A distance measurement system and its relative accuracy determination method, device and equipment

Abstract

The present invention provides a distance measurement system and a method, device, and apparatus for determining relative accuracy thereof. The method comprises: obtaining an ambient photon count and a signal photon count; wherein the signal photon count is an electrical signal output by a collector when light signals reflected from an object to be measured are collected; calculating relative accuracy based on the ambient photon count, the signal photon count, and a preset relative accuracy calculation rule, wherein the preset relative accuracy calculation rule is obtained according to the following steps: obtaining a historical ambient photon count and a historical signal photon count, and obtaining the relative accuracy of ranging corresponding to the historical ambient photon count and the historical signal photon count; and constructing a fitting function based on the historical ambient photon count, the historical signal photon count, and the relative accuracy of ranging to obtain the preset relative accuracy calculation rule. The present invention extracts the signal photon count and the ambient photon count in real time from a single-frame image and calculates the relative accuracy in real time using a single-frame image. This allows for real-time performance evaluation and elimination of ranging results from the distance measurement system, ensuring that only 3D points with relatively low noise are retained in the output depth data, thereby improving the overall 3D point cloud effect.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a distance measurement system and a method, device and equipment for determining relative accuracy thereof. Background Art

[0002] Relative accuracy is a crucial metric for distance measurement systems. It reflects the noise level of the 3D surface measurements of the object being measured. High relative accuracy results in a smooth, low-noise 3D point cloud. Low relative accuracy, however, indicates significant fluctuations in the 3D points on the surface, leading to invalid points that need to be excluded.

[0003] In the existing technology, when obtaining relative accuracy, it is necessary to obtain multiple frames of 3D point cloud data in advance for calculation. It is impossible to obtain relative accuracy in a single frame in real time, and it is impossible to determine whether certain points in a single frame image have low relative accuracy or large fluctuation values, and thus it is impossible to exclude points with low relative accuracy and large fluctuation values ​​in real time. Summary of the Invention

[0004] To overcome the problems existing in the prior art, embodiments of the present invention provide a distance measurement system and a method, apparatus, and device for determining relative accuracy thereof.

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

[0006] The technical solution of embodiment 1 of the present invention is:

[0007] A distance measurement system includes: a transmitter, a collector, and a processing circuit;

[0008] The transmitter is configured to transmit a signal light beam;

[0009] The collector includes a pixel unit and a readout circuit. The pixel unit includes a plurality of pixels. The pixels are used to respond to a single photon in the reflected light beam and output a photon signal. The readout circuit is used to receive the photon signal, process it, and output a histogram.

[0010] The processing circuit is connected to the transmitter and the collector, and is used to receive the histogram to obtain the number of ambient photons and the number of signal photons, and calculate the relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule; wherein the number of signal photons is the number of photons in the signal beam emitted by the transmitter and collected by the collector;

[0011] The preset relative accuracy calculation rule is obtained according to the following steps:

[0012] Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count;

[0013] A fitting function is constructed according to the historical environmental photon number, the historical signal photon number and the relative ranging accuracy to obtain a preset relative accuracy calculation rule.

[0014] Furthermore, the processing circuit is also used to calculate the distance value of the object to be measured, and determine whether the relative accuracy of the distance value exceeds a preset relative accuracy threshold. If it exceeds the preset relative accuracy threshold, the distance value is shielded.

[0015] Furthermore, the preset relative accuracy calculation rule is a function model, and the function model is:

[0016]

[0017] 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; R is the relative accuracy.

[0018] Another technical solution of the embodiment of the present invention is:

[0019] A method for determining the relative accuracy of a distance measurement system, comprising:

[0020] Acquire the number of ambient photons and the number of signal photons; wherein the number of signal photons is the electrical signal output by the collector when collecting the light signal reflected by the object to be measured;

[0021] Calculating relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule;

[0022] The preset relative accuracy calculation rule is obtained according to the following steps:

[0023] Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count;

[0024] A fitting function is constructed according to the historical environmental photon number, the historical signal photon number and the relative ranging accuracy to obtain a preset relative accuracy calculation rule.

[0025] Furthermore, the preset relative accuracy calculation rule is a function model, and the function model is:

[0026]

[0027] Among them, C s is the number of signal photons; C nis the number of ambient photons; a, b, c, d are all parameters; R is the relative accuracy.

[0028] Furthermore, it also includes:

[0029] Calculating the resolution according to the number of ambient photons, the number of signal photons, and a preset resolution calculation rule;

[0030] The relative accuracy of the distance measurement system is calculated based on the resolution.

[0031] Furthermore, obtaining the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count includes:

[0032] Obtain target distance measurement value, target actual distance value and target distance measurement average value;

[0033] The relative accuracy of distance measurement is calculated according to the target distance measurement value, the target actual distance value and the target distance measurement average value.

[0034] Another technical solution of the embodiment of the present invention is:

[0035] A device for determining the relative accuracy of a distance measurement system, comprising:

[0036] A first acquisition unit is configured to acquire the number of ambient photons and the number of signal photons; wherein the number of signal photons is an electrical signal output by a collector when collecting light signals reflected by the object to be measured;

[0037] A first processing unit is configured to calculate relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule;

[0038] The preset relative accuracy calculation rule is obtained according to the following steps:

[0039] Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count;

[0040] A fitting function is constructed according to the historical environmental photon number, the historical signal photon number and the relative ranging accuracy to obtain a preset relative accuracy calculation rule.

[0041] Furthermore, the first processing unit is further configured to:

[0042] Calculating the resolution according to the number of ambient photons, the number of signal photons, and a preset resolution calculation rule;

[0043] The relative accuracy of the distance measurement system is calculated based on the resolution.

[0044] Yet another technical solution of the embodiment of the present invention is:

[0045] A device for determining the relative accuracy of a distance measurement 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 determining the relative accuracy of the distance measurement system described in the technical solution of the aforementioned embodiment is implemented.

[0046] Compared with the existing technology, the present invention extracts the number of signal photons and ambient photons in a single-frame image in real time, calculates the relative accuracy in a real-time single frame, and can perform performance evaluation and elimination of the ranging results of the DTOF distance measurement system in real time, so that only 3D points with less noise are retained in the output depth data, thereby improving the overall 3D point cloud effect.

[0047] 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.

[0048] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic diagram of a distance measurement system according to an exemplary embodiment of the present invention;

[0050] Figure 2 A schematic flow chart of a method for determining the relative accuracy of a distance measurement system according to an exemplary embodiment of the present invention;

[0051] Figure 3 This is a flow chart of steps S103 to S104 in a method for determining relative accuracy of a distance measurement system according to an exemplary embodiment of the present invention;

[0052] Figure 4 A schematic structural diagram of a device for determining relative accuracy of a distance measurement system according to an exemplary embodiment of the present invention;

[0053] Figure 5 2 is a schematic diagram of a device for determining relative accuracy of a distance measurement system provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0054] 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.

[0055] 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.

[0056] See also Figure 1 , Figure 1 A schematic diagram of a distance measurement system is shown for an exemplary embodiment of the present invention. The distance measurement system includes: a transmitter, a collector, and a processing circuit;

[0057] a transmitter 11 configured to transmit a signal beam;

[0058] The collector 12 includes a pixel unit and a readout circuit. The pixel unit includes a plurality of pixels. The pixels are used to respond to a single photon in the light beam reflected by the object under test and output a photon signal. The readout circuit is used to receive the photon signal, process it, and output a histogram.

[0059] The processing circuit 13 is connected to the emitter and the collector, and is used to obtain the number of ambient photons and the number of signal photons, and calculate the relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule; wherein the number of signal photons is the electrical signal output by the collector when collecting the light signal reflected by the object to be measured;

[0060] The preset relative accuracy calculation rule is obtained according to the following steps:

[0061] Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count;

[0062] A fitting function is constructed according to the historical environmental photon number, the historical signal photon number and the relative ranging accuracy to obtain a preset relative accuracy calculation rule.

[0063] Specifically, the transmitter 11 is used to transmit a signal light beam 30 to the object to be measured 20, and the reflected light signal 40 reflected back by the object to be measured is received by the collector; wherein, the transmitter 11 and the collector 12 can be set on a substrate, specifically, they can be set on the same substrate or on different substrates.

[0064] The collector 12 includes a pixel unit 121, a filter unit 123 and a receiving optical element 122; wherein the receiving optical element 122 is used to image the spot light beam reflected back by the object to be measured onto the pixel unit 121; the filter unit 123 is used to suppress the background light noise in the remaining bands different from the wavelength of the light source; the pixel unit 121 can be a pixel array composed of a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), an avalanche diode (AD), a single photon avalanche diode (SPAD), etc. The size of the array represents the resolution of the depth camera, such as 320x240. Generally, a readout circuit (not shown in the figure) 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 unit 121. These circuits can be integrated with the pixel unit 121 as part of the collector 12, or as part of the processing circuit.

[0065] In an optional embodiment, the pixel unit 121 includes at least one pixel, which is a single-photon detector, such as a SPAD. Each pixel responds to a single photon in the reflected light beam and outputs a photon signal indicating the corresponding arrival time of the received photon at each SPAD. The readout circuit receives the photon signal and performs signal processing, and counts the number of collected photons to form continuous time bins. These time bins are connected together to form a statistical histogram for reproducing the time series of the reflected light beam.

[0066] The processing circuit 13 receives the histogram and processes it to calculate the flight time of the signal beam from emission to reception. For example, it uses peak matching and filtering detection to identify the flight time of the reflected beam from emission to reception. In some embodiments, the processing circuit 13 includes a readout circuit (not shown) composed of one or more components such as a signal amplifier, a time-to-digital converter (TDC), and a digital-to-analog converter (ADC). These circuits can be integrated with the pixel or as part of the processing circuit 13.

[0067] The processing circuit 13 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 processing circuit.

[0068] In an optional embodiment, the processing circuit is further used to calculate the distance value of the object to be measured and determine whether the relative accuracy of the distance value exceeds a preset relative accuracy threshold. If it exceeds the preset relative accuracy threshold, the distance value is shielded.

[0069] An embodiment of a method for determining the relative accuracy of a distance measurement system will be described in detail later. The processing circuit calculates the relative accuracy of the distance measurement system according to the determination method.

[0070] See also Figure 2 , Figure 2 This is a flow chart illustrating a method for determining the relative accuracy of a distance measurement system according to an exemplary embodiment of the present invention. The method is performed by a device for determining the relative accuracy of a distance measurement system (hereinafter referred to as the device), and includes the following steps:

[0071] S101: Acquire the number of ambient photons and the number of signal photons; wherein the number of signal photons is the electrical signal output by the collector when collecting the light signal reflected by the measured target object.

[0072] It should be noted that, in this embodiment, the distance measurement system is a DTOF ranging system. The collector of the DTOF ranging system includes a pixel unit and a readout circuit. The pixel unit includes a plurality of pixels; the pixel is a single-photon detector, such as a SPAD, and each pixel responds to a single photon in the reflected light beam and outputs a photon signal. The electrical signal is a photon signal indicating the corresponding arrival time of the received photon at each SPAD, and the readout circuit includes a TDC circuit and a histogram circuit. Among them, the TDC circuit is used to receive and calculate the time interval of the photon signal, and convert the time interval into a time code; the histogram circuit counts according to the time code output by the TDC circuit to draw a histogram. The number of ambient photons and the number of signal photons are calculated based on the histogram output by the histogram circuit.

[0073] During ranging, when the collector is triggered to begin collecting photons, the ambient light signal influences the histogram, resulting in a large number of ambient photons, evenly distributed across all time bins. Therefore, before calculating the signal photon count, it is necessary to first determine the mean ambient photon count within the histogram—that is, the number of collected ambient photons within each time bin. Specifically, n time intervals away from the pulse position are selected within the histogram. The average of the photon counts within these n time intervals is calculated and recorded as the mean ambient photon count, where n is an arbitrary integer.

[0074] The number of signal photons is calculated by intercepting the pulse area from the histogram according to the pulse peak position and pulse width. Generally, the time interval in the histogram is from tens to tens of picoseconds. The photon signal of a pulse beam emitted by the transmitter is distributed in multiple continuous time intervals in the histogram. According to the pulse width of the pulse beam and the time interval in the histogram, it can be determined that the photon signal of a pulse is distributed in multiple continuous time intervals in a corresponding interval in the histogram. The total number of photon counts in the area is calculated minus the number of ambient photons in the interval to determine the number of signal photons. For example, if the interval includes m time intervals, then the number of signal photons is C nm is the total number of photon counts in this interval, is the average number of ambient photons.

[0075] Furthermore, the number of ambient photons is calculated based on the mean number of ambient photons. The number of ambient photons is the number of ambient photons collected synchronously when the collector collects photons in the signal beam reflected by the object under test, that is, the number of ambient photons included in an interval corresponding to the distribution of a pulse in the histogram, where is the number of ambient photons.

[0076] In some other embodiments, other methods may also be used to calculate the number of ambient photons and the number of signal photons, which is not specifically limited in the present invention.

[0077] S102: Calculating relative accuracy according to the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule.

[0078] The device calculates relative accuracy based on the ambient photon count, signal photon count, and a preset relative accuracy calculation rule. The device pre-stores the preset relative accuracy calculation rule, which specifies the relationship between the ambient photon count, signal photon count, and relative accuracy. The device calculates relative accuracy based on this relationship.

[0079] In this embodiment, there is no specific limitation on the preset relative accuracy calculation rule. When the preset relative accuracy calculation rule is a function model, it can be a function model in various forms. For example, the preset relative accuracy calculation rule can be the following function model:

[0080]

[0081] 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; R is the relative accuracy.

[0082] The preset relative accuracy calculation rule can also be the following function model:

[0083]

[0084] 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; f represents the focal length of the collector lens.

[0085] In an optional embodiment, the resolution can be calculated first. The device calculates the resolution based on the number of ambient photons and the number of signal photons and a preset resolution calculation rule. The relative accuracy of the distance measurement system is then calculated based on the resolution. Specifically, the device can calculate the relative accuracy of the distance measurement system based on the resolution and a preset triple standard deviation law. According to the triple standard deviation law, the relationship between resolution and relative accuracy is:

[0086] R=1 / 3×E Resolution

[0087] Among them, R is the relative accuracy, E Resolution is the resolution.

[0088] In order to obtain accurate relative accuracy calculation results, the sampled data can be fitted or trained to obtain a function model of the preset relative accuracy calculation rules. Before the calculation, a fitting function can be constructed to fit the function model of the relative accuracy calculation. Before step S102, steps S103 to S104 can also be included. Figure 3 As shown, steps S103 to S104 are specifically as follows:

[0089] S103: Obtain historical ambient photon numbers, historical signal photon numbers, and relative ranging accuracies corresponding to the historical ambient photon numbers and the historical signal photon numbers.

[0090] The device obtains historical ambient photon counts, historical signal photon counts, and the resolutions corresponding to these historical ambient photon counts and signal photon counts. The historical ambient photon counts, historical signal photon counts, and the relative ranging accuracy corresponding to these two numbers can be used as a set of calibration data. By acquiring multiple sets of calibration data and performing fitting, a preset relative accuracy calculation rule can be derived. It should be noted that the terms "historical ambient photon counts" and "historical signal photon counts" are merely names, representing the ambient photon counts and signal photon counts sampled over multiple times, and do not refer to past or historical data.

[0091] Specifically, the simulation experiment method can be used to obtain the historical environmental photon number and the historical signal photon number, which can be obtained by changing the incident angle cosθ of the light beam and the ambient light intensity I AL , reflectivity, distance L of the object to be measured and other parameters that affect the relative accuracy of distance measurement, and a set of calibration data is obtained by continuously measuring each point multiple times.

[0092] In an optional embodiment, the relative accuracy of the distance measurement is obtained by a pre-calibrated method, and the device calculates the relative accuracy of the distance measurement by obtaining the target distance measurement value, the target actual distance value, and the target distance measurement average value. Specifically, assuming that the target point is set to be at a distance L from the distance measurement system m , (m=1, 2, 3…, M), for example, when m=1, set L1=1m, when m=2, set L2=1.1m, when m=3, set L3=1.3m, etc. Among them, set L1=1m, L1 is the actual distance value of the target, and the target distance measurement value l1-ln is obtained by continuous measurement n times. The number of ambient photons C is obtained in each measurement process. nn and the number of signal photons Csn The standard deviation between the n-times target distance measurement value and the actual target distance value is recorded as the relative accuracy of the distance measurement, and the mean of the historical ambient photon number and the historical signal photon number of the n-times measurement is calculated to obtain a set of calibration data with the target point L1. The process of obtaining the relative accuracy after n-times measurement is as follows:

[0093] According to the distance calculation formula of the TOF distance measurement system:

[0094]

[0095] Where c is the speed of light, which is approximately 3×10 8 m / s,t i is the light flight time of the i-th measurement. Then calculate the target distance measurement value d of the i-th measurement in n consecutive measurements i , and the average target distance measurement of n measurements The resolution of the distance measurement system is then:

[0096]

[0097] Among them, d i Represents the distance value obtained by the i-th measurement, and the number of tests ranges from 1 to n, with a total of n times. represents the average value of n measurements, It can be expressed as:

[0098]

[0099] Generally speaking, according to the triple standard deviation law, the relationship between resolution and relative accuracy of ranging is:

[0100] R=1 / 3×E Resolution

[0101] The relative accuracy of ranging is calculated after n samplings, and a set of calibration data can be obtained by calculating the average of n historical ambient photon numbers and historical signal photon numbers.

[0102] During the sampling process, parameters such as the incident angle, ambient light intensity, or reflectivity can be adjusted, and the above sampling process can be repeated 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 parameters can be randomly adjusted using a random number generation pattern, or the size of the parameters 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.

[0103] S104: Constructing a fitting function according to the historical environmental photon number, the historical signal photon number and the ranging relative accuracy to obtain a preset relative accuracy calculation rule.

[0104] The device constructs a fitting function based on the historical number of ambient photons, the historical number of signal photons, and the relative accuracy of ranging. Common fitting methods include least squares curve fitting, and polyfit can also be used in MATLAB to fit polynomials. After obtaining the fitting function, the preset relative accuracy calculation rules can be obtained.

[0105] The present invention extracts the number of signal photons and ambient photons in a single-frame image in real time, calculates the relative accuracy in a real-time single-frame, and can perform performance evaluation and elimination of ranging results of the DTOF distance measurement system in real time, so that only 3D points with relatively low noise are retained in the output depth data, thereby improving the overall 3D point cloud effect.

[0106] See Figure 4 , Figure 4 This is a schematic diagram of a device for determining the relative accuracy of a distance measurement system according to an exemplary embodiment of the present invention. Figure 2 and Figure 3 For details of the steps in the corresponding embodiment, please refer to Figure 2 and Figure 3 For the convenience of explanation, only the parts related to this embodiment are shown. Figure 4 , the device 4 for determining the relative accuracy of the distance measurement system includes:

[0107] A first acquisition unit 410 is configured to acquire the number of ambient photons and the number of signal photons; wherein the number of signal photons is an electrical signal output by a collector when collecting light signals reflected by the object to be measured;

[0108] A first processing unit 420 is configured to calculate relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule;

[0109] The preset relative accuracy calculation rule is obtained according to the following steps:

[0110] Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count;

[0111] A fitting function is constructed according to the historical environmental photon number, the historical signal photon number and the relative ranging accuracy to obtain a preset relative accuracy calculation rule.

[0112] Furthermore, the first processing unit 420 is further configured to:

[0113] Calculating the resolution according to the number of ambient photons, the number of signal photons, and a preset resolution calculation rule;

[0114] The relative accuracy of the distance measurement system is calculated based on the resolution.

[0115] Furthermore, the first processing unit 420 is specifically configured to:

[0116] The relative accuracy of the distance measurement system is calculated according to the resolution and a preset three-times standard deviation law.

[0117] Furthermore, the device for determining the relative accuracy of the distance measurement system further includes:

[0118] A second acquisition unit is used to obtain the historical number of ambient photons, the historical number of signal photons, and the relative accuracy of ranging corresponding to the historical number of ambient photons and the historical number of signal photons;

[0119] The second processing unit is used to construct a fitting function according to the historical environmental photon number, the historical signal photon number and the ranging relative accuracy to obtain a preset relative accuracy calculation rule.

[0120] Furthermore, the device for determining the relative accuracy of the distance measurement system further includes:

[0121] a third acquiring unit, configured to acquire a target distance measurement value, a target actual distance value, and a target distance measurement average value;

[0122] The third acquisition unit is configured to calculate a relative distance measurement accuracy based on the target distance measurement value, the target actual distance value, and the target distance measurement average value.

[0123] See Figure 5 , Figure 5 FIG. 1 is a schematic diagram of a device for determining the relative accuracy of a distance measurement system provided by an exemplary embodiment of the present invention. Figure 5 As shown, the device 5 for determining the relative accuracy of a distance measurement system in this embodiment includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50, such as a program for determining the relative accuracy of a distance measurement system. When the processor 50 executes the computer program 52, the steps of the above-mentioned methods for determining the relative accuracy of a distance measurement system are implemented, such as Figure 2 Alternatively, when the processor 50 executes the computer program 52, the functions of the modules / units in the above-mentioned device embodiments are realized, for example, Figure 4 Functions of units 410 to 420 are shown.

[0124] Exemplarily, the computer program 52 can be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 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, and the instruction segments are used to describe the execution process of the computer program 52 in the device 5 for determining the relative accuracy of the distance measurement system. For example, the computer program 52 can be divided into a first acquisition module and a first processing module, and the functions of each module are as follows:

[0125] A first acquisition module is used to acquire the number of ambient photons and the number of signal photons; wherein the number of signal photons is the electrical signal output by the collector when collecting the light signal reflected by the object to be measured;

[0126] The first processing module is used to calculate the relative accuracy according to the number of ambient photons, the number of signal photons and a preset relative accuracy calculation rule.

[0127] The device 5 for determining the relative accuracy of the distance measurement system may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will appreciate that Figure 5 It is only an example of the device 5 for determining the relative accuracy of the distance measurement system and does not constitute a limitation of the device 5 for determining the relative accuracy of the distance measurement 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 5 for determining the relative accuracy of the distance measurement system may also include input and output devices, network access devices, buses, etc.

[0128] The processor 50 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.

[0129] The memory 51 can be an internal storage unit of the device 5 for determining the relative accuracy of the distance measurement system, such as a hard disk or memory of the device 5 for determining the relative accuracy of the distance measurement system. The memory 51 can also be an external storage device of the device 5 for determining the relative accuracy of the distance measurement system, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the device 5 for determining the relative accuracy of the distance measurement system. Furthermore, the memory 51 can include both an internal storage unit of the device 5 for determining the relative accuracy of the distance measurement system and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the device 5 for determining the relative accuracy of the distance measurement system. The memory 51 can also be used to temporarily store data that has been output or is about to be output.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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 distance measurement system, characterized in that: include: transmitter, collector, and processing circuit; The transmitter is configured to transmit a signal light beam; The collector includes a pixel unit and a readout circuit. The pixel unit includes a plurality of pixels. The pixels are used to respond to a single photon in the reflected light beam and output a photon signal. The readout circuit is used to receive the photon signal, process it, and output a histogram. The processing circuit is connected to the transmitter and the collector, and is used to receive the histogram to obtain the number of ambient photons and the number of signal photons, and calculate the relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule; wherein the number of signal photons is the number of photons in the signal beam emitted by the transmitter and collected by the collector; The preset relative accuracy calculation rule is obtained according to the following steps: Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count; Constructing a fitting function based on the historical environmental photon number, the historical signal photon number and the relative accuracy of ranging to obtain a preset relative accuracy calculation rule; The process of obtaining the relative accuracy of the ranging is as follows: According to the distance calculation formula, the target distance measurement value d of the i-th measurement in n consecutive measurements is calculated. i , and the average target distance measurement of n measurements , then the resolution of the distance measurement system is: Among them, d i Indicates the distance value obtained by the i-th measurement, the number of tests ranges from 1 to n, a total of n times, represents the average value of n measurements, It can be expressed as: According to the triple standard deviation law, the relationship between resolution and relative ranging accuracy is: The relative accuracy of the distance measurement is calculated after n samplings.

2. The distance measurement system according to claim 1, characterized in that The processing circuit is further configured to calculate the distance value of the object to be measured and determine whether the relative accuracy of the distance value exceeds a preset relative accuracy threshold. If the relative accuracy exceeds the preset relative accuracy threshold, the distance value is shielded.

3. The distance measurement system according to claim 1 or 2, characterized in that The preset relative accuracy calculation rule is a function model, and the function model is: 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; R is the relative accuracy.

4. A method for determining the relative accuracy of a distance measurement system, characterized in that: include: Acquire the number of ambient photons and the number of signal photons; wherein the number of signal photons is the electrical signal output by the collector when collecting the light signal reflected by the object to be measured; Calculating relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule; The preset relative accuracy calculation rule is obtained according to the following steps: Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count; Constructing a fitting function based on the historical environmental photon number, the historical signal photon number and the relative accuracy of ranging to obtain a preset relative accuracy calculation rule; The process of obtaining the relative accuracy of the ranging is as follows: According to the distance calculation formula, the target distance measurement value d of the i-th measurement in n consecutive measurements is calculated. i , and the average target distance measurement of n measurements , then the resolution of the distance measurement system is: Among them, d i Indicates the distance value obtained by the i-th measurement, the number of tests ranges from 1 to n, a total of n times, represents the average value of n measurements, It can be expressed as: According to the triple standard deviation law, the relationship between resolution and relative ranging accuracy is: The relative accuracy of the distance measurement is calculated after n samplings.

5. The method for determining the relative accuracy of a distance measurement system according to claim 4, wherein: The preset relative accuracy calculation rule is a function model, and the function model is: 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; R is the relative accuracy.

6. The method for determining the relative accuracy of a distance measurement system according to claim 4, wherein: Also includes: Calculating the resolution according to the number of ambient photons, the number of signal photons, and a preset resolution calculation rule; The relative accuracy of the distance measurement system is calculated based on the resolution.

7. The method for determining the relative accuracy of a distance measurement system according to claim 4, wherein: The obtaining of the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count includes: Obtain target distance measurement value, target actual distance value and target distance measurement average value; The relative accuracy of distance measurement is calculated according to the target distance measurement value, the target actual distance value and the target distance measurement average value.

8. A device for determining the relative accuracy of a distance measurement system, characterized in that: include: A first acquisition unit is configured to acquire the number of ambient photons and the number of signal photons; wherein the number of signal photons is an electrical signal output by a collector when collecting light signals reflected by the object to be measured; A first processing unit is configured to calculate relative accuracy based on the number of ambient photons, the number of signal photons, and a preset relative accuracy calculation rule; The preset relative accuracy calculation rule is obtained according to the following steps: Obtain the historical ambient photon count, the historical signal photon count, and the relative ranging accuracy corresponding to the historical ambient photon count and the historical signal photon count; Constructing a fitting function based on the historical environmental photon number, the historical signal photon number and the relative accuracy of ranging to obtain a preset relative accuracy calculation rule; The process of obtaining the relative accuracy of the ranging is as follows: According to the distance calculation formula, the target distance measurement value d of the i-th measurement in n consecutive measurements is calculated. i , and the average target distance measurement of n measurements , then the resolution of the distance measurement system is: Among them, d i Indicates the distance value obtained by the i-th measurement, the number of tests ranges from 1 to n, a total of n times, represents the average value of n measurements, It can be expressed as: According to the triple standard deviation law, the relationship between resolution and relative ranging accuracy is: The relative accuracy of the distance measurement is calculated after n samplings.

9. The device for determining the relative accuracy of a distance measurement system according to claim 8, characterized in that: The first processing unit is further configured to: Calculating the resolution according to the number of ambient photons, the number of signal photons, and a preset resolution calculation rule; The relative accuracy of the distance measurement system is calculated based on the resolution.

10. A device for determining the relative accuracy of a distance measurement system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for determining the relative accuracy of a distance measurement system according to any one of claims 4 to 7 is implemented.

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