A ranging method, system and electronic device of dTOF

Abstract

Embodiments of the present application provide a ranging method and system of dTOF and electronic equipment, which are used for fitting a complete waveform signal by using a small amount of discrete sampling points in a reflected laser signal, and reducing the ranging error. The method of the embodiments of the present application comprises: controlling a transmitter to emit a laser signal to a target object, and controlling a receiver to receive the laser signal reflected by the target object; generating a first histogram based on the received laser signal, sampling the waveform in the first histogram to obtain N discrete points; obtaining the maximum value of the count value in the N discrete points, denoted as a first peak value, and obtaining the first half-height width of the waveform in the emitted laser signal; performing Gaussian waveform fitting on the N discrete points based on the first peak value and the first half-height width, and outputting a second histogram; extracting the waveform feature information of the second histogram to obtain a second peak value and a second half-height width, and calculating a compensation value.

Description

Technical Field

[0001] This application relates to the field of electromagnetic wave ranging, and more particularly to a dTOF ranging method, system, and electronic device. Background Technology

[0002] As the number of pixels in a Single Photon Avalanche Detector (SPAD) array gradually increases, the ranging distance also increases, leading to a corresponding increase in the number of rectangles in the histogram and consequently, a multiple increase in the amount of output data. For example, taking a 192x256 pixel, 672-bin histogram, assuming each bin is 12 bits, the amount of data output per frame is 396 Mb. If the desired frame rate is 10 fps, the data transmission interface rate needs to meet 4 Gb / s. Such a data volume poses a significant challenge to both the interface rate and the backend data processing capabilities.

[0003] Currently, most mainstream SPAD array chips have built-in digital signal processing (DSP). During the initial data processing of the original histogram, the shape features of the histogram are lost due to the large amount of data compression. When facing targets with strong original echo signals, the back-end cannot perform depth compensation, which leads to signal pile-up under extremely strong original echo signals, ultimately resulting in inaccurate measurements. Summary of the Invention

[0004] This application provides a dTOF ranging method, system, and electronic device for fitting a complete waveform signal from a small number of discrete sampling points in a reflected laser signal, thereby reducing ranging errors.

[0005] The first aspect of this application provides a dTOF ranging method, including:

[0006] The transmitter is controlled to emit a laser signal toward the target object, and the receiver is controlled to receive the laser signal reflected by the target object.

[0007] Based on the received laser signal, a first histogram is generated, and the waveform in the first histogram is sampled to obtain N discrete points.

[0008] Obtain the value with the largest count among the N discrete points, and record it as the first peak value; and obtain the first half-width and height of the waveform in the emitted laser signal.

[0009] Based on the first peak value and the first half-width, Gaussian waveform fitting is performed on the N discrete points to output a second histogram;

[0010] The waveform feature information of the second histogram is extracted to obtain the second peak value and the second half-width and height, and the compensation value is calculated.

[0011] Optionally, the step of extracting waveform feature information from the second histogram to obtain the second peak value and the second half-width and height, and calculating the compensation value, further includes:

[0012] The initial depth value is obtained based on the second histogram;

[0013] The measurement distance of the target object is calculated based on the initial depth value and the compensation value.

[0014] Optionally, the step of extracting waveform feature information from the second histogram to obtain the second peak value and the second half-width and height, and calculating the compensation value, further includes:

[0015] The initial depth value is obtained based on the largest count value among the N discrete points;

[0016] The measurement distance of the target object is calculated based on the initial depth value and the compensation value.

[0017] Optionally, the step of performing Gaussian waveform fitting on the N discrete points based on the first peak value and the first half-width at half-maximum (WWHM) to output a second histogram includes:

[0018] The first peak value and the first half-width at half-maximum (WWHM) are input into a Gaussian waveform fitting formula to perform Gaussian waveform fitting, thereby obtaining the second histogram; wherein, the Gaussian waveform fitting formula is: Amp is the first peak value; σ is the first half-width at half-maximum; μ is 0; GaussFitting is the photon count value after Gaussian waveform fitting; x is the time bin.

[0019] Optionally, the step of extracting waveform feature information from the second histogram to obtain the second peak value and the second half-width and height, and calculating the compensation value, further includes:

[0020] The formula for calculating the input error of the second peak value and the second half-width is as follows: The error calculation formula is...

[0021] Wherein, f(FWHM,Height) represents the error value, and p n ,g n Here, n is the order of the polynomial, FWHM is the second half-width, and Height is the second peak value.

[0022] A second aspect of this application provides a dTOF ranging system, comprising:

[0023] A transmitter used to emit laser signals toward a target object;

[0024] A receiver for receiving the laser signal reflected by the target object;

[0025] The controller is configured to generate a first histogram based on the received laser signal, sample the waveform in the first histogram to obtain N discrete points, obtain the value with the largest count among the N discrete points as the first peak value, and obtain the first half-width of the waveform in the emitted laser signal; perform Gaussian waveform fitting on the N discrete points based on the first peak value and the first half-width, and output a second histogram; extract waveform feature information from the second histogram to obtain the second peak value and the second half-width, and calculate a compensation value.

[0026] Optionally, the receiver may include a number of SPADs exceeding a predetermined value.

[0027] Optionally, the waveforms in the first histogram and the waveforms in the second histogram have the same feature information, including peak value and full width at half maximum (FWHM).

[0028] Optionally, the controller is further configured to obtain an initial depth value based on a second histogram, so as to calculate the measurement distance of the target object according to the compensation value.

[0029] A third aspect of this application provides an electronic device including the dTOF ranging system described in the second aspect.

[0030] As can be seen from the above technical solutions, the embodiments of this application have the following advantages: the dTOF ranging method disclosed in the embodiments of this application can use the received laser signal to extract a small number of discrete points from the complete histogram data to reduce the amount of data and facilitate transmission, and then use Gaussian fitting to obtain the complete histogram waveform signal, and use the waveform signal to calculate the depth compensation value, thereby improving the ranging accuracy. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0032] Figure 1a This is a diagram showing the changes in the working state of an existing SPAD.

[0033] Figure 1b This is a schematic diagram of the histogram and laser waveform under a weak signal condition.

[0034] Figure 1c This is a schematic diagram of histogram acquisition under a strong signal.

[0035] Figure 2 This is a schematic diagram of an existing DSP data processing method;

[0036] Figure 3 This is a flowchart illustrating a dTOF ranging method disclosed in an embodiment of this application.

[0037] Figure 4 This is a flowchart illustrating another dTOF ranging method disclosed in an embodiment of this application.

[0038] Figure 5 This is a schematic diagram of a laser waveform disclosed in an embodiment of this application;

[0039] Figure 6 This is a schematic diagram of an echo shape based on sampling point fitting disclosed in an embodiment of this application;

[0040] Figure 7 This is a comparison diagram of ranging errors before and after correction, as disclosed in an embodiment of this application.

[0041] Figure 8 This is a schematic diagram of the structure of a dTOF ranging system disclosed in an embodiment of this application;

[0042] Figure 9 This is a schematic diagram of the structure of a dTOF electronic device disclosed in an embodiment of this application. Detailed Implementation

[0043] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0046] SPAD-based direct time-of-flight (dTOF) ranging systems are resistant to sunlight and interference. Specifically, the SPAD can be divided into three states during its operation, which can be found in the following documentation. Figure 1a , Figure 1a This is a graph showing the operating state changes of an existing SPAD (horizontal axis is time, vertical axis is voltage).

[0047] 1. Avalanching: When a SPAD device receives a photon, it triggers an avalanche, generating a negative pressure.

[0048] 2. Quenching: After an avalanche occurs in a SPAD device, in order to prevent the voltage from increasing indefinitely and burning out the device, an active or passive method is used to suppress the avalanche and stop the circuit from working.

[0049] 3. Recharging: This process returns the SPAD device to its state before photon triggering, allowing it to wait for the next trigger.

[0050] Therefore, it can be concluded that SPAD experiences a recovery time—a "dead time"—before it can detect the next photon after an avalanche. When the echo signal is weak, photons will not arrive continuously within a short period (dead time). Consequently, in the time-photon number histogram formed under measurement, the shape of the signal peak closely resembles the laser emission waveform. Figure 1b , Figure 1bThis is a schematic diagram of a histogram and laser waveform under a weak signal. However, as the signal gradually strengthens, a large number of photons arrive in a short time; see [reference needed]. Figure 1c , Figure 1c This is a schematic diagram illustrating the acquisition of a histogram under a strong signal. Specifically, in... Figure 1c In the process, SPAD is triggered prematurely and enters its dead time, losing its detection capability. This ultimately causes the signal peak in the histogram to shift forward, resulting in inaccurate ranging.

[0051] Although most mainstream SPAD array chips currently have built-in DSP modules for preliminary data processing of the original histograms, please refer to [link / reference needed]. Figure 2 , Figure 2 This is a schematic diagram of a current DSP data processing method. The on-chip DSP locates the signal echo using a peak-finding module. To further compress the output data, a point-sampling operation is performed on the signal echo, reducing the entire echo data to several sampling points before outputting it to the back-end data processing module for depth calibration and point cloud generation. For example, assuming the chip supports 5-echo peak-finding, with 5 sampling points per echo and each sampling point having a bit width of 12 bits, each frame of data is 480 bits, only one millionth of the original histogram. However, this extensive data compression also results in the loss of histogram shape features, making it impossible for the back-end to perform depth compensation when facing strong echo signal targets.

[0052] To resolve the technical issues mentioned above, please refer to [link / reference]. Figure 3 , Figure 3 This is a flowchart illustrating a dTOF ranging method disclosed in an embodiment of this application. It includes steps 301-305.

[0053] 301. Control the transmitter to emit laser signals toward the target object, and control the receiver to receive the laser signals reflected by the target object.

[0054] Considering the various issues mentioned above, the laser signal needs to be adjusted. Therefore, in one feasible solution, for easier understanding of the emitted laser signal waveform, please refer to... Figure 5 , Figure 5 This is a schematic diagram of a laser waveform disclosed in an embodiment of this application. Figure 5It is known that an ideal laser waveform is a triangular wave, and the increase in energy is linear with the increase in laser emission time. However, in real-world scenarios, the laser waveform is closer to a Gaussian waveform, meaning the laser energy increases slowly and nonlinearly. Based on this characteristic, the features of the Gaussian waveform can be used to fit the acquired signal. Specifically, this embodiment proposes a ranging system including a transmitter, a receiver, and a controller. The transmitter, receiver, and controller will be described in detail later, and will not be repeated here. The receiver includes a number of SPADs exceeding a predetermined value.

[0055] Specifically, the ranging system first controls the transmitter to emit a laser signal towards the target object. Upon reaching the target object, the laser signal is reflected. The ranging system then controls the receiver to receive the reflected laser signal.

[0056] In one specific embodiment, the signal strength of the transmitter when emitting laser signals should also be controlled.

[0057] 302. Based on the received laser signal, generate the first histogram, sample the waveform in the first histogram, and obtain N discrete points.

[0058] After the ranging system receives the reflected laser signal, the controller can generate a first histogram based on the received laser signal, and then sample and detect the waveform in the first histogram to obtain N discrete points.

[0059] In one specific embodiment, the controller calculates the distance by measuring the round-trip time of the laser pulse and analyzes the reflection characteristics of the target object's surface by measuring the signal intensity of the reflected laser signal. Further, before generating the histogram, filtering algorithms (such as Gaussian filtering or median filtering) can be used to remove noise. The signal intensity or distance value is then normalized to a characteristic range (e.g., 0-255). If the laser signal contains multiple reflection peaks, it needs to be segmented. Then, the distribution of different distance values ​​or the distribution of reflected signal intensities are statistically analyzed to generate a first histogram. The waveform in the first histogram is then randomly sampled (points can be densely selected at the peaks and sparsely selected at the edges) to obtain N discrete points. It can also be understood that each discrete point corresponds to a timebox, and each timebox corresponds to a photon count.

[0060] 303. Obtain the largest count value among N discrete points, denoted as the first peak value, and obtain the first half-width of the waveform in the emitted laser signal.

[0061] Based on step 302, the controller compares and filters the value with the largest count among N discrete points, and records this value as the first peak value. Further, the controller also needs to obtain the first half-width at half-maximum (HWHM) of the laser signal waveform emitted by the transmitter. It should be noted that HWHM is commonly used to describe the width of a signal, waveform, or distribution. It represents the width at half the height of the peak value. Specifically, first, the maximum value (peak value) of the emitted laser signal waveform is found. Then, a horizontal line is drawn at half the height of the peak value. The distance between the two points where this horizontal line intersects the curve is calculated; this is the HWHM, which is the difference between the two time boxes.

[0062] In one specific embodiment, in the reflected laser signal, the maximum value (first peak value) among N discrete points in a first histogram generated by the reflected laser signal is calculated. In the emitted laser signal, the full width at half maximum (FWHM) of the waveform in the emitted laser signal is determined.

[0063] 304. Based on the first peak value and the first half-width, perform Gaussian waveform fitting on N discrete points and output the second histogram.

[0064] Then, Gaussian waveform fitting can be performed on N discrete points using the first peak value and the first half-width, thereby outputting the second histogram.

[0065] In one specific embodiment, since the waveform of the controlled laser exhibits Gaussian characteristics, the waveform features of the first peak value and the first half-width at half-maximum (FWHM) in the laser signal are used to fit N discrete points. This allows the shape information, such as the height or width of another signal peak, to be obtained from the waveform fitting result, and subsequently, a second histogram is fitted. It should be noted that the waveforms in the first and second histograms have the same feature information, including the peak value and FWHM.

[0066] 305. Extract the waveform feature information of the second histogram to obtain the second peak value and the second half-width and height, and calculate the compensation value.

[0067] Therefore, after obtaining the second histogram through Gaussian fitting, it is necessary to extract the waveform feature information from the second histogram to obtain the second peak value and the second half-width. The compensation value is then calculated using the second peak value and the second half-width. It should be noted that this compensation value is used to improve ranging accuracy.

[0068] Furthermore, the second peak value is understood as the peak in the waveform corresponding to the second histogram, and the corresponding second half-width is the distance between two points at half the height of the peak value. The specific method for obtaining this value has been described in the preceding steps and will not be repeated here.

[0069] In one specific embodiment, by extracting the waveform features of the second histogram, more accurate width and height data, as well as the peak value data of the second histogram, can be obtained, and the position of the corresponding time box can be further determined, which will be described in detail later. Then, the compensation value (which can also be understood as the error value) corresponding to the laser signal can be determined by the second peak value and the second half-width.

[0070] The dTOF ranging method disclosed in this embodiment can extract a small number of discrete points from the complete histogram data using the received laser signal to reduce the data volume and facilitate transmission. Then, Gaussian fitting is used to obtain the complete histogram waveform signal, and the depth compensation value is calculated using the waveform signal, thereby improving the ranging accuracy.

[0071] Please see Figure 4 , Figure 4 This is a flowchart illustrating another dTOF ranging method disclosed in an embodiment of this application. It includes steps 401-404.

[0072] 401. Input the first peak value and the first half-width into the Gaussian waveform fitting formula to perform Gaussian waveform fitting and obtain the second histogram.

[0073] In this embodiment, step 401 is the same as the aforementioned Figure 3 Step 304 is similar. Specifically, the first peak value and the first half-width can be input into the Gaussian waveform fitting formula to perform Gaussian waveform fitting, thereby obtaining the second histogram. It should be noted that the Gaussian waveform fitting formula is... Amp represents the first peak value, i.e., the number of photons corresponding to the peak value of the signal in the first histogram; σ represents the first half-width at half-maximum (FWHM), i.e., the standard deviation (the FWHM corresponding to the waveform configuration of the emitted laser signal); μ represents the mean; GaussFitting represents the photon count value after Gaussian waveform fitting; and x represents the time bin. Furthermore, since μ is the deviation value relative to 0, it can be considered the location of the signal peak (bin index). However, in the current fitting scheme, only the shape information such as the height and width of the signal peak needs to be obtained from the fitting results; therefore, to simplify the calculation, μ can be considered as 0.

[0074] 402. Input the second peak value and the second half-width into the error calculation formula to obtain the error value.

[0075] In this embodiment, step 402 is the same as described above. Figure 3 Step 305 is similar. Specifically, the second peak value and the second half-width are obtained by analyzing the second histogram. Then, the second peak value and the second half-width are input into the error calculation formula to obtain the error value. It should be noted that the error calculation formula is as follows:

[0076]

[0077] Where f(FWHM,Height) represents the error value, p n ,g n Here, f(FWHM, Height) is a coefficient, n is the order of the polynomial, FWHM is the second half-width, and Height is the second peak value, representing the peak-to-peak value of the signal. Generally, the larger n is, the more accurate the calculation of f(FWHM, Height) becomes. However, in this embodiment, n = 3 is sufficient. Specifically, histograms and ranging errors can be collected in the laboratory and production line using multiple modules and multiple pixels at different known distances (GT, Ground Truth) to obtain the fitting relationship f(FWHM, Height) between waveform features (FWHM and Height) and ranging errors. This allows for the calculation of the corresponding compensation value, i.e., the error value, in practical applications.

[0078] Furthermore, for ease of understanding, please refer to... Figure 6 , Figure 6 This is a schematic diagram of an echo shape based on sampling point fitting disclosed in an embodiment of this application. Figure 6 The results demonstrate the effectiveness of Gaussian fitting based on a small number of points, effectively reconstructing the echo waveform. If the full width at half maximum (FWHM) (the bin index corresponding to half the peak height) is calculated based on data from only a few sampling points, only bins 5 and 7 satisfy the condition, resulting in a FWHM of 3 (time bin), thus introducing noticeable errors. However, by fitting the waveform, the accurate decimal part can be calculated, reducing the error in calculating the FWHM.

[0079] Therefore, the measured distance of the target object can be obtained in different ways, i.e., by executing step 403 or step 404.

[0080] 403. Based on the largest count value among N discrete points, obtain the initial depth value, and calculate the measurement distance of the target object according to the initial depth value and the compensation value.

[0081] In one feasible technical solution, the initial depth value can be obtained by calculating the maximum count value among N discrete points. Then, based on the initial depth value and the compensation value, the measurement distance of the target object can be calculated.

[0082] In one specific embodiment, the distance value corresponding to the largest count value among N discrete points, i.e., the value with the largest photon count, is considered as the initial depth value. Then, the measured distance of the target object is calculated by subtracting the initial depth value from the compensation value.

[0083] 404. Obtain the initial depth value based on the second histogram, and calculate the measurement distance of the target object based on the initial depth value and the compensation value.

[0084] In one feasible technical solution, the initial depth value can be obtained directly through the second histogram, and the measurement distance of the target object can be calculated based on the initial depth value and the compensation value.

[0085] In one specific embodiment, by analyzing the distribution in the second histogram, features such as peaks or valleys (including peak values ​​and half-width at half-maximum) are identified. Furthermore, an initial depth value can be obtained by calculating the quantiles (e.g., median, quartiles, etc.) in the second histogram, where the histogram pattern (peak) corresponds to the depth value that appears most frequently in the data. Then, the measured distance to the target object is calculated by subtracting the initial depth value from the compensation value.

[0086] For details, please refer to step 403 or step 404. Figure 7 , Figure 7 This is a comparison diagram of ranging errors before and after correction, as disclosed in an embodiment of this application. Figure 7 The results showed the ranging error of 200 pixels based on this scheme. Before correction, the ranging error exceeded 60cm. After correction, the ranging error of most pixels was less than ±5cm, which greatly improved the ranging accuracy.

[0087] The dTOF ranging method disclosed in this embodiment restores the original signal waveform by fitting (Gaussian fitting) based on the characteristics of the laser waveform with a limited number of sampling points. Simultaneously, it corrects for inaccuracies under strong echo conditions using the fitted waveform characteristics, thereby improving ranging accuracy.

[0088] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the steps or stages of other steps.

[0089] Please refer to the following: Figure 8 , Figure 8 This is a schematic diagram of the structure of a dTOF ranging system disclosed in an embodiment of this application.

[0090] The ranging system 800 of the dTOF includes a transmitter 801, a receiver 803, and a controller 804.

[0091] The transmitter 801 is used to emit a laser signal towards the target object 802; the receiver 803 is used to receive the laser signal reflected by the target object 802; the controller 804 is used to generate a first histogram based on the received laser signal, sample the waveform in the first histogram to obtain N discrete points; obtain the value with the largest count among the N discrete points and record it as the first peak value, and obtain the first half-width of the waveform in the emitted laser signal; perform Gaussian waveform fitting on the N discrete points based on the first peak value and the first half-width, and output a second histogram; extract the waveform feature information of the second histogram to obtain the second peak value and the second half-width, and calculate the compensation value.

[0092] Furthermore, the receiver 803 includes a number of SPADs exceeding a predetermined value.

[0093] Furthermore, the waveforms in the first histogram and the waveforms in the second histogram have the same feature information, including peak value and full width at half maximum (FWHM).

[0094] Furthermore, the controller 804 is also used to obtain an initial depth value based on the second histogram, so as to calculate the measurement distance of the target object 802 according to the compensation value.

[0095] The dTOF ranging system in this embodiment is used to perform the aforementioned... Figure 2 or Figure 3 The dTOF ranging method in the illustrated embodiment.

[0096] Please refer to the following: Figure 9 The schematic diagram of a dTOF electronic device disclosed in this application includes:

[0097] Central processing unit 901, memory 905, input / output interface 904, wired or wireless network interface 903, and power supply 902;

[0098] Memory 905 is either a short-term storage memory or a persistent storage memory;

[0099] The central processing unit 901 is configured to communicate with the memory 905 and execute instructions stored in the memory 905 to perform the aforementioned operations. Figure 2 or Figure 3 The dTOF ranging method in the illustrated embodiment, or, Figure 8 The dTOF ranging system in the illustrated embodiment.

[0100] This application also provides a chip system, which includes at least one processor and a communication interface. The communication interface and the at least one processor are interconnected via a circuit. The at least one processor is used to run computer programs or instructions to perform the aforementioned... Figure 2 or Figure 3 The dTOF ranging method in the illustrated embodiment, or, Figure 8 The dTOF ranging system in the illustrated embodiment.

[0101] This application also provides a computer-readable storage medium, which includes instructions that, when executed on a computer, cause the computer to perform the aforementioned actions. Figure 2 or Figure 3 The dTOF ranging method in the illustrated embodiment, or, Figure 8 The dTOF ranging system in the illustrated embodiment.

[0102] This application also provides a computer program product containing instructions, which, when run on a computer, causes the computer to perform the aforementioned... Figure 2 or Figure 3 The dTOF ranging method in the illustrated embodiment, or, Figure 8 The dTOF ranging system in the illustrated embodiment.

[0103] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0104] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of 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 coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0105] 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.

[0106] 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 integrated unit can be implemented in hardware or as a software functional unit.

[0107] If the integrated 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, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A dTOF ranging method, characterized in that, The method includes: The transmitter is controlled to emit a laser signal toward the target object, and the receiver is controlled to receive the laser signal reflected by the target object. Based on the received laser signal, a first histogram is generated, and the waveform in the first histogram is sampled to obtain N discrete points. Obtain the value with the largest count among the N discrete points, and record it as the first peak value; and obtain the first half-width and height of the waveform in the emitted laser signal. Based on the first peak value and the first half-width, Gaussian waveform fitting is performed on the N discrete points to output a second histogram; Extract the waveform feature information from the second histogram to obtain the second peak value and the second half-width and height, and calculate the compensation value; The step of extracting waveform feature information from the second histogram to obtain the second peak value and the second half-width and height, and calculating the compensation value, further includes: The formula for calculating the input error of the second peak value and the second half-width is as follows: The error calculation formula is... , Among them, the Used to represent error values, the As a coefficient, the Let be the order of the polynomial, the The second half-width and height, the This is the second peak value.

2. The dTOF ranging method according to claim 1, characterized in that, The step of extracting waveform feature information from the second histogram to obtain the second peak value and the second half-width and height, and calculating the compensation value, further includes: The initial depth value is obtained based on the second histogram; The measurement distance of the target object is calculated based on the initial depth value and the compensation value.

3. The dTOF ranging method according to claim 1, characterized in that, The step of extracting waveform feature information from the second histogram to obtain the second peak value and the second half-width and height, and calculating the compensation value, further includes: The initial depth value is obtained based on the largest count value among the N discrete points; The measurement distance of the target object is calculated based on the initial depth value and the compensation value.

4. The dTOF ranging method according to claim 1, characterized in that, The step of performing Gaussian waveform fitting on the N discrete points based on the first peak value and the first half-width at half-maximum (WWHM) to output a second histogram includes: The first peak value and the first half-width at half-maximum (WWHM) are input into a Gaussian waveform fitting formula to perform Gaussian waveform fitting, thereby obtaining the second histogram; wherein, the Gaussian waveform fitting formula is: The The first peak value; The first half-width; =0; the The photon count value is obtained after fitting a Gaussian waveform; For time boxes.

5. A dTOF ranging system, characterized in that, The system includes: A transmitter used to emit laser signals toward a target object; A receiver for receiving the laser signal reflected by the target object; The controller is configured to generate a first histogram based on the received laser signal, sample the waveform in the first histogram to obtain N discrete points, obtain the value with the largest count among the N discrete points as the first peak value, and obtain the first half-width of the waveform in the emitted laser signal; perform Gaussian waveform fitting on the N discrete points based on the first peak value and the first half-width, and output a second histogram; extract waveform feature information from the second histogram to obtain the second peak value and the second half-width, and calculate a compensation value. The controller is further configured to use a formula to calculate the error between the second peak value and the second half-width; wherein the error calculation formula is: , wherein Used to represent error values, the As a coefficient, the Let be the order of the polynomial, the The second half-width and height, the This is the second peak value.

6. The ranging system as described in claim 5, characterized in that, The receiver includes a number of SPADs that exceed a predetermined value.

7. The ranging system as described in claim 5, characterized in that, The waveforms in the first histogram and the waveforms in the second histogram have the same feature information, which includes peak value and full width at half maximum (FWHM).

8. The ranging system as described in claim 5, characterized in that, The controller is further configured to obtain an initial depth value based on a second histogram, and to calculate the measurement distance of the target object according to the compensation value.

9. An electronic device, characterized in that, Includes the ranging system as described in any one of claims 5 to 8.

Images