes a fifth generation submodule, a sixth generation submodule, and a seventh generation submodule.

[0170] The fifth generation submodule is used to generate the echo photon time distribution probability function based on 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 ​​based on the echo photon time distribution probability function and the time corresponding to the i-th peak point in the target echo light 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 and generate the initial delay time of the target echo optical signal.

[0173] According to embodiments of this disclosure, the determining module 870 includes a seventh generating submodule, an eighth generating submodule, and a target distance determining submodule.

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

[0175] The eighth generation submodule is used to generate the target delay time of the target echo optical signal based on the estimated likelihood function.

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

[0177] According to embodiments of this disclosure, any plurality of modules among the modulation module 810, the light-emitting 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 combined into one module, or any one of these modules can be split into multiple modules. Alternatively, at least a portion of the functionality of one or more of these modules can be combined with at least a portion of the functionality of other modules and implemented in one module. According to embodiments of this disclosure, at least one of the modulation module 810, the light-emitting 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 hardware circuitry, 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-package, an application-specific integrated circuit (ASIC), or implemented in hardware or firmware by any other reasonable means of integrating or packaging the circuitry, or implemented in any one of software, hardware, and firmware methods, or in a suitable combination of any of these methods. Alternatively, at least one of the modulation module 810, the light-emitting 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 may be at least partially implemented as a computer program module, which can perform corresponding functions when the computer program module is run.

[0178] Figure 9 A block diagram schematically illustrates an apparatus suitable for implementing a continuous laser single-photon ranging method according to an embodiment of the present disclosure.

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

[0180] According to an embodiment of this disclosure, a continuous laser emitting component 910 is configured to generate a continuous light wave, and a continuous laser single-photon ranging device 800 receives the continuous light wave generated by the continuous laser emitting component.

[0181] The modulation module 810 is used to periodically modulate the received continuous light wave to generate a target optical signal, wherein the target optical signal represents an optical signal that reaches the target bandwidth.

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

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

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

[0185] The signal processing module 850 is used to process the output electrical pulse signal at the output time to generate the target echo light signal.

[0186] The generation module 860 is used to generate the initial delay time of the target echo optical signal based on the waveform of the target echo optical signal.

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

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

[0189] like Figure 10 As shown, an 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 portion 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 an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1001 may also include 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] RAM 1003 stores various programs and data required for the operation of electronic device 1000. Processor 1001, ROM 1002, and RAM 1003 are interconnected via bus 1004. Processor 1001 performs various operations of the method flow according to embodiments of the present disclosure by executing programs in ROM 1002 and / or RAM 1003. It should be noted that programs may also be stored in one or more memories other than ROM 1002 and RAM 1003. Processor 1001 may also perform various operations of the method flow according to embodiments of the present disclosure by executing programs stored in one or more memories.

[0191] According to embodiments of this disclosure, the electronic device 1000 may further include an input / output (I / O) interface 1005, which is also connected to a bus 1004. The electronic device 1000 may also include one or more of the following components connected to the I / O interface 1005: an input section 1006 including a keyboard, mouse, etc.; an output section 1007 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 1008 including a hard disk, etc.; and a communication section 1009 including a network interface card such as a LAN card, modem, etc. The communication section 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 disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 1010 as needed so that computer programs read from it can be installed into the storage section 1008 as needed.

[0192] This disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of this disclosure.

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

[0194] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code is used to enable the computer system to implement the continuous laser single-photon ranging method provided in the embodiments of this disclosure.

[0195] When the computer program is executed by the processor 1001, it performs the functions defined in the system / apparatus of this disclosure embodiments. According to embodiments of this disclosure, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

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

[0197] In such an embodiment, the computer program can be downloaded and installed from a network via communication section 1009, and / or installed from removable medium 1011. When the computer program is executed by processor 1001, it performs the functions defined in the system of this disclosure embodiment. According to embodiments of this disclosure, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0198] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can execute entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0199] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0200] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0201] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A continuous laser single-photon ranging method, comprising: The received continuous light wave is periodically modulated to generate a target optical signal, wherein the target optical signal represents an optical signal that reaches the target bandwidth; The target optical signal is emitted to the target object, and the initial echo optical signal reflected from the target object is received; The initial echo optical signal is converted into an electrical pulse signal; The output time of the electrical pulse signal and the start time of the period of the target optical signal are measured, wherein the start time of the period of the target optical signal is characterized as the emission time of the target optical signal; For a given period, based on the start time of the period, the output time is preprocessed to generate first time data; For multiple periods, the first time data within each period is merged to generate the second time data; Based on the target bandwidth of the periodic modulation, a first filtering rule is determined; Based on the second time data, a discrete sampled time-domain signal is generated; The discrete sampled time-domain signal is filtered and converted using the first filtering rule to generate an intermediate echo optical signal. Based on the periodically modulated signal waveform, determine the second filtering rule; The intermediate echo optical signal is compressed using the second filtering rule to generate the target echo optical signal; Based on the waveform of the target echo optical signal, the initial delay time of the target echo optical signal is generated; The target distance is determined based on the initial delay time of the target echo optical signal and the start time of the period of the target optical signal.

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

3. The method according to claim 1, wherein, Based on the waveform of the target echo optical signal, the initial delay time of the target echo optical signal is generated, including: Based on the waveform of the target echo optical signal and the initial overall probability coefficient, generate the echo photon time distribution probability function; Based on the echo photon time distribution probability function and the times corresponding to the top i peak points in the target echo signal, i probability values ​​are generated, where, , i represents the preset value; The peak time corresponding to the maximum probability value is selected to generate the initial delay time of the target echo optical signal.

4. The method according to claim 3, wherein, Determining the target distance based on the initial delay time of the target echo optical signal and the start time of the period of the target optical signal includes: Based on the initial overall probability coefficient, the initial delay time, and the echo photon time distribution probability function, an estimated likelihood function is generated; Based on the estimated likelihood function, the target delay time of the target echo optical signal is generated; The target distance is determined based on the time difference between the target delay time and the start time of the period.

5. A continuous laser single-photon ranging device, comprising: A modulation module is used to periodically modulate the received continuous light wave to generate a target optical signal, wherein the target optical signal represents an optical signal that reaches a target bandwidth. The light-emitting module is used to transmit the target light signal to the target object and receive the initial echo light signal reflected from the target object. A single-photon detector module is used to convert the initial echo optical signal into an electrical pulse signal; A time measurement module is used to measure the output time of the electrical pulse signal and the start time of the period of the target optical signal, wherein the start time of the period of the target optical signal is characterized as the emission time of the target optical signal; The signal processing module is used to perform signal processing at the output time of the output electrical pulse signal to generate the target echo light signal. The signal processing module includes a first generation submodule, a second generation submodule, a third generation submodule and a fourth generation submodule. The first generation submodule is used to perform data preprocessing on the output time according to the start time of the cycle for a period, and generate first time data. The second generation submodule is used to merge the first time data in each of multiple periods to generate second time data. The third generation submodule is used to perform preliminary signal processing based on the second time data to generate an intermediate echo optical signal. The third generation submodule includes a second generation unit, a third generation unit, and a fourth generation unit. The second generation unit is used to determine the first filtering rule based on the target bandwidth of the periodic modulation. The third generation unit is used to generate a discrete sampled time-domain signal based on the second time data; The fourth generation unit is used to filter and transform the discrete sampled time-domain signal using the first filtering rule to generate the intermediate echo optical signal; The fourth generation submodule is used to perform final signal processing based on the intermediate echo optical signal to generate the target echo optical signal. The fourth generation submodule includes a fifth generation unit and a sixth generation unit. The fifth generation unit is used to determine the second filtering rule based on the periodically modulated signal waveform; The sixth generation unit is used to compress the intermediate echo optical signal using the second filtering rule to generate the target echo optical signal; The generation module is used to generate the initial delay time of the target echo optical signal based on the waveform of the target echo optical signal; The determination module is used to determine the target distance based on the initial delay time of the target echo optical signal and the period start time of the target optical signal.

6. A continuous laser single-photon ranging device, comprising: A continuous laser emitting component, configured to generate continuous light waves; The continuous laser single-photon ranging device according to claim 5 is configured to receive continuous light waves generated by a continuous laser emitting component.

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