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 wave light beam, controlling multiple signal acquisition components to sequentially start a continuous sampling time interval in a detection sampling period, wherein the time length corresponding to the sampling time interval of each signal acquisition component is different; for each signal acquisition component, acquiring a gray information set corresponding to a preset four-phase offset of the signal acquisition component, wherein each gray information in the gray information set corresponds to a different phase offset in the four-phase offset; and determining the time of flight of the to-be-measured object according to the gray information set of each signal acquisition component. Thus, different signal acquisition components do not have to be set to have the same sampling time length, and the application range of the time-of-flight measurement system sensor can be expanded.

Description

TECHNICAL FIELD

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

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

[0003] At present, the measurement distance of the PM-iToF modulation technology measurement means 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 lengthened. However, the lengthening of the pulse width of the modulation and demodulation signal will lead to an increase in power consumption and a decrease in measurement accuracy, and thus cannot meet market demand.

[0004] In addition, the CW-iToF technology is mainly applied to a measurement system constructed based on a multi-tap sensor, and the core measurement algorithm is a modulation and demodulation method with different phases. However, in the demodulation process of the sensor of the current time-of-flight measurement system, due to the limitation of the algorithm, multiple taps can only be designed to have equal sampling time lengths, which limits the application range of the sensor.

[0005] At present, there is no better solution in the industry for the above problems. SUMMARY

[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 that the demodulation time of multiple taps of the sensor of the flight measurement system in the current CW-iToF technology is limited by equal sampling time lengths.

[0007] The first aspect of the embodiment of the present application provides a time-of-flight measurement method, comprising: for a to-be-measured object irradiated by a modulated continuous wave light beam, controlling multiple signal acquisition components to sequentially start a sampling time interval in a detection sampling period, wherein the lengths of the sampling time intervals of the signal acquisition components are different; for each of the signal acquisition components, acquiring a gray information set corresponding to a preset four-phase offset of the signal acquisition component, wherein each gray information in the gray information set corresponds to a different phase offset; and determining a time-of-flight corresponding to the to-be-measured object according to the gray information set of each of the signal acquisition components.

[0008] The second aspect of the embodiment of the present application provides a time-of-flight measurement device, comprising: a signal acquisition component starting unit configured to, for a to-be-measured object irradiated by a modulated continuous wave light beam, control multiple signal acquisition components to sequentially start a sampling time interval in a detection sampling period, wherein the lengths of the sampling time intervals of the signal acquisition components are different; an offset gray sampling unit configured to, for each of the signal acquisition components, acquire a gray information set corresponding to a preset four-phase offset of the signal acquisition component, wherein each gray information in the gray information set corresponds to a different phase offset; and a time-of-flight determination unit configured to determine a time-of-flight corresponding to the to-be-measured object according to the gray information set of each of the signal acquisition components.

[0009] The third aspect of the 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 configured to control the light source to emit a modulated continuous wave light beam towards a to-be-measured object; a receiving module comprising an image sensor composed of at least one pixel, each of the pixels comprising multiple signal acquisition components, and being configured to receive a light signal reflected from the to-be-measured object; and a control module connected with the transmitting module and the receiving module, and being configured to: for a to-be-measured object irradiated by a modulated continuous wave light beam, control multiple signal acquisition components to sequentially start a sampling time interval in a detection sampling period, wherein the lengths of the sampling time intervals of the signal acquisition components are different; for each of the signal acquisition components, acquire a gray information set corresponding to a preset four-phase offset of the signal acquisition component, wherein each gray information in the gray information set corresponds to a different phase offset; and determine a time-of-flight corresponding to the to-be-measured object according to the sampling time interval and the corresponding gray information set of each of the signal acquisition components.

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

[0011] The fifth aspect of the embodiment of the present application provides a computer readable storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the above method.

[0012] The sixth aspect of the embodiment of the present application provides a computer program product, when the computer program product runs on an electronic device, so that the electronic device implements the steps of the above method.

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

[0014] Through the embodiment of the present application, different sampling time lengths can be used for each signal acquisition component, and the corresponding gray scale information set can be obtained by applying multiple phase offsets to different signal acquisition components, so that the light flight time can be determined by synthesizing or accumulating the gray scale information of each signal acquisition component under different offsets, so that different signal acquisition components do not have to be set to have the same sampling time length, and the application range of the time flight measurement system sensor can be expanded. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

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

[0017] Figure 2 A tap sampling signal distribution diagram of an example of charge integration ranging by multi-tap in the CW-iToF technology is shown;

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

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

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

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

[0022] Figure 7 An effect diagram showing an example of the effect of time signal crosstalk and space signal crosstalk on tap sampling results;

[0023] Figure 8 A flow chart showing an example of a time-of-flight measurement method according to an embodiment of the present application;

[0024] Figure 9 A flow chart showing an example of updating the K value corresponding to the customized probe sampling period according to an embodiment of the present application;

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

[0026] Figure 11 A flow chart showing an example of a time-of-flight measurement method according to an embodiment of the present application;

[0027] Figure 12 A flow chart showing an example of determining each sampling time interval in the probe sampling period according to an embodiment of the present application;

[0028] Figure 13 A flow chart showing an example of determining the time of flight of the to-be-measured object according to each gray scale information according to an embodiment of the present application;

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

[0030] Figure 15 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 are set forth, such as particular system configurations, techniques, etc., in order to provide a thorough understanding of the present application. However, persons skilled in the art will understand that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

[0032] In order to illustrate the technical solutions described in the present application, the following will be described through specific embodiments.

[0033] It should be understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do 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 the specification and the appended claims are intended to be interpreted broadly and in a manner that is most consistent with the meaning promised by their promoters. As used in the specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0035] It should further be understood that the term "and / or" as used in the specification and the appended claims, means any one or more of the associated listed items, as well as all possible combinations of the items.

[0036] As used in the specification and the appended claims, the term "if' can be interpreted as meaning "when" or "once" or "in response to a determination" or "in response to a detection" depending on the context. Similarly, the phrase "if determined" or "if detected [the recited condition or event]" can be interpreted as meaning "once determined" or "in response to a determination" or "once detected [the recited condition or event]" or "in response to a detection [the recited condition or event]" depending on the context.

[0037] In particular implementations, the electronic device described in the embodiments of the present application includes, but is not limited to, other portable devices such as mobile telephones, laptop computers, or tablet computers having touch-sensitive surfaces (e.g., touch screen displays and / or touch pads). It should also be understood that in some embodiments the device is not a portable communication device, but a computer having a touch-sensitive surface (e.g., a touch screen display).

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

[0039] Various applications can be executed on the electronic device, which 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 the corresponding information displayed on the terminal can be adjusted and / or changed in between applications and / or within respective applications. By way of example, the terminal's common physical architecture (e.g., touch-sensitive surface) can support various applications with a user- intuitive and transparent user interface.

[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 energy integration device for demodulation is shared by the same pixel (i.e. photodiode or other light-sensitive element) when performing photon integration, for example, several different readout and charge accumulation devices (referred to as taps) are connected to the same pixel, and in the process of collecting signals in different time periods, the signal gain and dark current of different taps are inconsistent. At the same time, the sinusoidal signal needs to be sampled in different time periods, including period sampling (i.e. multiple taps sample in one period) and exposure sampling (i.e. the sampling time of the tap is phase delayed in different exposure times).

[0046] It should be noted that in period sampling, the period sampling method of multiple taps in one period is often unable to accurately calculate the distance value of the light flight due to the inconsistency of the sampling interference factors (such as gain and dark current) of different taps. At this time, through the sampling method of exposure, the same tap is collected multiple times, and the data of multiple collections are added, subtracted, multiplied and divided to eliminate the influence of the sampling interference factor term, and finally the purpose of improving the accuracy of distance measurement is achieved.

[0047] However, in the demodulation of the sensor of the traditional time-of-flight measurement system, the demodulation time configuration of multiple taps can only select multiple taps with the same energy integration time (i.e. having equal sampling time length in the detection period) due to the limitation of the algorithm.

[0048] Figure 2 A tap sampling signal distribution diagram according to an example of charge integration ranging of multiple taps in the CW-iToF technology is shown.

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

[0050] In view of this, Figure 3 A flow chart of an example of the time-of-flight measurement method according to the embodiments of the present application is shown. The execution subject of the embodiments of the present application can be various measurement systems or processors with computing or processing functions, for example, it can be the control module 13 in the time-of-flight depth camera 10.

[0051] As Figure 3As shown, in step 310, for the object to be measured irradiated by the modulated continuous carrier light beam, the plurality of signal acquisition components are controlled to sequentially start the sampling time interval in a detection sampling period. Here, the sampling time interval of each signal acquisition component corresponds to different lengths, that is, the starting time point of the sampling operation corresponding to different signal acquisition components is not the same, and there is also a difference between the sampling time length corresponding to different signal acquisition components.

[0052] Exemplarily, each signal acquisition component (also referred to as a tap) in a pixel can be sequentially opened at different time points in the detection sampling period, and each signal acquisition component can have different sampling time lengths. For example, a pixel has four taps, and the plurality of taps can be controlled to be sequentially opened and integrated for different sampling time in an exposure time, for example, assuming that the detection sampling period is T, tap A can be the first to be opened, and the sampling time length can be T / 8, while tap B can be started later, and the sampling time length can be T / 4 or other values.

[0053] It should be noted that the sampling time length of each signal acquisition component can be non-fixed, for example, it can also be adjusted according to different business scenarios or needs. In addition, the above-mentioned "plurality of signal acquisition components" can be used to represent at least two signal acquisition components, and generally three, four or more.

[0054] In step 320, for each signal acquisition component, a corresponding preset four-phase offset is applied to the signal acquisition component to obtain a corresponding set of gray scale information. Here, each gray scale information in the gray scale information set corresponds to a different phase offset.

[0055] Exemplarily, different phase delay amounts can be applied to the transmitted light signal, and the signal acquisition components are respectively called to collect the corresponding gray scale information. Specifically, each tap can collect a signal to complete a frame of measurement when no phase delay is applied; then, after applying a phase delay of 90 degrees, 180 degrees and 270 degrees to the transmitted signal, the corresponding measurement frame is repeatedly collected, a total of 4 frames of sampling signals can be obtained.

[0056] In step 330, the time of flight corresponding to the object to be measured is determined according to the set of gray scale information of each signal acquisition component. For example, the time of flight corresponding to the object to be measured can be calculated based on a preset relationship between the gray scale sampling signal and the time of flight, and more details will be expanded below.

[0057] Through the embodiments of the present application, a new time flight calculation method is proposed, which simulates the process of accumulating the amount of pulse modulation in the integration calculation process in one detection sampling period of CW-iToF, so that the demodulation time of multiple taps is not limited by the same integration sampling time, and the application range of the sensor is expanded. In addition, when the flight time of one frame is calculated, it needs to be measured by different signal acquisition components, which is equivalent to multiple measurements for average value, and also improves the accuracy of the determined flight time.

[0058] In some embodiments, after step 330, the measurement system can also determine the distance between the to-be-measured body according to the flight time of the to-be-measured body.

[0059] Exemplarily, the distance between the measurement system and the to-be-measured body can be determined by the following formula:

[0060]

[0061] Wherein, d is the distance between the to-be-measured body, C is the speed of light, and t is the flight time.

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

[0063] As shown in Figure 4 , in step 410, a sampling interval setting instruction is obtained. Exemplarily, the measurement system can receive a sampling time length setting instruction from a user terminal.

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

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

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

[0067] In step 520, based on the initial flight time determined by each signal acquisition component, the flight time corresponding to the to-be-measured body is determined. Here, various statistical methods can be used to integrate the initial flight times of different signal acquisition components, so as to obtain the final flight time corresponding to the to-be-measured body.

[0068] Exemplarily, the average value of the initial time of flight of the plurality of signal collection components can be calculated to determine the time of flight corresponding to the object to be measured. Here, the phase time delay can be directly taken as the time of flight corresponding to the object to be measured, or the average value of the initial time of flight corresponding to each tap can be calibrated to obtain the corresponding time of flight, so as to eliminate the time delay caused by some other unspecified factors.

[0069] Therefore, the sampling results of the plurality of taps are comprehensively considered, the sampling time lengths of the plurality of taps are inconsistent, the time of flight obtained for each tap is averaged, the design requirement for the sampling time length of the tap can be reduced in design, and the measurement accuracy can be improved.

[0070] Regarding the implementation details of the above step 510, the initial time of flight can be determined according to the preset initial time of flight relationship and the gray scale information. Here, the initial time of flight relationship can be the correlation between the gray scale information and the initial time of flight. Specifically, the initial time of flight relationship can adopt the example in the following formula (2):

[0071]

[0072] Wherein, t′ A represents the initial time of flight corresponding to the signal collection component A, T represents the detection sampling period, the sampling time interval of the signal collection component A is [0, 3 / 4T], and I A,0 、 and represent the gray scale information corresponding to the signal collection component A when the phase offset is 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 the time of flight measurement system is an imaging device based on a photoelectric conversion device, which is essentially still a photon energy integrator device, and the tap is a readout and storage element, which has an amplification circuit and dark current noise inside. However, at present, the light energy collected by the tap is accumulated photocharge, which has not been quantized. In this paper, the number of incident photons can be used to represent the light energy collected by the tap.

[0075] Specifically, the gray scale value I of the imaging (which can also be written as the light energy collected by the tap) and the number of incident photons C Signal,Photon , the tap gain G, and the dark current C Dark,Electron are related as follows:

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

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

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

[0079]

[0080]

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

[0082]

[0083] Where T can represent the modulation period (i.e., the detection sampling period), a represents the amplitude of the change in the received photon number over time, t0 is the time at which the tap begins to integrate within a single period, Δt is the integration time (i.e., the sampling time length) of the tap within a single period, t' is the fixed phase delay caused by the waveform light flight time, ρ (Ambient,Photon) represents the environmental photon time density, and is a constant related to t0, Δt and T, which is a representation obtained from the intermediate process of photon number integration. Accumulation of N detection periods can complete an exposure and collect a sub-frame.

[0084] In the embodiments of the present application, the modulated continuous wave light beam is a sine wave, and of course it can be replaced by a square wave or other waveforms. Here, only a two-tap sensor is taken as an example for description, which can also be a 3-tap, 4-tap, etc. In a detection period, the two taps are continuously turned on and the integration sampling times are different from each other. The integration times of the two taps can be arbitrarily set, for example, taps A and B are set to 3T / 4 and T / 4 respectively; that is, in a detection period, the integration sampling time (i.e., the sampling time interval) of tap A is 0 to 3T / 4, and the integration sampling time of tap B is 3T / 4 to T; when Δt = 3T / 4, And when Δt = T / 4,

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

[0086]

[0087]

[0088] Where t A , t Brespectively, are the times when the two taps start to collect, respectively, 0 and 3T / 4. Further, there are

[0089]

[0090]

[0091] It should be noted that, if the time delay t' caused by the light flight time and other factors is to be calculated according to the gray values I A and I B collected by the two taps, the errors caused by the gain and dark current of different taps need to be eliminated, and the sampling data of the same tap at multiple phase delays can be collected.

[0092] Exemplarily, in the split-exposure sampling process, four phase-delay exposure collection operations can be performed on each tap, i.e., t A takes 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 embodiments of the present application, and the exposure phase delay is fixed, which is completely different from the conventional four-phase sampling method.

[0093] Taking tap A as an example, four delay exposures can obtain:

[0094]

[0095]

[0096]

[0097]

[0098] According to the relationship between the phase delay Φ and the time delay t', the following can be obtained:

[0099]

[0100] Therefore, by first defining the calculation expression of the tap output gray value, the gray value output by each tap of each frame can be obtained, and then the relationship between the phase delay and the time delay can be obtained by combining the four gray values I collected at four phase-delay exposures. Since the relationship between the phase delay and the four-phase gray value is The time delay of each tap can be calculated.

[0101] Then, the time delay t' caused by the light flight time and other factors 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 6As shown, the time-of-flight measurement device 600 comprises a signal acquisition component starting unit 610, an offset grayscale sampling unit 620, and a time-of-flight determination unit 630.

[0116] The signal acquisition component starting unit 610 is configured to, for a to-be-measured object irradiated by the modulated continuous carrier light beam, control a plurality of signal acquisition components to sequentially start in a detection sampling period and each have a sampling time interval of different length.

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

[0118] The time-of-flight determination unit 630 is configured to determine a time-of-flight of the to-be-measured object according to the grayscale information set of each of the signal acquisition components.

[0119] It should be noted that the information interaction, execution process, and the like between the above devices / units, since based on the same concept as the method embodiments of the present application, the specific functions and the resulting technical effects can be referred to the method embodiments part, and will not be repeated here.

[0120] Regarding another aspect of the embodiments of the present application, it should be noted that the current time-of-flight measurement system still has some places that need to be improved. Generally, the demodulation energy integration device is shared by the same pixel (i.e. photodiode or other photosensitive element) when integrating photons, and different readout and charge accumulation devices (called taps) are connected to the same pixel. In the process of time-sharing signal acquisition, it is inevitable that there will be time crosstalk and spatial crosstalk between different taps in receiving charge signals.

[0121] Figure 7 An effect diagram showing an example of time signal crosstalk and spatial signal crosstalk affecting tap sampling results is shown.

[0122] Here, the time signal crosstalk refers to, due to the spatial area of the pixel and the discrete spatial distribution of the tap, as shown in Figure 7 part of the charge signals generated when the first tap is opened for collection do not enter the tap due to the spatial distance; instead, they enter the next tap to generate signals when the next tap is opened for collection. In addition, the spatial crosstalk refers to, when a tap is opened for charge collection, the electric potential field gradient of the tap that is opened for charge collection increases, and the electric potential field gradient of the tap that is not opened for charge collection decreases; however, even if the electric potential field gradient of the tap that is not opened for charge collection is low, as shown in Figure 7As 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 5The measurement system can determine the initial flight time of each signal acquisition component based on the sampling time interval of the signal acquisition component and the collected grayscale information set. Then, the measurement system can determine the flight time of the object to be measured based on the initial flight time determined by each signal acquisition component. For example, the measurement system can calculate the average value of the initial flight times of the plurality of signal acquisition components to determine the flight time of the object to be measured.

[0131] Figure 9 FIG. 10 shows 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.

[0132] As shown in FIG. 10, in step 910, a customized detection sampling period setting instruction is acquired. For example, the measurement system can receive the customized detection sampling period setting instruction from the user terminal. Figure 9

[0133] In step 920, the K value of the customized detection sampling period is updated based on the customized detection sampling period setting instruction. In this way, the detection sampling period with an extended time length can be customized for the signal acquisition component, and the detection sampling period can be adjusted through the instruction interaction, thereby meeting the requirements of different user demands or business scenarios.

[0134] Specifically, the initial flight time can be determined in the following manner:

[0135]

[0136] where t' A represents the initial flight time of 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 represent the grayscale information corresponding to the signal acquisition component A when the phase offset is 0, 1 / 4T, 2 / 4T, and 3 / 4T, respectively.

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

[0138] Here, in the specific demodulation process of the measurement system, the measurement system can use the period sampling manner and the exposure sampling manner for demodulation. For the derivation process of formula (11) above, the derivation details of formula (2) above can be 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, The sub-period sampling operation is completed. Then, four phase delay exposure collections are performed on each tap t A 0, Four exposures are performed.

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

[0153]

[0154]

[0155]

[0156]

[0157]

[0158] Therefore, even if the sampling time length of different taps is extended, the time flight calculation operation can be completed through the above relationship. At the same time, due to the increase of signal photons in single tap integration, and the total number of crosstalk photons remains unchanged, the signal-to-noise ratio of the signal is relatively increased, and the measurement accuracy is improved.

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

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

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

[0162] The offset grayscale sampling unit 1020 is configured to obtain a grayscale information set corresponding to a preset four-phase offset for each signal acquisition component, wherein each grayscale information in the grayscale information set corresponds to a different phase offset.

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

[0164] It should be noted that the information interaction, execution process and the like between the above apparatuses / units are based on the same concept as the method embodiments of the present application, and specific functions and brought technical effects can be referred to the method embodiments part, which will not be repeated here.

[0165] As to another aspect of the embodiments of the present application, it should be noted that there are still some aspects that need to be improved in the current time-of-flight measurement system. For a sensor with multiple taps corresponding to one pixel, since the same pixel needs multiple readout circuits, for example, referring to the example of the tapped sensor in Figure 7 , the volume 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 11 a flowchart of an example of a time-of-flight measurement method according to the embodiments of the present application is shown. As to the execution subject of the embodiments of the present application, it can be various measurement systems or processors with computing or processing functions, for example, it can be the control module 13 in the time-of-flight depth camera 10.

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

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

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

[0170] Exemplarily, multiple phase offsets can be applied to the single tap in the pixel respectively, and multiple exposures are performed respectively to make the tap record the corresponding multiple sampling values, so as to complete the split exposure sampling operation.

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

[0172] It should be noted that in the related art, the energy collected by the tap is output to the subsequent circuit for processing after the collection is completed, which causes time consumption and has a high requirement on the capacity of the tap, and also cannot guarantee the accuracy of the measurement result. However, in the embodiments of the present application, the corresponding time of flight can be directly calculated by using a single tap.

[0173] Therefore, under the premise of not affecting the measurement function of the time-of-flight measurement sensor, by adopting the single-tap pixel layout, the chip design and processing difficulty can be reduced, the area of a single pixel is reduced, and the resolution of the sensor is improved.

[0174] In some embodiments, after step 830, the method further includes determining the distance between the to-be-measured body according to the time of flight corresponding to the to-be-measured body, for example, substituting the time of flight into the above formula (1) to obtain the distance relative to the to-be-measured body.

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

[0176] As Figure 12 shown, in step 1210, a sampling time interval setting instruction is acquired. Exemplarily, the measurement system can receive the sampling time interval setting instruction from a user terminal.

[0177] In step 1220, each sampling time interval in the detection sampling period is determined according to the sampling time interval setting instruction. Thus, different sampling time intervals, including the start time of each sampling stage and the corresponding sampling time length, can be set in the signal acquisition component, which can be adjusted through instruction interaction to meet the needs of different users or business scenarios.

[0178] Regarding the specific implementation details of the above step 1130, on the one hand, the time of flight corresponding to the to-be-measured body can be determined according to each gray scale information and a preset time of flight relationship. Here, the time of flight relationship is the association between the gray scale information and the time of flight. Thus, the measurement system can directly substitute the gray scale information at different phase shifts into the relationship to calculate and quickly obtain the corresponding time of flight.

[0179] In some embodiments, the corresponding time of flight can be determined in the following manner:

[0180]

[0181] Where t' represents the time of flight corresponding to the to-be-measured body, the single sampling interval time length of the signal acquisition component is 1 / 4T, and I A,0 、 and represent the gray scale information corresponding to the signal acquisition component A when the phase shift is 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 mode and the exposure sampling mode for demodulation. For the derivation process and details of the above formula (16), reference can also be made to the description of other related parts in the above.

[0183] For the specific implementation details of the above step 1130, on the other hand, reference can also be made to the operation in the flow of Figure 12 . Figure 13 A flowchart showing an example of determining the time of flight of the corresponding object to be measured according to various gray scale information according to an embodiment of the present application is shown.

[0184] As shown in Figure 13 , in step 1310, for each gray scale information, the phase shift information relationship corresponding to the gray scale information is determined. Here, the phase shift information expression is a relationship containing the time of flight variable.

[0185] In step 1320, the corresponding phase shift information is determined according to each gray scale information.

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

[0187] Exemplarily, the phase delay generated by the single-tap after the delayed exposure can be represented using the following phase shift information relationship, by analogy with the description of formula (9) in the above:

[0188]

[0189] At this time, the corresponding phase shift information can be calculated as:

[0190]

[0191] Further, the above two factors about Φ can be combined to solve t', and the light time of flight is obtained.

[0192] Thus, first, the photon number calculation expression of the tap output gray scale value is defined, the gray scale value output by the tap per frame can be solved, and the relationship between the phase delay and the time delay is obtained by combining the gray scale values collected under four-phase delay (the phase delay is 0, T / 4, 2T / 4 and 3T / 4 respectively) exposure obtained by multiple exposures, and the inherent relationship between the phase delay and the four-phase gray scale value is considered comprehensively, and the time delay of the tap can be calculated.

[0193] In the embodiments of the present application, only one readout circuit (i.e., one tap for each pixel) is used in one pixel. By adjusting the start and end readout times of the tap, the sampling and demodulation process of a multi-tap sensor can be simulated, and a more accurate measurement result can still be obtained. Since only one tap is used in each pixel, the difficulty of circuit design is greatly reduced, and the area of each pixel is reduced, so that the resolution of the time-of-flight measurement chip can be improved.

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

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

[0196] The signal acquisition component starting unit 1410 is configured to control a single signal acquisition component to start a plurality of sampling time intervals in a detection sampling period for a to-be-measured object irradiated by a modulated continuous wave light beam, where each sampling time interval has an equal sampling time interval length.

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

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

[0199] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units, since based on the same concept as the method embodiments of the present application, the specific functions and the technical effects brought by them can be referred to the method embodiments part, which will not be repeated here.

[0200] Figure 15 is a schematic diagram of an example of an electronic device according to an embodiment of the present application. As shown in Figure 15 , 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. The processor 1510 implements the steps in the above-mentioned time-of-flight measurement method embodiments when executing the computer program 1530, such as the steps 310 to 330 shown in Figure 3 , or the steps 810 to 830, or the steps 1110 to 1130. Alternatively, the processor 1510 implements the functions of each module / unit in the above-mentioned device embodiments when executing the computer program 1530, such as the signal acquisition component starting unit 1410, the offset sampling unit 1420, and the time-of-flight determination unit 1430.Figure 6 the functions of the units 610-630 as described above, or Figure 10 the units 1010-1030 as described above, or Figure 14 the units 1410-1430 as described above.

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

[0202] In one example of the embodiments of the present application, the computer program 1530 can be divided into a signal acquisition component starting program module, an offset gray scale sampling program module, and a time of flight determination program module, and the specific functions of each program module are as follows:

[0203] The signal acquisition component starting program module is configured to control a plurality of signal acquisition components to sequentially start in a detection sampling period and have different sampling time intervals in length for a to-be-measured object irradiated by a modulated continuous carrier light beam.

[0204] The offset gray scale sampling program module is configured to obtain a gray scale information set corresponding to a preset four-phase offset for each signal acquisition component, wherein each gray scale information in the gray scale information set corresponds to a different phase offset in the four-phase offset.

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

[0206] In another example of the embodiments of the present application, the computer program 1530 can be divided into a signal acquisition component starting program module, an offset gray scale sampling program module, and a time of flight determination program module, and the specific functions of each program module are as follows:

[0207] The signal acquisition component starting program module is configured to control M signal acquisition components to sequentially start in a customized detection sampling period for a to-be-measured object irradiated by a modulated continuous carrier light beam, and the customized detection sampling period includes K original detection sampling periods T, M and K are positive integers greater than 1, and the sampling time interval length of each signal acquisition component is (K / M)*T.

[0208] The offset gray scale sampling program module is configured to acquire a gray scale information set corresponding to each of the four preset phase offsets of each of the signal acquisition components, wherein each of the gray scale information in the gray scale information set corresponds to a different phase offset;

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

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

[0211] The signal acquisition component starting program module is 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 irradiated by a modulated continuous wave light beam;

[0212] The offset sampling program module is configured to acquire each of the gray scale information corresponding to the four preset phase offsets of the signal acquisition component;

[0213] The time of flight determination program module is configured to determine the time of flight of the object to be measured according to the gray scale information.

[0214] The electronic device 1500 can be a desktop computer, a notebook, a palm computer and a cloud server, etc. The electronic device can include, but is not limited to, a processor 1510 and a memory 1520. Those skilled in the art can understand that, Figure 15 The electronic device 1500 is only an example and does not constitute a limitation on the electronic device 1500, which can include more or fewer components than shown, or combine certain components, or different components, for example, the electronic device can also include an input / output device, a network access device, a bus, etc.

[0215] The processor 1510 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0216] The memory 1520 can be an internal storage unit of the electronic device 1500, for example, a hard disk or a memory of the electronic device 1500. The memory 1520 can also be an external storage device of the electronic device 1500, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, or the like equipped on the electronic device 1500. Further, the memory 1520 can include both the internal storage unit and the external storage device of the electronic device 1500. The memory 1520 is used to store the computer programs and other programs and data required by the electronic device. The memory 1520 can also be used to temporarily store data that has been output or will 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 functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of software functional unit. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the present 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.

[0218] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0219] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or in combination of computer software and electronic hardware. Whether the functions are executed 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 the present application.

[0220] In the embodiments of the present application, it should be understood that the disclosed apparatus / equipment and method can be implemented by other manners. For example, the apparatus / equipment embodiments described above are merely illustrative, for example, the division of the modules or units is merely a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or components shown or discussed can be indirect coupling or communication connection through some interfaces, apparatuses or units, which can be electrical, mechanical or other forms.

[0221] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. can be located in one place or distributed on a plurality of network units. Part or all of the units can be selected to achieve the purpose of the embodiment scheme according to actual needs.

[0222] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The above-mentioned units can be realized in the form of hardware or in the form of software.

[0223] The integrated module / unit, if realized in the form of software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by computer programs instructing related hardware, and the computer programs can be stored in a computer readable storage medium. When the processor executes the computer programs, the steps of each method embodiment described above can be implemented. The computer programs include computer program codes, which can be in the form of source code, object code, executable files or some intermediate forms. The computer readable medium can include any entity or device capable of carrying the computer program codes, recording medium, U disk, 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, etc. It should be noted that the contents included 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, the computer readable medium does not include electric carrier signal and telecommunication signal.

[0224] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A time-of-flight measurement method, characterized in that: include: For an object to be measured that is illuminated by a modulated continuous carrier beam, controlling multiple signal acquisition components to sequentially start continuous sampling time intervals within a detection sampling cycle, wherein the durations corresponding to the sampling time intervals of the respective signal acquisition components are different; For each of the signal acquisition components, obtaining a grayscale information set of four preset phase offsets corresponding to the signal acquisition component, wherein each grayscale information in the grayscale information set corresponds to a different phase offset among the four phase offsets; Determining the flight time of the object to be measured by integrating or accumulating the grayscale information of each signal acquisition component at different offsets according to the grayscale information set of each signal acquisition component, including: For each of the signal acquisition components, determining a corresponding initial flight time based on the sampling time interval of the signal acquisition component and the acquired grayscale information set; Calculating an average value corresponding to the initial flight times of the plurality of signal acquisition components to determine a flight time corresponding to the object to be measured; The method further includes determining the corresponding initial flight time by the following relationship: 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.

2. The method according to claim 1, wherein The method further comprises: Get the sampling interval setting instruction; Based on the sampling interval setting instruction, the sampling time intervals respectively corresponding to the signal acquisition components are updated.

3. The method according to claim 1, wherein After determining the flight time corresponding to the object to be measured based on the grayscale information set of each signal acquisition component, 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.

4. A time-of-flight measurement device, characterized in that: include: A signal acquisition component activation unit is configured to control multiple signal acquisition components to be activated sequentially 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; an offset grayscale sampling unit 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; The flight time determination unit is configured to determine the flight time corresponding to the object to be measured by integrating or accumulating the grayscale information of each signal acquisition component at different offsets based on the grayscale information set of each signal acquisition component, including: For each of the signal acquisition components, determining a corresponding initial flight time based on the sampling time interval of the signal acquisition component and the acquired grayscale information set; Calculating an average value corresponding to the initial flight times of the plurality of signal acquisition components to determine a flight time corresponding to the object to be measured; The flight time measurement device further includes determining the corresponding initial flight time by the following relationship: 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.

5. 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 plurality of signal acquisition components for receiving light signals 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 an object to be measured that is illuminated by a modulated continuous carrier beam, controlling multiple signal acquisition components to sequentially start continuous sampling time intervals within a detection sampling cycle, wherein the durations corresponding to the sampling time intervals of the respective signal acquisition components are different; For each of the signal acquisition components, obtaining a grayscale information set of four preset phase offsets corresponding to the signal acquisition component, wherein each grayscale information in the grayscale information set corresponds to a different phase offset among the four phase offsets; Determining the flight time of the object to be measured by integrating or accumulating the grayscale information of each signal acquisition component at different offsets according to the grayscale information set of each signal acquisition component, including: For each of the signal acquisition components, determining a corresponding initial flight time based on the sampling time interval of the signal acquisition component and the acquired grayscale information set; Calculating an average value corresponding to the initial flight times of the plurality of signal acquisition components to determine the flight time corresponding to the object to be measured; The time-of-flight depth camera also includes determining the corresponding initial flight time by the following relationship: 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.

6. 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 3 when executing the computer program.

7. A computer-readable storage medium storing a computer program, wherein the computer program is configured to implement the steps of the method according to any one of claims 1 to 3 when executed by a processor.

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