Method, device and equipment for shielding fuzzy distance value of ranging system

Abstract

The present invention provides a method, device, and apparatus for shielding fuzzy distance values ​​in a ranging system, including: obtaining an electrical signal corresponding to a signal beam reflected by an object to be measured; calculating a target distance value for the object to be measured based on the electrical signal; determining whether the target distance value is a fuzzy distance value based on the electrical signal and a preset threshold, and shielding the fuzzy distance value. Based on the preset threshold, the present invention addresses the issue of shielding fuzzy distance values ​​in a ranging system, achieving single-frequency ranging and improving the measurement frame rate, thereby simultaneously resolving the problem of fuzzy ranging and improving the system frame rate.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a method, device and equipment for shielding fuzzy distance values ​​of a distance measurement system. Background Art

[0002] For a distance measurement system based on the time-of-flight (TOF) principle, the distance calculation formula is: Where c is the speed of light, which is approximately 3×10 8 m / s, f is the modulation frequency of the transmitted light signal, and k is a positive integer representing the number of integer cycles. If only one modulation frequency is used for distance measurement, the system usually defaults to k = 0 in a measurement. When the reflected light signal collected by the collector comes from the target outside the maximum ranging range corresponding to the modulation frequency, it is impossible to confirm the actual distance of the target in which distance cycle, that is, it is impossible to confirm the k value. The measured distance of the target is much smaller than the actual distance. This phenomenon is called distance ambiguity in TOF ranging. When the modulation frequency is f, the distance value corresponding to an integer number of cycles is called the ambiguity distance corresponding to the distance value at the current modulation frequency.

[0003] Existing methods for resolving TOF distance ambiguity primarily involve dual-frequency ranging to address distance aliasing. Dual-frequency ranging involves measuring the same target using two different frequencies, and determining the true distance from these two measurements. However, this method requires two consecutive measurements of the distance to each target point using two different frequencies, significantly reducing the measurement frame rate. Traditional TOF ranging methods, which use a single frequency to measure distance, also suffer from distance ambiguity. Therefore, resolving distance ambiguity without sacrificing system frame rate is an urgent issue. Summary of the Invention

[0004] To overcome the problems existing in the prior art, embodiments of the present invention provide a method, apparatus, and device for shielding fuzzy distance values ​​of a ranging system.

[0005] To achieve the above-mentioned purpose, the technical solution of the embodiment of the present invention is implemented as follows:

[0006] A method for shielding fuzzy distance values ​​of a distance measurement system, comprising:

[0007] Obtaining an electrical signal corresponding to the signal light beam reflected by the object to be measured;

[0008] Calculating the target distance value of the object to be measured according to the electrical signal;

[0009] Determine whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and mask the fuzzy distance value.

[0010] In some embodiments, determining whether the target distance value is a fuzzy distance value based on the electrical signal and a preset threshold, and shielding the fuzzy distance value, includes:

[0011] Acquiring a signal photon number and an ambient photon number; wherein the signal photon number and the ambient photon number are determined based on the electrical signal;

[0012] If the target distance value is determined to be a fuzzy distance value based on the ambient photon number, the signal photon number and a resolution threshold, or based on the signal photon number and a preset signal photon number threshold, the fuzzy distance value is shielded.

[0013] In some embodiments, if the target distance value is determined to be a fuzzy distance value based on the ambient photon count, the signal photon count, and a resolution threshold, or based on the signal photon count and a preset signal photon count threshold, then shielding the fuzzy distance value includes:

[0014] Calculating the target resolution of the object to be measured based on the number of signal photons and the number of ambient photons; if it is determined that the target resolution is greater than a resolution threshold, or the target resolution is greater than or equal to the resolution threshold, determining the target distance value as a fuzzy distance value, and shielding the fuzzy distance value; or,

[0015] If it is determined that the number of signal photons is less than the signal photon number threshold, or the number of signal photons is less than or equal to the signal photon number threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is shielded.

[0016] In some embodiments, the target resolution of the object to be measured is calculated according to the following first function model or second function model:

[0017] The first function model is:

[0018] The second function model is:

[0019] Among them, C s is the number of signal photons; C n is the number of ambient photons; a, b, c, d, and e are all parameters; f represents the focal length of the collector lens; and Resolution is the target resolution.

[0020] In some embodiments, the emission pulse period of the signal light beam is a first time, the effective acquisition time of the signal light beam is a second time, and the second time is less than the first time; the resolution threshold includes a preset quantitative resolution threshold;

[0021] Before determining whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold and shielding the fuzzy distance value, the method further includes:

[0022] Determine a first ranging range and a second ranging range according to the first time and the second time; obtain a first resolution range corresponding to the first ranging range and a second resolution range corresponding to the second ranging range; and determine the preset quantitative resolution threshold according to the first resolution range and the second resolution range.

[0023] In some embodiments, the resolution threshold comprises a variable resolution threshold;

[0024] After obtaining the number of signal photons and the number of ambient photons, the method further includes:

[0025] The mean ambient light illuminance is calculated based on the number of signal photons and the number of ambient photons; the variable resolution threshold is determined based on the mean ambient light illuminance and a preset fitting function relationship, wherein the preset fitting function relationship includes the relationship between the variable resolution threshold and the mean ambient light illuminance.

[0026] In some embodiments, calculating the average ambient light illumination value according to the number of signal photons and the number of ambient photons includes:

[0027] Obtaining signal photon numbers and ambient photon numbers corresponding to different initial sampling points, and calculating a sampling resolution of each of the initial sampling points based on the signal photon numbers and the ambient photon numbers; if the sampling resolution of any initial sampling point is less than a preset sampling resolution threshold, or the sampling resolution is less than or equal to the preset sampling resolution threshold, marking the initial sampling point as a target sampling point; and calculating a mean ambient light illumination value based on the signal photon numbers and the ambient photon numbers of the target sampling point.

[0028] In some embodiments, calculating the mean ambient light illumination value based on the number of signal photons and the number of ambient photons at the target sampling point includes:

[0029] The reflectivity corresponding to each target sampling point is calculated according to the number of signal photons at each target sampling point and a pre-stored reflectivity calculation rule; the sampling ambient light irradiance corresponding to each target sampling point is calculated according to the number of ambient photons at each target sampling point, the corresponding reflectivity, and a pre-stored ambient light irradiance calculation rule; the sampling ambient light illuminance corresponding to each target sampling point is calculated according to the sampling ambient light irradiance corresponding to each target sampling point, and the average ambient light illuminance is calculated according to the sampling ambient light illuminance corresponding to each target sampling point.

[0030] In some embodiments, the pre-stored reflectivity calculation rule is:

[0031]

[0032] Where Re is the reflectivity of the object under test at any target sampling point; C ns is the number of signal photons at the target sampling point; TCSPC is the number of pulses emitted in the prior single-frame measurement; θ is the incident angle of light; L is the measurement distance of the object being measured; P t is the peak power of the signal beam emitted by the light source; k1 is the first preset coefficient.

[0033] In some embodiments, the pre-stored calculation rule for ambient light irradiance is:

[0034]

[0035] Among them, I AL is the ambient light irradiance at any target sampling point; C ns is the number of signal photons at the target sampling point; C nn is the number of ambient photons at the target sampling point; θ is the incident angle of light; L is the measurement distance of the object under test; f represents the focal length of the collector lens; k2 is the second preset coefficient, and k3 is the third preset coefficient.

[0036] In some embodiments, the preset threshold is a preset maximum distance measurement value of the ranging system.

[0037] The determining whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and shielding the fuzzy distance value, includes:

[0038] Obtaining a preset maximum distance measurement value of the ranging system; if it is determined that the target distance value is greater than, or greater than or equal to, the preset maximum distance measurement value, determining that the target distance value is a fuzzy distance value, and shielding the fuzzy distance value.

[0039] In some embodiments, the preset threshold is a resolution threshold;

[0040] The determining whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and shielding the fuzzy distance value, includes:

[0041] Ambient light data and sampling signal data are obtained based on the amount of charge corresponding to the light signal reflected back by the object to be measured, and the target resolution of the object to be measured is calculated based on the ambient light data and the sampling signal data; if it is determined that the target resolution is greater than, or greater than or equal to, the resolution threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is shielded.

[0042] In some embodiments, the target resolution of the object to be measured is calculated according to the following third function model or fourth function model:

[0043] The third function model is:

[0044] The fourth function model is:

[0045] Among them, C s is the sampling signal data; C n is the ambient light data; a, b, c, d, e are all parameters; f represents the focal length of the collector lens; Resolution is the target resolution.

[0046] In some embodiments, the resolution threshold includes a preset quantitative resolution threshold or a variable resolution threshold, and the variable resolution threshold is determined according to an average value of ambient light illumination.

[0047] In some embodiments, after obtaining the ambient light data and the sampled signal data according to the charge amount corresponding to the light signal reflected by the object to be measured, the method further includes:

[0048] The mean ambient light illuminance is calculated based on the sampled signal data and the ambient light data; the variable resolution threshold is determined based on the mean ambient light illuminance and a preset fitting function relationship, wherein the preset fitting function relationship includes the relationship between the variable resolution threshold and the mean ambient light illuminance.

[0049] In some embodiments, the calculating the average ambient light illumination value according to the sampled signal data and the ambient light data includes:

[0050] Acquire sampling signal data and ambient light data corresponding to different initial sampling points, and calculate the sampling resolution of each of the initial sampling points; if the sampling resolution of any of the initial sampling points is less than a preset sampling resolution threshold, or the sampling resolution is less than or equal to the preset sampling resolution threshold, mark the initial sampling point as a target sampling point; and calculate the average ambient light illumination value based on the sampling signal data and ambient light data of each of the target sampling points.

[0051] In some embodiments, the calculating the average ambient light illumination value based on the sampling signal data and the ambient light data of each target sampling point includes:

[0052] The reflectivity corresponding to each target sampling point is calculated according to the sampling signal data of each target sampling point and a pre-stored reflectivity calculation rule; the sampling ambient light irradiance corresponding to each target sampling point is calculated according to the ambient light data of each target sampling point, the corresponding reflectivity, and a pre-stored ambient light irradiance calculation rule; the sampling ambient light illuminance corresponding to each target sampling point is calculated according to the sampling ambient light irradiance corresponding to each target sampling point, and the ambient light illuminance average is calculated according to the sampling ambient light illuminance corresponding to each target sampling point.

[0053] In some embodiments, the pre-stored reflectivity calculation rule is:

[0054]

[0055] Among them, R e is the reflectivity of the object under test at any target sampling point; C s is the sampling signal data of the target sampling point; N is the number of exposures required by the tap within the integration time of a single frame measurement; θ is the incident angle of light; L is the measurement distance of the object being measured; P t is the peak power of the signal beam emitted by the light source; k1 is the first preset coefficient;

[0056] The calculation rule of the pre-stored ambient light irradiance is:

[0057]

[0058] Among them, I AL is the ambient light irradiance at any target sampling point; C s is the sampling signal data of the target sampling point; C n is the ambient light data of the target sampling point; θ is the incident angle of light; L is the measurement distance of the object under test; f represents the focal length of the collector lens; k2 is the second preset coefficient, and k3 is the third preset coefficient.

[0059] In some embodiments, the preset threshold is a preset sampling signal data threshold;

[0060] The determining whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and shielding the fuzzy distance value, includes:

[0061] The sampled signal data is obtained based on the charge amount corresponding to the light signal reflected back by the object to be measured. If it is determined that the sampled signal data is less than, or less than or equal to, the sampled signal data threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is shielded. Another technical solution of the embodiment of the present invention is:

[0062] A device for shielding fuzzy distance values ​​of a distance measurement system, comprising:

[0063] an acquisition unit, configured to acquire an electrical signal corresponding to a signal light beam reflected by the object to be measured;

[0064] a calculation unit, configured to calculate a target distance value of the object to be measured according to the electrical signal;

[0065] The processing unit is configured to determine whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and to shield the fuzzy distance value.

[0066] Yet another technical solution of the embodiment of the present invention is:

[0067] A device for shielding fuzzy distance values ​​of a ranging system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for shielding fuzzy distance values ​​of a ranging system described in any of the technical solutions of the aforementioned embodiments is implemented.

[0068] Yet another technical solution of the embodiment of the present invention is:

[0069] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the method for shielding fuzzy distance values ​​of a ranging system as described in any of the technical solutions of the aforementioned embodiments.

[0070] Compared to existing technologies, the present invention obtains the electrical signal corresponding to the signal beam reflected by the object to be measured; calculates the target distance value of the object to be measured based on the electrical signal; determines whether the target distance value is a fuzzy distance value based on the target distance value and a preset threshold, and then blocks the fuzzy distance value. Based on the preset threshold, the present invention solves the problem of blocking fuzzy distance values ​​in the ranging system, realizes single-frequency ranging, and improves the measurement frame rate, thus simultaneously solving the problem of fuzzy ranging and improving the system frame rate.

[0071] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.

[0072] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 A schematic flow chart of a method for shielding fuzzy distance values ​​of a ranging system according to an exemplary embodiment of the present invention;

[0074] Figure 2 A schematic structural diagram of a device for shielding fuzzy distance values ​​of a ranging system according to an exemplary embodiment of the present invention;

[0075] Figure 3 2 is a schematic diagram of a device for shielding fuzzy distance values ​​of a ranging system provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0076] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent like or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0077] The terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the invention. The singular forms "a," "the," and "the" used in this invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0078] See also Figure 1 , Figure 1 This is a flow chart illustrating a method for shielding fuzzy distance values ​​of a ranging system according to an exemplary embodiment of the present invention. The method is performed by a device for shielding fuzzy distance values ​​of a ranging system (hereinafter referred to as the device), and includes the following steps:

[0079] S101: Acquire an electrical signal corresponding to a signal light beam reflected by the object to be measured.

[0080] In an embodiment of the present invention, the transmitter emits a signal light beam, which is reflected by the object to be measured and then received by the collector, which then outputs an electrical signal. The device then obtains the electrical signal corresponding to the signal light beam reflected by the object to be measured.

[0081] S102: Calculating a target distance value of the object to be measured according to the electrical signal.

[0082] The device calculates the target distance value of the object to be measured according to the electrical signal. It should be noted that the method for calculating the target distance value is not limited in the embodiment of the present invention.

[0083] S103: Determine whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and mask the fuzzy distance value.

[0084] The device pre-stores a preset threshold value, which may be a resolution threshold value, a signal photon count threshold value, or the like. This will be described in detail in subsequent embodiments and is not limited here. The device determines whether the target distance value is a fuzzy distance value based on the target distance value and the preset threshold value. If the target distance value is determined to be a fuzzy distance value, the fuzzy distance value is masked.

[0085] In some embodiments, it should be noted that for the DTOF ranging system and the ITOF ranging system, the methods of determining whether the target distance value is a fuzzy distance value and whether it needs to be shielded are different, which will be described in detail below.

[0086] In some embodiments, the distance measurement system is a DTOF ranging system, and the DTOF ranging system includes:

[0087] A transmitter configured to transmit a signal light beam having a pulse period of a first time toward the object to be measured;

[0088] a collector configured to collect a portion of the signal light beam reflected by the object to be measured and output an electrical signal, wherein the effective working time of the collector is a second time, and the second time is less than the first time;

[0089] The processing circuit is connected to the transmitter and the collector. The processing circuit can also be built into the device for shielding the fuzzy distance value of the ranging system to implement the method for shielding the fuzzy distance value of the ranging system in this application.

[0090] The transmitter is used to transmit a light beam to the target area. The light beam is emitted into the target area space to illuminate the target object in the space. At least part of the transmitted light beam is reflected by the target area to form a reflected light beam, and at least part of the reflected light beam is received by the collector. The processing circuit is connected to the transmitter and collector respectively, and synchronizes the trigger signals of the transmitter and collector to calculate the time required for the light beam to be transmitted and reflected back and received, that is, the flight time t between the transmitted light beam and the reflected light beam. Furthermore, the distance D of the corresponding point on the target object can be calculated by the following formula:

[0091] D=c·t / 2

[0092] Where c is the speed of light.

[0093] Specifically, the collector includes a pixel unit, etc. The pixel unit includes a two-dimensional pixel array composed of a plurality of pixels. In one embodiment, the pixel unit is a pixel array composed of single-photon avalanche photodiodes (SPADs), which can respond to incident single photons and output a signal indicating the corresponding arrival time of the received photons at each SPAD, and utilize methods such as time-correlated single-photon counting (TCSPC) to realize the collection of weak light signals and the calculation of flight time. Generally, a readout circuit composed of one or more devices such as a signal amplifier, a time-to-digital converter (TDC), and a digital-to-analog converter (ADC) is also connected to the pixel. These circuits can be integrated with the pixel unit as part of the collector or as part of the processing circuit.

[0094] In some embodiments, the collector includes a readout circuit, which includes a TDC circuit and a histogram circuit. The TDC circuit is used to receive and calculate the time-of-flight information of photons and convert the time-of-flight information into a time code. The time code is input into the histogram circuit to address the corresponding time bin (represented as the unit time of the collector sampling) and increase the photon count value within the corresponding time bin. After a frame of measurement is completed, a statistical histogram is plotted based on the photon count values ​​within all time bins. The statistical histogram includes consecutive time intervals (time bins). The horizontal axis of the histogram represents the flight time, and the vertical axis represents the photon count value. The photon count value within each time interval includes ambient photons and / or signal photons. The processing circuit calculates the number of ambient photons and the number of signal photons based on the histogram output by the histogram circuit. The number of signal photons is the sampling signal, which is the number of photons in the signal beam reflected by the object being measured collected by the collector. The number of ambient photons is the environmental data, which is the number of ambient photons collected by the collector when collecting photons in the signal beam reflected by the object being measured. Specifically, first, a local area is cut out from the histogram to calculate the mean number of ambient photons, and then a local area away from the pulse peak position is selected according to the pulse peak position in the histogram to calculate the mean number of ambient photons. In an optional embodiment, the mean number of ambient photons can also be calculated according to all time intervals of the histogram, and the sum of the number of photons in all time intervals is removed from the sum of the number of photons at the pulse peak position and then the average is calculated to obtain the mean number of ambient photons, which is the number of ambient photons included in each time interval in the histogram. In addition, according to the pulse peak position and pulse width, a pulse area is cut out from the histogram to calculate the sum of the number of photons in the area and the number of ambient photons, and the number of signal photons is further calculated. In some other embodiments, other methods can also be used to calculate the number of ambient photons and the number of signal photons, which are not specifically limited in the present invention.

[0095] For the DTOF ranging system, assuming that the maximum measurement range of the system is D, the pulse period is usually set to time T, T=2D / c. When designing the system, the working time of the TDC circuit corresponds to T, and the number of time bins configured in the histogram circuit is designed according to T. In an embodiment of the present application, the pulse period of the modulated emitted light pulse is a first time T1, and the collector is modulated to collect the reflected light signal within a second time T2 that is less than the first time T1. In the time period of T1-T2, the TDC is in a reset state and no longer counts. Then the effective working time of the collector is the second time T2, and the effective working time of the TDC is also the second time T2. Then the number of time bins configured in the histogram circuit is designed according to the second time T2.

[0096] For example, if T1 = 125ns, the corresponding ranging range is 18.75m. If T2 = 66.66ns, the corresponding ranging range is 10m. Then, for targets between 10m and 18.75m, the collector cannot collect the reflected light signal. If the target is between 18.75m and 28.75m and the reflected light signal can be collected by the collector, distance ambiguity may occur, that is, the distance value measured by the ranging system will still be within the range of 0 to 10m.

[0097] When the pulse period is set to T1 = 125 ns, the time-correlated single-photon counting (TCSPC) times are determined as:

[0098]

[0099] The total number of TCSPCs is approximately 64,000.

[0100] In order to improve the signal-to-noise ratio, in one embodiment, n pulses can be emitted in each pulse period to form a pulse train, and the intervals between the pulses are randomly configured, for example, they can be set to t1, t2, ...tn, and t1+t2+...+tn=T1, and the number of equivalent TCSPCs is 64000*n, where n is the number of pulse beams in one period.

[0101] In an optional embodiment, a preset quantitative resolution threshold can be used to determine whether the object to be measured is within the ranging range. Specifically, the device obtains the number of signal photons and the number of ambient photons, and then calculates the target resolution of the object to be measured based on the number of signal photons and the number of ambient photons. If the target resolution is greater than, or greater than or equal to, the preset quantitative resolution threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is suppressed.

[0102] In one embodiment, the preset quantitative resolution threshold may be pre-set in the following manner.

[0103] Among them, the emission pulse period of the signal light beam is the first time; the effective acquisition time of the signal light beam is the second time; the second time is less than the first time; the first ranging range and the second ranging range are determined according to the first time and the second time; the first resolution range corresponding to the first ranging range and the second resolution range corresponding to the second ranging range are obtained; and the preset quantitative resolution threshold is determined according to the first resolution range and the second resolution range.

[0104] Specifically, for the range ambiguity problem, taking T1 = 125ns as an example, since the modulation pulse period corresponds to a ranging range of 18.75m, and the collector is controlled to only receive reflected light signals from targets within the first 10m, the next period corresponding to the next range ambiguity signal will be between 18.75 and 28.75m.

[0105] In order to avoid the ranging signal of 18.75 to 28.75m in the next cycle interfering with the ranging accuracy of the normal 0 to 10m, the resolution distribution under different peak power, incident angle, ambient light and reflectivity when the object to be measured is respectively located in the first ranging range of 0 to 10m and the second ranging range of 18.75 to 28.75m is measured, and the resolution within the first ranging range of 0 to 10m and the second ranging range of 18.75 to 28.75m is compared. Among them, when the object to be measured is at a certain preset distance, it is necessary to measure n times continuously and calculate the variance of the n distance values ​​as the resolution, and adjust the peak power, incident angle, ambient light, reflectivity and other parameters differently, and repeat the above sampling process to obtain multiple sets of calibration data. It is understandable that only one of the influencing parameters can be adjusted or multiple parameters can be adjusted simultaneously. The size of the parameter can be randomly adjusted using a random number generation mode, or the size of the parameter can be adjusted according to a certain rule, such as an adjustment mode from small to large or from large to small. The specific adjustment method is not limited in this application.

[0106] When the measured object has different reflectivities and the ambient light intensity varies, there is a significant difference in resolution between the two ranging ranges of 0 to 10m and 18.75 to 28.75m. Furthermore, as the ambient light increases, the overlapping resolutions in the two ranges decrease. By fitting a large amount of measurement data, we determined that the resolution distribution in the 0 to 10m range is the first resolution range [0, R1], and the resolution distribution in the 18.75 to 28.75m range is the second resolution range [R2, R3], with R2 ≤ R1. Therefore, a fixed value, R, can be selected as the resolution threshold to suppress ranging ambiguity. R is typically set to a value less than R2.

[0107] During actual measurement, the system calculates the real-time target resolution and compares it with a preset quantitative resolution threshold to suppress fuzzy distance values. Specifically, the distance measurement system calculates the ambient photon count and signal photon count based on the histogram output by the histogram circuit. The target resolution is then calculated based on these numbers and a preset resolution calculation rule. The system pre-stores a preset resolution calculation rule, which identifies the relationship between the ambient photon count, signal photon count, and resolution. The target resolution is calculated based on this pre-stored resolution calculation rule.

[0108] In this embodiment, there is no specific limitation on the preset resolution calculation rule. When the preset resolution calculation rule is a function model, it can be a function model in various forms. For example, the preset resolution calculation rule can be the following function model:

[0109]

[0110] Among them, C s is the number of signal photons; C n is the number of ambient photons; a, b, c, d are all parameters; Resolution is the resolution.

[0111] For another example, the preset resolution calculation rule may also be the following function model:

[0112]

[0113] Among them, C s is the number of signal photons; C n is the number of ambient photons; a, b, c, d, e are all parameters; f represents the focal length of the collector lens.

[0114] In order to accurately obtain the calculation result of the resolution, the sampling data can be fitted or trained to obtain a function model of the preset resolution calculation rule.

[0115] The device determines the difference between the target resolution and the preset quantitative resolution threshold. If the target resolution is greater than, or greater than or equal to, the target distance value is determined to be fuzzy and is masked. During ranging, the real-time target resolution R4 is calculated based on the real-time signal photon count and ambient photon count. If R4 > R, the target distance value is fuzzy and needs to be masked.

[0116] Although the method of presetting quantitative resolution shielding solves the ranging ambiguity, it sacrifices a large ranging range, especially in the case of long distance, high ambient light and low reflectivity, the ranging range is greatly reduced.

[0117] In an optional embodiment, to overcome ranging ambiguity without sacrificing too much ranging range, a variable resolution threshold can be determined to determine whether the object to be measured is within the ranging range, wherein the variable resolution threshold is determined based on the real-time average ambient light illumination. The device can obtain the number of signal photons and the number of ambient photons; calculate the target resolution of the object to be measured based on the number of signal photons and the number of ambient photons; calculate the average ambient light illumination based on the number of ambient photons and the number of signal photons; determine the variable resolution threshold based on the calculated average ambient light illumination and a fitted function relationship between a preset variable resolution threshold and the average ambient light illumination; if the target resolution is greater than, or greater than or equal to, the determined variable resolution threshold, then determine that the target distance value is a fuzzy distance value, and mask the fuzzy distance value.

[0118] Specifically, the device obtains the number of signal photons and the number of ambient photons, and calculates the target resolution of the object to be measured based on the number of signal photons and the number of ambient photons. The specific details can be referred to the detailed description above and will not be repeated here.

[0119] The device obtains the signal photon count and ambient photon count corresponding to different initial sampling points and calculates the sampling resolution of each initial sampling point based on the signal photon count and the ambient photon count. If the sampling resolution is less than a preset sampling resolution threshold, or if the sampling resolution is less than or equal to the preset sampling resolution threshold, the initial sampling point is marked as a target sampling point. In other words, initial sampling points with a sampling resolution greater than or greater than or equal to the preset sampling resolution threshold are masked out, and the remaining initial sampling points are marked as target sampling points.

[0120] Then, the mean ambient light illuminance is calculated based on the number of signal photons and the number of ambient photons at the target sampling point; finally, the variable resolution threshold is determined based on the calculated mean ambient light illuminance, the fitted function relationship between the preset variable resolution threshold and the mean ambient light illuminance.

[0121] The sampling resolution of each initial sampling point can be calculated according to the preset resolution calculation rules provided above. The preset sampling resolution threshold can be set by referring to the setting method of the preset quantitative resolution threshold above, which will not be repeated here. The target sampling point is the sampling point that meets the preset quantitative resolution threshold constraint.

[0122] When calculating the mean ambient light illuminance based on the number of signal photons and the number of ambient photons at the target sampling point, the reflectance corresponding to each target sampling point is first calculated based on the number of signal photons at each target sampling point and a pre-stored reflectance calculation rule; then, the sampled ambient light irradiance corresponding to each target sampling point is calculated based on the number of ambient photons at each target sampling point, the corresponding reflectance, and the pre-stored ambient light irradiance calculation rule; finally, the sampled ambient light irradiance corresponding to each target sampling point is calculated based on the sampled ambient light irradiance corresponding to each target sampling point, and the mean ambient light illuminance is calculated based on the sampled ambient light irradiance corresponding to each target sampling point.

[0123] In some embodiments, the device pre-stores a reflectivity calculation rule, that is, the correspondence between the number of signal photons and the reflectivity, and the reflectivity of the object under test is calculated based on the correspondence between the number of signal photons and the reflectivity.

[0124] The corresponding relationship between the number of signal photons and reflectivity is derived. The number of signal photons collected by the collector is affected not only by the reflectivity of the object being measured but also by factors such as the number of pulses emitted in a single frame, the angle of incidence of the light, the measurement distance from the object being measured, and the peak power of the signal beam emitted by the light source. Therefore, by calibrating the corresponding relationship between the number of signal photons and reflectivity while keeping these other factors fixed, we can derive the calculation rules for reflectivity.

[0125] When calculating the reflectivity, the device first obtains information such as the number of pulses emitted in a known single-frame measurement, the incident angle of light, the measurement distance of the object to be measured, and the peak power of the signal beam emitted by the light source. It then calculates the reflectivity of the object to be measured based on the determined parameters and pre-stored reflectivity calculation rules.

[0126] In an optional embodiment, the pre-stored reflectivity calculation rule may be:

[0127]

[0128] Where Re is the reflectivity of the object under test at any target sampling point; C ns is the number of signal photons at the target sampling point; TCSPC is the number of pulses emitted in the prior single-frame measurement; θ is the incident angle of light; L is the measurement distance of the object being measured; P t is the peak power of the signal beam emitted by the light source; k1 is the first preset coefficient, which is a constant determined according to the design of the ranging system. The constant k1 will change for different ranging system designs.

[0129] According to the above-mentioned pre-stored reflectivity calculation rules, the reflectivity corresponding to each target sampling point can be calculated respectively. It can be understood that the corresponding relationship between the number of signal photons and reflectivity is not limited to the above-mentioned relationship, and the above-mentioned relationship does not impose any specific restrictions on the corresponding relationship between the number of signal photons and reflectivity.

[0130] In some embodiments, the device can calculate the sampled ambient light irradiance based on the number of ambient photons, the number of signal photons, the focal length of the collector lens, the light incident angle, the reflectivity, and a pre-stored ambient light irradiance calculation rule.

[0131] In an optional embodiment, the pre-stored ambient light irradiance calculation rule is:

[0132]

[0133] Among them, I AL is the ambient light irradiance at any target sampling point; C ns is the number of signal photons at the target sampling point; C nn is the number of ambient photons at the target sampling point; θ is the incident angle of light; L is the measurement distance; f represents the focal length of the collector lens; k2 is the second preset coefficient, and k3 is the third preset coefficient. The second and third preset coefficients are constants determined according to the design of the ranging system, and this constant will change for different ranging system designs.

[0134] Based on the above-mentioned pre-stored ambient light irradiance calculation rules, the sampled ambient light irradiance calculation rules corresponding to each target sampling point can be calculated respectively. It can be understood that the pre-stored ambient light irradiance calculation rules are not limited to the above-mentioned relationship, and the above-mentioned relationship does not specifically limit the pre-stored ambient light irradiance calculation rules.

[0135] In some embodiments, the device first calculates the sampled ambient light illuminance corresponding to each target sampling point based on the sampled ambient light irradiance corresponding to each target sampling point, and then sums the sampled ambient light illuminance corresponding to each target sampling point to obtain an average ambient light illuminance.

[0136] In an optional embodiment, the sampling ambient light irradiance of each target sampling point is first calculated based on the calculated sampling ambient light irradiance, and the following formula can be used for specific calculation:

[0137]

[0138] Among them, E i is the sampling ambient illumination of the target sampling point i, I AL is the sampled ambient light irradiance at target sampling point i, i is the number of the target sampling point, i = 1, 2, 3…n. n is the total number of target sampling points.

[0139] Then, the sampled ambient light illuminance of multiple n target sampling points that meet the preset quantitative resolution threshold constraint is averaged to obtain the ambient light illuminance mean E:

[0140]

[0141] It should be noted that, in this embodiment, the target sampling points are numbered sequentially. It should be understood that sequential numbering may not be used in other embodiments.

[0142] In some embodiments, the fitting function relationship between the variable resolution threshold and the mean ambient light illumination value may be specifically set in the following manner.

[0143] A linear function relationship between the resolution threshold and the mean ambient light intensity is constructed as: Resolution = aE + b. The resolution threshold that blocks distance blur under different ambient lighting conditions is obtained, and calibration data for multiple sets of mean ambient light intensity values ​​and resolution thresholds is obtained. The coefficients a and b are determined based on this calibration data. In actual distance measurement, the variable resolution threshold, Resolution, can be determined in real time based on the calculated mean ambient light intensity E.

[0144] In an optional embodiment, to avoid sacrificing ranging range, a signal photon count threshold can be used to mask ranging ambiguity. The device obtains the real-time signal photon count. If the signal photon count is less than, or less than or equal to, the target distance value is determined to be an ambiguous distance value and the ambiguous distance value is masked.

[0145] Specifically, for the range ambiguity problem, since the ranging range corresponding to the modulation pulse cycle is 18.75 meters, and the collector is controlled to only receive reflected light signals within the first 10 meters of the target, the range corresponding to the next cycle of the next range ambiguity signal is 18.75 to 28.75 meters.

[0146] In order to prevent the ranging signal of 18.75 to 28.75m from interfering with the normal ranging accuracy of 0 to 10m in the next cycle, the resolution distribution under different peak power, incident angle, ambient light, and reflectivity is measured when the object to be measured is located in the first ranging range of 0 to 10m and the second ranging range of 18.75 to 28.75m. Among them, when the object to be measured is at a certain preset distance, it is necessary to continuously measure n times to calculate the variance of the distance value as the resolution, and adjust the parameters such as peak power, incident angle, ambient light, and reflectivity differently. The parameters such as incident angle, ambient light illumination or reflectivity can be adjusted, and the above sampling process is repeated to obtain multiple sets of calibration data. At the same time, the signal photon number thresholds in the range of 0 to 10m and the range of 18.75m to 28.75m can be determined. Since the signal photon number is inversely proportional to the square of the distance, the minimum signal photon number in the range of 0 to 10m can be determined based on the calibration data and set as the signal photon number threshold. When the number of signal photons monitored in real time is less than the signal photon number threshold, the ranging value is invalid.

[0147] In some embodiments, the distance measurement system is an ITOF ranging system, and the ITOF ranging system includes:

[0148] A transmitter configured to transmit a signal light beam of a first frequency toward the object to be measured, wherein the first frequency is less than a maximum frequency of the transmitted light signal corresponding to a preset maximum distance measurement value of the distance measurement system;

[0149] a collector configured to collect a portion of the signal light beam reflected by the object to be measured and output an electrical signal;

[0150] The processing circuit is connected to the transmitter and the collector. The processing circuit can be built into a device for shielding the fuzzy distance value of the ranging system to implement the method for shielding the fuzzy distance value of the ranging system in this application.

[0151] The transmitter emits a light beam into the target space to illuminate the object to be measured in the space. At least a portion of the transmitted light beam (i.e., the signal light beam) is reflected by the object to be measured to form a reflected light beam, and at least a portion of the reflected light beam is collected by the collector. The processing circuit is connected to the transmitter and collector respectively, and synchronizes the trigger signals of the transmitter and collector to calculate the time required for the light beam to be emitted by the transmitter and received by the collector, i.e., the flight time t between the transmitted light beam and the reflected light beam. Furthermore, the distance D of the corresponding point on the object can be calculated by the following formula:

[0152]

[0153] Where c is the speed of light and t is the flight time between the emitted and reflected beams.

[0154] The emitter includes a light source and a light source driver. The light source can be a light emitting diode (LED), edge emitting laser (EEL), vertical cavity surface emitting laser (VCSEL), or a light source array consisting of multiple light sources. The light beam emitted by the light source can be visible light, infrared light, ultraviolet light, etc.

[0155] The collector includes an image sensor, a lens unit, a filter, etc. The lens unit receives at least a portion of the light beam reflected by the object and directs it to the image sensor. The filter is a narrowband filter that matches the wavelength of the light source and is used to suppress background light noise or stray light in other wavelength bands. The image sensor can be an image sensor array composed of a charge-coupled device (CCD), a complementary metal oxide semiconductor (CMOS), etc. The array size represents the resolution of the distance measurement system, such as 320×240. In an embodiment of the present invention, the image sensor includes at least one pixel, each of which includes multiple taps for storing and reading or discharging charge signals generated by incident photons under the control of corresponding electrodes. Ambient light data and signal data are calculated based on the amount of charge accumulated in the taps during the integration time. For example, each pixel includes two taps, which are switched in a certain order within a single frame period (or a single exposure time) to collect the corresponding light signal, receive the light signal, convert it into an electrical signal, and read the charge signal data. For another example, each pixel includes three taps, and the taps are switched in sequence in a certain order within a single frame period to collect corresponding light signals, and one of the taps is used to collect an ambient light signal.

[0156] The processing circuit may be an independent dedicated circuit, such as a dedicated SOC chip, FPGA chip, ASIC chip, etc. composed of a CPU, memory, bus, etc., or may include a general-purpose processing circuit.

[0157] In some embodiments, the processing circuit is used to provide the modulation signal (transmission signal) required for the light source to emit laser light. Under the control of the modulation signal, the light source emits a pulsed light beam toward the object under test. In addition, the processing circuit also provides a demodulation signal (acquisition signal) for the taps in each pixel of the image sensor. Under the control of the demodulation signal, the taps collect the charge signal generated by the pulsed light beam reflected back from the object under test and calculate the phase difference based on the charge signal to obtain the distance to the object under test. For example, in the case of two taps, the expression for calculating the distance to the object under test is as follows:

[0158]

[0159] Where c is the speed of light; T is the exposure period; Q1 and Q2 are the charges accumulated in the two taps respectively.

[0160] In an embodiment of the present invention, a transmitter is configured to transmit a signal light beam of a first frequency toward an object to be measured, wherein the first frequency is less than a maximum frequency corresponding to a preset maximum distance measurement value of a ranging system; a collector is configured to collect a portion of the signal light beam reflected back by the object to be measured and output a charge signal; a processing circuit is connected to the transmitter and the collector, calculates a target distance value of the object to be measured based on the charge signal, determines whether the target distance value is a fuzzy distance value based on the target distance value and a preset threshold, and masks the fuzzy distance value.

[0161] Specifically, the processing circuit obtains the ranging maximum value corresponding to the preset maximum frequency of the emitted light signal, and uses the ranging maximum value as the preset threshold; if the target distance value is greater than the preset threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is shielded.

[0162] Specifically, assuming that the maximum measurement range of the system is D, the period is usually set to time T, T = 2D / c, then the frequency of the emitted light signal is Assume that the system is designed with a transmitted optical signal frequency of f = 15 MHz, corresponding to a period of 66.66 ns, and a maximum ranging range of 10 meters. In this embodiment of the present invention, to address range aliasing, the transmitted optical signal is modulated to a frequency f1, where f1 < f. For example, f1 = 8 MHz, corresponding to a period of 125 ns, extending the system's actual ranging range to 18.75 meters. Correspondingly, the collector's single-frequency sampling time is also extended to 125 ns.

[0163] In an optional embodiment, the processing circuit determines whether the object to be measured is within the ranging range by using a preset quantitative resolution threshold. Specifically, the processing circuit obtains ambient light data and sampling signal data based on the amount of charge corresponding to the light signal reflected back by the object to be measured, and calculates the target resolution of the object to be measured based on the ambient light data and the sampling signal data; if the target resolution is greater than the preset quantitative resolution threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is shielded.

[0164] In the embodiment of the present invention, the ambient light data and the sampled signal data are obtained based on the charge signal accumulated by the tap of the pixel during the integration time. Assume that each pixel includes 3 taps, collects the reflected light signal during the integration time and outputs the charge amount A 1-3 Two of the taps are used to collect reflected light signals, and the charge amounts A1 and A2 collected by these two taps are used to represent the collected sampling signal data. The other tap is used to collect ambient light signals, and the charge amount A3 collected by the tap output is used to represent the ambient light data.

[0165] In an optional embodiment, when each pixel includes multiple taps, the sinusoidal waveform of the reflected signal collected by the collector can be fitted based on the output charge of the multiple taps. For example, the fitted sinusoidal curve is: y = a + b * cost + c * sint. The amplitude and DC value can be determined based on the fitted curve, where the amplitude is used to represent the sampled signal data and the DC value is used to represent the ambient light data. In an optional embodiment, the amplitude of the sine wave fitting curve is The DC flow is Then, the sampled signal data is expressed as Ambient light data is represented as

[0166] The processing circuit calculates the target resolution based on the ambient light data, the sampled signal data, and a preset resolution calculation rule. The system pre-stores the preset resolution calculation rule, i.e., the correspondence between the ambient light data, the sampled signal data, and the resolution. The processing circuit calculates the target resolution based on the pre-stored resolution calculation rule.

[0167] It should be noted that, in this embodiment, there is no specific limitation on the preset resolution calculation rule. When the preset resolution calculation rule is a function model, it can be a function model in various forms. For example, the preset resolution calculation rule can be the following function model:

[0168]

[0169] Among them, C s is the sampling signal data; C n is the ambient light data; a, b, c, d are parameters; Resolution is the resolution.

[0170] For another example, the preset resolution calculation rule may also be the following function model:

[0171]

[0172] Among them, C s is the sampling signal data; C n is the ambient light data; a, b, c, d, e are all parameters; f represents the focal length of the collector lens.

[0173] In order to accurately obtain the calculation result of the resolution, the sampling data can be fitted or trained to obtain a function model of the preset resolution calculation rule.

[0174] The processing circuit determines the size between the target resolution and the preset quantitative resolution threshold. If the target resolution is greater than, or greater than or equal to the preset quantitative resolution threshold, the target distance value is determined to be a fuzzy distance value and the fuzzy distance value is shielded.

[0175] It should be noted that although the method of presetting quantitative resolution shielding solves the ranging ambiguity, it sacrifices a large ranging range, especially in long-range, high ambient light, and low reflectivity conditions, where the ranging range is greatly reduced. In order to overcome the ranging ambiguity without sacrificing too much ranging range, a new method is proposed.

[0176] In an optional embodiment, whether the object to be measured is within the range can be determined by determining a variable resolution threshold, wherein the variable resolution threshold is determined based on the mean ambient light illumination value. A processing circuit obtains sampled signal data and ambient light data, calculates a target resolution of the object to be measured based on the sampled signal data and the ambient light data, calculates the mean ambient light illumination value based on the sampled signal data and the ambient light data, determines the variable resolution threshold based on the calculated mean ambient light illumination value and a fitted function relationship between a preset variable resolution threshold and the mean ambient light illumination value, and determines that the target distance value is a fuzzy distance value if the target resolution is greater than, or greater than or equal to, the preset variable resolution threshold, and masks the fuzzy distance value.

[0177] Specifically, the specific details of how the processing circuit calculates the target resolution of the object to be measured based on the sampled signal data and the ambient light data can be referred to the detailed description above and will not be repeated here.

[0178] The processing circuit first obtains the sampled signal data and ambient light data corresponding to different initial sampling points, and calculates the sampling resolution of each initial sampling point based on the sampled signal data and the ambient light data. If the sampling resolution is less than a preset sampling resolution threshold, or less than or equal to the preset sampling resolution threshold, the initial sampling point is marked as a target sampling point. In other words, initial sampling points with a sampling resolution greater than, or greater than or equal to the preset sampling resolution threshold are masked out, and the remaining initial sampling points are marked as target sampling points.

[0179] Then, the mean ambient light illuminance is calculated based on the sampling signal data and ambient light data of each target sampling point; finally, the variable resolution threshold is determined based on the fitting function relationship between the ambient light illuminance mean, the preset ambient light illuminance mean and the variable resolution threshold.

[0180] The sampling resolution of each initial sampling point can be calculated according to the preset resolution calculation rules provided above. The preset sampling resolution threshold can be set by referring to the setting method of the preset quantitative resolution threshold above, which will not be repeated here. The target sampling point is the sampling point that meets the preset quantitative resolution threshold constraint.

[0181] When calculating the mean ambient light illuminance based on the sampled signal data and ambient light data of the target sampling points, first calculate the reflectance corresponding to each target sampling point based on the sampled signal data of each target sampling point and a pre-stored reflectance calculation rule; then, calculate the sampled ambient light irradiance corresponding to each target sampling point based on the ambient light data of each target sampling point, the corresponding reflectance, and the pre-stored ambient light irradiance calculation rule; finally, calculate the mean sampled ambient light illuminance corresponding to each target sampling point based on the sampled ambient light irradiance corresponding to each target sampling point, and calculate the mean ambient light illuminance based on the mean sampled ambient light illuminance corresponding to each target sampling point.

[0182] In some embodiments, a reflectivity calculation rule is pre-stored in the system, that is, a correspondence between sampled signal data and reflectivity, and the reflectivity of the object under test is calculated based on the correspondence between the sampled signal data and reflectivity.

[0183] Among them, the correspondence between the sampling signal data and the reflectivity can be derived based on the relationship between the sampling signal data and the reflectivity. In addition to being affected by the reflectivity of the object being measured, the sampling signal data collected by the collector will also be affected by factors such as the number of tap exposures, the incident angle of light, the measurement distance of the object being measured, and the peak power of the signal beam emitted by the light source. Therefore, when other factors are fixed, the correspondence between the sampling signal data and the reflectivity is calibrated to derive the calculation rule of the reflectivity. When using the ITOF ranging system for ranging, the device can obtain information such as the number of tap exposures, the incident angle of light, the measurement distance of the object being measured, the peak power of the signal beam emitted by the light source, and calculate the reflectivity of the object being measured based on the pre-stored reflectivity calculation rule.

[0184] In an optional embodiment, the pre-stored reflectivity calculation rule may be:

[0185]

[0186] Among them, R e is the reflectivity of the object under test at any target sampling point; C s is the sampling signal data of the target sampling point; N is the number of exposures required by the tap within the integration time of a single frame measurement; θ is the incident angle of light; L is the measurement distance of the object being measured; P t is the peak power of the signal beam emitted by the light source; k1 is the first preset coefficient, which is a constant determined according to the design of the system. For different system designs, the constant k1 will change.

[0187] According to the above-mentioned pre-stored reflectivity calculation rules, the reflectivity corresponding to each target sampling point can be calculated respectively. It can be understood that the correspondence between the sampled signal data and the reflectivity is not limited to the above-mentioned relationship, and the above-mentioned relationship does not specifically limit the correspondence between the sampled signal data and the reflectivity.

[0188] In some embodiments, the ambient light irradiance is calculated based on the ambient light data and the reflectivity and a calculation rule of the ambient light irradiance pre-stored in the device.

[0189] Specifically, the device can calculate the ambient light irradiance based on the ambient light data, the sampled signal data, the focal length of the collector lens, the light incident angle, the reflectivity, and the calculation rules of the ambient light irradiance pre-stored in the device.

[0190] As a non-limiting example, the pre-stored calculation rule for ambient light irradiance is:

[0191]

[0192] Among them, I AL is the ambient light irradiance at any target sampling point; C s is the sampling signal data of the target sampling point; C n is the ambient light data of the target sampling point; θ is the incident angle of light; L is the measurement distance of the object to be measured; f represents the focal length of the collector lens; k2 is the second preset coefficient, k3 is the third preset coefficient, the second preset coefficient and the third preset coefficient are constants determined according to the design of the system, and this constant will change for different system designs.

[0193] Based on the above-mentioned pre-stored ambient light irradiance calculation rules, the sampled ambient light irradiance calculation rules corresponding to each target sampling point can be calculated respectively. It can be understood that the pre-stored ambient light irradiance calculation rules are not limited to the above-mentioned relationship, and the above-mentioned relationship does not specifically limit the pre-stored ambient light irradiance calculation rules.

[0194] In some embodiments, the sampling ambient light illuminance corresponding to each target sampling point is first calculated based on the sampling ambient light irradiance corresponding to each target sampling point, and then the sampling ambient light illuminance corresponding to each target sampling point is averaged to obtain the ambient light illuminance mean.

[0195] In an optional embodiment, the sampling ambient light irradiance of each target sampling point is first calculated based on the calculated sampling ambient light irradiance, and the following formula can be used for specific calculation:

[0196]

[0197] Among them, E i is the sampling ambient illumination of the target sampling point i, IAL is the sampled ambient light irradiance at target sampling point i, i is the number of the target sampling point, i = 1, 2, 3…n. n is the total number of target sampling points.

[0198] Then, the sampled ambient light illuminance of multiple n target sampling points that meet the preset quantitative resolution threshold constraint is averaged to obtain the ambient light illuminance mean E:

[0199]

[0200] It should be noted that, in this embodiment, the target sampling points are numbered sequentially. It should be understood that sequential numbering may not be used in other embodiments.

[0201] In some embodiments, the fitting function relationship between the variable resolution threshold and the mean ambient light illumination value may be specifically set in the following manner.

[0202] The linear function relationship between the resolution threshold and the mean ambient light irradiance is constructed as: Resolution = aE + b. The resolution threshold that blocks distance blur under different ambient lighting conditions is obtained to obtain calibration data for multiple sets of ambient light irradiance mean and resolution threshold values. The coefficients a and b are determined based on this calibration data. In actual distance measurement, the real-time variable resolution threshold, Resolution, can be determined based on the calculated ambient light mean E. Simulations are performed to simulate the resolution threshold that blocks distance blur under different ambient lighting conditions, and a linear function relationship between the resolution threshold and ambient light irradiance is obtained: Resolution = aE + b. After obtaining E, the preset variable resolution threshold can be obtained.

[0203] In an optional embodiment, to avoid sacrificing the ranging range, a sampling signal data threshold can be used to mask ranging ambiguity. Specifically, a sampling signal data threshold is pre-set, and the processor obtains real-time sampling signal data. If the sampling signal data is less than, or less than or equal to, the sampling signal data threshold, the target distance value is determined to be an ambiguous distance value and the ambiguous distance value is masked.

[0204] See Figure 2 , Figure 2 The schematic diagram of the structure of the device for shielding the fuzzy distance value of the ranging system is shown as an exemplary embodiment of the present invention. The units included are used to perform Figure 1 For details of the steps in the corresponding embodiment, please refer to Figure 1 For the convenience of explanation, only the parts related to this embodiment are shown. Figure 2 , the device 2 for shielding the fuzzy distance value of the ranging system includes:

[0205] An acquisition unit 210 is configured to acquire an electrical signal corresponding to a signal light beam reflected by the object to be measured;

[0206] A calculation unit 220 is configured to calculate a target distance value of the object to be measured based on the electrical signal;

[0207] The processing unit 230 is configured to determine whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and mask the fuzzy distance value.

[0208] See Figure 3 , Figure 3 FIG. 1 is a schematic diagram of a device for shielding fuzzy distance values ​​of a ranging system provided by an exemplary embodiment of the present invention. Figure 3 As shown, the device 3 for shielding the fuzzy distance value of the ranging system in this embodiment includes: a processor 30, a memory 31, and a computer program 32 stored in the memory 31 and executable on the processor 30, such as a fuzzy distance value shielding program. When the processor 30 executes the computer program 32, the steps in the above-mentioned embodiments of the method for shielding the fuzzy distance value of the ranging system are implemented, such as Figure 1 Alternatively, when the processor 30 executes the computer program 32, the functions of the modules / units in the above-mentioned device embodiments are realized, for example, Figure 2 The functions of the units 210 to 230 are shown.

[0209] Exemplarily, the computer program 32 can be divided into one or more modules / units, which are stored in the memory 31 and executed by the processor 30 to implement the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 32 in the device 3 for shielding the ambiguity of the distance value of the ranging system. For example, the computer program 32 can be divided into an acquisition module, a calculation module, and a processing module, each module having the following functions:

[0210] An acquisition module, used to acquire an electrical signal corresponding to a signal light beam reflected by the object to be measured;

[0211] a calculation module, configured to calculate a target distance value of the object to be measured according to the electrical signal;

[0212] The processing module is configured to determine whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and to shield the fuzzy distance value.

[0213] The device 3 for shielding the fuzzy distance value of the ranging system may include, but is not limited to, a processor 30 and a memory 31. It will be understood by those skilled in the art that Figure 3It is only an example of the device 3 for shielding the fuzzy distance value of the ranging system and does not constitute a limitation on the device 3 for shielding the fuzzy distance value of the ranging system. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the device 3 for shielding the fuzzy distance value of the ranging system may also include input and output devices, network access devices, buses, etc.

[0214] The processor 30 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0215] The memory 31 can be an internal storage unit of the device 3 for shielding the fuzzy distance value of the ranging system, such as a hard disk or memory of the device 3 for shielding the fuzzy distance value of the ranging system. The memory 31 can also be an external storage device of the device 3 for shielding the fuzzy distance value of the ranging system, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card, etc. equipped on the device 3 for shielding the fuzzy distance value of the ranging system. Furthermore, the memory 31 can also include both the internal storage unit of the device 3 for shielding the fuzzy distance value of the ranging system and an external storage device. The memory 31 is used to store the computer program and other programs and data required by the device for shielding the fuzzy distance value of the ranging system. The memory 31 can also be used to temporarily store data that has been output or is about to be output.

[0216] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0217] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0218] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0219] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0220] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0221] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0222] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of each of the above-mentioned method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals. The present invention is not limited to the above-mentioned embodiments. If various changes or modifications of the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims of the present invention and equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A method for shielding fuzzy distance values ​​of a ranging system, characterized in that: include: Obtaining an electrical signal corresponding to the signal light beam reflected by the object to be measured; Calculating the target distance value of the object to be measured according to the electrical signal; determining whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and shielding the fuzzy distance value; The determining whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and shielding the fuzzy distance value, includes: Acquiring a signal photon number and an ambient photon number; wherein the signal photon number and the ambient photon number are determined based on the electrical signal; If the target distance value is determined to be a fuzzy distance value based on the ambient photon number, the signal photon number and a resolution threshold, or based on the signal photon number and a preset signal photon number threshold, the fuzzy distance value is shielded.

2. The method for shielding the fuzzy distance value of the ranging system according to claim 1, characterized in that: If the target distance value is determined to be a fuzzy distance value based on the number of ambient photons, the number of signal photons, and a resolution threshold, or based on the number of signal photons and a preset signal photon number threshold, then shielding the fuzzy distance value includes: Calculating the target resolution of the object to be measured based on the number of signal photons and the number of ambient photons; if it is determined that the target resolution is greater than a resolution threshold, or the target resolution is greater than or equal to the resolution threshold, determining the target distance value as a fuzzy distance value, and shielding the fuzzy distance value; or, If it is determined that the number of signal photons is less than the signal photon number threshold, or the number of signal photons is less than or equal to the signal photon number threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is shielded.

3. The method for shielding the fuzzy distance value of the ranging system according to claim 2, characterized in that: The resolution threshold includes a preset quantitative resolution threshold or a variable resolution threshold, and the variable resolution threshold is determined according to the average value of the ambient light illumination.

4. The method for shielding the fuzzy distance value of the ranging system according to claim 1, characterized in that: The preset threshold is a resolution threshold; The determining whether the target distance value is a fuzzy distance value according to the electrical signal and a preset threshold, and shielding the fuzzy distance value, includes: Ambient light data and sampling signal data are obtained based on the amount of charge corresponding to the light signal reflected back by the object to be measured, and the target resolution of the object to be measured is calculated based on the ambient light data and the sampling signal data; if it is determined that the target resolution is greater than, or greater than or equal to, the resolution threshold, the target distance value is determined to be a fuzzy distance value, and the fuzzy distance value is shielded.

5. The method for shielding the fuzzy distance value of the ranging system according to claim 4, characterized in that: The resolution threshold includes a preset quantitative resolution threshold or a variable resolution threshold, and the variable resolution threshold is determined according to the average value of the ambient light illumination.

6. A device for shielding fuzzy distance values ​​of a ranging system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for shielding the fuzzy distance value of the ranging system according to any one of claims 1 to 5 is implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for shielding fuzzy distance values ​​of a ranging system according to any one of claims 1 to 5 is implemented.

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