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

Abstract

This application applies to the field of optical measurement technology and provides a time-of-flight measurement method, device, and time-of-flight depth camera. The method comprises: controlling a single signal acquisition component to initiate a sampling time interval within a detection sampling period for an object to be measured that is illuminated by a modulated continuous carrier beam; obtaining grayscale information corresponding to four preset phase offsets of the signal acquisition component; and determining the time-of-flight corresponding to the object to be measured based on each grayscale information. This method achieves a single-tap pixel layout without affecting the measurement function of the time-of-flight measurement sensor, reducing chip design and processing difficulties and improving sensor resolution.

Description

Technical Field

[0001] The present application relates to the field of optical measurement technology, and in particular to a time-of-flight measurement method, device, and time-of-flight depth camera. Background Art

[0002] ToF (Time-of-Flight) ranging is a technology that achieves precise ranging by measuring the round-trip flight time of a light pulse between a transmitting / receiving device and a target object. Within ToF technology, the technique of directly measuring the light flight time is called dToF (direct-TOF); the measurement technique of periodically modulating the transmitted light signal, measuring the phase delay of the reflected light signal relative to the transmitted light signal, and then calculating the flight time from the phase delay is called iToF (Indirect-TOF) technology. Based on the different types of modulation and demodulation, it can be divided into continuous wave (CW) modulation and demodulation and pulse modulated (PM) modulation and demodulation.

[0003] At present, the measurement distance of PM-iToF modulation technology is currently 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, the extension of the pulse width of the modulation and demodulation signal will lead to increased power consumption and decreased measurement accuracy, and therefore cannot meet market demand.

[0004] Furthermore, CW-iToF technology is primarily used in measurement systems based on multi-tap sensors. Its core measurement algorithm is a phase-variable modulation and demodulation method. However, for sensors where each pixel corresponds to multiple taps, the size of the pixel is limited by the readout circuits, making it difficult to minimize the size. This significantly limits the sensor's pixel resolution. Furthermore, the design and manufacture of multiple time-sharing circuits is challenging.

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

[0006] In view of this, the embodiments of the present application provide a time-of-flight measurement method, device and time-of-flight depth camera to at least solve the problem of the difficulty in designing and manufacturing the time-sharing readout circuit caused by setting multiple taps for one pixel in the current CW-iToF technology.

[0007] A first aspect of an embodiment of the present application provides a time-of-flight measurement method, comprising: controlling a single signal acquisition component to start a sampling time interval within a detection sampling period for an object to be measured that is illuminated by a modulated continuous carrier beam; obtaining each grayscale information corresponding to a preset four-phase offset of the signal acquisition component; and determining the flight time corresponding to the object to be measured based on the each grayscale information.

[0008] A second aspect of an embodiment of the present application provides a time-of-flight measurement device, comprising: a signal acquisition component starting unit, configured to control a single signal acquisition component to start a sampling time interval within a detection sampling period for an object to be measured that is irradiated by a modulated continuous carrier beam; an offset sampling unit, configured to obtain each grayscale information corresponding to a preset four-phase offset of the signal acquisition component; and a flight time determination unit, configured to determine the flight time corresponding to the object to be measured based on the each grayscale information.

[0009] A third aspect of an embodiment of the present application provides a time-of-flight depth camera, comprising: a transmitting module, comprising a light source and a light modulator, the light modulator being used to control the light source to emit a modulated continuous carrier light beam toward an object to be measured; a receiving module, comprising an image sensor composed of at least one pixel, each of the pixel comprising a single signal acquisition component, being used to receive a light signal reflected back from the object to be measured; a control module, connected to the transmitting module and the receiving module, and configured to: for an object to be measured irradiated by the modulated continuous carrier light beam, control the single signal acquisition component to start a sampling time interval within a detection sampling period; obtain each grayscale information of the signal acquisition component corresponding to a preset four-phase offset; and determine the flight time corresponding to the object to be measured based on the each grayscale information.

[0010] A fourth aspect of an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0011] A fifth aspect of an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

[0012] A sixth aspect of the embodiments of the present application provides a computer program product, which, when executed on an electronic device, enables the electronic device to implement the steps of the above method.

[0013] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0014] Through the embodiments of the present application, a single signal acquisition component can be used to perform offset sampling, and the flight time of the object to be measured can be calculated based on the grayscale information under different corresponding offset amounts, thereby realizing a single-tap pixel layout without affecting the measurement function of the time-of-flight measurement sensor, reducing the difficulty of chip design and processing, and improving the resolution of the time-of-flight measurement system sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

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

[0017] Figure 2 FIG4 shows a distribution diagram of tap sampling signals according to an example of charge integration ranging using multiple taps in CW-iToF technology;

[0018] Figure 3 A flowchart showing an example of a method for measuring time of flight according to an embodiment of the present application is shown;

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

[0020] Figure 5 A flowchart of an example of determining the flight time of a corresponding object to be measured according to an embodiment of the present application is shown;

[0021] Figure 6 A structural block diagram of an example of a flight time measurement device according to an embodiment of the present application is shown;

[0022] Figure 7 A schematic diagram showing an example of the effect of temporal signal crosstalk and spatial signal crosstalk on tap sampling results;

[0023] Figure 8 A flowchart showing an example of a method for measuring time of flight according to an embodiment of the present application is shown;

[0024] Figure 9 A flowchart illustrating an example of updating a K value corresponding to a customized detection sampling period according to an embodiment of the present application is shown;

[0025] Figure 10A block diagram showing a structure of an example of a time-of-flight measurement device according to an embodiment of the present application is shown;

[0026] Figure 11 A flowchart showing an example of a method for measuring time of flight according to an embodiment of the present application is shown;

[0027] Figure 12 A flowchart of an example of determining each sampling time interval in a detection sampling period according to an embodiment of the present application is shown;

[0028] Figure 13 A flowchart showing an example of determining the flight time of a corresponding object to be measured based on each grayscale information according to an embodiment of the present application is shown;

[0029] Figure 14 A structural block diagram of an example of a flight time measurement device according to an embodiment of the present application is shown;

[0030] Figure 15 is a schematic diagram of an example of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0031] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0032] In order to illustrate the technical solution described in this application, specific embodiments are provided below.

[0033] It will be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0034] It should also be understood that the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the present 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.

[0035] It should be further understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0036] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0037] In specific implementations, the electronic devices described in the embodiments of the present application include, but are not limited to, other portable devices such as mobile phones, laptop computers, or tablet computers with touch-sensitive surfaces (e.g., touch screen displays and / or touchpads). It should also be understood that in some embodiments, the above-mentioned devices are not portable communication devices, but rather computers with touch-sensitive surfaces (e.g., touch screen displays).

[0038] In the following discussion, an electronic device including a display and a touch-sensitive surface is described. However, it should be understood that the electronic device may include one or more other physical user interface devices such as a physical keyboard, mouse, and / or joystick.

[0039] Various applications that can be executed on an electronic device can use at least one common physical user interface device, such as a touch-sensitive surface. One or more functions of the touch-sensitive surface and corresponding information displayed on the terminal can be adjusted and / or changed between applications and / or within a corresponding application. In this way, the common physical architecture of the terminal (e.g., the touch-sensitive surface) can support a variety of applications with user interfaces that are intuitive and transparent to the user.

[0040] Figure 1 A schematic diagram showing the structural principle of an example of a time-of-flight depth camera according to an embodiment of the present application is shown.

[0041] 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, and the control module 13 is connected to the transmitting module 11 and the receiving module 12. Here, the transmitting module 11 can transmit an optical signal (e.g., a modulated continuous carrier beam) 102 to the object to be measured 20, and the receiving module 12 can receive an optical signal 103 reflected from the object to be measured 20. The control module 13 can calculate the reflected optical signal to obtain a distance 104 to the object to be measured 20. In some cases, the sampling operation of the receiving module 12 can also be controlled by the control module 13, such as adjusting the sampling period or time, to meet the needs of different measurement scenarios.

[0042] 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. The combination of these devices can achieve richer functions, such as 3D texture modeling, infrared face recognition, SLAM, and other functions.

[0043] In some embodiments, the transmitting module 11 may include a light source (not shown) and an optical modulator (not shown). The optical modulator may control the light source to emit a modulated continuous carrier beam toward the object to be measured 20. Furthermore, the receiving module 12 may include an image sensor composed of at least one pixel, with each pixel including multiple signal acquisition components. Here, the signal acquisition component may refer to a component that collects optical signals, which may be a device for reading and accumulating charge. For example, the signal acquisition component may employ a tap.

[0044] Specifically, the time-of-flight depth camera 10 can adopt an indirect time-of-flight measurement method, and can modulate the power waveform of the emitted light to be close to a sine wave (or other waveform, such as a square wave), and the demodulation device (such as a sensor, i-TOFSensor) performs energy integration on the power of the received light in different time periods. Generally speaking, the demodulation device will have several different acquisition time periods. This time-divided acquisition of the echoed sinusoidal signal is equivalent to multi-point sampling of the sinusoidal signal. Furthermore, the demodulation device outputs multiple sampling values of the echoed sinusoidal signal, so that the control module 13 calculates the phase delay of the echoed sinusoidal signal and calculates the flight distance of the light signal between the time-of-flight depth camera 10 and the object under test 20.

[0045] Here, the demodulated energy integration device shares the same pixel (i.e., a 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 the time-sharing signal acquisition process, the signal gain and dark current of different taps are inconsistent. At the same time, it is necessary to sample the sinusoidal signal in different time periods, including periodic sampling (i.e., multiple taps are sampled within a period) and exposure sampling (i.e., the sampling time of the taps is phase-delayed during different exposure times).

[0046] It should be noted that in periodic sampling, where multiple taps are sampled in a period, the distance traveled by the light often cannot be accurately calculated due to inconsistencies in sampling interference factors (e.g., gain and dark current) across different taps. In this case, using a split-exposure sampling method, multiple acquisitions are performed on the same tap, and addition, subtraction, multiplication, and division operations are performed on the data collected from these multiple acquisitions. This eliminates the influence of the sampling interference factor and ultimately improves distance measurement accuracy.

[0047] However, in the demodulation of traditional time-of-flight measurement system sensors, the demodulation time configuration of multiple taps can only be selected to have the same energy integration time (i.e., the same sampling time length within the detection period) due to algorithm limitations.

[0048] Figure 2 FIG1 shows a distribution diagram of tap sampling signals according to an example of charge integration ranging using multiple taps in CW-iToF technology.

[0049] like Figure 2 As shown, after obtaining a frame of depth image based on the periodic sampling method, another frame of depth image based on the exposure sampling method is required to eliminate the measurement error caused by the sampling interference factor.

[0050] In view of this, Figure 3 The flowchart of an example of a time-of-flight measurement method according to an embodiment of the present application is shown. The execution subject of the embodiment of the present application can be any measurement system or processor with computing or processing functions, for example, it can be the control module 13 in the time-of-flight depth camera 10.

[0051] like Figure 3 As shown, in step 310, for the object to be measured that is illuminated by the modulated continuous carrier beam, multiple signal acquisition components are controlled to sequentially initiate continuous sampling time intervals within a detection sampling cycle. Here, the sampling time intervals corresponding to the various signal acquisition components have different durations. In other words, the sampling operation starts at different times for different signal acquisition components, and the sampling time lengths corresponding to different signal acquisition components also vary.

[0052] For example, the signal acquisition components (also referred to as taps) in a pixel can be sequentially activated at different time points during a detection sampling period, and each signal acquisition component can have a different sampling time length. For example, if a pixel has four taps, multiple taps can be controlled to be continuously activated within a detection period during a single exposure time, with different integration sampling times. For example, assuming the detection sampling period is T, tap A can be activated first and have a sampling time length of T / 8, while tap B can be activated later and have a sampling time length of T / 4 or another value.

[0053] It should be noted that the sampling time length of each signal acquisition component may not be fixed, for example, it can be adjusted according to different business scenarios or needs. In addition, the above-mentioned "multiple signal acquisition components" can be used to represent at least two signal acquisition components, and generally three or four or more.

[0054] In step 320, the four preset phase offsets are applied to each signal acquisition component to obtain a corresponding grayscale information set. Here, each grayscale information in the grayscale information set corresponds to a different phase offset.

[0055] For example, different phase delays can be applied to the transmitted optical signal, and the signal acquisition component can be used to collect the corresponding grayscale information. Specifically, each tap can collect signals to complete a frame of measurement without applying a phase delay. Then, after applying phase delays of 90 degrees, 180 degrees, and 270 degrees to the transmitted signal, the corresponding measurement frames are repeatedly collected, resulting in a total of four frames of sampled signals.

[0056] In step 330, the flight time of the corresponding object under test is determined based on the grayscale information set of each signal acquisition component. For example, the flight time of the corresponding object under test can be calculated based on a preset relationship between the grayscale sampling signal and the flight time. More details will be expanded below.

[0057] Through the embodiments of this application, a new time-of-flight calculation method is proposed. This simulates the integral calculation process within a CW-iToF detection sampling period to the cumulative amount of pulse modulation. This eliminates the demodulation time of multiple taps from being restricted by the same integral sampling time, thus expanding the sensor's applicability. Furthermore, when calculating the time-of-flight of a frame, it is necessary to measure it separately using different signal acquisition components, which is equivalent to averaging multiple measurements, further improving the accuracy of the determined time-of-flight.

[0058] In some embodiments, after step 330 , the measurement system may further determine the distance to the object to be measured based on the flight time with respect to the object to be measured.

[0059] For example, the distance between the measurement system and the object to be measured can be determined by the following formula:

[0060]

[0061] Where d is the distance to the object to be measured, C is the speed of light, and t is the flight time.

[0062] Figure 4 A flowchart of an example of updating the sampling time intervals of each signal acquisition component according to an embodiment of the present application is shown.

[0063] like Figure 4 As shown, in step 410, a sampling interval setting instruction is obtained. For example, the measurement system may receive a sampling duration setting instruction from a user terminal.

[0064] In step 420, the sampling time intervals corresponding to each signal acquisition component are updated based on the sampling interval setting instruction. Thus, different sampling time intervals can be set for each signal acquisition component and adjusted through instruction interaction, meeting the needs of different users or business scenarios.

[0065] Figure 5 A flowchart of an example of determining the flight time of a corresponding object to be measured according to an embodiment of the present application is shown.

[0066] like Figure 5 As shown, in step 510, for each signal acquisition component, the corresponding initial flight time is determined based on the sampling time interval of the signal acquisition component and the collected grayscale information set.

[0067] In step 520, the flight time of the object under test is determined based on the initial flight time determined by each signal acquisition component. Here, the initial flight times of different signal acquisition components can be combined through various statistical methods to obtain the final flight time of the object under test.

[0068] For example, the initial flight times of multiple signal acquisition components can be used to calculate the corresponding average value to determine the flight time of the corresponding object under test. Here, the phase time delay can be directly used as the flight time of the corresponding object under test. Alternatively, the corresponding flight time can be obtained by calibrating the average value corresponding to each initial flight time to eliminate delays caused by other unspecified factors.

[0069] Therefore, the sampling results of multiple taps are comprehensively considered, and the sampling time lengths of each tap are inconsistent. By averaging the flight time obtained for each tap, the design requirements for the sampling time length of the tap can be reduced, and the measurement accuracy can be improved.

[0070] Regarding the implementation details of the above step 510, the initial flight time can be determined based on the grayscale information and a preset initial flight time relationship. Here, the initial flight time relationship can be the correlation relationship between the grayscale information and the initial flight time. Specifically, the initial flight time relationship can be the example in the following formula (2):

[0071]

[0072] Where t′ A represents the initial flight time corresponding to the signal acquisition component A, T represents the detection sampling period, the sampling time interval of the signal acquisition component A is [0, 3 / 4T], and I A,0 、 and It represents the grayscale information corresponding to the signal acquisition component A when the phase offsets are 0, 1 / 4T, 2 / 4T and 3 / 4T respectively.

[0073] For the above formula (2), the corresponding derivation process will be described in detail below.

[0074] It should be noted that time-of-flight measurement systems are imaging devices based on photoelectric conversion devices, which are essentially photon energy integrators. The tap, acting as a readout and storage element, contains internal amplification circuits and dark current noise. However, currently, the light energy collected by the tap is the accumulated photocharge, not quantified. In this paper, the number of incident photons can be used to characterize the light energy collected by the tap.

[0075] Specifically, the grayscale value I of the image (which can also be written as the light energy collected by the tap) is related to the number of incident photons C Signal，Photon , tap gain G, dark current C Dark，Electron The relationship between them is:

[0076] I=G(C Signal,Photon +C Dark,Electron ) (3)

[0077] Here, the grayscale value I output by the tap represents the amount of charge collected by the pixel, which is the charge generated by the photoelectric effect emitted by light incident on the pixel, and can also be defined as the number of collected photons.

[0078] Taking a two-tap sensor as an example, the grayscale values sampled by the two taps A and B are:

[0079]

[0080]

[0081] The grayscale values collected by the two taps form two-point sampling of the sine curve. Among them, the number of signal photons received by the tap is the integral of the time distribution of the number of incident photons:

[0082]

[0083] Where T represents the modulation period (i.e., the detection sampling period), a represents the amplitude of the received photon number changing with time, t0 is the time when the tap starts integrating within a single period, Δt is the integration time of the tap within a single period (i.e., the sampling time length), t' is the fixed phase delay caused by the waveform light flight time, and ρ (Ambient,Photon) represents the ambient photon temporal density, and is a constant related to t0, Δt, and T, and is a characterizing quantity obtained during the intermediate process of photon number integration. Repeating the accumulation of N detection cycles completes one exposure and captures one subframe.

[0084] In the embodiment of the present application, the modulated continuous carrier beam is a sine wave, which can of course be replaced by other waveforms such as square waves. Here, only a two-tap sensor is used as an example for explanation, and it can also be 3-tap, 4-tap, and so on. In one detection cycle, the two taps are continuously turned on and the integral sampling time is different from each other. The integral time of the two taps can be set arbitrarily. For example, taps A and B are set to 3T / 4 and T / 4 respectively; that is, in one detection cycle, the integral sampling time of tap A (that is, the sampling time interval) is 0 to 3T / 4, and the integral sampling time of tap B is 3T / 4 to T; when Δt=3T / 4, When Δt=T / 4,

[0085] Then, the number of photons collected after integration of the two taps A and B is:

[0086]

[0087]

[0088] Among them, t A , t B are the time when the two taps start collecting, which are 0 and 3T / 4 respectively.

[0089]

[0090]

[0091] It should be noted that if the gray value I collected by the two taps is A and I B To calculate the time delay t' caused by factors such as the light flight time, it is necessary to eliminate the errors caused by the gain and dark current of different taps, and this can be achieved by collecting sampling data of the same tap under multiple phase delays.

[0092] For example, in the exposure sampling process, four phase-delayed exposure acquisition operations can be performed on each tap, that is, t A Four exposures are performed at 0, T / 4, 2T / 4, and 3T / 4, respectively. It should be noted that four exposures are used in the split-exposure sampling process of the embodiment of the present application, and the exposure phase delay is fixed, which is completely different from the traditional four-phase sampling method.

[0093] Taking tap A as an example, after four delayed exposures, we can get:

[0094]

[0095]

[0096]

[0097]

[0098] According to the relationship between phase delay Φ and time delay t', we can get:

[0099]

[0100] Therefore, by first defining the calculation expression of the tap output grayscale value, the grayscale value output by each tap per frame can be calculated, and then the grayscale value I collected under the four-phase delayed exposure is obtained by combining the four exposures, and the relationship between the phase delay and the time delay is obtained. In addition, due to the relationship between the phase delay and the four-phase grayscale value The time delay of each tap can be calculated.

[0101] Then, the time delay t' caused by factors such as light flight time is:

[0102]

[0103]

[0104]

[0105] Through the above-mentioned exposure sampling process, four phase-delayed exposure acquisition operations are performed on each tap, and the grayscale acquisition results of different phases and the corresponding sampling time intervals are used to calculate their respective time delays, and the various time delays are averaged to finally obtain a phase delay with higher accuracy.

[0106] It should be noted that in addition to directly using the above-mentioned initial flight time relationship to calculate the initial flight time corresponding to the grayscale information, the initial flight time can also be calculated by other methods. For example, for each grayscale information in the signal acquisition component A, a phase offset information relationship corresponding to the grayscale information can be determined. Here, the phase offset information relationship can be a relationship that includes the initial flight time variable and is used to represent the phase offset information.

[0107] For example, referring to the description of formula (9) above, the phase delay generated by the signal acquisition component A after delayed exposure can be expressed using the following phase offset information relationship:

[0108]

[0109] Among them, φ A It can represent the phase offset information corresponding to the signal acquisition component A.

[0110] Then, the corresponding phase offset information can be determined based on each grayscale information. It should be understood that there is an inherent relationship between the phase offset information and the grayscale information with different offsets, which can be expressed as:

[0111]

[0112] Furthermore, the above two A Combine the factors of t A ’, and obtain the initial flight time corresponding to the signal acquisition component A.

[0113] In the embodiment of the present application, the integration time of the tap is not restricted, and the flight time of the light can also be solved, so that the demodulation time of multiple taps is not restricted by the same integration time, thereby expanding the scope of application of the time-of-flight measurement system sensor.

[0114] Figure 6 A structural block diagram of an example of a flight time measurement device according to an embodiment of the present application is shown.

[0115] like Figure 6 As shown, the flight time measurement device 600 includes a signal acquisition component starting unit 610 , an offset grayscale sampling unit 620 and a flight time determination unit 630 .

[0116] The signal acquisition component starting unit 610 is configured to control multiple signal acquisition components to start sequentially within a detection sampling period with each component having a sampling time interval of different length for the object to be detected that is illuminated by the modulated continuous carrier beam.

[0117] The offset grayscale sampling unit 620 is configured to obtain, for each signal acquisition component, a grayscale information set corresponding to the preset four phase offsets of the signal acquisition component, wherein each grayscale information in the grayscale information set corresponds to a different phase offset of the four phase offsets.

[0118] The flight time determining unit 630 is configured to determine the flight time corresponding to the object to be measured according to the grayscale information set of each signal acquisition component.

[0119] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of this application. Their specific functions and technical effects can be found in the method embodiment section and will not be repeated here.

[0120] Regarding another aspect of the embodiments of the present application, it should be noted that there are still some areas that need improvement in current time-of-flight measurement systems. Generally speaking, when performing photon integration, the demodulated energy integration device shares the same pixel (i.e., a photodiode or other photosensitive element). Different readout and charge accumulation devices (called taps) are connected to the same pixel. During the time-sharing signal acquisition process, temporal and spatial crosstalk between the received charge signals of different taps is inevitable.

[0121] Figure 7 The figure shows an example of the effect of temporal signal crosstalk and spatial signal crosstalk on tap sampling results.

[0122] Here, temporal signal crosstalk refers to the spatial area of pixels and the discrete spatial distribution of taps, such as Figure 7 As shown in the figure, part of the charge signal generated when the first tap is turned on for collection does not enter the tap due to the spatial distance; instead, when the next tap is turned on for collection, it enters the next tap to generate a signal. In addition, spatial crosstalk means that when a tap turns on for charge collection, the potential field gradient pointing to the tap that is turned on for charge collection increases, and the potential field gradient pointing to the tap that is not turned on for charge collection decreases; however, even if the potential field gradient of the tap that is not turned on for charge collection is low, as shown in the figure, Figure 7 As shown in Figure 1, due to Brownian motion of charge, some signal charge in pixels close to the closed taps can still enter the closed taps, generating spatial signal crosstalk. Therefore, both temporal and spatial crosstalk are a form of noise in the measurement, affecting measurement accuracy.

[0123] In view of this, Figure 8 The flowchart of an example of a time-of-flight measurement method according to an embodiment of the present application is shown. The execution subject of the embodiment of the present application can be any measurement system or processor with computing or processing functions, for example, it can be the control module 13 in the time-of-flight depth camera 10.

[0124] like Figure 8 As shown, in step 810, for an object under test illuminated by a modulated continuous carrier beam, M signal acquisition components are controlled to sequentially initiate continuous sampling time intervals within a customized detection sampling period. Here, the customized detection sampling period comprises K original detection sampling periods T, where M and K are both positive integers greater than 1, and the sampling time interval length of each signal acquisition component is (K / M)*T. Thus, the sampling time interval of each signal acquisition component is extended by K times.

[0125] Here, the customized detection sampling period includes multiple original detection sampling periods (eg, sinusoidal wave periods), which expands the detection period and lays the foundation for extending the sampling time length of each signal acquisition component.

[0126] In step 820, grayscale information sets corresponding to the four preset phase offsets of each signal acquisition component are obtained. Here, each grayscale information in the grayscale information set corresponds to a different phase offset of the four phase offsets.

[0127] In step 830, the flight time of the corresponding object to be measured is determined according to the grayscale information set of each signal acquisition component.

[0128] Through the embodiments of the present application, a new tap demodulation method is proposed without affecting the measurement function of the time-of-flight measurement sensor. Under the condition that the number of crosstalk photons cannot be changed, the energy integration time of each tap is increased, so that the crosstalk photons are reduced relative to the signal photons, thereby improving the signal-to-noise ratio of the signal.

[0129] In some embodiments, after step 830, the method further includes: determining the distance to the object to be measured based on the flight time of the object to be measured, for example, substituting the flight time into the above formula (1) to obtain the distance relative to the object to be measured.

[0130] Regarding the implementation details of the above step 830, you can refer to the above combined Figure 5 Specifically, the measurement system can determine the corresponding initial flight time for each signal acquisition component based on the sampling time interval of the signal acquisition component and the grayscale information set collected. Furthermore, based on the initial flight time determined by each signal acquisition component, the flight time of the corresponding object to be measured can be determined. For example, an average value corresponding to the initial flight times of multiple signal acquisition components can be calculated to determine the flight time of the corresponding object to be measured.

[0131] Figure 9 A flowchart of an example of updating the K value corresponding to the customized detection sampling period according to an embodiment of the present application is shown.

[0132] like Figure 9 As shown, in step 910, a customized detection sampling period setting instruction is obtained. Exemplarily, the measurement system may receive the customized detection sampling period setting instruction from a user terminal.

[0133] In step 920, based on the customized detection sampling period setting instruction, the K value of the customized detection sampling period is updated. This allows for customized detection sampling periods with extended time lengths for signal acquisition components, and allows for adjustments through interactive instruction processing, meeting the needs of different users or business scenarios.

[0134] Specifically, the corresponding initial flight time can be determined by:

[0135]

[0136] Among them, T′ a Indicates the initial flight time corresponding to the signal acquisition component A, the customized detection sampling period is 3T, the sampling interval time of the signal acquisition component A in the four-tap sensor is [0,3 / 4T], and I a,0 、 and It represents the grayscale information corresponding to the signal acquisition component A when the phase offsets are 0, 1 / 4T, 2 / 4T and 3 / 4T respectively.

[0137] The following will describe the derivation details of formula (11) in detail using a four-tap sensor as an example. It should be understood that in the embodiment of the present application, a two-tap sensor can also be used, that is, the two taps have equal sampling time lengths in one customized detection cycle.

[0138] Here, in the specific demodulation process of the measurement system, it can be demodulated using a period sampling method and a exposure sampling method. Regarding the derivation process of the above formula (11), the derivation details of the above formula (2) can be partially referred to.

[0139] When the original sine wave period T is used as the detection sampling period, the integration time of each tap A, B, C, and D in the four-tap sensor is T / 4, and the corresponding time delays are:

[0140]

[0141]

[0142]

[0143]

[0144] Then, the time delay t' caused by factors such as the light flight time is:

[0145]

[0146] Generally speaking, four taps collect a signal of one cycle, so that when Δt=T / 4, However, due to the existence of temporal and spatial crosstalk, crosstalk photons are noise interference signals, and the number of crosstalk photons accounts for a certain proportion of the number of photons in a single cycle, so there is a certain amount of crosstalk in each detection cycle. In order to reduce the interference of crosstalk photons on signal photons, it is proposed in the embodiments of the present application that while the total number of detection cycles remains unchanged, the integration time collected by four taps in the four-tap sensor can be increased, that is, the sum of the integration time of the four taps corresponds to multiple detection cycles, so that the number of signal photons is greatly increased while the number of crosstalk photons remains unchanged, which can significantly improve the signal-to-noise ratio.

[0147] In some examples of the embodiments of the present application, K original detection sampling periods T can be combined into a customized detection sampling period. For each tap, the original sampling time length is T / 4, and the sampling time length after the expansion period becomes KT / 4.

[0148] Here, the number of taps M and the number K of original sampling periods T included in the corresponding customized sampling period should satisfy the following equation:

[0149]

[0150] Here, s represents an integer.

[0151] For example, the number K of original sampling periods in the customized detection sampling period can be set to 3, at which time t A , t B , t C , t D They are 0, Then, four phase-delayed exposure acquisitions are performed on each tap, t A Take 0, Take four exposures.

[0152] Then, the time delay t' caused by factors such as light flight time is:

[0153]

[0154]

[0155]

[0156]

[0157]

[0158] Therefore, even if the sampling time lengths of different taps are extended, the time-of-flight calculation operation can be completed using the above relationship. At the same time, because the number of signal photons integrated by a single tap increases while the total number of crosstalk photons remains unchanged, the signal-to-noise ratio is relatively increased, achieving improved measurement accuracy.

[0159] Figure 10 A structural block diagram of an example of a flight time measurement device according to an embodiment of the present application is shown.

[0160] like Figure 10 As shown, the flight time measurement device 1000 includes a signal acquisition component starting unit 1010 , an offset grayscale sampling unit 1020 and a flight time determination unit 1030 .

[0161] The signal acquisition component starting unit 1010 is configured to control M signal acquisition components to sequentially start continuous sampling time intervals within a customized detection sampling period for the object to be tested that is irradiated by a modulated continuous carrier beam, wherein the customized detection sampling period includes K original detection sampling periods T, M and K are both positive integers greater than 1, and the length of the sampling time interval of each of the signal acquisition components is (K / M)*T.

[0162] The offset grayscale sampling unit 1020 is configured to obtain grayscale information sets corresponding to four preset phase offsets for each of the signal acquisition components, wherein each grayscale information in the grayscale information set corresponds to a different phase offset;

[0163] The flight time determining unit 1030 is configured to determine the flight time corresponding to the object to be measured according to the grayscale information set of each signal acquisition component.

[0164] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of this application. Their specific functions and technical effects can be found in the method embodiment section and will not be repeated here.

[0165] Regarding another aspect of the embodiment of the present application, it should be noted that there are still some areas that need to be improved in the current time-of-flight measurement system. For a sensor in which one pixel corresponds to multiple taps, since the same pixel requires multiple readout circuits, for example, Figure 7 In the example of a mid-tap sensor, the size of the pixel will be limited by the readout circuit and cannot be made very small, which will greatly limit the pixel resolution of the sensor; at the same time, the design and manufacture of multiple time-sharing circuits are difficult.

[0166] In view of this, Figure 11The flowchart of an example of a time-of-flight measurement method according to an embodiment of the present application is shown. The execution subject of the embodiment of the present application can be any measurement system or processor with computing or processing functions, for example, it can be the control module 13 in the time-of-flight depth camera 10.

[0167] like Figure 11 As shown, in step 1110, for the object to be measured that is illuminated by the modulated continuous carrier beam, a single signal acquisition component is controlled to start a sampling time interval within a detection sampling period.

[0168] It should be noted that the sampling time length of the tap can be set arbitrarily or as needed. For example, when it is set to 3T / 4, the tap no longer collects the energy corresponding to the remaining T / 4 of the input, and this part of the energy can be directly drawn out and ignored.

[0169] In step 1120, grayscale information corresponding to the preset four phase offsets of the signal acquisition component is obtained.

[0170] Exemplarily, multiple phase offsets may be applied to a single tap in a pixel, and multiple exposures may be performed to cause the tap to record corresponding multiple sampling values, thereby completing a split-exposure sampling operation.

[0171] In step 1130 , the flight time of the corresponding object to be measured is determined according to each grayscale information.

[0172] It should be noted that in current related technologies, the energy collected by the tap is output to subsequent circuits for processing after collection, which is time-consuming and places high demands on the tap capacity, and the accuracy of the measurement results cannot be guaranteed. However, in the embodiments of the present application, a single tap can be used to directly calculate the corresponding flight time.

[0173] Therefore, without affecting the measurement function of the time-of-flight measurement sensor, by adopting a single-tap pixel layout, the difficulty of chip design and processing can be reduced, the area of a single pixel can be reduced, and the resolution of the sensor can be improved.

[0174] In some embodiments, after step 830, the method further includes: determining the distance to the object to be measured based on the flight time of the object to be measured, for example, substituting the flight time into the above formula (1) to obtain the distance relative to the object to be measured.

[0175] Figure 12 A flowchart of an example of determining each sampling time interval in a detection sampling period according to an embodiment of the present application is shown.

[0176] like Figure 12As shown, in step 1210, a sampling time interval setting instruction is obtained. For example, the measurement system may receive the sampling time interval setting instruction from a user terminal.

[0177] In step 1220, the sampling time intervals within the detection sampling period are determined based on the sampling time interval setting instruction. This allows different sampling time intervals to be set within the signal acquisition component, including the start time and corresponding sampling time duration of each sampling phase. These can be adjusted interactively through instructions, meeting the needs of different users or business scenarios.

[0178] Regarding the specific implementation details of step 1130, the flight time of the corresponding object under test can be determined based on the grayscale information and a preset flight time equation. Here, the flight time equation represents the correlation between grayscale information and flight time. Thus, the measurement system can directly substitute the grayscale information at different offsets into the equation to quickly calculate the corresponding flight time.

[0179] In some embodiments, the corresponding flight time may be determined by:

[0180]

[0181] Where t' represents the flight time of the object to be measured, the single sampling interval length of the signal acquisition component is 1 / 4T, and I A,0 、 and It represents the grayscale information corresponding to the signal acquisition component A when the phase offsets are 0, 1 / 4T, 2 / 4T and 3 / 4T respectively.

[0182] Here, in the specific demodulation process of the measurement system, it can adopt the period sampling method and the exposure sampling method for demodulation. Regarding the derivation process and details of the above formula (16), reference can also be made to the description of other relevant parts above.

[0183] Regarding the specific implementation details of the above step 1130, on the other hand, you can also refer to Figure 12 operations in the process. Figure 13 A flowchart of an example of determining the flight time of a corresponding object to be measured based on various grayscale information according to an embodiment of the present application is shown.

[0184] like Figure 13 As shown, in step 1310, for each grayscale information, a phase offset information relationship expression corresponding to the grayscale information is determined. Here, the phase offset information expression is a relationship expression including a flight time variable.

[0185] In step 1320, corresponding phase offset information is determined according to each grayscale information.

[0186] In step 1330, the flight time variable is solved according to the phase offset information and the phase offset information relationship to obtain the flight time corresponding to the object to be measured.

[0187] For example, referring to the description of formula (9) above, the phase delay generated by a single tap after delayed exposure can be expressed using the following phase offset information relationship:

[0188]

[0189] At this point, the corresponding phase offset information can be calculated as:

[0190]

[0191] Furthermore, the above two factors of Φ can be combined to solve for t' and obtain the time of flight of light.

[0192] Therefore, the photon number calculation expression of the tap output grayscale value is first defined, and the grayscale value output by the tap in each frame can be calculated. Then, the grayscale values collected under four phase delays (for example, the phase delay is 0, T / 4, 2T / 4 and 3T / 4) are obtained by combining multiple exposures to obtain the relationship between phase delay and time delay. Taking into account the inherent relationship between the phase delay and the four-phase grayscale values, the time delay of the tap can be calculated.

[0193] In this embodiment, a single readout circuit can be used in a pixel (i.e., the pixel has only one tap). By adjusting the start and end readout times of this tap, the sampling and demodulation process of a multi-tap sensor can be simulated, still achieving relatively accurate measurement results. Since a single pixel has only one tap, the circuit design difficulty is greatly reduced. This also reduces the area of a single pixel, allowing for a smaller pixel size, thereby improving the resolution of the time-of-flight measurement chip.

[0194] Figure 14 A structural block diagram of an example of a flight time measurement device according to an embodiment of the present application is shown.

[0195] like Figure 14 As shown, the flight time measurement device 1400 includes a signal acquisition component starting unit 1410 , an offset sampling unit 1420 and a flight time determination unit 1430 .

[0196] The signal acquisition component starting unit 1410 is configured to control a single signal acquisition component to continuously start multiple sampling time intervals within a detection sampling period for the object to be measured that is illuminated by the modulated continuous carrier beam, wherein each of the sampling time intervals has an equal sampling time interval length.

[0197] The offset sampling unit 1420 is configured to obtain each grayscale information corresponding to the preset four-phase offset of the signal acquisition component.

[0198] The flight time determining unit 1430 is configured to determine the flight time corresponding to the object to be measured according to each of the grayscale information and the length of the sampling time interval.

[0199] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of this application. Their specific functions and technical effects can be found in the method embodiment section and will not be repeated here.

[0200] Figure 15 FIG is a schematic diagram of an example of an electronic device according to an embodiment of the present application. Figure 15 As shown, the electronic device 1500 of this embodiment includes: a processor 1510, a memory 1520, and a computer program 1530 stored in the memory 1520 and executable on the processor 1510. When the processor 1510 executes the computer program 1530, the steps in the above-mentioned time-of-flight measurement method embodiment are implemented, for example Figure 3 Steps 310 to 330, or steps 810 to 830, or steps 1110 to 1130 are shown. Alternatively, when the processor 1510 executes the computer program 1530, the functions of the modules / units in the above-mentioned device embodiments are realized, for example Figure 6 The functions of the units 610 to 630 shown, or as Figure 10 Units 1010 to 1030 shown, or as Figure 14 Units 1410 to 1430 are shown.

[0201] Exemplarily, the computer program 1530 may be divided into one or more modules / units, which are stored in the memory 1520 and executed by the processor 1510 to implement the present application. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 1530 in the electronic device 1500.

[0202] In one example of the embodiment of the present application, the computer program 1530 may be divided into a signal acquisition component startup program module, an offset grayscale sampling program module, and a flight time determination program module. The specific functions of each program module are as follows:

[0203] A signal acquisition component startup program module is configured to control multiple signal acquisition components to be sequentially activated within a detection sampling period with each component having a sampling time interval of different lengths for the object to be detected that is illuminated by the modulated continuous carrier beam;

[0204] an offset grayscale sampling program module configured to obtain, for each of the signal acquisition components, a grayscale information set corresponding to four preset phase offsets of the signal acquisition component, wherein each grayscale information in the grayscale information set corresponds to a different phase offset of the four phase offsets;

[0205] The flight time determination program module is configured to determine the flight time corresponding to the object to be measured according to the grayscale information set of each signal acquisition component.

[0206] In another example of the embodiment of the present application, the computer program 1530 may be divided into a signal acquisition component startup program module, an offset grayscale sampling program module, and a flight time determination program module. The specific functions of each program module are as follows:

[0207] a signal acquisition component startup program module configured to control, for a test object illuminated by a modulated continuous carrier beam, M signal acquisition components to sequentially start continuous sampling time intervals within a customized detection sampling period, wherein the customized detection sampling period includes K original detection sampling periods T, M and K are both positive integers greater than 1, and the sampling time interval length of each signal acquisition component is (K / M)*T;

[0208] an offset grayscale sampling program module, configured to obtain grayscale information sets corresponding to four preset phase offsets for each of the signal acquisition components, wherein each grayscale information in the grayscale information set corresponds to a different phase offset;

[0209] The flight time determination program module is configured to determine the flight time corresponding to the object to be measured according to the grayscale information set of each signal acquisition component.

[0210] In another example of the embodiment of the present application, the computer program 1530 may be divided into a signal acquisition component startup program module, an offset sampling program module, and a flight time determination program module. The specific functions of each program module are as follows:

[0211] The signal acquisition component startup program module is configured to control a single signal acquisition component to start a sampling time interval within a detection sampling period for the object to be detected that is illuminated by the modulated continuous carrier beam;

[0212] An offset sampling program module is configured to obtain grayscale information corresponding to the preset four-phase offsets of the signal acquisition component;

[0213] The flight time determination program module is configured to determine the flight time corresponding to the object to be measured according to the various grayscale information.

[0214] The electronic device 1500 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device may include, but is not limited to, a processor 1510 and a memory 1520. It will be understood by those skilled in the art that Figure 15 It is only an example of electronic device 1500 and does not constitute a limitation of electronic device 1500. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0215] The processor 1510 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), 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.

[0216] The memory 1520 may be an internal storage unit of the electronic device 1500, such as a hard disk or memory of the electronic device 1500. The memory 1520 may also be an external storage device of the electronic device 1500, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 1500. Furthermore, the memory 1520 may also include both an internal storage unit of the electronic device 1500 and an external storage device. The memory 1520 is used to store the computer program and other programs and data required by the electronic device. The memory 1520 may also be used to temporarily store data that has been output or is about to be output.

[0217] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by 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 embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment.

[0218] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0219] Those skilled in the art will appreciate that the units and algorithm steps of each example 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 performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel 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.

[0220] In the embodiments provided in the present 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 schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0221] The units described as separate components may or may not be physically separate, and 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 these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0222] In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above units may be implemented in the form of hardware or software.

[0223] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased 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 electric carrier signals and telecommunication signals.

[0224] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for measuring time of flight, characterized in that: include: For the object to be measured that is illuminated by the modulated continuous carrier beam, controlling a single signal acquisition component to start a sampling time interval within a detection sampling period; Obtaining grayscale information corresponding to the four preset phase offsets of the signal acquisition component, including: applying multiple phase offsets to a single signal acquisition component, and performing multiple exposures to enable the single signal acquisition component to record corresponding multiple sampling values, thereby completing a split-exposure sampling operation; According to the grayscale information, the flight time corresponding to the object to be measured is determined, and then the corresponding flight time is directly calculated using a single signal acquisition component; the flight time relationship is: Wherein, t' represents the flight time corresponding to the object to be detected, T represents the detection sampling period, the length of the sampling time interval of the signal acquisition component is 1 / 4T, and I A,0 、 and It represents the grayscale information corresponding to the signal acquisition component A when the phase offsets are 0, 1 / 4T, 2 / 4T and 3 / 4T respectively.

2. The method according to claim 1, wherein in, Determining the flight time corresponding to the object to be measured according to the respective grayscale information includes: The flight time corresponding to the object to be measured is determined according to each of the grayscale information and a preset flight time relationship equation, wherein the flight time relationship equation is a correlation relationship between the grayscale information and the flight time.

3. The method according to claim 1, wherein Determining the flight time corresponding to the object to be measured according to the respective grayscale information includes: For each grayscale information, determining a phase offset information relationship expression corresponding to the grayscale information, wherein the phase offset information relationship expression includes a flight time variable and is used to represent the phase offset information; Determining corresponding phase shift information according to each of the grayscale information; The flight time variable is solved according to the phase offset information and the phase offset information relationship formula to obtain the flight time corresponding to the object to be measured.

4. The method according to claim 1, wherein The method further comprises: Get the sampling time interval setting instruction; According to the sampling time interval setting instruction, each sampling time interval in the detection sampling period is determined.

5. The method according to claim 1, wherein After determining the flight time corresponding to the object to be measured based on the plurality of grayscale information and the length of the sampling time interval, the method further includes: The distance between the object to be measured and the object to be measured is determined according to the flight time corresponding to the object to be measured.

6. A time-of-flight measurement device, characterized in that: include: The signal acquisition component starting unit is configured to control a single signal acquisition component to start a sampling time interval within a detection sampling period for the object to be detected that is illuminated by the modulated continuous carrier beam; an offset sampling unit configured to obtain grayscale information corresponding to the four preset phase offsets of the signal acquisition component, specifically comprising: applying multiple phase offsets to a single signal acquisition component, and performing multiple exposures to enable the single signal acquisition component to record corresponding multiple sampling values, thereby completing a split-exposure sampling operation; The flight time determination unit is configured to determine the flight time corresponding to the object to be measured based on the grayscale information, thereby directly calculating the corresponding flight time using a single signal acquisition component; the flight time relationship is: Wherein, t' represents the flight time corresponding to the object to be detected, T represents the detection sampling period, the length of the sampling time interval of the signal acquisition component is 1 / 4T, and I A,0 、 and It represents the grayscale information corresponding to the signal acquisition component A when the phase offsets are 0, 1 / 4T, 2 / 4T and 3 / 4T respectively.

7. A time-of-flight depth camera, characterized in that include: A transmitting module, comprising a light source and a light modulator, wherein the light modulator is used to control the light source to emit a modulated continuous carrier beam toward the object to be measured; A receiving module, comprising an image sensor composed of at least one pixel, each of the pixels comprising a single signal acquisition component for receiving a light signal reflected from the object to be detected; The control module is connected to the transmitting module and the receiving module and is configured to: For the object to be measured that is illuminated by the modulated continuous carrier beam, controlling a single signal acquisition component to start a sampling time interval within a detection sampling period; Obtaining grayscale information corresponding to the four preset phase offsets of the signal acquisition component, including: applying multiple phase offsets to a single signal acquisition component, and performing multiple exposures to enable the single signal acquisition component to record corresponding multiple sampling values, thereby completing a split-exposure sampling operation; According to the grayscale information, the flight time corresponding to the object to be measured is determined, and then the corresponding flight time is directly calculated using a single signal acquisition component; the flight time relationship is: Wherein, t' represents the flight time corresponding to the object to be detected, T represents the detection sampling period, the length of the sampling time interval of the signal acquisition component is 1 / 4T, and I A,0 、 and It represents the grayscale information corresponding to the signal acquisition component A when the phase offsets are 0, 1 / 4T, 2 / 4T and 3 / 4T respectively.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method according to any one of claims 1 to 5 when executing the computer program.

9. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 5.

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