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 body irradiated by a modulated continuous wave light beam, controlling M signal acquisition components to sequentially start a sampling time interval in a customized detection sampling period, wherein the sampling time interval length of each signal acquisition component is (K / M)*T; acquiring a gray information set corresponding to a preset four-phase offset for each 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 body according to the gray information set of each signal acquisition component. Thus, the integration time of a single tap is increased, the crosstalk photons are reduced relative to the signal photons, and the signal-to-noise ratio of the signal can be improved.

Description

Technical Field

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

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

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

[0004] Furthermore, CW-iToF technology is primarily applied to measurement systems built upon multi-tap sensors, with its core measurement algorithm employing a modulation and demodulation method based on different phases. However, generally, the energy integration devices used in demodulation share the same pixel (i.e., a photodiode or other photosensitive element) during photon integration. With several different readout and charge accumulation devices (called taps) connected to the same pixel, temporal and spatial crosstalk between the different taps inevitably occurs during time-division multiplexing of signals, affecting measurement accuracy.

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

[0006] In view of this, embodiments of this application provide a time-of-flight measurement method, apparatus, and time-of-flight depth camera to at least solve the problem in current CW-iToF technology where the demodulation time of multiple taps of the sensor in the flight measurement system is limited by equal sampling time lengths.

[0007] A first aspect of this application provides a time-of-flight measurement method, comprising: for a test object irradiated by a modulated continuous carrier beam, controlling M signal acquisition components to sequentially start a continuous sampling time interval 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 of the signal acquisition components is (K / M)*T; acquiring grayscale information sets of preset four-phase offsets corresponding to each of the signal acquisition components, wherein each grayscale information in the grayscale information set corresponds to a different phase offset; and determining the time of flight of the test object corresponding to the grayscale information set of each of the signal acquisition components.

[0008] A second aspect of this application provides a time-of-flight measurement device, comprising: a signal acquisition component activation unit configured to control M signal acquisition components to sequentially activate continuous sampling time intervals within a customized detection sampling period for a test object 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 sampling time interval length of each of the signal acquisition components is (K / M)*T; an offset grayscale sampling unit configured to acquire grayscale information sets corresponding to preset four-phase offsets for each of the signal acquisition components, wherein each grayscale information in the grayscale information set corresponds to a different phase offset; and a time-of-flight determination unit configured to determine the time of flight corresponding to the test object based on the grayscale information sets of each of the signal acquisition components.

[0009] A third aspect of this application provides a time-of-flight depth camera, comprising: a transmitting module including a light source and a light modulator, the light modulator being used to control the light source to emit a modulated continuous carrier beam toward a test object; a receiving module including an image sensor composed of at least one pixel, each pixel including multiple signal acquisition components for receiving light signals reflected back from the test object; and a control module connected to the transmitting module and the receiving module, configured to: control M signal acquisition components to sequentially start continuous sampling time intervals within a customized detection sampling period for a test object irradiated by the 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 sampling time interval length of each signal acquisition component is (K / M)*T; acquire grayscale information sets corresponding to preset four-phase offsets for each signal acquisition component, wherein each grayscale information in the grayscale information set corresponds to a different phase offset; and determine the flight time of the test object based on the sampling time interval of each signal acquisition component and the corresponding grayscale information set.

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

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

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

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

[0014] By setting a customized detection sampling period for the measurement system that is longer than the original detection sampling period through the embodiments of this application, the sampling time length of each signal acquisition component can be increased, thereby reducing the reduction of crosstalk photons relative to signal photons and increasing the signal-to-noise ratio of the signal without affecting the measurement function of the time-of-flight measurement sensor. Attached Figure Description

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

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

[0017] Figure 2 The diagram shows an example of the tap sampling signal distribution when performing charge integration ranging using multi-tap technology in CW-iToF.

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

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

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

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

[0022] Figure 7 This diagram illustrates an example of how temporal and spatial crosstalk affects tap sampling results.

[0023] Figure 8 A flowchart illustrating an example of a time-of-flight measurement method according to an embodiment of this application is shown;

[0024] Figure 9 A flowchart illustrating an example of an updated custom detection sampling period corresponding to the K value according to an embodiment of this application is shown.

[0025] Figure 10 A structural block diagram of an example of a time-of-flight measuring device according to an embodiment of this application is shown;

[0026] Figure 11 A flowchart illustrating an example of a time-of-flight measurement method according to an embodiment of this application is shown;

[0027] Figure 12 A flowchart illustrating an example of determining various sampling time intervals within a detection sampling period according to an embodiment of this application is shown;

[0028] Figure 13 A flowchart illustrating an example of determining the flight time of a corresponding test object based on various grayscale information according to an embodiment of this application is shown.

[0029] Figure 14 A structural block diagram of an example of a time-of-flight measuring device according to an embodiment of this application is shown;

[0030] Figure 15 This is a schematic diagram of an example of an electronic device according to an embodiment of this application. Detailed Implementation

[0031] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

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

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

[0034] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0035] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0036] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrases "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0037] In specific implementations, the electronic devices described in the embodiments of this 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., touchscreen displays and / or touchpads). It should also be understood that in some embodiments, the aforementioned devices are not portable communication devices, but rather computers with touch-sensitive surfaces (e.g., touchscreen displays).

[0038] The following discussion describes electronic devices including displays and touch-sensitive surfaces. However, it should be understood that electronic devices may include one or more other physical user interface devices such as physical keyboards, mice, and / or joysticks.

[0039] Various applications that can run on electronic devices 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 between and / or within applications. In this way, the common physical architecture of the terminal (e.g., the touch-sensitive surface) can support various applications with user interfaces that are intuitive and transparent to the user.

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

[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, with the control module 13 connected to both 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 under test 20. The receiving module 12 can receive the optical signal 103 reflected back from the object under test 20. The control module 13 can calculate the distance 104 between the reflected optical signal and the object under test 20. In some cases, the control module 13 can also regulate the sampling operation of the receiving module 12, such as adjusting the sampling period 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. Combining these devices can enable richer functions, such as 3D texture modeling, infrared face recognition, and SLAM.

[0043] In some embodiments, the transmitting module 11 may include a light source (not shown) and a light modulator (not shown), the light modulator controlling the light source to emit a modulated continuous carrier beam toward the object under test 20. Furthermore, the receiving module 12 may include an image sensor consisting of at least one pixel, and each pixel includes multiple signal acquisition components. Here, the signal acquisition components may refer to components that acquire optical signals; they may be devices for readout and charge accumulation, for example, the signal acquisition components may employ taps.

[0044] Specifically, the time-of-flight depth camera 10 can employ an indirect time-of-flight measurement method. It can modulate the power waveform of the emitted light to a near-sine wave (or other waveforms, such as a square wave), and the demodulation device (e.g., an i-TOFS sensor) integrates the power of the received light at different time intervals. Generally, the demodulation device will have several different acquisition time intervals; this time-segmented acquisition of the echo sinusoidal signal is equivalent to multi-point sampling of the sinusoidal signal. Furthermore, the demodulation device outputs multiple sampled values ​​of the echo sinusoidal signal, enabling the control module 13 to calculate the phase delay of the echo sinusoidal signal and the flight distance of the light signal between the time-of-flight depth camera 10 and the object 20.

[0045] Here, the demodulation energy integrators all share the same pixel (i.e., photodiode or other photosensitive element) when performing photon integration. For example, several different readout and charge accumulation devices (called taps) are connected to the same pixel. During time-division multiplexing of signals, the signal gain and dark current of different taps are inconsistent. At the same time, it is necessary to sample the sine wave signal for different time periods, including periodic sampling (i.e., multiple taps sample within one period) and exposure-division sampling (i.e., the sampling time of the taps is phase-delayed at different exposure times).

[0046] It should be noted that in periodic sampling, the time-division sampling method using multiple taps within a single period often fails to accurately calculate the distance traveled by light due to inconsistencies in sampling interference factors (e.g., gain and dark current) among different taps. In this case, by using a multi-exposure sampling method, the same tap is sampled multiple times, and the data from these multiple samplings are used for addition, subtraction, multiplication, and division operations. This eliminates the influence of sampling interference factors, ultimately improving the accuracy of distance measurement.

[0047] However, in the demodulation of sensors in traditional time-of-flight measurement systems, the demodulation time configuration of multiple taps is limited by the algorithm, which can only select multiple taps with the same energy integration time (i.e., with equal sampling time lengths within the detection period).

[0048] Figure 2 The diagram shows an example of the tap sampling signal distribution when performing charge integration ranging using multi-tap technology in CW-iToF.

[0049] like Figure 2 As shown, after obtaining a depth image based on the periodic sampling method, another 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 flowchart illustrating an example of a time-of-flight measurement method according to an embodiment of this application is shown. The implementing entity of this embodiment can be various measurement systems or processors with computing or processing capabilities, such as the control module 13 in the time-of-flight depth camera 10.

[0051] like Figure 3As shown, in step 310, for the test object illuminated by the modulated continuous carrier beam, multiple signal acquisition components are controlled to sequentially start continuous sampling time intervals within a detection sampling period. Here, the sampling time intervals of each signal acquisition component are different in duration; that is, the start time of the sampling operation for different signal acquisition components is different, and the sampling time lengths corresponding to different signal acquisition components also differ.

[0052] For example, the individual signal acquisition components (also referred to as taps) in a pixel can be activated sequentially at different points in time during the detection sampling period, and each signal acquisition component can have a different sampling time length. For instance, a pixel may have four taps, and multiple taps can be controlled to be activated consecutively 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 its sampling time length can be T / 8, while tap B can be activated later, and its sampling time length can be T / 4 or other values.

[0053] It should be noted that the sampling time of each signal acquisition component can be non-fixed, and can be adjusted according to different business scenarios or requirements. In addition, the above "multiple signal acquisition components" can be used to refer to at least two signal acquisition components, but generally three or four or more.

[0054] In step 320, a preset four-phase offset is 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 invoked to acquire the corresponding grayscale information. Specifically, each tap can acquire the signal to complete one frame 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 can be repeatedly acquired, resulting in a total of 4 frames of sampled signals.

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

[0057] This application proposes a novel time-of-flight calculation method that simulates the accumulation process of pulse modulation within one detection sampling period of CW-iToF. This allows the demodulation time of multiple taps to be unrestricted by the same integration sampling time, expanding the sensor's applicability. Furthermore, calculating the flight time of a frame requires separate measurements using different signal acquisition components, effectively averaging multiple measurements and improving the accuracy of the determined flight time.

[0058] In some implementations, after step 330, the measurement system may also determine the distance to the object being measured based on the flight time for the object.

[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 between the object being measured, C is the speed of light, and t is the time of flight.

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

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

[0064] In step 420, the sampling time interval corresponding to each signal acquisition component is updated based on the sampling interval setting command. This allows for setting different sampling time intervals for each signal acquisition component, which can be adjusted via command interaction, meeting the needs of different users or business scenarios.

[0065] Figure 5 A flowchart illustrating an example of determining the flight time of a corresponding test object according to an embodiment of this 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 acquired grayscale information set.

[0067] In step 520, the flight time of the corresponding test object 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 using various statistical methods to obtain the final flight time of the corresponding test object.

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

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

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

[0071]

[0072] Where, t′ A Let T represent the initial flight time corresponding to signal acquisition component A, T represent the detection sampling period, and the sampling time interval of signal acquisition component A is [0, 3 / 4T]. A,0 , and This represents the grayscale information corresponding to signal acquisition component A when the phase offset is 0, 1 / 4T, 2 / 4T, and 3 / 4T.

[0073] The derivation process for equation (2) above will be described in detail below.

[0074] It should be noted that the time-of-flight measurement system is an imaging device based on photoelectric conversion devices, which is essentially a photon energy integrator. The tap, as a readout and storage element, contains internal amplification circuitry and dark current noise. However, currently, the light energy collected by the tap is the accumulated photocharge, which has not been quantified. In this paper, the incident photon count 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 acquired 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 when light is 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 as follows:

[0079]

[0080]

[0081] The grayscale values ​​collected by the two taps form two-point samples of the sine curve. The number of signal photons received by each tap is the integral of the time distribution of the incident photon number.

[0082]

[0083] Where T represents the modulation period (i.e., the detection sampling period), a represents the amplitude of the number of received photons changing with time, t0 is the time when the tap begins integration 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 flight time of the waveform light, and ρ (Ambient,Photon) Represents the ambient photon temporal density, and It is a constant related to t0, Δt, and T, and is a characterization obtained from the intermediate process of photon number integration. One exposure is completed by repeating the accumulation of N detection cycles, acquiring one subframe.

[0084] In this embodiment, the modulated continuous carrier beam is a sine wave, but it can also be replaced with other waveforms such as a square wave. Here, only a two-tap sensor is used as an example; it can also be a three-tap, four-tap, etc. Within one detection cycle, the two taps are continuously activated with different integration sampling times. The integration times of the two taps can be arbitrarily set; for example, taps A and B can be set to 3T / 4 and T / 4 respectively. That is, within one detection cycle, the integration sampling time (i.e., the sampling time interval) of tap A is from 0 to 3T / 4, and the integration sampling time of tap B is from 3T / 4 to T. When Δt = 3T / 4, When Δt = T / 4

[0085] Therefore, the number of photons collected after integrating from taps A and B is:

[0086]

[0087]

[0088] Among them, t A t BThese represent the start times of the two taps, 0 and 3T / 4 respectively. Therefore, we have...

[0089]

[0090]

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

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

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

[0094]

[0095]

[0096]

[0097]

[0098] Based on the relationship between phase delay Φ and time delay t', we can obtain:

[0099]

[0100] Therefore, by first defining the calculation expression for the grayscale value of the tap output, the grayscale value output by each tap per frame can be obtained. Then, by combining the grayscale values ​​I collected under four phase-delay exposures obtained from four exposures, the relationship between phase delay and time delay can be obtained. Furthermore, due to the relationship between phase delay and the four-phase grayscale values... It can calculate the time delay of each tap.

[0101] Therefore, the time delay t' caused by factors such as the time of light travel is:

[0102]

[0103]

[0104]

[0105] In the above-mentioned exposure sampling process, four phase-delay exposure acquisition operations are performed on each tap, and the time delay of each tap is calculated using the grayscale acquisition results of different phases and the corresponding sampling time intervals. The time delays are then averaged to obtain a phase delay with high accuracy.

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

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

[0108]

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

[0110] Next, the corresponding phase shift information can be determined based on the various grayscale values. It should be understood that there is an inherent relationship between the phase shift information and the grayscale information with different shift amounts, which can be expressed as:

[0111]

[0112] Furthermore, the two points mentioned above regarding φ can be... A By combining the factors, we can solve for t. A ′, thus obtaining the initial flight time corresponding to signal acquisition component A.

[0113] In this embodiment, the integration time of the taps is not limited, and the time of flight of light can still be calculated. This means that the demodulation time of multiple taps is not limited by the same integration time, thus expanding the applicability of the time-of-flight measurement system sensor.

[0114] Figure 6 A structural block diagram of an example of a time-of-flight measuring device according to an embodiment of this application is shown.

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

[0116] The signal acquisition component activation unit 610 is configured to control multiple signal acquisition components to be turned on sequentially within a detection sampling period for the test object irradiated by a modulated continuous carrier beam, each having a sampling time interval of different lengths.

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

[0118] The flight time determination unit 630 is configured to determine the flight time of the object under test based on the grayscale information set of each of the signal acquisition components.

[0119] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0120] Regarding another aspect of the embodiments of this application, it should be noted that current time-of-flight measurement systems still have some areas that need improvement. Generally, when demodulating energy integration devices perform photon integration, they share the same pixel (i.e., photodiode or other photosensitive element). Different readout and charge accumulation devices (called taps) are connected to the same pixel. During time-division multiplexing of signal acquisition, temporal and spatial crosstalk of received charge signals between different taps is inevitable.

[0121] Figure 7 This diagram illustrates an example of how temporal and spatial crosstalk affects tap sampling results.

[0122] Here, time signal crosstalk refers to the interference caused by the spatial area of ​​pixels and the discrete spatial distribution of taps, such as... Figure 7 As shown, some of the charge signals generated when the first tap is activated for charge acquisition do not enter that tap due to spatial distance; instead, they enter the next tap and generate signals when the next tap is activated for acquisition. Furthermore, spatial crosstalk refers to the phenomenon that when a tap is activated for charge acquisition, the potential field gradient pointing towards the tap with activated charge acquisition increases, while the potential field gradient pointing towards the tap without activated charge acquisition decreases; however, even if the potential field gradient of the tap without activated charge acquisition is low, as... Figure 7As shown, due to the Brownian motion of charges, signal charges from pixels near the unactivated taps can still enter the unactivated taps, generating spatial crosstalk. Therefore, both temporal and spatial crosstalk are forms of noise in measurements and can affect measurement accuracy.

[0123] In view of this, Figure 8 A flowchart illustrating an example of a time-of-flight measurement method according to an embodiment of this application is shown. The implementing entity of this embodiment can be various measurement systems or processors with computing or processing capabilities, such as the control module 13 in the time-of-flight depth camera 10.

[0124] like Figure 8 As shown, in step 810, for the test object illuminated by the modulated continuous carrier beam, M signal acquisition components are controlled to sequentially start continuous sampling time intervals within a customized detection sampling period. Here, the customized detection sampling period includes 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. Therefore, the sampling time interval of the signal acquisition components is extended by a factor of K.

[0125] Here, the customized detection sampling period includes multiple original detection sampling periods (e.g., sine 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 preset four-phase offsets are acquired for each signal acquisition component. Here, each grayscale information in the grayscale information set corresponds to a different phase offset in the four-phase offset.

[0127] In step 830, the flight time of the corresponding test object is determined based on the grayscale information set of each signal acquisition component.

[0128] Through the embodiments of this 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 number of crosstalk photons is 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 between the object and the object based on the flight time of the object to be measured, for example, by substituting the flight time into the above formula (1) to obtain the distance relative to the object.

[0130] For details regarding the implementation of step 830 above, please refer to or combine the above text with relevant information. Figure 5The description is as follows. 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 acquired grayscale information set. Then, based on the initial flight time determined by each signal acquisition component, the flight time of the corresponding test object is determined. For example, the average value corresponding to the initial flight times of multiple signal acquisition components can be calculated to determine the flight time of the corresponding test object.

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

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

[0133] In step 920, the K value of the customized detection sampling period is updated based on the customized detection sampling period setting command. This allows for the customization of a detection sampling period with an extended duration for the signal acquisition component, and enables adjustment via command interaction, meeting the needs of different users or business scenarios.

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

[0135]

[0136] Where, t′ A This represents the initial flight time corresponding to signal acquisition component A. The customized detection sampling period is 3T. The sampling interval time of signal acquisition component A in the four-tap sensor is [0, 3 / 4T], and I... A,0 , and This represents the grayscale information corresponding to signal acquisition component A when the phase offset is 0, 1 / 4T, 2 / 4T, and 3 / 4T.

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

[0138] Here, in the specific demodulation process of the measurement system, demodulation can be performed using periodic sampling and exposure sampling methods. Regarding the derivation process of the above equation (11), the derivation details of equation (2) above 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 their corresponding time delays are as follows:

[0140]

[0141]

[0142]

[0143]

[0144] Therefore, the time delay t' caused by factors such as the time of light travel is:

[0145]

[0146] Generally, four taps are used to acquire a signal for one cycle, such that when Δt = T / 4, However, due to temporal and spatial crosstalk, crosstalk photons constitute noise interference signals, and the proportion of crosstalk photons to the total number of photons in a single period is constant, meaning a certain amount of crosstalk exists in each detection period. To reduce the interference of crosstalk photons on signal photons, this application proposes, in embodiments where the total number of detection periods remains constant, to increase the integration time of the four taps in the four-tap sensor. That is, the sum of the integration times of the four taps corresponds to multiple detection periods, significantly increasing the number of signal photons while keeping the number of crosstalk photons constant, thereby substantially improving the signal-to-noise ratio.

[0147] In some examples of embodiments of this 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, while the sampling time length after the period is extended becomes KT / 4.

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

[0149]

[0150] Where s represents an integer.

[0151] For example, the number K of the original sampling periods in the customized detection sampling period can be set to 3, and the time t at which the four taps begin sampling can be set to 3. A t B t C t D They are 0 and 0 respectively. The periodic sampling operation is completed. Then, four phase-delayed exposure acquisitions are performed for each tap, t A Take 0 respectively, Four exposures were performed.

[0152] Therefore, the time delay t' caused by factors such as the time of light travel is:

[0153]

[0154]

[0155]

[0156]

[0157]

[0158] Therefore, even with extended sampling times for different taps, time-of-flight calculations can still be performed using the aforementioned formula. Furthermore, because the number of signal photons integrated from a single tap increases while the total number of crosstalk photons remains constant, the signal-to-noise ratio relatively increases, thus improving measurement accuracy.

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

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

[0161] The signal acquisition component activation unit 1010 is configured to control M signal acquisition components to sequentially start a continuous sampling time interval within a customized detection sampling period for the test object irradiated by the modulated continuous carrier beam. The customized detection sampling period includes 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.

[0162] The offset grayscale sampling unit 1020 is configured to acquire grayscale information sets corresponding to preset four-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 determination unit 1030 is configured to determine the flight time of the object under test based on the grayscale information set of each of the signal acquisition components.

[0164] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0165] Regarding another aspect of the embodiments of this application, it should be noted that current time-of-flight measurement systems still have some areas that require improvement. For sensors where one pixel corresponds to multiple taps, since the same pixel requires multiple readout circuits, for example, referring to... Figure 7 In the example of a tapped sensor, the size of the pixels is 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 manufacturing of multiple time-division circuits are quite difficult.

[0166] In view of this, Figure 11 A flowchart illustrating an example of a time-of-flight measurement method according to an embodiment of this application is shown. The implementing entity of this embodiment can be various measurement systems or processors with computing or processing capabilities, such as the control module 13 in the time-of-flight depth camera 10.

[0167] like Figure 11 As shown, in step 1110, for the test object illuminated by the modulated continuous carrier beam, a 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 needed. For example, when set to 3T / 4, the tap can stop collecting the energy of the remaining T / 4 of the input and can directly extract and ignore this part of the energy.

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

[0170] For example, multiple phase offsets can be applied to a single tap in a pixel, and multiple exposures can be performed to make the tap record multiple corresponding sample values, so as to complete the exposure sampling operation.

[0171] In step 1130, the flight time of the corresponding test object is determined based on each grayscale information.

[0172] It should be noted that, in current related technologies, the energy collected by taps is output to subsequent circuits for processing after collection, resulting in time consumption and high requirements for tap capacity, and the accuracy of the measurement results cannot be guaranteed. However, in the embodiments of this application, the corresponding flight time can be directly calculated using a single tap.

[0173] Therefore, without affecting the measurement function of the time-of-flight measurement sensor, by adopting a single-tap pixel layout, the chip design and manufacturing difficulty 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 between the object and the object based on the flight time of the object to be measured, for example, by substituting the flight time into the above formula (1) to obtain the distance relative to the object.

[0175] Figure 12 A flowchart illustrating an example of determining various sampling time intervals in a detection sampling period according to an embodiment of this application is shown.

[0176] like Figure 12 As shown, in step 1210, a sampling time interval setting instruction is obtained. For example, the measurement system can 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 according to the sampling time interval setting instruction. This allows for the setting of different sampling time intervals in the signal acquisition component, including the start time and corresponding sampling time length for each sampling stage, which can be adjusted via instruction interaction to meet the needs of different users or business scenarios.

[0178] Regarding the specific implementation details of step 1130 above, on the one hand, the flight time of the corresponding object to be measured can be determined based on the various grayscale information and the preset flight time relationship. Here, the flight time relationship is the correlation between grayscale information and flight time. Thus, the measurement system can directly substitute the grayscale information at different offsets into the relationship to calculate and quickly obtain the corresponding flight time.

[0179] In some implementations, the corresponding flight time can be determined in the following ways:

[0180]

[0181] Where t' represents the flight time of the target object, the time length of a single sampling interval of the signal acquisition component is 1 / 4T, and I A,0 , and This represents the grayscale information corresponding to signal acquisition component A when the phase offset is 0, 1 / 4T, 2 / 4T, and 3 / 4T.

[0182] Here, in the specific demodulation process of the measurement system, demodulation can be performed using periodic sampling and exposure sampling methods. For the derivation process and details of the above equation (16), please refer to the descriptions of other relevant parts above.

[0183] Regarding the specific implementation details of step 1130 above, on the other hand, one can also refer to, as follows: Figure 12 The operations in the process. Figure 13 A flowchart illustrating an example of determining the flight time of a corresponding test object based on various grayscale information according to an embodiment of this application is shown.

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

[0185] In step 1320, the corresponding phase offset information is determined based on each grayscale information.

[0186] In step 1330, the flight time variable is solved according to the phase offset information and the relationship between the phase offset information to obtain the flight time of the object under test.

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

[0188]

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

[0190]

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

[0192] Therefore, the photon count calculation expression for the grayscale value output by the tap is first defined, which can be used to calculate the grayscale value output by the tap in each frame. Then, by combining the grayscale values ​​collected under four-phase delay (e.g., phase delays of 0, T / 4, 2T / 4 and 3T / 4) exposures obtained by multiple exposures, the relationship between phase delay and time delay is obtained. By comprehensively considering the inherent relationship between phase delay and four-phase grayscale values, the time delay of the tap can be calculated.

[0193] In this embodiment, only one readout circuit can be installed in a single 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, and relatively accurate measurement results can still be obtained. Since only one tap is installed per pixel, the difficulty of circuit design is greatly reduced; at the same time, the area of ​​a single pixel is reduced, allowing the pixel to be made very small, thereby improving the resolution of the time-of-flight measurement chip.

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

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

[0196] The signal acquisition component activation unit 1410 is configured to control a single signal acquisition component to continuously activate multiple sampling time intervals within a detection sampling period for a test object irradiated by a 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 acquire grayscale information of each of the preset four-phase offsets corresponding to the signal acquisition component.

[0198] The flight time determination unit 1430 is configured to determine the flight time of the object to be tested based on each of the grayscale information and the length of the sampling time interval.

[0199] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0200] Figure 15 This is a schematic diagram of an example of an electronic device according to an embodiment of this 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, it implements the steps in the above-described time-of-flight measurement method embodiment, for example... Figure 3 The steps shown are 310 to 330, or 810 to 830, or 1110 to 1130. Alternatively, when the processor 1510 executes the computer program 1530, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 6 The functions of units 610 to 630 shown, or as follows: Figure 10 Units 1010 to 1030 shown, or as Figure 14 Units 1410 to 1430 are shown.

[0201] For example, 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 complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 1530 in the electronic device 1500.

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

[0203] The signal acquisition component startup module is configured to control multiple signal acquisition components to be turned on sequentially within a detection sampling period for the test object irradiated by a modulated continuous carrier beam, and each component has a sampling time interval of different lengths.

[0204] The offset grayscale sampling program module is configured to acquire a set of grayscale information corresponding to a preset four-phase offset for each of the signal acquisition components, wherein each grayscale information in the set of grayscale information corresponds to a different phase offset in the four-phase offset.

[0205] The flight time determination module is configured to determine the flight time of the object under test based on the grayscale information set of each of the signal acquisition components.

[0206] In another example of this application embodiment, the computer program 1530 can be divided into a signal acquisition component startup program module, an offset grayscale 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 startup module is configured to control M signal acquisition components to sequentially start a continuous sampling time interval within a customized detection sampling period for the test object irradiated by the modulated continuous carrier beam. The customized detection sampling period includes 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.

[0208] The offset grayscale sampling program module is configured to acquire grayscale information sets corresponding to preset four-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 module is configured to determine the flight time of the object under test based on the grayscale information set of each of the signal acquisition components.

[0210] In another example of this application embodiment, the computer program 1530 can be divided into a signal acquisition component startup 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 startup module is configured to control a single signal acquisition component to start the sampling time interval within the detection sampling period for the test object irradiated by the modulated continuous carrier beam.

[0212] The offset sampling module is configured to acquire grayscale information of each preset four-phase offset corresponding to the signal acquisition component;

[0213] The flight time determination module is configured to determine the flight time of the object under test based on the various grayscale information.

[0214] The electronic device 1500 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. The electronic device may include, but is not limited to, a processor 1510 and a memory 1520. Those skilled in the art will understand that... Figure 15 This is merely an example of electronic device 1500 and does not constitute a limitation on electronic device 1500. It may include more or fewer components than shown, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0215] The processor 1510 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0216] The memory 1520 can 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 can also be an external storage device of the electronic device 1500, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the electronic device 1500. Furthermore, the memory 1520 can include both internal and external storage units of the electronic device 1500. The memory 1520 is used to store the computer program 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 will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments.

[0218] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0219] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0220] In the embodiments provided in this application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0221] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0222] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The aforementioned units can be implemented in hardware or software.

[0223] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0224] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for measuring time of flight, characterized in that, include: For the test object irradiated by a modulated continuous carrier beam, control M Each signal acquisition component sequentially initiates a continuous sampling time interval within a customized detection sampling period, wherein the customized detection sampling period includes... K One original detection sampling cycle T , M and K All are positive integers greater than 1, and the sampling time interval length of each of the signal acquisition components is ( K / M )* T ; Obtain grayscale information sets corresponding to preset four-phase offsets for each of the signal acquisition components, wherein each grayscale information in the grayscale information set corresponds to a different phase offset. The flight time of the corresponding test object is determined based on the grayscale information set of each of the signal acquisition components. The determination of the flight time of the target object based on the grayscale information set of each signal acquisition component includes: For each of the signal acquisition components, the corresponding initial flight time is determined based on the sampling time interval of the signal acquisition component and the acquired grayscale information set; Based on the initial flight time determined by each of the signal acquisition components, the flight time of the corresponding test object is determined; The corresponding initial flight time is determined in the following way: in, This indicates the initial flight time corresponding to signal acquisition component A, with a customized detection sampling period of 3. T The sampling interval time of signal acquisition component A in the four-tap sensor is [0, 3 / 4]. T ],as well as , , and This indicates that signal acquisition component A has phase offsets of 0 and 1 / 4, respectively. T 2 / 4 T and 3 / 4 T The grayscale information corresponding to the time.

2. The method as described in claim 1, characterized in that, Determining the flight time of the corresponding object under test based on the initial flight time determined by each of the signal acquisition components includes: Calculate the average value corresponding to the initial flight time of the plurality of signal acquisition components as the flight time of the corresponding test object.

3. The method as described in claim 1, characterized in that, The method further includes: Obtain the command to set the customized detection sampling period; Based on the customized detection sampling period setting instruction, update the customized detection sampling period. K value.

4. The method as described in claim 1 or 3, characterized in that, The K The value satisfies the following conditions: in, s Represents an integer.

5. A time-of-flight measuring device, characterized in that, include: The signal acquisition component activation unit is configured to control the object under test illuminated by a modulated continuous carrier beam. M Each signal acquisition component sequentially initiates a continuous sampling time interval within a customized detection sampling period, wherein the customized detection sampling period includes... K One original detection sampling cycle T , M and K All are positive integers greater than 1, and the sampling time interval length of each of the signal acquisition components is ( K / M )* T ; The offset grayscale sampling unit is configured to acquire a grayscale information set of preset four-phase offsets corresponding to each of the signal acquisition components, wherein each grayscale information in the grayscale information set corresponds to a different phase offset. The flight time determination unit is configured to determine the flight time of the object under test based on the grayscale information set of each of the signal acquisition components. The flight time determination unit is specifically used to: determine the corresponding initial flight time for each of the signal acquisition components based on the sampling time interval of the signal acquisition component and the acquired grayscale information set; Based on the initial flight time determined by each of the signal acquisition components, the flight time of the corresponding test object is determined; The corresponding initial flight time is determined in the following way: in, This indicates the initial flight time corresponding to signal acquisition component A, with a customized detection sampling period of 3. T The sampling interval time of signal acquisition component A in the four-tap sensor is [0, 3 / 4]. T ],as well as , , and This indicates that signal acquisition component A has phase offsets of 0 and 1 / 4, respectively. T 2 / 4 T and 3 / 4 T The grayscale information corresponding to the time.

6. A time-flight depth camera, characterized in that, include: The transmitting module includes a light source and an optical modulator, wherein the optical modulator is used to control the light source to emit a modulated continuous carrier beam toward the object under test; The receiving module includes an image sensor consisting of at least one pixel, each pixel including multiple signal acquisition components for receiving light signals reflected back from the object under test; The control module, connected to the transmitting and receiving modules, is configured as follows: For the test object irradiated by a modulated continuous carrier beam, control M Each signal acquisition component sequentially initiates a continuous sampling time interval within a customized detection sampling period, wherein the customized detection sampling period includes... K One original detection sampling cycle T , M and K All are positive integers greater than 1, and the sampling time interval length of each of the signal acquisition components is ( K / M )* T ; Obtain grayscale information sets corresponding to preset four-phase offsets for each of the signal acquisition components, wherein each grayscale information in the grayscale information set corresponds to a different phase offset. The flight time of the target object is determined based on the sampling time interval of each signal acquisition component and the corresponding grayscale information set. The determination of the flight time of the target object based on the grayscale information set of each signal acquisition component includes: For each of the signal acquisition components, the corresponding initial flight time is determined based on the sampling time interval of the signal acquisition component and the acquired grayscale information set; Based on the initial flight time determined by each of the signal acquisition components, the flight time of the corresponding test object is determined; The corresponding initial flight time is determined in the following way: in, This indicates the initial flight time corresponding to signal acquisition component A, with a customized detection sampling period of 3. T The sampling interval time of signal acquisition component A in the four-tap sensor is [0, 3 / 4]. T ],as well as , , and This indicates that signal acquisition component A has phase offsets of 0 and 1 / 4, respectively. T 2 / 4 T and 3 / 4 T The grayscale information corresponding to the time.

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

8. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method as claimed in any one of claims 1-4.

Images