Time-of-flight measurement method, apparatus and time-of-flight depth camera

Abstract

The application is suitable for the field of optical measurement technology, and provides a time-of-flight measurement method, device and time-of-flight depth camera, wherein the method comprises: for a to-be-measured object irradiated by a modulated continuous carrier light beam, a plurality of signal acquisition components are sequentially started according to a preset sampling time length in a detection sampling period, so as to respectively acquire corresponding gray sampling information; a sampling interference factor respectively corresponding to each signal acquisition component is acquired; and a time of flight corresponding to the to-be-measured object is determined according to the sampling interference factor of each signal acquisition component and the corresponding gray sampling information. Thus, the sampling interference factor respectively corresponding to each signal acquisition component can be directly calibrated without performing a split exposure sampling operation, so that the same depth signal does not need to be exposed for multiple times, and the measurement frame rate can be greatly improved.

Description

Technical Field

[0001] This application relates to the field of optical measurement technology, and in particular to a time-of-flight measurement method, apparatus and time-of-flight depth camera. Background Technology

[0002] Time-of-Flight (ToF) ranging is a technique that achieves precise distance measurement by measuring the round-trip time of a light pulse between a transmitting / receiving device and a target object. In ToF technology, the technique that directly measures the time of flight of light is called dToF (direct-TOF); the technique that periodically modulates the emitted light signal, measures the phase delay of the reflected light signal relative to the emitted light signal, and then calculates the time of flight from the phase delay is called iToF (indirect-TOF). Based on the modulation and demodulation type, it can be divided into continuous wave (CW) modulation and demodulation methods and pulse modulation (PM) modulation and demodulation methods.

[0003] Currently, the measurement distance of PM-iToF modulation technology is limited by the pulse width of the modulation and demodulation signal. When long-distance measurement is required, the pulse width of the modulation and demodulation signal needs to be extended. However, extending the pulse width of the modulation and demodulation signal will lead to increased power consumption and decreased measurement accuracy, thus failing to meet market demands.

[0004] In addition, CW-iToF technology is mainly used in measurement systems built on multi-tap sensors. The core measurement algorithm is a modulation and demodulation method with different phases, which requires simultaneous periodic sampling and exposure sampling. Exposure sampling can eliminate measurement errors caused by sampling interference factors, but it also requires multiple exposures of the same depth signal, resulting in a low frame rate.

[0005] There is currently no good solution in the industry to address the above problems. Summary of the Invention

[0006] In view of this, embodiments of this application provide a time-of-flight measurement method, apparatus, and time-of-flight depth camera to at least solve the problem of low measurement frame rate in current CW-iToF technology.

[0007] A first aspect of this application provides a time-of-flight measurement method, comprising: sequentially activating multiple signal acquisition components for a test object irradiated by a modulated continuous carrier beam, according to a preset sampling time length in a detection sampling period, to acquire corresponding grayscale sampling information respectively; obtaining the sampling interference factor corresponding to each of the signal acquisition components; and determining the time of flight for the test object based on the sampling interference factor of each of the signal acquisition components, the sampling time length, and the corresponding grayscale sampling information.

[0008] A second aspect of this application provides a time-of-flight measurement device, comprising: a grayscale sampling control unit configured to sequentially activate multiple signal acquisition components for a test object irradiated by a modulated continuous carrier beam, according to a preset sampling time length in a detection sampling period, to acquire corresponding grayscale sampling information respectively; a sampling interference factor acquisition unit configured to acquire the sampling interference factor corresponding to each of the signal acquisition components; and a time-of-flight determination unit configured to determine the time of flight for the test object based on the sampling interference factor of each of the signal acquisition components, the sampling time length, and the corresponding grayscale sampling information.

[0009] A third aspect of this application provides a time-of-flight depth camera, comprising: a transmitting module including a light source and a light modulator, the light modulator being used to control the light source to emit a modulated continuous carrier beam toward a test object; a receiving module including an image sensor composed of at least one pixel, each pixel including multiple signal acquisition components for receiving light signals reflected back from the test object; and a control module connected to the transmitting module and the receiving module, configured to: sequentially activate multiple signal acquisition components according to a preset sampling time length in a detection sampling period for the test object illuminated by the modulated continuous carrier beam, so as to acquire corresponding grayscale sampling information respectively; obtain the sampling interference factor corresponding to each of the signal acquisition components; and determine the flight time for the test object based on the sampling interference factor of each of the signal acquisition components, the sampling time length, and the corresponding grayscale sampling information.

[0010] A fourth aspect of this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described above.

[0011] A fifth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method described above.

[0012] A sixth aspect of this application provides a computer program product that, when run on an electronic device, causes the electronic device to perform the steps of the method described above.

[0013] The beneficial effects of the embodiments in this application compared with the prior art are:

[0014] Through the embodiments of this application, when different signal acquisition components acquire corresponding grayscale sampling information of the subject, the sampling interference factor corresponding to each signal acquisition component can be used for direct calibration without performing separate exposure sampling operations. This eliminates the need for multiple exposures of the same depth signal, which can significantly improve the measurement frame rate. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram illustrating the structural principle of an example depth camera according to an embodiment of this application is shown;

[0017] Figure 2 The diagram shows an example of the tap sampling signal distribution in a multi-tap charge integration ranging operation in a CW-iToF system based on current related technologies.

[0018] Figure 3 A flowchart illustrating an example of a time-of-flight measurement method according to an embodiment of this application is shown;

[0019] Figure 4 A flowchart illustrating an example of updating the sampling time length of each signal acquisition component according to an embodiment of this application is shown;

[0020] Figure 5 A structural block diagram of an example of a time-of-flight measuring device according to an embodiment of this application is shown;

[0021] Figure 6 This is a schematic diagram of an example of an electronic device according to an embodiment of this application. Detailed Implementation

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0023] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0024] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0025] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] Figure 1 A schematic diagram illustrating the structural principle of an example time-of-flight depth camera according to an embodiment of this application is shown.

[0027] like Figure 1 As shown, the time-of-flight depth camera 10 includes a transmitting module 11, a receiving module 12, and a control module 13, with the control module 13 connected to both the transmitting module 11 and the receiving module 12. Here, the transmitting module 11 transmits an optical signal (e.g., a modulated continuous carrier beam) 102 to the object under test 20. The receiving module 12 receives the optical signal 103 reflected back from the object under test 20. The control module 13 calculates the distance 104 between the reflected optical signal and the object under test 20. In some cases, the control module 13 can also regulate the sampling operation of the receiving module 12, such as adjusting the sampling period, to meet the needs of different measurement scenarios.

[0028] It should be understood that the time-of-flight depth camera 10 may also include devices such as a color camera, an infrared camera, and an IMU. Combining these devices can enable richer functions, such as 3D texture modeling, infrared face recognition, and SLAM.

[0029] In some embodiments, the transmitting module 11 may include a light source (not shown) and a light modulator (not shown), the light modulator controlling the light source to emit a modulated continuous carrier beam toward the object under test 20. Furthermore, the receiving module 12 may include an image sensor consisting of at least one pixel, and each pixel includes multiple signal acquisition components. Here, the signal acquisition components may refer to components that acquire optical signals; they may be devices for readout and charge accumulation, for example, the signal acquisition components may employ taps.

[0030] Specifically, the time-of-flight depth camera 10 can employ an indirect time-of-flight measurement method. It can modulate the power waveform of the emitted light to a near-sine wave, and the demodulation device (e.g., an i-TOF sensor) integrates the power of the received light at different time intervals. Generally, the demodulation device will have several different acquisition time intervals; this time-segmented acquisition of the echo sinusoidal signal is equivalent to multi-point sampling of the sinusoidal signal. Furthermore, the demodulation device outputs multiple sampled values ​​of the echo sinusoidal signal, enabling the control module 13 to calculate the phase value of the echo sinusoidal signal and compare it with the phase value of the emitted sinusoidal signal to obtain the flight distance of the light signal between the time-of-flight depth camera 10 and the object 20.

[0031] Generally, demodulation energy integrators share the same pixel (i.e., photodiode or other photosensitive element) when performing photon integration. For example, several different readout and charge accumulation devices (called taps) are connected to the same pixel. During time-division multiplexing of signals, the signal gain and dark current of different taps are inconsistent. Simultaneously, it is necessary to sample the sine wave signal for different time periods, including periodic sampling (i.e., multiple taps sample within one period) and exposure-division sampling (i.e., the sampling time of the taps is phase-delayed at different exposure times).

[0032] It should be noted that in periodic sampling, the time-division sampling method using multiple taps within a single period often fails to accurately calculate the distance traveled by light due to inconsistencies in sampling interference factors (e.g., gain and dark current) among different taps. In this case, by using a multi-exposure sampling method, the same tap is sampled multiple times, and the data from these multiple samplings are used for addition, subtraction, multiplication, and division operations. This eliminates the influence of sampling interference factors, ultimately improving the accuracy of distance measurement.

[0033] However, split-exposure sampling requires multiple exposures of the same depth signal, which increases the exposure time for calculating a single depth and reduces the frame rate.

[0034] Figure 2The diagram shows an example of the tap sampling signal distribution in CW-iToF for charge integration ranging using multiple taps according to current related technologies.

[0035] like Figure 2 As shown, in current related technologies, in addition to needing a grayscale image obtained based on periodic sampling, another grayscale image obtained based on exposure sampling is also required. That is, two grayscale images are needed to calculate a depth map, which reduces the frame rate of the measurement system.

[0036] In view of this, Figure 3 A flowchart illustrating an example of a time-of-flight measurement method according to an embodiment of this application is shown. The implementing entity of this embodiment can be various measurement systems or processors with calculation or processing functions, such as the control module 13 in the time-of-flight depth camera 10.

[0037] like Figure 3 As shown, in step 310, for the test object illuminated by the modulated continuous carrier beam, multiple signal acquisition components are sequentially activated according to the preset sampling time length in the detection sampling period to acquire the corresponding grayscale sampling information respectively.

[0038] For example, the signal acquisition components within a pixel can be sequentially activated and can each run for a separate sampling time to acquire corresponding grayscale sampling information. Furthermore, each signal acquisition component can have the same sampling time; for instance, a pixel may have four taps, assuming the detection sampling period is... T Then the sampling time length of each signal acquisition component can be T / 4 or other values.

[0039] It should be noted that the sampling time of each signal acquisition component can be non-fixed, and can be adjusted according to different business scenarios or needs.

[0040] In step 320, the sampling interference factor corresponding to each signal acquisition component is obtained.

[0041] It should be noted that the sampling interference factor can be any factor that can interfere with the sampling process of the signal acquisition component, such as tap gain and dark current.

[0042] In one example of this application embodiment, the measurement system stores pre-calibrated (e.g., factory-calibrated) sampling interference factors for each tap in its setting storage space. The corresponding sampling interference factors can be obtained by reading this setting storage space. In another example of this application embodiment, the measurement system can receive user-defined sampling interference factors from a user terminal.

[0043] In step 330, the flight time of the corresponding test object is determined based on the sampling interference factor of each signal acquisition component and the corresponding grayscale sampling information.

[0044] Through the embodiments of this application, calibration can be performed directly using the sampling interference factors corresponding to each signal acquisition component, without the need for separate exposure sampling operations to eliminate errors caused by sampling interference factors at different taps. This allows measurement to be completed using a single frame depth image, thereby improving the measurement frame rate without reducing ranging accuracy.

[0045] In some implementations, after step 330, the measurement system may also determine the distance to the object being measured based on the flight time for the object.

[0046] For example, the distance between the measurement system and the object to be measured can be determined by the following formula:

[0047] Equation (1)

[0048] in, d The distance between the object being measured and the test object. C At the speed of light, t For flight time.

[0049] Regarding the implementation details of step 310 above, for the test object illuminated by a continuous carrier beam corresponding to a single exposure time, multiple signal acquisition components are sequentially activated according to a preset sampling time length in the detection sampling period to acquire corresponding grayscale sampling information. Therefore, the light flight time can be directly calculated in a single frame through a single exposure operation with corresponding periodic sampling.

[0050] Figure 4 A flowchart illustrating an example of updating the sampling time length of each signal acquisition component according to an embodiment of this application is shown.

[0051] like Figure 4 As shown, in step 410, a sampling duration setting instruction is obtained. For example, the measurement system can receive the sampling duration setting instruction from a user terminal.

[0052] In step 420, the sampling time length of each signal acquisition component is reset according to the updated sampling time length in the sampling duration setting instruction. This allows for adjustment of the sampling time length of the signal acquisition components in the measurement system to meet the needs of different users or business scenarios.

[0053] In some examples of embodiments of this application, the gain and dark current of each tap in the measurement system can be pre-calibrated at the factory, so that the time of light flight can be directly calculated using a single frame image, thereby improving the measurement frame rate without reducing the accuracy of ranging.

[0054] Regarding the implementation details of step 330 above, the grayscale sampling information, sampling time length and sampling interference factor corresponding to each signal acquisition component can be substituted into the preset time delay calculation formula to obtain the corresponding phase time delay.

[0055] Here, the formula for calculating time delay is:

[0056] Equation (2)

[0057] in, t’ Indicates phase time delay, T Indicating the detection sampling period, the sampling time lengths of signal acquisition components A, B, C, and D in the four-tap sensor are respectively... T / 4, I A , I B , I C and I D These represent the grayscale sampling information corresponding to signal acquisition components A, B, C, and D in a single frame of depth image, respectively. G A , G B , G C and G D These represent the gains corresponding to signal acquisition components A, B, C, and D, respectively. , , and These represent the dark currents corresponding to signal acquisition components A, B, C, and D, respectively.

[0058] Furthermore, based on the phase time delay t’ Determine the flight time of the corresponding test object. t For example, the phase time can be directly delayed. t’ Determine the flight time of the corresponding test object. t Alternatively, it can be achieved by delaying the phase time. t’ Calibration is performed to obtain the corresponding flight time. t This is to eliminate delays caused by other unspecified factors.

[0059] The derivation process for the time delay calculation formula described above will be described in detail below.

[0060] It should be noted that, since the time-of-flight measurement system is an imaging device based on photoelectric conversion devices, it is essentially a photon energy integrator. The taps, acting as readout and storage elements, contain internal amplification circuitry and dark current noise. The image grayscale value... I With the number of incident photons Tap gain Dark current The relationship between them is:

[0061] Equation (3)

[0062] Taking a four-tap sensor as an example, the grayscale values ​​sampled by the four taps A, B, C, and D are as follows:

[0063]

[0064]

[0065]

[0066] Equation (4)

[0067] Gray values ​​collected by the four taps This resulted in a four-point sampling of the sine curve. Assume that... These represent the start times of data collection for the four taps, which are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 ... T / 4、2 T / 4 and 3 T / 4 If T is the period of the sine curve, then the grayscale value can be obtained using the following formula. :

[0068]

[0069]

[0070]

[0071] Equation (5)

[0072] in, Δt = T / 4, It should be noted that if you want to use the grayscale values ​​collected from the four taps... I A , I B , I C and I D Calculate the time delay caused by factors such as the time of light flight. t'This requires correction of errors caused by the gain and dark current of different taps. Currently, multi-exposure sampling (e.g., four delayed exposures) is generally used to collect data from the same tap with multiple phase delays.

[0073] For example, during the exposure sampling process, four phase-delay exposure sampling operations can be performed on each tap separately, i.e. t A Take 0 respectively, T / 4、2 T / 4 and 3 T Four exposures were performed at 4 o'clock.

[0074] Taking tap A as an example, we can obtain:

[0075]

[0076]

[0077]

[0078] Equation (6)

[0079] So, time delay caused by factors such as the time of light travel t' for

[0080]

[0081]

[0082]

[0083]

[0084] Equation (7)

[0085] During the aforementioned exposure sampling process, four phase-delay exposure sampling operations were performed on each tap, resulting in a 4-fold reduction in frame rate.

[0086] In contrast, in this embodiment, by calibrating the tap gain and dark current, it is not necessary to perform four phase-delayed exposures on the taps. Specifically, the gain of each tap can be obtained in advance at the factory using sensor performance calibration methods. G A , G B , G C and G D and dark current , , and And it is stored in the control module.

[0087] When capturing grayscale values ​​of four taps in a single frame, time delay caused by factors such as light flight time is considered. t' It can be directly derived from the above equation (7), and the corresponding solution can be obtained. t' The time delay calculation formula is:

[0088]

[0089] Equation (8)

[0090] Therefore, by calibrating the tap gain and dark current at the factory, the time of flight of light can be directly calculated using a single frame image, thereby improving the measurement frame rate while ensuring ranging accuracy.

[0091] Figure 5 A structural block diagram of an example of a time-of-flight measuring device according to an embodiment of this application is shown.

[0092] like Figure 5 As shown, the flight time measurement device 500 includes a grayscale sampling control unit 510, a sampling interference factor acquisition unit 520, and a flight time determination unit 530.

[0093] The grayscale sampling control unit 510 is configured to sequentially activate multiple signal acquisition components according to a preset sampling time length in the detection sampling period for the test object illuminated by the modulated continuous carrier beam, so as to acquire the corresponding grayscale sampling information respectively.

[0094] The sampling interference factor acquisition unit 520 is configured to acquire the sampling interference factor corresponding to each of the signal acquisition components.

[0095] The flight time determination unit 530 is configured to determine the flight time of the object under test based on the sampling interference factor of each of the signal acquisition components and the corresponding grayscale sampling information.

[0096] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0097] Figure 6 This is a schematic diagram of an example of an electronic device according to an embodiment of this application. Figure 6As shown, the electronic device 600 of this embodiment includes: a processor 610, a memory 620, and a computer program 630 stored in the memory 620 and executable on the processor 610. When the processor 610 executes the computer program 630, it implements the steps in the above-described time-of-flight measurement method embodiment, for example... Figure 3 Steps 310 to 330 are shown. Alternatively, when the processor 610 executes the computer program 630, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 5 The functions of units 510 to 530 are shown.

[0098] For example, the computer program 630 can be divided into one or more modules / units, which are stored in the memory 620 and executed by the processor 610 to complete this application. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 630 in the electronic device 600. For example, the computer program 630 can be divided into a grayscale sampling control program module, a sampling interference factor acquisition program module, and a time-of-flight determination program module, with the specific functions of each program module as follows:

[0099] The grayscale sampling control module is configured to sequentially activate multiple signal acquisition components according to a preset sampling time length in the detection sampling period for the test object illuminated by the modulated continuous carrier beam, so as to acquire the corresponding grayscale sampling information respectively.

[0100] The sampling interference factor acquisition module is configured to acquire the sampling interference factor corresponding to each of the signal acquisition components.

[0101] The flight time determination module is configured to determine the flight time of the object under test based on the sampling interference factor of each of the signal acquisition components and the corresponding grayscale sampling information.

[0102] The electronic device 600 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. The electronic device may include, but is not limited to, a processor 610 and a memory 620. Those skilled in the art will understand that... Figure 6 This is merely an example of electronic device 600 and does not constitute a limitation on electronic device 600. It may include more or fewer components than shown, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0103] The processor 610 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0104] The memory 620 can be an internal storage unit of the electronic device 600, such as a hard disk or memory of the electronic device 600. The memory 620 can also be an external storage device of the electronic device 600, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 600. Furthermore, the memory 620 can include both internal and external storage units of the electronic device 600. The memory 620 is used to store the computer program and other programs and data required by the electronic device. The memory 620 can also be used to temporarily store data that has been output or will be output.

[0105] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments.

[0106] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0107] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0108] In the embodiments provided in this application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0109] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0110] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The aforementioned units can be implemented in hardware or software.

[0111] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0112] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A time-of-flight measurement method, characterized by, The method comprises the following steps: For the object to be measured irradiated by the modulated continuous carrier light beam, a plurality of signal acquisition components are sequentially started according to the preset sampling time length in the detection sampling period to respectively collect corresponding gray scale sampling information; Obtain the sampling interference factor corresponding to each signal acquisition component; the sampling interference factor is the gain and dark current of the signal acquisition component calibrated in advance; According to the sampling interference factor of each signal acquisition component and the corresponding gray scale sampling information, the time of flight corresponding to the object to be measured is determined; specifically, the gray scale sampling information, the sampling time length and the sampling interference factor corresponding to each signal acquisition component are substituted into the preset time delay calculation formula to obtain the corresponding phase time delay; according to the phase time delay, the time of flight corresponding to the object to be measured is determined; The time delay calculation formula is: ； wherein, t’ denotes a phase time delay, T denotes a probe sampling period, and the sampling time length of the signal acquisition components A, B, C and D is T / 4, I A , I B , I C and I D respectively denote the gray scale sampling information corresponding to the signal acquisition components A, B, C and D respectively in a single frame of depth image, G A , G B , G C and G D respectively denote the gain corresponding to the signal acquisition components A, B, C and D respectively, , , and respectively denote the dark current corresponding to the signal acquisition components A, B, C and D respectively.

2. The method of claim 1, wherein, The method comprises the following steps: For the object to be measured irradiated by the continuous carrier light beam corresponding to the single exposure time, a plurality of signal acquisition components are sequentially started according to the preset sampling time length in the detection sampling period to respectively collect corresponding gray scale sampling information.

3. The method of claim 1, wherein, The method further comprises: Obtain the sampling time length setting instruction; According to the updated sampling time length in the sampling time length setting instruction, the sampling time length is reset.

4. The method of claim 1, wherein, After calculating the time of flight of the object to be measured according to the sampling interference factor of each signal acquisition component and the corresponding gray scale sampling information, the method further comprises: According to the time of flight of the object to be measured, the distance between the object to be measured and the object to be measured is determined.

5. A time-of-flight measurement device, characterized by The method comprises the following steps: The gray scale sampling control unit is configured to sequentially start a plurality of signal acquisition components according to the preset sampling time length in the detection sampling period for the object to be measured irradiated by the modulated continuous carrier light beam to respectively collect corresponding gray scale sampling information; The sampling interference factor acquisition unit is configured to obtain the sampling interference factor corresponding to each signal acquisition component; the sampling interference factor is the gain and dark current of the signal acquisition component calibrated in advance; The time of flight determination unit is configured to determine the time of flight corresponding to the object to be measured according to the sampling interference factor of each signal acquisition component and the corresponding gray scale sampling information; specifically, the gray scale sampling information, the sampling time length and the sampling interference factor corresponding to each signal acquisition component are substituted into the preset time delay calculation formula to obtain the corresponding phase time delay; according to the phase time delay, the time of flight corresponding to the object to be measured is determined; The time delay calculation formula is: ； wherein, t’ represents a phase time delay, T represents a probe sampling period, and the sampling time length of the signal acquisition components A, B, C and D is T / 4, I A , I B , I C and I D respectively represent the gray scale sampling information corresponding to the signal acquisition components A, B, C and D respectively under a single frame depth image, G A , G B , G C and G D respectively represent the gain corresponding to the signal acquisition components A, B, C and D respectively, , , and respectively represent the dark current corresponding to the signal acquisition components A, B, C and D respectively.

6. A time-of-flight depth camera characterized by, The method comprises the following steps: The emission module comprises a light source and a light modulator, and the light modulator is used to control the light source to emit a modulated continuous carrier light beam towards the object to be measured; The receiving module comprises an image sensor composed of at least one pixel, each of the pixels comprising a plurality of signal acquisition components for receiving the light signal reflected from the object to be measured; The control module is connected with the transmitting module and the receiving module, and is configured to: For the object to be measured irradiated by the modulated continuous carrier light beam, the plurality of signal acquisition components are sequentially started according to the preset sampling time length in the detection sampling period, so as to respectively collect corresponding gray scale sampling information; Obtaining the sampling interference factors respectively corresponding to each of the signal acquisition components; the sampling interference factor is the gain and dark current of the signal acquisition component calibrated in advance; According to the sampling interference factors of each of the signal acquisition components and the corresponding gray scale sampling information, the time of flight corresponding to the object to be measured is determined; specifically, the gray scale sampling information, the sampling time length and the sampling interference factor corresponding to each of the signal acquisition components are substituted into a preset time delay calculation formula to obtain a corresponding phase time delay; according to the phase time delay, the time of flight corresponding to the object to be measured is determined; The time delay calculation formula is: wherein, t’ denotes a phase time delay, T denotes a probe sampling period, and the sampling time length of the signal acquisition components A, B, C and D are T / 4, I A , I B , I C and I D respectively denote the gray scale sampling information corresponding to the signal acquisition components A, B, C and D respectively under a single frame depth image, G A , G B , G C and G D respectively denote the gain corresponding to the signal acquisition components A, B, C and D respectively, , , and respectively denote the dark current corresponding to the signal acquisition components A, B, C and D respectively.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the method according to any one of claims 1-4 when executing the computer program.

8. A computer readable storage medium storing a computer program, the computer program implementing the steps of the method according to any one of claims 1-4 when executed by a processor.

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