Distance deviation value elimination method and device of dtof system and storage medium

Abstract

The embodiment of the application discloses a distance deviation value elimination method and device of a DTOF system and a storage medium, and relates to the technical field of computers and the technical field of laser detection. The method comprises the following steps: after a laser device in a transmitting end transmits a laser signal to a target object, a back light signal reflected by the target object to a single photon avalanche diode array in a receiving end is acquired, and a histogram is generated; then, the histogram is analyzed and processed, an initial detection distance and a shape characteristic value of a graph are obtained, and further based on the shape characteristic value of the graph, a distance deviation value is obtained; finally, according to the distance deviation value, the initial detection distance is corrected and processed, and an actual detection distance is obtained. By adopting the embodiment of the application, the distance error caused by the stacking phenomenon can be eliminated.

Description

Technical Field

[0001] This application relates to the fields of computer technology and laser detection technology, and in particular to a method, apparatus and storage medium for eliminating distance deviation values ​​in a dtof system. Background Technology

[0002] In direct time-of-flight (dtof) systems, the shape of the final measured signal histogram varies due to differences in the signal strength of the returned laser signal and the inherent characteristics of the devices. When the returned signal strength is low, the number of photon triggers is small, resulting in a more typical signal histogram shape. Therefore, a more accurate laser flight time can be calculated using methods such as matched filtering, leading to an accurate flight distance. However, when the returned signal strength is high, the presence of a dead time due to the large number of photon triggers causes a pileup effect. This results in the signal histogram waveform being more biased towards the rising edge, causing an error between the calculated and actual flight distances. Therefore, eliminating the distance error caused by the pileup effect is a pressing problem that needs to be solved. Summary of the Invention

[0003] This application provides a method, apparatus, and storage medium for eliminating distance deviation values ​​in a dtof system, which can eliminate distance errors caused by stacking phenomena.

[0004] On the one hand, embodiments of this application provide a method for eliminating distance deviation values ​​in a dtof system, including:

[0005] After the laser device in the transmitting end emits a laser signal to the target object, the reflected light signal from the target object to the single-photon avalanche diode array in the receiving end is acquired, and a histogram is generated; the histogram is used to characterize the mapping relationship between the number of received photons and the time box;

[0006] The histogram is analyzed to obtain the initial detection distance and the shape representation value of the graph; the shape representation value of the graph is used to indicate the shape distribution of the highest peak in the histogram.

[0007] The distance deviation value is obtained from the shape representation value of the graphic; the distance deviation value is negatively correlated with the shape representation value of the graphic, and the distance deviation value is used to indicate the degree of deviation between the initial detection distance and the true distance;

[0008] Based on the distance deviation value, the initial detection distance is corrected to obtain the actual detection distance.

[0009] On one hand, embodiments of this application provide a distance deviation value elimination device for a dtof system, the distance deviation value elimination device for a dtof system including an acquisition unit, a processing unit, and a correction unit, wherein:

[0010] The acquisition unit is used to acquire the return signal reflected by the target object to the single-photon avalanche diode array in the receiving end after the laser device in the transmitting end emits a laser signal to the target object, and generate a histogram; the histogram is used to characterize the mapping relationship between the number of received photons and the time box;

[0011] The processing unit is used to analyze and process the histogram to obtain the initial detection distance and the shape characterization value of the graph; the shape characterization value of the graph is used to indicate the shape distribution of the highest peak in the histogram;

[0012] The processing unit is further configured to obtain a distance deviation value based on the shape representation value of the graphic; the distance deviation value is negatively correlated with the shape representation value of the graphic, and the distance deviation value is used to indicate the degree of deviation between the initial detection distance and the true distance;

[0013] The correction unit is used to correct the initial detection distance based on the distance deviation value to obtain the actual detection distance;

[0014] On one hand, embodiments of this application provide an electronic device, which includes an input interface and an output interface, and further includes:

[0015] A processor, adapted to implement one or more instructions; and,

[0016] A storage medium storing one or more instructions adapted for loading and execution by the processor of the distance deviation elimination method of the dtof system described above.

[0017] On one hand, embodiments of this application provide a storage medium storing one or more computer programs adapted for loading and executing by a processor the distance deviation value elimination method of the dtof system described above.

[0018] On one hand, embodiments of this application provide a computer program product or computer program, the computer program product or computer program including computer instructions, the computer instructions being stored in a computer-readable storage medium; a processor of an electronic device reads the computer instructions from the computer-readable storage medium, the processor executes the computer instructions, and when the computer instructions are executed by the processor, they are used to perform the distance deviation value elimination method of the above-described dtof system.

[0019] In this embodiment, since the flight distance calculated by the DTof system is mainly due to distance deviation caused by stacking, the distance deviation value is related to the data stacking situation in the histogram. The data stacking situation in the histogram can be reflected by the shape representation value of the graph obtained through histogram analysis. That is, the distance deviation value and the shape representation value of the graph are correlated, and typically, they are negatively correlated. Therefore, in this embodiment, the shape representation value of the graph can be obtained through histogram analysis; then, the distance deviation value can be obtained from the shape representation value, thereby correcting the initial detection distance to obtain the actual detection distance. Thus, this embodiment obtains the corresponding distance deviation value through histogram correlation analysis and processing, thereby accurately correcting the initial detection distance and achieving the goal of eliminating distance errors caused by stacking. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a histogram of objects with different reflectivities at the same distance, provided in an embodiment of this application.

[0022] Figure 2 This is a schematic diagram of the structure of a distance deviation value elimination system for a dtof system provided in an embodiment of this application;

[0023] Figure 3 This is a flowchart illustrating a method for eliminating distance deviation values ​​in a dtof system provided in an embodiment of this application;

[0024] Figure 4 This is a flowchart illustrating another method for eliminating distance deviation values ​​in a dtof system provided in an embodiment of this application;

[0025] Figure 5a This is a schematic diagram illustrating the relationship between a distance deviation value and the actual distance, provided in an embodiment of this application.

[0026] Figure 5b This is a schematic diagram illustrating the relationship between the shape representation value of a graphic and the actual distance, provided in an embodiment of this application.

[0027] Figure 5c This is a schematic diagram illustrating the relationship between a distance deviation value and a shape representation value of a graphic, provided in an embodiment of this application.

[0028] Figure 6 This is a schematic diagram of the structure of a distance deviation elimination device for a dtof system provided in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0031] Direct Time-of-Flight (dtof) systems are used to directly measure flight time. The core components of a dtof system include a Vertical-Cavity Surface-Emitting Laser (VCSEL), a Single-Photon Avalanche Diode (SPAD), and a Time-to-Digital Converter (TDC).

[0032] In the dtof system, the VCSEL emits laser signals (i.e., emits pulses) into the scene containing the object to be detected, while the SPAD receives the reflected light signals (i.e., receives pulses) from the object. The time-of-flight register (TDC) records the time of flight of each received reflected light signal, which is the time interval between the emitted and received pulses. The dtof system emits and receives signals multiple times within a single frame measurement time, then performs histogram analysis on the multiple flight times recorded by the TDC. Based on the histogram analysis, the flight time of the signal is determined, and the distance between the object to be detected and the dtof system is calculated.

[0033] When the intensity of the return signal is high, due to the large number of photon triggers, the existence of the dead time will cause a pileup effect, which means that the waveform of the signal histogram is more biased towards the rising edge side, resulting in a shorter calculated flight time, thus causing an error in the flight distance calculated based on the flight time.

[0034] For specific implementation details, please refer to [link / reference]. Figure 1 This shows a histogram of objects with different reflectivities at the same distance. Figure 1The vertical axis represents the number of photons (count), and the horizontal axis represents time (bin, where 1 bin = 34 picoseconds, etc.), hence it can also be called a timebox. Line A represents the mapping between the number of photons in the reflected laser signal from an object with 88% reflectivity and the timebox, while line B represents the mapping between the number of photons in the reflected laser signal from an object with 10% reflectivity and the timebox. Higher reflectivity results in a higher intensity reflected laser signal. Figure 1 The time bin corresponding to the peak of the middle broken line A is shorter, which leads to the stacking phenomenon.

[0035] Based on this, this application provides a distance deviation elimination scheme for a DTFO system. After acquiring the histogram of the backlight signal, the scheme analyzes and processes the histogram to obtain the initial detection distance and the shape representation value of the pattern. This allows for the subsequent calculation of the distance deviation value based on the shape representation value. The distance deviation value is negatively correlated with the shape representation value, and it indicates the degree of deviation between the initial detection distance and the true distance. Finally, the initial detection distance is corrected based on the distance deviation value to obtain the actual detection distance.

[0036] In this context, the reflected signal refers to the signal that is reflected from the laser device at the transmitting end of the DTOF system to the target object and then back to the single-photon avalanche diode array at the receiving end of the DTOF system. The target object is the object that reflects the laser signal; the single-photon avalanche diode array can consist of one or more single-photon avalanche diodes.

[0037] Furthermore, the initial detection distance refers to the parameters generated by the return signal traveling from the target object to the single-photon avalanche diode array. The histogram is used to characterize the mapping relationship between the number of photons and the time bins; the number of photons refers to the number of photons in the return signal that trigger the single-photon avalanche diode array; the time bin corresponding to any number of photons refers to the time point at which the corresponding number of photons triggers the single-photon avalanche diode array. The shape representation value of the graph indicates the degree of bulging of the discrete array distribution in the histogram; a discrete array includes a photon number and a time bin.

[0038] It is clear that after analyzing the initial detection distance based on the histogram, this scheme further corrects the initial detection distance to obtain the actual detection distance. The flight distance deviation is mainly caused by data stacking, therefore the distance deviation value is related to the data stacking situation of the histogram (i.e., the shape representation value of the graph). Typically, the distance deviation value and the shape representation value of the graph are negatively correlated. Therefore, the distance deviation value can be obtained through the shape representation value of the graph, thereby correcting the initial detection distance to obtain the actual detection distance. Thus, this scheme can correct the initial detection distance using the distance deviation value, achieving the goal of eliminating the distance error caused by stacking.

[0039] Based on the distance deviation value elimination method of the above-mentioned DTof system, this application provides a distance deviation value elimination system for the DTof system, which can be found in [reference]. Figure 2 , Figure 2 The distance deviation elimination system of the dtof system shown may include multiple terminal devices 201 and multiple servers 202. A communication connection is established between any terminal device and any server. Terminal device 201 may be any one or more of the following: smartphone, tablet, laptop, desktop computer, smart vehicle, and smart wearable device. Terminal device 201 may run game clients, multimedia playback clients, social clients, browser clients, information streaming clients, educational clients, etc. Server 202 may be a server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms. Terminal devices 201 and servers 202 may communicate directly or indirectly via wired or wireless communication; this application does not impose any limitations on this.

[0040] In one embodiment, the distance deviation elimination method of the above-mentioned dtof system can be achieved solely by... Figure 2The distance deviation elimination system of the DTof system shown is executed by terminal device 201, which includes a laser device and a single-photon avalanche diode array at the transmitting end. The specific execution process is as follows: Terminal device 201 controls the laser device at the transmitting end to emit a laser signal. After the laser signal is emitted to the target object, the return signal reflected from the target object to the single-photon avalanche diode array at the receiving end is acquired, and a histogram is generated. Then, terminal device 201 analyzes the histogram to obtain the initial detection distance and the shape representation value of the histogram; and based on the shape representation value, the distance deviation value can be obtained. Finally, terminal device 201 corrects the initial detection distance based on the distance deviation value to obtain the actual detection distance.

[0041] Optionally, the distance deviation elimination method of the above-mentioned dtof system can also be achieved solely by... Figure 2 The distance deviation value elimination system of the dtof system shown is executed by server 202 in the system. At this time, server 202 includes laser device, single-photon avalanche diode array, etc. in the transmitter. The specific execution process can be referred to the specific execution process of terminal device 201, which will not be repeated here.

[0042] In another embodiment, the distance deviation elimination method of the dtof system described above can be run in a distance deviation elimination system of the dtof system, which may include a terminal device and a server. Specifically, the distance deviation elimination method of the dtof system can be provided by... Figure 2 The distance deviation elimination system of the DTof system shown is jointly completed by the terminal device 201 and the server 202. The terminal device 201 may include a laser device and a single-photon avalanche diode array in the transmitting end. Specifically, the terminal device 201 controls the laser device in the transmitting end to emit a laser signal. After the laser signal is emitted to the target object, the terminal device acquires the reflected light signal from the target object to the single-photon avalanche diode array in the receiving end, generating a histogram. The terminal device 201 then sends the histogram to the server 202. The server 202 then analyzes the histogram to obtain the initial detection distance and the shape representation value of the histogram. Based on the shape representation value, the server 202 can then obtain the distance deviation value. Finally, the server 202 can correct the initial detection distance based on the distance deviation value to obtain the actual detection distance. Optionally, the server 202 can also send the actual detection distance to the terminal device 201.

[0043] Based on the aforementioned distance deviation elimination scheme and system for the dtof system, this application provides a method for eliminating distance deviation values ​​in a dtof system. See also... Figure 3 This is a flowchart illustrating a method for eliminating distance deviation values ​​in a dtof system provided in an embodiment of this application. Figure 3 The distance deviation elimination method of the dtof system shown can be achieved by... Figure 2 The server or terminal device shown is used for execution. Figure 3 The distance deviation elimination method for the dtof system shown may include steps S301-S304:

[0044] S301: After the laser device in the transmitting end emits a laser signal to the target object, it acquires the return signal reflected by the target object to the single-photon avalanche diode array in the receiving end and generates a histogram.

[0045] In this embodiment, the laser device in the transmitting end refers to a device capable of emitting laser light. Specifically, the laser device can be a vertical-cavity surface-emitting laser, a helium-neon laser, a free-electron laser, etc. The target object refers to an object that reflects the laser signal. The target object can be a pre-defined object for reflecting the laser signal, or it can be an object that the laser signal randomly comes into contact with. The single-photon avalanche diode array can be composed of one or more single-photon avalanche diodes.

[0046] Furthermore, the reflected light signal refers to the signal reflected back to the single-photon avalanche diode array at the transmitting end after the laser device emits a laser signal to the target object. The histogram of the reflected light signal is used to characterize the mapping relationship between the number of photons and the time bin. The number of photons refers to the number of photons in the reflected light signal that triggers the single-photon avalanche diode array; the time bin corresponding to any number of photons refers to the time point at which the corresponding number of photons triggers the single-photon avalanche diode array, and its unit is bin.

[0047] Optionally, the specific method for obtaining the histogram of the return signal of the single-photon avalanche diode array reflected from the target object to the transmitter end can be: detecting the number of photons that trigger the single-photon avalanche diode array in the return signal and recording the time box corresponding to each number of photons; generating a histogram of the return signal based on the multiple photon numbers and the time box corresponding to each number of photons.

[0048] S302, the histogram is analyzed and processed to obtain the initial detection distance and the shape characterization value of the pattern.

[0049] In this embodiment, the initial detection distance refers to the distance the return signal travels from the target object to the single-photon avalanche diode array. The shape representation value of the graph is used to indicate the degree of bulge in the discrete array distribution in the histogram, where each discrete array includes a photon count and a time bin.

[0050] In one embodiment, the specific process of analyzing and processing the histogram may include: removing bottom noise from the histogram to obtain a noise-removed histogram; and performing a moving average process on the noise-removed histogram to obtain a processed histogram.

[0051] In one embodiment, the specific method for analyzing the histogram to obtain the initial detection distance can be as follows: determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value, wherein the number of photons at the peak value of the signal peak is the maximum number of photons in the histogram; and obtain the initial detection distance based on the time bin corresponding to the peak value. Specifically, the specific method for obtaining the initial detection distance based on the time bin corresponding to the peak value is to multiply the speed of light by the time bin corresponding to the peak value to obtain the initial flight distance.

[0052] In one embodiment, the specific method for analyzing and processing the histogram to obtain the shape representation value of the graph can be as follows: determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value; sum the number of photons near the peak value to obtain the total number of peak values, and sum the number of photons of the entire signal peak to obtain the total number of signal peaks; and obtain the shape representation value of the graph by calculating the ratio of the total number of peak values ​​to the total number of signal peaks.

[0053] Optionally, the number of photons near the peak can include the peak value and the number of photons in each time box within N1 time boxes from the peak value. The number of photons in the entire signal peak can refer to the number of photons in each time box within N2 time boxes of the entire signal peak; where N1 is less than N2 / 5.

[0054] Therefore, another specific way to analyze and process the histogram to obtain the shape representation value of the graph is as follows: determine the peak value of the signal peak in the processed histogram and the time box corresponding to the peak value; sum the number of photons in N1 time boxes near the peak value to obtain the total number of peak values, and sum the number of photons in the entire signal peak including N2 time boxes to obtain the total number of signal peaks. The shape representation value of the graph is obtained by calculating the ratio of the total number of peak values ​​to the total number of signal peaks.

[0055] For example, it can be set Figure 1 The broken line A in the graph is the histogram obtained after removing the noise floor and applying a moving average to the backlight signal M. Figure 1We know that the peak value of line A is 440, and the corresponding time bin is 34 Bin. At the same time, the signal peak of line A includes 22 time bins from 29 Bin to 50 Bin, i.e., N2 = 22. Then, 22 / 5 = 4.4. Since N1 is less than 4.4, we can take N1 = 3 here.

[0056] So, by Figure 1 It can be seen that the total number of signal peaks is the sum of the number of photons corresponding to each time box from 29 to 50 bits, which is 2800. The total number of peak values ​​is the sum of the number of photons corresponding to each time box from 33 to 35 bits, which is 1230. Finally, dividing the total number of peak values ​​by the total number of signal peaks yields the shape representation value of the reflected light signal M, which is 0.439, i.e., 1230 / 2800 = 0.439.

[0057] In one embodiment, the specific method for analyzing and processing the histogram to obtain the shape representation value of the graph can be as follows: determine the peak value of the signal peak and the time bin corresponding to the peak value in the processed histogram; determine the width of the time bin corresponding to half the peak value of the signal peak, which is called the first width; determine the width of the time bin corresponding to 0.1 times the peak value of the signal peak, which is called the second width; and obtain the shape representation value of the graph by calculating the ratio of the first width to the second width.

[0058] For example, it can be set Figure 1 The broken line A in the graph is the histogram obtained after removing the noise floor and applying a moving average to the backlight signal M. Figure 1 We know that the peak value of line A is 440, half of the peak value is 220, and 0.1 times the peak value is 44. Therefore, we can determine that the first width is 31.5 to 37 Bin (5.5), and the second width is 30 to 43 Bin (13). Finally, we can determine that the shape representation value of the graph is 5 divided by 13, which is approximately 0.423.

[0059] In one possible implementation, the specific method for analyzing and processing the histogram to obtain the shape representation value of the graph can be as follows: determine the peak value of the signal peak and the time bin corresponding to the peak value in the processed histogram; sum the number of photons near the peak value to obtain the total number of peak values, and sum the number of photons of the entire signal peak to obtain the total number of signal peaks; determine the width of the time bin corresponding to half the peak value of the signal peak, and designate it as the first width; determine the width of the time bin corresponding to 0.1 times the peak value of the signal peak, and designate it as the second width; obtain the shape representation value of the graph by calculating the average of the ratio of the total number of peak values ​​to the total number of signal peaks and the ratio of the first width to the second width.

[0060] S303, based on the shape representation value of the graphic, obtain the distance deviation value.

[0061] In this embodiment, the distance deviation value is negatively correlated with the shape representation value of the graphic, and the distance deviation value is used to indicate the degree of deviation between the initial detection distance and the actual detection distance. The distance deviation value can be positive or negative.

[0062] In one embodiment, the specific way to obtain the distance deviation value based on the shape representation value of the graphic can be: based on the pre-established mapping relationship between the shape representation value and the distance deviation value, obtain the distance deviation value corresponding to the shape representation value of the graphic.

[0063] The pre-established mapping relationship between shape representation values ​​and distance deviation values ​​can be represented in various forms, such as parametric mapping models and parametric mapping functions. Optionally, the pre-established mapping relationship between shape representation values ​​and distance deviation values ​​can be obtained by data regression, data fitting, etc., based on a set of distance deviation values ​​and a set of shape representation values ​​of objects at different distances and with different reflectivities; there is no limitation on this.

[0064] S304. Based on the distance deviation value, the initial detection distance is corrected to obtain the actual detection distance.

[0065] In this embodiment of the application, the specific method for correcting the initial detection distance based on the distance deviation value to obtain the actual detection distance can be: adding the distance deviation value and the initial detection distance to obtain the actual detection distance.

[0066] Since the distance deviation detected by the DTFOF system is mainly caused by data stacking, the distance deviation value is related to the data stacking situation of the histogram. The data stacking situation of the histogram can be reflected by the shape representation value of the graph obtained through histogram data analysis. In other words, there is a correlation between the distance deviation value and the shape representation value of the graph, and typically, the distance deviation value and the shape representation value of the graph are negatively correlated. Therefore, in this embodiment, the shape representation value of the graph can be obtained through histogram analysis; then, the distance deviation value can be obtained from the shape representation value of the graph, thereby correcting the initial detection distance to obtain the actual detection distance. Thus, this embodiment obtains the corresponding distance deviation value by performing correlation analysis and processing on the histogram, thereby accurately correcting the initial detection distance and achieving the purpose of eliminating the error caused by stacking.

[0067] Based on the aforementioned distance deviation elimination scheme and system for the dtof system, this application provides another method for eliminating distance deviation in the dtof system. See also... Figure 4 This is a flowchart illustrating another method for eliminating distance deviation values ​​in a dtof system provided in an embodiment of this application.

[0068] Figure 4 The distance deviation elimination method of the dtof system shown can be achieved by... Figure 2 The server or terminal device shown in the figure executes the command. Figure 4 The distance deviation elimination method for the dtof system shown may include the following steps:

[0069] S401: After the laser device in the transmitting end emits a laser signal to the target object, it acquires the return signal reflected by the target object to the single-photon avalanche diode array in the receiving end and generates a histogram.

[0070] S402, the histogram is analyzed and processed to obtain the initial detection distance and the shape characterization value of the graph.

[0071] The specific implementation methods of steps S401 to S402 can be found in the specific implementation methods of steps S301 to S302 described above, and will not be repeated here.

[0072] S403, Get parameter mapping function.

[0073] In this embodiment of the application, the parameter mapping function is used to indicate the mapping relationship between at least one shape representation value of a graphic and at least one distance deviation value.

[0074] Specifically, the parameter mapping function can be generated by: obtaining a set of distance deviation values ​​and a set of shape representation values ​​of objects at different distances and with different reflectivities; performing data fitting processing on the shape representation values ​​of each shape and the corresponding distance deviation values ​​to obtain the parameter mapping function.

[0075] Data fitting, also known as curve fitting, is a method of representing existing discrete data by substituting it into a mathematical expression (which can be a continuous function). Since data fitting is a commonly used technique in this field, it will not be elaborated upon here.

[0076] In practical applications, when the flight parameter is the flight distance, please refer to the appendix. Figure 5a This diagram illustrates the relationship between a distance deviation value and the actual distance. Figure 5a The horizontal axis represents the actual distance between the diode in the transmitting end and the object, in mm; the vertical axis represents the distance deviation value, which is the deviation between the initial detection distance and the actual distance obtained by directly analyzing the histogram of the corresponding return light signal, in mm.

[0077] Furthermore, line X represents the relationship between the distance deviation value obtained from analyzing the first histogram and the actual distance. The first histogram is generated based on the backlight signal obtained after reflecting a laser signal from an object with a reflectivity of 10%. Line Y represents the relationship between the distance deviation value obtained from analyzing the second histogram and the actual distance. The second histogram is generated based on the backlight signal obtained after reflecting a laser signal from an object with a reflectivity of 50%. Line Z represents the relationship between the distance deviation value obtained from analyzing the third histogram and the actual distance. The third histogram is generated based on the backlight signal obtained after reflecting a laser signal from an object with a reflectivity of 88%.

[0078] Please also see the appendix. Figure 5b This diagram illustrates the relationship between the shape representation value of a graphic and the actual distance. Figure 5b The horizontal axis represents the actual distance between the single-photon avalanche diode array at the transmitting end and the object, in mm; the vertical axis represents the shape representation value of the graph, i.e., the shape representation value of the graph obtained after analyzing the corresponding histogram. Furthermore, line M represents the relationship between the shape representation value of the graph obtained from analyzing the third histogram and the actual distance. Line N represents the relationship between the shape representation value of the graph obtained from analyzing the second histogram and the actual distance. Line P represents the relationship between the shape representation value of the graph obtained from analyzing the first histogram and the actual distance.

[0079] Depend on Figure 5a and Figure 5b It can be seen that the actual distance and the distance deviation value are positively correlated; the larger the actual distance, the smaller the shape representation value of the graphic. Therefore, it can be determined that the distance deviation value and the shape representation value of the graphic are negatively correlated. Furthermore, the distance deviation values ​​and the shape representation values ​​of the graphic, calculated when the actual distances are the same, can be grouped into a discrete data set, thus obtaining multiple discrete data sets. Then, please refer to the appendix. Figure 5c This diagram illustrates the relationship between distance deviation values ​​and the shape representation values ​​of a graphic. Figure 5c The horizontal axis represents the shape representation of the graphic; the vertical axis represents the distance deviation, in mm. Figure 5c Any data point in the dataset represents a discrete data set. Figure 5c By performing data fitting on multiple discrete data sets, the final result can be obtained as follows: Figure 5c The function curve R shown is the parametric mapping function. In actual calculations, the parametric mapping function is y = -0.138x. 3 +0.825x 2 -0.989x+0.191.

[0080] S404, based on the parameter mapping function and the shape representation value of the graph, obtains the distance deviation value.

[0081] In this embodiment of the application, the specific method for obtaining the distance deviation value based on the parameter mapping function and the shape representation value of the graphic can be as follows: substitute the shape representation value of the graphic into the parameter mapping function to obtain the distance deviation value. For example, when the shape representation value of the graphic is 0.5, substitute 0.5 into the parameter mapping function mentioned in step S404, i.e., y = -0.138(0.5). 3 +0.825(0.5) 2 -0.989×0.5+0.191=-0.1145, thus the distance deviation value can be determined to be -0.1145.

[0082] S405, based on the distance deviation value, the initial detection distance is corrected to obtain the actual detection distance.

[0083] The specific implementation of step S405 can be found in the specific implementation of step S304 above, and will not be repeated here.

[0084] Since distance deviation is mainly caused by data stacking, the distance deviation value is related to the data stacking situation of the histogram. The data stacking situation of the histogram can be reflected by the shape representation value of the graph obtained through histogram data analysis. In other words, there is a correlation between the distance deviation value and the shape representation value of the graph, and actual calculations show a negative correlation between the distance deviation value and the shape representation value. Therefore, in this embodiment, a parameter mapping function representing the mapping relationship between the distance deviation value and the shape representation value of the graph can be found in advance through data fitting processing. Then, after analyzing the shape representation value of the graph obtained from the histogram, the distance deviation value is obtained with the help of the parameter mapping function and the shape representation value, thereby correcting the initial detection distance to obtain the actual detection distance. Thus, by finding a parameter mapping function between the shape representation value of the histogram and the distance deviation value, this embodiment can achieve a relatively accurate distance deviation value using only the parameter mapping function and the histogram, thereby accurately correcting the initial detection distance and eliminating the error caused by data stacking.

[0085] Based on the description of the distance deviation value elimination method for the DTof system above, this application also discloses a distance deviation value elimination device for the DTof system. This distance deviation value elimination device for the DTof system can be a computer program (including program code) running on the aforementioned computer device. This distance deviation value elimination device for the DTof system can perform actions such as... Figure 3 and Figure 4For the distance deviation elimination method of the dtof system shown, please refer to [link / reference]. Figure 6 The distance deviation elimination device of the dtof system may include at least: an acquisition unit 601, a processing unit 602, and a correction unit 603.

[0086] The acquisition unit 601 is used to acquire the return signal reflected by the target object to the single-photon avalanche diode array in the receiving end after the laser device in the transmitting end emits a laser signal to the target object, and generate a histogram; the histogram is used to characterize the mapping relationship between the number of received photons and the time box;

[0087] Processing unit 602 is used to analyze and process the histogram to obtain an initial detection distance and a shape representation value of the graph; the shape representation value of the graph is used to indicate the shape distribution of the highest peak in the histogram;

[0088] The processing unit 602 is further configured to obtain a distance deviation value based on the shape representation value of the graphic; the distance deviation value is negatively correlated with the shape representation value of the graphic, and the distance deviation value is used to indicate the degree of deviation between the initial detection distance and the true distance;

[0089] The correction unit 603 is used to correct the initial detection distance based on the distance deviation value to obtain the actual detection distance;

[0090] In one embodiment, when the processing unit 602 obtains the distance deviation value based on the shape representation value of the graphic, it may specifically perform the following:

[0091] Obtain a parameter mapping function, which indicates the mapping relationship between at least one shape representation value of a graphic and at least one distance deviation value;

[0092] The distance deviation value is obtained based on the parameter mapping function and the shape representation value of the graph.

[0093] In yet another embodiment, the processing unit 602 may also be used to perform:

[0094] Obtain a set of distance deviation values ​​and a set of shape characterization values ​​for objects at different distances and with different reflectivities;

[0095] The shape representation values ​​and corresponding distance deviation values ​​of each graphic are subjected to data fitting processing to obtain the parameter mapping function.

[0096] In another embodiment, when processing the histogram, the processing unit 602 may further perform the following:

[0097] Remove the bottom noise from the histogram to obtain a noise-removed histogram;

[0098] The noise-removed histogram is subjected to a moving average process to obtain the processed histogram.

[0099] In one embodiment, when the processing unit 602 analyzes the histogram to obtain the shape representation value of the graph, it may also specifically perform the following:

[0100] Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0101] The total number of peaks is obtained by summing the number of photons near the peaks, and the total number of signal peaks is obtained by summing the number of photons over the entire signal peak.

[0102] The shape representation value of the graph is obtained by calculating the ratio of the total number of peaks to the total number of signal peaks.

[0103] In one embodiment, when the processing unit 602 analyzes the histogram to obtain the shape representation value of the graph, it may also specifically perform the following:

[0104] Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0105] The total number of peaks is obtained by summing the photon counts of N1 time boxes near the peak, and the total number of signal peaks is obtained by summing the photon counts of the entire signal peak including N2 time boxes. The shape characterization value of the graph is obtained by calculating the ratio of the total number of peaks to the total number of signal peaks; where N1 is less than N2 / 5.

[0106] In one embodiment, when the processing unit 602 performs data analysis processing on the histogram to obtain the shape representation value of the graph, it can specifically perform the following:

[0107] Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0108] The time bin width corresponding to half the peak value of the signal peak is determined and recorded as the first width; the time bin width corresponding to 0.1 times the peak value of the signal peak is determined and recorded as the second width.

[0109] The shape representation value of the graphic is obtained by calculating the ratio of the first width to the second width.

[0110] In one embodiment, when the processing unit 602 performs data analysis processing on the histogram to obtain the shape representation value of the graph, it can specifically perform the following: determining the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0111] The total number of peaks is obtained by summing the number of photons near the peaks, and the total number of signal peaks is obtained by summing the number of photons over the entire signal peak.

[0112] The time bin width corresponding to half the peak value of the signal peak is determined and recorded as the first width; the time bin width corresponding to 0.1 times the peak value of the signal peak is determined and recorded as the second width.

[0113] The shape representation value of the graphic is obtained by calculating the average of the ratio of the total number of peaks to the total number of signal peaks and the ratio of the first width to the second width.

[0114] According to one embodiment of this application, Figure 3 and Figure 4 The steps involved in the method shown can be derived from... Figure 6 The distance deviation value elimination device of the dtof system shown is executed by each unit. For example, Figure 3 The step S301 shown can be performed by Figure 6 The acquisition unit 601 in the distance deviation value elimination device of the dtof system shown is used to perform the steps; steps S302 to S303 can be performed by Figure 6 The processing unit 602 in the distance deviation value elimination device of the dtof system shown is responsible for executing step S304; step S304 can be performed by... Figure 6 The correction unit 603 in the distance deviation value elimination device of the dtof system shown performs this operation. For example, Figure 4 The step S401 shown can be performed by Figure 6 The acquisition unit 601 in the distance deviation value elimination device of the dtof system shown is used to perform the steps; steps S402 to S404 can be performed by Figure 6 The processing unit 602 in the distance deviation value elimination device of the dtof system shown is responsible for executing step S405; step S405 can be performed by... Figure 6 The correction unit 603 in the distance deviation value elimination device of the dtof system shown performs the correction.

[0115] According to another embodiment of this application, Figure 6 The distance deviation elimination device of the dtof system shown is based on logical function division. Each of these units can be individually or entirely merged into one or more other units, or some of these units can be further divided into multiple functionally smaller units. This achieves the same operation without affecting the technical effects of the embodiments of this application. In other embodiments of this application, the distance deviation elimination device based on the dtof system may also include other units. In practical applications, these functions can also be implemented with the assistance of other units, and multiple units can cooperate to achieve them.

[0116] According to another embodiment of this application, a general-purpose computing device, such as a computer device, including processing elements and storage elements such as a central processing unit (CPU), random access memory (RAM), and read-only memory (ROM), can be used to run an application capable of performing tasks such as... Figure 3 or Figure 4 The computer program (including program code) involved in each step of the method shown is used to construct, for example... Figure 6 The present invention describes a distance deviation value elimination device for a dtof system and a distance deviation value elimination method for implementing the dtof system according to embodiments of the present application. The computer program may be recorded on, for example, a storage medium, loaded onto the aforementioned computer device via the storage medium, and run therein.

[0117] Based on the above method and apparatus embodiments, this application also provides an electronic device. See also Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 7 The electronic device shown may include at least a processor 701, an input interface 702, an output interface 703, and a storage medium 704. The processor 701, input interface 702, output interface 703, and storage medium 704 may be connected via a bus or other means.

[0118] Storage medium 704 can be stored in the memory of the electronic device. Storage medium 704 is used to store computer programs, which include program instructions. Processor 701 is used to execute the program instructions stored in storage medium 704. Processor 701 (or CPU (Central Processing Unit)) is the computing and control core of the electronic device. It is suitable for implementing one or more instructions, specifically for loading and executing one or more instructions to realize the distance deviation value elimination method or corresponding function of the above-mentioned dtof system.

[0119] This application embodiment also provides a storage medium (Memory), which is a memory device in an electronic device used to store programs and data. It is understood that the storage medium here can include the built-in storage medium in a terminal, or it can include extended storage media supported by the terminal. The storage medium provides storage space, which stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by the processor 701. These instructions can be one or more computer programs (including program code). It should be noted that the storage medium here can be high-speed random access memory (RAM), or it can be non-volatile memory, such as at least one disk storage device; optionally, it can also be at least one storage medium located remotely from the aforementioned processor.

[0120] In one embodiment, the processor 701 may load and execute one or more instructions stored in the storage medium to implement the aforementioned related... Figure 3 and Figure 4 In the embodiment of the method for eliminating distance deviation values ​​in the dtof system, the corresponding steps of the method are as follows: In a specific implementation, one or more instructions in the storage medium are loaded and executed by the processor 701:

[0121] After the laser device in the transmitter of the processor 701 emits a laser signal to the target object, it acquires the return signal reflected by the target object to the single-photon avalanche diode array in the receiver and generates a histogram; the histogram is used to characterize the mapping relationship between the number of received photons and the time box;

[0122] The processor 701 analyzes and processes the histogram to obtain the initial detection distance and the shape characterization value of the graph; the shape characterization value of the graph is used to indicate the shape distribution of the peak in the histogram.

[0123] The processor 701 obtains a distance deviation value based on the shape representation value of the graphic; the distance deviation value is negatively correlated with the shape representation value of the graphic, and the distance deviation value is used to indicate the degree of deviation between the initial detection distance and the true distance;

[0124] The processor 701 performs correction processing on the initial detection distance based on the distance deviation value to obtain the actual detection distance;

[0125] In one embodiment, when the processor 701 obtains the distance deviation value based on the shape representation value of the graphic, it may further be used to perform:

[0126] Obtain a parameter mapping function, which indicates the mapping relationship between at least one shape representation value of a graphic and at least one distance deviation value;

[0127] The distance deviation value is obtained based on the parameter mapping function and the shape representation value of the graph.

[0128] In one embodiment, processor 701 can also be used to perform:

[0129] Obtain a set of distance deviation values ​​and a set of shape characterization values ​​for objects at different distances and with different reflectivities;

[0130] The shape representation values ​​and corresponding distance deviation values ​​of each graphic are subjected to data fitting processing to obtain the parameter mapping function.

[0131] In one embodiment, when the processor 701 analyzes and processes the histogram, it may further perform the following:

[0132] Remove the bottom noise from the histogram to obtain a noise-removed histogram;

[0133] The noise-removed histogram is subjected to a moving average process to obtain the processed histogram.

[0134] In one embodiment, when the processor 701 analyzes the histogram to obtain the shape representation value of the graph, it may further perform the following:

[0135] Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0136] The total number of peaks is obtained by summing the number of photons near the peaks, and the total number of signal peaks is obtained by summing the number of photons over the entire signal peak.

[0137] The shape representation value of the graph is obtained by calculating the ratio of the total number of peaks to the total number of signal peaks.

[0138] In one embodiment, when the processor 701 analyzes the histogram to obtain the shape representation value of the graph, it can also be used to perform:

[0139] Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0140] The total number of peaks is obtained by summing the photon counts of N1 time boxes near the peak, and the total number of signal peaks is obtained by summing the photon counts of the entire signal peak including N2 time boxes. The shape characterization value of the graph is obtained by calculating the ratio of the total number of peaks to the total number of signal peaks; where N1 is less than N2 / 5.

[0141] In one embodiment, when the processor 701 performs data analysis processing on the histogram to obtain the shape representation value of the graph, it can also be used to perform:

[0142] Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0143] The time bin width corresponding to half the peak value of the signal peak is determined and recorded as the first width; the time bin width corresponding to 0.1 times the peak value of the signal peak is determined and recorded as the second width.

[0144] The shape representation value of the graphic is obtained by calculating the ratio of the first width to the second width.

[0145] In one embodiment, when the processor 701 analyzes the histogram to obtain the shape representation value of the graph, it can also be used to perform:

[0146] Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value;

[0147] The total number of peaks is obtained by summing the number of photons near the peaks, and the total number of signal peaks is obtained by summing the number of photons over the entire signal peak.

[0148] The time bin width corresponding to half the peak value of the signal peak is determined and recorded as the first width; the time bin width corresponding to 0.1 times the peak value of the signal peak is determined and recorded as the second width.

[0149] The shape representation value of the graphic is obtained by calculating the average of the ratio of the total number of peaks to the total number of signal peaks and the ratio of the first width to the second width.

[0150] This application provides a computer program product or computer program that includes computer instructions stored in a computer-readable storage medium. The processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the aforementioned actions. Figure 3 and Figure 4 The method embodiment shown. The computer-readable storage medium may be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0151] The distance deviation elimination method of the dtof system in this embodiment of the invention is mainly illustrated by the direct measurement time of flight detection system. The distance deviation elimination method of the dtof system in this embodiment of the invention can also be applied to other scenarios for measuring distance, and is not limited here.

[0152] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims. Furthermore, this application does not limit the execution order of the various steps in the specific embodiments.

Claims

1. A method for eliminating distance deviation values ​​in a dtof system, characterized in that, include: After the laser device in the transmitting end emits a laser signal to the target object, the return signal reflected by the target object to the single-photon avalanche diode array in the receiving end is acquired, and a histogram is generated. The histogram is used to characterize the mapping relationship between the number of received photons and the timebox; The histogram is analyzed to obtain an initial detection distance and a shape representation value. The shape representation value indicates the shape distribution of the signal peaks in the histogram. The method for analyzing the histogram to obtain the shape representation value includes any of the following: determining the peak value of the signal peak in the histogram and the time bin corresponding to the peak value; summing the number of photons adjacent to the peak value to obtain the total number of peaks; summing the number of photons for the entire signal peak to obtain the total number of signal peaks; and calculating the ratio of the total number of peaks to the total number of signal peaks to obtain the shape representation value; or, determining the peak value of the signal peak in the histogram and the time bin corresponding to the peak value; determining the width of the time bin corresponding to half of the peak value; and calculating... The first width is defined as the width of the time bin corresponding to 0.1 times the peak value of the signal peak, which is then defined as the second width. The shape characterization value is obtained by calculating the ratio of the first width to the second width. Alternatively, the peak value of the signal peak in the histogram and the time bin corresponding to the peak value are determined. The number of photons adjacent to the peak value is summed to obtain the total number of peak values, and the number of photons of the entire signal peak is summed to obtain the total number of signal peaks. The time bin width corresponding to half the peak value of the signal peak is defined as the first width, and the time bin width corresponding to 0.1 times the peak value of the signal peak is defined as the second width. The ratio of the total number of peak values ​​to the total number of signal peaks is arithmetically averaged with the ratio of the first width to the second width to obtain the shape characterization value. Based on the shape characterization value, a distance deviation value is obtained; the distance deviation value is negatively correlated with the shape characterization value, and the distance deviation value is used to indicate the degree of deviation between the initial detection distance and the true distance; Based on the distance deviation value, the initial detection distance is corrected to obtain the actual detection distance.

2. The method according to claim 1, characterized in that, The process of obtaining the distance deviation value based on the shape representation value includes: Obtain a parameter mapping function, which indicates the mapping relationship between at least one shape representation value and at least one distance deviation value; The distance deviation value is obtained based on the parameter mapping function and the shape representation value.

3. The method according to claim 2, characterized in that, The method further includes: Obtain a set of distance deviation values ​​and a set of shape characterization values ​​for objects at different distances and with different reflectivities; The obtained shape representation values ​​and corresponding distance deviation values ​​are subjected to data fitting processing to obtain the parameter mapping function.

4. The method according to any one of claims 1-3, characterized in that, The analysis and processing of the histogram specifically includes: Remove the bottom noise from the histogram to obtain a noise-removed histogram; The noise-removed histogram is subjected to a moving average process to obtain the processed histogram.

5. The method according to claim 4, characterized in that, The method of analyzing and processing the histogram to obtain the shape characterization value includes: determining the peak value of the signal peak in the histogram and the time bin corresponding to the peak value; summing the number of photons adjacent to the peak value to obtain the total number of peak values; summing the number of photons of the entire signal peak to obtain the total number of signal peak values; and obtaining the shape characterization value by calculating the ratio of the total number of peak values ​​to the total number of signal peak values. Determining the peak value of the signal peak in the histogram and the time bin corresponding to the peak value includes: Determine the peak value of the signal peak in the processed histogram and the time bin corresponding to the peak value; The process of summing the number of photons adjacent to the peak to obtain the total number of peaks, and summing the number of photons over the entire signal peak to obtain the total number of signal peaks, includes: The total number of peaks is obtained by summing the photon counts of the peaks over N1 adjacent time boxes, and the total number of signal peaks is obtained by summing the photon counts of the entire signal peak over N2 time boxes; where N1 is less than N2 / 5.

6. A distance deviation elimination device for a dtof system, characterized in that, The distance deviation elimination device of the dtof system includes an acquisition unit, a processing unit, and a correction unit, wherein: The acquisition unit is used to acquire the return signal reflected by the target object to the single-photon avalanche diode array in the receiving end after the laser device in the transmitting end emits a laser signal to the target object, and generate a histogram; the histogram is used to characterize the mapping relationship between the number of received photons and the time box; The processing unit is configured to analyze and process the histogram to obtain an initial detection distance and a shape representation value; the shape representation value is used to indicate the shape distribution of signal peaks in the histogram; wherein, the method of analyzing and processing the histogram to obtain the shape representation value includes any of the following: determining the peak value of the signal peak in the histogram and the time bin corresponding to the peak value, summing the number of photons adjacent to the peak value to obtain the total number of peaks, and summing the number of photons of the entire signal peak to obtain the total number of signal peaks, and obtaining the shape representation value by calculating the ratio of the total number of peaks to the total number of signal peaks; or, determining the peak value of the signal peak in the histogram and the time bin corresponding to the peak value, and determining the time bin corresponding to half of the peak value of the signal peak. The first width is defined as the width of the time box corresponding to 0.1 times the peak value of the signal peak. The second width is defined as the width of the time box corresponding to the peak value of the signal peak. The shape characterization value is obtained by calculating the ratio of the first width to the second width. Alternatively, the peak value of the signal peak in the histogram and the time box corresponding to the peak value are determined. The number of photons adjacent to the peak value is summed to obtain the total number of peak values. The number of photons of the entire signal peak is summed to obtain the total number of signal peak values. The width of the time box corresponding to half the peak value of the signal peak is defined as the first width. The width of the time box corresponding to 0.1 times the peak value of the signal peak is defined as the second width. The ratio of the total number of peak values ​​to the total number of signal peak values ​​is arithmetically averaged with the ratio of the first width to the second width to obtain the shape characterization value. The processing unit is further configured to obtain a distance deviation value based on the shape representation value; the distance deviation value is negatively correlated with the shape representation value, and the distance deviation value is used to indicate the degree of deviation between the initial detection distance and the true distance; The correction unit is further configured to correct the initial detection distance based on the distance deviation value to obtain the actual detection distance.

7. A storage medium, characterized in that, The storage medium stores one or more computer programs, which are adapted to be loaded by a processor and executed by the distance deviation elimination method of the dtof system as described in any one of claims 1-5.

8. An electronic device, characterized in that, The electronic device includes an input interface and an output interface, and further includes: A processor, adapted to implement one or more instructions; and, A storage medium storing one or more instructions, the one or more instructions being adapted to be loaded by the processor and executed as described in any one of claims 1-5, for the distance deviation elimination method of the dtof system.

9. A computer program product, characterized in that, The computer program product includes computer instructions stored in a computer-readable storage medium; a processor of an electronic device reads the computer instructions from the computer-readable storage medium, executes the computer instructions, and when the computer instructions are executed by the processor, performs the distance deviation value elimination method of the dtof system as described in any one of claims 1-5.

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